Commit | Line | Data |
---|---|---|
31e4c28d VG |
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> | |
22084190 VG |
14 | #include <linux/seq_file.h> |
15 | #include <linux/kdev_t.h> | |
9d6a986c | 16 | #include <linux/module.h> |
accee785 | 17 | #include <linux/err.h> |
9195291e | 18 | #include <linux/blkdev.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
31e4c28d | 20 | #include "blk-cgroup.h" |
34d0f179 | 21 | #include <linux/genhd.h> |
3e252066 | 22 | |
84c124da DS |
23 | #define MAX_KEY_LEN 100 |
24 | ||
3e252066 VG |
25 | static DEFINE_SPINLOCK(blkio_list_lock); |
26 | static LIST_HEAD(blkio_list); | |
b1c35769 | 27 | |
31e4c28d | 28 | struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; |
9d6a986c VG |
29 | EXPORT_SYMBOL_GPL(blkio_root_cgroup); |
30 | ||
67523c48 BB |
31 | static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *, |
32 | struct cgroup *); | |
33 | static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, | |
34 | struct task_struct *, bool); | |
35 | static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, | |
36 | struct cgroup *, struct task_struct *, bool); | |
37 | static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); | |
38 | static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); | |
39 | ||
062a644d VG |
40 | /* for encoding cft->private value on file */ |
41 | #define BLKIOFILE_PRIVATE(x, val) (((x) << 16) | (val)) | |
42 | /* What policy owns the file, proportional or throttle */ | |
43 | #define BLKIOFILE_POLICY(val) (((val) >> 16) & 0xffff) | |
44 | #define BLKIOFILE_ATTR(val) ((val) & 0xffff) | |
45 | ||
67523c48 BB |
46 | struct cgroup_subsys blkio_subsys = { |
47 | .name = "blkio", | |
48 | .create = blkiocg_create, | |
49 | .can_attach = blkiocg_can_attach, | |
50 | .attach = blkiocg_attach, | |
51 | .destroy = blkiocg_destroy, | |
52 | .populate = blkiocg_populate, | |
53 | #ifdef CONFIG_BLK_CGROUP | |
54 | /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */ | |
55 | .subsys_id = blkio_subsys_id, | |
56 | #endif | |
57 | .use_id = 1, | |
58 | .module = THIS_MODULE, | |
59 | }; | |
60 | EXPORT_SYMBOL_GPL(blkio_subsys); | |
61 | ||
34d0f179 GJ |
62 | static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg, |
63 | struct blkio_policy_node *pn) | |
64 | { | |
65 | list_add(&pn->node, &blkcg->policy_list); | |
66 | } | |
67 | ||
062a644d VG |
68 | static inline bool cftype_blkg_same_policy(struct cftype *cft, |
69 | struct blkio_group *blkg) | |
70 | { | |
71 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
72 | ||
73 | if (blkg->plid == plid) | |
74 | return 1; | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | /* Determines if policy node matches cgroup file being accessed */ | |
80 | static inline bool pn_matches_cftype(struct cftype *cft, | |
81 | struct blkio_policy_node *pn) | |
82 | { | |
83 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
84 | int fileid = BLKIOFILE_ATTR(cft->private); | |
85 | ||
86 | return (plid == pn->plid && fileid == pn->fileid); | |
87 | } | |
88 | ||
34d0f179 GJ |
89 | /* Must be called with blkcg->lock held */ |
90 | static inline void blkio_policy_delete_node(struct blkio_policy_node *pn) | |
91 | { | |
92 | list_del(&pn->node); | |
93 | } | |
94 | ||
95 | /* Must be called with blkcg->lock held */ | |
96 | static struct blkio_policy_node * | |
062a644d VG |
97 | blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev, |
98 | enum blkio_policy_id plid, int fileid) | |
34d0f179 GJ |
99 | { |
100 | struct blkio_policy_node *pn; | |
101 | ||
102 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
062a644d | 103 | if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid) |
34d0f179 GJ |
104 | return pn; |
105 | } | |
106 | ||
107 | return NULL; | |
108 | } | |
109 | ||
31e4c28d VG |
110 | struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) |
111 | { | |
112 | return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), | |
113 | struct blkio_cgroup, css); | |
114 | } | |
9d6a986c | 115 | EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup); |
31e4c28d | 116 | |
062a644d VG |
117 | static inline void |
118 | blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight) | |
119 | { | |
120 | struct blkio_policy_type *blkiop; | |
121 | ||
122 | list_for_each_entry(blkiop, &blkio_list, list) { | |
123 | /* If this policy does not own the blkg, do not send updates */ | |
124 | if (blkiop->plid != blkg->plid) | |
125 | continue; | |
126 | if (blkiop->ops.blkio_update_group_weight_fn) | |
127 | blkiop->ops.blkio_update_group_weight_fn(blkg, weight); | |
128 | } | |
129 | } | |
130 | ||
9195291e DS |
131 | /* |
132 | * Add to the appropriate stat variable depending on the request type. | |
133 | * This should be called with the blkg->stats_lock held. | |
134 | */ | |
84c124da DS |
135 | static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction, |
136 | bool sync) | |
9195291e | 137 | { |
84c124da DS |
138 | if (direction) |
139 | stat[BLKIO_STAT_WRITE] += add; | |
9195291e | 140 | else |
84c124da DS |
141 | stat[BLKIO_STAT_READ] += add; |
142 | if (sync) | |
143 | stat[BLKIO_STAT_SYNC] += add; | |
9195291e | 144 | else |
84c124da | 145 | stat[BLKIO_STAT_ASYNC] += add; |
9195291e DS |
146 | } |
147 | ||
cdc1184c DS |
148 | /* |
149 | * Decrements the appropriate stat variable if non-zero depending on the | |
150 | * request type. Panics on value being zero. | |
151 | * This should be called with the blkg->stats_lock held. | |
152 | */ | |
153 | static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync) | |
154 | { | |
155 | if (direction) { | |
156 | BUG_ON(stat[BLKIO_STAT_WRITE] == 0); | |
157 | stat[BLKIO_STAT_WRITE]--; | |
158 | } else { | |
159 | BUG_ON(stat[BLKIO_STAT_READ] == 0); | |
160 | stat[BLKIO_STAT_READ]--; | |
161 | } | |
162 | if (sync) { | |
