The attached dmesg log shows the results of trying to cat a file on a BTRFS filesystem when running the latest Debian/Unstable kernel (upstream 3.12.8 with some Debian patches that probably aren't relevant to BTRFS). I've rebooted the Thinkpad in question and repeated the problem after a reboot. So I am fairly sure that the problem isn't directly caused by memory corruption. I presume that it's corruption on disk causing this repeatable problem and such corruption could be caused by a memory error (which is something I've had happen before on a different system). But I don't think that such corruption should cause a GPF. So while I think we should consider the possibility that the filesystem was corrupted due to a hardware fault (of which there are several possibilities when dealing with a laptop) the inability to recover seems like a bug in BTRFS. When this happens every process that tries to access the file in question is reported as being stuck in D state. Sometimes such processes respond to kill -9 (I thought that was impossible) and sometimes they remain until reboot. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/