From peterjeremy@acm.org  Fri Jan  8 21:45:01 2010
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Date: Sat, 9 Jan 2010 08:44:50 +1100 (EST)
From: Peter Jeremy <peterjeremy@acm.org>
Reply-To: Peter Jeremy <peterjeremy@acm.org>
To: FreeBSD-gnats-submit@freebsd.org
Subject: [lor] allproc/zfs LOR
X-Send-Pr-Version: 3.113
X-GNATS-Notify:

>Number:         142489
>Category:       kern
>Synopsis:       [zfs] [lor] allproc/zfs LOR
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-fs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Jan 08 21:50:02 UTC 2010
>Closed-Date:    
>Last-Modified:  Fri Oct 19 15:40:00 UTC 2012
>Originator:     Peter Jeremy
>Release:        FreeBSD 8.0-STABLE amd64
>Organization:
n/a
>Environment:
System: FreeBSD server.vk2pj.dyndns.org 8.0-STABLE FreeBSD 8.0-STABLE #11: Mon Nov 30 16:36:34 EST 2009 root@server.vk2pj.dyndns.org:/var/obj/usr/src/sys/server amd64

>Description:
	New LOR:
lock order reversal:
 1st 0xffffffff807417c0 allproc (allproc) @ /usr/src/sys/vm/vm_meter.c:130
 2nd 0xffffff002c263ba8 zfs (zfs) @ /usr/src/sys/kern/vfs_subr.c:2188
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
_witness_debugger() at _witness_debugger+0x2c
witness_checkorder() at witness_checkorder+0x66f
__lockmgr_args() at __lockmgr_args+0x475
vop_stdlock() at vop_stdlock+0x39
VOP_LOCK1_APV() at VOP_LOCK1_APV+0x52
_vn_lock() at _vn_lock+0x47
vrele() at vrele+0xc3
vm_object_deallocate() at vm_object_deallocate+0x1ad
_vm_map_unlock() at _vm_map_unlock+0x70
vm_map_remove() at vm_map_remove+0x6f
vmspace_free() at vmspace_free+0x56
vmtotal() at vmtotal+0x3d5
sysctl_root() at sysctl_root+0xa1
userland_sysctl() at userland_sysctl+0x158
__sysctl() at __sysctl+0xaa
syscall() at syscall+0x1ac
Xfast_syscall() at Xfast_syscall+0xe1
--- syscall (202, FreeBSD ELF64, __sysctl), rip = 0x800bc5a9c, rsp = 0x7fffffffdaf8, rbp = 0x7fffffffdb08 ---

>How-To-Repeat:
	Possibly running 'vmstat -m'
>Fix:
	Unknown


>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: freebsd-bugs->freebsd-fs 
Responsible-Changed-By: linimon 
Responsible-Changed-When: Sat Jan 9 00:24:13 UTC 2010 
Responsible-Changed-Why:  
Over to maintainer(s). 

http://www.freebsd.org/cgi/query-pr.cgi?pr=142489 

From: John Baldwin <jhb@freebsd.org>
To: bug-followup@freebsd.org,
 peterjeremy@acm.org
Cc:  
Subject: Re: kern/142489: [zfs] [lor] allproc/zfs LOR
Date: Fri, 19 Oct 2012 11:20:12 -0400

 I think this order is correct.  Something in ZFS must be calling pfind() or 
 the like while holding a vnode lock.  I think that is probably the "wrong" 
 order.
 
 -- 
 John Baldwin
>Unformatted:
