hi,

> Module Name:	src
> Committed By:	wrstuden
> Date:		Sat May 29 23:49:32 UTC 2004
> 
> Modified Files:
> 	src/sys/fs/union: union_vfsops.c
> 
> Log Message:
> unionfs can use layerfs_snapshot() too.

"file-system union" doesn't pull in layer_vfsops.c.
and you need to include layer_extern.h.

although i doubt the benefit to use layerfs_snapshot here.
(the concept "snapshot through layered filesystem" isn't clear to me.)

YAMAMOTO Takashi