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Merge branch 'master' into next
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / block / blk-cgroup.c
CommitLineData
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		 25static DEFINE_SPINLOCK(blkio_list_lock);
26static LIST_HEAD(blkio_list);
b1c35769 27
31e4c28d 28struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
9d6a986c
VG		 29EXPORT_SYMBOL_GPL(blkio_root_cgroup);
30
67523c48
BB		 31static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
32 struct cgroup *);
33static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
34 struct task_struct *, bool);
35static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
36 struct cgroup *, struct task_struct *, bool);
37static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
38static 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		 46struct 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};
60EXPORT_SYMBOL_GPL(blkio_subsys);
61
34d0f179
GJ		 62static 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		 68static 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 */
80static 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 */
90static 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 */
96static struct blkio_policy_node *
062a644d
VG		 97blkio_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		 110struct 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 115EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
31e4c28d 116
70087dc3
VG		 117struct 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}
122EXPORT_SYMBOL_GPL(task_blkio_cgroup);
123
062a644d
VG		 124static inline void
125blkio_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		 139static 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		 162static 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		 189static 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 */
207static 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. */
227static 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. */
239static 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. */
253static 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
266void 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}
276EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats);
277
278void 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}
294EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats);
295
a11cdaa7 296void 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		 310EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
311
e5ff082e 312void 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}
340EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time);
341
a11cdaa7
DS		 342void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
343 unsigned long dequeue)
344{
345 blkg->stats.dequeue += dequeue;
346}
347EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
812df48d
DS		 348#else
349static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg,
350 struct blkio_group *curr_blkg) {}
351static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {}
cdc1184c
DS		 352#endif
353
a11cdaa7 354void 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 367EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats);
cdc1184c 368
a11cdaa7 369void 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 379EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
cdc1184c 380
167400d3
JT		 381void 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;
167400d3 388 blkg->stats.unaccounted_time += unaccounted_time;
303a3acb 389 spin_unlock_irqrestore(&blkg->stats_lock, flags);
22084190 390}
303a3acb 391EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
22084190 392
84c124da
DS		 393void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
394 uint64_t bytes, bool direction, bool sync)
9195291e
DS		 395{
396 struct blkio_group_stats *stats;
397 unsigned long flags;
398
399 spin_lock_irqsave(&blkg->stats_lock, flags);
400 stats = &blkg->stats;
84c124da
DS		 401 stats->sectors += bytes >> 9;
402 blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction,
403 sync);
404 blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes,
405 direction, sync);
9195291e
DS		 406 spin_unlock_irqrestore(&blkg->stats_lock, flags);
407}
84c124da 408EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);
9195291e 409
84c124da
DS		 410void blkiocg_update_completion_stats(struct blkio_group *blkg,
411 uint64_t start_time, uint64_t io_start_time, bool direction, bool sync)
9195291e
DS		 412{
413 struct blkio_group_stats *stats;
414 unsigned long flags;
415 unsigned long long now = sched_clock();
416
417 spin_lock_irqsave(&blkg->stats_lock, flags);
418 stats = &blkg->stats;
84c124da
DS		 419 if (time_after64(now, io_start_time))
420 blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME],
421 now - io_start_time, direction, sync);
422 if (time_after64(io_start_time, start_time))
423 blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME],
424 io_start_time - start_time, direction, sync);
9195291e
DS		 425 spin_unlock_irqrestore(&blkg->stats_lock, flags);
426}
84c124da 427EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats);
9195291e 428
812d4026
DS		 429void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
430 bool sync)
431{
432 unsigned long flags;
433
434 spin_lock_irqsave(&blkg->stats_lock, flags);
435 blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction,
436 sync);
437 spin_unlock_irqrestore(&blkg->stats_lock, flags);
438}
439EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
440
31e4c28d 441void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
062a644d
VG		 442 struct blkio_group *blkg, void *key, dev_t dev,
443 enum blkio_policy_id plid)
31e4c28d
VG		 444{
445 unsigned long flags;
446
447 spin_lock_irqsave(&blkcg->lock, flags);
8d2a91f8 448 spin_lock_init(&blkg->stats_lock);
31e4c28d 449 rcu_assign_pointer(blkg->key, key);
b1c35769 450 blkg->blkcg_id = css_id(&blkcg->css);
31e4c28d 451 hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
062a644d 452 blkg->plid = plid;
31e4c28d 453 spin_unlock_irqrestore(&blkcg->lock, flags);
2868ef7b
VG		 454 /* Need to take css reference ? */
455 cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
22084190 456 blkg->dev = dev;
31e4c28d 457}
9d6a986c 458EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group);
31e4c28d 459
b1c35769
VG		 460static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
461{
462 hlist_del_init_rcu(&blkg->blkcg_node);
463 blkg->blkcg_id = 0;
464}
465
466/*
467 * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1
468 * indicating that blk_group was unhashed by the time we got to it.
469 */
31e4c28d
VG		 470int blkiocg_del_blkio_group(struct blkio_group *blkg)
471{
b1c35769
VG		 472 struct blkio_cgroup *blkcg;
473 unsigned long flags;
474 struct cgroup_subsys_state *css;
475 int ret = 1;
476
477 rcu_read_lock();
478 css = css_lookup(&blkio_subsys, blkg->blkcg_id);
0f3942a3
JA		 479 if (css) {
480 blkcg = container_of(css, struct blkio_cgroup, css);
481 spin_lock_irqsave(&blkcg->lock, flags);
482 if (!hlist_unhashed(&blkg->blkcg_node)) {
483 __blkiocg_del_blkio_group(blkg);
484 ret = 0;
485 }
486 spin_unlock_irqrestore(&blkcg->lock, flags);
b1c35769 487 }
0f3942a3 488
b1c35769
VG		 489 rcu_read_unlock();
490 return ret;
31e4c28d 491}
9d6a986c 492EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group);
31e4c28d
VG		 493
494/* called under rcu_read_lock(). */
495struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
496{
497 struct blkio_group *blkg;
498 struct hlist_node *n;
499 void *__key;
500
501 hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {
502 __key = blkg->key;
503 if (__key == key)
504 return blkg;
505 }
506
507 return NULL;
508}
9d6a986c 509EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
31e4c28d 510
303a3acb 511static int
84c124da 512blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
303a3acb
DS		 513{
514 struct blkio_cgroup *blkcg;
515 struct blkio_group *blkg;
812df48d 516 struct blkio_group_stats *stats;
303a3acb 517 struct hlist_node *n;
cdc1184c
DS		 518 uint64_t queued[BLKIO_STAT_TOTAL];
519 int i;
812df48d
DS		 520#ifdef CONFIG_DEBUG_BLK_CGROUP
521 bool idling, waiting, empty;
522 unsigned long long now = sched_clock();
523#endif
303a3acb
DS		 524
525 blkcg = cgroup_to_blkio_cgroup(cgroup);
526 spin_lock_irq(&blkcg->lock);
527 hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
528 spin_lock(&blkg->stats_lock);
812df48d
DS		 529 stats = &blkg->stats;
530#ifdef CONFIG_DEBUG_BLK_CGROUP
531 idling = blkio_blkg_idling(stats);
532 waiting = blkio_blkg_waiting(stats);
533 empty = blkio_blkg_empty(stats);
534#endif
cdc1184c 535 for (i = 0; i < BLKIO_STAT_TOTAL; i++)
812df48d
DS		 536 queued[i] = stats->stat_arr[BLKIO_STAT_QUEUED][i];
537 memset(stats, 0, sizeof(struct blkio_group_stats));
cdc1184c 538 for (i = 0; i < BLKIO_STAT_TOTAL; i++)
812df48d
DS		 539 stats->stat_arr[BLKIO_STAT_QUEUED][i] = queued[i];
540#ifdef CONFIG_DEBUG_BLK_CGROUP
541 if (idling) {
542 blkio_mark_blkg_idling(stats);
543 stats->start_idle_time = now;
544 }
545 if (waiting) {
546 blkio_mark_blkg_waiting(stats);
547 stats->start_group_wait_time = now;
548 }
549 if (empty) {
550 blkio_mark_blkg_empty(stats);
551 stats->start_empty_time = now;
552 }
553#endif
303a3acb
DS		 554 spin_unlock(&blkg->stats_lock);
555 }
556 spin_unlock_irq(&blkcg->lock);
557 return 0;
558}
559
84c124da
DS		 560static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str,
561 int chars_left, bool diskname_only)
303a3acb 562{
84c124da 563 snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev));
303a3acb
DS		 564 chars_left -= strlen(str);
565 if (chars_left <= 0) {
566 printk(KERN_WARNING
567 "Possibly incorrect cgroup stat display format");
568 return;
569 }
84c124da
DS		 570 if (diskname_only)
571 return;
303a3acb 572 switch (type) {
84c124da 573 case BLKIO_STAT_READ:
303a3acb
DS		 574 strlcat(str, " Read", chars_left);
575 break;
84c124da 576 case BLKIO_STAT_WRITE:
303a3acb
DS		 577 strlcat(str, " Write", chars_left);
578 break;
84c124da 579 case BLKIO_STAT_SYNC:
303a3acb
DS		 580 strlcat(str, " Sync", chars_left);
581 break;
84c124da 582 case BLKIO_STAT_ASYNC:
303a3acb
DS		 583 strlcat(str, " Async", chars_left);
584 break;
84c124da 585 case BLKIO_STAT_TOTAL:
303a3acb
DS		 586 strlcat(str, " Total", chars_left);
587 break;
588 default:
589 strlcat(str, " Invalid", chars_left);
590 }
591}
592
84c124da
DS		 593static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val,
594 struct cgroup_map_cb *cb, dev_t dev)
595{
596 blkio_get_key_name(0, dev, str, chars_left, true);
597 cb->fill(cb, str, val);
598 return val;
599}
303a3acb 600
84c124da
DS		 601/* This should be called with blkg->stats_lock held */
602static uint64_t blkio_get_stat(struct blkio_group *blkg,
603 struct cgroup_map_cb *cb, dev_t dev, enum stat_type type)
303a3acb
DS		 604{
605 uint64_t disk_total;
606 char key_str[MAX_KEY_LEN];
84c124da
DS		 607 enum stat_sub_type sub_type;
608
609 if (type == BLKIO_STAT_TIME)
610 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
611 blkg->stats.time, cb, dev);
612 if (type == BLKIO_STAT_SECTORS)
613 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
614 blkg->stats.sectors, cb, dev);
9026e521 615#ifdef CONFIG_DEBUG_BLK_CGROUP
167400d3
JT		 616 if (type == BLKIO_STAT_UNACCOUNTED_TIME)
617 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
618 blkg->stats.unaccounted_time, cb, dev);
cdc1184c
DS		 619 if (type == BLKIO_STAT_AVG_QUEUE_SIZE) {
620 uint64_t sum = blkg->stats.avg_queue_size_sum;
621 uint64_t samples = blkg->stats.avg_queue_size_samples;
622 if (samples)
623 do_div(sum, samples);
624 else
625 sum = 0;
626 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, sum, cb, dev);
627 }
812df48d
DS		 628 if (type == BLKIO_STAT_GROUP_WAIT_TIME)
629 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
630 blkg->stats.group_wait_time, cb, dev);
631 if (type == BLKIO_STAT_IDLE_TIME)
632 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
633 blkg->stats.idle_time, cb, dev);
634 if (type == BLKIO_STAT_EMPTY_TIME)
635 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
636 blkg->stats.empty_time, cb, dev);
84c124da
DS		 637 if (type == BLKIO_STAT_DEQUEUE)
638 return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
639 blkg->stats.dequeue, cb, dev);
640#endif
303a3acb 641
84c124da
DS		 642 for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
643 sub_type++) {
644 blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false);
645 cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]);
303a3acb 646 }
84c124da
DS		 647 disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] +
648 blkg->stats.stat_arr[type][BLKIO_STAT_WRITE];
649 blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false);
303a3acb
DS		 650 cb->fill(cb, key_str, disk_total);
651 return disk_total;
652}
653
34d0f179
GJ		 654static int blkio_check_dev_num(dev_t dev)
655{
656 int part = 0;
657 struct gendisk *disk;
658
659 disk = get_gendisk(dev, &part);
660 if (!disk || part)
661 return -ENODEV;
662
663 return 0;
664}
665
666static int blkio_policy_parse_and_set(char *buf,
062a644d 667 struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)
34d0f179
GJ		 668{
669 char *s[4], *p, *major_s = NULL, *minor_s = NULL;
670 int ret;
671 unsigned long major, minor, temp;
672 int i = 0;
673 dev_t dev;
9355aede 674 u64 bps, iops;
34d0f179
GJ		 675
676 memset(s, 0, sizeof(s));
677
678 while ((p = strsep(&buf, " ")) != NULL) {
679 if (!*p)
680 continue;
681
682 s[i++] = p;
683
684 /* Prevent from inputing too many things */
685 if (i == 3)
686 break;
687 }
688
689 if (i != 2)
690 return -EINVAL;
691
692 p = strsep(&s[0], ":");
693 if (p != NULL)
694 major_s = p;
695 else
696 return -EINVAL;
697
698 minor_s = s[0];
699 if (!minor_s)
700 return -EINVAL;
701
702 ret = strict_strtoul(major_s, 10, &major);
703 if (ret)
704 return -EINVAL;
705
706 ret = strict_strtoul(minor_s, 10, &minor);
707 if (ret)
708 return -EINVAL;
709
710 dev = MKDEV(major, minor);
711
712 ret = blkio_check_dev_num(dev);
713 if (ret)
714 return ret;
715
716 newpn->dev = dev;
717
718 if (s[1] == NULL)
719 return -EINVAL;
720
062a644d
VG		 721 switch (plid) {
722 case BLKIO_POLICY_PROP:
723 ret = strict_strtoul(s[1], 10, &temp);
724 if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
725 temp > BLKIO_WEIGHT_MAX)
726 return -EINVAL;
34d0f179 727
062a644d
VG		 728 newpn->plid = plid;
729 newpn->fileid = fileid;
4c9eefa1
VG		 730 newpn->val.weight = temp;
731 break;
732 case BLKIO_POLICY_THROTL:
7702e8f4
VG		 733 switch(fileid) {
734 case BLKIO_THROTL_read_bps_device:
735 case BLKIO_THROTL_write_bps_device:
736 ret = strict_strtoull(s[1], 10, &bps);
737 if (ret)
738 return -EINVAL;
4c9eefa1 739
7702e8f4
VG		 740 newpn->plid = plid;
741 newpn->fileid = fileid;
742 newpn->val.bps = bps;
743 break;
744 case BLKIO_THROTL_read_iops_device:
745 case BLKIO_THROTL_write_iops_device:
9355aede 746 ret = strict_strtoull(s[1], 10, &iops);
7702e8f4
VG		 747 if (ret)
748 return -EINVAL;
749
9355aede
VG		 750 if (iops > THROTL_IOPS_MAX)
751 return -EINVAL;
752
7702e8f4
VG		 753 newpn->plid = plid;
754 newpn->fileid = fileid;
9355aede 755 newpn->val.iops = (unsigned int)iops;
7702e8f4
VG		 756 break;
757 }
062a644d
VG		 758 break;
759 default:
760 BUG();
761 }
34d0f179
GJ		 762
763 return 0;
764}
765
766unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
767 dev_t dev)
768{
769 struct blkio_policy_node *pn;
770
062a644d
VG		 771 pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
772 BLKIO_PROP_weight_device);
34d0f179 773 if (pn)
4c9eefa1 774 return pn->val.weight;
34d0f179
GJ		 775 else
776 return blkcg->weight;
777}
778EXPORT_SYMBOL_GPL(blkcg_get_weight);
779
4c9eefa1
VG		 780uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev)
781{
782 struct blkio_policy_node *pn;
783
784 pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
785 BLKIO_THROTL_read_bps_device);
786 if (pn)
787 return pn->val.bps;
788 else
789 return -1;
790}
791
792uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
793{
794 struct blkio_policy_node *pn;
795 pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
796 BLKIO_THROTL_write_bps_device);