163 | BUG_ON(stat[BLKIO_STAT_SYNC] == 0); | |
164 | stat[BLKIO_STAT_SYNC]--; | |
165 | } else { | |
166 | BUG_ON(stat[BLKIO_STAT_ASYNC] == 0); | |
167 | stat[BLKIO_STAT_ASYNC]--; | |
168 | } | |
169 | } | |
170 | ||
171 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
812df48d DS |
172 | /* This should be called with the blkg->stats_lock held. */ |
173 | static void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
174 | struct blkio_group *curr_blkg) | |
175 | { | |
176 | if (blkio_blkg_waiting(&blkg->stats)) | |
177 | return; | |
178 | if (blkg == curr_blkg) | |
179 | return; | |
180 | blkg->stats.start_group_wait_time = sched_clock(); | |
181 | blkio_mark_blkg_waiting(&blkg->stats); | |
182 | } | |
183 | ||
184 | /* This should be called with the blkg->stats_lock held. */ | |
185 | static void blkio_update_group_wait_time(struct blkio_group_stats *stats) | |
186 | { | |
187 | unsigned long long now; | |
188 | ||
189 | if (!blkio_blkg_waiting(stats)) | |
190 | return; | |
191 | ||
192 | now = sched_clock(); | |
193 | if (time_after64(now, stats->start_group_wait_time)) | |
194 | stats->group_wait_time += now - stats->start_group_wait_time; | |
195 | blkio_clear_blkg_waiting(stats); | |
196 | } | |
197 | ||
198 | /* This should be called with the blkg->stats_lock held. */ | |
199 | static void blkio_end_empty_time(struct blkio_group_stats *stats) | |
200 | { | |
201 | unsigned long long now; | |
202 | ||
203 | if (!blkio_blkg_empty(stats)) | |
204 | return; | |
205 | ||
206 | now = sched_clock(); | |
207 | if (time_after64(now, stats->start_empty_time)) | |
208 | stats->empty_time += now - stats->start_empty_time; | |
209 | blkio_clear_blkg_empty(stats); | |
210 | } | |
211 | ||
212 | void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) | |
213 | { | |
214 | unsigned long flags; | |
215 | ||
216 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
217 | BUG_ON(blkio_blkg_idling(&blkg->stats)); | |
218 | blkg->stats.start_idle_time = sched_clock(); | |
219 | blkio_mark_blkg_idling(&blkg->stats); | |
220 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
221 | } | |
222 | EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats); | |
223 | ||
224 | void blkiocg_update_idle_time_stats(struct blkio_group *blkg) | |
225 | { | |
226 | unsigned long flags; | |
227 | unsigned long long now; | |
228 | struct blkio_group_stats *stats; | |
229 | ||
230 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
231 | stats = &blkg->stats; | |
232 | if (blkio_blkg_idling(stats)) { | |
233 | now = sched_clock(); | |
234 | if (time_after64(now, stats->start_idle_time)) | |
235 | stats->idle_time += now - stats->start_idle_time; | |
236 | blkio_clear_blkg_idling(stats); | |
237 | } | |
238 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
239 | } | |
240 | EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats); | |
241 | ||
a11cdaa7 | 242 | void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) |
cdc1184c DS |
243 | { |
244 | unsigned long flags; | |
245 | struct blkio_group_stats *stats; | |
246 | ||
247 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
248 | stats = &blkg->stats; | |
249 | stats->avg_queue_size_sum += | |
250 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] + | |
251 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]; | |
252 | stats->avg_queue_size_samples++; | |
812df48d | 253 | blkio_update_group_wait_time(stats); |
cdc1184c DS |
254 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
255 | } | |
a11cdaa7 DS |
256 | EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats); |
257 | ||
e5ff082e | 258 | void blkiocg_set_start_empty_time(struct blkio_group *blkg) |
28baf442 DS |
259 | { |
260 | unsigned long flags; | |
261 | struct blkio_group_stats *stats; | |
262 | ||
263 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
264 | stats = &blkg->stats; | |
265 | ||
266 | if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] || | |
267 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]) { | |
268 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
269 | return; | |
270 | } | |
271 | ||
272 | /* | |
e5ff082e VG |
273 | * group is already marked empty. This can happen if cfqq got new |
274 | * request in parent group and moved to this group while being added | |
275 | * to service tree. Just ignore the event and move on. | |
28baf442 | 276 | */ |
e5ff082e VG |
277 | if(blkio_blkg_empty(stats)) { |
278 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
279 | return; | |
280 | } | |
281 | ||
28baf442 DS |
282 | stats->start_empty_time = sched_clock(); |
283 | blkio_mark_blkg_empty(stats); | |
284 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
285 | } | |
286 | EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time); | |
287 | ||
a11cdaa7 DS |
288 | void blkiocg_update_dequeue_stats(struct blkio_group *blkg, |
289 | unsigned long dequeue) | |
290 | { | |
291 | blkg->stats.dequeue += dequeue; | |
292 | } | |
293 | EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats); | |
812df48d DS |
294 | #else |
295 | static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
296 | struct blkio_group *curr_blkg) {} | |
297 | static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {} | |
cdc1184c DS |
298 | #endif |
299 | ||
a11cdaa7 | 300 | void blkiocg_update_io_add_stats(struct blkio_group *blkg, |
cdc1184c DS |
301 | struct blkio_group *curr_blkg, bool direction, |
302 | bool sync) | |
303 | { | |
304 | unsigned long flags; | |
305 | ||
306 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
307 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], 1, direction, | |
308 | sync); | |
812df48d DS |
309 | blkio_end_empty_time(&blkg->stats); |
310 | blkio_set_start_group_wait_time(blkg, curr_blkg); | |
cdc1184c DS |
