f2fs: fix to handle error paths of {new,change}_curseg()

{new,change}_curseg() may return error in some special cases,
error handling should be did in their callers, and this will also
facilitate subsequent error path expansion in {new,change}_curseg().

Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: unify the error handling of f2fs_is_valid_blkaddr

There are some cases of f2fs_is_valid_blkaddr not handled as
ERROR_INVALID_BLKADDR,so unify the error handling about all of
f2fs_is_valid_blkaddr.
Do f2fs_handle_error in __f2fs_is_valid_blkaddr for cleanup.

Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce SEGS_TO_BLKS/BLKS_TO_SEGS for cleanup

Just cleanup, no functional change.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to check return value of f2fs_gc_range

f2fs_gc_range may return error, so its caller
f2fs_allocate_pinning_section should determine whether
to do retry based on ist return value.

Also just do f2fs_gc_range when f2fs_allocate_new_section
return -EAGAIN, and check cp error case in f2fs_gc_range.

Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to handle segment allocation failure correctly

If CONFIG_F2FS_CHECK_FS is off, and for very rare corner case that
we run out of free segment, we should not panic kernel, instead,
let's handle such error correctly in its caller.

Signed-off-by: Chao Yu <chao@kernel.org>
Tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support file pinning for zoned devices

Support file pinning with conventional storage area for zoned devices

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: kill heap-based allocation

No one uses this feature. Let's kill it.

Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: separate f2fs_gc_range() to use GC for a range

Make f2fs_gc_range() an extenal function to use it for GC for a range.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use BLKS_PER_SEG, BLKS_PER_SEC, and SEGS_PER_SEC

No functional change.

Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: deprecate io_bits

Let's deprecate an unused io_bits feature to save CPU cycles and memory.

Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Add error handling for negative returns from do_garbage_collect

The function do_garbage_collect can return a value less than 0 due
to f2fs_cp_error being true or page allocation failure, as a result
of calling f2fs_get_sum_page. However, f2fs_gc does not account for
such cases, which could potentially lead to an abnormal total_freed
and thus cause subsequent code to behave unexpectedly. Given that
an f2fs_cp_error is irrecoverable, and considering that
do_garbage_collect already retries page allocation errors through
its call to f2fs_get_sum_page->f2fs_get_meta_page_retry, any error
reported by do_garbage_collect should immediately terminate the
current GC.

Signed-off-by: Yongpeng Yang <yangyongpeng1@oppo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Use wait_event_freezable_timeout() for freezable kthread

A freezable kernel thread can enter frozen state during freezing by
either calling try_to_freeze() or using wait_event_freezable() and its
variants. So for the following snippet of code in a kernel thread loop:
wait_event_interruptible_timeout();
try_to_freeze();

We can change it to a simple wait_event_freezable_timeout() and then
eliminate the function calls to try_to_freeze() and freezing().

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_invalidate_internal_cache() for cleanup

Just cleanup, no logic changes.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: delete obsolete FI_FIRST_BLOCK_WRITTEN

Commit 3c6c2bebef79 ("f2fs: avoid punch_hole overhead when releasing
volatile data") introduced FI_FIRST_BLOCK_WRITTEN as below reason:

This patch is to avoid some punch_hole overhead when releasing volatile
data. If volatile data was not written yet, we just can make the first
page as zero.

After commit 7bc155fec5b3 ("f2fs: kill volatile write support"), we
won't support volatile write, but it missed to remove obsolete
FI_FIRST_BLOCK_WRITTEN, delete it in this patch.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to account cp stats correctly

cp_foreground_calls sysfs entry shows total CP call count rather than
foreground CP call count, fix it.

Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to account gc stats correctly

As reported, status debugfs entry shows inconsistent GC stats as below:

GC calls: 6008 (BG: 6161)
- data segments : 3053 (BG: 3053)
- node segments : 2955 (BG: 2955)

Total GC calls is larger than BGGC calls, the reason is:
- f2fs_stat_info.call_count accounts total migrated section count
by f2fs_gc()
- f2fs_stat_info.bg_gc accounts total call times of f2fs_gc() from
background gc_thread

Another issue is gc_foreground_calls sysfs entry shows total GC call
count rather than FGGC call count.

This patch changes as below for fix:
- account GC calls and migrated segment count separately
- support to account migrated section count if it enables large section
mode
- fix to show correct value in gc_foreground_calls sysfs entry

Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs: distinguish between user initiated freeze and kernel initiated freeze

Userspace can freeze a filesystem using the FIFREEZE ioctl or by
suspending the block device; this state persists until userspace thaws
the filesystem with the FITHAW ioctl or resuming the block device.
Since commit 18e9e5104fcd ("Introduce freeze_super and thaw_super for
the fsfreeze ioctl") we only allow the first freeze command to succeed.

The kernel may decide that it is necessary to freeze a filesystem for
its own internal purposes, such as suspends in progress, filesystem fsck
activities, or quiescing a device prior to removal. Userspace thaw
commands must never break a kernel freeze, and kernel thaw commands
shouldn't undo userspace's freeze command.

Introduce a couple of freeze holder flags and wire it into the
sb_writers state. One kernel and one userspace freeze are allowed to
coexist at the same time; the filesystem will not thaw until both are
lifted.

I wonder if the f2fs/gfs2 code should be using a kernel freeze here, but
for now we'll use FREEZE_HOLDER_USERSPACE to preserve existing
behaviors.

Cc: mcgrof@kernel.org
Cc: jack@suse.cz
Cc: hch@infradead.org
Cc: ruansy.fnst@fujitsu.com
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>

f2fs: check return value of freeze_super()

freeze_super() can fail, it needs to check its return value and do
error handling in f2fs_resize_fs().

Fixes: 04f0b2eaa3b3 ("f2fs: ioctl for removing a range from F2FS")
Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid NULL pointer dereference f2fs_write_end_io()

butt3rflyh4ck reports a bug as below:

When a thread always calls F2FS_IOC_RESIZE_FS to resize fs, if resize fs is
failed, f2fs kernel thread would invoke callback function to update f2fs io
info, it would call f2fs_write_end_io and may trigger null-ptr-deref in
NODE_MAPPING.

general protection fault, probably for non-canonical address
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
RIP: 0010:NODE_MAPPING fs/f2fs/f2fs.h:1972 [inline]
RIP: 0010:f2fs_write_end_io+0x727/0x1050 fs/f2fs/data.c:370
<TASK>
bio_endio+0x5af/0x6c0 block/bio.c:1608
req_bio_endio block/blk-mq.c:761 [inline]
blk_update_request+0x5cc/0x1690 block/blk-mq.c:906
blk_mq_end_request+0x59/0x4c0 block/blk-mq.c:1023
lo_complete_rq+0x1c6/0x280 drivers/block/loop.c:370
blk_complete_reqs+0xad/0xe0 block/blk-mq.c:1101
__do_softirq+0x1d4/0x8ef kernel/softirq.c:571
run_ksoftirqd kernel/softirq.c:939 [inline]
run_ksoftirqd+0x31/0x60 kernel/softirq.c:931
smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164
kthread+0x33e/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The root cause is below race case can cause leaving dirty metadata
in f2fs after filesystem is remount as ro:

Thread A Thread B
- f2fs_ioc_resize_fs
- f2fs_readonly --- return false
- f2fs_resize_fs
- f2fs_remount
- write_checkpoint
- set f2fs as ro
- free_segment_range
- update meta_inode's data

Then, if f2fs_put_super() fails to write_checkpoint due to readonly
status, and meta_inode's dirty data will be writebacked after node_inode
is put, finally, f2fs_write_end_io will access NULL pointer on
sbi->node_inode.

Thread A IRQ context
- f2fs_put_super
- write_checkpoint fails
- iput(node_inode)
- node_inode = NULL
- iput(meta_inode)
- write_inode_now
- f2fs_write_meta_page
- f2fs_write_end_io
- NODE_MAPPING(sbi)
: access NULL pointer on node_inode

Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress")
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Closes: https://lore.kernel.org/r/1684480657-2375-1-git-send-email-yangtiezhu@loongson.cn
Tested-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix over-estimating free section during FG GC

There was a bug that finishing FG GC unconditionally because free sections
are over-estimated after checkpoint in FG GC.
This patch initializes sec_freed by every checkpoint in FG GC.

Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support errors=remount-ro|continue|panic mountoption

This patch supports errors=remount-ro|continue|panic mount option
for f2fs.

f2fs behaves as below in three different modes:
mode continue remount-ro panic
access ops normal noraml N/A
syscall errors -EIO -EROFS N/A
mount option rw ro N/A
pending dir write keep keep N/A
pending non-dir write drop keep N/A
pending node write drop keep N/A
pending meta write keep keep N/A

By default it uses "continue" mode.

[Yangtao helps to clean up function's name]
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove power-of-two limitation of zoned device

In f2fs, there's no reason to force po2.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add has_enough_free_secs()

Replace !has_not_enough_free_secs w/ has_enough_free_secs.
BTW avoid nested 'if' statements in f2fs_balance_fs().

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: refactor f2fs_gc to call checkpoint in urgent condition

The major change is to call checkpoint, if there's not enough space while having
some prefree segments in FG_GC case.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to keep consistent i_gc_rwsem lock order

i_gc_rwsem[WRITE] and i_gc_rwsem[READ] lock order is reversed
in gc_data_segment() and f2fs_dio_write_iter(), fix to keep
consistent lock order as below:
1. lock i_gc_rwsem[WRITE]
2. lock i_gc_rwsem[READ]

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix system crash due to lack of free space in LFS

When f2fs tries to checkpoint during foreground gc in LFS mode, system
crash occurs due to lack of free space if the amount of dirty node and
dentry pages generated by data migration exceeds free space.
The reproduction sequence is as follows.

- 20GiB capacity block device (null_blk)
- format and mount with LFS mode
- create a file and write 20,000MiB
- 4k random write on full range of the file

RIP: 0010:new_curseg+0x48a/0x510 [f2fs]
Code: 55 e7 f5 89 c0 48 0f af c3 48 8b 5d c0 48 c1 e8 20 83 c0 01 89 43 6c 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc <0f> 0b f0 41 80 4f 48 04 45 85 f6 0f 84 ba fd ff ff e9 ef fe ff ff
RSP: 0018:ffff977bc397b218 EFLAGS: 00010246
RAX: 00000000000027b9 RBX: 0000000000000000 RCX: 00000000000027c0
RDX: 0000000000000000 RSI: 00000000000027b9 RDI: ffff8c25ab4e74f8
RBP: ffff977bc397b268 R08: 00000000000027b9 R09: ffff8c29e4a34b40
R10: 0000000000000001 R11: ffff977bc397b0d8 R12: 0000000000000000
R13: ffff8c25b4dd81a0 R14: 0000000000000000 R15: ffff8c2f667f9000
FS: 0000000000000000(0000) GS:ffff8c344ec80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00055d000 CR3: 0000000e30810003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
allocate_segment_by_default+0x9c/0x110 [f2fs]
f2fs_allocate_data_block+0x243/0xa30 [f2fs]
? __mod_lruvec_page_state+0xa0/0x150
do_write_page+0x80/0x160 [f2fs]
f2fs_do_write_node_page+0x32/0x50 [f2fs]
__write_node_page+0x339/0x730 [f2fs]
f2fs_sync_node_pages+0x5a6/0x780 [f2fs]
block_operations+0x257/0x340 [f2fs]
f2fs_write_checkpoint+0x102/0x1050 [f2fs]
f2fs_gc+0x27c/0x630 [f2fs]
? folio_mark_dirty+0x36/0x70
f2fs_balance_fs+0x16f/0x180 [f2fs]

This patch adds checking whether free sections are enough before checkpoint
during gc.

Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
[Jaegeuk Kim: code clean-up]
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove struct victim_selection default_v_ops

There is only single instance of these ops, and Jaegeuk point out that:

Originally this was intended to give a chance to provide other
allocation option. Anyway, it seems quit hard to do it anymore.

So remove the indirection and call f2fs_get_victim() directly.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: factor out victim_entry usage from general rb_tree use

Let's reduce the complexity of mixed use of rb_tree in victim_entry from
extent_cache and discard_cmd.

This should fix arm32 memory alignment issue caused by shared rb_entry.

[struct victim_entry] [struct rb_entry]
[0] struct rb_node rb_node; [0] struct rb_node rb_node;
union {
struct {
unsigned int ofs;
unsigned int len;
};
[16] unsigned long long mtime; [12] unsigned long long key;
} __packed;

Cc: <stable@vger.kernel.org>
Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix uninitialized skipped_gc_rwsem

When f2fs skipped a gc round during victim migration, there was a bug which
would skip all upcoming gc rounds unconditionally because skipped_gc_rwsem
was not initialized. It fixes the bug by correctly initializing the
skipped_gc_rwsem inside the gc loop.

Fixes: 6f8d4455060d ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc")
Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: reduce stack memory cost by using bitfield in struct f2fs_io_info

This patch tries to use bitfield in struct f2fs_io_info to improve
memory usage.

struct f2fs_io_info {
...
unsigned int need_lock:8; /* indicate we need to lock cp_rwsem */
unsigned int version:8; /* version of the node */
unsigned int submitted:1; /* indicate IO submission */
unsigned int in_list:1; /* indicate fio is in io_list */
unsigned int is_por:1; /* indicate IO is from recovery or not */
unsigned int retry:1; /* need to reallocate block address */
unsigned int encrypted:1; /* indicate file is encrypted */
unsigned int post_read:1; /* require post read */
...
};

After this patch, size of struct f2fs_io_info reduces from 136 to 120.

[Nathan: fix a compile warning (single-bit-bitfield-constant-conversion)]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: convert discard_wake and gc_wake to bool type

discard_wake and gc_wake have only two values, 0 or 1.
So there is no need to use int type to store them.

BTW, move discard_wake to the end of the
discard_cmd_control structure.

Before:

- sizeof(struct discard_cmd_control): 8392

After move:

- sizeof(struct discard_cmd_control): 8384

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: merge f2fs_show_injection_info() into time_to_inject()

There is no need to additionally use f2fs_show_injection_info()
to output information. Concatenate time_to_inject() and
__time_to_inject() via a macro. In the new __time_to_inject()
function, pass in the caller function name and parent function.

In this way, we no longer need the f2fs_show_injection_info() function,
and let's remove it.

Suggested-by: Chao Yu <chao@kernel.org>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid to check PG_error flag

After below changes:
commit 14db0b3c7b83 ("fscrypt: stop using PG_error to track error status")
commit 98dc08bae678 ("fsverity: stop using PG_error to track error status")

There is no place in f2fs we will set PG_error flag in page, let's remove
other PG_error usage in f2fs, as a step towards freeing the PG_error flag
for other uses.

Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add a f2fs_lookup_extent_cache_block helper

All but three callers of f2fs_lookup_extent_cache just want the block
address. Add a small helper to simplify them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: reset wait_ms to default if any of the victims have been selected

In non-foreground gc mode, if no victim is selected, the gc process
will wait for no_gc_sleep_time before waking up again. In this
subsequent time, even though a victim will be selected, the gc process
still waits for no_gc_sleep_time before waking up. The configuration
of wait_ms is not reasonable.

After any of the victims have been selected, we need to reset wait_ms to
default sleep time from no_gc_sleep_time.

Signed-off-by: Yuwei Guan <Yuwei.Guan@zeekrlife.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: refactor extent_cache to support for read and more

This patch prepares extent_cache to be ready for addition.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do some cleanup for f2fs module init

Just for cleanup, no functional changes.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid victim selection from previous victim section

When f2fs chooses GC victim in large section & LFS mode,
next_victim_seg[gc_type] is referenced first. After segment is freed,
next_victim_seg[gc_type] has the next segment number.
However, next_victim_seg[gc_type] still has the last segment number
even after the last segment of section is freed. In this case, when f2fs
chooses a victim for the next GC round, the last segment of previous victim
section is chosen as a victim.

Initialize next_victim_seg[gc_type] to NULL_SEGNO for the last segment in
large section.

