Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Common Block IO controller cgroup interface |
| 3 | * |
| 4 | * Based on ideas and code from CFQ, CFS and BFQ: |
| 5 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
| 6 | * |
| 7 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> |
| 8 | * Paolo Valente <paolo.valente@unimore.it> |
| 9 | * |
| 10 | * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> |
| 11 | * Nauman Rafique <nauman@google.com> |
| 12 | */ |
| 13 | #include <linux/ioprio.h> |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 14 | #include <linux/seq_file.h> |
| 15 | #include <linux/kdev_t.h> |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 16 | #include <linux/module.h> |
Stephen Rothwell | accee78 | 2009-12-07 19:29:39 +1100 | [diff] [blame] | 17 | #include <linux/err.h> |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 18 | #include <linux/blkdev.h> |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 19 | #include "blk-cgroup.h" |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 20 | |
| 21 | static DEFINE_SPINLOCK(blkio_list_lock); |
| 22 | static LIST_HEAD(blkio_list); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 23 | |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 24 | struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 25 | EXPORT_SYMBOL_GPL(blkio_root_cgroup); |
| 26 | |
Ben Blum | 67523c4 | 2010-03-10 15:22:11 -0800 | [diff] [blame] | 27 | static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *, |
| 28 | struct cgroup *); |
| 29 | static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, |
| 30 | struct task_struct *, bool); |
| 31 | static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, |
| 32 | struct cgroup *, struct task_struct *, bool); |
| 33 | static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); |
| 34 | static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); |
| 35 | |
| 36 | struct cgroup_subsys blkio_subsys = { |
| 37 | .name = "blkio", |
| 38 | .create = blkiocg_create, |
| 39 | .can_attach = blkiocg_can_attach, |
| 40 | .attach = blkiocg_attach, |
| 41 | .destroy = blkiocg_destroy, |
| 42 | .populate = blkiocg_populate, |
| 43 | #ifdef CONFIG_BLK_CGROUP |
| 44 | /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */ |
| 45 | .subsys_id = blkio_subsys_id, |
| 46 | #endif |
| 47 | .use_id = 1, |
| 48 | .module = THIS_MODULE, |
| 49 | }; |
| 50 | EXPORT_SYMBOL_GPL(blkio_subsys); |
| 51 | |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 52 | struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) |
| 53 | { |
| 54 | return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), |
| 55 | struct blkio_cgroup, css); |
| 56 | } |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 57 | EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 58 | |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 59 | /* |
| 60 | * Add to the appropriate stat variable depending on the request type. |
| 61 | * This should be called with the blkg->stats_lock held. |
| 62 | */ |
| 63 | void io_add_stat(uint64_t *stat, uint64_t add, unsigned int flags) |
| 64 | { |
| 65 | if (flags & REQ_RW) |
| 66 | stat[IO_WRITE] += add; |
| 67 | else |
| 68 | stat[IO_READ] += add; |
| 69 | /* |
| 70 | * Everywhere in the block layer, an IO is treated as sync if it is a |
| 71 | * read or a SYNC write. We follow the same norm. |
| 72 | */ |
| 73 | if (!(flags & REQ_RW) || flags & REQ_RW_SYNC) |
| 74 | stat[IO_SYNC] += add; |
| 75 | else |
| 76 | stat[IO_ASYNC] += add; |
| 77 | } |
| 78 | |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 79 | void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time) |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 80 | { |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 81 | unsigned long flags; |
| 82 | |
| 83 | spin_lock_irqsave(&blkg->stats_lock, flags); |
| 84 | blkg->stats.time += time; |
