From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:33210 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751706AbaEZVFQ (ORCPT ); Mon, 26 May 2014 17:05:16 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Wp24x-0008Kk-OP for linux-btrfs@vger.kernel.org; Mon, 26 May 2014 23:05:07 +0200 Received: from md5i.com ([75.151.244.229]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 26 May 2014 23:05:07 +0200 Received: from mwd by md5i.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 26 May 2014 23:05:07 +0200 To: linux-btrfs@vger.kernel.org From: Michael Welsh Duggan Subject: Re: btrfs send ioctl failed with -5: Input/output error Date: Mon, 26 May 2014 17:04:55 -0400 Message-ID: <87k398z1xk.fsf@maru2.md5i.com> References: <8761l2he31.fsf@maru2.md5i.com> Mime-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: Michael Welsh Duggan writes: > I am now getting the following error when trying to do a btrfs send: > > root@maru2:/usr/local/src/btrfs-progs# ./btrfs send > /usr/local/snapshots/2014-05-15 > /backup/intermediate > At subvol /usr/local/snapshots/2014-05-15 > ERROR: send ioctl failed with -5: Input/output error > > I'm running a 3.14.4 kernel, and Btrfs progs v3.14.1. > > root@maru2:/usr/local/src/btrfs-progs# uname -a > Linux maru2 3.14-1-amd64 #1 SMP Debian 3.14.4-1 (2014-05-13) x86_64 GNU/Linux > > root@maru2:/usr/local/src/btrfs-progs# ./btrfs --version > Btrfs v3.14.1 > > Is there anything I can do to help debug this issue? I'd like to find out what is happening here. I am an experienced C programmer, but have not dealt with kernel hacking before. I _do_ know how to build and install a kernel. I'd like some hints on what logging, etc., I could add in order to determine where in the send ioctl processing the IO error is coming from. From there, I hope to move to "why." Ideally I'd be able to run gdb on this, but nothing I have read online about kernel debugging with gdb sounds promising. I'd make an image, but the amount of data is enough to make this prohibitive. -- Michael Welsh Duggan (md5i@md5i.com)