Subject: Re: kernel: page fault trap, code=0 / panic: unmount: dangling vnode
To: Michael K. Sanders <msanders@confusion.net>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: port-i386
Date: 02/19/1999 10:08:03
On Fri, 19 Feb 1999 09:34:31 -0700 
 "Michael K. Sanders" <msanders@confusion.net> wrote:

 > Today was an unhappy morning for our NFS server.  
 > 
 > There were several mb_map full messages on the console, followed by a
 > drop into the debugger with:

You didn't say which version of NetBSD this was.  I added some code to
-current some time ago to avoid just this problem.

 > 
 > vm_fault(0xf0995900, deadb000, 1, 0) -> 1
 > kernel: page fault trap, code=0
 > Stopped at _ip_freef+0x10: movl 0(%ebx), %edi
 > 
 > A trace showed:
 > 
 > ip_freef
 > ip_drain
 > m_reclaim
 > m_clalloc
 > fxp_add_rfabuf
 > fxp_intr
 > Xintr
 > --- interrupt ---
 > ip_reass
 > ipintr
 > Xsoftnet
 > --- interrupt ---
 > Bad frame pointer: 0xf0988e00
 > 0xf0987e20
 > 
 > Continuing from the debugger caused repeated stops at _ip_freef.
 > 
 > Trying to reboot resulted in a panic, and then a sucessful dump.
 > 
 > db>reboot
 > Syncing disks... done
 > panic: unmount: dangling vnode
 > 
 > 
 > Obviously, I can increase NMBCLUSTERS and hope this never happens
 > again... any other ideas?
 > 

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>