6.5-stable review patch. If anyone has any objections, please let me know.
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From: Chao Yu chao@kernel.org
[ 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@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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,