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

Pull block updates and fixes from Jens Axboe:

 - NVMe updates and fixes that missed the first pull request. This
   includes bug fixes, and support for autonomous power management.

 - Fix from Christoph for missing clear of the request payload, causing
   a problem with (at least) the storvsc driver.

 - Further fixes for the queue/bdi life time issues from Jan.

 - The Kconfig mq scheduler update from me.

 - Fixing a use-after-free in dm-rq, spotted by Bart, introduced in this
   merge window.

 - Three fixes for nbd from Josef.

 - Bug fix from Omar, fixing a bug in sas transport code that oopses
   when bsg ioctls were used. From Omar.

 - Improvements to the queue restart and tag wait from from Omar.

 - Set of fixes for the sed/opal code from Scott.

 - Three trivial patches to cciss from Tobin

* 'for-linus' of git://git.kernel.dk/linux-block: (41 commits)
  dm-rq: don't dereference request payload after ending request
  blk-mq-sched: separate mark hctx and queue restart operations
  blk-mq: use sbq wait queues instead of restart for driver tags
  block/sed-opal: Propagate original error message to userland.
  nvme/pci: re-check security protocol support after reset
  block/sed-opal: Introduce free_opal_dev to free the structure and clean up state
  nvme: detect NVMe controller in recent MacBooks
  nvme-rdma: add support for host_traddr
  nvmet-rdma: Fix error handling
  nvmet-rdma: use nvme cm status helper
  nvme-rdma: move nvme cm status helper to .h file
  nvme-fc: don't bother to validate ioccsz and iorcsz
  nvme/pci: No special case for queue busy on IO
  nvme/core: Fix race kicking freed request_queue
  nvme/pci: Disable on removal when disconnected
  nvme: Enable autonomous power state transitions
  nvme: Add a quirk mechanism that uses identify_ctrl
  nvme: make nvmf_register_transport require a create_ctrl callback
  nvme: Use CNS as 8-bit field and avoid endianness conversion
  nvme: add semicolon in nvme_command setting
  ...

1 files changed, 13 insertions, 6 deletions

diff --git a/block/elevator.c b/block/elevator.c
index 699d10f71a2c..ac1c9f481a98 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -220,17 +220,24 @@ int elevator_init(struct request_queue *q, char *name)
 	}
 
 	if (!e) {
-		if (q->mq_ops && q->nr_hw_queues == 1)
-			e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false);
-		else if (q->mq_ops)
-			e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false);
-		else
+		/*
+		 * For blk-mq devices, we default to using mq-deadline,
+		 * if available, for single queue devices. If deadline
+		 * isn't available OR we have multiple queues, default
+		 * to "none".
+		 */
+		if (q->mq_ops) {
+			if (q->nr_hw_queues == 1)
+				e = elevator_get("mq-deadline", false);
+			if (!e)
+				return 0;
+		} else
 			e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
 
 		if (!e) {
 			printk(KERN_ERR
 				"Default I/O scheduler not found. " \
-				"Using noop/none.\n");
+				"Using noop.\n");
 			e = elevator_get("noop", false);
 		}
 	}