From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q28NfImx097965 for ; Thu, 8 Mar 2012 17:41:18 -0600 Received: from mail.sandeen.net (sandeen.net [63.231.237.45]) by cuda.sgi.com with ESMTP id 7lKBJiNmJieL2l10 for ; Thu, 08 Mar 2012 15:41:17 -0800 (PST) Message-ID: <4F59439C.5040804@sandeen.net> Date: Thu, 08 Mar 2012 17:41:16 -0600 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: [PATCH] default to 64 bit inodes & add feature flag References: <4F5798F9.2050809@redhat.com> <20120308013413.GL3592@dastard> <4F5813D8.8070305@sandeen.net> <20120308153721.GS7762@sgi.com> <4F58D35D.7080504@sandeen.net> <20120308163832.GV8545@sgi.com> <20120308233953.GP5091@dastard> In-Reply-To: <20120308233953.GP5091@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: Josef 'Jeff' Sipek , Ben Myers , xfs-oss On 3/8/12 5:39 PM, Dave Chinner wrote: > On Thu, Mar 08, 2012 at 10:38:32AM -0600, Ben Myers wrote: >> On Thu, Mar 08, 2012 at 09:42:21AM -0600, Eric Sandeen wrote: >>> So, after thinking about this (and talking on irc) some more, I'm >>> not convinced that a feature flag is the way to go. >>> >>> If we set a feature flag, suddenly old filesystems with 64-bit >>> inodes will grow a new feature, and this will force a userspace >>> upgrade - but there is no real new feature. This seems like a bad >>> idea. My original patch (which Dave responded to with this one) >>> simply made inode64 default, with no feature flags. >>> >>> Unless someone has a really compelling argument for the flag, >>> I'm thinking this is the wrong approach after all. >>> >>> Perhaps I should resend the just-make-it-default patch. >>> >>> Comments? >> >> Ew! Forcing a userspace upgrade is not desireable. Since we would only >> want to set the feature bit if userspace were already upgraded, and only >> if there are 64 bit inos... How about two bits: one is set by mkfs and >> checked by the kernel to see if it is ok to set the other. ;) >> >> The first bit could also act as 'now its ok to default to inode64'. > > Too complex, IMO. Just add an xfs_admin command to set the inode64 > feature bit. That then overrides the inode64/inode32 mount option, > and guarantees that the user has already upgraded userspace. > > i.e. the mount options are only valid if the feature bit it not set, > and the feature bit can only be set via xfs_admin after a userspace > upgrade. Kernels that don't understand the feature bit will refuse > to mount, keeping in line with the current practise of requiring > both kernel and userspace upgrades to occur in step to use new > features.... Yep, I think that's the right path forward (had been thinking along these lines too, today). Thanks, -Eric > Cheers, > > Dave. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs