>Number:         5476
>Category:       kern
>Synopsis:       panic mounting nullfs filesystem
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed May 20 20:50:01 1998
>Last-Modified:
>Originator:     Simon Burge
>Organization:
	IBM Global Services Australia
>Release:        NetBSD-current mid May, 1998.
>Environment:
	System: NetBSD mona 1.3E NetBSD 1.3E (MONA) #0: Tue May 19 12:02:25 EST 1998 simonb@mona:/src/sys/arch/pmax/compile/MONA pmax


>Description:
	Mounting a nullfs filesystem causes a "lockmgr: locking against
	myself" panic on a -current NetBSD/pmax system.  I have the same
	setup on a 1.3.1 NetBSD/i386 system without any problems.

>How-To-Repeat:
	On a pmax (unable to test any other architecture), mount a nullfs
	filesystem:

	init: copying out flags `-s' 3
	init: copying out path `/sbin/init' 11
	Enter pathname of shell or RETURN for sh: 
	# mount /z		# "/dev/rz0e /z ffs rw 1 3" in /etc/fstab
	# mount /usr/src        # "/z/src /usr/src null rw" in /etc/fstab
	panic: lockmgr: locking against myself
	_cpu_reboot+4c (100,0,0,0) ra 8005c2a0 sz 40
	_panic+94 (8015099c,0,0,0) ra 8004f974 sz 32
	_lockmgr+408 (8015099c,0,0,0) ra 80108204 sz 40
	_ufs_lock+24 (8015099c,0,0,0) ra 80086304 sz 24
	_null_bypass+144 (8015099c,0,0,0) ra 800867cc sz 184
	_null_lock+3c (8015099c,0,0,0) ra 80081c90 sz 24
	_vn_lock+88 (8015099c,0,0,0) ra 80085cb0 sz 64
	_null_node_create+c0 (8015099c,0,0,0) ra 80085db0 sz 48
	_nullfs_mount+d0 (8015099c,0,0,0) ra 8007c758 sz 72
	_sys_mount+4a8 (8015099c,0,0,0) ra 8011f12c sz 288
	_syscall+26c (8015099c,0,0,0) ra 80030dd8 sz 96
	_mips1_UserGenException+244 (8015099c,0,0,4035a0) ra 0 sz 0
	User-level: pid 11
	syncing disks... 1 1 done

	dumping to dev 21,1 offset 278847


        This is repeatable - the first occurance happening in multi user
        mode.  I then tried exactly the same mount from single user mode
        and got the same panic.

>Fix:
	Not known.
>Audit-Trail:
>Unformatted: