mtd: ubi: block: use notifier to create ubiblock from parameter

Use UBI_VOLUME_ADDED notification to create ubiblock device specified
on kernel cmdline or module parameter.
This makes thing more simple and has the advantage that ubiblock devices
on volumes which are not present at the time the ubi module is probed
will still be created.

Suggested-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubiblock: pass queue_limits to blk_mq_alloc_disk

Pass the few limits ubiblock imposes directly to blk_mq_alloc_disk
instead of setting them one at a time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20240215070300.2200308-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a queue_limits argument to blk_mq_alloc_disk

Pass a queue_limits to blk_mq_alloc_disk and apply it if non-NULL. This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ubi: block: fix memleak in ubiblock_create()

If idr_alloc() fails, dev->gd will be put after goto out_cleanup_disk in
ubiblock_create(), but dev->gd has not been assigned yet at this time, and
'gd' will not be put anymore. Fix it by putting 'gd' directly.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: block: Fix use-after-free in ubiblock_cleanup

The following BUG is reported when a ubiblock is removed:

==================================================================
BUG: KASAN: slab-use-after-free in ubiblock_cleanup+0x88/0xa0 [ubi]
Read of size 4 at addr ffff88810c8f3804 by task ubiblock/1716

CPU: 5 PID: 1716 Comm: ubiblock Not tainted 6.6.0-rc2+ #135
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x37/0x50
print_report+0xd0/0x620
kasan_report+0xb6/0xf0
ubiblock_cleanup+0x88/0xa0 [ubi]
ubiblock_remove+0x121/0x190 [ubi]
vol_cdev_ioctl+0x355/0x630 [ubi]
__x64_sys_ioctl+0xc7/0x100
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7f08d7445577
Code: b3 66 90 48 8b 05 11 89 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 8
RSP: 002b:00007ffde05a3018 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f08d7445577
RDX: 0000000000000000 RSI: 0000000000004f08 RDI: 0000000000000003
RBP: 0000000000816010 R08: 00000000008163a7 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000206 R12: 0000000000000003
R13: 00007ffde05a3130 R14: 0000000000000000 R15: 0000000000000000
</TASK>

Allocated by task 1715:
kasan_save_stack+0x22/0x50
kasan_set_track+0x25/0x30
__kasan_kmalloc+0x7f/0x90
__alloc_disk_node+0x40/0x2b0
__blk_mq_alloc_disk+0x3e/0xb0
ubiblock_create+0x2ba/0x620 [ubi]
vol_cdev_ioctl+0x581/0x630 [ubi]
__x64_sys_ioctl+0xc7/0x100
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Freed by task 0:
kasan_save_stack+0x22/0x50
kasan_set_track+0x25/0x30
kasan_save_free_info+0x2b/0x50
__kasan_slab_free+0x10e/0x190
__kmem_cache_free+0x96/0x220
bdev_free_inode+0xa4/0xf0
rcu_core+0x496/0xec0
__do_softirq+0xeb/0x384

The buggy address belongs to the object at ffff88810c8f3800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 4 bytes inside of
freed 1024-byte region [ffff88810c8f3800, ffff88810c8f3c00)

The buggy address belongs to the physical page:
page:00000000d03de848 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10c8f0
head:00000000d03de848 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000840(slab|head|node=0|zone=2)
page_type: 0xffffffff()
raw: 0200000000000840 ffff888100042dc0 ffffea0004244400 dead000000000002
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88810c8f3700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88810c8f3780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88810c8f3800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88810c8f3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88810c8f3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Fix it by using a local variable to record the gendisk ID.

Fixes: 77567b25ab9f ("ubi: use blk_mq_alloc_disk and blk_cleanup_disk")
Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

block: replace fmode_t with a block-specific type for block open flags

The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove the unused mode argument to ->release

The mode argument to the ->release block_device_operation is never used,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a gendisk to ->open

->open is only called on the whole device. Make that explicit by
passing a gendisk instead of the block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ubi: block: Fix missing blk_mq_end_request

Switching to BLK_MQ_F_BLOCKING wrongly removed the call to
blk_mq_end_request(). Add it back to have our IOs finished

Fixes: 91cc8fbcc8c7 ("ubi: block: set BLK_MQ_F_BLOCKING")
Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Daniel Palmer <daniel@0x0f.com>
Link: https://lore.kernel.org/linux-mtd/CAHk-=wi29bbBNh3RqJKu3PxzpjDN5D5K17gEVtXrb7-6bfrnMQ@mail.gmail.com/
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Daniel Palmer <daniel@0x0f.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ubi: block: Fix a possible use-after-free bug in ubiblock_create()

Smatch warns:
drivers/mtd/ubi/block.c:438 ubiblock_create()
warn: '&dev->list' not removed from list

'dev' is freed in 'out_free_dev:, but it is still on the list.

To fix this, delete the list item before freeing.

Fixes: 91cc8fbcc8c7 ("ubi: block: set BLK_MQ_F_BLOCKING")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

mtd: ubi: block: wire-up device parent

ubiblock devices were previously only identifyable by their name, but
not connected to their parent UBI volume device e.g. in sysfs.
Properly parent ubiblock device as descendant of a UBI volume device
to reflect device model hierachy.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: block: set BLK_MQ_F_BLOCKING

Set BLK_MQ_F_BLOCKING so that the block layer always calls ->queue_rq
from process context and drop the driver internal workqueue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: block: Reduce warning print to info for static volumes

If volume size is not multiple of the sector size 512 a warning is
printed saying that the last non-sector aligned bytes will be ignored.

This should be valid for resizable volumes, but when creating static
volumes which are read only this will always be printed even if the
unaligned data is deliberate.

The message is still valid but the severity should be lowered for static
volumes.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: block: Fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: block: Remove in vain semicolon

Remove the repeated ';' from code, it is not
needed.

Signed-off-by: Li zeming <zeming@nfschina.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
[rw: Massaged commit message a bit]
Signed-off-by: Richard Weinberger <richard@nod.at>

block: remove blk_cleanup_disk

blk_cleanup_disk is nothing but a trivial wrapper for put_disk now,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove GENHD_FL_EXT_DEVT

All modern drivers can support extra partitions using the extended
dev_t. In fact except for the ioctl method drivers never even see
partitions in normal operation.

So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all
block devices that do support partitions, and require those that
do not support partitions to explicit disallow them using
GENHD_FL_NO_PART.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove rq_flush_dcache_pages

This function is trivial, and flush_dcache_page is always defined, so
just open code it in the 2.5 callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20211117061404.331732-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

mtd/ubi/block: 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/20211103230437.1639990-10-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ubi: use blk_mq_alloc_disk and blk_cleanup_disk

Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ubi: block: Warn if volume size is not multiple of 512

If volume size is not a multiple of 512, ubi block cuts
off the last bytes of an volume since the block layer works
on 512 byte sectors.
This can happen especially on NOR flash with minimal io
size of 1.

To avoid unpleasant surprises, print a warning.

Signed-off-by: Richard Weinberger <richard@nod.at>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 this program is distributed
in the hope that it will be useful but without any warranty without
even the implied warranty of merchantability or fitness for a
particular purpose see the gnu general public license for more
details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 97 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ubi: Fix error for write access

When opening a device with write access, ubiblock_open returns an error
code. Currently, this error code is -EPERM, but this is not the right
value.

The open function for other block devices returns -EROFS when opening
read-only devices with FMODE_WRITE set. When used with dm-verity, the
veritysetup userspace tool is expecting EROFS, and refuses to use the
ubiblock device.

Use -EROFS for ubiblock as well. As a result, veritysetup accepts the
ubiblock device as valid.

Cc: stable@vger.kernel.org
Fixes: 9d54c8a33eec (UBI: R/O block driver on top of UBI volumes)
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: block: Fix locking for idr_alloc/idr_remove

This fixes a race with idr_alloc where gd->first_minor can be set to the
same value for two simultaneous calls to ubiblock_create. Each instance
calls device_add_disk with the same first_minor. device_add_disk calls
bdi_register_owner which generates several warnings.

WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31
sysfs_warn_dup+0x68/0x88
sysfs: cannot create duplicate filename '/devices/virtual/bdi/252:2'

WARNING: CPU: 1 PID: 179 at kernel-source/lib/kobject.c:240
kobject_add_internal+0x1ec/0x2f8
kobject_add_internal failed for 252:2 with -EEXIST, don't try to
register things with the same name in the same directory

WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31
sysfs_warn_dup+0x68/0x88
sysfs: cannot create duplicate filename '/dev/block/252:2'

However, device_add_disk does not error out when bdi_register_owner
returns an error. Control continues until reaching blk_register_queue.
It then BUGs.

kernel BUG at kernel-source/fs/sysfs/group.c:113!
[<c01e26cc>] (internal_create_group) from [<c01e2950>]
(sysfs_create_group+0x20/0x24)
[<c01e2950>] (sysfs_create_group) from [<c00e3d38>]
(blk_trace_init_sysfs+0x18/0x20)
[<c00e3d38>] (blk_trace_init_sysfs) from [<c02bdfbc>]
(blk_register_queue+0xd8/0x154)
[<c02bdfbc>] (blk_register_queue) from [<c02cec84>]
(device_add_disk+0x194/0x44c)
[<c02cec84>] (device_add_disk) from [<c0436ec8>]
(ubiblock_create+0x284/0x2e0)
[<c0436ec8>] (ubiblock_create) from [<c0427bb8>]
(vol_cdev_ioctl+0x450/0x554)
[<c0427bb8>] (vol_cdev_ioctl) from [<c0189110>] (vfs_ioctl+0x30/0x44)
[<c0189110>] (vfs_ioctl) from [<c01892e0>] (do_vfs_ioctl+0xa0/0x790)
[<c01892e0>] (do_vfs_ioctl) from [<c0189a14>] (SyS_ioctl+0x44/0x68)
[<c0189a14>] (SyS_ioctl) from [<c0010640>] (ret_fast_syscall+0x0/0x34)

Locking idr_alloc/idr_remove removes the race and keeps gd->first_minor
unique.

Fixes: 2bf50d42f3a4 ("UBI: block: Dynamically allocate minor numbers")
Cc: stable@vger.kernel.org
Signed-off-by: Bradley Bolen <bradleybolen@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

ubi: pr_err() strings should end with newlines

In build.c, the following pr_err calls should be terminated with
a new-line to avoid other messages being concatenated onto the end.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

blk-mq: switch ->queue_rq return value to blk_status_t

Use the same values for use for request completion errors as the return
value from ->queue_rq. BLK_STS_RESOURCE is special cased to cause
a requeue, and all the others are completed as-is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

block: introduce new block status code type

Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings. This patch
instead introduces a new blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning. Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-mq: update ->init_request and ->exit_request prototypes

Remove the request_idx parameter, which can't be used safely now that we
support I/O schedulers with blk-mq. Except for a superflous check in
mtip32xx it was unused anyway.

Also pass the tag_set instead of just the driver data - this allows drivers
to avoid some code duplication in a follow on cleanup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-mq: constify struct blk_mq_ops

Constify all instances of blk_mq_ops, as they are never modified.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block: fold cmd_type into the REQ_OP_ space

Instead of keeping two levels of indirection for requests types, fold it
all into the operations. The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

Instead this patch adds new REQ_OP_* for SCSI passthrough and driver
private requests, althought it has to add two for each so that we
can communicate the data in/out nature of the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-mq: remove ->map_queue

All drivers use the default, so provide an inline version of it. If we
ever need other queue mapping we can add an optional method back,
although supporting will also require major changes to the queue setup
code.

This provides better code generation, and better debugability as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

UBI: block: Dynamically allocate minor numbers

This patch makes ubiblock devices have minor numbers beginning from
0, allocated dynamically independently of the ubi device/volume
number. This property becomes useful because, on 32-bit architectures
with LFS turned off in a userspace program, device minor numbers
over 8 bits cause stat to return -EOVERFLOW. If the device number is
high (>1) due to multiple MTD partitions, such an overflow will occur.
While enabling LFS is clearly a nicer solution, it's often difficult
to turn on in practice globally as many widely distributed packages
don't work with LFS on.

Other storage systems have their own workarounds, with SCSI making
multiple device majors and MMC having a config option for the number
of partitions per device. A completely dynamic minor numbering is
simpler than these. It is unlikely that anyone is depending on a
static minor number since the major is dynamic anyway. In addition,
ubiblock is still relatively new, so now is the time to make such
changes.

Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Acked-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Richard Weinberger <richard@nod.at>

kernel/params: constify struct kernel_param_ops uses

Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

* allnoconfig
* allmodconfig
* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

UBI: block: Add missing cache flushes

Block drivers are responsible for calling flush_dcache_page() on each
BIO request. This operation keeps the I$ coherent with the D$ on
architectures that don't have hardware coherency support. Without this
flush, random crashes are seen when executing user programs from an ext4
filesystem backed by a ubiblock device.

This patch is based on the change implemented in commit 2d4dc890b5c8
("block: add helpers to run flush_dcache_page() against a bio and a
request's pages").

Fixes: 9d54c8a33eec ("UBI: R/O block driver on top of UBI volumes")
Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

UBI: block: Fix checking for NULL instead of IS_ERR()

We recently switched from allocating ->rq using blk_init_queue() to
use blk_mq_init_queue() so we need to update the error handling to
check for IS_ERR() instead of NULL.

Fixes: ff1f48ee3bb3 ('UBI: Block: Add blk-mq support')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

UBI: block: Continue creating ubiblocks after an initialization error

If one ubi volume is corrupted but another is not, it should be
possible to initialize that ubiblock from a kernel commandline which
includes both of them. This patch changes the error handling behavior
in initializing ubiblock to ensure that all parameters are attempted
even if one fails. If there is a failure, it is logged on dmesg.
It also makes error messages more descriptive by including the
name of the UBI volume that failed.

Tested: Formatted ubi volume /dev/ubi5_0 in a corrupt way and
dev/ubi3_0 properly and included "ubi.block=5,0 ubi.block=3,0" on
the kernel command line. At boot, I see the following in the console:
[ 21.082420] UBI error: ubiblock_create_from_param: block: can't open volume on ubi5_0, err=-19
[ 21.084268] UBI: ubiblock3_0 created from ubi3:0(rootfs)

Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Richard Weinberger <richard@nod.at>

UBI: Block: Explain usage of blk_rq_map_sg()

Signed-off-by: Richard Weinberger <richard@nod.at>

UBI: Block: Add blk-mq support

Convert the driver to blk-mq.
Beside of moving to the modern block interface this change boosts
also the performance of the driver.

nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
nand: Micron NAND 256MiB 3,3V 8-bit
nand: 256MiB, SLC, page size: 2048, OOB size: 64

root@debian-armhf:~# dd if=/dev/ubiblock0_0 of=/dev/zero bs=1M
243+1 records in
243+1 records out
255080448 bytes (255 MB) copied, 4.39295 s, 58.1 MB/s

vs.

root@debian-armhf:~# dd if=/dev/ubiblock0_0 of=/dev/zero bs=1M
243+1 records in
243+1 records out
255080448 bytes (255 MB) copied, 2.87676 s, 88.7 MB/s

Cc: hch@infradead.org
Cc: axboe@fb.com
Cc: tom.leiming@gmail.com
Signed-off-by: Richard Weinberger <richard@nod.at>
Tested-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Jens Axboe <axboe@fb.com>
Acked-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

UBI: Extend UBI layer debug/messaging capabilities

If there is more then one UBI device mounted, there is no way to
distinguish between messages from different UBI devices.
Add device number to all ubi layer message types.

The R/O block driver messages were replaced by pr_* since
ubi_device structure is not used by it.

Amended a bit by Artem.

Signed-off-by: Tanya Brokhman <tlinder@codeaurora.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: Add support for the UBI_VOLUME_UPDATED notification

Static volumes can change its 'used_bytes' when they get updated,
and so the block interface must listen to the UBI_VOLUME_UPDATED
notification to resize the block device accordingly.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org # v3.15+

UBI: block: Fix block device size setting

We are currently taking the block device size from the ubi_volume_info.size
field. However, this is not the amount of data in the volume, but the
number of reserved physical eraseblocks, and hence leads to an incorrect
representation of the volume.

In particular, this produces I/O errors on static volumes as the block
interface may attempt to read unmapped PEBs:

$ cat /dev/ubiblock0_0 > /dev/null
UBI error: ubiblock_read_to_buf: ubiblock0_0 ubi_read error -22
end_request: I/O error, dev ubiblock0_0, sector 9536
Buffer I/O error on device ubiblock0_0, logical block 2384
[snip]

Fix this by using the ubi_volume_info.used_bytes field which is set to the
actual number of data bytes for both static and dynamic volumes.

While here, improve the error message to be less stupid and more useful:
UBI error: ubiblock_read_to_buf: ubiblock0_1 ubi_read error -9 on LEB=0, off=15872, len=512

It's worth noticing that the 512-byte sector representation of the volume
is only correct if the volume size is multiple of 512-bytes. This is true for
virtually any NAND device, given eraseblocks and pages are 512-byte multiple
and hence so is the LEB size.

Artem: tweak the error message and make it look more like other UBI error
messages.

