Re: [PATCH v5 1/4] NFSD: refactoring courtesy_client_reaper to a generic low memory shrinker

[dai.ngo@xxxxxxxxxx]

On 11/17/22 6:45 AM, Chuck Lever III wrote:
> > On Nov 16, 2022, at 10:44 PM, Dai Ngo <dai.ngo@xxxxxxxxxx> wrote:
> >
> > Refactoring courtesy_client_reaper to generic low memory
> > shrinker so it can be used for other purposes.
> >
> > Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> > ---
> > fs/nfsd/nfs4state.c | 25 ++++++++++++++++---------
> > 1 file changed, 16 insertions(+), 9 deletions(-)
> >
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index 836bd825ca4a..142481bc96de 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -4347,7 +4347,7 @@ nfsd4_init_slabs(void)
> > }
> >
> > static unsigned long
> > -nfsd_courtesy_client_count(struct shrinker *shrink, struct shrink_control *sc)
> > +nfsd_lowmem_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
> > {
> > 	int cnt;
> > 	struct nfsd_net *nn = container_of(shrink,
> > @@ -4360,7 +4360,7 @@ nfsd_courtesy_client_count(struct shrinker *shrink, struct shrink_control *sc)
> > }
> >
> > static unsigned long
> > -nfsd_courtesy_client_scan(struct shrinker *shrink, struct shrink_control *sc)
> > +nfsd_lowmem_shrinker_scan(struct shrinker *shrink, struct shrink_control *sc)
> > {
> > 	return SHRINK_STOP;
> > }
> > @@ -4387,8 +4387,8 @@ nfsd4_init_leases_net(struct nfsd_net *nn)
> > 	nn->nfs4_max_clients = max_t(int, max_clients, NFS4_CLIENTS_PER_GB);
> >
> > 	atomic_set(&nn->nfsd_courtesy_clients, 0);
> > -	nn->nfsd_client_shrinker.scan_objects = nfsd_courtesy_client_scan;
> > -	nn->nfsd_client_shrinker.count_objects = nfsd_courtesy_client_count;
> > +	nn->nfsd_client_shrinker.scan_objects = nfsd_lowmem_shrinker_scan;
> > +	nn->nfsd_client_shrinker.count_objects = nfsd_lowmem_shrinker_count;
> > 	nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS;
> > 	return register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client");
> > }
> > @@ -6125,17 +6125,24 @@ laundromat_main(struct work_struct *laundry)
> > }
> >
> > static void
> > -courtesy_client_reaper(struct work_struct *reaper)
> > +courtesy_client_reaper(struct nfsd_net *nn)
> > {
> > 	struct list_head reaplist;
> > -	struct delayed_work *dwork = to_delayed_work(reaper);
> > -	struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
> > -					nfsd_shrinker_work);
> >
> > 	nfs4_get_courtesy_client_reaplist(nn, &reaplist);
> > 	nfs4_process_client_reaplist(&reaplist);
> > }
> >
> > +static void
> > +nfsd4_lowmem_shrinker(struct work_struct *work)
> All shrinkers run due to low memory, so I think this name
> is a bit redundant. How about nfsd4_state_shrinker?

ok, it makes sense.

Thanks,
-Dai

> > +{
> > +	struct delayed_work *dwork = to_delayed_work(work);
> > +	struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
> > +				nfsd_shrinker_work);
> > +
> > +	courtesy_client_reaper(nn);
> > +}
> > +
> > static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp)
> > {
> > 	if (!fh_match(&fhp->fh_handle, &stp->sc_file->fi_fhandle))
> > @@ -7958,7 +7965,7 @@ static int nfs4_state_create_net(struct net *net)
> > 	INIT_LIST_HEAD(&nn->blocked_locks_lru);
> >
> > 	INIT_DELAYED_WORK(&nn->laundromat_work, laundromat_main);
> > -	INIT_DELAYED_WORK(&nn->nfsd_shrinker_work, courtesy_client_reaper);
> > +	INIT_DELAYED_WORK(&nn->nfsd_shrinker_work, nfsd4_lowmem_shrinker);
> > 	get_net(net);
> >
> > 	return 0;
> > --
> > 2.9.5
> --
> Chuck Lever