proto_ops: Add locked held versions of sendmsg and sendpage

Add new proto_ops sendmsg_locked and sendpage_locked that can be
called when the socket lock is already held. Correspondingly, add
kernel_sendmsg_locked and kernel_sendpage_locked as front end
functions.

These functions will be used in zero proxy so that we can take
the socket lock in a ULP sendmsg/sendpage and then directly call the
backend transport proto_ops functions.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 0 deletions

diff --git a/net/socket.c b/net/socket.c
index cb0fdf799f40..b332d1e8e4e4 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -652,6 +652,20 @@ int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 }
 EXPORT_SYMBOL(kernel_sendmsg);
 
+int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
+			  struct kvec *vec, size_t num, size_t size)
+{
+	struct socket *sock = sk->sk_socket;
+
+	if (!sock->ops->sendmsg_locked)
+		sock_no_sendmsg_locked(sk, msg, size);
+
+	iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
+
+	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
+}
+EXPORT_SYMBOL(kernel_sendmsg_locked);
+
 static bool skb_is_err_queue(const struct sk_buff *skb)
 {
 	/* pkt_type of skbs enqueued on the error queue are set to
@@ -3376,6 +3390,19 @@ int kernel_sendpage(struct socket *sock, struct page *page, int offset,
 }
 EXPORT_SYMBOL(kernel_sendpage);
 
+int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
+			   size_t size, int flags)
+{
+	struct socket *sock = sk->sk_socket;
+
+	if (sock->ops->sendpage_locked)
+		return sock->ops->sendpage_locked(sk, page, offset, size,
+						  flags);
+
+	return sock_no_sendpage_locked(sk, page, offset, size, flags);
+}
+EXPORT_SYMBOL(kernel_sendpage_locked);
+
 int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg)
 {
 	mm_segment_t oldfs = get_fs();