The function cached_dev_make_request() and flash_dev_make_request() call
generic_start_io_acct() with (struct bcache_device)->disk when they start a
closure. Then the function bio_complete() calls generic_end_io_acct() with
(struct search)->orig_bio->bi_disk when the closure has done.
Since the `bi_disk` is not the bcache device, the generic_end_io_acct() is
called with a wrong device queue.

It causes the "inflight" (in struct hd_struct) counter keep increasing
without decreasing.

This patch fix the problem by calling generic_end_io_acct() with
(struct bcache_device)->disk.

Signed-off-by: Zhai Zhaoxuan <redacted>
---
drivers/md/bcache/request.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 643c3021624f..83de85fe4542 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c

@@ -611,8 +611,8 @@ static void request_endio(struct bio *bio)

static void bio_complete(struct search *s)
{
    if (s->orig_bio) {
-        struct request_queue *q = s->orig_bio->bi_disk->queue;
-        generic_end_io_acct(q, bio_data_dir(s->orig_bio),
+        generic_end_io_acct(s->d->disk->queue,
+                    bio_data_dir(s->orig_bio),
                    &s->d->disk->part0, s->start_time);

        trace_bcache_request_end(s->d, s->orig_bio);
-- 
2.15.1