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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 | |
06b285bd TH |
92 | * embed a blkcg_policy_data in it. cpd_init() is invoked to let |
93 | * each policy handle per-blkcg data. | |
e48453c3 AA |
94 | */ |
95 | struct blkcg_policy_data { | |
96 | /* the policy id this per-policy data belongs to */ | |
97 | int plid; | |
e48453c3 AA |
98 | }; |
99 | ||
3c798398 TH |
100 | /* association between a blk cgroup and a request queue */ |
101 | struct blkcg_gq { | |
c875f4d0 | 102 | /* Pointer to the associated request_queue */ |
36558c8a TH |
103 | struct request_queue *q; |
104 | struct list_head q_node; | |
105 | struct hlist_node blkcg_node; | |
3c798398 | 106 | struct blkcg *blkcg; |
3c547865 | 107 | |
ce7acfea TH |
108 | /* |
109 | * Each blkg gets congested separately and the congestion state is | |
110 | * propagated to the matching bdi_writeback_congested. | |
111 | */ | |
112 | struct bdi_writeback_congested *wb_congested; | |
113 | ||
3c547865 TH |
114 | /* all non-root blkcg_gq's are guaranteed to have access to parent */ |
115 | struct blkcg_gq *parent; | |
116 | ||
a051661c TH |
117 | /* request allocation list for this blkcg-q pair */ |
118 | struct request_list rl; | |
3c547865 | 119 | |
1adaf3dd | 120 | /* reference count */ |
a5049a8a | 121 | atomic_t refcnt; |
22084190 | 122 | |
f427d909 TH |
123 | /* is this blkg online? protected by both blkcg and q locks */ |
124 | bool online; | |
125 | ||
36558c8a | 126 | struct blkg_policy_data *pd[BLKCG_MAX_POLS]; |
1adaf3dd | 127 | |
36558c8a | 128 | struct rcu_head rcu_head; |
31e4c28d VG |
129 | }; |
130 | ||
e48453c3 | 131 | typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg); |
3c798398 | 132 | typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg); |
f427d909 TH |
133 | typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg); |
134 | typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg); | |
3c798398 TH |
135 | typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg); |
136 | typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg); | |
3e252066 | 137 | |
3c798398 | 138 | struct blkcg_policy { |
36558c8a TH |
139 | int plid; |
140 | /* policy specific private data size */ | |
f95a04af | 141 | size_t pd_size; |
e48453c3 AA |
142 | /* policy specific per-blkcg data size */ |
143 | size_t cpd_size; | |
36558c8a TH |
144 | /* cgroup files for the policy */ |
145 | struct cftype *cftypes; | |
f9fcc2d3 TH |
146 | |
147 | /* operations */ | |
e48453c3 | 148 | blkcg_pol_init_cpd_fn *cpd_init_fn; |
f9fcc2d3 | 149 | blkcg_pol_init_pd_fn *pd_init_fn; |
f427d909 TH |
150 | blkcg_pol_online_pd_fn *pd_online_fn; |
151 | blkcg_pol_offline_pd_fn *pd_offline_fn; | |
f9fcc2d3 TH |
152 | blkcg_pol_exit_pd_fn *pd_exit_fn; |
153 | blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; | |
3e252066 VG |
154 | }; |
155 | ||
3c798398 | 156 | extern struct blkcg blkcg_root; |
496d5e75 | 157 | extern struct cgroup_subsys_state * const blkcg_root_css; |
36558c8a | 158 | |
3c798398 TH |
159 | struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q); |
160 | struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, | |
161 | struct request_queue *q); | |
36558c8a TH |
162 | int blkcg_init_queue(struct request_queue *q); |
163 | void blkcg_drain_queue(struct request_queue *q); | |
164 | void blkcg_exit_queue(struct request_queue *q); | |
5efd6113 | 165 | |
3e252066 | 166 | /* Blkio controller policy registration */ |
d5bf0291 | 167 | int blkcg_policy_register(struct blkcg_policy *pol); |
3c798398 | 168 | void blkcg_policy_unregister(struct blkcg_policy *pol); |
36558c8a | 169 | int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 170 | const struct blkcg_policy *pol); |
36558c8a | 171 | void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 | 172 | const struct blkcg_policy *pol); |
3e252066 | 173 | |
3c798398 | 174 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
f95a04af TH |
175 | u64 (*prfill)(struct seq_file *, |
176 | struct blkg_policy_data *, int), | |
3c798398 | 177 | const struct blkcg_policy *pol, int data, |
ec399347 | 178 | bool show_total); |
f95a04af TH |
179 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); |
180 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
829fdb50 | 181 | const struct blkg_rwstat *rwstat); |
f95a04af TH |
182 | u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off); |
183 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
184 | int off); | |
829fdb50 | 185 | |
16b3de66 TH |
186 | u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off); |
187 | struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd, | |
188 | int off); | |
189 | ||
829fdb50 | 190 | struct blkg_conf_ctx { |
36558c8a | 191 | struct gendisk *disk; |
3c798398 | 192 | struct blkcg_gq *blkg; |
36558c8a | 193 | u64 v; |
829fdb50 TH |
194 | }; |
195 | ||
3c798398 TH |
196 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
197 | const char *input, struct blkg_conf_ctx *ctx); | |
829fdb50 TH |
198 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); |
199 | ||
200 | ||
a7c6d554 TH |
201 | static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) |
202 | { | |
203 | return css ? container_of(css, struct blkcg, css) : NULL; | |
204 | } | |
205 | ||
b1208b56 TH |
206 | static inline struct blkcg *task_blkcg(struct task_struct *tsk) |
207 | { | |
073219e9 | 208 | return css_to_blkcg(task_css(tsk, blkio_cgrp_id)); |
b1208b56 TH |
209 | } |
210 | ||
211 | static inline struct blkcg *bio_blkcg(struct bio *bio) | |
212 | { | |
213 | if (bio && bio->bi_css) | |
a7c6d554 | 214 | return css_to_blkcg(bio->bi_css); |
b1208b56 TH |
215 | return task_blkcg(current); |
216 | } | |
217 | ||
fd383c2d TH |
218 | static inline struct cgroup_subsys_state * |
219 | task_get_blkcg_css(struct task_struct *task) | |
220 | { | |
221 | return task_get_css(task, blkio_cgrp_id); | |
222 | } | |
223 | ||
3c547865 TH |
224 | /** |
225 | * blkcg_parent - get the parent of a blkcg | |
226 | * @blkcg: blkcg of interest | |
227 | * | |
228 | * Return the parent blkcg of @blkcg. Can be called anytime. | |
229 | */ | |
230 | static inline struct blkcg *blkcg_parent(struct blkcg *blkcg) | |
231 | { | |
5c9d535b | 232 | return css_to_blkcg(blkcg->css.parent); |
3c547865 TH |
233 | } |
234 | ||
0381411e TH |
235 | /** |
236 | * blkg_to_pdata - get policy private data | |
237 | * @blkg: blkg of interest | |
238 | * @pol: policy of interest | |
239 | * | |
240 | * Return pointer to private data associated with the @blkg-@pol pair. | |
241 | */ | |
f95a04af TH |
242 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
243 | struct blkcg_policy *pol) | |
0381411e | 244 | { |
f95a04af | 245 | return blkg ? blkg->pd[pol->plid] : NULL; |
0381411e TH |
246 | } |
247 | ||
e48453c3 AA |
248 | static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg, |
249 | struct blkcg_policy *pol) | |
250 | { | |
251 | return blkcg ? blkcg->pd[pol->plid] : NULL; | |
252 | } | |
253 | ||
0381411e TH |
254 | /** |
255 | * pdata_to_blkg - get blkg associated with policy private data | |
f95a04af | 256 | * @pd: policy private data of interest |
0381411e | 257 | * |
f95a04af | 258 | * @pd is policy private data. Determine the blkg it's associated with. |
0381411e | 259 | */ |
f95a04af | 260 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) |
0381411e | 261 | { |
f95a04af | 262 | return pd ? pd->blkg : NULL; |
0381411e TH |
263 | } |
264 | ||
54e7ed12 TH |
265 | /** |
266 | * blkg_path - format cgroup path of blkg | |
267 | * @blkg: blkg of interest | |
268 | * @buf: target buffer | |
269 | * @buflen: target buffer length | |
270 | * | |
271 | * Format the path of the cgroup of @blkg into @buf. | |
272 | */ | |
3c798398 | 273 | static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen) |
afc24d49 | 274 | { |
e61734c5 | 275 | char *p; |
54e7ed12 | 276 | |
e61734c5 TH |
277 | p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen); |
278 | if (!p) { | |
54e7ed12 | 279 | strncpy(buf, "<unavailable>", buflen); |
e61734c5 TH |
280 | return -ENAMETOOLONG; |
281 | } | |
282 | ||
283 | memmove(buf, p, buf + buflen - p); | |
284 | return 0; | |
afc24d49 VG |
285 | } |
286 | ||
1adaf3dd TH |
287 | /** |
288 | * blkg_get - get a blkg reference | |
289 | * @blkg: blkg to get | |
290 | * | |
a5049a8a | 291 | * The caller should be holding an existing reference. |
1adaf3dd | 292 | */ |
3c798398 | 293 | static inline void blkg_get(struct blkcg_gq *blkg) |
1adaf3dd | 294 | { |
a5049a8a TH |
295 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
296 | atomic_inc(&blkg->refcnt); | |
1adaf3dd TH |
297 | } |
298 | ||
2a4fd070 | 299 | void __blkg_release_rcu(struct rcu_head *rcu); |
1adaf3dd TH |
300 | |
301 | /** | |
302 | * blkg_put - put a blkg reference | |
303 | * @blkg: blkg to put | |
1adaf3dd | 304 | */ |
3c798398 | 305 | static inline void blkg_put(struct blkcg_gq *blkg) |
1adaf3dd | 306 | { |
a5049a8a TH |
307 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
308 | if (atomic_dec_and_test(&blkg->refcnt)) | |
2a4fd070 | 309 | call_rcu(&blkg->rcu_head, __blkg_release_rcu); |
1adaf3dd TH |
310 | } |
311 | ||
dd4a4ffc TH |
312 | struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q, |
313 | bool update_hint); | |
314 | ||
315 | /** | |
316 | * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants | |
317 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 318 | * @pos_css: used for iteration |
dd4a4ffc TH |
319 | * @p_blkg: target blkg to walk descendants of |
320 | * | |
321 | * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU | |
322 | * read locked. If called under either blkcg or queue lock, the iteration | |
323 | * is guaranteed to include all and only online blkgs. The caller may | |
492eb21b | 324 | * update @pos_css by calling css_rightmost_descendant() to skip subtree. |
bd8815a6 | 325 | * @p_blkg is included in the iteration and the first node to be visited. |
dd4a4ffc | 326 | */ |
492eb21b TH |
327 | #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \ |
328 | css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \ | |
329 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
dd4a4ffc TH |
330 | (p_blkg)->q, false))) |
331 | ||
aa539cb3 TH |
332 | /** |
333 | * blkg_for_each_descendant_post - post-order walk of a blkg's descendants | |
334 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 335 | * @pos_css: used for iteration |
aa539cb3 TH |
336 | * @p_blkg: target blkg to walk descendants of |
337 | * | |
338 | * Similar to blkg_for_each_descendant_pre() but performs post-order | |
bd8815a6 TH |
339 | * traversal instead. Synchronization rules are the same. @p_blkg is |
340 | * included in the iteration and the last node to be visited. | |
aa539cb3 | 341 | */ |
492eb21b TH |
342 | #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \ |
343 | css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \ | |
344 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
aa539cb3 TH |
345 | (p_blkg)->q, false))) |
346 | ||
a051661c TH |
347 | /** |
348 | * blk_get_rl - get request_list to use | |
349 | * @q: request_queue of interest | |
350 | * @bio: bio which will be attached to the allocated request (may be %NULL) | |
351 | * | |
352 | * The caller wants to allocate a request from @q to use for @bio. Find | |
353 | * the request_list to use and obtain a reference on it. Should be called | |
354 | * under queue_lock. This function is guaranteed to return non-%NULL | |
355 | * request_list. | |
356 | */ | |
357 | static inline struct request_list *blk_get_rl(struct request_queue *q, | |
358 | struct bio *bio) | |
359 | { | |
360 | struct blkcg *blkcg; | |
361 | struct blkcg_gq *blkg; | |
362 | ||
363 | rcu_read_lock(); | |
364 | ||
365 | blkcg = bio_blkcg(bio); | |
366 | ||
367 | /* bypass blkg lookup and use @q->root_rl directly for root */ | |
368 | if (blkcg == &blkcg_root) | |
369 | goto root_rl; | |
370 | ||
371 | /* | |
372 | * Try to use blkg->rl. blkg lookup may fail under memory pressure | |
373 | * or if either the blkcg or queue is going away. Fall back to | |
374 | * root_rl in such cases. | |
375 | */ | |
376 | blkg = blkg_lookup_create(blkcg, q); | |
41609892 | 377 | if (IS_ERR(blkg)) |
a051661c TH |
378 | goto root_rl; |
379 | ||
380 | blkg_get(blkg); | |
381 | rcu_read_unlock(); | |
382 | return &blkg->rl; | |
383 | root_rl: | |
384 | rcu_read_unlock(); | |
385 | return &q->root_rl; | |
386 | } | |
387 | ||
388 | /** | |
389 | * blk_put_rl - put request_list | |
390 | * @rl: request_list to put | |
391 | * | |
392 | * Put the reference acquired by blk_get_rl(). Should be called under | |
393 | * queue_lock. | |
394 | */ | |
395 | static inline void blk_put_rl(struct request_list *rl) | |
396 | { | |
397 | /* root_rl may not have blkg set */ | |
398 | if (rl->blkg && rl->blkg->blkcg != &blkcg_root) | |
399 | blkg_put(rl->blkg); | |
400 | } | |
401 | ||
402 | /** | |
403 | * blk_rq_set_rl - associate a request with a request_list | |
404 | * @rq: request of interest | |
405 | * @rl: target request_list | |
406 | * | |
407 | * Associate @rq with @rl so that accounting and freeing can know the | |
408 | * request_list @rq came from. | |
409 | */ | |
410 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) | |
411 | { | |
412 | rq->rl = rl; | |
413 | } | |
414 | ||
415 | /** | |
416 | * blk_rq_rl - return the request_list a request came from | |
417 | * @rq: request of interest | |
418 | * | |
419 | * Return the request_list @rq is allocated from. | |
420 | */ | |
421 | static inline struct request_list *blk_rq_rl(struct request *rq) | |
422 | { | |
423 | return rq->rl; | |
424 | } | |
425 | ||
426 | struct request_list *__blk_queue_next_rl(struct request_list *rl, | |
427 | struct request_queue *q); | |
428 | /** | |
429 | * blk_queue_for_each_rl - iterate through all request_lists of a request_queue | |
430 | * | |
431 | * Should be used under queue_lock. | |
432 | */ | |
433 | #define blk_queue_for_each_rl(rl, q) \ | |
434 | for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q))) | |
435 | ||
90d3839b PZ |
436 | static inline void blkg_stat_init(struct blkg_stat *stat) |
437 | { | |
438 | u64_stats_init(&stat->syncp); | |
439 | } | |
440 | ||
edcb0722 TH |
441 | /** |
442 | * blkg_stat_add - add a value to a blkg_stat | |
443 | * @stat: target blkg_stat | |
444 | * @val: value to add | |
445 | * | |
446 | * Add @val to @stat. The caller is responsible for synchronizing calls to | |
447 | * this function. | |
448 | */ | |
449 | static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) | |
450 | { | |
451 | u64_stats_update_begin(&stat->syncp); | |
452 | stat->cnt += val; | |
453 | u64_stats_update_end(&stat->syncp); | |
454 | } | |
455 | ||
456 | /** | |
457 | * blkg_stat_read - read the current value of a blkg_stat | |
458 | * @stat: blkg_stat to read | |
459 | * | |
460 | * Read the current value of @stat. This function can be called without | |
461 | * synchroniztion and takes care of u64 atomicity. | |
462 | */ | |
463 | static inline uint64_t blkg_stat_read(struct blkg_stat *stat) | |
464 | { | |
465 | unsigned int start; | |
466 | uint64_t v; | |
467 | ||
468 | do { | |
57a7744e | 469 | start = u64_stats_fetch_begin_irq(&stat->syncp); |
edcb0722 | 470 | v = stat->cnt; |
57a7744e | 471 | } while (u64_stats_fetch_retry_irq(&stat->syncp, start)); |
edcb0722 TH |
472 | |
473 | return v; | |
474 | } | |
475 | ||
476 | /** | |
477 | * blkg_stat_reset - reset a blkg_stat | |
478 | * @stat: blkg_stat to reset | |
479 | */ | |
480 | static inline void blkg_stat_reset(struct blkg_stat *stat) | |
481 | { | |
482 | stat->cnt = 0; | |
483 | } | |
484 | ||
16b3de66 TH |
485 | /** |
486 | * blkg_stat_merge - merge a blkg_stat into another | |
487 | * @to: the destination blkg_stat | |
488 | * @from: the source | |
489 | * | |
490 | * Add @from's count to @to. | |
491 | */ | |
492 | static inline void blkg_stat_merge(struct blkg_stat *to, struct blkg_stat *from) | |
493 | { | |
494 | blkg_stat_add(to, blkg_stat_read(from)); | |
495 | } | |
496 | ||
90d3839b PZ |
497 | static inline void blkg_rwstat_init(struct blkg_rwstat *rwstat) |
498 | { | |
499 | u64_stats_init(&rwstat->syncp); | |
500 | } | |
501 | ||
edcb0722 TH |
502 | /** |
503 | * blkg_rwstat_add - add a value to a blkg_rwstat | |
504 | * @rwstat: target blkg_rwstat | |
505 | * @rw: mask of REQ_{WRITE|SYNC} | |
506 | * @val: value to add | |
507 | * | |
508 | * Add @val to @rwstat. The counters are chosen according to @rw. The | |
509 | * caller is responsible for synchronizing calls to this function. | |
510 | */ | |
511 | static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, | |
512 | int rw, uint64_t val) | |
513 | { | |
514 | u64_stats_update_begin(&rwstat->syncp); | |
515 | ||
516 | if (rw & REQ_WRITE) | |
517 | rwstat->cnt[BLKG_RWSTAT_WRITE] += val; | |
518 | else | |
519 | rwstat->cnt[BLKG_RWSTAT_READ] += val; | |
520 | if (rw & REQ_SYNC) | |
521 | rwstat->cnt[BLKG_RWSTAT_SYNC] += val; | |
522 | else | |
523 | rwstat->cnt[BLKG_RWSTAT_ASYNC] += val; | |
524 | ||
525 | u64_stats_update_end(&rwstat->syncp); | |
526 | } | |
527 | ||
528 | /** | |
529 | * blkg_rwstat_read - read the current values of a blkg_rwstat | |
530 | * @rwstat: blkg_rwstat to read | |
531 | * | |
532 | * Read the current snapshot of @rwstat and return it as the return value. | |
533 | * This function can be called without synchronization and takes care of | |
534 | * u64 atomicity. | |
535 | */ | |
c94bed89 | 536 | static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) |
edcb0722 TH |
537 | { |
538 | unsigned int start; | |
539 | struct blkg_rwstat tmp; | |
540 | ||
541 | do { | |
57a7744e | 542 | start = u64_stats_fetch_begin_irq(&rwstat->syncp); |
edcb0722 | 543 | tmp = *rwstat; |
57a7744e | 544 | } while (u64_stats_fetch_retry_irq(&rwstat->syncp, start)); |
edcb0722 TH |
545 | |
546 | return tmp; | |
547 | } | |
548 | ||
549 | /** | |
4d5e80a7 | 550 | * blkg_rwstat_total - read the total count of a blkg_rwstat |
edcb0722 TH |
551 | * @rwstat: blkg_rwstat to read |
552 | * | |
553 | * Return the total count of @rwstat regardless of the IO direction. This | |
554 | * function can be called without synchronization and takes care of u64 | |
555 | * atomicity. | |
556 | */ | |
4d5e80a7 | 557 | static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat) |
edcb0722 TH |
558 | { |
559 | struct blkg_rwstat tmp = blkg_rwstat_read(rwstat); | |
560 | ||
561 | return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]; | |
562 | } | |
563 | ||
564 | /** | |
565 | * blkg_rwstat_reset - reset a blkg_rwstat | |
566 | * @rwstat: blkg_rwstat to reset | |
567 | */ | |
568 | static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) | |
569 | { | |
570 | memset(rwstat->cnt, 0, sizeof(rwstat->cnt)); | |
571 | } | |
572 | ||
16b3de66 TH |
573 | /** |
574 | * blkg_rwstat_merge - merge a blkg_rwstat into another | |
575 | * @to: the destination blkg_rwstat | |
576 | * @from: the source | |
577 | * | |
578 | * Add @from's counts to @to. | |
579 | */ | |
580 | static inline void blkg_rwstat_merge(struct blkg_rwstat *to, | |
581 | struct blkg_rwstat *from) | |
582 | { | |
583 | struct blkg_rwstat v = blkg_rwstat_read(from); | |
584 | int i; | |
585 | ||
586 | u64_stats_update_begin(&to->syncp); | |
587 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
588 | to->cnt[i] += v.cnt[i]; | |
589 | u64_stats_update_end(&to->syncp); | |
590 | } | |
591 | ||
36558c8a TH |
592 | #else /* CONFIG_BLK_CGROUP */ |
593 | ||
efa7d1c7 TH |
594 | struct blkcg { |
595 | }; | |
2f5ea477 | 596 | |
f95a04af TH |
597 | struct blkg_policy_data { |
598 | }; | |
599 | ||
e48453c3 AA |
600 | struct blkcg_policy_data { |
601 | }; | |
602 | ||
3c798398 | 603 | struct blkcg_gq { |
2f5ea477 JA |
604 | }; |
605 | ||
3c798398 | 606 | struct blkcg_policy { |
3e252066 VG |
607 | }; |
608 | ||
496d5e75 TH |
609 | #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL)) |
610 | ||
fd383c2d TH |
611 | static inline struct cgroup_subsys_state * |
612 | task_get_blkcg_css(struct task_struct *task) | |
613 | { | |
614 | return NULL; | |
615 | } | |
616 | ||
efa7d1c7 TH |
617 | #ifdef CONFIG_BLOCK |
618 | ||
3c798398 | 619 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } |
5efd6113 TH |
620 | static inline int blkcg_init_queue(struct request_queue *q) { return 0; } |
621 | static inline void blkcg_drain_queue(struct request_queue *q) { } | |
622 | static inline void blkcg_exit_queue(struct request_queue *q) { } | |
d5bf0291 | 623 | static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } |
3c798398 | 624 | static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } |
a2b1693b | 625 | static inline int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 626 | const struct blkcg_policy *pol) { return 0; } |
a2b1693b | 627 | static inline void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 TH |
628 | const struct blkcg_policy *pol) { } |
629 | ||
b1208b56 | 630 | static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } |
a051661c | 631 | |
f95a04af TH |
632 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
633 | struct blkcg_policy *pol) { return NULL; } | |
634 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } | |
3c798398 TH |
635 | static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } |
636 | static inline void blkg_get(struct blkcg_gq *blkg) { } | |
637 | static inline void blkg_put(struct blkcg_gq *blkg) { } | |
afc24d49 | 638 | |
a051661c TH |
639 | static inline struct request_list *blk_get_rl(struct request_queue *q, |
640 | struct bio *bio) { return &q->root_rl; } | |
641 | static inline void blk_put_rl(struct request_list *rl) { } | |
642 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { } | |
643 | static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; } | |
644 | ||
645 | #define blk_queue_for_each_rl(rl, q) \ | |
646 | for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) | |
647 | ||
efa7d1c7 | 648 | #endif /* CONFIG_BLOCK */ |
36558c8a TH |
649 | #endif /* CONFIG_BLK_CGROUP */ |
650 | #endif /* _BLK_CGROUP_H */ |