Merge: nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2735

Bugzilla: https://bugzilla.redhat.com/2215429

This patch fixes a regression that crept into upstream kernels and 9.3 with an earlier backport. Since the procfiles are available when nfsd isn't running, we also need to make sure that the percpu counters are always initialized.

Signed-off-by: Jeffrey Layton <jlayton@redhat.com>

Approved-by: Eirik Fuller <efuller@redhat.com>
Approved-by: Scott Mayhew <smayhew@redhat.com>
Approved-by: Benjamin Coddington <bcodding@redhat.com>

Signed-off-by: Jan Stancek <jstancek@redhat.com>

Author: jstancek

fs/nfsd/cache.h

@@ -80,6 +80,8 @@ enum {
 
 int	nfsd_drc_slab_create(void);
 void	nfsd_drc_slab_free(void);
+int	nfsd_net_reply_cache_init(struct nfsd_net *nn);
+void	nfsd_net_reply_cache_destroy(struct nfsd_net *nn);
 int	nfsd_reply_cache_init(struct nfsd_net *);
 void	nfsd_reply_cache_shutdown(struct nfsd_net *);
 int	nfsd_cache_lookup(struct svc_rqst *);

fs/nfsd/nfscache.c

@@ -148,12 +148,23 @@ void nfsd_drc_slab_free(void)
 	kmem_cache_destroy(drc_slab);
 }
 
-static int nfsd_reply_cache_stats_init(struct nfsd_net *nn)
+/**
+ * nfsd_net_reply_cache_init - per net namespace reply cache set-up
+ * @nn: nfsd_net being initialized
+ *
+ * Returns zero on succes; otherwise a negative errno is returned.
+ */
+int nfsd_net_reply_cache_init(struct nfsd_net *nn)
 {
 	return nfsd_percpu_counters_init(nn->counter, NFSD_NET_COUNTERS_NUM);
 }
 
-static void nfsd_reply_cache_stats_destroy(struct nfsd_net *nn)
+/**
+ * nfsd_net_reply_cache_destroy - per net namespace reply cache tear-down
+ * @nn: nfsd_net being freed
+ *
+ */
+void nfsd_net_reply_cache_destroy(struct nfsd_net *nn)
 {
 	nfsd_percpu_counters_destroy(nn->counter, NFSD_NET_COUNTERS_NUM);
 }
@@ -169,17 +180,13 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 	hashsize = nfsd_hashsize(nn->max_drc_entries);
 	nn->maskbits = ilog2(hashsize);
 
-	status = nfsd_reply_cache_stats_init(nn);
-	if (status)
-		goto out_nomem;
-
 	nn->nfsd_reply_cache_shrinker.scan_objects = nfsd_reply_cache_scan;
 	nn->nfsd_reply_cache_shrinker.count_objects = nfsd_reply_cache_count;
 	nn->nfsd_reply_cache_shrinker.seeks = 1;
 	status = register_shrinker(&nn->nfsd_reply_cache_shrinker,
 				   "nfsd-reply:%s", nn->nfsd_name);
 	if (status)
-		goto out_stats_destroy;
+		return status;
 
 	nn->drc_hashtbl = kvzalloc(array_size(hashsize,
 				sizeof(*nn->drc_hashtbl)), GFP_KERNEL);
@@ -195,9 +202,6 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 	return 0;
 out_shrinker:
 	unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
-out_stats_destroy:
-	nfsd_reply_cache_stats_destroy(nn);
-out_nomem:
 	printk(KERN_ERR "nfsd: failed to allocate reply cache\n");
 	return -ENOMEM;
 }
@@ -217,7 +221,6 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
 									rp, nn);
 		}
 	}
-	nfsd_reply_cache_stats_destroy(nn);
 
 	kvfree(nn->drc_hashtbl);
 	nn->drc_hashtbl = NULL;

fs/nfsd/nfsctl.c

@@ -1487,6 +1487,9 @@ static __net_init int nfsd_init_net(struct net *net)
 	retval = nfsd_idmap_init(net);
 	if (retval)
 		goto out_idmap_error;
+	retval = nfsd_net_reply_cache_init(nn);
+	if (retval)
+		goto out_repcache_error;
 	nn->nfsd_versions = NULL;
 	nn->nfsd4_minorversions = NULL;
 	nfsd4_init_leases_net(nn);
@@ -1495,6 +1498,8 @@ static __net_init int nfsd_init_net(struct net *net)
 
 	return 0;
 
+out_repcache_error:
+	nfsd_idmap_shutdown(net);
 out_idmap_error:
 	nfsd_export_shutdown(net);
 out_export_error:
@@ -1503,9 +1508,12 @@ static __net_init int nfsd_init_net(struct net *net)
 
 static __net_exit void nfsd_exit_net(struct net *net)
 {
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfsd_net_reply_cache_destroy(nn);
 	nfsd_idmap_shutdown(net);
 	nfsd_export_shutdown(net);
-	nfsd_netns_free_versions(net_generic(net, nfsd_net_id));
+	nfsd_netns_free_versions(nn);
 }
 
 static struct pernet_operations nfsd_net_ops = {