[NET]: Add the helper kernel_sock_shutdown()

...and fix a couple of bugs in the NBD, CIFS and OCFS2 socket handlers.

Looking at the sock->op->shutdown() handlers, it looks as if all of them
take a SHUT_RD/SHUT_WR/SHUT_RDWR argument instead of the
RCV_SHUTDOWN/SEND_SHUTDOWN arguments.
Add a helper, and then define the SHUT_* enum to ensure that kernel users
of shutdown() don't get confused.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Mark Fasheh <mark.fasheh@oracle.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/block/nbd.c

@@ -28,6 +28,7 @@
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <net/sock.h>
+#include <linux/net.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -126,7 +127,7 @@ static void sock_shutdown(struct nbd_device *lo, int lock)
 	if (lo->sock) {
 		printk(KERN_WARNING "%s: shutting down socket\n",
 			lo->disk->disk_name);
-		lo->sock->ops->shutdown(lo->sock, SEND_SHUTDOWN|RCV_SHUTDOWN);
+		kernel_sock_shutdown(lo->sock, SHUT_RDWR);
 		lo->sock = NULL;
 	}
 	if (lock)

fs/cifs/connect.c

@@ -160,7 +160,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
 	if (server->ssocket) {
 		cFYI(1, ("State: 0x%x Flags: 0x%lx", server->ssocket->state,
 			server->ssocket->flags));
-		server->ssocket->ops->shutdown(server->ssocket, SEND_SHUTDOWN);
+		kernel_sock_shutdown(server->ssocket, SHUT_WR);
 		cFYI(1, ("Post shutdown state: 0x%x Flags: 0x%lx",
 			server->ssocket->state,
 			server->ssocket->flags));

fs/ocfs2/cluster/tcp.c

@@ -58,6 +58,7 @@
 #include <linux/slab.h>
 #include <linux/idr.h>
 #include <linux/kref.h>
+#include <linux/net.h>
 #include <net/tcp.h>
 
 #include <asm/uaccess.h>
@@ -616,8 +617,7 @@ static void o2net_shutdown_sc(struct work_struct *work)
 		del_timer_sync(&sc->sc_idle_timeout);
 		o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
 		sc_put(sc);
-		sc->sc_sock->ops->shutdown(sc->sc_sock,
-					   RCV_SHUTDOWN|SEND_SHUTDOWN);
+		kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
 	}
 
 	/* not fatal so failed connects before the other guy has our

include/linux/net.h

@@ -95,6 +95,12 @@ enum sock_type {
 
 #endif /* ARCH_HAS_SOCKET_TYPES */
 
+enum sock_shutdown_cmd {
+	SHUT_RD		= 0,
+	SHUT_WR		= 1,
+	SHUT_RDWR	= 2,
+};
+
 /**
  *  struct socket - general BSD socket
  *  @state: socket state (%SS_CONNECTED, etc)
@@ -223,6 +229,8 @@ extern int kernel_setsockopt(struct socket *sock, int level, int optname,
 extern int kernel_sendpage(struct socket *sock, struct page *page, int offset,
 			   size_t size, int flags);
 extern int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg);
+extern int kernel_sock_shutdown(struct socket *sock,
+				enum sock_shutdown_cmd how);
 
 #ifndef CONFIG_SMP
 #define SOCKOPS_WRAPPED(name) name

net/rxrpc/ar-local.c

@@ -114,7 +114,7 @@ static int rxrpc_create_local(struct rxrpc_local *local)
 	return 0;
 
 error:
-	local->socket->ops->shutdown(local->socket, 2);
+	kernel_sock_shutdown(local->socket, SHUT_RDWR);
 	local->socket->sk->sk_user_data = NULL;
 	sock_release(local->socket);
 	local->socket = NULL;
@@ -267,7 +267,7 @@ static void rxrpc_destroy_local(struct work_struct *work)
 	/* finish cleaning up the local descriptor */
 	rxrpc_purge_queue(&local->accept_queue);
 	rxrpc_purge_queue(&local->reject_queue);
-	local->socket->ops->shutdown(local->socket, 2);
+	kernel_sock_shutdown(local->socket, SHUT_RDWR);
 	sock_release(local->socket);
 
 	up_read(&rxrpc_local_sem);

net/socket.c

@@ -2319,6 +2319,11 @@ int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg)
 	return err;
 }
 
+int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
+{
+	return sock->ops->shutdown(sock, how);
+}
+
 /* ABI emulation layers need these two */
 EXPORT_SYMBOL(move_addr_to_kernel);
 EXPORT_SYMBOL(move_addr_to_user);
@@ -2345,3 +2350,4 @@ EXPORT_SYMBOL(kernel_getsockopt);
 EXPORT_SYMBOL(kernel_setsockopt);
 EXPORT_SYMBOL(kernel_sendpage);
 EXPORT_SYMBOL(kernel_sock_ioctl);
+EXPORT_SYMBOL(kernel_sock_shutdown);