kern/161169: ZFS causes kernel panic in dbuf_dirty

[Jakub Szafrański]

>Number:         161169
>Category:       kern
>Synopsis:       ZFS causes kernel panic in dbuf_dirty
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 30 18:50:02 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Jakub Szafrański
>Release:        8.2-RELEASE-p3
>Organization:
admin.net.pl
>Environment:
FreeBSD mydevil.mydevil.net 8.2-RELEASE-p3 FreeBSD 8.2-RELEASE-p3 #7: Wed Sep 28 17:06:07 CEST 2011     root at mydevil.mydevil.net:/usr/obj/usr/src/sys/mydevil  amd64

>Description:
FreeBSD 8.2-RELEASE-p3 seems to panic with ZFS dbuf_dirty function:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address  = 0x28
fault code             = supervisor read data, page not present
instruction pointer    = 0x20:0xffffffff80b488cb
stack pointer          = 0x28:0xffffff851544a550
frame pointer          = 0x28:0xffffff851544a600
code segment           = base 0x0, limit 0xfffff, type 0x1b
                       = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags       = interrupt enabled, resume, IOPL = 0
current process        = 46860 (nginx)
[thread pid 46860 tid 101076 ]
Stopped at      dbuf_dirty+0x1b:      movq     0x28(%rax),%rax
>How-To-Repeat:
I don't know how to reproduce this bug, it happened only once.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: