crush: assume weight_set != null imples weight_set_size > 0

Reflects ceph.git commit 5e8fa3e06b68fae1582c9230a3a8d1abc6146286.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

net/ceph/crush/mapper.c

@@ -306,7 +306,7 @@ static __u32 *get_choose_arg_weights(const struct crush_bucket_straw2 *bucket,
 				     const struct crush_choose_arg *arg,
 				     int position)
 {
-	if (!arg || !arg->weight_set || arg->weight_set_size == 0)
+	if (!arg || !arg->weight_set)
 		return bucket->item_weights;
 
 	if (position >= arg->weight_set_size)

net/ceph/osdmap.c

@@ -295,6 +295,10 @@ static int decode_choose_args(void **p, void *end, struct crush_map *c)
 			ret = decode_choose_arg(p, end, arg);
 			if (ret)
 				goto fail;
+
+			if (arg->ids_size &&
+			    arg->ids_size != c->buckets[bucket_index]->size)
+				goto e_inval;
 		}
 
 		insert_choose_arg_map(&c->choose_args, arg_map);