nfs: check hostname in nfs_get_client

We reference cl_hostname in many places. Add a check to make
sure it exists.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 1d09289c8f0e..b213ee8fb012 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -482,8 +482,13 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
         struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
         const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
 
+        if (cl_init->hostname == NULL) {
+                WARN_ON(1);
+                return NULL;
+        }
+
         dprintk("--> nfs_get_client(%s,v%u)\n",
-                cl_init->hostname ?: "", rpc_ops->version);
+                cl_init->hostname, rpc_ops->version);
 
         /* see if the client already exists */
         do {
@@ -510,7 +515,7 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
         } while (!IS_ERR(new));
 
         dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
-                cl_init->hostname ?: "", PTR_ERR(new));
+                cl_init->hostname, PTR_ERR(new));
         return new;
 }
 EXPORT_SYMBOL_GPL(nfs_get_client);