Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block

Pull core block layer updates from Jens Axboe:
 "This is the main pull request for block storage for 4.15-rc1.

  Nothing out of the ordinary in here, and no API changes or anything
  like that. Just various new features for drivers, core changes, etc.
  In particular, this pull request contains:

   - A patch series from Bart, closing the whole on blk/scsi-mq queue
     quescing.

   - A series from Christoph, building towards hidden gendisks (for
     multipath) and ability to move bio chains around.

   - NVMe
        - Support for native multipath for NVMe (Christoph).
        - Userspace notifications for AENs (Keith).
        - Command side-effects support (Keith).
        - SGL support (Chaitanya Kulkarni)
        - FC fixes and improvements (James Smart)
        - Lots of fixes and tweaks (Various)

   - bcache
        - New maintainer (Michael Lyle)
        - Writeback control improvements (Michael)
        - Various fixes (Coly, Elena, Eric, Liang, et al)

   - lightnvm updates, mostly centered around the pblk interface
     (Javier, Hans, and Rakesh).

   - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph)

   - Writeback series that fix the much discussed hundreds of millions
     of sync-all units. This goes all the way, as discussed previously
     (me).

   - Fix for missing wakeup on writeback timer adjustments (Yafang
     Shao).

   - Fix laptop mode on blk-mq (me).

   - {mq,name} tupple lookup for IO schedulers, allowing us to have
     alias names. This means you can use 'deadline' on both !mq and on
     mq (where it's called mq-deadline). (me).

   - blktrace race fix, oopsing on sg load (me).

   - blk-mq optimizations (me).

   - Obscure waitqueue race fix for kyber (Omar).

   - NBD fixes (Josef).

   - Disable writeback throttling by default on bfq, like we do on cfq
     (Luca Miccio).

   - Series from Ming that enable us to treat flush requests on blk-mq
     like any other request. This is a really nice cleanup.

   - Series from Ming that improves merging on blk-mq with schedulers,
     getting us closer to flipping the switch on scsi-mq again.

   - BFQ updates (Paolo).

   - blk-mq atomic flags memory ordering fixes (Peter Z).

   - Loop cgroup support (Shaohua).

   - Lots of minor fixes from lots of different folks, both for core and
     driver code"

* 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits)
  nvme: fix visibility of "uuid" ns attribute
  blk-mq: fixup some comment typos and lengths
  ide: ide-atapi: fix compile error with defining macro DEBUG
  blk-mq: improve tag waiting setup for non-shared tags
  brd: remove unused brd_mutex
  blk-mq: only run the hardware queue if IO is pending
  block: avoid null pointer dereference on null disk
  fs: guard_bio_eod() needs to consider partitions
  xtensa/simdisk: fix compile error
  nvme: expose subsys attribute to sysfs
  nvme: create 'slaves' and 'holders' entries for hidden controllers
  block: create 'slaves' and 'holders' entries for hidden gendisks
  nvme: also expose the namespace identification sysfs files for mpath nodes
  nvme: implement multipath access to nvme subsystems
  nvme: track shared namespaces
  nvme: introduce a nvme_ns_ids structure
  nvme: track subsystems
  block, nvme: Introduce blk_mq_req_flags_t
  block, scsi: Make SCSI quiesce and resume work reliably
  block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag
  ...

1 files changed, 10 insertions, 16 deletions

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 9adfb5445f8d..5f2a4240a204 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -288,15 +288,6 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
 		cmd->status = BLK_STS_TIMEOUT;
 		return BLK_EH_HANDLED;
 	}
-
-	/* If we are waiting on our dead timer then we could get timeout
-	 * callbacks for our request.  For this we just want to reset the timer
-	 * and let the queue side take care of everything.
-	 */
-	if (!completion_done(&cmd->send_complete)) {
-		nbd_config_put(nbd);
-		return BLK_EH_RESET_TIMER;
-	}
 	config = nbd->config;
 
 	if (config->num_connections > 1) {
@@ -723,9 +714,9 @@ static int wait_for_reconnect(struct nbd_device *nbd)
 		return 0;
 	if (test_bit(NBD_DISCONNECTED, &config->runtime_flags))
 		return 0;
-	wait_event_interruptible_timeout(config->conn_wait,
-					 atomic_read(&config->live_connections),
-					 config->dead_conn_timeout);
+	wait_event_timeout(config->conn_wait,
+			   atomic_read(&config->live_connections),
+			   config->dead_conn_timeout);
 	return atomic_read(&config->live_connections);
 }
 
@@ -740,6 +731,7 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 	if (!refcount_inc_not_zero(&nbd->config_refs)) {
 		dev_err_ratelimited(disk_to_dev(nbd->disk),
 				    "Socks array is empty\n");
+		blk_mq_start_request(req);
 		return -EINVAL;
 	}
 	config = nbd->config;
@@ -748,6 +740,7 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 		dev_err_ratelimited(disk_to_dev(nbd->disk),
 				    "Attempted send on invalid socket\n");
 		nbd_config_put(nbd);
+		blk_mq_start_request(req);
 		return -EINVAL;
 	}
 	cmd->status = BLK_STS_OK;
@@ -771,6 +764,7 @@ again:
 			 */
 			sock_shutdown(nbd);
 			nbd_config_put(nbd);
+			blk_mq_start_request(req);
 			return -EIO;
 		}
 		goto again;
@@ -781,6 +775,7 @@ again:
 	 * here so that it gets put _after_ the request that is already on the
 	 * dispatch list.
 	 */
+	blk_mq_start_request(req);
 	if (unlikely(nsock->pending && nsock->pending != req)) {
 		blk_mq_requeue_request(req, true);
 		ret = 0;
@@ -793,10 +788,10 @@ again:
 	ret = nbd_send_cmd(nbd, cmd, index);
 	if (ret == -EAGAIN) {
 		dev_err_ratelimited(disk_to_dev(nbd->disk),
-				    "Request send failed trying another connection\n");
+				    "Request send failed, requeueing\n");
 		nbd_mark_nsock_dead(nbd, nsock, 1);
-		mutex_unlock(&nsock->tx_lock);
-		goto again;
+		blk_mq_requeue_request(req, true);
+		ret = 0;
 	}
 out:
 	mutex_unlock(&nsock->tx_lock);
@@ -820,7 +815,6 @@ static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
 	 * done sending everything over the wire.
 	 */
 	init_completion(&cmd->send_complete);
-	blk_mq_start_request(bd->rq);
 
 	/* We can be called directly from the user space process, which means we
 	 * could possibly have signals pending so our sendmsg will fail.  In