3 files changed, 58 insertions, 6 deletions

diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index b2e9caa1ad1a..63d15e8f80e9 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -25,6 +25,8 @@
 #include <net/sock.h>
 #include <net/netprio_cgroup.h>
 
+#include <linux/fdtable.h>
+
 #define PRIOIDX_SZ 128
 
 static unsigned long prioidx_map[PRIOIDX_SZ];
@@ -272,6 +274,56 @@ out_free_devname:
 	return ret;
 }
 
+void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+{
+	struct task_struct *p;
+	char *tmp = kzalloc(sizeof(char) * PATH_MAX, GFP_KERNEL);
+
+	if (!tmp) {
+		pr_warn("Unable to attach cgrp due to alloc failure!\n");
+		return;
+	}
+
+	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;
+		}
+
+		rcu_read_lock();
+		fdt = files_fdtable(files);
+		for (fd = 0; fd < fdt->max_fds; fd++) {
+			char *path;
+			struct file *file;
+			struct socket *sock;
+			unsigned long s;
+			int rv, err = 0;
+
+			file = fcheck_files(files, fd);
+			if (!file)
+				continue;
+
+			path = d_path(&file->f_path, tmp, PAGE_SIZE);
+			rv = sscanf(path, "socket:[%lu]", &s);
+			if (rv <= 0)
+				continue;
+
+			sock = sock_from_file(file, &err);
+			if (!err)
+				sock_update_netprioidx(sock->sk, p);
+		}
+		rcu_read_unlock();
+		task_unlock(p);
+	}
+	kfree(tmp);
+}
+
 static struct cftype ss_files[] = {
 	{
 		.name = "prioidx",
@@ -289,6 +341,7 @@ struct cgroup_subsys net_prio_subsys = {
 	.name		= "net_prio",
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
+	.attach		= net_prio_attach,
 #ifdef CONFIG_NETPRIO_CGROUP
 	.subsys_id	= net_prio_subsys_id,
 #endif
diff --git a/net/core/sock.c b/net/core/sock.c
index 24039ac12426..2676a88f533e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1180,12 +1180,12 @@ void sock_update_classid(struct sock *sk)
 }
 EXPORT_SYMBOL(sock_update_classid);
 
-void sock_update_netprioidx(struct sock *sk)
+void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
 {
 	if (in_interrupt())
 		return;
 
-	sk->sk_cgrp_prioidx = task_netprioidx(current);
+	sk->sk_cgrp_prioidx = task_netprioidx(task);
 }
 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
 #endif
@@ -1215,7 +1215,7 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
 		atomic_set(&sk->sk_wmem_alloc, 1);
 
 		sock_update_classid(sk);
-		sock_update_netprioidx(sk);
+		sock_update_netprioidx(sk, current);
 	}
 
 	return sk;
diff --git a/net/socket.c b/net/socket.c
index 0452dca4cd24..dfe5b66c97e0 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -398,7 +398,7 @@ int sock_map_fd(struct socket *sock, int flags)
 }
 EXPORT_SYMBOL(sock_map_fd);
 
-static struct socket *sock_from_file(struct file *file, int *err)
+struct socket *sock_from_file(struct file *file, int *err)
 {
 	if (file->f_op == &socket_file_ops)
 		return file->private_data;	/* set in sock_map_fd */
@@ -406,6 +406,7 @@ static struct socket *sock_from_file(struct file *file, int *err)
 	*err = -ENOTSOCK;
 	return NULL;
 }
+EXPORT_SYMBOL(sock_from_file);
 
 /**
  *	sockfd_lookup - Go from a file number to its socket slot
@@ -554,8 +555,6 @@ static inline int __sock_sendmsg_nosec(struct kiocb *iocb, struct socket *sock,
 
 	sock_update_classid(sock->sk);
 
-	sock_update_netprioidx(sock->sk);
-
 	si->sock = sock;
 	si->scm = NULL;
 	si->msg = msg;