Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 66 insertions, 3 deletions

diff --git a/kernel/drivers/s390/scsi/zfcp_erp.c b/kernel/drivers/s390/scsi/zfcp_erp.c
index 3fb410977..7ccfce559 100644
--- a/kernel/drivers/s390/scsi/zfcp_erp.c
+++ b/kernel/drivers/s390/scsi/zfcp_erp.c
@@ -3,7 +3,7 @@
  *
  * Error Recovery Procedures (ERP).
  *
- * Copyright IBM Corp. 2002, 2010
+ * Copyright IBM Corp. 2002, 2016
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -1204,6 +1204,62 @@ static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
 	}
 }
 
+/**
+ * zfcp_erp_try_rport_unblock - unblock rport if no more/new recovery
+ * @port: zfcp_port whose fc_rport we should try to unblock
+ */
+static void zfcp_erp_try_rport_unblock(struct zfcp_port *port)
+{
+	unsigned long flags;
+	struct zfcp_adapter *adapter = port->adapter;
+	int port_status;
+	struct Scsi_Host *shost = adapter->scsi_host;
+	struct scsi_device *sdev;
+
+	write_lock_irqsave(&adapter->erp_lock, flags);
+	port_status = atomic_read(&port->status);
+	if ((port_status & ZFCP_STATUS_COMMON_UNBLOCKED)    == 0 ||
+	    (port_status & (ZFCP_STATUS_COMMON_ERP_INUSE |
+			    ZFCP_STATUS_COMMON_ERP_FAILED)) != 0) {
+		/* new ERP of severity >= port triggered elsewhere meanwhile or
+		 * local link down (adapter erp_failed but not clear unblock)
+		 */
+		zfcp_dbf_rec_run_lvl(4, "ertru_p", &port->erp_action);
+		write_unlock_irqrestore(&adapter->erp_lock, flags);
+		return;
+	}
+	spin_lock(shost->host_lock);
+	__shost_for_each_device(sdev, shost) {
+		struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
+		int lun_status;
+
+		if (zsdev->port != port)
+			continue;
+		/* LUN under port of interest */
+		lun_status = atomic_read(&zsdev->status);
+		if ((lun_status & ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
+			continue; /* unblock rport despite failed LUNs */
+		/* LUN recovery not given up yet [maybe follow-up pending] */
+		if ((lun_status & ZFCP_STATUS_COMMON_UNBLOCKED) == 0 ||
+		    (lun_status & ZFCP_STATUS_COMMON_ERP_INUSE) != 0) {
+			/* LUN blocked:
+			 * not yet unblocked [LUN recovery pending]
+			 * or meanwhile blocked [new LUN recovery triggered]
+			 */
+			zfcp_dbf_rec_run_lvl(4, "ertru_l", &zsdev->erp_action);
+			spin_unlock(shost->host_lock);
+			write_unlock_irqrestore(&adapter->erp_lock, flags);
+			return;
+		}
+	}
+	/* now port has no child or all children have completed recovery,
+	 * and no ERP of severity >= port was meanwhile triggered elsewhere
+	 */
+	zfcp_scsi_schedule_rport_register(port);
+	spin_unlock(shost->host_lock);
+	write_unlock_irqrestore(&adapter->erp_lock, flags);
+}
+
 static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
 {
 	struct zfcp_adapter *adapter = act->adapter;
@@ -1214,11 +1270,18 @@ static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
 	case ZFCP_ERP_ACTION_REOPEN_LUN:
 		if (!(act->status & ZFCP_STATUS_ERP_NO_REF))
 			scsi_device_put(sdev);
+		zfcp_erp_try_rport_unblock(port);
 		break;
 
 	case ZFCP_ERP_ACTION_REOPEN_PORT:
-		if (result == ZFCP_ERP_SUCCEEDED)
-			zfcp_scsi_schedule_rport_register(port);
+		/* This switch case might also happen after a forced reopen
+		 * was successfully done and thus overwritten with a new
+		 * non-forced reopen at `ersfs_2'. In this case, we must not
+		 * do the clean-up of the non-forced version.
+		 */
+		if (act->step != ZFCP_ERP_STEP_UNINITIALIZED)
+			if (result == ZFCP_ERP_SUCCEEDED)
+				zfcp_erp_try_rport_unblock(port);
 		/* fall through */
 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
 		put_device(&port->dev);