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31e4c28d VG |
1 | #ifndef _BLK_CGROUP_H |
2 | #define _BLK_CGROUP_H | |
3 | /* | |
4 | * Common Block IO controller cgroup interface | |
5 | * | |
6 | * Based on ideas and code from CFQ, CFS and BFQ: | |
7 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> | |
8 | * | |
9 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> | |
10 | * Paolo Valente <paolo.valente@unimore.it> | |
11 | * | |
12 | * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> | |
13 | * Nauman Rafique <nauman@google.com> | |
14 | */ | |
15 | ||
16 | #include <linux/cgroup.h> | |
575969a0 | 17 | #include <linux/u64_stats_sync.h> |
829fdb50 | 18 | #include <linux/seq_file.h> |
a637120e | 19 | #include <linux/radix-tree.h> |
a051661c | 20 | #include <linux/blkdev.h> |
a5049a8a | 21 | #include <linux/atomic.h> |
31e4c28d | 22 | |
9355aede VG |
23 | /* Max limits for throttle policy */ |
24 | #define THROTL_IOPS_MAX UINT_MAX | |
25 | ||
f48ec1d7 TH |
26 | #ifdef CONFIG_BLK_CGROUP |
27 | ||
edcb0722 TH |
28 | enum blkg_rwstat_type { |
29 | BLKG_RWSTAT_READ, | |
30 | BLKG_RWSTAT_WRITE, | |
31 | BLKG_RWSTAT_SYNC, | |
32 | BLKG_RWSTAT_ASYNC, | |
33 | ||
34 | BLKG_RWSTAT_NR, | |
35 | BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR, | |
303a3acb DS |
36 | }; |
37 | ||
a637120e TH |
38 | struct blkcg_gq; |
39 | ||
3c798398 | 40 | struct blkcg { |
36558c8a TH |
41 | struct cgroup_subsys_state css; |
42 | spinlock_t lock; | |
a637120e TH |
43 | |
44 | struct radix_tree_root blkg_tree; | |
45 | struct blkcg_gq *blkg_hint; | |
36558c8a | 46 | struct hlist_head blkg_list; |
9a9e8a26 | 47 | |
e48453c3 | 48 | struct blkcg_policy_data *pd[BLKCG_MAX_POLS]; |
52ebea74 | 49 | |
7876f930 | 50 | struct list_head all_blkcgs_node; |
52ebea74 TH |
51 | #ifdef CONFIG_CGROUP_WRITEBACK |
52 | struct list_head cgwb_list; | |
53 | #endif | |
31e4c28d VG |
54 | }; |
55 | ||
edcb0722 TH |
56 | struct blkg_stat { |
57 | struct u64_stats_sync syncp; | |
58 | uint64_t cnt; | |
59 | }; | |
60 | ||
61 | struct blkg_rwstat { | |
62 | struct u64_stats_sync syncp; | |
63 | uint64_t cnt[BLKG_RWSTAT_NR]; | |
64 | }; | |
65 | ||
f95a04af TH |
66 | /* |
67 | * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a | |
68 | * request_queue (q). This is used by blkcg policies which need to track | |
69 | * information per blkcg - q pair. | |
70 | * | |
71 | * There can be multiple active blkcg policies and each has its private | |
72 | * data on each blkg, the size of which is determined by | |
73 | * blkcg_policy->pd_size. blkcg core allocates and frees such areas | |
74 | * together with blkg and invokes pd_init/exit_fn() methods. | |
75 | * | |
76 | * Such private data must embed struct blkg_policy_data (pd) at the | |
77 | * beginning and pd_size can't be smaller than pd. | |
78 | */ | |
0381411e | 79 | struct blkg_policy_data { |
b276a876 | 80 | /* the blkg and policy id this per-policy data belongs to */ |
3c798398 | 81 | struct blkcg_gq *blkg; |
b276a876 | 82 | int plid; |
0381411e | 83 | |
a2b1693b | 84 | /* used during policy activation */ |
36558c8a | 85 | struct list_head alloc_node; |
0381411e TH |
86 | }; |
87 | ||
e48453c3 AA |
88 | /* |
89 | * Policies that need to keep per-blkcg data which is independent | |
90 | * from any request_queue associated to it must specify its size | |
91 | * with the cpd_size field of the blkcg_policy structure and | |
92 | * embed a blkcg_policy_data in it. blkcg core allocates | |
93 | * policy-specific per-blkcg structures lazily the first time | |
94 | * they are actually needed, so it handles them together with | |
95 | * blkgs. cpd_init() is invoked to let each policy handle | |
