NFSv4: Move the DNS resolver into the NFSv4 module

The other protocols don't use it, so make it local to NFSv4, and
remove the EXPORT.
Also ensure that we only compile in cache_lib.o if we're using
the legacy DNS resolver.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>

fs/nfs/Makefile

@@ -6,8 +6,7 @@ obj-$(CONFIG_NFS_FS) += nfs.o
 
 nfs-y 			:= client.o dir.o file.o getroot.o inode.o super.o \
 			   direct.o pagelist.o read.o symlink.o unlink.o \
-			   write.o namespace.o mount_clnt.o \
-			   dns_resolve.o cache_lib.o
+			   write.o namespace.o mount_clnt.o
 nfs-$(CONFIG_ROOT_NFS)	+= nfsroot.o
 nfs-$(CONFIG_SYSCTL)	+= sysctl.o
 nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o
@@ -22,7 +21,8 @@ nfsv3-$(CONFIG_NFS_V3_ACL) += nfs3acl.o
 obj-$(CONFIG_NFS_V4) += nfsv4.o
 nfsv4-y := nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o nfs4super.o nfs4file.o \
 	  delegation.o idmap.o callback.o callback_xdr.o callback_proc.o \
-	  nfs4namespace.o nfs4getroot.o nfs4client.o
+	  nfs4namespace.o nfs4getroot.o nfs4client.o dns_resolve.o
+nfsv4-$(CONFIG_NFS_USE_LEGACY_DNS) += cache_lib.o
 nfsv4-$(CONFIG_SYSCTL)	+= nfs4sysctl.o
 nfsv4-$(CONFIG_NFS_V4_1)	+= nfs4session.o pnfs.o pnfs_dev.o
 

fs/nfs/dns_resolve.c

@@ -29,7 +29,6 @@ ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen,
 	kfree(ip_addr);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(nfs_dns_resolve_name);
 
 #else
 
@@ -351,7 +350,6 @@ ssize_t nfs_dns_resolve_name(struct net *net, char *name,
 		ret = -ESRCH;
 	return ret;
 }
-EXPORT_SYMBOL_GPL(nfs_dns_resolve_name);
 
 static struct cache_detail nfs_dns_resolve_template = {
 	.owner		= THIS_MODULE,
@@ -396,6 +394,21 @@ void nfs_dns_resolver_cache_destroy(struct net *net)
 	cache_destroy_net(nn->nfs_dns_resolve, net);
 }
 
+static int nfs4_dns_net_init(struct net *net)
+{
+	return nfs_dns_resolver_cache_init(net);
+}
+
+static void nfs4_dns_net_exit(struct net *net)
+{
+	nfs_dns_resolver_cache_destroy(net);
+}
+
+static struct pernet_operations nfs4_dns_resolver_ops = {
+	.init = nfs4_dns_net_init,
+	.exit = nfs4_dns_net_exit,
+};
+
 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 			   void *ptr)
 {
@@ -432,11 +445,24 @@ static struct notifier_block nfs_dns_resolver_block = {
 
 int nfs_dns_resolver_init(void)
 {
-	return rpc_pipefs_notifier_register(&nfs_dns_resolver_block);
+	int err;
+
+	err = register_pernet_subsys(&nfs4_dns_resolver_ops);
+	if (err < 0)
+		goto out;
+	err = rpc_pipefs_notifier_register(&nfs_dns_resolver_block);
+	if (err < 0)
+		goto out1;
+	return 0;
+out1:
+	unregister_pernet_subsys(&nfs4_dns_resolver_ops);
+out:
+	return err;
 }
 
 void nfs_dns_resolver_destroy(void)
 {
 	rpc_pipefs_notifier_unregister(&nfs_dns_resolver_block);
+	unregister_pernet_subsys(&nfs4_dns_resolver_ops);
 }
 #endif

fs/nfs/inode.c

@@ -48,7 +48,6 @@
 #include "iostat.h"
 #include "internal.h"
 #include "fscache.h"
-#include "dns_resolve.h"
 #include "pnfs.h"
 #include "nfs.h"
 #include "netns.h"
@@ -1646,12 +1645,11 @@ EXPORT_SYMBOL_GPL(nfs_net_id);
 static int nfs_net_init(struct net *net)
 {
 	nfs_clients_init(net);
-	return nfs_dns_resolver_cache_init(net);
+	return 0;
 }
 
 static void nfs_net_exit(struct net *net)
 {
-	nfs_dns_resolver_cache_destroy(net);
 	nfs_cleanup_cb_ident_idr(net);
 }
 
@@ -1669,10 +1667,6 @@ static int __init init_nfs_fs(void)
 {
 	int err;
 
-	err = nfs_dns_resolver_init();
-	if (err < 0)
-		goto out10;;
-
 	err = register_pernet_subsys(&nfs_net_ops);
 	if (err < 0)
 		goto out9;
@@ -1738,8 +1732,6 @@ static int __init init_nfs_fs(void)
 out8:
 	unregister_pernet_subsys(&nfs_net_ops);
 out9:
-	nfs_dns_resolver_destroy();
-out10:
 	return err;
 }
 
@@ -1752,7 +1744,6 @@ static void __exit exit_nfs_fs(void)
 	nfs_destroy_nfspagecache();
 	nfs_fscache_unregister();
 	unregister_pernet_subsys(&nfs_net_ops);
-	nfs_dns_resolver_destroy();
 #ifdef CONFIG_PROC_FS
 	rpc_proc_unregister(&init_net, "nfs");
 #endif

fs/nfs/nfs4super.c

@@ -9,6 +9,7 @@
 #include "delegation.h"
 #include "internal.h"
 #include "nfs4_fs.h"
+#include "dns_resolve.h"
 #include "pnfs.h"
 #include "nfs.h"
 
@@ -331,18 +332,24 @@ static int __init init_nfs_v4(void)
 {
 	int err;
 
-	err = nfs_idmap_init();
+	err = nfs_dns_resolver_init();
 	if (err)
 		goto out;
 
-	err = nfs4_register_sysctl();
+	err = nfs_idmap_init();
 	if (err)
 		goto out1;
 
+	err = nfs4_register_sysctl();
+	if (err)
+		goto out2;
+
 	register_nfs_version(&nfs_v4);
 	return 0;
-out1:
+out2:
 	nfs_idmap_quit();
+out1:
+	nfs_dns_resolver_destroy();
 out:
 	return err;
 }
@@ -352,6 +359,7 @@ static void __exit exit_nfs_v4(void)
 	unregister_nfs_version(&nfs_v4);
 	nfs4_unregister_sysctl();
 	nfs_idmap_quit();
+	nfs_dns_resolver_destroy();
 }
 
 MODULE_LICENSE("GPL");