1 files changed, 27 insertions, 75 deletions

diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index c75e3f9d060f..79285a36035f 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -73,7 +73,6 @@ static int extend_netdev_table(struct net_device *dev, u32 new_len)
 			   ((sizeof(u32) * new_len));
 	struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
 	struct netprio_map *old_priomap;
-	int i;
 
 	old_priomap  = rtnl_dereference(dev->priomap);
 
@@ -82,10 +81,10 @@ static int extend_netdev_table(struct net_device *dev, u32 new_len)
 		return -ENOMEM;
 	}
 
-	for (i = 0;
-	     old_priomap && (i < old_priomap->priomap_len);
-	     i++)
-		new_priomap->priomap[i] = old_priomap->priomap[i];
+	if (old_priomap)
+		memcpy(new_priomap->priomap, old_priomap->priomap,
+		       old_priomap->priomap_len *
+		       sizeof(old_priomap->priomap[0]));
 
 	new_priomap->priomap_len = new_len;
 
@@ -109,32 +108,6 @@ static int write_update_netdev_table(struct net_device *dev)
 	return ret;
 }
 
-static int update_netdev_tables(void)
-{
-	int ret = 0;
-	struct net_device *dev;
-	u32 max_len;
-	struct netprio_map *map;
-
-	rtnl_lock();
-	max_len = atomic_read(&max_prioidx) + 1;
-	for_each_netdev(&init_net, dev) {
-		map = rtnl_dereference(dev->priomap);
-		/*
-		 * don't allocate priomap if we didn't
-		 * change net_prio.ifpriomap (map == NULL),
-		 * this will speed up skb_update_prio.
-		 */
-		if (map && map->priomap_len < max_len) {
-			ret = extend_netdev_table(dev, max_len);
-			if (ret < 0)
-				break;
-		}
-	}
-	rtnl_unlock();
-	return ret;
-}
-
 static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
 {
 	struct cgroup_netprio_state *cs;
@@ -153,12 +126,6 @@ static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
 		goto out;
 	}
 
-	ret = update_netdev_tables();
-	if (ret < 0) {
-		put_prioidx(cs->prioidx);
-		goto out;
-	}
-
 	return &cs->css;
 out:
 	kfree(cs);
@@ -272,38 +239,24 @@ out_free_devname:
 	return ret;
 }
 
+static int update_netprio(const void *v, struct file *file, unsigned n)
+{
+	int err;
+	struct socket *sock = sock_from_file(file, &err);
+	if (sock)
+		sock->sk->sk_cgrp_prioidx = (u32)(unsigned long)v;
+	return 0;
+}
+
 void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
 	struct task_struct *p;
+	void *v;
 
 	cgroup_taskset_for_each(p, cgrp, tset) {
-		unsigned int fd;
-		struct fdtable *fdt;
-		struct files_struct *files;
-
 		task_lock(p);
-		files = p->files;
-		if (!files) {
-			task_unlock(p);
-			continue;
-		}
-
-		spin_lock(&files->file_lock);
-		fdt = files_fdtable(files);
-		for (fd = 0; fd < fdt->max_fds; fd++) {
-			struct file *file;
-			struct socket *sock;
-			int err;
-
-			file = fcheck_files(files, fd);
-			if (!file)
-				continue;
-
-			sock = sock_from_file(file, &err);
-			if (sock)
-				sock_update_netprioidx(sock->sk, p);
-		}
-		spin_unlock(&files->file_lock);
+		v = (void *)(unsigned long)task_netprioidx(p);
+		iterate_fd(p->files, 0, update_netprio, v);
 		task_unlock(p);
 	}
 }
@@ -326,11 +279,19 @@ struct cgroup_subsys net_prio_subsys = {
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.attach		= net_prio_attach,
-#ifdef CONFIG_NETPRIO_CGROUP
 	.subsys_id	= net_prio_subsys_id,
-#endif
 	.base_cftypes	= ss_files,
-	.module		= THIS_MODULE
+	.module		= THIS_MODULE,
+
+	/*
+	 * net_prio has artificial limit on the number of cgroups and
+	 * disallows nesting making it impossible to co-mount it with other
+	 * hierarchical subsystems.  Remove the artificially low PRIOIDX_SZ
+	 * limit and properly nest configuration such that children follow
+	 * their parents' configurations by default and are allowed to
+	 * override and remove the following.
+	 */
+	.broken_hierarchy = true,
 };
 
 static int netprio_device_event(struct notifier_block *unused,
@@ -366,10 +327,6 @@ static int __init init_cgroup_netprio(void)
 	ret = cgroup_load_subsys(&net_prio_subsys);
 	if (ret)
 		goto out;
-#ifndef CONFIG_NETPRIO_CGROUP
-	smp_wmb();
-	net_prio_subsys_id = net_prio_subsys.subsys_id;
-#endif
 
 	register_netdevice_notifier(&netprio_device_notifier);
 
@@ -386,11 +343,6 @@ static void __exit exit_cgroup_netprio(void)
 
 	cgroup_unload_subsys(&net_prio_subsys);
 
-#ifndef CONFIG_NETPRIO_CGROUP
-	net_prio_subsys_id = -1;
-	synchronize_rcu();
-#endif
-
 	rtnl_lock();
 	for_each_netdev(&init_net, dev) {
 		old = rtnl_dereference(dev->priomap);