Re: [PATCH v2 2/2] btrfs: qgroup: add sysfs interface for debug

Qu Wenruo
2020-07-16T06:21:42Z

On 2020/7/16 上午8:40, Chris Down wrote:
> Qu Wenruo writes:
>> Would you please provide the full call trace (especially the address
>> causing the NULL pointer deref) and the reproducer (if possible)?
>
> I'll try to reproduce it again when I have time. I didn't have kdump
> set, and am not currently running linux-next, so until then, you can
> have this crappy photo that I rushed to take earlier before panic=30
> took effect :-)

The linux-next is using an older version of that patch, which has a bad
memory allocation inside atomic critical section.

If you're unlucky enough, it could cause various weird bugs.
Thankfully, David has exposed it and the latest version in btrfs tree
should have it fixed.

If you're uncertain if that's the case, feel free to try the latest
misc-next branch to see if it's fixed.
https://github.com/kdave/btrfs-devel/tree/misc-next

Thanks for your report,
Qu