releases/4.7.7/blk-mq-actually-hook-up-defer-list-when-running-requests.patch

   1 From 52b9c330c6a8a4b5a1819bdaddf4ec76ab571e81 Mon Sep 17 00:00:00 2001
   2 From: Omar Sandoval <osandov@fb.com>
   3 Date: Wed, 8 Jun 2016 18:22:20 -0700
   4 Subject: blk-mq: actually hook up defer list when running requests
   5
   6 From: Omar Sandoval <osandov@fb.com>
   7
   8 commit 52b9c330c6a8a4b5a1819bdaddf4ec76ab571e81 upstream.
   9
  10 If ->queue_rq() returns BLK_MQ_RQ_QUEUE_OK, we use continue and skip
  11 over the rest of the loop body. However, dptr is assigned later in the
  12 loop body, and the BLK_MQ_RQ_QUEUE_OK case is exactly the case that we'd
  13 want it for.
  14
  15 NVMe isn't actually using BLK_MQ_F_DEFER_ISSUE yet, nor is any other
  16 in-tree driver, but if the code's going to be there, it might as well
  17 work.
  18
  19 Fixes: 74c450521dd8 ("blk-mq: add a 'list' parameter to ->queue_rq()")
  20 Signed-off-by: Omar Sandoval <osandov@fb.com>
  21 Signed-off-by: Jens Axboe <axboe@fb.com>
  22 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  23
  24 ---
  25  block/blk-mq.c |    2 +-
  26  1 file changed, 1 insertion(+), 1 deletion(-)
  27
  28 --- a/block/blk-mq.c
  29 +++ b/block/blk-mq.c
  30 @@ -784,7 +784,7 @@ static void __blk_mq_run_hw_queue(struct
  31                 switch (ret) {
  32                 case BLK_MQ_RQ_QUEUE_OK:
  33                         queued++;
  34 -                       continue;
  35 +                       break;
  36                 case BLK_MQ_RQ_QUEUE_BUSY:
  37                         list_add(&rq->queuelist, &rq_list);
  38                         __blk_mq_requeue_request(rq);