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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> | |
14 | #include <linux/seq_file.h> | |
15 | #include <linux/kdev_t.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/blkdev.h> | |
19 | #include <linux/slab.h> | |
20 | #include "blk-cgroup.h" | |
21 | #include <linux/genhd.h> | |
22 | ||
23 | #define MAX_KEY_LEN 100 | |
24 | ||
25 | static DEFINE_SPINLOCK(blkio_list_lock); | |
26 | static LIST_HEAD(blkio_list); | |
27 | ||
28 | struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; | |
29 | EXPORT_SYMBOL_GPL(blkio_root_cgroup); | |
30 | ||
31 | static struct cgroup_subsys_state *blkiocg_create(struct cgroup *); | |
32 | static int blkiocg_can_attach(struct cgroup *, struct cgroup_taskset *); | |
33 | static void blkiocg_attach(struct cgroup *, struct cgroup_taskset *); | |
34 | static void blkiocg_destroy(struct cgroup *); | |
35 | static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); | |
36 | ||
37 | /* for encoding cft->private value on file */ | |
38 | #define BLKIOFILE_PRIVATE(x, val) (((x) << 16) | (val)) | |
39 | /* What policy owns the file, proportional or throttle */ | |
40 | #define BLKIOFILE_POLICY(val) (((val) >> 16) & 0xffff) | |
41 | #define BLKIOFILE_ATTR(val) ((val) & 0xffff) | |
42 | ||
43 | struct cgroup_subsys blkio_subsys = { | |
44 | .name = "blkio", | |
45 | .create = blkiocg_create, | |
46 | .can_attach = blkiocg_can_attach, | |
47 | .attach = blkiocg_attach, | |
48 | .destroy = blkiocg_destroy, | |
49 | .populate = blkiocg_populate, | |
50 | #ifdef CONFIG_BLK_CGROUP | |
51 | /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */ | |
52 | .subsys_id = blkio_subsys_id, | |
53 | #endif | |
54 | .use_id = 1, | |
55 | .module = THIS_MODULE, | |
56 | }; | |
57 | EXPORT_SYMBOL_GPL(blkio_subsys); | |
58 | ||
59 | static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg, | |
60 | struct blkio_policy_node *pn) | |
61 | { | |
62 | list_add(&pn->node, &blkcg->policy_list); | |
63 | } | |
64 | ||
65 | static inline bool cftype_blkg_same_policy(struct cftype *cft, | |
66 | struct blkio_group *blkg) | |
67 | { | |
68 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
69 | ||
70 | if (blkg->plid == plid) | |
71 | return 1; | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | /* Determines if policy node matches cgroup file being accessed */ | |
77 | static inline bool pn_matches_cftype(struct cftype *cft, | |
78 | struct blkio_policy_node *pn) | |
79 | { | |
80 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
81 | int fileid = BLKIOFILE_ATTR(cft->private); | |
82 | ||
83 | return (plid == pn->plid && fileid == pn->fileid); | |
84 | } | |
85 | ||
86 | /* Must be called with blkcg->lock held */ | |
87 | static inline void blkio_policy_delete_node(struct blkio_policy_node *pn) | |
88 | { | |
89 | list_del(&pn->node); | |
90 | } | |
91 | ||
92 | /* Must be called with blkcg->lock held */ | |
93 | static struct blkio_policy_node * | |
94 | blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev, | |
95 | enum blkio_policy_id plid, int fileid) | |
96 | { | |
97 | struct blkio_policy_node *pn; | |
98 | ||
99 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
100 | if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid) | |
101 | return pn; | |
102 | } | |
103 | ||
104 | return NULL; | |
105 | } | |
106 | ||
107 | struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) | |
108 | { | |
109 | return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), | |
110 | struct blkio_cgroup, css); | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup); | |
113 | ||
114 | struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk) | |
115 | { | |
116 | return container_of(task_subsys_state(tsk, blkio_subsys_id), | |
117 | struct blkio_cgroup, css); | |
118 | } | |
119 | EXPORT_SYMBOL_GPL(task_blkio_cgroup); | |
120 | ||
121 | static inline void | |
122 | blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight) | |
123 | { | |
124 | struct blkio_policy_type *blkiop; | |
125 | ||
126 | list_for_each_entry(blkiop, &blkio_list, list) { | |
127 | /* If this policy does not own the blkg, do not send updates */ | |
128 | if (blkiop->plid != blkg->plid) | |
129 | continue; | |
130 | if (blkiop->ops.blkio_update_group_weight_fn) | |
131 | blkiop->ops.blkio_update_group_weight_fn(blkg->key, | |
132 | blkg, weight); | |
133 | } | |
134 | } | |
135 | ||
136 | static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps, | |
137 | int fileid) | |
138 | { | |
139 | struct blkio_policy_type *blkiop; | |
140 | ||
141 | list_for_each_entry(blkiop, &blkio_list, list) { | |
142 | ||
143 | /* If this policy does not own the blkg, do not send updates */ | |
144 | if (blkiop->plid != blkg->plid) | |
145 | continue; | |
146 | ||
147 | if (fileid == BLKIO_THROTL_read_bps_device | |
148 | && blkiop->ops.blkio_update_group_read_bps_fn) | |
149 | blkiop->ops.blkio_update_group_read_bps_fn(blkg->key, | |
150 | blkg, bps); | |
151 | ||
152 | if (fileid == BLKIO_THROTL_write_bps_device | |
153 | && blkiop->ops.blkio_update_group_write_bps_fn) | |
154 | blkiop->ops.blkio_update_group_write_bps_fn(blkg->key, | |
155 | blkg, bps); | |
156 | } | |
157 | } | |
158 | ||
159 | static inline void blkio_update_group_iops(struct blkio_group *blkg, | |
160 | unsigned int iops, int fileid) | |
161 | { | |
162 | struct blkio_policy_type *blkiop; | |
163 | ||
164 | list_for_each_entry(blkiop, &blkio_list, list) { | |
165 | ||
166 | /* If this policy does not own the blkg, do not send updates */ | |
167 | if (blkiop->plid != blkg->plid) | |
168 | continue; | |
169 | ||
170 | if (fileid == BLKIO_THROTL_read_iops_device | |
171 | && blkiop->ops.blkio_update_group_read_iops_fn) | |
172 | blkiop->ops.blkio_update_group_read_iops_fn(blkg->key, | |
173 | blkg, iops); | |
174 | ||
175 | if (fileid == BLKIO_THROTL_write_iops_device | |
176 | && blkiop->ops.blkio_update_group_write_iops_fn) | |
177 | blkiop->ops.blkio_update_group_write_iops_fn(blkg->key, | |
178 | blkg,iops); | |
179 | } | |
180 | } | |
181 | ||
182 | /* | |
183 | * Add to the appropriate stat variable depending on the request type. | |
184 | * This should be called with the blkg->stats_lock held. | |
185 | */ | |
186 | static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction, | |
187 | bool sync) | |
188 | { | |
189 | if (direction) | |
190 | stat[BLKIO_STAT_WRITE] += add; | |
191 | else | |
192 | stat[BLKIO_STAT_READ] += add; | |
193 | if (sync) | |
194 | stat[BLKIO_STAT_SYNC] += add; | |
195 | else | |
196 | stat[BLKIO_STAT_ASYNC] += add; | |
197 | } | |
198 | ||
199 | /* | |
200 | * Decrements the appropriate stat variable if non-zero depending on the | |
201 | * request type. Panics on value being zero. | |
202 | * This should be called with the blkg->stats_lock held. | |
203 | */ | |
204 | static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync) | |
205 | { | |
206 | if (direction) { | |
207 | BUG_ON(stat[BLKIO_STAT_WRITE] == 0); | |
208 | stat[BLKIO_STAT_WRITE]--; | |
209 | } else { | |
210 | BUG_ON(stat[BLKIO_STAT_READ] == 0); | |
211 | stat[BLKIO_STAT_READ]--; | |
212 | } | |
213 | if (sync) { | |
214 | BUG_ON(stat[BLKIO_STAT_SYNC] == 0); | |
215 | stat[BLKIO_STAT_SYNC]--; | |
