diff options
| author | Ming Lei <ming.lei@redhat.com> | 2020-06-24 16:00:58 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2020-07-07 12:00:01 -0400 |
| commit | 85067747cf9888249fa11fa49ef75af5192d3988 (patch) | |
| tree | 4ae28ab98db5eec5c1eae0e14f15a99df4e0604d /drivers/md/dm-rq.c | |
| parent | dcb7fd82c75ee2d6e6f9d8cc71c52519ed52e258 (diff) | |
dm: do not use waitqueue for request-based DM
Given request-based DM now uses blk-mq's blk_mq_queue_inflight() to
determine if outstanding IO has completed (and DM has no control over
the blk-mq state machine used to track outstanding IO) it is unsafe to
wakeup waiter (dm_wait_for_completion) before blk-mq has cleared a
request's state bits (e.g. MQ_RQ_IN_FLIGHT or MQ_RQ_COMPLETE). As
such dm_wait_for_completion() could be left to wait indefinitely if no
other requests complete.
Fix this by eliminating request-based DM's use of waitqueue to wait
for blk-mq requests to complete in dm_wait_for_completion.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Depends-on: 3c94d83cb3526 ("blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-rq.c')
| -rw-r--r-- | drivers/md/dm-rq.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index f60c02512121..85e0daabad49 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -146,10 +146,6 @@ static void rq_end_stats(struct mapped_device *md, struct request *orig) */ static void rq_completed(struct mapped_device *md) { - /* nudge anyone waiting on suspend queue */ - if (unlikely(wq_has_sleeper(&md->wait))) - wake_up(&md->wait); - /* * dm_put() must be at the end of this function. See the comment above */ |