From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cahost.average.org ([72.55.133.117]:35443 "EHLO cahost.average.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754918Ab2LRPaa (ORCPT ); Tue, 18 Dec 2012 10:30:30 -0500 Message-ID: <50D08C0A.4010003@average.org> Date: Tue, 18 Dec 2012 19:30:18 +0400 From: Eugene Crosser MIME-Version: 1.0 To: Hugo Mills , linux-btrfs@vger.kernel.org Subject: Re: btrfs in the kernel 2.6.31 References: <50D079AB.2030805@average.org> <20121218143521.GN19051@carfax.org.uk> <20121218143759.GO19051@carfax.org.uk> (sfid-20121218_183805_520610_34744205) In-Reply-To: <20121218143759.GO19051@carfax.org.uk> (sfid-20121218_183805_520610_34744205) Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig626159A078878821B979F2C2" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig626159A078878821B979F2C2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Hugo! The idea to bring the hardware support forward to the current kernel was = my first thing to check. It seems that a few people (more experienced than m= yself) tried this and could not make it work reliably. Tweaking btrfs in 2.6.31 = was my "plan B". Now it looks like both endeavours are beyond my knowledge/resou= rce budget. Oh well. Generally, the idea of using btrfs on a home NAS is very attractive: fast= initialization of raid1 and especially filesystem-level snapshots are exa= ctly what I want from my file server. Thanks again, Eugene On 12/18/2012 06:37 PM, Hugo Mills wrote: > On Tue, Dec 18, 2012 at 02:35:21PM +0000, Hugo Mills wrote: >> On Tue, Dec 18, 2012 at 06:11:55PM +0400, Eugene Crosser wrote: >>> I have a board based on PLX7821 aka OX820 ARM SoC. It is not >=20 > Oh, I forgot to mention -- there's some problems with the btrfs > userspace tools on ARM, related to unaligned accesses. You will need > to get hold of the patch (from Arne, in October this year, on this > mailing list, shout if you can't find it) which fixes those issues. > It's not made it to the upstream btrfs-progs repo yet. >=20 > Hugo. >=20 >>> supported in the mainline kernel; the vendor supplied the source of >>> the kernel 2.6.31 with necessary updates for this platform, and it >>> works. I understand that there have been no successful attempts to >>> bring support of this platform to newer kernels. >> >>> I would like to use btrfs on this system, but it is labelled >>> "experimental" in the kernel. My question is: is it "safe" to use >>> btrfs as it is in 2.6.31? In other words, where there "data >>> destroying" bugs found and fixed since then? If the answer is yes, >>> then is it possible (and how difficult) to compile newer btrfs code >>> against this kernel, or backport the fixes? >> >> 2.6.31 is *insanely* old in btrfs terms, and definitely contains >> serious filesystem-corrupting bugs that have been fixed since. You >> should be looking at running 3.7 (right now) or 3.8-rc1 (when that >> comes out next week), from a btrfs point of view. I really wouldn't >> recommend running the btrfs code from 2.6.31. >> >> Backporting current btrfs code to a kernel that old is likely to be= >> a difficult proposition, simply because other things (in the VFS and >> block layers) will have changed underneath it. Similarly, if the >> patches for your board haven't been updated as the kernel progressed, >> you're going to have a hard time forward-porting them. Given the >> option of where to put in the work, I'd recommend forward-porting the >> hardware support to a more recent kernel, and getting that pushed to >> mainline, as it's more likely to be useful in the future, and useful >> to more people. >> >> Hugo. >> >> >=20 --------------enig626159A078878821B979F2C2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iD8DBQFQ0IwKfrw/cIw6UWkRAl62AJ49c6Q7IOhef5AoN2TdZ3Ejh11U9wCgizkb wMBgEOfZP1OuSngs4rhgT7Y= =Acr+ -----END PGP SIGNATURE----- --------------enig626159A078878821B979F2C2--