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Commit | Line | Data |
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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 | |
70087dc3 VG |
117 | struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk) |
118 | { | |
119 | return container_of(task_subsys_state(tsk, blkio_subsys_id), | |
120 | struct blkio_cgroup, css); | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(task_blkio_cgroup); | |
123 | ||
062a644d VG |
124 | static inline void |
125 | blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight) | |
126 | { | |
127 | struct blkio_policy_type *blkiop; | |
128 | ||
129 | list_for_each_entry(blkiop, &blkio_list, list) { | |
130 | /* If this policy does not own the blkg, do not send updates */ | |
131 | if (blkiop->plid != blkg->plid) | |
132 | continue; | |
133 | if (blkiop->ops.blkio_update_group_weight_fn) | |
fe071437 VG |
134 | blkiop->ops.blkio_update_group_weight_fn(blkg->key, |
135 | blkg, weight); | |
062a644d VG |
136 | } |
137 | } | |
138 | ||
4c9eefa1 VG |
139 | static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps, |
140 | int fileid) | |
141 | { | |
142 | struct blkio_policy_type *blkiop; | |
143 | ||
144 | list_for_each_entry(blkiop, &blkio_list, list) { | |
145 | ||
146 | /* If this policy does not own the blkg, do not send updates */ | |
147 | if (blkiop->plid != blkg->plid) | |
148 | continue; | |
149 | ||
150 | if (fileid == BLKIO_THROTL_read_bps_device | |
151 | && blkiop->ops.blkio_update_group_read_bps_fn) | |
fe071437 VG |
152 | blkiop->ops.blkio_update_group_read_bps_fn(blkg->key, |
153 | blkg, bps); | |
4c9eefa1 VG |
154 | |
155 | if (fileid == BLKIO_THROTL_write_bps_device | |
156 | && blkiop->ops.blkio_update_group_write_bps_fn) | |
fe071437 VG |
157 | blkiop->ops.blkio_update_group_write_bps_fn(blkg->key, |
158 | blkg, bps); | |
4c9eefa1 VG |
159 | } |
160 | } | |
161 | ||
7702e8f4 VG |
162 | static inline void blkio_update_group_iops(struct blkio_group *blkg, |
163 | unsigned int iops, int fileid) | |
164 | { | |
165 | struct blkio_policy_type *blkiop; | |
166 | ||
167 | list_for_each_entry(blkiop, &blkio_list, list) { | |
168 | ||
169 | /* If this policy does not own the blkg, do not send updates */ | |
170 | if (blkiop->plid != blkg->plid) | |
171 | continue; | |
172 | ||
173 | if (fileid == BLKIO_THROTL_read_iops_device | |
174 | && blkiop->ops.blkio_update_group_read_iops_fn) | |
fe071437 VG |
175 | blkiop->ops.blkio_update_group_read_iops_fn(blkg->key, |
176 | blkg, iops); | |
7702e8f4 VG |
177 | |
178 | if (fileid == BLKIO_THROTL_write_iops_device | |
179 | && blkiop->ops.blkio_update_group_write_iops_fn) | |
fe071437 VG |
180 | blkiop->ops.blkio_update_group_write_iops_fn(blkg->key, |
181 | blkg,iops); | |
7702e8f4 VG |
182 | } |
183 | } | |
184 | ||
9195291e DS |
185 | /* |
186 | * Add to the appropriate stat variable depending on the request type. | |
187 | * This should be called with the blkg->stats_lock held. | |
188 | */ | |
84c124da DS |
189 | static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction, |
190 | bool sync) | |
9195291e | 191 | { |
84c124da DS |
192 | if (direction) |
193 | stat[BLKIO_STAT_WRITE] += add; | |
9195291e | 194 | else |
84c124da DS |
195 | stat[BLKIO_STAT_READ] += add; |
196 | if (sync) | |
197 | stat[BLKIO_STAT_SYNC] += add; | |
9195291e | 198 | else |
84c124da | 199 | stat[BLKIO_STAT_ASYNC] += add; |
9195291e DS |
200 | } |
201 | ||
cdc1184c DS |
202 | /* |
203 | * Decrements the appropriate stat variable if non-zero depending on the | |
204 | * request type. Panics on value being zero. | |
205 | * This should be called with the blkg->stats_lock held. | |
206 | */ | |
207 | static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync) | |
208 | { | |
209 | if (direction) { | |
210 | BUG_ON(stat[BLKIO_STAT_WRITE] == 0); | |
211 | stat[BLKIO_STAT_WRITE]--; | |
212 | } else { | |
213 | BUG_ON(stat[BLKIO_STAT_READ] == 0); | |
214 | stat[BLKIO_STAT_READ]--; | |
215 | } | |
216 | if (sync) { | |
217 | BUG_ON(stat[BLKIO_STAT_SYNC] == 0); | |
218 | stat[BLKIO_STAT_SYNC]--; | |
219 | } else { | |
220 | BUG_ON(stat[BLKIO_STAT_ASYNC] == 0); | |
221 | stat[BLKIO_STAT_ASYNC]--; | |
222 | } | |
223 | } | |
224 | ||
225 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
812df48d DS |
226 | /* This should be called with the blkg->stats_lock held. */ |
227 | static void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
228 | struct blkio_group *curr_blkg) | |
229 | { | |
230 | if (blkio_blkg_waiting(&blkg->stats)) | |
231 | return; | |
232 | if (blkg == curr_blkg) | |
233 | return; | |
234 | blkg->stats.start_group_wait_time = sched_clock(); | |
235 | blkio_mark_blkg_waiting(&blkg->stats); | |
236 | } | |
237 | ||
238 | /* This should be called with the blkg->stats_lock held. */ | |
239 | static void blkio_update_group_wait_time(struct blkio_group_stats *stats) | |
240 | { | |
241 | unsigned long long now; | |
242 | ||
243 | if (!blkio_blkg_waiting(stats)) | |
244 | return; | |
245 | ||
246 | now = sched_clock(); | |
247 | if (time_after64(now, stats->start_group_wait_time)) | |
248 | stats->group_wait_time += now - stats->start_group_wait_time; | |
249 | blkio_clear_blkg_waiting(stats); | |
250 | } | |
251 | ||
252 | /* This should be called with the blkg->stats_lock held. */ | |
253 | static void blkio_end_empty_time(struct blkio_group_stats *stats) | |
254 | { | |
255 | unsigned long long now; | |
256 | ||
257 | if (!blkio_blkg_empty(stats)) | |
258 | return; | |
259 | ||
260 | now = sched_clock(); | |
261 | if (time_after64(now, stats->start_empty_time)) | |
262 | stats->empty_time += now - stats->start_empty_time; | |
263 | blkio_clear_blkg_empty(stats); | |
264 | } | |
265 | ||
266 | void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) | |
267 | { | |
268 | unsigned long flags; | |
269 | ||
270 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
271 | BUG_ON(blkio_blkg_idling(&blkg->stats)); | |
272 | blkg->stats.start_idle_time = sched_clock(); | |
273 | blkio_mark_blkg_idling(&blkg->stats); | |
274 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
275 | } | |
276 | EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats); | |
277 | ||
278 | void blkiocg_update_idle_time_stats(struct blkio_group *blkg) | |
279 | { | |
280 | unsigned long flags; | |
281 | unsigned long long now; | |
282 | struct blkio_group_stats *stats; | |
283 | ||
284 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
285 | stats = &blkg->stats; | |
286 | if (blkio_blkg_idling(stats)) { | |
287 | now = sched_clock(); | |
