linux-stable.git/fs/f2fs/segment.c, branch linux-5.4.y

f2fs: fix to do sanity check in update_sit_entry

2024-09-04T11:14:56+00:00

[ Upstream commit 36959d18c3cf09b3c12157c6950e18652067de77 ]

If GET_SEGNO return NULL_SEGNO for some unecpected case,
update_sit_entry will access invalid memory address,
cause system crash. It is better to do sanity check about
GET_SEGNO just like update_segment_mtime & locate_dirty_segment.

Also remove some redundant judgment code.

Signed-off-by: Zhiguo Niu 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix normal discard process

2023-01-18T10:41:17+00:00

[ Upstream commit b5f1a218ae5e4339130d6e733f0e63d623e09a2c ]

In the DPOLICY_BG mode, there is a conflict between
the two conditions "i + 1 < dpolicy->granularity" and
"i < DEFAULT_DISCARD_GRANULARITY". If i = 15, the first
condition is false, it will enter the second condition
and dispatch all small granularity discards in function
 __issue_discard_cmd_orderly. The restrictive effect
of the first condition to small discards will be
invalidated. These two conditions should align.

Fixes: 20ee4382322c ("f2fs: issue small discard by LBA order")
Signed-off-by: Dongdong Zhang 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix dereference of stale list iterator after loop body

2022-06-14T16:11:42+00:00

[ Upstream commit 2aaf51dd39afb6d01d13f1e6fe20b684733b37d5 ]

The list iterator variable will be a bogus pointer if no break was hit.
Dereferencing it (cur->page in this case) could load an out-of-bounds/undefined
value making it unsafe to use that in the comparision to determine if the
specific element was found.

Since 'cur->page' *can* be out-ouf-bounds it cannot be guaranteed that
by chance (or intention of an attacker) it matches the value of 'page'
even though the correct element was not found.

This is fixed by using a separate list iterator variable for the loop
and only setting the original variable if a suitable element was found.
Then determing if the element was found is simply checking if the
variable is set.

Fixes: 8c242db9b8c0 ("f2fs: fix stale ATOMIC_WRITTEN_PAGE private pointer")
Signed-off-by: Jakob Koschel 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: show f2fs instance in printk_ratelimited

2021-09-22T10:26:23+00:00

[ Upstream commit c45d6002ff7a322022560e9b19ad867b01fec77f ]

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 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: handle errors of f2fs_get_meta_page_nofail

2020-11-05T10:43:14+00:00

[ Upstream commit 86f33603f8c51537265ff7ac0320638fd2cbdb1b ]

First problem is we hit BUG_ON() in f2fs_get_sum_page given EIO on
f2fs_get_meta_page_nofail().

Quick fix was not to give any error with infinite loop, but syzbot caught
a case where it goes to that loop from fuzzed image. In turned out we abused
f2fs_get_meta_page_nofail() like in the below call stack.

- f2fs_fill_super
 - f2fs_build_segment_manager
  - build_sit_entries
   - get_current_sit_page

INFO: task syz-executor178:6870 can't die for more than 143 seconds.
task:syz-executor178 state:R
 stack:26960 pid: 6870 ppid:  6869 flags:0x00004006
Call Trace:

Showing all locks held in the system:
1 lock held by khungtaskd/1179:
 #0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6242
1 lock held by systemd-journal/3920:
1 lock held by in:imklog/6769:
 #0: ffff88809eebc130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
1 lock held by syz-executor178/6870:
 #0: ffff8880925120e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229

Actually, we didn't have to use _nofail in this case, since we could return
error to mount(2) already with the error handler.

As a result, this patch tries to 1) remove _nofail callers as much as possible,
2) deal with error case in last remaining caller, f2fs_get_sum_page().

Reported-by: syzbot+ee250ac8137be41d7b13@syzkaller.appspotmail.com
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: Fix deadlock in f2fs_gc() context during atomic files handling

2020-01-04T18:18:18+00:00

[ Upstream commit 677017d196ba2a4cfff13626b951cc9a206b8c7c ]

The FS got stuck in the below stack when the storage is almost
full/dirty condition (when FG_GC is being done).

schedule_timeout
io_schedule_timeout
congestion_wait
f2fs_drop_inmem_pages_all
f2fs_gc
f2fs_balance_fs
__write_node_page
f2fs_fsync_node_pages
f2fs_do_sync_file
f2fs_ioctl

The root cause for this issue is there is a potential infinite loop
in f2fs_drop_inmem_pages_all() for the case where gc_failure is true
and when there an inode whose i_gc_failures[GC_FAILURE_ATOMIC] is
not set. Fix this by keeping track of the total atomic files
currently opened and using that to exit from this condition.

