From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f182.google.com ([209.85.212.182]:37683 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055AbbE0UZb (ORCPT ); Wed, 27 May 2015 16:25:31 -0400 Received: by wifw1 with SMTP id w1so36760719wif.0 for ; Wed, 27 May 2015 13:25:30 -0700 (PDT) Received: from Arch-1 (p3E9EE884.dip0.t-ipconnect.de. [62.158.232.132]) by mx.google.com with ESMTPSA id b10sm5317659wic.1.2015.05.27.13.25.29 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 May 2015 13:25:29 -0700 (PDT) From: Philip Seeger Message-ID: <1432758326.4187.135.camel@googlemail.com> Subject: Re: Got 10 csum errors according to dmesg but 0 errors according to dev stats To: linux-btrfs@vger.kernel.org Date: Wed, 27 May 2015 22:25:26 +0200 In-Reply-To: References: <554F6D43.2060806@googlemail.com> <554F7232.9080804@googlemail.com> <5557F490.5000606@googlemail.com> <1432385390.4187.15.camel@googlemail.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Sat, 2015-05-23 at 16:52 +0000, Duncan wrote: > Philip Seeger posted on Sat, 23 May 2015 14:49:50 +0200 as excerpted: > > > Is this a known side effect, that files could get corrupted if no > > balance is run (not counting the balance with 4.0 which doesn't > > work due > > to that commit) after an ext4 conversion? > > I'm not sure. > > What I am sure of is that I'd not trust a btrfs converted from ext* > until > the saved subvol is deleted, and a defrag and balance run. Even I agree. I did delete the saved subvolume right away, but given that I effectively did not run a balance (due to this bug, the balance had no effect) and then had new files corrupted (repeatedly) as a consequence makes this pretty clear. Maybe there should be a warning in the wiki ("run a complete balance before you start using the converted fs, otherwise your files might get corrupted.")? Though I'd be more interested in some details as to how this might have happened. It seems wrong that corruption occurs after a successful conversion (before a proper balance). Is there anyone else who has had this issue? Maybe someone who's converted to btrfs, using a btrfs version with the balance bug? Philip