Commit | Line | Data |
---|---|---|
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> | |
24bdb8ef | 17 | #include <linux/percpu_counter.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 | |
24bdb8ef TH |
23 | /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ |
24 | #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) | |
25 | ||
9355aede VG |
26 | /* Max limits for throttle policy */ |
27 | #define THROTL_IOPS_MAX UINT_MAX | |
28 | ||
f48ec1d7 TH |
29 | #ifdef CONFIG_BLK_CGROUP |
30 | ||
edcb0722 TH |
31 | enum blkg_rwstat_type { |
32 | BLKG_RWSTAT_READ, | |
33 | BLKG_RWSTAT_WRITE, | |
34 | BLKG_RWSTAT_SYNC, | |
35 | BLKG_RWSTAT_ASYNC, | |
36 | ||
37 | BLKG_RWSTAT_NR, | |
38 | BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR, | |
303a3acb DS |
39 | }; |
40 | ||
a637120e TH |
41 | struct blkcg_gq; |
42 | ||
3c798398 | 43 | struct blkcg { |
36558c8a TH |
44 | struct cgroup_subsys_state css; |
45 | spinlock_t lock; | |
a637120e TH |
46 | |
47 | struct radix_tree_root blkg_tree; | |
48 | struct blkcg_gq *blkg_hint; | |
36558c8a | 49 | struct hlist_head blkg_list; |
9a9e8a26 | 50 | |
81437648 | 51 | struct blkcg_policy_data *cpd[BLKCG_MAX_POLS]; |
52ebea74 | 52 | |
7876f930 | 53 | struct list_head all_blkcgs_node; |
52ebea74 TH |
54 | #ifdef CONFIG_CGROUP_WRITEBACK |
55 | struct list_head cgwb_list; | |
56 | #endif | |
31e4c28d VG |
57 | }; |
58 | ||
e6269c44 TH |
59 | /* |
60 | * blkg_[rw]stat->aux_cnt is excluded for local stats but included for | |
24bdb8ef TH |
61 | * recursive. Used to carry stats of dead children, and, for blkg_rwstat, |
62 | * to carry result values from read and sum operations. | |
e6269c44 | 63 | */ |
edcb0722 | 64 | struct blkg_stat { |
24bdb8ef | 65 | struct percpu_counter cpu_cnt; |
e6269c44 | 66 | atomic64_t aux_cnt; |
edcb0722 TH |
67 | }; |
68 | ||
69 | struct blkg_rwstat { | |
24bdb8ef | 70 | struct percpu_counter cpu_cnt[BLKG_RWSTAT_NR]; |
e6269c44 | 71 | atomic64_t aux_cnt[BLKG_RWSTAT_NR]; |
edcb0722 TH |
72 | }; |
73 | ||
f95a04af TH |
74 | /* |
75 | * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a | |
76 | * request_queue (q). This is used by blkcg policies which need to track | |
77 | * information per blkcg - q pair. | |
78 | * | |
001bea73 TH |
79 | * There can be multiple active blkcg policies and each blkg:policy pair is |
80 | * represented by a blkg_policy_data which is allocated and freed by each | |
81 | * policy's pd_alloc/free_fn() methods. A policy can allocate private data | |
82 | * area by allocating larger data structure which embeds blkg_policy_data | |
83 | * at the beginning. | |
f95a04af | 84 | */ |
0381411e | 85 | struct blkg_policy_data { |
b276a876 | 86 | /* the blkg and policy id this per-policy data belongs to */ |
3c798398 | 87 | struct blkcg_gq *blkg; |
b276a876 | 88 | int plid; |
0381411e TH |
89 | }; |
90 | ||
e48453c3 | 91 | /* |
e4a9bde9 TH |
92 | * Policies that need to keep per-blkcg data which is independent from any |
93 | * request_queue associated to it should implement cpd_alloc/free_fn() | |
94 | * methods. A policy can allocate private data area by allocating larger | |
95 | * data structure which embeds blkcg_policy_data at the beginning. | |
96 | * cpd_init() is invoked to let each policy handle per-blkcg data. | |
e48453c3 AA |
97 | */ |
98 | struct blkcg_policy_data { | |
81437648 TH |
99 | /* the blkcg and policy id this per-policy data belongs to */ |
100 | struct blkcg *blkcg; | |
e48453c3 | 101 | int plid; |
e48453c3 AA |
102 | }; |
103 | ||
3c798398 TH |
104 | /* association between a blk cgroup and a request queue */ |
105 | struct blkcg_gq { | |
c875f4d0 | 106 | /* Pointer to the associated request_queue */ |
36558c8a TH |
107 | struct request_queue *q; |
108 | struct list_head q_node; | |
