f2fs: Make flush bios explicitely sync
Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions. generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.
Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.
Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3
Cc: [email protected] # 4.9+
CC: Jaegeuk Kim <[email protected]>
CC: [email protected]
Signed-off-by: Jan Kara <[email protected]>
Acked-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6e1c8cf..de31030 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -446,7 +446,7 @@ static int __submit_flush_wait(struct f2fs_sb_info *sbi,
struct bio *bio = f2fs_bio_alloc(0);
int ret;
- bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
+ bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
bio->bi_bdev = bdev;
ret = submit_bio_wait(bio);
bio_put(bio);
