ceph: fix crush recursion

There was a longstanding problem with recursion through intervening
bucket types on complex hierarchies.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/crush/mapper.c b/fs/ceph/crush/mapper.c
index 9ba54ef..804e6d5 100644
--- a/fs/ceph/crush/mapper.c
+++ b/fs/ceph/crush/mapper.c
@@ -366,6 +366,7 @@
 					BUG_ON(item >= 0 ||
 					       (-1-item) >= map->max_buckets);
 					in = map->buckets[-1-item];
+					retry_bucket = 1;
 					continue;
 				}