216 | } else { | |
217 | BUG_ON(stat[BLKIO_STAT_ASYNC] == 0); | |
218 | stat[BLKIO_STAT_ASYNC]--; | |
219 | } | |
220 | } | |
221 | ||
222 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
223 | /* This should be called with the blkg->stats_lock held. */ | |
224 | static void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
225 | struct blkio_group *curr_blkg) | |
226 | { | |
227 | if (blkio_blkg_waiting(&blkg->stats)) | |
228 | return; | |
229 | if (blkg == curr_blkg) | |
230 | return; | |
231 | blkg->stats.start_group_wait_time = sched_clock(); | |
232 | blkio_mark_blkg_waiting(&blkg->stats); | |
233 | } | |
234 | ||
235 | /* This should be called with the blkg->stats_lock held. */ | |
236 | static void blkio_update_group_wait_time(struct blkio_group_stats *stats) | |
237 | { | |
238 | unsigned long long now; | |
239 | ||
240 | if (!blkio_blkg_waiting(stats)) | |
241 | return; | |
242 | ||
243 | now = sched_clock(); | |
244 | if (time_after64(now, stats->start_group_wait_time)) | |
245 | stats->group_wait_time += now - stats->start_group_wait_time; | |
246 | blkio_clear_blkg_waiting(stats); | |
247 | } | |
248 | ||
249 | /* This should be called with the blkg->stats_lock held. */ | |
250 | static void blkio_end_empty_time(struct blkio_group_stats *stats) | |
251 | { | |
252 | unsigned long long now; | |
253 | ||
254 | if (!blkio_blkg_empty(stats)) | |
255 | return; | |
256 | ||
257 | now = sched_clock(); | |
258 | if (time_after64(now, stats->start_empty_time)) | |
259 | stats->empty_time += now - stats->start_empty_time; | |
260 | blkio_clear_blkg_empty(stats); | |
261 | } | |
262 | ||
263 | void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) | |
264 | { | |
265 | unsigned long flags; | |
266 | ||
267 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
268 | BUG_ON(blkio_blkg_idling(&blkg->stats)); | |
269 | blkg->stats.start_idle_time = sched_clock(); | |
270 | blkio_mark_blkg_idling(&blkg->stats); | |
271 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
272 | } | |
273 | EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats); | |
274 | ||
275 | void blkiocg_update_idle_time_stats(struct blkio_group *blkg) | |
276 | { | |
277 | unsigned long flags; | |
278 | unsigned long long now; | |
279 | struct blkio_group_stats *stats; | |
280 | ||
281 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
282 | stats = &blkg->stats; | |
283 | if (blkio_blkg_idling(stats)) { | |
284 | now = sched_clock(); | |
285 | if (time_after64(now, stats->start_idle_time)) | |
286 | stats->idle_time += now - stats->start_idle_time; | |
287 | blkio_clear_blkg_idling(stats); | |
288 | } | |
289 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
290 | } | |
291 | EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats); | |
292 | ||
293 | void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) | |
294 | { | |
295 | unsigned long flags; | |
296 | struct blkio_group_stats *stats; | |
297 | ||
298 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
299 | stats = &blkg->stats; | |
300 | stats->avg_queue_size_sum += | |
301 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] + | |
302 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]; | |
303 | stats->avg_queue_size_samples++; | |
304 | blkio_update_group_wait_time(stats); | |
305 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
306 | } | |
307 | EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats); | |
308 | ||
309 | void blkiocg_set_start_empty_time(struct blkio_group *blkg) | |
310 | { | |
311 | unsigned long flags; | |
312 | struct blkio_group_stats *stats; | |
313 | ||
314 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
315 | stats = &blkg->stats; | |
316 | ||
317 | if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] || | |
318 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]) { | |
319 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
320 | return; | |
321 | } | |
322 | ||
323 | /* | |
324 | * group is already marked empty. This can happen if cfqq got new | |
325 | * request in parent group and moved to this group while being added | |
326 | * to service tree. Just ignore the event and move on. | |
327 | */ | |
328 | if(blkio_blkg_empty(stats)) { | |
329 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
330 | return; | |
331 | } | |
332 | ||
333 | stats->start_empty_time = sched_clock(); | |
334 | blkio_mark_blkg_empty(stats); | |
335 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
336 | } | |
337 | EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time); | |
338 | ||
339 | void blkiocg_update_dequeue_stats(struct blkio_group *blkg, | |
340 | unsigned long dequeue) | |
341 | { | |
342 | blkg->stats.dequeue += dequeue; | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats); | |
345 | #else | |
346 | static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
347 | struct blkio_group *curr_blkg) {} | |
348 | static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {} | |
349 | #endif | |
350 | ||
351 | void blkiocg_update_io_add_stats(struct blkio_group *blkg, | |
352 | struct blkio_group *curr_blkg, bool direction, | |
353 | bool sync) | |
354 | { | |
355 | unsigned long flags; | |
356 | ||
357 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
358 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], 1, direction, | |
359 | sync); | |
360 | blkio_end_empty_time(&blkg->stats); | |
361 | blkio_set_start_group_wait_time(blkg, curr_blkg); | |
362 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
363 | } | |
364 | EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats); | |
365 | ||
366 | void blkiocg_update_io_remove_stats(struct blkio_group *blkg, | |
367 | bool direction, bool sync) | |
368 | { | |
369 | unsigned long flags; | |
370 | ||
371 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
372 | blkio_check_and_dec_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], | |
373 | direction, sync); | |
374 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats); | |
377 | ||
378 | void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time, | |
379 | unsigned long unaccounted_time) | |
380 | { | |
381 | unsigned long flags; | |
382 | ||
383 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
384 | blkg->stats.time += time; | |
385 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
386 | blkg->stats.unaccounted_time += unaccounted_time; | |
387 | #endif | |
388 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
389 | } | |
390 | EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used); | |
391 | ||
392 | /* | |
393 | * should be called under rcu read lock or queue lock to make sure blkg pointer | |
394 | * is valid. | |
395 | */ | |
396 | void blkiocg_update_dispatch_stats(struct blkio_group *blkg, | |
397 | uint64_t bytes, bool direction, bool sync) | |
398 | { | |
399 | struct blkio_group_stats_cpu *stats_cpu; | |
400 | unsigned long flags; | |
401 | ||
402 | /* | |
403 | * Disabling interrupts to provide mutual exclusion between two | |
404 | * writes on same cpu. It probably is not needed for 64bit. Not | |
405 | * optimizing that case yet. | |
406 | */ | |
407 | local_irq_save(flags); | |
408 | ||
409 | stats_cpu = this_cpu_ptr(blkg->stats_cpu); | |
410 | ||
411 | u64_stats_update_begin(&stats_cpu->syncp); | |
412 | stats_cpu->sectors += bytes >> 9; | |
413 | blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICED], | |
414 | 1, direction, sync); | |
415 | blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICE_BYTES], | |
416 | bytes, direction, sync); | |
417 | u64_stats_update_end(&stats_cpu->syncp); | |
418 | local_irq_restore(flags); | |
419 | } | |
420 | EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats); | |
421 | ||
422 | void blkiocg_update_completion_stats(struct blkio_group *blkg, | |
423 | uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) | |
424 | { | |
425 | struct blkio_group_stats *stats; | |
426 | unsigned long flags; | |
427 | unsigned long long now = sched_clock(); | |
428 | ||
429 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
430 | stats = &blkg->stats; | |
431 | if (time_after64(now, io_start_time)) | |
432 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME], | |
433 | now - io_start_time, direction, sync); | |
434 | if (time_after64(io_start_time, start_time)) | |
435 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME], | |
436 | io_start_time - start_time, direction, sync); | |
437 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
438 | } | |
439 | EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats); | |
440 | ||
441 | /* Merged stats are per cpu. */ | |
442 | void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction, | |
443 | bool sync) | |
444 | { | |
445 | struct blkio_group_stats_cpu *stats_cpu; | |
446 | unsigned long flags; | |
447 | ||
448 | /* | |
449 | * Disabling interrupts to provide mutual exclusion between two | |
450 | * writes on same cpu. It probably is not needed for 64bit. Not | |
451 | * optimizing that case yet. | |
452 | */ | |
453 | local_irq_save(flags); | |
454 | ||
455 | stats_cpu = this_cpu_ptr(blkg->stats_cpu); | |
456 | ||
457 | u64_stats_update_begin(&stats_cpu->syncp); | |
458 | blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_MERGED], 1, | |
459 | direction, sync); | |
460 | u64_stats_update_end(&stats_cpu->syncp); | |
461 | local_irq_restore(flags); | |
462 | } | |
463 | EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats); | |
464 | ||
465 | /* | |
466 | * This function allocates the per cpu stats for blkio_group. Should be called | |
467 | * from sleepable context as alloc_per_cpu() requires that. | |
468 | */ | |
469 | int blkio_alloc_blkg_stats(struct blkio_group *blkg) | |
470 | { | |
471 | /* Allocate memory for per cpu stats */ | |
472 | blkg->stats_cpu = alloc_percpu(struct blkio_group_stats_cpu); | |
473 | if (!blkg->stats_cpu) | |
474 | return -ENOMEM; | |
475 | return 0; | |
476 | } | |
477 | EXPORT_SYMBOL_GPL(blkio_alloc_blkg_stats); | |
478 | ||
479 | void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, | |
480 | struct blkio_group *blkg, void *key, dev_t dev, | |
481 | enum blkio_policy_id plid) | |
482 | { | |
483 | unsigned long flags; | |
484 | ||
485 | spin_lock_irqsave(&blkcg->lock, flags); | |
486 | spin_lock_init(&blkg->stats_lock); | |
487 | rcu_assign_pointer(blkg->key, key); | |
488 | blkg->blkcg_id = css_id(&blkcg->css); | |
489 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); | |
490 | blkg->plid = plid; | |
491 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
492 | /* Need to take css reference ? */ | |
493 | cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); | |
494 | blkg->dev = dev; | |
495 | } | |
496 | EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); | |
497 | ||
498 | static void __blkiocg_del_blkio_group(struct blkio_group *blkg) | |
499 | { | |
500 | hlist_del_init_rcu(&blkg->blkcg_node); | |
501 | blkg->blkcg_id = 0; | |
502 | } | |
503 | ||
504 | /* | |
505 | * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1 | |
506 | * indicating that blk_group was unhashed by the time we got to it. | |
507 | */ | |
508 | int blkiocg_del_blkio_group(struct blkio_group *blkg) | |
509 | { | |
510 | struct blkio_cgroup *blkcg; | |
511 | unsigned long flags; | |
512 | struct cgroup_subsys_state *css; | |
513 | int ret = 1; | |
514 | ||
515 | rcu_read_lock(); | |
516 | css = css_lookup(&blkio_subsys, blkg->blkcg_id); | |
517 | if (css) { | |
518 | blkcg = container_of(css, struct blkio_cgroup, css); | |
519 | spin_lock_irqsave(&blkcg->lock, flags); | |
520 | if (!hlist_unhashed(&blkg->blkcg_node)) { | |
521 | __blkiocg_del_blkio_group(blkg); | |
522 | ret = 0; | |
523 | } | |
524 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
525 | } | |
526 | ||
527 | rcu_read_unlock(); | |
528 | return ret; | |
529 | } | |
530 | EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); | |
531 | ||
532 | /* called under rcu_read_lock(). */ | |
533 | struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) | |
534 | { | |
535 | struct blkio_group *blkg; | |
536 | struct hlist_node *n; | |
537 | void *__key; | |
538 | ||
539 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
540 | __key = blkg->key; | |
541 | if (__key == key) | |
542 | return blkg; | |
543 | } | |
544 | ||
545 | return NULL; | |
546 | } | |
547 | EXPORT_SYMBOL_GPL(blkiocg_lookup_group); | |
548 | ||
549 | static void blkio_reset_stats_cpu(struct blkio_group *blkg) | |
550 | { | |
551 | struct blkio_group_stats_cpu *stats_cpu; | |
552 | int i, j, k; | |
553 | /* | |
554 | * Note: On 64 bit arch this should not be an issue. This has the | |
555 | * possibility of returning some inconsistent value on 32bit arch | |
556 | * as 64bit update on 32bit is non atomic. Taking care of this | |
557 | * corner case makes code very complicated, like sending IPIs to | |
558 | * cpus, taking care of stats of offline cpus etc. | |
559 | * | |
560 | * reset stats is anyway more of a debug feature and this sounds a | |
561 | * corner case. So I am not complicating the code yet until and | |
562 | * unless this becomes a real issue. | |
563 | */ | |
564 | for_each_possible_cpu(i) { | |
565 | stats_cpu = per_cpu_ptr(blkg->stats_cpu, i); | |
566 | stats_cpu->sectors = 0; | |
567 | for(j = 0; j < BLKIO_STAT_CPU_NR; j++) | |
568 | for (k = 0; k < BLKIO_STAT_TOTAL; k++) | |
569 | stats_cpu->stat_arr_cpu[j][k] = 0; | |
570 | } | |
571 | } | |
572 | ||
573 | static int | |
574 | blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) | |
575 | { | |
576 | struct blkio_cgroup *blkcg; | |
577 | struct blkio_group *blkg; | |
578 | struct blkio_group_stats *stats; | |
579 | struct hlist_node *n; | |
580 | uint64_t queued[BLKIO_STAT_TOTAL]; | |
581 | int i; | |
582 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
583 | bool idling, waiting, empty; | |
584 | unsigned long long now = sched_clock(); | |
585 | #endif | |
586 | ||
587 | blkcg = cgroup_to_blkio_cgroup(cgroup); | |
588 | spin_lock_irq(&blkcg->lock); | |
589 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
590 | spin_lock(&blkg->stats_lock); | |
591 | stats = &blkg->stats; | |
592 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
593 | idling = blkio_blkg_idling(stats); | |
594 | waiting = blkio_blkg_waiting(stats); | |
595 | empty = blkio_blkg_empty(stats); | |
596 | #endif | |
597 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) | |
598 | queued[i] = stats->stat_arr[BLKIO_STAT_QUEUED][i]; | |
599 | memset(stats, 0, sizeof(struct blkio_group_stats)); | |
600 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) | |
601 | stats->stat_arr[BLKIO_STAT_QUEUED][i] = queued[i]; | |
602 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
603 | if (idling) { | |
604 | blkio_mark_blkg_idling(stats); | |
605 | stats->start_idle_time = now; | |
606 | } | |
607 | if (waiting) { | |
608 | blkio_mark_blkg_waiting(stats); | |
609 | stats->start_group_wait_time = now; | |
610 | } | |
611 | if (empty) { | |
612 | blkio_mark_blkg_empty(stats); | |
613 | stats->start_empty_time = now; | |
614 | } | |
615 | #endif | |
616 | spin_unlock(&blkg->stats_lock); | |
617 | ||
618 | /* Reset Per cpu stats which don't take blkg->stats_lock */ | |
619 | blkio_reset_stats_cpu(blkg); | |
620 | } | |
621 | ||
622 | spin_unlock_irq(&blkcg->lock); | |
623 | return 0; | |
624 | } | |
625 | ||
626 | static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str, | |
627 | int chars_left, bool diskname_only) | |
628 | { | |
629 | snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev)); | |
630 | chars_left -= strlen(str); | |
631 | if (chars_left <= 0) { | |
632 | printk(KERN_WARNING | |
633 | "Possibly incorrect cgroup stat display format"); | |
634 | return; | |
635 | } | |
636 | if (diskname_only) | |
637 | return; | |
638 | switch (type) { | |
639 | case BLKIO_STAT_READ: | |
640 | strlcat(str, " Read", chars_left); | |
641 | break; | |
642 | case BLKIO_STAT_WRITE: | |
643 | strlcat(str, " Write", chars_left); | |
644 | break; | |
645 | case BLKIO_STAT_SYNC: | |
646 | strlcat(str, " Sync", chars_left); | |
647 | break; | |
648 | case BLKIO_STAT_ASYNC: | |
649 | strlcat(str, " Async", chars_left); | |
650 | break; | |
651 | case BLKIO_STAT_TOTAL: | |
652 | strlcat(str, " Total", chars_left); | |
653 | break; | |
654 | default: | |
655 | strlcat(str, " Invalid", chars_left); | |
656 | } | |
657 | } | |
658 | ||
659 | static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val, | |
660 | struct cgroup_map_cb *cb, dev_t dev) | |
661 | { | |
662 | blkio_get_key_name(0, dev, str, chars_left, true); | |
663 | cb->fill(cb, str, val); | |
664 | return val; | |
665 | } | |
666 | ||
667 | ||
668 | static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg, | |
669 | enum stat_type_cpu type, enum stat_sub_type sub_type) | |
670 | { | |
671 | int cpu; | |
672 | struct blkio_group_stats_cpu *stats_cpu; | |
673 | u64 val = 0, tval; | |
674 | ||
675 | for_each_possible_cpu(cpu) { | |
676 | unsigned int start; | |
677 | stats_cpu = per_cpu_ptr(blkg->stats_cpu, cpu); | |
678 | ||
679 | do { | |
680 | start = u64_stats_fetch_begin(&stats_cpu->syncp); | |
681 | if (type == BLKIO_STAT_CPU_SECTORS) | |
682 | tval = stats_cpu->sectors; | |
683 | else | |
684 | tval = stats_cpu->stat_arr_cpu[type][sub_type]; | |
685 | } while(u64_stats_fetch_retry(&stats_cpu->syncp, start)); | |
686 | ||
687 | val += tval; | |
688 | } | |
689 | ||
690 | return val; | |
691 | } | |
692 | ||
693 | static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg, | |
694 | struct cgroup_map_cb *cb, dev_t dev, enum stat_type_cpu type) | |
695 | { | |
696 | uint64_t disk_total, val; | |
697 | char key_str[MAX_KEY_LEN]; | |
698 | enum stat_sub_type sub_type; | |
699 | ||
700 | if (type == BLKIO_STAT_CPU_SECTORS) { | |
701 | val = blkio_read_stat_cpu(blkg, type, 0); | |
702 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, val, cb, dev); | |
703 | } | |
704 | ||
705 | for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; | |
706 | sub_type++) { | |
707 | blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false); | |
708 | val = blkio_read_stat_cpu(blkg, type, sub_type); | |
709 | cb->fill(cb, key_str, val); | |
710 | } | |
711 | ||
712 | disk_total = blkio_read_stat_cpu(blkg, type, BLKIO_STAT_READ) + | |
713 | blkio_read_stat_cpu(blkg, type, BLKIO_STAT_WRITE); | |
714 | ||
715 | blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false); | |
716 | cb->fill(cb, key_str, disk_total); | |
717 | return disk_total; | |
718 | } | |
719 | ||
720 | /* This should be called with blkg->stats_lock held */ | |
721 | static uint64_t blkio_get_stat(struct blkio_group *blkg, | |
722 | struct cgroup_map_cb *cb, dev_t dev, enum stat_type type) | |
723 | { | |
724 | uint64_t disk_total; | |
725 | char key_str[MAX_KEY_LEN]; | |
726 | enum stat_sub_type sub_type; | |
727 | ||
728 | if (type == BLKIO_STAT_TIME) | |
729 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
730 | blkg->stats.time, cb, dev); | |
731 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
732 | if (type == BLKIO_STAT_UNACCOUNTED_TIME) | |
733 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
734 | blkg->stats.unaccounted_time, cb, dev); | |
735 | if (type == BLKIO_STAT_AVG_QUEUE_SIZE) { | |
736 | uint64_t sum = blkg->stats.avg_queue_size_sum; | |
737 | uint64_t samples = blkg->stats.avg_queue_size_samples; | |
738 | if (samples) | |
739 | do_div(sum, samples); | |
740 | else | |
741 | sum = 0; | |
742 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, sum, cb, dev); | |
743 | } | |
744 | if (type == BLKIO_STAT_GROUP_WAIT_TIME) | |
745 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
746 | blkg->stats.group_wait_time, cb, dev); | |
747 | if (type == BLKIO_STAT_IDLE_TIME) | |
748 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
749 | blkg->stats.idle_time, cb, dev); | |
750 | if (type == BLKIO_STAT_EMPTY_TIME) | |
751 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
752 | blkg->stats.empty_time, cb, dev); | |
753 | if (type == BLKIO_STAT_DEQUEUE) | |
754 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
755 | blkg->stats.dequeue, cb, dev); | |
756 | #endif | |
757 | ||
758 | for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; | |
759 | sub_type++) { | |
760 | blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false); | |
761 | cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]); | |
762 | } | |
763 | disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] + | |
764 | blkg->stats.stat_arr[type][BLKIO_STAT_WRITE]; | |
765 | blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false); | |
766 | cb->fill(cb, key_str, disk_total); | |
767 | return disk_total; | |
768 | } | |
769 | ||
770 | static int blkio_policy_parse_and_set(char *buf, | |
771 | struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid) | |
772 | { | |
773 | struct gendisk *disk = NULL; | |
774 | char *s[4], *p, *major_s = NULL, *minor_s = NULL; | |
775 | unsigned long major, minor; | |
776 | int i = 0, ret = -EINVAL; | |
777 | int part; | |
778 | dev_t dev; | |
779 | u64 temp; | |
780 | ||
781 | memset(s, 0, sizeof(s)); | |
782 | ||
783 | while ((p = strsep(&buf, " ")) != NULL) { | |
784 | if (!*p) | |
785 | continue; | |
786 | ||
787 | s[i++] = p; | |
788 | ||
789 | /* Prevent from inputing too many things */ | |
790 | if (i == 3) | |
791 | break; | |
792 | } | |
793 | ||
794 | if (i != 2) | |
795 | goto out; | |
796 | ||
797 | p = strsep(&s[0], ":"); | |
798 | if (p != NULL) | |
799 | major_s = p; | |
800 | else | |
801 | goto out; | |
802 | ||
803 | minor_s = s[0]; | |
804 | if (!minor_s) | |
805 | goto out; | |
806 | ||
807 | if (strict_strtoul(major_s, 10, &major)) | |
808 | goto out; | |
809 | ||
810 | if (strict_strtoul(minor_s, 10, &minor)) | |
811 | goto out; | |
812 | ||
813 | dev = MKDEV(major, minor); | |
814 | ||
815 | if (strict_strtoull(s[1], 10, &temp)) | |
816 | goto out; | |
817 | ||
818 | /* For rule removal, do not check for device presence. */ | |
819 | if (temp) { | |
820 | disk = get_gendisk(dev, &part); | |
821 | if (!disk || part) { | |
822 | ret = -ENODEV; | |
823 | goto out; | |
824 | } | |
825 | } | |
826 | ||
827 | newpn->dev = dev; | |
828 | ||
829 | switch (plid) { | |
830 | case BLKIO_POLICY_PROP: | |
831 | if ((temp < BLKIO_WEIGHT_MIN && temp > 0) || | |
832 | temp > BLKIO_WEIGHT_MAX) | |
833 | goto out; | |
834 | ||
835 | newpn->plid = plid; | |
836 | newpn->fileid = fileid; | |
837 | newpn->val.weight = temp; | |
838 | break; | |
839 | case BLKIO_POLICY_THROTL: | |
840 | switch(fileid) { | |
841 | case BLKIO_THROTL_read_bps_device: | |
842 | case BLKIO_THROTL_write_bps_device: | |
843 | newpn->plid = plid; | |
844 | newpn->fileid = fileid; | |
845 | newpn->val.bps = temp; | |
846 | break; | |
847 | case BLKIO_THROTL_read_iops_device: | |
848 | case BLKIO_THROTL_write_iops_device: | |
849 | if (temp > THROTL_IOPS_MAX) | |
850 | goto out; | |
851 | ||
852 | newpn->plid = plid; | |
853 | newpn->fileid = fileid; | |
854 | newpn->val.iops = (unsigned int)temp; | |
855 | break; | |
856 | } | |
857 | break; | |
858 | default: | |
859 | BUG(); | |
860 | } | |
861 | ret = 0; | |
862 | out: | |
863 | put_disk(disk); | |
864 | return ret; | |
865 | } | |
866 | ||
867 | unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, | |
868 | dev_t dev) | |
869 | { | |
870 | struct blkio_policy_node *pn; | |
871 | unsigned long flags; | |
872 | unsigned int weight; | |
873 | ||
874 | spin_lock_irqsave(&blkcg->lock, flags); | |
875 | ||
876 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP, | |
877 | BLKIO_PROP_weight_device); | |
878 | if (pn) | |
879 | weight = pn->val.weight; | |
880 | else | |
881 | weight = blkcg->weight; | |
882 | ||
883 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
884 | ||
885 | return weight; | |
886 | } | |
887 | EXPORT_SYMBOL_GPL(blkcg_get_weight); | |
888 | ||
889 | uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev) | |
890 | { | |
891 | struct blkio_policy_node *pn; | |
892 | unsigned long flags; | |
893 | uint64_t bps = -1; | |
894 | ||
895 | spin_lock_irqsave(&blkcg->lock, flags); | |
896 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
897 | BLKIO_THROTL_read_bps_device); | |
898 | if (pn) | |
899 | bps = pn->val.bps; | |
900 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
901 | ||
902 | return bps; | |
903 | } | |
904 | ||
905 | uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev) | |
906 | { | |
907 | struct blkio_policy_node *pn; | |
908 | unsigned long flags; | |
909 | uint64_t bps = -1; | |
910 | ||
911 | spin_lock_irqsave(&blkcg->lock, flags); | |
912 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
913 | BLKIO_THROTL_write_bps_device); | |
914 | if (pn) | |
915 | bps = pn->val.bps; | |
916 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
917 | ||
918 | return bps; | |
919 | } | |
920 | ||
921 | unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev) | |
922 | { | |
923 | struct blkio_policy_node *pn; | |
924 | unsigned long flags; | |
925 | unsigned int iops = -1; | |
926 | ||
927 | spin_lock_irqsave(&blkcg->lock, flags); | |
928 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
929 | BLKIO_THROTL_read_iops_device); | |
930 | if (pn) | |
931 | iops = pn->val.iops; | |
932 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
933 | ||
934 | return iops; | |
935 | } | |
936 | ||
937 | unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev) | |
938 | { | |
939 | struct blkio_policy_node *pn; | |
940 | unsigned long flags; | |
941 | unsigned int iops = -1; | |
942 | ||
943 | spin_lock_irqsave(&blkcg->lock, flags); | |
944 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
945 | BLKIO_THROTL_write_iops_device); | |
946 | if (pn) | |
947 | iops = pn->val.iops; | |
948 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
949 | ||
950 | return iops; | |
951 | } | |
952 | ||
953 | /* Checks whether user asked for deleting a policy rule */ | |
954 | static bool blkio_delete_rule_command(struct blkio_policy_node *pn) | |
955 | { | |
956 | switch(pn->plid) { | |
957 | case BLKIO_POLICY_PROP: | |
958 | if (pn->val.weight == 0) | |
959 | return 1; | |
960 | break; | |
961 | case BLKIO_POLICY_THROTL: | |
962 | switch(pn->fileid) { | |
963 | case BLKIO_THROTL_read_bps_device: | |
964 | case BLKIO_THROTL_write_bps_device: | |
965 | if (pn->val.bps == 0) | |
966 | return 1; | |
967 | break; | |
968 | case BLKIO_THROTL_read_iops_device: | |
969 | case BLKIO_THROTL_write_iops_device: | |
970 | if (pn->val.iops == 0) | |
971 | return 1; | |
972 | } | |
973 | break; | |
974 | default: | |
975 | BUG(); | |
976 | } | |
977 | ||
978 | return 0; | |
979 | } | |
980 | ||
981 | static void blkio_update_policy_rule(struct blkio_policy_node *oldpn, | |
982 | struct blkio_policy_node *newpn) | |
983 | { | |
984 | switch(oldpn->plid) { | |
985 | case BLKIO_POLICY_PROP: | |
986 | oldpn->val.weight = newpn->val.weight; | |
987 | break; | |
988 | case BLKIO_POLICY_THROTL: | |
989 | switch(newpn->fileid) { | |
990 | case BLKIO_THROTL_read_bps_device: | |
991 | case BLKIO_THROTL_write_bps_device: | |
992 | oldpn->val.bps = newpn->val.bps; | |
993 | break; | |
994 | case BLKIO_THROTL_read_iops_device: | |
995 | case BLKIO_THROTL_write_iops_device: | |
996 | oldpn->val.iops = newpn->val.iops; | |
997 | } | |
998 | break; | |
999 | default: | |
1000 | BUG(); | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | /* | |
1005 | * Some rules/values in blkg have changed. Propagate those to respective | |
1006 | * policies. | |
1007 | */ | |
1008 | static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg, | |
1009 | struct blkio_group *blkg, struct blkio_policy_node *pn) | |
1010 | { | |
1011 | unsigned int weight, iops; | |
1012 | u64 bps; | |
1013 | ||
1014 | switch(pn->plid) { | |
1015 | case BLKIO_POLICY_PROP: | |
1016 | weight = pn->val.weight ? pn->val.weight : | |
1017 | blkcg->weight; | |
1018 | blkio_update_group_weight(blkg, weight); | |
1019 | break; | |
1020 | case BLKIO_POLICY_THROTL: | |
1021 | switch(pn->fileid) { | |
1022 | case BLKIO_THROTL_read_bps_device: | |
1023 | case BLKIO_THROTL_write_bps_device: | |
1024 | bps = pn->val.bps ? pn->val.bps : (-1); | |
1025 | blkio_update_group_bps(blkg, bps, pn->fileid); | |
1026 | break; | |
1027 | case BLKIO_THROTL_read_iops_device: | |
1028 | case BLKIO_THROTL_write_iops_device: | |
1029 | iops = pn->val.iops ? pn->val.iops : (-1); | |
1030 | blkio_update_group_iops(blkg, iops, pn->fileid); | |
1031 | break; | |
1032 | } | |
1033 | break; | |
1034 | default: | |
1035 | BUG(); | |
1036 | } | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * A policy node rule has been updated. Propagate this update to all the | |
1041 | * block groups which might be affected by this update. | |
1042 | */ | |
1043 | static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg, | |
1044 | struct blkio_policy_node *pn) | |
1045 | { | |
