Commit | Line | Data |
---|---|---|
31e4c28d VG |
1 | /* |
2 | * Common Block IO controller cgroup interface | |
3 | * | |
4 | * Based on ideas and code from CFQ, CFS and BFQ: | |
5 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> | |
6 | * | |
7 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> | |
8 | * Paolo Valente <paolo.valente@unimore.it> | |
9 | * | |
10 | * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> | |
11 | * Nauman Rafique <nauman@google.com> | |
12 | */ | |
13 | #include <linux/ioprio.h> | |
22084190 VG |
14 | #include <linux/seq_file.h> |
15 | #include <linux/kdev_t.h> | |
9d6a986c | 16 | #include <linux/module.h> |
accee785 | 17 | #include <linux/err.h> |
9195291e | 18 | #include <linux/blkdev.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
31e4c28d | 20 | #include "blk-cgroup.h" |
34d0f179 | 21 | #include <linux/genhd.h> |
3e252066 | 22 | |
84c124da DS |
23 | #define MAX_KEY_LEN 100 |
24 | ||
3e252066 VG |
25 | static DEFINE_SPINLOCK(blkio_list_lock); |
26 | static LIST_HEAD(blkio_list); | |
b1c35769 | 27 | |
31e4c28d | 28 | struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; |
9d6a986c VG |
29 | EXPORT_SYMBOL_GPL(blkio_root_cgroup); |
30 | ||
67523c48 BB |
31 | static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *, |
32 | struct cgroup *); | |
33 | static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, | |
34 | struct task_struct *, bool); | |
35 | static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, | |
36 | struct cgroup *, struct task_struct *, bool); | |
37 | static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); | |
38 | static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); | |
39 | ||
062a644d VG |
40 | /* for encoding cft->private value on file */ |
41 | #define BLKIOFILE_PRIVATE(x, val) (((x) << 16) | (val)) | |
42 | /* What policy owns the file, proportional or throttle */ | |
43 | #define BLKIOFILE_POLICY(val) (((val) >> 16) & 0xffff) | |
44 | #define BLKIOFILE_ATTR(val) ((val) & 0xffff) | |
45 | ||
67523c48 BB |
46 | struct cgroup_subsys blkio_subsys = { |
47 | .name = "blkio", | |
48 | .create = blkiocg_create, | |
49 | .can_attach = blkiocg_can_attach, | |
50 | .attach = blkiocg_attach, | |
51 | .destroy = blkiocg_destroy, | |
52 | .populate = blkiocg_populate, | |
53 | #ifdef CONFIG_BLK_CGROUP | |
54 | /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */ | |
55 | .subsys_id = blkio_subsys_id, | |
56 | #endif | |
57 | .use_id = 1, | |
58 | .module = THIS_MODULE, | |
59 | }; | |
60 | EXPORT_SYMBOL_GPL(blkio_subsys); | |
61 | ||
34d0f179 GJ |
62 | static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg, |
63 | struct blkio_policy_node *pn) | |
64 | { | |
65 | list_add(&pn->node, &blkcg->policy_list); | |
66 | } | |
67 | ||
062a644d VG |
68 | static inline bool cftype_blkg_same_policy(struct cftype *cft, |
69 | struct blkio_group *blkg) | |
70 | { | |
71 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
72 | ||
73 | if (blkg->plid == plid) | |
74 | return 1; | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | /* Determines if policy node matches cgroup file being accessed */ | |
80 | static inline bool pn_matches_cftype(struct cftype *cft, | |
81 | struct blkio_policy_node *pn) | |
82 | { | |
83 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
84 | int fileid = BLKIOFILE_ATTR(cft->private); | |
85 | ||
86 | return (plid == pn->plid && fileid == pn->fileid); | |
87 | } | |
88 | ||
34d0f179 GJ |
89 | /* Must be called with blkcg->lock held */ |
90 | static inline void blkio_policy_delete_node(struct blkio_policy_node *pn) | |
91 | { | |
92 | list_del(&pn->node); | |
93 | } | |
94 | ||
95 | /* Must be called with blkcg->lock held */ | |
96 | static struct blkio_policy_node * | |
062a644d VG |
97 | blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev, |
98 | enum blkio_policy_id plid, int fileid) | |
34d0f179 GJ |
99 | { |
100 | struct blkio_policy_node *pn; | |
101 | ||
102 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
062a644d | 103 | if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid) |
34d0f179 GJ |
104 | return pn; |
105 | } | |
106 | ||
107 | return NULL; | |
108 | } | |
109 | ||
31e4c28d VG |
110 | struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) |
111 | { | |
112 | return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), | |
113 | struct blkio_cgroup, css); | |
114 | } | |
9d6a986c | 115 | EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup); |
31e4c28d | 116 | |
062a644d VG |
117 | static inline void |
118 | blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight) | |
119 | { | |
120 | struct blkio_policy_type *blkiop; | |
121 | ||
122 | list_for_each_entry(blkiop, &blkio_list, list) { | |
123 | /* If this policy does not own the blkg, do not send updates */ | |
124 | if (blkiop->plid != blkg->plid) | |
125 | continue; | |
126 | if (blkiop->ops.blkio_update_group_weight_fn) | |
fe071437 VG |
127 | blkiop->ops.blkio_update_group_weight_fn(blkg->key, |
128 | blkg, weight); | |
062a644d VG |
129 | } |
130 | } | |
131 | ||
4c9eefa1 VG |
132 | static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps, |
133 | int fileid) | |
134 | { | |
135 | struct blkio_policy_type *blkiop; | |
136 | ||
137 | list_for_each_entry(blkiop, &blkio_list, list) { | |
138 | ||
139 | /* If this policy does not own the blkg, do not send updates */ | |
140 | if (blkiop->plid != blkg->plid) | |
141 | continue; | |
142 | ||
143 | if (fileid == BLKIO_THROTL_read_bps_device | |
144 | && blkiop->ops.blkio_update_group_read_bps_fn) | |
fe071437 VG |
145 | blkiop->ops.blkio_update_group_read_bps_fn(blkg->key, |
146 | blkg, bps); | |
4c9eefa1 VG |
147 | |
148 | if (fileid == BLKIO_THROTL_write_bps_device | |
149 | && blkiop->ops.blkio_update_group_write_bps_fn) | |
fe071437 VG |
150 | blkiop->ops.blkio_update_group_write_bps_fn(blkg->key, |
151 | blkg, bps); | |
4c9eefa1 VG |
152 | } |
153 | } | |
154 | ||
7702e8f4 VG |
155 | static inline void blkio_update_group_iops(struct blkio_group *blkg, |
156 | unsigned int iops, int fileid) | |
157 | { | |
158 | struct blkio_policy_type *blkiop; | |
159 | ||
160 | list_for_each_entry(blkiop, &blkio_list, list) { | |
161 | ||
162 | /* If this policy does not own the blkg, do not send updates */ | |
163 | if (blkiop->plid != blkg->plid) | |
164 | continue; | |
165 | ||
166 | if (fileid == BLKIO_THROTL_read_iops_device | |
167 | && blkiop->ops.blkio_update_group_read_iops_fn) | |
fe071437 VG |
168 | blkiop->ops.blkio_update_group_read_iops_fn(blkg->key, |
169 | blkg, iops); | |
7702e8f4 VG |
170 | |
171 | if (fileid == BLKIO_THROTL_write_iops_device | |
172 | && blkiop->ops.blkio_update_group_write_iops_fn) | |
fe071437 VG |
173 | blkiop->ops.blkio_update_group_write_iops_fn(blkg->key, |
174 | blkg,iops); | |
7702e8f4 VG |
175 | } |
176 | } | |
177 | ||
9195291e DS |
178 | /* |
179 | * Add to the appropriate stat variable depending on the request type. | |
180 | * This should be called with the blkg->stats_lock held. | |
181 | */ | |
