From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from len.romanrm.net ([91.229.20.24]:39502 "EHLO len.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754141Ab3JKJqo (ORCPT ); Fri, 11 Oct 2013 05:46:44 -0400 Date: Fri, 11 Oct 2013 15:35:46 +0600 From: Roman Mamedov To: Stefan Behrens Cc: Wang Shilong , Ilya Dryomov , linux-btrfs@vger.kernel.org, Chris Mason Subject: Re: [PATCH] Btrfs: disallow 'btrfs {balance,replace} cancel' on ro mounts Message-ID: <20131011153546.424d69c4@natsu> In-Reply-To: <5257C378.1060507@giantdisaster.de> References: <1381426821-31981-1-git-send-email-idryomov@gmail.com> <525750B4.4090009@cn.fujitsu.com> <5257C378.1060507@giantdisaster.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/a=xTavhI_d0YcsKCp2tvekr"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --Sig_/a=xTavhI_d0YcsKCp2tvekr Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 11 Oct 2013 11:23:04 +0200 Stefan Behrens wrote: > On Fri, 11 Oct 2013 09:13:24 +0800, Wang Shilong wrote: > > On 10/11/2013 01:40 AM, Ilya Dryomov wrote: > >=20 > > I have a question in my mind. > >=20 > > Can we reach a state that there is operation in progress when filesystem > > has been readonly?If we do cancel operations on a ro filesystem, we sho= uld > > get "No operations in progress" . >=20 > Well, it's arguable what ro means. No write to the devices at all? If I had an FS image and mounted it as -o loop,ro I'd simply expect md5sum = of that image to match before mount and after unmount, i.e. no writes at all. Really, how can one argue with what "read only" means? If it will mean something else than a complete absence of writes, then how can we mount devices or FS images to do forensics, etc? Or do a recovery from a difficult corruption or try to debug an FS crash. --=20 With respect, Roman --Sig_/a=xTavhI_d0YcsKCp2tvekr Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlJXxnIACgkQTLKSvz+PZwg4ZACgiDQQdMPxW5Pf3ZT2xg5PsnmY qSEAn2uM8PRNFO0zny2jzsQi2zMUJ6K+ =oSei -----END PGP SIGNATURE----- --Sig_/a=xTavhI_d0YcsKCp2tvekr--