Merge tag 'io_uring-5.9-2020-08-23' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Sagi:
       - nvme completion rework from Christoph and Chao that mostly came
         from a bit of divergence of how we classify errors related to
         pathing/retry etc.
       - nvmet passthru fixes from Chaitanya
       - minor nvmet fixes from Amit and I
       - mpath round-robin path selection fix from Martin
       - ignore noiob for zoned devices from Keith
       - minor nvme-fc fix from Tianjia"

 - BFQ cgroup leak fix (Dmitry)

 - block layer MAINTAINERS addition (Geert)

 - fix null_blk FUA checking (Hou)

 - get_max_io_size() size fix (Keith)

 - fix block page_is_mergeable() for compound pages (Matthew)

 - discard granularity fixes (Ming)

 - IO scheduler ordering fix (Ming)

 - misc fixes

* tag 'io_uring-5.9-2020-08-23' of git://git.kernel.dk/linux-block: (31 commits)
  null_blk: fix passing of REQ_FUA flag in null_handle_rq
  nvmet: Disable keep-alive timer when kato is cleared to 0h
  nvme: redirect commands on dying queue
  nvme: just check the status code type in nvme_is_path_error
  nvme: refactor command completion
  nvme: rename and document nvme_end_request
  nvme: skip noiob for zoned devices
  nvme-pci: fix PRP pool size
  nvme-pci: Use u32 for nvme_dev.q_depth and nvme_queue.q_depth
  nvme: Use spin_lock_irq() when taking the ctrl->lock
  nvmet: call blk_mq_free_request() directly
  nvmet: fix oops in pt cmd execution
  nvmet: add ns tear down label for pt-cmd handling
  nvme: multipath: round-robin: eliminate "fallback" variable
  nvme: multipath: round-robin: fix single non-optimized path case
  nvme-fc: Fix wrong return value in __nvme_fc_init_request()
  nvmet-passthru: Reject commands with non-sgl flags set
  nvmet: fix a memory leak
  blkcg: fix memleak for iolatency
  MAINTAINERS: Add missing header files to BLOCK LAYER section
  ...

1 files changed, 12 insertions, 1 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0015a1892153..b3d2785eefe9 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1438,6 +1438,15 @@ out:
 		spin_unlock(&hctx->lock);
 
 		/*
+		 * Order adding requests to hctx->dispatch and checking
+		 * SCHED_RESTART flag. The pair of this smp_mb() is the one
+		 * in blk_mq_sched_restart(). Avoid restart code path to
+		 * miss the new added requests to hctx->dispatch, meantime
+		 * SCHED_RESTART is observed here.
+		 */
+		smp_mb();
+
+		/*
 		 * If SCHED_RESTART was set by the caller of this function and
 		 * it is no longer set that means that it was cleared by another
 		 * thread and hence that a queue rerun is needed.
@@ -1834,6 +1843,7 @@ void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 /**
  * blk_mq_request_bypass_insert - Insert a request at dispatch list.
  * @rq: Pointer to request to be inserted.
+ * @at_head: true if the request should be inserted at the head of the list.
  * @run_queue: If we should run the hardware queue after inserting the request.
  *
  * Should only be used carefully, when the caller knows we want to
@@ -2016,7 +2026,8 @@ insert:
 	if (bypass_insert)
 		return BLK_STS_RESOURCE;
 
-	blk_mq_request_bypass_insert(rq, false, run_queue);
+	blk_mq_sched_insert_request(rq, false, run_queue, false);
+
 	return BLK_STS_OK;
 }