Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A smaller collection of fixes for the block core that would be nice to
  have in -rc2.  This pull request contains:

   - Fixes for races in the wait/wakeup logic used in blk-mq from
     Alexander.  No issues have been observed, but it is definitely a
     bit flakey currently.  Alternatively, we may drop the cyclic
     wakeups going forward, but that needs more testing.

   - Some cleanups from Christoph.

   - Fix for an oops in null_blk if queue_mode=1 and softirq completions
     are used.  From me.

   - A fix for a regression caused by the chunk size setting.  It
     inadvertently used max_hw_sectors instead of max_sectors, which is
     incorrect, and causes hangs on btrfs multi-disk setups (where hw
     sectors apparently isn't set).  From me.

   - Removal of WQ_POWER_EFFICIENT in the kblockd creation.  This was a
     recent addition as well, but it actually breaks blk-mq which relies
     on strict scheduling.  If the workqueue power_efficient mode is
     turned on, this breaks blk-mq.  From Matias.

   - null_blk module parameter description fix from Mike"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: bitmap tag: fix races in bt_get() function
  blk-mq: bitmap tag: fix race on blk_mq_bitmap_tags::wake_cnt
  blk-mq: bitmap tag: fix races on shared ::wake_index fields
  block: blk_max_size_offset() should check ->max_sectors
  null_blk: fix softirq completions for queue_mode == 1
  blk-mq: merge blk_mq_drain_queue and __blk_mq_drain_queue
  blk-mq: properly drain stopped queues
  block: remove WQ_POWER_EFFICIENT from kblockd
  null_blk: fix name and description of 'queue_mode' module parameter
  block: remove elv_abort_queue and blk_abort_flushes

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 77087a29b127..a3b042c4d448 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -79,7 +79,7 @@ MODULE_PARM_DESC(home_node, "Home node for the device");
 
 static int queue_mode = NULL_Q_MQ;
 module_param(queue_mode, int, S_IRUGO);
-MODULE_PARM_DESC(use_mq, "Use blk-mq interface (0=bio,1=rq,2=multiqueue)");
+MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)");
 
 static int gb = 250;
 module_param(gb, int, S_IRUGO);
@@ -227,7 +227,10 @@ static void null_cmd_end_timer(struct nullb_cmd *cmd)
 
 static void null_softirq_done_fn(struct request *rq)
 {
-	end_cmd(blk_mq_rq_to_pdu(rq));
+	if (queue_mode == NULL_Q_MQ)
+		end_cmd(blk_mq_rq_to_pdu(rq));
+	else
+		end_cmd(rq->special);
 }
 
 static inline void null_handle_cmd(struct nullb_cmd *cmd)