311 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
312 | } | |
a11cdaa7 | 313 | EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats); |
cdc1184c | 314 | |
a11cdaa7 | 315 | void blkiocg_update_io_remove_stats(struct blkio_group *blkg, |
cdc1184c DS |
316 | bool direction, bool sync) |
317 | { | |
318 | unsigned long flags; | |
319 | ||
320 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
321 | blkio_check_and_dec_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], | |
322 | direction, sync); | |
323 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
324 | } | |
a11cdaa7 | 325 | EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats); |
cdc1184c | 326 | |
303a3acb | 327 | void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time) |
22084190 | 328 | { |
303a3acb DS |
329 | unsigned long flags; |
330 | ||
331 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
332 | blkg->stats.time += time; | |
333 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
22084190 | 334 | } |
303a3acb | 335 | EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used); |
22084190 | 336 | |
84c124da DS |
337 | void blkiocg_update_dispatch_stats(struct blkio_group *blkg, |
338 | uint64_t bytes, bool direction, bool sync) | |
9195291e DS |
339 | { |
340 | struct blkio_group_stats *stats; | |
341 | unsigned long flags; | |
342 | ||
343 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
344 | stats = &blkg->stats; | |
84c124da DS |
345 | stats->sectors += bytes >> 9; |
346 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction, | |
347 | sync); | |
348 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes, | |
349 | direction, sync); | |
9195291e DS |
350 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
351 | } | |
84c124da | 352 | EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats); |
9195291e | 353 | |
84c124da DS |
354 | void blkiocg_update_completion_stats(struct blkio_group *blkg, |
355 | uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) | |
9195291e DS |
356 | { |
357 | struct blkio_group_stats *stats; | |
358 | unsigned long flags; | |
359 | unsigned long long now = sched_clock(); | |
360 | ||
361 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
362 | stats = &blkg->stats; | |
84c124da DS |
363 | if (time_after64(now, io_start_time)) |
364 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME], | |
365 | now - io_start_time, direction, sync); | |
366 | if (time_after64(io_start_time, start_time)) | |
367 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME], | |
368 | io_start_time - start_time, direction, sync); | |
9195291e DS |
369 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
370 | } | |
84c124da | 371 | EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats); |
9195291e | 372 | |
812d4026 DS |
373 | void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction, |
374 | bool sync) | |
375 | { | |
376 | unsigned long flags; | |
377 | ||
378 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
379 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction, | |
380 | sync); | |
381 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
382 | } | |
383 | EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats); | |
384 | ||
31e4c28d | 385 | void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, |
062a644d VG |
386 | struct blkio_group *blkg, void *key, dev_t dev, |
387 | enum blkio_policy_id plid) | |
31e4c28d VG |
388 | { |
389 | unsigned long flags; | |
390 | ||
391 | spin_lock_irqsave(&blkcg->lock, flags); | |
8d2a91f8 | 392 | spin_lock_init(&blkg->stats_lock); |
31e4c28d | 393 | rcu_assign_pointer(blkg->key, key); |
b1c35769 | 394 | blkg->blkcg_id = css_id(&blkcg->css); |
31e4c28d | 395 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); |
062a644d | 396 | blkg->plid = plid; |
31e4c28d | 397 | spin_unlock_irqrestore(&blkcg->lock, flags); |
2868ef7b VG |
398 | /* Need to take css reference ? */ |
399 | cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); | |
22084190 | 400 | blkg->dev = dev; |
31e4c28d | 401 | } |
9d6a986c | 402 | EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); |
31e4c28d | 403 | |
b1c35769 VG |
404 | static void __blkiocg_del_blkio_group(struct blkio_group *blkg) |
405 | { | |
406 | hlist_del_init_rcu(&blkg->blkcg_node); | |
407 | blkg->blkcg_id = 0; | |
408 | } | |
409 | ||
410 | /* | |
411 | * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1 | |
412 | * indicating that blk_group was unhashed by the time we got to it. | |
413 | */ | |
31e4c28d VG |
414 | int blkiocg_del_blkio_group(struct blkio_group *blkg) |
415 | { | |
b1c35769 VG |
416 | struct blkio_cgroup *blkcg; |
417 | unsigned long flags; | |
418 | struct cgroup_subsys_state *css; | |
419 | int ret = 1; | |
420 | ||
421 | rcu_read_lock(); | |
422 | css = css_lookup(&blkio_subsys, blkg->blkcg_id); | |
0f3942a3 JA |
423 | if (css) { |
424 | blkcg = container_of(css, struct blkio_cgroup, css); | |
425 | spin_lock_irqsave(&blkcg->lock, flags); | |
426 | if (!hlist_unhashed(&blkg->blkcg_node)) { | |
427 | __blkiocg_del_blkio_group(blkg); | |
428 | ret = 0; | |
429 | } | |
430 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
b1c35769 | 431 | } |
0f3942a3 | 432 | |
b1c35769 VG |
433 | rcu_read_unlock(); |
434 | return ret; | |
31e4c28d | 435 | } |
9d6a986c | 436 | EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); |
31e4c28d VG |
437 | |
438 | /* called under rcu_read_lock(). */ | |
439 | struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) | |
440 | { | |
441 | struct blkio_group *blkg; | |
442 | struct hlist_node *n; | |
443 | void *__key; | |
444 | ||
445 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
446 | __key = blkg->key; | |
447 | if (__key == key) | |
448 | return blkg; | |
449 | } | |
450 | ||
451 | return NULL; | |
