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 | |
| 32 | static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgrp) |
| 33 | { |
| 34 | return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id), |
| 35 | struct cgroup_netprio_state, css); |
| 36 | } |
| 37 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 38 | /* |
| 39 | * Extend @dev->priomap so that it's large enough to accomodate |
| 40 | * @target_idx. @dev->priomap.priomap_len > @target_idx after successful |
| 41 | * return. Must be called under rtnl lock. |
| 42 | */ |
| 43 | static int extend_netdev_table(struct net_device *dev, u32 target_idx) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 44 | { |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 45 | struct netprio_map *old, *new; |
| 46 | size_t new_sz, new_len; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 47 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 48 | /* is the existing priomap large enough? */ |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 49 | old = rtnl_dereference(dev->priomap); |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 50 | if (old && old->priomap_len > target_idx) |
| 51 | return 0; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 52 | |
Tejun Heo | 4a6ee25 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 53 | /* |
| 54 | * Determine the new size. Let's keep it power-of-two. We start |
| 55 | * from PRIOMAP_MIN_SZ and double it until it's large enough to |
| 56 | * accommodate @target_idx. |
| 57 | */ |
| 58 | new_sz = PRIOMAP_MIN_SZ; |
| 59 | while (true) { |
| 60 | new_len = (new_sz - offsetof(struct netprio_map, priomap)) / |
| 61 | sizeof(new->priomap[0]); |
| 62 | if (new_len > target_idx) |
| 63 | break; |
| 64 | new_sz *= 2; |
| 65 | /* overflowed? */ |
| 66 | if (WARN_ON(new_sz < PRIOMAP_MIN_SZ)) |
| 67 | return -ENOSPC; |
| 68 | } |
| 69 | |
| 70 | /* allocate & copy */ |
| 71 | new = kzalloc(new_sz, GFP_KERNEL); |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 72 | if (!new) { |
Joe Perches | e005d19 | 2012-05-16 19:58:40 +0000 | [diff] [blame] | 73 | pr_warn("Unable to alloc new priomap!\n"); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 74 | return -ENOMEM; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 75 | } |
| 76 | |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 77 | if (old) |
| 78 | memcpy(new->priomap, old->priomap, |
| 79 | old->priomap_len * sizeof(old->priomap[0])); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 80 | |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 81 | new->priomap_len = new_len; |
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 | /* install the new priomap */ |
Tejun Heo | 52bca93 | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 84 | rcu_assign_pointer(dev->priomap, new); |
| 85 | if (old) |
| 86 | kfree_rcu(old, rcu); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 87 | return 0; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 88 | } |
| 89 | |
Tejun Heo | 666b0eb | 2012-11-22 07:32:47 -0800 | [diff] [blame^] | 90 | /** |
| 91 | * netprio_prio - return the effective netprio of a cgroup-net_device pair |
| 92 | * @cgrp: cgroup part of the target pair |
| 93 | * @dev: net_device part of the target pair |
| 94 | * |
| 95 | * Should be called under RCU read or rtnl lock. |
| 96 | */ |
| 97 | static u32 netprio_prio(struct cgroup *cgrp, struct net_device *dev) |
| 98 | { |
| 99 | struct netprio_map *map = rcu_dereference_rtnl(dev->priomap); |
| 100 | |
| 101 | if (map && cgrp->id < map->priomap_len) |
| 102 | return map->priomap[cgrp->id]; |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * netprio_set_prio - set netprio on a cgroup-net_device pair |
| 108 | * @cgrp: cgroup part of the target pair |
| 109 | * @dev: net_device part of the target pair |
| 110 | * @prio: prio to set |
| 111 | * |
| 112 | * Set netprio to @prio on @cgrp-@dev pair. Should be called under rtnl |
| 113 | * lock and may fail under memory pressure for non-zero @prio. |
| 114 | */ |
| 115 | static int netprio_set_prio(struct cgroup *cgrp, struct net_device *dev, |
| 116 | u32 prio) |
| 117 | { |
| 118 | struct netprio_map *map; |
| 119 | int ret; |
| 120 | |
| 121 | /* avoid extending priomap for zero writes */ |
| 122 | map = rtnl_dereference(dev->priomap); |
| 123 | if (!prio && (!map || map->priomap_len <= cgrp->id)) |
| 124 | return 0; |
| 125 | |
| 126 | ret = extend_netdev_table(dev, cgrp->id); |
| 127 | if (ret) |
| 128 | return ret; |
| 129 | |
