From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:42278 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756764AbcHYQWG (ORCPT ); Thu, 25 Aug 2016 12:22:06 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1bcwtJ-0003te-W2 for linux-btrfs@vger.kernel.org; Thu, 25 Aug 2016 17:48:29 +0200 To: linux-btrfs@vger.kernel.org From: Lutz Vieweg Subject: Re: 6TB partition, Data only 2TB - aka When you haven't hit the "usual" problem Date: Thu, 25 Aug 2016 17:48:23 +0200 Message-ID: <57BF1347.9010005@5t9.de> References: <20160109202659.GC6060@carfax.org.uk> <20160109210429.GD6060@carfax.org.uk> <5693A8B3.2090508@gmail.com> <57A372F3.5090400@5t9.de> <5ee26e48-d949-502e-5884-6369c9e6b278@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed In-Reply-To: <5ee26e48-d949-502e-5884-6369c9e6b278@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 08/05/2016 10:03 PM, Gabriel C wrote: > On 04.08.2016 18:53, Lutz Vieweg wrote: >> >> I was today hit by what I think is probably the same bug: >> A btrfs on a close-to-4TB sized block device, only half filled >> to almost exactly 2 TB, suddenly says "no space left on device" >> upon any attempt to write to it. The filesystem was NOT automatically >> switched to read-only by the kernel, I should mention. >> >> Re-mounting (which is a pain as this filesystem is used for >> $HOMEs of a multitude of active users who I have to kick from >> the server for doing things like re-mounting) removed the symptom >> for now, but from what I can read in linux-btrfs mailing list >> archives, it pretty likely the symptom will re-appear. >> >> Here are some more details: >> >> Software versions: >>> linux-4.6.1 (vanilla from kernel.org) > ... >> >> dmesg output from the time the "no space left on device"-symptom >> appeared: >> >>> [5171203.601620] WARNING: CPU: 4 PID: 23208 at fs/btrfs/inode.c:9261 btrfs_destroy_inode+0x263/0x2a0 [btrfs] > > .... >> ... >>> [5171230.306037] WARNING: CPU: 18 PID: 12656 at fs/btrfs/extent-tree.c:4233 btrfs_free_reserved_data_space_noquota+0xf3/0x100 [btrfs] > > Sounds like the bug I hit too also .. > > To fix this you'll need : > > crazy@zwerg:~/Work/linux-git$ git show 8b8b08cbf > commit 8b8b08cbfb9021af4b54b4175fc4c51d655aac8c > Author: Chris Mason > Date: Tue Jul 19 05:52:36 2016 -0700 > > Btrfs: fix delalloc accounting after copy_from_user faults Thanks for this hint! Yesterday (20 days after the first time this bug struck us, and after re-mounting the filesystem) we were hit by the same bug again - twice! - once in the morning, and again in the evening. That called for immediate action, and short of reverting the whole setup to XFS, installing a new kernel with the above (and other) btrfs fix(es) was the one thing I could try. The system is now running linux-4.7.2, which does contain those patches. If that doesn't fix it, we're really running out of options. Regards, Lutz Vieweg