--- ceph-12.1.1.orig/src/rocksdb/util/murmurhash.cc	2017-04-27 01:13:46.000000000 +0100
+++ ceph-12.1.1.orig/src/rocksdb/util/murmurhash.cc	2017-07-25 11:37:28.910266684 +0100
@@ -113,8 +113,8 @@ unsigned int MurmurHash2 ( const void *
 
     switch(len)
     {
-    case 3: h ^= data[2] << 16;
-    case 2: h ^= data[1] << 8;
+    case 3: h ^= data[2] << 16; // fallthrough
+    case 2: h ^= data[1] << 8; // fallthrough
     case 1: h ^= data[0];
         h *= m;
     };