| 130 | map = rtnl_dereference(dev->priomap); |
| 131 | map->priomap[cgrp->id] = prio; |
| 132 | return 0; |
| 133 | } |
| 134 | |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 135 | static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 136 | { |
| 137 | struct cgroup_netprio_state *cs; |
Tejun Heo | 88d642f | 2012-11-22 07:32:47 -0800 | [diff] [blame] | 138 | |
| 139 | if (cgrp->parent && cgrp->parent->id) |
| 140 | return ERR_PTR(-EINVAL); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 141 | |
| 142 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
| 143 | if (!cs) |
| 144 | return ERR_PTR(-ENOMEM); |
| 145 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 146 | return &cs->css; |
| 147 | } |
| 148 | |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 149 | static void cgrp_css_free(struct cgroup *cgrp) |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 150 | { |
Tejun Heo | 88d642f | 2012-11-22 07:32:47 -0800 | [diff] [blame] | 151 | struct cgroup_netprio_state *cs = cgrp_netprio_state(cgrp); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 152 | struct net_device *dev; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 153 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 154 | rtnl_lock(); |
Tejun Heo | 666b0eb | 2012-11-22 07:32:47 -0800 | [diff] [blame^] | 155 | for_each_netdev(&init_net, dev) |
| 156 | WARN_ON_ONCE(netprio_set_prio(cgrp, dev, 0)); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 157 | rtnl_unlock(); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 158 | kfree(cs); |
| 159 | } |
| 160 | |
| 161 | static u64 read_prioidx(struct cgroup *cgrp, struct cftype *cft) |
| 162 | { |
Tejun Heo | 88d642f | 2012-11-22 07:32:47 -0800 | [diff] [blame] | 163 | return cgrp->id; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 164 | } |
| 165 | |
| 166 | static int read_priomap(struct cgroup *cont, struct cftype *cft, |
| 167 | struct cgroup_map_cb *cb) |
| 168 | { |
| 169 | struct net_device *dev; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 170 | |
| 171 | rcu_read_lock(); |
Tejun Heo | 666b0eb | 2012-11-22 07:32:47 -0800 | [diff] [blame^] | 172 | for_each_netdev_rcu(&init_net, dev) |
| 173 | cb->fill(cb, dev->name, netprio_prio(cont, dev)); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 174 | rcu_read_unlock(); |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | static int write_priomap(struct cgroup *cgrp, struct cftype *cft, |
| 179 | const char *buffer) |
| 180 | { |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 181 | char devname[IFNAMSIZ + 1]; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 182 | struct net_device *dev; |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 183 | u32 prio; |
| 184 | int ret; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 185 | |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 186 | if (sscanf(buffer, "%"__stringify(IFNAMSIZ)"s %u", devname, &prio) != 2) |
| 187 | return -EINVAL; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 188 | |
| 189 | dev = dev_get_by_name(&init_net, devname); |
| 190 | if (!dev) |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 191 | return -ENODEV; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 192 | |
John Fastabend | 476ad15 | 2012-08-14 12:34:35 +0000 | [diff] [blame] | 193 | rtnl_lock(); |
Tejun Heo | 6d5759d | 2012-11-22 07:32:46 -0800 | [diff] [blame] | 194 | |
Tejun Heo | 666b0eb | 2012-11-22 07:32:47 -0800 | [diff] [blame^] | 195 | ret = netprio_set_prio(cgrp, dev, prio); |
Gao feng | ef209f1 | 2012-07-11 21:50:15 +0000 | [diff] [blame] | 196 | |
John Fastabend | 476ad15 | 2012-08-14 12:34:35 +0000 | [diff] [blame] | 197 | rtnl_unlock(); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 198 | dev_put(dev); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 199 | return ret; |
| 200 | } |
| 201 | |
Al Viro | c3c073f | 2012-08-21 22:32:06 -0400 | [diff] [blame] | 202 | static int update_netprio(const void *v, struct file *file, unsigned n) |
| 203 | { |
| 204 | int err; |
| 205 | struct socket *sock = sock_from_file(file, &err); |
| 206 | if (sock) |
| 207 | sock->sk->sk_cgrp_prioidx = (u32)(unsigned long)v; |
| 208 | return 0; |
| 209 | } |
| 210 | |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 211 | void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) |
| 212 | { |
| 213 | struct task_struct *p; |
Al Viro | c3c073f | 2012-08-21 22:32:06 -0400 | [diff] [blame] | 214 | void *v; |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 215 | |
