Searched +hist:3 +hist:e08773c (Results 1 - 25 of 36) sorted by path

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/linux-master/arch/m68k/emu/
H A Dnfblock.cdiff 2cfe0104 Thu Feb 15 00:10:48 MST 2024 Christoph Hellwig <hch@lst.de> nfblock: pass queue_limits to blk_mq_alloc_disk

Pass the queue limits directly to blk_alloc_disk instead of setting them
one at a time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
/linux-master/arch/xtensa/platforms/iss/
H A Dsimdisk.cdiff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d3a6a20 Wed Jul 08 06:25:45 MDT 2020 Christoph Hellwig <hch@lst.de> xtensa/simdisk: remove the call to check_disk_change

The simdisk driver doesn't support event notifications, which means
that check_disk_change is a no-op.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
/linux-master/block/
H A Dbio.cdiff 6ef02df1 Mon Dec 04 10:34:19 MST 2023 Christoph Hellwig <hch@lst.de> block: support adding less than len in bio_add_hw_page

bio_add_hw_page currently always fails or succeeds. This is fine for
the existing callers that always add PAGE_SIZE worth given that the
max_segment_size and max_sectors must always allow at least a page
worth of data. But when we want to add it for bigger amounts of data
this means it can also fail when adding the data to a bio, and creating
a fallback for that becomes really annoying in the callers.

Make use of the existing API design that allows to return a smaller
length than the one passed in and add up to max_segment_size worth
of data from a larger input. All the existing callers are fine with
this - not because they handle this return correctly, but because they
never pass more than a page in.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20231204173419.782378-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3f034c37 Mon Dec 04 10:34:18 MST 2023 Christoph Hellwig <hch@lst.de> block: prevent an integer overflow in bvec_try_merge_hw_page

Reordered a check to avoid a possible overflow when adding len to bv_len.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20231204173419.782378-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 168145f6 Sun Aug 13 12:26:35 MDT 2023 Kent Overstreet <kent.overstreet@linux.dev> block: Allow bio_iov_iter_get_pages() with bio->bi_bdev unset

bio_iov_iter_get_pages() trims the IO based on the block size of the
block device the IO will be issued to.

However, bcachefs is a multi device filesystem; when we're creating the
bio we don't yet know which block device the bio will be submitted to -
we have to handle the alignment checks elsewhere.

Thus this is needed to avoid a null ptr deref.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Link: https://lore.kernel.org/r/20230813182636.2966159-3-kent.overstreet@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 6850b2dd Mon Jul 24 10:54:27 MDT 2023 Christoph Hellwig <hch@lst.de> block: use SECTOR_SHIFT bio_add_hw_page

Use the SECTOR_SHIFT magic constant instead of the magic number.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinyoung Choi <j-young.choi@samsung.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230724165433.117645-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff e97424fd Tue Jul 12 09:32:56 MDT 2022 Keith Busch <kbusch@kernel.org> block: fix leaking page ref on truncated direct io

The size being added to a bio from an iov is aligned to a block size
after the pages were gotten. If the new aligned size truncates the last
page, its reference was being leaked. Ensure all pages that were not
added to the bio have their reference released.

Since this essentially requires doing the same that bio_put_pages(), and
there was only one caller for that function, this patch makes the
put_page() loop common for everyone.

Fixes: b1a000d3b8ec5 ("block: relax direct io memory alignment")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20220712153256.2202024-3-kbusch@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff c58c0074 Fri Jun 10 01:58:21 MDT 2022 Keith Busch <kbusch@kernel.org> block/bio: remove duplicate append pages code

The getting pages setup for zone append and normal IO are identical. Use
common code for each.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-3-kbusch@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 7ecc56c6 Wed May 04 08:29:50 MDT 2022 Christoph Hellwig <hch@lst.de> block: allow passing a NULL bdev to bio_alloc_clone/bio_init_clone

Device mapper wants to allocate a bio before knowing the device it
gets send to, so add explicit support for that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20220504142950.567582-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff b53f3dcd Thu Mar 24 14:35:25 MDT 2022 Mike Snitzer <snitzer@kernel.org> block: allow use of per-cpu bio alloc cache by block drivers

Refine per-cpu bio alloc cache interfaces so that DM and other block
drivers can properly create and use the cache:

DM uses bioset_init_from_src() to do its final bioset initialization,
so must update bioset_init_from_src() to set BIOSET_PERCPU_CACHE if
%src bioset has a cache.

Also move bio_clear_polled() to include/linux/bio.h to allow users
outside of block core.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220324203526.62306-3-snitzer@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3b005bf6 Mon Jan 24 02:11:01 MST 2022 Christoph Hellwig <hch@lst.de> block: move blk_next_bio to bio.c

Keep blk_next_bio next to the core bio infrastructure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3ee859e3 Sun Jan 09 02:36:43 MST 2022 OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> block: Fix wrong offset in bio_truncate()

bio_truncate() clears the buffer outside of last block of bdev, however
current bio_truncate() is using the wrong offset of page. So it can
return the uninitialized data.

This happened when both of truncated/corrupted FS and userspace (via
bdev) are trying to read the last of bdev.

Reported-by: syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/875yqt1c9g.fsf@mail.parknet.co.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dblk-core.cdiff 3ec48489 Wed Apr 10 21:23:48 MDT 2024 Yu Kuai <yukuai3@huawei.com> block: fix that blk_time_get_ns() doesn't update time after schedule

While monitoring the throttle time of IO from iocost, it's found that
such time is always zero after the io_schedule() from ioc_rqos_throttle,
for example, with the following debug patch:

+ printk("%s-%d: %s enter %llu\n", current->comm, current->pid, __func__, blk_time_get_ns());
while (true) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (wait.committed)
break;
io_schedule();
}
+ printk("%s-%d: %s exit %llu\n", current->comm, current->pid, __func__, blk_time_get_ns());

It can be observerd that blk_time_get_ns() always return the same time:

[ 1068.096579] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.272587] fio-1268: ioc_rqos_throttle exit 1067901962288
[ 1068.274389] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.472690] fio-1268: ioc_rqos_throttle exit 1067901962288
[ 1068.474485] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.672656] fio-1268: ioc_rqos_throttle exit 1067901962288
[ 1068.674451] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.872655] fio-1268: ioc_rqos_throttle exit 1067901962288

And I think the root cause is that 'PF_BLOCK_TS' is always cleared
by blk_flush_plug() before scheduel(), hence blk_plug_invalidate_ts()
will never be called:

blk_time_get_ns
plug->cur_ktime = ktime_get_ns();
current->flags |= PF_BLOCK_TS;

io_schedule:
io_schedule_prepare
blk_flush_plug
__blk_flush_plug
/* the flag is cleared, while time is not */
current->flags &= ~PF_BLOCK_TS;
schedule
sched_update_worker
/* the flag is not set, hence plug->cur_ktime is not cleared */
if (tsk->flags & PF_BLOCK_TS)
blk_plug_invalidate_ts()

blk_time_get_ns
/* got the time stashed before schedule */
return plug->cur_ktime;

Fix the problem by clearing cached time in __blk_flush_plug().

Fixes: 06b23f92af87 ("block: update cached timestamp post schedule/preemption")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240411032349.3051233-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 67d995e0 Tue Nov 28 05:30:27 MST 2023 Yu Kuai <yukuai3@huawei.com> block: warn once for each partition in bio_check_ro()

Commit 1b0a151c10a6 ("blk-core: use pr_warn_ratelimited() in
bio_check_ro()") fix message storm by limit the rate, however, there
will still be lots of message in the long term. Fix it better by warn
once for each partition.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231128123027.971610-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 7ba15083 Fri Apr 07 14:05:35 MDT 2023 Mike Christie <michael.christie@oracle.com> block: Rename BLK_STS_NEXUS to BLK_STS_RESV_CONFLICT

BLK_STS_NEXUS is used for NVMe/SCSI reservation conflicts and DASD's
locking feature which works similar to NVMe/SCSI reservations where a
host can get a lock on a device and when the lock is taken it will get
failures.

This patch renames BLK_STS_NEXUS so it better reflects this type of
use.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230407200551.12660-3-michael.christie@oracle.com
Acked-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff 3eb96946 Wed May 24 00:05:38 MDT 2023 Christoph Hellwig <hch@lst.de> block: make bio_check_eod work for zero sized devices

Since the dawn of time bio_check_eod has a check for a non-zero size of
the device. This doesn't really make any sense as we never want to send
I/O to a device that's been set to zero size, or never moved out of that.

I am a bit surprised we haven't caught this for a long time, but the
removal of the extra validation inside of zram caused syzbot to trip
over this issue recently. I've added a Fixes tag for that commit, but
the issue really goes back way before git history.

Fixes: 9fe95babc742 ("zram: remove valid_io_request")
Reported-by: syzbot+b8d61a58b7c7ebd2c8e0@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230524060538.1593686-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff a13bd91b Fri Apr 14 02:40:08 MDT 2023 Yu Kuai <yukuai3@huawei.com> block/rq_qos: protect rq_qos apis with a new lock

commit 50e34d78815e ("block: disable the elevator int del_gendisk")
move rq_qos_exit() from disk_release() to del_gendisk(), this will
introduce some problems:

1) If rq_qos_add() is triggered by enabling iocost/iolatency through
cgroupfs, then it can concurrent with del_gendisk(), it's not safe to
write 'q->rq_qos' concurrently.

2) Activate cgroup policy that is relied on rq_qos will call
rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is
called in the middle, null-ptr-dereference will be triggered in
blkcg_activate_policy().

3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the
disk, then if rq_qos_exit() from del_gendisk() is done before
rq_qos_add(), then memory will be leaked.

This patch add a new disk level mutex 'rq_qos_mutex':

1) The lock will protect rq_qos_exit() directly.

2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be
called from disk initialization for now because wbt can't be
destructed until rq_qos_exit(), so it's safe not to protect wbt for
now. Hoever, in case that rq_qos dynamically destruction is supported
in the furture, this patch also protect rq_qos_add() from wbt_init()
directly, this is enough because blk-sysfs already synchronize
writers with disk removal.

3) For iocost and iolatency, in order to synchronize disk removal and
cgroup configuration, the lock is held after blkdev_get_no_open()
from blkg_conf_open_bdev(), and is released in blkg_conf_exit().
In order to fix the above memory leak, disk_live() is checked after
holding the new lock.

Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230414084008.2085155-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff a13bd91b Fri Apr 14 02:40:08 MDT 2023 Yu Kuai <yukuai3@huawei.com> block/rq_qos: protect rq_qos apis with a new lock

commit 50e34d78815e ("block: disable the elevator int del_gendisk")
move rq_qos_exit() from disk_release() to del_gendisk(), this will
introduce some problems:

1) If rq_qos_add() is triggered by enabling iocost/iolatency through
cgroupfs, then it can concurrent with del_gendisk(), it's not safe to
write 'q->rq_qos' concurrently.

2) Activate cgroup policy that is relied on rq_qos will call
rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is
called in the middle, null-ptr-dereference will be triggered in
blkcg_activate_policy().

3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the
disk, then if rq_qos_exit() from del_gendisk() is done before
rq_qos_add(), then memory will be leaked.

This patch add a new disk level mutex 'rq_qos_mutex':

1) The lock will protect rq_qos_exit() directly.

2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be
called from disk initialization for now because wbt can't be
destructed until rq_qos_exit(), so it's safe not to protect wbt for
now. Hoever, in case that rq_qos dynamically destruction is supported
in the furture, this patch also protect rq_qos_add() from wbt_init()
directly, this is enough because blk-sysfs already synchronize
writers with disk removal.

3) For iocost and iolatency, in order to synchronize disk removal and
cgroup configuration, the lock is held after blkdev_get_no_open()
from blkg_conf_open_bdev(), and is released in blkg_conf_exit().
In order to fix the above memory leak, disk_live() is checked after
holding the new lock.

Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230414084008.2085155-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 0f7c8f0f Wed Feb 15 20:22:50 MST 2023 Jinke Han <hanjinke.666@bytedance.com> block: Fix io statistics for cgroup in throttle path

In the current code, io statistics are missing for cgroup when bio
was throttled by blk-throttle. Fix it by moving the unreaching code
to submit_bio_noacct_nocheck.

Fixes: 3f98c753717c ("block: don't check bio in blk_throtl_dispatch_work_fn")
Signed-off-by: Jinke Han <hanjinke.666@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230216032250.74230-1-hanjinke.666@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 33391eec Fri Jan 20 07:51:07 MST 2023 Jens Axboe <axboe@kernel.dk> block: treat poll queue enter similarly to timeouts

We ran into an issue where a production workload would randomly grind to
a halt and not continue until the pending IO had timed out. This turned
out to be a complicated interaction between queue freezing and polled
IO:

1) You have an application that does polled IO. At any point in time,
there may be polled IO pending.

2) You have a monitoring application that issues a passthrough command,
which is marked with side effects such that it needs to freeze the
queue.

3) Passthrough command is started, which calls blk_freeze_queue_start()
on the device. At this point the queue is marked frozen, and any
attempt to enter the queue will fail (for non-blocking) or block.

4) Now the driver calls blk_mq_freeze_queue_wait(), which will return
when the queue is quiesced and pending IO has completed.

5) The pending IO is polled IO, but any attempt to poll IO through the
normal iocb_bio_iopoll() -> bio_poll() will fail when it gets to
bio_queue_enter() as the queue is frozen. Rather than poll and
complete IO, the polling threads will sit in a tight loop attempting
to poll, but failing to enter the queue to do so.

The end result is that progress for either application will be stalled
until all pending polled IO has timed out. This causes obvious huge
latency issues for the application doing polled IO, but also long delays
for passthrough command.

Fix this by treating queue enter for polled IO just like we do for
timeouts. This allows quick quiesce of the queue as we still poll and
complete this IO, while still disallowing queueing up new IO.

Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff e29b2100 Tue Jan 10 07:36:34 MST 2023 Pankaj Raghav <p.raghav@samsung.com> block: add a new helper bdev_{is_zone_start, offset_from_zone_start}

Instead of open coding to check for zone start, add a helper to improve
readability and store the logic in one place.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230110143635.77300-3-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 77e7ffd7 Thu Jul 14 12:06:28 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Use enum req_op where appropriate

Change the type of the arguments that are used to pass a REQ_OP_* value
from int or unsigned int into enum req_op to improve static type
checking.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dblk-mq.cdiff af550e4c Fri Feb 23 08:57:49 MST 2024 Qais Yousef <qyousef@layalina.io> block/blk-mq: Don't complete locally if capacities are different

The logic in blk_mq_complete_need_ipi() assumes SMP systems where all
CPUs have equal compute capacities and only LLC cache can make
a different on perceived performance. But this assumption falls apart on
HMP systems where LLC is shared, but the CPUs have different capacities.
Staying local then can have a big performance impact if the IO request
was done from a CPU with higher capacity but the interrupt is serviced
on a lower capacity CPU.

Use the new cpus_equal_capacity() function to check if we need to send
an IPI.

Without the patch I see the BLOCK softirq always running on little cores
(where the hardirq is serviced). With it I can see it running on all
cores.

This was noticed after the topology change [1] where now on a big.LITTLE
we truly get that the LLC is shared between all cores where as in the
past it was being misrepresented for historical reasons. The logic
exposed a missing dependency on capacities for such systems where there
can be a big performance difference between the CPUs.

This of course introduced a noticeable change in behavior depending on
how the topology is presented. Leading to regressions in some workloads
as the performance of the BLOCK softirq on littles can be noticeably
worse on some platforms.

Worth noting that we could have checked for capacities being greater
than or equal instead for equality. This will lead to favouring higher
performance always. But opted for equality instead to match the
performance of the requester without making an assumption that can lead
to power trade-offs which these systems tend to be sensitive about. If
the requester would like to run faster, it's better to rely on the
scheduler to give the IO requester via some facility to run on a faster
core; and then if the interrupt triggered on a CPU with different
capacity we'll make sure to match the performance the requester is
supposed to run at.

[1] https://lpc.events/event/16/contributions/1342/attachments/962/1883/LPC-2022-Android-MC-Phantom-Domains.pdf

Signed-off-by: Qais Yousef <qyousef@layalina.io>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240223155749.2958009-3-qyousef@layalina.io
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 337e89fe Wed Jan 24 02:26:57 MST 2024 Christoph Hellwig <hch@lst.de> blk-mq: introduce a blk_mq_peek_cached_request helper

Add a new helper to check if there is suitable cached request in
blk_mq_submit_bio. This removes open coded logic in blk_mq_submit_bio
and moves some checks that so far are in blk_mq_use_cached_rq to
be performed earlier. This avoids the case where we first do check
with the cached request but then later end up allocating a new one
anyway and need to grab a queue reference.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240124092658.2258309-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 48554df6 Wed Sep 13 09:16:13 MDT 2023 Chengming Zhou <zhouchengming@bytedance.com> blk-mq: remove RQF_MQ_INFLIGHT

Since the previous patch change to only account active requests when
we really allocate the driver tag, the RQF_MQ_INFLIGHT can be removed
and no double account problem.

1. none elevator: flush request will use the first pending request's
driver tag, won't double account.

2. other elevator: flush request will be accounted when allocate driver
tag when issue, and will be unaccounted when it put the driver tag.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230913151616.3164338-3-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 7222657e Mon Aug 21 03:56:02 MDT 2023 Chengming Zhou <zhouchengming@bytedance.com> blk-mq: prealloc tags when increase tagset nr_hw_queues

Just like blk_mq_alloc_tag_set(), it's better to prepare all tags before
using to map to queue ctxs in blk_mq_map_swqueue(), which now have to
consider empty set->tags[].

The good point is that we can fallback easily if increasing nr_hw_queues
fail, instead of just mapping to hctx[0] when fail in blk_mq_map_swqueue().

And the fallback path already has tags free & clean handling, so all
is good.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230821095602.70742-3-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff e1dd7bc9 Mon Aug 21 03:56:00 MDT 2023 Chengming Zhou <zhouchengming@bytedance.com> blk-mq: fix tags leak when shrink nr_hw_queues

Although we don't need to realloc set->tags[] when shrink nr_hw_queues,
we need to free them. Or these tags will be leaked.

