From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NHdnf-0002Rt-95 for qemu-devel@nongnu.org; Mon, 07 Dec 2009 08:38:51 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NHdnd-0002Ps-JQ for qemu-devel@nongnu.org; Mon, 07 Dec 2009 08:38:50 -0500 Received: from [199.232.76.173] (port=58855 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NHdnd-0002PU-2a for qemu-devel@nongnu.org; Mon, 07 Dec 2009 08:38:49 -0500 Received: from alpha.arachsys.com ([91.203.57.7]:53561) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NHdnc-0006BC-FM for qemu-devel@nongnu.org; Mon, 07 Dec 2009 08:38:48 -0500 Date: Mon, 7 Dec 2009 13:38:42 +0000 From: Chris Webb Subject: Re: [Qemu-devel] [PATCH] Disk image shared and exclusive locks. Message-ID: <20091207133842.GL2271@arachsys.com> References: <20091204165301.GA4167@amd.home.annexia.org> <20091207103908.GI2271@arachsys.com> <4B1D03E0.5080006@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B1D03E0.5080006@codemonkey.ws> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: "Richard W.M. Jones" , qemu-devel@nongnu.org Anthony Liguori writes: > I've resisted this because I'm concerned that if we delay the > opening of the file on the destination, it could fail. That's a > very late failure and that makes me uncomfortable as just a work > around for NFS. I don't know much about NFS's semantics with cache-coherency, but I take it there isn't some sort of synchronisation operation that works on a file descriptor and could be done instead as the vm starts and stops to avoid having to delay the open itself? I agree with you that failing this late could make for some rather nasty behaviour compared to the current version. Cheers, Chris.