288 | if (time_after64(now, stats->start_idle_time)) | |
289 | stats->idle_time += now - stats->start_idle_time; | |
290 | blkio_clear_blkg_idling(stats); | |
291 | } | |
292 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
293 | } | |
294 | EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats); | |
295 | ||
a11cdaa7 | 296 | void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) |
cdc1184c DS |
297 | { |
298 | unsigned long flags; | |
299 | struct blkio_group_stats *stats; | |
300 | ||
301 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
302 | stats = &blkg->stats; | |
303 | stats->avg_queue_size_sum += | |
304 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] + | |
305 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]; | |
306 | stats->avg_queue_size_samples++; | |
812df48d | 307 | blkio_update_group_wait_time(stats); |
cdc1184c DS |
308 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
309 | } | |
a11cdaa7 DS |
310 | EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats); |
311 | ||
e5ff082e | 312 | void blkiocg_set_start_empty_time(struct blkio_group *blkg) |
28baf442 DS |
313 | { |
314 | unsigned long flags; | |
315 | struct blkio_group_stats *stats; | |
316 | ||
317 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
318 | stats = &blkg->stats; | |
319 | ||
320 | if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] || | |
321 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]) { | |
322 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
323 | return; | |
324 | } | |
325 | ||
326 | /* | |
e5ff082e VG |
327 | * group is already marked empty. This can happen if cfqq got new |
328 | * request in parent group and moved to this group while being added | |
329 | * to service tree. Just ignore the event and move on. | |
28baf442 | 330 | */ |
e5ff082e VG |
331 | if(blkio_blkg_empty(stats)) { |
332 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
333 | return; | |
334 | } | |
335 | ||
28baf442 DS |
336 | stats->start_empty_time = sched_clock(); |
337 | blkio_mark_blkg_empty(stats); | |
338 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
339 | } | |
340 | EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time); | |
341 | ||
a11cdaa7 DS |
342 | void blkiocg_update_dequeue_stats(struct blkio_group *blkg, |
343 | unsigned long dequeue) | |
344 | { | |
345 | blkg->stats.dequeue += dequeue; | |
346 | } | |
347 | EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats); | |
812df48d DS |
348 | #else |
349 | static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
350 | struct blkio_group *curr_blkg) {} | |
351 | static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {} | |
cdc1184c DS |
352 | #endif |
353 | ||
a11cdaa7 | 354 | void blkiocg_update_io_add_stats(struct blkio_group *blkg, |
cdc1184c DS |
355 | struct blkio_group *curr_blkg, bool direction, |
356 | bool sync) | |
357 | { | |
358 | unsigned long flags; | |
359 | ||
360 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
361 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], 1, direction, | |
362 | sync); | |
812df48d DS |
363 | blkio_end_empty_time(&blkg->stats); |
364 | blkio_set_start_group_wait_time(blkg, curr_blkg); | |
cdc1184c DS |
365 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
366 | } | |
a11cdaa7 | 367 | EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats); |
cdc1184c | 368 | |
a11cdaa7 | 369 | void blkiocg_update_io_remove_stats(struct blkio_group *blkg, |
cdc1184c DS |
370 | bool direction, bool sync) |
371 | { | |
372 | unsigned long flags; | |
373 | ||
374 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
375 | blkio_check_and_dec_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], | |
376 | direction, sync); | |
377 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
378 | } | |
a11cdaa7 | 379 | EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats); |
cdc1184c | 380 | |
167400d3 JT |
381 | void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time, |
382 | unsigned long unaccounted_time) | |
22084190 | 383 | { |
303a3acb DS |
384 | unsigned long flags; |
385 | ||
386 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
387 | blkg->stats.time += time; | |
a23e6869 | 388 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
167400d3 | 389 | blkg->stats.unaccounted_time += unaccounted_time; |
a23e6869 | 390 | #endif |
303a3acb | 391 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
22084190 | 392 | } |
303a3acb | 393 | EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used); |
22084190 | 394 | |
84c124da DS |
395 | void blkiocg_update_dispatch_stats(struct blkio_group *blkg, |
396 | uint64_t bytes, bool direction, bool sync) | |
9195291e DS |
397 | { |
398 | struct blkio_group_stats *stats; | |
399 | unsigned long flags; | |
400 | ||
401 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
402 | stats = &blkg->stats; | |
84c124da DS |
403 | stats->sectors += bytes >> 9; |
404 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction, | |
405 | sync); | |
406 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes, | |
407 | direction, sync); | |
9195291e DS |
408 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
409 | } | |
84c124da | 410 | EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats); |
9195291e | 411 | |
84c124da DS |
412 | void blkiocg_update_completion_stats(struct blkio_group *blkg, |
413 | uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) | |
9195291e DS |
414 | { |
415 | struct blkio_group_stats *stats; | |
416 | unsigned long flags; | |
417 | unsigned long long now = sched_clock(); | |
418 | ||
419 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
420 | stats = &blkg->stats; | |
84c124da DS |
421 | if (time_after64(now, io_start_time)) |
422 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME], | |
423 | now - io_start_time, direction, sync); | |
424 | if (time_after64(io_start_time, start_time)) | |
425 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME], | |
426 | io_start_time - start_time, direction, sync); | |
9195291e DS |
427 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
428 | } | |
84c124da | 429 | EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats); |
9195291e | 430 | |
812d4026 DS |
431 | void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction, |
432 | bool sync) | |
433 | { | |
434 | unsigned long flags; | |
435 | ||
436 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
437 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction, | |
438 | sync); | |
439 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
