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Commit 88d642fa authored by Tejun Heo's avatar Tejun Heo
Browse files

netprio_cgroup: use cgroup->id instead of cgroup_netprio_state->prioidx 



With priomap expansion no longer depending on knowing max id
allocated, netprio_cgroup can use cgroup->id insted of cs->prioidx.
Drop prioidx alloc/free logic and convert all uses to cgroup->id.

* In cgrp_css_alloc(), parent->id test is moved above @cs allocation
  to simplify error path.

* In cgrp_css_free(), @cs assignment is made initialization.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Tested-and-Acked-by: default avatarDaniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4a6ee25c

include/net/netprio_cgroup.h

+4 −7
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ struct netprio_map { 


struct cgroup_netprio_state {

	struct cgroup_subsys_state css;

	u32 prioidx;

};



extern void sock_update_netprioidx(struct sock *sk, struct task_struct *task);
@@ -36,13 +35,12 @@ extern void sock_update_netprioidx(struct sock *sk, struct task_struct *task); 


static inline u32 task_netprioidx(struct task_struct *p)

{

	struct cgroup_netprio_state *state;

	struct cgroup_subsys_state *css;

	u32 idx;



	rcu_read_lock();

	state = container_of(task_subsys_state(p, net_prio_subsys_id),

			     struct cgroup_netprio_state, css);

	idx = state->prioidx;

	css = task_subsys_state(p, net_prio_subsys_id);

	idx = css->cgroup->id;

	rcu_read_unlock();

	return idx;

}
@@ -57,8 +55,7 @@ static inline u32 task_netprioidx(struct task_struct *p) 
	rcu_read_lock();

	css = task_subsys_state(p, net_prio_subsys_id);

	if (css)

		idx = container_of(css,

				   struct cgroup_netprio_state, css)->prioidx;

		idx = css->cgroup->id;

	rcu_read_unlock();

	return idx;

}

net/core/netprio_cgroup.c

+11 −54
Original line number Diff line number Diff line
@@ -28,10 +28,6 @@ 
#include <linux/fdtable.h>



#define PRIOMAP_MIN_SZ		128

#define PRIOIDX_SZ 128



static unsigned long prioidx_map[PRIOIDX_SZ];

static DEFINE_SPINLOCK(prioidx_map_lock);



static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgrp)

{
@@ -39,32 +35,6 @@ static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgr 
			    struct cgroup_netprio_state, css);

}



static int get_prioidx(u32 *prio)

{

	unsigned long flags;

	u32 prioidx;



	spin_lock_irqsave(&prioidx_map_lock, flags);

	prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ);

	if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) {

		spin_unlock_irqrestore(&prioidx_map_lock, flags);

		return -ENOSPC;

	}

	set_bit(prioidx, prioidx_map);

	spin_unlock_irqrestore(&prioidx_map_lock, flags);

	*prio = prioidx;

	return 0;

}



static void put_prioidx(u32 idx)

{

	unsigned long flags;



	spin_lock_irqsave(&prioidx_map_lock, flags);

	clear_bit(idx, prioidx_map);

	spin_unlock_irqrestore(&prioidx_map_lock, flags);

}



/*

 * Extend @dev->priomap so that it's large enough to accomodate

 * @target_idx.  @dev->priomap.priomap_len > @target_idx after successful
@@ -120,62 +90,50 @@ static int extend_netdev_table(struct net_device *dev, u32 target_idx) 
static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp)

{

	struct cgroup_netprio_state *cs;

	int ret = -EINVAL;



	if (cgrp->parent && cgrp->parent->id)

		return ERR_PTR(-EINVAL);



	cs = kzalloc(sizeof(*cs), GFP_KERNEL);

	if (!cs)

		return ERR_PTR(-ENOMEM);



	if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx)

		goto out;



	ret = get_prioidx(&cs->prioidx);

	if (ret < 0) {

		pr_warn("No space in priority index array\n");

		goto out;

	}



	return &cs->css;

out:

	kfree(cs);

	return ERR_PTR(ret);

}



static void cgrp_css_free(struct cgroup *cgrp)

{

	struct cgroup_netprio_state *cs;

	struct cgroup_netprio_state *cs = cgrp_netprio_state(cgrp);

	struct net_device *dev;

	struct netprio_map *map;



	cs = cgrp_netprio_state(cgrp);

	rtnl_lock();

	for_each_netdev(&init_net, dev) {

		map = rtnl_dereference(dev->priomap);

		if (map && cs->prioidx < map->priomap_len)

			map->priomap[cs->prioidx] = 0;

		if (map && cgrp->id < map->priomap_len)

			map->priomap[cgrp->id] = 0;

	}

	rtnl_unlock();

	put_prioidx(cs->prioidx);

	kfree(cs);

}



static u64 read_prioidx(struct cgroup *cgrp, struct cftype *cft)

{

	return (u64)cgrp_netprio_state(cgrp)->prioidx;

	return cgrp->id;

}



static int read_priomap(struct cgroup *cont, struct cftype *cft,

			struct cgroup_map_cb *cb)

{

	struct net_device *dev;

	u32 prioidx = cgrp_netprio_state(cont)->prioidx;

	u32 id = cont->id;

	u32 priority;

	struct netprio_map *map;



	rcu_read_lock();

	for_each_netdev_rcu(&init_net, dev) {

		map = rcu_dereference(dev->priomap);

		priority = (map && prioidx < map->priomap_len) ? map->priomap[prioidx] : 0;

		priority = (map && id < map->priomap_len) ? map->priomap[id] : 0;

		cb->fill(cb, dev->name, priority);

	}

	rcu_read_unlock();
@@ -185,7 +143,6 @@ static int read_priomap(struct cgroup *cont, struct cftype *cft, 
static int write_priomap(struct cgroup *cgrp, struct cftype *cft,

			 const char *buffer)

{

	u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;

	char devname[IFNAMSIZ + 1];

	struct net_device *dev;

	struct netprio_map *map;
@@ -201,13 +158,13 @@ static int write_priomap(struct cgroup *cgrp, struct cftype *cft, 


	rtnl_lock();



	ret = extend_netdev_table(dev, prioidx);

	ret = extend_netdev_table(dev, cgrp->id);

	if (ret)

		goto out_unlock;



	map = rtnl_dereference(dev->priomap);

	if (map)

		map->priomap[prioidx] = prio;

		map->priomap[cgrp->id] = prio;

out_unlock:

	rtnl_unlock();

	dev_put(dev);