[PATCH v2 2/5] SUNRPC: create unix gid cache per network namespace

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

v2:
1) fixed silly usage of template cache as a real one (this code left from
static global cache for all)

This patch makes unix_gid_cache cache detail allocated and registered per
network namespace context.
Thus with this patch unix_gid_cache contents for network namespace "X" are
controlled from proc file system mount for the same network namespace "X".

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>

---
 net/sunrpc/netns.h        |    1 +
 net/sunrpc/sunrpc_syms.c  |   14 ++++++++---
 net/sunrpc/svcauth_unix.c |   55 ++++++++++++++++++++++++++++++++++-----------
 3 files changed, 52 insertions(+), 18 deletions(-)

diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index 1fdeb1b..309f88d 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -9,6 +9,7 @@ struct cache_detail;
 struct sunrpc_net {
 	struct proc_dir_entry *proc_net_rpc;
 	struct cache_detail *ip_map_cache;
+	struct cache_detail *unix_gid_cache;
 
 	struct super_block *pipefs_sb;
 	struct mutex pipefs_sb_lock;
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index b4217dc..38a72a1 100644
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -26,6 +26,9 @@
 
 int sunrpc_net_id;
 
+extern int unix_gid_cache_create(struct net *net);
+extern int unix_gid_cache_destroy(struct net *net);
+
 static __net_init int sunrpc_init_net(struct net *net)
 {
 	int err;
@@ -39,11 +42,17 @@ static __net_init int sunrpc_init_net(struct net *net)
 	if (err)
 		goto err_ipmap;
 
+	err = unix_gid_cache_create(net);
+	if (err)
+		goto err_unixgid;
+
 	rpc_pipefs_init_net(net);
 	INIT_LIST_HEAD(&sn->all_clients);
 	spin_lock_init(&sn->rpc_client_lock);
 	return 0;
 
+err_unixgid:
+	ip_map_cache_destroy(net);
 err_ipmap:
 	rpc_proc_exit(net);
 err_proc:
@@ -52,6 +61,7 @@ err_proc:
 
 static __net_exit void sunrpc_exit_net(struct net *net)
 {
+	unix_gid_cache_destroy(net);
 	ip_map_cache_destroy(net);
 	rpc_proc_exit(net);
 }
@@ -63,8 +73,6 @@ static struct pernet_operations sunrpc_net_ops = {
 	.size = sizeof(struct sunrpc_net),
 };
 
-extern struct cache_detail unix_gid_cache;
-
 static int __init
 init_sunrpc(void)
 {
@@ -86,7 +94,6 @@ init_sunrpc(void)
 #ifdef RPC_DEBUG
 	rpc_register_sysctl();
 #endif
-	cache_register(&unix_gid_cache);
 	svc_init_xprt_sock();	/* svc sock transport */
 	init_socket_xprt();	/* clnt sock transport */
 	return 0;
@@ -109,7 +116,6 @@ cleanup_sunrpc(void)
 	svc_cleanup_xprt_sock();
 	unregister_rpc_pipefs();
 	rpc_destroy_mempool();
-	cache_unregister(&unix_gid_cache);
 	unregister_pernet_subsys(&sunrpc_net_ops);
 #ifdef RPC_DEBUG
 	rpc_unregister_sysctl();
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 2f8c426..a6eef38 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -436,7 +436,6 @@ struct unix_gid {
 	uid_t			uid;
 	struct group_info	*gi;
 };
-static struct cache_head	*gid_table[GID_HASHMAX];
 
 static void unix_gid_put(struct kref *kref)
 {
@@ -494,8 +493,7 @@ static int unix_gid_upcall(struct cache_detail *cd, struct cache_head *h)
 	return sunrpc_cache_pipe_upcall(cd, h, unix_gid_request);
 }
 