84c124da DS |
182 | static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction, |
183 | bool sync) | |
9195291e | 184 | { |
84c124da DS |
185 | if (direction) |
186 | stat[BLKIO_STAT_WRITE] += add; | |
9195291e | 187 | else |
84c124da DS |
188 | stat[BLKIO_STAT_READ] += add; |
189 | if (sync) | |
190 | stat[BLKIO_STAT_SYNC] += add; | |
9195291e | 191 | else |
84c124da | 192 | stat[BLKIO_STAT_ASYNC] += add; |
9195291e DS |
193 | } |
194 | ||
cdc1184c DS |
195 | /* |
196 | * Decrements the appropriate stat variable if non-zero depending on the | |
197 | * request type. Panics on value being zero. | |
198 | * This should be called with the blkg->stats_lock held. | |
199 | */ | |
200 | static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync) | |
201 | { | |
202 | if (direction) { | |
203 | BUG_ON(stat[BLKIO_STAT_WRITE] == 0); | |
204 | stat[BLKIO_STAT_WRITE]--; | |
205 | } else { | |
206 | BUG_ON(stat[BLKIO_STAT_READ] == 0); | |
207 | stat[BLKIO_STAT_READ]--; | |
208 | } | |
209 | if (sync) { | |
210 | BUG_ON(stat[BLKIO_STAT_SYNC] == 0); | |
211 | stat[BLKIO_STAT_SYNC]--; | |
212 | } else { | |
213 | BUG_ON(stat[BLKIO_STAT_ASYNC] == 0); | |
214 | stat[BLKIO_STAT_ASYNC]--; | |
215 | } | |
216 | } | |
217 | ||
218 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
812df48d DS |
219 | /* This should be called with the blkg->stats_lock held. */ |
220 | static void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
221 | struct blkio_group *curr_blkg) | |
222 | { | |
223 | if (blkio_blkg_waiting(&blkg->stats)) | |
224 | return; | |
225 | if (blkg == curr_blkg) | |
226 | return; | |
227 | blkg->stats.start_group_wait_time = sched_clock(); | |
228 | blkio_mark_blkg_waiting(&blkg->stats); | |
229 | } | |
230 | ||
231 | /* This should be called with the blkg->stats_lock held. */ | |
232 | static void blkio_update_group_wait_time(struct blkio_group_stats *stats) | |
233 | { | |
234 | unsigned long long now; | |
235 | ||
236 | if (!blkio_blkg_waiting(stats)) | |
237 | return; | |
238 | ||
239 | now = sched_clock(); | |
240 | if (time_after64(now, stats->start_group_wait_time)) | |
241 | stats->group_wait_time += now - stats->start_group_wait_time; | |
242 | blkio_clear_blkg_waiting(stats); | |
243 | } | |
244 | ||
245 | /* This should be called with the blkg->stats_lock held. */ | |
246 | static void blkio_end_empty_time(struct blkio_group_stats *stats) | |
247 | { | |
248 | unsigned long long now; | |
249 | ||
250 | if (!blkio_blkg_empty(stats)) | |
251 | return; | |
252 | ||
253 | now = sched_clock(); | |
254 | if (time_after64(now, stats->start_empty_time)) | |
255 | stats->empty_time += now - stats->start_empty_time; | |
256 | blkio_clear_blkg_empty(stats); | |
257 | } | |
258 | ||
259 | void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg) | |
260 | { | |
261 | unsigned long flags; | |
262 | ||
263 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
264 | BUG_ON(blkio_blkg_idling(&blkg->stats)); | |
265 | blkg->stats.start_idle_time = sched_clock(); | |
266 | blkio_mark_blkg_idling(&blkg->stats); | |
267 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
268 | } | |
269 | EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats); | |
270 | ||
271 | void blkiocg_update_idle_time_stats(struct blkio_group *blkg) | |
272 | { | |
273 | unsigned long flags; | |
274 | unsigned long long now; | |
275 | struct blkio_group_stats *stats; | |
276 | ||
277 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
278 | stats = &blkg->stats; | |
279 | if (blkio_blkg_idling(stats)) { | |
280 | now = sched_clock(); | |
281 | if (time_after64(now, stats->start_idle_time)) | |
282 | stats->idle_time += now - stats->start_idle_time; | |
283 | blkio_clear_blkg_idling(stats); | |
284 | } | |
285 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats); | |
288 | ||
a11cdaa7 | 289 | void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) |
cdc1184c DS |
290 | { |
291 | unsigned long flags; | |
292 | struct blkio_group_stats *stats; | |
293 | ||
294 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
295 | stats = &blkg->stats; | |
296 | stats->avg_queue_size_sum += | |
297 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] + | |
298 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]; | |
299 | stats->avg_queue_size_samples++; | |
812df48d | 300 | blkio_update_group_wait_time(stats); |
cdc1184c DS |
301 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
302 | } | |
a11cdaa7 DS |
303 | EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats); |
304 | ||
e5ff082e | 305 | void blkiocg_set_start_empty_time(struct blkio_group *blkg) |
28baf442 DS |
306 | { |
307 | unsigned long flags; | |
308 | struct blkio_group_stats *stats; | |
309 | ||
310 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
311 | stats = &blkg->stats; | |
312 | ||
313 | if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] || | |
314 | stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]) { | |
315 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
316 | return; | |
317 | } | |
318 | ||
319 | /* | |
e5ff082e VG |
320 | * group is already marked empty. This can happen if cfqq got new |
321 | * request in parent group and moved to this group while being added | |
322 | * to service tree. Just ignore the event and move on. | |
28baf442 | 323 | */ |
e5ff082e VG |
324 | if(blkio_blkg_empty(stats)) { |
325 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
326 | return; | |
327 | } | |
328 | ||
28baf442 DS |
329 | stats->start_empty_time = sched_clock(); |
330 | blkio_mark_blkg_empty(stats); | |
331 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
332 | } | |
333 | EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time); | |
334 | ||
a11cdaa7 DS |
335 | void blkiocg_update_dequeue_stats(struct blkio_group *blkg, |
336 | unsigned long dequeue) | |
337 | { | |
338 | blkg->stats.dequeue += dequeue; | |
339 | } | |
340 | EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats); | |
812df48d DS |
341 | #else |
342 | static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg, | |
343 | struct blkio_group *curr_blkg) {} | |
344 | static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {} | |
cdc1184c DS |
345 | #endif |
346 | ||
a11cdaa7 | 347 | void blkiocg_update_io_add_stats(struct blkio_group *blkg, |
cdc1184c DS |
348 | struct blkio_group *curr_blkg, bool direction, |
349 | bool sync) | |
350 | { | |
351 | unsigned long flags; | |
352 | ||
353 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
354 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], 1, direction, | |
355 | sync); | |
812df48d DS |
356 | blkio_end_empty_time(&blkg->stats); |
357 | blkio_set_start_group_wait_time(blkg, curr_blkg); | |
cdc1184c DS |
358 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
359 | } | |
a11cdaa7 | 360 | EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats); |
cdc1184c | 361 | |
a11cdaa7 | 362 | void blkiocg_update_io_remove_stats(struct blkio_group *blkg, |
cdc1184c DS |
363 | bool direction, bool sync) |
