[SCSI] hpsa: fix physical device lun and target numbering problem

If a physical device exposed to the OS by hpsa
is replaced (e.g. one hot plug tape drive is replaced
by another, or a tape drive is placed into "OBDR" mode
in which it acts like a CD-ROM device) and a rescan is
initiated, the replaced device will be added to the
SCSI midlayer with target and lun numbers set to -1.
After that, a panic is likely to ensue.  When a physical
device is replaced, the lun and target number should be
preserved.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 1f32f06..b200b73 100644 (file)
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -676,6 +676,16 @@ static void hpsa_scsi_replace_entry(struct ctlr_info *h, int hostno,
        BUG_ON(entry < 0 || entry >= HPSA_MAX_SCSI_DEVS_PER_HBA);
        removed[*nremoved] = h->dev[entry];
        (*nremoved)++;
+
+       /*
+        * New physical devices won't have target/lun assigned yet
+        * so we need to preserve the values in the slot we are replacing.
+        */
+       if (new_entry->target == -1) {
+               new_entry->target = h->dev[entry]->target;
+               new_entry->lun = h->dev[entry]->lun;
+       }
+
        h->dev[entry] = new_entry;
        added[*nadded] = new_entry;
        (*nadded)++;