440 | } | |
441 | EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats); | |
442 | ||
31e4c28d | 443 | void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, |
062a644d VG |
444 | struct blkio_group *blkg, void *key, dev_t dev, |
445 | enum blkio_policy_id plid) | |
31e4c28d VG |
446 | { |
447 | unsigned long flags; | |
448 | ||
449 | spin_lock_irqsave(&blkcg->lock, flags); | |
8d2a91f8 | 450 | spin_lock_init(&blkg->stats_lock); |
31e4c28d | 451 | rcu_assign_pointer(blkg->key, key); |
b1c35769 | 452 | blkg->blkcg_id = css_id(&blkcg->css); |
31e4c28d | 453 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); |
062a644d | 454 | blkg->plid = plid; |
31e4c28d | 455 | spin_unlock_irqrestore(&blkcg->lock, flags); |
2868ef7b VG |
456 | /* Need to take css reference ? */ |
457 | cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); | |
22084190 | 458 | blkg->dev = dev; |
31e4c28d | 459 | } |
9d6a986c | 460 | EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); |
31e4c28d | 461 | |
b1c35769 VG |
462 | static void __blkiocg_del_blkio_group(struct blkio_group *blkg) |
463 | { | |
464 | hlist_del_init_rcu(&blkg->blkcg_node); | |
465 | blkg->blkcg_id = 0; | |
466 | } | |
467 | ||
468 | /* | |
469 | * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1 | |
470 | * indicating that blk_group was unhashed by the time we got to it. | |
471 | */ | |
31e4c28d VG |
472 | int blkiocg_del_blkio_group(struct blkio_group *blkg) |
473 | { | |
b1c35769 VG |
474 | struct blkio_cgroup *blkcg; |
475 | unsigned long flags; | |
476 | struct cgroup_subsys_state *css; | |
477 | int ret = 1; | |
478 | ||
479 | rcu_read_lock(); | |
480 | css = css_lookup(&blkio_subsys, blkg->blkcg_id); | |
0f3942a3 JA |
481 | if (css) { |
482 | blkcg = container_of(css, struct blkio_cgroup, css); | |
483 | spin_lock_irqsave(&blkcg->lock, flags); | |
484 | if (!hlist_unhashed(&blkg->blkcg_node)) { | |
485 | __blkiocg_del_blkio_group(blkg); | |
486 | ret = 0; | |
487 | } | |
488 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
b1c35769 | 489 | } |
0f3942a3 | 490 | |
b1c35769 VG |
491 | rcu_read_unlock(); |
492 | return ret; | |
31e4c28d | 493 | } |
9d6a986c | 494 | EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); |
31e4c28d VG |
495 | |
496 | /* called under rcu_read_lock(). */ | |
497 | struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) | |
498 | { | |
499 | struct blkio_group *blkg; | |
500 | struct hlist_node *n; | |
501 | void *__key; | |
502 | ||
503 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
504 | __key = blkg->key; | |
505 | if (__key == key) | |
506 | return blkg; | |
507 | } | |
508 | ||
509 | return NULL; | |
510 | } | |
9d6a986c | 511 | EXPORT_SYMBOL_GPL(blkiocg_lookup_group); |
31e4c28d | 512 | |
303a3acb | 513 | static int |
84c124da | 514 | blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) |
303a3acb DS |
515 | { |
516 | struct blkio_cgroup *blkcg; | |
517 | struct blkio_group *blkg; | |
812df48d | 518 | struct blkio_group_stats *stats; |
303a3acb | 519 | struct hlist_node *n; |
cdc1184c DS |
520 | uint64_t queued[BLKIO_STAT_TOTAL]; |
521 | int i; | |
812df48d DS |
522 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
523 | bool idling, waiting, empty; | |
524 | unsigned long long now = sched_clock(); | |
525 | #endif | |
303a3acb DS |
526 | |
527 | blkcg = cgroup_to_blkio_cgroup(cgroup); | |
528 | spin_lock_irq(&blkcg->lock); | |
529 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
530 | spin_lock(&blkg->stats_lock); | |
812df48d DS |
531 | stats = &blkg->stats; |
532 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
533 | idling = blkio_blkg_idling(stats); | |
534 | waiting = blkio_blkg_waiting(stats); | |
535 | empty = blkio_blkg_empty(stats); | |
536 | #endif | |
cdc1184c | 537 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) |
812df48d DS |
538 | queued[i] = stats->stat_arr[BLKIO_STAT_QUEUED][i]; |
539 | memset(stats, 0, sizeof(struct blkio_group_stats)); | |
cdc1184c | 540 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) |
812df48d DS |
541 | stats->stat_arr[BLKIO_STAT_QUEUED][i] = queued[i]; |
542 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
543 | if (idling) { | |
544 | blkio_mark_blkg_idling(stats); | |
545 | stats->start_idle_time = now; | |
546 | } | |
547 | if (waiting) { | |
548 | blkio_mark_blkg_waiting(stats); | |
549 | stats->start_group_wait_time = now; | |
550 | } | |
551 | if (empty) { | |
552 | blkio_mark_blkg_empty(stats); | |
553 | stats->start_empty_time = now; | |
554 | } | |
555 | #endif | |
303a3acb DS |
556 | spin_unlock(&blkg->stats_lock); |
557 | } | |
558 | spin_unlock_irq(&blkcg->lock); | |
559 | return 0; | |
560 | } | |
561 | ||
84c124da DS |
562 | static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str, |
563 | int chars_left, bool diskname_only) | |
303a3acb | 564 | { |
84c124da | 565 | snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev)); |
303a3acb DS |
566 | chars_left -= strlen(str); |
567 | if (chars_left <= 0) { | |
568 | printk(KERN_WARNING | |
569 | "Possibly incorrect cgroup stat display format"); | |
570 | return; | |
571 | } | |
84c124da DS |
572 | if (diskname_only) |
573 | return; | |
303a3acb | 574 | switch (type) { |
84c124da | 575 | case BLKIO_STAT_READ: |
303a3acb DS |
576 | strlcat(str, " Read", chars_left); |
577 | break; | |
84c124da | 578 | case BLKIO_STAT_WRITE: |
303a3acb DS |
579 | strlcat(str, " Write", chars_left); |
580 | break; | |
84c124da | 581 | case BLKIO_STAT_SYNC: |
303a3acb DS |
582 | strlcat(str, " Sync", chars_left); |
583 | break; | |
84c124da | 584 | case BLKIO_STAT_ASYNC: |
303a3acb DS |
585 | strlcat(str, " Async", chars_left); |
586 | break; | |
84c124da | 587 | case BLKIO_STAT_TOTAL: |
303a3acb DS |
588 | strlcat(str, " Total", chars_left); |
589 | break; | |
590 | default: | |
591 | strlcat(str, " Invalid", chars_left); | |
592 | } | |
593 | } | |
594 | ||
84c124da DS |
595 | static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val, |
596 | struct cgroup_map_cb *cb, dev_t dev) | |
597 | { | |
598 | blkio_get_key_name(0, dev, str, chars_left, true); | |
599 | cb->fill(cb, str, val); | |
600 | return val; | |
601 | } | |
303a3acb | 602 | |
84c124da DS |
603 | /* This should be called with blkg->stats_lock held */ |
604 | static uint64_t blkio_get_stat(struct blkio_group *blkg, | |
605 | struct cgroup_map_cb *cb, dev_t dev, enum stat_type type) | |
303a3acb DS |
606 | { |
607 | uint64_t disk_total; | |
608 | char key_str[MAX_KEY_LEN]; | |
84c124da DS |
609 | enum stat_sub_type sub_type; |
610 | ||