96 | * per-blkcg data. | |
97 | */ | |
98 | struct blkcg_policy_data { | |
99 | /* the policy id this per-policy data belongs to */ | |
100 | int plid; | |
101 | ||
102 | /* used during policy activation */ | |
103 | struct list_head alloc_node; | |
104 | }; | |
105 | ||
3c798398 TH |
106 | /* association between a blk cgroup and a request queue */ |
107 | struct blkcg_gq { | |
c875f4d0 | 108 | /* Pointer to the associated request_queue */ |
36558c8a TH |
109 | struct request_queue *q; |
110 | struct list_head q_node; | |
111 | struct hlist_node blkcg_node; | |
3c798398 | 112 | struct blkcg *blkcg; |
3c547865 | 113 | |
ce7acfea TH |
114 | /* |
115 | * Each blkg gets congested separately and the congestion state is | |
116 | * propagated to the matching bdi_writeback_congested. | |
117 | */ | |
118 | struct bdi_writeback_congested *wb_congested; | |
119 | ||
3c547865 TH |
120 | /* all non-root blkcg_gq's are guaranteed to have access to parent */ |
121 | struct blkcg_gq *parent; | |
122 | ||
a051661c TH |
123 | /* request allocation list for this blkcg-q pair */ |
124 | struct request_list rl; | |
3c547865 | 125 | |
1adaf3dd | 126 | /* reference count */ |
a5049a8a | 127 | atomic_t refcnt; |
22084190 | 128 | |
f427d909 TH |
129 | /* is this blkg online? protected by both blkcg and q locks */ |
130 | bool online; | |
131 | ||
36558c8a | 132 | struct blkg_policy_data *pd[BLKCG_MAX_POLS]; |
1adaf3dd | 133 | |
36558c8a | 134 | struct rcu_head rcu_head; |
31e4c28d VG |
135 | }; |
136 | ||
e48453c3 | 137 | typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg); |
3c798398 | 138 | typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg); |
f427d909 TH |
139 | typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg); |
140 | typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg); | |
3c798398 TH |
141 | typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg); |
142 | typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg); | |
3e252066 | 143 | |
3c798398 | 144 | struct blkcg_policy { |
36558c8a TH |
145 | int plid; |
146 | /* policy specific private data size */ | |
f95a04af | 147 | size_t pd_size; |
e48453c3 AA |
148 | /* policy specific per-blkcg data size */ |
149 | size_t cpd_size; | |
36558c8a TH |
150 | /* cgroup files for the policy */ |
151 | struct cftype *cftypes; | |
f9fcc2d3 TH |
152 | |
153 | /* operations */ | |
e48453c3 | 154 | blkcg_pol_init_cpd_fn *cpd_init_fn; |
f9fcc2d3 | 155 | blkcg_pol_init_pd_fn *pd_init_fn; |
f427d909 TH |
156 | blkcg_pol_online_pd_fn *pd_online_fn; |
157 | blkcg_pol_offline_pd_fn *pd_offline_fn; | |
f9fcc2d3 TH |
158 | blkcg_pol_exit_pd_fn *pd_exit_fn; |
159 | blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; | |
3e252066 VG |
160 | }; |
161 | ||
3c798398 | 162 | extern struct blkcg blkcg_root; |
496d5e75 | 163 | extern struct cgroup_subsys_state * const blkcg_root_css; |
36558c8a | 164 | |
3c798398 TH |
165 | struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q); |
166 | struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, | |
167 | struct request_queue *q); | |
36558c8a TH |
168 | int blkcg_init_queue(struct request_queue *q); |
169 | void blkcg_drain_queue(struct request_queue *q); | |
170 | void blkcg_exit_queue(struct request_queue *q); | |
5efd6113 | 171 | |
3e252066 | 172 | /* Blkio controller policy registration */ |
d5bf0291 | 173 | int blkcg_policy_register(struct blkcg_policy *pol); |
3c798398 | 174 | void blkcg_policy_unregister(struct blkcg_policy *pol); |
36558c8a | 175 | int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 176 | const struct blkcg_policy *pol); |
