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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 | ||
3381cb8d TH |
26 | /* CFQ specific, out here for blkcg->cfq_weight */ |
27 | #define CFQ_WEIGHT_MIN 10 | |
28 | #define CFQ_WEIGHT_MAX 1000 | |
29 | #define CFQ_WEIGHT_DEFAULT 500 | |
30 | ||
f48ec1d7 TH |
31 | #ifdef CONFIG_BLK_CGROUP |
32 | ||
edcb0722 TH |
33 | enum blkg_rwstat_type { |
34 | BLKG_RWSTAT_READ, | |
35 | BLKG_RWSTAT_WRITE, | |
36 | BLKG_RWSTAT_SYNC, | |
37 | BLKG_RWSTAT_ASYNC, | |
38 | ||
39 | BLKG_RWSTAT_NR, | |
40 | BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR, | |
303a3acb DS |
41 | }; |
42 | ||
a637120e TH |
43 | struct blkcg_gq; |
44 | ||
3c798398 | 45 | struct blkcg { |
36558c8a TH |
46 | struct cgroup_subsys_state css; |
47 | spinlock_t lock; | |
a637120e TH |
48 | |
49 | struct radix_tree_root blkg_tree; | |
50 | struct blkcg_gq *blkg_hint; | |
36558c8a | 51 | struct hlist_head blkg_list; |
9a9e8a26 TH |
52 | |
53 | /* for policies to test whether associated blkcg has changed */ | |
36558c8a | 54 | uint64_t id; |
3381cb8d | 55 | |
3c798398 | 56 | /* TODO: per-policy storage in blkcg */ |
36558c8a | 57 | unsigned int cfq_weight; /* belongs to cfq */ |
e71357e1 | 58 | unsigned int cfq_leaf_weight; |
31e4c28d VG |
59 | }; |
60 | ||
edcb0722 TH |
61 | struct blkg_stat { |
62 | struct u64_stats_sync syncp; | |
63 | uint64_t cnt; | |
64 | }; | |
65 | ||
66 | struct blkg_rwstat { | |
67 | struct u64_stats_sync syncp; | |
68 | uint64_t cnt[BLKG_RWSTAT_NR]; | |
69 | }; | |
70 | ||
f95a04af TH |
71 | /* |
72 | * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a | |
73 | * request_queue (q). This is used by blkcg policies which need to track | |
74 | * information per blkcg - q pair. | |
75 | * | |
76 | * There can be multiple active blkcg policies and each has its private | |
77 | * data on each blkg, the size of which is determined by | |
78 | * blkcg_policy->pd_size. blkcg core allocates and frees such areas | |
79 | * together with blkg and invokes pd_init/exit_fn() methods. | |
80 | * | |
81 | * Such private data must embed struct blkg_policy_data (pd) at the | |
82 | * beginning and pd_size can't be smaller than pd. | |
83 | */ | |
0381411e | 84 | struct blkg_policy_data { |
b276a876 | 85 | /* the blkg and policy id this per-policy data belongs to */ |
3c798398 | 86 | struct blkcg_gq *blkg; |
b276a876 | 87 | int plid; |
0381411e | 88 | |
a2b1693b | 89 | /* used during policy activation */ |
36558c8a | 90 | struct list_head alloc_node; |
0381411e TH |
91 | }; |
92 | ||
3c798398 TH |
93 | /* association between a blk cgroup and a request queue */ |
94 | struct blkcg_gq { | |
c875f4d0 | 95 | /* Pointer to the associated request_queue */ |
36558c8a TH |
96 | struct request_queue *q; |
97 | struct list_head q_node; | |
98 | struct hlist_node blkcg_node; | |
3c798398 | 99 | struct blkcg *blkcg; |
3c547865 TH |
100 | |
101 | /* all non-root blkcg_gq's are guaranteed to have access to parent */ | |
102 | struct blkcg_gq *parent; | |
103 | ||
a051661c TH |
104 | /* request allocation list for this blkcg-q pair */ |
105 | struct request_list rl; | |
3c547865 | 106 | |
1adaf3dd | 107 | /* reference count */ |
a5049a8a | 108 | atomic_t refcnt; |
22084190 | 109 | |
f427d909 TH |
110 | /* is this blkg online? protected by both blkcg and q locks */ |
111 | bool online; | |
112 | ||
36558c8a | 113 | struct blkg_policy_data *pd[BLKCG_MAX_POLS]; |
1adaf3dd | 114 | |
36558c8a | 115 | struct rcu_head rcu_head; |
31e4c28d VG |
116 | }; |
117 | ||
3c798398 | 118 | typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg); |
f427d909 TH |
119 | typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg); |
120 | typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg); | |
3c798398 TH |
121 | typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg); |
122 | typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg); | |
3e252066 | 123 | |
3c798398 | 124 | struct blkcg_policy { |
36558c8a TH |
125 | int plid; |
126 | /* policy specific private data size */ | |
f95a04af | 127 | size_t pd_size; |
36558c8a TH |
128 | /* cgroup files for the policy */ |
129 | struct cftype *cftypes; | |
f9fcc2d3 TH |
130 | |
131 | /* operations */ | |
132 | blkcg_pol_init_pd_fn *pd_init_fn; | |
f427d909 TH |
133 | blkcg_pol_online_pd_fn *pd_online_fn; |
134 | blkcg_pol_offline_pd_fn *pd_offline_fn; | |
f9fcc2d3 TH |
135 | blkcg_pol_exit_pd_fn *pd_exit_fn; |
136 | blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; | |
3e252066 VG |
137 | }; |
138 | ||
3c798398 | 139 | extern struct blkcg blkcg_root; |
36558c8a | 140 | |
3c798398 TH |
141 | struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q); |
142 | struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, | |
143 | struct request_queue *q); | |
36558c8a TH |
144 | int blkcg_init_queue(struct request_queue *q); |
145 | void blkcg_drain_queue(struct request_queue *q); | |
146 | void blkcg_exit_queue(struct request_queue *q); | |
5efd6113 | 147 | |
3e252066 | 148 | /* Blkio controller policy registration */ |
d5bf0291 | 149 | int blkcg_policy_register(struct blkcg_policy *pol); |
3c798398 | 150 | void blkcg_policy_unregister(struct blkcg_policy *pol); |
36558c8a | 151 | int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 152 | const struct blkcg_policy *pol); |
36558c8a | 153 | void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 | 154 | const struct blkcg_policy *pol); |
3e252066 | 155 | |
3c798398 | 156 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
f95a04af TH |
157 | u64 (*prfill)(struct seq_file *, |
158 | struct blkg_policy_data *, int), | |
3c798398 | 159 | const struct blkcg_policy *pol, int data, |
ec399347 | 160 | bool show_total); |
f95a04af TH |
161 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); |
162 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
829fdb50 | 163 | const struct blkg_rwstat *rwstat); |
f95a04af TH |
164 | u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off); |
165 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
166 | int off); | |
829fdb50 | 167 | |
16b3de66 TH |
168 | u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off); |
169 | struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd, | |
170 | int off); | |
171 | ||
829fdb50 | 172 | struct blkg_conf_ctx { |
36558c8a | 173 | struct gendisk *disk; |
3c798398 | 174 | struct blkcg_gq *blkg; |
36558c8a | 175 | u64 v; |
829fdb50 TH |
176 | }; |
177 | ||
3c798398 TH |
178 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
179 | const char *input, struct blkg_conf_ctx *ctx); | |
829fdb50 TH |
180 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); |
181 | ||
182 | ||
a7c6d554 TH |
183 | static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) |
184 | { | |
185 | return css ? container_of(css, struct blkcg, css) : NULL; | |
186 | } | |
187 | ||
b1208b56 TH |
188 | static inline struct blkcg *task_blkcg(struct task_struct *tsk) |
189 | { | |
073219e9 | 190 | return css_to_blkcg(task_css(tsk, blkio_cgrp_id)); |
b1208b56 TH |
191 | } |
192 | ||
193 | static inline struct blkcg *bio_blkcg(struct bio *bio) | |
194 | { | |
195 | if (bio && bio->bi_css) | |
a7c6d554 | 196 | return css_to_blkcg(bio->bi_css); |
b1208b56 TH |
197 | return task_blkcg(current); |
198 | } | |
199 | ||
3c547865 TH |
200 | /** |
201 | * blkcg_parent - get the parent of a blkcg | |
202 | * @blkcg: blkcg of interest | |
203 | * | |
204 | * Return the parent blkcg of @blkcg. Can be called anytime. | |
205 | */ | |
206 | static inline struct blkcg *blkcg_parent(struct blkcg *blkcg) | |
207 | { | |
