Re: [PATCH] btrfs: ctree: Dump the leaf before BUG_ON()

[Qu Wenruo <wqu@suse.de>]

On 2019/4/24 下午9:53, Filipe Manana wrote:
> On Wed, Apr 24, 2019 at 1:57 PM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>>
>>
>>
>> On 2019/4/24 下午8:52, Nikolay Borisov wrote:
>>>
>>>
>>> On 24.04.19 г. 15:48 ч., Qu Wenruo wrote:
>>>> Let's dump the leaf content before triggering BUG_ON() so that we can
>>>> have some clue on what's going wrong.
>>>> The output of tree locks should help us to debug such problem.
>>>>
>>>
>>> The reason is some sort of in-memory corruption/confusion of the extent
>>> maps, causing overlapping extents. However so far it hasn't been
>>> possible to reproduce that on-demand to actually debug it. Filipe
>>> suspected it has to do with extent mapping merging logic. This only
>>> occurs when working with the log tree which takes its data from the
>>> in-memory extent mapping tree.
>>
>> Anyway, this won't hurt. right?
>>
>> If it gives us some clue, that's the best case.
>> If not, it won't make the current situation worse, right?
> 
> Right, but dumping the leaf alone, may not tell you much (I've been there).
> Printing the new key and slot, together with the leaf dump, helps much more.

Right, I'd add them.

Thanks,
Qu

> 
> Thanks.
> 
>>
>> Thanks,
>> Qu
> 
> 
>