797 if (pn)
798 return pn->val.bps;
799 else
800 return -1;
801}
802
7702e8f4
VG		 803unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
804{
805 struct blkio_policy_node *pn;
806
807 pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
808 BLKIO_THROTL_read_iops_device);
809 if (pn)
810 return pn->val.iops;
811 else
812 return -1;
813}
814
815unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
816{
817 struct blkio_policy_node *pn;
818 pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
819 BLKIO_THROTL_write_iops_device);
820 if (pn)
821 return pn->val.iops;
822 else
823 return -1;
824}
825
062a644d
VG		 826/* Checks whether user asked for deleting a policy rule */
827static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
828{
829 switch(pn->plid) {
830 case BLKIO_POLICY_PROP:
4c9eefa1
VG		 831 if (pn->val.weight == 0)
832 return 1;
833 break;
834 case BLKIO_POLICY_THROTL:
7702e8f4
VG		 835 switch(pn->fileid) {
836 case BLKIO_THROTL_read_bps_device:
837 case BLKIO_THROTL_write_bps_device:
838 if (pn->val.bps == 0)
839 return 1;
840 break;
841 case BLKIO_THROTL_read_iops_device:
842 case BLKIO_THROTL_write_iops_device:
843 if (pn->val.iops == 0)
844 return 1;
845 }
062a644d
VG		 846 break;
847 default:
848 BUG();
849 }
850
851 return 0;
852}
853
854static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
855 struct blkio_policy_node *newpn)
856{
857 switch(oldpn->plid) {
858 case BLKIO_POLICY_PROP:
4c9eefa1
VG		 859 oldpn->val.weight = newpn->val.weight;
860 break;
861 case BLKIO_POLICY_THROTL:
7702e8f4
VG		 862 switch(newpn->fileid) {
863 case BLKIO_THROTL_read_bps_device:
864 case BLKIO_THROTL_write_bps_device:
865 oldpn->val.bps = newpn->val.bps;
866 break;
867 case BLKIO_THROTL_read_iops_device:
868 case BLKIO_THROTL_write_iops_device:
869 oldpn->val.iops = newpn->val.iops;
870 }
062a644d
VG		 871 break;
872 default:
873 BUG();
874 }
875}
876
877/*
25985edc 878 * Some rules/values in blkg have changed. Propagate those to respective
062a644d
VG		 879 * policies.
880 */
881static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
882 struct blkio_group *blkg, struct blkio_policy_node *pn)
883{
7702e8f4 884 unsigned int weight, iops;
4c9eefa1 885 u64 bps;
062a644d
VG		 886
887 switch(pn->plid) {
888 case BLKIO_POLICY_PROP:
4c9eefa1 889 weight = pn->val.weight ? pn->val.weight :
062a644d
VG		 890 blkcg->weight;
891 blkio_update_group_weight(blkg, weight);
892 break;
4c9eefa1
VG		 893 case BLKIO_POLICY_THROTL:
894 switch(pn->fileid) {
895 case BLKIO_THROTL_read_bps_device:
896 case BLKIO_THROTL_write_bps_device:
897 bps = pn->val.bps ? pn->val.bps : (-1);
898 blkio_update_group_bps(blkg, bps, pn->fileid);
899 break;
7702e8f4
VG		 900 case BLKIO_THROTL_read_iops_device:
901 case BLKIO_THROTL_write_iops_device:
902 iops = pn->val.iops ? pn->val.iops : (-1);
903 blkio_update_group_iops(blkg, iops, pn->fileid);
904 break;
4c9eefa1
VG		 905 }
906 break;
062a644d
VG		 907 default:
908 BUG();
909 }
910}
911
912/*
25985edc 913 * A policy node rule has been updated. Propagate this update to all the
062a644d
VG		 914 * block groups which might be affected by this update.
915 */
916static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg,
917 struct blkio_policy_node *pn)
918{
919 struct blkio_group *blkg;
920 struct hlist_node *n;
921
922 spin_lock(&blkio_list_lock);
923 spin_lock_irq(&blkcg->lock);
34d0f179 924
062a644d
VG		 925 hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
926 if (pn->dev != blkg->dev || pn->plid != blkg->plid)
927 continue;
928 blkio_update_blkg_policy(blkcg, blkg, pn);
929 }
930
931 spin_unlock_irq(&blkcg->lock);
932 spin_unlock(&blkio_list_lock);
933}
34d0f179 934
062a644d
VG		 935static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft,
936 const char *buffer)
34d0f179
GJ		 937{
938 int ret = 0;
939 char *buf;
940 struct blkio_policy_node *newpn, *pn;
941 struct blkio_cgroup *blkcg;
34d0f179 942 int keep_newpn = 0;
062a644d
VG		 943 enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
944 int fileid = BLKIOFILE_ATTR(cft->private);
34d0f179
GJ		 945
946 buf = kstrdup(buffer, GFP_KERNEL);
947 if (!buf)
948 return -ENOMEM;
949
950 newpn = kzalloc(sizeof(*newpn), GFP_KERNEL);
951 if (!newpn) {
952 ret = -ENOMEM;
953 goto free_buf;
954 }
955
062a644d 956 ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid);
34d0f179
GJ		 957 if (ret)
958 goto free_newpn;
959
960 blkcg = cgroup_to_blkio_cgroup(cgrp);
961
962 spin_lock_irq(&blkcg->lock);
963
062a644d 964 pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid);
34d0f179 965 if (!pn) {
062a644d 966 if (!blkio_delete_rule_command(newpn)) {
34d0f179
GJ		 967 blkio_policy_insert_node(blkcg, newpn);
968 keep_newpn = 1;
969 }
970 spin_unlock_irq(&blkcg->lock);
971 goto update_io_group;
972 }
973
062a644d 974 if (blkio_delete_rule_command(newpn)) {
34d0f179
GJ		 975 blkio_policy_delete_node(pn);
976 spin_unlock_irq(&blkcg->lock);
977 goto update_io_group;
978 }
979 spin_unlock_irq(&blkcg->lock);
980
062a644d 981 blkio_update_policy_rule(pn, newpn);
34d0f179
GJ		 982
983update_io_group:
062a644d 984 blkio_update_policy_node_blkg(blkcg, newpn);
34d0f179
GJ		 985
986free_newpn:
987 if (!keep_newpn)
988 kfree(newpn);
989free_buf:
990 kfree(buf);
991 return ret;
992}
993
062a644d
VG		 994static void
995blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
34d0f179 996{
062a644d
VG		 997 switch(pn->plid) {
998 case BLKIO_POLICY_PROP:
999 if (pn->fileid == BLKIO_PROP_weight_device)
1000 seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
4c9eefa1
VG		 1001 MINOR(pn->dev), pn->val.weight);
1002 break;
1003 case BLKIO_POLICY_THROTL:
7702e8f4
VG		 1004 switch(pn->fileid) {
1005 case BLKIO_THROTL_read_bps_device:
1006 case BLKIO_THROTL_write_bps_device:
4c9eefa1
VG		 1007 seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
1008 MINOR(pn->dev), pn->val.bps);
7702e8f4
VG		 1009 break;
1010 case BLKIO_THROTL_read_iops_device:
1011 case BLKIO_THROTL_write_iops_device:
1012 seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
1013 MINOR(pn->dev), pn->val.iops);
1014 break;
1015 }
062a644d
VG		 1016 break;
1017 default:
1018 BUG();
1019 }
1020}
34d0f179 1021
062a644d
VG		 1022/* cgroup files which read their data from policy nodes end up here */
1023static void blkio_read_policy_node_files(struct cftype *cft,
1024 struct blkio_cgroup *blkcg, struct seq_file *m)
34d0f179 1025{
34d0f179 1026 struct blkio_policy_node *pn;
34d0f179 1027
0f3942a3
JA		 1028 if (!list_empty(&blkcg->policy_list)) {
1029 spin_lock_irq(&blkcg->lock);
1030 list_for_each_entry(pn, &blkcg->policy_list, node) {
062a644d
VG		 1031 if (!pn_matches_cftype(cft, pn))
1032 continue;
1033 blkio_print_policy_node(m, pn);
0f3942a3
JA		 1034 }
1035 spin_unlock_irq(&blkcg->lock);
34d0f179 1036 }
062a644d
VG		 1037}
1038
1039static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
1040 struct seq_file *m)
1041{
1042 struct blkio_cgroup *blkcg;
1043 enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
1044 int name = BLKIOFILE_ATTR(cft->private);
1045
1046 blkcg = cgroup_to_blkio_cgroup(cgrp);
1047
1048 switch(plid) {
1049 case BLKIO_POLICY_PROP:
1050 switch(name) {
1051 case BLKIO_PROP_weight_device:
1052 blkio_read_policy_node_files(cft, blkcg, m);
1053 return 0;
1054 default:
1055 BUG();
1056 }
1057 break;
4c9eefa1
VG		 1058 case BLKIO_POLICY_THROTL:
1059 switch(name){
1060 case BLKIO_THROTL_read_bps_device:
1061 case BLKIO_THROTL_write_bps_device:
7702e8f4
VG		 1062 case BLKIO_THROTL_read_iops_device:
1063 case BLKIO_THROTL_write_iops_device:
4c9eefa1
VG		 1064 blkio_read_policy_node_files(cft, blkcg, m);
1065 return 0;
1066 default:
1067 BUG();
1068 }
1069 break;
062a644d
VG		 1070 default:
1071 BUG();
1072 }
1073
1074 return 0;
1075}
1076
1077static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg,
1078 struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type,
1079 bool show_total)
1080{
1081 struct blkio_group *blkg;
1082 struct hlist_node *n;
1083 uint64_t cgroup_total = 0;
1084
1085 rcu_read_lock();
1086 hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {
1087 if (blkg->dev) {
1088 if (!cftype_blkg_same_policy(cft, blkg))
1089 continue;
1090 spin_lock_irq(&blkg->stats_lock);
1091 cgroup_total += blkio_get_stat(blkg, cb, blkg->dev,
1092 type);
1093 spin_unlock_irq(&blkg->stats_lock);
1094 }
1095 }
1096 if (show_total)
1097 cb->fill(cb, "Total", cgroup_total);
1098 rcu_read_unlock();
1099 return 0;
1100}
1101
1102/* All map kind of cgroup file get serviced by this function */
1103static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft,
1104 struct cgroup_map_cb *cb)
1105{
1106 struct blkio_cgroup *blkcg;
1107 enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
1108 int name = BLKIOFILE_ATTR(cft->private);
1109
1110 blkcg = cgroup_to_blkio_cgroup(cgrp);
1111
1112 switch(plid) {
1113 case BLKIO_POLICY_PROP:
1114 switch(name) {
1115 case BLKIO_PROP_time:
1116 return blkio_read_blkg_stats(blkcg, cft, cb,
1117 BLKIO_STAT_TIME, 0);
1118 case BLKIO_PROP_sectors:
1119 return blkio_read_blkg_stats(blkcg, cft, cb,
1120 BLKIO_STAT_SECTORS, 0);
1121 case BLKIO_PROP_io_service_bytes:
1122 return blkio_read_blkg_stats(blkcg, cft, cb,
1123 BLKIO_STAT_SERVICE_BYTES, 1);
1124 case BLKIO_PROP_io_serviced:
1125 return blkio_read_blkg_stats(blkcg, cft, cb,
1126 BLKIO_STAT_SERVICED, 1);
1127 case BLKIO_PROP_io_service_time:
1128 return blkio_read_blkg_stats(blkcg, cft, cb,
1129 BLKIO_STAT_SERVICE_TIME, 1);
1130 case BLKIO_PROP_io_wait_time:
1131 return blkio_read_blkg_stats(blkcg, cft, cb,
1132 BLKIO_STAT_WAIT_TIME, 1);
1133 case BLKIO_PROP_io_merged:
1134 return blkio_read_blkg_stats(blkcg, cft, cb,
1135 BLKIO_STAT_MERGED, 1);
1136 case BLKIO_PROP_io_queued:
1137 return blkio_read_blkg_stats(blkcg, cft, cb,
1138 BLKIO_STAT_QUEUED, 1);
1139#ifdef CONFIG_DEBUG_BLK_CGROUP
9026e521
JT		 1140 case BLKIO_PROP_unaccounted_time:
1141 return blkio_read_blkg_stats(blkcg, cft, cb,
1142 BLKIO_STAT_UNACCOUNTED_TIME, 0);
062a644d
VG		 1143 case BLKIO_PROP_dequeue:
1144 return blkio_read_blkg_stats(blkcg, cft, cb,
1145 BLKIO_STAT_DEQUEUE, 0);
1146 case BLKIO_PROP_avg_queue_size:
1147 return blkio_read_blkg_stats(blkcg, cft, cb,
1148 BLKIO_STAT_AVG_QUEUE_SIZE, 0);
1149 case BLKIO_PROP_group_wait_time:
1150 return blkio_read_blkg_stats(blkcg, cft, cb,
1151 BLKIO_STAT_GROUP_WAIT_TIME, 0);
1152 case BLKIO_PROP_idle_time:
1153 return blkio_read_blkg_stats(blkcg, cft, cb,
1154 BLKIO_STAT_IDLE_TIME, 0);
1155 case BLKIO_PROP_empty_time:
1156 return blkio_read_blkg_stats(blkcg, cft, cb,
1157 BLKIO_STAT_EMPTY_TIME, 0);
1158#endif
1159 default:
1160 BUG();
1161 }
1162 break;
4c9eefa1
VG		 1163 case BLKIO_POLICY_THROTL:
1164 switch(name){
1165 case BLKIO_THROTL_io_service_bytes:
1166 return blkio_read_blkg_stats(blkcg, cft, cb,
1167 BLKIO_STAT_SERVICE_BYTES, 1);
1168 case BLKIO_THROTL_io_serviced:
1169 return blkio_read_blkg_stats(blkcg, cft, cb,
1170 BLKIO_STAT_SERVICED, 1);
1171 default:
1172 BUG();
1173 }
1174 break;
062a644d
VG		 1175 default:
1176 BUG();
1177 }
1178
1179 return 0;
1180}
1181
1182static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val)
1183{
1184 struct blkio_group *blkg;
1185 struct hlist_node *n;
1186 struct blkio_policy_node *pn;
1187
1188 if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
1189 return -EINVAL;
1190
1191 spin_lock(&blkio_list_lock);
1192 spin_lock_irq(&blkcg->lock);
1193 blkcg->weight = (unsigned int)val;
1194
1195 hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
1196 pn = blkio_policy_search_node(blkcg, blkg->dev,
1197 BLKIO_POLICY_PROP, BLKIO_PROP_weight_device);
1198 if (pn)
1199 continue;
1200
1201 blkio_update_group_weight(blkg, blkcg->weight);
1202 }
1203 spin_unlock_irq(&blkcg->lock);
1204 spin_unlock(&blkio_list_lock);
1205 return 0;
1206}
1207
1208static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) {
1209 struct blkio_cgroup *blkcg;
1210 enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
1211 int name = BLKIOFILE_ATTR(cft->private);
1212
1213 blkcg = cgroup_to_blkio_cgroup(cgrp);
1214
1215 switch(plid) {
1216 case BLKIO_POLICY_PROP:
1217 switch(name) {
1218 case BLKIO_PROP_weight:
1219 return (u64)blkcg->weight;
1220 }
1221 break;
1222 default:
1223 BUG();
1224 }
1225 return 0;
1226}
1227
1228static int
1229blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
1230{
1231 struct blkio_cgroup *blkcg;
1232 enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
1233 int name = BLKIOFILE_ATTR(cft->private);
1234
1235 blkcg = cgroup_to_blkio_cgroup(cgrp);
1236
1237 switch(plid) {
1238 case BLKIO_POLICY_PROP:
1239 switch(name) {
1240 case BLKIO_PROP_weight:
1241 return blkio_weight_write(blkcg, val);
1242 }
1243 break;
1244 default:
1245 BUG();
1246 }
34d0f179 1247
34d0f179
GJ		 1248 return 0;
1249}
1250
31e4c28d 1251struct cftype blkio_files[] = {
34d0f179
GJ		 1252 {
1253 .name = "weight_device",
062a644d
VG		 1254 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1255 BLKIO_PROP_weight_device),
1256 .read_seq_string = blkiocg_file_read,
1257 .write_string = blkiocg_file_write,
34d0f179
GJ		 1258 .max_write_len = 256,
1259 },
31e4c28d
VG		 1260 {
1261 .name = "weight",
062a644d
VG		 1262 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1263 BLKIO_PROP_weight),
1264 .read_u64 = blkiocg_file_read_u64,
1265 .write_u64 = blkiocg_file_write_u64,
31e4c28d 1266 },
22084190
VG		 1267 {
1268 .name = "time",
062a644d
VG		 1269 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1270 BLKIO_PROP_time),
1271 .read_map = blkiocg_file_read_map,
22084190
VG		 1272 },
1273 {
1274 .name = "sectors",
062a644d
VG		 1275 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1276 BLKIO_PROP_sectors),
1277 .read_map = blkiocg_file_read_map,
303a3acb
DS		 1278 },
1279 {
1280 .name = "io_service_bytes",
062a644d
VG		 1281 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1282 BLKIO_PROP_io_service_bytes),
1283 .read_map = blkiocg_file_read_map,
303a3acb
DS		 1284 },
1285 {
1286 .name = "io_serviced",
062a644d
VG		 1287 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1288 BLKIO_PROP_io_serviced),
1289 .read_map = blkiocg_file_read_map,
303a3acb
DS		 1290 },
1291 {
1292 .name = "io_service_time",
062a644d
VG		 1293 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1294 BLKIO_PROP_io_service_time),
1295 .read_map = blkiocg_file_read_map,
303a3acb