109 | struct hlist_node blkcg_node; | |
3c798398 | 110 | struct blkcg *blkcg; |
3c547865 | 111 | |
ce7acfea TH |
112 | /* |
113 | * Each blkg gets congested separately and the congestion state is | |
114 | * propagated to the matching bdi_writeback_congested. | |
115 | */ | |
116 | struct bdi_writeback_congested *wb_congested; | |
117 | ||
3c547865 TH |
118 | /* all non-root blkcg_gq's are guaranteed to have access to parent */ |
119 | struct blkcg_gq *parent; | |
120 | ||
a051661c TH |
121 | /* request allocation list for this blkcg-q pair */ |
122 | struct request_list rl; | |
3c547865 | 123 | |
1adaf3dd | 124 | /* reference count */ |
a5049a8a | 125 | atomic_t refcnt; |
22084190 | 126 | |
f427d909 TH |
127 | /* is this blkg online? protected by both blkcg and q locks */ |
128 | bool online; | |
129 | ||
36558c8a | 130 | struct blkg_policy_data *pd[BLKCG_MAX_POLS]; |
1adaf3dd | 131 | |
36558c8a | 132 | struct rcu_head rcu_head; |
31e4c28d VG |
133 | }; |
134 | ||
e4a9bde9 | 135 | typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp); |
81437648 | 136 | typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd); |
e4a9bde9 | 137 | typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd); |
001bea73 | 138 | typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node); |
a9520cd6 TH |
139 | typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd); |
140 | typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd); | |
141 | typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd); | |
001bea73 | 142 | typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd); |
a9520cd6 | 143 | typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd); |
3e252066 | 144 | |
3c798398 | 145 | struct blkcg_policy { |
36558c8a | 146 | int plid; |
36558c8a TH |
147 | /* cgroup files for the policy */ |
148 | struct cftype *cftypes; | |
f9fcc2d3 TH |
149 | |
150 | /* operations */ | |
e4a9bde9 | 151 | blkcg_pol_alloc_cpd_fn *cpd_alloc_fn; |
e48453c3 | 152 | blkcg_pol_init_cpd_fn *cpd_init_fn; |
e4a9bde9 TH |
153 | blkcg_pol_free_cpd_fn *cpd_free_fn; |
154 | ||
001bea73 | 155 | blkcg_pol_alloc_pd_fn *pd_alloc_fn; |
f9fcc2d3 | 156 | blkcg_pol_init_pd_fn *pd_init_fn; |
f427d909 TH |
157 | blkcg_pol_online_pd_fn *pd_online_fn; |
158 | blkcg_pol_offline_pd_fn *pd_offline_fn; | |
001bea73 | 159 | blkcg_pol_free_pd_fn *pd_free_fn; |
f9fcc2d3 | 160 | blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; |
3e252066 VG |
161 | }; |
162 | ||
3c798398 | 163 | extern struct blkcg blkcg_root; |
496d5e75 | 164 | extern struct cgroup_subsys_state * const blkcg_root_css; |
36558c8a | 165 | |
24f29046 TH |
166 | struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg, |
167 | struct request_queue *q, bool update_hint); | |
3c798398 TH |
168 | struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, |
169 | struct request_queue *q); | |
36558c8a TH |
170 | int blkcg_init_queue(struct request_queue *q); |
171 | void blkcg_drain_queue(struct request_queue *q); | |
172 | void blkcg_exit_queue(struct request_queue *q); | |
5efd6113 | 173 | |
3e252066 | 174 | /* Blkio controller policy registration */ |
d5bf0291 | 175 | int blkcg_policy_register(struct blkcg_policy *pol); |
3c798398 | 176 | void blkcg_policy_unregister(struct blkcg_policy *pol); |
36558c8a | 177 | int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 178 | const struct blkcg_policy *pol); |
36558c8a | 179 | void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 | 180 | const struct blkcg_policy *pol); |
3e252066 | 181 | |
3c798398 | 182 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
f95a04af TH |
183 | u64 (*prfill)(struct seq_file *, |
184 | struct blkg_policy_data *, int), | |
3c798398 | 185 | const struct blkcg_policy *pol, int data, |
ec399347 | 186 | bool show_total); |
f95a04af TH |
187 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); |
188 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
829fdb50 | 189 | const struct blkg_rwstat *rwstat); |
f95a04af TH |
190 | u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off); |
191 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
192 | int off); | |
829fdb50 | 193 | |
16b3de66 TH |
194 | u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off); |
195 | struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd, | |
196 | int off); | |
197 | ||
829fdb50 | 198 | struct blkg_conf_ctx { |
36558c8a | 199 | struct gendisk *disk; |
3c798398 | 200 | struct blkcg_gq *blkg; |
36558c8a | 201 | u64 v; |
829fdb50 TH |
202 | }; |
203 | ||
3c798398 TH |
204 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
205 | const char *input, struct blkg_conf_ctx *ctx); | |
829fdb50 TH |
206 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); |
207 | ||
208 | ||
a7c6d554 TH |
209 | static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) |
210 | { | |
211 | return css ? container_of(css, struct blkcg, css) : NULL; | |
212 | } | |
213 | ||
b1208b56 TH |
214 | static inline struct blkcg *task_blkcg(struct task_struct *tsk) |
215 | { | |
073219e9 | 216 | return css_to_blkcg(task_css(tsk, blkio_cgrp_id)); |
b1208b56 TH |
217 | } |
218 | ||
219 | static inline struct blkcg *bio_blkcg(struct bio *bio) | |
220 | { | |
221 | if (bio && bio->bi_css) | |
a7c6d554 | 222 | return css_to_blkcg(bio->bi_css); |
b1208b56 TH |
223 | return task_blkcg(current); |
224 | } | |
225 | ||
fd383c2d TH |
226 | static inline struct cgroup_subsys_state * |
227 | task_get_blkcg_css(struct task_struct *task) | |
228 | { | |
229 | return task_get_css(task, blkio_cgrp_id); | |
230 | } | |
231 | ||
3c547865 TH |
232 | /** |
233 | * blkcg_parent - get the parent of a blkcg | |
234 | * @blkcg: blkcg of interest | |
235 | * | |
236 | * Return the parent blkcg of @blkcg. Can be called anytime. | |
237 | */ | |
238 | static inline struct blkcg *blkcg_parent(struct blkcg *blkcg) | |
239 | { | |
5c9d535b | 240 | return css_to_blkcg(blkcg->css.parent); |
3c547865 TH |
241 | } |
242 | ||
24f29046 TH |
243 | /** |
244 | * __blkg_lookup - internal version of blkg_lookup() | |
245 | * @blkcg: blkcg of interest | |
246 | * @q: request_queue of interest | |
247 | * @update_hint: whether to update lookup hint with the result or not | |
248 | * | |
249 | * This is internal version and shouldn't be used by policy | |
250 | * implementations. Looks up blkgs for the @blkcg - @q pair regardless of | |
251 | * @q's bypass state. If @update_hint is %true, the caller should be | |
252 | * holding @q->queue_lock and lookup hint is updated on success. | |
253 | */ | |
254 | static inline struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, | |
255 | struct request_queue *q, | |
256 | bool update_hint) | |
257 | { | |
258 | struct blkcg_gq *blkg; | |
259 | ||
85b6bc9d TH |
260 | if (blkcg == &blkcg_root) |
261 | return q->root_blkg; | |
262 | ||
24f29046 TH |
263 | blkg = rcu_dereference(blkcg->blkg_hint); |
264 | if (blkg && blkg->q == q) | |
265 | return blkg; | |
266 | ||
267 | return blkg_lookup_slowpath(blkcg, q, update_hint); | |
268 | } | |
269 | ||
270 | /** | |
271 | * blkg_lookup - lookup blkg for the specified blkcg - q pair | |
272 | * @blkcg: blkcg of interest | |
273 | * @q: request_queue of interest | |
274 | * | |
275 | * Lookup blkg for the @blkcg - @q pair. This function should be called | |
276 | * under RCU read lock and is guaranteed to return %NULL if @q is bypassing | |
277 | * - see blk_queue_bypass_start() for details. | |
278 | */ | |
279 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, | |
280 | struct request_queue *q) | |
