SUNRPC: Allow rpc_auth to run clean up before the rpc_client is destroyed

RPCSEC_GSS needs to be able to send NULL RPC calls to the server in order
to free up any remaining GSS contexts.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 98df44e453fe58b9e7e4ee2e8b3c058648202d85..28a789419f6488878b45ffd036569e37493f8896 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -352,10 +352,6 @@ rpc_free_client(struct kref *kref)
 
        dprintk("RPC:       destroying %s client for %s\n",
                        clnt->cl_protname, clnt->cl_server);
-       if (clnt->cl_auth) {
-               rpcauth_release(clnt->cl_auth);
-               clnt->cl_auth = NULL;
-       }
        if (!IS_ERR(clnt->cl_dentry)) {
                rpc_rmdir(clnt->cl_dentry);
                rpc_put_mount();
@@ -375,6 +371,30 @@ out_free:
        kfree(clnt);
 }
 
+/*
+ * Free an RPC client
+ */
+static void
+rpc_free_auth(struct kref *kref)
+{
+       struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
+
+       if (clnt->cl_auth == NULL) {
+               rpc_free_client(kref);
+               return;
+       }
+
+       /*
+        * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
+        *       release remaining GSS contexts. This mechanism ensures
+        *       that it can do so safely.
+        */
+       kref_init(kref);
+       rpcauth_release(clnt->cl_auth);
+       clnt->cl_auth = NULL;
+       kref_put(kref, rpc_free_client);
+}
+
 /*
  * Release reference to the RPC client
  */
@@ -385,7 +405,7 @@ rpc_release_client(struct rpc_clnt *clnt)
 
        if (list_empty(&clnt->cl_tasks))
                wake_up(&destroy_wait);
-       kref_put(&clnt->cl_kref, rpc_free_client);
+       kref_put(&clnt->cl_kref, rpc_free_auth);
 }
 
 /**