From: Rajashekhar M A <rajs@netapp.com>
Subject: I/O errors for ALUA state transitions
References: bnc#491289
Patch-mainline: not yet, <hare: will be revisiting, Oct 4, 2017>

When a SLES11 host is configured with a few LUNs and IO is running,
injecting FC faults repeatedly leads to path recovery problems.
The LUNs have 4 paths each and 3 of them come back active after
say an FC fault which makes two of the paths go down, instead of
all 4. This happens after several iterations of continuous FC faults.

Reason here is that we're returning an I/O error whenever we're
encountering sense code 06/04/0a (LOGICAL UNIT NOT ACCESSIBLE,
ASYMMETRIC ACCESS STATE TRANSITION) instead of retrying.

Signed-off-by: Hannes Reinecke <hare@suse.de>

---
 drivers/scsi/scsi_error.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -376,7 +376,8 @@ static int scsi_check_sense(struct scsi_
 		 * if the device is in the process of becoming ready, we
 		 * should retry.
 		 */
-		if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
+		if ((sshdr.asc == 0x04) &&
+		    (sshdr.ascq == 0x01 || sshdr.ascq == 0x0a))
 			return NEEDS_RETRY;
 		/*
 		 * if the device is not started, we need to wake