as root. This is important especially when LoopbackFileSystem
is used in combination with AutoUnionFs and the root one of
the overlays is a symlink - in that case we don't want to
link out of the overlay directory structure.

Allows autoconfiguration of symlinked directories

the root path.

within 32-bits.

This is needed to deal with 32-bits programs that use stat().  If the
inode number exceeds 32 bit, that will return an ERANGE error.

twice.

This is needed for creating allow_other filesystems with proper
permission checking

notify automatically.

negative lookups.

Mkdir a)