On Sat, 18 Nov 2023, Chuck Lever wrote:
> On Fri, Nov 17, 2023 at 01:18:52PM +1100, NeilBrown wrote:
> > For NFSv4.1 and later the client easily discovers if there is any
> > admin-revoked state and will then find and explicitly free it.
> >
> > For NFSv4.0 there is no such mechanism. The client can only find that
> > state is admin-revoked if it tries to use that state, and there is no
> > way for it to explicitly free the state. So the server must hold on to
> > the stateid (at least) for an indefinite amount of time. A
> > RELEASE_LOCKOWNER request might justify forgetting some of these
> > stateids, as would the whole clients lease lapsing, but these are not
> > reliable.
> >
> > This patch takes two approaches.
> >
> > Whenever a client uses an revoked stateid, that stateid is then
> > discarded and will not be recognised again. This might confuse a client
> > which expect to get NFS4ERR_ADMIN_REVOKED consistently once it get it at
> > all, but should mostly work. Hopefully one error will lead to other
> > resources being closed (e.g. process exits), which will result in more
> > stateid being freed when a CLOSE attempt gets NFS4ERR_ADMIN_REVOKED.
> >
> > Also, any admin-revoked stateids that have been that way for more than
> > one lease time are periodically revoke.
> >
> > No actual freeing of state happens in this patch. That will come in
> > future patches which handle the different sorts of revoked state.
> >
> > Signed-off-by: NeilBrown <neilb@xxxxxxx>
> > ---
> > fs/nfsd/netns.h | 4 ++
> > fs/nfsd/nfs4state.c | 97 ++++++++++++++++++++++++++++++++++++++++++++-
> > 2 files changed, 100 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> > index ec49b200b797..02f8fa095b0f 100644
> > --- a/fs/nfsd/netns.h
> > +++ b/fs/nfsd/netns.h
> > @@ -197,6 +197,10 @@ struct nfsd_net {
> > atomic_t nfsd_courtesy_clients;
> > struct shrinker nfsd_client_shrinker;
> > struct work_struct nfsd_shrinker_work;
> > +
> > + /* last time an admin-revoke happened for NFSv4.0 */
> > + time64_t nfs40_last_revoke;
> > +
> > };
>
> This hunk doesn't apply to nfsd-next due to v6.7-rc changes to NFSD
> to implement a dynamic shrinker. So I stopped my review here for
> now.
I didn't a rebase onto nfsd-next and there were no conflicts!
I guess the change from
struct work_struct nfsd_shrinker_work;
to
struct work_struct *nfsd_shrinker_work;
was technically a conflict but I'm surprised your tool complained..
NeilBrown
