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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
31e4c28d VG |
2 | #ifndef _BLK_CGROUP_H |
3 | #define _BLK_CGROUP_H | |
4 | /* | |
5 | * Common Block IO controller cgroup interface | |
6 | * | |
7 | * Based on ideas and code from CFQ, CFS and BFQ: | |
8 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> | |
9 | * | |
10 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> | |
11 | * Paolo Valente <paolo.valente@unimore.it> | |
12 | * | |
13 | * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> | |
14 | * Nauman Rafique <nauman@google.com> | |
15 | */ | |
16 | ||
17 | #include <linux/cgroup.h> | |
24bdb8ef | 18 | #include <linux/percpu_counter.h> |
829fdb50 | 19 | #include <linux/seq_file.h> |
a637120e | 20 | #include <linux/radix-tree.h> |
a051661c | 21 | #include <linux/blkdev.h> |
a5049a8a | 22 | #include <linux/atomic.h> |
902ec5b6 | 23 | #include <linux/kthread.h> |
5cdf2e3f | 24 | #include <linux/fs.h> |
31e4c28d | 25 | |
24bdb8ef TH |
26 | /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ |
27 | #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) | |
28 | ||
9355aede VG |
29 | /* Max limits for throttle policy */ |
30 | #define THROTL_IOPS_MAX UINT_MAX | |
31 | ||
f48ec1d7 TH |
32 | #ifdef CONFIG_BLK_CGROUP |
33 | ||
edcb0722 TH |
34 | enum blkg_rwstat_type { |
35 | BLKG_RWSTAT_READ, | |
36 | BLKG_RWSTAT_WRITE, | |
37 | BLKG_RWSTAT_SYNC, | |
38 | BLKG_RWSTAT_ASYNC, | |
636620b6 | 39 | BLKG_RWSTAT_DISCARD, |
edcb0722 TH |
40 | |
41 | BLKG_RWSTAT_NR, | |
42 | BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR, | |
303a3acb DS |
43 | }; |
44 | ||
a637120e TH |
45 | struct blkcg_gq; |
46 | ||
3c798398 | 47 | struct blkcg { |
36558c8a TH |
48 | struct cgroup_subsys_state css; |
49 | spinlock_t lock; | |
a637120e TH |
50 | |
51 | struct radix_tree_root blkg_tree; | |
55679c8d | 52 | struct blkcg_gq __rcu *blkg_hint; |
36558c8a | 53 | struct hlist_head blkg_list; |
9a9e8a26 | 54 | |
81437648 | 55 | struct blkcg_policy_data *cpd[BLKCG_MAX_POLS]; |
52ebea74 | 56 | |
7876f930 | 57 | struct list_head all_blkcgs_node; |
52ebea74 TH |
58 | #ifdef CONFIG_CGROUP_WRITEBACK |
59 | struct list_head cgwb_list; | |
59b57717 | 60 | refcount_t cgwb_refcnt; |
52ebea74 | 61 | #endif |
31e4c28d VG |
62 | }; |
63 | ||
e6269c44 TH |
64 | /* |
65 | * blkg_[rw]stat->aux_cnt is excluded for local stats but included for | |
24bdb8ef TH |
66 | * recursive. Used to carry stats of dead children, and, for blkg_rwstat, |
67 | * to carry result values from read and sum operations. | |
e6269c44 | 68 | */ |
edcb0722 | 69 | struct blkg_stat { |
24bdb8ef | 70 | struct percpu_counter cpu_cnt; |
e6269c44 | 71 | atomic64_t aux_cnt; |
edcb0722 TH |
72 | }; |
73 | ||
74 | struct blkg_rwstat { | |
24bdb8ef | 75 | struct percpu_counter cpu_cnt[BLKG_RWSTAT_NR]; |
e6269c44 | 76 | atomic64_t aux_cnt[BLKG_RWSTAT_NR]; |
edcb0722 TH |
77 | }; |
78 | ||
f95a04af TH |
79 | /* |
80 | * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a | |
81 | * request_queue (q). This is used by blkcg policies which need to track | |
82 | * information per blkcg - q pair. | |
83 | * | |
001bea73 TH |
84 | * There can be multiple active blkcg policies and each blkg:policy pair is |
85 | * represented by a blkg_policy_data which is allocated and freed by each | |
86 | * policy's pd_alloc/free_fn() methods. A policy can allocate private data | |
87 | * area by allocating larger data structure which embeds blkg_policy_data | |
88 | * at the beginning. | |
f95a04af | 89 | */ |
0381411e | 90 | struct blkg_policy_data { |
b276a876 | 91 | /* the blkg and policy id this per-policy data belongs to */ |
3c798398 | 92 | struct blkcg_gq *blkg; |
b276a876 | 93 | int plid; |
0381411e TH |
94 | }; |
95 | ||
e48453c3 | 96 | /* |
e4a9bde9 TH |
97 | * Policies that need to keep per-blkcg data which is independent from any |
98 | * request_queue associated to it should implement cpd_alloc/free_fn() | |
99 | * methods. A policy can allocate private data area by allocating larger | |
100 | * data structure which embeds blkcg_policy_data at the beginning. | |
101 | * cpd_init() is invoked to let each policy handle per-blkcg data. | |
e48453c3 AA |
102 | */ |
103 | struct blkcg_policy_data { | |
81437648 TH |
104 | /* the blkcg and policy id this per-policy data belongs to */ |
105 | struct blkcg *blkcg; | |
e48453c3 | 106 | int plid; |
e48453c3 AA |
107 | }; |
108 | ||
3c798398 TH |
109 | /* association between a blk cgroup and a request queue */ |
110 | struct blkcg_gq { | |
c875f4d0 | 111 | /* Pointer to the associated request_queue */ |
36558c8a TH |
112 | struct request_queue *q; |
113 | struct list_head q_node; | |
114 | struct hlist_node blkcg_node; | |
3c798398 | 115 | struct blkcg *blkcg; |
3c547865 | 116 | |
ce7acfea TH |
117 | /* |
118 | * Each blkg gets congested separately and the congestion state is | |
119 | * propagated to the matching bdi_writeback_congested. | |
120 | */ | |
121 | struct bdi_writeback_congested *wb_congested; | |
122 | ||
3c547865 TH |
123 | /* all non-root blkcg_gq's are guaranteed to have access to parent */ |
124 | struct blkcg_gq *parent; | |
125 | ||
1adaf3dd | 126 | /* reference count */ |
7fcf2b03 | 127 | struct percpu_ref refcnt; |
22084190 | 128 | |
f427d909 TH |
129 | /* is this blkg online? protected by both blkcg and q locks */ |
130 | bool online; | |
131 | ||
77ea7338 TH |
132 | struct blkg_rwstat stat_bytes; |
133 | struct blkg_rwstat stat_ios; | |
134 | ||
36558c8a | 135 | struct blkg_policy_data *pd[BLKCG_MAX_POLS]; |
1adaf3dd | 136 | |
36558c8a | 137 | struct rcu_head rcu_head; |
d09d8df3 JB |
138 | |
139 | atomic_t use_delay; | |
140 | atomic64_t delay_nsec; | |
141 | atomic64_t delay_start; | |
142 | u64 last_delay; | |
143 | int last_use; | |
31e4c28d VG |
144 | }; |
145 | ||
e4a9bde9 | 146 | typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp); |
81437648 | 147 | typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd); |
e4a9bde9 | 148 | typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd); |
69d7fde5 | 149 | typedef void (blkcg_pol_bind_cpd_fn)(struct blkcg_policy_data *cpd); |
001bea73 | 150 | typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node); |
a9520cd6 TH |
151 | typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd); |
152 | typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd); | |
153 | typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd); | |
001bea73 | 154 | typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd); |
a9520cd6 | 155 | typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd); |
903d23f0 JB |
156 | typedef size_t (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, char *buf, |
157 | size_t size); | |
3e252066 | 158 | |
3c798398 | 159 | struct blkcg_policy { |
36558c8a | 160 | int plid; |
36558c8a | 161 | /* cgroup files for the policy */ |
2ee867dc | 162 | struct cftype *dfl_cftypes; |
880f50e2 | 163 | struct cftype *legacy_cftypes; |
f9fcc2d3 TH |
164 | |
165 | /* operations */ | |
e4a9bde9 | 166 | blkcg_pol_alloc_cpd_fn *cpd_alloc_fn; |
e48453c3 | 167 | blkcg_pol_init_cpd_fn *cpd_init_fn; |
e4a9bde9 | 168 | blkcg_pol_free_cpd_fn *cpd_free_fn; |
69d7fde5 | 169 | blkcg_pol_bind_cpd_fn *cpd_bind_fn; |
e4a9bde9 | 170 | |
001bea73 | 171 | blkcg_pol_alloc_pd_fn *pd_alloc_fn; |
f9fcc2d3 | 172 | blkcg_pol_init_pd_fn *pd_init_fn; |
f427d909 TH |
173 | blkcg_pol_online_pd_fn *pd_online_fn; |
174 | blkcg_pol_offline_pd_fn *pd_offline_fn; | |
001bea73 | 175 | blkcg_pol_free_pd_fn *pd_free_fn; |
f9fcc2d3 | 176 | blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; |
