scsi_dh_alua: use flag for RTPG extended header

We should be using a flag when RTPG extended header is not
supported, that saves us sending RTPG twice for older arrays.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index fdf6557f68bfc2f2e3a5ec7bef436c1b1b91485d..d99fc14370cca18c60c6ff8c45e3c6eb1349708c 100644 (file)
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -59,8 +59,9 @@
 #define ALUA_FAILOVER_TIMEOUT          60
 #define ALUA_FAILOVER_RETRIES          5
 
-/* flags passed from user level */
+/* device handler flags */
 #define ALUA_OPTIMIZE_STPG             1
+#define ALUA_RTPG_EXT_HDR_UNSUPP       2
 
 struct alua_dh_data {
        int                     group_id;
@@ -134,8 +135,7 @@ static struct request *get_alua_req(struct scsi_device *sdev,
  * 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,
-                           bool rtpg_ext_hdr_req)
+static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
 {
        struct request *rq;
        int err = 0;
@@ -148,7 +148,7 @@ static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h,
 
        /* Prepare the command. */
        rq->cmd[0] = MAINTENANCE_IN;
-       if (rtpg_ext_hdr_req)
+       if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP))
                rq->cmd[1] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT;
        else
                rq->cmd[1] = MI_REPORT_TARGET_PGS;
@@ -490,7 +490,6 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
        int len, k, off, valid_states = 0;
        unsigned char *ucp;
        unsigned err, retval;
-       bool rtpg_ext_hdr_req = 1;
        unsigned long expiry, interval = 0;
        unsigned int tpg_desc_tbl_off;
        unsigned char orig_transition_tmo;
@@ -501,7 +500,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
                expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ);
 
  retry:
-       retval = submit_rtpg(sdev, h, rtpg_ext_hdr_req);
+       retval = submit_rtpg(sdev, h);
        if (retval) {
                if (!scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
                                          &sense_hdr)) {
@@ -521,10 +520,10 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
                 * The retry without rtpg_ext_hdr_req set
                 * handles this.
                 */
-               if (rtpg_ext_hdr_req == 1 &&
+               if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
                    sense_hdr.sense_key == ILLEGAL_REQUEST &&
                    sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) {
-                       rtpg_ext_hdr_req = 0;
+                       h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
                        goto retry;
                }