Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752868AbYHLT1v (ORCPT ); Tue, 12 Aug 2008 15:27:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751748AbYHLT1m (ORCPT ); Tue, 12 Aug 2008 15:27:42 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:37828 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751700AbYHLT1m (ORCPT ); Tue, 12 Aug 2008 15:27:42 -0400 Date: Tue, 12 Aug 2008 15:27:41 -0400 From: Christoph Hellwig To: "Serge E. Hallyn" Cc: Mimi Zohar , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Al Viro , Stephen Smalley , James Morris , Randy Dunlap , safford@watson.ibm.com, serue@linux.vnet.ibm.com, sailer@watson.ibm.com, Mimi Zohar Subject: Re: [PATCH 3/4] integrity: Linux Integrity Module(LIM) Message-ID: <20080812192741.GB18034@infradead.org> References: <20080808184349.999902616@linux.vnet.ibm.com> <1218221761.4444.13.camel@localhost.localdomain> <20080809185340.GC22905@infradead.org> <20080811170255.GA2662@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080811170255.GA2662@us.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1744 Lines: 33 On Mon, Aug 11, 2008 at 12:02:55PM -0500, Serge E. Hallyn wrote: > > > Sorry, but I don't think we can bloat the inode even further for this. > > > > The original version of IMA was LSM based, using i_security. Based > > on discussions on the LSM mailing list, it was decided that the LSM hooks > > were meant only for access control. During the same time frame, there > > was a lot of work done in stacking LSM modules and i_security, but that > > approach was dropped. It was suggested that we define a separate set of > > hooks for integrity, which this patch set provides. Caching integrity > > results is an important aspect. Any suggestions in lieu of defining > > i_integrity? > > The i_integrity is only bloating the inode if LIM is enabled. Surely > that beats having LIM define its own hash table and locking to track > integrity labels on inodes? Do you have another suggestion? > > Or is the concern about having more #ifdefs in the struct inode > definition? No, the concern is over bloating the inode for a rather academic fringe feature. As this comes from IBM I'm pretty sure someone will pressure the big distro to turn it on. And inode growth is a concern for fileserving or other inode heavy workload. Mimi mentioned this is just a cache of information, so consider using something like XFS's mru cache which is used for something similar where the xfs_inode was kept small despite a very niche feature needing a cache attached to the inode: fs/xfs/xfs_mru_cache.c -- 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/