From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754680Ab1BMQbv (ORCPT ); Sun, 13 Feb 2011 11:31:51 -0500 Received: from frost.carfax.org.uk ([212.13.194.111]:3683 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750826Ab1BMQbo (ORCPT ); Sun, 13 Feb 2011 11:31:44 -0500 Date: Sun, 13 Feb 2011 16:31:42 +0000 From: Hugo Mills To: Marti Raudsepp Cc: btrfs hackers , Kernel hackers Subject: Re: btrfs: compression breaks cp and cross-FS mv, FS_IOC_FIEMAP bug? Message-ID: <20110213163142.GA5484@carfax.org.uk> Mail-Followup-To: Hugo Mills , Marti Raudsepp , btrfs hackers , Kernel hackers References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="W/nzBZO5zC0uMSeA" Content-Disposition: inline In-Reply-To: X-GPG-Fingerprint: 8C59 86C7 81F3 93FE BB02 DDB1 20AC B3BE 515C 238D X-GPG-Key: 515C238D X-Parrot: It is no more. It has joined the choir invisible. X-IRC-Nicks: darksatanic darkersatanic darkling darkthing User-Agent: Mutt/1.5.20 (2009-06-14) X-frost.carfax.org.uk-Spam-Score: -0.0 (/) X-frost.carfax.org.uk-Spam-Report: Spam detection software, running on the system "spamd2.lon.bitfolk.com", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: On Sun, Feb 13, 2011 at 05:49:42PM +0200, Marti Raudsepp wrote: > Hi list! > > It seems I have found a serious regression in compressed btrfs in > kernel 2.6.37. When creating a small file (less than the block size) > and then cp/mv it to *another* file system, an appropriate number of > zeroes gets written to the destination file. Case in point: [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --W/nzBZO5zC0uMSeA Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Feb 13, 2011 at 05:49:42PM +0200, Marti Raudsepp wrote: > Hi list! > > It seems I have found a serious regression in compressed btrfs in > kernel 2.6.37. When creating a small file (less than the block size) > and then cp/mv it to *another* file system, an appropriate number of > zeroes gets written to the destination file. Case in point: [snip] > I'm currently running on 2.6.37, x86_64 using Arch Linux -testing with > coreutils 8.10. Filesystem is mounted from LVM2 to /usr/src with -o > noatime,compress > > This only seems to occur with compressed file systems (either zlib or > LZO). A person on IRC also reproduced the same problem in 2.6.28-rc. > I'm pretty sure this used to work correctly around 2.6.35 or 2.6.36. This would seem to be the same effect that we've had reported on IRC by at least two Gentoo users, of files full of zeroes in their build system. We'll follow up with them over there and see if it's the same bug. Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- I must be musical: I've got *loads* of CDs --- --W/nzBZO5zC0uMSeA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iD8DBQFNWAdtIKyzvlFcI40RAh4EAKCFpHiqBlqrI9ypiD+H4c3PqN3HcwCgyKeV vvKGo7n+pm2T6RIZcmzf17A= =24mt -----END PGP SIGNATURE----- --W/nzBZO5zC0uMSeA--