mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![]() As Ju Hyung Park reported:
"When 'fstrim' is called for manual trim, a BUG() can be triggered
randomly with this patch.
I'm seeing this issue on both x86 Desktop and arm64 Android phone.
On x86 Desktop, this was caused during Ubuntu boot-up. I have a
cronjob installed which calls 'fstrim -v /' during boot. On arm64
Android, this was caused during GC looping with 1ms gc_min_sleep_time
& gc_max_sleep_time."
Root cause of this issue is that f2fs_wait_discard_bios can only be
used by f2fs_put_super, because during put_super there must be no
other referrers, so it can ignore discard entry's reference count
when removing the entry, otherwise in other caller we will hit bug_on
in __remove_discard_cmd as there may be other issuer added reference
count in discard entry.
Thread A Thread B
- issue_discard_thread
- f2fs_ioc_fitrim
- f2fs_trim_fs
- f2fs_wait_discard_bios
- __issue_discard_cmd
- __submit_discard_cmd
- __wait_discard_cmd
- dc->ref++
- __wait_one_discard_bio
- __wait_discard_cmd
- __remove_discard_cmd
- f2fs_bug_on(sbi, dc->ref)
Fixes:
|
||
---|---|---|
.. | ||
acl.c | ||
acl.h | ||
checkpoint.c | ||
data.c | ||
debug.c | ||
dir.c | ||
extent_cache.c | ||
f2fs.h | ||
file.c | ||
gc.c | ||
gc.h | ||
hash.c | ||
inline.c | ||
inode.c | ||
Kconfig | ||
Makefile | ||
namei.c | ||
node.c | ||
node.h | ||
recovery.c | ||
segment.c | ||
segment.h | ||
shrinker.c | ||
super.c | ||
sysfs.c | ||
trace.c | ||
trace.h | ||
xattr.c | ||
xattr.h |