mds: fix possible null dereference

Fix null deref on forward and req (!mdr) caller.

Signed-off-by: Sage Weil <sage.weil@dreamhost.com>

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index d0af5f0c183c87a7d0eefecdec969a99cd071223..a91e4df019367f925fd46e2551b115fb61f80f01 100644 (file)
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -6481,7 +6481,7 @@ int MDCache::path_traverse(MDRequest *mdr, Message *req,     // who
       pair<int,int> dauth = curdir->authority();
 
       if (onfail == MDS_TRAVERSE_FORWARD &&
-         snapid && mdr->client_request &&
+         snapid && mdr && mdr->client_request &&
          (int)depth < mdr->client_request->get_retry_attempt()) {
        dout(7) << "traverse: snap " << snapid << " and depth " << depth
                << " < retry " << mdr->client_request->get_retry_attempt()