NFSD/SUNRPC: Check rpc_xprt out of xs_setup_bc_tcp

Besides checking rpc_xprt out of xs_setup_bc_tcp,
increase it's reference (it's important).

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 8097b9df6773..3e5efb2b236e 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -295,13 +295,24 @@ int			xprt_adjust_timeout(struct rpc_rqst *req);
 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 void                    xprt_release(struct rpc_task *task);
-struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 void                    xprt_put(struct rpc_xprt *xprt);
 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
                                 unsigned int num_prealloc,
                                 unsigned int max_req);
 void                    xprt_free(struct rpc_xprt *);
 
+/**
+ * xprt_get - return a reference to an RPC transport.
+ * @xprt: pointer to the transport
+ *
+ */
+static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
+{
+        if (atomic_inc_not_zero(&xprt->count))
+                return xprt;
+        return NULL;
+}
+
 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 {
         return p + xprt->tsh_size;