On Tue, Apr 29, 2025 at 09:28:50PM +0200, Max Kellermann wrote:
> On Tue, Apr 29, 2025 at 9:22 PM Joe Damato <jdamato@xxxxxxxxxx> wrote:
> > In commit 0a65bc27bd64 ("eventpoll: Set epoll timeout if it's in the
> > future"), a bug was introduced causing the loop in ep_poll to hang under
> > certain circumstances.
> >
> > When the timeout is non-NULL and ep_schedule_timeout returns false, the
> > flag timed_out was not set to true. This causes a hang.
> >
> > Adjust the logic and set timed_out, if needed, fixing the original code.
>
> Hi Joe,
>
> we have been working on the fix at the same time, this is my fix:
>
> https://lore.kernel.org/linux-fsdevel/20250429185827.3564438-1-max.kellermann@xxxxxxxxx/T/#u
>
> I think mine is better because it checks "eavail" before setting
> "timed_out", preserving the old behavior (before commit 0a65bc27bd64).
> Your version may set "timed_out" and thus does an unnecessary
> list_empty() call in the following block. (And maybe it can reset
> "evail" to false?)
I think it's up to the maintainers to decide which patch is
preferred; I don't really have a preference.
