Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262784AbUKXSnO (ORCPT ); Wed, 24 Nov 2004 13:43:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262772AbUKXSkp (ORCPT ); Wed, 24 Nov 2004 13:40:45 -0500 Received: from mail.euroweb.hu ([193.226.220.4]:60321 "HELO mail.euroweb.hu") by vger.kernel.org with SMTP id S262784AbUKXScq (ORCPT ); Wed, 24 Nov 2004 13:32:46 -0500 To: avi@argo.co.il CC: alan@lxorguk.ukuu.org.uk, torvalds@osdl.org, hbryan@us.ibm.com, akpm@osdl.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pavel@ucw.cz In-reply-to: <41A47B67.6070108@argo.co.il> (message from Avi Kivity on Wed, 24 Nov 2004 14:15:35 +0200) Subject: Re: [PATCH] [Request for inclusion] Filesystem in Userspace References: <1100798975.6018.26.camel@localhost.localdomain> <41A47B67.6070108@argo.co.il> Message-Id: From: Miklos Szeredi Date: Wed, 24 Nov 2004 14:05:51 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1398 Lines: 34 > http://lkml.org/lkml/2004/7/26/68 > > discusses a userspace filesystem (implemented as a userspace nfs server > mounted on a loopback nfs mount), the problem, a solution (exactly your > suggestion), and a more generic solution. Thanks for the pointer, very interesting read. However, I don't like the idea that the userspace filesystem must cooperate with the kernel in this regard. With this you lose one of the advantages of doing filesystem in userspace: namely that you can be sure, that anything you do cannot bring the system down. And I firmly believe that this can be done without having to special case filesystem serving processes. There are already "strange" filesystems in the kernel which cannot really get rid of dirty data. I'm thinking of tmpfs and ramfs. Neither of them are prone to deadlock, though both of them are "worse off" than a userspace filesystem, in the sense that they have not even the remotest chance of getting rid of the dirty data. Of course, implementing this is probably not trivial. But I don't see it as a theoretical problem as Linus does. Is there something which I'm missing here? Thanks, Miklos - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/