How to reproduce:
1. mount -t configfs configfs /mnt
2. modprobe null_blk nr_devices=0 submit_queues=8
3. mkdir /mnt/nullb/nullb0
4. echo 1 > /mnt/nullb/nullb0/power
5. echo 4 > /mnt/nullb/nullb0/submit_queues
6. rmdir /mnt/nullb/nullb0

In step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then
in step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue).
At last in step 6, only these 5 tags are freed, the other 4 tags leaked.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230821095602.70742-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff fdcab6cd Wed May 17 23:31:00 MDT 2023 Christoph Hellwig <hch@lst.de> blk-mq: remove RQF_ELVPRIV

RQF_ELVPRIV is set for all non-flush requests that have RQF_ELV set.
Expand this condition in the two users of the flag and remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230518053101.760632-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff c20a1a2c Thu Apr 13 00:06:48 MDT 2023 Christoph Hellwig <hch@lst.de> blk-mq: remove the blk_mq_hctx_stopped check in blk_mq_run_work_fn

blk_mq_hctx_stopped is already checked in blk_mq_sched_dispatch_requests
under blk_mq_run_dispatch_ops() protection, so remove the duplicate check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413060651.694656-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff bebe84eb Thu Apr 13 00:40:39 MDT 2023 Christoph Hellwig <hch@lst.de> blk-mq: remove blk-mq-tag.h

blk-mq-tag.h is always included by blk-mq.h, and causes recursive
inclusion hell with further changes. Just merge it into blk-mq.h
instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 34c9f547 Wed Jan 18 02:37:19 MST 2023 Kemeng Shi <shikemeng@huaweicloud.com> blk-mq: make blk_mq_commit_rqs a general function for all commits

1. move blk_mq_commit_rqs forward before functions need commits.
2. add queued check and only commits request if any request was queued
in blk_mq_commit_rqs to keep commit behavior consistent and remove
unnecessary commit.
3. split the queued clearing from blk_mq_plug_commit_rqs as it is
not wanted general.
4. sync current caller of blk_mq_commit_rqs with new general
blk_mq_commit_rqs.
5. document rule for unusual cases which need explicit commit_rqs.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e368fb0 Wed Jan 18 02:37:18 MST 2023 Kemeng Shi <shikemeng@huaweicloud.com> blk-mq: remove unncessary from_schedule parameter in blk_mq_plug_issue_direct

Function blk_mq_plug_issue_direct tries to issue batch requests in plug
list to driver directly. We will only issue plug request to driver if we
are not from scheduler, so from_scheduler parameter of
blk_mq_plug_issue_direct is always false.
Remove unncessary from_scheduler of blk_mq_plug_issue_direct.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dblk-mq.hdiff 4f1731df Fri Jun 09 20:30:43 MDT 2023 Yu Kuai <yukuai3@huawei.com> blk-mq: fix potential io hang by wrong 'wake_batch'

In __blk_mq_tag_busy/idle(), updating 'active_queues' and calculating
'wake_batch' is not atomic:

t1: t2:
_blk_mq_tag_busy blk_mq_tag_busy
inc active_queues
// assume 1->2
inc active_queues
// 2 -> 3
blk_mq_update_wake_batch
// calculate based on 3
blk_mq_update_wake_batch
/* calculate based on 2, while active_queues is actually 3. */

Fix this problem by protecting them wih 'tags->lock', this is not a hot
path, so performance should not be concerned. And now that all writers
are inside the lock, switch 'actives_queues' from atomic to unsigned
int.

Fixes: 180dccb0dba4 ("blk-mq: fix tag_get wait task can't be awakened")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230610023043.2559121-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 4f1731df Fri Jun 09 20:30:43 MDT 2023 Yu Kuai <yukuai3@huawei.com> blk-mq: fix potential io hang by wrong 'wake_batch'

In __blk_mq_tag_busy/idle(), updating 'active_queues' and calculating
'wake_batch' is not atomic:

t1: t2:
_blk_mq_tag_busy blk_mq_tag_busy
inc active_queues
// assume 1->2
inc active_queues
// 2 -> 3
blk_mq_update_wake_batch
// calculate based on 3
blk_mq_update_wake_batch
/* calculate based on 2, while active_queues is actually 3. */

Fix this problem by protecting them wih 'tags->lock', this is not a hot
path, so performance should not be concerned. And now that all writers
are inside the lock, switch 'actives_queues' from atomic to unsigned
int.

Fixes: 180dccb0dba4 ("blk-mq: fix tag_get wait task can't be awakened")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230610023043.2559121-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 4f1731df Fri Jun 09 20:30:43 MDT 2023 Yu Kuai <yukuai3@huawei.com> blk-mq: fix potential io hang by wrong 'wake_batch'

In __blk_mq_tag_busy/idle(), updating 'active_queues' and calculating
'wake_batch' is not atomic:

t1: t2:
_blk_mq_tag_busy blk_mq_tag_busy
inc active_queues
// assume 1->2
inc active_queues
// 2 -> 3
blk_mq_update_wake_batch
// calculate based on 3
blk_mq_update_wake_batch
/* calculate based on 2, while active_queues is actually 3. */

Fix this problem by protecting them wih 'tags->lock', this is not a hot
path, so performance should not be concerned. And now that all writers
are inside the lock, switch 'actives_queues' from atomic to unsigned
int.

Fixes: 180dccb0dba4 ("blk-mq: fix tag_get wait task can't be awakened")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230610023043.2559121-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff bebe84eb Thu Apr 13 00:40:39 MDT 2023 Christoph Hellwig <hch@lst.de> blk-mq: remove blk-mq-tag.h

blk-mq-tag.h is always included by blk-mq.h, and causes recursive
inclusion hell with further changes. Just merge it into blk-mq.h
instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 7e923f40 Wed Jun 15 16:55:48 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Rename a blk_mq_map_queue() argument

Before the introduction of blk_mq_get_hctx_type(), blk_mq_map_queue()
only used the flags from its second argument. Since the introduction of
blk_mq_get_hctx_type(), blk_mq_map_queue() uses both the operation and
the flags encoded in that argument. Rename the second argument of
blk_mq_map_queue() to make this clear.

Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220615225549.1054905-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 704b914f Fri Dec 03 06:15:32 MST 2021 Ming Lei <ming.lei@redhat.com> blk-mq: move srcu from blk_mq_hw_ctx to request_queue

In case of BLK_MQ_F_BLOCKING, per-hctx srcu is used to protect dispatch
critical area. However, this srcu instance stays at the end of hctx, and
it often takes standalone cacheline, often cold.

Inside srcu_read_lock() and srcu_read_unlock(), WRITE is always done on
the indirect percpu variable which is allocated from heap instead of
being embedded, srcu->srcu_idx is read only in srcu_read_lock(). It
doesn't matter if srcu structure stays in hctx or request queue.

So switch to per-request-queue srcu for protecting dispatch, and this
way simplifies quiesce a lot, not mention quiesce is always done on the
request queue wide.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211203131534.3668411-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 2a904d00 Fri Dec 03 06:15:31 MST 2021 Ming Lei <ming.lei@redhat.com> blk-mq: remove hctx_lock and hctx_unlock

Remove hctx_lock and hctx_unlock, and add one helper of
blk_mq_run_dispatch_ops() to run code block defined in dispatch_ops
with rcu/srcu read held.

Compared with hctx_lock()/hctx_unlock():

1) remove 2 branch to 1, so we just need to check
(hctx->flags & BLK_MQ_F_BLOCKING) once when running one dispatch_ops

2) srcu_idx needn't to be touched in case of non-blocking

3) might_sleep_if() can be moved to the blocking branch

Also put the added blk_mq_run_dispatch_ops() in private header, so that
the following patch can use it out of blk-mq.c.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211203131534.3668411-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3b87c6ea Tue Nov 02 09:36:19 MDT 2021 Ming Lei <ming.lei@redhat.com> blk-mq: update hctx->nr_active in blk_mq_end_request_batch()

In case of shared tags and none io sched, batched completion still may
be run into, and hctx->nr_active is accounted when getting driver tag,
so it has to be updated in blk_mq_end_request_batch().

Otherwise, hctx->nr_active may become same with queue depth, then
hctx_may_queue() always return false, then io hang is caused.

Fixes the issue by updating the counter in batched way.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: f794f3351f26 ("block: add support for blk_mq_end_request_batch()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211102153619.3627505-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff dbb6f764 Wed Oct 20 08:41:17 MDT 2021 Christoph Hellwig <hch@lst.de> blk-mq: move blk_mq_flush_plug_list to block/blk-mq.h

This helper is internal to the block layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211020144119.142582-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dfops.cdiff 3c435a0f Thu Jun 01 08:58:56 MDT 2023 Christoph Hellwig <hch@lst.de> filemap: add a kiocb_write_and_wait helper

Factor out a helper that does filemap_write_and_wait_range for the range
covered by a read kiocb, or returns -EAGAIN if the kiocb is marked as
nowait and there would be pages to write.

Link: https://lkml.kernel.org/r/20230601145904.1385409-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff e9833d87 Tue May 09 09:19:09 MDT 2023 Jens Axboe <axboe@kernel.dk> block: mark bdev files as FMODE_NOWAIT if underlying device supports it

We set this unconditionally, but it really should be dependent on if
the underlying device is nowait compliant.

Cc: linux-block@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230509151910.183637-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e1f941d Tue Feb 01 03:04:20 MST 2022 Ilya Dryomov <idryomov@gmail.com> block: fix DIO handling regressions in blkdev_read_iter()

Commit ceaa762527f4 ("block: move direct_IO into our own read_iter
handler") introduced several regressions for bdev DIO:

1. read spanning EOF always returns 0 instead of the number of bytes
read. This is because "count" is assigned early and isn't updated
when the iterator is truncated:

$ lsblk -o name,size /dev/vdb
NAME SIZE
vdb 1G
$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 0/4194304 bytes at offset 1070596096
0.000000 bytes, 0 ops; 0.0007 sec (0.000000 bytes/sec and 0.0000 ops/sec)

instead of

$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 3145728/4194304 bytes at offset 1070596096
3 MiB, 1 ops; 0.0007 sec (3.865 GiB/sec and 1319.2612 ops/sec)

2. truncated iterator isn't reexpanded
3. iterator isn't reverted on blkdev_direct_IO() error
4. zero size read no longer skips atime update

Fixes: ceaa762527f4 ("block: move direct_IO into our own read_iter handler")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220201100420.25875-1-idryomov@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e1f941d Tue Feb 01 03:04:20 MST 2022 Ilya Dryomov <idryomov@gmail.com> block: fix DIO handling regressions in blkdev_read_iter()

Commit ceaa762527f4 ("block: move direct_IO into our own read_iter
handler") introduced several regressions for bdev DIO:

1. read spanning EOF always returns 0 instead of the number of bytes
read. This is because "count" is assigned early and isn't updated
when the iterator is truncated:

$ lsblk -o name,size /dev/vdb
NAME SIZE
vdb 1G
$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 0/4194304 bytes at offset 1070596096
0.000000 bytes, 0 ops; 0.0007 sec (0.000000 bytes/sec and 0.0000 ops/sec)

instead of

$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 3145728/4194304 bytes at offset 1070596096
3 MiB, 1 ops; 0.0007 sec (3.865 GiB/sec and 1319.2612 ops/sec)

2. truncated iterator isn't reexpanded
3. iterator isn't reverted on blkdev_direct_IO() error
4. zero size read no longer skips atime update

Fixes: ceaa762527f4 ("block: move direct_IO into our own read_iter handler")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220201100420.25875-1-idryomov@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e1f941d Tue Feb 01 03:04:20 MST 2022 Ilya Dryomov <idryomov@gmail.com> block: fix DIO handling regressions in blkdev_read_iter()

Commit ceaa762527f4 ("block: move direct_IO into our own read_iter
handler") introduced several regressions for bdev DIO:

1. read spanning EOF always returns 0 instead of the number of bytes
read. This is because "count" is assigned early and isn't updated
when the iterator is truncated:

$ lsblk -o name,size /dev/vdb
NAME SIZE
vdb 1G
$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 0/4194304 bytes at offset 1070596096
0.000000 bytes, 0 ops; 0.0007 sec (0.000000 bytes/sec and 0.0000 ops/sec)

instead of

$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 3145728/4194304 bytes at offset 1070596096
3 MiB, 1 ops; 0.0007 sec (3.865 GiB/sec and 1319.2612 ops/sec)

2. truncated iterator isn't reexpanded
3. iterator isn't reverted on blkdev_direct_IO() error
4. zero size read no longer skips atime update

Fixes: ceaa762527f4 ("block: move direct_IO into our own read_iter handler")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220201100420.25875-1-idryomov@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 138c1a38 Thu Nov 04 15:13:17 MDT 2021 Jens Axboe <axboe@kernel.dk> block: use new bdev_nr_bytes() helper for blkdev_{read,write}_iter()

We have new helpers for this, use them rather than the slower inode
size reads. This makes the read/write path consistent with most of
the rest of block as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/a72767cd-3c6d-47f7-80f4-aa025a17b2cb@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 71fc3f5e Tue Oct 12 05:12:12 MDT 2021 Christoph Hellwig <hch@lst.de> block: don't try to poll multi-bio I/Os in __blkdev_direct_IO

If an iocb is split into multiple bios we can't poll for both. So don't
even bother to try to poll in that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012111226.760968-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
/linux-master/drivers/block/
H A Dbrd.cdiff 3f89ac58 Mon Apr 24 17:46:28 MDT 2023 Chaitanya Kulkarni <kch@nvidia.com> block/drivers: remove dead clear of random flag

QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk",
"brd", "nbd", "zram", and "bcache" since by default we don't set
"QUEUE_FLAG_ADD_RANDOM" to MQ ops.

Remove dead clear of QUEUE_FLAG_ADD_RANDOM in above listed drivers.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> #zram
Link: https://lore.kernel.org/r/20230424234628.45544-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 86947df3 Thu Jul 14 12:06:29 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Change the type of the last .rw_page() argument

All .rw_page() callers pass an enum req_op value as last argument. Make
this explicit by changing the type of the last argument into enum req_op.
See also commit 3f289dcb4b26 ("block: make bdev_ops->rw_page() take a
REQ_OP instead of bool").

Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-4-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff f4be591f Fri Apr 16 15:18:29 MDT 2021 Calvin Owens <calvinowens@fb.com> brd: expose number of allocated pages in debugfs

While the maximum size of each ramdisk is defined either as a module
parameter, or compile time default, it's impossible to know how many pages
have currently been allocated by each ram%d device, since they're
allocated when used and never freed.

This patch creates a new directory at this location:

/sys/kernel/debug/ramdisk_pages/

which will contain a file named "ram%d" for each instantiated ramdisk on
the system. The file is read-only, and read() will output the number of
pages currently held by that ramdisk.

We lose track how much memory a ramdisk is using as pages once used are
simply recycled but never freed.

In instances where we exhaust the size of the ramdisk with a file that
exceeds it, encounter ENOSPC and delete the file for mitigation; df would
show decrease in used and increase in available blocks but the since we
have touched all pages, the memory footprint of the ramdisk does not
reflect the blocks used/available count

...
[root@localhost ~]# mkfs.ext2 /dev/ram15
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 4096 1k blocks and 1024 inodes
[root@localhost ~]# mount /dev/ram15 /mnt/ram15/

[root@localhost ~]# cat
/sys/kernel/debug/ramdisk_pages/ram15
58
[root@kerneltest008.06.prn3 ~]# df /dev/ram15
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/ram15 3963 31 3728 1% /mnt/ram15
[root@kerneltest008.06.prn3 ~]# dd if=/dev/urandom of=/mnt/ram15/test2
bs=1M count=5
dd: error writing '/mnt/ram15/test2': No space left on device
4+0 records in
3+0 records out
4005888 bytes (4.0 MB, 3.8 MiB) copied, 0.0446614 s, 89.7 MB/s
[root@kerneltest008.06.prn3 ~]# df /mnt/ram15/
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/ram15 3963 3960 0 100% /mnt/ram15
[root@kerneltest008.06.prn3 ~]# cat
/sys/kernel/debug/ramdisk_pages/ram15
1024
[root@kerneltest008.06.prn3 ~]# rm /mnt/ram15/test2
rm: remove regular file '/mnt/ram15/test2'? y
[root@kerneltest008.06.prn3 /var]# df /dev/ram15
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/ram15 3963 31 3728 1% /mnt/ram15

# Acutal memory footprint
[root@kerneltest008.06.prn3 /var]# cat
/sys/kernel/debug/ramdisk_pages/ram15
1024
...

This debugfs counter will always reveal the accurate number of
permanently allocated pages to the ramdisk.

Signed-off-by: Calvin Owens <calvinowens@fb.com>
[cleaned up the !CONFIG_DEBUG_FS case and API changes for HEAD]
Signed-off-by: Kyle McMartin <jkkm@fb.com>
[rebased]
Signed-off-by: Saravanan D <saravanand@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff c8ab4225 Tue Feb 04 04:30:20 MST 2020 Zhiqiang Liu <liuzhiqiang26@huawei.com> brd: check and limit max_part par

In brd_init func, rd_nr num of brd_device are firstly allocated
and add in brd_devices, then brd_devices are traversed to add each
brd_device by calling add_disk func. When allocating brd_device,
the disk->first_minor is set to i * max_part, if rd_nr * max_part
is larger than MINORMASK, two different brd_device may have the same
devt, then only one of them can be successfully added.
when rmmod brd.ko, it will cause oops when calling brd_exit.

Follow those steps:
# modprobe brd rd_nr=3 rd_size=102400 max_part=1048576
# rmmod brd
then, the oops will appear.

Oops log:
[ 726.613722] Call trace:
[ 726.614175] kernfs_find_ns+0x24/0x130
[ 726.614852] kernfs_find_and_get_ns+0x44/0x68
[ 726.615749] sysfs_remove_group+0x38/0xb0
[ 726.616520] blk_trace_remove_sysfs+0x1c/0x28
[ 726.617320] blk_unregister_queue+0x98/0x100
[ 726.618105] del_gendisk+0x144/0x2b8
[ 726.618759] brd_exit+0x68/0x560 [brd]
[ 726.619501] __arm64_sys_delete_module+0x19c/0x2a0
[ 726.620384] el0_svc_common+0x78/0x130
[ 726.621057] el0_svc_handler+0x38/0x78
[ 726.621738] el0_svc+0x8/0xc
[ 726.622259] Code: aa0203f6 aa0103f7 aa1e03e0 d503201f (7940e260)

Here, we add brd_check_and_reset_par func to check and limit max_part par.

--
V5->V6:
- remove useless code

V4->V5:(suggested by Ming Lei)
- make sure max_part is not larger than DISK_MAX_PARTS

V3->V4:(suggested by Ming Lei)
- remove useless change
- add one limit of max_part

V2->V3: (suggested by Ming Lei)
- clear .minors when running out of consecutive minor space in brd_alloc
- remove limit of rd_nr

V1->V2:
- add more checks in brd_check_par_valid as suggested by Ming Lei.

Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 36582a5a Wed Dec 04 04:31:14 MST 2019 Ming Lei <ming.lei@redhat.com> brd: remove max_hw_sectors queue limit

Now we depend on blk_queue_split() to respect most of queue limit
(the only one exception could be dma alignment), however
blk_queue_split() isn't used for brd, so this limit isn't respected
since v4.3.

Also max_hw_sectors limit doesn't play a big role for brd, which is
added since brd is added to tree for unknown reason.

So remove it.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 153fcd5f Thu Nov 01 18:50:51 MDT 2018 Ming Lei <ming.lei@redhat.com> block: brd: associate with queue until adding disk

brd_free() may be called in failure path on one brd instance which
disk isn't added yet, so release handler of gendisk may free the
associated request_queue early and causes the following use-after-free[1].

This patch fixes this issue by associating gendisk with request_queue
just before adding disk.