452 | } | |
9d6a986c | 453 | EXPORT_SYMBOL_GPL(blkiocg_lookup_group); |
31e4c28d | 454 | |
303a3acb | 455 | static int |
84c124da | 456 | blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) |
303a3acb DS |
457 | { |
458 | struct blkio_cgroup *blkcg; | |
459 | struct blkio_group *blkg; | |
812df48d | 460 | struct blkio_group_stats *stats; |
303a3acb | 461 | struct hlist_node *n; |
cdc1184c DS |
462 | uint64_t queued[BLKIO_STAT_TOTAL]; |
463 | int i; | |
812df48d DS |
464 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
465 | bool idling, waiting, empty; | |
466 | unsigned long long now = sched_clock(); | |
467 | #endif | |
303a3acb DS |
468 | |
469 | blkcg = cgroup_to_blkio_cgroup(cgroup); | |
470 | spin_lock_irq(&blkcg->lock); | |
471 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
472 | spin_lock(&blkg->stats_lock); | |
812df48d DS |
473 | stats = &blkg->stats; |
474 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
475 | idling = blkio_blkg_idling(stats); | |
476 | waiting = blkio_blkg_waiting(stats); | |
477 | empty = blkio_blkg_empty(stats); | |
478 | #endif | |
cdc1184c | 479 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) |
812df48d DS |
480 | queued[i] = stats->stat_arr[BLKIO_STAT_QUEUED][i]; |
481 | memset(stats, 0, sizeof(struct blkio_group_stats)); | |
cdc1184c | 482 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) |
812df48d DS |
483 | stats->stat_arr[BLKIO_STAT_QUEUED][i] = queued[i]; |
484 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
485 | if (idling) { | |
486 | blkio_mark_blkg_idling(stats); | |
487 | stats->start_idle_time = now; | |
488 | } | |
489 | if (waiting) { | |
490 | blkio_mark_blkg_waiting(stats); | |
491 | stats->start_group_wait_time = now; | |
492 | } | |
493 | if (empty) { | |
494 | blkio_mark_blkg_empty(stats); | |
495 | stats->start_empty_time = now; | |
496 | } | |
497 | #endif | |
303a3acb DS |
498 | spin_unlock(&blkg->stats_lock); |
499 | } | |
500 | spin_unlock_irq(&blkcg->lock); | |
501 | return 0; | |
502 | } | |
503 | ||
84c124da DS |
504 | static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str, |
505 | int chars_left, bool diskname_only) | |
303a3acb | 506 | { |
84c124da | 507 | snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev)); |
303a3acb DS |
508 | chars_left -= strlen(str); |
509 | if (chars_left <= 0) { | |
510 | printk(KERN_WARNING | |
511 | "Possibly incorrect cgroup stat display format"); | |
512 | return; | |
513 | } | |
84c124da DS |
514 | if (diskname_only) |
515 | return; | |
303a3acb | 516 | switch (type) { |
84c124da | 517 | case BLKIO_STAT_READ: |
303a3acb DS |
518 | strlcat(str, " Read", chars_left); |
519 | break; | |
84c124da | 520 | case BLKIO_STAT_WRITE: |
303a3acb DS |
521 | strlcat(str, " Write", chars_left); |
522 | break; | |
84c124da | 523 | case BLKIO_STAT_SYNC: |
303a3acb DS |
524 | strlcat(str, " Sync", chars_left); |
525 | break; | |
84c124da | 526 | case BLKIO_STAT_ASYNC: |
303a3acb DS |
527 | strlcat(str, " Async", chars_left); |
528 | break; | |
84c124da | 529 | case BLKIO_STAT_TOTAL: |
303a3acb DS |
530 | strlcat(str, " Total", chars_left); |
531 | break; | |
532 | default: | |
533 | strlcat(str, " Invalid", chars_left); | |
534 | } | |
535 | } | |
536 | ||
84c124da DS |
537 | static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val, |
538 | struct cgroup_map_cb *cb, dev_t dev) | |
539 | { | |
540 | blkio_get_key_name(0, dev, str, chars_left, true); | |
541 | cb->fill(cb, str, val); | |
542 | return val; | |
543 | } | |
303a3acb | 544 | |
84c124da DS |
545 | /* This should be called with blkg->stats_lock held */ |
546 | static uint64_t blkio_get_stat(struct blkio_group *blkg, | |
547 | struct cgroup_map_cb *cb, dev_t dev, enum stat_type type) | |
303a3acb DS |
548 | { |
549 | uint64_t disk_total; | |
550 | char key_str[MAX_KEY_LEN]; | |
84c124da DS |
551 | enum stat_sub_type sub_type; |
552 | ||
553 | if (type == BLKIO_STAT_TIME) | |
554 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
555 | blkg->stats.time, cb, dev); | |
556 | if (type == BLKIO_STAT_SECTORS) | |
557 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
558 | blkg->stats.sectors, cb, dev); | |
559 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
cdc1184c DS |
560 | if (type == BLKIO_STAT_AVG_QUEUE_SIZE) { |
561 | uint64_t sum = blkg->stats.avg_queue_size_sum; | |
562 | uint64_t samples = blkg->stats.avg_queue_size_samples; | |
563 | if (samples) | |
564 | do_div(sum, samples); | |
565 | else | |
566 | sum = 0; | |
567 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, sum, cb, dev); | |
568 | } | |
812df48d DS |
569 | if (type == BLKIO_STAT_GROUP_WAIT_TIME) |
570 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
571 | blkg->stats.group_wait_time, cb, dev); | |
572 | if (type == BLKIO_STAT_IDLE_TIME) | |
573 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
574 | blkg->stats.idle_time, cb, dev); | |
575 | if (type == BLKIO_STAT_EMPTY_TIME) | |
576 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
577 | blkg->stats.empty_time, cb, dev); | |
84c124da DS |
578 | if (type == BLKIO_STAT_DEQUEUE) |
579 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
580 | blkg->stats.dequeue, cb, dev); | |
581 | #endif | |
303a3acb | 582 | |
84c124da DS |
583 | for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; |
584 | sub_type++) { | |
585 | blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false); | |
586 | cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]); | |
303a3acb | 587 | } |
84c124da DS |
588 | disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] + |
589 | blkg->stats.stat_arr[type][BLKIO_STAT_WRITE]; | |
590 | blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false); | |
303a3acb DS |
591 | cb->fill(cb, key_str, disk_total); |
592 | return disk_total; | |
