[PATCH] xfs: fix node forward in xfs_node_toosmall

[Mark Tinguely]

On 09/23/13 16:34, Michael L. Semon wrote:
> On 09/20/2013 06:05 PM, Mark Tinguely wrote:
>> Commit f5ea1100 cleans up the disk to host conversions for
>> node directory entries, but because a variable is reused in
>> xfs_node_toosmall() the next node is not correctly found.
>> If the original node is small enough (<= 3/8 of the node size),
>> this change may incorrectly cause a node collapse when it should
>> not. That will cause an assert in xfstest generic/319:
>>
>>     Assertion failed: first<= last&&  last<  BBTOB(bp->b_length),
>>     file: /root/newest/xfs/fs/xfs/xfs_trans_buf.c, line: 569
>>
>> Keep the original node header to get the correct forward node.
>
> This works for xfstests generic/319 on 32-bit x86.  The xfstests
> run was okay, with a lockdep in the middle and a crash in xfs/300.
> Neither the lockdep nor the crash could reproduced by running
> individual tests one by one.
>
> generic/319 itself fails only because it couldn't find its
> _cleanup routine.  I'm not sure if I'm using v1 or v2 of
> generic/319.
>
> The kernel is set to the commit just before the latest aio-next
> merge, which is causing severe problems here.  xfsprogs was the
> latest production xfsprogs because my copy of xfstests is having
> trouble checking v4 XFS filesystems otherwise.
>
> Will test xfs_node_toosmall patch v2 once I get home.
>
> Thanks!
>
> Michael
>

319 v1 had the cleanup and removed in v2 because of feedback.
IMO, it should be there even basically empty.

--Mark.