[1] KASAN: use-after-free Read in del_timer_syncNon-volatile memory driver v1.3
Linux agpgart interface v0.103
[drm] Initialized vgem 1.0.0 20120112 for virtual device on minor 0
usbcore: registered new interface driver udl
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20
kernel/locking/lockdep.c:3218
Read of size 8 at addr ffff8801d1b6b540 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x244/0x39d lib/dump_stack.c:113
print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
__lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218
lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
del_timer_sync+0xb7/0x270 kernel/time/timer.c:1283
blk_cleanup_queue+0x413/0x710 block/blk-core.c:809
brd_free+0x5d/0x71 drivers/block/brd.c:422
brd_init+0x2eb/0x393 drivers/block/brd.c:518
do_one_initcall+0x145/0x957 init/main.c:890
do_initcall_level init/main.c:958 [inline]
do_initcalls init/main.c:966 [inline]
do_basic_setup init/main.c:984 [inline]
kernel_init_freeable+0x5c6/0x6b9 init/main.c:1148
kernel_init+0x11/0x1ae init/main.c:1068
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350

Reported-by: syzbot+3701447012fe951dabb2@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3f289dcb Wed Jul 18 05:47:36 MDT 2018 Tejun Heo <tj@kernel.org> block: make bdev_ops->rw_page() take a REQ_OP instead of bool

c11f0c0b5bb9 ("block/mm: make bdev_ops->rw_page() take a bool for
read/write") replaced @op with boolean @is_write, which limited the
amount of information going into ->rw_page() and more importantly
page_endio(), which removed the need to expose block internals to mm.

Unfortunately, we want to track discards separately and @is_write
isn't enough information. This patch updates bdev_ops->rw_page() to
take REQ_OP instead but leaves page_endio() to take bool @is_write.
This allows the block part of operations to have enough information
while not leaking it to mm.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dn64cart.cdiff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dpktcdvd.cdiff 40685508 Thu Feb 22 00:36:47 MST 2024 Christoph Hellwig <hch@lst.de> pktcdvd: set queue limits at disk allocation time

Remove pkt_init_queue and just pass the two parameters directly to
blk_alloc_disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240222073647.3776769-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3bb5746c Fri Mar 10 09:45:43 MST 2023 Andy Shevchenko <andriy.shevchenko@linux.intel.com> pktcdvd: use sysfs_emit() to instead of scnprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 1a0ddd56 Fri Mar 10 09:45:42 MST 2023 Andy Shevchenko <andriy.shevchenko@linux.intel.com> pktcdvd: replace sscanf() by kstrtoul()

The checkpatch.pl warns: "Prefer kstrto<type> to single variable sscanf".
Fix the code accordingly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230310164549.22133-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a41db53 Fri Mar 10 09:45:41 MST 2023 Andy Shevchenko <andriy.shevchenko@linux.intel.com> pktcdvd: Get rid of custom printing macros

We may use traditional dev_*() macros instead of custom ones
provided by the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e9900f3 Mon Jan 16 08:51:05 MST 2023 Jens Axboe <axboe@kernel.dk> pktcdvd: check for NULL returna fter calling bio_split_to_limits()

The revert of the removal of this driver happened after we fixed up
the split limits for NOWAIT issue, hence it got missed. Ensure that
we check for a NULL bio after splitting, in case it should be retried.

Marking this as fixing both commits, so that stable backport will do
this correctly.

Cc: stable@vger.kernel.org
Fixes: 9cea62b2cbab ("block: don't allow splitting of a REQ_NOWAIT bio")
Fixes: 4b83e99ee709 ("Revert "pktcdvd: remove driver."")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 0bf6d96c Mon Oct 25 01:05:07 MDT 2021 Christoph Hellwig <hch@lst.de> block: remove blk_{get,put}_request

These are now pointless wrappers around blk_mq_{alloc,free}_request,
so remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20211025070517.1548584-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3f3942ac Tue May 15 07:57:23 MDT 2018 Christoph Hellwig <hch@lst.de> proc: introduce proc_create_single{,_data}

Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
H A Dps3vram.cdiff 3c30883a Fri Oct 15 17:52:17 MDT 2021 Luis Chamberlain <mcgrof@kernel.org> ps3vram: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Geoff Levand <geoff@infradead.org>
Link: https://lore.kernel.org/r/20211015235219.2191207-12-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 3f3942ac Tue May 15 07:57:23 MDT 2018 Christoph Hellwig <hch@lst.de> proc: introduce proc_create_single{,_data}

Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
diff 5a0e3ad6 Wed Mar 24 02:04:11 MDT 2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
/linux-master/drivers/block/drbd/
H A Ddrbd_int.hdiff 136160c1 Wed Nov 30 16:03:47 MST 2022 Christoph Böhmwalder <christoph.boehmwalder@linbit.com> drbd: split polymorph printk to its own file

Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20221201110349.1282687-3-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff e16fb3a8 Tue Jan 22 23:33:09 MST 2019 Gustavo A. R. Silva <gustavo@embeddedor.com> block: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

This patch fixes the following warnings:

drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3093:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3120:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_req.c:856:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
diff e16fb3a8 Tue Jan 22 23:33:09 MST 2019 Gustavo A. R. Silva <gustavo@embeddedor.com> block: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

This patch fixes the following warnings:

drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3093:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3120:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_req.c:856:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
diff 3d0e6375 Mon Aug 06 17:32:16 MDT 2018 Kees Cook <keescook@chromium.org> drbd: Convert from ahash to shash

In preparing to remove all stack VLA usage from the kernel[1], this
removes the discouraged use of AHASH_REQUEST_ON_STACK in favor of
the smaller SHASH_DESC_ON_STACK by converting from ahash-wrapped-shash
to direct shash. By removing a layer of indirection this both improves
performance and reduces stack usage. The stack allocation will be made
a fixed size in a later patch to the crypto subsystem.

The bulk of the lines in this change are simple s/ahash/shash/, but the
main logic differences are in drbd_csum_ee() and drbd_csum_bio(), which
externalizes the page walking with k(un)map_atomic() instead of using
scattergather.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3f07c014 Wed Feb 08 10:51:30 MST 2017 Ingo Molnar <mingo@kernel.org> sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>

We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff 3b52beff Wed Jul 06 02:57:39 MDT 2011 Andreas Gruenbacher <agruen@linbit.com> drbd: Turn drbd_printk() into a polymorphic macro

This allows drbd_alert(), drbd_err(), drbd_warn(), and drbd_info() to work for
a resource, device, or connection so that we don't have to introduce three
separate sets of macros for that.

The drbd_printk() macro itself is pretty ugly, but that problem is limited to
one place in the code. Using drbd_printk() on an object type which it doesn't
understand results in an undefined drbd_printk_with_wrong_object_type symbol.

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
diff d752b269 Tue Jun 25 08:50:08 MDT 2013 Philipp Reisner <philipp.reisner@linbit.com> drbd: Allow online change of al-stripes and al-stripe-size

Allow to change the AL layout with an resize operation. For that
the reisze command gets two new fields: al_stripes and al_stripe_size.

In order to make the operation crash save:
1) Lock out all IO and MD-IO
2) Write the super block with MDF_PRIMARY_IND clear
3) write the bitmap to the new location (all zeros, since
we allow only while connected)
4) Initialize the new AL-area
5) Write the super block with the restored MDF_PRIMARY_IND.
6) Unfreeze all IO

Since the AL-layout has no influence on the protocol, this operation
needs to be beforemed on both sides of a resource (if intended).

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a4d4eb3 Tue Mar 19 11:16:44 MDT 2013 Lars Ellenberg <lars.ellenberg@linbit.com> drbd: prepare for new striped layout of activity log

Introduce two new on-disk meta data fields: al_stripes and al_stripe_size_4k
The intended use case is activity log on RAID 0 or similar.
Logically consecutive transactions will advance their on-disk position
by al_stripe_size_4k 4kB (transaction sized) blocks.

Right now, these are still asserted to be the backward compatible
values al_stripes = 1, al_stripe_size_4k = 8 (which amounts to 32kB).

Also introduce a caching member for meta_dev_idx in the in-core
structure: even though it is initially passed in in the rcu-protected
disk_conf structure, it cannot change without a detach/attach cycle.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Ddrbd_req.cdiff a34592ff Wed Feb 09 01:28:23 MST 2022 Christoph Hellwig <hch@lst.de> scsi: drbd: Remove WRITE_SAME support

REQ_OP_WRITE_SAME was only ever submitted by the legacy Linux zeroing code,
which has switched to use REQ_OP_WRITE_ZEROES long ago.

Link: https://lore.kernel.org/r/20220209082828.2629273-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff ec45a263 Wed Nov 27 20:09:30 MST 2019 zhengbin <zhengbin13@huawei.com> drbd: Remove unneeded semicolon

Fixes coccicheck warning:

drivers/block/drbd/drbd_req.c:887:2-3: Unneeded semicolon

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff e16fb3a8 Tue Jan 22 23:33:09 MST 2019 Gustavo A. R. Silva <gustavo@embeddedor.com> block: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

This patch fixes the following warnings:

drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3093:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3120:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_req.c:856:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
diff e16fb3a8 Tue Jan 22 23:33:09 MST 2019 Gustavo A. R. Silva <gustavo@embeddedor.com> block: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

This patch fixes the following warnings:

drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_int.h:1774:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3093:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_receiver.c:3120:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/block/drbd/drbd_req.c:856:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
diff 3b9d35d7 Mon Nov 10 09:21:13 MST 2014 Lars Ellenberg <lars.ellenberg@linbit.com> drbd: merge_bvec_fn: properly remap bvm->bi_bdev

This was not noticed for many years. Affects operation if
md raid is used a backing device for DRBD.

CC: stable@kernel.org # v3.2+
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff 3b9ef85e Mon Jul 30 01:06:26 MDT 2012 Lars Ellenberg <lars.ellenberg@linbit.com> drbd: fix null pointer dereference with on-congestion policy when diskless

We must not look at mdev->actlog, unless we have a get_ldev() reference.
It also does not make much sense to try to disconnect or pull-ahead of
the peer, if we don't have good local data.

Only even consider congestion policies, if our local disk is D_UP_TO_DATE.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff 3b03ad59 Fri Jul 15 05:53:06 MDT 2011 Philipp Reisner <philipp.reisner@linbit.com> drbd: Do not mod_timer() with a past time

In case we can not find out why the request takes too long
(happens e.g. when IO got suspended on DRBD level). rearm
the timer with a reasonable value.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
/linux-master/drivers/block/null_blk/
H A Dmain.cdiff e32b0855 Tue Feb 20 02:32:45 MST 2024 Christoph Hellwig <hch@lst.de> null_blk: initialize the tag_set timeout in null_init_tag_set

Otherwise it will be reset to the always same value when initializing a
device using the shared tag_set.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 8cfb9819 Mon Jun 05 00:23:53 MDT 2023 Nitesh Shetty <nj.shetty@samsung.com> null_blk: Fix: memory release when memory_backed=1

Memory/pages are not freed, when unloading nullblk driver.

Steps to reproduce issue
1.free -h
total used free shared buff/cache available
Mem: 7.8Gi 260Mi 7.1Gi 3.0Mi 395Mi 7.3Gi
Swap: 0B 0B 0B
2.modprobe null_blk memory_backed=1
3.dd if=/dev/urandom of=/dev/nullb0 oflag=direct bs=1M count=1000
4.modprobe -r null_blk
5.free -h
total used free shared buff/cache available
Mem: 7.8Gi 1.2Gi 6.1Gi 3.0Mi 398Mi 6.3Gi
Swap: 0B 0B 0B

Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
Link: https://lore.kernel.org/r/20230605062354.24785-1-nj.shetty@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3f89ac58 Mon Apr 24 17:46:28 MDT 2023 Chaitanya Kulkarni <kch@nvidia.com> block/drivers: remove dead clear of random flag

QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk",
"brd", "nbd", "zram", and "bcache" since by default we don't set
"QUEUE_FLAG_ADD_RANDOM" to MQ ops.

Remove dead clear of QUEUE_FLAG_ADD_RANDOM in above listed drivers.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> #zram
Link: https://lore.kernel.org/r/20230424234628.45544-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 63f8793e Sun Apr 16 16:03:39 MDT 2023 Chaitanya Kulkarni <kch@nvidia.com> null_blk: Always check queue mode setting from configfs

Make sure to check device queue mode in the null_validate_conf() and
return error for NULL_Q_RQ as we don't allow legacy I/O path, without
this patch we get OOPs when queue mode is set to 1 from configfs,
following are repro steps :-

modprobe null_blk nr_devices=0
mkdir config/nullb/nullb0
echo 1 > config/nullb/nullb0/memory_backed
echo 4096 > config/nullb/nullb0/blocksize
echo 20480 > config/nullb/nullb0/size
echo 1 > config/nullb/nullb0/queue_mode
echo 1 > config/nullb/nullb0/power

Entering kdb (current=0xffff88810acdd080, pid 2372) on processor 42 Oops: (null)
due to oops @ 0xffffffffc041c329
CPU: 42 PID: 2372 Comm: sh Tainted: G O N 6.3.0-rc5lblk+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:null_add_dev.part.0+0xd9/0x720 [null_blk]
Code: 01 00 00 85 d2 0f 85 a1 03 00 00 48 83 bb 08 01 00 00 00 0f 85 f7 03 00 00 80 bb 62 01 00 00 00 48 8b 75 20 0f 85 6d 02 00 00 <48> 89 6e 60 48 8b 75 20 bf 06 00 00 00 e8 f5 37 2c c1 48 8b 75 20
RSP: 0018:ffffc900052cbde0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: ffff88811084d800 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888100042e00
RBP: ffff8881053d8200 R08: ffffc900052cbd68 R09: ffff888105db2000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: ffff888104765200 R14: ffff88810eec1748 R15: ffff88810eec1740
FS: 00007fd445fd1740(0000) GS:ffff8897dfc80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 0000000166a00000 CR4: 0000000000350ee0
DR0: ffffffff8437a488 DR1: ffffffff8437a489 DR2: ffffffff8437a48a
DR3: ffffffff8437a48b DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nullb_device_power_store+0xd1/0x120 [null_blk]
configfs_write_iter+0xb4/0x120
vfs_write+0x2ba/0x3c0
ksys_write+0x5f/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fd4460c57a7
Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007ffd3792a4a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd4460c57a7
RDX: 0000000000000002 RSI: 000055b43c02e4c0 RDI: 0000000000000001
RBP: 000055b43c02e4c0 R08: 000000000000000a R09: 00007fd44615b4e0
R10: 00007fd44615b3e0 R11: 0000000000000246 R12: 0000000000000002
R13: 00007fd446198520 R14: 0000000000000002 R15: 00007fd446198700
</TASK>

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Link: https://lore.kernel.org/r/20230416220339.43845-1-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff bb4c19e0 Mon Mar 27 08:37:33 MDT 2023 Akinobu Mita <akinobu.mita@gmail.com> block: null_blk: make fault-injection dynamically configurable per device

The null_blk driver has multiple driver-specific fault injection
mechanisms. Each fault injection configuration can only be specified by a
module parameter and cannot be reconfigured without reloading the driver.
Also, each configuration is common to all devices and is initialized every
time a new device is added.

This change adds the following subdirectories for each null_blk device.

/sys/kernel/config/nullb/<disk>/timeout_inject
/sys/kernel/config/nullb/<disk>/requeue_inject
/sys/kernel/config/nullb/<disk>/init_hctx_fault_inject

Each fault injection attribute can be dynamically set per device by a
corresponding file in these directories.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Link: https://lore.kernel.org/r/20230327143733.14599-3-akinobu.mita@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff a4e1d0b7 Mon Aug 15 11:00:43 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Change the return type of blk_mq_map_queues() into void

Since blk_mq_map_queues() and the .map_queues() callbacks always return 0,
change their return type into void. Most callers ignore the returned value
anyway.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Acked-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20220815170043.19489-3-bvanassche@acm.org
[axboe: fold in fix from Bart]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 7012eef5 Fri Jul 08 11:49:49 MDT 2022 Vincent Fu <vincent.fu@samsung.com> null_blk: add configfs variables for 2 options

Allow setting via configfs these two options:

no_sched
shared_tag_bitmap

Previously these could only be activated as module parameters.

Still missing are:

shared_tags
timeout
requeue
init_hctx

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220708174943.87787-3-vincent.fu@samsung.com
[axboe: fold in nullb == NULL fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff b3a0a73e Tue Apr 19 18:57:16 MDT 2022 Damien Le Moal <damien.lemoal@opensource.wdc.com> block: null_blk: Cleanup device creation and deletion

Introduce the null_create_dev() and null_destroy_dev() helper functions
to respectivel create nullb devices on modprobe and destroy them on
rmmod. The null_destroy_dev() helper avoids duplicated code in the
null_init() and null_exit() functions for deleting devices.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220420005718.3780004-3-damien.lemoal@opensource.wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e3876d3 Wed Apr 13 02:48:36 MDT 2022 Ming Lei <ming.lei@redhat.com> block: null_blk: end timed out poll request

When poll request is timed out, it is removed from the poll list,
but not completed, so the request is leaked, and never get chance
to complete.

Fix the issue by ending it in timeout handler.

Fixes: 0a593fbbc245 ("null_blk: poll queue support")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220413084836.1571995-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff df00b1d2 Tue Feb 22 08:28:52 MST 2022 Chaitanya Kulkarni <kch@nvidia.com> null_blk: null_alloc_page() cleanup

Remove goto labels and use direct returns as error unwinding code only
needs to free t_page variable if we alloc_pages() call fails as having
two labels for one kfree() can be avoided easily.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220222152852.26043-3-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
/linux-master/drivers/block/zram/
H A Dzram_drv.cdiff 3f89ac58 Mon Apr 24 17:46:28 MDT 2023 Chaitanya Kulkarni <kch@nvidia.com> block/drivers: remove dead clear of random flag

QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk",
"brd", "nbd", "zram", and "bcache" since by default we don't set
"QUEUE_FLAG_ADD_RANDOM" to MQ ops.

Remove dead clear of QUEUE_FLAG_ADD_RANDOM in above listed drivers.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> #zram
Link: https://lore.kernel.org/r/20230424234628.45544-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 9fe95bab Tue Apr 11 11:14:44 MDT 2023 Christoph Hellwig <hch@lst.de> zram: remove valid_io_request

All bios hande to drivers from the block layer are checked against the
device size and for logical block alignment already (and have been since
long before zram was merged), so don't duplicate those checks.

Link: https://lkml.kernel.org/r/20230411171459.567614-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff ca9d081b Tue Apr 18 07:47:15 MDT 2023 Greg Kroah-Hartman <gregkh@linuxfoundation.org> zram: fix up permission for the hot_add sysfs file

Commit 75a2d4226b53 ("driver core: class: mark the struct class for
sysfs callbacks as constant") changed the attribute to use
CLASS_ATTR_RO() which changed the permission from 0400 to 0444. But
this atribute is "special" in that reading it modifies the system state,
so it MUST be set to 0400 so that only root processes can muck around
with it.

Fix this all up, AND document this so that I don't change it again in
3-4 years when I stumble across it and wonder why it's an open-coded
_ATTR() macro.

