Return-Path: Received: from borg.medozas.de ([188.40.89.202]:37562 "EHLO borg.medozas.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755761Ab0GVRgY (ORCPT ); Thu, 22 Jul 2010 13:36:24 -0400 Date: Thu, 22 Jul 2010 19:36:22 +0200 (CEST) From: Jan Engelhardt To: Trond Myklebust cc: Linus Torvalds , Jeremy Allison , Volker.Lendecke@sernet.de, David Howells , linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] In-Reply-To: <1279818967.3621.23.camel@heimdal.trondhjem.org> Message-ID: References: <20100715021709.5544.64506.stgit@warthog.procyon.org.uk> <20100715021712.5544.44845.stgit@warthog.procyon.org.uk> <30448.1279800887@redhat.com> <20100722162712.GB10352@jeremy-laptop> <1279818967.3621.23.camel@heimdal.trondhjem.org> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Thursday 2010-07-22 19:16, Trond Myklebust wrote: >> >But the fact is, th Unix ctime semantics are insane and largely >> >useless. There's a damn good reason almost nobody uses ctime under >> >unix. >> >> I beg to differ. ctime is not completely useless. It reflects changes on >> the inode for when you don't you change the content. It's like an mtime >> for the metadata. It comes useful when you go around in your filesystem >> trying to figure out who of your co-admins screwed up the permissions on >> /etc/passwd... and if the mtime is the same as that of the last backup, >> I can at least have a reasonable assurance that it was /only/ the >> metadata that was tampered with. (SHA1 check, yeah yeah, costly on large >> files.) > >Errr... Only if you eliminate utimes() from your syscall table. >Otherwise it is trivial to reset the mtime after changing the file >contents. Well yes; I had implicitly implied that evil people with malicious intent are absent.