Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030604AbVKXFPf (ORCPT ); Thu, 24 Nov 2005 00:15:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030605AbVKXFPf (ORCPT ); Thu, 24 Nov 2005 00:15:35 -0500 Received: from bee.hiwaay.net ([216.180.54.11]:35357 "EHLO bee.hiwaay.net") by vger.kernel.org with ESMTP id S1030604AbVKXFPe (ORCPT ); Thu, 24 Nov 2005 00:15:34 -0500 Date: Wed, 23 Nov 2005 23:15:28 -0600 From: Chris Adams To: Andi Kleen Cc: linux-kernel@vger.kernel.org Subject: Re: Generation numbers in stat was Re: what is slashdot's answer to ZFS? Message-ID: <20051124051528.GB1121157@hiwaay.net> References: <20051122161712.GA942598@hiwaay.net> <1132690779.20233.74.camel@localhost.localdomain> <20051122195652.GB660478@hiwaay.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1497 Lines: 29 Once upon a time, Andi Kleen said: > Chris Adams writes: > > [Tru64 UNIX] However, in the rare case when a user application has been > > deleting open files, and a file serial number is reused, a third structure > > member in , the file generation number, is needed to uniquely > > identify a file. This member, st_gen, is used in addition to st_ino and > > st_dev. > > Sounds like a cool idea. Many fs already maintain this information > in the kernel. We still had some unused pad space in the struct stat > so it could be implemented without any compatibility issues > (e.g. in place of __pad0). On old kernels it would be always 0. Searching around some, I see that OS X has st_gen, but the man page I found says it is only available for super-user. It also appears that AIX and at least some of the BSDs have it (which would make sense I guess as Tru64, OS X, and IIRC AIX are all BSD derived). Also, I ses someone pitched it to linux-kernel several years ago but it didn't appear to go anywhere. Maybe time to rethink that? -- Chris Adams Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble. - 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/