36558c8a | 177 | void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 | 178 | const struct blkcg_policy *pol); |
3e252066 | 179 | |
3c798398 | 180 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
f95a04af TH |
181 | u64 (*prfill)(struct seq_file *, |
182 | struct blkg_policy_data *, int), | |
3c798398 | 183 | const struct blkcg_policy *pol, int data, |
ec399347 | 184 | bool show_total); |
f95a04af TH |
185 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); |
186 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
829fdb50 | 187 | const struct blkg_rwstat *rwstat); |
f95a04af TH |
188 | u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off); |
189 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
190 | int off); | |
829fdb50 | 191 | |
16b3de66 TH |
192 | u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off); |
193 | struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd, | |
194 | int off); | |
195 | ||
829fdb50 | 196 | struct blkg_conf_ctx { |
36558c8a | 197 | struct gendisk *disk; |
3c798398 | 198 | struct blkcg_gq *blkg; |
36558c8a | 199 | u64 v; |
829fdb50 TH |
200 | }; |
201 | ||
3c798398 TH |
202 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
203 | const char *input, struct blkg_conf_ctx *ctx); | |
829fdb50 TH |
204 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); |
205 | ||
206 | ||
a7c6d554 TH |
207 | static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) |
208 | { | |
209 | return css ? container_of(css, struct blkcg, css) : NULL; | |
210 | } | |
211 | ||
b1208b56 TH |
212 | static inline struct blkcg *task_blkcg(struct task_struct *tsk) |
213 | { | |
073219e9 | 214 | return css_to_blkcg(task_css(tsk, blkio_cgrp_id)); |
b1208b56 TH |
215 | } |
216 | ||
217 | static inline struct blkcg *bio_blkcg(struct bio *bio) | |
218 | { | |
219 | if (bio && bio->bi_css) | |
a7c6d554 | 220 | return css_to_blkcg(bio->bi_css); |
b1208b56 TH |
221 | return task_blkcg(current); |
222 | } | |
223 | ||
fd383c2d TH |
224 | static inline struct cgroup_subsys_state * |
225 | task_get_blkcg_css(struct task_struct *task) | |
226 | { | |
227 | return task_get_css(task, blkio_cgrp_id); | |
228 | } | |
229 | ||
3c547865 TH |
230 | /** |
231 | * blkcg_parent - get the parent of a blkcg | |
232 | * @blkcg: blkcg of interest | |
233 | * | |
234 | * Return the parent blkcg of @blkcg. Can be called anytime. | |
235 | */ | |
236 | static inline struct blkcg *blkcg_parent(struct blkcg *blkcg) | |
237 | { | |
5c9d535b | 238 | return css_to_blkcg(blkcg->css.parent); |
3c547865 TH |
239 | } |
240 | ||
0381411e TH |
241 | /** |
242 | * blkg_to_pdata - get policy private data | |
243 | * @blkg: blkg of interest | |
244 | * @pol: policy of interest | |
245 | * | |
246 | * Return pointer to private data associated with the @blkg-@pol pair. | |
247 | */ | |
f95a04af TH |
248 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
249 | struct blkcg_policy *pol) | |
0381411e | 250 | { |
f95a04af | 251 | return blkg ? blkg->pd[pol->plid] : NULL; |
0381411e TH |
252 | } |
253 | ||
e48453c3 AA |
254 | static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg, |
255 | struct blkcg_policy *pol) | |
256 | { | |
257 | return blkcg ? blkcg->pd[pol->plid] : NULL; | |
258 | } | |
259 | ||
0381411e TH |
260 | /** |
261 | * pdata_to_blkg - get blkg associated with policy private data | |
f95a04af | 262 | * @pd: policy private data of interest |
0381411e | 263 | * |
f95a04af | 264 | * @pd is policy private data. Determine the blkg it's associated with. |
0381411e | 265 | */ |
f95a04af | 266 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) |
0381411e | 267 | { |
f95a04af | 268 | return pd ? pd->blkg : NULL; |
0381411e TH |
