diff options
author | Mikulas Patocka <mpatocka@redhat.com> | 2009-06-22 05:12:25 -0400 |
---|---|---|
committer | Alasdair G Kergon <agk@redhat.com> | 2009-06-22 05:12:25 -0400 |
commit | 494b3ee7d4f69210def80aecce28d08c3f0755d5 (patch) | |
tree | 8cd8fc4de72cf9a1a56e45518019a3cae106515a | |
parent | 8627921fa2ef6d40fd9b787e163ba3a9ff8f471d (diff) |
dm snapshot: support barriers
Flush support for dm-snapshot target.
This patch just forwards the flush request to either the origin or the snapshot
device. (It doesn't flush exception store metadata.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-rw-r--r-- | drivers/md/dm-snap.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index d73f17fc7778..d573165cd2b7 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c | |||
@@ -678,6 +678,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |||
678 | 678 | ||
679 | ti->private = s; | 679 | ti->private = s; |
680 | ti->split_io = s->store->chunk_size; | 680 | ti->split_io = s->store->chunk_size; |
681 | ti->num_flush_requests = 1; | ||
681 | 682 | ||
682 | return 0; | 683 | return 0; |
683 | 684 | ||
@@ -1030,6 +1031,11 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio, | |||
1030 | chunk_t chunk; | 1031 | chunk_t chunk; |
1031 | struct dm_snap_pending_exception *pe = NULL; | 1032 | struct dm_snap_pending_exception *pe = NULL; |
1032 | 1033 | ||
1034 | if (unlikely(bio_empty_barrier(bio))) { | ||
1035 | bio->bi_bdev = s->store->cow->bdev; | ||
1036 | return DM_MAPIO_REMAPPED; | ||
1037 | } | ||
1038 | |||
1033 | chunk = sector_to_chunk(s->store, bio->bi_sector); | 1039 | chunk = sector_to_chunk(s->store, bio->bi_sector); |
1034 | 1040 | ||
1035 | /* Full snapshots are not usable */ | 1041 | /* Full snapshots are not usable */ |
@@ -1338,6 +1344,8 @@ static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |||
1338 | } | 1344 | } |
1339 | 1345 | ||
1340 | ti->private = dev; | 1346 | ti->private = dev; |
1347 | ti->num_flush_requests = 1; | ||
1348 | |||
1341 | return 0; | 1349 | return 0; |
1342 | } | 1350 | } |
1343 | 1351 | ||
@@ -1353,6 +1361,9 @@ static int origin_map(struct dm_target *ti, struct bio *bio, | |||
1353 | struct dm_dev *dev = ti->private; | 1361 | struct dm_dev *dev = ti->private; |
1354 | bio->bi_bdev = dev->bdev; | 1362 | bio->bi_bdev = dev->bdev; |
1355 | 1363 | ||
1364 | if (unlikely(bio_empty_barrier(bio))) | ||
1365 | return DM_MAPIO_REMAPPED; | ||
1366 | |||
1356 | /* Only tell snapshots if this is a write */ | 1367 | /* Only tell snapshots if this is a write */ |
1357 | return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED; | 1368 | return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED; |
1358 | } | 1369 | } |