Reported-by: Denis Efremov <efremov@linux.com>
Fixes: 75a2d4226b53 ("driver core: class: mark the struct class for sysfs callbacks as constant")
Link: https://lore.kernel.org/r/2023041810-angelic-conical-52d8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 84b33bf7 Wed Nov 09 04:50:38 MST 2022 Sergey Senozhatsky <senozhatsky@chromium.org> zram: introduce recompress sysfs knob

Allow zram to recompress (using secondary compression streams)
pages.

Re-compression algorithms (we support up to 3 at this stage)
are selected via recomp_algorithm:

echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm

Please read documentation for more details.

We support several recompression modes:

1) IDLE pages recompression is activated by `idle` mode

echo "type=idle" > /sys/block/zram0/recompress

2) Since there may be many idle pages user-space may pass a size
threshold value (in bytes) and we will recompress pages only
of equal or greater size:

echo "threshold=888" > /sys/block/zram0/recompress

3) HUGE pages recompression is activated by `huge` mode

echo "type=huge" > /sys/block/zram0/recompress

4) HUGE_IDLE pages recompression is activated by `huge_idle` mode

echo "type=huge_idle" > /sys/block/zram0/recompress

[senozhatsky@chromium.org: we should always zero out err variable in recompress loop[
Link: https://lkml.kernel.org/r/20221110143423.3250790-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20221109115047.2921851-5-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 84b33bf7 Wed Nov 09 04:50:38 MST 2022 Sergey Senozhatsky <senozhatsky@chromium.org> zram: introduce recompress sysfs knob

Allow zram to recompress (using secondary compression streams)
pages.

Re-compression algorithms (we support up to 3 at this stage)
are selected via recomp_algorithm:

echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm

Please read documentation for more details.

We support several recompression modes:

1) IDLE pages recompression is activated by `idle` mode

echo "type=idle" > /sys/block/zram0/recompress

2) Since there may be many idle pages user-space may pass a size
threshold value (in bytes) and we will recompress pages only
of equal or greater size:

echo "threshold=888" > /sys/block/zram0/recompress

3) HUGE pages recompression is activated by `huge` mode

echo "type=huge" > /sys/block/zram0/recompress

4) HUGE_IDLE pages recompression is activated by `huge_idle` mode

echo "type=huge_idle" > /sys/block/zram0/recompress

[senozhatsky@chromium.org: we should always zero out err variable in recompress loop[
Link: https://lkml.kernel.org/r/20221110143423.3250790-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20221109115047.2921851-5-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 001d9273 Wed Nov 09 04:50:36 MST 2022 Sergey Senozhatsky <senozhatsky@chromium.org> zram: add recompression algorithm sysfs knob

Introduce recomp_algorithm sysfs knob that controls secondary algorithm
selection used for recompression.

We will support up to 3 secondary compression algorithms which are sorted
in order of their priority. To select an algorithm user has to provide
its name and priority:

echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm
echo "algo=deflate priority=2" > /sys/block/zramX/recomp_algorithm

During recompression zram iterates through the list of registered
secondary algorithms in order of their priorities.

We also have a short version for cases when there is only
one secondary compression algorithm:

echo "algo=zstd" > /sys/block/zramX/recomp_algorithm

This will register zstd as the secondary algorithm with priority 1.

Link: https://lkml.kernel.org/r/20221109115047.2921851-3-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 001d9273 Wed Nov 09 04:50:36 MST 2022 Sergey Senozhatsky <senozhatsky@chromium.org> zram: add recompression algorithm sysfs knob

Introduce recomp_algorithm sysfs knob that controls secondary algorithm
selection used for recompression.

We will support up to 3 secondary compression algorithms which are sorted
in order of their priority. To select an algorithm user has to provide
its name and priority:

echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm
echo "algo=deflate priority=2" > /sys/block/zramX/recomp_algorithm

During recompression zram iterates through the list of registered
secondary algorithms in order of their priorities.

We also have a short version for cases when there is only
one secondary compression algorithm:

echo "algo=zstd" > /sys/block/zramX/recomp_algorithm

This will register zstd as the secondary algorithm with priority 1.

Link: https://lkml.kernel.org/r/20221109115047.2921851-3-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 86947df3 Thu Jul 14 12:06:29 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Change the type of the last .rw_page() argument

All .rw_page() callers pass an enum req_op value as last argument. Make
this explicit by changing the type of the last argument into enum req_op.
See also commit 3f289dcb4b26 ("block: make bdev_ops->rw_page() take a
REQ_OP instead of bool").

Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-4-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff d666e20e Tue Mar 29 23:29:04 MDT 2022 Christoph Hellwig <hch@lst.de> zram: cleanup reset_store

Use a local variable for the gendisk instead of the part0 block_device,
as the gendisk is what this function actually operates on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 8c54499a Sun Oct 24 20:54:24 MDT 2021 Ming Lei <ming.lei@redhat.com> zram: don't fail to remove zram during unloading module

When the zram module is being unloaded, no one should be using the
zram disks. However even while being unloaded the zram module's
sysfs attributes might be poked at to re-configure zram devices.
This is expected, and kernfs ensures that these operations complete
before device_del() completes.

But reset_store() may set ->claim which will fail zram_remove(), when
this happens, zram_reset_device() is bypassed, and zram->comp can't
be destroyed, so the warning of 'Error: Removing state 63 which has
instances left.' is triggered during unloading module, together with
memory leak and sort of thing.

Fixes the issue by not failing zram_remove() if ->claim is set, and
we actually need to do nothing in case that zram_reset() is running
since del_gendisk() will wait until zram_reset() is done.

Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Link: https://lore.kernel.org/r/20211025025426.2815424-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
/linux-master/drivers/md/bcache/
H A Drequest.cdiff 9dca4168 Tue Apr 19 10:04:25 MDT 2022 Coly Li <colyli@suse.de> bcache: fix wrong bdev parameter when calling bio_alloc_clone() in do_bio_hook()

Commit abfc426d1b2f ("block: pass a block_device to bio_clone_fast")
calls the modified bio_alloc_clone() in bcache code as:
bio_init_clone(bio->bi_bdev, bio, orig_bio, GFP_NOIO);

But the first parameter is wrong, where bio->bi_bdev should be
orig_bio->bi_bdev. The wrong bi_bdev panics the kernel when submitting
cache bio.

This patch fixes the wrong bdev parameter usage and avoid the panic.

Fixes: abfc426d1b2f ("block: pass a block_device to bio_clone_fast")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220419160425.4148-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 41fe8d08 Mon Jun 07 06:50:52 MDT 2021 Coly Li <colyli@suse.de> bcache: avoid oversized read request in cache missing code path

In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);

Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.

Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,

1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;

All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.

Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);

Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.

And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.

Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })

Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);

Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).

Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.

From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().

From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.

Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.

By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.

Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.

Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 41fe8d08 Mon Jun 07 06:50:52 MDT 2021 Coly Li <colyli@suse.de> bcache: avoid oversized read request in cache missing code path

In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);

Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.

Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,

1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;

All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.

Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);

Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.

And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.

Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })

Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);

Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).

Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.

From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().

From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.

Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.

By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.

Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.

Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 41fe8d08 Mon Jun 07 06:50:52 MDT 2021 Coly Li <colyli@suse.de> bcache: avoid oversized read request in cache missing code path

In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);

Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.

Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,

1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;

All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.

Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);

Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.

And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.

Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })

Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);

Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).

Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.

From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().

From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.

Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.

By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.

Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.

Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 41fe8d08 Mon Jun 07 06:50:52 MDT 2021 Coly Li <colyli@suse.de> bcache: avoid oversized read request in cache missing code path

In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);

Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.

Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,

1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;

All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.

Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);

Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.

And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.

Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })

Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);

Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).

Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.

From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().

From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.

Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.

By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.

Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.

Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 41fe8d08 Mon Jun 07 06:50:52 MDT 2021 Coly Li <colyli@suse.de> bcache: avoid oversized read request in cache missing code path

In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);

Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.

Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,

1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;

All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.

Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);

Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.

And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.

Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })

Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);

Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).

Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.

From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().

From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.

Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.

By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.

Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.

Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 41fe8d08 Mon Jun 07 06:50:52 MDT 2021 Coly Li <colyli@suse.de> bcache: avoid oversized read request in cache missing code path

In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);

Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.

Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,

1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;

All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.

Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);

Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.

And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.

Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })

Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);

Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).

Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.

From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().

From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.

Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.

By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.

Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.

Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Drequest.hdiff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3a394727 Wed Apr 24 10:48:30 MDT 2019 George Spelvin <lkml@sdf.org> bcache: Clean up bch_get_congested()

There are a few nits in this function. They could in theory all
be separate patches, but that's probably taking small commits
too far.

1) I added a brief comment saying what it does.

2) I like to declare pointer parameters "const" where possible
for documentation reasons.

3) It uses bitmap_weight(&rand, BITS_PER_LONG) to compute the Hamming
weight of a 32-bit random number (giving a random integer with
mean 16 and variance 8). Passing by reference in a 64-bit variable
is silly; just use hweight32().

4) Its helper function fract_exp_two is unnecessarily tangled.
Gcc can optimize the multiply by (1 << x) to a shift, but it can
be written in a much more straightforward way at the cost of one
more bit of internal precision. Some analysis reveals that this
bit is always available.

This shrinks the object code for fract_exp_two(x, 6) from 23 bytes:

0000000000000000 <foo1>:
0: 89 f9 mov %edi,%ecx
2: c1 e9 06 shr $0x6,%ecx
5: b8 01 00 00 00 mov $0x1,%eax
a: d3 e0 shl %cl,%eax
c: 83 e7 3f and $0x3f,%edi
f: d3 e7 shl %cl,%edi
11: c1 ef 06 shr $0x6,%edi
14: 01 f8 add %edi,%eax
16: c3 retq

To 19:

0000000000000017 <foo2>:
17: 89 f8 mov %edi,%eax
19: 83 e0 3f and $0x3f,%eax
1c: 83 c0 40 add $0x40,%eax
1f: 89 f9 mov %edi,%ecx
21: c1 e9 06 shr $0x6,%ecx
24: d3 e0 shl %cl,%eax
26: c1 e8 06 shr $0x6,%eax
29: c3 retq

(Verified with 0 <= frac_bits <= 8, 0 <= x < 16<<frac_bits;
both versions produce the same output.)

5) And finally, the call to bch_get_congested() in check_should_bypass()
is separated from the use of the value by multiple tests which
could moot the need to compute it. Move the computation down to
where it's needed. This also saves a local register to hold the
computed value.

Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3fd3c5c0 Mon Oct 08 06:41:16 MDT 2018 Shenghui Wang <shhuiw@foxmail.com> bcache: remove unused bch_passthrough_cache

struct kmem_cache *bch_passthrough_cache is not used in
bcache code. Remove it.

Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
/linux-master/drivers/md/
H A Ddm.cdiff a9ce3853 Fri Sep 15 13:14:23 MDT 2023 Jens Axboe <axboe@kernel.dk> dm: don't attempt to queue IO under RCU protection

dm looks up the table for IO based on the request type, with an
assumption that if the request is marked REQ_NOWAIT, it's fine to
attempt to submit that IO while under RCU read lock protection. This
is not OK, as REQ_NOWAIT just means that we should not be sleeping
waiting on other IO, it does not mean that we can't potentially
schedule.

A simple test case demonstrates this quite nicely:

int main(int argc, char *argv[])
{
struct iovec iov;
int fd;

fd = open("/dev/dm-0", O_RDONLY | O_DIRECT);
posix_memalign(&iov.iov_base, 4096, 4096);
iov.iov_len = 4096;
preadv2(fd, &iov, 1, 0, RWF_NOWAIT);
return 0;
}

which will instantly spew:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5580, name: dm-nowait
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
CPU: 7 PID: 5580 Comm: dm-nowait Not tainted 6.6.0-rc1-g39956d2dcd81 #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x11d/0x1b0
__might_resched+0x3c3/0x5e0
? preempt_count_sub+0x150/0x150
mempool_alloc+0x1e2/0x390
? mempool_resize+0x7d0/0x7d0
? lock_sync+0x190/0x190
? lock_release+0x4b7/0x670
? internal_get_user_pages_fast+0x868/0x2d40
bio_alloc_bioset+0x417/0x8c0
? bvec_alloc+0x200/0x200
? internal_get_user_pages_fast+0xb8c/0x2d40
bio_alloc_clone+0x53/0x100
dm_submit_bio+0x27f/0x1a20
? lock_release+0x4b7/0x670
? blk_try_enter_queue+0x1a0/0x4d0
? dm_dax_direct_access+0x260/0x260
? rcu_is_watching+0x12/0xb0
? blk_try_enter_queue+0x1cc/0x4d0
__submit_bio+0x239/0x310
? __bio_queue_enter+0x700/0x700
? kvm_clock_get_cycles+0x40/0x60
? ktime_get+0x285/0x470
submit_bio_noacct_nocheck+0x4d9/0xb80
? should_fail_request+0x80/0x80
? preempt_count_sub+0x150/0x150
? lock_release+0x4b7/0x670
? __bio_add_page+0x143/0x2d0
? iov_iter_revert+0x27/0x360
submit_bio_noacct+0x53e/0x1b30
submit_bio_wait+0x10a/0x230
? submit_bio_wait_endio+0x40/0x40
__blkdev_direct_IO_simple+0x4f8/0x780
? blkdev_bio_end_io+0x4c0/0x4c0
? stack_trace_save+0x90/0xc0
? __bio_clone+0x3c0/0x3c0
? lock_release+0x4b7/0x670
? lock_sync+0x190/0x190
? atime_needs_update+0x3bf/0x7e0
? timestamp_truncate+0x21b/0x2d0
? inode_owner_or_capable+0x240/0x240
blkdev_direct_IO.part.0+0x84a/0x1810
? rcu_is_watching+0x12/0xb0
? lock_release+0x4b7/0x670
? blkdev_read_iter+0x40d/0x530
? reacquire_held_locks+0x4e0/0x4e0
? __blkdev_direct_IO_simple+0x780/0x780
? rcu_is_watching+0x12/0xb0
? __mark_inode_dirty+0x297/0xd50
? preempt_count_add+0x72/0x140
blkdev_read_iter+0x2a4/0x530
do_iter_readv_writev+0x2f2/0x3c0
? generic_copy_file_range+0x1d0/0x1d0
? fsnotify_perm.part.0+0x25d/0x630
? security_file_permission+0xd8/0x100
do_iter_read+0x31b/0x880
? import_iovec+0x10b/0x140
vfs_readv+0x12d/0x1a0
? vfs_iter_read+0xb0/0xb0
? rcu_is_watching+0x12/0xb0
? rcu_is_watching+0x12/0xb0
? lock_release+0x4b7/0x670
do_preadv+0x1b3/0x260
? do_readv+0x370/0x370
__x64_sys_preadv2+0xef/0x150
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5af41ad806
Code: 41 54 41 89 fc 55 44 89 c5 53 48 89 cb 48 83 ec 18 80 3d e4 dd 0d 00 00 74 7a 45 89 c1 49 89 ca 45 31 c0 b8 47 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 be 00 00 00 48 85 c0 79 4a 48 8b 0d da 55
RSP: 002b:00007ffd3145c7f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000147
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5af41ad806
RDX: 0000000000000001 RSI: 00007ffd3145c850 RDI: 0000000000000003
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffd3145c850 R14: 000055f5f0431dd8 R15: 0000000000000001
</TASK>

where in fact it is dm itself that attempts to allocate a bio clone with
GFP_NOIO under the rcu read lock, regardless of the request type.

Fix this by getting rid of the special casing for REQ_NOWAIT, and just
use the normal SRCU protected table lookup. Get rid of the bio based
table locking helpers at the same time, as they are now unused.

Cc: stable@vger.kernel.org
Fixes: 563a225c9fd2 ("dm: introduce dm_{get,put}_live_table_bio called from dm_submit_bio")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff a9ce3853 Fri Sep 15 13:14:23 MDT 2023 Jens Axboe <axboe@kernel.dk> dm: don't attempt to queue IO under RCU protection

dm looks up the table for IO based on the request type, with an
assumption that if the request is marked REQ_NOWAIT, it's fine to
attempt to submit that IO while under RCU read lock protection. This
is not OK, as REQ_NOWAIT just means that we should not be sleeping
waiting on other IO, it does not mean that we can't potentially
schedule.

A simple test case demonstrates this quite nicely:

int main(int argc, char *argv[])
{
struct iovec iov;
int fd;

fd = open("/dev/dm-0", O_RDONLY | O_DIRECT);
posix_memalign(&iov.iov_base, 4096, 4096);
iov.iov_len = 4096;
preadv2(fd, &iov, 1, 0, RWF_NOWAIT);
return 0;
}

which will instantly spew:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5580, name: dm-nowait
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
CPU: 7 PID: 5580 Comm: dm-nowait Not tainted 6.6.0-rc1-g39956d2dcd81 #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x11d/0x1b0
__might_resched+0x3c3/0x5e0
? preempt_count_sub+0x150/0x150
mempool_alloc+0x1e2/0x390
? mempool_resize+0x7d0/0x7d0
? lock_sync+0x190/0x190
? lock_release+0x4b7/0x670
? internal_get_user_pages_fast+0x868/0x2d40
bio_alloc_bioset+0x417/0x8c0
? bvec_alloc+0x200/0x200
? internal_get_user_pages_fast+0xb8c/0x2d40
bio_alloc_clone+0x53/0x100
dm_submit_bio+0x27f/0x1a20
? lock_release+0x4b7/0x670
? blk_try_enter_queue+0x1a0/0x4d0
? dm_dax_direct_access+0x260/0x260
? rcu_is_watching+0x12/0xb0
? blk_try_enter_queue+0x1cc/0x4d0
__submit_bio+0x239/0x310
? __bio_queue_enter+0x700/0x700
? kvm_clock_get_cycles+0x40/0x60
? ktime_get+0x285/0x470
submit_bio_noacct_nocheck+0x4d9/0xb80
? should_fail_request+0x80/0x80
? preempt_count_sub+0x150/0x150
? lock_release+0x4b7/0x670
? __bio_add_page+0x143/0x2d0
? iov_iter_revert+0x27/0x360
submit_bio_noacct+0x53e/0x1b30
submit_bio_wait+0x10a/0x230
? submit_bio_wait_endio+0x40/0x40
__blkdev_direct_IO_simple+0x4f8/0x780
? blkdev_bio_end_io+0x4c0/0x4c0
? stack_trace_save+0x90/0xc0
? __bio_clone+0x3c0/0x3c0
? lock_release+0x4b7/0x670
? lock_sync+0x190/0x190
? atime_needs_update+0x3bf/0x7e0
? timestamp_truncate+0x21b/0x2d0
? inode_owner_or_capable+0x240/0x240
blkdev_direct_IO.part.0+0x84a/0x1810
? rcu_is_watching+0x12/0xb0
? lock_release+0x4b7/0x670
? blkdev_read_iter+0x40d/0x530
? reacquire_held_locks+0x4e0/0x4e0
? __blkdev_direct_IO_simple+0x780/0x780
? rcu_is_watching+0x12/0xb0
? __mark_inode_dirty+0x297/0xd50
? preempt_count_add+0x72/0x140
blkdev_read_iter+0x2a4/0x530
do_iter_readv_writev+0x2f2/0x3c0
? generic_copy_file_range+0x1d0/0x1d0
? fsnotify_perm.part.0+0x25d/0x630
? security_file_permission+0xd8/0x100
do_iter_read+0x31b/0x880
? import_iovec+0x10b/0x140
vfs_readv+0x12d/0x1a0
? vfs_iter_read+0xb0/0xb0
? rcu_is_watching+0x12/0xb0
? rcu_is_watching+0x12/0xb0
? lock_release+0x4b7/0x670
do_preadv+0x1b3/0x260
? do_readv+0x370/0x370
__x64_sys_preadv2+0xef/0x150
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5af41ad806
Code: 41 54 41 89 fc 55 44 89 c5 53 48 89 cb 48 83 ec 18 80 3d e4 dd 0d 00 00 74 7a 45 89 c1 49 89 ca 45 31 c0 b8 47 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 be 00 00 00 48 85 c0 79 4a 48 8b 0d da 55
RSP: 002b:00007ffd3145c7f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000147
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5af41ad806
RDX: 0000000000000001 RSI: 00007ffd3145c850 RDI: 0000000000000003
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffd3145c850 R14: 000055f5f0431dd8 R15: 0000000000000001
</TASK>

where in fact it is dm itself that attempts to allocate a bio clone with
GFP_NOIO under the rcu read lock, regardless of the request type.

