Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull first round of SCSI updates from James Bottomley:
 "The most important feature of this patch set is the new async
  infrastructure that makes sure async_synchronize_full() synchronizes
  all domains and allows us to remove all the hacks (like having
  scsi_complete_async_scans() in the device base code) and means that
  the async infrastructure will "just work" in future.

  The rest is assorted driver updates (aacraid, bnx2fc, virto-scsi,
  megaraid, bfa, lpfc, qla2xxx, qla4xxx) plus a lot of infrastructure
  work in sas and FC.

  Signed-off-by: James Bottomley <JBottomley@Parallels.com>"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (97 commits)
  [SCSI] Revert "[SCSI] fix async probe regression"
  [SCSI] cleanup usages of scsi_complete_async_scans
  [SCSI] queue async scan work to an async_schedule domain
  [SCSI] async: make async_synchronize_full() flush all work regardless of domain
  [SCSI] async: introduce 'async_domain' type
  [SCSI] bfa: Fix to set correct return error codes and misc cleanup.
  [SCSI] aacraid: Series 7 Async. (performance) mode support
  [SCSI] aha152x: Allow use on 64bit systems
  [SCSI] virtio-scsi: Add vdrv->scan for post VIRTIO_CONFIG_S_DRIVER_OK LUN scanning
  [SCSI] bfa: squelch lockdep complaint with a spin_lock_init
  [SCSI] qla2xxx: remove unnecessary reads of PCI_CAP_ID_EXP
  [SCSI] qla4xxx: remove unnecessary read of PCI_CAP_ID_EXP
  [SCSI] ufs: fix incorrect return value about SUCCESS and FAILED
  [SCSI] ufs: reverse the ufshcd_is_device_present logic
  [SCSI] ufs: use module_pci_driver
  [SCSI] usb-storage: update usb devices for write cache quirk in quirk list.
  [SCSI] usb-storage: add support for write cache quirk
  [SCSI] set to WCE if usb cache quirk is present.
  [SCSI] virtio-scsi: hotplug support for virtio-scsi
  [SCSI] virtio-scsi: split scatterlist per target
  ...

114 files changed, 2509 insertions, 1018 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e714a025c99..c2619ef44a7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2936,6 +2936,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 					initial READ(10) command);
 				o = CAPACITY_OK (accept the capacity
 					reported by the device);
+				p = WRITE_CACHE (the device cache is ON
+					by default);
 				r = IGNORE_RESIDUE (the device reports
 					bogus residue values);
 				s = SINGLE_LUN (the device has only one
diff --git a/block/blk-exec.c b/block/blk-exec.c
index fb2cbd55162..8b6dc5bd4dd 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -43,6 +43,9 @@ static void blk_end_sync_rq(struct request *rq, int error)
  * Description:
  *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution.  Don't wait for completion.
+ *
+ * Note:
+ *    This function will invoke @done directly if the queue is dead.
  */
 void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 			   struct request *rq, int at_head,
@@ -51,18 +54,20 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 	int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
 
 	WARN_ON(irqs_disabled());
+
+	rq->rq_disk = bd_disk;
+	rq->end_io = done;
+
 	spin_lock_irq(q->queue_lock);
 
 	if (unlikely(blk_queue_dead(q))) {
-		spin_unlock_irq(q->queue_lock);
 		rq->errors = -ENXIO;
 		if (rq->end_io)
 			rq->end_io(rq, rq->errors);
+		spin_unlock_irq(q->queue_lock);
 		return;
 	}
 
-	rq->rq_disk = bd_disk;
-	rq->end_io = done;
 	__elv_add_request(q, rq, where);
 	__blk_run_queue(q);
 	/* the queue is stopped so it won't be run */
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index cece3a4d11e..3fe1202c61c 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -80,6 +80,8 @@ const struct ata_port_operations ata_base_port_ops = {
 	.prereset		= ata_std_prereset,
 	.postreset		= ata_std_postreset,
 	.error_handler		= ata_std_error_handler,
+	.sched_eh		= ata_std_sched_eh,
+	.end_eh			= ata_std_end_eh,
 };
 
 const struct ata_port_operations sata_port_ops = {
@@ -6642,6 +6644,8 @@ struct ata_port_operations ata_dummy_port_ops = {
 	.qc_prep		= ata_noop_qc_prep,
 	.qc_issue		= ata_dummy_qc_issue,
 	.error_handler		= ata_dummy_error_handler,
+	.sched_eh		= ata_std_sched_eh,
+	.end_eh			= ata_std_end_eh,
 };
 
 const struct ata_port_info ata_dummy_port_info = {
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 6d53cf9b3b6..77fc80640e2 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -793,12 +793,12 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
 		ata_for_each_link(link, ap, HOST_FIRST)
 			memset(&link->eh_info, 0, sizeof(link->eh_info));
 
-		/* Clear host_eh_scheduled while holding ap->lock such
-		 * that if exception occurs after this point but
-		 * before EH completion, SCSI midlayer will
+		/* end eh (clear host_eh_scheduled) while holding
+		 * ap->lock such that if exception occurs after this
+		 * point but before EH completion, SCSI midlayer will
 		 * re-initiate EH.
 		 */
-		host->host_eh_scheduled = 0;
+		ap->ops->end_eh(ap);
 
 		spin_unlock_irqrestore(ap->lock, flags);
 		ata_eh_release(ap);
@@ -986,16 +986,13 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
 }
 
 /**
- *	ata_port_schedule_eh - schedule error handling without a qc
- *	@ap: ATA port to schedule EH for
- *
- *	Schedule error handling for @ap.  EH will kick in as soon as
- *	all commands are drained.
+ * ata_std_sched_eh - non-libsas ata_ports issue eh with this common routine
+ * @ap: ATA port to schedule EH for
  *
- *	LOCKING:
+ *	LOCKING: inherited from ata_port_schedule_eh
  *	spin_lock_irqsave(host lock)
  */
-void ata_port_schedule_eh(struct ata_port *ap)
+void ata_std_sched_eh(struct ata_port *ap)
 {
 	WARN_ON(!ap->ops->error_handler);
 
@@ -1007,6 +1004,44 @@ void ata_port_schedule_eh(struct ata_port *ap)
 
 	DPRINTK("port EH scheduled\n");
 }
+EXPORT_SYMBOL_GPL(ata_std_sched_eh);
+
+/**
+ * ata_std_end_eh - non-libsas ata_ports complete eh with this common routine
+ * @ap: ATA port to end EH for
+ *
+ * In the libata object model there is a 1:1 mapping of ata_port to
+ * shost, so host fields can be directly manipulated under ap->lock, in
+ * the libsas case we need to hold a lock at the ha->level to coordinate
+ * these events.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ */
+void ata_std_end_eh(struct ata_port *ap)
+{
+	struct Scsi_Host *host = ap->scsi_host;
+
+	host->host_eh_scheduled = 0;
+}
+EXPORT_SYMBOL(ata_std_end_eh);
+
+
+/**
+ *	ata_port_schedule_eh - schedule error handling without a qc
+ *	@ap: ATA port to schedule EH for
+ *
+ *	Schedule error handling for @ap.  EH will kick in as soon as
+ *	all commands are drained.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ */
+void ata_port_schedule_eh(stru