From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:10147 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753921AbaCNSva (ORCPT ); Fri, 14 Mar 2014 14:51:30 -0400 Message-ID: <53234FAA.5060204@fb.com> Date: Fri, 14 Mar 2014 14:51:22 -0400 From: Josef Bacik MIME-Version: 1.0 To: Hugo Mills , Subject: Re: [PATCH] Btrfs: remove transaction from send References: <1394739733-500-1-git-send-email-jbacik@fb.com> <20140313221628.GF6151@carfax.org.uk> In-Reply-To: <20140313221628.GF6151@carfax.org.uk> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 03/13/2014 06:16 PM, Hugo Mills wrote: > On Thu, Mar 13, 2014 at 03:42:13PM -0400, Josef Bacik wrote: >> Lets try this again. We can deadlock the box if we send on a box and try to >> write onto the same fs with the app that is trying to listen to the send pipe. >> This is because the writer could get stuck waiting for a transaction commit >> which is being blocked by the send. So fix this by making sure looking at the >> commit roots is always going to be consistent. We do this by keeping track of >> which roots need to have their commit roots swapped during commit, and then >> taking the commit_root_sem and swapping them all at once. Then make sure we >> take a read lock on the commit_root_sem in cases where we search the commit root >> to make sure we're always looking at a consistent view of the commit roots. >> Previously we had problems with this because we would swap a fs tree commit root >> and then swap the extent tree commit root independently which would cause the >> backref walking code to screw up sometimes. With this patch we no longer >> deadlock and pass all the weird send/receive corner cases. Thanks, > > There's something still going on here. I managed to get about twice > as far through my test as I had before, but I again got an "unexpected > EOF in stream", with btrfs send returning 1. As before, I have this in > syslog: > > Mar 13 22:09:12 s_src@amelia kernel: BTRFS error (device sda2): did not find backref in send_root. inode=1786631, offset=825257984, disk_byte=36504023040 found extent=36504023040\x0a > I just noticed that the offset you have there is freaking gigantic, like 700mb, which is way larger than what an extent should be. Here is a newer debug patch, just chuck the old on and put this instead and re-run http://paste.fedoraproject.org/85486/39482301 thanks, Josef