From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f170.google.com ([209.85.213.170]:34566 "EHLO mail-ig0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754598AbaLVT4x (ORCPT ); Mon, 22 Dec 2014 14:56:53 -0500 Received: by mail-ig0-f170.google.com with SMTP id r2so5790424igi.3 for ; Mon, 22 Dec 2014 11:56:52 -0800 (PST) Message-ID: <5498777F.8070808@gmail.com> Date: Mon, 22 Dec 2014 14:56:47 -0500 From: Austin S Hemmelgarn MIME-Version: 1.0 To: Chris Murphy CC: Btrfs BTRFS Subject: Re: Can BTRFS handle XATTRs larger than 4K? References: <54982A79.1090102@gmail.com> <54985E4C.40003@gmail.com> In-Reply-To: Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms080802020700070400040004" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms080802020700070400040004 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable On 2014-12-22 13:43, Chris Murphy wrote: > On Mon, Dec 22, 2014 at 11:09 AM, Austin S Hemmelgarn > wrote: > >> Personally, I'd love to see unlimited length xattr's like NTFS and HFS= + do, >> as that would greatly improve interoperability (both Windows and OS X = use >> xattrs, although they call them 'alternative data streams' and 'forks'= >> respectively), and provide a higher likelihood that xattrs would start= >> getting used more. > > This is two years old, but it looks like NFS will not support xattr. > http://comments.gmane.org/gmane.linux.nfs/53259 > > It looks like SMB does support xattr (and sometimes requires it) but I > have no idea to what degree, including the host/client preservation on > different filesystems. [1] It would still be helpful for cp and rsync > to be able to preserve xattr, however Apple has moved to a new on-disk > format that makes the future of reading OS X volumes on Linux an open > question. [2] > > > > > [1]e.g. Btrfs > Samba- server > SMB over TCP > "Apple SMB2" > HFS+. > And then the OS X client pushing a file to the server is a separate > test. Next test would be OS X as server and Linux as client to do HFS+ >> "Apple SMB2" > SMB over TCP > Samba-client > Btrfs, and then Linux > client pushing a file to OS X is a separate test. So it's four tests > for any combination of filesystems. > > [2] Apple has a logical volume manager called CoreStorage. Until > recently it's mainly used to implement full disk (volume) encryption, > but encryption is actually optional. It's also used to combine SSD+HDD > partitions into a single logical volume using the SSD as a cache. > Starting with 10.10 "Yosemite" it's used by default for the main > HFSJ/X volume for system/apps/user data, and even legacy OS X only > installations are converted to a CoreStorage logical volume upon > upgrading. There's no pre-baked support on linux for this right now, > and I'm not really sure if/when we'd ever see this in a distribution > by default. > http://www.cl.cam.ac.uk/~osc22/docs/cl_fv2_presentation_2012.pdf > https://github.com/libyal/libfvde/ > > I'm more thinking along the lines of not having to jump through hoops to = get _ALL_ the data in a tar file from OS X to extract on a Linux box.=20 Also, Windows has been using it's 'alternative data streams'=20 functionality from NTFS more in recent years (the new 'file history'=20 functionality in Win8/8.1 uses ADS for storing old copies of files), and = these are essentially just forks with a extra compatibility interface.