From se@x01.mi.uni-koeln.de  Wed Dec 14 12:47:12 1994
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Message-Id: <199412142046.VAA00259@x01.mi.uni-koeln.de>
Date: Wed, 14 Dec 1994 21:46:50 +0100
From: Stefan Esser <se@x01.mi.uni-koeln.de>
Reply-To: se@mi.uni-koeln.de
To: FreeBSD-gnats-submit@freebsd.org
Subject: Panic accessing NFS mounted file system
X-Send-Pr-Version: 3.2

>Number:         51
>Category:       kern
>Synopsis:       Panic accessing NFS mounted file system
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    se
>State:          closed
>Quarter:
>Keywords:
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Dec 14 12:50:01 1994
>Closed-Date:    Wed Feb 7 14:09:07 PST 1996
>Last-Modified:  Wed Feb  7 14:15:43 PST 1996
>Originator:     Stefan Esser
>Release:        FreeBSD 2.0-RELEASE i386
>Organization:
not organized
>Environment:
ASUS SP3G 486DX2/66
FreeBSD-2.1.0 (Development)
>Description:
Accesses to certain files on an NFS mounted file system make the system
panic with a page fault in kernel mode. The file system is accessed through 
an AFS-NFS translator, AFS accesses from other systems work, NFS accesses 
from a SunOS 4.1.3 system hang, but can be interrupted.
(There seems to be something wrong with that file system, accesses to files 
owned by one particular UID fail. But user mode accesses shouldn't crash 
the kernel ...)

Panic messages:

Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x28
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xf0123eb2
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 877 (tar)
interrupt mask		= 
panic: page fault

Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x28
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xf0123eb2
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 152 (tar)
interrupt mask		= 
panic: page fault

>How-To-Repeat:

mount rs2.rrz.uni-koeln.de:/afs/rrz/pub /ftp
cat /ftp/tex/graphics/bm2font/*

(Please don't NFS mount that file system, except for testing ...)

The instruction pointer indicates a problem in vn_open(), it starts
at 0xf0123aac and ends before 0xf0123f30 in my /kernel ...

>Fix:
	
None I know of ...
>Release-Note:
>Audit-Trail:
State-Changed-From-To: open->feedback 
State-Changed-By: pst 
State-Changed-When: Tue Feb 6 23:34:52 PST 1996 
State-Changed-Why:  
Stefan, please verify this has been fixed, if so, please close it. 


Responsible-Changed-From-To: core->se 
Responsible-Changed-By: pst 
Responsible-Changed-When: Tue Feb 6 23:34:52 PST 1996 
Responsible-Changed-Why:  
awaiting feedback 
State-Changed-From-To: feedback->closed 
State-Changed-By: se 
State-Changed-When: Wed Feb 7 14:09:07 PST 1996 
State-Changed-Why:  
Fixed by Doug Rabson, commit message was: 

dfr         95/07/07 04:01:32 

Modified:    sys/nfs   nfs_bio.c nfs_vfsops.c 
Log: 
Use a consistent blocksize for sizing bufs to avoid panicing the bio system. 
>Unformatted:


Crash at access to some NFS mounted files (SunOS only hangs)
