TUR path is down after adapter gets reset in multipath configuration

Multipath devices using the TUR path checker need to see the sense code for a failed TUR command in their device handler. Since commit
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/
drivers/scsi/scsi_error.c?id=14216561e164671ce147458653b1fea06a we always return success for mid layer issued TUR commands before calling the device handler, which stopped the TUR path checker from working.

Move the call to the device handler check sense method before the early return for TUR commands to give the device handler a chance to intercept them.

Signed-off-by Christoph Hellwig <[email protected]>

Tested-by Wen Xiong <[email protected]>

---
 drivers/scsi/scsi_error.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Index: b/drivers/scsi/scsi_error.c
===================================================================

drivers/scsi/scsi_error.c +1 -8

@@ -459,14 +459,6 @@ static int scsi_check_sense(struct scsi_
 	if (! scsi_command_normalize_sense(scmd, &sshdr))
 		return FAILED;	/* no valid sense data */
 
-	if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
-		/*
-		 * nasty: for mid-layer issued TURs, we need to return the
-		 * actual sense data without any recovery attempt.  For eh
-		 * issued ones, we need to try to recover and interpret
-		 */
-		return SUCCESS;
-
 	scsi_report_sense(sdev, &sshdr);
 
 	if (scsi_sense_is_deferred(&sshdr))

@@ -482,6 +474,14 @@ static int scsi_check_sense(struct scsi_
 		/* handler does not care. Drop down to default handling */
 	}
 
+	if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)

This patch fixes an issue with multipath ipr SAS devices which require a start unit command to be issued following an adapter reset. Without this patch, paths get marked failed following an adapter reset and since the error handler never gets invoked to issue the start unit, the paths are never recovered. Returning FAILED for this case ensures the error handler wakes up to issue the start unit.

Signed-off-by Brian King <[email protected]>

Teste-by Wen Xiong <[email protected]>

---
 drivers/scsi/device_handler/scsi_dh_alua.c |    7 +++++++
 1 file changed, 7 insertions(+)

Index: b/drivers/scsi/device_handler/scsi_dh_alua.c
===================================================================

drivers/scsi/device_handler/scsi_dh_alua.c +0 -0

@@ -474,6 +474,13 @@ static int alua_check_sense(struct scsi_
 			 * LUN Not Ready -- Offline
 			 */
 			return SUCCESS;