From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mr001msb.fastweb.it ([85.18.95.85]:50256 "EHLO mr001msb.fastweb.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751788AbdEENTs (ORCPT ); Fri, 5 May 2017 09:19:48 -0400 Received: from ceres.assyoma.it (93.63.55.57) by mr001msb.fastweb.it (8.5.140.05) id 58FDB0C300796200 for linux-xfs@vger.kernel.org; Fri, 5 May 2017 15:19:46 +0200 Subject: Re: XFS and multiple mounts protection (aka preventing multiple mounts) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 05 May 2017 15:19:45 +0200 From: Gionatan Danti In-Reply-To: <20170505122547.6gvqmdoxfaqxh3mi@eorzea.usersys.redhat.com> References: <3cf2f8cd-d18f-2a65-c540-5527a366d2fb@assyoma.it> <20170505113219.dovbzhbmt6e3ooem@eorzea.usersys.redhat.com> <2e45f5c8-0b8f-ef99-a8a5-cd3ebb89911e@assyoma.it> <20170505122547.6gvqmdoxfaqxh3mi@eorzea.usersys.redhat.com> Message-ID: Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Gionatan Danti , linux-xfs@vger.kernel.org Il 05-05-2017 14:25 Carlos Maiolino ha scritto: > > As far as I know, don't, I can always be wrong, but, I re-checked xfs > superblock, and could not find anything that actually protects it. > So, how do you protect iSCSI targets from erroneous multiple mount? Do you protect them only at the target/lun level (eg: access list on the target/lun)? > > Eh, I really don't know much about EXT4, but this only works if the > clocks are > properly adjusted (not really hard to achieve though), but still racy. > I think that the mechanism tracks the relative change in the mmp structure, rather than absolute value. Sort of "look at it, sleep, relook, if the value changed, then does not mount"... Thanks. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8