io_uring: move send/recv IOPOLL check into prep

Fail recv/send in case of IORING_SETUP_IOPOLL earlier during prep,
so it'd be done only once. Removes duplication as well

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -3556,6 +3556,9 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	struct io_async_ctx *io = req->io;
 	int ret;
 
+	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+		return -EINVAL;
+
 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
 	sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
 	sr->len = READ_ONCE(sqe->len);
@@ -3585,9 +3588,6 @@ static int io_sendmsg(struct io_kiocb *req, bool force_nonblock)
 	struct socket *sock;
 	int ret;
 
-	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-		return -EINVAL;
-
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_async_ctx io;
@@ -3641,9 +3641,6 @@ static int io_send(struct io_kiocb *req, bool force_nonblock)
 	struct socket *sock;
 	int ret;
 
-	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-		return -EINVAL;
-
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_sr_msg *sr = &req->sr_msg;
@@ -3796,6 +3793,9 @@ static int io_recvmsg_prep(struct io_kiocb *req,
 	struct io_async_ctx *io = req->io;
 	int ret;
 
+	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+		return -EINVAL;
+
 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
 	sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
 	sr->len = READ_ONCE(sqe->len);
@@ -3824,9 +3824,6 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
 	struct socket *sock;
 	int ret, cflags = 0;
 
-	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-		return -EINVAL;
-
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_buffer *kbuf;
@@ -3888,9 +3885,6 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock)
 	struct socket *sock;
 	int ret, cflags = 0;
 
-	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-		return -EINVAL;
-
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_sr_msg *sr = &req->sr_msg;