From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 08 Jul 2008 23:58:59 -0700 (PDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.168.29]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m696wsJS020013 for ; Tue, 8 Jul 2008 23:58:54 -0700 Received: from ipmail01.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id C016F2CCC83 for ; Tue, 8 Jul 2008 23:59:58 -0700 (PDT) Received: from ipmail01.adl6.internode.on.net (ipmail01.adl6.internode.on.net [203.16.214.146]) by cuda.sgi.com with ESMTP id ss6UxDx18WfqtSiz for ; Tue, 08 Jul 2008 23:59:58 -0700 (PDT) Date: Wed, 9 Jul 2008 16:59:50 +1000 From: Dave Chinner Subject: Re: [PATCH 3/3] Add timeout feature Message-ID: <20080709065950.GR11558@disturbed> References: <20080701081026.GB16691@infradead.org> <20080707110730.GG5643@ucw.cz> <20080708231026.GP11558@disturbed> <20080708232031.GE18195@elf.ucw.cz> <20080709005254.GQ11558@disturbed> <20080709010922.GE9957@mit.edu> <20080709061621.GA5260@infradead.org> <20080708234120.5072111f@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080708234120.5072111f@infradead.org> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Arjan van de Ven Cc: Miklos Szeredi , hch@infradead.org, tytso@mit.edu, pavel@suse.cz, t-sato@yk.jp.nec.com, akpm@linux-foundation.org, viro@ZenIV.linux.org.uk, linux-ext4@vger.kernel.org, xfs@oss.sgi.com, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, axboe@kernel.dk, mtk.manpages@googlemail.com On Tue, Jul 08, 2008 at 11:41:20PM -0700, Arjan van de Ven wrote: > On Wed, 09 Jul 2008 08:22:56 +0200 > Miklos Szeredi wrote: > > > On Wed, Jul 09, 2008 at 08:13:21AM +0200, Miklos Szeredi wrote: > > > > This would mean that freeze and thaw will have to be done on the > > > > same file descriptor, but this isn't unreasonable to expect, is > > > > it? > > > > > > It is certainly not the current use case, where you run one command > > > to freeze the filesystem and another one to unfreeze it. > > > > So instead of > > > > freeze_fs mountpoint > > backup-command > > unfreeze_fs mountpoint > > > > the user would have do to > > > > run_freezed mountpoint backup-command > > > > I find the second one nicer, regardless of any reliability issues. > > nah he needs to do > > make_snapshot ; backup-command ; unref_snapshot. > > freezing isn't the right solution for the backup problem ;) You're forgetting that to take a snapshot you generally need to freeze the filesystem. ;) i.e: freeze; make_snapshot; unfreeze backup-command unref_snapshot Yes, dm_snapshot does the freeze/snapshot/unfreeze for you, but the point is there is a freeze in the example you gave. The argument against Miklos' version is that there may be multiple commands to execute while the fs is frozen. Cheers, Dave. -- Dave Chinner david@fromorbit.com