From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Goyal Subject: Re: [PATCH v6 03/15] ovl: Provide a mount option metacopy=on/off for metadata copyup Date: Wed, 15 Nov 2017 11:04:00 -0500 Message-ID: <20171115160400.GD13895@redhat.com> References: <20171109205019.11409-1-vgoyal@redhat.com> <20171109205019.11409-4-vgoyal@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35820 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756489AbdKOQEB (ORCPT ); Wed, 15 Nov 2017 11:04:01 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-unionfs-owner@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org To: Amir Goldstein Cc: overlayfs , Miklos Szeredi On Fri, Nov 10, 2017 at 09:14:49AM +0200, Amir Goldstein wrote: > On Fri, Nov 10, 2017 at 9:07 AM, Amir Goldstein wrote: > > On Thu, Nov 9, 2017 at 10:50 PM, Vivek Goyal wrote: > >> By default metadata only copy up is disabled. Provide a mount option so > >> that users can choose one way or other. > >> > >> Also provide a kernel config and module option to enable/disable > >> metacopy feature. > >> > >> Like index feature, we verify on mount that upper root is not being > >> reused with a different lower root. This hopes to get the configuration > >> right and detect the copied layers use case. But this does only so > >> much as we don't verify all the lowers. So it is possible that a lower is > >> missing and later data copy up fails. > >> > >> Signed-off-by: Vivek Goyal > > > > Fine, as long as Miklos agrees not to enforce exclusive dir lock, > > it's fine by me. > > > > Please take a look at my ovl-features patches and say what you think. > > It is time we started to enforce some order with all the inter-dependencies > > between features. > > With my proposal, it will make mounting an overlay with metacopy object > > on older kernel slightly harder (but not impossible), so it can help admins > > from tripping over themselves. > > > > Reviewed-by: Amir Goldstein > > > > On second though, hold that Reviewed-by, there is one more thing > that this patch should check, see path: > "ovl: disable redirect_dir and index when no xattr support" > from my verify_dir patches: > https://github.com/amir73il/linux/commits/ovl-verify-dir > > You may cherry-pick it at beginning of your series and then this > patch should also disable metacopy on mount with noxattr with a warning to user, > instead of silently not doing the metacopies, but claiming in mount options that > metacopy is on. Makes sense. Will do. Vivek