364 | { | |
365 | unsigned long flags; | |
366 | ||
367 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
368 | blkio_check_and_dec_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], | |
369 | direction, sync); | |
370 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
371 | } | |
a11cdaa7 | 372 | EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats); |
cdc1184c | 373 | |
167400d3 JT |
374 | void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time, |
375 | unsigned long unaccounted_time) | |
22084190 | 376 | { |
303a3acb DS |
377 | unsigned long flags; |
378 | ||
379 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
380 | blkg->stats.time += time; | |
167400d3 | 381 | blkg->stats.unaccounted_time += unaccounted_time; |
303a3acb | 382 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
22084190 | 383 | } |
303a3acb | 384 | EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used); |
22084190 | 385 | |
84c124da DS |
386 | void blkiocg_update_dispatch_stats(struct blkio_group *blkg, |
387 | uint64_t bytes, bool direction, bool sync) | |
9195291e DS |
388 | { |
389 | struct blkio_group_stats *stats; | |
390 | unsigned long flags; | |
391 | ||
392 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
393 | stats = &blkg->stats; | |
84c124da DS |
394 | stats->sectors += bytes >> 9; |
395 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction, | |
396 | sync); | |
397 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes, | |
398 | direction, sync); | |
9195291e DS |
399 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
400 | } | |
84c124da | 401 | EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats); |
9195291e | 402 | |
84c124da DS |
403 | void blkiocg_update_completion_stats(struct blkio_group *blkg, |
404 | uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) | |
9195291e DS |
405 | { |
406 | struct blkio_group_stats *stats; | |
407 | unsigned long flags; | |
408 | unsigned long long now = sched_clock(); | |
409 | ||
410 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
411 | stats = &blkg->stats; | |
84c124da DS |
412 | if (time_after64(now, io_start_time)) |
413 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME], | |
414 | now - io_start_time, direction, sync); | |
415 | if (time_after64(io_start_time, start_time)) | |
416 | blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME], | |
417 | io_start_time - start_time, direction, sync); | |
9195291e DS |
418 | spin_unlock_irqrestore(&blkg->stats_lock, flags); |
419 | } | |
84c124da | 420 | EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats); |
9195291e | 421 | |
812d4026 DS |
422 | void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction, |
423 | bool sync) | |
424 | { | |
425 | unsigned long flags; | |
426 | ||
427 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
428 | blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction, | |
429 | sync); | |
430 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
431 | } | |
432 | EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats); | |
433 | ||
31e4c28d | 434 | void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, |
062a644d VG |
435 | struct blkio_group *blkg, void *key, dev_t dev, |
436 | enum blkio_policy_id plid) | |
31e4c28d VG |
437 | { |
438 | unsigned long flags; | |
439 | ||
440 | spin_lock_irqsave(&blkcg->lock, flags); | |
8d2a91f8 | 441 | spin_lock_init(&blkg->stats_lock); |
31e4c28d | 442 | rcu_assign_pointer(blkg->key, key); |
b1c35769 | 443 | blkg->blkcg_id = css_id(&blkcg->css); |
31e4c28d | 444 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); |
062a644d | 445 | blkg->plid = plid; |
31e4c28d | 446 | spin_unlock_irqrestore(&blkcg->lock, flags); |
2868ef7b VG |
447 | /* Need to take css reference ? */ |
448 | cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); | |
22084190 | 449 | blkg->dev = dev; |
31e4c28d | 450 | } |
9d6a986c | 451 | EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); |
31e4c28d | 452 | |
b1c35769 VG |
453 | static void __blkiocg_del_blkio_group(struct blkio_group *blkg) |
454 | { | |
455 | hlist_del_init_rcu(&blkg->blkcg_node); | |
456 | blkg->blkcg_id = 0; | |
457 | } | |
458 | ||
459 | /* | |
460 | * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1 | |
461 | * indicating that blk_group was unhashed by the time we got to it. | |
462 | */ | |
31e4c28d VG |
463 | int blkiocg_del_blkio_group(struct blkio_group *blkg) |
464 | { | |
b1c35769 VG |
465 | struct blkio_cgroup *blkcg; |
466 | unsigned long flags; | |
467 | struct cgroup_subsys_state *css; | |
468 | int ret = 1; | |
469 | ||
470 | rcu_read_lock(); | |
471 | css = css_lookup(&blkio_subsys, blkg->blkcg_id); | |
0f3942a3 JA |
472 | if (css) { |
473 | blkcg = container_of(css, struct blkio_cgroup, css); | |
474 | spin_lock_irqsave(&blkcg->lock, flags); | |
475 | if (!hlist_unhashed(&blkg->blkcg_node)) { | |
476 | __blkiocg_del_blkio_group(blkg); | |
477 | ret = 0; | |
478 | } | |
479 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
b1c35769 | 480 | } |
0f3942a3 | 481 | |
b1c35769 VG |
482 | rcu_read_unlock(); |
483 | return ret; | |
31e4c28d | 484 | } |
9d6a986c | 485 | EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); |
31e4c28d VG |
486 | |
487 | /* called under rcu_read_lock(). */ | |
488 | struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) | |
489 | { | |
490 | struct blkio_group *blkg; | |
491 | struct hlist_node *n; | |
492 | void *__key; | |
493 | ||
494 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
495 | __key = blkg->key; | |
496 | if (__key == key) | |
497 | return blkg; | |
498 | } | |
499 | ||
500 | return NULL; | |
501 | } | |
9d6a986c | 502 | EXPORT_SYMBOL_GPL(blkiocg_lookup_group); |
31e4c28d | 503 | |
303a3acb | 504 | static int |
84c124da | 505 | blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) |
303a3acb DS |
506 | { |
507 | struct blkio_cgroup *blkcg; | |
508 | struct blkio_group *blkg; | |
812df48d | 509 | struct blkio_group_stats *stats; |
303a3acb | 510 | struct hlist_node *n; |
cdc1184c DS |
511 | uint64_t queued[BLKIO_STAT_TOTAL]; |
512 | int i; | |
812df48d DS |
513 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
514 | bool idling, waiting, empty; | |
515 | unsigned long long now = sched_clock(); | |
516 | #endif | |
303a3acb DS |
517 | |
518 | blkcg = cgroup_to_blkio_cgroup(cgroup); | |
519 | spin_lock_irq(&blkcg->lock); | |
520 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
521 | spin_lock(&blkg->stats_lock); | |
812df48d DS |
522 | stats = &blkg->stats; |
523 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
524 | idling = blkio_blkg_idling(stats); | |
525 | waiting = blkio_blkg_waiting(stats); | |
526 | empty = blkio_blkg_empty(stats); | |
527 | #endif | |
cdc1184c | 528 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) |
812df48d DS |
529 | queued[i] = stats->stat_arr[BLKIO_STAT_QUEUED][i]; |
530 | memset(stats, 0, sizeof(struct blkio_group_stats)); | |
cdc1184c | 531 | for (i = 0; i < BLKIO_STAT_TOTAL; i++) |
812df48d DS |
