libceph: gracefully handle large reply messages from the mon

We preallocate a few of the message types we get back from the mon. If we get a larger message than we are expecting, fall back to trying to allocate a new one instead of blindly using the one we have. CC: [email protected] Signed-off-by: Sage Weil <[email protected]> Reviewed-by: Ilya Dryomov <[email protected]>
thomasl · Sep 10, 2014 · 73c3d48 · 73c3d48
1 parent 255939e
commit 73c3d48
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
@@ -1181,7 +1181,15 @@ static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
 	if (!m) {
 		pr_info("alloc_msg unknown type %d\n", type);
 		*skip = 1;
+	} else if (front_len > m->front_alloc_len) {
+		pr_warning("mon_alloc_msg front %d > prealloc %d (%u#%llu)\n",
+			   front_len, m->front_alloc_len,
+			   (unsigned int)con->peer_name.type,
+			   le64_to_cpu(con->peer_name.num));
+		ceph_msg_put(m);
+		m = ceph_msg_new(type, front_len, GFP_NOFS, false);
 	}
+
 	return m;
 }