Re: [lkp] [parallel lookups machinery, part 2] 96352435af: kernel BUG at mm/slab.c:2599!

[Al Viro]

On Mon, Apr 18, 2016 at 09:06:35AM +0800, kernel test robot wrote:
> FYI, we noticed the below changes on
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git testing.lookups
> commit 96352435afd792d713ec91e2d5693bdcf40a6b03 ("parallel lookups machinery, part 2")

Very odd.  All stores in that commit are to ->d_parent->d_inode->i_dir_seq
of in-lookup dentries.  And if ->d_parent in those gets buggered, we were
really deep in trouble.  Could you try to reproduce that without __d_move()
or __d_add() parts and see which one ends up triggering that crap?

Note that we don't *use* ->i_dir_seq yet...