DragonFly kernel List (threaded) for 2004-08
Re: VFS ROADMAP (and vfs01.patch stage 1 available for testing)
On Thu, Aug 12, 2004 at 06:19:40PM -0700, Matthew Dillon wrote:
> This represents the first of the many stages that will be needed to
> thread the VFS subsystem. I am going to have commit the work
> incrementally, stage by stage, to keep the number of bugs to a minimum.
> fetch http://leaf.dragonflybsd.org/~dillon/vfs01.patch
> Some testing would be appreciated. This patch will go in tomorrow.
> ROADMAP FOR THREADED VFS's
> The really nasty stuff starts at stage 3. Before I can implement the
> messaging interface I have to:
So I guess people can expect a little bit of instability in the
vnode interface for the next while (-- meaning frequent changes not
necessarily bugs).. ;)
> * VM objects will become mandatory for all filesystems and will
> also be made directly accessible to the kernel without having
> to enter the VFS layer (ultimately this will result in greatly
> improved read() and write() performance).
> * Implement a bottom-up cache invalidation abstraction for
> namespace, attribute, and file data, so layered filesystems
> work properly.
This could support a write to either the lower layer or the upper
layer and cache would be coherent between layers?
> This is a pretty ambitious plan, it could take me into next year to
> finish it all but when it is done we will be extremely well positioned
> for the ultimate goal of implementing fully transparent clustering.
Allan Fields, AFRSL - http://afields.ca
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