io_uring/net: don't lose partial send/recv on fail

Just as with rw, partial send/recv may end up in
io_req_complete_failed() and loose the result, make sure we return the
number of bytes processed.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a4ff95897b5419356fca9ea55db91ac15b2975f9.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/net.c

@@ -1093,6 +1093,16 @@ int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
 	return IOU_OK;
 }
 
+void io_sendrecv_fail(struct io_kiocb *req)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	int res = req->cqe.res;
+
+	if (req->flags & REQ_F_PARTIAL_IO)
+		res = sr->done_io;
+	io_req_set_res(req, res, req->cqe.flags);
+}
+
 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);

io_uring/net.h

@@ -43,6 +43,8 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags);
 int io_recv(struct io_kiocb *req, unsigned int issue_flags);
 
+void io_sendrecv_fail(struct io_kiocb *req);
+
 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 int io_accept(struct io_kiocb *req, unsigned int issue_flags);
 

io_uring/opdef.c

@@ -158,6 +158,7 @@ const struct io_op_def io_op_defs[] = {
 		.issue			= io_sendmsg,
 		.prep_async		= io_sendmsg_prep_async,
 		.cleanup		= io_sendmsg_recvmsg_cleanup,
+		.fail			= io_sendrecv_fail,
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif
@@ -176,6 +177,7 @@ const struct io_op_def io_op_defs[] = {
 		.issue			= io_recvmsg,
 		.prep_async		= io_recvmsg_prep_async,
 		.cleanup		= io_sendmsg_recvmsg_cleanup,
+		.fail			= io_sendrecv_fail,
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif
@@ -318,6 +320,7 @@ const struct io_op_def io_op_defs[] = {
 #if defined(CONFIG_NET)
 		.prep			= io_sendmsg_prep,
 		.issue			= io_send,
+		.fail			= io_sendrecv_fail,
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif
@@ -333,6 +336,7 @@ const struct io_op_def io_op_defs[] = {
 #if defined(CONFIG_NET)
 		.prep			= io_recvmsg_prep,
 		.issue			= io_recv,
+		.fail			= io_sendrecv_fail,
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif