btrfs: scrub: add explicit plugging

With the removal of the implicit plugging scrub ends up doing more and
smaller I/O than necessary. This patch adds explicit plugging per chunk.

Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Arne Jansen 2011-05-28 20:58:38 +00:00 committed by Chris Mason
parent a4689d2bd3
commit e7786c3ae5

View file

@ -348,9 +348,6 @@ static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
int ret;
DECLARE_COMPLETION_ONSTACK(complete);
/* we are going to wait on this IO */
rw |= REQ_SYNC;
bio = bio_alloc(GFP_NOFS, 1);
bio->bi_bdev = bdev;
bio->bi_sector = sector;
@ -359,6 +356,7 @@ static int scrub_fixup_io(int rw, struct block_device *bdev, sector_t sector,
bio->bi_private = &complete;
submit_bio(rw, bio);
/* this will also unplug the queue */
wait_for_completion(&complete);
ret = !test_bit(BIO_UPTODATE, &bio->bi_flags);
@ -743,6 +741,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_root *csum_root = fs_info->csum_root;
struct btrfs_extent_item *extent;
struct blk_plug plug;
u64 flags;
int ret;
int slot;
@ -847,6 +846,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
* the scrub. This might currently (crc32) end up to be about 1MB
*/
start_stripe = 0;
blk_start_plug(&plug);
again:
logical = base + offset + start_stripe * increment;
for (i = start_stripe; i < nstripes; ++i) {
@ -988,6 +988,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
scrub_submit(sdev);
out:
blk_finish_plug(&plug);
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}