| 216 | cgroup_taskset_for_each(p, cgrp, tset) { |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 217 | task_lock(p); |
Al Viro | c3c073f | 2012-08-21 22:32:06 -0400 | [diff] [blame] | 218 | v = (void *)(unsigned long)task_netprioidx(p); |
| 219 | iterate_fd(p->files, 0, update_netprio, v); |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 220 | task_unlock(p); |
| 221 | } |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 222 | } |
| 223 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 224 | static struct cftype ss_files[] = { |
| 225 | { |
| 226 | .name = "prioidx", |
| 227 | .read_u64 = read_prioidx, |
| 228 | }, |
| 229 | { |
| 230 | .name = "ifpriomap", |
| 231 | .read_map = read_priomap, |
| 232 | .write_string = write_priomap, |
| 233 | }, |
Tejun Heo | 4baf6e3 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 234 | { } /* terminate */ |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 235 | }; |
| 236 | |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 237 | struct cgroup_subsys net_prio_subsys = { |
| 238 | .name = "net_prio", |
Tejun Heo | 92fb974 | 2012-11-19 08:13:38 -0800 | [diff] [blame] | 239 | .css_alloc = cgrp_css_alloc, |
| 240 | .css_free = cgrp_css_free, |
John Fastabend | 406a3c6 | 2012-07-20 10:39:25 +0000 | [diff] [blame] | 241 | .attach = net_prio_attach, |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 242 | .subsys_id = net_prio_subsys_id, |
Tejun Heo | 4baf6e3 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 243 | .base_cftypes = ss_files, |
Tejun Heo | 8c7f6ed | 2012-09-13 12:20:58 -0700 | [diff] [blame] | 244 | .module = THIS_MODULE, |
| 245 | |
| 246 | /* |
| 247 | * net_prio has artificial limit on the number of cgroups and |
| 248 | * disallows nesting making it impossible to co-mount it with other |
| 249 | * hierarchical subsystems. Remove the artificially low PRIOIDX_SZ |
| 250 | * limit and properly nest configuration such that children follow |
| 251 | * their parents' configurations by default and are allowed to |
| 252 | * override and remove the following. |
| 253 | */ |
| 254 | .broken_hierarchy = true, |
Tejun Heo | 676f7c8 | 2012-04-01 12:09:55 -0700 | [diff] [blame] | 255 | }; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 256 | |
| 257 | static int netprio_device_event(struct notifier_block *unused, |
| 258 | unsigned long event, void *ptr) |
| 259 | { |
| 260 | struct net_device *dev = ptr; |
| 261 | struct netprio_map *old; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 262 | |
| 263 | /* |
| 264 | * Note this is called with rtnl_lock held so we have update side |
| 265 | * protection on our rcu assignments |
| 266 | */ |
| 267 | |
| 268 | switch (event) { |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 269 | case NETDEV_UNREGISTER: |
| 270 | old = rtnl_dereference(dev->priomap); |
Eric Dumazet | 2cfa5a0 | 2011-11-23 07:09:32 +0000 | [diff] [blame] | 271 | RCU_INIT_POINTER(dev->priomap, NULL); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 272 | if (old) |
| 273 | kfree_rcu(old, rcu); |
| 274 | break; |
| 275 | } |
| 276 | return NOTIFY_DONE; |
| 277 | } |
| 278 | |
| 279 | static struct notifier_block netprio_device_notifier = { |
| 280 | .notifier_call = netprio_device_event |
| 281 | }; |
| 282 | |
| 283 | static int __init init_cgroup_netprio(void) |
| 284 | { |
| 285 | int ret; |
| 286 | |
| 287 | ret = cgroup_load_subsys(&net_prio_subsys); |
| 288 | if (ret) |
| 289 | goto out; |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 290 | |
| 291 | register_netdevice_notifier(&netprio_device_notifier); |
| 292 | |
| 293 | out: |
| 294 | return ret; |
| 295 | } |
| 296 | |
| 297 | static void __exit exit_cgroup_netprio(void) |
| 298 | { |
| 299 | struct netprio_map *old; |
| 300 | struct net_device *dev; |
| 301 | |
| 302 | unregister_netdevice_notifier(&netprio_device_notifier); |
| 303 | |
| 304 | cgroup_unload_subsys(&net_prio_subsys); |
| 305 | |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 306 | rtnl_lock(); |
| 307 | for_each_netdev(&init_net, dev) { |
| 308 | old = rtnl_dereference(dev->priomap); |
Eric Dumazet | 2cfa5a0 | 2011-11-23 07:09:32 +0000 | [diff] [blame] | 309 | RCU_INIT_POINTER(dev->priomap, NULL); |
Neil Horman | 5bc1421 | 2011-11-22 05:10:51 +0000 | [diff] [blame] | 310 | if (old) |
| 311 | kfree_rcu(old, rcu); |
| 312 | } |
| 313 | rtnl_unlock(); |
| 314 | } |
| 315 | |
| 316 | module_init(init_cgroup_netprio); |
| 317 | module_exit(exit_cgroup_netprio); |
| 318 | MODULE_LICENSE("GPL v2"); |