nfsd: make expkey cache allocated per network namespace context

This patch also changes svcauth_unix_purge() function: added network namespace
as a parameter and thus loop over all networks was replaced by only one call
for ip map cache purge.

Signed-off-by: Stanislav Kinsbursky <[e-mail]>
Signed-off-by: J. Bruce Fields <[e-mail]>

fs/nfsd/export.c

···
 #define	EXPKEY_HASHBITS		8
 #define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
 #define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
-static struct cache_head *expkey_table[EXPKEY_HASHMAX];
 
 static void expkey_put(struct kref *ref)
 {
···
 		return NULL;
 }
 
-static struct cache_detail svc_expkey_cache = {
+static struct cache_detail svc_expkey_cache_template = {
 	.owner		= THIS_MODULE,
 	.hash_size	= EXPKEY_HASHMAX,
-	.hash_table	= expkey_table,
 	.name		= "nfsd.fh",
 	.cache_put	= expkey_put,
 	.cache_upcall	= expkey_upcall,
···
 				   u32 *fsidv, struct cache_req *reqp)
 {
 	struct svc_export *exp;
-	struct svc_expkey *ek = exp_find_key(&svc_expkey_cache, clp, fsid_type, fsidv, reqp);
+	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
+	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
 	if (IS_ERR(ek))
 		return ERR_CAST(ek);
 
 	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
-	cache_put(&ek->h, &svc_expkey_cache);
+	cache_put(&ek->h, nn->svc_expkey_cache);
 
 	if (IS_ERR(exp))
 		return ERR_CAST(exp);
···
 	.show	= e_show,
 };
 
-
 /*
  * Initialize the exports module.
  */
···
 	if (rv)
 		goto destroy_export_cache;
 
-	rv = cache_register_net(&svc_expkey_cache, net);
-	if (rv)
+	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
+	if (IS_ERR(nn->svc_expkey_cache)) {
+		rv = PTR_ERR(nn->svc_expkey_cache);
 		goto unregister_export_cache;
+	}
+	rv = cache_register_net(nn->svc_expkey_cache, net);
+	if (rv)
+		goto destroy_expkey_cache;
 	return 0;
 
+destroy_expkey_cache:
+	cache_destroy_net(nn->svc_expkey_cache, net);
 unregister_export_cache:
 	cache_unregister_net(nn->svc_export_cache, net);
 destroy_export_cache:
···
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	cache_purge(&svc_expkey_cache);
+	cache_purge(nn->svc_expkey_cache);
 	cache_purge(nn->svc_export_cache);
 }
 
···
 
 	dprintk("nfsd: shutting down export module (net: %p).\n", net);
 
-	cache_unregister_net(&svc_expkey_cache, net);
+	cache_unregister_net(nn->svc_expkey_cache, net);
 	cache_unregister_net(nn->svc_export_cache, net);
+	cache_destroy_net(nn->svc_expkey_cache, net);
 	cache_destroy_net(nn->svc_export_cache, net);
-	svcauth_unix_purge();
+	svcauth_unix_purge(net);
 
 	dprintk("nfsd: export shutdown complete (net: %p).\n", net);
 }

fs/nfsd/netns.h

···
 struct nfsd_net {
 	struct cld_net *cld_net;
 
+	struct cache_detail *svc_expkey_cache;
 	struct cache_detail *svc_export_cache;
 };
 

fs/nfsd/nfsctl.c

···
 {
 	int err;
 	struct seq_file *seq;
+	struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
 
 	err = seq_open(file, &nfs_exports_op);
 	if (err)
 		return err;
 
 	seq = file->private_data;
-	seq->private = &svc_export_cache;
+	seq->private = nn->svc_export_cache;
 	return 0;
 }
 

include/linux/nfsd/export.h

···
 __be32			exp_pseudoroot(struct svc_rqst *, struct svc_fh *);
 __be32			nfserrno(int errno);
 
-extern struct cache_detail svc_export_cache;
-
 static inline void exp_put(struct svc_export *exp)
 {
 	cache_put(&exp->h, exp->cd);

include/linux/sunrpc/svcauth.h

···
 extern struct auth_domain *auth_domain_find(char *name);
 extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
 extern int auth_unix_forget_old(struct auth_domain *dom);
-extern void svcauth_unix_purge(void);
+extern void svcauth_unix_purge(struct net *net);
 extern void svcauth_unix_info_release(struct svc_xprt *xpt);
 extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
 

net/sunrpc/svcauth_unix.c

···
 	return __ip_map_update(sn->ip_map_cache, ipm, udom, expiry);
 }
 
-
-void svcauth_unix_purge(void)
+void svcauth_unix_purge(struct net *net)
 {
-	struct net *net;
+	struct sunrpc_net *sn;
 
-	for_each_net(net) {
-		struct sunrpc_net *sn;
-
-		sn = net_generic(net, sunrpc_net_id);
-		cache_purge(sn->ip_map_cache);
-	}
+	sn = net_generic(net, sunrpc_net_id);
+	cache_purge(sn->ip_map_cache);
 }
 EXPORT_SYMBOL_GPL(svcauth_unix_purge);