>Number:         28372
>Category:       kern
>Synopsis:       layered filesystem getpages breakage
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Nov 21 02:04:00 +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) #1868: Sun Nov 14 21:56:35 JST 2004 takashi@kaeru:/usr/home/takashi/work/kernel/build.kaeru i386
Architecture: i386
Machine: i386
>Description:
	there're many codes in uvm which assume,
	if a page pg is obtained by pgo_get with an uvm object uobj,
	pg->uobject == uobj.  this assumption is wrong for
	the most of our layered filesystems.

	eg.
		pgo_get(uobj, ..., &pg, ...);
		simple_lock(&uobj->vmobjlock);
		manipulate pg->flags; /* broken if pg->uobject != uobj */
		simple_unlock(&uobj->vmobjlock);

>How-To-Repeat:
	code inspection.
>Fix:
	

>Unformatted: