On Tue, Sep 08, 2020 at 07:29:05AM -0600, Jens Axboe wrote:
> On 9/8/20 7:11 AM, Jens Axboe wrote:
> > 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.
>
> Here it is:
>
>
> commit d0ea3f3d17cf891244f17f8ceb43d4988c170471
> Author: Jens Axboe <axboe@xxxxxxxxx>
> Date: Tue Sep 8 07:16:12 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>
Much nicer, that worked, thanks!
greg k-h
