scsi_dh_alua: Use vpd_pg83 information

The SCSI device now has the VPD page 0x83 information attached,
so there is no need to query it again.

[mkp: Fixed a checkpatch warning]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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 7d01ef0b66cc518931e95bbfca0b05c372522682..87c5ba86aff2a5813544577f104de80315ccd9ad 100644 (file)
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -130,43 +130,6 @@ static struct request *get_alua_req(struct scsi_device *sdev,
        return rq;
 }
 
-/*
- * submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command
- * @sdev: sdev the command should be sent to
- */
-static int submit_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
-{
-       struct request *rq;
-       int err = SCSI_DH_RES_TEMP_UNAVAIL;
-
-       rq = get_alua_req(sdev, h->buff, h->bufflen, READ);
-       if (!rq)
-               goto done;
-
-       /* Prepare the command. */
-       rq->cmd[0] = INQUIRY;
-       rq->cmd[1] = 1;
-       rq->cmd[2] = 0x83;
-       rq->cmd[4] = h->bufflen;
-       rq->cmd_len = COMMAND_SIZE(INQUIRY);
-
-       rq->sense = h->sense;
-       memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
-       rq->sense_len = h->senselen = 0;
-
-       err = blk_execute_rq(rq->q, NULL, rq, 1);
-       if (err == -EIO) {
-               sdev_printk(KERN_INFO, sdev,
-                           "%s: evpd inquiry failed with %x\n",
-                           ALUA_DH_NAME, rq->errors);
-               h->senselen = rq->sense_len;
-               err = SCSI_DH_IO;
-       }
-       blk_put_request(rq);
-done:
-       return err;
-}
-
 /*
  * submit_rtpg - Issue a REPORT TARGET GROUP STATES command
  * @sdev: sdev the command should be sent to
@@ -359,43 +322,29 @@ static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h)
 }
 
 /*
- * alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83
+ * alua_check_vpd - Evaluate INQUIRY vpd page 0x83
  * @sdev: device to be checked
  *
  * Extract the relative target port and the target port group
  * descriptor from the list of identificators.
  */
-static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
+static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
 {
-       int len;
-       unsigned err;
        unsigned char *d;
+       unsigned char __rcu *vpd_pg83;
 
- retry:
-       err = submit_vpd_inquiry(sdev, h);
-
-       if (err != SCSI_DH_OK)
-               return err;
-
-       /* Check if vpd page exceeds initial buffer */
-       len = (h->buff[2] << 8) + h->buff[3] + 4;
-       if (len > h->bufflen) {
-               /* Resubmit with the correct length */
-               if (realloc_buffer(h, len)) {
-                       sdev_printk(KERN_WARNING, sdev,
-                                   "%s: kmalloc buffer failed\n",
-                                   ALUA_DH_NAME);
-                       /* Temporary failure, bypass */
-                       return SCSI_DH_DEV_TEMP_BUSY;
-               }
-               goto retry;
+       rcu_read_lock();
+       if (!rcu_dereference(sdev->vpd_pg83)) {
+               rcu_read_unlock();
+               return SCSI_DH_DEV_UNSUPP;
        }
 
        /*
-        * Now look for the correct descriptor.
+        * Look for the correct descriptor.
         */
-       d = h->buff + 4;
-       while (d < h->buff + len) {
+       vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
+       d = vpd_pg83 + 4;
+       while (d < vpd_pg83 + sdev->vpd_pg83_len) {
                switch (d[1] & 0xf) {
                case 0x4:
                        /* Relative target port */
@@ -410,6 +359,7 @@ static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
                }
                d += d[3] + 4;
        }
+       rcu_read_unlock();
 
        if (h->group_id == -1) {
                /*
@@ -422,14 +372,13 @@ static int alua_vpd_inquiry(struct scsi_device *sdev, struct alua_dh_data *h)
                            ALUA_DH_NAME);
                h->state = TPGS_STATE_OPTIMIZED;
                h->tpgs = TPGS_MODE_NONE;
-               err = SCSI_DH_DEV_UNSUPP;
-       } else {
-               sdev_printk(KERN_INFO, sdev,
-                           "%s: port group %02x rel port %02x\n",
-                           ALUA_DH_NAME, h->group_id, h->rel_port);
+               return SCSI_DH_DEV_UNSUPP;
        }
+       sdev_printk(KERN_INFO, sdev,
+                   "%s: port group %02x rel port %02x\n",
+                   ALUA_DH_NAME, h->group_id, h->rel_port);
 
-       return err;
+       return 0;
 }
 
 static char print_alua_state(int state)
@@ -692,7 +641,7 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
        if (err != SCSI_DH_OK)
                goto out;
 
-       err = alua_vpd_inquiry(sdev, h);
+       err = alua_check_vpd(sdev, h);
        if (err != SCSI_DH_OK)
                goto out;