K 10
svn:author
V 4
kato
K 8
svn:date
V 27
1997-04-19T06:04:13.000000Z
K 7
svn:log
V 340
Avoid `lock against myself' panic by following operation:

	# mount -t union (or null) dir1 dir2
	# mount -t union (or null) dir2 dir1

The function namei in union_mount calls union_root.  The upper vnode
has been already locked and vn_lock in union_root causes above panic.

Add printf's included in `#ifdef DIAGNOSTIC' for EDEADLK cases.

END