BUG: spinlock recursion (sys_chdir, user_path_at, do_path_lookup ...)

[Peter Zijlstra]

On Wed, 2011-01-12 at 23:52 +0100, Thomas Gleixner wrote:
> On Wed, 12 Jan 2011, Uwe Kleine-König wrote:
> > > Reverting: fs: rcu-walk aware d_revalidate method
> > > commit: 34286d6662308d82aed891852d04c7c3a2649b16
> > I found that one, too, in the meantime.  Currently debugging that with
> > tglx on irc.
> 
> The last finding is that parent and dentry in
> nameidata_dentry_drop_rcu() are the same, which explains the lock
> recursion nicely. 
> 
> @nick: Anything you want us to add to the debugging ?
> 
> @peterz: Why does lockdep ignore the lock recursion in that
>          spin_lock_nested() call?

$ git show 34286d6662308d82aed891852d04c7c3a2649b16 | grep spin_lock_nested | wc -l
0

Uhm, whot?!