903d23f0 | 177 | blkcg_pol_stat_pd_fn *pd_stat_fn; |
3e252066 VG |
178 | }; |
179 | ||
3c798398 | 180 | extern struct blkcg blkcg_root; |
496d5e75 | 181 | extern struct cgroup_subsys_state * const blkcg_root_css; |
36558c8a | 182 | |
24f29046 TH |
183 | struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg, |
184 | struct request_queue *q, bool update_hint); | |
b978962a DZ |
185 | struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, |
186 | struct request_queue *q); | |
3c798398 TH |
187 | struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, |
188 | struct request_queue *q); | |
36558c8a TH |
189 | int blkcg_init_queue(struct request_queue *q); |
190 | void blkcg_drain_queue(struct request_queue *q); | |
191 | void blkcg_exit_queue(struct request_queue *q); | |
5efd6113 | 192 | |
3e252066 | 193 | /* Blkio controller policy registration */ |
d5bf0291 | 194 | int blkcg_policy_register(struct blkcg_policy *pol); |
3c798398 | 195 | void blkcg_policy_unregister(struct blkcg_policy *pol); |
36558c8a | 196 | int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 197 | const struct blkcg_policy *pol); |
36558c8a | 198 | void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 | 199 | const struct blkcg_policy *pol); |
3e252066 | 200 | |
dd165eb3 | 201 | const char *blkg_dev_name(struct blkcg_gq *blkg); |
3c798398 | 202 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, |
f95a04af TH |
203 | u64 (*prfill)(struct seq_file *, |
204 | struct blkg_policy_data *, int), | |
3c798398 | 205 | const struct blkcg_policy *pol, int data, |
ec399347 | 206 | bool show_total); |
f95a04af TH |
207 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); |
208 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
829fdb50 | 209 | const struct blkg_rwstat *rwstat); |
f95a04af TH |
210 | u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off); |
211 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
212 | int off); | |
77ea7338 TH |
213 | int blkg_print_stat_bytes(struct seq_file *sf, void *v); |
214 | int blkg_print_stat_ios(struct seq_file *sf, void *v); | |
215 | int blkg_print_stat_bytes_recursive(struct seq_file *sf, void *v); | |
216 | int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v); | |
829fdb50 | 217 | |
f12c74ca TH |
218 | u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg, |
219 | struct blkcg_policy *pol, int off); | |
220 | struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, | |
221 | struct blkcg_policy *pol, int off); | |
16b3de66 | 222 | |
829fdb50 | 223 | struct blkg_conf_ctx { |
36558c8a | 224 | struct gendisk *disk; |
3c798398 | 225 | struct blkcg_gq *blkg; |
36aa9e5f | 226 | char *body; |
829fdb50 TH |
227 | }; |
228 | ||
3c798398 | 229 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, |
36aa9e5f | 230 | char *input, struct blkg_conf_ctx *ctx); |
829fdb50 TH |
231 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); |
232 | ||
0fe061b9 DZ |
233 | /** |
234 | * blkcg_css - find the current css | |
235 | * | |
236 | * Find the css associated with either the kthread or the current task. | |
237 | * This may return a dying css, so it is up to the caller to use tryget logic | |
238 | * to confirm it is alive and well. | |
239 | */ | |
240 | static inline struct cgroup_subsys_state *blkcg_css(void) | |
241 | { | |
242 | struct cgroup_subsys_state *css; | |
243 | ||
244 | css = kthread_blkcg(); | |
245 | if (css) | |
246 | return css; | |
247 | return task_css(current, io_cgrp_id); | |
248 | } | |
249 | ||
a7c6d554 TH |
250 | static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) |
251 | { | |
252 | return css ? container_of(css, struct blkcg, css) : NULL; | |
253 | } | |
254 | ||
0fe061b9 DZ |
255 | /** |
256 | * __bio_blkcg - internal, inconsistent version to get blkcg | |
