Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 1 | /* |
| 2 | * net/core/netprio_cgroup.c Priority Control Group |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Neil Horman <nhorman@tuxdriver.com> |
| 10 | */ |
| 11 | |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 13 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 14 | #include <linux/module.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <linux/types.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/errno.h> |
| 19 | #include <linux/skbuff.h> |
| 20 | #include <linux/cgroup.h> |
| 21 | #include <linux/rcupdate.h> |
| 22 | #include <linux/atomic.h> |
| 23 | #include <net/rtnetlink.h> |
| 24 | #include <net/pkt_cls.h> |
| 25 | #include <net/sock.h> |
| 26 | #include <net/netprio_cgroup.h> |
| 27 | |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 28 | #include <linux/fdtable.h> |
| 29 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 30 | #define PRIOMAP_MIN_SZ 128 |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 31 | #define PRIOIDX_SZ 128 |
| 32 | |
| 33 | static unsigned long prioidx_map[PRIOIDX_SZ]; |
| 34 | static DEFINE_SPINLOCK(prioidx_map_lock); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 35 | |
| 36 | static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgrp) |
| 37 | { |
| 38 | return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id), |
| 39 | struct cgroup_netprio_state, css); |
| 40 | } |
| 41 | |
| 42 | static int get_prioidx(u32 *prio) |
| 43 | { |
| 44 | unsigned long flags; |
| 45 | u32 prioidx; |
| 46 | |
| 47 | spin_lock_irqsave(&prioidx_map_lock, flags); |
| 48 | prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ); |
Neil Horman | 5962b35 | 2012-02-03 05:18:43 +0000 | [diff] [blame] | 49 | if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) { |
| 50 | spin_unlock_irqrestore(&prioidx_map_lock, flags); |
| 51 | return -ENOSPC; |
| 52 | } |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 53 | set_bit(prioidx, prioidx_map); |
| 54 | spin_unlock_irqrestore(&prioidx_map_lock, flags); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 55 | *prio = prioidx; |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | static void put_prioidx(u32 idx) |
| 60 | { |
| 61 | unsigned long flags; |
| 62 | |
| 63 | spin_lock_irqsave(&prioidx_map_lock, flags); |
| 64 | clear_bit(idx, prioidx_map); |
| 65 | spin_unlock_irqrestore(&prioidx_map_lock, flags); |
| 66 | } |
| 67 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 68 | /* |
| 69 | * Extend @dev->priomap so that it's large enough to accomodate |
| 70 | * @target_idx. @dev->priomap.priomap_len > @target_idx after successful |
| 71 | * return. Must be called under rtnl lock. |
| 72 | */ |
| 73 | static int extend_netdev_table(struct net_device *dev, u32 target_idx) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 74 | { |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 75 | struct netprio_map *old, *new; |
| 76 | size_t new_sz, new_len; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 77 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 78 | /* is the existing priomap large enough? */ |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 79 | old = rtnl_dereference(dev->priomap); |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 80 | if (old && old->priomap_len > target_idx) |
| 81 | return 0; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 82 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 83 | /* |
| 84 | * Determine the new size. Let's keep it power-of-two. We start |
| 85 | * from PRIOMAP_MIN_SZ and double it until it's large enough to |
| 86 | * accommodate @target_idx. |
| 87 | */ |
| 88 | new_sz = PRIOMAP_MIN_SZ; |
| 89 | while (true) { |
| 90 | new_len = (new_sz - offsetof(struct netprio_map, priomap)) / |
| 91 | sizeof(new->priomap[0]); |
| 92 | if (new_len > target_idx) |
| 93 | break; |
| 94 | new_sz *= 2; |
| 95 | /* overflowed? */ |
| 96 | if (WARN_ON(new_sz < PRIOMAP_MIN_SZ)) |
| 97 | return -ENOSPC; |
| 98 | } |
| 99 | |
| 100 | /* allocate & copy */ |
| 101 | new = kzalloc(new_sz, GFP_KERNEL); |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 102 | if (!new) { |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 103 | pr_warn("Unable to alloc new priomap!\n"); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 104 | return -ENOMEM; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 105 | } |
| 106 | |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 107 | if (old) |
| 108 | memcpy(new->priomap, old->priomap, |
| 109 | old->priomap_len * sizeof(old->priomap[0])); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 110 | |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 111 | new->priomap_len = new_len; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 112 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 113 | /* install the new priomap */ |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 114 | rcu_assign_pointer(dev->priomap, new); |
| 115 | if (old) |
| 116 | kfree_rcu(old, rcu); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 117 | return 0; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 118 | } |
| 119 | |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 120 | static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 121 | { |
| 122 | struct cgroup_netprio_state *cs; |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 123 | int ret = -EINVAL; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 124 | |
| 125 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
| 126 | if (!cs) |
| 127 | return ERR_PTR(-ENOMEM); |
| 128 | |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 129 | if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) |
| 130 | goto out; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 131 | |
| 132 | ret = get_prioidx(&cs->prioidx); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 133 | if (ret < 0) { |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 134 | pr_warn("No space in priority index array\n"); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 135 | goto out; |
| 136 | } |
| 137 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 138 | return &cs->css; |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 139 | out: |
| 140 | kfree(cs); |
| 141 | return ERR_PTR(ret); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 142 | } |
| 143 | |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 144 | static void cgrp_css_free(struct cgroup *cgrp) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 145 | { |
| 146 | struct cgroup_netprio_state *cs; |
| 147 | struct net_device *dev; |
| 148 | struct netprio_map *map; |
| 149 | |
| 150 | cs = cgrp_netprio_state(cgrp); |
| 151 | rtnl_lock(); |
| 152 | for_each_netdev(&init_net, dev) { |
| 153 | map = rtnl_dereference(dev->priomap); |
Eric Dumazet | 91c68ce | 2012-07-08 21:45:10 +0000 | [diff] [blame] | 154 | if (map && cs->prioidx < map->priomap_len) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 155 | map->priomap[cs->prioidx] = 0; |
| 156 | } |
| 157 | rtnl_unlock(); |
| 158 | put_prioidx(cs->prioidx); |
| 159 | kfree(cs); |
| 160 | } |
| 161 | |
| 162 | static u64 read_prioidx(struct cgroup *cgrp, struct cftype *cft) |
| 163 | { |
| 164 | return (u64)cgrp_netprio_state(cgrp)->prioidx; |
| 165 | } |
| 166 | |
| 167 | static int read_priomap(struct cgroup *cont, struct cftype *cft, |
| 168 | struct cgroup_map_cb *cb) |
| 169 | { |
| 170 | struct net_device *dev; |
| 171 | u32 prioidx = cgrp_netprio_state(cont)->prioidx; |
| 172 | u32 priority; |
| 173 | struct netprio_map *map; |
| 174 | |
| 175 | rcu_read_lock(); |
| 176 | for_each_netdev_rcu(&init_net, dev) { |
| 177 | map = rcu_dereference(dev->priomap); |
Eric Dumazet | 91c68ce | 2012-07-08 21:45:10 +0000 | [diff] [blame] | 178 | priority = (map && prioidx < map->priomap_len) ? map->priomap[prioidx] : 0; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 179 | cb->fill(cb, dev->name, priority); |
| 180 | } |
| 181 | rcu_read_unlock(); |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | static int write_priomap(struct cgroup *cgrp, struct cftype *cft, |
| 186 | const char *buffer) |
| 187 | { |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 188 | u32 prioidx = cgrp_netprio_state(cgrp)->prioidx; |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 189 | char devname[IFNAMSIZ + 1]; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 190 | struct net_device *dev; |
| 191 | struct netprio_map *map; |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 192 | u32 prio; |
| 193 | int ret; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 194 | |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 195 | if (sscanf(buffer, "%"__stringify(IFNAMSIZ)"s %u", devname, &prio) != 2) |
| 196 | return -EINVAL; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 197 | |
| 198 | dev = dev_get_by_name(&init_net, devname); |
| 199 | if (!dev) |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 200 | return -ENODEV; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 201 | |
John Fastabend | 476ad15 | 2012-08-14 12:34:35 +0000 | [diff] [blame] | 202 | rtnl_lock(); |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 203 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame^] | 204 | ret = extend_netdev_table(dev, prioidx); |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 205 | if (ret) |
| 206 | goto out_unlock; |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 207 | |
John Fastabend | 476ad15 | 2012-08-14 12:34:35 +0000 | [diff] [blame] | 208 | map = rtnl_dereference(dev->priomap); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 209 | if (map) |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 210 | map->priomap[prioidx] = prio; |
| 211 | out_unlock: |
John Fastabend | 476ad15 | 2012-08-14 12:34:35 +0000 | [diff] [blame] | 212 | rtnl_unlock(); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 213 | dev_put(dev); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 214 | return ret; |
| 215 | } |
| 216 | |