-static struct unix_gid *unix_gid_lookup(uid_t uid);
-extern struct cache_detail unix_gid_cache;
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, uid_t uid);
 
 static int unix_gid_parse(struct cache_detail *cd,
 			char *mesg, int mlen)
@@ -539,19 +537,19 @@ static int unix_gid_parse(struct cache_detail *cd,
 		GROUP_AT(ug.gi, i) = gid;
 	}
 
-	ugp = unix_gid_lookup(uid);
+	ugp = unix_gid_lookup(cd, uid);
 	if (ugp) {
 		struct cache_head *ch;
 		ug.h.flags = 0;
 		ug.h.expiry_time = expiry;
-		ch = sunrpc_cache_update(&unix_gid_cache,
+		ch = sunrpc_cache_update(cd,
 					 &ug.h, &ugp->h,
 					 hash_long(uid, GID_HASHBITS));
 		if (!ch)
 			err = -ENOMEM;
 		else {
 			err = 0;
-			cache_put(ch, &unix_gid_cache);
+			cache_put(ch, cd);
 		}
 	} else
 		err = -ENOMEM;
@@ -587,10 +585,9 @@ static int unix_gid_show(struct seq_file *m,
 	return 0;
 }
 
-struct cache_detail unix_gid_cache = {
+static struct cache_detail unix_gid_cache_template = {
 	.owner		= THIS_MODULE,
 	.hash_size	= GID_HASHMAX,
-	.hash_table	= gid_table,
 	.name		= "auth.unix.gid",
 	.cache_put	= unix_gid_put,
 	.cache_upcall	= unix_gid_upcall,
@@ -602,14 +599,42 @@ struct cache_detail unix_gid_cache = {
 	.alloc		= unix_gid_alloc,
 };
 
-static struct unix_gid *unix_gid_lookup(uid_t uid)
+int unix_gid_cache_create(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd;
+	int err;
+
+	cd = cache_create_net(&unix_gid_cache_template, net);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+	err = cache_register_net(cd, net);
+	if (err) {
+		cache_destroy_net(cd, net);
+		return err;
+	}
+	sn->unix_gid_cache = cd;
+	return 0;
+}
+
+void unix_gid_cache_destroy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd = sn->unix_gid_cache;
+
+	sn->unix_gid_cache = NULL;
+	cache_purge(cd);
+	cache_unregister_net(cd, net);
+	cache_destroy_net(cd, net);
+}
+
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, uid_t uid)
 {
 	struct unix_gid ug;
 	struct cache_head *ch;
 
 	ug.uid = uid;
-	ch = sunrpc_cache_lookup(&unix_gid_cache, &ug.h,
-				 hash_long(uid, GID_HASHBITS));
+	ch = sunrpc_cache_lookup(cd, &ug.h, hash_long(uid, GID_HASHBITS));
 	if (ch)
 		return container_of(ch, struct unix_gid, h);
 	else
@@ -621,11 +646,13 @@ static struct group_info *unix_gid_find(uid_t uid, struct svc_rqst *rqstp)
 	struct unix_gid *ug;
 	struct group_info *gi;
 	int ret;
+	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net,
+					    sunrpc_net_id);
 
-	ug = unix_gid_lookup(uid);
+	ug = unix_gid_lookup(sn->unix_gid_cache, uid);
 	if (!ug)
 		return ERR_PTR(-EAGAIN);
-	ret = cache_check(&unix_gid_cache, &ug->h, &rqstp->rq_chandle);
+	ret = cache_check(sn->unix_gid_cache, &ug->h, &rqstp->rq_chandle);
 	switch (ret) {
 	case -ENOENT:
 		return ERR_PTR(-ENOENT);
@@ -633,7 +660,7 @@ static struct group_info *unix_gid_find(uid_t uid, struct svc_rqst *rqstp)
 		return ERR_PTR(-ESHUTDOWN);
 	case 0:
 		gi = get_group_info(ug->gi);
-		cache_put(&ug->h, &unix_gid_cache);
+		cache_put(&ug->h, sn->unix_gid_cache);
 		return gi;
 	default:
 		return ERR_PTR(-EAGAIN);