DS		 1296 },
1297 {
1298 .name = "io_wait_time",
062a644d
VG		 1299 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1300 BLKIO_PROP_io_wait_time),
1301 .read_map = blkiocg_file_read_map,
84c124da 1302 },
812d4026
DS		 1303 {
1304 .name = "io_merged",
062a644d
VG		 1305 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1306 BLKIO_PROP_io_merged),
1307 .read_map = blkiocg_file_read_map,
812d4026 1308 },
cdc1184c
DS		 1309 {
1310 .name = "io_queued",
062a644d
VG		 1311 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1312 BLKIO_PROP_io_queued),
1313 .read_map = blkiocg_file_read_map,
cdc1184c 1314 },
84c124da
DS		 1315 {
1316 .name = "reset_stats",
1317 .write_u64 = blkiocg_reset_stats,
22084190 1318 },
13f98250
VG		 1319#ifdef CONFIG_BLK_DEV_THROTTLING
1320 {
1321 .name = "throttle.read_bps_device",
1322 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
1323 BLKIO_THROTL_read_bps_device),
1324 .read_seq_string = blkiocg_file_read,
1325 .write_string = blkiocg_file_write,
1326 .max_write_len = 256,
1327 },
1328
1329 {
1330 .name = "throttle.write_bps_device",
1331 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
1332 BLKIO_THROTL_write_bps_device),
1333 .read_seq_string = blkiocg_file_read,
1334 .write_string = blkiocg_file_write,
1335 .max_write_len = 256,
1336 },
1337
1338 {
1339 .name = "throttle.read_iops_device",
1340 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
1341 BLKIO_THROTL_read_iops_device),
1342 .read_seq_string = blkiocg_file_read,
1343 .write_string = blkiocg_file_write,
1344 .max_write_len = 256,
1345 },
1346
1347 {
1348 .name = "throttle.write_iops_device",
1349 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
1350 BLKIO_THROTL_write_iops_device),
1351 .read_seq_string = blkiocg_file_read,
1352 .write_string = blkiocg_file_write,
1353 .max_write_len = 256,
1354 },
1355 {
1356 .name = "throttle.io_service_bytes",
1357 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
1358 BLKIO_THROTL_io_service_bytes),
1359 .read_map = blkiocg_file_read_map,
1360 },
1361 {
1362 .name = "throttle.io_serviced",
1363 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
1364 BLKIO_THROTL_io_serviced),
1365 .read_map = blkiocg_file_read_map,
1366 },
1367#endif /* CONFIG_BLK_DEV_THROTTLING */
1368
22084190 1369#ifdef CONFIG_DEBUG_BLK_CGROUP
cdc1184c
DS		 1370 {
1371 .name = "avg_queue_size",
062a644d
VG		 1372 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1373 BLKIO_PROP_avg_queue_size),
1374 .read_map = blkiocg_file_read_map,
cdc1184c 1375 },
812df48d
DS		 1376 {
1377 .name = "group_wait_time",
062a644d
VG		 1378 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1379 BLKIO_PROP_group_wait_time),
1380 .read_map = blkiocg_file_read_map,
812df48d
DS		 1381 },
1382 {
1383 .name = "idle_time",
062a644d
VG		 1384 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1385 BLKIO_PROP_idle_time),
1386 .read_map = blkiocg_file_read_map,
812df48d
DS		 1387 },
1388 {
1389 .name = "empty_time",
062a644d
VG		 1390 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1391 BLKIO_PROP_empty_time),
1392 .read_map = blkiocg_file_read_map,
812df48d 1393 },
cdc1184c 1394 {
22084190 1395 .name = "dequeue",
062a644d
VG		 1396 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1397 BLKIO_PROP_dequeue),
1398 .read_map = blkiocg_file_read_map,
cdc1184c 1399 },
9026e521
JT		 1400 {
1401 .name = "unaccounted_time",
1402 .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
1403 BLKIO_PROP_unaccounted_time),
1404 .read_map = blkiocg_file_read_map,
1405 },
22084190 1406#endif
31e4c28d
VG		 1407};
1408
1409static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup)
1410{
1411 return cgroup_add_files(cgroup, subsys, blkio_files,
1412 ARRAY_SIZE(blkio_files));
1413}
1414
1415static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
1416{
1417 struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
b1c35769
VG		 1418 unsigned long flags;
1419 struct blkio_group *blkg;
1420 void *key;
3e252066 1421 struct blkio_policy_type *blkiop;
34d0f179 1422 struct blkio_policy_node *pn, *pntmp;
b1c35769
VG		 1423
1424 rcu_read_lock();
0f3942a3
JA		 1425 do {
1426 spin_lock_irqsave(&blkcg->lock, flags);
b1c35769 1427
0f3942a3
JA		 1428 if (hlist_empty(&blkcg->blkg_list)) {
1429 spin_unlock_irqrestore(&blkcg->lock, flags);
1430 break;
1431 }
b1c35769 1432
0f3942a3
JA		 1433 blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group,
1434 blkcg_node);
1435 key = rcu_dereference(blkg->key);
1436 __blkiocg_del_blkio_group(blkg);
31e4c28d 1437
0f3942a3 1438 spin_unlock_irqrestore(&blkcg->lock, flags);
b1c35769 1439
0f3942a3
JA		 1440 /*
1441 * This blkio_group is being unlinked as associated cgroup is
1442 * going away. Let all the IO controlling policies know about
61014e96 1443 * this event.
