libceph: gracefully handle large reply messages from the mon
commit 73c3d4812b4c755efeca0140f606f83772a39ce4 upstream.
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.
Signed-off-by: Sage Weil <sage@redhat.com>
Reviewed-by: Ilya Dryomov <ilya.dryomov@inktank.com>
[lizf: Backported to 3.4: s/front_alloc_len/front_max/g]
Signed-off-by: Zefan Li <lizefan@huawei.com>
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 6765da3..bc293c0 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -1042,7 +1042,15 @@
if (!m) {
pr_info("alloc_msg unknown type %d\n", type);
*skip = 1;
+ } else if (front_len > m->front_max) {
+ pr_warning("mon_alloc_msg front %d > prealloc %d (%u#%llu)\n",
+ front_len, m->front_max,
+ (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;
}