io_uring/net: don't skip notifs for failed requests

[ upstream commit 6ae91ac9a6aa7d6005c3c6d0f4d263fbab9f377f ]

We currently only add a notification CQE when the send succeded, i.e.
cqe.res >= 0. However, it'd be more robust to do buffer notifications
for failed requests as well in case drivers decide do something fanky.

Always return a buffer notification after initial prep, don't hide it.
This behaviour is better aligned with documentation and the patch also
helps the userspace to respect it.

Cc: stable@vger.kernel.org # 6.0
Suggested-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9c8bead87b2b980fcec441b8faef52188b4a6588.1664292100.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/io_uring/net.c b/io_uring/net.c
index a09611d25a0696034ae30ae0cd8dc88d1bc958d4..c7926a4ac7520d2a4efa47add638d6f35ad7eb9e 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -879,7 +879,6 @@ void io_send_zc_cleanup(struct io_kiocb *req)
 {
        struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
 
-       zc->notif->flags |= REQ_F_CQE_SKIP;
        io_notif_flush(zc->notif);
        zc->notif = NULL;
 }
@@ -996,7 +995,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
        struct msghdr msg;
        struct iovec iov;
        struct socket *sock;
-       unsigned msg_flags, cflags;
+       unsigned msg_flags;
        int ret, min_ret = 0;
 
        sock = sock_from_file(req->file);
@@ -1064,8 +1063,6 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
                        req->flags |= REQ_F_PARTIAL_IO;
                        return io_setup_async_addr(req, addr, issue_flags);
                }
-               if (ret < 0 && !zc->done_io)
-                       zc->notif->flags |= REQ_F_CQE_SKIP;
                if (ret == -ERESTARTSYS)
                        ret = -EINTR;
                req_set_fail(req);
@@ -1078,8 +1075,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
 
        io_notif_flush(zc->notif);
        req->flags &= ~REQ_F_NEED_CLEANUP;
-       cflags = ret >= 0 ? IORING_CQE_F_MORE : 0;
-       io_req_set_res(req, ret, cflags);
+       io_req_set_res(req, ret, IORING_CQE_F_MORE);
        return IOU_OK;
 }
 
@@ -1096,17 +1092,11 @@ void io_sendrecv_fail(struct io_kiocb *req)
 void io_send_zc_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) {
-               if (req->flags & REQ_F_NEED_CLEANUP) {
-                       io_notif_flush(sr->notif);
-                       sr->notif = NULL;
-                       req->flags &= ~REQ_F_NEED_CLEANUP;
-               }
-               res = sr->done_io;
-       }
-       io_req_set_res(req, res, req->cqe.flags);
+       if (req->flags & REQ_F_PARTIAL_IO)
+               req->cqe.res = sr->done_io;
+       if (req->flags & REQ_F_NEED_CLEANUP)
+               req->cqe.flags |= IORING_CQE_F_MORE;
 }
 
 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)