532 | stats->stat_arr[BLKIO_STAT_QUEUED][i] = queued[i]; |
533 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
534 | if (idling) { | |
535 | blkio_mark_blkg_idling(stats); | |
536 | stats->start_idle_time = now; | |
537 | } | |
538 | if (waiting) { | |
539 | blkio_mark_blkg_waiting(stats); | |
540 | stats->start_group_wait_time = now; | |
541 | } | |
542 | if (empty) { | |
543 | blkio_mark_blkg_empty(stats); | |
544 | stats->start_empty_time = now; | |
545 | } | |
546 | #endif | |
303a3acb DS |
547 | spin_unlock(&blkg->stats_lock); |
548 | } | |
549 | spin_unlock_irq(&blkcg->lock); | |
550 | return 0; | |
551 | } | |
552 | ||
84c124da DS |
553 | static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str, |
554 | int chars_left, bool diskname_only) | |
303a3acb | 555 | { |
84c124da | 556 | snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev)); |
303a3acb DS |
557 | chars_left -= strlen(str); |
558 | if (chars_left <= 0) { | |
559 | printk(KERN_WARNING | |
560 | "Possibly incorrect cgroup stat display format"); | |
561 | return; | |
562 | } | |
84c124da DS |
563 | if (diskname_only) |
564 | return; | |
303a3acb | 565 | switch (type) { |
84c124da | 566 | case BLKIO_STAT_READ: |
303a3acb DS |
567 | strlcat(str, " Read", chars_left); |
568 | break; | |
84c124da | 569 | case BLKIO_STAT_WRITE: |
303a3acb DS |
570 | strlcat(str, " Write", chars_left); |
571 | break; | |
84c124da | 572 | case BLKIO_STAT_SYNC: |
303a3acb DS |
573 | strlcat(str, " Sync", chars_left); |
574 | break; | |
84c124da | 575 | case BLKIO_STAT_ASYNC: |
303a3acb DS |
576 | strlcat(str, " Async", chars_left); |
577 | break; | |
84c124da | 578 | case BLKIO_STAT_TOTAL: |
303a3acb DS |
579 | strlcat(str, " Total", chars_left); |
580 | break; | |
581 | default: | |
582 | strlcat(str, " Invalid", chars_left); | |
583 | } | |
584 | } | |
585 | ||
84c124da DS |
586 | static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val, |
587 | struct cgroup_map_cb *cb, dev_t dev) | |
588 | { | |
589 | blkio_get_key_name(0, dev, str, chars_left, true); | |
590 | cb->fill(cb, str, val); | |
591 | return val; | |
592 | } | |
303a3acb | 593 | |
84c124da DS |
594 | /* This should be called with blkg->stats_lock held */ |
595 | static uint64_t blkio_get_stat(struct blkio_group *blkg, | |
596 | struct cgroup_map_cb *cb, dev_t dev, enum stat_type type) | |
303a3acb DS |
597 | { |
598 | uint64_t disk_total; | |
599 | char key_str[MAX_KEY_LEN]; | |
84c124da DS |
600 | enum stat_sub_type sub_type; |
601 | ||
602 | if (type == BLKIO_STAT_TIME) | |
603 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
604 | blkg->stats.time, cb, dev); | |
605 | if (type == BLKIO_STAT_SECTORS) | |
606 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
607 | blkg->stats.sectors, cb, dev); | |
9026e521 | 608 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
167400d3 JT |
609 | if (type == BLKIO_STAT_UNACCOUNTED_TIME) |
610 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
611 | blkg->stats.unaccounted_time, cb, dev); | |
cdc1184c DS |
612 | if (type == BLKIO_STAT_AVG_QUEUE_SIZE) { |
613 | uint64_t sum = blkg->stats.avg_queue_size_sum; | |
614 | uint64_t samples = blkg->stats.avg_queue_size_samples; | |
615 | if (samples) | |
616 | do_div(sum, samples); | |
617 | else | |
618 | sum = 0; | |
619 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, sum, cb, dev); | |
620 | } | |
812df48d DS |
621 | if (type == BLKIO_STAT_GROUP_WAIT_TIME) |
622 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
623 | blkg->stats.group_wait_time, cb, dev); | |
624 | if (type == BLKIO_STAT_IDLE_TIME) | |
625 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
626 | blkg->stats.idle_time, cb, dev); | |
627 | if (type == BLKIO_STAT_EMPTY_TIME) | |
628 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
629 | blkg->stats.empty_time, cb, dev); | |
84c124da DS |
630 | if (type == BLKIO_STAT_DEQUEUE) |
631 | return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, | |
632 | blkg->stats.dequeue, cb, dev); | |
633 | #endif | |
303a3acb | 634 | |
84c124da DS |
635 | for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL; |
636 | sub_type++) { | |
637 | blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false); | |
638 | cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]); | |
303a3acb | 639 | } |
84c124da DS |
640 | disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] + |
641 | blkg->stats.stat_arr[type][BLKIO_STAT_WRITE]; | |
642 | blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false); | |
303a3acb DS |
643 | cb->fill(cb, key_str, disk_total); |
644 | return disk_total; | |
645 | } | |
646 | ||
34d0f179 GJ |
647 | static int blkio_check_dev_num(dev_t dev) |
648 | { | |
649 | int part = 0; | |
650 | struct gendisk *disk; | |
651 | ||
652 | disk = get_gendisk(dev, &part); | |
653 | if (!disk || part) | |
654 | return -ENODEV; | |
655 | ||
656 | return 0; | |
657 | } | |
658 | ||
659 | static int blkio_policy_parse_and_set(char *buf, | |
062a644d | 660 | struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid) |
34d0f179 GJ |
661 | { |
662 | char *s[4], *p, *major_s = NULL, *minor_s = NULL; | |
663 | int ret; | |
664 | unsigned long major, minor, temp; | |
665 | int i = 0; | |
666 | dev_t dev; | |
9355aede | 667 | u64 bps, iops; |
34d0f179 GJ |
668 | |
669 | memset(s, 0, sizeof(s)); | |
670 | ||
671 | while ((p = strsep(&buf, " ")) != NULL) { | |
672 | if (!*p) | |
673 | continue; | |
674 | ||
675 | s[i++] = p; | |
676 | ||
677 | /* Prevent from inputing too many things */ | |
678 | if (i == 3) | |
679 | break; | |
680 | } | |
681 | ||
682 | if (i != 2) | |
683 | return -EINVAL; | |
684 | ||
685 | p = strsep(&s[0], ":"); | |
686 | if (p != NULL) | |
687 | major_s = p; | |
688 | else | |
689 | return -EINVAL; | |
690 | ||
691 | minor_s = s[0]; | |
692 | if (!minor_s) | |
693 | return -EINVAL; | |
694 | ||
695 | ret = strict_strtoul(major_s, 10, &major); | |
696 | if (ret) | |
697 | return -EINVAL; | |
698 | ||
699 | ret = strict_strtoul(minor_s, 10, &minor); | |
700 | if (ret) | |
701 | return -EINVAL; | |
702 | ||
703 | dev = MKDEV(major, minor); | |
704 | ||
705 | ret = blkio_check_dev_num(dev); | |
706 | if (ret) | |
707 | return ret; | |
708 | ||
709 | newpn->dev = dev; | |
710 | ||
711 | if (s[1] == NULL) | |
712 | return -EINVAL; | |
713 | ||
062a644d VG |
714 | switch (plid) { |
715 | case BLKIO_POLICY_PROP: | |
716 | ret = strict_strtoul(s[1], 10, &temp); | |
717 | if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) || | |
718 | temp > BLKIO_WEIGHT_MAX) | |
719 | return -EINVAL; | |
34d0f179 | 720 | |
062a644d VG |
721 | newpn->plid = plid; |
722 | newpn->fileid = fileid; | |
4c9eefa1 VG |
723 | newpn->val.weight = temp; |
724 | break; | |
725 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
726 | switch(fileid) { |
727 | case BLKIO_THROTL_read_bps_device: | |
728 | case BLKIO_THROTL_write_bps_device: | |
729 | ret = strict_strtoull(s[1], 10, &bps); | |
730 | if (ret) | |
731 | return -EINVAL; | |
4c9eefa1 | 732 | |
7702e8f4 VG |