Fix this by getting rid of the special casing for REQ_NOWAIT, and just
use the normal SRCU protected table lookup. Get rid of the bio based
table locking helpers at the same time, as they are now unused.

Cc: stable@vger.kernel.org
Fixes: 563a225c9fd2 ("dm: introduce dm_{get,put}_live_table_bio called from dm_submit_bio")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff 666eed46 Thu Mar 30 13:09:29 MDT 2023 Mike Snitzer <snitzer@kernel.org> dm: fix __send_duplicate_bios() to always allow for splitting IO

Commit 7dd76d1feec70 ("dm: improve bio splitting and associated IO
accounting") only called setup_split_accounting() from
__send_duplicate_bios() if a single bio were being issued. But the case
where duplicate bios are issued must call it too.

Otherwise the bio won't be split and resubmitted (via recursion through
block core back to DM) to submit the later portions of a bio (which may
map to an entirely different target).

For example, when discarding an entire DM striped device with the
following DM table:
vg-lvol0: 0 159744 striped 2 128 7:0 2048 7:1 2048
vg-lvol0: 159744 45056 striped 2 128 7:2 2048 7:3 2048

Before (broken, discards the first striped target's devices twice):
device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
device-mapper: striped: target_stripe=0, bdev=7:0, start=2049 len=22528
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=22528

After (works as expected):
device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
device-mapper: striped: target_stripe=0, bdev=7:2, start=2048 len=22528
device-mapper: striped: target_stripe=1, bdev=7:3, start=2048 len=22528

Fixes: 7dd76d1feec70 ("dm: improve bio splitting and associated IO accounting")
Cc: stable@vger.kernel.org
Reported-by: Orange Kao <orange@aiven.io>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff 666eed46 Thu Mar 30 13:09:29 MDT 2023 Mike Snitzer <snitzer@kernel.org> dm: fix __send_duplicate_bios() to always allow for splitting IO

Commit 7dd76d1feec70 ("dm: improve bio splitting and associated IO
accounting") only called setup_split_accounting() from
__send_duplicate_bios() if a single bio were being issued. But the case
where duplicate bios are issued must call it too.

Otherwise the bio won't be split and resubmitted (via recursion through
block core back to DM) to submit the later portions of a bio (which may
map to an entirely different target).

For example, when discarding an entire DM striped device with the
following DM table:
vg-lvol0: 0 159744 striped 2 128 7:0 2048 7:1 2048
vg-lvol0: 159744 45056 striped 2 128 7:2 2048 7:3 2048

Before (broken, discards the first striped target's devices twice):
device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
device-mapper: striped: target_stripe=0, bdev=7:0, start=2049 len=22528
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=22528

After (works as expected):
device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
device-mapper: striped: target_stripe=0, bdev=7:2, start=2048 len=22528
device-mapper: striped: target_stripe=1, bdev=7:3, start=2048 len=22528

Fixes: 7dd76d1feec70 ("dm: improve bio splitting and associated IO accounting")
Cc: stable@vger.kernel.org
Reported-by: Orange Kao <orange@aiven.io>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff f7b58a69 Thu Mar 30 12:56:38 MDT 2023 Mike Snitzer <snitzer@kernel.org> dm: fix improper splitting for abnormal bios

"Abnormal" bios include discards, write zeroes and secure erase. By no
longer passing the calculated 'len' pointer, commit 7dd06a2548b2 ("dm:
allow dm_accept_partial_bio() for dm_io without duplicate bios") took a
senseless approach to disallowing dm_accept_partial_bio() from working
for duplicate bios processed using __send_duplicate_bios().

It inadvertently and incorrectly stopped the use of 'len' when
initializing a target's io (in alloc_tio). As such the resulting tio
could address more area of a device than it should.

For example, when discarding an entire DM striped device with the
following DM table:
vg-lvol0: 0 159744 striped 2 128 7:0 2048 7:1 2048
vg-lvol0: 159744 45056 striped 2 128 7:2 2048 7:3 2048

Before this fix:

device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=102400
blkdiscard: attempt to access beyond end of device
loop0: rw=2051, sector=2048, nr_sectors = 102400 limit=81920

device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=102400
blkdiscard: attempt to access beyond end of device
loop1: rw=2051, sector=2048, nr_sectors = 102400 limit=81920

After this fix;

device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872

Fixes: 7dd06a2548b2 ("dm: allow dm_accept_partial_bio() for dm_io without duplicate bios")
Cc: stable@vger.kernel.org
Reported-by: Orange Kao <orange@aiven.io>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff 3bd94003 Wed Jan 25 13:00:44 MST 2023 Heinz Mauelshagen <heinzm@redhat.com> dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <jwiele@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff 992ec6a9 Tue Nov 15 07:10:46 MST 2022 Christoph Hellwig <hch@lst.de> dm: remove free_table_devices

free_table_devices just warns and frees all table_device structures when
the target removal did not remove them. This should never happen, but
if it did, just freeing the structure without deleting them from the
list or cleaning up the resources would not help at all. So just WARN on
a non-empty list instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20221115141054.1051801-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 8dd87f3c Sun Jul 17 16:45:05 MDT 2022 Mike Christie <michael.christie@oracle.com> dm: Allow dm_call_pr to be used for path searches

The specs state that if you send a reserve down a path that is already
the holder success must be returned and if it goes down a path that
is not the holder reservation conflict must be returned. Windows
failover clustering will send a second reservation and expects that a
device returns success. The problem for multipathing is that for an
All Registrants reservation, we can send the reserve down any path but
for all other reservation types there is one path that is the holder.

To handle this we could add PR state to dm but that can get nasty.
Look at target_core_pr.c for an example of the type of things we'd
have to track. It will also get more complicated because other
initiators can change the state so we will have to add in async
event/sense handling.

This commit, and the 3 commits that follow, tries to keep dm simple
and keep just doing passthrough. This commit modifies dm_call_pr to be
able to find the first usable path that can execute our pr_op then
return. When dm_pr_reserve is converted to dm_call_pr in the next
commit for the normal case we will use the same path for every
reserve.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff 444fe04f Fri Jun 24 08:12:53 MDT 2022 Ming Lei <ming.lei@redhat.com> dm: improve BLK_STS_DM_REQUEUE and BLK_STS_AGAIN handling

If either BLK_STS_DM_REQUEUE or BLK_STS_AGAIN is returned for POLLED
io, we requeue the original bio into deferred list and kick md->wq to
re-submit it to block layer.

Improve the handling in the following way:

1) Factor out dm_handle_requeue() for handling dm_io requeue.

2) Unify handling for BLK_STS_DM_REQUEUE and BLK_STS_AGAIN: clear
REQ_POLLED for BLK_STS_DM_REQUEUE too, for the sake of simplicity,
given BLK_STS_DM_REQUEUE is very unusual.

3) Queue md->wq explicitly in dm_handle_requeue(), so requeue handling
becomes more robust.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
diff c3949322 Tue Jun 14 03:09:30 MDT 2022 Christoph Hellwig <hch@lst.de> dm: open code blk_max_size_offset in max_io_len

max_io_len always passes an explicitly non-zero chunk_sectors into
blk_max_size_offset. That means much of blk_max_size_offset is not
needed and can be open coded to simplify the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20220614090934.570632-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
H A Dmd.cdiff 28be4fd3 Sun Mar 03 07:01:41 MST 2024 Christoph Hellwig <hch@lst.de> md: add a mddev_add_trace_msg helper

Add a small wrapper around blk_add_trace_msg that hides some argument
dereferences and the check for a DM-mapped MD device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed--by: Song Liu <song@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240303140150.5435-3-hch@lst.de
diff 41425f96 Tue Mar 05 00:23:05 MST 2024 Yu Kuai <yukuai3@huawei.com> dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape

For raid456, if reshape is still in progress, then IO across reshape
position will wait for reshape to make progress. However, for dm-raid,
in following cases reshape will never make progress hence IO will hang:

1) the array is read-only;
2) MD_RECOVERY_WAIT is set;
3) MD_RECOVERY_FROZEN is set;

After commit c467e97f079f ("md/raid6: use valid sector values to determine
if an I/O should wait on the reshape") fix the problem that IO across
reshape position doesn't wait for reshape, the dm-raid test
shell/lvconvert-raid-reshape.sh start to hang:

[root@fedora ~]# cat /proc/979/stack
[<0>] wait_woken+0x7d/0x90
[<0>] raid5_make_request+0x929/0x1d70 [raid456]
[<0>] md_handle_request+0xc2/0x3b0 [md_mod]
[<0>] raid_map+0x2c/0x50 [dm_raid]
[<0>] __map_bio+0x251/0x380 [dm_mod]
[<0>] dm_submit_bio+0x1f0/0x760 [dm_mod]
[<0>] __submit_bio+0xc2/0x1c0
[<0>] submit_bio_noacct_nocheck+0x17f/0x450
[<0>] submit_bio_noacct+0x2bc/0x780
[<0>] submit_bio+0x70/0xc0
[<0>] mpage_readahead+0x169/0x1f0
[<0>] blkdev_readahead+0x18/0x30
[<0>] read_pages+0x7c/0x3b0
[<0>] page_cache_ra_unbounded+0x1ab/0x280
[<0>] force_page_cache_ra+0x9e/0x130
[<0>] page_cache_sync_ra+0x3b/0x110
[<0>] filemap_get_pages+0x143/0xa30
[<0>] filemap_read+0xdc/0x4b0
[<0>] blkdev_read_iter+0x75/0x200
[<0>] vfs_read+0x272/0x460
[<0>] ksys_read+0x7a/0x170
[<0>] __x64_sys_read+0x1c/0x30
[<0>] do_syscall_64+0xc6/0x230
[<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74

This is because reshape can't make progress.

For md/raid, the problem doesn't exist because register new sync_thread
doesn't rely on the IO to be done any more:

1) If array is read-only, it can switch to read-write by ioctl/sysfs;
2) md/raid never set MD_RECOVERY_WAIT;
3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold
'reconfig_mutex', hence it can be cleared and reshape can continue by
sysfs api 'sync_action'.

However, I'm not sure yet how to avoid the problem in dm-raid yet. This
patch on the one hand make sure raid_message() can't change
sync_thread() through raid_message() after presuspend(), on the other
hand detect the above 3 cases before wait for IO do be done in
dm_suspend(), and let dm-raid requeue those IO.

Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-9-yukuai1@huaweicloud.com
diff 41425f96 Tue Mar 05 00:23:05 MST 2024 Yu Kuai <yukuai3@huawei.com> dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape

For raid456, if reshape is still in progress, then IO across reshape
position will wait for reshape to make progress. However, for dm-raid,
in following cases reshape will never make progress hence IO will hang:

1) the array is read-only;
2) MD_RECOVERY_WAIT is set;
3) MD_RECOVERY_FROZEN is set;

After commit c467e97f079f ("md/raid6: use valid sector values to determine
if an I/O should wait on the reshape") fix the problem that IO across
reshape position doesn't wait for reshape, the dm-raid test
shell/lvconvert-raid-reshape.sh start to hang:

[root@fedora ~]# cat /proc/979/stack
[<0>] wait_woken+0x7d/0x90
[<0>] raid5_make_request+0x929/0x1d70 [raid456]
[<0>] md_handle_request+0xc2/0x3b0 [md_mod]
[<0>] raid_map+0x2c/0x50 [dm_raid]
[<0>] __map_bio+0x251/0x380 [dm_mod]
[<0>] dm_submit_bio+0x1f0/0x760 [dm_mod]
[<0>] __submit_bio+0xc2/0x1c0
[<0>] submit_bio_noacct_nocheck+0x17f/0x450
[<0>] submit_bio_noacct+0x2bc/0x780
[<0>] submit_bio+0x70/0xc0
[<0>] mpage_readahead+0x169/0x1f0
[<0>] blkdev_readahead+0x18/0x30
[<0>] read_pages+0x7c/0x3b0
[<0>] page_cache_ra_unbounded+0x1ab/0x280
[<0>] force_page_cache_ra+0x9e/0x130
[<0>] page_cache_sync_ra+0x3b/0x110
[<0>] filemap_get_pages+0x143/0xa30
[<0>] filemap_read+0xdc/0x4b0
[<0>] blkdev_read_iter+0x75/0x200
[<0>] vfs_read+0x272/0x460
[<0>] ksys_read+0x7a/0x170
[<0>] __x64_sys_read+0x1c/0x30
[<0>] do_syscall_64+0xc6/0x230
[<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74

This is because reshape can't make progress.

For md/raid, the problem doesn't exist because register new sync_thread
doesn't rely on the IO to be done any more:

1) If array is read-only, it can switch to read-write by ioctl/sysfs;
2) md/raid never set MD_RECOVERY_WAIT;
3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold
'reconfig_mutex', hence it can be cleared and reshape can continue by
sysfs api 'sync_action'.

However, I'm not sure yet how to avoid the problem in dm-raid yet. This
patch on the one hand make sure raid_message() can't change
sync_thread() through raid_message() after presuspend(), on the other
hand detect the above 3 cases before wait for IO do be done in
dm_suspend(), and let dm-raid requeue those IO.

Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-9-yukuai1@huaweicloud.com
diff 41425f96 Tue Mar 05 00:23:05 MST 2024 Yu Kuai <yukuai3@huawei.com> dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape

For raid456, if reshape is still in progress, then IO across reshape
position will wait for reshape to make progress. However, for dm-raid,
in following cases reshape will never make progress hence IO will hang:

1) the array is read-only;
2) MD_RECOVERY_WAIT is set;
3) MD_RECOVERY_FROZEN is set;

After commit c467e97f079f ("md/raid6: use valid sector values to determine
if an I/O should wait on the reshape") fix the problem that IO across
reshape position doesn't wait for reshape, the dm-raid test
shell/lvconvert-raid-reshape.sh start to hang:

[root@fedora ~]# cat /proc/979/stack
[<0>] wait_woken+0x7d/0x90
[<0>] raid5_make_request+0x929/0x1d70 [raid456]
[<0>] md_handle_request+0xc2/0x3b0 [md_mod]
[<0>] raid_map+0x2c/0x50 [dm_raid]
[<0>] __map_bio+0x251/0x380 [dm_mod]
[<0>] dm_submit_bio+0x1f0/0x760 [dm_mod]
[<0>] __submit_bio+0xc2/0x1c0
[<0>] submit_bio_noacct_nocheck+0x17f/0x450
[<0>] submit_bio_noacct+0x2bc/0x780
[<0>] submit_bio+0x70/0xc0
[<0>] mpage_readahead+0x169/0x1f0
[<0>] blkdev_readahead+0x18/0x30
[<0>] read_pages+0x7c/0x3b0
[<0>] page_cache_ra_unbounded+0x1ab/0x280
[<0>] force_page_cache_ra+0x9e/0x130
[<0>] page_cache_sync_ra+0x3b/0x110
[<0>] filemap_get_pages+0x143/0xa30
[<0>] filemap_read+0xdc/0x4b0
[<0>] blkdev_read_iter+0x75/0x200
[<0>] vfs_read+0x272/0x460
[<0>] ksys_read+0x7a/0x170
[<0>] __x64_sys_read+0x1c/0x30
[<0>] do_syscall_64+0xc6/0x230
[<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74

This is because reshape can't make progress.

For md/raid, the problem doesn't exist because register new sync_thread
doesn't rely on the IO to be done any more:

1) If array is read-only, it can switch to read-write by ioctl/sysfs;
2) md/raid never set MD_RECOVERY_WAIT;
3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold
'reconfig_mutex', hence it can be cleared and reshape can continue by
sysfs api 'sync_action'.

However, I'm not sure yet how to avoid the problem in dm-raid yet. This
patch on the one hand make sure raid_message() can't change
sync_thread() through raid_message() after presuspend(), on the other
hand detect the above 3 cases before wait for IO do be done in
dm_suspend(), and let dm-raid requeue those IO.

Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-9-yukuai1@huaweicloud.com
diff 16c4770c Tue Mar 05 00:23:02 MST 2024 Yu Kuai <yukuai3@huawei.com> dm-raid: really frozen sync_thread during suspend

1) commit f52f5c71f3d4 ("md: fix stopping sync thread") remove
MD_RECOVERY_FROZEN from __md_stop_writes() and doesn't realize that
dm-raid relies on __md_stop_writes() to frozen sync_thread
indirectly. Fix this problem by adding MD_RECOVERY_FROZEN in
md_stop_writes(), and since stop_sync_thread() is only used for
dm-raid in this case, also move stop_sync_thread() to
md_stop_writes().
2) The flag MD_RECOVERY_FROZEN doesn't mean that sync thread is frozen,
it only prevent new sync_thread to start, and it can't stop the
running sync thread; In order to frozen sync_thread, after seting the
flag, stop_sync_thread() should be used.
3) The flag MD_RECOVERY_FROZEN doesn't mean that writes are stopped, use
it as condition for md_stop_writes() in raid_postsuspend() doesn't
look correct. Consider that reentrant stop_sync_thread() do nothing,
always call md_stop_writes() in raid_postsuspend().
4) raid_message can set/clear the flag MD_RECOVERY_FROZEN at anytime,
and if MD_RECOVERY_FROZEN is cleared while the array is suspended,
new sync_thread can start unexpected. Fix this by disallow
raid_message() to change sync_thread status during suspend.

Note that after commit f52f5c71f3d4 ("md: fix stopping sync thread"), the
test shell/lvconvert-raid-reshape.sh start to hang in stop_sync_thread(),
and with previous fixes, the test won't hang there anymore, however, the
test will still fail and complain that ext4 is corrupted. And with this
patch, the test won't hang due to stop_sync_thread() or fail due to ext4
is corrupted anymore. However, there is still a deadlock related to
dm-raid456 that will be fixed in following patches.

