From owner-freebsd-geom@FreeBSD.ORG Sun Apr 22 16:46:39 2007 Return-Path: X-Original-To: freebsd-geom@FreeBSD.org Delivered-To: freebsd-geom@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 3335816A401 for ; Sun, 22 Apr 2007 16:46:39 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (arm132.internetdsl.tpnet.pl [83.17.198.132]) by mx1.freebsd.org (Postfix) with ESMTP id C86CE13C4BA for ; Sun, 22 Apr 2007 16:46:38 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 17D31487F2; Sun, 22 Apr 2007 18:46:37 +0200 (CEST) Received: from localhost (public-gprs38729.centertel.pl [91.94.23.121]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id 61DBC45683; Sun, 22 Apr 2007 18:46:15 +0200 (CEST) Date: Sun, 22 Apr 2007 18:45:28 +0200 From: Pawel Jakub Dawidek To: Ivan Voras Message-ID: <20070422164528.GE52622@garage.freebsd.pl> References: <20070422123852.GA52622@garage.freebsd.pl> <462B83D7.1010905@fer.hr> <20070422162601.GD52622@garage.freebsd.pl> <462B8D25.3000303@fer.hr> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="//IivP0gvsAy3Can" Content-Disposition: inline In-Reply-To: <462B8D25.3000303@fer.hr> X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 7.0-CURRENT i386 User-Agent: mutt-ng/devel-r804 (FreeBSD) X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=BAYES_00,RCVD_IN_NJABL_DUL autolearn=no version=3.0.4 Cc: freebsd-geom@FreeBSD.org Subject: Re: gjournal & async X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 Apr 2007 16:46:39 -0000 --//IivP0gvsAy3Can Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Apr 22, 2007 at 06:28:21PM +0200, Ivan Voras wrote: > Pawel Jakub Dawidek wrote: > > On Sun, Apr 22, 2007 at 05:48:39PM +0200, Ivan Voras wrote: > >> Pawel Jakub Dawidek wrote: > >>> On Sun, Apr 22, 2007 at 02:43:29AM +0200, Ivan Voras wrote: > >>>> How does gjournal guarantee corectness if UFS is mounted async? AFAIK > >>>> the "async" handling of IO requests is done by the UFS, the writes a= re > >>>> not rescheduled at the GEOM layer? > >>> GJournal has some minimum knowledge about VFS. Before it does journal > >>> switch, it synchronize and suspends file system. This way we can be s= ure > >>> everything is on disk in a consistent state. > >> Thanks. So, this (async support) could actually work with other file > >> systems, like ext2 and msdos? > >=20 > > Once gjournal is taught about them, yes. >=20 > Then you're not interfacing in the VFS layer, you're hooking directly > into UFS? GJournal talks to VFS to sync/suspend file system, but it also needs to have some knowledge about file system to mark it as clean, so fsck won't complain. Look at sys/geom/journal/g_journal_ufs.c (dirty method is mostly not used, it is there for consistency and in case journal itself become broken/corrupted). --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --//IivP0gvsAy3Can Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (FreeBSD) iD8DBQFGK5EoForvXbEpPzQRAtBpAKCFTSL8Dh7Uj8jgCuivm9R1hnms1gCgl4Tz dXlHRMaaAMxf9dR81VaA9ZQ= =8wfy -----END PGP SIGNATURE----- --//IivP0gvsAy3Can--