dm: switch to bdev based IO accounting interfaces

DM splits flush with data into empty flush followed by bio with data
payload, switch dm_io_acct() to use bdev_{start,end}_io_acct() to do
this accoiunting more naturally (rather than temporarily changing the
bio's bi_size).

This will allow DM to more easily account bios that are split (in
following commit).

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2b99ee2a6131e01c63cba0780a1b8691e701c767..30578ee0cbe3c7eaef54862ee0b715e1c0b4952d 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -508,30 +508,28 @@ 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 REQ_PREFLUSH set, don't account payload, it will be
+        * submitted (and accounted) after this flush completes.
+        */
+       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 (static_branch_unlikely(&stats_enabled) &&
            unlikely(dm_stats_used(&md->stats)))
                dm_stats_account_io(&md->stats, bio_data_dir(bio),
-                                   bio->bi_iter.bi_sector, bio_sectors(bio),
+                                   bio->bi_iter.bi_sector, sectors,
                                    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)