[DLCI]: Fix tiny race between module unload and sock_ioctl.

This is a narrow pedantry :) but the dlci_ioctl_hook check and call
should not be parted with the mutex lock.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 4 deletions

diff --git a/net/socket.c b/net/socket.c
index b6d35cd72a50..9d3fbfbc8535 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -909,11 +909,10 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
                         if (!dlci_ioctl_hook)
                                 request_module("dlci");
 
-                        if (dlci_ioctl_hook) {
-                                mutex_lock(&dlci_ioctl_mutex);
+                        mutex_lock(&dlci_ioctl_mutex);
+                        if (dlci_ioctl_hook)
                                 err = dlci_ioctl_hook(cmd, argp);
-                                mutex_unlock(&dlci_ioctl_mutex);
-                        }
+                        mutex_unlock(&dlci_ioctl_mutex);
                         break;
                 default:
                         err = sock->ops->ioctl(sock, cmd, arg);