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| author | Jan Kara <jack@suse.cz> | 2017-05-02 17:03:50 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-05-16 15:42:01 +0200 |
| commit | 8d91012528b3c95c159e6b6779e367421df9cbb5 (patch) | |
| tree | 7a10ebc80a4d62384bdf0e72e2d522f18aba1c63 /fs | |
| parent | 4751832da990a927c37526ae67b9226ea01eb99e (diff) | |
| download | op-kernel-dev-8d91012528b3c95c159e6b6779e367421df9cbb5.zip op-kernel-dev-8d91012528b3c95c159e6b6779e367421df9cbb5.tar.gz | |
btrfs: 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.
CC: David Sterba <dsterba@suse.com>
CC: linux-btrfs@vger.kernel.org
Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/disk-io.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6831942..b3579d1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3488,10 +3488,12 @@ static int write_dev_supers(struct btrfs_device *device, * we fua the first super. The others we allow * to go down lazy. */ - if (i == 0) - ret = btrfsic_submit_bh(REQ_OP_WRITE, REQ_FUA, bh); - else + if (i == 0) { + ret = btrfsic_submit_bh(REQ_OP_WRITE, + REQ_SYNC | REQ_FUA, bh); + } else { ret = btrfsic_submit_bh(REQ_OP_WRITE, REQ_SYNC, bh); + } if (ret) errors++; } @@ -3556,7 +3558,7 @@ static int write_dev_flush(struct btrfs_device *device, int wait) bio->bi_end_io = btrfs_end_empty_barrier; bio->bi_bdev = device->bdev; - bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; + bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH; init_completion(&device->flush_wait); bio->bi_private = &device->flush_wait; device->flush_bio = bio; |
