Chao Yu 638164a271 f2fs: fix potential panic during fstrim ... 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: 969d1b180d Reported-by: Ju Hyung Park <qkrwngud825@gmail.com> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>		2017-10-03 08:06:05 -07:00
..
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