593 | } | |
594 | ||
34d0f179 GJ |
595 | static int blkio_check_dev_num(dev_t dev) |
596 | { | |
597 | int part = 0; | |
598 | struct gendisk *disk; | |
599 | ||
600 | disk = get_gendisk(dev, &part); | |
601 | if (!disk || part) | |
602 | return -ENODEV; | |
603 | ||
604 | return 0; | |
605 | } | |
606 | ||
607 | static int blkio_policy_parse_and_set(char *buf, | |
062a644d | 608 | struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid) |
34d0f179 GJ |
609 | { |
610 | char *s[4], *p, *major_s = NULL, *minor_s = NULL; | |
611 | int ret; | |
612 | unsigned long major, minor, temp; | |
613 | int i = 0; | |
614 | dev_t dev; | |
615 | ||
616 | memset(s, 0, sizeof(s)); | |
617 | ||
618 | while ((p = strsep(&buf, " ")) != NULL) { | |
619 | if (!*p) | |
620 | continue; | |
621 | ||
622 | s[i++] = p; | |
623 | ||
624 | /* Prevent from inputing too many things */ | |
625 | if (i == 3) | |
626 | break; | |
627 | } | |
628 | ||
629 | if (i != 2) | |
630 | return -EINVAL; | |
631 | ||
632 | p = strsep(&s[0], ":"); | |
633 | if (p != NULL) | |
634 | major_s = p; | |
635 | else | |
636 | return -EINVAL; | |
637 | ||
638 | minor_s = s[0]; | |
639 | if (!minor_s) | |
640 | return -EINVAL; | |
641 | ||
642 | ret = strict_strtoul(major_s, 10, &major); | |
643 | if (ret) | |
644 | return -EINVAL; | |
645 | ||
646 | ret = strict_strtoul(minor_s, 10, &minor); | |
647 | if (ret) | |
648 | return -EINVAL; | |
649 | ||
650 | dev = MKDEV(major, minor); | |
651 | ||
652 | ret = blkio_check_dev_num(dev); | |
653 | if (ret) | |
654 | return ret; | |
655 | ||
656 | newpn->dev = dev; | |
657 | ||
658 | if (s[1] == NULL) | |
659 | return -EINVAL; | |
660 | ||
062a644d VG |
661 | switch (plid) { |
662 | case BLKIO_POLICY_PROP: | |
663 | ret = strict_strtoul(s[1], 10, &temp); | |
664 | if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) || | |
665 | temp > BLKIO_WEIGHT_MAX) | |
666 | return -EINVAL; | |
34d0f179 | 667 | |
062a644d VG |
668 | newpn->plid = plid; |
669 | newpn->fileid = fileid; | |
670 | newpn->weight = temp; | |
671 | break; | |
672 | default: | |
673 | BUG(); | |
674 | } | |
34d0f179 GJ |
675 | |
676 | return 0; | |
677 | } | |
678 | ||
679 | unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, | |
680 | dev_t dev) | |
681 | { | |
682 | struct blkio_policy_node *pn; | |
683 | ||
062a644d VG |
684 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP, |
685 | BLKIO_PROP_weight_device); | |
34d0f179 GJ |
686 | if (pn) |
687 | return pn->weight; | |
688 | else | |
689 | return blkcg->weight; | |
690 | } | |
691 | EXPORT_SYMBOL_GPL(blkcg_get_weight); | |
692 | ||
062a644d VG |
693 | /* Checks whether user asked for deleting a policy rule */ |
694 | static bool blkio_delete_rule_command(struct blkio_policy_node *pn) | |
695 | { | |
696 | switch(pn->plid) { | |
697 | case BLKIO_POLICY_PROP: | |
698 | if (pn->weight == 0) | |
699 | return 1; | |
700 | break; | |
701 | default: | |
702 | BUG(); | |
703 | } | |
704 | ||
705 | return 0; | |
706 | } | |
707 | ||
708 | static void blkio_update_policy_rule(struct blkio_policy_node *oldpn, | |
709 | struct blkio_policy_node *newpn) | |
710 | { | |
711 | switch(oldpn->plid) { | |
712 | case BLKIO_POLICY_PROP: | |
713 | oldpn->weight = newpn->weight; | |
714 | break; | |
715 | default: | |
716 | BUG(); | |
717 | } | |
718 | } | |
719 | ||
720 | /* | |
721 | * Some rules/values in blkg have changed. Propogate those to respective | |
722 | * policies. | |
723 | */ | |
724 | static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg, | |
725 | struct blkio_group *blkg, struct blkio_policy_node *pn) | |
726 | { | |
727 | unsigned int weight; | |
728 | ||
729 | switch(pn->plid) { | |
730 | case BLKIO_POLICY_PROP: | |
731 | weight = pn->weight ? pn->weight : | |
732 | blkcg->weight; | |
733 | blkio_update_group_weight(blkg, weight); | |
734 | break; | |
735 | default: | |
736 | BUG(); | |
737 | } | |
738 | } | |
739 | ||
740 | /* | |
741 | * A policy node rule has been updated. Propogate this update to all the | |
742 | * block groups which might be affected by this update. | |
743 | */ | |
744 | static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg, | |
745 | struct blkio_policy_node *pn) | |
746 | { | |
747 | struct blkio_group *blkg; | |
748 | struct hlist_node *n; | |
749 | ||
750 | spin_lock(&blkio_list_lock); | |
751 | spin_lock_irq(&blkcg->lock); | |
34d0f179 | 752 | |
062a644d VG |
753 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { |
754 | if (pn->dev != blkg->dev || pn->plid != blkg->plid) | |
755 | continue; | |
756 | blkio_update_blkg_policy(blkcg, blkg, pn); | |
757 | } | |
758 | ||
759 | spin_unlock_irq(&blkcg->lock); | |
760 | spin_unlock(&blkio_list_lock); | |
761 | } | |
762 | ||
763 | static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, | |
764 | const char *buffer) | |
34d0f179 GJ |
765 | { |
766 | int ret = 0; | |
767 | char *buf; | |
768 | struct blkio_policy_node *newpn, *pn; | |
769 | struct blkio_cgroup *blkcg; | |
34d0f179 | 770 | int keep_newpn = 0; |
062a644d VG |
771 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); |
772 | int fileid = BLKIOFILE_ATTR(cft->private); | |
34d0f179 GJ |
773 | |
774 | buf = kstrdup(buffer, GFP_KERNEL); | |
775 | if (!buf) | |
776 | return -ENOMEM; | |
777 | ||
778 | newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); | |
779 | if (!newpn) { | |
780 | ret = -ENOMEM; | |
781 | goto free_buf; | |
782 | } | |
783 | ||
062a644d | 784 | ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid); |
34d0f179 GJ |
785 | if (ret) |
786 | goto free_newpn; | |
787 | ||
788 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
789 | ||
790 | spin_lock_irq(&blkcg->lock); | |
791 | ||
062a644d | 792 | pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid); |
34d0f179 | 793 | if (!pn) { |