=20 There are other potentially interesting uses though, for example,=20 storing multiple localized versions of a text file as a single=20 user-visible 'file'. --------------ms080802020700070400040004 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIFuDCC BbQwggOcoAMCAQICAw9gVDANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w HAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmlu ZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZzAeFw0xNDA4 MDgxMTMwNDRaFw0xNTAyMDQxMTMwNDRaMGMxGDAWBgNVBAMTD0NBY2VydCBXb1QgVXNlcjEj MCEGCSqGSIb3DQEJARYUYWhmZXJyb2luN0BnbWFpbC5jb20xIjAgBgkqhkiG9w0BCQEWE2Fo ZW1tZWxnQG9oaW9ndC5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDdmm8R BM5D6fGiB6rpogPZbLYu6CkU6834rcJepfmxKnLarYUYM593/VGygfaaHAyuc8qLaRA3u1M0 Qp29flqmhv1VDTBZ+zFu6JgHjTDniBii1KOZRo0qV3jC5NvaS8KUM67+eQBjm29LhBWVi3+e a8jLxmogFXV0NGej+GHIr5zA9qKz2WJOEoGh0EfqZ2MQTmozcGI43/oqIYhRj8fRMkWXLUAF WsLzPQMpK19hD8fqwlxQWhBV8gsGRG54K5pyaQsjne7m89SF5M8JkNJPH39tHEvfv2Vhf7EM Y4WGyhLAULSlym1AI1uUHR1FfJaj3AChaEJZli/AdajYsqc7AgMBAAGjggFZMIIBVTAMBgNV HRMBAf8EAjAAMFYGCWCGSAGG+EIBDQRJFkdUbyBnZXQgeW91ciBvd24gY2VydGlmaWNhdGUg Zm9yIEZSRUUgaGVhZCBvdmVyIHRvIGh0dHA6Ly93d3cuQ0FjZXJ0Lm9yZzAOBgNVHQ8BAf8E BAMCA6gwQAYDVR0lBDkwNwYIKwYBBQUHAwQGCCsGAQUFBwMCBgorBgEEAYI3CgMEBgorBgEE AYI3CgMDBglghkgBhvhCBAEwMgYIKwYBBQUHAQEEJjAkMCIGCCsGAQUFBzABhhZodHRwOi8v b2NzcC5jYWNlcnQub3JnMDEGA1UdHwQqMCgwJqAkoCKGIGh0dHA6Ly9jcmwuY2FjZXJ0Lm9y Zy9yZXZva2UuY3JsMDQGA1UdEQQtMCuBFGFoZmVycm9pbjdAZ21haWwuY29tgRNhaGVtbWVs Z0BvaGlvZ3QuY29tMA0GCSqGSIb3DQEBDQUAA4ICAQCr4klxcZU/PDRBpUtlb+d6JXl2dfto OUP/6g19dpx6Ekt2pV1eujpIj5whh5KlCSPUgtHZI7BcksLSczQbxNDvRu6LNKqGJGvcp99k cWL1Z6BsgtvxWKkOmy1vB+2aPfDiQQiMCCLAqXwHiNDZhSkwmGsJ7KHMWgF/dRVDnsl6aOQZ jAcBMpUZxzA/bv4nY2PylVdqJWp9N7x86TF9sda1zRZiyUwy83eFTDNzefYPtc4MLppcaD4g Wt8U6T2ffQfCWVzDirhg4WmDH3MybDItjkSB2/+pgGOS4lgtEBMHzAGQqQ+5PojTHRyqu9Jc O59oIGrTaOtKV9nDeDtzNaQZgygJItJi9GoAl68AmIHxpS1rZUNV6X8ydFrEweFdRTVWhUEL 70Cnx84YBojXv01LYBSZaq18K8cERPLaIrUD2go+2ffjdE9ejvYDhNBllY+ufvRizIjQA1uC OdktVAN6auQob94kOOsWpoMSrzHHvOvVW/kbokmKzaLtcs9+nJoL+vPi2AyzbaoQASVZYOGW pE3daA0F5FJfcPZKCwd5wdnmT3dU1IRUxa5vMmgjP20lkfP8tCPtvZv2mmI2Nw5SaXNY4gVu WQrvkV2in+TnGqgEIwUrLVbx9G6PSYZZs07czhO+Q1iVuKdAwjL/AYK0Us9v50acIzbl5CWw ZGj3wjGCA6EwggOdAgEBMIGAMHkxEDAOBgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6 Ly93d3cuY2FjZXJ0Lm9yZzEiMCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEh MB8GCSqGSIb3DQEJARYSc3VwcG9ydEBjYWNlcnQub3JnAgMPYFQwCQYFKw4DAhoFAKCCAfUw GAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTQxMjIyMTk1NjQ3 WjAjBgkqhkiG9w0BCQQxFgQULWs+wZh9NqqxWp6J6ARJ2nyny/IwbAYJKoZIhvcNAQkPMV8w XTALBglghkgBZQMEASowCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIA gDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKDCBkQYJKwYBBAGCNxAE MYGDMIGAMHkxEDAOBgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0 Lm9yZzEiMCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJ ARYSc3VwcG9ydEBjYWNlcnQub3JnAgMPYFQwgZMGCyqGSIb3DQEJEAILMYGDoIGAMHkxEDAO BgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0Lm9yZzEiMCAGA1UE AxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJARYSc3VwcG9ydEBj YWNlcnQub3JnAgMPYFQwDQYJKoZIhvcNAQEBBQAEggEAJqBqEeNR3C3PQ9LIbXpnPE4CO7PR 4GVfmj8D2SIfL7vKViFbK9n2Oz5BrtvPzkG6zvLz0iZ1i4qZ71gW9t7NOfWOUbkkaAjqZPIp CghuJkmXPgISvzjhOUl5CA3FIHaEj8NpYHAMc4N8cE/ZlwRtEoVeLlk/3WoLTJ24YY79vVjk ZAL54XHtD+Y9U2K8cyl05zvGAq9MW6/y05TpuioHIryicSR9P+vr4qTQRffB7Wq2YpRY24Ag 3ruukWbEwDmcRtYfBle6Rz/UH7d8L7OlJazI0LQYRdUQCqh6xaQX/KKcpry87lovloVgbveZ qzkhu3scLZ9edKSTiz39GDyPgQAAAAAAAA== --------------ms080802020700070400040004--