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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 3 May 2024 14:52:38 -0700
Message-ID: <CAHk-=wgC+QpveKCJpeqsaORu7htoNNKA8mp+d9mvJEXmSKjhbw@mail.gmail.com>
Subject: Re: [PATCH] epoll: try to be a _bit_ better about file lifetimes
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: keescook@chromium.org, axboe@kernel.dk, brauner@kernel.org, 
	christian.koenig@amd.com, dri-devel@lists.freedesktop.org, 
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On Fri, 3 May 2024 at 14:45, Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> How do you get through eventpoll_release_file() while someone
> has entered ep_item_poll()?

Doesn't matter.

Look, it's enough that the file count has gone down to zero. You may
not even have gotten to eventpoll_release_file() yet - the important
part is that you're on your *way* to it.

That means that the file will be released - and it means that you have
violated all the refcounting rules for poll().

So I think you're barking up the wrong tree.

                  Linus