Fixes: e3080b0120a1 ("f2fs: support subsectional garbage collection")
Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check on i_extra_isize in is_alive()

syzbot found a f2fs bug:

BUG: KASAN: slab-out-of-bounds in data_blkaddr fs/f2fs/f2fs.h:2891 [inline]
BUG: KASAN: slab-out-of-bounds in is_alive fs/f2fs/gc.c:1117 [inline]
BUG: KASAN: slab-out-of-bounds in gc_data_segment fs/f2fs/gc.c:1520 [inline]
BUG: KASAN: slab-out-of-bounds in do_garbage_collect+0x386a/0x3df0 fs/f2fs/gc.c:1734
Read of size 4 at addr ffff888076557568 by task kworker/u4:3/52

CPU: 1 PID: 52 Comm: kworker/u4:3 Not tainted 6.1.0-rc4-syzkaller-00362-gfef7fd48922d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:284 [inline]
print_report+0x15e/0x45d mm/kasan/report.c:395
kasan_report+0xbb/0x1f0 mm/kasan/report.c:495
data_blkaddr fs/f2fs/f2fs.h:2891 [inline]
is_alive fs/f2fs/gc.c:1117 [inline]
gc_data_segment fs/f2fs/gc.c:1520 [inline]
do_garbage_collect+0x386a/0x3df0 fs/f2fs/gc.c:1734
f2fs_gc+0x88c/0x20a0 fs/f2fs/gc.c:1831
f2fs_balance_fs+0x544/0x6b0 fs/f2fs/segment.c:410
f2fs_write_inode+0x57e/0xe20 fs/f2fs/inode.c:753
write_inode fs/fs-writeback.c:1440 [inline]
__writeback_single_inode+0xcfc/0x1440 fs/fs-writeback.c:1652
writeback_sb_inodes+0x54d/0xf90 fs/fs-writeback.c:1870
wb_writeback+0x2c5/0xd70 fs/fs-writeback.c:2044
wb_do_writeback fs/fs-writeback.c:2187 [inline]
wb_workfn+0x2dc/0x12f0 fs/fs-writeback.c:2227
process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The root cause is that we forgot to do sanity check on .i_extra_isize
in below path, result in accessing invalid address later, fix it.
- gc_data_segment
- is_alive
- data_blkaddr
- offset_in_addr

Reported-by: syzbot+f8f3dfa4abc489e768a1@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-f2fs-devel/0000000000003cb3c405ed5c17f9@google.com/T/#u
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: optimize iteration over sparse directories

Wei Chen reports a kernel bug as blew:

INFO: task syz-executor.0:29056 blocked for more than 143 seconds.
Not tainted 5.15.0-rc5 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:14632 pid:29056 ppid: 6574 flags:0x00000004
Call Trace:
__schedule+0x4a1/0x1720
schedule+0x36/0xe0
rwsem_down_write_slowpath+0x322/0x7a0
fscrypt_ioctl_set_policy+0x11f/0x2a0
__f2fs_ioctl+0x1a9f/0x5780
f2fs_ioctl+0x89/0x3a0
__x64_sys_ioctl+0xe8/0x140
do_syscall_64+0x34/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae

Eric did some investigation on this issue, quoted from reply of Eric:

"Well, the quality of this bug report has a lot to be desired (not on
upstream kernel, reproducer is full of totally irrelevant stuff, not
sent to the mailing list of the filesystem whose disk image is being
fuzzed, etc.). But what is going on is that f2fs_empty_dir() doesn't
consider the case of a directory with an extremely large i_size on a
malicious disk image.

Specifically, the reproducer mounts an f2fs image with a directory
that has an i_size of 14814520042850357248, then calls
FS_IOC_SET_ENCRYPTION_POLICY on it.

That results in a call to f2fs_empty_dir() to check whether the
directory is empty. f2fs_empty_dir() then iterates through all
3616826182336513 blocks the directory allegedly contains to check
whether any contain anything. i_rwsem is held during this, so
anything else that tries to take it will hang."

In order to solve this issue, let's use f2fs_get_next_page_offset()
to speed up iteration by skipping holes for all below functions:
- f2fs_empty_dir
- f2fs_readdir
- find_in_level

The way why we can speed up iteration was described in
'commit 3cf4574705b4 ("f2fs: introduce get_next_page_offset to speed
up SEEK_DATA")'.

Meanwhile, in f2fs_empty_dir(), let's use f2fs_find_data_page()
instead f2fs_get_lock_data_page(), due to i_rwsem was held in
caller of f2fs_empty_dir(), there shouldn't be any races, so it's
fine to not lock dentry page during lookuping dirents in the page.

Link: https://lore.kernel.org/lkml/536944df-a0ae-1dd8-148f-510b476e1347@kernel.org/T/
Reported-by: Wei Chen <harperchen1110@gmail.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: replace gc_urgent_high_remaining with gc_remaining_trials

The user can set the trial count limit for GC urgent and
idle mode with replaced gc_remaining_trials.. If GC thread gets
to the limit, the mode will turn back to GC normal mode finally.

It was applied only to GC_URGENT, while this patch expands it for
GC_IDLE.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix return val in f2fs_start_ckpt_thread()

Return PTR_ERR(cprc->f2fs_issue_ckpt) instead of -ENOMEM;

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix gc mode when gc_urgent_high_remaining is 1

Under the current logic, when gc_urgent_high_remaining is set to 1,
the mode will be switched to normal at the beginning, instead of
running in gc_urgent mode.

Let's switch the gc mode back to normal when the gc ends.

Fixes: 265576181b4a ("f2fs: remove gc_urgent_high_limited for cleanup")
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix the race condition of resize flag between resizefs

Because the set/clear SBI_IS_RESIZEFS flag not between any locks,
In the following case:
thread1 thread2
->ioctl(resizefs)
->set RESIZEFS flag ->ioctl(resizefs)
... ->set RESIZEFS flag
->clear RESIZEFS flag
->resizefs stream
# No RESIZEFS flag in the stream

Also before freeze_super, the resizefs not started, we should not set
the SBI_IS_RESIZEFS flag.

So move the set/clear SBI_IS_RESIZEFS flag between the cp_mutex and
gc_lock.

Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: should put a page when checking the summary info

The commit introduces another bug.

Cc: stable@vger.kernel.org
Fixes: c6ad7fd16657e ("f2fs: fix to do sanity check on summary info")
Signed-off-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

treewide: use prandom_u32_max() when possible, part 1

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}

@drop_var@
type T;
identifier VAR;
@@

{
- T VAR;
... when != VAR
}

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

f2fs: support recording errors into superblock

This patch supports to record detail reason of FSCORRUPTED error into
f2fs_super_block.s_errors[].

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support recording stop_checkpoint reason into super_block

This patch supports to record stop_checkpoint error into
f2fs_super_block.s_stop_reason[].

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check on summary info

As Wenqing Liu reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=216456

BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs]
Read of size 4 at addr ffff8881464dcd80 by task mount/1013

CPU: 3 PID: 1013 Comm: mount Tainted: G W 6.0.0-rc4 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
dump_stack_lvl+0x45/0x5e
print_report.cold+0xf3/0x68d
kasan_report+0xa8/0x130
recover_data+0x63ae/0x6ae0 [f2fs]
f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs]
f2fs_fill_super+0x4665/0x61e0 [f2fs]
mount_bdev+0x2cf/0x3b0
legacy_get_tree+0xed/0x1d0
vfs_get_tree+0x81/0x2b0
path_mount+0x47e/0x19d0
do_mount+0xce/0xf0
__x64_sys_mount+0x12c/0x1a0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The root cause is: in fuzzed image, SSA table is corrupted: ofs_in_node
is larger than ADDRS_PER_PAGE(), result in out-of-range access on 4k-size
page.

- recover_data
- do_recover_data
- check_index_in_prev_nodes
- f2fs_data_blkaddr

This patch adds sanity check on summary info in recovery and GC flow
in where the flows rely on them.

After patch:
[ 29.310883] F2FS-fs (loop0): Inconsistent ofs_in_node:65286 in summary, ino:0, nid:6, max:1018

Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove gc_urgent_high_limited for cleanup

Remove redundant sbi->gc_urgent_high_limited.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: iostat: support accounting compressed IO

Previously, we supported to account FS_CDATA_READ_IO type IO only,
in this patch, it adds to account more type IO for compressed file:
- APP_BUFFERED_CDATA_IO
- APP_MAPPED_CDATA_IO
- FS_CDATA_IO
- APP_BUFFERED_CDATA_READ_IO
- APP_MAPPED_CDATA_READ_IO

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix wrong continue condition in GC

We should decrease the frozen counter.

Cc: stable@vger.kernel.org
Fixes: 325163e9892b ("f2fs: add gc_urgent_high_remaining sysfs node")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't bother wait_ms by foreground gc

f2fs_gc returns -EINVAL via f2fs_balance_fs when there is enough free
secs after write checkpoint, but with gc_merge enabled, it will cause
the sleep time of gc thread to be set to no_gc_sleep_time even if there
are many dirty segments can be selected.

Signed-off-by: qixiaoyu1 <qixiaoyu1@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: adjust zone capacity when considering valid block count

This patch fixes counting unusable blocks set by zone capacity when
checking the valid block count in a section.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not stop GC when requiring a free section

The f2fs_gc uses a bitmap to indicate pinned sections, but when disabling
chckpoint, we call f2fs_gc() with NULL_SEGNO which selects the same dirty
segment as a victim all the time, resulting in checkpoint=disable failure,
for example. Let's pick another one, if we fail to collect it.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: keep wait_ms if EAGAIN happens

In f2fs_gc thread, let's keep wait_ms when sec_freed was zero.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_gc_control to consolidate f2fs_gc parameters

No functional change.

- remove checkpoint=disable check for f2fs_write_checkpoint
- get sec_freed all the time

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change the current atomic write way

Current atomic write has three major issues like below.
- keeps the updates in non-reclaimable memory space and they are even
hard to be migrated, which is not good for contiguous memory
allocation.
- disk spaces used for atomic files cannot be garbage collected, so
this makes it difficult for the filesystem to be defragmented.
- If atomic write operations hit the threshold of either memory usage
or garbage collection failure count, All the atomic write operations
will fail immediately.

To resolve the issues, I will keep a COW inode internally for all the
updates to be flushed from memory, when we need to flush them out in a
situation like high memory pressure. These COW inodes will be tagged
as orphan inodes to be reclaimed in case of sudden power-cut or system
failure during atomic writes.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: give priority to select unpinned section for foreground GC

Previously, during foreground GC, if victims contain data of pinned file,
it will fail migration of the data, and meanwhile i_gc_failures of that
pinned file may increase, and when it exceeds threshold, GC will unpin
the file, result in breaking pinfile's semantics.

In order to mitigate such condition, let's record and skip section which
has pinned file's data and give priority to select unpinned one.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: write checkpoint during FG_GC

If there's not enough free sections each of which consistis of large segments,
we can hit no free section for upcoming section allocation. Let's reclaim some
prefree segments by writing checkpoints.

Signed-off-by: Byungki Lee <dominicus79@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't set GC_FAILURE_PIN for background GC

So that it can reduce the possibility that file be unpinned forcely by
foreground GC due to .i_gc_failures[GC_FAILURE_PIN] exceeds threshold.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check pinfile in gc_data_segment() in advance

In order to skip migrating section which contains data of pinned
file in advance.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce gc_urgent_mid mode

We need a mid level of gc urgent mode to do GC forcibly in a period
of given gc_urgent_sleep_time, but not like using greedy GC approach
and switching to SSR mode such as gc urgent high mode. This can be
used for more aggressive periodic storage clean up.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to unlock page correctly in error path of is_alive()

As Pavel Machek reported in below link [1]:

After commit 77900c45ee5c ("f2fs: fix to do sanity check in is_alive()"),
node page should be unlock via calling f2fs_put_page() in the error path
of is_alive(), otherwise, f2fs may hang when it tries to lock the node
page, fix it.

[1] https://lore.kernel.org/stable/20220124203637.GA19321@duo.ucw.cz/

Fixes: 77900c45ee5c ("f2fs: fix to do sanity check in is_alive()")
Cc: <stable@vger.kernel.org>
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: move f2fs to use reader-unfair rwsems

f2fs rw_semaphores work better if writers can starve readers,
especially for the checkpoint thread, because writers are strictly
more important than reader threads. This prevents significant priority
inversion between low-priority readers that blocked while trying to
acquire the read lock and a second acquisition of the write lock that
might be blocking high priority work.

Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not bother checkpoint by f2fs_get_node_info

This patch tries to mitigate lock contention between f2fs_write_checkpoint and
f2fs_get_node_info along with nat_tree_lock.

The idea is, if checkpoint is currently running, other threads that try to grab
nat_tree_lock would be better to wait for checkpoint.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add gc_urgent_high_remaining sysfs node

Added a new sysfs node called gc_urgent_high_remaining. The user can
set the trial count limit for GC urgent high mode with this value. If
GC thread gets to the limit, the mode will turn back to GC normal mode.
By default, the value is zero, which means there is no limit like before.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check in is_alive()

In fuzzed image, SSA table may indicate that a data block belongs to
invalid node, which node ID is out-of-range (0, 1, 2 or max_nid), in
order to avoid migrating inconsistent data in such corrupted image,
let's do sanity check anyway before data block migration.

Cc: stable@vger.kernel.org
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid panic in is_alive() if metadata is inconsistent

As report by Wenqing Liu in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215231

If we enable CONFIG_F2FS_CHECK_FS config, and with fuzzed image attached
in above link, we will encounter panic when executing below script:

1. mkdir mnt
2. mount -t f2fs tmp1.img mnt
3. touch tmp

F2FS-fs (loop11): mismatched blkaddr 5765 (source_blkaddr 1) in seg 3
kernel BUG at fs/f2fs/gc.c:1042!
do_garbage_collect+0x90f/0xa80 [f2fs]
f2fs_gc+0x294/0x12a0 [f2fs]
f2fs_balance_fs+0x2c5/0x7d0 [f2fs]
f2fs_create+0x239/0xd90 [f2fs]
lookup_open+0x45e/0xa90
open_last_lookups+0x203/0x670
path_openat+0xae/0x490
do_filp_open+0xbc/0x160
do_sys_openat2+0x2f1/0x500
do_sys_open+0x5e/0xa0
__x64_sys_openat+0x28/0x40

Previously, f2fs tries to catch data inconcistency exception in between
SSA and SIT table during GC, however once the exception is caught, it will
call f2fs_bug_on to hang kernel, it's not needed, instead, let's set
SBI_NEED_FSCK flag and skip migrating current block.

Fixes: bbf9f7d90f21 ("f2fs: Fix indefinite loop in f2fs_gc()")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check on inode type during garbage collection

As report by Wenqing Liu in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215231

- Overview
kernel NULL pointer dereference triggered in folio_mark_dirty() when mount and operate on a crafted f2fs image

- Reproduce
tested on kernel 5.16-rc3, 5.15.X under root

1. mkdir mnt
2. mount -t f2fs tmp1.img mnt
3. touch tmp
4. cp tmp mnt

F2FS-fs (loop0): sanity_check_inode: inode (ino=49) extent info [5942, 4294180864, 4] is incorrect, run fsck to fix
F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=31340049, run fsck to fix.
BUG: kernel NULL pointer dereference, address: 0000000000000000
folio_mark_dirty+0x33/0x50
move_data_page+0x2dd/0x460 [f2fs]
do_garbage_collect+0xc18/0x16a0 [f2fs]
f2fs_gc+0x1d3/0xd90 [f2fs]
f2fs_balance_fs+0x13a/0x570 [f2fs]
f2fs_create+0x285/0x840 [f2fs]
path_openat+0xe6d/0x1040
do_filp_open+0xc5/0x140
do_sys_openat2+0x23a/0x310
do_sys_open+0x57/0x80

The root cause is for special file: e.g. character, block, fifo or socket file,
f2fs doesn't assign address space operations pointer array for mapping->a_ops field,
so, in a fuzzed image, SSA table indicates a data block belong to special file, when
f2fs tries to migrate that block, it causes NULL pointer access once move_data_page()
calls a_ops->set_dirty_page().

Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

mm: introduce memalloc_retry_wait()

Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying. Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:

- a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
- a need to check for the process being signalled between failures
- the possibility that other recovery actions could be performed
- the allocation is quite deep in support code, and passing down an
extra flag to say if __GFP_NOFAIL is wanted would be clumsy.

Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.

It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.

This patch introduces memalloc_retry_wait() with takes on that
responsibility. Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used. It will wait
however is appropriate.

For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests. If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing. So there is no need for much
further waiting. memalloc_retry_wait() will wait until the current
jiffie ends. If this condition is not met, then alloc_page() won't have
waited much if at all. In that case memalloc_retry_wait() waits about
200ms. This is the delay that most current loops uses.

linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.

Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

f2fs: introduce fragment allocation mode mount option

Added two options into "mode=" mount option to make it possible for
developers to simulate filesystem fragmentation/after-GC situation
itself. The developers use these modes to understand filesystem
fragmentation/after-GC condition well, and eventually get some
insights to handle them better.

"fragment:segment": f2fs allocates a new segment in ramdom position.
With this, we can simulate the after-GC condition.
"fragment:block" : We can scatter block allocation with
"max_fragment_chunk" and "max_fragment_hole" sysfs
nodes. f2fs will allocate 1..<max_fragment_chunk>
blocks in a chunk and make a hole in the length of
1..<max_fragment_hole> by turns in a newly allocated
free segment. Plus, this mode implicitly enables
"fragment:segment" option for more randomness.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to account missing .skipped_gc_rwsem

There is a missing place we forgot to account .skipped_gc_rwsem, fix it.

Fixes: 6f8d4455060d ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: separate out iostat feature

Added F2FS_IOSTAT config option to support getting IO statistics through
sysfs and printing out periodic IO statistics tracepoint events and
moved I/O statistics related codes into separate files for better
maintenance.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Jaegeuk Kim: set default=y]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support fault injection for f2fs_kmem_cache_alloc()

This patch supports to inject fault into f2fs_kmem_cache_alloc().

Usage:
a) echo 32768 > /sys/fs/f2fs/<dev>/inject_type or
b) mount -o fault_type=32768 <dev> <mountpoint>

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Revert "f2fs: Fix indefinite loop in f2fs_gc() v1"

This reverts commit 957fa47823dfe449c5a15a944e4e7a299a6601db.

The patch "f2fs: Fix indefinite loop in f2fs_gc()" v1 and v4 are all
merged. Patch v4 is test info for patch v1. Patch v1 doesn't work and
may cause that sbi->cur_victim_sec can't be resetted to NULL_SEGNO,
which makes SSR unable to get segment of sbi->cur_victim_sec.
So it should be reverted.

The mails record:
[1] https://lore.kernel.org/linux-f2fs-devel/7288dcd4-b168-7656-d1af-7e2cafa4f720@huawei.com/T/
[2] https://lore.kernel.org/linux-f2fs-devel/20190809153653.GD93481@jaegeuk-macbookpro.roam.corp.google.com/T/

Signed-off-by: Jia Yang <jiayang5@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add sysfs nodes to get GC info for each GC mode

Added gc_reclaimed_segments and gc_segment_mode sysfs nodes.
1) "gc_reclaimed_segments" shows how many segments have been
reclaimed by GC during a specific GC mode.
2) "gc_segment_mode" is used to control for which gc mode
the "gc_reclaimed_segments" node shows.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove false alarm on iget failure during GC

This patch removes setting SBI_NEED_FSCK when GC gets an error on f2fs_iget,
since f2fs_iget can give ENOMEM and others by race condition.
If we set this critical fsck flag, we'll get EIO during fsync via the below
code path.

In f2fs_inplace_write_data(),

if (is_sbi_flag_set(sbi, SBI_NEED_FSCK) || f2fs_cp_error(sbi)) {
err = -EIO;
goto drop_bio;
}

Fixes: 9557727876674 ("f2fs: drop inplace IO if fs status is abnormal")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: add compress_inode to cache compressed blocks

Support to use address space of inner inode to cache compressed block,
in order to improve cache hit ratio of random read.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: logging neatening

Update the logging uses that have unnecessary newlines as the f2fs_printk
function and so its f2fs_<level> macro callers already adds one.

This allows searching single line logging entries with an easier grep and
also avoids unnecessary blank lines in the logging.

Miscellanea:

o Coalesce formats
o Align to open parenthesis

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: atgc: fix to set default age threshold

Default age threshold value is missed to set, fix it.

Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
Reported-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: restructure f2fs page.private layout

Restruct f2fs page private layout for below reasons:

There are some cases that f2fs wants to set a flag in a page to
indicate a specified status of page:
a) page is in transaction list for atomic write
b) page contains dummy data for aligned write
c) page is migrating for GC
d) page contains inline data for inline inode flush
e) page belongs to merkle tree, and is verified for fsverity
f) page is dirty and has filesystem/inode reference count for writeback
g) page is temporary and has decompress io context reference for compression

There are existed places in page structure we can use to store
f2fs private status/data:
- page.flags: PG_checked, PG_private
- page.private

However it was a mess when we using them, which may cause potential
confliction:
page.private PG_private PG_checked page._refcount (+1 at most)
a) -1 set +1
b) -2 set
c), d), e) set
f) 0 set +1
g) pointer set

The other problem is page.flags has no free slot, if we can avoid set
zero to page.private and set PG_private flag, then we use non-zero value
to indicate PG_private status, so that we may have chance to reclaim
PG_private slot for other usage. [1]

The other concern is f2fs has bad scalability in aspect of indicating
more page status.

So in this patch, let's restructure f2fs' page.private as below to
solve above issues:

Layout A: lowest bit should be 1
| bit0 = 1 | bit1 | bit2 | ... | bit MAX | private data .... |
bit 0 PAGE_PRIVATE_NOT_POINTER
bit 1 PAGE_PRIVATE_ATOMIC_WRITE
bit 2 PAGE_PRIVATE_DUMMY_WRITE
bit 3 PAGE_PRIVATE_ONGOING_MIGRATION
bit 4 PAGE_PRIVATE_INLINE_INODE
bit 5 PAGE_PRIVATE_REF_RESOURCE
bit 6- f2fs private data

Layout B: lowest bit should be 0
page.private is a wrapped pointer.

After the change:
page.private PG_private PG_checked page._refcount (+1 at most)
a) 11 set +1
b) 101 set +1
c) 1001 set +1
d) 10001 set +1
e) set
f) 100001 set +1
g) pointer set +1

[1] https://lore.kernel.org/linux-f2fs-devel/20210422154705.GO3596236@casper.infradead.org/T/#u

Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up build warnings

This patch combined the below three clean-up patches.

- modify open brace '{' following function definitions
- ERROR: spaces required around that ':'
- ERROR: spaces required before the open parenthesis '('
- ERROR: spaces prohibited before that ','
- Made suggested modifications from checkpatch in reference to WARNING:
Missing a blank line after declarations

Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com>
Signed-off-by: Jia Yang <jiayang5@huawei.com>
Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce gc_merge mount option

In this patch, we will add two new mount options: "gc_merge" and
"nogc_merge", when background_gc is on, "gc_merge" option can be
set to let background GC thread to handle foreground GC requests,
it can eliminate the sluggish issue caused by slow foreground GC
operation when GC is triggered from a process with limited I/O
and CPU resources.

Original idea is from Xiang.

Signed-off-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid touching checkpointed data in get_victim()

In CP disabling mode, there are two issues when using LFS or SSR | AT_SSR
mode to select victim:

1. LFS is set to find source section during GC, the victim should have
no checkpointed data, since after GC, section could not be set free for
reuse.

Previously, we only check valid chpt blocks in current segment rather
than section, fix it.

2. SSR | AT_SSR are set to find target segment for writes which can be
fully filled by checkpointed and newly written blocks, we should never
select such segment, otherwise it can cause panic or data corruption
during allocation, potential case is described as below:

a) target segment has 'n' (n < 512) ckpt valid blocks
b) GC migrates 'n' valid blocks to other segment (segment is still
in dirty list)
c) GC migrates '512 - n' blocks to target segment (segment has 'n'
cp_vblocks and '512 - n' vblocks)
d) If GC selects target segment via {AT,}SSR allocator, however there
is no free space in targe segment.

Fixes: 4354994f097d ("f2fs: checkpoint disabling")
Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not use AT_SSR mode in FG_GC & high urgent BG_GC

AT_SSR mode is introduced by age threshold based GC for better
hot/cold data seperation and avoiding free segment cost. However,
LFS write mode is preferred in the scenario of foreground or high
urgent GC, which should be finished ASAP. Let's only use AT_SSR
in background GC and not high urgent GC modes.

Signed-off-by: Weichao Guo <guoweichao@oppo.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix panic during f2fs_resize_fs()

f2fs_resize_fs() hangs in below callstack with testcase:
- mkfs 16GB image & mount image
- dd 8GB fileA
- dd 8GB fileB
- sync
- rm fileA
- sync
- resize filesystem to 8GB

kernel BUG at segment.c:2484!
Call Trace:
allocate_segment_by_default+0x92/0xf0 [f2fs]
f2fs_allocate_data_block+0x44b/0x7e0 [f2fs]
do_write_page+0x5a/0x110 [f2fs]
f2fs_outplace_write_data+0x55/0x100 [f2fs]
f2fs_do_write_data_page+0x392/0x850 [f2fs]
move_data_page+0x233/0x320 [f2fs]
do_garbage_collect+0x14d9/0x1660 [f2fs]
free_segment_range+0x1f7/0x310 [f2fs]
f2fs_resize_fs+0x118/0x330 [f2fs]
__f2fs_ioctl+0x487/0x3680 [f2fs]
__x64_sys_ioctl+0x8e/0xd0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9

The root cause is we forgot to check that whether we have enough space
in resized filesystem to store all valid blocks in before-resizing
filesystem, then allocator will run out-of-space during block migration
in free_segment_range().

Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to allow migrating fully valid segment

F2FS_IOC_FLUSH_DEVICE/F2FS_IOC_RESIZE_FS needs to migrate all blocks of
target segment to other place, no matter the segment has partially or fully
valid blocks.

However, after commit 803e74be04b3 ("f2fs: stop GC when the victim becomes
fully valid"), we may skip migration due to target segment is fully valid,
result in failing the ioctl interface, fix this.

Fixes: 803e74be04b3 ("f2fs: stop GC when the victim becomes fully valid")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: trival cleanup in move_data_block()

Trival cleanups:
- relocate set_summary() before its use
- relocate "allocate block address" to correct place
- remove unneeded f2fs_wait_on_page_writeback()

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change to use rwsem for cp_mutex

Use rwsem to ensure serialization of the callers and to avoid
starvation of high priority tasks, when the system is under
heavy IO workload.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up kvfree

After commit 0b6d4ca04a86 ("f2fs: don't return vmalloc() memory from
f2fs_kmalloc()"), f2fs_k{m,z}alloc() will not return vmalloc()'ed
memory, so clean up to use kfree() instead of kvfree() to free
vmalloc()'ed memory.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support age threshold based garbage collection

There are several issues in current background GC algorithm:
- valid blocks is one of key factors during cost overhead calculation,
so if segment has less valid block, however even its age is young or
it locates hot segment, CB algorithm will still choose the segment as
victim, it's not appropriate.
- GCed data/node will go to existing logs, no matter in-there datas'
update frequency is the same or not, it may mix hot and cold data
again.
- GC alloctor mainly use LFS type segment, it will cost free segment
more quickly.

This patch introduces a new algorithm named age threshold based
garbage collection to solve above issues, there are three steps
mainly:

1. select a source victim:
- set an age threshold, and select candidates beased threshold:
e.g.
0 means youngest, 100 means oldest, if we set age threshold to 80
then select dirty segments which has age in range of [80, 100] as
candiddates;
- set candidate_ratio threshold, and select candidates based the
ratio, so that we can shrink candidates to those oldest segments;
- select target segment with fewest valid blocks in order to
migrate blocks with minimum cost;

2. select a target victim:
- select candidates beased age threshold;
- set candidate_radius threshold, search candidates whose age is
around source victims, searching radius should less than the
radius threshold.
- select target segment with most valid blocks in order to avoid
migrating current target segment.

3. merge valid blocks from source victim into target victim with
SSR alloctor.

Test steps:
- create 160 dirty segments:
* half of them have 128 valid blocks per segment
* left of them have 384 valid blocks per segment
- run background GC

Benefit: GC count and block movement count both decrease obviously:

- Before:
- Valid: 86
- Dirty: 1
- Prefree: 11
- Free: 6001 (6001)

GC calls: 162 (BG: 220)
- data segments : 160 (160)
- node segments : 2 (2)
Try to move 41454 blocks (BG: 41454)
- data blocks : 40960 (40960)
- node blocks : 494 (494)

IPU: 0 blocks
SSR: 0 blocks in 0 segments
LFS: 41364 blocks in 81 segments

- After:

- Valid: 87
- Dirty: 0
- Prefree: 4
- Free: 6008 (6008)

GC calls: 75 (BG: 76)
- data segments : 74 (74)
- node segments : 1 (1)
Try to move 12813 blocks (BG: 12813)
- data blocks : 12544 (12544)
- node blocks : 269 (269)

IPU: 0 blocks
SSR: 12032 blocks in 77 segments
LFS: 855 blocks in 2 segments

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix a bug along with pinfile in-mem segment & clean up]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: inherit mtime of original block during GC

Don't let f2fs inner GC ruins original aging degree of segment.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce inmem curseg

Previous implementation of aligned pinfile allocation will:
- allocate new segment on cold data log no matter whether last used
segment is partially used or not, it makes IOs more random;
- force concurrent cold data/GCed IO going into warm data area, it
can make a bad effect on hot/cold data separation;

In this patch, we introduce a new type of log named 'inmem curseg',
the differents from normal curseg is:
- it reuses existed segment type (CURSEG_XXX_NODE/DATA);
- it only exists in memory, its segno, blkofs, summary will not b
persisted into checkpoint area;

With this new feature, we can enhance scalability of log, special
allocators can be created for purposes:
- pure lfs allocator for aligned pinfile allocation or file
defragmentation
- pure ssr allocator for later feature

So that, let's update aligned pinfile allocation to use this new
inmem curseg fwk.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support zone capacity less than zone size

NVMe Zoned Namespace devices can have zone-capacity less than zone-size.
Zone-capacity indicates the maximum number of sectors that are usable in
a zone beginning from the first sector of the zone. This makes the sectors
sectors after the zone-capacity till zone-size to be unusable.
This patch set tracks zone-size and zone-capacity in zoned devices and
calculate the usable blocks per segment and usable segments per section.

If zone-capacity is less than zone-size mark only those segments which
start before zone-capacity as free segments. All segments at and beyond
zone-capacity are treated as permanently used segments. In cases where
zone-capacity does not align with segment size the last segment will start
before zone-capacity and end beyond the zone-capacity of the zone. For
such spanning segments only sectors within the zone-capacity are used.

During writes and GC manage the usable segments in a section and usable
blocks per segment. Segments which are beyond zone-capacity are never
allocated, and do not need to be garbage collected, only the segments
which are before zone-capacity needs to garbage collected.
For spanning segments based on the number of usable blocks in that
segment, write to blocks only up to zone-capacity.

Zone-capacity is device specific and cannot be configured by the user.
Since NVMe ZNS device zones are sequentially write only, a block device
with conventional zones or any normal block device is needed along with
the ZNS device for the metadata operations of F2fs.

A typical nvme-cli output of a zoned device shows zone start and capacity
and write pointer as below:

SLBA: 0x0 WP: 0x0 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
SLBA: 0x20000 WP: 0x20000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
SLBA: 0x40000 WP: 0x40000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ

Here zone size is 64MB, capacity is 49MB, WP is at zone start as the zones
are in EMPTY state. For each zone, only zone start + 49MB is usable area,
any lba/sector after 49MB cannot be read or written to, the drive will fail
any attempts to read/write. So, the second zone starts at 64MB and is
usable till 113MB (64 + 49) and the range between 113 and 128MB is
again unusable. The next zone starts at 128MB, and so on.

Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add GC_URGENT_LOW mode in gc_urgent

Added a new gc_urgent mode, GC_URGENT_LOW, in which mode
F2FS will lower the bar of checking idle in order to
process outstanding discard commands and GC a little bit
aggressively.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix return value of move_data_block()

If f2fs_grab_cache_page() fails, it needs to return -ENOMEM.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add f2fs_gc exception handle in f2fs_ioc_gc_range

When f2fs_ioc_gc_range performs multiple segments gc ops, the return
value of f2fs_ioc_gc_range is determined by the last segment gc ops.
If its ops failed, the f2fs_ioc_gc_range will be considered to be failed
despite some of previous segments gc ops succeeded. Therefore, so we
fix: Redefine the return value of getting victim ops and add exception
handle for f2fs_gc. In particular, 1).if target has no valid block, it
will go on. 2).if target sectoion has valid block(s), but it is current
section, we will reminder the caller.

Signed-off-by: Qilong Zhang <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up parameter of f2fs_allocate_data_block()

Use validation of @fio to inidcate whether caller want to serialize IOs
in io.io_list or not, then @add_list will be redundant, remove it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add prefix for exported symbols

to avoid polluting global symbol namespace.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: get the right gc victim section when section has several segments

Assume each section has 4 segment:
.___________________________.
|_Segment0_|_..._|_Segment3_|
. .
. .
.__________.
|_section0_|

Segment 0~2 has 0 valid block, segment 3 has 512 valid blocks.
It will fail if we want to gc section0 in this scenes,
because all 4 segments in section0 is not dirty.
So we should use dirty section bitmap instead of dirty segment bitmap
to get right victim section.

Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add compressed/gc data read IO stat

in order to account data read IOs more accurately.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: refactor resize_fs to avoid meta updates in progress

Sahitya raised an issue:
- prevent meta updates while checkpoint is in progress

allocate_segment_for_resize() can cause metapage updates if
it requires to change the current node/data segments for resizing.
Stop these meta updates when there is a checkpoint already
in progress to prevent inconsistent CP data.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support read iostat

Adds to support accounting read IOs from userspace/kernel.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't trigger data flush in foreground operation

Data flush can generate heavy IO and cause long latency during
flush, so it's not appropriate to trigger it in foreground
operation.

And also, we may face below potential deadlock during data flush:
- f2fs_write_multi_pages
- f2fs_write_raw_pages
- f2fs_write_single_data_page
- f2fs_balance_fs
- f2fs_balance_fs_bg
- f2fs_sync_dirty_inodes
- filemap_fdatawrite -- stuck on flush same cluster

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to update f2fs_super_block fields under sb_lock

Fields in struct f2fs_super_block should be updated under coverage
of sb_lock, fix to adjust update_sb_metadata() for that rule.

Fixes: 04f0b2eaa3b3 ("f2fs: ioctl for removing a range from F2FS")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix mount failure due to SPO after a successful online resize FS

Even though online resize is successfully done, a SPO immediately
after resize, still causes below error in the next mount.

[ 11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856
[ 11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint

This is because after FS metadata is updated in update_fs_metadata()
if the SBI_IS_DIRTY is not dirty, then CP will not be done to reflect
the new user_block_count.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: skip migration only when BG_GC is called

FG_GC needs to move entire section more quickly.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce DEFAULT_IO_TIMEOUT

As Geert Uytterhoeven reported:

for parameter HZ/50 in congestion_wait(BLK_RW_ASYNC, HZ/50);

On some platforms, HZ can be less than 50, then unexpected 0 timeout
jiffies will be set in congestion_wait().

This patch introduces a macro DEFAULT_IO_TIMEOUT to wrap a determinate
value with msecs_to_jiffies(20) to instead HZ/50 to avoid such issue.

Quoted from Geert Uytterhoeven:

"A timeout of HZ means 1 second.
HZ/50 means 20 ms, but has the risk of being zero, if HZ < 50.

If you want to use a timeout of 20 ms, you best use msecs_to_jiffies(20),
as that takes care of the special cases, and never returns 0."

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: skip GC when section is full

This fixes skipping GC when segment is full in large section.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add migration count iff migration happens

If first segment is empty and migration_granularity is 1, we can't move this
at all.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up bggc mount option

There are three status for background gc: on, off and sync, it's
a little bit confused to use test_opt(BG_GC) and test_opt(FORCE_FG_GC)
combinations to indicate status of background gc.

So let's remove F2FS_MOUNT_BG_GC and F2FS_MOUNT_FORCE_FG_GC mount
options, and add F2FS_OPTION().bggc_mode with below three status
to clean up codes and enhance bggc mode's scalability.

enum {
BGGC_MODE_ON, /* background gc is on */
BGGC_MODE_OFF, /* background gc is off */
BGGC_MODE_SYNC, /*
* background gc is on, migrating blocks
* like foreground gc
*/
};

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up lfs/adaptive mount option

This patch removes F2FS_MOUNT_ADAPTIVE and F2FS_MOUNT_LFS mount options,
and add F2FS_OPTION.fs_mode with below two status to indicate filesystem
mode.

enum {
FS_MODE_ADAPTIVE, /* use both lfs/ssr allocation */
FS_MODE_LFS, /* use lfs allocation only */
};

It can enhance code readability and fs mode's scalability.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up codes with {f2fs_,}data_blkaddr()

- rename datablock_addr() to data_blkaddr().
- wrap data_blkaddr() with f2fs_data_blkaddr() to clean up
parameters.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix inconsistent comments

Lack of maintenance on comments may mislead developers, fix them.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Add f2fs stats to sysfs

Currently f2fs stats are only available from /d/f2fs/status. This patch
adds some of the f2fs stats to sysfs so that they are accessible even
when debugfs is not mounted.

The following sysfs nodes are added:
-/sys/fs/f2fs/<disk>/free_segments
-/sys/fs/f2fs/<disk>/cp_foreground_calls
-/sys/fs/f2fs/<disk>/cp_background_calls
-/sys/fs/f2fs/<disk>/gc_foreground_calls
-/sys/fs/f2fs/<disk>/gc_background_calls
-/sys/fs/f2fs/<disk>/moved_blocks_foreground
-/sys/fs/f2fs/<disk>/moved_blocks_background
-/sys/fs/f2fs/<disk>/avg_vblocks

Signed-off-by: Hridya Valsaraju <hridya@google.com>
[Jaegeuk Kim: allow STAT_FS without DEBUG_FS]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change to use rwsem for gc_mutex

Mutex lock won't serialize callers, in order to avoid starving of unlucky
caller, let's use rwsem lock instead.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: run fsck when getting bad inode during GC

This is to avoid inifinite GC when trying to disable checkpoint.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: stop GC when the victim becomes fully valid

We must stop GC, once the segment becomes fully valid. Otherwise, it can
produce another dirty segments by moving valid blocks in the segment partially.

Ramon hit no free segment panic sometimes and saw this case happens when
validating reliable file pinning feature.

Signed-off-by: Ramon Pantin <pantin@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: show f2fs instance in printk_ratelimited

As Eric mentioned, bare printk{,_ratelimited} won't show which
filesystem instance these message is coming from, this patch tries
to show fs instance with sb->s_id field in all places we missed
before.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: update multi-dev metadata in resize_fs

Multi-device metadata should be updated in resize_fs as well.

Also, we check that the new FS size still reaches the last device.

Signed-off-by: Qiuyang Sun <sunqiuyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix indefinite loop in f2fs_gc()

Policy - foreground GC, LFS mode and greedy GC mode.

Under this policy, f2fs_gc() loops forever to GC as it doesn't have
enough free segements to proceed and thus it keeps calling gc_more
for the same victim segment. This can happen if the selected victim
segment could not be GC'd due to failed blkaddr validity check i.e.
is_alive() returns false for the blocks set in current validity map.

Fix this by not resetting the sbi->cur_victim_sec to NULL_SEGNO, when
the segment selected could not be GC'd. This helps to select another
segment for GC and thus helps to proceed forward with GC.

[Note]
This can happen due to is_alive as well as atomic_file which skipps
GC.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix indefinite loop in f2fs_gc()

Policy - Foreground GC, LFS and greedy GC mode.

Under this policy, f2fs_gc() loops forever to GC as it doesn't have
enough free segements to proceed and thus it keeps calling gc_more
for the same victim segment. This can happen if the selected victim
segment could not be GC'd due to failed blkaddr validity check i.e.
is_alive() returns false for the blocks set in current validity map.

Fix this by keeping track of such invalid segments and skip those
segments for selection in get_victim_by_default() to avoid endless
GC loop under such error scenarios. Currently, add this logic under
CONFIG_F2FS_CHECK_FS to be able to root cause the issue in debug
version.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix wrong bitmap size]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to read source block before invalidating it

f2fs_allocate_data_block() invalidates old block address and enable new block
address. Then, if we try to read old block by f2fs_submit_page_bio(), it will
give WARN due to reading invalid blocks.

Let's make the order sanely back.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use generic EFSBADCRC/EFSCORRUPTED

f2fs uses EFAULT as error number to indicate filesystem is corrupted
all the time, but generic filesystems use EUCLEAN for such condition,
we need to change to follow others.

This patch adds two new macros as below to wrap more generic error
code macros, and spread them in code.

EFSBADCRC EBADMSG /* Bad CRC detected */
EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_<level> macros to wrap f2fs_printk()

- Add and use f2fs_<level> macros
- Convert f2fs_msg to f2fs_printk
- Remove level from f2fs_printk and embed the level in the format
- Coalesce formats and align multi-line arguments
- Remove unnecessary duplicate extern f2fs_msg f2fs.h

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: ioctl for removing a range from F2FS

This ioctl shrinks a given length (aligned to sections) from end of the
main area. Any cursegs and valid blocks will be moved out before
invalidating the range.

This feature can be used for adjusting partition sizes online.

History of the patch:

Sahitya Tummala:
- Add this ioctl for f2fs_compat_ioctl() as well.
- Fix debugfs status to reflect the online resize changes.
- Fix potential race between online resize path and allocate new data
block path or gc path.

Others:
- Rename some identifiers.
- Add some error handling branches.
- Clear sbi->next_victim_seg[BG_GC/FG_GC] in shrinking range.
- Implement this interface as ext4's, and change the parameter from shrunk
bytes to new block count of F2FS.
- During resizing, force to empty sit_journal and forbid adding new
entries to it, in order to avoid invalid segno in journal after resize.
- Reduce sbi->user_block_count before resize starts.
- Commit the updated superblock first, and then update in-memory metadata
only when the former succeeds.
- Target block count must align to sections.
- Write checkpoint before and after committing the new superblock, w/o
CP_FSCK_FLAG respectively, so that the FS can be fixed by fsck even if
resize fails after the new superblock is committed.
- In free_segment_range(), reduce granularity of gc_mutex.
- Add protection on curseg migration.
- Add freeze_bdev() and thaw_bdev() for resize fs.
- Remove CUR_MAIN_SECS and use MAIN_SECS directly for allocation.
- Recover super_block and FS metadata when resize fails.
- No need to clear CP_FSCK_FLAG in update_ckpt_flags().
- Clean up the sb and fs metadata update functions for resize_fs.

Geert Uytterhoeven:
- Use div_u64*() for 64-bit divisions

Arnd Bergmann:
- Not all architectures support get_user() with a 64-bit argument:
ERROR: "__get_user_bad" [fs/f2fs/f2fs.ko] undefined!
Use copy_from_user() here, this will always work.

Signed-off-by: Qiuyang Sun <sunqiuyang@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: allow ssr block allocation during checkpoint=disable period

This patch allows to use ssr during checkpoint is disabled.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce DATA_GENERIC_ENHANCE

Previously, f2fs_is_valid_blkaddr(, blkaddr, DATA_GENERIC) will check
whether @blkaddr locates in main area or not.

That check is weak, since the block address in range of main area can
point to the address which is not valid in segment info table, and we
can not detect such condition, we may suffer worse corruption as system
continues running.

So this patch introduce DATA_GENERIC_ENHANCE to enhance the sanity check
which trigger SIT bitmap check rather than only range check.

This patch did below changes as wel:
- set SBI_NEED_FSCK in f2fs_is_valid_blkaddr().
- get rid of is_valid_data_blkaddr() to avoid panic if blkaddr is invalid.
- introduce verify_fio_blkaddr() to wrap fio {new,old}_blkaddr validation check.
- spread blkaddr check in:
* f2fs_get_node_info()
* __read_out_blkaddrs()
* f2fs_submit_page_read()
* ra_data_block()
* do_recover_data()

This patch can fix bug reported from bugzilla below:

https://bugzilla.kernel.org/show_bug.cgi?id=203215
https://bugzilla.kernel.org/show_bug.cgi?id=203223
https://bugzilla.kernel.org/show_bug.cgi?id=203231
https://bugzilla.kernel.org/show_bug.cgi?id=203235
https://bugzilla.kernel.org/show_bug.cgi?id=203241

= Update by Jaegeuk Kim =

DATA_GENERIC_ENHANCE enhanced to validate block addresses on read/write paths.
But, xfstest/generic/446 compalins some generated kernel messages saying invalid
bitmap was detected when reading a block. The reaons is, when we get the
block addresses from extent_cache, there is no lock to synchronize it from
truncating the blocks in parallel.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: allow address pointer number of dnode aligning to specified size

This patch expands scalability of dnode layout, it allows address pointer
number of dnode aligning to specified size (now, the size is one byte by
default), and later the number can align to compress cluster size
(1 << n bytes, n=[2,..)), it can avoid cluster acrossing two dnode, making
design of compress meta layout simple.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid deadloop in foreground GC

As Jungyeon reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=203211

- Overview
When mounting the attached crafted image and making a new file, I got this error and the error messages keep repeating.

The image is intentionally fuzzed from a normal f2fs image for testing and I run with option CONFIG_F2FS_CHECK_FS on.

- Reproduces
mkdir test
mount -t f2fs tmp.img test
cd test
touch t

- Messages
[ 58.820451] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.821485] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.822530] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.823571] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.824616] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.825640] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.826663] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.827698] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.828719] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.829759] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.830783] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.831828] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.832869] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.833888] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.834945] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.835996] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.837028] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.838051] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.839072] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.840100] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.841147] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.842186] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.843214] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.844267] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.845282] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.846305] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
[ 58.847341] F2FS-fs (sdb): Inconsistent segment (1) type [1, 0] in SSA and SIT
... (repeating)

During GC, if segment type stored in SSA and SIT is inconsistent, we just
skip migrating current segment directly, since we need to know the exact
type to decide the migration function we use.

So in foreground GC, we will easily run into a infinite loop as we may
select the same victim segment which has inconsistent type due to greedy
policy. In order to end up this, we choose to shutdown filesystem. For
backgrond GC, we need to do that as well, so that we can avoid latter
potential infinite looped foreground GC.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix use of number of devices

For a single device mount using a zoned block device, the zone
information for the device is stored in the sbi->devs single entry
array and sbi->s_ndevs is set to 1. This differs from a single device
mount using a regular block device which does not allocate sbi->devs
and sets sbi->s_ndevs to 0.

However, sbi->s_devs == 0 condition is used throughout the code to
differentiate a single device mount from a multi-device mount where
sbi->s_ndevs is always larger than 1. This results in problems with
single zoned block device volumes as these are treated as multi-device
mounts but do not have the start_blk and end_blk information set. One
of the problem observed is skipping of zone discard issuing resulting in
write commands being issued to full zones or unaligned to a zone write
pointer.

Fix this problem by simply treating the cases sbi->s_ndevs == 0 (single
regular block device mount) and sbi->s_ndevs == 1 (single zoned block
device mount) in the same manner. This is done by introducing the
helper function f2fs_is_multi_device() and using this helper in place
of direct tests of sbi->s_ndevs value, improving code readability.

Fixes: 7bb3a371d199 ("f2fs: Fix zoned block device support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check PageWriteback flag for ordered case

For all ordered cases in f2fs_wait_on_page_writeback(), we need to
check PageWriteback status, so let's clean up to relocate the check
into f2fs_wait_on_page_writeback().

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use kvmalloc, if kmalloc is failed

One report says memalloc failure during mount.

(unwind_backtrace) from [<c010cd4c>] (show_stack+0x10/0x14)
(show_stack) from [<c049c6b8>] (dump_stack+0x8c/0xa0)
(dump_stack) from [<c024fcf0>] (warn_alloc+0xc4/0x160)
(warn_alloc) from [<c0250218>] (__alloc_pages_nodemask+0x3f4/0x10d0)
(__alloc_pages_nodemask) from [<c0270450>] (kmalloc_order_trace+0x2c/0x120)
(kmalloc_order_trace) from [<c03fa748>] (build_node_manager+0x35c/0x688)
(build_node_manager) from [<c03de494>] (f2fs_fill_super+0xf0c/0x16cc)
(f2fs_fill_super) from [<c02a5864>] (mount_bdev+0x15c/0x188)
(mount_bdev) from [<c03da624>] (f2fs_mount+0x18/0x20)
(f2fs_mount) from [<c02a68b8>] (mount_fs+0x158/0x19c)
(mount_fs) from [<c02c3c9c>] (vfs_kern_mount+0x78/0x134)
(vfs_kern_mount) from [<c02c76ac>] (do_mount+0x474/0xca4)
(do_mount) from [<c02c8264>] (SyS_mount+0x94/0xbc)
(SyS_mount) from [<c0108180>] (ret_fast_syscall+0x0/0x48)

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to reorder set_page_dirty and wait_on_page_writeback

This patch reorders flow from

- update page
- set_page_dirty
- wait_on_page_writeback

to

- wait_on_page_writeback
- update page
- set_page_dirty

The reason is:
- set_page_dirty will increase reference of dirty page, the reference
should be cleared before wait_on_page_writeback to keep its consistency.
- some devices need stable page during page writebacking, so we
should not change page's data.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: adjust trace print in f2fs_get_victim() to cover all paths

Adjust the trace print in f2fs_get_victim() to cover GC done by
F2FS_IOC_GARBAGE_COLLECT_RANGE.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to allow node segment for GC by ioctl path

Allow node type segments also to be GC'd via f2fs ioctl
F2FS_IOC_GARBAGE_COLLECT_RANGE.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support subsectional garbage collection

Section is minimal garbage collection unit of f2fs, in zoned block
device, or ancient block mapping flash device, in order to improve
GC efficiency, we can align GC unit to lower device erase unit,
normally, it consists of multiple of segments.

Once background or foreground GC triggers, it brings a large number
of IOs, which will impact user IO, and also occupy cpu/memory resource
intensively.

So, to reduce impact of GC on large size section, this patch supports
subsectional GC, in one cycle of GC, it only migrate partial segment{s}
in victim section. Currently, by default, we use sbi->segs_per_sec as
migration granularity.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce __is_large_section() for cleanup

Introduce a wrapper __is_large_section() to clean up codes.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix count of seg_freed to make sec_freed correct

When sbi->segs_per_sec > 1, and if some segno has 0 valid blocks before
gc starts, do_garbage_collect will skip counting seg_freed++, and this
will cause seg_freed < sbi->segs_per_sec and finally skip sec_freed++.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid GC causing encrypted file corrupted

The encrypted file may be corrupted by GC in following case:

Time 1: | segment 1 blkaddr = A | GC -> | segment 2 blkaddr = B |
Encrypted block 1 is moved from blkaddr A of segment 1 to blkaddr B of
segment 2,

Time 2: | segment 1 blkaddr = B | GC -> | segment 3 blkaddr = C |

Before page 1 is written back and if segment 2 become a victim, then
page 1 is moved from blkaddr B of segment 2 to blkaddr Cof segment 3,
during the GC process of Time 2, f2fs should wait for page 1 written back
before reading it, or move_data_block will read a garbage block from
blkaddr B since page is not written back to blkaddr B yet.

Commit 6aa58d8a ("f2fs: readahead encrypted block during GC") introduce
ra_data_block to read encrypted block, but it forgets to add
f2fs_wait_on_page_writeback to avoid racing between GC and flush.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: submit cached bio to avoid endless PageWriteback

When migrating encrypted block from background GC thread, we only add
them into f2fs inner bio cache, but forget to submit the cached bio, it
may cause potential deadlock when we are waiting page writebacked, fix
it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: checkpoint disabling

Note that, it requires "f2fs: return correct errno in f2fs_gc".

This adds a lightweight non-persistent snapshotting scheme to f2fs.

To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add to account skip count of background GC

This patch adds to account skip count of background GC, and show stat
info via 'status' debugfs entry.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: return correct errno in f2fs_gc

This fixes overriding error number in f2fs_gc.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid f2fs_bug_on if f2fs_get_meta_page_nofail got EIO

This patch avoids BUG_ON when f2fs_get_meta_page_nofail got EIO during
xfstests/generic/475.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add new idle interval timing for discard and gc paths

This helps to control the frequency of submission of discard and
GC requests independently, based on the need.

Suggested-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add SPDX license identifiers

Remove the verbose license text from f2fs files and replace them with
SPDX tags. This does not change the license of any of the code.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: readahead encrypted block during GC

During GC, for each encrypted block, we will read block synchronously
into meta page, and then submit it into current cold data log area.

So this block read model with 4k granularity can make poor performance,
like migrating non-encrypted block, let's readahead encrypted block
as well to improve migration performance.

To implement this, we choose meta page that its index is old block
address of the encrypted block, and readahead ciphertext into this
page, later, if readaheaded page is still updated, we will load its
data into target meta page, and submit the write IO.

Note that for OPU, truncation, deletion, we need to invalid meta
page after we invalid old block address, to make sure we won't load
invalid data from target meta page during encrypted block migration.

for ((i = 0; i < 1000; i++))
do {
xfs_io -f /mnt/f2fs/dir/$i -c "pwrite 0 128k" -c "fsync";
} done

for ((i = 0; i < 1000; i+=2))
do {
rm /mnt/f2fs/dir/$i;
} done

ret = ioctl(fd, F2FS_IOC_GARBAGE_COLLECT, 0);

Before:
gc-6549 [001] d..1 214682.212797: block_rq_insert: 8,32 RA 32768 () 786400 + 64 [gc]
gc-6549 [001] d..1 214682.212802: block_unplug: [gc] 1
gc-6549 [001] .... 214682.213892: block_bio_queue: 8,32 R 67494144 + 8 [gc]
gc-6549 [001] .... 214682.213899: block_getrq: 8,32 R 67494144 + 8 [gc]
gc-6549 [001] .... 214682.213902: block_plug: [gc]
gc-6549 [001] d..1 214682.213905: block_rq_insert: 8,32 R 4096 () 67494144 + 8 [gc]
gc-6549 [001] d..1 214682.213908: block_unplug: [gc] 1
gc-6549 [001] .... 214682.226405: block_bio_queue: 8,32 R 67494152 + 8 [gc]
gc-6549 [001] .... 214682.226412: block_getrq: 8,32 R 67494152 + 8 [gc]
gc-6549 [001] .... 214682.226414: block_plug: [gc]
gc-6549 [001] d..1 214682.226417: block_rq_insert: 8,32 R 4096 () 67494152 + 8 [gc]
gc-6549 [001] d..1 214682.226420: block_unplug: [gc] 1
gc-6549 [001] .... 214682.226904: block_bio_queue: 8,32 R 67494160 + 8 [gc]
gc-6549 [001] .... 214682.226910: block_getrq: 8,32 R 67494160 + 8 [gc]
gc-6549 [001] .... 214682.226911: block_plug: [gc]
gc-6549 [001] d..1 214682.226914: block_rq_insert: 8,32 R 4096 () 67494160 + 8 [gc]
gc-6549 [001] d..1 214682.226916: block_unplug: [gc] 1

After:
gc-5678 [003] .... 214327.025906: block_bio_queue: 8,32 R 67493824 + 8 [gc]
gc-5678 [003] .... 214327.025908: block_bio_backmerge: 8,32 R 67493824 + 8 [gc]
gc-5678 [003] .... 214327.025915: block_bio_queue: 8,32 R 67493832 + 8 [gc]
gc-5678 [003] .... 214327.025917: block_bio_backmerge: 8,32 R 67493832 + 8 [gc]
gc-5678 [003] .... 214327.025923: block_bio_queue: 8,32 R 67493840 + 8 [gc]
gc-5678 [003] .... 214327.025925: block_bio_backmerge: 8,32 R 67493840 + 8 [gc]
gc-5678 [003] .... 214327.025932: block_bio_queue: 8,32 R 67493848 + 8 [gc]
gc-5678 [003] .... 214327.025934: block_bio_backmerge: 8,32 R 67493848 + 8 [gc]
gc-5678 [003] .... 214327.025941: block_bio_queue: 8,32 R 67493856 + 8 [gc]
gc-5678 [003] .... 214327.025943: block_bio_backmerge: 8,32 R 67493856 + 8 [gc]
gc-5678 [003] .... 214327.025953: block_bio_queue: 8,32 R 67493864 + 8 [gc]
gc-5678 [003] .... 214327.025955: block_bio_backmerge: 8,32 R 67493864 + 8 [gc]
gc-5678 [003] .... 214327.025962: block_bio_queue: 8,32 R 67493872 + 8 [gc]
gc-5678 [003] .... 214327.025964: block_bio_backmerge: 8,32 R 67493872 + 8 [gc]
gc-5678 [003] .... 214327.025970: block_bio_queue: 8,32 R 67493880 + 8 [gc]
gc-5678 [003] .... 214327.025972: block_bio_backmerge: 8,32 R 67493880 + 8 [gc]
gc-5678 [003] .... 214327.026000: block_bio_queue: 8,32 WS 34123776 + 2048 [gc]
gc-5678 [003] .... 214327.026019: block_getrq: 8,32 WS 34123776 + 2048 [gc]
gc-5678 [003] d..1 214327.026021: block_rq_insert: 8,32 R 131072 () 67493632 + 256 [gc]
gc-5678 [003] d..1 214327.026023: block_unplug: [gc] 1
gc-5678 [003] d..1 214327.026026: block_rq_issue: 8,32 R 131072 () 67493632 + 256 [gc]
gc-5678 [003] .... 214327.026046: block_plug: [gc]

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc

The f2fs_gc() called by f2fs_balance_fs() requires to be called outside of
fi->i_gc_rwsem[WRITE], since f2fs_gc() can try to grab it in a loop.

If it hits the miximum retrials in GC, let's give a chance to release
gc_mutex for a short time in order not to go into live lock in the worst
case.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: rework fault injection handling to avoid a warning

When CONFIG_F2FS_FAULT_INJECTION is disabled, we get a warning about an
unused label:

fs/f2fs/segment.c: In function '__submit_discard_cmd':
fs/f2fs/segment.c:1059:1: error: label 'submit' defined but not used [-Werror=unused-label]

This could be fixed by adding another #ifdef around it, but the more
reliable way of doing this seems to be to remove the other #ifdefs
where that is easily possible.

By defining time_to_inject() as a trivial stub, most of the checks for
CONFIG_F2FS_FAULT_INJECTION can go away. This also leads to nicer
formatting of the code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to propagate error from __get_meta_page()

If caller of __get_meta_page() can handle error, let's propagate error
from __get_meta_page().

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to skip GC if type in SSA and SIT is inconsistent

If segment type in SSA and SIT is inconsistent, we will encounter below
BUG_ON during GC, to avoid this panic, let's just skip doing GC on such
segment.

The bug is triggered with image reported in below link:

https://bugzilla.kernel.org/show_bug.cgi?id=200223

[ 388.060262] ------------[ cut here ]------------
[ 388.060268] kernel BUG at /home/y00370721/git/devf2fs/gc.c:989!
[ 388.061172] invalid opcode: 0000 [#1] SMP
[ 388.061773] Modules linked in: f2fs(O) bluetooth ecdh_generic xt_tcpudp iptable_filter ip_tables x_tables lp ttm drm_kms_helper drm intel_rapl sb_edac crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel fb_sys_fops ppdev aes_x86_64 syscopyarea crypto_simd sysfillrect parport_pc joydev sysimgblt glue_helper parport cryptd i2c_piix4 serio_raw mac_hid btrfs hid_generic usbhid hid raid6_pq psmouse pata_acpi floppy
[ 388.064247] CPU: 7 PID: 4151 Comm: f2fs_gc-7:0 Tainted: G O 4.13.0-rc1+ #26
[ 388.065306] Hardware name: Xen HVM domU, BIOS 4.1.2_115-900.260_ 11/06/2015
[ 388.066058] task: ffff880201583b80 task.stack: ffffc90004d7c000
[ 388.069948] RIP: 0010:do_garbage_collect+0xcc8/0xcd0 [f2fs]
[ 388.070766] RSP: 0018:ffffc90004d7fc68 EFLAGS: 00010202
[ 388.071783] RAX: ffff8801ed227000 RBX: 0000000000000001 RCX: ffffea0007b489c0
[ 388.072700] RDX: ffff880000000000 RSI: 0000000000000001 RDI: ffffea0007b489c0
[ 388.073607] RBP: ffffc90004d7fd58 R08: 0000000000000003 R09: ffffea0007b489dc
[ 388.074619] R10: 0000000000000000 R11: 0052782ab317138d R12: 0000000000000018
[ 388.075625] R13: 0000000000000018 R14: ffff880211ceb000 R15: ffff880211ceb000
[ 388.076687] FS: 0000000000000000(0000) GS:ffff880214fc0000(0000) knlGS:0000000000000000
[ 388.083277] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 388.084536] CR2: 0000000000e18c60 CR3: 00000001ecf2e000 CR4: 00000000001406e0
[ 388.085748] Call Trace:
[ 388.086690] ? find_next_bit+0xb/0x10
[ 388.088091] f2fs_gc+0x1a8/0x9d0 [f2fs]
[ 388.088888] ? lock_timer_base+0x7d/0xa0
[ 388.090213] ? try_to_del_timer_sync+0x44/0x60
[ 388.091698] gc_thread_func+0x342/0x4b0 [f2fs]
[ 388.092892] ? wait_woken+0x80/0x80
[ 388.094098] kthread+0x109/0x140
[ 388.095010] ? f2fs_gc+0x9d0/0x9d0 [f2fs]
[ 388.096043] ? kthread_park+0x60/0x60
[ 388.097281] ret_from_fork+0x25/0x30
[ 388.098401] Code: ff ff 48 83 e8 01 48 89 44 24 58 e9 27 f8 ff ff 48 83 e8 01 e9 78 fc ff ff 48 8d 78 ff e9 17 fb ff ff 48 83 ef 01 e9 4d f4 ff ff <0f> 0b 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55
[ 388.100864] RIP: do_garbage_collect+0xcc8/0xcd0 [f2fs] RSP: ffffc90004d7fc68
[ 388.101810] ---[ end trace 81c73d6e6b7da61d ]---

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: let sync node IO interrupt async one

Although mixed sync/async IOs can have continuous LBA, as they have
different IO priority, block IO scheduler will add them into different
queues and commit them separately, result in splited IOs which causes
wrose performance.

This patch gives high priority to synchronous IO of nodes, means that
once synchronous flow starts, it can interrupt asynchronous writeback
flow of system flusher, so more big IOs can be expected.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up symbol namespace

As Ted reported:

"Hi, I was looking at f2fs's sources recently, and I noticed that there
is a very large number of non-static symbols which don't have a f2fs
prefix. There's well over a hundred (see attached below).

As one example, in fs/f2fs/dir.c there is:

unsigned char get_de_type(struct f2fs_dir_entry *de)

This function is clearly only useful for f2fs, but it has a generic
name. This means that if any other file system tries to have the same
symbol name, there will be a symbol conflict and the kernel would not
successfully build. It also means that when someone is looking f2fs
sources, it's not at all obvious whether a function such as
read_data_page(), invalidate_blocks(), is a generic kernel function
found in the fs, mm, or block layers, or a f2fs specific function.

You might want to fix this at some point. Hopefully Kent's bcachefs
isn't similarly using genericly named functions, since that might
cause conflicts with f2fs's functions --- but just as this would be a
problem that we would rightly insist that Kent fix, this is something
that we should have rightly insisted that f2fs should have fixed
before it was integrated into the mainline kernel.

acquire_orphan_inode
add_ino_entry
add_orphan_inode
allocate_data_block
allocate_new_segments
alloc_nid
alloc_nid_done
alloc_nid_failed
available_free_memory
...."

This patch adds "f2fs_" prefix for all non-static symbols in order to:
a) avoid conflict with other kernel generic symbols;
b) to indicate the function is f2fs specific one instead of generic
one;

Reported-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to let caller retry allocating block address

Configure io_bits with 2 and enable LFS mode, generic/013 reports below dmesg:

BUG: unable to handle kernel NULL pointer dereference at 00000104
*pdpt = 0000000029b7b001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: crc32_generic zram f2fs(O) rfcomm bnep bluetooth ecdh_generic snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq pcbc joydev snd_seq_device aesni_intel snd_timer aes_i586 snd crypto_simd cryptd soundcore i2c_piix4 serio_raw mac_hid video parport_pc ppdev lp parport hid_generic psmouse usbhid hid e1000
CPU: 0 PID: 11161 Comm: fsstress Tainted: G O 4.17.0-rc2 #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs]
EFLAGS: 00010206 CPU: 0
EAX: e863dcd8 EBX: 00000000 ECX: 00000100 EDX: 00000200
ESI: e863dcf4 EDI: f6f82768 EBP: e863dbb0 ESP: e863db74
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 80050033 CR2: 00000104 CR3: 29a62020 CR4: 000406f0
Call Trace:
do_write_page+0x6f/0xc0 [f2fs]
write_data_page+0x4a/0xd0 [f2fs]
do_write_data_page+0x327/0x630 [f2fs]
__write_data_page+0x34b/0x820 [f2fs]
__f2fs_write_data_pages+0x42d/0x8c0 [f2fs]
f2fs_write_data_pages+0x27/0x30 [f2fs]
do_writepages+0x1a/0x70
__filemap_fdatawrite_range+0x94/0xd0
filemap_write_and_wait_range+0x3d/0xa0
__generic_file_write_iter+0x11a/0x1f0
f2fs_file_write_iter+0xdd/0x3b0 [f2fs]
__vfs_write+0xd2/0x150
vfs_write+0x9b/0x190
ksys_write+0x45/0x90
sys_write+0x16/0x20
do_fast_syscall_32+0xaa/0x22c
entry_SYSENTER_32+0x4c/0x7b
EIP: 0xb7fc8c51
EFLAGS: 00000246 CPU: 0
EAX: ffffffda EBX: 00000003 ECX: 09cde000 EDX: 00001000
ESI: 00000003 EDI: 00001000 EBP: 00000000 ESP: bfbded38
DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Code: e8 f9 77 34 c9 8b 45 e0 8b 80 b8 00 00 00 39 45 d8 0f 84 bb 02 00 00 8b 45 e0 8b 80 b8 00 00 00 8d 50 d8 8b 08 89 55 f0 8b 50 04 <89> 51 04 89 0a c7 00 00 01 00 00 c7 40 04 00 02 00 00 8b 45 dc
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs] SS:ESP: 0068:e863db74
CR2: 0000000000000104
---[ end trace 4cac79c0d1305ee6 ]---

allocate_data_block will submit all sequential pending IOs sorted by a
FIFO list, If we failed to submit other user's IO due to unaligned write,
we will retry to allocate new block address for current IO, then it will
initialize fio.list again, if fio was in the list before, it can break
FIFO list, result in above panic.

