1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index ac6fddf99e9..5a344885696 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -178,7 +178,8 @@ done:
  * submit_rtpg - Issue a REPORT TARGET GROUP STATES command
  * @sdev: sdev the command should be sent to
  */
-static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
+static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h,
+                            bool rtpg_ext_hdr_req)
 {
         struct request *rq;
         int err = SCSI_DH_RES_TEMP_UNAVAIL;
@@ -189,7 +190,10 @@ static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
 
         /* Prepare the command. */
         rq->cmd[0] = MAINTENANCE_IN;
-        rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT;
+        if (rtpg_ext_hdr_req)
+                rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT;
+        else
+                rq->cmd[1] = MI_REPORT_TARGET_PGS;
         rq->cmd[6] = (h->bufflen >> 24) & 0xff;
         rq->cmd[7] = (h->bufflen >> 16) & 0xff;
         rq->cmd[8] = (h->bufflen >>  8) & 0xff;
@@ -522,6 +526,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
         int len, k, off, valid_states = 0;
         unsigned char *ucp;
         unsigned err;
+        bool rtpg_ext_hdr_req = 1;
         unsigned long expiry, interval = 1000;
         unsigned int tpg_desc_tbl_off;
         unsigned char orig_transition_tmo;
@@ -532,7 +537,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
                 expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ);
 
  retry:
-        err = submit_rtpg(sdev, h);
+        err = submit_rtpg(sdev, h, rtpg_ext_hdr_req);
 
         if (err == SCSI_DH_IO && h->senselen > 0) {
                 err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
@@ -540,6 +545,21 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
                 if (!err)
                         return SCSI_DH_IO;
 
+                /*
+                 * submit_rtpg() has failed on existing arrays
+                 * when requesting extended header info, and
+                 * the array doesn't support extended headers,
+                 * even though it shouldn't according to T10.
+                 * The retry without rtpg_ext_hdr_req set
+                 * handles this.
+                 */
+                if (rtpg_ext_hdr_req == 1 &&
+                    sense_hdr.sense_key == ILLEGAL_REQUEST &&
+                    sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) {
+                        rtpg_ext_hdr_req = 0;
+                        goto retry;
+                }
+
                 err = alua_check_sense(sdev, &sense_hdr);
                 if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry))
                         goto retry;