From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: silent semantic changes with reiser4 Date: Tue, 31 Aug 2004 22:54:23 +0200 Message-ID: <20040831205422.GD16110@elf.ucw.cz> References: <200408311931.i7VJV8kt028102@laptop11.inf.utfsm.cl> <20040831203226.GB16110@elf.ucw.cz> Mime-Version: 1.0 Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com Content-Disposition: inline In-Reply-To: List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linus Torvalds Cc: Horst von Brand , David Masover , Jamie Lokier , Chris Wedgwood , viro@parcelfarce.linux.theplanet.co.uk, Christoph Hellwig , Hans Reiser , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Lyamin aka FLX , ReiserFS List Hi! > > It buys me caching. > > I'll actually buy into that. If only because I consider caching to be one > of the more important things that the kernel does (caches are a _classic_ > case of "shared data that needs synchronization"). > > However, that said, user space can trivially cache things in the > filesystem, so while this may be a convenient feature, I think you should > look at perhaps doing it in the _shell_ instead.. That cache should disappear as soon as I need disk space. I.e. userspace should never see -ENOSPC because of this kind of caching. This need some kernel support. Ouch and cached file should atomically go away as soon as main file changes, otherwise I do not see how multiple processes could cooperate on caching... chattr +kill-this-file-when-low-on-disk-space patch.bz2...ubz would solve first problem. Not sure how to do the second one. Pavel -- People were complaining that M$ turns users into beta-testers... ...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!