Thread A Thread B
- do_write_page
- allocate_data_block
- list_add_tail
: fioA cached in FIFO list.
- do_write_page
- allocate_data_block
- list_add_tail
: fioB cached in FIFO list.
- f2fs_submit_page_write
: fail to submit IO
- allocate_data_block
- INIT_LIST_HEAD
- f2fs_submit_page_write
- list_del <-- NULL pointer dereference

This patch adds fio.retry parameter to indicate failure status for each
IO, and avoid bailing out if there is still pending IO in FIFO list for
fixing.

Signed-off-by: Chao Yu <yuchao0@huawei.com>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix error path of move_data_page

This patch fixes error path of move_data_page:
- clear cold data flag if it fails to write page.
- redirty page for non-ENOMEM case.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid stucking GC due to atomic write

f2fs doesn't allow abuse on atomic write class interface, so except
limiting in-mem pages' total memory usage capacity, we need to limit
atomic-write usage as well when filesystem is seriously fragmented,
otherwise we may run into infinite loop during foreground GC because
target blocks in victim segment are belong to atomic opened file for
long time.

Now, we will detect failure due to atomic write in foreground GC, if
the count exceeds threshold, we will drop all atomic written data in
cache, by this, I expect it can keep our system running safely to
prevent Dos attack.

In addition, his patch adds to show GC skip information in debugfs,
now it just shows count of skipped caused by atomic write.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce sbi->gc_mode to determine the policy

This is to avoid sbi->gc_thread pointer access.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: keep migration IO order in LFS mode

For non-migration IO, we will keep order of data/node blocks' submitting
as allocation sequence by sorting IOs in per log io_list list, but for
migration IO, it could be out-of-order.

In LFS mode, we should keep all IOs including migration IO be ordered,
so that this patch fixes to add an additional lock to keep submitting
order.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Revert "f2fs: add ovp valid_blocks check for bg gc victim to fg_gc"

For extreme case:
10 section, op = 10%, no_fggc_threshold = 90%
All section usage: 85% 85% 85% 85% 90% 90% 95% 95% 95% 95%

During foreground GC, if we skip select dirty section whose usage
is larger than no_fggc_threshold, we can only recycle 80% invalid
space from four 85% usage sections and two 90% usage sections,
result in encountering out-of-space issue.

This reverts commit e93b9865251a0503d83fd570e7d5a7c8bc351715 to
fix this issue, besides, we keep the logic that we scan all dirty
section when searching a victim, so that GC can select victim with
least valid blocks.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: rename dio_rwsem to i_gc_rwsem

RW semphore dio_rwsem in struct f2fs_inode_info is introduced to avoid
race between dio and data gc, but now, it is more wildly used to avoid
foreground operation vs data gc. So rename it to i_gc_rwsem to improve
its readability.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clear PageError on writepage

This patch clears PageError in some pages tagged by read path, but when we
write the pages with valid contents, writepage should clear the bit likewise
ext4.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: refactor read path to allow multiple postprocessing steps

Currently f2fs's ->readpage() and ->readpages() assume that either the
data undergoes no postprocessing, or decryption only. But with
fs-verity, there will be an additional authenticity verification step,
and it may be needed either by itself, or combined with decryption.

To support this, store a 'struct bio_post_read_ctx' in ->bi_private
which contains a work struct, a bitmask of postprocessing steps that are
enabled, and an indicator of the current step. The bio completion
routine, if there was no I/O error, enqueues the first postprocessing
step. When that completes, it continues to the next step. Pages that
fail any postprocessing step have PageError set. Once all steps have
completed, pages without PageError set are set Uptodate, and all pages
are unlocked.

Also replace f2fs_encrypted_file() with a new function
f2fs_post_read_required() in places like direct I/O and garbage
collection that really should be testing whether the file needs special
I/O processing, not whether it is encrypted specifically.

This may also be useful for other future f2fs features such as
compression.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

xarray: add the xa_lock to the radix_tree_root

This results in no change in structure size on 64-bit machines as it
fits in the padding between the gfp_t and the void *. 32-bit machines
will grow the structure from 8 to 12 bytes. Almost all radix trees are
protected with (at least) a spinlock, so as they are converted from
radix trees to xarrays, the data structures will shrink again.

Initialising the spinlock requires a name for the benefit of lockdep, so
RADIX_TREE_INIT() now needs to know the name of the radix tree it's
initialising, and so do IDR_INIT() and IDA_INIT().

Also add the xa_lock() and xa_unlock() family of wrappers to make it
easier to use the lock. If we could rely on -fplan9-extensions in the
compiler, we could avoid all of this syntactic sugar, but that wasn't
added until gcc 4.6.

Link: http://lkml.kernel.org/r/20180313132639.17387-8-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

f2fs: do gc in greedy mode for whole range if gc_urgent mode is set

Otherwise, f2fs conducts GC on 8GB range only based on slow cost-benefit.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't stop GC if GC is contended

Let's do GC as much as possible, while gc_urgent is set.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix heap mode to reset it back

Commit 7a20b8a61eff81bdb7097a578752a74860e9d142 ("f2fs: allocate node
and hot data in the beginning of partition") introduces another mount
option, heap, to reset it back. But it does not do anything for heap
mode, so fix it.

Cc: stable@vger.kernel.org
Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid hungtask when GC encrypted block if io_bits is set

When io_bits is set, GCing encrypted block may hit the following hungtask.
Since io_bits requires aligned block address, f2fs_submit_page_write may
return -EAGAIN if new_blkaddr does not satisify io_bits alignment. As a
result, the encrypted page will never be writtenback.

This patch makes move_data_block aware the EAGAIN error and cancel the
writeback.

[ 246.751371] INFO: task kworker/u4:4:797 blocked for more than 90 seconds.
[ 246.752423] Not tainted 4.15.0-rc4+ #11
[ 246.754176] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 246.755336] kworker/u4:4 D25448 797 2 0x80000000
[ 246.755597] Workqueue: writeback wb_workfn (flush-7:0)
[ 246.755616] Call Trace:
[ 246.755695] ? __schedule+0x322/0xa90
[ 246.755761] ? blk_init_request_from_bio+0x120/0x120
[ 246.755773] ? pci_mmcfg_check_reserved+0xb0/0xb0
[ 246.755801] ? __radix_tree_create+0x19e/0x200
[ 246.755813] ? delete_node+0x136/0x370
[ 246.755838] schedule+0x43/0xc0
[ 246.755904] io_schedule+0x17/0x40
[ 246.755939] wait_on_page_bit_common+0x17b/0x240
[ 246.755950] ? wake_page_function+0xa0/0xa0
[ 246.755961] ? add_to_page_cache_lru+0x160/0x160
[ 246.755972] ? page_cache_tree_insert+0x170/0x170
[ 246.755983] ? __lru_cache_add+0x96/0xb0
[ 246.756086] __filemap_fdatawait_range+0x14f/0x1c0
[ 246.756097] ? wait_on_page_bit_common+0x240/0x240
[ 246.756120] ? __wake_up_locked_key_bookmark+0x20/0x20
[ 246.756167] ? wait_on_all_pages_writeback+0xc9/0x100
[ 246.756179] ? __remove_ino_entry+0x120/0x120
[ 246.756192] ? wait_woken+0x100/0x100
[ 246.756204] filemap_fdatawait_range+0x9/0x20
[ 246.756216] write_checkpoint+0x18a1/0x1f00
[ 246.756254] ? blk_get_request+0x10/0x10
[ 246.756265] ? cpumask_next_and+0x43/0x60
[ 246.756279] ? f2fs_sync_inode_meta+0x160/0x160
[ 246.756289] ? remove_element.isra.4+0xa0/0xa0
[ 246.756300] ? __put_compound_page+0x40/0x40
[ 246.756310] ? f2fs_sync_fs+0xec/0x1c0
[ 246.756320] ? f2fs_sync_fs+0x120/0x1c0
[ 246.756329] f2fs_sync_fs+0x120/0x1c0
[ 246.756357] ? trace_event_raw_event_f2fs__page+0x260/0x260
[ 246.756393] ? ata_build_rw_tf+0x173/0x410
[ 246.756397] f2fs_balance_fs_bg+0x198/0x390
[ 246.756405] ? drop_inmem_page+0x230/0x230
[ 246.756415] ? ahci_qc_prep+0x1bb/0x2e0
[ 246.756418] ? ahci_qc_issue+0x1df/0x290
[ 246.756422] ? __accumulate_pelt_segments+0x42/0xd0
[ 246.756426] ? f2fs_write_node_pages+0xd1/0x380
[ 246.756429] f2fs_write_node_pages+0xd1/0x380
[ 246.756437] ? sync_node_pages+0x8f0/0x8f0
[ 246.756440] ? update_curr+0x53/0x220
[ 246.756444] ? __accumulate_pelt_segments+0xa2/0xd0
[ 246.756448] ? __update_load_avg_se.isra.39+0x349/0x360
[ 246.756452] ? do_writepages+0x2a/0xa0
[ 246.756456] do_writepages+0x2a/0xa0
[ 246.756460] __writeback_single_inode+0x70/0x490
[ 246.756463] ? check_preempt_wakeup+0x199/0x310
[ 246.756467] writeback_sb_inodes+0x2a2/0x660
[ 246.756471] ? is_empty_dir_inode+0x40/0x40
[ 246.756474] ? __writeback_single_inode+0x490/0x490
[ 246.756477] ? string+0xbf/0xf0
[ 246.756480] ? down_read_trylock+0x35/0x60
[ 246.756484] __writeback_inodes_wb+0x9f/0xf0
[ 246.756488] wb_writeback+0x41d/0x4b0
[ 246.756492] ? writeback_inodes_wb.constprop.55+0x150/0x150
[ 246.756498] ? set_worker_desc+0xf7/0x130
[ 246.756502] ? current_is_workqueue_rescuer+0x60/0x60
[ 246.756511] ? _find_next_bit+0x2c/0xa0
[ 246.756514] ? wb_workfn+0x400/0x5d0
[ 246.756518] wb_workfn+0x400/0x5d0
[ 246.756521] ? finish_task_switch+0xdf/0x2a0
[ 246.756525] ? inode_wait_for_writeback+0x30/0x30
[ 246.756529] process_one_work+0x3a7/0x6f0
[ 246.756533] worker_thread+0x82/0x750
[ 246.756537] kthread+0x16f/0x1c0
[ 246.756541] ? trace_event_raw_event_workqueue_work+0x110/0x110
[ 246.756544] ? kthread_create_worker_on_cpu+0xb0/0xb0
[ 246.756548] ret_from_fork+0x1f/0x30

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add an ioctl to disable GC for specific file

This patch gives a flag to disable GC on given file, which would be useful, when
user wants to keep its block map. It also conducts in-place-update for dontmove
file.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Rename superblock flags (MS_xyz -> SB_xyz)

This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"

SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

for f in $L; do sed -i $f $SED_PROG; done

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

f2fs: avoid race in between GC and block exchange

During block exchange in {insert,collapse,move}_range, page-block mapping
is unstable due to mapping moving or recovery, so there should be no
concurrent cache read operation rely on such mapping, nor cache write
operation to mess up block exchange.

So this patch let background GC be aware of that.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use rw_semaphore to protect SIT cache

There are some cases user didn't update SIT cache under this lock,
so let's use rw_semaphore instead of mutex to enhance concurrently
accessing.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support get_page error injection

This patch adds to support get_page error injection to simulate
out-of-memory test scenario.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enhance multiple device flush

When multiple device feature is enabled, during ->fsync we will issue
flush in all devices to make sure node/data of the file being persisted
into storage. But some flushes of device could be unneeded as file's
data may be not writebacked into those devices. So this patch adds and
manage bitmap per inode in global cache to indicate which device is
dirty and it needs to issue flush during ->fsync, hence, we could improve
performance of fsync in scenario of multiple device.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Revert "f2fs: node segment is prior to data segment selected victim"

This reverts commit b9cd20619e359d199b755543474c3d853c8e3415.

That patch causes much fewer node segments (which can be used for SSR)
than before, and in the corner case (e.g. create and delete *.txt files in
one same directory, there will be very few node segments but many data
segments), if the reserved free segments are all used up during gc, then
the write_checkpoint can still flush dentry pages to data ssr segments,
but will probably fail to flush node pages to node ssr segments, since
there are not enough node ssr segments left (the left ones are all
full).

So revert this patch to give a fair chance to let node segments remain
for SSR, which provides more robustness for corner cases.

Conflicts:
fs/f2fs/gc.c

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use generic terms used for encrypted block management

This patch renames functions regarding to buffer management via META_MAPPING
used for encrypted blocks especially. We can actually use them in generic way.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_encrypted_file for clean-up

This patch replaces (f2fs_encrypted_inode() && S_ISREG()) with
f2fs_encrypted_file(), which gives no functional change.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Revert "f2fs: add a new function get_ssr_cost"

This reverts commit b7b7c4cf1c9ef0272a65f1480457cbfdadcda19d.

se->ckpt_valid_blocks will never be smaller than se->valid_blocks, so just
remove get_ssr_cost.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid race in between aio and gc

We won't wait DIO synchronously when doing AIO, so there will be potential
IO reorder in between AIO and GC, which will cause data corruption.

This patch adds inode_dio_wait to serialize aio and data GC to avoid this
issue.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add tracepoint for f2fs_gc

This patch adds tracepoint for f2fs_gc.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix potential overflow when adjusting GC cycle

While comparing signed and unsigned variables, compiler will converts the
signed value to unsigned one, due to this reason, {in,de}crease_sleep_time
may return overflowed result.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce gc_urgent mode for background GC

This patch adds a sysfs entry to control urgent mode for background GC.
If this is set, background GC thread conducts GC with gc_urgent_sleep_time
all the time.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add app/fs io stat

This patch enables inner app/fs io stats and introduces below virtual fs
nodes for exposing stats info:
/sys/fs/f2fs/<dev>/iostat_enable
/proc/fs/f2fs/<dev>/iostat_info

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix wrong stat assignment]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enhance on-disk inode structure scalability

This patch add new flag F2FS_EXTRA_ATTR storing in inode.i_inline
to indicate that on-disk structure of current inode is extended.

In order to extend, we changed the inode structure a bit:

Original one:

struct f2fs_inode {
...
struct f2fs_extent i_ext;
__le32 i_addr[DEF_ADDRS_PER_INODE];
__le32 i_nid[DEF_NIDS_PER_INODE];
}

Extended one:

struct f2fs_inode {
...
struct f2fs_extent i_ext;
union {
struct {
__le16 i_extra_isize;
__le16 i_padding;
__le32 i_extra_end[0];
};
__le32 i_addr[DEF_ADDRS_PER_INODE];
};
__le32 i_nid[DEF_NIDS_PER_INODE];
}

Once F2FS_EXTRA_ATTR is set, we will steal four bytes in the head of
i_addr field for storing i_extra_isize and i_padding. with i_extra_isize,
we can calculate actual size of reserved space in i_addr, available
attribute fields included in total extra attribute fields for current
inode can be described as below:

+--------------------+
| .i_mode |
| ... |
| .i_ext |
+--------------------+
| .i_extra_isize |-----+
| .i_padding | |
| .i_prjid | |
| .i_atime_extra | |
| .i_ctime_extra | |
| .i_mtime_extra |<----+
| .i_inode_cs |<----- store blkaddr/inline from here
| .i_xattr_cs |
| ... |
+--------------------+
| |
| block address |
| |
+--------------------+
| .i_nid |
+--------------------+
| node_footer |
| (nid, ino, offset) |
+--------------------+

Hence, with this patch, we would enhance scalability of f2fs inode for
storing more newly added attribute.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: make background threads of f2fs being aware of freezing

When ->freeze_fs is called from lvm for doing snapshot, it needs to
make sure there will be no more changes in filesystem's data, however,
previously, background threads like GC thread wasn't aware of freezing,
so in environment with active background threads, data of snapshot
becomes unstable.