062a644d | 794 | if (!blkio_delete_rule_command(newpn)) { |
34d0f179 GJ |
795 | blkio_policy_insert_node(blkcg, newpn); |
796 | keep_newpn = 1; | |
797 | } | |
798 | spin_unlock_irq(&blkcg->lock); | |
799 | goto update_io_group; | |
800 | } | |
801 | ||
062a644d | 802 | if (blkio_delete_rule_command(newpn)) { |
34d0f179 GJ |
803 | blkio_policy_delete_node(pn); |
804 | spin_unlock_irq(&blkcg->lock); | |
805 | goto update_io_group; | |
806 | } | |
807 | spin_unlock_irq(&blkcg->lock); | |
808 | ||
062a644d | 809 | blkio_update_policy_rule(pn, newpn); |
34d0f179 GJ |
810 | |
811 | update_io_group: | |
062a644d | 812 | blkio_update_policy_node_blkg(blkcg, newpn); |
34d0f179 GJ |
813 | |
814 | free_newpn: | |
815 | if (!keep_newpn) | |
816 | kfree(newpn); | |
817 | free_buf: | |
818 | kfree(buf); | |
819 | return ret; | |
820 | } | |
821 | ||
062a644d VG |
822 | static void |
823 | blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn) | |
824 | { | |
825 | switch(pn->plid) { | |
826 | case BLKIO_POLICY_PROP: | |
827 | if (pn->fileid == BLKIO_PROP_weight_device) | |
828 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
829 | MINOR(pn->dev), pn->weight); | |
830 | break; | |
831 | default: | |
832 | BUG(); | |
833 | } | |
834 | } | |
835 | ||
836 | /* cgroup files which read their data from policy nodes end up here */ | |
837 | static void blkio_read_policy_node_files(struct cftype *cft, | |
838 | struct blkio_cgroup *blkcg, struct seq_file *m) | |
34d0f179 | 839 | { |
34d0f179 GJ |
840 | struct blkio_policy_node *pn; |
841 | ||
0f3942a3 JA |
842 | if (!list_empty(&blkcg->policy_list)) { |
843 | spin_lock_irq(&blkcg->lock); | |
844 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
062a644d VG |
845 | if (!pn_matches_cftype(cft, pn)) |
846 | continue; | |
847 | blkio_print_policy_node(m, pn); | |
0f3942a3 JA |
848 | } |
849 | spin_unlock_irq(&blkcg->lock); | |
34d0f179 | 850 | } |
062a644d VG |
851 | } |
852 | ||
853 | static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, | |
854 | struct seq_file *m) | |
855 | { | |
856 | struct blkio_cgroup *blkcg; | |
857 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
858 | int name = BLKIOFILE_ATTR(cft->private); | |
859 | ||
860 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
861 | ||
862 | switch(plid) { | |
863 | case BLKIO_POLICY_PROP: | |
864 | switch(name) { | |
865 | case BLKIO_PROP_weight_device: | |
866 | blkio_read_policy_node_files(cft, blkcg, m); | |
867 | return 0; | |
868 | default: | |
869 | BUG(); | |
870 | } | |
871 | break; | |
872 | default: | |
873 | BUG(); | |
874 | } | |
875 | ||
876 | return 0; | |
877 | } | |
878 | ||
879 | static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg, | |
880 | struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type, | |
881 | bool show_total) | |
882 | { | |
883 | struct blkio_group *blkg; | |
884 | struct hlist_node *n; | |
885 | uint64_t cgroup_total = 0; | |
886 | ||
887 | rcu_read_lock(); | |
888 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
889 | if (blkg->dev) { | |
890 | if (!cftype_blkg_same_policy(cft, blkg)) | |
891 | continue; | |
892 | spin_lock_irq(&blkg->stats_lock); | |
893 | cgroup_total += blkio_get_stat(blkg, cb, blkg->dev, | |
894 | type); | |
895 | spin_unlock_irq(&blkg->stats_lock); | |
896 | } | |
897 | } | |
898 | if (show_total) | |
899 | cb->fill(cb, "Total", cgroup_total); | |
900 | rcu_read_unlock(); | |
901 | return 0; | |
902 | } | |
903 | ||
904 | /* All map kind of cgroup file get serviced by this function */ | |
905 | static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft, | |
906 | struct cgroup_map_cb *cb) | |
907 | { | |
908 | struct blkio_cgroup *blkcg; | |
909 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
910 | int name = BLKIOFILE_ATTR(cft->private); | |
911 | ||
912 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
913 | ||
914 | switch(plid) { | |
915 | case BLKIO_POLICY_PROP: | |
916 | switch(name) { | |
917 | case BLKIO_PROP_time: | |
918 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
919 | BLKIO_STAT_TIME, 0); | |
920 | case BLKIO_PROP_sectors: | |
921 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
922 | BLKIO_STAT_SECTORS, 0); | |
923 | case BLKIO_PROP_io_service_bytes: | |
924 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
925 | BLKIO_STAT_SERVICE_BYTES, 1); | |
926 | case BLKIO_PROP_io_serviced: | |
927 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
928 | BLKIO_STAT_SERVICED, 1); | |
929 | case BLKIO_PROP_io_service_time: | |
930 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
931 | BLKIO_STAT_SERVICE_TIME, 1); | |
932 | case BLKIO_PROP_io_wait_time: | |
933 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
934 | BLKIO_STAT_WAIT_TIME, 1); | |
935 | case BLKIO_PROP_io_merged: | |
936 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
937 | BLKIO_STAT_MERGED, 1); | |
938 | case BLKIO_PROP_io_queued: | |
939 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
940 | BLKIO_STAT_QUEUED, 1); | |
941 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
942 | case BLKIO_PROP_dequeue: | |
943 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
944 | BLKIO_STAT_DEQUEUE, 0); | |
945 | case BLKIO_PROP_avg_queue_size: | |
946 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
947 | BLKIO_STAT_AVG_QUEUE_SIZE, 0); | |
948 | case BLKIO_PROP_group_wait_time: | |
949 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
950 | BLKIO_STAT_GROUP_WAIT_TIME, 0); | |
951 | case BLKIO_PROP_idle_time: | |
952 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
953 | BLKIO_STAT_IDLE_TIME, 0); | |
954 | case BLKIO_PROP_empty_time: | |
955 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
956 | BLKIO_STAT_EMPTY_TIME, 0); | |
957 | #endif | |
958 | default: | |
