From: Dave Chinner Subject: Re: [PATCH 3/3] Add timeout feature Date: Wed, 9 Jul 2008 09:10:27 +1000 Message-ID: <20080708231026.GP11558@disturbed> References: <20080630212450t-sato@mail.jp.nec.com> <20080701081026.GB16691@infradead.org> <20080707110730.GG5643@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Christoph Hellwig , Takashi Sato , 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 To: Pavel Machek Return-path: Received: from ipmail01.adl6.internode.on.net ([203.16.214.146]:53291 "EHLO ipmail01.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752500AbYGHXKc (ORCPT ); Tue, 8 Jul 2008 19:10:32 -0400 Content-Disposition: inline In-Reply-To: <20080707110730.GG5643@ucw.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Jul 07, 2008 at 01:07:31PM +0200, Pavel Machek wrote: > Hi! >=20 > > I still disagree with this whole patch. There is not reason to let > > the freeze request timeout - an auto-unfreezing will only confuse t= he > > hell out of the caller. The only reason where the current XFS free= ze > > call can hang and this would be theoretically useful is when the >=20 > What happens when someone dirties so much data that vm swaps out > whatever process that frozen the filesystem? a) you can't dirty a frozen filesystem - by definition a frozen filesystem is a *clean filesystem* and *cannot be dirtied*. b) Swap doesn't write through the filesystem c) you can still read from a frozen filesystem to page your executable=D1=95 in. d) if dirtying another unfrozen filesystem swaps out your application so it can't run, then there's a major VM bug. Regardless, until the app completes it is relying on the filesystem being frozen, so it better remain frozen.... > I though that was why the timeout was there... Not that I know of.=20 Cheers, Dave. --=20 Dave Chinner david@fromorbit.com -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html