From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030196AbVI1HMf (ORCPT ); Wed, 28 Sep 2005 03:12:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030200AbVI1HMf (ORCPT ); Wed, 28 Sep 2005 03:12:35 -0400 Received: from qproxy.gmail.com ([72.14.204.205]:28638 "EHLO qproxy.gmail.com") by vger.kernel.org with ESMTP id S1030196AbVI1HMe convert rfc822-to-8bit (ORCPT ); Wed, 28 Sep 2005 03:12:34 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=J8I1tVol129gw592MMDChIMmzfy93I6Xi2xt8MLqQdB0PE38JYWeqyKPeF0D2dITSFCZKGRsM08i9oDER5cQyuWrd3mdSCber4qVfBNb3huFsMbkOe4FUeVIVPwJZDdvsAQbYgkEOz1X+fsVLnmQlcg9IcjmokAfQolAW0eusiM= Message-ID: <98b62faa050928001275d28771@mail.gmail.com> Date: Wed, 28 Sep 2005 00:12:33 -0700 From: Reply-To: iodophlymiaelo@gmail.com To: linux-kernel@vger.kernel.org Subject: raw aio write guarantee MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi all, Just a quick question: How can a user-mode application ensure that an AIO write on a raw block device (i.e. open()ed with O_DIRECT) has really -really- been written to the disk and not residing in an on-disk write cache where it could be lost in case of a power failure? Is physical write guaranteed to have taken place before the AIO completion? Or is there a system call that sends a cache flush command to the drive (and waits for the drive to commit)?