From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757932AbcJQUFH (ORCPT ); Mon, 17 Oct 2016 16:05:07 -0400 Received: from verein.lst.de ([213.95.11.211]:60798 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756739AbcJQUE7 (ORCPT ); Mon, 17 Oct 2016 16:04:59 -0400 Date: Mon, 17 Oct 2016 22:04:57 +0200 From: Christoph Hellwig To: Jeff Moyer Cc: Peter Zijlstra , Christoph Hellwig , 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 , Mikulas Patocka 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> <20161017185552.GA24653@lst.de> <20161017195454.GA3568@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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..