diff mbox

[3/4] net: use cgroup_attach method to migrate socket priotiy and classid

Message ID 1324478390-22036-4-git-send-email-nhorman@tuxdriver.com
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Neil Horman Dec. 21, 2011, 2:39 p.m. UTC 
Now that we have an owner identified for each socket, we can use the
cgroup_attach method to migrate sockets owned by migrating tasks to their new
cgroup instances.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Thomas Graf <tgraf@infradead.org>
CC: "David S. Miller" <davem@davemloft.net>
---
 net/core/netprio_cgroup.c |   40 +++++++++++++++++++++++++++++++++++++++-
 net/sched/cls_cgroup.c    |   39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 1 deletions(-)

Comments

Al Viro Dec. 21, 2011, 3:40 p.m. UTC | #1 
On Wed, Dec 21, 2011 at 09:39:49AM -0500, Neil Horman wrote:
> +static void cgrp_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
> +			struct cgroup *old_cgrp, struct task_struct *tsk)
> +{
> +	int fd, err;
> +	struct files_struct *files;
> +	struct file *file;
> +	struct socket *sock;
> +	struct cgroup_netprio_state *old, *new;
> +	pid_t task_pid;
> + 
> +	files = get_files_struct(tsk);
> +	task_pid = task_pid_nr(tsk);
> + 
> +	old = cgrp_netprio_state(old_cgrp);
> +	new = cgrp_netprio_state(cgrp);
> + 
> +	spin_lock(&files->file_lock);
> +	for (fd=0; fd < files_fdtable(files)->max_fds; fd++) {
> +		file = fcheck_files(files, fd);
> +		if (!file)
> +			continue;
> +		sock = sock_from_file(file, &err);
> +		if (!sock)
> +			continue;
> +		if (!sock->sk)
> +			continue;
> +		if (sock->sk->sk_cgrp_owner == task_pid)
> +			sock->sk->sk_cgrp_prioidx = new->prioidx;

This looks bogus *and* racy; what about e.g. files currently in SCM_RIGHTS
datagrams?
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diff mbox

Patch

diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 3a9fd48..32eef0f 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -18,6 +18,7 @@ 
 #include <linux/cgroup.h>
 #include <linux/rcupdate.h>
 #include <linux/atomic.h>
+#include <linux/fdtable.h>
 #include <net/rtnetlink.h>
 #include <net/pkt_cls.h>
 #include <net/sock.h>
@@ -27,12 +28,14 @@  static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
 					       struct cgroup *cgrp);
 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
-
+static void cgrp_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+			struct cgroup *old_cgrp, struct task_struct *tsk);
 struct cgroup_subsys net_prio_subsys = {
 	.name		= "net_prio",
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.populate	= cgrp_populate,
+	.attach		= cgrp_attach,
 #ifdef CONFIG_NETPRIO_CGROUP
 	.subsys_id	= net_prio_subsys_id,
 #endif
@@ -265,6 +268,41 @@  static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
 	return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
 }
 
+static void cgrp_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+			struct cgroup *old_cgrp, struct task_struct *tsk)
+{
+	int fd, err;
+	struct files_struct *files;
+	struct file *file;
+	struct socket *sock;
+	struct cgroup_netprio_state *old, *new;
+	pid_t task_pid;
+ 
+	files = get_files_struct(tsk);
+	task_pid = task_pid_nr(tsk);
+ 
+	old = cgrp_netprio_state(old_cgrp);
+	new = cgrp_netprio_state(cgrp);
+ 
+	spin_lock(&files->file_lock);
+	for (fd=0; fd < files_fdtable(files)->max_fds; fd++) {
+		file = fcheck_files(files, fd);
+		if (!file)
+			continue;
+		sock = sock_from_file(file, &err);
+		if (!sock)
+			continue;
+		if (!sock->sk)
+			continue;
+		if (sock->sk->sk_cgrp_owner == task_pid)
+			sock->sk->sk_cgrp_prioidx = new->prioidx;
+	}
+	spin_unlock(&files->file_lock);
+ 
+	put_files_struct(files);
+}
+ 
+
 static int netprio_device_event(struct notifier_block *unused,
 				unsigned long event, void *ptr)
 {
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index f84fdc3..7020cda 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -17,6 +17,7 @@ 
 #include <linux/skbuff.h>
 #include <linux/cgroup.h>
 #include <linux/rcupdate.h>
+#include <linux/fdtable.h>
 #include <net/rtnetlink.h>
 #include <net/pkt_cls.h>
 #include <net/sock.h>
@@ -26,12 +27,15 @@  static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
 					       struct cgroup *cgrp);
 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
+static void cgrp_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+			struct cgroup *old_cgrp, struct task_struct *tsk);
 
 struct cgroup_subsys net_cls_subsys = {
 	.name		= "net_cls",
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.populate	= cgrp_populate,
+	.attach		= cgrp_attach,
 #ifdef CONFIG_NET_CLS_CGROUP
 	.subsys_id	= net_cls_subsys_id,
 #endif
@@ -95,6 +99,41 @@  static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
 	return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
 }
 
+static void cgrp_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+			struct cgroup *old_cgrp, struct task_struct *tsk)
+{
+	int fd, err;
+	struct files_struct *files;
+	struct file *file;
+	struct socket *sock;
+	struct cgroup_cls_state *old, *new;
+	pid_t task_pid;
+ 
+	files = get_files_struct(tsk);
+	task_pid = task_pid_nr(tsk);
+ 
+	old = cgrp_cls_state(old_cgrp);
+	new = cgrp_cls_state(cgrp);
+ 
+	spin_lock(&files->file_lock);
+	for (fd=0; fd < files_fdtable(files)->max_fds; fd++) {
+		file = fcheck_files(files, fd);
+		if (!file)
+			continue;
+		sock = sock_from_file(file, &err);
+		if (!sock)
+			continue;
+		if (!sock->sk)
+			continue;
+		if (sock->sk->sk_cgrp_owner == task_pid)
+			sock->sk->sk_classid = new->classid;
+	}
+	spin_unlock(&files->file_lock);
+ 
+	put_files_struct(files);
+}
+ 
+
 struct cls_cgroup_head {
 	u32			handle;
 	struct tcf_exts		exts;