btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

[Chris Murphy]

This is v4.14.

I've filed a bug which contains the build steps, versions. It's
crashing on all volumes I try it on so far.


-- 
Chris Murphy

Re: btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

[Su Yue]

Hi,

On 12/18/2017 10:50 AM, Chris Murphy wrote:
> This is v4.14.
> 
> I've filed a bug which contains the build steps, versions. It's
> crashing on all volumes I try it on so far.
> 
> 

It was fixed by Qu's patch
   btrfs-progs: backref: Allow backref walk to handle direct parent ref
which is available on his github
https://github.com/adam900710/btrfs-progs/tree/lowmem_fix

Thanks,
Su

Re: btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

[Chris Murphy]

On Sun, Dec 17, 2017 at 8:07 PM, Su Yue <suy.fnst@cn.fujitsu.com> wrote:
> Hi,
>
> On 12/18/2017 10:50 AM, Chris Murphy wrote:
>>
>> This is v4.14.
>>
>> I've filed a bug which contains the build steps, versions. It's
>> crashing on all volumes I try it on so far.
>>
>>
>
> It was fixed by Qu's patch
>   btrfs-progs: backref: Allow backref walk to handle direct parent ref
> which is available on his github
> https://github.com/adam900710/btrfs-progs/tree/lowmem_fix
>
 OK that fixed the crashing problem on all tested volumes. One volume
so far has a bunch of these:

ERROR: data extent[1218774720512 167936] backref lost

With the same numbers for each line. Is that fixed in kdave devel
branch? Or pending?

-- 
Chris Murphy

Re: btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

[Su Yue]

On 12/19/2017 09:34 AM, Chris Murphy wrote:
> On Sun, Dec 17, 2017 at 8:07 PM, Su Yue <suy.fnst@cn.fujitsu.com>
> wrote:
>> Hi,
>> 
>> On 12/18/2017 10:50 AM, Chris Murphy wrote:
>>> 
>>> This is v4.14.
>>> 
>>> I've filed a bug which contains the build steps, versions. It's 
>>> crashing on all volumes I try it on so far.
>>> 
>>> 
>> 
>> It was fixed by Qu's patch btrfs-progs: backref: Allow backref walk
>> to handle direct parent ref which is available on his github 
>> https://github.com/adam900710/btrfs-progs/tree/lowmem_fix
>> 
> OK that fixed the crashing problem on all tested volumes. One volume 
> so far has a bunch of these:
> 
> ERROR: data extent[1218774720512 167936] backref lost
> 

Did you apply all patches on this branch?
If only the patch mentioned above is applied, you can try another
patch named
  btrfs-progs: lowmem check: Fix false backref lost warning for keyed
     extent data ref
which exists in same branch.

Otherwise, it seems a bug of lowmem check. Would you please
provide some dump of btrfs-debug-tree?

# btrfs-debug-tree /$device  |\
   grep -C10 1218774720512

You can erase filenames if you think they are private.

> With the same numbers for each line. Is that fixed in kdave devel 
> branch? Or pending? All commits in this brach are pending.

Thanks,
Su

Re: btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

[Chris Murphy]

On Mon, Dec 18, 2017 at 7:19 PM, Su Yue <suy.fnst@cn.fujitsu.com> wrote:
>
>
> On 12/19/2017 09:34 AM, Chris Murphy wrote:
>>
>> On Sun, Dec 17, 2017 at 8:07 PM, Su Yue <suy.fnst@cn.fujitsu.com>
>> wrote:
>>>
>>> Hi,
>>>
>>> On 12/18/2017 10:50 AM, Chris Murphy wrote:
>>>>
>>>>
>>>> This is v4.14.
>>>>
>>>> I've filed a bug which contains the build steps, versions. It's crashing
>>>> on all volumes I try it on so far.
>>>>
>>>>
>>>
>>> It was fixed by Qu's patch btrfs-progs: backref: Allow backref walk
>>> to handle direct parent ref which is available on his github
>>> https://github.com/adam900710/btrfs-progs/tree/lowmem_fix
>>>
>> OK that fixed the crashing problem on all tested volumes. One volume so
>> far has a bunch of these:
>>
>> ERROR: data extent[1218774720512 167936] backref lost
>>
>
> Did you apply all patches on this branch?

Yes, I think so:

git


> If only the patch mentioned above is applied, you can try another
> patch named
>  btrfs-progs: lowmem check: Fix false backref lost warning for keyed
>     extent data ref
> which exists in same branch.
>
> Otherwise, it seems a bug of lowmem check. Would you please
> provide some dump of btrfs-debug-tree?
>
> # btrfs-debug-tree /$device  |\
>   grep -C10 1218774720512
>

There are two errors repeated many times:

ERROR: data extent[1214681899008 21139456] backref lost
ERROR: data extent[1218774720512 167936] backref lost

URLs for both:

https://drive.google.com/open?id=1hdgjYZg-QFeVbT_xVUxlZRC9Q0PP29eS
https://drive.google.com/open?id=1zomVGrtw6TX6ZNL5QmBn4nhgV4OgUI92


-- 
Chris Murphy

Re: btrfs check lowmem crash, backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed

[Chris Murphy]

On Mon, Dec 18, 2017 at 8:26 PM, Chris Murphy <lists@colorremedies.com> wrote:
> On Mon, Dec 18, 2017 at 7:19 PM, Su Yue <suy.fnst@cn.fujitsu.com> wrote:

>>>
>>
>> Did you apply all patches on this branch?
>
> Yes, I think so:


 1032  git remote add qu https://github.com/adam900710/btrfs-progs
 1033  git fetch qu
 1034  git checkout -b qulowmemfix qu/lowmem_fix


And then rebuilt. Also checkedout kdave devel branch and rebuilt, same results.



-- 
Chris Murphy