Subject: Re: softdep-related panic?
To: Simon Burge <simonb@wasabisystems.com>
From: Chuck Silvers <chuq@chuq.com>
List: current-users
Date: 11/24/2000 10:52:08
this problem is probably better attributed to UVM than softdeps,
but either way it'll be fixed once UBC is in the tree, ie. very soon now.

-Chuck


On Thu, Nov 23, 2000 at 10:36:32PM +1100, Simon Burge wrote:
> While my Alpha PC164 with all filesystems on a raidframe mirror was
> under a relatively light load (building a package), I got a the
> following panic:
> 
> 	panic: vref used where vget required, vp 0xfffffc00021a9868
> 
> The kernel trace was (hand copied):
> 
> 	panic
> 	vref
> 	uvm_vnp_uncache
> 	ffs_truncate
> 	vfs_inactive
> 	vput
> 	handle_workitem_remove
> 	softdep_process_worklist
> 	sched_sync
> 	esigcode
> 
> Look familar?  I'm not putting in a PR, since the box locked up when I
> tried to force a crash dump.  Since it has softdep in the backtrace,
> I've now disabled them.  The box has been stable for ages with no
> softdeps, and got the above panic within a fortnight of starting to use
> them.  Once bitten, twice shy...
> 
> Also, I had a very hard time convincing the root filesystem to disable
> softdeps.  Merely removing the ",softdep" from /etc/fstab was not
> enough.  No matter what sequence of commands I tried in single user
> mode, I couldn't get it to boot without softdeps on the root filesystem.
> Some of the things I tried were:
> 
> 	boot to single user
> 	mount -u -o nosoftdep /
> 	dumpfs /dev/rraid0a - shows "softdep enabled"
> 	reboot
> 
> 	boot to single user
> 	(using a static tunefs with TUNEFS_SOFTDEP defined):
> 	/tunefs -n disable /dev/rraid0a
> 	dumpfs /dev/rraid0a - shows "softdep disabled"
> 	reboot
> 	softdeps enabled again!
> 
> what finally worked was
> 
> 	boot off install floppy
> 	(/dev/wd0h starts 64 blocks after /dev/raid0a)
> 	mount -u -o nosoftdep /dev/wd0h /mnt
> 	umount /mnt
> 	reboot
> 
> Is there meant to be a simple way to disable softdeps on a root
> filesystem?
> 
> Simon.
> --
> Simon Burge                            <simonb@wasabisystems.com>
> NetBSD Sales, Support and Service:  http://www.wasabisystems.com/