Fixes: 9d54c8a33eec ("UBI: R/O block driver on top of UBI volumes")
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org # v3.15+

UBI: block: fix dereference on uninitialized dev

commit 4df38926f337 ("UBI: block: Avoid disk size integer overflow")
introduced a dereference on dev (which is not initialized at that
point) when printing a warning message. Re-order disk_capacity check
after the dev is found.

Found by cppcheck:
[drivers/mtd/ubi/block.c:509]: (error) Uninitialized variable: dev

Artem: tweak the error message a bit

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: Avoid disk size integer overflow

This patch fixes the issue that on very large UBI volumes
UBI block does not work correctly.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: Set disk_capacity out of the mutex

There's no need to set the disk capacity with the mutex held, so this
commit takes the variable setting out of the mutex. This simplifies
the disk capacity fix for very large volumes in a follow up commit.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: Make ubiblock_resize return something

Currently, ubiblock_resize() can fail if the device is not found
in the list. This commit changes the return type, so the function can
return something meaningful on error paths.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: Fix error path on alloc_workqueue failure

Otherwise we'd return a random value if allocation of the workqueue fails.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: avoid workqueue format string leak

When building the name for the workqueue thread, make sure a format
string cannot leak in from the disk name.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

block: remove struct request buffer member

This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.

Convert old style drivers to just use bio_data().

For the discard payload use case, just reference the page
in the bio.

Signed-off-by: Jens Axboe <axboe@fb.com>

UBI: block: Remove __initdata from ubiblock_param_ops

You cannot mark these parameters as __initdata.
Otherwise the data is gone upon module exit.

Fixes:
[ 172.045465] BUG: unable to handle kernel paging request at ffffffffa001db38
[ 172.046020] IP: [<ffffffff81067aa4>] destroy_params+0x24/0x50

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: rename block device ioctls

Rename the UBI_IOCVOLATTBLK and UBI_IOCVOLDETBLK to UBI_IOCVOLCRBLK and
UBI_IOCVOLRMBLK, because we do not use terms "attach" and "detach" for the R/O
block devices on top of UBI volumes. Instead, we use terms "create" and
"remove". This patch also amends the related commentaries.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>

UBI: block: Use 'u64' for the 64-bit dividend

Fixes the following warning on ARCH=avr32:

drivers/mtd/ubi/block.c: In function 'ubiblock_read':
drivers/mtd/ubi/block.c:207: warning: comparison of distinct pointer types lacks a cast

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: Mark init-only symbol as __initdata

ubiblock_param_ops should be marked as __init as it's only used to set
a driver parameter on insertion time. This commit fixes the following:

WARNING: drivers/mtd/built-in.o(.text+0x653ac): Section mismatch in
reference from the variable ubiblock_param_ops to the function
.init.text:ubiblock_set_param()

The function ubiblock_param_ops() references the function __init
ubiblock_set_param(). This is often because ubiblock_param_ops lacks a
__init annotation or the annotation of ubiblock_set_param is wrong.

Given gcc errors if the struct is marked const __initdata, this commit
drops the const mark from it.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: block: do not use term "attach"

We already use term attach/detach for UBI->MTD relations, let's not use this
for UBI->ubiblock relations to avoid confusion. Just use 'create' and 'remove'
instead. E.g., "create a R/O block device on top of a UBI volume".

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI: R/O block driver on top of UBI volumes

This commit introduces read-only block device emulation on top of UBI volumes.

Given UBI takes care of wear leveling and bad block management it's possible
to add a thin layer to enable block device access to UBI volumes.
This allows to use a block-oriented filesystem on a flash device.

The UBI block devices are meant to be used in conjunction with any
regular, block-oriented file system (e.g. ext4), although it's primarily
targeted at read-only file systems, such as squashfs.

Block devices are created upon user request through new ioctls:
UBI_IOCVOLATTBLK to attach and UBI_IOCVOLDETBLK to detach.
Also, a new UBI module parameter is added 'ubi.block'. This parameter is
needed in order to attach a block device on boot-up time, allowing to
mount the rootfs on a ubiblock device.
For instance, you could have these kernel parameters:

ubi.mtd=5 ubi.block=0,0 root=/dev/ubiblock0_0

Or, if you compile ubi as a module:

$ modprobe ubi mtd=/dev/mtd5 block=/dev/ubi0_0

Artem: amend commentaries and massage the patch a little bit.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>