linux-kernel - Re: [PATCH] aio: Fix incorrect usage of eventfd_signal

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Message-ID: <YbOiO7xlOL0kkuYF@sol.localdomain>
Date:   Fri, 10 Dec 2021 10:53:47 -0800
From:   Eric Biggers <ebiggers@...nel.org>
To:     Xie Yongji <xieyongji@...edance.com>
Cc:     bcrl@...ck.org, viro@...iv.linux.org.uk, tglx@...utronix.de,
        axboe@...nel.dk, linux-aio@...ck.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] aio: Fix incorrect usage of eventfd_signal_allowed()

On Tue, Dec 07, 2021 at 03:33:47PM -0800, Eric Biggers wrote:
> On Mon, Sep 13, 2021 at 07:19:28PM +0800, Xie Yongji wrote:
> > We should defer eventfd_signal() to the workqueue when
> > eventfd_signal_allowed() return false rather than return
> > true.
> > 
> > Fixes: b542e383d8c0 ("eventfd: Make signal recursion protection a task bit")
> > Signed-off-by: Xie Yongji <xieyongji@...edance.com>
> > ---
> >  fs/aio.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/fs/aio.c b/fs/aio.c
> > index 51b08ab01dff..8822e3ed4566 100644
> > --- a/fs/aio.c
> > +++ b/fs/aio.c
> > @@ -1695,7 +1695,7 @@ static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
> >  		list_del(&iocb->ki_list);
> >  		iocb->ki_res.res = mangle_poll(mask);
> >  		req->done = true;
> > -		if (iocb->ki_eventfd && eventfd_signal_allowed()) {
> > +		if (iocb->ki_eventfd && !eventfd_signal_allowed()) {
> >  			iocb = NULL;
> >  			INIT_WORK(&req->work, aio_poll_put_work);
> >  			schedule_work(&req->work);
> > -- 
> > 2.11.0
> > 
> 
> Since I was just working with this file...:
> 
> Reviewed-by: Eric Biggers <ebiggers@...gle.com>
> 
> I don't know who is taking aio fixes these days, but whoever does so probably
> should take this one at the same time as mine
> (https://lore.kernel.org/linux-fsdevel/20211207095726.169766-1-ebiggers@kernel.org).

Apparently no one is, so I've included this patch in the pull request I've sent
(https://lore.kernel.org/r/YbOdV8CPbyPAF234@sol.localdomain).

- Eric