From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:9233 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S965137AbbEMAyh convert rfc822-to-8bit (ORCPT ); Tue, 12 May 2015 20:54:37 -0400 Message-ID: <5552A0C9.2010108@cn.fujitsu.com> Date: Wed, 13 May 2015 08:54:33 +0800 From: Qu Wenruo MIME-Version: 1.0 To: Anand Jain , CC: Subject: Re: [PATCH 0/8] Introduce offline fsid/chunk tree uuid change for btrfstune. References: <1430806606-3226-1-git-send-email-quwenruo@cn.fujitsu.com> <20150505152055.GH5099@twin.jikos.cz> <5549651D.6020005@cn.fujitsu.com> <20150506154347.GC23255@twin.jikos.cz> <554C7A6A.8040404@cn.fujitsu.com> <20150511162423.GV23255@twin.jikos.cz> <555160DF.9050902@cn.fujitsu.com> <55517ADC.6000300@oracle.com> In-Reply-To: <55517ADC.6000300@oracle.com> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: -------- Original Message -------- Subject: Re: [PATCH 0/8] Introduce offline fsid/chunk tree uuid change for btrfstune. From: Anand Jain To: Qu Wenruo , Date: 2015年05月12日 12:00 > > > On 05/12/2015 10:09 AM, Qu Wenruo wrote: >> >> >> -------- Original Message -------- >> Subject: Re: [PATCH 0/8] Introduce offline fsid/chunk tree uuid change >> for btrfstune. >> From: David Sterba >> To: Qu Wenruo >> Date: 2015年05月12日 00:24 >> >>> On Fri, May 08, 2015 at 04:57:14PM +0800, Qu Wenruo wrote: >>>>> Respecting the current syntax, the way to set the uuid is: >>>>> >>>>> btrfs prop set -t filesytem /dev/sdx uuid ...UUID... >>>>> >>>>> In this special case, the property handler should check if the >>>>> device is >>>>> unmounted (and is a btrfs filesystem) and then do the rest. >>>> This is one good idea, but I'm afraid it may still be confusing. >>>> And things may get even worse when we try to move everything into >>>> btrfs-prop, >>>> E.g. if we auto move seeding flag to prop, we must give a quite >>>> detailed >>>> explain on which property is offline. >>>> >>>> So I prefer to add a new type called offline, and put uuid change with >>>> other btrfstune function into this type. >>>> IMHO this should provide a good explain on which is online and which is >>>> offline. >>>> >>>> How do you think about this method? >>> >>> I don't think that 'offline' is a good choice. The type should denote >>> the modified object, ie device, inode, filesystem. What's 'offline' in >>> this context? >> Right, 'offline' type here is just a easy trick for me to code, not a >> meaningful type. >>> >>> The property interface can be used to modify other features both for >>> mounted and unmounted filesystem, I agree that this should be done in a >>> way that's not confusing. There are operations that are allowed on an >>> unmounted fs (seeding), mounted + unmounted (extref feature) etc. so I >>> think we could add options like --check-unmounted that would not allow >>> to act on a mounted filesystem. >> >> Nice idea, but i prefer a option like "--offline" to enable the usage of >> offline operations. >> E.g, for normal online operations, nothing is changed. >> >> And for "btrfs prop set uuid ", "--offline" must be >> specified to work. >> Or a message will be output to info user. >> >> What about this one? > > > Qu, Thanks for the feature. > > Qu/David, > > I strongly recommend this feature to be part of btrfstune as > of now, as originally planned by Qu. When its time to move > to btrfs cli we could. If we do it wrongly now it would stay > there forever. > > We could take better call, when all the features of progs are > in place. > > Thanks, Anand This is much easier for me, no need to consider the format of new online-offline mixed parameter for btrfs progs. But the decision is on David. Thanks, Qu > >> Thanks, >> Qu >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html