611 | if (type == BLKIO_STAT_TIME) | |
612 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
613 | blkg->stats.time, cb, dev); | |
614 | if (type == BLKIO_STAT_SECTORS) | |
615 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
616 | blkg->stats.sectors, cb, dev); | |
9026e521 | 617 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
167400d3 JT |
618 | if (type == BLKIO_STAT_UNACCOUNTED_TIME) |
619 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
620 | blkg->stats.unaccounted_time, cb, dev); | |
cdc1184c DS |
621 | if (type == BLKIO_STAT_AVG_QUEUE_SIZE) { |
622 | uint64_t sum = blkg->stats.avg_queue_size_sum; | |
623 | uint64_t samples = blkg->stats.avg_queue_size_samples; | |
624 | if (samples) | |
625 | do_div(sum, samples); | |
626 | else | |
627 | sum = 0; | |
628 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, sum, cb, dev); | |
629 | } | |
812df48d DS |
630 | if (type == BLKIO_STAT_GROUP_WAIT_TIME) |
631 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
632 | blkg->stats.group_wait_time, cb, dev); | |
633 | if (type == BLKIO_STAT_IDLE_TIME) | |
634 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
635 | blkg->stats.idle_time, cb, dev); | |
636 | if (type == BLKIO_STAT_EMPTY_TIME) | |
637 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
638 | blkg->stats.empty_time, cb, dev); | |
84c124da DS |
639 | if (type == BLKIO_STAT_DEQUEUE) |
640 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
641 | blkg->stats.dequeue, cb, dev); | |
642 | #endif | |
303a3acb | 643 | |
84c124da DS |
644 | for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; |
645 | sub_type++) { | |
646 | blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false); | |
647 | cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]); | |
303a3acb | 648 | } |
84c124da DS |
649 | disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] + |
650 | blkg->stats.stat_arr[type][BLKIO_STAT_WRITE]; | |
651 | blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false); | |
303a3acb DS |
652 | cb->fill(cb, key_str, disk_total); |
653 | return disk_total; | |
654 | } | |
655 | ||
34d0f179 GJ |
656 | static int blkio_check_dev_num(dev_t dev) |
657 | { | |
658 | int part = 0; | |
659 | struct gendisk *disk; | |
660 | ||
661 | disk = get_gendisk(dev, &part); | |
662 | if (!disk || part) | |
663 | return -ENODEV; | |
664 | ||
665 | return 0; | |
666 | } | |
667 | ||
668 | static int blkio_policy_parse_and_set(char *buf, | |
062a644d | 669 | struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid) |
34d0f179 GJ |
670 | { |
671 | char *s[4], *p, *major_s = NULL, *minor_s = NULL; | |
672 | int ret; | |
673 | unsigned long major, minor, temp; | |
674 | int i = 0; | |
675 | dev_t dev; | |
9355aede | 676 | u64 bps, iops; |
34d0f179 GJ |
677 | |
678 | memset(s, 0, sizeof(s)); | |
679 | ||
680 | while ((p = strsep(&buf, " ")) != NULL) { | |
681 | if (!*p) | |
682 | continue; | |
683 | ||
684 | s[i++] = p; | |
685 | ||
686 | /* Prevent from inputing too many things */ | |
687 | if (i == 3) | |
688 | break; | |
689 | } | |
690 | ||
691 | if (i != 2) | |
692 | return -EINVAL; | |
693 | ||
694 | p = strsep(&s[0], ":"); | |
695 | if (p != NULL) | |
696 | major_s = p; | |
697 | else | |
698 | return -EINVAL; | |
699 | ||
700 | minor_s = s[0]; | |
701 | if (!minor_s) | |
702 | return -EINVAL; | |
703 | ||
704 | ret = strict_strtoul(major_s, 10, &major); | |
705 | if (ret) | |
706 | return -EINVAL; | |
707 | ||
708 | ret = strict_strtoul(minor_s, 10, &minor); | |
709 | if (ret) | |
710 | return -EINVAL; | |
711 | ||
712 | dev = MKDEV(major, minor); | |
713 | ||
714 | ret = blkio_check_dev_num(dev); | |
715 | if (ret) | |
716 | return ret; | |
717 | ||
718 | newpn->dev = dev; | |
719 | ||
720 | if (s[1] == NULL) | |
721 | return -EINVAL; | |
722 | ||
062a644d VG |
723 | switch (plid) { |
724 | case BLKIO_POLICY_PROP: | |
725 | ret = strict_strtoul(s[1], 10, &temp); | |
726 | if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) || | |
727 | temp > BLKIO_WEIGHT_MAX) | |
728 | return -EINVAL; | |
34d0f179 | 729 | |
062a644d VG |
730 | newpn->plid = plid; |
731 | newpn->fileid = fileid; | |
4c9eefa1 VG |
732 | newpn->val.weight = temp; |
733 | break; | |
734 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
735 | switch(fileid) { |
736 | case BLKIO_THROTL_read_bps_device: | |
737 | case BLKIO_THROTL_write_bps_device: | |
738 | ret = strict_strtoull(s[1], 10, &bps); | |
739 | if (ret) | |
740 | return -EINVAL; | |
4c9eefa1 | 741 | |
7702e8f4 VG |
742 | newpn->plid = plid; |
743 | newpn->fileid = fileid; | |
744 | newpn->val.bps = bps; | |
745 | break; | |
746 | case BLKIO_THROTL_read_iops_device: | |
747 | case BLKIO_THROTL_write_iops_device: | |
9355aede | 748 | ret = strict_strtoull(s[1], 10, &iops); |
7702e8f4 VG |
749 | if (ret) |
750 | return -EINVAL; | |
751 | ||
9355aede VG |
752 | if (iops > THROTL_IOPS_MAX) |
753 | return -EINVAL; | |
754 | ||
7702e8f4 VG |
755 | newpn->plid = plid; |
756 | newpn->fileid = fileid; | |
9355aede | 757 | newpn->val.iops = (unsigned int)iops; |
7702e8f4 VG |
758 | break; |
759 | } | |
062a644d VG |
760 | break; |
761 | default: | |
762 | BUG(); | |
763 | } | |
34d0f179 GJ |
764 | |
765 | return 0; | |
766 | } | |
767 | ||
768 | unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, | |
769 | dev_t dev) | |
770 | { | |
771 | struct blkio_policy_node *pn; | |
772 | ||
062a644d VG |
773 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP, |
774 | BLKIO_PROP_weight_device); | |
34d0f179 | 775 | if (pn) |
4c9eefa1 | 776 | return pn->val.weight; |
34d0f179 GJ |
777 | else |
778 | return blkcg->weight; | |
779 | } | |
780 | EXPORT_SYMBOL_GPL(blkcg_get_weight); | |
781 | ||
4c9eefa1 VG |
782 | uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev) |
783 | { | |
784 | struct blkio_policy_node *pn; | |
785 | ||
786 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
787 | BLKIO_THROTL_read_bps_device); | |
788 | if (pn) | |
789 | return pn->val.bps; | |
790 | else | |
791 | return -1; | |
792 | } | |
793 | ||
794 | uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev) | |
795 | { | |
796 | struct blkio_policy_node *pn; | |
797 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
798 | BLKIO_THROTL_write_bps_device); | |
799 | if (pn) | |
800 | return pn->val.bps; | |
801 | else | |
802 | return -1; | |
803 | } | |
804 | ||
7702e8f4 VG |
805 | unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev) |
806 | { | |
807 | struct blkio_policy_node *pn; | |
808 | ||
809 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
810 | BLKIO_THROTL_read_iops_device); | |
