Re: WARNING at fs/btrfs/super.c:260 __btrfs_abort_transaction (error -17)

[Sophie Dexter <Just4pLeisure@gmail.com>]

On 01/04/2015 15:13, Chris Mason wrote:
>
>
> On Tue, Mar 24, 2015 at 6:23 PM, Sophie <just4pleisure@gmail.com> wrote:
>> On 24/03/15 17:34, Chris Mason wrote:
>>>
>>>
>>> On Tue, Mar 24, 2015 at 9:43 AM, Sophie Dexter <Just4pLeisure@gmail.com>
>>> wrote:
>>>> On 20/03/2015 15:19, Sophie Dexter wrote:
>>>>> I'm given to understand that this is the right place to report a btrfs
>>>>> problem, I apologise if not :-(
>>>>>
>>>>> I have been using my router as a simple NFS NAS for around 2 years
>>>>> with an ext3 formatted 2 TB Western Digital 2.5" USB Passport disk. I
>>>>> have been slowly moving to BTRFS and thought it about time to convert
>>>>> this disk too but unfortunately BTRFS is unreliable on my router :-(.
>>>>> It doesn't take long for an error to happen causing a 'ro' remount.
>>>>> However the disk is unreadable after the remount, both for NFS and
>>>>> locally. Rebooting the router seems to be the only way to access the
>>>>> disk again.
>>>>>
>>>>> I also have a 1 GB swap partition on the disk although swap doesn't
>>>>> appear to be a factor as the problem occurs whether or not swap is
>>>>> enabled (this report is without swap).
>>>>>
>>>>> I used my laptop to convert the fs to btrfs, not my router. My laptop
>>>>> has Fedora 21 with 3.18 kernel and tools. No problems are found when I
>>>>> use my laptop to check and scrub the disk (i.e. with the disk
>>>>> connected directly to my laptop).
>>>
>>> You have great timing, there are two reports of a very similar abort
>>> with 4.0-rc5, but your report makes it clear these are not a regression
>>> from 4.0-rc4.
>>>
>>> Are you able to run btrfsck on this filesystem?  I'd like to check for
>>> metadata inconsistencies.
>>>
>>> -chris
>>>
>> Hi Chris,
>>
>> Haha, great timing is the secret of good comedy lol
>>
>> OpenWrt has only very recently signed off the 3.18 kernel as the
>> default kernel for my router, I was using a build with 3.14 when I
>> converted my disk and saw the same problem :!: I may have posted
>> something I haven't repeated here in the OpenWrt ticket I opened:
>>
>> https://dev.openwrt.org/ticket/19216
>>
>> I previously checked and scrubbed the disk when the problem first
>> occurred and happily no problems were found then. Although, I had to
>> use another computer because btrfs check doesn't complete on my
>> router, the process is killed due to lack of memory (btrfs invoked
>> oom-killer) :-( Should I start another topic for this or just accept
>> that that problem is due to a lack of memory?
>>
>> I have just run btrfs check again using (yet another) laptop and I
>> think everything is still OK:
>>
>> # btrfs check /dev/sdb1
>> Checking filesystem on /dev/sdb1
>> UUID: ########-####-####-####-############
>> checking extents
>> checking free space cache
>> checking fs roots
>> checking csums
>> checking root refs
>> found 930516788539 bytes used err is 0
>> total csum bytes: 1234353920
>> total tree bytes: 1458515968
>> total fs tree bytes: 54571008
>> total extent tree bytes: 66936832
>> btree space waste bytes: 73372568
>> file data blocks allocated: 1264250781696
>>  referenced 1264250781696
>> Btrfs v3.14.1
>> # uname -a
>> Linux ######-########-#### 3.16.0-31-generic #43-Ubuntu SMP Tue Mar 10
>> 17:37:36 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
>
> Sophie, can you please grab the latest btrfs progs from git:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git
>
> And try with that btrfsck?
>
> The other image that is reproducing this has an error in the free space
> cache, so I'd like to confirm if you're hitting the same problem.
>
> -chris
>
Hi Chris,

I compiled the tools on my Fedora laptop this lunchtime (and noticed a 
few omissions on the btrfs wiki source repositories page so have 
requested a wiki account so that I can update that page). I don't have 
the problematic disk with me at the moment but will btrfsck it again 
when I get home.

Is it helpful to test my disk with different systems? I could build the 
latest tools on my Ubuntu laptop and I see that OpenWRT updated to 
3.19.1 btrfs progs a few days ago too. I will try them on my router 
anyway to see if btrfsck now completes or if the oom-killer steps in still.

I don't know what version of tools are on my Raspbian Raspberry Pi but 
if they're not the new ones I could try to (cross?) compile those to, 
but tthat might take me a little while as I haven't compiled anything 
for my Raspberry Pi before.

Happy Easter :-)
Sophie x