NFS version 4.0 for FreeBSD-CURRENT
Alfred Perlstein
alfred at freebsd.org
Sun Mar 15 14:07:54 PDT 2009
* Rick Macklem <rmacklem at uoguelph.ca> [090315 13:57] wrote:
>
> As far as the server goes, I'd have to look. NFSv4 locking
> doesn't use lockd, but my server does grab byte range locks
> through the VFS and I suspect lockd sees those, just like
> any other process sees them. (One advantage of NFSv4 is
> integrated locking that seems to work well.)
I think the way that kernel server NFS lockd works is that it sits
here:
V TCPIP
V lockd -> calls ASYNC locks down (expects callback)
V VFS -> calls back to lockd when locks are acquired
It's _not_ like this:
V TCPIP
V lockd -> calls SYNC locks down
V VFS
V lockd -> stuff
so unless your server uses the async lock facility, you'll
wind up with your server context blocked in VFS waiting
for locks.
(I think.)
-Alfred
More information about the freebsd-arch
mailing list