811 | if (pn) | |
812 | return pn->val.iops; | |
813 | else | |
814 | return -1; | |
815 | } | |
816 | ||
817 | unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev) | |
818 | { | |
819 | struct blkio_policy_node *pn; | |
820 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
821 | BLKIO_THROTL_write_iops_device); | |
822 | if (pn) | |
823 | return pn->val.iops; | |
824 | else | |
825 | return -1; | |
826 | } | |
827 | ||
062a644d VG |
828 | /* Checks whether user asked for deleting a policy rule */ |
829 | static bool blkio_delete_rule_command(struct blkio_policy_node *pn) | |
830 | { | |
831 | switch(pn->plid) { | |
832 | case BLKIO_POLICY_PROP: | |
4c9eefa1 VG |
833 | if (pn->val.weight == 0) |
834 | return 1; | |
835 | break; | |
836 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
837 | switch(pn->fileid) { |
838 | case BLKIO_THROTL_read_bps_device: | |
839 | case BLKIO_THROTL_write_bps_device: | |
840 | if (pn->val.bps == 0) | |
841 | return 1; | |
842 | break; | |
843 | case BLKIO_THROTL_read_iops_device: | |
844 | case BLKIO_THROTL_write_iops_device: | |
845 | if (pn->val.iops == 0) | |
846 | return 1; | |
847 | } | |
062a644d VG |
848 | break; |
849 | default: | |
850 | BUG(); | |
851 | } | |
852 | ||
853 | return 0; | |
854 | } | |
855 | ||
856 | static void blkio_update_policy_rule(struct blkio_policy_node *oldpn, | |
857 | struct blkio_policy_node *newpn) | |
858 | { | |
859 | switch(oldpn->plid) { | |
860 | case BLKIO_POLICY_PROP: | |
4c9eefa1 VG |
861 | oldpn->val.weight = newpn->val.weight; |
862 | break; | |
863 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
864 | switch(newpn->fileid) { |
865 | case BLKIO_THROTL_read_bps_device: | |
866 | case BLKIO_THROTL_write_bps_device: | |
867 | oldpn->val.bps = newpn->val.bps; | |
868 | break; | |
869 | case BLKIO_THROTL_read_iops_device: | |
870 | case BLKIO_THROTL_write_iops_device: | |
871 | oldpn->val.iops = newpn->val.iops; | |
872 | } | |
062a644d VG |
873 | break; |
874 | default: | |
875 | BUG(); | |
876 | } | |
877 | } | |
878 | ||
879 | /* | |
25985edc | 880 | * Some rules/values in blkg have changed. Propagate those to respective |
062a644d VG |
881 | * policies. |
882 | */ | |
883 | static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg, | |
884 | struct blkio_group *blkg, struct blkio_policy_node *pn) | |
885 | { | |
7702e8f4 | 886 | unsigned int weight, iops; |
4c9eefa1 | 887 | u64 bps; |
062a644d VG |
888 | |
889 | switch(pn->plid) { | |
890 | case BLKIO_POLICY_PROP: | |
4c9eefa1 | 891 | weight = pn->val.weight ? pn->val.weight : |
062a644d VG |
892 | blkcg->weight; |
893 | blkio_update_group_weight(blkg, weight); | |
894 | break; | |
4c9eefa1 VG |
895 | case BLKIO_POLICY_THROTL: |
896 | switch(pn->fileid) { | |
897 | case BLKIO_THROTL_read_bps_device: | |
898 | case BLKIO_THROTL_write_bps_device: | |
899 | bps = pn->val.bps ? pn->val.bps : (-1); | |
900 | blkio_update_group_bps(blkg, bps, pn->fileid); | |
901 | break; | |
7702e8f4 VG |
902 | case BLKIO_THROTL_read_iops_device: |
903 | case BLKIO_THROTL_write_iops_device: | |
904 | iops = pn->val.iops ? pn->val.iops : (-1); | |
905 | blkio_update_group_iops(blkg, iops, pn->fileid); | |
906 | break; | |
4c9eefa1 VG |
907 | } |
908 | break; | |
062a644d VG |
909 | default: |
910 | BUG(); | |
911 | } | |
912 | } | |
913 | ||
914 | /* | |
25985edc | 915 | * A policy node rule has been updated. Propagate this update to all the |
062a644d VG |
916 | * block groups which might be affected by this update. |
917 | */ | |
918 | static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg, | |
919 | struct blkio_policy_node *pn) | |
920 | { | |
921 | struct blkio_group *blkg; | |
922 | struct hlist_node *n; | |
923 | ||
924 | spin_lock(&blkio_list_lock); | |
925 | spin_lock_irq(&blkcg->lock); | |
34d0f179 | 926 | |
062a644d VG |
927 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { |
928 | if (pn->dev != blkg->dev || pn->plid != blkg->plid) | |
929 | continue; | |
930 | blkio_update_blkg_policy(blkcg, blkg, pn); | |
931 | } | |
932 | ||
933 | spin_unlock_irq(&blkcg->lock); | |
934 | spin_unlock(&blkio_list_lock); | |
935 | } | |
34d0f179 | 936 | |
062a644d VG |
937 | static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, |
938 | const char *buffer) | |
34d0f179 GJ |
939 | { |
940 | int ret = 0; | |
941 | char *buf; | |
942 | struct blkio_policy_node *newpn, *pn; | |
943 | struct blkio_cgroup *blkcg; | |
34d0f179 | 944 | int keep_newpn = 0; |
062a644d VG |
945 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); |
946 | int fileid = BLKIOFILE_ATTR(cft->private); | |
34d0f179 GJ |
947 | |
948 | buf = kstrdup(buffer, GFP_KERNEL); | |
949 | if (!buf) | |
950 | return -ENOMEM; | |
951 | ||
952 | newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); | |
953 | if (!newpn) { | |
954 | ret = -ENOMEM; | |
955 | goto free_buf; | |
956 | } | |
957 | ||
062a644d | 958 | ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid); |
34d0f179 GJ |
959 | if (ret) |
960 | goto free_newpn; | |
961 | ||
962 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
963 | ||
964 | spin_lock_irq(&blkcg->lock); | |
965 | ||
062a644d | 966 | pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid); |
34d0f179 | 967 | if (!pn) { |
062a644d | 968 | if (!blkio_delete_rule_command(newpn)) { |
34d0f179 GJ |
969 | blkio_policy_insert_node(blkcg, newpn); |
970 | keep_newpn = 1; | |
971 | } | |
972 | spin_unlock_irq(&blkcg->lock); | |
973 | goto update_io_group; | |
974 | } | |
975 | ||
062a644d | 976 | if (blkio_delete_rule_command(newpn)) { |
34d0f179 GJ |
977 | blkio_policy_delete_node(pn); |
978 | spin_unlock_irq(&blkcg->lock); | |
979 | goto update_io_group; | |
980 | } | |
981 | spin_unlock_irq(&blkcg->lock); | |
982 | ||
062a644d | 983 | blkio_update_policy_rule(pn, newpn); |
34d0f179 GJ |
984 | |
985 | update_io_group: | |
062a644d | 986 | blkio_update_policy_node_blkg(blkcg, newpn); |
34d0f179 GJ |
987 | |
988 | free_newpn: | |
989 | if (!keep_newpn) | |
990 | kfree(newpn); | |
991 | free_buf: | |
992 | kfree(buf); | |
993 | return ret; | |
994 | } | |
995 | ||
062a644d VG |
996 | static void |
997 | blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn) | |
34d0f179 | 998 | { |
062a644d VG |
999 | switch(pn->plid) { |
1000 | case BLKIO_POLICY_PROP: | |
1001 | if (pn->fileid == BLKIO_PROP_weight_device) | |
1002 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
4c9eefa1 VG |
1003 | MINOR(pn->dev), pn->val.weight); |
1004 | break; | |
1005 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
1006 | switch(pn->fileid) { |
1007 | case BLKIO_THROTL_read_bps_device: | |
1008 | case BLKIO_THROTL_write_bps_device: | |
4c9eefa1 VG |
1009 | seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev), |
1010 | MINOR(pn->dev), pn->val.bps); | |
7702e8f4 VG |
1011 | break; |
1012 | case BLKIO_THROTL_read_iops_device: | |
1013 | case BLKIO_THROTL_write_iops_device: | |
1014 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
1015 | MINOR(pn->dev), pn->val.iops); | |
1016 | break; | |
1017 | } | |
062a644d VG |
1018 | break; |
1019 | default: | |
1020 | BUG(); | |
1021 | } | |
1022 | } | |
34d0f179 | 1023 | |
062a644d VG |
1024 | /* cgroup files which read their data from policy nodes end up here */ |
1025 | static void blkio_read_policy_node_files(struct cftype *cft, | |
1026 | struct blkio_cgroup *blkcg, struct seq_file *m) | |
34d0f179 | 1027 | { |
34d0f179 | 1028 | struct blkio_policy_node *pn; |
34d0f179 | 1029 | |
0f3942a3 JA |
1030 | if (!list_empty(&blkcg->policy_list)) { |
1031 | spin_lock_irq(&blkcg->lock); | |
1032 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
062a644d VG |
1033 | if (!pn_matches_cftype(cft, pn)) |
1034 | continue; | |
1035 | blkio_print_policy_node(m, pn); | |
0f3942a3 JA |
1036 | } |
1037 | spin_unlock_irq(&blkcg->lock); | |
34d0f179 | 1038 | } |
062a644d VG |
1039 | } |
1040 | ||
1041 | static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, | |
1042 | struct seq_file *m) | |
1043 | { | |
1044 | struct blkio_cgroup *blkcg; | |
1045 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1046 | int name = BLKIOFILE_ATTR(cft->private); | |
1047 | ||
1048 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1049 | ||
1050 | switch(plid) { | |
1051 | case BLKIO_POLICY_PROP: | |
1052 | switch(name) { | |
1053 | case BLKIO_PROP_weight_device: | |
1054 | blkio_read_policy_node_files(cft, blkcg, m); | |
1055 | return 0; | |
1056 | default: | |
1057 | BUG(); | |
1058 | } | |
1059 | break; | |
4c9eefa1 VG |
1060 | case BLKIO_POLICY_THROTL: |
1061 | switch(name){ | |
1062 | case BLKIO_THROTL_read_bps_device: | |
1063 | case BLKIO_THROTL_write_bps_device: | |
7702e8f4 VG |
1064 | case BLKIO_THROTL_read_iops_device: |
1065 | case BLKIO_THROTL_write_iops_device: | |
4c9eefa1 VG |
1066 | blkio_read_policy_node_files(cft, blkcg, m); |
1067 | return 0; | |
1068 | default: | |
1069 | BUG(); | |
1070 | } | |
1071 | break; | |
062a644d VG |
1072 | default: |
1073 | BUG(); | |
1074 | } | |
1075 | ||
1076 | return 0; | |
1077 | } | |
1078 | ||
1079 | static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg, | |
1080 | struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type, | |
1081 | bool show_total) | |
1082 | { | |
1083 | struct blkio_group *blkg; | |
1084 | struct hlist_node *n; | |
1085 | uint64_t cgroup_total = 0; | |
1086 | ||
1087 | rcu_read_lock(); | |
1088 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1089 | if (blkg->dev) { | |
1090 | if (!cftype_blkg_same_policy(cft, blkg)) | |
1091 | continue; | |
1092 | spin_lock_irq(&blkg->stats_lock); | |
1093 | cgroup_total += blkio_get_stat(blkg, cb, blkg->dev, | |
1094 | type); | |
1095 | spin_unlock_irq(&blkg->stats_lock); | |
1096 | } | |
1097 | } | |
1098 | if (show_total) | |
1099 | cb->fill(cb, "Total", cgroup_total); | |
1100 | rcu_read_unlock(); | |
1101 | return 0; | |
1102 | } | |
1103 | ||
1104 | /* All map kind of cgroup file get serviced by this function */ | |
1105 | static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft, | |
1106 | struct cgroup_map_cb *cb) | |
1107 | { | |
1108 | struct blkio_cgroup *blkcg; | |
1109 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1110 | int name = BLKIOFILE_ATTR(cft->private); | |
1111 | ||
1112 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1113 | ||
1114 | switch(plid) { | |
1115 | case BLKIO_POLICY_PROP: | |
1116 | switch(name) { | |
1117 | case BLKIO_PROP_time: | |
1118 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1119 | BLKIO_STAT_TIME, 0); | |
1120 | case BLKIO_PROP_sectors: | |
1121 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1122 | BLKIO_STAT_SECTORS, 0); | |
1123 | case BLKIO_PROP_io_service_bytes: | |
1124 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1125 | BLKIO_STAT_SERVICE_BYTES, 1); | |
1126 | case BLKIO_PROP_io_serviced: | |
1127 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1128 | BLKIO_STAT_SERVICED, 1); | |
1129 | case BLKIO_PROP_io_service_time: | |
1130 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1131 | BLKIO_STAT_SERVICE_TIME, 1); | |
1132 | case BLKIO_PROP_io_wait_time: | |
1133 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1134 | BLKIO_STAT_WAIT_TIME, 1); | |
1135 | case BLKIO_PROP_io_merged: | |
1136 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1137 | BLKIO_STAT_MERGED, 1); | |
1138 | case BLKIO_PROP_io_queued: | |
1139 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1140 | BLKIO_STAT_QUEUED, 1); | |
1141 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
9026e521 JT |
1142 | case BLKIO_PROP_unaccounted_time: |
1143 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1144 | BLKIO_STAT_UNACCOUNTED_TIME, 0); | |
062a644d VG |
1145 | case BLKIO_PROP_dequeue: |
1146 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1147 | BLKIO_STAT_DEQUEUE, 0); | |
1148 | case BLKIO_PROP_avg_queue_size: | |
1149 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1150 | BLKIO_STAT_AVG_QUEUE_SIZE, 0); | |
1151 | case BLKIO_PROP_group_wait_time: | |
1152 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1153 | BLKIO_STAT_GROUP_WAIT_TIME, 0); | |
1154 | case BLKIO_PROP_idle_time: | |
1155 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1156 | BLKIO_STAT_IDLE_TIME, 0); | |
1157 | case BLKIO_PROP_empty_time: | |
1158 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1159 | BLKIO_STAT_EMPTY_TIME, 0); | |
1160 | #endif | |
1161 | default: | |
1162 | BUG(); | |
1163 | } | |
1164 | break; | |
4c9eefa1 VG |
1165 | case BLKIO_POLICY_THROTL: |
1166 | switch(name){ | |
1167 | case BLKIO_THROTL_io_service_bytes: | |
1168 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1169 | BLKIO_STAT_SERVICE_BYTES, 1); | |
1170 | case BLKIO_THROTL_io_serviced: | |
1171 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1172 | BLKIO_STAT_SERVICED, 1); | |
1173 | default: | |
1174 | BUG(); | |
1175 | } | |
1176 | break; | |
062a644d VG |
1177 | default: |
1178 | BUG(); | |
1179 | } | |
1180 | ||
1181 | return 0; | |
1182 | } | |
1183 | ||
1184 | static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val) | |
1185 | { | |
1186 | struct blkio_group *blkg; | |
