6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chao Yu <chao@xxxxxxxxxx>
[ Upstream commit 005abf9e5e0d4dcfce318ae5dbcac32b7bf6b647 ]
Previously, we have two mechanisms to cache & submit small discards:
a) set max small discard number in /sys/fs/f2fs/vdb/max_small_discards,
and checkpoint will cache small discard candidates w/ configured maximum
number.
b) call FITRIM ioctl, also, checkpoint in f2fs_trim_fs() will cache small
discard candidates w/ configured discard granularity, but w/o limitation
of number. FSTRIM interface is asynchronized, so it won't submit discard
directly.
Finally, discard thread will submit them in background periodically.
However, after commit 9ac00e7cef10 ("f2fs: do not issue small discard
commands during checkpoint"), the mechanism a) is broken, since no matter
how we configure the sysfs entry /sys/fs/f2fs/vdb/max_small_discards,
checkpoint will not cache small discard candidates any more.
echo 0 > /sys/fs/f2fs/vdb/max_small_discards
xfs_io -f /mnt/f2fs/file -c "pwrite 0 2m" -c "fsync"
xfs_io /mnt/f2fs/file -c "fpunch 0 4k"
sync
cat /proc/fs/f2fs/vdb/discard_plist_info |head -2
echo 100 > /sys/fs/f2fs/vdb/max_small_discards
rm /mnt/f2fs/file
xfs_io -f /mnt/f2fs/file -c "pwrite 0 2m" -c "fsync"
xfs_io /mnt/f2fs/file -c "fpunch 0 4k"
sync
cat /proc/fs/f2fs/vdb/discard_plist_info |head -2
Before the patch:
Discard pend list(Show diacrd_cmd count on each entry, .:not exist):
0 . . . . . . . .
Discard pend list(Show diacrd_cmd count on each entry, .:not exist):
0 3 1 . . . . . .
After the patch:
Discard pend list(Show diacrd_cmd count on each entry, .:not exist):
0 . . . . . . . .
Discard pend list(Show diacrd_cmd count on each entry, .:not exist):
0 . . . . . . . .
This patch reverts commit 9ac00e7cef10 ("f2fs: do not issue small discard
commands during checkpoint") in order to fix this issue.
Fixes: 9ac00e7cef10 ("f2fs: do not issue small discard commands during checkpoint")
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/f2fs/segment.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index a31a47b066d1d..be08be6f4bfd6 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2211,7 +2211,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
len = next_pos - cur_pos;
if (f2fs_sb_has_blkzoned(sbi) ||
- !force || len < cpc->trim_minlen)
+ (force && len < cpc->trim_minlen))
goto skip;
f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos,
--
2.40.1