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Closes: https://lore.kernel.org/all/e5e8afe2-e9a8-49a2-5ab0-958d4065c55e@redhat.com/
Fixes: 1af2048a3e87 ("dm raid: fix deadlock caused by premature md_stop_writes()")
Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target")
Fixes: f52f5c71f3d4 ("md: fix stopping sync thread")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-6-yukuai1@huaweicloud.com
diff 7a2347e2 Tue Mar 05 00:22:59 MST 2024 Yu Kuai <yukuai3@huawei.com> md: export helpers to stop sync_thread

Add new helpers:

void md_idle_sync_thread(struct mddev *mddev);
void md_frozen_sync_thread(struct mddev *mddev);
void md_unfrozen_sync_thread(struct mddev *mddev);

The helpers will be used in dm-raid in later patches to fix regressions
and prevent calling md_reap_sync_thread() directly.

Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-3-yukuai1@huaweicloud.com
diff 4e265939 Sun Feb 25 20:14:37 MST 2024 Li Nan <linan122@huawei.com> md: changed the switch of RAID_VERSION to if

There is only one case of this 'switch'. Change it to 'if'.

Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240226031444.3606764-3-linan666@huaweicloud.com
diff faeaf210 Thu Dec 28 05:55:52 MST 2023 Yu Kuai <yukuai3@huawei.com> md: remove redundant md_wakeup_thread()

On the one hand, mddev_unlock() will call md_wakeup_thread()
unconditionally; on the other hand, md_check_recovery() can't make
progress if 'reconfig_mutex' can't be grabbed. Hence, it really doesn't
make sense to wake up daemon thread while 'reconfig_mutex' is still
grabbed.

Remove all the md_wakup_thread() for 'mddev->thread' while
'reconfig_mtuex' is still grabbed.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231228125553.2697765-3-yukuai1@huaweicloud.com
diff 61c90765 Thu Dec 28 05:55:51 MST 2023 Yu Kuai <yukuai3@huawei.com> md: remove redundant check of 'mddev->sync_thread'

The lifetime of sync_thread:

1) Set MD_RECOVERY_NEEDED and wake up daemon thread (by ioctl/sysfs or
other events);
2) Daemon thread woke up, md_check_recovery() found that
MD_RECOVERY_NEEDED is set:
a) try to grab reconfig_mutex;
b) set MD_RECOVERY_RUNNING;
c) clear MD_RECOVERY_NEEDED, and then queue sync_work;
3) md_start_sync() choose sync_action, then register sync_thread;
4) md_do_sync() is done, set MD_RECOVERY_DONE and wake up daemon thread;
5) Daemon thread woke up, md_check_recovery() found that
MD_RECOVERY_DONE is set:
a) try to grab reconfig_mutex;
b) unregister sync_thread;
c) clear MD_RECOVERY_RUNNING and MD_RECOVERY_DONE;

Hence there is no such case that MD_RECOVERY_RUNNING is not set, while
sync_thread is registered.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231228125553.2697765-2-yukuai1@huaweicloud.com
diff 9e46c70e Thu Feb 01 02:25:50 MST 2024 Yu Kuai <yukuai3@huawei.com> md: Don't suspend the array for interrupted reshape

md_start_sync() will suspend the array if there are spares that can be
added or removed from conf, however, if reshape is still in progress,
this won't happen at all or data will be corrupted(remove_and_add_spares
won't be called from md_choose_sync_action for reshape), hence there is
no need to suspend the array if reshape is not done yet.

Meanwhile, there is a potential deadlock for raid456:

1) reshape is interrupted;

2) set one of the disk WantReplacement, and add a new disk to the array,
however, recovery won't start until the reshape is finished;

3) then issue an IO across reshpae position, this IO will wait for
reshape to make progress;

4) continue to reshape, then md_start_sync() found there is a spare disk
that can be added to conf, mddev_suspend() is called;

Step 4 and step 3 is waiting for each other, deadlock triggered. Noted
this problem is found by code review, and it's not reporduced yet.

Fix this porblem by don't suspend the array for interrupted reshape,
this is safe because conf won't be changed until reshape is done.

Fixes: bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-6-yukuai1@huaweicloud.com
diff 9e46c70e Thu Feb 01 02:25:50 MST 2024 Yu Kuai <yukuai3@huawei.com> md: Don't suspend the array for interrupted reshape

md_start_sync() will suspend the array if there are spares that can be
added or removed from conf, however, if reshape is still in progress,
this won't happen at all or data will be corrupted(remove_and_add_spares
won't be called from md_choose_sync_action for reshape), hence there is
no need to suspend the array if reshape is not done yet.

Meanwhile, there is a potential deadlock for raid456:

1) reshape is interrupted;

2) set one of the disk WantReplacement, and add a new disk to the array,
however, recovery won't start until the reshape is finished;

3) then issue an IO across reshpae position, this IO will wait for
reshape to make progress;

4) continue to reshape, then md_start_sync() found there is a spare disk
that can be added to conf, mddev_suspend() is called;

Step 4 and step 3 is waiting for each other, deadlock triggered. Noted
this problem is found by code review, and it's not reporduced yet.

Fix this porblem by don't suspend the array for interrupted reshape,
this is safe because conf won't be changed until reshape is done.

Fixes: bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-6-yukuai1@huaweicloud.com
/linux-master/drivers/nvdimm/
H A Dbtt.cdiff 86947df3 Thu Jul 14 12:06:29 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Change the type of the last .rw_page() argument

All .rw_page() callers pass an enum req_op value as last argument. Make
this explicit by changing the type of the last argument into enum req_op.
See also commit 3f289dcb4b26 ("block: make bdev_ops->rw_page() take a
REQ_OP instead of bool").

Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-4-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 16be7974 Wed Nov 03 17:04:25 MDT 2021 Luis Chamberlain <mcgrof@kernel.org> nvdimm/btt: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103230437.1639990-3-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3aefb5ee Wed Nov 03 10:58:43 MDT 2021 Luis Chamberlain <mcgrof@kernel.org> nvdimm/btt: do not call del_gendisk() if not needed

del_gendisk() should not called if the disk has not been added. Fix this.

Fixes: 41cd8b70c37a ("libnvdimm, btt: add support for blk integrity")
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103165843.1402142-1-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3f289dcb Wed Jul 18 05:47:36 MDT 2018 Tejun Heo <tj@kernel.org> block: make bdev_ops->rw_page() take a REQ_OP instead of bool

c11f0c0b5bb9 ("block/mm: make bdev_ops->rw_page() take a bool for
read/write") replaced @op with boolean @is_write, which limited the
amount of information going into ->rw_page() and more importantly
page_endio(), which removed the need to expose block internals to mm.

Unfortunately, we want to track discards separately and @is_write
isn't enough information. This patch updates bdev_ops->rw_page() to
take REQ_OP instead but leaves page_endio() to take bool @is_write.
This allows the block part of operations to have enough information
while not leaking it to mm.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3ffb0ba9 Mon Mar 05 16:56:13 MST 2018 Vishal Verma <vishal.l.verma@intel.com> libnvdimm, {btt, blk}: do integrity setup before add_disk()

Prior to 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk")
we needed to temporarily add a zero-capacity disk before registering for
blk-integrity. But adding a zero-capacity disk caused the partition
table scanning to bail early, and this resulted in partitions not coming
up after a probe of the BTT or blk namespaces.

We can now register for integrity before the disk has been added, and
this fixes the rescan problems.

Fixes: 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk")
Reported-by: Dariusz Dokupil <dariusz.dokupil@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff 23c47d2a Wed Nov 15 18:33:00 MST 2017 Minchan Kim <minchan@kernel.org> bdi: introduce BDI_CAP_SYNCHRONOUS_IO

As discussed at

https://lkml.kernel.org/r/<20170728165604.10455-1-ross.zwisler@linux.intel.com>

someday we will remove rw_page(). If so, we need something to detect
such super-fast storage on which synchronous IO operations like the
current rw_page are always a win.

Introduces BDI_CAP_SYNCHRONOUS_IO to indicate such devices. With it, we
could use various optimization techniques.

Link: http://lkml.kernel.org/r/1505886205-9671-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 04c3c982 Fri Sep 08 10:36:57 MDT 2017 Randy Dunlap <rdunlap@infradead.org> libnvdimm, btt: fix format string warnings

Fix format warnings (seen on i386) in nvdimm/btt.c:

../drivers/nvdimm/btt.c: In function ‘btt_map_init’:
../drivers/nvdimm/btt.c:430:3: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘size_t’ [-Wformat=]
dev_WARN_ONCE(to_dev(arena), size < 512,
^
../drivers/nvdimm/btt.c: In function ‘btt_log_init’:
../drivers/nvdimm/btt.c:474:3: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘size_t’ [-Wformat=]
dev_WARN_ONCE(to_dev(arena), size < 512,
^

Fixes: 86652d2eb347 ("libnvdimm, btt: clean up warning and error messages")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff 04c3c982 Fri Sep 08 10:36:57 MDT 2017 Randy Dunlap <rdunlap@infradead.org> libnvdimm, btt: fix format string warnings

Fix format warnings (seen on i386) in nvdimm/btt.c:

../drivers/nvdimm/btt.c: In function ‘btt_map_init’:
../drivers/nvdimm/btt.c:430:3: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘size_t’ [-Wformat=]
dev_WARN_ONCE(to_dev(arena), size < 512,
^
../drivers/nvdimm/btt.c: In function ‘btt_log_init’:
../drivers/nvdimm/btt.c:474:3: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘size_t’ [-Wformat=]
dev_WARN_ONCE(to_dev(arena), size < 512,
^

Fixes: 86652d2eb347 ("libnvdimm, btt: clean up warning and error messages")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
H A Dpmem.cdiff 86947df3 Thu Jul 14 12:06:29 MDT 2022 Bart Van Assche <bvanassche@acm.org> block: Change the type of the last .rw_page() argument

All .rw_page() callers pass an enum req_op value as last argument. Make
this explicit by changing the type of the last argument into enum req_op.
See also commit 3f289dcb4b26 ("block: make bdev_ops->rw_page() take a
REQ_OP instead of bool").

Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-4-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff e765f13e Wed Sep 22 11:34:30 MDT 2021 Christoph Hellwig <hch@lst.de> nvdimm/pmem: move dax_attribute_group from dax to pmem

dax_attribute_group is only used by the pmem driver, and can avoid the
completely pointless lookup by the disk name if moved there. This
leaves just a single caller of dax_get_by_host, so move dax_get_by_host
into the same ifdef block as that caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20210922173431.2454024-3-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff accf58af Wed Nov 03 17:04:28 MDT 2021 Luis Chamberlain <mcgrof@kernel.org> nvdimm/pmem: cleanup the disk if pmem_release_disk() is yet assigned

Prior to devm being able to use pmem_release_disk() there are other
failure which can occur for which we must account for and release the
disk for. Address those few cases.

Fixes: 3dd60fb9d95d ("nvdimm/pmem: stop using q_usage_count as external pgmap refcount")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103230437.1639990-6-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3dd60fb9 Tue Oct 19 01:36:40 MDT 2021 Christoph Hellwig <hch@lst.de> nvdimm/pmem: stop using q_usage_count as external pgmap refcount

Originally all DAX access when through block_device operations and thus
needed a queue reference. But since commit cccbce671582
("filesystem-dax: convert to dax_direct_access()") all this happens at
the DAX device level which uses its own refcounting. Having the external
refcount thus wasn't needed but has otherwise been harmless for long
time.

But now that "block: drain file system I/O on del_gendisk" waits for
q_usage_count to reach 0 in del_gendisk this whole scheme can't work
anymore (and pmem is the only driver abusing q_usage_count like that).
So switch to the internal reference and remove the unbalanced
blk_freeze_queue_start that is taken care of by del_gendisk.

Fixes: 8e141f9eb803 ("block: drain file system I/O on del_gendisk")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211019073641.2323410-2-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff f605a263 Fri Feb 28 09:34:52 MST 2020 Vivek Goyal <vgoyal@redhat.com> dax, pmem: Add a dax operation zero_page_range

Add a dax operation zero_page_range, to zero a page. This will also clear any
known poison in the page being zeroed.

As of now, zeroing of one page is allowed in a single call. There
are no callers which are trying to zero more than a page in a single call.
Once we grow the callers which zero more than a page in single call, we
can add that support. Primary reason for not doing that yet is that this
will add little complexity in dm implementation where a range might be
spanning multiple underlying targets and one will have to split the range
into multiple sub ranges and call zero_page_range() on individual targets.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: https://lore.kernel.org/r/20200228163456.1587-3-vgoyal@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 1c97afa7 Thu Sep 05 09:45:58 MDT 2019 Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> libnvdimm/pmem: Advance namespace seed for specific probe errors

In order to support marking namespaces with unsupported feature/versions
disabled, nvdimm core should advance the namespace seed on these
probe failures. Otherwise, these failed namespaces will be considered a
seed namespace and will be wrongly used while creating new namespaces.

Add -EOPNOTSUPP as return from pmem probe callback to indicate a namespace
initialization failures due to pfn superblock feature/version mismatch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190905154603.10349-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff 3f289dcb Wed Jul 18 05:47:36 MDT 2018 Tejun Heo <tj@kernel.org> block: make bdev_ops->rw_page() take a REQ_OP instead of bool

c11f0c0b5bb9 ("block/mm: make bdev_ops->rw_page() take a bool for
read/write") replaced @op with boolean @is_write, which limited the
amount of information going into ->rw_page() and more importantly
page_endio(), which removed the need to expose block internals to mm.

Unfortunately, we want to track discards separately and @is_write
isn't enough information. This patch updates bdev_ops->rw_page() to
take REQ_OP instead but leaves page_endio() to take bool @is_write.
This allows the block part of operations to have enough information
while not leaking it to mm.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
/linux-master/drivers/nvme/host/
H A Dmultipath.cdiff 9408d8a3 Mon Jun 12 01:03:43 MDT 2023 Keith Busch <kbusch@kernel.org> nvme: improved uring polling

Drivers can poll requests directly, so use that. We just need to ensure
the driver's request was allocated from a polled hctx, so a special
driver flag is added to struct io_uring_cmd.

The allows unshared and multipath namespaces to use the same polling
callback, and multipath is guaranteed to get the same queue as the
command was submitted on. Previously multipath polling might check a
different path and poll the wrong info.

The other bonus is we don't need a bio payload in order to poll,
allowing commands like 'flush' and 'write zeroes' to be submitted on the
same high priority queue as read and write commands.

Finally, using the request based polling skips the unnecessary bio
overhead.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230612190343.2087040-3-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 899d2a05 Fri Nov 18 16:27:56 MST 2022 Caleb Sander <csander@purestorage.com> nvme: fix SRCU protection of nvme_ns_head list

Walking the nvme_ns_head siblings list is protected by the head's srcu
in nvme_ns_head_submit_bio() but not nvme_mpath_revalidate_paths().
Removing namespaces from the list also fails to synchronize the srcu.
Concurrent scan work can therefore cause use-after-frees.

Hold the head's srcu lock in nvme_mpath_revalidate_paths() and
synchronize with the srcu, not the global RCU, in nvme_ns_remove().

Observed the following panic when making NVMe/RDMA connections
with native multipath on the Rocky Linux 8.6 kernel
(it seems the upstream kernel has the same race condition).
Disassembly shows the faulting instruction is cmp 0x50(%rdx),%rcx;
computing capacity != get_capacity(ns->disk).
Address 0x50 is dereferenced because ns->disk is NULL.
The NULL disk appears to be the result of concurrent scan work
freeing the namespace (note the log line in the middle of the panic).

[37314.206036] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
[37314.206036] nvme0n3: detected capacity change from 0 to 11811160064
[37314.299753] PGD 0 P4D 0
[37314.299756] Oops: 0000 [#1] SMP PTI
[37314.299759] CPU: 29 PID: 322046 Comm: kworker/u98:3 Kdump: loaded Tainted: G W X --------- - - 4.18.0-372.32.1.el8test86.x86_64 #1
[37314.299762] Hardware name: Dell Inc. PowerEdge R720/0JP31P, BIOS 2.7.0 05/23/2018
[37314.299763] Workqueue: nvme-wq nvme_scan_work [nvme_core]
[37314.299783] RIP: 0010:nvme_mpath_revalidate_paths+0x26/0xb0 [nvme_core]
[37314.299790] Code: 1f 44 00 00 66 66 66 66 90 55 53 48 8b 5f 50 48 8b 83 c8 c9 00 00 48 8b 13 48 8b 48 50 48 39 d3 74 20 48 8d 42 d0 48 8b 50 20 <48> 3b 4a 50 74 05 f0 80 60 70 ef 48 8b 50 30 48 8d 42 d0 48 39 d3
[37315.058803] RSP: 0018:ffffabe28f913d10 EFLAGS: 00010202
[37315.121316] RAX: ffff927a077da800 RBX: ffff92991dd70000 RCX: 0000000001600000
[37315.206704] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff92991b719800
[37315.292106] RBP: ffff929a6b70c000 R08: 000000010234cd4a R09: c0000000ffff7fff
[37315.377501] R10: 0000000000000001 R11: ffffabe28f913a30 R12: 0000000000000000
[37315.462889] R13: ffff92992716600c R14: ffff929964e6e030 R15: ffff92991dd70000
[37315.548286] FS: 0000000000000000(0000) GS:ffff92b87fb80000(0000) knlGS:0000000000000000
[37315.645111] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[37315.713871] CR2: 0000000000000050 CR3: 0000002208810006 CR4: 00000000000606e0
[37315.799267] Call Trace:
[37315.828515] nvme_update_ns_info+0x1ac/0x250 [nvme_core]
[37315.892075] nvme_validate_or_alloc_ns+0x2ff/0xa00 [nvme_core]
[37315.961871] ? __blk_mq_free_request+0x6b/0x90
[37316.015021] nvme_scan_work+0x151/0x240 [nvme_core]
[37316.073371] process_one_work+0x1a7/0x360
[37316.121318] ? create_worker+0x1a0/0x1a0
[37316.168227] worker_thread+0x30/0x390
[37316.212024] ? create_worker+0x1a0/0x1a0
[37316.258939] kthread+0x10a/0x120
[37316.297557] ? set_kthread_struct+0x50/0x50
[37316.347590] ret_from_fork+0x35/0x40
[37316.390360] Modules linked in: nvme_rdma nvme_tcp(X) nvme_fabrics nvme_core netconsole iscsi_tcp libiscsi_tcp dm_queue_length dm_service_time nf_conntrack_netlink br_netfilter bridge stp llc overlay nft_chain_nat ipt_MASQUERADE nf_nat xt_addrtype xt_CT nft_counter xt_state xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment xt_multiport nft_compat nf_tables libcrc32c nfnetlink dm_multipath tg3 rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm intel_rapl_msr iTCO_wdt iTCO_vendor_support dcdbas intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel ipmi_ssif kvm irqbypass crct10dif_pclmul crc32_pclmul mlx5_ib ghash_clmulni_intel ib_uverbs rapl intel_cstate intel_uncore ib_core ipmi_si joydev mei_me pcspkr ipmi_devintf mei lpc_ich wmi ipmi_msghandler acpi_power_meter ext4 mbcache jbd2 sd_mod t10_pi sg mgag200 mlx5_core drm_kms_helper syscopyarea
[37316.390419] sysfillrect ahci sysimgblt fb_sys_fops libahci drm crc32c_intel libata mlxfw pci_hyperv_intf tls i2c_algo_bit psample dm_mirror dm_region_hash dm_log dm_mod fuse [last unloaded: nvme_core]
[37317.645908] CR2: 0000000000000050

Fixes: e7d65803e2bb ("nvme-multipath: revalidate paths during rescan")
Signed-off-by: Caleb Sander <csander@purestorage.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff 899d2a05 Fri Nov 18 16:27:56 MST 2022 Caleb Sander <csander@purestorage.com> nvme: fix SRCU protection of nvme_ns_head list

Walking the nvme_ns_head siblings list is protected by the head's srcu
in nvme_ns_head_submit_bio() but not nvme_mpath_revalidate_paths().
Removing namespaces from the list also fails to synchronize the srcu.
Concurrent scan work can therefore cause use-after-frees.