| 85 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 86 | } |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 87 | EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 88 | |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 89 | void blkiocg_update_request_dispatch_stats(struct blkio_group *blkg, |
| 90 | struct request *rq) |
| 91 | { |
| 92 | struct blkio_group_stats *stats; |
| 93 | unsigned long flags; |
| 94 | |
| 95 | spin_lock_irqsave(&blkg->stats_lock, flags); |
| 96 | stats = &blkg->stats; |
| 97 | stats->sectors += blk_rq_sectors(rq); |
| 98 | io_add_stat(stats->io_serviced, 1, rq->cmd_flags); |
| 99 | io_add_stat(stats->io_service_bytes, blk_rq_sectors(rq) << 9, |
| 100 | rq->cmd_flags); |
| 101 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
| 102 | } |
| 103 | |
| 104 | void blkiocg_update_request_completion_stats(struct blkio_group *blkg, |
| 105 | struct request *rq) |
| 106 | { |
| 107 | struct blkio_group_stats *stats; |
| 108 | unsigned long flags; |
| 109 | unsigned long long now = sched_clock(); |
| 110 | |
| 111 | spin_lock_irqsave(&blkg->stats_lock, flags); |
| 112 | stats = &blkg->stats; |
| 113 | if (time_after64(now, rq->io_start_time_ns)) |
| 114 | io_add_stat(stats->io_service_time, now - rq->io_start_time_ns, |
| 115 | rq->cmd_flags); |
| 116 | if (time_after64(rq->io_start_time_ns, rq->start_time_ns)) |
| 117 | io_add_stat(stats->io_wait_time, |
| 118 | rq->io_start_time_ns - rq->start_time_ns, |
| 119 | rq->cmd_flags); |
| 120 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
| 121 | } |
| 122 | EXPORT_SYMBOL_GPL(blkiocg_update_request_completion_stats); |
| 123 | |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 124 | void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 125 | struct blkio_group *blkg, void *key, dev_t dev) |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 126 | { |
| 127 | unsigned long flags; |
| 128 | |
| 129 | spin_lock_irqsave(&blkcg->lock, flags); |
| 130 | rcu_assign_pointer(blkg->key, key); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 131 | blkg->blkcg_id = css_id(&blkcg->css); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 132 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); |
| 133 | spin_unlock_irqrestore(&blkcg->lock, flags); |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 134 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
| 135 | /* Need to take css reference ? */ |
| 136 | cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); |
| 137 | #endif |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 138 | blkg->dev = dev; |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 139 | } |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 140 | EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 141 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 142 | static void __blkiocg_del_blkio_group(struct blkio_group *blkg) |
| 143 | { |
| 144 | hlist_del_init_rcu(&blkg->blkcg_node); |
| 145 | blkg->blkcg_id = 0; |
| 146 | } |
| 147 | |
| 148 | /* |
| 149 | * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1 |
| 150 | * indicating that blk_group was unhashed by the time we got to it. |
| 151 | */ |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 152 | int blkiocg_del_blkio_group(struct blkio_group *blkg) |
| 153 | { |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 154 | struct blkio_cgroup *blkcg; |
| 155 | unsigned long flags; |
| 156 | struct cgroup_subsys_state *css; |
| 157 | int ret = 1; |
| 158 | |
| 159 | rcu_read_lock(); |
| 160 | css = css_lookup(&blkio_subsys, blkg->blkcg_id); |
| 161 | if (!css) |
| 162 | goto out; |
| 163 | |
| 164 | blkcg = container_of(css, struct blkio_cgroup, css); |
| 165 | spin_lock_irqsave(&blkcg->lock, flags); |
| 166 | if (!hlist_unhashed(&blkg->blkcg_node)) { |
| 167 | __blkiocg_del_blkio_group(blkg); |
| 168 | ret = 0; |
| 169 | } |
| 170 | spin_unlock_irqrestore(&blkcg->lock, flags); |
| 171 | out: |
| 172 | rcu_read_unlock(); |
| 173 | return ret; |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 174 | } |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 175 | EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 176 | |
