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

[Jens Axboe <axboe@kernel.dk>]

On 7/14/25 9:30 AM, Pavel Begunkov wrote:
> On 7/14/25 15:56, Jens Axboe wrote:
>> On 7/14/25 4:59 AM, Pavel Begunkov wrote:
>>> 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;
>>
>> Is this req->apoll_events masking necessary or useful?
> 
> good point, shouldn't be here

Do you want to send a v2?

-- 
Jens Axboe