959 | BUG(); | |
960 | } | |
961 | break; | |
962 | ||
963 | default: | |
964 | BUG(); | |
965 | } | |
966 | ||
967 | return 0; | |
968 | } | |
969 | ||
970 | static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val) | |
971 | { | |
972 | struct blkio_group *blkg; | |
973 | struct hlist_node *n; | |
974 | struct blkio_policy_node *pn; | |
975 | ||
976 | if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) | |
977 | return -EINVAL; | |
978 | ||
979 | spin_lock(&blkio_list_lock); | |
980 | spin_lock_irq(&blkcg->lock); | |
981 | blkcg->weight = (unsigned int)val; | |
982 | ||
983 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
984 | pn = blkio_policy_search_node(blkcg, blkg->dev, | |
985 | BLKIO_POLICY_PROP, BLKIO_PROP_weight_device); | |
986 | if (pn) | |
987 | continue; | |
988 | ||
989 | blkio_update_group_weight(blkg, blkcg->weight); | |
990 | } | |
991 | spin_unlock_irq(&blkcg->lock); | |
992 | spin_unlock(&blkio_list_lock); | |
993 | return 0; | |
994 | } | |
995 | ||
996 | static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) { | |
997 | struct blkio_cgroup *blkcg; | |
998 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
999 | int name = BLKIOFILE_ATTR(cft->private); | |
1000 | ||
1001 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1002 | ||
1003 | switch(plid) { | |
1004 | case BLKIO_POLICY_PROP: | |
1005 | switch(name) { | |
1006 | case BLKIO_PROP_weight: | |
1007 | return (u64)blkcg->weight; | |
1008 | } | |
1009 | break; | |
1010 | default: | |
1011 | BUG(); | |
1012 | } | |
1013 | return 0; | |
1014 | } | |
1015 | ||
1016 | static int | |
1017 | blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) | |
1018 | { | |
1019 | struct blkio_cgroup *blkcg; | |
1020 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1021 | int name = BLKIOFILE_ATTR(cft->private); | |
1022 | ||
1023 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1024 | ||
1025 | switch(plid) { | |
1026 | case BLKIO_POLICY_PROP: | |
1027 | switch(name) { | |
1028 | case BLKIO_PROP_weight: | |
1029 | return blkio_weight_write(blkcg, val); | |
1030 | } | |
1031 | break; | |
1032 | default: | |
1033 | BUG(); | |
1034 | } | |
34d0f179 | 1035 | |
34d0f179 GJ |
1036 | return 0; |
1037 | } | |
1038 | ||
31e4c28d | 1039 | struct cftype blkio_files[] = { |
34d0f179 GJ |
1040 | { |
1041 | .name = "weight_device", | |
062a644d VG |
1042 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1043 | BLKIO_PROP_weight_device), | |
1044 | .read_seq_string = blkiocg_file_read, | |
1045 | .write_string = blkiocg_file_write, | |
34d0f179 GJ |
1046 | .max_write_len = 256, |
1047 | }, | |
31e4c28d VG |
1048 | { |
1049 | .name = "weight", | |
062a644d VG |
1050 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1051 | BLKIO_PROP_weight), | |
1052 | .read_u64 = blkiocg_file_read_u64, | |
1053 | .write_u64 = blkiocg_file_write_u64, | |
31e4c28d | 1054 | }, |
22084190 VG |
1055 | { |
1056 | .name = "time", | |
062a644d VG |
1057 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1058 | BLKIO_PROP_time), | |
1059 | .read_map = blkiocg_file_read_map, | |
22084190 VG |
1060 | }, |
1061 | { | |
1062 | .name = "sectors", | |
062a644d VG |
1063 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1064 | BLKIO_PROP_sectors), | |
1065 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1066 | }, |
1067 | { | |
1068 | .name = "io_service_bytes", | |
062a644d VG |
1069 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1070 | BLKIO_PROP_io_service_bytes), | |
1071 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1072 | }, |
1073 | { | |
1074 | .name = "io_serviced", | |
062a644d VG |
1075 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1076 | BLKIO_PROP_io_serviced), | |
1077 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1078 | }, |
1079 | { | |
1080 | .name = "io_service_time", | |
062a644d VG |
1081 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1082 | BLKIO_PROP_io_service_time), | |
1083 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1084 | }, |
1085 | { | |
1086 | .name = "io_wait_time", | |
062a644d VG |
1087 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1088 | BLKIO_PROP_io_wait_time), | |
1089 | .read_map = blkiocg_file_read_map, | |
84c124da | 1090 | }, |
812d4026 DS |
1091 | { |
1092 | .name = "io_merged", | |
062a644d VG |
1093 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1094 | BLKIO_PROP_io_merged), | |
1095 | .read_map = blkiocg_file_read_map, | |
812d4026 | 1096 | }, |
cdc1184c DS |
1097 | { |
1098 | .name = "io_queued", | |
062a644d VG |
1099 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1100 | BLKIO_PROP_io_queued), | |
1101 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1102 | }, |
84c124da DS |
1103 | { |
1104 | .name = "reset_stats", | |
1105 | .write_u64 = blkiocg_reset_stats, | |
22084190 VG |
1106 | }, |
1107 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
cdc1184c DS |
1108 | { |
1109 | .name = "avg_queue_size", | |
062a644d VG |
1110 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1111 | BLKIO_PROP_avg_queue_size), | |
1112 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1113 | }, |
812df48d DS |
1114 | { |
1115 | .name = "group_wait_time", | |
062a644d VG |
1116 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1117 | BLKIO_PROP_group_wait_time), | |
1118 | .read_map = blkiocg_file_read_map, | |
812df48d DS |
1119 | }, |
1120 | { | |
1121 | .name = "idle_time", | |
062a644d VG |
1122 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1123 | BLKIO_PROP_idle_time), | |
1124 | .read_map = blkiocg_file_read_map, | |
812df48d DS |
1125 | }, |
1126 | { | |
1127 | .name = "empty_time", | |
062a644d VG |
1128 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1129 | BLKIO_PROP_empty_time), | |
1130 | .read_map = blkiocg_file_read_map, | |