This patch fixes this issue by adding sb_{start,end}_intwrite in
below background threads:
- GC thread
- flush thread
- discard thread

Note that, don't use sb_start_intwrite() in gc_thread_func() due to:

generic/241 reports below bug:

======================================================
WARNING: possible circular locking dependency detected
4.13.0-rc1+ #32 Tainted: G O
------------------------------------------------------
f2fs_gc-250:0/22186 is trying to acquire lock:
(&sbi->gc_mutex){+.+...}, at: [<f8fa7f0b>] f2fs_sync_fs+0x7b/0x1b0 [f2fs]

but task is already holding lock:
(sb_internal#2){++++.-}, at: [<f8fb5609>] gc_thread_func+0x159/0x4a0 [f2fs]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (sb_internal#2){++++.-}:
__lock_acquire+0x405/0x7b0
lock_acquire+0xae/0x220
__sb_start_write+0x11d/0x1f0
f2fs_evict_inode+0x2d6/0x4e0 [f2fs]
evict+0xa8/0x170
iput+0x1fb/0x2c0
f2fs_sync_inode_meta+0x3f/0xf0 [f2fs]
write_checkpoint+0x1b1/0x750 [f2fs]
f2fs_sync_fs+0x85/0x1b0 [f2fs]
f2fs_do_sync_file.isra.24+0x137/0xa30 [f2fs]
f2fs_sync_file+0x34/0x40 [f2fs]
vfs_fsync_range+0x4a/0xa0
do_fsync+0x3c/0x60
SyS_fdatasync+0x15/0x20
do_fast_syscall_32+0xa1/0x1b0
entry_SYSENTER_32+0x4c/0x7b

-> #1 (&sbi->cp_mutex){+.+...}:
__lock_acquire+0x405/0x7b0
lock_acquire+0xae/0x220
__mutex_lock+0x4f/0x830
mutex_lock_nested+0x25/0x30
write_checkpoint+0x2f/0x750 [f2fs]
f2fs_sync_fs+0x85/0x1b0 [f2fs]
sync_filesystem+0x67/0x80
generic_shutdown_super+0x27/0x100
kill_block_super+0x22/0x50
kill_f2fs_super+0x3a/0x40 [f2fs]
deactivate_locked_super+0x3d/0x70
deactivate_super+0x40/0x60
cleanup_mnt+0x39/0x70
__cleanup_mnt+0x10/0x20
task_work_run+0x69/0x80
exit_to_usermode_loop+0x57/0x92
do_fast_syscall_32+0x18c/0x1b0
entry_SYSENTER_32+0x4c/0x7b

-> #0 (&sbi->gc_mutex){+.+...}:
validate_chain.isra.36+0xc50/0xdb0
__lock_acquire+0x405/0x7b0
lock_acquire+0xae/0x220
__mutex_lock+0x4f/0x830
mutex_lock_nested+0x25/0x30
f2fs_sync_fs+0x7b/0x1b0 [f2fs]
f2fs_balance_fs_bg+0xb9/0x200 [f2fs]
gc_thread_func+0x302/0x4a0 [f2fs]
kthread+0xe9/0x120
ret_from_fork+0x19/0x24

other info that might help us debug this:

Chain exists of:
&sbi->gc_mutex --> &sbi->cp_mutex --> sb_internal#2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(sb_internal#2);
lock(&sbi->cp_mutex);
lock(sb_internal#2);
lock(&sbi->gc_mutex);

*** DEADLOCK ***

1 lock held by f2fs_gc-250:0/22186:
#0: (sb_internal#2){++++.-}, at: [<f8fb5609>] gc_thread_func+0x159/0x4a0 [f2fs]

stack backtrace:
CPU: 2 PID: 22186 Comm: f2fs_gc-250:0 Tainted: G O 4.13.0-rc1+ #32
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
Call Trace:
dump_stack+0x5f/0x92
print_circular_bug+0x1b3/0x1bd
validate_chain.isra.36+0xc50/0xdb0
? __this_cpu_preempt_check+0xf/0x20
__lock_acquire+0x405/0x7b0
lock_acquire+0xae/0x220
? f2fs_sync_fs+0x7b/0x1b0 [f2fs]
__mutex_lock+0x4f/0x830
? f2fs_sync_fs+0x7b/0x1b0 [f2fs]
mutex_lock_nested+0x25/0x30
? f2fs_sync_fs+0x7b/0x1b0 [f2fs]
f2fs_sync_fs+0x7b/0x1b0 [f2fs]
f2fs_balance_fs_bg+0xb9/0x200 [f2fs]
gc_thread_func+0x302/0x4a0 [f2fs]
? preempt_schedule_common+0x2f/0x4d
? f2fs_gc+0x540/0x540 [f2fs]
kthread+0xe9/0x120
? f2fs_gc+0x540/0x540 [f2fs]
? kthread_create_on_node+0x30/0x30
ret_from_fork+0x19/0x24

The deadlock occurs in below condition:
GC Thread Thread B
- sb_start_intwrite
- f2fs_sync_file
- f2fs_sync_fs
- mutex_lock(&sbi->gc_mutex)
- write_checkpoint
- block_operations
- f2fs_sync_inode_meta
- iput
- sb_start_intwrite
- mutex_lock(&sbi->gc_mutex)

Fix this by altering sb_start_intwrite to sb_start_write_trylock.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce io_list for serialize data/node IOs

Serialize data/node IOs by using fifo list instead of mutex lock,
it will help to enhance concurrency of f2fs, meanwhile keeping LFS
IO semantics.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: try to freeze in gc and discard threads

This allows to freeze gc and discard threads.

Cc: stable@vger.kernel.org
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add a new function get_ssr_cost

This patch add a new method get_ssr_cost to select
SSR segment more accurately.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid f2fs_lock_op for IPU writes

Currently, if we do get_node_of_data before f2fs_lock_op, there may be dead lock
as follows, where process A would be in infinite loop, and B will NOT be awaked.

Process A(cp): Process B:
f2fs_lock_all(sbi)
get_dnode_of_data <---- lock dn.node_page
flush_nodes f2fs_lock_op

So, this patch adds f2fs_trylock_op to avoid f2fs_lock_op done by IPU.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split bio cache

Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unnecessary read cases in merged IO flow

Merged IO flow doesn't need to care about read IOs.

f2fs_submit_merged_bio -> f2fs_submit_merged_write
f2fs_submit_merged_bios -> f2fs_submit_merged_writes
f2fs_submit_merged_bio_cond -> f2fs_submit_merged_write_cond

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: make sure f2fs_gc returns consistent errno

By default, f2fs_gc returns -EINVAL in general error cases, e.g., no victim
was selected. However, the default errno may be overwritten in two cases:
gc_more and BG_GC -> FG_GC. We should return consistent errno in such cases.

Signed-off-by: Weichao Guo <guoweichao@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: release cp and dnode lock before IPU

We don't need to rewrite the page under cp_rwsem and dnode locks.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: lookup extent cache first under IPU scenario

If a page is cold, NOT atomit written and need_ipu now, there is
a high probability that IPU should be adapted. For IPU, we try to
check extent tree to get the block index first, instead of reading
the dnode page, where may lead to an useless dnode IO, since no need to
update the dnode index for IPU.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: assign allocation hint for warm/cold data

This patch gives slower device region to warm/cold data area more eagerly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add ioctl to flush data from faster device to cold area

This patch adds an ioctl to flush data in faster device to cold area. User can
give device number and number of segments to move. It doesn't move it if there
is only one device.

The parameter looks like:

struct f2fs_flush_device {
u32 dev_num; /* device number to flush */
u32 segments; /* # of segments to flush */
};

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid frequent checkpoint during f2fs_gc

Now we're doing SSR aggressively more than ever before, so once we reach to
the reserved_segment, f2fs_balance_fs will call f2fs_gc, which triggers
checkpoint everytime. We actually must avoid that.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up some macros in terms of GET_SEGNO

This patch cleans several macros by introducing:
- BLKS_PER_SEC
- GET_SEC_FROM_SEG
- GET_SEG_FROM_SEC
- GET_ZONE_FROM_SEC
- GET_ZONE_FROM_SEG

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up get_valid_blocks with consistent parameter

This patch cleans up get_valid_blocks, which has no functional change.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: relax node version check for victim data in gc

- has_not_enough_free_secs
node_secs: 0 dent_secs: 0 freed:0 free_segments:103 reserved:104

- f2fs_gc
- get_victim_by_default
alloc_mode 0, gc_mode 1, max_search 2672, offset 4654, ofs_unit 1

- do_garbage_collect
start_segno 3976, end_segno 3977 type 0

- is_alive
nid 22797, blkaddr 2131882, ofs_in_node 0, version 0x8/0x0

- gc_data_segment 766, segno 3976, block 512/426 not alive

So, this patch fixes subtle corrupted case where node version does not match
to summary version which results in infinite loop by gc.

Reported-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: allocate node and hot data in the beginning of partition

In order to give more spatial locality, this patch changes the block allocation
policy which assigns beginning of partition for small and hot data/node blocks.
In order to do this, we set noheap allocation by default and introduce another
mount option, heap, to reset it back.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix wrong max cost initialization

This patch fixes missing increased max cost caused by a patch that we increased
cose of data segments in greedy algorithm.

Cc: <stable@vger.kernel.org> # v4.10+
Fixes: b9cd20619 "f2fs: node segment is prior to data segment selected victim"
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix recording invalid last_victim

When doing garbage collection, we try to record segment offset which
locates at next one of last victim, using it as the start offset in
next searching.

But in some corner cases, recorded offset may cross the end of main
segment area, it will cause incorrectly searching in dirty_segmap
bitmap. This patch adds modular operation to avoid this issue.

Reported-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix a plint compile warning

fix such pclint warning:
...
Loss of precision (arg. no. 2) (unsigned long long to unsigned int))

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid bggc->fggc when enough free segments are avaliable after cp

We use has_not_enough_free_secs to check if there are enough free segments,

(free_sections(sbi) + freed) <=
(node_secs + 2 * dent_secs + imeta_secs +
reserved_sections(sbi) + needed);

Under scenario with large number of dirty nodes, these nodes would be flushed
during cp, as a result, right side of the inequality would be decreased, while
left side stays unchanged if these nodes are flushed in SSR way, which means
there are enough free segments after this cp.

For this case, we just do a bggc instead of fggc.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: show simple call stack in fault injection message

Previously kernel message can show that in which function we do the
injection, but unfortunately, most of the caller are the same, for
tracking more information of injection path, it needs to show upper
caller's name. This patch supports that ability.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unnecessary condition check for write_checkpoint in f2fs_gc

Since has_not_enough_free_secs(sbi, 0, 0) must be true if has_not_enough_
free_secs(sbi, sec_freed, 0) is true, write_checkpoint is sure to execute in
both conditions.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: node segment is prior to data segment selected victim

As data segment gc may lead dnode dirty, so the greedy cost for data segment
should be valid blocks * 2, that is data segment is prior to node segment.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add ovp valid_blocks check for bg gc victim to fg_gc

For foreground gc, greedy algorithm should be adapted, which makes
this formula work well:

(2 * (100 / config.overprovision + 1) + 6)

But currently, we fg_gc have a prior to select bg_gc victim segments to gc
first, these victims are selected by cost-benefit algorithm, we can't guarantee
such segments have the small valid blocks, which may destroy the f2fs rule, on
the worstest case, would consume all the free segments.

This patch fix this by add a filter in check_bg_victims, if segment's has # of
valid blocks over overprovision ratio, skip such segments.

Cc: <stable@vger.kernel.org>
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: replace __get_victim by dirty_segments in FG_GC

In FG_GC process, it will search victim section twice. This will
cause some dirty section with less valid blocks skip garbage
collection.

section # 26425 : valid blocks # 3
142.037567: get_victim_by_default: victim 26425 : valid blocks # 3
142.037585: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26425 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 244
142.039494: f2fs_get_victim: dev = (259,30), type = Hot DATA, policy = (Background GC, SSR-mode, Greedy), victim = 19022 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 24
142.070247: new_curseg: Debug: alloc new segment 26746
142.244341: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26054 ofs_unit = 1, pre_victim_secno = 26054, prefree = 0, free = 243
142.254475: do_garbage_collect: Debug: FG_GC, seg_freed = 1
142.293131: f2fs_get_victim: dev = (259,30), type = Warm DATA, policy = (Background GC, SSR-mode, Greedy), victim = 23466 ofs_unit = 1, pre_victim_secno = -1, prefree = 0, free = 244
142.319001: f2fs_get_victim: dev = (259,30), type = Warm DATA, policy = (Background GC, SSR-mode, Greedy), victim = 23467 ofs_unit = 1, pre_victim_secno = -1, prefree = 0, free = 244
142.368879: get_victim_by_default: victim 26425 : valid blocks # 3
142.368894: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26425 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 244
142.378127: f2fs_get_victim: dev = (259,30), type = Hot DATA, policy = (Background GC, SSR-mode, Greedy), victim = 19612 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 24
142.416917: new_curseg: Debug: alloc new segment 26054
142.656794: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 25404 ofs_unit = 1, pre_victim_secno = 25404, prefree = 0, free = 243
142.662139: do_garbage_collect: Debug: FG_GC, seg_freed = 1
142.684159: new_curseg: Debug: alloc new segment 25197
142.685059: get_victim_by_default: victim 26425 : valid blocks # 3
142.685079: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26425 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 243
142.701427: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26238 ofs_unit = 1, pre_victim_secno = 26238, prefree = 0, free = 243
142.707105: do_garbage_collect: Debug: FG_GC, seg_freed = 1
142.802444: f2fs_get_victim: dev = (259,30), type = Warm DATA, policy = (Background GC, SSR-mode, Greedy), victim = 23473 ofs_unit = 1, pre_victim_secno = -1, prefree = 0, free = 244
142.804422: get_victim_by_default: victim 26425 : valid blocks # 3
142.804443: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26425 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 244
142.851567: f2fs_get_victim: dev = (259,30), type = Hot DATA, policy = (Background GC, SSR-mode, Greedy), victim = 19092 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 24
142.865014: new_curseg: Debug: alloc new segment 26238
143.082245: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26307 ofs_unit = 1, pre_victim_secno = 26307, prefree = 0, free = 244
143.088252: do_garbage_collect: Debug: FG_GC, seg_freed = 1
143.128307: new_curseg: Debug: alloc new segment 25404
143.181846: get_victim_by_default: victim 26425 : valid blocks # 3
143.181872: f2fs_get_victim: dev = (259,30), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 26425 ofs_unit = 1, pre_victim_secno = 26425, prefree = 0, free = 244

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce FI_ATOMIC_COMMIT

This patch introduces a new flag to indicate inode status of doing atomic
write committing, so that, we can keep atomic write status for inode
during atomic committing, then we can skip GCing pages of atomic write inode,
that avoids random GCed datas being mixed with current transaction, so
isolation of transaction can be kept.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't wait writeback for datas during checkpoint

Normally, while committing checkpoint, we will wait on all pages to be
writebacked no matter the page is data or metadata, so in scenario where
there are lots of data IO being submitted with metadata, we may suffer
long latency for waiting writeback during checkpoint.

Indeed, we only care about persistence for pages with metadata, but not
pages with data, as file system consistent are only related to metadate,
so in order to avoid encountering long latency in above scenario, let's
recognize and reference metadata in submitted IOs, wait writeback only
for metadatas.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid BG_GC in f2fs_balance_fs

If many threads hit has_not_enough_free_secs() in f2fs_balance_fs() at the same
time, all the threads would do FG_GC or BG_GC.
In this critical path, we totally don't need to do BG_GC at all.
Let's avoid that.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: return directly if block has been removed from the victim

If one block has been to written to a new place, just return
in move data process. This patch check it again with holding
page lock.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: give a chance to detach from dirty list

If there is no dirty pages in inode, we should give a chance to detach
the inode from global dirty list, otherwise it needs to call another
unnecessary .writepages for detaching.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

block,fs: use REQ_* flags directly

Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly. Where applicable this also drops usage of the
bio_set_op_attrs wrapper.

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

f2fs: fix wrong sum_page pointer in f2fs_gc

This patch fixes using a wrong pointer for sum_page in f2fs_gc.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove dead variable

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support checkpoint error injection

This patch adds to support checkpoint error injection in f2fs for testing
fatal error tolerance, it will be useful that it can simulate abnormal
power off by f2fs itself instead of calling godown ioctl by running apps.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support configuring fault injection per superblock

Previously, we only support global fault injection configuration, so that
when we configure type/rate of fault injection through sysfs, mount
option, it will influence all f2fs partition which is being used.

It is not make sence, since it will be not convenient if developer want
to test separated partitions with different fault injection rate/type
simultaneously, also it's not possible to enable fault injection in one
partition and disable fault injection in other one.