269 | } |
270 | ||
54e7ed12 TH |
271 | /** |
272 | * blkg_path - format cgroup path of blkg | |
273 | * @blkg: blkg of interest | |
274 | * @buf: target buffer | |
275 | * @buflen: target buffer length | |
276 | * | |
277 | * Format the path of the cgroup of @blkg into @buf. | |
278 | */ | |
3c798398 | 279 | static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen) |
afc24d49 | 280 | { |
e61734c5 | 281 | char *p; |
54e7ed12 | 282 | |
e61734c5 TH |
283 | p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen); |
284 | if (!p) { | |
54e7ed12 | 285 | strncpy(buf, "<unavailable>", buflen); |
e61734c5 TH |
286 | return -ENAMETOOLONG; |
287 | } | |
288 | ||
289 | memmove(buf, p, buf + buflen - p); | |
290 | return 0; | |
afc24d49 VG |
291 | } |
292 | ||
1adaf3dd TH |
293 | /** |
294 | * blkg_get - get a blkg reference | |
295 | * @blkg: blkg to get | |
296 | * | |
a5049a8a | 297 | * The caller should be holding an existing reference. |
1adaf3dd | 298 | */ |
3c798398 | 299 | static inline void blkg_get(struct blkcg_gq *blkg) |
1adaf3dd | 300 | { |
a5049a8a TH |
301 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
302 | atomic_inc(&blkg->refcnt); | |
1adaf3dd TH |
303 | } |
304 | ||
2a4fd070 | 305 | void __blkg_release_rcu(struct rcu_head *rcu); |
1adaf3dd TH |
306 | |
307 | /** | |
308 | * blkg_put - put a blkg reference | |
309 | * @blkg: blkg to put | |
1adaf3dd | 310 | */ |
3c798398 | 311 | static inline void blkg_put(struct blkcg_gq *blkg) |
1adaf3dd | 312 | { |
a5049a8a TH |
313 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
314 | if (atomic_dec_and_test(&blkg->refcnt)) | |
2a4fd070 | 315 | call_rcu(&blkg->rcu_head, __blkg_release_rcu); |
1adaf3dd TH |
316 | } |
317 | ||
dd4a4ffc TH |
318 | struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q, |
319 | bool update_hint); | |
320 | ||
321 | /** | |
322 | * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants | |
323 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 324 | * @pos_css: used for iteration |
dd4a4ffc TH |
325 | * @p_blkg: target blkg to walk descendants of |
326 | * | |
327 | * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU | |
328 | * read locked. If called under either blkcg or queue lock, the iteration | |
329 | * is guaranteed to include all and only online blkgs. The caller may | |
492eb21b | 330 | * update @pos_css by calling css_rightmost_descendant() to skip subtree. |
bd8815a6 | 331 | * @p_blkg is included in the iteration and the first node to be visited. |
dd4a4ffc | 332 | */ |
492eb21b TH |
333 | #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \ |
334 | css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \ | |
335 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
dd4a4ffc TH |
336 | (p_blkg)->q, false))) |
337 | ||
aa539cb3 TH |
338 | /** |
339 | * blkg_for_each_descendant_post - post-order walk of a blkg's descendants | |
340 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 341 | * @pos_css: used for iteration |
aa539cb3 TH |
342 | * @p_blkg: target blkg to walk descendants of |
343 | * | |
344 | * Similar to blkg_for_each_descendant_pre() but performs post-order | |
bd8815a6 TH |
345 | * traversal instead. Synchronization rules are the same. @p_blkg is |
346 | * included in the iteration and the last node to be visited. | |
aa539cb3 | 347 | */ |
492eb21b TH |
348 | #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \ |
349 | css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \ | |
350 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
aa539cb3 TH |
351 | (p_blkg)->q, false))) |
352 | ||
a051661c TH |
353 | /** |
354 | * blk_get_rl - get request_list to use | |
