Re: Move the vnode lock into file systems

[Juergen Hannken-Illjes <hannken%eis.cs.tu-bs.de@localhost>]

On Mon, Jun 28, 2010 at 09:06:57AM +0000, Andrew Doran wrote:
> On Sat, Jun 26, 2010 at 10:39:27AM +0200, Juergen Hannken-Illjes wrote:
> > The vnode lock operations currently work on a rw lock located inside the
> > vnode.  I propose to move this lock into the file system node.
> > 
> > This place is more logical as we lock a file system node and not a vnode.
> > This becomes clear if we think of a file system where one file system node
> > is attached to more than one vnode.  Ptyfs allowing multiple mounts is such
> > a candidate.
> > 
> > A diff implemeting this for ufs, lfs and ext2fs is attached.
> > 
> > Comments or objections anyone?
> 
> I like this idea.  Any reason this cannot live in genfs_node?

Genfs_node is missing from many file systems that do locking (kernfs,
ptyfs, ...).  We could of course add the genfs_node here.

-- 
Juergen Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig 
(Germany)