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authorMike Snitzer <snitzer@redhat.com>2022-01-28 18:58:41 +0300
committerJens Axboe <axboe@kernel.dk>2022-01-28 22:28:15 +0300
commitb879f915bc48a18d4f4462729192435bb0f17052 (patch)
treea6872f00546c3ee5ae32a73dadc02712a7c27b65
parentf524d9c95fab54783d0038f7a3e8c014d5b56857 (diff)
downloadlinux-b879f915bc48a18d4f4462729192435bb0f17052.tar.xz
dm: properly fix redundant bio-based IO accounting
Record the start_time for a bio but defer the starting block core's IO accounting until after IO is submitted using bio_start_io_acct_time(). This approach avoids the need to mess around with any of the individual IO stats in response to a bio_split() that follows bio submission. Reported-by: Bud Brown <bubrown@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org Depends-on: e45c47d1f94e ("block: add bio_start_io_acct_time() to control start_time") Signed-off-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220128155841.39644-4-snitzer@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/md/dm.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 9849114b3c08..dcbd6d201619 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -489,7 +489,7 @@ static void start_io_acct(struct dm_io *io)
struct mapped_device *md = io->md;
struct bio *bio = io->orig_bio;
- io->start_time = bio_start_io_acct(bio);
+ bio_start_io_acct_time(bio, io->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),
@@ -535,7 +535,7 @@ static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
io->md = md;
spin_lock_init(&io->endio_lock);
- start_io_acct(io);
+ io->start_time = jiffies;
return io;
}
@@ -1482,6 +1482,7 @@ static void __split_and_process_bio(struct mapped_device *md,
submit_bio_noacct(bio);
}
}
+ start_io_acct(ci.io);
/* drop the extra reference count */
dm_io_dec_pending(ci.io, errno_to_blk_status(error));