355 | * @q: request_queue of interest | |
356 | * @bio: bio which will be attached to the allocated request (may be %NULL) | |
357 | * | |
358 | * The caller wants to allocate a request from @q to use for @bio. Find | |
359 | * the request_list to use and obtain a reference on it. Should be called | |
360 | * under queue_lock. This function is guaranteed to return non-%NULL | |
361 | * request_list. | |
362 | */ | |
363 | static inline struct request_list *blk_get_rl(struct request_queue *q, | |
364 | struct bio *bio) | |
365 | { | |
366 | struct blkcg *blkcg; | |
367 | struct blkcg_gq *blkg; | |
368 | ||
369 | rcu_read_lock(); | |
370 | ||
371 | blkcg = bio_blkcg(bio); | |
372 | ||
373 | /* bypass blkg lookup and use @q->root_rl directly for root */ | |
374 | if (blkcg == &blkcg_root) | |
375 | goto root_rl; | |
376 | ||
377 | /* | |
378 | * Try to use blkg->rl. blkg lookup may fail under memory pressure | |
379 | * or if either the blkcg or queue is going away. Fall back to | |
380 | * root_rl in such cases. | |
381 | */ | |
382 | blkg = blkg_lookup_create(blkcg, q); | |
383 | if (unlikely(IS_ERR(blkg))) | |
384 | goto root_rl; | |
385 | ||
386 | blkg_get(blkg); | |
387 | rcu_read_unlock(); | |
388 | return &blkg->rl; | |
389 | root_rl: | |
390 | rcu_read_unlock(); | |
391 | return &q->root_rl; | |
392 | } | |
393 | ||
394 | /** | |
395 | * blk_put_rl - put request_list | |
396 | * @rl: request_list to put | |
397 | * | |
398 | * Put the reference acquired by blk_get_rl(). Should be called under | |
399 | * queue_lock. | |
400 | */ | |
401 | static inline void blk_put_rl(struct request_list *rl) | |
402 | { | |
403 | /* root_rl may not have blkg set */ | |
404 | if (rl->blkg && rl->blkg->blkcg != &blkcg_root) | |
405 | blkg_put(rl->blkg); | |
406 | } | |
407 | ||
408 | /** | |
409 | * blk_rq_set_rl - associate a request with a request_list | |
410 | * @rq: request of interest | |
411 | * @rl: target request_list | |
412 | * | |
413 | * Associate @rq with @rl so that accounting and freeing can know the | |
414 | * request_list @rq came from. | |
415 | */ | |
416 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) | |
417 | { | |
418 | rq->rl = rl; | |
419 | } | |
420 | ||
421 | /** | |
422 | * blk_rq_rl - return the request_list a request came from | |
423 | * @rq: request of interest | |
424 | * | |
425 | * Return the request_list @rq is allocated from. | |
426 | */ | |
427 | static inline struct request_list *blk_rq_rl(struct request *rq) | |
428 | { | |
429 | return rq->rl; | |
430 | } | |
431 | ||
432 | struct request_list *__blk_queue_next_rl(struct request_list *rl, | |
433 | struct request_queue *q); | |
434 | /** | |
435 | * blk_queue_for_each_rl - iterate through all request_lists of a request_queue | |
436 | * | |
437 | * Should be used under queue_lock. | |
438 | */ | |
439 | #define blk_queue_for_each_rl(rl, q) \ | |
440 | for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q))) | |
441 | ||
90d3839b PZ |
442 | static inline void blkg_stat_init(struct blkg_stat *stat) |
443 | { | |
444 | u64_stats_init(&stat->syncp); | |
445 | } | |
446 | ||
edcb0722 TH |
447 | /** |
448 | * blkg_stat_add - add a value to a blkg_stat | |
449 | * @stat: target blkg_stat | |
450 | * @val: value to add | |
451 | * | |
452 | * Add @val to @stat. The caller is responsible for synchronizing calls to | |
453 | * this function. | |
454 | */ | |
455 | static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) | |
456 | { | |
457 | u64_stats_update_begin(&stat->syncp); | |
458 | stat->cnt += val; | |
459 | u64_stats_update_end(&stat->syncp); | |
460 | } | |
461 | ||
462 | /** | |