1046 | struct blkio_group *blkg; | |
1047 | struct hlist_node *n; | |
1048 | ||
1049 | spin_lock(&blkio_list_lock); | |
1050 | spin_lock_irq(&blkcg->lock); | |
1051 | ||
1052 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1053 | if (pn->dev != blkg->dev || pn->plid != blkg->plid) | |
1054 | continue; | |
1055 | blkio_update_blkg_policy(blkcg, blkg, pn); | |
1056 | } | |
1057 | ||
1058 | spin_unlock_irq(&blkcg->lock); | |
1059 | spin_unlock(&blkio_list_lock); | |
1060 | } | |
1061 | ||
1062 | static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, | |
1063 | const char *buffer) | |
1064 | { | |
1065 | int ret = 0; | |
1066 | char *buf; | |
1067 | struct blkio_policy_node *newpn, *pn; | |
1068 | struct blkio_cgroup *blkcg; | |
1069 | int keep_newpn = 0; | |
1070 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1071 | int fileid = BLKIOFILE_ATTR(cft->private); | |
1072 | ||
1073 | buf = kstrdup(buffer, GFP_KERNEL); | |
1074 | if (!buf) | |
1075 | return -ENOMEM; | |
1076 | ||
1077 | newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); | |
1078 | if (!newpn) { | |
1079 | ret = -ENOMEM; | |
1080 | goto free_buf; | |
1081 | } | |
1082 | ||
1083 | ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid); | |
1084 | if (ret) | |
1085 | goto free_newpn; | |
1086 | ||
1087 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1088 | ||
1089 | spin_lock_irq(&blkcg->lock); | |
1090 | ||
1091 | pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid); | |
1092 | if (!pn) { | |
1093 | if (!blkio_delete_rule_command(newpn)) { | |
1094 | blkio_policy_insert_node(blkcg, newpn); | |
1095 | keep_newpn = 1; | |
1096 | } | |
1097 | spin_unlock_irq(&blkcg->lock); | |
1098 | goto update_io_group; | |
1099 | } | |
1100 | ||
1101 | if (blkio_delete_rule_command(newpn)) { | |
1102 | blkio_policy_delete_node(pn); | |
1103 | kfree(pn); | |
1104 | spin_unlock_irq(&blkcg->lock); | |
1105 | goto update_io_group; | |
1106 | } | |
1107 | spin_unlock_irq(&blkcg->lock); | |
1108 | ||
1109 | blkio_update_policy_rule(pn, newpn); | |
1110 | ||
1111 | update_io_group: | |
1112 | blkio_update_policy_node_blkg(blkcg, newpn); | |
1113 | ||
1114 | free_newpn: | |
1115 | if (!keep_newpn) | |
1116 | kfree(newpn); | |
1117 | free_buf: | |
1118 | kfree(buf); | |
1119 | return ret; | |
1120 | } | |
1121 | ||
1122 | static void | |
1123 | blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn) | |
1124 | { | |
1125 | switch(pn->plid) { | |
1126 | case BLKIO_POLICY_PROP: | |
1127 | if (pn->fileid == BLKIO_PROP_weight_device) | |
1128 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
1129 | MINOR(pn->dev), pn->val.weight); | |
1130 | break; | |
1131 | case BLKIO_POLICY_THROTL: | |
1132 | switch(pn->fileid) { | |
1133 | case BLKIO_THROTL_read_bps_device: | |
1134 | case BLKIO_THROTL_write_bps_device: | |
1135 | seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev), | |
1136 | MINOR(pn->dev), pn->val.bps); | |
1137 | break; | |
1138 | case BLKIO_THROTL_read_iops_device: | |
1139 | case BLKIO_THROTL_write_iops_device: | |
1140 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
1141 | MINOR(pn->dev), pn->val.iops); | |
1142 | break; | |
1143 | } | |
1144 | break; | |
1145 | default: | |
1146 | BUG(); | |
1147 | } | |
1148 | } | |
1149 | ||
1150 | /* cgroup files which read their data from policy nodes end up here */ | |
1151 | static void blkio_read_policy_node_files(struct cftype *cft, | |
1152 | struct blkio_cgroup *blkcg, struct seq_file *m) | |
1153 | { | |
1154 | struct blkio_policy_node *pn; | |
1155 | ||
1156 | if (!list_empty(&blkcg->policy_list)) { | |
1157 | spin_lock_irq(&blkcg->lock); | |
1158 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
1159 | if (!pn_matches_cftype(cft, pn)) | |
1160 | continue; | |
1161 | blkio_print_policy_node(m, pn); | |
1162 | } | |
1163 | spin_unlock_irq(&blkcg->lock); | |
1164 | } | |
1165 | } | |
1166 | ||
1167 | static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, | |
1168 | struct seq_file *m) | |
1169 | { | |
1170 | struct blkio_cgroup *blkcg; | |
1171 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1172 | int name = BLKIOFILE_ATTR(cft->private); | |
1173 | ||
1174 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1175 | ||
1176 | switch(plid) { | |
1177 | case BLKIO_POLICY_PROP: | |
1178 | switch(name) { | |
1179 | case BLKIO_PROP_weight_device: | |
1180 | blkio_read_policy_node_files(cft, blkcg, m); | |
1181 | return 0; | |
1182 | default: | |
1183 | BUG(); | |
1184 | } | |
1185 | break; | |
1186 | case BLKIO_POLICY_THROTL: | |
1187 | switch(name){ | |
1188 | case BLKIO_THROTL_read_bps_device: | |
1189 | case BLKIO_THROTL_write_bps_device: | |
1190 | case BLKIO_THROTL_read_iops_device: | |
1191 | case BLKIO_THROTL_write_iops_device: | |
1192 | blkio_read_policy_node_files(cft, blkcg, m); | |
1193 | return 0; | |
1194 | default: | |
1195 | BUG(); | |
1196 | } | |
1197 | break; | |
1198 | default: | |
1199 | BUG(); | |
1200 | } | |
1201 | ||
1202 | return 0; | |
1203 | } | |
1204 | ||
1205 | static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg, | |
1206 | struct cftype *cft, struct cgroup_map_cb *cb, | |
1207 | enum stat_type type, bool show_total, bool pcpu) | |
1208 | { | |
1209 | struct blkio_group *blkg; | |
1210 | struct hlist_node *n; | |
1211 | uint64_t cgroup_total = 0; | |
1212 | ||
1213 | rcu_read_lock(); | |
1214 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1215 | if (blkg->dev) { | |
1216 | if (!cftype_blkg_same_policy(cft, blkg)) | |
1217 | continue; | |
1218 | if (pcpu) | |
1219 | cgroup_total += blkio_get_stat_cpu(blkg, cb, | |
1220 | blkg->dev, type); | |
1221 | else { | |
1222 | spin_lock_irq(&blkg->stats_lock); | |
1223 | cgroup_total += blkio_get_stat(blkg, cb, | |
1224 | blkg->dev, type); | |
1225 | spin_unlock_irq(&blkg->stats_lock); | |
1226 | } | |
1227 | } | |
1228 | } | |
1229 | if (show_total) | |
1230 | cb->fill(cb, "Total", cgroup_total); | |
1231 | rcu_read_unlock(); | |
1232 | return 0; | |
1233 | } | |
1234 | ||
1235 | /* All map kind of cgroup file get serviced by this function */ | |
1236 | static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft, | |
1237 | struct cgroup_map_cb *cb) | |
1238 | { | |
1239 | struct blkio_cgroup *blkcg; | |
1240 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1241 | int name = BLKIOFILE_ATTR(cft->private); | |
1242 | ||
1243 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1244 | ||
1245 | switch(plid) { | |
1246 | case BLKIO_POLICY_PROP: | |
1247 | switch(name) { | |
1248 | case BLKIO_PROP_time: | |
1249 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1250 | BLKIO_STAT_TIME, 0, 0); | |
1251 | case BLKIO_PROP_sectors: | |
1252 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1253 | BLKIO_STAT_CPU_SECTORS, 0, 1); | |
1254 | case BLKIO_PROP_io_service_bytes: | |
1255 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1256 | BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1); | |
1257 | case BLKIO_PROP_io_serviced: | |
1258 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1259 | BLKIO_STAT_CPU_SERVICED, 1, 1); | |
1260 | case BLKIO_PROP_io_service_time: | |
1261 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1262 | BLKIO_STAT_SERVICE_TIME, 1, 0); | |
