From dbd3bbd291a03f1383de6242e7999e8487cb869b Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Thu, 6 Dec 2018 11:41:17 -0500
Subject: [PATCH] dm rq: leverage blk_mq_queue_busy() to check for outstanding
IO
Now that request-based dm-multipath only supports blk-mq, make use of
the newly introduced blk_mq_queue_busy() to check for outstanding IO --
rather than (ab)using the block core's in_flight counters.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/md/dm-rq.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 1f1fe9a618ea9..d2397d8fcbd1c 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -130,11 +130,11 @@ static void rq_end_stats(struct mapped_device *md, struct request *orig)
*/
static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
{
- atomic_dec(&md->pending[rw]);
-
/* nudge anyone waiting on suspend queue */
- if (!md_in_flight(md))
- wake_up(&md->wait);
+ if (unlikely(waitqueue_active(&md->wait))) {
+ if (!blk_mq_queue_busy(md->queue))
+ wake_up(&md->wait);
+ }
/*
* dm_put() must be at the end of this function. See the comment above
@@ -436,7 +436,6 @@ ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
static void dm_start_request(struct mapped_device *md, struct request *orig)
{
blk_mq_start_request(orig);
- atomic_inc(&md->pending[rq_data_dir(orig)]);
if (unlikely(dm_stats_used(&md->stats))) {
struct dm_rq_target_io *tio = tio_from_request(orig);
--
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