281 | { | |
282 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
283 | ||
284 | if (unlikely(blk_queue_bypass(q))) | |
285 | return NULL; | |
286 | return __blkg_lookup(blkcg, q, false); | |
287 | } | |
288 | ||
0381411e TH |
289 | /** |
290 | * blkg_to_pdata - get policy private data | |
291 | * @blkg: blkg of interest | |
292 | * @pol: policy of interest | |
293 | * | |
294 | * Return pointer to private data associated with the @blkg-@pol pair. | |
295 | */ | |
f95a04af TH |
296 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
297 | struct blkcg_policy *pol) | |
0381411e | 298 | { |
f95a04af | 299 | return blkg ? blkg->pd[pol->plid] : NULL; |
0381411e TH |
300 | } |
301 | ||
e48453c3 AA |
302 | static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg, |
303 | struct blkcg_policy *pol) | |
304 | { | |
81437648 | 305 | return blkcg ? blkcg->cpd[pol->plid] : NULL; |
e48453c3 AA |
306 | } |
307 | ||
0381411e TH |
308 | /** |
309 | * pdata_to_blkg - get blkg associated with policy private data | |
f95a04af | 310 | * @pd: policy private data of interest |
0381411e | 311 | * |
f95a04af | 312 | * @pd is policy private data. Determine the blkg it's associated with. |
0381411e | 313 | */ |
f95a04af | 314 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) |
0381411e | 315 | { |
f95a04af | 316 | return pd ? pd->blkg : NULL; |
0381411e TH |
317 | } |
318 | ||
81437648 TH |
319 | static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd) |
320 | { | |
321 | return cpd ? cpd->blkcg : NULL; | |
322 | } | |
323 | ||
54e7ed12 TH |
324 | /** |
325 | * blkg_path - format cgroup path of blkg | |
326 | * @blkg: blkg of interest | |
327 | * @buf: target buffer | |
328 | * @buflen: target buffer length | |
329 | * | |
330 | * Format the path of the cgroup of @blkg into @buf. | |
331 | */ | |
3c798398 | 332 | static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen) |
afc24d49 | 333 | { |
e61734c5 | 334 | char *p; |
54e7ed12 | 335 | |
e61734c5 TH |
336 | p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen); |
337 | if (!p) { | |
54e7ed12 | 338 | strncpy(buf, "<unavailable>", buflen); |
e61734c5 TH |
339 | return -ENAMETOOLONG; |
340 | } | |
341 | ||
342 | memmove(buf, p, buf + buflen - p); | |
343 | return 0; | |
afc24d49 VG |
344 | } |
345 | ||
1adaf3dd TH |
346 | /** |
347 | * blkg_get - get a blkg reference | |
348 | * @blkg: blkg to get | |
349 | * | |
a5049a8a | 350 | * The caller should be holding an existing reference. |
1adaf3dd | 351 | */ |
3c798398 | 352 | static inline void blkg_get(struct blkcg_gq *blkg) |
1adaf3dd | 353 | { |
a5049a8a TH |
354 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
355 | atomic_inc(&blkg->refcnt); | |
1adaf3dd TH |
356 | } |
357 | ||
2a4fd070 | 358 | void __blkg_release_rcu(struct rcu_head *rcu); |
1adaf3dd TH |
359 | |
360 | /** | |
361 | * blkg_put - put a blkg reference | |
362 | * @blkg: blkg to put | |
1adaf3dd | 363 | */ |
3c798398 | 364 | static inline void blkg_put(struct blkcg_gq *blkg) |
1adaf3dd | 365 | { |
a5049a8a TH |
366 | WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0); |
367 | if (atomic_dec_and_test(&blkg->refcnt)) | |
2a4fd070 | 368 | call_rcu(&blkg->rcu_head, __blkg_release_rcu); |
1adaf3dd TH |
369 | } |
370 | ||
dd4a4ffc TH |
371 | /** |
372 | * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants | |
373 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 374 | * @pos_css: used for iteration |
dd4a4ffc TH |
375 | * @p_blkg: target blkg to walk descendants of |
376 | * | |
377 | * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU | |
378 | * read locked. If called under either blkcg or queue lock, the iteration | |
379 | * is guaranteed to include all and only online blkgs. The caller may | |