1263 | case BLKIO_PROP_io_wait_time: | |
1264 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1265 | BLKIO_STAT_WAIT_TIME, 1, 0); | |
1266 | case BLKIO_PROP_io_merged: | |
1267 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1268 | BLKIO_STAT_CPU_MERGED, 1, 1); | |
1269 | case BLKIO_PROP_io_queued: | |
1270 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1271 | BLKIO_STAT_QUEUED, 1, 0); | |
1272 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1273 | case BLKIO_PROP_unaccounted_time: | |
1274 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1275 | BLKIO_STAT_UNACCOUNTED_TIME, 0, 0); | |
1276 | case BLKIO_PROP_dequeue: | |
1277 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1278 | BLKIO_STAT_DEQUEUE, 0, 0); | |
1279 | case BLKIO_PROP_avg_queue_size: | |
1280 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1281 | BLKIO_STAT_AVG_QUEUE_SIZE, 0, 0); | |
1282 | case BLKIO_PROP_group_wait_time: | |
1283 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1284 | BLKIO_STAT_GROUP_WAIT_TIME, 0, 0); | |
1285 | case BLKIO_PROP_idle_time: | |
1286 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1287 | BLKIO_STAT_IDLE_TIME, 0, 0); | |
1288 | case BLKIO_PROP_empty_time: | |
1289 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1290 | BLKIO_STAT_EMPTY_TIME, 0, 0); | |
1291 | #endif | |
1292 | default: | |
1293 | BUG(); | |
1294 | } | |
1295 | break; | |
1296 | case BLKIO_POLICY_THROTL: | |
1297 | switch(name){ | |
1298 | case BLKIO_THROTL_io_service_bytes: | |
1299 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1300 | BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1); | |
1301 | case BLKIO_THROTL_io_serviced: | |
1302 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1303 | BLKIO_STAT_CPU_SERVICED, 1, 1); | |
1304 | default: | |
1305 | BUG(); | |
1306 | } | |
1307 | break; | |
1308 | default: | |
1309 | BUG(); | |
1310 | } | |
1311 | ||
1312 | return 0; | |
1313 | } | |
1314 | ||
1315 | static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val) | |
1316 | { | |
1317 | struct blkio_group *blkg; | |
1318 | struct hlist_node *n; | |
1319 | struct blkio_policy_node *pn; | |
1320 | ||
1321 | if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) | |
1322 | return -EINVAL; | |
1323 | ||
1324 | spin_lock(&blkio_list_lock); | |
1325 | spin_lock_irq(&blkcg->lock); | |
1326 | blkcg->weight = (unsigned int)val; | |
1327 | ||
1328 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1329 | pn = blkio_policy_search_node(blkcg, blkg->dev, | |
1330 | BLKIO_POLICY_PROP, BLKIO_PROP_weight_device); | |
1331 | if (pn) | |
1332 | continue; | |
1333 | ||
1334 | blkio_update_group_weight(blkg, blkcg->weight); | |
1335 | } | |
1336 | spin_unlock_irq(&blkcg->lock); | |
1337 | spin_unlock(&blkio_list_lock); | |
1338 | return 0; | |
1339 | } | |
1340 | ||
1341 | static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) { | |
1342 | struct blkio_cgroup *blkcg; | |
1343 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1344 | int name = BLKIOFILE_ATTR(cft->private); | |
1345 | ||
1346 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1347 | ||
1348 | switch(plid) { | |
1349 | case BLKIO_POLICY_PROP: | |
1350 | switch(name) { | |
1351 | case BLKIO_PROP_weight: | |
1352 | return (u64)blkcg->weight; | |
1353 | } | |
1354 | break; | |
1355 | default: | |
1356 | BUG(); | |
1357 | } | |
1358 | return 0; | |
1359 | } | |
1360 | ||
1361 | static int | |
1362 | blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) | |
1363 | { | |
1364 | struct blkio_cgroup *blkcg; | |
1365 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1366 | int name = BLKIOFILE_ATTR(cft->private); | |
1367 | ||
1368 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1369 | ||
1370 | switch(plid) { | |
1371 | case BLKIO_POLICY_PROP: | |
1372 | switch(name) { | |
1373 | case BLKIO_PROP_weight: | |
1374 | return blkio_weight_write(blkcg, val); | |
1375 | } | |
1376 | break; | |
1377 | default: | |
1378 | BUG(); | |
1379 | } | |
1380 | ||
1381 | return 0; | |
1382 | } | |
1383 | ||
1384 | struct cftype blkio_files[] = { | |
1385 | { | |
1386 | .name = "weight_device", | |
1387 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1388 | BLKIO_PROP_weight_device), | |
1389 | .read_seq_string = blkiocg_file_read, | |
1390 | .write_string = blkiocg_file_write, | |
1391 | .max_write_len = 256, | |
1392 | }, | |
1393 | { | |
1394 | .name = "weight", | |
1395 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1396 | BLKIO_PROP_weight), | |
1397 | .read_u64 = blkiocg_file_read_u64, | |
1398 | .write_u64 = blkiocg_file_write_u64, | |
1399 | }, | |
1400 | { | |
1401 | .name = "time", | |
1402 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1403 | BLKIO_PROP_time), | |
1404 | .read_map = blkiocg_file_read_map, | |
1405 | }, | |
1406 | { | |
1407 | .name = "sectors", | |
1408 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1409 | BLKIO_PROP_sectors), | |
1410 | .read_map = blkiocg_file_read_map, | |
1411 | }, | |
1412 | { | |
1413 | .name = "io_service_bytes", | |
1414 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1415 | BLKIO_PROP_io_service_bytes), | |
1416 | .read_map = blkiocg_file_read_map, | |
1417 | }, | |
1418 | { | |
1419 | .name = "io_serviced", | |
1420 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1421 | BLKIO_PROP_io_serviced), | |
1422 | .read_map = blkiocg_file_read_map, | |
1423 | }, | |
1424 | { | |
1425 | .name = "io_service_time", | |
1426 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1427 | BLKIO_PROP_io_service_time), | |
1428 | .read_map = blkiocg_file_read_map, | |
1429 | }, | |
1430 | { | |
1431 | .name = "io_wait_time", | |
1432 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1433 | BLKIO_PROP_io_wait_time), | |
1434 | .read_map = blkiocg_file_read_map, | |
1435 | }, | |
1436 | { | |
1437 | .name = "io_merged", | |
1438 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1439 | BLKIO_PROP_io_merged), | |
1440 | .read_map = blkiocg_file_read_map, | |
1441 | }, | |
1442 | { | |
1443 | .name = "io_queued", | |
1444 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1445 | BLKIO_PROP_io_queued), | |
1446 | .read_map = blkiocg_file_read_map, | |
1447 | }, | |
1448 | { | |
1449 | .name = "reset_stats", | |
1450 | .write_u64 = blkiocg_reset_stats, | |
1451 | }, | |
1452 | #ifdef CONFIG_BLK_DEV_THROTTLING | |
1453 | { | |
1454 | .name = "throttle.read_bps_device", | |
1455 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1456 | BLKIO_THROTL_read_bps_device), | |
1457 | .read_seq_string = blkiocg_file_read, | |
1458 | .write_string = blkiocg_file_write, | |
1459 | .max_write_len = 256, | |
1460 | }, | |
1461 | ||
1462 | { | |
1463 | .name = "throttle.write_bps_device", | |
1464 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1465 | BLKIO_THROTL_write_bps_device), | |
1466 | .read_seq_string = blkiocg_file_read, | |
1467 | .write_string = blkiocg_file_write, | |
1468 | .max_write_len = 256, | |
1469 | }, | |
1470 | ||
1471 | { | |
1472 | .name = "throttle.read_iops_device", | |
1473 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1474 | BLKIO_THROTL_read_iops_device), | |
1475 | .read_seq_string = blkiocg_file_read, | |