733 | newpn->plid = plid; |
734 | newpn->fileid = fileid; | |
735 | newpn->val.bps = bps; | |
736 | break; | |
737 | case BLKIO_THROTL_read_iops_device: | |
738 | case BLKIO_THROTL_write_iops_device: | |
9355aede | 739 | ret = strict_strtoull(s[1], 10, &iops); |
7702e8f4 VG |
740 | if (ret) |
741 | return -EINVAL; | |
742 | ||
9355aede VG |
743 | if (iops > THROTL_IOPS_MAX) |
744 | return -EINVAL; | |
745 | ||
7702e8f4 VG |
746 | newpn->plid = plid; |
747 | newpn->fileid = fileid; | |
9355aede | 748 | newpn->val.iops = (unsigned int)iops; |
7702e8f4 VG |
749 | break; |
750 | } | |
062a644d VG |
751 | break; |
752 | default: | |
753 | BUG(); | |
754 | } | |
34d0f179 GJ |
755 | |
756 | return 0; | |
757 | } | |
758 | ||
759 | unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, | |
760 | dev_t dev) | |
761 | { | |
762 | struct blkio_policy_node *pn; | |
763 | ||
062a644d VG |
764 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP, |
765 | BLKIO_PROP_weight_device); | |
34d0f179 | 766 | if (pn) |
4c9eefa1 | 767 | return pn->val.weight; |
34d0f179 GJ |
768 | else |
769 | return blkcg->weight; | |
770 | } | |
771 | EXPORT_SYMBOL_GPL(blkcg_get_weight); | |
772 | ||
4c9eefa1 VG |
773 | uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev) |
774 | { | |
775 | struct blkio_policy_node *pn; | |
776 | ||
777 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
778 | BLKIO_THROTL_read_bps_device); | |
779 | if (pn) | |
780 | return pn->val.bps; | |
781 | else | |
782 | return -1; | |
783 | } | |
784 | ||
785 | uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev) | |
786 | { | |
787 | struct blkio_policy_node *pn; | |
788 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
789 | BLKIO_THROTL_write_bps_device); | |
790 | if (pn) | |
791 | return pn->val.bps; | |
792 | else | |
793 | return -1; | |
794 | } | |
795 | ||
7702e8f4 VG |
796 | unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev) |
797 | { | |
798 | struct blkio_policy_node *pn; | |
799 | ||
800 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
801 | BLKIO_THROTL_read_iops_device); | |
802 | if (pn) | |
803 | return pn->val.iops; | |
804 | else | |
805 | return -1; | |
806 | } | |
807 | ||
808 | unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev) | |
809 | { | |
810 | struct blkio_policy_node *pn; | |
811 | pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, | |
812 | BLKIO_THROTL_write_iops_device); | |
813 | if (pn) | |
814 | return pn->val.iops; | |
815 | else | |
816 | return -1; | |
817 | } | |
818 | ||
062a644d VG |
819 | /* Checks whether user asked for deleting a policy rule */ |
820 | static bool blkio_delete_rule_command(struct blkio_policy_node *pn) | |
821 | { | |
822 | switch(pn->plid) { | |
823 | case BLKIO_POLICY_PROP: | |
4c9eefa1 VG |
824 | if (pn->val.weight == 0) |
825 | return 1; | |
826 | break; | |
827 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
828 | switch(pn->fileid) { |
829 | case BLKIO_THROTL_read_bps_device: | |
830 | case BLKIO_THROTL_write_bps_device: | |
831 | if (pn->val.bps == 0) | |
832 | return 1; | |
833 | break; | |
834 | case BLKIO_THROTL_read_iops_device: | |
835 | case BLKIO_THROTL_write_iops_device: | |
836 | if (pn->val.iops == 0) | |
837 | return 1; | |
838 | } | |
062a644d VG |
839 | break; |
840 | default: | |
841 | BUG(); | |
842 | } | |
843 | ||
844 | return 0; | |
845 | } | |
846 | ||
847 | static void blkio_update_policy_rule(struct blkio_policy_node *oldpn, | |
848 | struct blkio_policy_node *newpn) | |
849 | { | |
850 | switch(oldpn->plid) { | |
851 | case BLKIO_POLICY_PROP: | |
4c9eefa1 VG |
852 | oldpn->val.weight = newpn->val.weight; |
853 | break; | |
854 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
855 | switch(newpn->fileid) { |
856 | case BLKIO_THROTL_read_bps_device: | |
857 | case BLKIO_THROTL_write_bps_device: | |
858 | oldpn->val.bps = newpn->val.bps; | |
859 | break; | |
860 | case BLKIO_THROTL_read_iops_device: | |
861 | case BLKIO_THROTL_write_iops_device: | |
862 | oldpn->val.iops = newpn->val.iops; | |
863 | } | |
062a644d VG |
864 | break; |
865 | default: | |
866 | BUG(); | |
867 | } | |
868 | } | |
869 | ||
870 | /* | |
25985edc | 871 | * Some rules/values in blkg have changed. Propagate those to respective |
062a644d VG |
872 | * policies. |
873 | */ | |
874 | static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg, | |
875 | struct blkio_group *blkg, struct blkio_policy_node *pn) | |
876 | { | |
7702e8f4 | 877 | unsigned int weight, iops; |
4c9eefa1 | 878 | u64 bps; |
062a644d VG |
879 | |
880 | switch(pn->plid) { | |
881 | case BLKIO_POLICY_PROP: | |
4c9eefa1 | 882 | weight = pn->val.weight ? pn->val.weight : |
062a644d VG |
883 | blkcg->weight; |
884 | blkio_update_group_weight(blkg, weight); | |
885 | break; | |
4c9eefa1 VG |
886 | case BLKIO_POLICY_THROTL: |
887 | switch(pn->fileid) { | |
888 | case BLKIO_THROTL_read_bps_device: | |
889 | case BLKIO_THROTL_write_bps_device: | |
890 | bps = pn->val.bps ? pn->val.bps : (-1); | |
891 | blkio_update_group_bps(blkg, bps, pn->fileid); | |
892 | break; | |
7702e8f4 VG |
893 | case BLKIO_THROTL_read_iops_device: |
894 | case BLKIO_THROTL_write_iops_device: | |
895 | iops = pn->val.iops ? pn->val.iops : (-1); | |
896 | blkio_update_group_iops(blkg, iops, pn->fileid); | |
897 | break; | |
4c9eefa1 VG |
898 | } |
899 | break; | |
062a644d VG |
900 | default: |
901 | BUG(); | |
902 | } | |
903 | } | |
904 | ||
905 | /* | |
25985edc | 906 | * A policy node rule has been updated. Propagate this update to all the |
062a644d VG |
907 | * block groups which might be affected by this update. |
908 | */ | |
909 | static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg, | |
910 | struct blkio_policy_node *pn) | |
911 | { | |
912 | struct blkio_group *blkg; | |
913 | struct hlist_node *n; | |
914 | ||
915 | spin_lock(&blkio_list_lock); | |
916 | spin_lock_irq(&blkcg->lock); | |
34d0f179 | 917 | |
062a644d VG |
918 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { |
919 | if (pn->dev != blkg->dev || pn->plid != blkg->plid) | |
920 | continue; | |
921 | blkio_update_blkg_policy(blkcg, blkg, pn); | |
922 | } | |
923 | ||
924 | spin_unlock_irq(&blkcg->lock); | |
925 | spin_unlock(&blkio_list_lock); | |
926 | } | |
34d0f179 | 927 | |
062a644d VG |
928 | static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft, |
929 | const char *buffer) | |
34d0f179 GJ |
930 | { |
931 | int ret = 0; | |
932 | char *buf; | |
933 | struct blkio_policy_node *newpn, *pn; | |
934 | struct blkio_cgroup *blkcg; | |
34d0f179 | 935 | int keep_newpn = 0; |
062a644d VG |
936 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); |
937 | int fileid = BLKIOFILE_ATTR(cft->private); | |
34d0f179 GJ |
938 | |
939 | buf = kstrdup(buffer, GFP_KERNEL); | |
940 | if (!buf) | |
941 | return -ENOMEM; | |
942 | ||
943 | newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); | |
944 | if (!newpn) { | |
945 | ret = -ENOMEM; | |
946 | goto free_buf; | |
947 | } | |
948 | ||
062a644d | 949 | ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid); |
34d0f179 GJ |
950 | if (ret) |
951 | goto free_newpn; | |
952 | ||
953 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
954 | ||
955 | spin_lock_irq(&blkcg->lock); | |
956 | ||
062a644d | 957 | pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid); |
34d0f179 | 958 | if (!pn) { |
062a644d | 959 | if (!blkio_delete_rule_command(newpn)) { |
34d0f179 GJ |
960 | blkio_policy_insert_node(blkcg, newpn); |
961 | keep_newpn = 1; | |
962 | } | |
963 | spin_unlock_irq(&blkcg->lock); | |
964 | goto update_io_group; | |
965 | } | |
966 | ||
062a644d | 967 | if (blkio_delete_rule_command(newpn)) { |
34d0f179 GJ |
968 | blkio_policy_delete_node(pn); |
969 | spin_unlock_irq(&blkcg->lock); | |
970 | goto update_io_group; | |
971 | } | |
972 | spin_unlock_irq(&blkcg->lock); | |
973 | ||
062a644d | 974 | blkio_update_policy_rule(pn, newpn); |
34d0f179 GJ |
975 | |
976 | update_io_group: | |
062a644d | 977 | blkio_update_policy_node_blkg(blkcg, newpn); |
34d0f179 GJ |
978 | |
979 | free_newpn: | |
980 | if (!keep_newpn) | |
981 | kfree(newpn); | |
982 | free_buf: | |
983 | kfree(buf); | |
984 | return ret; | |
985 | } | |
986 | ||
062a644d VG |
987 | static void |
988 | blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn) | |
34d0f179 | 989 | { |
062a644d VG |
990 | switch(pn->plid) { |
991 | case BLKIO_POLICY_PROP: | |
992 | if (pn->fileid == BLKIO_PROP_weight_device) | |
993 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
4c9eefa1 VG |
994 | MINOR(pn->dev), pn->val.weight); |
995 | break; | |
996 | case BLKIO_POLICY_THROTL: | |
7702e8f4 VG |
997 | switch(pn->fileid) { |
998 | case BLKIO_THROTL_read_bps_device: | |
999 | case BLKIO_THROTL_write_bps_device: | |
4c9eefa1 VG |
1000 | seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev), |
1001 | MINOR(pn->dev), pn->val.bps); | |
7702e8f4 VG |
1002 | break; |
1003 | case BLKIO_THROTL_read_iops_device: | |
1004 | case BLKIO_THROTL_write_iops_device: | |
1005 | seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev), | |
1006 | MINOR(pn->dev), pn->val.iops); | |
1007 | break; | |
1008 | } | |
062a644d VG |
1009 | break; |
1010 | default: | |
1011 | BUG(); | |
1012 | } | |
1013 | } | |
34d0f179 | 1014 | |
062a644d VG |
1015 | /* cgroup files which read their data from policy nodes end up here */ |
1016 | static void blkio_read_policy_node_files(struct cftype *cft, | |
1017 | struct blkio_cgroup *blkcg, struct seq_file *m) | |
34d0f179 | 1018 | { |
34d0f179 | 1019 | struct blkio_policy_node *pn; |
34d0f179 | 1020 | |
0f3942a3 JA |
1021 | if (!list_empty(&blkcg->policy_list)) { |
1022 | spin_lock_irq(&blkcg->lock); | |
1023 | list_for_each_entry(pn, &blkcg->policy_list, node) { | |
062a644d VG |
1024 | if (!pn_matches_cftype(cft, pn)) |
1025 | continue; | |
1026 | blkio_print_policy_node(m, pn); | |
0f3942a3 JA |
1027 | } |
1028 | spin_unlock_irq(&blkcg->lock); | |
34d0f179 | 1029 | } |
062a644d VG |
1030 | } |
1031 | ||
1032 | static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft, | |
1033 | struct seq_file *m) | |
1034 | { | |
1035 | struct blkio_cgroup *blkcg; | |
1036 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1037 | int name = BLKIOFILE_ATTR(cft->private); | |
1038 | ||
1039 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1040 | ||
1041 | switch(plid) { | |
1042 | case BLKIO_POLICY_PROP: | |
1043 | switch(name) { | |
1044 | case BLKIO_PROP_weight_device: | |
1045 | blkio_read_policy_node_files(cft, blkcg, m); | |
1046 | return 0; | |
1047 | default: | |
1048 | BUG(); | |
1049 | } | |
1050 | break; | |
4c9eefa1 VG |
1051 | case BLKIO_POLICY_THROTL: |
1052 | switch(name){ | |
1053 | case BLKIO_THROTL_read_bps_device: | |
1054 | case BLKIO_THROTL_write_bps_device: | |
7702e8f4 VG |
1055 | case BLKIO_THROTL_read_iops_device: |
1056 | case BLKIO_THROTL_write_iops_device: | |
4c9eefa1 VG |
1057 | blkio_read_policy_node_files(cft, blkcg, m); |
1058 | return 0; | |
1059 | default: | |
1060 | BUG(); | |
1061 | } | |
1062 | break; | |
062a644d VG |
1063 | default: |
1064 | BUG(); | |
1065 | } | |
1066 | ||
1067 | return 0; | |
1068 | } | |
1069 | ||
1070 | static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg, | |
1071 | struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type, | |
1072 | bool show_total) | |
1073 | { | |
1074 | struct blkio_group *blkg; | |
1075 | struct hlist_node *n; | |
1076 | uint64_t cgroup_total = 0; | |
1077 | ||
1078 | rcu_read_lock(); | |
1079 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1080 | if (blkg->dev) { | |
1081 | if (!cftype_blkg_same_policy(cft, blkg)) | |
1082 | continue; | |
1083 | spin_lock_irq(&blkg->stats_lock); | |
1084 | cgroup_total += blkio_get_stat(blkg, cb, blkg->dev, | |
1085 | type); | |
1086 | spin_unlock_irq(&blkg->stats_lock); | |
1087 | } | |
1088 | } | |
1089 | if (show_total) | |
1090 | cb->fill(cb, "Total", cgroup_total); | |
1091 | rcu_read_unlock(); | |
1092 | return 0; | |
1093 | } | |
1094 | ||
1095 | /* All map kind of cgroup file get serviced by this function */ | |
1096 | static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft, | |
1097 | struct cgroup_map_cb *cb) | |
1098 | { | |
1099 | struct blkio_cgroup *blkcg; | |
1100 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1101 | int name = BLKIOFILE_ATTR(cft->private); | |
1102 | ||
1103 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1104 | ||
1105 | switch(plid) { | |
1106 | case BLKIO_POLICY_PROP: | |
1107 | switch(name) { | |
1108 | case BLKIO_PROP_time: | |
1109 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1110 | BLKIO_STAT_TIME, 0); | |
1111 | case BLKIO_PROP_sectors: | |
1112 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1113 | BLKIO_STAT_SECTORS, 0); | |
1114 | case BLKIO_PROP_io_service_bytes: | |
1115 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1116 | BLKIO_STAT_SERVICE_BYTES, 1); | |
1117 | case BLKIO_PROP_io_serviced: | |
1118 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1119 | BLKIO_STAT_SERVICED, 1); | |
1120 | case BLKIO_PROP_io_service_time: | |
1121 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1122 | BLKIO_STAT_SERVICE_TIME, 1); | |
1123 | case BLKIO_PROP_io_wait_time: | |
1124 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1125 | BLKIO_STAT_WAIT_TIME, 1); | |
1126 | case BLKIO_PROP_io_merged: | |
1127 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1128 | BLKIO_STAT_MERGED, 1); | |
1129 | case BLKIO_PROP_io_queued: | |
1130 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1131 | BLKIO_STAT_QUEUED, 1); | |
1132 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
9026e521 JT |
1133 | case BLKIO_PROP_unaccounted_time: |
1134 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1135 | BLKIO_STAT_UNACCOUNTED_TIME, 0); | |
062a644d VG |
1136 | case BLKIO_PROP_dequeue: |
1137 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1138 | BLKIO_STAT_DEQUEUE, 0); | |
1139 | case BLKIO_PROP_avg_queue_size: | |
1140 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1141 | BLKIO_STAT_AVG_QUEUE_SIZE, 0); | |