812df48d | 1131 | }, |
cdc1184c | 1132 | { |
22084190 | 1133 | .name = "dequeue", |
062a644d VG |
1134 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1135 | BLKIO_PROP_dequeue), | |
1136 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1137 | }, |
22084190 | 1138 | #endif |
31e4c28d VG |
1139 | }; |
1140 | ||
1141 | static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1142 | { | |
1143 | return cgroup_add_files(cgroup, subsys, blkio_files, | |
1144 | ARRAY_SIZE(blkio_files)); | |
1145 | } | |
1146 | ||
1147 | static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1148 | { | |
1149 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); | |
b1c35769 VG |
1150 | unsigned long flags; |
1151 | struct blkio_group *blkg; | |
1152 | void *key; | |
3e252066 | 1153 | struct blkio_policy_type *blkiop; |
34d0f179 | 1154 | struct blkio_policy_node *pn, *pntmp; |
b1c35769 VG |
1155 | |
1156 | rcu_read_lock(); | |
0f3942a3 JA |
1157 | do { |
1158 | spin_lock_irqsave(&blkcg->lock, flags); | |
b1c35769 | 1159 | |
0f3942a3 JA |
1160 | if (hlist_empty(&blkcg->blkg_list)) { |
1161 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
1162 | break; | |
1163 | } | |
b1c35769 | 1164 | |
0f3942a3 JA |
1165 | blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, |
1166 | blkcg_node); | |
1167 | key = rcu_dereference(blkg->key); | |
1168 | __blkiocg_del_blkio_group(blkg); | |
31e4c28d | 1169 | |
0f3942a3 | 1170 | spin_unlock_irqrestore(&blkcg->lock, flags); |
b1c35769 | 1171 | |
0f3942a3 JA |
1172 | /* |
1173 | * This blkio_group is being unlinked as associated cgroup is | |
1174 | * going away. Let all the IO controlling policies know about | |
1175 | * this event. Currently this is static call to one io | |
1176 | * controlling policy. Once we have more policies in place, we | |
1177 | * need some dynamic registration of callback function. | |
1178 | */ | |
1179 | spin_lock(&blkio_list_lock); | |
1180 | list_for_each_entry(blkiop, &blkio_list, list) | |
1181 | blkiop->ops.blkio_unlink_group_fn(key, blkg); | |
1182 | spin_unlock(&blkio_list_lock); | |
1183 | } while (1); | |
34d0f179 | 1184 | |
34d0f179 GJ |
1185 | list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { |
1186 | blkio_policy_delete_node(pn); | |
1187 | kfree(pn); | |
1188 | } | |
0f3942a3 | 1189 | |
31e4c28d | 1190 | free_css_id(&blkio_subsys, &blkcg->css); |
b1c35769 | 1191 | rcu_read_unlock(); |
67523c48 BB |
1192 | if (blkcg != &blkio_root_cgroup) |
1193 | kfree(blkcg); | |
31e4c28d VG |
1194 | } |
1195 | ||
1196 | static struct cgroup_subsys_state * | |
1197 | blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1198 | { | |
0341509f LZ |
1199 | struct blkio_cgroup *blkcg; |
1200 | struct cgroup *parent = cgroup->parent; | |
31e4c28d | 1201 | |
0341509f | 1202 | if (!parent) { |
31e4c28d VG |
1203 | blkcg = &blkio_root_cgroup; |
1204 | goto done; | |
1205 | } | |
1206 | ||
1207 | /* Currently we do not support hierarchy deeper than two level (0,1) */ | |
0341509f | 1208 | if (parent != cgroup->top_cgroup) |
31e4c28d VG |
1209 | return ERR_PTR(-EINVAL); |
1210 | ||
1211 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); | |
1212 | if (!blkcg) | |
1213 | return ERR_PTR(-ENOMEM); | |
1214 | ||
1215 | blkcg->weight = BLKIO_WEIGHT_DEFAULT; | |
1216 | done: | |
1217 | spin_lock_init(&blkcg->lock); | |
1218 | INIT_HLIST_HEAD(&blkcg->blkg_list); | |
1219 | ||
34d0f179 | 1220 | INIT_LIST_HEAD(&blkcg->policy_list); |
31e4c28d VG |
1221 | return &blkcg->css; |
1222 | } | |
1223 | ||
1224 | /* | |
1225 | * We cannot support shared io contexts, as we have no mean to support | |
1226 | * two tasks with the same ioc in two different groups without major rework | |
1227 | * of the main cic data structures. For now we allow a task to change | |
1228 | * its cgroup only if it's the only owner of its ioc. | |
1229 | */ | |
1230 | static int blkiocg_can_attach(struct cgroup_subsys *subsys, | |
1231 | struct cgroup *cgroup, struct task_struct *tsk, | |
1232 | bool threadgroup) | |
1233 | { | |
1234 | struct io_context *ioc; | |
1235 | int ret = 0; | |
1236 | ||
1237 | /* task_lock() is needed to avoid races with exit_io_context() */ | |
1238 | task_lock(tsk); | |
1239 | ioc = tsk->io_context; | |
1240 | if (ioc && atomic_read(&ioc->nr_tasks) > 1) | |
1241 | ret = -EINVAL; | |
1242 | task_unlock(tsk); | |
1243 | ||
1244 | return ret; | |
1245 | } | |
1246 | ||
1247 | static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup, | |
1248 | struct cgroup *prev, struct task_struct *tsk, | |
1249 | bool threadgroup) | |
1250 | { | |
1251 | struct io_context *ioc; | |
1252 | ||
1253 | task_lock(tsk); | |
1254 | ioc = tsk->io_context; | |
1255 | if (ioc) | |
1256 | ioc->cgroup_changed = 1; | |
1257 | task_unlock(tsk); | |
1258 | } | |
1259 | ||
3e252066 VG |
1260 | void blkio_policy_register(struct blkio_policy_type *blkiop) |
1261 | { | |
1262 | spin_lock(&blkio_list_lock); | |
1263 | list_add_tail(&blkiop->list, &blkio_list); | |
1264 | spin_unlock(&blkio_list_lock); | |
1265 | } | |
1266 | EXPORT_SYMBOL_GPL(blkio_policy_register); | |
1267 | ||
1268 | void blkio_policy_unregister(struct blkio_policy_type *blkiop) | |
1269 | { | |
1270 | spin_lock(&blkio_list_lock); | |
1271 | list_del_init(&blkiop->list); | |
1272 | spin_unlock(&blkio_list_lock); | |
1273 | } | |
1274 | EXPORT_SYMBOL_GPL(blkio_policy_unregister); | |
67523c48 BB |
1275 | |
1276 | static int __init init_cgroup_blkio(void) | |
1277 | { | |
1278 | return cgroup_load_subsys(&blkio_subsys); | |
1279 | } | |
1280 | ||
1281 | static void __exit exit_cgroup_blkio(void) | |
1282 | { | |
1283 | cgroup_unload_subsys(&blkio_subsys); | |
1284 | } | |
1285 | ||
1286 | module_init(init_cgroup_blkio); | |
1287 | module_exit(exit_cgroup_blkio); | |
1288 | MODULE_LICENSE("GPL"); |