netprio_cgroup: implement netprio[_set]_prio() helpers (666b0ebe) · Commits · 戴 / test

net/core/netprio_cgroup.c

+50 −22

Original line number	Diff line number	Diff line
		@@ -87,6 +87,51 @@ static int extend_netdev_table(struct net_device *dev, u32 target_idx)
		return 0;
		}

		/**
		* netprio_prio - return the effective netprio of a cgroup-net_device pair
		* @cgrp: cgroup part of the target pair
		* @dev: net_device part of the target pair
		*
		* Should be called under RCU read or rtnl lock.
		*/
		static u32 netprio_prio(struct cgroup cgrp, struct net_device dev)
		{
		struct netprio_map *map = rcu_dereference_rtnl(dev->priomap);

		if (map && cgrp->id < map->priomap_len)
		return map->priomap[cgrp->id];
		return 0;
		}

		/**
		* netprio_set_prio - set netprio on a cgroup-net_device pair
		* @cgrp: cgroup part of the target pair
		* @dev: net_device part of the target pair
		* @prio: prio to set
		*
		* Set netprio to @prio on @cgrp-@dev pair. Should be called under rtnl
		* lock and may fail under memory pressure for non-zero @prio.
		*/
		static int netprio_set_prio(struct cgroup cgrp, struct net_device dev,
		u32 prio)
		{
		struct netprio_map *map;
		int ret;

		/* avoid extending priomap for zero writes */
		map = rtnl_dereference(dev->priomap);
		if (!prio && (!map \|\| map->priomap_len <= cgrp->id))
		return 0;

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

		map = rtnl_dereference(dev->priomap);
		map->priomap[cgrp->id] = prio;
		return 0;
		}

		static struct cgroup_subsys_state cgrp_css_alloc(struct cgroup cgrp)
		{
		struct cgroup_netprio_state *cs;
		@@ -105,14 +150,10 @@ static void cgrp_css_free(struct cgroup *cgrp)
		{
		struct cgroup_netprio_state *cs = cgrp_netprio_state(cgrp);
		struct net_device *dev;
		struct netprio_map *map;

		rtnl_lock();
		for_each_netdev(&init_net, dev) {
		map = rtnl_dereference(dev->priomap);
		if (map && cgrp->id < map->priomap_len)
		map->priomap[cgrp->id] = 0;
		}
		for_each_netdev(&init_net, dev)
		WARN_ON_ONCE(netprio_set_prio(cgrp, dev, 0));
		rtnl_unlock();
		kfree(cs);
		}
		@@ -126,16 +167,10 @@ static int read_priomap(struct cgroup cont, struct cftype cft,
		struct cgroup_map_cb *cb)
		{
		struct net_device *dev;
		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 && id < map->priomap_len) ? map->priomap[id] : 0;
		cb->fill(cb, dev->name, priority);
		}
		for_each_netdev_rcu(&init_net, dev)
		cb->fill(cb, dev->name, netprio_prio(cont, dev));
		rcu_read_unlock();
		return 0;
		}
		@@ -145,7 +180,6 @@ static int write_priomap(struct cgroup cgrp, struct cftype cft,
		{
		char devname[IFNAMSIZ + 1];
		struct net_device *dev;
		struct netprio_map *map;
		u32 prio;
		int ret;

		@@ -158,14 +192,8 @@ static int write_priomap(struct cgroup cgrp, struct cftype cft,

		rtnl_lock();

		ret = extend_netdev_table(dev, cgrp->id);
		if (ret)
		goto out_unlock;
		ret = netprio_set_prio(cgrp, dev, prio);

		map = rtnl_dereference(dev->priomap);
		if (map)
		map->priomap[cgrp->id] = prio;
		out_unlock:
		rtnl_unlock();
		dev_put(dev);
		return ret;

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