![Linus Torvalds](/assets/img/avatar_default.png)
Pull cgroup updates from Tejun Heo: "cgroup file type addition / removal is updated so that file types are added and removed instead of individual files so that dynamic file type addition / removal can be implemented by cgroup and used by controllers. blkio controller changes which will come through block tree are dependent on this. Other changes include res_counter cleanup and disallowing kthread / PF_THREAD_BOUND threads to be attached to non-root cgroups. There's a reported bug with the file type addition / removal handling which can lead to oops on cgroup umount. The issue is being looked into. It shouldn't cause problems for most setups and isn't a security concern." Fix up trivial conflict in Documentation/feature-removal-schedule.txt * 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) res_counter: Account max_usage when calling res_counter_charge_nofail() res_counter: Merge res_counter_charge and res_counter_charge_nofail cgroups: disallow attaching kthreadd or PF_THREAD_BOUND threads cgroup: remove cgroup_subsys->populate() cgroup: get rid of populate for memcg cgroup: pass struct mem_cgroup instead of struct cgroup to socket memcg cgroup: make css->refcnt clearing on cgroup removal optional cgroup: use negative bias on css->refcnt to block css_tryget() cgroup: implement cgroup_rm_cftypes() cgroup: introduce struct cfent cgroup: relocate __d_cgrp() and __d_cft() cgroup: remove cgroup_add_file[s]() cgroup: convert memcg controller to the new cftype interface memcg: always create memsw files if CONFIG_CGROUP_MEM_RES_CTLR_SWAP cgroup: convert all non-memcg controllers to the new cftype interface cgroup: relocate cftype and cgroup_subsys definitions in controllers cgroup: merge cft_release_agent cftype array into the base files array cgroup: implement cgroup_add_cftypes() and friends cgroup: build list of all cgroups under a given cgroupfs_root cgroup: move cgroup_clear_directory() call out of cgroup_populate_dir() ...
332 lines
7.1 KiB
C
332 lines
7.1 KiB
C
/*
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* net/core/netprio_cgroup.c Priority Control Group
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Neil Horman <nhorman@tuxdriver.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <linux/cgroup.h>
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#include <linux/rcupdate.h>
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#include <linux/atomic.h>
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#include <net/rtnetlink.h>
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#include <net/pkt_cls.h>
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#include <net/sock.h>
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#include <net/netprio_cgroup.h>
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#define PRIOIDX_SZ 128
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static unsigned long prioidx_map[PRIOIDX_SZ];
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static DEFINE_SPINLOCK(prioidx_map_lock);
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static atomic_t max_prioidx = ATOMIC_INIT(0);
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static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgrp)
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{
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return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id),
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struct cgroup_netprio_state, css);
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}
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static int get_prioidx(u32 *prio)
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{
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unsigned long flags;
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u32 prioidx;
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spin_lock_irqsave(&prioidx_map_lock, flags);
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prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ);
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if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) {
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spin_unlock_irqrestore(&prioidx_map_lock, flags);
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return -ENOSPC;
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}
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set_bit(prioidx, prioidx_map);
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spin_unlock_irqrestore(&prioidx_map_lock, flags);
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atomic_set(&max_prioidx, prioidx);
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*prio = prioidx;
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return 0;
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}
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static void put_prioidx(u32 idx)
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{
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unsigned long flags;
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spin_lock_irqsave(&prioidx_map_lock, flags);
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clear_bit(idx, prioidx_map);
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spin_unlock_irqrestore(&prioidx_map_lock, flags);
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}
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static void extend_netdev_table(struct net_device *dev, u32 new_len)
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{
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size_t new_size = sizeof(struct netprio_map) +
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((sizeof(u32) * new_len));
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struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
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struct netprio_map *old_priomap;
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int i;
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old_priomap = rtnl_dereference(dev->priomap);
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if (!new_priomap) {
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pr_warn("Unable to alloc new priomap!\n");
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return;
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}
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for (i = 0;
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old_priomap && (i < old_priomap->priomap_len);
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i++)
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new_priomap->priomap[i] = old_priomap->priomap[i];
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new_priomap->priomap_len = new_len;
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rcu_assign_pointer(dev->priomap, new_priomap);
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if (old_priomap)
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kfree_rcu(old_priomap, rcu);
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}
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static void update_netdev_tables(void)
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{
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struct net_device *dev;
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u32 max_len = atomic_read(&max_prioidx) + 1;
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struct netprio_map *map;
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rtnl_lock();
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for_each_netdev(&init_net, dev) {
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map = rtnl_dereference(dev->priomap);
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if ((!map) ||
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(map->priomap_len < max_len))
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extend_netdev_table(dev, max_len);
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}
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rtnl_unlock();
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}
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static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
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{
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struct cgroup_netprio_state *cs;
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int ret;
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cs = kzalloc(sizeof(*cs), GFP_KERNEL);
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if (!cs)
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return ERR_PTR(-ENOMEM);
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if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) {
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kfree(cs);
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return ERR_PTR(-EINVAL);
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}
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ret = get_prioidx(&cs->prioidx);
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if (ret != 0) {
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pr_warn("No space in priority index array\n");
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kfree(cs);
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return ERR_PTR(ret);
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}
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return &cs->css;
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}
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static void cgrp_destroy(struct cgroup *cgrp)
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{
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struct cgroup_netprio_state *cs;
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struct net_device *dev;
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struct netprio_map *map;
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cs = cgrp_netprio_state(cgrp);
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rtnl_lock();
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for_each_netdev(&init_net, dev) {
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map = rtnl_dereference(dev->priomap);
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if (map)
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map->priomap[cs->prioidx] = 0;
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}
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rtnl_unlock();
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put_prioidx(cs->prioidx);
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kfree(cs);
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}
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static u64 read_prioidx(struct cgroup *cgrp, struct cftype *cft)
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{
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return (u64)cgrp_netprio_state(cgrp)->prioidx;
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}