| 177 | /* called under rcu_read_lock(). */ |
| 178 | struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) |
| 179 | { |
| 180 | struct blkio_group *blkg; |
| 181 | struct hlist_node *n; |
| 182 | void *__key; |
| 183 | |
| 184 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { |
| 185 | __key = blkg->key; |
| 186 | if (__key == key) |
| 187 | return blkg; |
| 188 | } |
| 189 | |
| 190 | return NULL; |
| 191 | } |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 192 | EXPORT_SYMBOL_GPL(blkiocg_lookup_group); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 193 | |
| 194 | #define SHOW_FUNCTION(__VAR) \ |
| 195 | static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup, \ |
| 196 | struct cftype *cftype) \ |
| 197 | { \ |
| 198 | struct blkio_cgroup *blkcg; \ |
| 199 | \ |
| 200 | blkcg = cgroup_to_blkio_cgroup(cgroup); \ |
| 201 | return (u64)blkcg->__VAR; \ |
| 202 | } |
| 203 | |
| 204 | SHOW_FUNCTION(weight); |
| 205 | #undef SHOW_FUNCTION |
| 206 | |
| 207 | static int |
| 208 | blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) |
| 209 | { |
| 210 | struct blkio_cgroup *blkcg; |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 211 | struct blkio_group *blkg; |
| 212 | struct hlist_node *n; |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 213 | struct blkio_policy_type *blkiop; |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 214 | |
| 215 | if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) |
| 216 | return -EINVAL; |
| 217 | |
| 218 | blkcg = cgroup_to_blkio_cgroup(cgroup); |
Gui Jianfeng | bcf4dd4 | 2010-02-01 09:58:54 +0100 | [diff] [blame] | 219 | spin_lock(&blkio_list_lock); |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 220 | spin_lock_irq(&blkcg->lock); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 221 | blkcg->weight = (unsigned int)val; |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 222 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 223 | list_for_each_entry(blkiop, &blkio_list, list) |
| 224 | blkiop->ops.blkio_update_group_weight_fn(blkg, |
| 225 | blkcg->weight); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 226 | } |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 227 | spin_unlock_irq(&blkcg->lock); |
Gui Jianfeng | bcf4dd4 | 2010-02-01 09:58:54 +0100 | [diff] [blame] | 228 | spin_unlock(&blkio_list_lock); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 229 | return 0; |
| 230 | } |
| 231 | |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 232 | static int |
| 233 | blkiocg_reset_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) |
| 234 | { |
| 235 | struct blkio_cgroup *blkcg; |
| 236 | struct blkio_group *blkg; |
| 237 | struct hlist_node *n; |
| 238 | struct blkio_group_stats *stats; |
| 239 | |
| 240 | blkcg = cgroup_to_blkio_cgroup(cgroup); |
| 241 | spin_lock_irq(&blkcg->lock); |
| 242 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { |
| 243 | spin_lock(&blkg->stats_lock); |
| 244 | stats = &blkg->stats; |
| 245 | memset(stats, 0, sizeof(struct blkio_group_stats)); |
| 246 | spin_unlock(&blkg->stats_lock); |
| 247 | } |
| 248 | spin_unlock_irq(&blkcg->lock); |
| 249 | return 0; |
| 250 | } |
| 251 | |
| 252 | void get_key_name(int type, char *disk_id, char *str, int chars_left) |
| 253 | { |
| 254 | strlcpy(str, disk_id, chars_left); |
| 255 | chars_left -= strlen(str); |
| 256 | if (chars_left <= 0) { |
| 257 | printk(KERN_WARNING |
| 258 | "Possibly incorrect cgroup stat display format"); |
| 259 | return; |
| 260 | } |
| 261 | switch (type) { |
| 262 | case IO_READ: |
| 263 | strlcat(str, " Read", chars_left); |
| 264 | break; |
| 265 | case IO_WRITE: |
| 266 | strlcat(str, " Write", chars_left); |
| 267 | break; |
| 268 | case IO_SYNC: |
| 269 | strlcat(str, " Sync", chars_left); |
| 270 | break; |
| 271 | case IO_ASYNC: |
| 272 | strlcat(str, " Async", chars_left); |
| 273 | break; |
| 274 | case IO_TYPE_MAX: |
| 275 | strlcat(str, " Total", chars_left); |
| 276 | break; |
| 277 | default: |
| 278 | strlcat(str, " Invalid", chars_left); |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | typedef uint64_t (get_var) (struct blkio_group *, int); |
| 283 | |
| 284 | #define MAX_KEY_LEN 100 |
| 285 | uint64_t get_typed_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb, |
| 286 | get_var *getvar, char *disk_id) |
| 287 | { |
| 288 | uint64_t disk_total; |
| 289 | char key_str[MAX_KEY_LEN]; |
| 290 | int type; |
| 291 | |
| 292 | for (type = 0; type < IO_TYPE_MAX; type++) { |
| 293 | get_key_name(type, disk_id, key_str, MAX_KEY_LEN); |
| 294 | cb->fill(cb, key_str, getvar(blkg, type)); |
| 295 | } |
| 296 | disk_total = getvar(blkg, IO_READ) + getvar(blkg, IO_WRITE); |
| 297 | get_key_name(IO_TYPE_MAX, disk_id, key_str, MAX_KEY_LEN); |
| 298 | cb->fill(cb, key_str, disk_total); |
| 299 | return disk_total; |
| 300 | } |
| 301 | |
| 302 | uint64_t get_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb, |
| 303 | get_var *getvar, char *disk_id) |
| 304 | { |
| 305 | uint64_t var = getvar(blkg, 0); |
| 306 | cb->fill(cb, disk_id, var); |
| 307 | return var; |
| 308 | } |
| 309 | |
| 310 | #define GET_STAT_INDEXED(__VAR) \ |
| 311 | uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int type) \ |
| 312 | { \ |
| 313 | return blkg->stats.__VAR[type]; \ |
| 314 | } \ |
| 315 | |
| 316 | GET_STAT_INDEXED(io_service_bytes); |
| 317 | GET_STAT_INDEXED(io_serviced); |
| 318 | GET_STAT_INDEXED(io_service_time); |
| 319 | GET_STAT_INDEXED(io_wait_time); |
| 320 | #undef GET_STAT_INDEXED |
| 321 | |
| 322 | #define GET_STAT(__VAR, __CONV) \ |
| 323 | uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int dummy) \ |
| 324 | { \ |
| 325 | uint64_t data = blkg->stats.__VAR; \ |
| 326 | if (__CONV) \ |
| 327 | data = (uint64_t)jiffies_to_msecs(data) * NSEC_PER_MSEC;\ |
| 328 | return data; \ |
| 329 | } |
| 330 | |
| 331 | GET_STAT(time, 1); |
| 332 | GET_STAT(sectors, 0); |
| 333 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
| 334 | GET_STAT(dequeue, 0); |
| 335 | #endif |
| 336 | #undef GET_STAT |
| 337 | |
| 338 | #define SHOW_FUNCTION_PER_GROUP(__VAR, get_stats, getvar, show_total) \ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 339 | static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \ |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 340 | struct cftype *cftype, struct cgroup_map_cb *cb) \ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 341 | { \ |
| 342 | struct blkio_cgroup *blkcg; \ |
| 343 | struct blkio_group *blkg; \ |
| 344 | struct hlist_node *n; \ |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 345 | uint64_t cgroup_total = 0; \ |
| 346 | char disk_id[10]; \ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 347 | \ |
| 348 | if (!cgroup_lock_live_group(cgroup)) \ |
| 349 | return -ENODEV; \ |
| 350 | \ |
| 351 | blkcg = cgroup_to_blkio_cgroup(cgroup); \ |
| 352 | rcu_read_lock(); \ |
| 353 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\ |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 354 | if (blkg->dev) { \ |
| 355 | spin_lock_irq(&blkg->stats_lock); \ |
| 356 | snprintf(disk_id, 10, "%u:%u", MAJOR(blkg->dev),\ |
| 357 | MINOR(blkg->dev)); \ |
| 358 | cgroup_total += get_stats(blkg, cb, getvar, \ |
| 359 | disk_id); \ |
| 360 | spin_unlock_irq(&blkg->stats_lock); \ |
| 361 | } \ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 362 | } \ |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 363 | if (show_total) \ |
| 364 | cb->fill(cb, "Total", cgroup_total); \ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 365 | rcu_read_unlock(); \ |
| 366 | cgroup_unlock(); \ |
| 367 | return 0; \ |
| 368 | } |
| 369 | |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 370 | SHOW_FUNCTION_PER_GROUP(time, get_stat, get_time_stat, 0); |
| 371 | SHOW_FUNCTION_PER_GROUP(sectors, get_stat, get_sectors_stat, 0); |
| 372 | SHOW_FUNCTION_PER_GROUP(io_service_bytes, get_typed_stat, |
| 373 | get_io_service_bytes_stat, 1); |
| 374 | SHOW_FUNCTION_PER_GROUP(io_serviced, get_typed_stat, get_io_serviced_stat, 1); |
| 375 | SHOW_FUNCTION_PER_GROUP(io_service_time, get_typed_stat, |
