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: stable@vger.kernel.org # 4.9+
CC: Jaegeuk Kim <jaegeuk@kernel.org>
CC: linux-f2fs-devel@lists.sourceforge.net
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 1254986dd6eb1f3f59d05966897c608abc869198..7c0f6bdf817d4370b74b36de9096fad73c75fbd4 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -309,7 +309,7 @@ static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
        if (type >= META_FLUSH) {
                io->fio.type = META_FLUSH;
                io->fio.op = REQ_OP_WRITE;
-               io->fio.op_flags = REQ_META | REQ_PRIO;
+               io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
                if (!test_opt(sbi, NOBARRIER))
                        io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
        }

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6e1c8cf757491ca9c273ee6ae453c3ffa4dc1f22..de31030b5041c4e618508f8478c7a5660de7a1de 100644 (file)
--- 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);

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 9a14b25903378ac351b8129a06b94e7d868a6017..83355ec4a92cdeb86d4be8d4630e01e7b0c96a28 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1325,7 +1325,7 @@ static int __f2fs_commit_super(struct buffer_head *bh,
        unlock_buffer(bh);
 
        /* it's rare case, we can do fua all the time */
-       return __sync_dirty_buffer(bh, REQ_PREFLUSH | REQ_FUA);
+       return __sync_dirty_buffer(bh, REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
 }
 
 static inline bool sanity_check_area_boundary(struct f2fs_sb_info *sbi,