[PATCH v1 net-next 3/6] af_unix: Define a per-netns hash table.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

This commit adds a per netns hash table for AF_UNIX.

Note that its size is fixed as UNIX_HASH_SIZE for now.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 include/net/af_unix.h    |  5 +++++
 include/net/netns/unix.h |  2 ++
 net/unix/af_unix.c       | 40 ++++++++++++++++++++++++++++++++++------
 3 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index acb56e463db1..0a17e49af0c9 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -24,6 +24,11 @@ extern unsigned int unix_tot_inflight;
 extern spinlock_t unix_table_locks[UNIX_HASH_SIZE];
 extern struct hlist_head unix_socket_table[UNIX_HASH_SIZE];
 
+struct unix_hashbucket {
+	spinlock_t		lock;
+	struct hlist_head	head;
+};
+
 struct unix_address {
 	refcount_t	refcnt;
 	int		len;
diff --git a/include/net/netns/unix.h b/include/net/netns/unix.h
index 91a3d7e39198..975c4e3f8a5b 100644
--- a/include/net/netns/unix.h
+++ b/include/net/netns/unix.h
@@ -5,8 +5,10 @@
 #ifndef __NETNS_UNIX_H__
 #define __NETNS_UNIX_H__
 
+struct unix_hashbucket;
 struct ctl_table_header;
 struct netns_unix {
+	struct unix_hashbucket	*hash;
 	int			sysctl_max_dgram_qlen;
 	struct ctl_table_header	*ctl;
 };
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index c0804ae9c96a..3c07702e2349 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -3559,7 +3559,7 @@ static const struct net_proto_family unix_family_ops = {
 
 static int __net_init unix_net_init(struct net *net)
 {
-	int error = -ENOMEM;
+	int i;
 
 	net->unx.sysctl_max_dgram_qlen = 10;
 	if (unix_sysctl_register(net))
@@ -3567,18 +3567,35 @@ static int __net_init unix_net_init(struct net *net)
 
 #ifdef CONFIG_PROC_FS
 	if (!proc_create_net("unix", 0, net->proc_net, &unix_seq_ops,
-			sizeof(struct seq_net_private))) {
-		unix_sysctl_unregister(net);
-		goto out;
+			     sizeof(struct seq_net_private)))
+		goto err_sysctl;
+#endif
+
+	net->unx.hash = kmalloc(sizeof(struct unix_hashbucket) * UNIX_HASH_SIZE,
+				GFP_KERNEL);
+	if (!net->unx.hash)
+		goto err_proc;
+
+	for (i = 0; i < UNIX_HASH_SIZE; i++) {
+		INIT_HLIST_HEAD(&net->unx.hash[i].head);
+		spin_lock_init(&net->unx.hash[i].lock);
 	}
+
+	return 0;
+
+err_proc:
+#ifdef CONFIG_PROC_FS
+	remove_proc_entry("unix", net->proc_net);
 #endif
-	error = 0;
+err_sysctl:
+	unix_sysctl_unregister(net);
 out:
-	return error;
+	return -ENOMEM;
 }
 
 static void __net_exit unix_net_exit(struct net *net)
 {
+	kfree(net->unx.hash);
 	unix_sysctl_unregister(net);
 	remove_proc_entry("unix", net->proc_net);
 }
@@ -3666,6 +3683,16 @@ static int __init af_unix_init(void)
 
 	BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof_field(struct sk_buff, cb));
 
+	init_net.unx.hash = kmalloc(sizeof(struct unix_hashbucket) * UNIX_HASH_SIZE,
+				    GFP_KERNEL);
+	if (!init_net.unx.hash)
+		goto out;
+
+	for (i = 0; i < UNIX_HASH_SIZE; i++) {
+		INIT_HLIST_HEAD(&init_net.unx.hash[i].head);
+		spin_lock_init(&init_net.unx.hash[i].lock);
+	}
+
 	for (i = 0; i < UNIX_HASH_SIZE; i++)
 		spin_lock_init(&unix_table_locks[i]);
 
@@ -3699,6 +3726,7 @@ static void __exit af_unix_exit(void)
 	proto_unregister(&unix_dgram_proto);
 	proto_unregister(&unix_stream_proto);
 	unregister_pernet_subsys(&unix_net_ops);
+	kfree(init_net.unx.hash);
 }
 
 /* Earlier than device_initcall() so that other drivers invoking
-- 
2.30.2