[SCSI] scsi_dh_rdac: fix for lun_table update for rdac device handler

During one of our testing, we noticed that mode select command sent
from the host did not have the lun_table updated.

Problem is root caused to the way lun table is updated. Lun table
update was done after the call to blk_rq_map_kern is made. This was
causing problem because kernel uses bounce buffer(bio_copy_kern) if
the address is not aligned.  The command buffer updated after the
call(blk_rq_map_kern) was not going on the wire. Moved the code to
update the lun_table before the call to fix the problem.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com>
Signed-off-by: Yanling Qi <Yanling.Qi@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 10 insertions, 12 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 5be3ae15cb7..7d83a84442a 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -281,11 +281,13 @@ static struct request *get_rdac_req(struct scsi_device *sdev,
 }
 
 static struct request *rdac_failover_get(struct scsi_device *sdev,
-                                         struct rdac_dh_data *h)
+                        struct rdac_dh_data *h, struct list_head *list)
 {
         struct request *rq;
         struct rdac_mode_common *common;
         unsigned data_size;
+        struct rdac_queue_data *qdata;
+        u8 *lun_table;
 
         if (h->ctlr->use_ms10) {
                 struct rdac_pg_expanded *rdac_pg;
@@ -298,6 +300,7 @@ static struct request *rdac_failover_get(struct scsi_device *sdev,
                 rdac_pg->subpage_code = 0x1;
                 rdac_pg->page_len[0] = 0x01;
                 rdac_pg->page_len[1] = 0x28;
+                lun_table = rdac_pg->lun_table;
         } else {
                 struct rdac_pg_legacy *rdac_pg;
 
@@ -307,11 +310,16 @@ static struct request *rdac_failover_get(struct scsi_device *sdev,
                 common = &rdac_pg->common;
                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
                 rdac_pg->page_len = 0x68;
+                lun_table = rdac_pg->lun_table;
         }
         common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
         common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
         common->rdac_options = RDAC_FORCED_QUIESENCE;
 
+        list_for_each_entry(qdata, list, entry) {
+                lun_table[qdata->h->lun] = 0x81;
+        }
+
         /* get request for block layer packet command */
         rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
         if (!rq)
@@ -565,7 +573,6 @@ static void send_mode_select(struct work_struct *work)
         int err, retry_cnt = RDAC_RETRY_COUNT;
         struct rdac_queue_data *tmp, *qdata;
         LIST_HEAD(list);
-        u8 *lun_table;
 
         spin_lock(&ctlr->ms_lock);
         list_splice_init(&ctlr->ms_head, &list);
@@ -573,21 +580,12 @@ static void send_mode_select(struct work_struct *work)
         ctlr->ms_sdev = NULL;
         spin_unlock(&ctlr->ms_lock);
 
-        if (ctlr->use_ms10)
-                lun_table = ctlr->mode_select.expanded.lun_table;
-        else
-                lun_table = ctlr->mode_select.legacy.lun_table;
-
 retry:
         err = SCSI_DH_RES_TEMP_UNAVAIL;
-        rq = rdac_failover_get(sdev, h);
+        rq = rdac_failover_get(sdev, h, &list);
         if (!rq)
                 goto done;
 
-        list_for_each_entry(qdata, &list, entry) {
-                lun_table[qdata->h->lun] = 0x81;
-        }
-
         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
                 "%s MODE_SELECT command",
                 (char *) h->ctlr->array_name, h->ctlr->index,