On 9/8/20 6:31 AM, Greg KH wrote:
> On Fri, Sep 04, 2020 at 03:06:28PM -0600, Jens Axboe wrote:
>> Hi,
>>
>> Linus just pulled 3 fixes from me - 1+2 should apply directly, here's
>> the 3rd one which will need some love for 5.8-stable. I'm including it
>> below to preempt the failed to apply message :-)
>>
>>
>> commit fb8d4046d50f77a26570101e5b8a7a026320a610
>> Author: Jens Axboe <axboe@xxxxxxxxx>
>> Date: Wed Sep 2 10:19:04 2020 -0600
>>
>> io_uring: no read/write-retry on -EAGAIN error and O_NONBLOCK marked file
>>
>> Actually two things that need fixing up here:
>>
>> - The io_rw_reissue() -EAGAIN retry is explicit to block devices and
>> regular files, so don't ever attempt to do that on other types of
>> files.
>>
>> - If we hit -EAGAIN on a nonblock marked file, don't arm poll handler for
>> it. It should just complete with -EAGAIN.
>>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Reported-by: Norman Maurer <norman.maurer@xxxxxxxxxxxxxx>
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index 82e15020d9a8..96be21ace79a 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -2726,6 +2726,12 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
>> ret = ret2;
>> goto done;
>> }
>> + /* no retry on NONBLOCK marked file */
>> + if (req->file->f_flags & O_NONBLOCK) {
>> + ret = ret2;
>> + goto done;
>> + }
>> +
>> /* some cases will consume bytes even on error returns */
>> iov_iter_revert(iter, iov_count - iov_iter_count(iter));
>> ret2 = 0;
>> @@ -2869,9 +2875,15 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
>> */
>> if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
>> ret2 = -EAGAIN;
>> + /* no retry on NONBLOCK marked file */
>> + if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) {
>> + ret = 0;
>> + goto done;
>> + }
>> if (!force_nonblock || ret2 != -EAGAIN) {
>> if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
>> goto copy_iov;
>> +done:
>> kiocb_done(kiocb, ret2);
>> } else {
>> copy_iov:
>>
>> --
>> Jens Axboe
>
>
> Thanks for the backport, but this didn't apply at all to the 5.8.y tree.
> What one did you make it against?
Oh, might have been because I have a pile of pending 5.8 stable patches...
Let me apply to pristine stable, test, and then I'll send it to you.
--
Jens Axboe
