[PATCH for-next] net: provide __sys_shutdown_sock() that takes a socket

[Jens Axboe <axboe@kernel.dk>]

No functional changes in this patch, needed to provide io_uring support
for shutdown(2).

Cc: netdev@vger.kernel.org
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

---

There's a trivial io_uring patch that depends on this one. If this one
is acceptable to you, I'd like to queue it up in the io_uring branch for
5.10.

diff --git a/include/linux/socket.h b/include/linux/socket.h
index e9cb30d8cbfb..385894b4a8bb 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -436,6 +436,7 @@ extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
 			     int __user *usockaddr_len);
 extern int __sys_socketpair(int family, int type, int protocol,
 			    int __user *usockvec);
+extern int __sys_shutdown_sock(struct socket *sock, int how);
 extern int __sys_shutdown(int fd, int how);
 
 extern struct ns_common *get_net_ns(struct ns_common *ns);
diff --git a/net/socket.c b/net/socket.c
index dbbe8ea7d395..59307db6097e 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2192,6 +2192,17 @@ SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
  *	Shutdown a socket.
  */
 
+int __sys_shutdown_sock(struct socket *sock, int how)
+{
+	int err;
+
+	err = security_socket_shutdown(sock, how);
+	if (!err)
+		err = sock->ops->shutdown(sock, how);
+
+	return err;
+}
+
 int __sys_shutdown(int fd, int how)
 {
 	int err, fput_needed;
@@ -2199,9 +2210,7 @@ int __sys_shutdown(int fd, int how)
 
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (sock != NULL) {
-		err = security_socket_shutdown(sock, how);
-		if (!err)
-			err = sock->ops->shutdown(sock, how);
+		err = __sys_shutdown_sock(sock, how);
 		fput_light(sock->file, fput_needed);
 	}
 	return err;

-- 
Jens Axboe