[PATCH 1/1] io_uring/poll: fix POLLERR handling

[Pavel Begunkov <asml.silence@gmail.com>]

8c8492ca64e7 ("io_uring/net: don't retry connect operation on EPOLLERR")
is a little dirty hack that
1) wrongfully assumes that POLLERR equals to a failed request, which
breaks all POLLERR users, e.g. all error queue recv interfaces.
2) deviates the connection request behaviour from connect(2), and
3) racy and solved at a wrong level.

Nothing can be done with 2) now, and 3) is beyond the scope of the
patch. At least solve 1) by moving the hack out of generic poll handling
into io_connect().

Cc: stable@vger.kernel.org
Fixes: 8c8492ca64e79 ("io_uring/net: don't retry connect operation on EPOLLERR")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/net.c  | 4 +++-
 io_uring/poll.c | 2 --
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 43a43522f406..e2213e4d9420 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1732,13 +1732,15 @@ int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
 {
+	struct poll_table_struct pt = { ._key = EPOLLERR };
 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
 	struct io_async_msghdr *io = req->async_data;
 	unsigned file_flags;
 	int ret;
 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
 
-	if (unlikely(req->flags & REQ_F_FAIL)) {
+	ret = vfs_poll(req->file, &pt) & req->apoll_events;
+	if (ret & EPOLLERR) {
 		ret = -ECONNRESET;
 		goto out;
 	}
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 0526062e2f81..20e9b46a4adf 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -273,8 +273,6 @@ static int io_poll_check_events(struct io_kiocb *req, io_tw_token_t tw)
 				return IOU_POLL_REISSUE;
 			}
 		}
-		if (unlikely(req->cqe.res & EPOLLERR))
-			req_set_fail(req);
 		if (req->apoll_events & EPOLLONESHOT)
 			return IOU_POLL_DONE;
 
-- 
2.49.0