1 files changed, 40 insertions, 23 deletions

diff --git a/net/socket.c b/net/socket.c
index 088fb3fd45e0..ac2219f90d5d 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -156,7 +156,7 @@ static const struct file_operations socket_file_ops = {
  */
 
 static DEFINE_SPINLOCK(net_family_lock);
-static const struct net_proto_family *net_families[NPROTO] __read_mostly;
+static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
 
 /*
  *      Statistics counters of the socket lists
@@ -262,6 +262,7 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 }
 
 
+
 static void wq_free_rcu(struct rcu_head *head)
 {
         struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
@@ -305,20 +306,6 @@ static const struct super_operations sockfs_ops = {
         .statfs         = simple_statfs,
 };
 
-static struct dentry *sockfs_mount(struct file_system_type *fs_type,
-                         int flags, const char *dev_name, void *data)
-{
-        return mount_pseudo(fs_type, "socket:", &sockfs_ops, SOCKFS_MAGIC);
-}
-
-static struct vfsmount *sock_mnt __read_mostly;
-
-static struct file_system_type sock_fs_type = {
-        .name =         "sockfs",
-        .mount =        sockfs_mount,
-        .kill_sb =      kill_anon_super,
-};
-
 /*
  * sockfs_dname() is called from d_path().
  */
@@ -332,6 +319,21 @@ static const struct dentry_operations sockfs_dentry_operations = {
         .d_dname  = sockfs_dname,
 };
 
+static struct dentry *sockfs_mount(struct file_system_type *fs_type,
+                         int flags, const char *dev_name, void *data)
+{
+        return mount_pseudo(fs_type, "socket:", &sockfs_ops,
+                &sockfs_dentry_operations, SOCKFS_MAGIC);
+}
+
+static struct vfsmount *sock_mnt __read_mostly;
+
+static struct file_system_type sock_fs_type = {
+        .name =         "sockfs",
+        .mount =        sockfs_mount,
+        .kill_sb =      kill_anon_super,
+};
+
 /*
  *      Obtains the first available file descriptor and sets it up for use.
  *
@@ -360,14 +362,13 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
         if (unlikely(fd < 0))
                 return fd;
 
-        path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name);
+        path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
         if (unlikely(!path.dentry)) {
                 put_unused_fd(fd);
                 return -ENOMEM;
         }
         path.mnt = mntget(sock_mnt);
 
-        path.dentry->d_op = &sockfs_dentry_operations;
         d_instantiate(path.dentry, SOCK_INODE(sock));
         SOCK_INODE(sock)->i_fop = &socket_file_ops;
 
@@ -1215,7 +1216,7 @@ int __sock_create(struct net *net, int family, int type, int protocol,
          * requested real, full-featured networking support upon configuration.
          * Otherwise module support will break!
          */
-        if (net_families[family] == NULL)
+        if (rcu_access_pointer(net_families[family]) == NULL)
                 request_module("net-pf-%d", family);
 #endif
 
@@ -2347,10 +2348,11 @@ int sock_register(const struct net_proto_family *ops)
         }
 
         spin_lock(&net_family_lock);
-        if (net_families[ops->family])
+        if (rcu_dereference_protected(net_families[ops->family],
+                                      lockdep_is_held(&net_family_lock)))
                 err = -EEXIST;
         else {
-                net_families[ops->family] = ops;
+                rcu_assign_pointer(net_families[ops->family], ops);
                 err = 0;
         }
         spin_unlock(&net_family_lock);
@@ -2378,7 +2380,7 @@ void sock_unregister(int family)
         BUG_ON(family < 0 || family >= NPROTO);
 
         spin_lock(&net_family_lock);
-        net_families[family] = NULL;
+        rcu_assign_pointer(net_families[family], NULL);
         spin_unlock(&net_family_lock);
 
         synchronize_rcu();
@@ -2389,6 +2391,8 @@ EXPORT_SYMBOL(sock_unregister);
 
 static int __init sock_init(void)
 {
+        int err;
+
         /*
          *      Initialize sock SLAB cache.
          */
@@ -2405,8 +2409,15 @@ static int __init sock_init(void)
          */
 
         init_inodecache();
-        register_filesystem(&sock_fs_type);
+
+        err = register_filesystem(&sock_fs_type);
+        if (err)
+                goto out_fs;
         sock_mnt = kern_mount(&sock_fs_type);
+        if (IS_ERR(sock_mnt)) {
+                err = PTR_ERR(sock_mnt);
+                goto out_mount;
+        }
 
         /* The real protocol initialization is performed in later initcalls.
          */
@@ -2419,7 +2430,13 @@ static int __init sock_init(void)
         skb_timestamping_init();
 #endif
 
-        return 0;
+out:
+        return err;
+
+out_mount:
+        unregister_filesystem(&sock_fs_type);
+out_fs:
+        goto out;
 }
 
 core_initcall(sock_init);       /* early initcall */