cciss: fix negative logical drive count in procfs

This patch fixes a problem where the logical volume count may go negative.
In some instances if several logical are configured on a controller and all
of them are deleted using the online utilities the volume count in /proc may
go negative with no way get it correct again.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cca.cpqcorp.net>
Signed-off-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 08255644e80a..9ffa821fbfd7 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1533,15 +1533,18 @@ mem_msg:
  * where new drives will be added.  If the index to be returned is greater
  * than the highest_lun index for the controller then highest_lun is set
  * to this new index.  If there are no available indexes then -1 is returned.
+ * "controller_node" is used to know if this is a real logical drive, or just
+ * the controller node, which determines if this counts towards highest_lun.
  */
-static int cciss_find_free_drive_index(int ctlr)
+static int cciss_find_free_drive_index(int ctlr, int controller_node)
 {
         int i;
 
         for (i = 0; i < CISS_MAX_LUN; i++) {
                 if (hba[ctlr]->drv[i].raid_level == -1) {
                         if (i > hba[ctlr]->highest_lun)
-                                hba[ctlr]->highest_lun = i;
+                                if (!controller_node)
+                                        hba[ctlr]->highest_lun = i;
                         return i;
                 }
         }
@@ -1557,11 +1560,11 @@ static int cciss_find_free_drive_index(int ctlr)
  * a means to talk to the controller in case no logical
  * drives have yet been configured.
  */
-static int cciss_add_gendisk(ctlr_info_t *h, __u32 lunid)
+static int cciss_add_gendisk(ctlr_info_t *h, __u32 lunid, int controller_node)
 {
         int drv_index;
 
-        drv_index = cciss_find_free_drive_index(h->ctlr);
+        drv_index = cciss_find_free_drive_index(h->ctlr, controller_node);
         if (drv_index == -1)
                 return -1;
         /*Check if the gendisk needs to be allocated */
@@ -1598,7 +1601,7 @@ static void cciss_add_controller_node(ctlr_info_t *h)
         if (h->gendisk[0] != NULL) /* already did this? Then bail. */
                 return;
 
-        drv_index = cciss_add_gendisk(h, 0);
+        drv_index = cciss_add_gendisk(h, 0, 1);
         if (drv_index == -1) {
                 printk(KERN_WARNING "cciss%d: could not "
                         "add disk 0.\n", h->ctlr);
@@ -1732,7 +1735,7 @@ static int rebuild_lun_table(ctlr_info_t *h, int first_time)
 
                 /* check if the drive was found already in the array */
                 if (!drv_found) {
-                        drv_index = cciss_add_gendisk(h, lunid);
+                        drv_index = cciss_add_gendisk(h, lunid, 0);
                         if (drv_index == -1)
                                 goto freeret;
                 }