NFS: simplify and clean cache library

This is a cleanup patch.
Such helpers like nfs_cache_init() and nfs_cache_destroy() are redundant,
because they are just a wrappers around sunrpc_init_cache_detail() and
sunrpc_destroy_cache_detail() respectively.
So let's remove them completely and move corresponding logic to
nfs_cache_register_net() and nfs_cache_unregister_net() respectively (since
they are called together anyway).

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfs/cache_lib.c

@@ -128,10 +128,13 @@ int nfs_cache_register_net(struct net *net, struct cache_detail *cd)
 	struct super_block *pipefs_sb;
 	int ret = 0;
 
+	sunrpc_init_cache_detail(cd);
 	pipefs_sb = rpc_get_sb_net(net);
 	if (pipefs_sb) {
 		ret = nfs_cache_register_sb(pipefs_sb, cd);
 		rpc_put_sb_net(net);
+		if (ret)
+			sunrpc_destroy_cache_detail(cd);
 	}
 	return ret;
 }
@@ -151,14 +154,5 @@ void nfs_cache_unregister_net(struct net *net, struct cache_detail *cd)
 		nfs_cache_unregister_sb(pipefs_sb, cd);
 		rpc_put_sb_net(net);
 	}
-}
-
-void nfs_cache_init(struct cache_detail *cd)
-{
-	sunrpc_init_cache_detail(cd);
-}
-
-void nfs_cache_destroy(struct cache_detail *cd)
-{
 	sunrpc_destroy_cache_detail(cd);
 }

fs/nfs/cache_lib.h

@@ -23,8 +23,6 @@ extern struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void);
 extern void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq);
 extern int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq);
 
-extern void nfs_cache_init(struct cache_detail *cd);
-extern void nfs_cache_destroy(struct cache_detail *cd);
 extern int nfs_cache_register_net(struct net *net, struct cache_detail *cd);
 extern void nfs_cache_unregister_net(struct net *net, struct cache_detail *cd);
 extern int nfs_cache_register_sb(struct super_block *sb,

fs/nfs/dns_resolve.c

@@ -377,14 +377,12 @@ int nfs_dns_resolver_cache_init(struct net *net)
 	if (IS_ERR(nn->nfs_dns_resolve))
 		return PTR_ERR(nn->nfs_dns_resolve);
 
-	nfs_cache_init(nn->nfs_dns_resolve);
 	err = nfs_cache_register_net(net, nn->nfs_dns_resolve);
 	if (err)
 		goto err_reg;
 	return 0;
 
 err_reg:
-	nfs_cache_destroy(nn->nfs_dns_resolve);
 	cache_destroy_net(nn->nfs_dns_resolve, net);
 	return err;
 }
@@ -392,10 +390,8 @@ err_reg:
 void nfs_dns_resolver_cache_destroy(struct net *net)
 {
 	struct nfs_net *nn = net_generic(net, nfs_net_id);
-	struct cache_detail *cd = nn->nfs_dns_resolve;
 
-	nfs_cache_unregister_net(net, cd);
-	nfs_cache_destroy(cd);
+	nfs_cache_unregister_net(net, nn->nfs_dns_resolve);
 	cache_destroy_net(nn->nfs_dns_resolve, net);
 }