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static int read_priomap(struct cgroup *cont, struct cftype *cft,
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struct cgroup_map_cb *cb)
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{
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struct net_device *dev;
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u32 prioidx = cgrp_netprio_state(cont)->prioidx;
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u32 priority;
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struct netprio_map *map;
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rcu_read_lock();
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for_each_netdev_rcu(&init_net, dev) {
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map = rcu_dereference(dev->priomap);
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priority = map ? map->priomap[prioidx] : 0;
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cb->fill(cb, dev->name, priority);
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}
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rcu_read_unlock();
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return 0;
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}
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static int write_priomap(struct cgroup *cgrp, struct cftype *cft,
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const char *buffer)
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{
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char *devname = kstrdup(buffer, GFP_KERNEL);
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int ret = -EINVAL;
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u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
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unsigned long priority;
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char *priostr;
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struct net_device *dev;
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struct netprio_map *map;
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if (!devname)
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return -ENOMEM;
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/*
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* Minimally sized valid priomap string
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*/
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if (strlen(devname) < 3)
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goto out_free_devname;
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priostr = strstr(devname, " ");
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if (!priostr)
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goto out_free_devname;
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/*
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*Separate the devname from the associated priority
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*and advance the priostr poitner to the priority value
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*/
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*priostr = '\0';
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priostr++;
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/*
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* If the priostr points to NULL, we're at the end of the passed
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* in string, and its not a valid write
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*/
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if (*priostr == '\0')
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goto out_free_devname;
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ret = kstrtoul(priostr, 10, &priority);
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if (ret < 0)
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goto out_free_devname;
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ret = -ENODEV;
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dev = dev_get_by_name(&init_net, devname);
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if (!dev)
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goto out_free_devname;
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update_netdev_tables();
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ret = 0;
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rcu_read_lock();
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map = rcu_dereference(dev->priomap);
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if (map)
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map->priomap[prioidx] = priority;
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rcu_read_unlock();
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dev_put(dev);
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out_free_devname:
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kfree(devname);
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return ret;
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}
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static struct cftype ss_files[] = {
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{
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.name = "prioidx",
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.read_u64 = read_prioidx,
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},
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{
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.name = "ifpriomap",
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.read_map = read_priomap,
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.write_string = write_priomap,
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},
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{ } /* terminate */
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};
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struct cgroup_subsys net_prio_subsys = {
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.name = "net_prio",
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.create = cgrp_create,
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.destroy = cgrp_destroy,
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#ifdef CONFIG_NETPRIO_CGROUP
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.subsys_id = net_prio_subsys_id,
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#endif
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.base_cftypes = ss_files,
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.module = THIS_MODULE
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};
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static int netprio_device_event(struct notifier_block *unused,
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unsigned long event, void *ptr)
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{
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struct net_device *dev = ptr;
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struct netprio_map *old;
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/*
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* Note this is called with rtnl_lock held so we have update side
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* protection on our rcu assignments
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*/
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switch (event) {
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case NETDEV_UNREGISTER:
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old = rtnl_dereference(dev->priomap);
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RCU_INIT_POINTER(dev->priomap, NULL);
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if (old)
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kfree_rcu(old, rcu);
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break;
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}
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return NOTIFY_DONE;
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}
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static struct notifier_block netprio_device_notifier = {
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.notifier_call = netprio_device_event
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};
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static int __init init_cgroup_netprio(void)
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{
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int ret;
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ret = cgroup_load_subsys(&net_prio_subsys);
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if (ret)
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goto out;
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#ifndef CONFIG_NETPRIO_CGROUP
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smp_wmb();
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net_prio_subsys_id = net_prio_subsys.subsys_id;
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#endif
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register_netdevice_notifier(&netprio_device_notifier);
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out:
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return ret;
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}
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static void __exit exit_cgroup_netprio(void)
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{
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struct netprio_map *old;
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struct net_device *dev;
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unregister_netdevice_notifier(&netprio_device_notifier);
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cgroup_unload_subsys(&net_prio_subsys);
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#ifndef CONFIG_NETPRIO_CGROUP
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net_prio_subsys_id = -1;
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synchronize_rcu();
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#endif
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rtnl_lock();
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for_each_netdev(&init_net, dev) {
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old = rtnl_dereference(dev->priomap);
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RCU_INIT_POINTER(dev->priomap, NULL);
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if (old)
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kfree_rcu(old, rcu);
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}
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rtnl_unlock();
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}
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module_init(init_cgroup_netprio);
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module_exit(exit_cgroup_netprio);
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MODULE_LICENSE("GPL v2");
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