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Date: Mon, 17 Oct 2016 22:04:57 +0200
From: Christoph Hellwig <hch@lst.de>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
        Christoph Hellwig <hch@lst.de>, viro@zeniv.linux.org.uk,
        jack@suse.cz, dmonakhov@openvz.org, linux-fsdevel@vger.kernel.org,
        linux-aio@kvack.org, linux-kernel@vger.kernel.org,
        Oleg Nesterov <oleg@redhat.com>,
        Mikulas Patocka <mpatocka@redhat.com>
Subject: Re: [PATCH] aio: fix a use after free (and fix freeze protection
        of aio writes)
Message-ID: <20161017200457.GA26365@lst.de>
References: <1476597082-15317-1-git-send-email-hch@lst.de> <x49twcabzy4.fsf@segfault.boston.devel.redhat.com> <20161017185552.GA24653@lst.de> <x49pomyydav.fsf@segfault.boston.devel.redhat.com> <20161017195454.GA3568@worktop.programming.kicks-ass.net> <x491szevj2n.fsf@segfault.boston.devel.redhat.com>
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On Mon, Oct 17, 2016 at 04:04:00PM -0400, Jeff Moyer wrote:
> >> Could we just change percpu_rw_semaphore->read_count to be a signed
> >> integer?  The down_write path sums up the counters from all cpus...
> >
> > To what point?
> 
> Duh, nevermind.  You're right, it should work as-is.

Ok, thanks.  That also explains why I didn't see any splat in
xfstests..