>From now on, we move global configuration of fault injection in module
into per-superblock, hence injection testing can be more flexible.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid gc in cp_error case

Otherwise, we can hit
f2fs_bug_on(sbi, !PageUptodate(sum_page));

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: should put_page for summary page

We should call put_page for preloaded summary pages in do_garbage_collect.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: assign return value in f2fs_gc

This patch adds a return value of write_checkpoint for f2fs_gc.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check free_sections for defragmentation

Fix wrong condition check for defragmentation of a file.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do in batch synchronously readahead during GC

In order to enhance performance, we try to readahead node page during
GC, but before loading node page we should get block address of node page
which is stored in NAT table, so synchronously read of single NAT page
block our readahead flow.

f2fs_submit_page_bio: dev = (251,0), ino = 2, page_index = 0xa1e, oldaddr = 0xa1e, newaddr = 0xa1e, rw = READ_SYNC(MP), type = META
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x35e9, oldaddr = 0x72d7a, newaddr = 0x72d7a, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 2, page_index = 0xc1f, oldaddr = 0xc1f, newaddr = 0xc1f, rw = READ_SYNC(MP), type = META
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x389d, oldaddr = 0x72d7d, newaddr = 0x72d7d, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x3a82, oldaddr = 0x72d7f, newaddr = 0x72d7f, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x3bfa, oldaddr = 0x72d86, newaddr = 0x72d86, rw = READAHEAD ^H, type = NODE

This patch adds one phase that do readahead NAT pages in batch before
readahead node page for more effeciently.

f2fs_submit_page_bio: dev = (251,0), ino = 2, page_index = 0x1952, oldaddr = 0x1952, newaddr = 0x1952, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc34, oldaddr = 0xc34, newaddr = 0xc34, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xa33, oldaddr = 0xa33, newaddr = 0xa33, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc30, oldaddr = 0xc30, newaddr = 0xc30, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc32, oldaddr = 0xc32, newaddr = 0xc32, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc26, oldaddr = 0xc26, newaddr = 0xc26, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xa2b, oldaddr = 0xa2b, newaddr = 0xa2b, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc23, oldaddr = 0xc23, newaddr = 0xc23, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc24, oldaddr = 0xc24, newaddr = 0xc24, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xa10, oldaddr = 0xa10, newaddr = 0xa10, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc2c, oldaddr = 0xc2c, newaddr = 0xc2c, rw = READ_SYNC(MP), type = META
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5db7, oldaddr = 0x6be00, newaddr = 0x6be00, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5db9, oldaddr = 0x6be17, newaddr = 0x6be17, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dbc, oldaddr = 0x6be1a, newaddr = 0x6be1a, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dc3, oldaddr = 0x6be20, newaddr = 0x6be20, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dc7, oldaddr = 0x6be24, newaddr = 0x6be24, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dc9, oldaddr = 0x6be25, newaddr = 0x6be25, rw = READAHEAD ^H, type = NODE

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up foreground GC flow

This patch changes to check valid block number of one GCed section
directly instead of checking the number in all segments of section
one by one in order to clean up codes of foreground GC.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: get victim segment again after new cp

Previous selected segment may become free after write_checkpoint,
if we do garbage collect on this segment, and then new_curseg happen
to reuse it, it may cause f2fs_bug_on as below.

panic+0x154/0x29c
do_garbage_collect+0x15c/0xaf4
f2fs_gc+0x2dc/0x444
f2fs_balance_fs.part.22+0xcc/0x14c
f2fs_balance_fs+0x28/0x34
f2fs_map_blocks+0x5ec/0x790
f2fs_preallocate_blocks+0xe0/0x100
f2fs_file_write_iter+0x64/0x11c
new_sync_write+0xac/0x11c
vfs_write+0x144/0x1e4
SyS_write+0x60/0xc0

Here, maybe we check sit and ssa type during reset_curseg. So, we check
segment is stale or not, and select a new victim to avoid this.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

block: get rid of bio_rw and READA

These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces. For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense. Any check for READA is replaced with an
explicit check for REQ_RAHEAD. Also remove the READA alias for
REQ_RAHEAD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

f2fs: use blk_plug in all the possible paths

This patch reverts 19a5f5e2ef37 (f2fs: drop any block plugging),
and adds blk_plug in write paths additionally.

The main reason is that blk_start_plug can be used to wake up from low-power
mode before submitting further bios.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid data update racing between GC and DIO

Datas in file can be operated by GC and DIO simultaneously, so we will
face race case as below:

For write case:
Thread A Thread B
- generic_file_direct_write
- invalidate_inode_pages2_range
- f2fs_direct_IO
- do_blockdev_direct_IO
- do_direct_IO
- get_more_blocks
- f2fs_gc
- do_garbage_collect
- gc_data_segment
- move_data_page
- do_write_data_page
migrate data block to new block address
- dio_bio_submit
update user data to old block address

For read case:
Thread A Thread B
- generic_file_direct_write
- invalidate_inode_pages2_range
- f2fs_direct_IO
- do_blockdev_direct_IO
- do_direct_IO
- get_more_blocks
- f2fs_balance_fs
- f2fs_gc
- do_garbage_collect
- gc_data_segment
- move_data_page
- do_write_data_page
migrate data block to new block address
- write_checkpoint
- do_checkpoint
- clear_prefree_segments
- f2fs_issue_discard
discard old block adress
- dio_bio_submit
update user buffer from obsolete block address

In order to fix this, for one file, we should let DIO and GC getting exclusion
against with each other.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to redirty page if fail to gc data page

If we fail to move data page during foreground GC, we should give another
chance to writeback that page which was set dirty previously by writer.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to detect truncation prior rather than EIO during read

In procedure of synchonized read, after sending out the read request, reader
will try to lock the page for waiting device to finish the read jobs and
unlock the page, but meanwhile, truncater will race with reader, so after
reader get lock of the page, it should check page's mapping to detect
whether someone has truncated the page in advance, then reader has the
chance to do the retry if truncation was done, otherwise read can be failed
due to previous condition check.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: skip clean segment for gc

If a segment in a section is clean or prefreed, we don't need to get its summary
and do gc.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: drop any block plugging

In f2fs, we don't need to keep block plugging for NODE and DATA writes, since
we already merged bios as much as possible.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use bio op accessors

Separate the op from the rq_flag_bits and have f2fs
set/get the bio using bio_set_op_attrs/bio_op.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

f2fs: use inode pointer for {set, clear}_inode_flag

This patch refactors to use inode pointer for set_inode_flag and
clear_inode_flag.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_kmalloc to wrap kmalloc

This patch adds f2fs_kmalloc.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: move node pages only in victim section during GC

For foreground GC, we cache node blocks in victim section and set them
dirty, then we call sync_node_pages to flush these node pages, but
meanwhile, those node pages which does not locate in victim section
will be flushed together, so more bandwidth and continuous free space
would be occupied.

So for this condition, it's better to leave those unrelated node page
in cache for further write hit, and let CP or VM to flush them afterward.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split sync_node_pages with fsync_node_pages

This patch splits the existing sync_node_pages into (f)sync_node_pages.
The fsync_node_pages is used for f2fs_sync_file only.

Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_update_data_blkaddr for cleanup

Add a new help f2fs_update_data_blkaddr to clean up redundant codes.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs crypto: fix incorrect positioning for GCing encrypted data page

For now, flow of GCing an encrypted data page:
1) try to grab meta page in meta inode's mapping with index of old block
address of that data page
2) load data of ciphertext into meta page
3) allocate new block address
4) write the meta page into new block address
5) update block address pointer in direct node page.

Other reader/writer will use f2fs_wait_on_encrypted_page_writeback to
check and wait on GCed encrypted data cached in meta page writebacked
in order to avoid inconsistence among data page cache, meta page cache
and data on-disk when updating.

However, we will use new block address updated in step 5) as an index to
lookup meta page in inner bio buffer. That would be wrong, and we will
never find the GCing meta page, since we use the old block address as
index of that page in step 1).

This patch fixes the issue by adjust the order of step 1) and step 3),
and in step 1) grab page with index generated in step 3).

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: trace old block address for CoWed page

This patch enables to trace old block address of CoWed page for better
debugging.

f2fs_submit_page_mbio: dev = (1,0), ino = 1, page_index = 0x1d4f0, oldaddr = 0xfe8ab, newaddr = 0xfee90 rw = WRITE_SYNC, type = NODE
f2fs_submit_page_mbio: dev = (1,0), ino = 1, page_index = 0x1d4f8, oldaddr = 0xfe8b0, newaddr = 0xfee91 rw = WRITE_SYNC, type = NODE
f2fs_submit_page_mbio: dev = (1,0), ino = 1, page_index = 0x1d4fa, oldaddr = 0xfe8ae, newaddr = 0xfee92 rw = WRITE_SYNC, type = NODE

f2fs_submit_page_mbio: dev = (1,0), ino = 134824, page_index = 0x96, oldaddr = 0xf049b, newaddr = 0x2bbe rw = WRITE, type = DATA
f2fs_submit_page_mbio: dev = (1,0), ino = 134824, page_index = 0x97, oldaddr = 0xf049c, newaddr = 0x2bbf rw = WRITE, type = DATA
f2fs_submit_page_mbio: dev = (1,0), ino = 134824, page_index = 0x98, oldaddr = 0xf049d, newaddr = 0x2bc0 rw = WRITE, type = DATA

f2fs_submit_page_mbio: dev = (1,0), ino = 135260, page_index = 0x47, oldaddr = 0xffffffff, newaddr = 0xf2631 rw = WRITE, type = DATA
f2fs_submit_page_mbio: dev = (1,0), ino = 135260, page_index = 0x48, oldaddr = 0xffffffff, newaddr = 0xf2632 rw = WRITE, type = DATA
f2fs_submit_page_mbio: dev = (1,0), ino = 135260, page_index = 0x49, oldaddr = 0xffffffff, newaddr = 0xf2633 rw = WRITE, type = DATA

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix the wrong stat count of calling gc

With a partition which was formated as multi segments in one section,
we stated incorrectly for count of gc operation.

e.g., for a partition with segs_per_sec = 4

cat /sys/kernel/debug/f2fs/status

GC calls: 208 (BG: 7)
- data segments : 104 (52)
- node segments : 104 (24)

GC called count should be (104 (data segs) + 104 (node segs)) / 4 = 52,
rather than 208. Fix it.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remain last victim segment number ascending order

This patch avoids to remain inefficient victim segment number selected by
a victim.

For example, if all the dirty segments has same valid blocks, we can get
the victim segments descending order due to keeping wrong last segment number.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unneeded pointer conversion

There are redundant pointer conversion in following call stack:
- at position a, inode was been converted to f2fs_file_info.
- at position b, f2fs_file_info was been converted to inode again.

- truncate_blocks(inode,..)
- fi = F2FS_I(inode) ---a
- ADDRS_PER_PAGE(node_page, fi)
- addrs_per_inode(fi)
- inode = &fi->vfs_inode ---b
- f2fs_has_inline_xattr(inode)
- fi = F2FS_I(inode)
- is_inode_flag_set(fi,..)

In order to avoid unneeded conversion, alter ADDRS_PER_PAGE and
addrs_per_inode to acept parameter with type of inode pointer.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid unnecessary search while finding victim in gc

variable nsearched in get_victim_by_default() indicates the number of
dirty segments we already checked. There are 2 problems about the way
it updates:
1. When p.ofs_unit is greater than 1, the victim we find consists
of multiple segments, possibly more than 1 dirty segment.
But nsearched always increases by 1.
2. If segments have been found but not been chosen, nsearched won't
increase. So even we have checked all dirty segments, nsearched
may still less than p.max_search.
All these problems could cause unnecessary search after all dirty
segments have already been checked.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use wait_for_stable_page to avoid contention

In write_begin, if storage supports stable_page, we don't need to wait for
writeback to update its contents.
This patch introduces to use wait_for_stable_page instead of
wait_on_page_writeback.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enhance foreground GC

If we configure section consist of multiple segments, foreground GC will
do the garbage collection with following approach:

for each segment in victim section
blk_start_plug
for each valid block in segment
write out by OPU method
submit bio cache <---
blk_finish_plug <---

There are two issue:
1) for most of the time, 'submit bio cache' will break the merging in
current bio buffer from writes of next segments, making a smaller bio
submitting.
2) block plug only cover IO submitting in one segment, which reduce
opportunity of merging IOs in plug with multiple segments.

So refactor the code as below structure to strive for biggest
opportunity of merging IOs:

blk_start_plug
for each segment in victim section
for each valid block in segment
write out by OPU method
submit bio cache
blk_finish_plug

Test method:
1. mkfs.f2fs -s 8 /dev/sdX
2. touch 32 files
3. write 2M data into each file
4. punch 1.5M data from offset 0 for each file
5. trigger foreground gc through ioctl

Before patch, there are totoally 40 bios submitted.
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65536, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65776, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66016, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66256, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66496, size = 32768
----repeat for 8 times

After patch, there are totally 35 bios submitted.
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65536, size = 122880
----repeat 34 times
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 73696, size = 16384

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to overcome inline_data floods

The scenario is:
1. create lots of node blocks
2. sync
3. write lots of inline_data
-> got panic due to no free space

In that case, we should flush node blocks when writing inline_data in #3,
and trigger gc as well.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: detect idle time depending on user behavior

This patch adds last time that user requested filesystem operations.
This information is used to detect whether system is idle or not later.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: let user being aware of IO error

Sometimes we keep dumb when IO error occur in lower layer device, so user
will not receive any error return value for some operation, but actually,
the operation did not succeed.

This sould be avoided, so this patch reports such kind of error to user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use sbi->blocks_per_seg to avoid unnecessary calculation

Use sbi->blocks_per_seg directly to avoid unnecessary calculation when using
1 << sbi->log_blocks_per_seg.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: relocate the tracepoint for background_gc

Once f2fs_gc is done, wait_ms is changed once more.
So, its tracepoint would be located after it.

Reported-by: He YunLei <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs crypto: fix racing of accessing encrypted page among

different competitors

Since we use different page cache (normally inode's page cache for R/W
and meta inode's page cache for GC) to cache the same physical block
which is belong to an encrypted inode. Writeback of these two page
cache should be exclusive, but now we didn't handle writeback state
well, so there may be potential racing problem:

a)
kworker: f2fs_gc:
- f2fs_write_data_pages
- f2fs_write_data_page
- do_write_data_page
- write_data_page
- f2fs_submit_page_mbio
(page#1 in inode's page cache was queued
in f2fs bio cache, and be ready to write
to new blkaddr)
- gc_data_segment
- move_encrypted_block
- pagecache_get_page
(page#2 in meta inode's page cache
was cached with the invalid datas
of physical block located in new
blkaddr)
- f2fs_submit_page_mbio
(page#1 was submitted, later, page#2
with invalid data will be submitted)

b)
f2fs_gc:
- gc_data_segment
- move_encrypted_block
- f2fs_submit_page_mbio
(page#1 in meta inode's page cache was
queued in f2fs bio cache, and be ready
to write to new blkaddr)
user thread:
- f2fs_write_begin
- f2fs_submit_page_bio
(we submit the request to block layer
to update page#2 in inode's page cache
with physical block located in new
blkaddr, so here we may read gabbage
data from new blkaddr since GC hasn't
writebacked the page#1 yet)

This patch fixes above potential racing problem for encrypted inode.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support lower priority asynchronous readahead in ra_meta_pages

Now, we use ra_meta_pages to reads continuous physical blocks as much as
possible to improve performance of following reads. However, ra_meta_pages
uses a synchronous readahead approach by submitting bio with READ, as READ
is with high priority, it can not be used in the case of preloading blocks,
and it's not sure when these RAed pages will be used.

This patch supports asynchronous readahead in ra_meta_pages by tagging bio
with READA flag in order to allow preloading.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: set GFP_NOFS for grab_cache_page

For normal inodes, their pages are allocated with __GFP_FS, which can cause
filesystem calls when reclaiming memory.
This can incur a dead lock condition accordingly.

So, this patch addresses this problem by introducing
f2fs_grab_cache_page(.., bool for_write), which calls
grab_cache_page_write_begin() with AOP_FLAG_NOFS.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add a tracepoint for background gc

This patch introduces a tracepoint to monitor background gc behaviors.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce background_gc=sync mount option

This patch introduce background_gc=sync enabling synchronous cleaning in
background.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support synchronous gc in ioctl

This patch drops in batches gc triggered through ioctl, since user
can easily control the gc by designing the loop around the ->ioctl.

We support synchronous gc by forcing using FG_GC in f2fs_gc, so with
it, user can make sure that in this round all blocks gced were
persistent in the device until ioctl returned.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>