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>
---
fs/btrfs/scrub.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 2d1f890..1204eab 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -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 @@ next:
scrub_submit(sdev);
out:
+ blk_finish_plug(&plug);
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}
--
1.7.3.4
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