From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37925) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzgMB-0007p4-HQ for qemu-devel@nongnu.org; Tue, 02 Jun 2015 03:11:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YzgM8-00041V-AS for qemu-devel@nongnu.org; Tue, 02 Jun 2015 03:11:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59606) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzgM8-00041L-5E for qemu-devel@nongnu.org; Tue, 02 Jun 2015 03:11:24 -0400 Message-ID: <1433229074.1637.7.camel@nilsson.home.kraxel.org> From: Gerd Hoffmann Date: Tue, 02 Jun 2015 09:11:14 +0200 In-Reply-To: <20150601203126.GK2120@HEDWIG.INI.CMU.EDU> References: <20150601141054.GA11304@redhat.com> <20150601141343.GH13155@redhat.com> <20150601153237.GE2120@HEDWIG.INI.CMU.EDU> <20150601174409-mutt-send-email-mst@redhat.com> <20150601180022.GI2120@HEDWIG.INI.CMU.EDU> <20150601203126.GK2120@HEDWIG.INI.CMU.EDU> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] fw cfg files cross-version migration races List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Gabriel L. Somlo" Cc: "Michael S. Tsirkin" , "Gabriel L. Somlo" , qemu-devel@nongnu.org, pbonzini@redhat.com, lersek@redhat.com Hi, > I guess the only reason this isn't a problem is that nobody currently > attempts to access fw_cfg after a migration ? :) Accessing fw_cfg after migration is fine. Problem is this ... (1) read directory (2) migrate (3) read file ... in case the file ordering happens to be different on the destination host due to initialization order changes. So, sorting entries (and the index assigned too) should fix this, right? That looks easiest to me. cheers, Gerd