0f3942a3
JA		 1444 */
1445 spin_lock(&blkio_list_lock);
61014e96
VG		 1446 list_for_each_entry(blkiop, &blkio_list, list) {
1447 if (blkiop->plid != blkg->plid)
1448 continue;
0f3942a3 1449 blkiop->ops.blkio_unlink_group_fn(key, blkg);
61014e96 1450 }
0f3942a3
JA		 1451 spin_unlock(&blkio_list_lock);
1452 } while (1);
34d0f179 1453
34d0f179
GJ		 1454 list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) {
1455 blkio_policy_delete_node(pn);
1456 kfree(pn);
1457 }
0f3942a3 1458
31e4c28d 1459 free_css_id(&blkio_subsys, &blkcg->css);
b1c35769 1460 rcu_read_unlock();
67523c48
BB		 1461 if (blkcg != &blkio_root_cgroup)
1462 kfree(blkcg);
31e4c28d
VG		 1463}
1464
1465static struct cgroup_subsys_state *
1466blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup)
1467{
0341509f
LZ		 1468 struct blkio_cgroup *blkcg;
1469 struct cgroup *parent = cgroup->parent;
31e4c28d 1470
0341509f 1471 if (!parent) {
31e4c28d
VG		 1472 blkcg = &blkio_root_cgroup;
1473 goto done;
1474 }
1475
31e4c28d
VG		 1476 blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
1477 if (!blkcg)
1478 return ERR_PTR(-ENOMEM);
1479
1480 blkcg->weight = BLKIO_WEIGHT_DEFAULT;
1481done:
1482 spin_lock_init(&blkcg->lock);
1483 INIT_HLIST_HEAD(&blkcg->blkg_list);
1484
34d0f179 1485 INIT_LIST_HEAD(&blkcg->policy_list);
31e4c28d
VG		 1486 return &blkcg->css;
1487}
1488
1489/*
1490 * We cannot support shared io contexts, as we have no mean to support
1491 * two tasks with the same ioc in two different groups without major rework
1492 * of the main cic data structures. For now we allow a task to change
1493 * its cgroup only if it's the only owner of its ioc.
1494 */
1495static int blkiocg_can_attach(struct cgroup_subsys *subsys,
1496 struct cgroup *cgroup, struct task_struct *tsk,
1497 bool threadgroup)
1498{
1499 struct io_context *ioc;
1500 int ret = 0;
1501
1502 /* task_lock() is needed to avoid races with exit_io_context() */
1503 task_lock(tsk);
1504 ioc = tsk->io_context;
1505 if (ioc && atomic_read(&ioc->nr_tasks) > 1)
1506 ret = -EINVAL;
1507 task_unlock(tsk);
1508
1509 return ret;
1510}
1511
1512static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup,
1513 struct cgroup *prev, struct task_struct *tsk,
1514 bool threadgroup)
1515{
1516 struct io_context *ioc;
1517
1518 task_lock(tsk);
1519 ioc = tsk->io_context;
1520 if (ioc)
1521 ioc->cgroup_changed = 1;
1522 task_unlock(tsk);
1523}
1524
3e252066
VG		 1525void blkio_policy_register(struct blkio_policy_type *blkiop)
1526{
1527 spin_lock(&blkio_list_lock);
1528 list_add_tail(&blkiop->list, &blkio_list);
1529 spin_unlock(&blkio_list_lock);
1530}
1531EXPORT_SYMBOL_GPL(blkio_policy_register);
1532
1533void blkio_policy_unregister(struct blkio_policy_type *blkiop)
1534{
1535 spin_lock(&blkio_list_lock);
1536 list_del_init(&blkiop->list);
1537 spin_unlock(&blkio_list_lock);
1538}
1539EXPORT_SYMBOL_GPL(blkio_policy_unregister);
67523c48
BB		 1540
1541static int __init init_cgroup_blkio(void)
1542{
1543 return cgroup_load_subsys(&blkio_subsys);
1544}
1545
1546static void __exit exit_cgroup_blkio(void)
1547{
1548 cgroup_unload_subsys(&blkio_subsys);
1549}
1550
1551module_init(init_cgroup_blkio);
1552module_exit(exit_cgroup_blkio);
1553MODULE_LICENSE("GPL");
kernel source for telekom puls (alcatel/mediatek)