257 | * | |
258 | * DO NOT USE. | |
259 | * This function is inconsistent and consequently is dangerous to use. The | |
260 | * first part of the function returns a blkcg where a reference is owned by the | |
261 | * bio. This means it does not need to be rcu protected as it cannot go away | |
262 | * with the bio owning a reference to it. However, the latter potentially gets | |
263 | * it from task_css(). This can race against task migration and the cgroup | |
264 | * dying. It is also semantically different as it must be called rcu protected | |
265 | * and is susceptible to failure when trying to get a reference to it. | |
266 | * Therefore, it is not ok to assume that *_get() will always succeed on the | |
267 | * blkcg returned here. | |
268 | */ | |
269 | static inline struct blkcg *__bio_blkcg(struct bio *bio) | |
27e6fa99 | 270 | { |
db6638d7 DZ |
271 | if (bio && bio->bi_blkg) |
272 | return bio->bi_blkg->blkcg; | |
0fe061b9 DZ |
273 | return css_to_blkcg(blkcg_css()); |
274 | } | |
b5f2954d | 275 | |
0fe061b9 DZ |
276 | /** |
277 | * bio_blkcg - grab the blkcg associated with a bio | |
278 | * @bio: target bio | |
279 | * | |
280 | * This returns the blkcg associated with a bio, %NULL if not associated. | |
281 | * Callers are expected to either handle %NULL or know association has been | |
282 | * done prior to calling this. | |
283 | */ | |
284 | static inline struct blkcg *bio_blkcg(struct bio *bio) | |
285 | { | |
db6638d7 DZ |
286 | if (bio && bio->bi_blkg) |
287 | return bio->bi_blkg->blkcg; | |
0fe061b9 | 288 | return NULL; |
fd383c2d TH |
289 | } |
290 | ||
d09d8df3 JB |
291 | static inline bool blk_cgroup_congested(void) |
292 | { | |
293 | struct cgroup_subsys_state *css; | |
294 | bool ret = false; | |
295 | ||
296 | rcu_read_lock(); | |
297 | css = kthread_blkcg(); | |
298 | if (!css) | |
299 | css = task_css(current, io_cgrp_id); | |
300 | while (css) { | |
301 | if (atomic_read(&css->cgroup->congestion_count)) { | |
302 | ret = true; | |
303 | break; | |
304 | } | |
305 | css = css->parent; | |
306 | } | |
307 | rcu_read_unlock(); | |
308 | return ret; | |
309 | } | |
310 | ||
c7c98fd3 JB |
311 | /** |
312 | * bio_issue_as_root_blkg - see if this bio needs to be issued as root blkg | |
313 | * @return: true if this bio needs to be submitted with the root blkg context. | |
314 | * | |
315 | * In order to avoid priority inversions we sometimes need to issue a bio as if | |
316 | * it were attached to the root blkg, and then backcharge to the actual owning | |
317 | * blkg. The idea is we do bio_blkcg() to look up the actual context for the | |
318 | * bio and attach the appropriate blkg to the bio. Then we call this helper and | |
319 | * if it is true run with the root blkg for that queue and then do any | |
320 | * backcharging to the originating cgroup once the io is complete. | |
321 | */ | |
322 | static inline bool bio_issue_as_root_blkg(struct bio *bio) | |
323 | { | |
0d1e0c7c | 324 | return (bio->bi_opf & (REQ_META | REQ_SWAP)) != 0; |
c7c98fd3 JB |
325 | } |
326 | ||
3c547865 TH |
327 | /** |
328 | * blkcg_parent - get the parent of a blkcg | |
329 | * @blkcg: blkcg of interest | |
330 | * | |
331 | * Return the parent blkcg of @blkcg. Can be called anytime. | |
332 | */ | |
333 | static inline struct blkcg *blkcg_parent(struct blkcg *blkcg) | |
334 | { | |
5c9d535b | 335 | return css_to_blkcg(blkcg->css.parent); |
3c547865 TH |
336 | } |
337 | ||
24f29046 TH |
338 | /** |
339 | * __blkg_lookup - internal version of blkg_lookup() | |
340 | * @blkcg: blkcg of interest | |
341 | * @q: request_queue of interest | |
342 | * @update_hint: whether to update lookup hint with the result or not | |
343 | * | |
344 | * This is internal version and shouldn't be used by policy | |
