From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailgw-02.dd24.net ([193.46.215.43]:41125 "EHLO mailgw-02.dd24.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932109AbcISTxA (ORCPT ); Mon, 19 Sep 2016 15:53:00 -0400 Message-ID: <1474314776.10189.24.camel@scientia.net> Subject: Re: stability matrix From: Christoph Anton Mitterer To: "Austin S. Hemmelgarn" , linux-btrfs@vger.kernel.org, dave@jikos.cz Date: Mon, 19 Sep 2016 21:52:56 +0200 In-Reply-To: References: <57D51BF9.2010907@online.no> <20160912142714.GE16983@twin.jikos.cz> <52304724-5bca-a1e6-527f-040085c7ab19@gmail.com> <20160912165107.GG16983@twin.jikos.cz> <58a954fc-bbd5-3fb5-9f23-008ed7f7121d@gmail.com> <20160915010759.GD32452@DigitalMercury.dynalias.net> <5dec6544a78a0301a8e0cd9086179f99@crc.id.au> <1473905644.8603.44.camel@scientia.net> <20160919152753.GG933@twin.jikos.cz> Content-Type: multipart/signed; micalg="sha-512"; protocol="application/x-pkcs7-signature"; boundary="=-xzcN7UwYFedUlq8rXOhL" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: --=-xzcN7UwYFedUlq8rXOhL Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2016-09-19 at 13:18 -0400, Austin S. Hemmelgarn wrote: > > > - even mounting a fs ro, may cause it to be changed > >=20 > > This would go to the UseCases > My same argument about the UUID issues applies here, just without > the=C2=A0 > security aspect. I personally could agree to have that "just" in the usecases. That a fs my be changed even though it's mounted ro is not unique to btrfs.... and the need for not having that happen goes probably rather into data-forensics and rescue use cases. IMO there's rather a general problem, namely that the different filesystems don't provide a mount option that implies every other mount options currently needed to get an actual "hard ro", i.e. one where the device is never written to. Qu was about to add such option when=C2=A0nologreplay was added, but IIRC h= e got some resistance by linux-fs, who probably didn't care enough whether the end-user can easily do such "hard ro" mount ;) Cheers, Chris. --=-xzcN7UwYFedUlq8rXOhL Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCCEmow ggXiMIIDyqADAgECAhBctkhuRwyYxn/2gNtkSuKNMA0GCSqGSIb3DQEBCwUAMH0xCzAJBgNVBAYT AklMMRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSswKQYDVQQLEyJTZWN1cmUgRGlnaXRhbCBDZXJ0 aWZpY2F0ZSBTaWduaW5nMSkwJwYDVQQDEyBTdGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0 eTAeFw0xNTEyMTYwMTAwMDVaFw0zMDEyMTYwMTAwMDVaMHUxCzAJBgNVBAYTAklMMRYwFAYDVQQK Ew1TdGFydENvbSBMdGQuMSkwJwYDVQQLEyBTdGFydENvbSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0 eTEjMCEGA1UEAxMaU3RhcnRDb20gQ2xhc3MgMiBDbGllbnQgQ0EwggEiMA0GCSqGSIb3DQEBAQUA 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