[PATCH] dm: dm-raid1.c: Enforce max of 9 mirrors

dm-raid1.c: Since kcopyd can currently only handle 1 source and up to 8
destinations, enforce a max of 9 mirrors when creating a dm-mirror device.
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/md/dm-raid1.c

@@ -1028,7 +1028,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	argc -= args_used;
 
 	if (!argc || sscanf(argv[0], "%u", &nr_mirrors) != 1 ||
-	    nr_mirrors < 2) {
+	    nr_mirrors < 2 || nr_mirrors > KCOPYD_MAX_REGIONS + 1) {
 		ti->error = "dm-mirror: Invalid number of mirrors";
 		dm_destroy_dirty_log(dl);
 		return -EINVAL;