Return-Path: Received: from frost.carfax.org.uk ([85.119.82.111]:53716 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753801AbbLBSxp (ORCPT ); Wed, 2 Dec 2015 13:53:45 -0500 Date: Wed, 2 Dec 2015 18:53:31 +0000 From: Hugo Mills To: Austin S Hemmelgarn Cc: Eric Sandeen , Qu Wenruo , Russell Coker , Chris Mason , Btrfs mailing list Subject: Re: Bug/regression: Read-only mount not read-only Message-ID: <20151202185331.GJ8775@carfax.org.uk> References: <20151128134634.GF24333@carfax.org.uk> <20151201190018.GD8918@ret.masoncoding.com> <565DEF65.4080900@redhat.com> <201512021725.32750.russell@coker.com.au> <565EB480.4010509@cn.fujitsu.com> <565EB878.9090501@cn.fujitsu.com> <565F2260.1080004@redhat.com> <565F2EF7.5000109@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="6b3yLyRKT1M6kiA0" In-Reply-To: <565F2EF7.5000109@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: --6b3yLyRKT1M6kiA0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 02, 2015 at 12:48:39PM -0500, Austin S Hemmelgarn wrote: > On 2015-12-02 11:54, Eric Sandeen wrote: > >On 12/2/15 3:23 AM, Qu Wenruo wrote: > >>Qu Wenruo wrote on 2015/12/02 17:06 +0800: > >>>Russell Coker wrote on 2015/12/02 17:25 +1100: > >>>>On Wed, 2 Dec 2015 06:05:09 AM Eric Sandeen wrote: > >>>>>yes, xfs does; we have "-o norecovery" if you don't want that, or need > >>>>>to mount a filesystem with a dirty log on a readonly device. > >>>> > >>>>That option also works with Ext3/4 so it seems to be a standard way of > >>>>dealing > >>>>with this. I think that BTRFS should do what Ext3/4 and XFS do in this > >>>>regard. [snip] > >so if you'd like btrfs to be consistent with these, I would not make > >norecovery imply ro; rather, make I would make it require an explicit ro, i.e. > > > >mount -o ro,norecovery > Agreed, with something like that, it should as blatantly obvious as > possible that you can't write to the FS. > > On a side note, do either XFS or ext4 support removing the > norecovery option from the mount flags through mount -o remount? > Even if they don't, that might be a nice feature to have in BTRFS if > we can safely support it. One minor awkwardness with "norecovery", I've just realised: we already have a "recovery" mount option. That's going to make things really confusing if we stick to that name. Hugo. -- Hugo Mills | Reintarnation: Coming back from the dead as a hugo@... carfax.org.uk | hillbilly http://carfax.org.uk/ | PGP: E2AB1DE4 | --6b3yLyRKT1M6kiA0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJWXz4rAAoJEFheFHXiqx3kakgP/R1GaRgjPbG4z2j8SnPKs1zQ uH5GlqlI29x/2EP3XbdaSDnmRGTPfigVYCyDHQGyiehWVBtUp8D+ChZQAQU64pen oKRlN15P2TKKLZnZNmYPhiXVJP3YTCkh4imdb/ceik468W/g3z+v/zPVJxhVU94H Ul7V09Bp60SNpWbkJuhD1vzqxxvDUOqqmzl33ZbHVXrHGlCF6LsIBWMVvuw2UbO6 eskk9C4TN47XQltRiUXx8N97MssFYC6kdzyf7mB1MQfoOKB5eQa/IeEX8wxfNQYt lbYIoJwKcIRrtLeqDdzbMnNIMhbOUesh/KD+HEeVckOWxxK+7IFDsEyEMRKuLEK6 3xGMcVEr3UAZ+Fw4aq8VZiy5UZZmKidX2kHKyOHx0MUDwXAx4AZSgVCuJB7PIJhK 9I/zdvU5v/0lmIH7fYT9ip3tJVTUkYsjY0iYGGvpe/IMDCPO7au2mQ8Mi1lPcG7G +lnLwBX1hHklPIaz4qLPyXE52hqQt22G0WweGpvrjytU9GHi62I6TqWjgoE9qovJ h8QekmXmvtW0xePRCel3vfqRUI28BqWb1liorwErKkAWB9qkgerdeKv3eGsLNMhP SYK5ug+b8TY/X8nKKc22fGnS+nTyXCW5W6sSY0vLhOC5N4B7N1YIpEdGsFvIbbbL F+Wnzar/dWl+YfhRo/OB =xdbB -----END PGP SIGNATURE----- --6b3yLyRKT1M6kiA0--