492eb21b | 380 | * update @pos_css by calling css_rightmost_descendant() to skip subtree. |
bd8815a6 | 381 | * @p_blkg is included in the iteration and the first node to be visited. |
dd4a4ffc | 382 | */ |
492eb21b TH |
383 | #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \ |
384 | css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \ | |
385 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
dd4a4ffc TH |
386 | (p_blkg)->q, false))) |
387 | ||
aa539cb3 TH |
388 | /** |
389 | * blkg_for_each_descendant_post - post-order walk of a blkg's descendants | |
390 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 391 | * @pos_css: used for iteration |
aa539cb3 TH |
392 | * @p_blkg: target blkg to walk descendants of |
393 | * | |
394 | * Similar to blkg_for_each_descendant_pre() but performs post-order | |
bd8815a6 TH |
395 | * traversal instead. Synchronization rules are the same. @p_blkg is |
396 | * included in the iteration and the last node to be visited. | |
aa539cb3 | 397 | */ |
492eb21b TH |
398 | #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \ |
399 | css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \ | |
400 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
aa539cb3 TH |
401 | (p_blkg)->q, false))) |
402 | ||
a051661c TH |
403 | /** |
404 | * blk_get_rl - get request_list to use | |
405 | * @q: request_queue of interest | |
406 | * @bio: bio which will be attached to the allocated request (may be %NULL) | |
407 | * | |
408 | * The caller wants to allocate a request from @q to use for @bio. Find | |
409 | * the request_list to use and obtain a reference on it. Should be called | |
410 | * under queue_lock. This function is guaranteed to return non-%NULL | |
411 | * request_list. | |
412 | */ | |
413 | static inline struct request_list *blk_get_rl(struct request_queue *q, | |
414 | struct bio *bio) | |
415 | { | |
416 | struct blkcg *blkcg; | |
417 | struct blkcg_gq *blkg; | |
418 | ||
419 | rcu_read_lock(); | |
420 | ||
421 | blkcg = bio_blkcg(bio); | |
422 | ||
423 | /* bypass blkg lookup and use @q->root_rl directly for root */ | |
424 | if (blkcg == &blkcg_root) | |
425 | goto root_rl; | |
426 | ||
427 | /* | |
428 | * Try to use blkg->rl. blkg lookup may fail under memory pressure | |
429 | * or if either the blkcg or queue is going away. Fall back to | |
430 | * root_rl in such cases. | |
431 | */ | |
ae118896 TH |
432 | blkg = blkg_lookup(blkcg, q); |
433 | if (unlikely(!blkg)) | |
a051661c TH |
434 | goto root_rl; |
435 | ||
436 | blkg_get(blkg); | |
437 | rcu_read_unlock(); | |
438 | return &blkg->rl; | |
439 | root_rl: | |
440 | rcu_read_unlock(); | |
441 | return &q->root_rl; | |
442 | } | |
443 | ||
444 | /** | |
445 | * blk_put_rl - put request_list | |
446 | * @rl: request_list to put | |
447 | * | |
448 | * Put the reference acquired by blk_get_rl(). Should be called under | |
449 | * queue_lock. | |
450 | */ | |
451 | static inline void blk_put_rl(struct request_list *rl) | |
452 | { | |
401efbf8 | 453 | if (rl->blkg->blkcg != &blkcg_root) |
a051661c TH |
454 | blkg_put(rl->blkg); |
455 | } | |
456 | ||
457 | /** | |
458 | * blk_rq_set_rl - associate a request with a request_list | |
459 | * @rq: request of interest | |
460 | * @rl: target request_list | |
461 | * | |
462 | * Associate @rq with @rl so that accounting and freeing can know the | |
463 | * request_list @rq came from. | |
464 | */ | |
465 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) | |
466 | { | |
467 | rq->rl = rl; | |
468 | } | |
469 | ||
470 | /** | |
471 | * blk_rq_rl - return the request_list a request came from | |
472 | * @rq: request of interest | |
473 | * | |
474 | * Return the request_list @rq is allocated from. | |
475 | */ | |
476 | static inline struct request_list *blk_rq_rl(struct request *rq) | |
477 | { | |
478 | return rq->rl; | |
479 | } | |
480 | ||
481 | struct request_list *__blk_queue_next_rl(struct request_list *rl, | |
482 | struct request_queue *q); | |
483 | /** | |
484 | * blk_queue_for_each_rl - iterate through all request_lists of a request_queue | |
485 | * | |
486 | * Should be used under queue_lock. | |
487 | */ | |
488 | #define blk_queue_for_each_rl(rl, q) \ | |
489 | for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q))) | |
490 | ||
24bdb8ef | 491 | static inline int blkg_stat_init(struct blkg_stat *stat, gfp_t gfp) |
90d3839b | 492 | { |
24bdb8ef TH |
493 | int ret; |
494 | ||
495 | ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp); | |
496 | if (ret) | |
497 | return ret; | |
498 | ||
e6269c44 | 499 | atomic64_set(&stat->aux_cnt, 0); |
24bdb8ef TH |
500 | return 0; |
501 | } | |
502 | ||
503 | static inline void blkg_stat_exit(struct blkg_stat *stat) | |
504 | { | |
505 | percpu_counter_destroy(&stat->cpu_cnt); | |
90d3839b PZ |
506 | } |
507 | ||
edcb0722 TH |
508 | /** |
509 | * blkg_stat_add - add a value to a blkg_stat | |
510 | * @stat: target blkg_stat | |
511 | * @val: value to add | |
512 | * | |
24bdb8ef TH |
513 | * Add @val to @stat. The caller must ensure that IRQ on the same CPU |
514 | * don't re-enter this function for the same counter. | |
edcb0722 TH |
515 | */ |
516 | static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) | |
517 | { | |
24bdb8ef | 518 | __percpu_counter_add(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH); |
edcb0722 TH |
519 | } |
520 | ||
521 | /** | |
522 | * blkg_stat_read - read the current value of a blkg_stat | |
523 | * @stat: blkg_stat to read | |
edcb0722 TH |
524 | */ |
525 | static inline uint64_t blkg_stat_read(struct blkg_stat *stat) | |
526 | { | |
24bdb8ef | 527 | return percpu_counter_sum_positive(&stat->cpu_cnt); |
edcb0722 TH |
528 | } |
529 | ||
530 | /** | |
531 | * blkg_stat_reset - reset a blkg_stat | |
532 | * @stat: blkg_stat to reset | |
533 | */ | |
534 | static inline void blkg_stat_reset(struct blkg_stat *stat) | |
535 | { | |
24bdb8ef | 536 | percpu_counter_set(&stat->cpu_cnt, 0); |
e6269c44 | 537 | atomic64_set(&stat->aux_cnt, 0); |
edcb0722 TH |
538 | } |
539 | ||
16b3de66 | 540 | /** |
e6269c44 | 541 | * blkg_stat_add_aux - add a blkg_stat into another's aux count |
16b3de66 TH |
542 | * @to: the destination blkg_stat |
543 | * @from: the source | |
544 | * | |
e6269c44 | 545 | * Add @from's count including the aux one to @to's aux count. |
16b3de66 | 546 | */ |
e6269c44 TH |
547 | static inline void blkg_stat_add_aux(struct blkg_stat *to, |
548 | struct blkg_stat *from) | |
16b3de66 | 549 | { |
e6269c44 TH |
550 | atomic64_add(blkg_stat_read(from) + atomic64_read(&from->aux_cnt), |
551 | &to->aux_cnt); | |
16b3de66 TH |
552 | } |
553 | ||
24bdb8ef | 554 | static inline int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp) |
90d3839b | 555 | { |
24bdb8ef TH |
556 | int i, ret; |
557 | ||
558 | for (i = 0; i < BLKG_RWSTAT_NR; i++) { | |
559 | ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp); | |
560 | if (ret) { | |
561 | while (--i >= 0) | |
562 | percpu_counter_destroy(&rwstat->cpu_cnt[i]); | |
563 | return ret; | |
564 | } | |
565 | atomic64_set(&rwstat->aux_cnt[i], 0); | |
566 | } | |
567 | return 0; | |
568 | } | |
e6269c44 | 569 | |
24bdb8ef TH |
570 | static inline void blkg_rwstat_exit(struct blkg_rwstat *rwstat) |
571 | { | |
572 | int i; | |
e6269c44 TH |
573 | |
574 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
24bdb8ef | 575 | percpu_counter_destroy(&rwstat->cpu_cnt[i]); |
90d3839b PZ |
576 | } |
577 | ||
edcb0722 TH |
578 | /** |
579 | * blkg_rwstat_add - add a value to a blkg_rwstat | |
580 | * @rwstat: target blkg_rwstat | |
581 | * @rw: mask of REQ_{WRITE|SYNC} | |
582 | * @val: value to add | |
583 | * | |
584 | * Add @val to @rwstat. The counters are chosen according to @rw. The | |
585 | * caller is responsible for synchronizing calls to this function. | |
586 | */ | |
587 | static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, | |
588 | int rw, uint64_t val) | |
589 | { | |
24bdb8ef | 590 | struct percpu_counter *cnt; |
edcb0722 TH |
591 | |
592 | if (rw & REQ_WRITE) | |
24bdb8ef | 593 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_WRITE]; |
edcb0722 | 594 | else |
24bdb8ef TH |
595 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ]; |
596 | ||
597 | __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH); | |
598 | ||
edcb0722 | 599 | if (rw & REQ_SYNC) |
24bdb8ef | 600 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_SYNC]; |
edcb0722 | 601 | else |
24bdb8ef | 602 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_ASYNC]; |
edcb0722 | 603 | |
24bdb8ef | 604 | __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH); |
edcb0722 TH |
605 | } |
606 | ||
607 | /** | |
608 | * blkg_rwstat_read - read the current values of a blkg_rwstat | |
609 | * @rwstat: blkg_rwstat to read | |
610 | * | |
24bdb8ef | 611 | * Read the current snapshot of @rwstat and return it in the aux counts. |
edcb0722 | 612 | */ |
c94bed89 | 613 | static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) |
edcb0722 | 614 | { |
24bdb8ef TH |
615 | struct blkg_rwstat result; |
616 | int i; | |
edcb0722 | 617 | |
24bdb8ef TH |
618 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
619 | atomic64_set(&result.aux_cnt[i], | |
620 | percpu_counter_sum_positive(&rwstat->cpu_cnt[i])); | |
621 | return result; | |
edcb0722 TH |
622 | } |
623 | ||
624 | /** | |
4d5e80a7 | 625 | * blkg_rwstat_total - read the total count of a blkg_rwstat |
edcb0722 TH |
626 | * @rwstat: blkg_rwstat to read |
627 | * | |
628 | * Return the total count of @rwstat regardless of the IO direction. This | |
629 | * function can be called without synchronization and takes care of u64 | |
630 | * atomicity. | |
631 | */ | |
4d5e80a7 | 632 | static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat) |
edcb0722 TH |
633 | { |
634 | struct blkg_rwstat tmp = blkg_rwstat_read(rwstat); | |
635 | ||
24bdb8ef TH |
636 | return atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + |
637 | atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); | |
edcb0722 TH |
638 | } |
639 | ||
640 | /** | |
641 | * blkg_rwstat_reset - reset a blkg_rwstat | |
642 | * @rwstat: blkg_rwstat to reset | |
643 | */ | |
644 | static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) | |
645 | { | |
e6269c44 TH |
646 | int i; |
647 | ||
24bdb8ef TH |
648 | for (i = 0; i < BLKG_RWSTAT_NR; i++) { |
649 | percpu_counter_set(&rwstat->cpu_cnt[i], 0); | |
e6269c44 | 650 | atomic64_set(&rwstat->aux_cnt[i], 0); |
24bdb8ef | 651 | } |
edcb0722 TH |
652 | } |
653 | ||
16b3de66 | 654 | /** |
e6269c44 | 655 | * blkg_rwstat_add_aux - add a blkg_rwstat into another's aux count |
16b3de66 TH |
656 | * @to: the destination blkg_rwstat |
657 | * @from: the source | |
658 | * | |
e6269c44 | 659 | * Add @from's count including the aux one to @to's aux count. |
16b3de66 | 660 | */ |
e6269c44 TH |
661 | static inline void blkg_rwstat_add_aux(struct blkg_rwstat *to, |
662 | struct blkg_rwstat *from) | |
16b3de66 TH |
663 | { |
664 | struct blkg_rwstat v = blkg_rwstat_read(from); | |
665 | int i; | |
666 | ||
16b3de66 | 667 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
24bdb8ef TH |
668 | atomic64_add(atomic64_read(&v.aux_cnt[i]) + |
669 | atomic64_read(&from->aux_cnt[i]), | |
e6269c44 | 670 | &to->aux_cnt[i]); |
16b3de66 TH |
671 | } |
672 | ||
ae118896 TH |
673 | #ifdef CONFIG_BLK_DEV_THROTTLING |
674 | extern bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, | |
675 | struct bio *bio); | |
676 | #else | |
677 | static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, | |
678 | struct bio *bio) { return false; } | |
679 | #endif | |
680 | ||
681 | static inline bool blkcg_bio_issue_check(struct request_queue *q, | |
682 | struct bio *bio) | |
683 | { | |
684 | struct blkcg *blkcg; | |
685 | struct blkcg_gq *blkg; | |
686 | bool throtl = false; | |
687 | ||
688 | rcu_read_lock(); | |
689 | blkcg = bio_blkcg(bio); | |
690 | ||
691 | blkg = blkg_lookup(blkcg, q); | |
692 | if (unlikely(!blkg)) { | |
693 | spin_lock_irq(q->queue_lock); | |
694 | blkg = blkg_lookup_create(blkcg, q); | |
695 | if (IS_ERR(blkg)) | |
696 | blkg = NULL; | |
697 | spin_unlock_irq(q->queue_lock); | |
698 | } | |
699 | ||
700 | throtl = blk_throtl_bio(q, blkg, bio); | |
701 | ||
702 | rcu_read_unlock(); | |
703 | return !throtl; | |
704 | } | |
705 | ||
36558c8a TH |
706 | #else /* CONFIG_BLK_CGROUP */ |
707 | ||
efa7d1c7 TH |
708 | struct blkcg { |
709 | }; | |
2f5ea477 | 710 | |
f95a04af TH |
711 | struct blkg_policy_data { |
712 | }; | |
713 | ||
e48453c3 AA |
714 | struct blkcg_policy_data { |
715 | }; | |
716 | ||
3c798398 | 717 | struct blkcg_gq { |
2f5ea477 JA |
718 | }; |
719 | ||
3c798398 | 720 | struct blkcg_policy { |
3e252066 VG |
721 | }; |
722 | ||
496d5e75 TH |
723 | #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL)) |
724 | ||
fd383c2d TH |
725 | static inline struct cgroup_subsys_state * |
726 | task_get_blkcg_css(struct task_struct *task) | |
727 | { | |
728 | return NULL; | |
729 | } | |
730 | ||
efa7d1c7 TH |
731 | #ifdef CONFIG_BLOCK |
732 | ||
3c798398 | 733 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } |
5efd6113 TH |
734 | static inline int blkcg_init_queue(struct request_queue *q) { return 0; } |
735 | static inline void blkcg_drain_queue(struct request_queue *q) { } | |
736 | static inline void blkcg_exit_queue(struct request_queue *q) { } | |
d5bf0291 | 737 | static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } |
3c798398 | 738 | static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } |
a2b1693b | 739 | static inline int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 740 | const struct blkcg_policy *pol) { return 0; } |
a2b1693b | 741 | static inline void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 TH |
742 | const struct blkcg_policy *pol) { } |
743 | ||
b1208b56 | 744 | static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } |
a051661c | 745 | |
f95a04af TH |
746 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
747 | struct blkcg_policy *pol) { return NULL; } | |
748 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } | |
3c798398 TH |
749 | static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } |
750 | static inline void blkg_get(struct blkcg_gq *blkg) { } | |
751 | static inline void blkg_put(struct blkcg_gq *blkg) { } | |
afc24d49 | 752 | |
a051661c TH |
753 | static inline struct request_list *blk_get_rl(struct request_queue *q, |
754 | struct bio *bio) { return &q->root_rl; } | |
755 | static inline void blk_put_rl(struct request_list *rl) { } | |
756 | static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { } | |
757 | static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; } | |
758 | ||
ae118896 TH |
759 | static inline bool blkcg_bio_issue_check(struct request_queue *q, |
760 | struct bio *bio) { return true; } | |
761 | ||
a051661c TH |
762 | #define blk_queue_for_each_rl(rl, q) \ |
763 | for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) | |
764 | ||
efa7d1c7 | 765 | #endif /* CONFIG_BLOCK */ |
36558c8a TH |
766 | #endif /* CONFIG_BLK_CGROUP */ |
767 | #endif /* _BLK_CGROUP_H */ |