From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Sat, 29 Oct 2016 00:18:48 +0000 (-0700)
Subject: blk-mq: Do not invoke .queue_rq() for a stopped queue
X-Git-Tag: firefly_0821_release~176^2~4^2~7^2~16
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f0898dc2852b2e12afabff150bbf2390efec0395;p=firefly-linux-kernel-4.4.55.git

blk-mq: Do not invoke .queue_rq() for a stopped queue

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@gmail.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c3e461ec40e4..9f99a01b00e8 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1313,9 +1313,9 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 		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;
 	}