From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f169.google.com ([209.85.223.169]:36289 "EHLO mail-io0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751957AbbKWQFk (ORCPT ); Mon, 23 Nov 2015 11:05:40 -0500 Received: by iofh3 with SMTP id h3so191934995iof.3 for ; Mon, 23 Nov 2015 08:05:39 -0800 (PST) Subject: Re: [PATCH v2 3/5] btrfs-progs: kernel based default features for mkfs To: Christoph Anton Mitterer , Anand Jain , linux-btrfs@vger.kernel.org References: <1448283378-10579-1-git-send-email-anand.jain@oracle.com> <1448283378-10579-4-git-send-email-anand.jain@oracle.com> <1448294271.2100.3.camel@scientia.net> From: Austin S Hemmelgarn Message-ID: <56533951.7090208@gmail.com> Date: Mon, 23 Nov 2015 11:05:37 -0500 MIME-Version: 1.0 In-Reply-To: <1448294271.2100.3.camel@scientia.net> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms030903030903090406030904" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms030903030903090406030904 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-11-23 10:57, Christoph Anton Mitterer wrote: > Hey. > > On Mon, 2015-11-23 at 20:56 +0800, Anand Jain wrote: >> This patch disables default features based on the running kernel. > Not sure if that's very realistic in practise (most people will have > some distro, whose btrfsprogs version probably matches the kernel), but= > purely from the end-user PoV: > > I would find it useful if btrfs gives a warning if it creates a > filesystem which (because unsupported in the current kernel) lacks > features which are considered default by then. It should give a warning if the user requests a feature that is=20 unsupported by the kernel it's being run on, but it should not by=20 default try to enable something that isn't supported by the kernel it's=20 running on. > > > AFAIU, really "clonding" (I mean including all snapshots, subvols, > etc.) a btrfs is not possible right now (or is it?), so a btrfs is > something that rather should stay longer (as one cannot easily > copy&swap it to/with a new one)... so for me as an end-user, it may be > easier to switch to a newer kernel, in order to get a feature which is > default, than to migrate the fs later. It is actually possible to clone a btrfs filesystem, just not in a way=20 that people used to stuff like ext4 would recognize. In essence, you=20 need to take the FS mostly off-line, force all subvolumes to read-only,=20 then use send-receive to transfer things, and finally make the=20 subvolumes writable again. I've been considering doing a script to do=20 this automatically, but have never gotten around to it as it's not=20 something that is quick to code, and it's not something I do very often. --------------ms030903030903090406030904 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Brgwgga0MIIEnKADAgECAgMRLfgwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwOTIxMTEzNTEzWhcNMTYwMzE5MTEzNTEzWjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz ZXIxIzAhBgkqhkiG9w0BCQEWFGFoZmVycm9pbjdAZ21haWwuY29tMSIwIAYJKoZIhvcNAQkB