Re: [PATCH] Avoid a NULL pointer in btrfs

[Liuwenyi <qingshenlwy@gmail.com>]

=E4=BA=8E 2011-1-19 23:52, Chris Mason =E5=86=99=E9=81=93:
> Excerpts from Josef Bacik's message of 2011-01-19 09:14:02 -0500:
>> On Wed, Jan 19, 2011 at 10:08:13PM +0800, Liuwenyi wrote:
>>> In Yang Ruirui's mail, the btrfs will create a oops. This is caused=
 by a
>>> null pointer in test_range_bit() while lock the spinlock.
>>>
>>> So, It is necessary to add a pointer check into test_range_bit()
>>>
>>
>> NAK, the tree shouldn't be null coming into this function, something=
 else is
>> going wrong.  What oops is this?  Thanks,
The mail is here http://lkml.org/lkml/2011/1/19/24

another mesg is here http://www.aei.mpg.de/~crmafra/dmesg-2.6.35.3.txt
> What was your metadata blocksize for this oops?  This call should nev=
er
> happen.
It is rare and hard to reproduced. So, I update this patch, just avoid =
a=20
null pointer calling.
> I think there is a larger problem, probably in the IO error handling
> code since the trace had io errors beforehand.
Yes, I agree. This situation is too strange to happen.
> -chris
---
Best Regards,
Liu Wenyi