Fix-suggested-by: Chao Yu 
Signed-off-by: Chao Yu 
Signed-off-by: Sahitya Tummala 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix to add missing F2FS_IO_ALIGNED() condition

2019-09-16T15:38:49+00:00

In f2fs_allocate_data_block(), we will reset fio.retry for IO
alignment feature instead of IO serialization feature.

In addition, spread F2FS_IO_ALIGNED() to check IO alignment
feature status explicitly.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: avoid infinite GC loop due to stale atomic files

2019-09-16T15:38:20+00:00

If committing atomic pages is failed when doing f2fs_do_sync_file(), we can
get commited pages but atomic_file being still set like:

- inmem:    0, atomic IO:    4 (Max.   10), volatile IO:    0 (Max.    0)

If GC selects this block, we can get an infinite loop like this:

f2fs_submit_page_bio: dev = (253,7), ino = 2, page_index = 0x2359a8, oldaddr = 0x2359a8, newaddr = 0x2359a8, rw = READ(), type = COLD_DATA
f2fs_submit_read_bio: dev = (253,7)/(253,7), rw = READ(), DATA, sector = 18533696, size = 4096
f2fs_get_victim: dev = (253,7), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 4355, cost = 1, ofs_unit = 1, pre_victim_secno = 4355, prefree = 0, free = 234
f2fs_iget: dev = (253,7), ino = 6247, pino = 5845, i_mode = 0x81b0, i_size = 319488, i_nlink = 1, i_blocks = 624, i_advise = 0x2c
f2fs_submit_page_bio: dev = (253,7), ino = 2, page_index = 0x2359a8, oldaddr = 0x2359a8, newaddr = 0x2359a8, rw = READ(), type = COLD_DATA
f2fs_submit_read_bio: dev = (253,7)/(253,7), rw = READ(), DATA, sector = 18533696, size = 4096
f2fs_get_victim: dev = (253,7), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 4355, cost = 1, ofs_unit = 1, pre_victim_secno = 4355, prefree = 0, free = 234
f2fs_iget: dev = (253,7), ino = 6247, pino = 5845, i_mode = 0x81b0, i_size = 319488, i_nlink = 1, i_blocks = 624, i_advise = 0x2c

In that moment, we can observe:

[Before]
Try to move 5084219 blocks (BG: 384508)
  - data blocks : 4962373 (274483)
  - node blocks : 121846 (110025)
Skipped : atomic write 4534686 (10)

[After]
Try to move 5088973 blocks (BG: 384508)
  - data blocks : 4967127 (274483)
  - node blocks : 121846 (110025)
Skipped : atomic write 4539440 (10)

So, refactor atomic_write flow like this:
1. start_atomic_write
 - add inmem_list and set atomic_file

2. write()
 - register it in inmem_pages

3. commit_atomic_write
 - if no error, f2fs_drop_inmem_pages()
 - f2fs_commit_inmme_pages() failed
   : __revoked_inmem_pages() was done
 - f2fs_do_sync_file failed
   : abort_atomic_write later

4. abort_atomic_write
 - f2fs_drop_inmem_pages

5. f2fs_drop_inmem_pages
 - clear atomic_file
 - remove inmem_list

Based on this change, when GC fails to move block in atomic_file,
f2fs_drop_inmem_pages_all() can call f2fs_drop_inmem_pages().

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: enhance f2fs_is_checkpoint_ready()'s readability

2019-09-06T23:18:26+00:00

This patch changes sematics of f2fs_is_checkpoint_ready()'s return
value as: return true when checkpoint is ready, other return false,
it can improve readability of below conditions.

f2fs_submit_page_write()
...
	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
				!f2fs_is_checkpoint_ready(sbi))
		__submit_merged_bio(io);

f2fs_balance_fs()
...
	if (!f2fs_is_checkpoint_ready(sbi))
		return;

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Fix indefinite loop in f2fs_gc()

2019-08-23T14:57:15+00:00

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 
Reviewed-by: Chao Yu 
[Jaegeuk Kim: fix wrong bitmap size]
Signed-off-by: Jaegeuk Kim