Subject: Re: New panic
To: Patrick Welche <prlw1@cam.ac.uk>
From: Frank van der Linden <frank@wins.uva.nl>
List: current-users
Date: 07/09/1997 13:36:08
Quoting Patrick Welche,

> Using a kernel without Frank v. L.'s locking code, and with a
> vnconfig.c of 8 July, I got a panic I hadn't seen yet:
> "locking against myself"

> Patrick

> (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. The new locking code
doesn't come into play here at all, as it is only used in:

	- the VM system (changes there were small, it was mostly renaming
	  functions)
	- the locks around inode/nfsnode hashing

None of this is involved here, so I suspect the error is in the vnd
code.

- Frank