1187 | struct hlist_node *n; | |
1188 | struct blkio_policy_node *pn; | |
1189 | ||
1190 | if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) | |
1191 | return -EINVAL; | |
1192 | ||
1193 | spin_lock(&blkio_list_lock); | |
1194 | spin_lock_irq(&blkcg->lock); | |
1195 | blkcg->weight = (unsigned int)val; | |
1196 | ||
1197 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1198 | pn = blkio_policy_search_node(blkcg, blkg->dev, | |
1199 | BLKIO_POLICY_PROP, BLKIO_PROP_weight_device); | |
1200 | if (pn) | |
1201 | continue; | |
1202 | ||
1203 | blkio_update_group_weight(blkg, blkcg->weight); | |
1204 | } | |
1205 | spin_unlock_irq(&blkcg->lock); | |
1206 | spin_unlock(&blkio_list_lock); | |
1207 | return 0; | |
1208 | } | |
1209 | ||
1210 | static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) { | |
1211 | struct blkio_cgroup *blkcg; | |
1212 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1213 | int name = BLKIOFILE_ATTR(cft->private); | |
1214 | ||
1215 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1216 | ||
1217 | switch(plid) { | |
1218 | case BLKIO_POLICY_PROP: | |
1219 | switch(name) { | |
1220 | case BLKIO_PROP_weight: | |
1221 | return (u64)blkcg->weight; | |
1222 | } | |
1223 | break; | |
1224 | default: | |
1225 | BUG(); | |
1226 | } | |
1227 | return 0; | |
1228 | } | |
1229 | ||
1230 | static int | |
1231 | blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) | |
1232 | { | |
1233 | struct blkio_cgroup *blkcg; | |
1234 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1235 | int name = BLKIOFILE_ATTR(cft->private); | |
1236 | ||
1237 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1238 | ||
1239 | switch(plid) { | |
1240 | case BLKIO_POLICY_PROP: | |
1241 | switch(name) { | |
1242 | case BLKIO_PROP_weight: | |
1243 | return blkio_weight_write(blkcg, val); | |
1244 | } | |
1245 | break; | |
1246 | default: | |
1247 | BUG(); | |
1248 | } | |
34d0f179 | 1249 | |
34d0f179 GJ |
1250 | return 0; |
1251 | } | |
1252 | ||
31e4c28d | 1253 | struct cftype blkio_files[] = { |
34d0f179 GJ |
1254 | { |
1255 | .name = "weight_device", | |
062a644d VG |
1256 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1257 | BLKIO_PROP_weight_device), | |
1258 | .read_seq_string = blkiocg_file_read, | |
1259 | .write_string = blkiocg_file_write, | |
34d0f179 GJ |
1260 | .max_write_len = 256, |
1261 | }, | |
31e4c28d VG |
1262 | { |
1263 | .name = "weight", | |
062a644d VG |
1264 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1265 | BLKIO_PROP_weight), | |
1266 | .read_u64 = blkiocg_file_read_u64, | |
1267 | .write_u64 = blkiocg_file_write_u64, | |
31e4c28d | 1268 | }, |
22084190 VG |
1269 | { |
1270 | .name = "time", | |
062a644d VG |
1271 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1272 | BLKIO_PROP_time), | |
1273 | .read_map = blkiocg_file_read_map, | |
22084190 VG |
1274 | }, |
1275 | { | |
1276 | .name = "sectors", | |
062a644d VG |
1277 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1278 | BLKIO_PROP_sectors), | |
1279 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1280 | }, |
1281 | { | |
1282 | .name = "io_service_bytes", | |
062a644d VG |
1283 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1284 | BLKIO_PROP_io_service_bytes), | |
1285 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1286 | }, |
1287 | { | |
1288 | .name = "io_serviced", | |
062a644d VG |
1289 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1290 | BLKIO_PROP_io_serviced), | |
1291 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1292 | }, |
1293 | { | |
1294 | .name = "io_service_time", | |
062a644d VG |
1295 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1296 | BLKIO_PROP_io_service_time), | |
1297 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1298 | }, |
1299 | { | |
1300 | .name = "io_wait_time", | |
062a644d VG |
1301 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1302 | BLKIO_PROP_io_wait_time), | |
1303 | .read_map = blkiocg_file_read_map, | |
84c124da | 1304 | }, |
812d4026 DS |
1305 | { |
1306 | .name = "io_merged", | |
062a644d VG |
1307 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1308 | BLKIO_PROP_io_merged), | |
1309 | .read_map = blkiocg_file_read_map, | |
812d4026 | 1310 | }, |
cdc1184c DS |
1311 | { |
1312 | .name = "io_queued", | |
062a644d VG |
1313 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1314 | BLKIO_PROP_io_queued), | |
1315 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1316 | }, |
84c124da DS |
1317 | { |
1318 | .name = "reset_stats", | |
1319 | .write_u64 = blkiocg_reset_stats, | |
22084190 | 1320 | }, |
13f98250 VG |
1321 | #ifdef CONFIG_BLK_DEV_THROTTLING |
1322 | { | |
1323 | .name = "throttle.read_bps_device", | |
1324 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1325 | BLKIO_THROTL_read_bps_device), | |
1326 | .read_seq_string = blkiocg_file_read, | |
1327 | .write_string = blkiocg_file_write, | |
1328 | .max_write_len = 256, | |
1329 | }, | |
1330 | ||
1331 | { | |
1332 | .name = "throttle.write_bps_device", | |
1333 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1334 | BLKIO_THROTL_write_bps_device), | |
1335 | .read_seq_string = blkiocg_file_read, | |
1336 | .write_string = blkiocg_file_write, | |
1337 | .max_write_len = 256, | |
1338 | }, | |
1339 | ||
1340 | { | |
1341 | .name = "throttle.read_iops_device", | |
1342 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1343 | BLKIO_THROTL_read_iops_device), | |
1344 | .read_seq_string = blkiocg_file_read, | |
1345 | .write_string = blkiocg_file_write, | |
1346 | .max_write_len = 256, | |
1347 | }, | |
1348 | ||
1349 | { | |
1350 | .name = "throttle.write_iops_device", | |
1351 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1352 | BLKIO_THROTL_write_iops_device), | |
1353 | .read_seq_string = blkiocg_file_read, | |
1354 | .write_string = blkiocg_file_write, | |
1355 | .max_write_len = 256, | |
1356 | }, | |
1357 | { | |
1358 | .name = "throttle.io_service_bytes", | |
1359 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1360 | BLKIO_THROTL_io_service_bytes), | |
1361 | .read_map = blkiocg_file_read_map, | |
1362 | }, | |
1363 | { | |
1364 | .name = "throttle.io_serviced", | |
1365 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1366 | BLKIO_THROTL_io_serviced), | |
1367 | .read_map = blkiocg_file_read_map, | |
1368 | }, | |
1369 | #endif /* CONFIG_BLK_DEV_THROTTLING */ | |
1370 | ||
22084190 | 1371 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
cdc1184c DS |
1372 | { |
1373 | .name = "avg_queue_size", | |
062a644d VG |