1142 | case BLKIO_PROP_group_wait_time: | |
1143 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1144 | BLKIO_STAT_GROUP_WAIT_TIME, 0); | |
1145 | case BLKIO_PROP_idle_time: | |
1146 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1147 | BLKIO_STAT_IDLE_TIME, 0); | |
1148 | case BLKIO_PROP_empty_time: | |
1149 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1150 | BLKIO_STAT_EMPTY_TIME, 0); | |
1151 | #endif | |
1152 | default: | |
1153 | BUG(); | |
1154 | } | |
1155 | break; | |
4c9eefa1 VG |
1156 | case BLKIO_POLICY_THROTL: |
1157 | switch(name){ | |
1158 | case BLKIO_THROTL_io_service_bytes: | |
1159 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1160 | BLKIO_STAT_SERVICE_BYTES, 1); | |
1161 | case BLKIO_THROTL_io_serviced: | |
1162 | return blkio_read_blkg_stats(blkcg, cft, cb, | |
1163 | BLKIO_STAT_SERVICED, 1); | |
1164 | default: | |
1165 | BUG(); | |
1166 | } | |
1167 | break; | |
062a644d VG |
1168 | default: |
1169 | BUG(); | |
1170 | } | |
1171 | ||
1172 | return 0; | |
1173 | } | |
1174 | ||
1175 | static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val) | |
1176 | { | |
1177 | struct blkio_group *blkg; | |
1178 | struct hlist_node *n; | |
1179 | struct blkio_policy_node *pn; | |
1180 | ||
1181 | if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) | |
1182 | return -EINVAL; | |
1183 | ||
1184 | spin_lock(&blkio_list_lock); | |
1185 | spin_lock_irq(&blkcg->lock); | |
1186 | blkcg->weight = (unsigned int)val; | |
1187 | ||
1188 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
1189 | pn = blkio_policy_search_node(blkcg, blkg->dev, | |
1190 | BLKIO_POLICY_PROP, BLKIO_PROP_weight_device); | |
1191 | if (pn) | |
1192 | continue; | |
1193 | ||
1194 | blkio_update_group_weight(blkg, blkcg->weight); | |
1195 | } | |
1196 | spin_unlock_irq(&blkcg->lock); | |
1197 | spin_unlock(&blkio_list_lock); | |
1198 | return 0; | |
1199 | } | |
1200 | ||
1201 | static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) { | |
1202 | struct blkio_cgroup *blkcg; | |
1203 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1204 | int name = BLKIOFILE_ATTR(cft->private); | |
1205 | ||
1206 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1207 | ||
1208 | switch(plid) { | |
1209 | case BLKIO_POLICY_PROP: | |
1210 | switch(name) { | |
1211 | case BLKIO_PROP_weight: | |
1212 | return (u64)blkcg->weight; | |
1213 | } | |
1214 | break; | |
1215 | default: | |
1216 | BUG(); | |
1217 | } | |
1218 | return 0; | |
1219 | } | |
1220 | ||
1221 | static int | |
1222 | blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) | |
1223 | { | |
1224 | struct blkio_cgroup *blkcg; | |
1225 | enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private); | |
1226 | int name = BLKIOFILE_ATTR(cft->private); | |
1227 | ||
1228 | blkcg = cgroup_to_blkio_cgroup(cgrp); | |
1229 | ||
1230 | switch(plid) { | |
1231 | case BLKIO_POLICY_PROP: | |
1232 | switch(name) { | |
1233 | case BLKIO_PROP_weight: | |
1234 | return blkio_weight_write(blkcg, val); | |
1235 | } | |
1236 | break; | |
1237 | default: | |
1238 | BUG(); | |
1239 | } | |
34d0f179 | 1240 | |
34d0f179 GJ |
1241 | return 0; |
1242 | } | |
1243 | ||
31e4c28d | 1244 | struct cftype blkio_files[] = { |
34d0f179 GJ |
1245 | { |
1246 | .name = "weight_device", | |
062a644d VG |
1247 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1248 | BLKIO_PROP_weight_device), | |
1249 | .read_seq_string = blkiocg_file_read, | |
1250 | .write_string = blkiocg_file_write, | |
34d0f179 GJ |
1251 | .max_write_len = 256, |
1252 | }, | |
31e4c28d VG |
1253 | { |
1254 | .name = "weight", | |
062a644d VG |
1255 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1256 | BLKIO_PROP_weight), | |
1257 | .read_u64 = blkiocg_file_read_u64, | |
1258 | .write_u64 = blkiocg_file_write_u64, | |
31e4c28d | 1259 | }, |
22084190 VG |
1260 | { |
1261 | .name = "time", | |
062a644d VG |
1262 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1263 | BLKIO_PROP_time), | |
1264 | .read_map = blkiocg_file_read_map, | |
22084190 VG |
1265 | }, |
1266 | { | |
1267 | .name = "sectors", | |
062a644d VG |
1268 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1269 | BLKIO_PROP_sectors), | |
1270 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1271 | }, |
1272 | { | |
1273 | .name = "io_service_bytes", | |
062a644d VG |
1274 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1275 | BLKIO_PROP_io_service_bytes), | |
1276 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1277 | }, |
1278 | { | |
1279 | .name = "io_serviced", | |
062a644d VG |
1280 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1281 | BLKIO_PROP_io_serviced), | |
1282 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1283 | }, |
1284 | { | |
1285 | .name = "io_service_time", | |
062a644d VG |
1286 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1287 | BLKIO_PROP_io_service_time), | |
1288 | .read_map = blkiocg_file_read_map, | |
303a3acb DS |
1289 | }, |
1290 | { | |
1291 | .name = "io_wait_time", | |
062a644d VG |
1292 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1293 | BLKIO_PROP_io_wait_time), | |
1294 | .read_map = blkiocg_file_read_map, | |
84c124da | 1295 | }, |
812d4026 DS |
1296 | { |
1297 | .name = "io_merged", | |
062a644d VG |
1298 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1299 | BLKIO_PROP_io_merged), | |
1300 | .read_map = blkiocg_file_read_map, | |
812d4026 | 1301 | }, |
cdc1184c DS |
1302 | { |
1303 | .name = "io_queued", | |
062a644d VG |
1304 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1305 | BLKIO_PROP_io_queued), | |
1306 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1307 | }, |
84c124da DS |
1308 | { |
1309 | .name = "reset_stats", | |
1310 | .write_u64 = blkiocg_reset_stats, | |
22084190 | 1311 | }, |
13f98250 VG |
1312 | #ifdef CONFIG_BLK_DEV_THROTTLING |
1313 | { | |
1314 | .name = "throttle.read_bps_device", | |
1315 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1316 | BLKIO_THROTL_read_bps_device), | |
1317 | .read_seq_string = blkiocg_file_read, | |
1318 | .write_string = blkiocg_file_write, | |
1319 | .max_write_len = 256, | |
1320 | }, | |
1321 | ||
1322 | { | |
1323 | .name = "throttle.write_bps_device", | |
1324 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1325 | BLKIO_THROTL_write_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.read_iops_device", | |
1333 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1334 | BLKIO_THROTL_read_iops_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.write_iops_device", | |
1342 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1343 | BLKIO_THROTL_write_iops_device), | |
1344 | .read_seq_string = blkiocg_file_read, | |
1345 | .write_string = blkiocg_file_write, | |
1346 | .max_write_len = 256, | |
1347 | }, | |
1348 | { | |
1349 | .name = "throttle.io_service_bytes", | |
1350 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1351 | BLKIO_THROTL_io_service_bytes), | |
1352 | .read_map = blkiocg_file_read_map, | |
1353 | }, | |
1354 | { | |
