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| author | Ming Lei <ming.lei@redhat.com> | 2020-07-07 11:04:33 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-16 08:16:47 +0200 |
| commit | 49a7ac29f6a0c3360f521ab2162dc2663f3b40a2 (patch) | |
| tree | f52dc81156180f1846120eb1eec577991f27d545 /block/blk-mq.c | |
| parent | 2dfd182451d99dfa007072cb4bc7c7b39938be9a (diff) | |
blk-mq: consider non-idle request as "inflight" in blk_mq_rq_inflight()
commit 05a4fed69ff00a8bd83538684cb602a4636b07a7 upstream.
dm-multipath is the only user of blk_mq_queue_inflight(). When
dm-multipath calls blk_mq_queue_inflight() to check if it has
outstanding IO it can get a false negative. The reason for this is
blk_mq_rq_inflight() doesn't consider requests that are no longer
MQ_RQ_IN_FLIGHT but that are now MQ_RQ_COMPLETE (->complete isn't
called or finished yet) as "inflight".
This causes request-based dm-multipath's dm_wait_for_completion() to
return before all outstanding dm-multipath requests have actually
completed. This breaks DM multipath's suspend functionality because
blk-mq requests complete after DM's suspend has finished -- which
shouldn't happen.
Fix this by considering any request not in the MQ_RQ_IDLE state
(so either MQ_RQ_COMPLETE or MQ_RQ_IN_FLIGHT) as "inflight" in
blk_mq_rq_inflight().
Fixes: 3c94d83cb3526 ("blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index f1b930a300a3..ae7d31cb5a4e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -829,10 +829,10 @@ static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq, void *priv, bool reserved) { /* - * If we find a request that is inflight and the queue matches, + * If we find a request that isn't idle and the queue matches, * we know the queue is busy. Return false to stop the iteration. */ - if (rq->state == MQ_RQ_IN_FLIGHT && rq->q == hctx->queue) { + if (blk_mq_request_started(rq) && rq->q == hctx->queue) { bool *busy = priv; *busy = true; |