463 | * blkg_stat_read - read the current value of a blkg_stat | |
464 | * @stat: blkg_stat to read | |
465 | * | |
466 | * Read the current value of @stat. This function can be called without | |
467 | * synchroniztion and takes care of u64 atomicity. | |
468 | */ | |
469 | static inline uint64_t blkg_stat_read(struct blkg_stat *stat) | |
470 | { | |
471 | unsigned int start; | |
472 | uint64_t v; | |
473 | ||
474 | do { | |
57a7744e | 475 | start = u64_stats_fetch_begin_irq(&stat->syncp); |
edcb0722 | 476 | v = stat->cnt; |
57a7744e | 477 | } while (u64_stats_fetch_retry_irq(&stat->syncp, start)); |
edcb0722 TH |
478 | |
479 | return v; | |
480 | } | |
481 | ||
482 | /** | |
483 | * blkg_stat_reset - reset a blkg_stat | |
484 | * @stat: blkg_stat to reset | |
485 | */ | |
486 | static inline void blkg_stat_reset(struct blkg_stat *stat) | |
487 | { | |
488 | stat->cnt = 0; | |
489 | } | |
490 | ||
16b3de66 TH |
491 | /** |
492 | * blkg_stat_merge - merge a blkg_stat into another | |
493 | * @to: the destination blkg_stat | |
494 | * @from: the source | |
495 | * | |
496 | * Add @from's count to @to. | |
497 | */ | |
498 | static inline void blkg_stat_merge(struct blkg_stat *to, struct blkg_stat *from) | |
499 | { | |
500 | blkg_stat_add(to, blkg_stat_read(from)); | |
501 | } | |
502 | ||
90d3839b PZ |
503 | static inline void blkg_rwstat_init(struct blkg_rwstat *rwstat) |
504 | { | |
505 | u64_stats_init(&rwstat->syncp); | |
506 | } | |
507 | ||
edcb0722 TH |
508 | /** |
509 | * blkg_rwstat_add - add a value to a blkg_rwstat | |
510 | * @rwstat: target blkg_rwstat | |
511 | * @rw: mask of REQ_{WRITE|SYNC} | |
512 | * @val: value to add | |
513 | * | |
514 | * Add @val to @rwstat. The counters are chosen according to @rw. The | |
515 | * caller is responsible for synchronizing calls to this function. | |
516 | */ | |
517 | static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, | |
518 | int rw, uint64_t val) | |
519 | { | |
520 | u64_stats_update_begin(&rwstat->syncp); | |
521 | ||
522 | if (rw & REQ_WRITE) | |
523 | rwstat->cnt[BLKG_RWSTAT_WRITE] += val; | |
524 | else | |
525 | rwstat->cnt[BLKG_RWSTAT_READ] += val; | |
526 | if (rw & REQ_SYNC) | |
527 | rwstat->cnt[BLKG_RWSTAT_SYNC] += val; | |
528 | else | |
529 | rwstat->cnt[BLKG_RWSTAT_ASYNC] += val; | |
530 | ||
531 | u64_stats_update_end(&rwstat->syncp); | |
532 | } | |
533 | ||
534 | /** | |
535 | * blkg_rwstat_read - read the current values of a blkg_rwstat | |
536 | * @rwstat: blkg_rwstat to read | |
537 | * | |
538 | * Read the current snapshot of @rwstat and return it as the return value. | |
539 | * This function can be called without synchronization and takes care of | |
540 | * u64 atomicity. | |
541 | */ | |
c94bed89 | 542 | static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) |
edcb0722 TH |
543 | { |
544 | unsigned int start; | |
545 | struct blkg_rwstat tmp; | |
546 | ||
547 | do { | |
57a7744e | 548 | start = u64_stats_fetch_begin_irq(&rwstat->syncp); |
edcb0722 | 549 | tmp = *rwstat; |
57a7744e | 550 | } while (u64_stats_fetch_retry_irq(&rwstat->syncp, start)); |
edcb0722 TH |
551 | |
552 | return tmp; | |
553 | } | |
554 | ||
555 | /** | |
4d5e80a7 | 556 | * blkg_rwstat_total - read the total count of a blkg_rwstat |
edcb0722 TH |
557 | * @rwstat: blkg_rwstat to read |
558 | * | |
559 | * Return the total count of @rwstat regardless of the IO direction. This | |
560 | * function can be called without synchronization and takes care of u64 | |
561 | * atomicity. | |
562 | */ | |
4d5e80a7 | 563 | static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat) |
edcb0722 TH |
564 | { |
565 | struct blkg_rwstat tmp = blkg_rwstat_read(rwstat); | |
