Quoting myself,

> > (the beginning of the trace in brief:
> > ufs_lock
> > vndstrategy
> > spec_strategy
> > bwrite
> > vn_bwrite
> > bawrite
> > getnewbuf
> > allocbuf
> > getblk
> > ufs_bmaparray
> > ufs_bmap
> > vndstrategy
> > spec_strategy
> > ufs_strategy
> > bwrite
> > vn_bwrite
> > bawrite
> > ...

> Hm, this would appear to be a possible vnd problem.

This appears to be the scenario:

	- call vndstrategy
	- vnode gets locked
	- ufs_bmap is called
	- an available buffer is looked for
	- while doing this, a DELWRI buffer on the same vnode is found
	- a bawrite() is done on it
	- vndstrategy again
	- try to lock the vnode as in step 2, but it's already locked.
	  -> panic


- Frank