[PATCH 4.8 62/85] blk-mq: Do not invoke .queue_rq() for a stopped queue

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>

commit bc27c01b5c46d3bfec42c96537c7a3fae0bb2cc4 upstream.

The meaning of the BLK_MQ_S_STOPPED flag is "do not call
.queue_rq()". Hence modify blk_mq_make_request() such that requests
are queued instead of issued if a queue has been stopped.

Reported-by: Ming Lei <tom.leiming@xxxxxxxxx>
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Ming Lei <tom.leiming@xxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 block/blk-mq.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1371,9 +1371,9 @@ static blk_qc_t blk_mq_make_request(stru
 		blk_mq_put_ctx(data.ctx);
 		if (!old_rq)
 			goto done;
-		if (!blk_mq_direct_issue_request(old_rq, &cookie))
-			goto done;
-		blk_mq_insert_request(old_rq, false, true, true);
+		if (test_bit(BLK_MQ_S_STOPPED, &data.hctx->state) ||
+		    blk_mq_direct_issue_request(old_rq, &cookie) != 0)
+			blk_mq_insert_request(old_rq, false, true, true);
 		goto done;
 	}