566 | ||
567 | return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]; | |
568 | } | |
569 | ||
570 | /** | |
571 | * blkg_rwstat_reset - reset a blkg_rwstat | |
572 | * @rwstat: blkg_rwstat to reset | |
573 | */ | |
574 | static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) | |
575 | { | |
576 | memset(rwstat->cnt, 0, sizeof(rwstat->cnt)); | |
577 | } | |
578 | ||
16b3de66 TH |
579 | /** |
580 | * blkg_rwstat_merge - merge a blkg_rwstat into another | |
581 | * @to: the destination blkg_rwstat | |
582 | * @from: the source | |
583 | * | |
584 | * Add @from's counts to @to. | |
585 | */ | |
586 | static inline void blkg_rwstat_merge(struct blkg_rwstat *to, | |
587 | struct blkg_rwstat *from) | |
588 | { | |
589 | struct blkg_rwstat v = blkg_rwstat_read(from); | |
590 | int i; | |
591 | ||
592 | u64_stats_update_begin(&to->syncp); | |
593 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
594 | to->cnt[i] += v.cnt[i]; | |
595 | u64_stats_update_end(&to->syncp); | |
596 | } | |
597 | ||
36558c8a TH |
598 | #else /* CONFIG_BLK_CGROUP */ |
599 | ||
efa7d1c7 TH |
600 | struct blkcg { |
601 | }; | |
2f5ea477 | 602 | |
f95a04af TH |
603 | struct blkg_policy_data { |
604 | }; | |
605 | ||
e48453c3 AA |
606 | struct blkcg_policy_data { |
607 | }; | |
608 | ||
3c798398 | 609 | struct blkcg_gq { |
2f5ea477 JA |
610 | }; |
611 | ||
3c798398 | 612 | struct blkcg_policy { |
3e252066 VG |
613 | }; |
614 | ||
496d5e75 TH |
615 | #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL)) |
616 | ||
fd383c2d TH |
617 | static inline struct cgroup_subsys_state * |
618 | task_get_blkcg_css(struct task_struct *task) | |
619 | { | |
620 | return NULL; | |
621 | } | |
622 | ||
efa7d1c7 TH |
623 | #ifdef CONFIG_BLOCK |
624 | ||
3c798398 | 625 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } |
5efd6113 TH |
626 | static inline int blkcg_init_queue(struct request_queue *q) { return 0; } |
627 | static inline void blkcg_drain_queue(struct request_queue *q) { } | |
628 | static inline void blkcg_exit_queue(struct request_queue *q) { } | |
d5bf0291 | 629 | static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } |
3c798398 | 630 | static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } |
a2b1693b | 631 | static inline int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 632 | const struct blkcg_policy *pol) { return 0; } |
a2b1693b | 633 | static inline void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 TH |
634 | const struct blkcg_policy *pol) { } |
635 | ||
b1208b56 | 636 | static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } |
a051661c | 637 | |
f95a04af TH |
638 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
639 | struct blkcg_policy *pol) { return NULL; } | |
640 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } | |
3c798398 TH |
641 | static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } |
642 | static inline void blkg_get(struct blkcg_gq *blkg) { } | |
643 | static inline void blkg_put(struct blkcg_gq *blkg) { } | |
afc24d49 | 644 | |
a051661c TH |
645 | static inline struct request_list *blk_get_rl(struct request_queue *q, |
646 | struct bio *bio) { return &q->root_rl; } | |
647 | static inline void blk_put_rl(struct request_list *rl) { } | |
648 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { } | |
649 | static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; } | |
650 | ||
651 | #define blk_queue_for_each_rl(rl, q) \ | |
652 | for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) | |
653 | ||
efa7d1c7 | 654 | #endif /* CONFIG_BLOCK */ |
36558c8a TH |
655 | #endif /* CONFIG_BLK_CGROUP */ |
656 | #endif /* _BLK_CGROUP_H */ |