| 376 | get_io_service_time_stat, 1); |
| 377 | SHOW_FUNCTION_PER_GROUP(io_wait_time, get_typed_stat, get_io_wait_time_stat, 1); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 378 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 379 | SHOW_FUNCTION_PER_GROUP(dequeue, get_stat, get_dequeue_stat, 0); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 380 | #endif |
| 381 | #undef SHOW_FUNCTION_PER_GROUP |
| 382 | |
| 383 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 384 | void blkiocg_update_dequeue_stats(struct blkio_group *blkg, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 385 | unsigned long dequeue) |
| 386 | { |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 387 | blkg->stats.dequeue += dequeue; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 388 | } |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 389 | EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 390 | #endif |
| 391 | |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 392 | struct cftype blkio_files[] = { |
| 393 | { |
| 394 | .name = "weight", |
| 395 | .read_u64 = blkiocg_weight_read, |
| 396 | .write_u64 = blkiocg_weight_write, |
| 397 | }, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 398 | { |
| 399 | .name = "time", |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 400 | .read_map = blkiocg_time_read, |
| 401 | .write_u64 = blkiocg_reset_write, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 402 | }, |
| 403 | { |
| 404 | .name = "sectors", |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 405 | .read_map = blkiocg_sectors_read, |
| 406 | .write_u64 = blkiocg_reset_write, |
| 407 | }, |
| 408 | { |
| 409 | .name = "io_service_bytes", |
| 410 | .read_map = blkiocg_io_service_bytes_read, |
| 411 | .write_u64 = blkiocg_reset_write, |
| 412 | }, |
| 413 | { |
| 414 | .name = "io_serviced", |
| 415 | .read_map = blkiocg_io_serviced_read, |
| 416 | .write_u64 = blkiocg_reset_write, |
| 417 | }, |
| 418 | { |
| 419 | .name = "io_service_time", |
| 420 | .read_map = blkiocg_io_service_time_read, |
| 421 | .write_u64 = blkiocg_reset_write, |
| 422 | }, |
| 423 | { |
| 424 | .name = "io_wait_time", |
| 425 | .read_map = blkiocg_io_wait_time_read, |
| 426 | .write_u64 = blkiocg_reset_write, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 427 | }, |
| 428 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
| 429 | { |
| 430 | .name = "dequeue", |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 431 | .read_map = blkiocg_dequeue_read, |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 432 | }, |
| 433 | #endif |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 434 | }; |
| 435 | |
| 436 | static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) |
| 437 | { |
| 438 | return cgroup_add_files(cgroup, subsys, blkio_files, |
| 439 | ARRAY_SIZE(blkio_files)); |
| 440 | } |
| 441 | |
| 442 | static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) |
| 443 | { |
| 444 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 445 | unsigned long flags; |
| 446 | struct blkio_group *blkg; |
| 447 | void *key; |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 448 | struct blkio_policy_type *blkiop; |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 449 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 450 | rcu_read_lock(); |
| 451 | remove_entry: |
| 452 | spin_lock_irqsave(&blkcg->lock, flags); |
| 453 | |
| 454 | if (hlist_empty(&blkcg->blkg_list)) { |
| 455 | spin_unlock_irqrestore(&blkcg->lock, flags); |
| 456 | goto done; |
| 457 | } |
| 458 | |
| 459 | blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, |
| 460 | blkcg_node); |
| 461 | key = rcu_dereference(blkg->key); |
| 462 | __blkiocg_del_blkio_group(blkg); |
| 463 | |
| 464 | spin_unlock_irqrestore(&blkcg->lock, flags); |
| 465 | |
| 466 | /* |
| 467 | * This blkio_group is being unlinked as associated cgroup is going |
| 468 | * away. Let all the IO controlling policies know about this event. |
| 469 | * |
| 470 | * Currently this is static call to one io controlling policy. Once |