1355 | .name = "throttle.io_serviced", | |
1356 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL, | |
1357 | BLKIO_THROTL_io_serviced), | |
1358 | .read_map = blkiocg_file_read_map, | |
1359 | }, | |
1360 | #endif /* CONFIG_BLK_DEV_THROTTLING */ | |
1361 | ||
22084190 | 1362 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
cdc1184c DS |
1363 | { |
1364 | .name = "avg_queue_size", | |
062a644d VG |
1365 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1366 | BLKIO_PROP_avg_queue_size), | |
1367 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1368 | }, |
812df48d DS |
1369 | { |
1370 | .name = "group_wait_time", | |
062a644d VG |
1371 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1372 | BLKIO_PROP_group_wait_time), | |
1373 | .read_map = blkiocg_file_read_map, | |
812df48d DS |
1374 | }, |
1375 | { | |
1376 | .name = "idle_time", | |
062a644d VG |
1377 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1378 | BLKIO_PROP_idle_time), | |
1379 | .read_map = blkiocg_file_read_map, | |
812df48d DS |
1380 | }, |
1381 | { | |
1382 | .name = "empty_time", | |
062a644d VG |
1383 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1384 | BLKIO_PROP_empty_time), | |
1385 | .read_map = blkiocg_file_read_map, | |
812df48d | 1386 | }, |
cdc1184c | 1387 | { |
22084190 | 1388 | .name = "dequeue", |
062a644d VG |
1389 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, |
1390 | BLKIO_PROP_dequeue), | |
1391 | .read_map = blkiocg_file_read_map, | |
cdc1184c | 1392 | }, |
9026e521 JT |
1393 | { |
1394 | .name = "unaccounted_time", | |
1395 | .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP, | |
1396 | BLKIO_PROP_unaccounted_time), | |
1397 | .read_map = blkiocg_file_read_map, | |
1398 | }, | |
22084190 | 1399 | #endif |
31e4c28d VG |
1400 | }; |
1401 | ||
1402 | static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1403 | { | |
1404 | return cgroup_add_files(cgroup, subsys, blkio_files, | |
1405 | ARRAY_SIZE(blkio_files)); | |
1406 | } | |
1407 | ||
1408 | static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1409 | { | |
1410 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); | |
b1c35769 VG |
1411 | unsigned long flags; |
1412 | struct blkio_group *blkg; | |
1413 | void *key; | |
3e252066 | 1414 | struct blkio_policy_type *blkiop; |
34d0f179 | 1415 | struct blkio_policy_node *pn, *pntmp; |
b1c35769 VG |
1416 | |
1417 | rcu_read_lock(); | |
0f3942a3 JA |
1418 | do { |
1419 | spin_lock_irqsave(&blkcg->lock, flags); | |
b1c35769 | 1420 | |
0f3942a3 JA |
1421 | if (hlist_empty(&blkcg->blkg_list)) { |
1422 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
1423 | break; | |
1424 | } | |
b1c35769 | 1425 | |
0f3942a3 JA |
1426 | blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, |
1427 | blkcg_node); | |
1428 | key = rcu_dereference(blkg->key); | |
1429 | __blkiocg_del_blkio_group(blkg); | |
31e4c28d | 1430 | |
0f3942a3 | 1431 | spin_unlock_irqrestore(&blkcg->lock, flags); |
b1c35769 | 1432 | |
0f3942a3 JA |
1433 | /* |
1434 | * This blkio_group is being unlinked as associated cgroup is | |
1435 | * going away. Let all the IO controlling policies know about | |
61014e96 | 1436 | * this event. |
0f3942a3 JA |
1437 | */ |
1438 | spin_lock(&blkio_list_lock); | |
61014e96 VG |
1439 | list_for_each_entry(blkiop, &blkio_list, list) { |
1440 | if (blkiop->plid != blkg->plid) | |
1441 | continue; | |
0f3942a3 | 1442 | blkiop->ops.blkio_unlink_group_fn(key, blkg); |
61014e96 | 1443 | } |
0f3942a3 JA |
1444 | spin_unlock(&blkio_list_lock); |
1445 | } while (1); | |
34d0f179 | 1446 | |
34d0f179 GJ |
1447 | list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { |
1448 | blkio_policy_delete_node(pn); | |
1449 | kfree(pn); | |
1450 | } | |
0f3942a3 | 1451 | |
31e4c28d | 1452 | free_css_id(&blkio_subsys, &blkcg->css); |
b1c35769 | 1453 | rcu_read_unlock(); |
67523c48 BB |
1454 | if (blkcg != &blkio_root_cgroup) |
1455 | kfree(blkcg); | |
31e4c28d VG |
1456 | } |
1457 | ||
1458 | static struct cgroup_subsys_state * | |
1459 | blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
1460 | { | |
0341509f LZ |
1461 | struct blkio_cgroup *blkcg; |
1462 | struct cgroup *parent = cgroup->parent; | |
31e4c28d | 1463 | |
0341509f | 1464 | if (!parent) { |
31e4c28d VG |
1465 | blkcg = &blkio_root_cgroup; |
1466 | goto done; | |
1467 | } | |
1468 | ||
31e4c28d VG |
1469 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); |
1470 | if (!blkcg) | |
1471 | return ERR_PTR(-ENOMEM); | |
1472 | ||
1473 | blkcg->weight = BLKIO_WEIGHT_DEFAULT; | |
1474 | done: | |
1475 | spin_lock_init(&blkcg->lock); | |
1476 | INIT_HLIST_HEAD(&blkcg->blkg_list); | |
1477 | ||
34d0f179 | 1478 | INIT_LIST_HEAD(&blkcg->policy_list); |
31e4c28d VG |
1479 | return &blkcg->css; |
1480 | } | |
1481 | ||
1482 | /* | |
1483 | * We cannot support shared io contexts, as we have no mean to support | |
1484 | * two tasks with the same ioc in two different groups without major rework | |
1485 | * of the main cic data structures. For now we allow a task to change | |
1486 | * its cgroup only if it's the only owner of its ioc. | |
1487 | */ | |
1488 | static int blkiocg_can_attach(struct cgroup_subsys *subsys, | |
1489 | struct cgroup *cgroup, struct task_struct *tsk, | |
1490 | bool threadgroup) | |
1491 | { | |
1492 | struct io_context *ioc; | |
1493 | int ret = 0; | |
1494 | ||
1495 | /* task_lock() is needed to avoid races with exit_io_context() */ | |
1496 | task_lock(tsk); | |
1497 | ioc = tsk->io_context; | |
1498 | if (ioc && atomic_read(&ioc->nr_tasks) > 1) | |
1499 | ret = -EINVAL; | |
1500 | task_unlock(tsk); | |
1501 | ||
1502 | return ret; | |
1503 | } | |
1504 | ||
1505 | static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup, | |
1506 | struct cgroup *prev, struct task_struct *tsk, | |
1507 | bool threadgroup) | |
1508 | { | |
1509 | struct io_context *ioc; | |
1510 | ||
1511 | task_lock(tsk); | |
1512 | ioc = tsk->io_context; | |
1513 | if (ioc) | |
1514 | ioc->cgroup_changed = 1; | |
1515 | task_unlock(tsk); | |
1516 | } | |
1517 | ||
3e252066 VG |
1518 | void blkio_policy_register(struct blkio_policy_type *blkiop) |
1519 | { | |
1520 | spin_lock(&blkio_list_lock); | |
1521 | list_add_tail(&blkiop->list, &blkio_list); | |
1522 | spin_unlock(&blkio_list_lock); | |
1523 | } | |
1524 | EXPORT_SYMBOL_GPL(blkio_policy_register); | |
1525 | ||
1526 | void blkio_policy_unregister(struct blkio_policy_type *blkiop) | |
1527 | { | |
1528 | spin_lock(&blkio_list_lock); | |
1529 | list_del_init(&blkiop->list); | |
1530 | spin_unlock(&blkio_list_lock); | |
1531 | } | |
1532 | EXPORT_SYMBOL_GPL(blkio_policy_unregister); | |
67523c48 BB |
1533 | |
1534 | static int __init init_cgroup_blkio(void) | |
1535 | { | |
1536 | return cgroup_load_subsys(&blkio_subsys); | |
1537 | } | |
1538 | ||
1539 | static void __exit exit_cgroup_blkio(void) | |
1540 | { | |
1541 | cgroup_unload_subsys(&blkio_subsys); | |
1542 | } | |
1543 | ||
1544 | module_init(init_cgroup_blkio); | |
1545 | module_exit(exit_cgroup_blkio); | |
1546 | MODULE_LICENSE("GPL"); |