5c9d535b | 208 | return css_to_blkcg(blkcg->css.parent); |
3c547865 TH |
209 | } |
210 | ||
0381411e TH |
211 | /** |
212 | * blkg_to_pdata - get policy private data | |
213 | * @blkg: blkg of interest | |
214 | * @pol: policy of interest | |
215 | * | |
216 | * Return pointer to private data associated with the @blkg-@pol pair. | |
217 | */ | |
f95a04af TH |
218 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
219 | struct blkcg_policy *pol) | |
0381411e | 220 | { |
f95a04af | 221 | return blkg ? blkg->pd[pol->plid] : NULL; |
0381411e TH |
222 | } |
223 | ||
224 | /** | |
225 | * pdata_to_blkg - get blkg associated with policy private data | |
f95a04af | 226 | * @pd: policy private data of interest |
0381411e | 227 | * |
f95a04af | 228 | * @pd is policy private data. Determine the blkg it's associated with. |
0381411e | 229 | */ |
f95a04af | 230 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) |
0381411e | 231 | { |
f95a04af | 232 | return pd ? pd->blkg : NULL; |
0381411e TH |
233 | } |
234 | ||
54e7ed12 TH |
235 | /** |
236 | * blkg_path - format cgroup path of blkg | |
237 | * @blkg: blkg of interest | |
238 | * @buf: target buffer | |
239 | * @buflen: target buffer length | |
240 | * | |
241 | * Format the path of the cgroup of @blkg into @buf. | |
242 | */ | |
3c798398 | 243 | static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen) |
afc24d49 | 244 | { |
e61734c5 | 245 | char *p; |
54e7ed12 | 246 | |
e61734c5 TH |
247 | p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen); |
248 | if (!p) { | |
54e7ed12 | 249 | strncpy(buf, "<unavailable>", buflen); |
e61734c5 TH |
250 | return -ENAMETOOLONG; |
251 | } | |
252 | ||
253 | memmove(buf, p, buf + buflen - p); | |
254 | return 0; | |
afc24d49 VG |
255 | } |
256 | ||
1adaf3dd TH |
257 | /** |
258 | * blkg_get - get a blkg reference | |
259 | * @blkg: blkg to get | |
260 | * | |
a5049a8a | 261 | * The caller should be holding an existing reference. |
1adaf3dd | 262 | */ |
3c798398 | 263 | static inline void blkg_get(struct blkcg_gq *blkg) |
1adaf3dd | 264 | { |
a5049a8a TH |
265 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
266 | atomic_inc(&blkg->refcnt); | |
1adaf3dd TH |
267 | } |
268 | ||
2a4fd070 | 269 | void __blkg_release_rcu(struct rcu_head *rcu); |
1adaf3dd TH |
270 | |
271 | /** | |
272 | * blkg_put - put a blkg reference | |
273 | * @blkg: blkg to put | |
1adaf3dd | 274 | */ |
3c798398 | 275 | static inline void blkg_put(struct blkcg_gq *blkg) |
1adaf3dd | 276 | { |
a5049a8a TH |
277 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
278 | if (atomic_dec_and_test(&blkg->refcnt)) | |
2a4fd070 | 279 | call_rcu(&blkg->rcu_head, __blkg_release_rcu); |
1adaf3dd TH |
280 | } |
281 | ||
dd4a4ffc TH |
282 | struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q, |
283 | bool update_hint); | |
284 | ||
285 | /** | |
286 | * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants | |
287 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 288 | * @pos_css: used for iteration |
dd4a4ffc TH |
289 | * @p_blkg: target blkg to walk descendants of |
290 | * | |
291 | * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU | |
292 | * read locked. If called under either blkcg or queue lock, the iteration | |
293 | * is guaranteed to include all and only online blkgs. The caller may | |
492eb21b | 294 | * update @pos_css by calling css_rightmost_descendant() to skip subtree. |
bd8815a6 | 295 | * @p_blkg is included in the iteration and the first node to be visited. |
dd4a4ffc | 296 | */ |
492eb21b TH |
297 | #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \ |
298 | css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \ | |
299 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
dd4a4ffc TH |
300 | (p_blkg)->q, false))) |
301 | ||
aa539cb3 TH |
302 | /** |
303 | * blkg_for_each_descendant_post - post-order walk of a blkg's descendants | |
304 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 305 | * @pos_css: used for iteration |
aa539cb3 TH |
306 | * @p_blkg: target blkg to walk descendants of |
307 | * | |
308 | * Similar to blkg_for_each_descendant_pre() but performs post-order | |
bd8815a6 TH |
309 | * traversal instead. Synchronization rules are the same. @p_blkg is |
310 | * included in the iteration and the last node to be visited. | |
aa539cb3 | 311 | */ |
492eb21b TH |
312 | #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \ |
313 | css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \ | |
314 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
aa539cb3 TH |
315 | (p_blkg)->q, false))) |
316 | ||
a051661c TH |
317 | /** |
318 | * blk_get_rl - get request_list to use | |
319 | * @q: request_queue of interest | |
320 | * @bio: bio which will be attached to the allocated request (may be %NULL) | |
321 | * | |
322 | * The caller wants to allocate a request from @q to use for @bio. Find | |
323 | * the request_list to use and obtain a reference on it. Should be called | |
324 | * under queue_lock. This function is guaranteed to return non-%NULL | |
325 | * request_list. | |
326 | */ | |
327 | static inline struct request_list *blk_get_rl(struct request_queue *q, | |
328 | struct bio *bio) | |
329 | { | |
330 | struct blkcg *blkcg; | |
331 | struct blkcg_gq *blkg; | |
332 | ||
333 | rcu_read_lock(); | |
334 | ||
335 | blkcg = bio_blkcg(bio); | |
336 | ||
337 | /* bypass blkg lookup and use @q->root_rl directly for root */ | |
338 | if (blkcg == &blkcg_root) | |
339 | goto root_rl; | |
340 | ||
341 | /* | |
342 | * Try to use blkg->rl. blkg lookup may fail under memory pressure | |
343 | * or if either the blkcg or queue is going away. Fall back to | |
344 | * root_rl in such cases. | |
345 | */ | |
346 | blkg = blkg_lookup_create(blkcg, q); | |
347 | if (unlikely(IS_ERR(blkg))) | |
348 | goto root_rl; | |
349 | ||
350 | blkg_get(blkg); | |
351 | rcu_read_unlock(); | |
352 | return &blkg->rl; | |
353 | root_rl: | |
354 | rcu_read_unlock(); | |
355 | return &q->root_rl; | |
356 | } | |
357 | ||
358 | /** | |
359 | * blk_put_rl - put request_list | |
360 | * @rl: request_list to put | |
361 | * | |
362 | * Put the reference acquired by blk_get_rl(). Should be called under | |
363 | * queue_lock. | |
364 | */ | |
365 | static inline void blk_put_rl(struct request_list *rl) | |
366 | { | |
367 | /* root_rl may not have blkg set */ | |
368 | if (rl->blkg && rl->blkg->blkcg != &blkcg_root) | |
369 | blkg_put(rl->blkg); | |
370 | } | |
371 | ||
372 | /** | |
373 | * blk_rq_set_rl - associate a request with a request_list | |
374 | * @rq: request of interest | |
375 | * @rl: target request_list | |
376 | * | |
377 | * Associate @rq with @rl so that accounting and freeing can know the | |
378 | * request_list @rq came from. | |
379 | */ | |
380 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) | |
381 | { | |
382 | rq->rl = rl; | |
383 | } | |
384 | ||
385 | /** | |
386 | * blk_rq_rl - return the request_list a request came from | |
387 | * @rq: request of interest | |
388 | * | |
389 | * Return the request_list @rq is allocated from. | |
390 | */ | |
391 | static inline struct request_list *blk_rq_rl(struct request *rq) | |
392 | { | |
393 | return rq->rl; | |
394 | } | |
395 | ||
396 | struct request_list *__blk_queue_next_rl(struct request_list *rl, | |
397 | struct request_queue *q); | |
398 | /** | |
399 | * blk_queue_for_each_rl - iterate through all request_lists of a request_queue | |
400 | * | |
401 | * Should be used under queue_lock. | |
402 | */ | |
403 | #define blk_queue_for_each_rl(rl, q) \ | |
404 | for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q))) | |
405 | ||
90d3839b PZ |
406 | static inline void blkg_stat_init(struct blkg_stat *stat) |
407 | { | |
408 | u64_stats_init(&stat->syncp); | |
409 | } | |
410 | ||
edcb0722 TH |
411 | /** |
412 | * blkg_stat_add - add a value to a blkg_stat | |
413 | * @stat: target blkg_stat | |
414 | * @val: value to add | |
415 | * | |
416 | * Add @val to @stat. The caller is responsible for synchronizing calls to | |
417 | * this function. | |
418 | */ | |
419 | static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) | |
420 | { | |
421 | u64_stats_update_begin(&stat->syncp); | |
422 | stat->cnt += val; | |
423 | u64_stats_update_end(&stat->syncp); | |
424 | } | |
425 | ||
426 | /** | |
427 | * blkg_stat_read - read the current value of a blkg_stat | |
428 | * @stat: blkg_stat to read | |
429 | * | |
430 | * Read the current value of @stat. This function can be called without | |
431 | * synchroniztion and takes care of u64 atomicity. | |
432 | */ | |
433 | static inline uint64_t blkg_stat_read(struct blkg_stat *stat) | |
434 | { | |
435 | unsigned int start; | |
436 | uint64_t v; | |
437 | ||
438 | do { | |
57a7744e | 439 | start = u64_stats_fetch_begin_irq(&stat->syncp); |
edcb0722 | 440 | v = stat->cnt; |
57a7744e | 441 | } while (u64_stats_fetch_retry_irq(&stat->syncp, start)); |
edcb0722 TH |
442 | |
443 | return v; | |
444 | } | |
445 | ||
446 | /** | |
447 | * blkg_stat_reset - reset a blkg_stat | |
448 | * @stat: blkg_stat to reset | |
449 | */ | |
450 | static inline void blkg_stat_reset(struct blkg_stat *stat) | |
451 | { | |
452 | stat->cnt = 0; | |
453 | } | |
454 | ||
16b3de66 TH |
455 | /** |
456 | * blkg_stat_merge - merge a blkg_stat into another | |
457 | * @to: the destination blkg_stat | |
458 | * @from: the source | |
459 | * | |
460 | * Add @from's count to @to. | |
461 | */ | |
462 | static inline void blkg_stat_merge(struct blkg_stat *to, struct blkg_stat *from) | |
463 | { | |
464 | blkg_stat_add(to, blkg_stat_read(from)); | |
465 | } | |
466 | ||
90d3839b PZ |
467 | static inline void blkg_rwstat_init(struct blkg_rwstat *rwstat) |
468 | { | |
469 | u64_stats_init(&rwstat->syncp); | |
470 | } | |
471 | ||
edcb0722 TH |
472 | /** |
473 | * blkg_rwstat_add - add a value to a blkg_rwstat | |
474 | * @rwstat: target blkg_rwstat | |
475 | * @rw: mask of REQ_{WRITE|SYNC} | |
476 | * @val: value to add | |
477 | * | |
478 | * Add @val to @rwstat. The counters are chosen according to @rw. The | |
479 | * caller is responsible for synchronizing calls to this function. | |
480 | */ | |
481 | static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, | |
482 | int rw, uint64_t val) | |
483 | { | |
484 | u64_stats_update_begin(&rwstat->syncp); | |
485 | ||
486 | if (rw & REQ_WRITE) | |
487 | rwstat->cnt[BLKG_RWSTAT_WRITE] += val; | |
488 | else | |
489 | rwstat->cnt[BLKG_RWSTAT_READ] += val; | |
490 | if (rw & REQ_SYNC) | |
491 | rwstat->cnt[BLKG_RWSTAT_SYNC] += val; | |
492 | else | |
493 | rwstat->cnt[BLKG_RWSTAT_ASYNC] += val; | |
494 | ||
495 | u64_stats_update_end(&rwstat->syncp); | |
496 | } | |
497 | ||
498 | /** | |
499 | * blkg_rwstat_read - read the current values of a blkg_rwstat | |
500 | * @rwstat: blkg_rwstat to read | |
501 | * | |
502 | * Read the current snapshot of @rwstat and return it as the return value. | |
503 | * This function can be called without synchronization and takes care of | |
504 | * u64 atomicity. | |
505 | */ | |
c94bed89 | 506 | static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) |
edcb0722 TH |
507 | { |
508 | unsigned int start; | |
509 | struct blkg_rwstat tmp; | |
510 | ||
511 | do { | |
57a7744e | 512 | start = u64_stats_fetch_begin_irq(&rwstat->syncp); |
edcb0722 | 513 | tmp = *rwstat; |
57a7744e | 514 | } while (u64_stats_fetch_retry_irq(&rwstat->syncp, start)); |
edcb0722 TH |
515 | |
516 | return tmp; | |
517 | } | |
518 | ||
519 | /** | |
4d5e80a7 | 520 | * blkg_rwstat_total - read the total count of a blkg_rwstat |
edcb0722 TH |
521 | * @rwstat: blkg_rwstat to read |
522 | * | |
523 | * Return the total count of @rwstat regardless of the IO direction. This | |
524 | * function can be called without synchronization and takes care of u64 | |
525 | * atomicity. | |
526 | */ | |
4d5e80a7 | 527 | static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat) |
edcb0722 TH |
528 | { |
529 | struct blkg_rwstat tmp = blkg_rwstat_read(rwstat); | |
530 | ||
531 | return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]; | |
532 | } | |
533 | ||
534 | /** | |
535 | * blkg_rwstat_reset - reset a blkg_rwstat | |
536 | * @rwstat: blkg_rwstat to reset | |
537 | */ | |
538 | static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) | |
539 | { | |
540 | memset(rwstat->cnt, 0, sizeof(rwstat->cnt)); | |
541 | } | |
542 | ||
16b3de66 TH |
543 | /** |
544 | * blkg_rwstat_merge - merge a blkg_rwstat into another | |
545 | * @to: the destination blkg_rwstat | |
546 | * @from: the source | |
547 | * | |
548 | * Add @from's counts to @to. | |
549 | */ | |
550 | static inline void blkg_rwstat_merge(struct blkg_rwstat *to, | |
551 | struct blkg_rwstat *from) | |
552 | { | |
553 | struct blkg_rwstat v = blkg_rwstat_read(from); | |
554 | int i; | |
555 | ||
556 | u64_stats_update_begin(&to->syncp); | |
557 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
558 | to->cnt[i] += v.cnt[i]; | |
559 | u64_stats_update_end(&to->syncp); | |
560 | } | |
561 | ||
36558c8a TH |
562 | #else /* CONFIG_BLK_CGROUP */ |
563 | ||
564 | struct cgroup; | |
b1208b56 | 565 | struct blkcg; |
2f5ea477 | 566 | |
f95a04af TH |
567 | struct blkg_policy_data { |
568 | }; | |
569 | ||
3c798398 | 570 | struct blkcg_gq { |
2f5ea477 JA |
571 | }; |
572 | ||
3c798398 | 573 | struct blkcg_policy { |
3e252066 VG |
574 | }; |
575 | ||
3c798398 | 576 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } |
5efd6113 TH |
577 | static inline int blkcg_init_queue(struct request_queue *q) { return 0; } |
578 | static inline void blkcg_drain_queue(struct request_queue *q) { } | |
579 | static inline void blkcg_exit_queue(struct request_queue *q) { } | |
d5bf0291 | 580 | static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } |
3c798398 | 581 | static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } |
a2b1693b | 582 | static inline int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 583 | const struct blkcg_policy *pol) { return 0; } |
a2b1693b | 584 | static inline void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 TH |
585 | const struct blkcg_policy *pol) { } |
586 | ||
b1208b56 | 587 | static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } |
a051661c | 588 | |
f95a04af TH |
589 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
590 | struct blkcg_policy *pol) { return NULL; } | |
591 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } | |
3c798398 TH |
592 | static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } |
593 | static inline void blkg_get(struct blkcg_gq *blkg) { } | |
594 | static inline void blkg_put(struct blkcg_gq *blkg) { } | |
afc24d49 | 595 | |
a051661c TH |
596 | static inline struct request_list *blk_get_rl(struct request_queue *q, |
597 | struct bio *bio) { return &q->root_rl; } | |
598 | static inline void blk_put_rl(struct request_list *rl) { } | |
599 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { } | |
600 | static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; } | |
601 | ||
602 | #define blk_queue_for_each_rl(rl, q) \ | |
603 | for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) | |
604 | ||
36558c8a TH |
605 | #endif /* CONFIG_BLK_CGROUP */ |
606 | #endif /* _BLK_CGROUP_H */ |