| 471 | * we have more policies in place, we need some dynamic registration |
| 472 | * of callback function. |
| 473 | */ |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 474 | spin_lock(&blkio_list_lock); |
| 475 | list_for_each_entry(blkiop, &blkio_list, list) |
| 476 | blkiop->ops.blkio_unlink_group_fn(key, blkg); |
| 477 | spin_unlock(&blkio_list_lock); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 478 | goto remove_entry; |
| 479 | done: |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 480 | free_css_id(&blkio_subsys, &blkcg->css); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 481 | rcu_read_unlock(); |
Ben Blum | 67523c4 | 2010-03-10 15:22:11 -0800 | [diff] [blame] | 482 | if (blkcg != &blkio_root_cgroup) |
| 483 | kfree(blkcg); |
Vivek Goyal | 31e4c28 | 2009-12-03 12:59:42 -0500 | [diff] [blame] | 484 | } |
| 485 | |
| 486 | static struct cgroup_subsys_state * |
| 487 | blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) |
| 488 | { |
| 489 | struct blkio_cgroup *blkcg, *parent_blkcg; |
| 490 | |
| 491 | if (!cgroup->parent) { |
| 492 | blkcg = &blkio_root_cgroup; |
| 493 | goto done; |
| 494 | } |
| 495 | |
| 496 | /* Currently we do not support hierarchy deeper than two level (0,1) */ |
| 497 | parent_blkcg = cgroup_to_blkio_cgroup(cgroup->parent); |
| 498 | if (css_depth(&parent_blkcg->css) > 0) |
| 499 | return ERR_PTR(-EINVAL); |
| 500 | |
| 501 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); |
| 502 | if (!blkcg) |
| 503 | return ERR_PTR(-ENOMEM); |
| 504 | |
| 505 | blkcg->weight = BLKIO_WEIGHT_DEFAULT; |
| 506 | done: |
| 507 | spin_lock_init(&blkcg->lock); |
| 508 | INIT_HLIST_HEAD(&blkcg->blkg_list); |
| 509 | |
| 510 | return &blkcg->css; |
| 511 | } |
| 512 | |
| 513 | /* |
| 514 | * We cannot support shared io contexts, as we have no mean to support |
| 515 | * two tasks with the same ioc in two different groups without major rework |
| 516 | * of the main cic data structures. For now we allow a task to change |
| 517 | * its cgroup only if it's the only owner of its ioc. |
| 518 | */ |
| 519 | static int blkiocg_can_attach(struct cgroup_subsys *subsys, |
| 520 | struct cgroup *cgroup, struct task_struct *tsk, |
| 521 | bool threadgroup) |
| 522 | { |
| 523 | struct io_context *ioc; |
| 524 | int ret = 0; |
| 525 | |
| 526 | /* task_lock() is needed to avoid races with exit_io_context() */ |
| 527 | task_lock(tsk); |
| 528 | ioc = tsk->io_context; |
| 529 | if (ioc && atomic_read(&ioc->nr_tasks) > 1) |
| 530 | ret = -EINVAL; |
| 531 | task_unlock(tsk); |
| 532 | |
| 533 | return ret; |
| 534 | } |
| 535 | |
| 536 | static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup, |
| 537 | struct cgroup *prev, struct task_struct *tsk, |
| 538 | bool threadgroup) |
| 539 | { |
| 540 | struct io_context *ioc; |
| 541 | |
| 542 | task_lock(tsk); |
| 543 | ioc = tsk->io_context; |
| 544 | if (ioc) |
| 545 | ioc->cgroup_changed = 1; |
| 546 | task_unlock(tsk); |
| 547 | } |
| 548 | |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 549 | void blkio_policy_register(struct blkio_policy_type *blkiop) |
| 550 | { |
| 551 | spin_lock(&blkio_list_lock); |
| 552 | list_add_tail(&blkiop->list, &blkio_list); |
| 553 | spin_unlock(&blkio_list_lock); |
| 554 | } |
| 555 | EXPORT_SYMBOL_GPL(blkio_policy_register); |
| 556 | |
| 557 | void blkio_policy_unregister(struct blkio_policy_type *blkiop) |
| 558 | { |
| 559 | spin_lock(&blkio_list_lock); |
| 560 | list_del_init(&blkiop->list); |
| 561 | spin_unlock(&blkio_list_lock); |
| 562 | } |
| 563 | EXPORT_SYMBOL_GPL(blkio_policy_unregister); |
Ben Blum | 67523c4 | 2010-03-10 15:22:11 -0800 | [diff] [blame] | 564 | |
| 565 | static int __init init_cgroup_blkio(void) |
| 566 | { |
| 567 | return cgroup_load_subsys(&blkio_subsys); |
| 568 | } |
| 569 | |
| 570 | static void __exit exit_cgroup_blkio(void) |
| 571 | { |
| 572 | cgroup_unload_subsys(&blkio_subsys); |
| 573 | } |
| 574 | |
| 575 | module_init(init_cgroup_blkio); |
| 576 | module_exit(exit_cgroup_blkio); |
| 577 | MODULE_LICENSE("GPL"); |