Hold the head's srcu lock in nvme_mpath_revalidate_paths() and
synchronize with the srcu, not the global RCU, in nvme_ns_remove().

Observed the following panic when making NVMe/RDMA connections
with native multipath on the Rocky Linux 8.6 kernel
(it seems the upstream kernel has the same race condition).
Disassembly shows the faulting instruction is cmp 0x50(%rdx),%rcx;
computing capacity != get_capacity(ns->disk).
Address 0x50 is dereferenced because ns->disk is NULL.
The NULL disk appears to be the result of concurrent scan work
freeing the namespace (note the log line in the middle of the panic).

[37314.206036] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
[37314.206036] nvme0n3: detected capacity change from 0 to 11811160064
[37314.299753] PGD 0 P4D 0
[37314.299756] Oops: 0000 [#1] SMP PTI
[37314.299759] CPU: 29 PID: 322046 Comm: kworker/u98:3 Kdump: loaded Tainted: G W X --------- - - 4.18.0-372.32.1.el8test86.x86_64 #1
[37314.299762] Hardware name: Dell Inc. PowerEdge R720/0JP31P, BIOS 2.7.0 05/23/2018
[37314.299763] Workqueue: nvme-wq nvme_scan_work [nvme_core]
[37314.299783] RIP: 0010:nvme_mpath_revalidate_paths+0x26/0xb0 [nvme_core]
[37314.299790] Code: 1f 44 00 00 66 66 66 66 90 55 53 48 8b 5f 50 48 8b 83 c8 c9 00 00 48 8b 13 48 8b 48 50 48 39 d3 74 20 48 8d 42 d0 48 8b 50 20 <48> 3b 4a 50 74 05 f0 80 60 70 ef 48 8b 50 30 48 8d 42 d0 48 39 d3
[37315.058803] RSP: 0018:ffffabe28f913d10 EFLAGS: 00010202
[37315.121316] RAX: ffff927a077da800 RBX: ffff92991dd70000 RCX: 0000000001600000
[37315.206704] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff92991b719800
[37315.292106] RBP: ffff929a6b70c000 R08: 000000010234cd4a R09: c0000000ffff7fff
[37315.377501] R10: 0000000000000001 R11: ffffabe28f913a30 R12: 0000000000000000
[37315.462889] R13: ffff92992716600c R14: ffff929964e6e030 R15: ffff92991dd70000
[37315.548286] FS: 0000000000000000(0000) GS:ffff92b87fb80000(0000) knlGS:0000000000000000
[37315.645111] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[37315.713871] CR2: 0000000000000050 CR3: 0000002208810006 CR4: 00000000000606e0
[37315.799267] Call Trace:
[37315.828515] nvme_update_ns_info+0x1ac/0x250 [nvme_core]
[37315.892075] nvme_validate_or_alloc_ns+0x2ff/0xa00 [nvme_core]
[37315.961871] ? __blk_mq_free_request+0x6b/0x90
[37316.015021] nvme_scan_work+0x151/0x240 [nvme_core]
[37316.073371] process_one_work+0x1a7/0x360
[37316.121318] ? create_worker+0x1a0/0x1a0
[37316.168227] worker_thread+0x30/0x390
[37316.212024] ? create_worker+0x1a0/0x1a0
[37316.258939] kthread+0x10a/0x120
[37316.297557] ? set_kthread_struct+0x50/0x50
[37316.347590] ret_from_fork+0x35/0x40
[37316.390360] Modules linked in: nvme_rdma nvme_tcp(X) nvme_fabrics nvme_core netconsole iscsi_tcp libiscsi_tcp dm_queue_length dm_service_time nf_conntrack_netlink br_netfilter bridge stp llc overlay nft_chain_nat ipt_MASQUERADE nf_nat xt_addrtype xt_CT nft_counter xt_state xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment xt_multiport nft_compat nf_tables libcrc32c nfnetlink dm_multipath tg3 rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm intel_rapl_msr iTCO_wdt iTCO_vendor_support dcdbas intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel ipmi_ssif kvm irqbypass crct10dif_pclmul crc32_pclmul mlx5_ib ghash_clmulni_intel ib_uverbs rapl intel_cstate intel_uncore ib_core ipmi_si joydev mei_me pcspkr ipmi_devintf mei lpc_ich wmi ipmi_msghandler acpi_power_meter ext4 mbcache jbd2 sd_mod t10_pi sg mgag200 mlx5_core drm_kms_helper syscopyarea
[37316.390419] sysfillrect ahci sysimgblt fb_sys_fops libahci drm crc32c_intel libata mlxfw pci_hyperv_intf tls i2c_algo_bit psample dm_mirror dm_region_hash dm_log dm_mod fuse [last unloaded: nvme_core]
[37317.645908] CR2: 0000000000000050

Fixes: e7d65803e2bb ("nvme-multipath: revalidate paths during rescan")
Signed-off-by: Caleb Sander <csander@purestorage.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff fe8714b0 Mon Oct 24 12:57:45 MDT 2022 Keith Busch <kbusch@kernel.org> nvme-multipath: set queue dma alignment to 3

NVMe spec requires all transports support dword aligned addresses, which
is already set in the namespace request_queue. Set the same limit in the
multipath device's request_queue as well.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff a4a6f3c8 Thu Mar 24 13:05:11 MDT 2022 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix hang when disk goes live over reconnect

nvme_mpath_init_identify() invoked from nvme_init_identify() fetches a
fresh ANA log from the ctrl. This is essential to have an up to date
path states for both existing namespaces and for those scan_work may
discover once the ctrl is up.

This happens in the following cases:
1) A new ctrl is being connected.
2) An existing ctrl is successfully reconnected.
3) An existing ctrl is being reset.

While in (1) ctrl->namespaces is empty, (2 & 3) may have namespaces, and
nvme_read_ana_log() may call nvme_update_ns_ana_state().

This result in a hang when the ANA state of an existing namespace changes
and makes the disk live: nvme_mpath_set_live() issues IO to the namespace
through the ctrl, which does NOT have IO queues yet.

See sample hang below.

Solution:
- nvme_update_ns_ana_state() to call set_live only if ctrl is live
- nvme_read_ana_log() call from nvme_mpath_init_identify()
therefore only fetches and parses the ANA log;
any erros in this process will fail the ctrl setup as appropriate;
- a separate function nvme_mpath_update()
is called in nvme_start_ctrl();
this parses the ANA log without fetching it.
At this point the ctrl is live,
therefore, disks can be set live normally.

Sample failure:
nvme nvme0: starting error recovery
nvme nvme0: Reconnecting in 10 seconds...
block nvme0n6: no usable path - requeuing I/O
INFO: task kworker/u8:3:312 blocked for more than 122 seconds.
Tainted: G E 5.14.5-1.el7.elrepo.x86_64 #1
Workqueue: nvme-wq nvme_tcp_reconnect_ctrl_work [nvme_tcp]
Call Trace:
__schedule+0x2a2/0x7e0
schedule+0x4e/0xb0
io_schedule+0x16/0x40
wait_on_page_bit_common+0x15c/0x3e0
do_read_cache_page+0x1e0/0x410
read_cache_page+0x12/0x20
read_part_sector+0x46/0x100
read_lba+0x121/0x240
efi_partition+0x1d2/0x6a0
bdev_disk_changed.part.0+0x1df/0x430
bdev_disk_changed+0x18/0x20
blkdev_get_whole+0x77/0xe0
blkdev_get_by_dev+0xd2/0x3a0
__device_add_disk+0x1ed/0x310
device_add_disk+0x13/0x20
nvme_mpath_set_live+0x138/0x1b0 [nvme_core]
nvme_update_ns_ana_state+0x2b/0x30 [nvme_core]
nvme_update_ana_state+0xca/0xe0 [nvme_core]
nvme_parse_ana_log+0xac/0x170 [nvme_core]
nvme_read_ana_log+0x7d/0xe0 [nvme_core]
nvme_mpath_init_identify+0x105/0x150 [nvme_core]
nvme_init_identify+0x2df/0x4d0 [nvme_core]
nvme_init_ctrl_finish+0x8d/0x3b0 [nvme_core]
nvme_tcp_setup_ctrl+0x337/0x390 [nvme_tcp]
nvme_tcp_reconnect_ctrl_work+0x24/0x40 [nvme_tcp]
process_one_work+0x1bd/0x360
worker_thread+0x50/0x3d0

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff a4a6f3c8 Thu Mar 24 13:05:11 MDT 2022 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix hang when disk goes live over reconnect

nvme_mpath_init_identify() invoked from nvme_init_identify() fetches a
fresh ANA log from the ctrl. This is essential to have an up to date
path states for both existing namespaces and for those scan_work may
discover once the ctrl is up.

This happens in the following cases:
1) A new ctrl is being connected.
2) An existing ctrl is successfully reconnected.
3) An existing ctrl is being reset.

While in (1) ctrl->namespaces is empty, (2 & 3) may have namespaces, and
nvme_read_ana_log() may call nvme_update_ns_ana_state().

This result in a hang when the ANA state of an existing namespace changes
and makes the disk live: nvme_mpath_set_live() issues IO to the namespace
through the ctrl, which does NOT have IO queues yet.

See sample hang below.

Solution:
- nvme_update_ns_ana_state() to call set_live only if ctrl is live
- nvme_read_ana_log() call from nvme_mpath_init_identify()
therefore only fetches and parses the ANA log;
any erros in this process will fail the ctrl setup as appropriate;
- a separate function nvme_mpath_update()
is called in nvme_start_ctrl();
this parses the ANA log without fetching it.
At this point the ctrl is live,
therefore, disks can be set live normally.

Sample failure:
nvme nvme0: starting error recovery
nvme nvme0: Reconnecting in 10 seconds...
block nvme0n6: no usable path - requeuing I/O
INFO: task kworker/u8:3:312 blocked for more than 122 seconds.
Tainted: G E 5.14.5-1.el7.elrepo.x86_64 #1
Workqueue: nvme-wq nvme_tcp_reconnect_ctrl_work [nvme_tcp]
Call Trace:
__schedule+0x2a2/0x7e0
schedule+0x4e/0xb0
io_schedule+0x16/0x40
wait_on_page_bit_common+0x15c/0x3e0
do_read_cache_page+0x1e0/0x410
read_cache_page+0x12/0x20
read_part_sector+0x46/0x100
read_lba+0x121/0x240
efi_partition+0x1d2/0x6a0
bdev_disk_changed.part.0+0x1df/0x430
bdev_disk_changed+0x18/0x20
blkdev_get_whole+0x77/0xe0
blkdev_get_by_dev+0xd2/0x3a0
__device_add_disk+0x1ed/0x310
device_add_disk+0x13/0x20
nvme_mpath_set_live+0x138/0x1b0 [nvme_core]
nvme_update_ns_ana_state+0x2b/0x30 [nvme_core]
nvme_update_ana_state+0xca/0xe0 [nvme_core]
nvme_parse_ana_log+0xac/0x170 [nvme_core]
nvme_read_ana_log+0x7d/0xe0 [nvme_core]
nvme_mpath_init_identify+0x105/0x150 [nvme_core]
nvme_init_identify+0x2df/0x4d0 [nvme_core]
nvme_init_ctrl_finish+0x8d/0x3b0 [nvme_core]
nvme_tcp_setup_ctrl+0x337/0x390 [nvme_tcp]
nvme_tcp_reconnect_ctrl_work+0x24/0x40 [nvme_tcp]
process_one_work+0x1bd/0x360
worker_thread+0x50/0x3d0

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff a4a6f3c8 Thu Mar 24 13:05:11 MDT 2022 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix hang when disk goes live over reconnect

nvme_mpath_init_identify() invoked from nvme_init_identify() fetches a
fresh ANA log from the ctrl. This is essential to have an up to date
path states for both existing namespaces and for those scan_work may
discover once the ctrl is up.

This happens in the following cases:
1) A new ctrl is being connected.
2) An existing ctrl is successfully reconnected.
3) An existing ctrl is being reset.

While in (1) ctrl->namespaces is empty, (2 & 3) may have namespaces, and
nvme_read_ana_log() may call nvme_update_ns_ana_state().

This result in a hang when the ANA state of an existing namespace changes
and makes the disk live: nvme_mpath_set_live() issues IO to the namespace
through the ctrl, which does NOT have IO queues yet.

See sample hang below.

Solution:
- nvme_update_ns_ana_state() to call set_live only if ctrl is live
- nvme_read_ana_log() call from nvme_mpath_init_identify()
therefore only fetches and parses the ANA log;
any erros in this process will fail the ctrl setup as appropriate;
- a separate function nvme_mpath_update()
is called in nvme_start_ctrl();
this parses the ANA log without fetching it.
At this point the ctrl is live,
therefore, disks can be set live normally.

Sample failure:
nvme nvme0: starting error recovery
nvme nvme0: Reconnecting in 10 seconds...
block nvme0n6: no usable path - requeuing I/O
INFO: task kworker/u8:3:312 blocked for more than 122 seconds.
Tainted: G E 5.14.5-1.el7.elrepo.x86_64 #1
Workqueue: nvme-wq nvme_tcp_reconnect_ctrl_work [nvme_tcp]
Call Trace:
__schedule+0x2a2/0x7e0
schedule+0x4e/0xb0
io_schedule+0x16/0x40
wait_on_page_bit_common+0x15c/0x3e0
do_read_cache_page+0x1e0/0x410
read_cache_page+0x12/0x20
read_part_sector+0x46/0x100
read_lba+0x121/0x240
efi_partition+0x1d2/0x6a0
bdev_disk_changed.part.0+0x1df/0x430
bdev_disk_changed+0x18/0x20
blkdev_get_whole+0x77/0xe0
blkdev_get_by_dev+0xd2/0x3a0
__device_add_disk+0x1ed/0x310
device_add_disk+0x13/0x20
nvme_mpath_set_live+0x138/0x1b0 [nvme_core]
nvme_update_ns_ana_state+0x2b/0x30 [nvme_core]
nvme_update_ana_state+0xca/0xe0 [nvme_core]
nvme_parse_ana_log+0xac/0x170 [nvme_core]
nvme_read_ana_log+0x7d/0xe0 [nvme_core]
nvme_mpath_init_identify+0x105/0x150 [nvme_core]
nvme_init_identify+0x2df/0x4d0 [nvme_core]
nvme_init_ctrl_finish+0x8d/0x3b0 [nvme_core]
nvme_tcp_setup_ctrl+0x337/0x390 [nvme_tcp]
nvme_tcp_reconnect_ctrl_work+0x24/0x40 [nvme_tcp]
process_one_work+0x1bd/0x360
worker_thread+0x50/0x3d0

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 79f528af Sun Sep 12 00:54:57 MDT 2021 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix ANA state updates when a namespace is not present

nvme_update_ana_state() has a deficiency that results in a failure to
properly update the ana state for a namespace in the following case:

NSIDs in ctrl->namespaces: 1, 3, 4
NSIDs in desc->nsids: 1, 2, 3, 4

Loop iteration 0:
ns index = 0, n = 0, ns->head->ns_id = 1, nsid = 1, MATCH.
Loop iteration 1:
ns index = 1, n = 1, ns->head->ns_id = 3, nsid = 2, NO MATCH.
Loop iteration 2:
ns index = 2, n = 2, ns->head->ns_id = 4, nsid = 4, MATCH.

Where the update to the ANA state of NSID 3 is missed. To fix this
increment n and retry the update with the same ns when ns->head->ns_id is
higher than nsid,

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
diff 79f528af Sun Sep 12 00:54:57 MDT 2021 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix ANA state updates when a namespace is not present

nvme_update_ana_state() has a deficiency that results in a failure to
properly update the ana state for a namespace in the following case:

NSIDs in ctrl->namespaces: 1, 3, 4
NSIDs in desc->nsids: 1, 2, 3, 4

Loop iteration 0:
ns index = 0, n = 0, ns->head->ns_id = 1, nsid = 1, MATCH.
Loop iteration 1:
ns index = 1, n = 1, ns->head->ns_id = 3, nsid = 2, NO MATCH.
Loop iteration 2:
ns index = 2, n = 2, ns->head->ns_id = 4, nsid = 4, MATCH.

Where the update to the ANA state of NSID 3 is missed. To fix this
increment n and retry the update with the same ns when ns->head->ns_id is
higher than nsid,

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
diff 79f528af Sun Sep 12 00:54:57 MDT 2021 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix ANA state updates when a namespace is not present

nvme_update_ana_state() has a deficiency that results in a failure to
properly update the ana state for a namespace in the following case:

NSIDs in ctrl->namespaces: 1, 3, 4
NSIDs in desc->nsids: 1, 2, 3, 4

Loop iteration 0:
ns index = 0, n = 0, ns->head->ns_id = 1, nsid = 1, MATCH.
Loop iteration 1:
ns index = 1, n = 1, ns->head->ns_id = 3, nsid = 2, NO MATCH.
Loop iteration 2:
ns index = 2, n = 2, ns->head->ns_id = 4, nsid = 4, MATCH.

Where the update to the ANA state of NSID 3 is missed. To fix this
increment n and retry the update with the same ns when ns->head->ns_id is
higher than nsid,

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
diff 79f528af Sun Sep 12 00:54:57 MDT 2021 Anton Eidelman <anton.eidelman@gmail.com> nvme-multipath: fix ANA state updates when a namespace is not present

nvme_update_ana_state() has a deficiency that results in a failure to
properly update the ana state for a namespace in the following case:

NSIDs in ctrl->namespaces: 1, 3, 4
NSIDs in desc->nsids: 1, 2, 3, 4

Loop iteration 0:
ns index = 0, n = 0, ns->head->ns_id = 1, nsid = 1, MATCH.
Loop iteration 1:
ns index = 1, n = 1, ns->head->ns_id = 3, nsid = 2, NO MATCH.
Loop iteration 2:
ns index = 2, n = 2, ns->head->ns_id = 4, nsid = 4, MATCH.

Where the update to the ANA state of NSID 3 is missed. To fix this
increment n and retry the update with the same ns when ns->head->ns_id is
higher than nsid,

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
/linux-master/drivers/s390/block/
H A Ddcssblk.cdiff 3b53d7b1 Tue Jul 11 09:41:37 MDT 2023 Alexander Gordeev <agordeev@linux.ibm.com> s390/dcssblk: fix virtual vs physical address confusion

Fix virtual vs physical address confusion (which currently are the same).

