From c2e76ef5e0716bc82364e6049e8023ffd5bbe395 Mon Sep 17 00:00:00 2001
From: Stanislav Kinsbursky <skinsbursky@parallels.com>
Date: Wed, 11 Apr 2012 17:32:51 +0400
Subject: [PATCH] nfsd: make id-to-name cache allocated per network namespace
 context

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/nfsd/netns.h     |  3 +++
 fs/nfsd/nfs4idmap.c | 33 +++++++++++++++++++++++----------
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 9794c6c7d133..948a718e24a4 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -31,6 +31,9 @@ struct nfsd_net {
 
 	struct cache_detail *svc_expkey_cache;
 	struct cache_detail *svc_export_cache;
+
+	struct cache_detail *idtoname_cache;
+
 };
 
 extern int nfsd_net_id;
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index d37405f7000a..b285a693af8c 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -36,9 +36,11 @@
 #include <linux/seq_file.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/sunrpc/svc_xprt.h>
 #include <net/net_namespace.h>
 #include "idmap.h"
 #include "nfsd.h"
+#include "netns.h"
 
 /*
  * Turn off idmapping when using AUTH_SYS.
@@ -107,8 +109,6 @@ ent_alloc(void)
  * ID -> Name cache
  */
 
-static struct cache_head *idtoname_table[ENT_HASHMAX];
-
 static uint32_t
 idtoname_hash(struct ent *ent)
 {
@@ -187,10 +187,9 @@ static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
 				   struct ent *);
 
-static struct cache_detail idtoname_cache = {
+static struct cache_detail idtoname_cache_template = {
 	.owner		= THIS_MODULE,
 	.hash_size	= ENT_HASHMAX,
-	.hash_table	= idtoname_table,
 	.name		= "nfs4.idtoname",
 	.cache_put	= ent_put,
 	.cache_upcall	= idtoname_upcall,
@@ -472,21 +471,34 @@ int
 nfsd_idmap_init(struct net *net)
 {
 	int rv;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	rv = cache_register_net(&idtoname_cache, net);
+	nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
+	if (IS_ERR(nn->idtoname_cache))
+		return PTR_ERR(nn->idtoname_cache);
+	rv = cache_register_net(nn->idtoname_cache, net);
 	if (rv)
-		return rv;
+		goto destroy_idtoname_cache;
 	rv = cache_register_net(&nametoid_cache, net);
 	if (rv)
-		cache_unregister_net(&idtoname_cache, net);
+		goto unregister_idtoname_cache;
+	return 0;
+
+unregister_idtoname_cache:
+	cache_unregister_net(nn->idtoname_cache, net);
+destroy_idtoname_cache:
+	cache_destroy_net(nn->idtoname_cache, net);
 	return rv;
 }
 
 void
 nfsd_idmap_shutdown(struct net *net)
 {
-	cache_unregister_net(&idtoname_cache, net);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cache_unregister_net(nn->idtoname_cache, net);
 	cache_unregister_net(&nametoid_cache, net);
+	cache_destroy_net(nn->idtoname_cache, net);
 }
 
 static int
@@ -553,9 +565,10 @@ idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 		.type = type,
 	};
 	int ret;
+	struct nfsd_net *nn = net_generic(rqstp->rq_xprt->xpt_net, nfsd_net_id);
 
 	strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
-	ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
+	ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
 	if (ret == -ENOENT)
 		return sprintf(name, "%u", id);
 	if (ret)
@@ -563,7 +576,7 @@ idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 	ret = strlen(item->name);
 	BUG_ON(ret > IDMAP_NAMESZ);
 	memcpy(name, item->name, ret);
-	cache_put(&item->h, &idtoname_cache);
+	cache_put(&item->h, nn->idtoname_cache);
 	return ret;
 }