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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> |
31e4c28d | 19 | |
062a644d VG |
20 | enum blkio_policy_id { |
21 | BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */ | |
4c9eefa1 | 22 | BLKIO_POLICY_THROTL, /* Throttling */ |
035d10b2 TH |
23 | |
24 | BLKIO_NR_POLICIES, | |
062a644d VG |
25 | }; |
26 | ||
9355aede VG |
27 | /* Max limits for throttle policy */ |
28 | #define THROTL_IOPS_MAX UINT_MAX | |
29 | ||
32e380ae | 30 | #ifdef CONFIG_BLK_CGROUP |
2f5ea477 | 31 | |
3381cb8d TH |
32 | /* CFQ specific, out here for blkcg->cfq_weight */ |
33 | #define CFQ_WEIGHT_MIN 10 | |
34 | #define CFQ_WEIGHT_MAX 1000 | |
35 | #define CFQ_WEIGHT_DEFAULT 500 | |
36 | ||
edcb0722 TH |
37 | enum blkg_rwstat_type { |
38 | BLKG_RWSTAT_READ, | |
39 | BLKG_RWSTAT_WRITE, | |
40 | BLKG_RWSTAT_SYNC, | |
41 | BLKG_RWSTAT_ASYNC, | |
42 | ||
43 | BLKG_RWSTAT_NR, | |
44 | BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR, | |
303a3acb DS |
45 | }; |
46 | ||
31e4c28d VG |
47 | struct blkio_cgroup { |
48 | struct cgroup_subsys_state css; | |
31e4c28d VG |
49 | spinlock_t lock; |
50 | struct hlist_head blkg_list; | |
9a9e8a26 TH |
51 | |
52 | /* for policies to test whether associated blkcg has changed */ | |
53 | uint64_t id; | |
3381cb8d TH |
54 | |
55 | /* TODO: per-policy storage in blkio_cgroup */ | |
56 | unsigned int cfq_weight; /* belongs to cfq */ | |
31e4c28d VG |
57 | }; |
58 | ||
edcb0722 TH |
59 | struct blkg_stat { |
60 | struct u64_stats_sync syncp; | |
61 | uint64_t cnt; | |
62 | }; | |
63 | ||
64 | struct blkg_rwstat { | |
65 | struct u64_stats_sync syncp; | |
66 | uint64_t cnt[BLKG_RWSTAT_NR]; | |
67 | }; | |
68 | ||
0381411e TH |
69 | /* per-blkg per-policy data */ |
70 | struct blkg_policy_data { | |
71 | /* the blkg this per-policy data belongs to */ | |
72 | struct blkio_group *blkg; | |
73 | ||
74 | /* pol->pdata_size bytes of private data used by policy impl */ | |
75 | char pdata[] __aligned(__alignof__(unsigned long long)); | |
76 | }; | |
77 | ||
31e4c28d | 78 | struct blkio_group { |
c875f4d0 TH |
79 | /* Pointer to the associated request_queue */ |
80 | struct request_queue *q; | |
e8989fae | 81 | struct list_head q_node; |
31e4c28d | 82 | struct hlist_node blkcg_node; |
7ee9c562 | 83 | struct blkio_cgroup *blkcg; |
2868ef7b VG |
84 | /* Store cgroup path */ |
85 | char path[128]; | |
1adaf3dd TH |
86 | /* reference count */ |
87 | int refcnt; | |
22084190 | 88 | |
549d3aa8 | 89 | struct blkg_policy_data *pd[BLKIO_NR_POLICIES]; |
1adaf3dd TH |
90 | |
91 | struct rcu_head rcu_head; | |
31e4c28d VG |
92 | }; |
93 | ||
0381411e | 94 | typedef void (blkio_init_group_fn)(struct blkio_group *blkg); |
9ade5ea4 TH |
95 | typedef void (blkio_exit_group_fn)(struct blkio_group *blkg); |
96 | typedef void (blkio_reset_group_stats_fn)(struct blkio_group *blkg); | |
3e252066 VG |
97 | |
98 | struct blkio_policy_ops { | |
0381411e | 99 | blkio_init_group_fn *blkio_init_group_fn; |
9ade5ea4 TH |
100 | blkio_exit_group_fn *blkio_exit_group_fn; |
101 | blkio_reset_group_stats_fn *blkio_reset_group_stats_fn; | |
3e252066 VG |
102 | }; |
103 | ||
104 | struct blkio_policy_type { | |
105 | struct list_head list; | |
106 | struct blkio_policy_ops ops; | |
062a644d | 107 | enum blkio_policy_id plid; |
0381411e | 108 | size_t pdata_size; /* policy specific private data size */ |
44ea53de | 109 | struct cftype *cftypes; /* cgroup files for the policy */ |
3e252066 VG |
110 | }; |
111 | ||
5efd6113 TH |
112 | extern int blkcg_init_queue(struct request_queue *q); |
113 | extern void blkcg_drain_queue(struct request_queue *q); | |
114 | extern void blkcg_exit_queue(struct request_queue *q); | |
115 | ||
3e252066 VG |
116 | /* Blkio controller policy registration */ |
117 | extern void blkio_policy_register(struct blkio_policy_type *); | |
118 | extern void blkio_policy_unregister(struct blkio_policy_type *); | |
e8989fae TH |
119 | extern void blkg_destroy_all(struct request_queue *q, bool destroy_root); |
120 | extern void update_root_blkg_pd(struct request_queue *q, | |
121 | enum blkio_policy_id plid); | |
3e252066 | 122 | |
829fdb50 | 123 | void blkcg_print_blkgs(struct seq_file *sf, struct blkio_cgroup *blkcg, |
d366e7ec | 124 | u64 (*prfill)(struct seq_file *, void *, int), |
829fdb50 | 125 | int pol, int data, bool show_total); |
d366e7ec TH |
126 | u64 __blkg_prfill_u64(struct seq_file *sf, void *pdata, u64 v); |
127 | u64 __blkg_prfill_rwstat(struct seq_file *sf, void *pdata, | |
829fdb50 | 128 | const struct blkg_rwstat *rwstat); |
5bc4afb1 TH |
129 | u64 blkg_prfill_stat(struct seq_file *sf, void *pdata, int off); |
130 | u64 blkg_prfill_rwstat(struct seq_file *sf, void *pdata, int off); | |
829fdb50 TH |
131 | |
132 | struct blkg_conf_ctx { | |
133 | struct gendisk *disk; | |
134 | struct blkio_group *blkg; | |
135 | u64 v; | |
136 | }; | |
137 | ||
138 | int blkg_conf_prep(struct blkio_cgroup *blkcg, const char *input, | |
139 | struct blkg_conf_ctx *ctx); | |
140 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); | |
141 | ||
142 | ||
0381411e TH |
143 | /** |
144 | * blkg_to_pdata - get policy private data | |
145 | * @blkg: blkg of interest | |
146 | * @pol: policy of interest | |
147 | * | |
148 | * Return pointer to private data associated with the @blkg-@pol pair. | |
149 | */ | |
150 | static inline void *blkg_to_pdata(struct blkio_group *blkg, | |
151 | struct blkio_policy_type *pol) | |
152 | { | |
549d3aa8 | 153 | return blkg ? blkg->pd[pol->plid]->pdata : NULL; |
0381411e TH |
154 | } |
155 | ||
156 | /** | |
157 | * pdata_to_blkg - get blkg associated with policy private data | |
158 | * @pdata: policy private data of interest | |
0381411e | 159 | * |
aaec55a0 | 160 | * @pdata is policy private data. Determine the blkg it's associated with. |
0381411e | 161 | */ |
aaec55a0 | 162 | static inline struct blkio_group *pdata_to_blkg(void *pdata) |
0381411e TH |
163 | { |
164 | if (pdata) { | |
165 | struct blkg_policy_data *pd = | |
166 | container_of(pdata, struct blkg_policy_data, pdata); | |
167 | return pd->blkg; | |
168 | } | |
169 | return NULL; | |
170 | } | |
171 | ||
afc24d49 VG |
172 | static inline char *blkg_path(struct blkio_group *blkg) |
173 | { | |
174 | return blkg->path; | |
175 | } | |
176 | ||
1adaf3dd TH |
177 | /** |
178 | * blkg_get - get a blkg reference | |
179 | * @blkg: blkg to get | |
180 | * | |
181 | * The caller should be holding queue_lock and an existing reference. | |
182 | */ | |
183 | static inline void blkg_get(struct blkio_group *blkg) | |
184 | { | |
185 | lockdep_assert_held(blkg->q->queue_lock); | |
186 | WARN_ON_ONCE(!blkg->refcnt); | |
187 | blkg->refcnt++; | |
188 | } | |
189 | ||
190 | void __blkg_release(struct blkio_group *blkg); | |
191 | ||
192 | /** | |
193 | * blkg_put - put a blkg reference | |
194 | * @blkg: blkg to put | |
195 | * | |
196 | * The caller should be holding queue_lock. | |
197 | */ | |
198 | static inline void blkg_put(struct blkio_group *blkg) | |
199 | { | |
200 | lockdep_assert_held(blkg->q->queue_lock); | |
201 | WARN_ON_ONCE(blkg->refcnt <= 0); | |
202 | if (!--blkg->refcnt) | |
203 | __blkg_release(blkg); | |
204 | } | |
205 | ||
edcb0722 TH |
206 | /** |
207 | * blkg_stat_add - add a value to a blkg_stat | |
208 | * @stat: target blkg_stat | |
209 | * @val: value to add | |
210 | * | |
211 | * Add @val to @stat. The caller is responsible for synchronizing calls to | |
212 | * this function. | |
213 | */ | |
214 | static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) | |
215 | { | |
216 | u64_stats_update_begin(&stat->syncp); | |
217 | stat->cnt += val; | |
218 | u64_stats_update_end(&stat->syncp); | |
219 | } | |
220 | ||
221 | /** | |
222 | * blkg_stat_read - read the current value of a blkg_stat | |
223 | * @stat: blkg_stat to read | |
224 | * | |
225 | * Read the current value of @stat. This function can be called without | |
226 | * synchroniztion and takes care of u64 atomicity. | |
227 | */ | |
228 | static inline uint64_t blkg_stat_read(struct blkg_stat *stat) | |
229 | { | |
230 | unsigned int start; | |
231 | uint64_t v; | |
232 | ||
233 | do { | |
234 | start = u64_stats_fetch_begin(&stat->syncp); | |
235 | v = stat->cnt; | |
236 | } while (u64_stats_fetch_retry(&stat->syncp, start)); | |
237 | ||
238 | return v; | |
239 | } | |
240 | ||
241 | /** | |
242 | * blkg_stat_reset - reset a blkg_stat | |
243 | * @stat: blkg_stat to reset | |
244 | */ | |
245 | static inline void blkg_stat_reset(struct blkg_stat *stat) | |
246 | { | |
247 | stat->cnt = 0; | |
248 | } | |
249 | ||
250 | /** | |
251 | * blkg_rwstat_add - add a value to a blkg_rwstat | |
252 | * @rwstat: target blkg_rwstat | |
253 | * @rw: mask of REQ_{WRITE|SYNC} | |
254 | * @val: value to add | |
255 | * | |
256 | * Add @val to @rwstat. The counters are chosen according to @rw. The | |
257 | * caller is responsible for synchronizing calls to this function. | |
258 | */ | |
259 | static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, | |
260 | int rw, uint64_t val) | |
261 | { | |
262 | u64_stats_update_begin(&rwstat->syncp); | |
263 | ||
264 | if (rw & REQ_WRITE) | |
265 | rwstat->cnt[BLKG_RWSTAT_WRITE] += val; | |
266 | else | |
267 | rwstat->cnt[BLKG_RWSTAT_READ] += val; | |
268 | if (rw & REQ_SYNC) | |
269 | rwstat->cnt[BLKG_RWSTAT_SYNC] += val; | |
270 | else | |
271 | rwstat->cnt[BLKG_RWSTAT_ASYNC] += val; | |
272 | ||
273 | u64_stats_update_end(&rwstat->syncp); | |
274 | } | |
275 | ||
276 | /** | |
277 | * blkg_rwstat_read - read the current values of a blkg_rwstat | |
278 | * @rwstat: blkg_rwstat to read | |
279 | * | |
280 | * Read the current snapshot of @rwstat and return it as the return value. | |
281 | * This function can be called without synchronization and takes care of | |
282 | * u64 atomicity. | |
283 | */ | |
284 | static struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) | |
285 | { | |
286 | unsigned int start; | |
287 | struct blkg_rwstat tmp; | |
288 | ||
289 | do { | |
290 | start = u64_stats_fetch_begin(&rwstat->syncp); | |
291 | tmp = *rwstat; | |
292 | } while (u64_stats_fetch_retry(&rwstat->syncp, start)); | |
293 | ||
294 | return tmp; | |
295 | } | |
296 | ||
297 | /** | |
298 | * blkg_rwstat_sum - read the total count of a blkg_rwstat | |
299 | * @rwstat: blkg_rwstat to read | |
300 | * | |
301 | * Return the total count of @rwstat regardless of the IO direction. This | |
302 | * function can be called without synchronization and takes care of u64 | |
303 | * atomicity. | |
304 | */ | |
305 | static inline uint64_t blkg_rwstat_sum(struct blkg_rwstat *rwstat) | |
306 | { | |
307 | struct blkg_rwstat tmp = blkg_rwstat_read(rwstat); | |
308 | ||
309 | return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]; | |
310 | } | |
311 | ||
312 | /** | |
313 | * blkg_rwstat_reset - reset a blkg_rwstat | |
314 | * @rwstat: blkg_rwstat to reset | |
315 | */ | |
316 | static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) | |
317 | { | |
318 | memset(rwstat->cnt, 0, sizeof(rwstat->cnt)); | |
319 | } | |
320 | ||
2f5ea477 JA |
321 | #else |
322 | ||
323 | struct blkio_group { | |
324 | }; | |
325 | ||
3e252066 VG |
326 | struct blkio_policy_type { |
327 | }; | |
328 | ||
5efd6113 TH |
329 | static inline int blkcg_init_queue(struct request_queue *q) { return 0; } |
330 | static inline void blkcg_drain_queue(struct request_queue *q) { } | |
331 | static inline void blkcg_exit_queue(struct request_queue *q) { } | |
3e252066 VG |
332 | static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { } |
333 | static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } | |
03aa264a | 334 | static inline void blkg_destroy_all(struct request_queue *q, |
03aa264a | 335 | bool destory_root) { } |
e8989fae TH |
336 | static inline void update_root_blkg_pd(struct request_queue *q, |
337 | enum blkio_policy_id plid) { } | |
3e252066 | 338 | |
0381411e TH |
339 | static inline void *blkg_to_pdata(struct blkio_group *blkg, |
340 | struct blkio_policy_type *pol) { return NULL; } | |
341 | static inline struct blkio_group *pdata_to_blkg(void *pdata, | |
342 | struct blkio_policy_type *pol) { return NULL; } | |
afc24d49 | 343 | static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } |
1adaf3dd TH |
344 | static inline void blkg_get(struct blkio_group *blkg) { } |
345 | static inline void blkg_put(struct blkio_group *blkg) { } | |
afc24d49 | 346 | |
2f5ea477 JA |
347 | #endif |
348 | ||
32e380ae | 349 | #ifdef CONFIG_BLK_CGROUP |
31e4c28d VG |
350 | extern struct blkio_cgroup blkio_root_cgroup; |
351 | extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup); | |
4f85cb96 | 352 | extern struct blkio_cgroup *bio_blkio_cgroup(struct bio *bio); |
cd1604fa | 353 | extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg, |
e8989fae | 354 | struct request_queue *q); |
cd1604fa TH |
355 | struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg, |
356 | struct request_queue *q, | |
cd1604fa | 357 | bool for_root); |
31e4c28d | 358 | #else |
2f5ea477 | 359 | struct cgroup; |
31e4c28d VG |
360 | static inline struct blkio_cgroup * |
361 | cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; } | |
70087dc3 | 362 | static inline struct blkio_cgroup * |
4f85cb96 | 363 | bio_blkio_cgroup(struct bio *bio) { return NULL; } |
31e4c28d | 364 | |
cd1604fa TH |
365 | static inline struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg, |
366 | void *key) { return NULL; } | |
31e4c28d VG |
367 | #endif |
368 | #endif /* _BLK_CGROUP_H */ |