1374 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1375 | BLKIO_PROP_avg_queue_size), | |
1376 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1377 | }, |
812df48d DS |
1378 | { |
1379 | .name = "group_wait_time", | |
062a644d VG |
1380 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1381 | BLKIO_PROP_group_wait_time), | |
1382 | .read_map = blkiocg_file_read_map, | |
812df48d DS |
1383 | }, |
1384 | { | |
1385 | .name = "idle_time", | |
062a644d VG |
1386 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1387 | BLKIO_PROP_idle_time), | |
1388 | .read_map = blkiocg_file_read_map, | |
812df48d DS |
1389 | }, |
1390 | { | |
1391 | .name = "empty_time", | |
062a644d VG |
1392 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1393 | BLKIO_PROP_empty_time), | |
1394 | .read_map = blkiocg_file_read_map, | |
812df48d | 1395 | }, |
cdc1184c | 1396 | { |
22084190 | 1397 | .name = "dequeue", |
062a644d VG |
1398 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1399 | BLKIO_PROP_dequeue), | |
1400 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1401 | }, |
9026e521 JT |
1402 | { |
1403 | .name = "unaccounted_time", | |
1404 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1405 | BLKIO_PROP_unaccounted_time), | |
1406 | .read_map = blkiocg_file_read_map, | |
1407 | }, | |
22084190 | 1408 | #endif |
31e4c28d VG |
1409 | }; |
1410 | ||
1411 | static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1412 | { | |
1413 | return cgroup_add_files(cgroup, subsys, blkio_files, | |
1414 | ARRAY_SIZE(blkio_files)); | |
1415 | } | |
1416 | ||
1417 | static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1418 | { | |
1419 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); | |
b1c35769 VG |
1420 | unsigned long flags; |
1421 | struct blkio_group *blkg; | |
1422 | void *key; | |
3e252066 | 1423 | struct blkio_policy_type *blkiop; |
34d0f179 | 1424 | struct blkio_policy_node *pn, *pntmp; |
b1c35769 VG |
1425 | |
1426 | rcu_read_lock(); | |
0f3942a3 JA |
1427 | do { |
1428 | spin_lock_irqsave(&blkcg->lock, flags); | |
b1c35769 | 1429 | |
0f3942a3 JA |
1430 | if (hlist_empty(&blkcg->blkg_list)) { |
1431 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
1432 | break; | |
1433 | } | |
b1c35769 | 1434 | |
0f3942a3 JA |
1435 | blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, |
1436 | blkcg_node); | |
1437 | key = rcu_dereference(blkg->key); | |
1438 | __blkiocg_del_blkio_group(blkg); | |
31e4c28d | 1439 | |
0f3942a3 | 1440 | spin_unlock_irqrestore(&blkcg->lock, flags); |
b1c35769 | 1441 | |
0f3942a3 JA |
1442 | /* |
1443 | * This blkio_group is being unlinked as associated cgroup is | |
1444 | * going away. Let all the IO controlling policies know about | |
61014e96 | 1445 | * this event. |
0f3942a3 JA |
1446 | */ |
1447 | spin_lock(&blkio_list_lock); | |
61014e96 VG |
1448 | list_for_each_entry(blkiop, &blkio_list, list) { |
1449 | if (blkiop->plid != blkg->plid) | |
1450 | continue; | |
0f3942a3 | 1451 | blkiop->ops.blkio_unlink_group_fn(key, blkg); |
61014e96 | 1452 | } |
0f3942a3 JA |
1453 | spin_unlock(&blkio_list_lock); |
1454 | } while (1); | |
34d0f179 | 1455 | |
34d0f179 GJ |
1456 | list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { |
1457 | blkio_policy_delete_node(pn); | |
1458 | kfree(pn); | |
1459 | } | |
0f3942a3 | 1460 | |
31e4c28d | 1461 | free_css_id(&blkio_subsys, &blkcg->css); |
b1c35769 | 1462 | rcu_read_unlock(); |
67523c48 BB |
1463 | if (blkcg != &blkio_root_cgroup) |
1464 | kfree(blkcg); | |
31e4c28d VG |
1465 | } |
1466 | ||
1467 | static struct cgroup_subsys_state * | |
1468 | blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1469 | { | |
0341509f LZ |
1470 | struct blkio_cgroup *blkcg; |
1471 | struct cgroup *parent = cgroup->parent; | |
31e4c28d | 1472 | |
0341509f | 1473 | if (!parent) { |
31e4c28d VG |
1474 | blkcg = &blkio_root_cgroup; |
1475 | goto done; | |
1476 | } | |
1477 | ||
31e4c28d VG |
1478 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); |
1479 | if (!blkcg) | |
1480 | return ERR_PTR(-ENOMEM); | |
1481 | ||
1482 | blkcg->weight = BLKIO_WEIGHT_DEFAULT; | |
1483 | done: | |
1484 | spin_lock_init(&blkcg->lock); | |
1485 | INIT_HLIST_HEAD(&blkcg->blkg_list); | |
1486 | ||
34d0f179 | 1487 | INIT_LIST_HEAD(&blkcg->policy_list); |
31e4c28d VG |
1488 | return &blkcg->css; |
1489 | } | |
1490 | ||
1491 | /* | |
1492 | * We cannot support shared io contexts, as we have no mean to support | |
1493 | * two tasks with the same ioc in two different groups without major rework | |
1494 | * of the main cic data structures. For now we allow a task to change | |
1495 | * its cgroup only if it's the only owner of its ioc. | |
1496 | */ | |
1497 | static int blkiocg_can_attach(struct cgroup_subsys *subsys, | |
1498 | struct cgroup *cgroup, struct task_struct *tsk, | |
1499 | bool threadgroup) | |
1500 | { | |
1501 | struct io_context *ioc; | |
1502 | int ret = 0; | |
1503 | ||
1504 | /* task_lock() is needed to avoid races with exit_io_context() */ | |
1505 | task_lock(tsk); | |
1506 | ioc = tsk->io_context; | |
1507 | if (ioc && atomic_read(&ioc->nr_tasks) > 1) | |
1508 | ret = -EINVAL; | |
1509 | task_unlock(tsk); | |
1510 | ||
1511 | return ret; | |
1512 | } | |
1513 | ||
1514 | static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup, | |
1515 | struct cgroup *prev, struct task_struct *tsk, | |
1516 | bool threadgroup) | |
1517 | { | |
1518 | struct io_context *ioc; | |
1519 | ||
1520 | task_lock(tsk); | |
1521 | ioc = tsk->io_context; | |
1522 | if (ioc) | |
1523 | ioc->cgroup_changed = 1; | |
1524 | task_unlock(tsk); | |
1525 | } | |
1526 | ||
3e252066 VG |
1527 | void blkio_policy_register(struct blkio_policy_type *blkiop) |
1528 | { | |
1529 | spin_lock(&blkio_list_lock); | |
1530 | list_add_tail(&blkiop->list, &blkio_list); | |
1531 | spin_unlock(&blkio_list_lock); | |
1532 | } | |
1533 | EXPORT_SYMBOL_GPL(blkio_policy_register); | |
1534 | ||
1535 | void blkio_policy_unregister(struct blkio_policy_type *blkiop) | |
1536 | { | |
1537 | spin_lock(&blkio_list_lock); | |
1538 | list_del_init(&blkiop->list); | |
1539 | spin_unlock(&blkio_list_lock); | |
1540 | } | |
1541 | EXPORT_SYMBOL_GPL(blkio_policy_unregister); | |
67523c48 BB |
1542 | |
1543 | static int __init init_cgroup_blkio(void) | |
1544 | { | |
1545 | return cgroup_load_subsys(&blkio_subsys); | |
1546 | } | |
1547 | ||
1548 | static void __exit exit_cgroup_blkio(void) | |
1549 | { | |
1550 | cgroup_unload_subsys(&blkio_subsys); | |
1551 | } | |
1552 | ||
1553 | module_init(init_cgroup_blkio); | |
1554 | module_exit(exit_cgroup_blkio); | |
1555 | MODULE_LICENSE("GPL"); |