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3d745ea5 Fri Mar 27 02:30:11 MDT 2020 Christoph Hellwig <hch@lst.de> block: simplify queue allocation

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 6396bb22 Tue Jun 12 15:03:40 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff 34c0fd54 Fri Jan 15 17:56:14 MST 2016 Dan Williams <dan.j.williams@intel.com> mm, dax, pmem: introduce pfn_t

For the purpose of communicating the optional presence of a 'struct
page' for the pfn returned from ->direct_access(), introduce a type that
encapsulates a page-frame-number plus flags. These flags contain the
historical "page_link" encoding for a scatterlist entry, but can also
denote "device memory". Where "device memory" is a set of pfns that are
not part of the kernel's linear mapping by default, but are accessed via
the same memory controller as ram.

The motivation for this new type is large capacity persistent memory
that needs struct page entries in the 'memmap' to support 3rd party DMA
(i.e. O_DIRECT I/O with a persistent memory source/target). However,
we also need it in support of maintaining a list of mapped inodes which
need to be unmapped at driver teardown or freeze_bdev() time.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave@sr71.net>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 3a9f9183 Tue Feb 24 09:41:50 MST 2015 Ameen Ali <ameenali023@gmail.com> s390/dcss: array index 'i' is used before limits check.

Avoid out-of-bounds-read by checking count before indexing.

Signed-off-by : Ameen Ali <Ameenali023@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
/linux-master/fs/btrfs/
H A Dinode.cdiff 3c6f0c5e Tue Mar 26 12:55:22 MDT 2024 Boris Burkov <boris@bur.io> btrfs: make btrfs_clear_delalloc_extent() free delalloc reserve

Currently, this call site in btrfs_clear_delalloc_extent() only converts
the reservation. We are marking it not delalloc, so I don't think it
makes sense to keep the rsv around. This is a path where we are not
sure to join a transaction, so it leads to incorrect free-ing during
umount.

Helps with the pass rate of generic/269 and generic/475.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 1bd96c92 Thu Feb 01 17:09:22 MST 2024 Filipe Manana <fdmanana@suse.com> btrfs: reject encoded write if inode has nodatasum flag set

Currently we allow an encoded write against inodes that have the NODATASUM
flag set, either because they are NOCOW files or they were created while
the filesystem was mounted with "-o nodatasum". This results in having
compressed extents without corresponding checksums, which is a filesystem
inconsistency reported by 'btrfs check'.

For example, running btrfs/281 with MOUNT_OPTIONS="-o nodatacow" triggers
this and 'btrfs check' errors out with:

[1/7] checking root items
[2/7] checking extents
[3/7] checking free space tree
[4/7] checking fs roots
root 256 inode 257 errors 1040, bad file extent, some csum missing
root 256 inode 258 errors 1040, bad file extent, some csum missing
ERROR: errors found in fs roots
(...)

So reject encoded writes if the target inode has NODATASUM set.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 7dc66abb Tue Nov 21 06:38:38 MST 2023 Filipe Manana <fdmanana@suse.com> btrfs: use a dedicated data structure for chunk maps

Currently we abuse the extent_map structure for two purposes:

1) To actually represent extents for inodes;
2) To represent chunk mappings.

This is odd and has several disadvantages:

1) To create a chunk map, we need to do two memory allocations: one for
an extent_map structure and another one for a map_lookup structure, so
more potential for an allocation failure and more complicated code to
manage and link two structures;

2) For a chunk map we actually only use 3 fields (24 bytes) of the
respective extent map structure: the 'start' field to have the logical
start address of the chunk, the 'len' field to have the chunk's size,
and the 'orig_block_len' field to contain the chunk's stripe size.

Besides wasting a memory, it's also odd and not intuitive at all to
have the stripe size in a field named 'orig_block_len'.

We are also using 'block_len' of the extent_map structure to contain
the chunk size, so we have 2 fields for the same value, 'len' and
'block_len', which is pointless;

3) When an extent map is associated to a chunk mapping, we set the bit
EXTENT_FLAG_FS_MAPPING on its flags and then make its member named
'map_lookup' point to the associated map_lookup structure. This means
that for an extent map associated to an inode extent, we are not using
this 'map_lookup' pointer, so wasting 8 bytes (on a 64 bits platform);

4) Extent maps associated to a chunk mapping are never merged or split so
it's pointless to use the existing extent map infrastructure.

So add a dedicated data structure named 'btrfs_chunk_map' to represent
chunk mappings, this is basically the existing map_lookup structure with
some extra fields:

1) 'start' to contain the chunk logical address;
2) 'chunk_len' to contain the chunk's length;
3) 'stripe_size' for the stripe size;
4) 'rb_node' for insertion into a rb tree;
5) 'refs' for reference counting.

This way we do a single memory allocation for chunk mappings and we don't
waste memory for them with unused/unnecessary fields from an extent_map.

We also save 8 bytes from the extent_map structure by removing the
'map_lookup' pointer, so the size of struct extent_map is reduced from
144 bytes down to 136 bytes, and we can now have 30 extents map per 4K
page instead of 28.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 7dc66abb Tue Nov 21 06:38:38 MST 2023 Filipe Manana <fdmanana@suse.com> btrfs: use a dedicated data structure for chunk maps

Currently we abuse the extent_map structure for two purposes:

1) To actually represent extents for inodes;
2) To represent chunk mappings.

This is odd and has several disadvantages:

1) To create a chunk map, we need to do two memory allocations: one for
an extent_map structure and another one for a map_lookup structure, so
more potential for an allocation failure and more complicated code to
manage and link two structures;

2) For a chunk map we actually only use 3 fields (24 bytes) of the
respective extent map structure: the 'start' field to have the logical
start address of the chunk, the 'len' field to have the chunk's size,
and the 'orig_block_len' field to contain the chunk's stripe size.

Besides wasting a memory, it's also odd and not intuitive at all to
have the stripe size in a field named 'orig_block_len'.

We are also using 'block_len' of the extent_map structure to contain
the chunk size, so we have 2 fields for the same value, 'len' and
'block_len', which is pointless;

3) When an extent map is associated to a chunk mapping, we set the bit
EXTENT_FLAG_FS_MAPPING on its flags and then make its member named
'map_lookup' point to the associated map_lookup structure. This means
that for an extent map associated to an inode extent, we are not using
this 'map_lookup' pointer, so wasting 8 bytes (on a 64 bits platform);

4) Extent maps associated to a chunk mapping are never merged or split so
it's pointless to use the existing extent map infrastructure.

So add a dedicated data structure named 'btrfs_chunk_map' to represent
chunk mappings, this is basically the existing map_lookup structure with
some extra fields:

1) 'start' to contain the chunk logical address;
2) 'chunk_len' to contain the chunk's length;
3) 'stripe_size' for the stripe size;
4) 'rb_node' for insertion into a rb tree;
5) 'refs' for reference counting.

This way we do a single memory allocation for chunk mappings and we don't
waste memory for them with unused/unnecessary fields from an extent_map.

We also save 8 bytes from the extent_map structure by removing the
'map_lookup' pointer, so the size of struct extent_map is reduced from
144 bytes down to 136 bytes, and we can now have 30 extents map per 4K
page instead of 28.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 7dc66abb Tue Nov 21 06:38:38 MST 2023 Filipe Manana <fdmanana@suse.com> btrfs: use a dedicated data structure for chunk maps

Currently we abuse the extent_map structure for two purposes:

1) To actually represent extents for inodes;
2) To represent chunk mappings.

This is odd and has several disadvantages:

1) To create a chunk map, we need to do two memory allocations: one for
an extent_map structure and another one for a map_lookup structure, so
more potential for an allocation failure and more complicated code to
manage and link two structures;

2) For a chunk map we actually only use 3 fields (24 bytes) of the
respective extent map structure: the 'start' field to have the logical
start address of the chunk, the 'len' field to have the chunk's size,
and the 'orig_block_len' field to contain the chunk's stripe size.

Besides wasting a memory, it's also odd and not intuitive at all to
have the stripe size in a field named 'orig_block_len'.

We are also using 'block_len' of the extent_map structure to contain
the chunk size, so we have 2 fields for the same value, 'len' and
'block_len', which is pointless;

3) When an extent map is associated to a chunk mapping, we set the bit
EXTENT_FLAG_FS_MAPPING on its flags and then make its member named
'map_lookup' point to the associated map_lookup structure. This means
that for an extent map associated to an inode extent, we are not using
this 'map_lookup' pointer, so wasting 8 bytes (on a 64 bits platform);

4) Extent maps associated to a chunk mapping are never merged or split so
it's pointless to use the existing extent map infrastructure.

So add a dedicated data structure named 'btrfs_chunk_map' to represent
chunk mappings, this is basically the existing map_lookup structure with
some extra fields:

1) 'start' to contain the chunk logical address;
2) 'chunk_len' to contain the chunk's length;
3) 'stripe_size' for the stripe size;
4) 'rb_node' for insertion into a rb tree;
5) 'refs' for reference counting.

This way we do a single memory allocation for chunk mappings and we don't
waste memory for them with unused/unnecessary fields from an extent_map.

We also save 8 bytes from the extent_map structure by removing the
'map_lookup' pointer, so the size of struct extent_map is reduced from
144 bytes down to 136 bytes, and we can now have 30 extents map per 4K
page instead of 28.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 4a4f8fe2 Wed Oct 04 04:38:50 MDT 2023 Filipe Manana <fdmanana@suse.com> btrfs: add and use helpers for reading and writing fs_info->generation

Currently the generation field of struct btrfs_fs_info is always modified
while holding fs_info->trans_lock locked. Most readers will access this
field without taking that lock but while holding a transaction handle,
which is safe to do due to the transaction life cycle.

However there are other readers that are neither holding the lock nor
holding a transaction handle open:

1) When reading an inode from disk, at btrfs_read_locked_inode();

2) When reading the generation to expose it to sysfs, at
btrfs_generation_show();

3) Early in the fsync path, at skip_inode_logging();

4) When creating a hole at btrfs_cont_expand(), during write paths,
truncate and reflinking;

5) In the fs_info ioctl (btrfs_ioctl_fs_info());

6) While mounting the filesystem, in the open_ctree() path. In these
cases it's safe to directly read fs_info->generation as no one
can concurrently start a transaction and update fs_info->generation.

In case of the fsync path, races here should be harmless, and in the worst
case they may cause a fsync to log an inode when it's not really needed,
so nothing bad from a functional perspective. In the other cases it's not
so clear if functional problems may arise, though in case 1 rare things
like a load/store tearing [1] may cause the BTRFS_INODE_NEEDS_FULL_SYNC
flag not being set on an inode and therefore result in incorrect logging
later on in case a fsync call is made.

To avoid data race warnings from tools like KCSAN and other issues such
as load and store tearing (amongst others, see [1]), create helpers to
access the generation field of struct btrfs_fs_info using READ_ONCE() and
WRITE_ONCE(), and use these helpers where needed.

[1] https://lwn.net/Articles/793253/

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 8e7f82de Tue Sep 12 04:45:39 MDT 2023 Filipe Manana <fdmanana@suse.com> btrfs: fix race between reading a directory and adding entries to it

When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:

Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc

The race leading to the problem happens like this:

1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());

2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.

Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...

3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...

4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;

5) Task B assigns 101 to the index_cnt field of inode X;

6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.

Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.

Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 8e7f82de Tue Sep 12 04:45:39 MDT 2023 Filipe Manana <fdmanana@suse.com> btrfs: fix race between reading a directory and adding entries to it

When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:

Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc

The race leading to the problem happens like this:

1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());

2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.

Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...

3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...

4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;

5) Task B assigns 101 to the index_cnt field of inode X;

6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.

Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.

Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 8e7f82de Tue Sep 12 04:45:39 MDT 2023 Filipe Manana <fdmanana@suse.com> btrfs: fix race between reading a directory and adding entries to it

When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:

Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc

The race leading to the problem happens like this:

1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());

2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.

Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...

3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...

4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;

5) Task B assigns 101 to the index_cnt field of inode X;

6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.

Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.

Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 8e7f82de Tue Sep 12 04:45:39 MDT 2023 Filipe Manana <fdmanana@suse.com> btrfs: fix race between reading a directory and adding entries to it

When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:

Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc

The race leading to the problem happens like this:

1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());

2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.

Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...

3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...

4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;

5) Task B assigns 101 to the index_cnt field of inode X;

6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.

Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.

Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff 8e7f82de Tue Sep 12 04:45:39 MDT 2023 Filipe Manana <fdmanana@suse.com> btrfs: fix race between reading a directory and adding entries to it

When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:

Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc

The race leading to the problem happens like this:

1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());

2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.

Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...

3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...

4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;

5) Task B assigns 101 to the index_cnt field of inode X;

6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.

Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.

Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
/linux-master/fs/ext4/
H A Dfile.cdiff eb8ab444 Fri Jun 16 10:50:49 MDT 2023 Jan Kara <jack@suse.cz> ext4: make ext4_forced_shutdown() take struct super_block

Currently ext4_forced_shutdown() takes struct ext4_sb_info but most
callers need to get it from struct super_block anyway. So just pass in
struct super_block to save all callers from some boilerplate code. No
functional changes.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230616165109.21695-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff 1d024e7a Fri Aug 18 14:23:35 MDT 2023 Matthew Wilcox (Oracle) <willy@infradead.org> mm: remove enum page_entry_size

Remove the unnecessary encoding of page order into an enum and pass the
page order directly. That lets us get rid of pe_order().

The switch constructs have to be changed to if/else constructs to prevent
GCC from warning on builds with 3-level page tables where PMD_ORDER and
PUD_ORDER have the same value.

If you are looking at this commit because your driver stopped compiling,
look at the previous commit as well and audit your driver to be sure it
doesn't depend on mmap_lock being held in its ->huge_fault method.

[willy@infradead.org: use "order %u" to match the (non dev_t) style]
Link: https://lkml.kernel.org/r/ZOUYekbtTv+n8hYf@casper.infradead.org
Link: https://lkml.kernel.org/r/20230818202335.2739663-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff 3e08773c Tue Oct 12 05:12:24 MDT 2021 Christoph Hellwig <hch@lst.de> block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff bc6385da Wed Dec 11 22:55:57 MST 2019 Ritesh Harjani <riteshh@linux.ibm.com> ext4: Move to shared i_rwsem even without dioread_nolock mount opt

We were using shared locking only in case of dioread_nolock mount option in case
of DIO overwrites. This mount condition is not needed anymore with current code,
since:-

1. No race between buffered writes & DIO overwrites. Since buffIO writes takes
exclusive lock & DIO overwrites will take shared locking. Also DIO path will
make sure to flush and wait for any dirty page cache data.

2. No race between buffered reads & DIO overwrites, since there is no block
allocation that is possible with DIO overwrites. So no stale data exposure
should happen. Same is the case between DIO reads & DIO overwrites.

3. Also other paths like truncate is protected, since we wait there for any DIO
in flight to be over.

Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20191212055557.11151-4-riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff aa9714d0 Wed Dec 11 22:55:56 MST 2019 Ritesh Harjani <riteshh@linux.ibm.com> ext4: Start with shared i_rwsem in case of DIO instead of exclusive

Earlier there was no shared lock in DIO read path. But this patch
(16c54688592ce: ext4: Allow parallel DIO reads)
simplified some of the locking mechanism while still allowing for parallel DIO
reads by adding shared lock in inode DIO read path.

But this created problem with mixed read/write workload. It is due to the fact
that in DIO path, we first start with exclusive lock and only when we determine
that it is a ovewrite IO, we downgrade the lock. This causes the problem, since
we still have shared locking in DIO reads.

So, this patch tries to fix this issue by starting with shared lock and then
switching to exclusive lock only when required based on ext4_dio_write_checks().

Other than that, it also simplifies below cases:-

1. Simplified ext4_unaligned_aio API to ext4_unaligned_io. Previous API was
abused in the sense that it was not really checking for AIO anywhere also it
used to check for extending writes. So this API was renamed and simplified to
ext4_unaligned_io() which actully only checks if the IO is really unaligned.

Now, in case of unaligned direct IO, iomap_dio_rw needs to do zeroing of partial
block and that will require serialization against other direct IOs in the same
block. So we take a exclusive inode lock for any unaligned DIO. In case of AIO
we also need to wait for any outstanding IOs to complete so that conversion from
unwritten to written is completed before anyone try to map the overlapping block.
Hence we take exclusive inode lock and also wait for inode_dio_wait() for
unaligned DIO case. Please note since we are anyway taking an exclusive lock in
unaligned IO, inode_dio_wait() becomes a no-op in case of non-AIO DIO.

2. Added ext4_extending_io(). This checks if the IO is extending the file.

3. Added ext4_dio_write_checks(). In this we start with shared inode lock and
only switch to exclusive lock if required. So in most cases with aligned,
non-extending, dioread_nolock & overwrites, it tries to write with a shared
lock. If not, then we restart the operation in ext4_dio_write_checks(), after
acquiring exclusive lock.

Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20191212055557.11151-3-riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff aa9714d0 Wed Dec 11 22:55:56 MST 2019 Ritesh Harjani <riteshh@linux.ibm.com> ext4: Start with shared i_rwsem in case of DIO instead of exclusive

Earlier there was no shared lock in DIO read path. But this patch
(16c54688592ce: ext4: Allow parallel DIO reads)
simplified some of the locking mechanism while still allowing for parallel DIO
reads by adding shared lock in inode DIO read path.

But this created problem with mixed read/write workload. It is due to the fact
that in DIO path, we first start with exclusive lock and only when we determine
that it is a ovewrite IO, we downgrade the lock. This causes the problem, since
we still have shared locking in DIO reads.

So, this patch tries to fix this issue by starting with shared lock and then
switching to exclusive lock only when required based on ext4_dio_write_checks().

Other than that, it also simplifies below cases:-

1. Simplified ext4_unaligned_aio API to ext4_unaligned_io. Previous API was
abused in the sense that it was not really checking for AIO anywhere also it
used to check for extending writes. So this API was renamed and simplified to
ext4_unaligned_io() which actully only checks if the IO is really unaligned.

Now, in case of unaligned direct IO, iomap_dio_rw needs to do zeroing of partial
block and that will require serialization against other direct IOs in the same
block. So we take a exclusive inode lock for any unaligned DIO. In case of AIO
we also need to wait for any outstanding IOs to complete so that conversion from
unwritten to written is completed before anyone try to map the overlapping block.
Hence we take exclusive inode lock and also wait for inode_dio_wait() for
unaligned DIO case. Please note since we are anyway taking an exclusive lock in
unaligned IO, inode_dio_wait() becomes a no-op in case of non-AIO DIO.

2. Added ext4_extending_io(). This checks if the IO is extending the file.

3. Added ext4_dio_write_checks(). In this we start with shared inode lock and
only switch to exclusive lock if required. So in most cases with aligned,
non-extending, dioread_nolock & overwrites, it tries to write with a shared
lock. If not, then we restart the operation in ext4_dio_write_checks(), after
acquiring exclusive lock.

Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20191212055557.11151-3-riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Completed in 1972 milliseconds

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