Patch "blk-mq: Do not invoke .queue_rq() for a stopped queue" has been added to the 4.8-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to the 4.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     blk-mq-do-not-invoke-.queue_rq-for-a-stopped-queue.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From bc27c01b5c46d3bfec42c96537c7a3fae0bb2cc4 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Fri, 28 Oct 2016 17:18:48 -0700
Subject: blk-mq: Do not invoke .queue_rq() for a stopped queue

From: Bart Van Assche <bart.vanassche@sandisk.com>

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>

---
 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;
 	}
 


Patches currently in stable-queue which might be from bart.vanassche@sandisk.com are

queue-4.8/dm-rq-fix-a-race-condition-in-rq_completed.patch
queue-4.8/blk-mq-do-not-invoke-.queue_rq-for-a-stopped-queue.patch
queue-4.8/dm-table-fix-all_blk_mq-inconsistency-when-an-empty-table-is-loaded.patch
queue-4.8/dm-table-an-all_blk_mq-table-must-be-loaded-for-a-blk-mq-dm-device.patch