From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: csum errors Date: Thu, 15 Jul 2010 15:35:51 -0400 Message-ID: <20100715193551.GM8623@think> References: <201007081627.24654.johannes.hirte@fem.tu-ilmenau.de> <201007152030.18431.johannes.hirte@fem.tu-ilmenau.de> <20100715190309.GI8623@think> <201007152132.13701.johannes.hirte@fem.tu-ilmenau.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org To: Johannes Hirte Return-path: In-Reply-To: <201007152132.13701.johannes.hirte@fem.tu-ilmenau.de> List-ID: On Thu, Jul 15, 2010 at 09:32:12PM +0200, Johannes Hirte wrote: > Am Donnerstag 15 Juli 2010, 21:03:09 schrieb Chris Mason: > > On Thu, Jul 15, 2010 at 08:30:17PM +0200, Johannes Hirte wrote: > > > Am Dienstag 13 Juli 2010, 14:23:58 schrieb Johannes Hirte: > > > > ino 1959333 off 898342912 csum 4271223884 private 4271223883 > > > > > > I think, this is a different error. I've only seen them on filesystems > > > from my Opteron system. It seems that the recorded csums are wrong and > > > it looks to me like rounding errors. The data itself should be correct, > > > as I've tested one affected file via md5sum against the original on > > > another filesystem. Any ideas what is going wrong here? > > > > Are you doing data mirroring? > > No, I don't. > > > We can map that block and do a raw read off the device to see what the > > data blocks actually contain. > > I've modified the btrfs-source a little to get the data. In inode.c I've > changed the code to: Great. The bad csums are all just one bit off, that can't be an accident. When were they written (which kernel?). Did you boot a 32 bit kernel on there at any time? -chris