FhNhaGVtbWVsZ0BvaGlvZ3QuY29tMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA nQ/81tq0QBQi5w316VsVNfjg6kVVIMx760TuwA1MUaNQgQ3NyUl+UyFtjhpkNwwChjgAqfGd LIMTHAdObcwGfzO5uI2o1a8MHVQna8FRsU3QGouysIOGQlX8jFYXMKPEdnlt0GoQcd+BtESr pivbGWUEkPs1CwM6WOrs+09bAJP3qzKIr0VxervFrzrC5Dg9Rf18r9WXHElBuWHg4GYHNJ2V Ab8iKc10h44FnqxZK8RDN8ts/xX93i9bIBmHnFfyNRfiOUtNVeynJbf6kVtdHP+CRBkXCNRZ qyQT7gbTGD24P92PS2UTmDfplSBcWcTn65o3xWfesbf02jF6PL3BCrVnDRI4RgYxG3zFBJuG qvMoEODLhHKSXPAyQhwZINigZNdw5G1NqjXqUw+lIqdQvoPijK9J3eijiakh9u2bjWOMaleI SMRR6XsdM2O5qun1dqOrCgRkM0XSNtBQ2JjY7CycIx+qifJWsRaYWZz0aQU4ZrtAI7gVhO9h pyNaAGjvm7PdjEBiXq57e4QcgpwzvNlv8pG1c/hnt0msfDWNJtl3b6elhQ2Pz4w/QnWifZ8E BrFEmjeeJa2dqjE3giPVWrsH+lOvQQONsYJOuVb8b0zao4vrWeGmW2q2e3pdv0Axzm/60cJQ haZUv8+JdX9ZzqxOm5w5eUQSclt84u+D+hsCAwEAAaOCAVkwggFVMAwGA1UdEwEB/wQCMAAw VgYJYIZIAYb4QgENBEkWR1RvIGdldCB5b3VyIG93biBjZXJ0aWZpY2F0ZSBmb3IgRlJFRSBo ZWFkIG92ZXIgdG8gaHR0cDovL3d3dy5DQWNlcnQub3JnMA4GA1UdDwEB/wQEAwIDqDBABgNV HSUEOTA3BggrBgEFBQcDBAYIKwYBBQUHAwIGCisGAQQBgjcKAwQGCisGAQQBgjcKAwMGCWCG SAGG+EIEATAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy dC5vcmcwMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL2NybC5jYWNlcnQub3JnL3Jldm9rZS5j cmwwNAYDVR0RBC0wK4EUYWhmZXJyb2luN0BnbWFpbC5jb22BE2FoZW1tZWxnQG9oaW9ndC5j b20wDQYJKoZIhvcNAQENBQADggIBADMnxtSLiIunh/TQcjnRdf63yf2D8jMtYUm4yDoCF++J jCXbPQBGrpCEHztlNSGIkF3PH7ohKZvlqF4XePWxpY9dkr/pNyCF1PRkwxUURqvuHXbu8Lwn 8D3U2HeOEU3KmrfEo65DcbanJCMTTW7+mU9lZICPP7ZA9/zB+L0Gm1UNFZ6AU50N/86vjQfY WgkCd6dZD4rQ5y8L+d/lRbJW7ZGEQw1bSFVTRpkxxDTOwXH4/GpQfnfqTAtQuJ1CsKT12e+H NSD/RUWGTr289dA3P4nunBlz7qfvKamxPymHeBEUcuICKkL9/OZrnuYnGROFwcdvfjGE5iLB kjp/ttrY4aaVW5EsLASNgiRmA6mbgEAMlw3RwVx0sVelbiIAJg9Twzk4Ct6U9uBKiJ8S0sS2 8RCSyTmCRhJs0vvva5W9QUFGmp5kyFQEoSfBRJlbZfGX2ehI2Hi3U2/PMUm2ONuQG1E+a0AP u7I0NJc/Xil7rqR0gdbfkbWp0a+8dAvaM6J00aIcNo+HkcQkUgtfrw+C2Oyl3q8IjivGXZqT 5UdGUb2KujLjqjG91Dun3/RJ/qgQlotH7WkVBs7YJVTCxfkdN36rToPcnMYOI30FWa0Q06gn F6gUv9/mo6riv3A5bem/BdbgaJoPnWQD9D8wSyci9G4LKC+HQAMdLmGoeZfpJzKHMYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUxMTIzMTYwNTM3WjBPBgkq hkiG9w0BCQQxQgRAjYedALKfquTWeN4ooRTJ7QFpxF+6NL1A/W42XyNaAW7IXsvN1oBaM0aE VpUK3o+hJecBT/k+dcCrjM6clOWULTBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgAJJ/g89dmhkAuEv8+X04hW1Jcmjwtu4toyyHnXhQfWwFuYngE4 vQ7jBqT7gkmPZM203RsnX+uVv5o3xZcqv/I6Zd7aZnFts8h0pM+v1URLqVqKmaSEybne2Kl5 4176POfI8dEEhencts7vxsGv96m0rZm11K840+ZixkhTrTHm2wVI38Qj2W1ncnSoLg4tNmFb vME3UyMe3V7Zc6VKzc8y9b1kCMNgSDTWQHQFpVs/JQoEE5k5mH5ar0bWxseBmEOwXyCz4ps6 hIQQt8knoCPkSYZ7QTBJlUmxrN8kii9dTnxoP/Ti//zzEPbAFV3RJi7gVBOKZYV16aWfnZiA fayDWRTuWd1mi3Hi94iHzwMbJYA1lcqtX95TwDXxp74tUK7hvsGLo/mXjaBcbtQXo82pwE/3 WBRiEhQrkLE3vcK9KL9+FSxCb2KCfXwAi0tiE8Z4vHCaOjUmpnedC4HxWopYCPvoGBjS4HY/ F5u80Dxdr1SRe3K6xX96t9JlasD8CPF8756twk2nMdEGKRjDOgudvshvSTR4KH+IAQmtclsW QLpfkOv9Ji6JM2ylg98o6b4kj3RZ8AqJzBG4hF3EB67lpaU/JSLTG5wdN6JKzg+dHqqCcdXt Eu1XfycA8webE240mtmUdl6PpBCWSUnaZPqZ2ZlxZ9kOK1YDUioKhZiHSgAAAAAAAA== --------------ms030903030903090406030904--