Al Viro | c3c073f | 2012-08-21 22:32:06 -0400 | [diff] [blame] | 217 | static int update_netprio(const void *v, struct file *file, unsigned n) |
| 218 | { |
| 219 | int err; |
| 220 | struct socket *sock = sock_from_file(file, &err); |
| 221 | if (sock) |
| 222 | sock->sk->sk_cgrp_prioidx = (u32)(unsigned long)v; |
| 223 | return 0; |
| 224 | } |
| 225 | |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 226 | void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) |
| 227 | { |
| 228 | struct task_struct *p; |
Al Viro | c3c073f | 2012-08-21 22:32:06 -0400 | [diff] [blame] | 229 | void *v; |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 230 | |
| 231 | cgroup_taskset_for_each(p, cgrp, tset) { |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 232 | task_lock(p); |
Al Viro | c3c073f | 2012-08-21 22:32:06 -0400 | [diff] [blame] | 233 | v = (void *)(unsigned long)task_netprioidx(p); |
| 234 | iterate_fd(p->files, 0, update_netprio, v); |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 235 | task_unlock(p); |
| 236 | } |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 237 | } |
| 238 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 239 | static struct cftype ss_files[] = { |
| 240 | { |
| 241 | .name = "prioidx", |
| 242 | .read_u64 = read_prioidx, |
| 243 | }, |
| 244 | { |
| 245 | .name = "ifpriomap", |
| 246 | .read_map = read_priomap, |
| 247 | .write_string = write_priomap, |
| 248 | }, |
Tejun Heo | 4baf6e3 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 249 | { } /* terminate */ |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 250 | }; |
| 251 | |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 252 | struct cgroup_subsys net_prio_subsys = { |
| 253 | .name = "net_prio", |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 254 | .css_alloc = cgrp_css_alloc, |
| 255 | .css_free = cgrp_css_free, |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 256 | .attach = net_prio_attach, |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 257 | .subsys_id = net_prio_subsys_id, |
Tejun Heo | 4baf6e3 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 258 | .base_cftypes = ss_files, |
Tejun Heo | 8c7f6ed | 2012-09-13 12:20:58 -0700 | [diff] [blame] | 259 | .module = THIS_MODULE, |
| 260 | |
| 261 | /* |
| 262 | * net_prio has artificial limit on the number of cgroups and |
| 263 | * disallows nesting making it impossible to co-mount it with other |
| 264 | * hierarchical subsystems. Remove the artificially low PRIOIDX_SZ |
| 265 | * limit and properly nest configuration such that children follow |
| 266 | * their parents' configurations by default and are allowed to |
| 267 | * override and remove the following. |
| 268 | */ |
| 269 | .broken_hierarchy = true, |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 270 | }; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 271 | |
| 272 | static int netprio_device_event(struct notifier_block *unused, |
| 273 | unsigned long event, void *ptr) |
| 274 | { |
| 275 | struct net_device *dev = ptr; |
| 276 | struct netprio_map *old; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 277 | |
| 278 | /* |
| 279 | * Note this is called with rtnl_lock held so we have update side |
| 280 | * protection on our rcu assignments |
| 281 | */ |
| 282 | |
| 283 | switch (event) { |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 284 | case NETDEV_UNREGISTER: |
| 285 | old = rtnl_dereference(dev->priomap); |
Eric Dumazet | 2cfa5a0 | 2011-11-23 07:09:32 +0000 | [diff] [blame] | 286 | RCU_INIT_POINTER(dev->priomap, NULL); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 287 | if (old) |
| 288 | kfree_rcu(old, rcu); |
| 289 | break; |
| 290 | } |
| 291 | return NOTIFY_DONE; |
| 292 | } |
| 293 | |
| 294 | static struct notifier_block netprio_device_notifier = { |
| 295 | .notifier_call = netprio_device_event |
| 296 | }; |
| 297 | |
| 298 | static int __init init_cgroup_netprio(void) |
| 299 | { |
| 300 | int ret; |
| 301 | |
| 302 | ret = cgroup_load_subsys(&net_prio_subsys); |
| 303 | if (ret) |
| 304 | goto out; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 305 | |
| 306 | register_netdevice_notifier(&netprio_device_notifier); |
| 307 | |
| 308 | out: |
| 309 | return ret; |
| 310 | } |
| 311 | |
| 312 | static void __exit exit_cgroup_netprio(void) |
| 313 | { |
| 314 | struct netprio_map *old; |
| 315 | struct net_device *dev; |
| 316 | |
| 317 | unregister_netdevice_notifier(&netprio_device_notifier); |
| 318 | |
| 319 | cgroup_unload_subsys(&net_prio_subsys); |
| 320 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 321 | rtnl_lock(); |
| 322 | for_each_netdev(&init_net, dev) { |
| 323 | old = rtnl_dereference(dev->priomap); |
Eric Dumazet | 2cfa5a0 | 2011-11-23 07:09:32 +0000 | [diff] [blame] | 324 | RCU_INIT_POINTER(dev->priomap, NULL); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 325 | if (old) |
| 326 | kfree_rcu(old, rcu); |
| 327 | } |
| 328 | rtnl_unlock(); |
| 329 | } |
| 330 | |
| 331 | module_init(init_cgroup_netprio); |
| 332 | module_exit(exit_cgroup_netprio); |
| 333 | MODULE_LICENSE("GPL v2"); |