1476 | .write_string = blkiocg_file_write, | |
1477 | .max_write_len = 256, | |
1478 | }, | |
1479 | ||
1480 | { | |
1481 | .name = "throttle.write_iops_device", | |
1482 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1483 | BLKIO_THROTL_write_iops_device), | |
1484 | .read_seq_string = blkiocg_file_read, | |
1485 | .write_string = blkiocg_file_write, | |
1486 | .max_write_len = 256, | |
1487 | }, | |
1488 | { | |
1489 | .name = "throttle.io_service_bytes", | |
1490 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1491 | BLKIO_THROTL_io_service_bytes), | |
1492 | .read_map = blkiocg_file_read_map, | |
1493 | }, | |
1494 | { | |
1495 | .name = "throttle.io_serviced", | |
1496 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1497 | BLKIO_THROTL_io_serviced), | |
1498 | .read_map = blkiocg_file_read_map, | |
1499 | }, | |
1500 | #endif /* CONFIG_BLK_DEV_THROTTLING */ | |
1501 | ||
1502 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1503 | { | |
1504 | .name = "avg_queue_size", | |
1505 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1506 | BLKIO_PROP_avg_queue_size), | |
1507 | .read_map = blkiocg_file_read_map, | |
1508 | }, | |
1509 | { | |
1510 | .name = "group_wait_time", | |
1511 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1512 | BLKIO_PROP_group_wait_time), | |
1513 | .read_map = blkiocg_file_read_map, | |
1514 | }, | |
1515 | { | |
1516 | .name = "idle_time", | |
1517 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1518 | BLKIO_PROP_idle_time), | |
1519 | .read_map = blkiocg_file_read_map, | |
1520 | }, | |
1521 | { | |
1522 | .name = "empty_time", | |
1523 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1524 | BLKIO_PROP_empty_time), | |
1525 | .read_map = blkiocg_file_read_map, | |
1526 | }, | |
1527 | { | |
1528 | .name = "dequeue", | |
1529 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1530 | BLKIO_PROP_dequeue), | |
1531 | .read_map = blkiocg_file_read_map, | |
1532 | }, | |
1533 | { | |
1534 | .name = "unaccounted_time", | |
1535 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1536 | BLKIO_PROP_unaccounted_time), | |
1537 | .read_map = blkiocg_file_read_map, | |
1538 | }, | |
1539 | #endif | |
1540 | }; | |
1541 | ||
1542 | static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1543 | { | |
1544 | return cgroup_add_files(cgroup, subsys, blkio_files, | |
1545 | ARRAY_SIZE(blkio_files)); | |
1546 | } | |
1547 | ||
1548 | static void blkiocg_destroy(struct cgroup *cgroup) | |
1549 | { | |
1550 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); | |
1551 | unsigned long flags; | |
1552 | struct blkio_group *blkg; | |
1553 | void *key; | |
1554 | struct blkio_policy_type *blkiop; | |
1555 | struct blkio_policy_node *pn, *pntmp; | |
1556 | ||
1557 | rcu_read_lock(); | |
1558 | do { | |
1559 | spin_lock_irqsave(&blkcg->lock, flags); | |
1560 | ||
1561 | if (hlist_empty(&blkcg->blkg_list)) { | |
1562 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
1563 | break; | |
1564 | } | |
1565 | ||
1566 | blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, | |
1567 | blkcg_node); | |
1568 | key = rcu_dereference(blkg->key); | |
1569 | __blkiocg_del_blkio_group(blkg); | |
1570 | ||
1571 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
1572 | ||
1573 | /* | |
1574 | * This blkio_group is being unlinked as associated cgroup is | |
1575 | * going away. Let all the IO controlling policies know about | |
1576 | * this event. | |
1577 | */ | |
1578 | spin_lock(&blkio_list_lock); | |
1579 | list_for_each_entry(blkiop, &blkio_list, list) { | |
1580 | if (blkiop->plid != blkg->plid) | |
1581 | continue; | |
1582 | blkiop->ops.blkio_unlink_group_fn(key, blkg); | |
1583 | } | |
1584 | spin_unlock(&blkio_list_lock); | |
1585 | } while (1); | |
1586 | ||
1587 | list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { | |
1588 | blkio_policy_delete_node(pn); | |
1589 | kfree(pn); | |
1590 | } | |
1591 | ||
1592 | free_css_id(&blkio_subsys, &blkcg->css); | |
1593 | rcu_read_unlock(); | |
1594 | if (blkcg != &blkio_root_cgroup) | |
1595 | kfree(blkcg); | |
1596 | } | |
1597 | ||
1598 | static struct cgroup_subsys_state *blkiocg_create(struct cgroup *cgroup) | |
1599 | { | |
1600 | struct blkio_cgroup *blkcg; | |
1601 | struct cgroup *parent = cgroup->parent; | |
1602 | ||
1603 | if (!parent) { | |
1604 | blkcg = &blkio_root_cgroup; | |
1605 | goto done; | |
1606 | } | |
1607 | ||
1608 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); | |
1609 | if (!blkcg) | |
1610 | return ERR_PTR(-ENOMEM); | |
1611 | ||
1612 | blkcg->weight = BLKIO_WEIGHT_DEFAULT; | |
1613 | done: | |
1614 | spin_lock_init(&blkcg->lock); | |
1615 | INIT_HLIST_HEAD(&blkcg->blkg_list); | |
1616 | ||
1617 | INIT_LIST_HEAD(&blkcg->policy_list); | |
1618 | return &blkcg->css; | |
1619 | } | |
1620 | ||
1621 | /* | |
1622 | * We cannot support shared io contexts, as we have no mean to support | |
1623 | * two tasks with the same ioc in two different groups without major rework | |
1624 | * of the main cic data structures. For now we allow a task to change | |
1625 | * its cgroup only if it's the only owner of its ioc. | |
1626 | */ | |
1627 | static int blkiocg_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) | |
1628 | { | |
1629 | struct task_struct *task; | |
1630 | struct io_context *ioc; | |
1631 | int ret = 0; | |
1632 | ||
1633 | /* task_lock() is needed to avoid races with exit_io_context() */ | |
1634 | cgroup_taskset_for_each(task, cgrp, tset) { | |
1635 | task_lock(task); | |
1636 | ioc = task->io_context; | |
1637 | if (ioc && atomic_read(&ioc->nr_tasks) > 1) | |
1638 | ret = -EINVAL; | |
1639 | task_unlock(task); | |
1640 | if (ret) | |
1641 | break; | |
1642 | } | |
1643 | return ret; | |
1644 | } | |
1645 | ||
1646 | static void blkiocg_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) | |
1647 | { | |
1648 | struct task_struct *task; | |
1649 | struct io_context *ioc; | |
1650 | ||
1651 | cgroup_taskset_for_each(task, cgrp, tset) { | |
1652 | /* we don't lose anything even if ioc allocation fails */ | |
1653 | ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE); | |
1654 | if (ioc) { | |
1655 | ioc_cgroup_changed(ioc); | |
1656 | put_io_context(ioc); | |
1657 | } | |
1658 | } | |
1659 | } | |
1660 | ||
1661 | void blkio_policy_register(struct blkio_policy_type *blkiop) | |
1662 | { | |
1663 | spin_lock(&blkio_list_lock); | |
1664 | list_add_tail(&blkiop->list, &blkio_list); | |
1665 | spin_unlock(&blkio_list_lock); | |
1666 | } | |
1667 | EXPORT_SYMBOL_GPL(blkio_policy_register); | |
1668 | ||
1669 | void blkio_policy_unregister(struct blkio_policy_type *blkiop) | |
1670 | { | |
1671 | spin_lock(&blkio_list_lock); | |
1672 | list_del_init(&blkiop->list); | |
1673 | spin_unlock(&blkio_list_lock); | |
1674 | } | |
1675 | EXPORT_SYMBOL_GPL(blkio_policy_unregister); | |
1676 | ||
1677 | static int __init init_cgroup_blkio(void) | |
1678 | { | |
1679 | return cgroup_load_subsys(&blkio_subsys); | |
1680 | } | |
1681 | ||
1682 | static void __exit exit_cgroup_blkio(void) | |
1683 | { | |
1684 | cgroup_unload_subsys(&blkio_subsys); | |
1685 | } | |
1686 | ||
1687 | module_init(init_cgroup_blkio); | |
1688 | module_exit(exit_cgroup_blkio); | |
1689 | MODULE_LICENSE("GPL"); |