[dm-devel] [PATCH 4/8] dm: switch to bdev based io accounting interface

[Ming Lei]

DM won't account sectors in flush IO, also we can retrieve sectors
from 'dm_io' for avoiding to allocate & update new original bio, which
will be done in the following patch.

So switch to bdev based io accounting interface.

Signed-off-by: Ming Lei <ming.lei at redhat.com>
---
 drivers/md/dm.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ed85cd1165a4..31eacc0e93ed 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -504,29 +504,24 @@ static void dm_io_acct(struct dm_io *io, bool end)
 	unsigned long start_time = io->start_time;
 	struct mapped_device *md = io->md;
 	struct bio *bio = io->orig_bio;
-	bool is_flush_with_data;
-	unsigned int bi_size;
+	unsigned int sectors;
 
 	/* If REQ_PREFLUSH set save any payload but do not account it */
-	is_flush_with_data = bio_is_flush_with_data(bio);
-	if (is_flush_with_data) {
-		bi_size = bio->bi_iter.bi_size;
-		bio->bi_iter.bi_size = 0;
-	}
+	if (bio_is_flush_with_data(bio))
+		sectors = 0;
+	else
+		sectors = bio_sectors(bio);
 
 	if (!end)
-		bio_start_io_acct_time(bio, start_time);
+		bdev_start_io_acct(bio->bi_bdev, sectors, bio_op(bio),
+				start_time);
 	else
-		bio_end_io_acct(bio, start_time);
+		bdev_end_io_acct(bio->bi_bdev, bio_op(bio), start_time);
 
 	if (unlikely(dm_stats_used(&md->stats)))
 		dm_stats_account_io(&md->stats, bio_data_dir(bio),
 				    bio->bi_iter.bi_sector, bio_sectors(bio),
 				    end, start_time, stats_aux);
-
-	/* Restore bio's payload so it does get accounted upon requeue */
-	if (is_flush_with_data)
-		bio->bi_iter.bi_size = bi_size;
 }
 
 static void __dm_start_io_acct(struct dm_io *io)
-- 
2.31.1