345 | * implementations. Looks up blkgs for the @blkcg - @q pair regardless of | |
346 | * @q's bypass state. If @update_hint is %true, the caller should be | |
347 | * holding @q->queue_lock and lookup hint is updated on success. | |
348 | */ | |
349 | static inline struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, | |
350 | struct request_queue *q, | |
351 | bool update_hint) | |
352 | { | |
353 | struct blkcg_gq *blkg; | |
354 | ||
85b6bc9d TH |
355 | if (blkcg == &blkcg_root) |
356 | return q->root_blkg; | |
357 | ||
24f29046 TH |
358 | blkg = rcu_dereference(blkcg->blkg_hint); |
359 | if (blkg && blkg->q == q) | |
360 | return blkg; | |
361 | ||
362 | return blkg_lookup_slowpath(blkcg, q, update_hint); | |
363 | } | |
364 | ||
365 | /** | |
366 | * blkg_lookup - lookup blkg for the specified blkcg - q pair | |
367 | * @blkcg: blkcg of interest | |
368 | * @q: request_queue of interest | |
369 | * | |
370 | * Lookup blkg for the @blkcg - @q pair. This function should be called | |
8f4236d9 | 371 | * under RCU read loc. |
24f29046 TH |
372 | */ |
373 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, | |
374 | struct request_queue *q) | |
375 | { | |
376 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
24f29046 TH |
377 | return __blkg_lookup(blkcg, q, false); |
378 | } | |
379 | ||
6bad9b21 | 380 | /** |
b86d865c | 381 | * blk_queue_root_blkg - return blkg for the (blkcg_root, @q) pair |
6bad9b21 BVA |
382 | * @q: request_queue of interest |
383 | * | |
384 | * Lookup blkg for @q at the root level. See also blkg_lookup(). | |
385 | */ | |
b86d865c | 386 | static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q) |
6bad9b21 | 387 | { |
b86d865c | 388 | return q->root_blkg; |
6bad9b21 BVA |
389 | } |
390 | ||
0381411e TH |
391 | /** |
392 | * blkg_to_pdata - get policy private data | |
393 | * @blkg: blkg of interest | |
394 | * @pol: policy of interest | |
395 | * | |
396 | * Return pointer to private data associated with the @blkg-@pol pair. | |
397 | */ | |
f95a04af TH |
398 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
399 | struct blkcg_policy *pol) | |
0381411e | 400 | { |
f95a04af | 401 | return blkg ? blkg->pd[pol->plid] : NULL; |
0381411e TH |
402 | } |
403 | ||
e48453c3 AA |
404 | static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg, |
405 | struct blkcg_policy *pol) | |
406 | { | |
81437648 | 407 | return blkcg ? blkcg->cpd[pol->plid] : NULL; |
e48453c3 AA |
408 | } |
409 | ||
0381411e TH |
410 | /** |
411 | * pdata_to_blkg - get blkg associated with policy private data | |
f95a04af | 412 | * @pd: policy private data of interest |
0381411e | 413 | * |
f95a04af | 414 | * @pd is policy private data. Determine the blkg it's associated with. |
0381411e | 415 | */ |
f95a04af | 416 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) |
0381411e | 417 | { |
f95a04af | 418 | return pd ? pd->blkg : NULL; |
0381411e TH |
419 | } |
420 | ||
81437648 TH |
421 | static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd) |
422 | { | |
423 | return cpd ? cpd->blkcg : NULL; | |
424 | } | |
425 | ||
59b57717 DZF |
426 | extern void blkcg_destroy_blkgs(struct blkcg *blkcg); |
427 | ||
428 | #ifdef CONFIG_CGROUP_WRITEBACK | |
429 | ||
430 | /** | |
431 | * blkcg_cgwb_get - get a reference for blkcg->cgwb_list | |
432 | * @blkcg: blkcg of interest | |
433 | * | |
434 | * This is used to track the number of active wb's related to a blkcg. | |
435 | */ | |
436 | static inline void blkcg_cgwb_get(struct blkcg *blkcg) | |
437 | { | |
438 | refcount_inc(&blkcg->cgwb_refcnt); | |
439 | } | |
440 | ||
441 | /** | |
442 | * blkcg_cgwb_put - put a reference for @blkcg->cgwb_list | |
443 | * @blkcg: blkcg of interest | |
444 | * | |
445 | * This is used to track the number of active wb's related to a blkcg. | |
446 | * When this count goes to zero, all active wb has finished so the | |
