[PATCH v2 3/8] raid5: fix missing io accounting in raid5_align_endio()

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

Io will only be accounted as done from raid5_align_endio() if the io
succeeded, and io inflight counter will be leaked if such io failed.

Fix this problem by switching to use md_account_bio() for io accounting.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Reviewed-by: Xiao Ni <xni@xxxxxxxxxx>
---
 drivers/md/raid5.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index cef0b400b2ee..4cdb35e54251 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5468,26 +5468,17 @@ static struct bio *remove_bio_from_retry(struct r5conf *conf,
  */
 static void raid5_align_endio(struct bio *bi)
 {
-	struct md_io_clone *md_io_clone = bi->bi_private;
-	struct bio *raid_bi = md_io_clone->orig_bio;
-	struct mddev *mddev;
-	struct r5conf *conf;
-	struct md_rdev *rdev;
+	struct bio *raid_bi = bi->bi_private;
+	struct md_rdev *rdev = (void *)raid_bi->bi_next;
+	struct mddev *mddev = rdev->mddev;
+	struct r5conf *conf = mddev->private;
 	blk_status_t error = bi->bi_status;
-	unsigned long start_time = md_io_clone->start_time;
 
 	bio_put(bi);
-
-	rdev = (void*)raid_bi->bi_next;
 	raid_bi->bi_next = NULL;
-	mddev = rdev->mddev;
-	conf = mddev->private;
-
 	rdev_dec_pending(rdev, conf->mddev);
 
 	if (!error) {
-		if (blk_queue_io_stat(raid_bi->bi_bdev->bd_disk->queue))
-			bio_end_io_acct(raid_bi, start_time);
 		bio_endio(raid_bi);
 		if (atomic_dec_and_test(&conf->active_aligned_reads))
 			wake_up(&conf->wait_for_quiescent);
@@ -5506,7 +5497,6 @@ static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio)
 	struct md_rdev *rdev;
 	sector_t sector, end_sector, first_bad;
 	int bad_sectors, dd_idx;
-	struct md_io_clone *md_io_clone;
 	bool did_inc;
 
 	if (!in_chunk_boundary(mddev, raid_bio)) {
@@ -5543,16 +5533,13 @@ static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio)
 		return 0;
 	}
 
-	align_bio = bio_alloc_clone(rdev->bdev, raid_bio, GFP_NOIO,
-				    &mddev->io_clone_set);
-	md_io_clone = container_of(align_bio, struct md_io_clone, bio_clone);
+	md_account_bio(mddev, &raid_bio);
 	raid_bio->bi_next = (void *)rdev;
-	if (blk_queue_io_stat(raid_bio->bi_bdev->bd_disk->queue))
-		md_io_clone->start_time = bio_start_io_acct(raid_bio);
-	md_io_clone->orig_bio = raid_bio;
 
+	align_bio = bio_alloc_clone(rdev->bdev, raid_bio, GFP_NOIO,
+				    &mddev->bio_set);
 	align_bio->bi_end_io = raid5_align_endio;
-	align_bio->bi_private = md_io_clone;
+	align_bio->bi_private = raid_bio;
 	align_bio->bi_iter.bi_sector = sector;
 
 	/* No reshape active, so we can trust rdev->data_offset */
-- 
2.39.2