From: Tomas Henzl <thenzl@redhat.com>
Date: Sun, 29 Aug 2010 15:49:26 -0400
Subject: [block] cciss: dont call putdisk excessively
Message-id: <1283097002-3341-28-git-send-email-thenzl@redhat.com>
Patchwork-id: 27883
O-Subject: [RHEL6 PATCH 27/63] cciss: dont call putdisk excessively
Bugzilla: 568830
RH-Acked-by: Neil Horman <nhorman@redhat.com>

don't call putdisk excessively
Fix bug that free_hba was calling put_disk for all gendisk[]
pointers -- all 1024 of them -- regardless of whether the were
used or not (NULL).  This bug could cause rmmod to oops if logical
drives had been deleted during the driver's lifetime.

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index eb82a20..8436470 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3828,15 +3828,16 @@ Enomem:
 	return -1;
 }
 
-static void free_hba(int i)
+static void free_hba(int n)
 {
-	ctlr_info_t *p = hba[i];
-	int n;
+	ctlr_info_t *h = hba[n];
+	int i;
 
-	hba[i] = NULL;
-	for (n = 0; n < CISS_MAX_LUN; n++)
-		put_disk(p->gendisk[n]);
-	kfree(p);
+	hba[n] = NULL;
+	for (i = 0; i < h->highest_lun + 1; i++)
+		if (h->gendisk[i] != NULL)
+			put_disk(h->gendisk[i]);
+	kfree(h);
 }
 
 /* Send a message CDB to the firmware. */