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

Ming Lei
2022-04-12T10:09:42Z

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@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