dm integrity: use plugging when writing the journal

When copying data from the journal to the appropriate place, we submit
many IOs.  Some of these IOs could go to adjacent areas.  Use on-stack
plugging so that adjacent IOs get merged during submission.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 4b2fd524e38d9d6a6bb276afca2487dbf5f882e6..be3b6f42095c6d0a047d49ad97239d851a1f6566 100644 (file)
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1823,6 +1823,9 @@ static void do_journal_write(struct dm_integrity_c *ic, unsigned write_start,
 {
        unsigned i, j, n;
        struct journal_completion comp;
+       struct blk_plug plug;
+
+       blk_start_plug(&plug);
 
        comp.ic = ic;
        comp.in_flight = (atomic_t)ATOMIC_INIT(1);
@@ -1947,6 +1950,8 @@ skip_io:
 
        dm_bufio_write_dirty_buffers_async(ic->bufio);
 
+       blk_finish_plug(&plug);
+
        complete_journal_op(&comp);
        wait_for_completion_io(&comp.comp);