>Number:         28448
>Category:       kern
>Synopsis:       stackable filesystems locking breakage when looking up DOTDOT
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Nov 28 23:42:00 +0000 2004
>Originator:     YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
>Release:        NetBSD 2.99.10
>Organization:

>Environment:
	
	
System: NetBSD kaeru 2.99.10 NetBSD 2.99.10 (build.kaeru) #1898: Sun Nov 28 20:43:05 JST 2004 takashi@kaeru:/usr/home/takashi/work/kernel/build.kaeru i386
Architecture: i386
Machine: i386
>Description:
	layer_lookup calls underlying filesystem's VOP_LOOKUP with
	dvp locked.  while underlying filesystem might perform relock dance
	for it's vnodes, it doesn't know about upper vnodes.
	thus it will deadlock in the case of DOTDOT.
>How-To-Repeat:
	code inspection.
>Fix:

>Unformatted: