[Unionfs] Kernel oops with 2.6.16

[hooanon05 at yahoo.co.jp]

> And there is a little strange implementaion about checking overlapping
> branches. The check is done at mount command only. So users can overlap
> branches by unionctl command. I don't know this is an expected behaviour
> or simply forgotten implementaion.

Correction: overlapp is checked in unionfs_ioctl_addbranch() too, which
is a function called in unionctl context.

Junjiro Okajima