447 | * blkcg can continue destruction by calling blkcg_destroy_blkgs(). | |
448 | * This work may occur in cgwb_release_workfn() on the cgwb_release | |
449 | * workqueue. | |
450 | */ | |
451 | static inline void blkcg_cgwb_put(struct blkcg *blkcg) | |
452 | { | |
453 | if (refcount_dec_and_test(&blkcg->cgwb_refcnt)) | |
454 | blkcg_destroy_blkgs(blkcg); | |
455 | } | |
456 | ||
457 | #else | |
458 | ||
459 | static inline void blkcg_cgwb_get(struct blkcg *blkcg) { } | |
460 | ||
461 | static inline void blkcg_cgwb_put(struct blkcg *blkcg) | |
462 | { | |
463 | /* wb isn't being accounted, so trigger destruction right away */ | |
464 | blkcg_destroy_blkgs(blkcg); | |
465 | } | |
466 | ||
467 | #endif | |
468 | ||
54e7ed12 TH |
469 | /** |
470 | * blkg_path - format cgroup path of blkg | |
471 | * @blkg: blkg of interest | |
472 | * @buf: target buffer | |
473 | * @buflen: target buffer length | |
474 | * | |
475 | * Format the path of the cgroup of @blkg into @buf. | |
476 | */ | |
3c798398 | 477 | static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen) |
afc24d49 | 478 | { |
4c737b41 | 479 | return cgroup_path(blkg->blkcg->css.cgroup, buf, buflen); |
afc24d49 VG |
480 | } |
481 | ||
1adaf3dd TH |
482 | /** |
483 | * blkg_get - get a blkg reference | |
484 | * @blkg: blkg to get | |
485 | * | |
a5049a8a | 486 | * The caller should be holding an existing reference. |
1adaf3dd | 487 | */ |
3c798398 | 488 | static inline void blkg_get(struct blkcg_gq *blkg) |
1adaf3dd | 489 | { |
7fcf2b03 | 490 | percpu_ref_get(&blkg->refcnt); |
1adaf3dd TH |
491 | } |
492 | ||
d09d8df3 | 493 | /** |
7754f669 | 494 | * blkg_tryget - try and get a blkg reference |
d09d8df3 JB |
495 | * @blkg: blkg to get |
496 | * | |
497 | * This is for use when doing an RCU lookup of the blkg. We may be in the midst | |
498 | * of freeing this blkg, so we can only use it if the refcnt is not zero. | |
499 | */ | |
7754f669 | 500 | static inline bool blkg_tryget(struct blkcg_gq *blkg) |
d09d8df3 | 501 | { |
6ab21879 | 502 | return blkg && percpu_ref_tryget(&blkg->refcnt); |
d09d8df3 JB |
503 | } |
504 | ||
beea9da0 | 505 | /** |
7754f669 | 506 | * blkg_tryget_closest - try and get a blkg ref on the closet blkg |
beea9da0 DZ |
507 | * @blkg: blkg to get |
508 | * | |
6ab21879 DZ |
509 | * This needs to be called rcu protected. As the failure mode here is to walk |
510 | * up the blkg tree, this ensure that the blkg->parent pointers are always | |
511 | * valid. This returns the blkg that it ended up taking a reference on or %NULL | |
512 | * if no reference was taken. | |
beea9da0 | 513 | */ |
7754f669 | 514 | static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg) |
beea9da0 | 515 | { |
6ab21879 DZ |
516 | struct blkcg_gq *ret_blkg = NULL; |
517 | ||
518 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
519 | ||
520 | while (blkg) { | |
521 | if (blkg_tryget(blkg)) { | |
522 | ret_blkg = blkg; | |
523 | break; | |
524 | } | |
beea9da0 | 525 | blkg = blkg->parent; |
6ab21879 | 526 | } |
beea9da0 | 527 | |
6ab21879 | 528 | return ret_blkg; |
beea9da0 | 529 | } |
07b05bcc | 530 | |
1adaf3dd TH |
531 | /** |
532 | * blkg_put - put a blkg reference | |
533 | * @blkg: blkg to put | |
1adaf3dd | 534 | */ |
3c798398 | 535 | static inline void blkg_put(struct blkcg_gq *blkg) |
1adaf3dd | 536 | { |
7fcf2b03 | 537 | percpu_ref_put(&blkg->refcnt); |
1adaf3dd TH |
538 | } |
539 | ||
dd4a4ffc TH |
540 | /** |
541 | * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants | |
542 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 543 | * @pos_css: used for iteration |
dd4a4ffc TH |
544 | * @p_blkg: target blkg to walk descendants of |
545 | * | |
546 | * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU | |
547 | * read locked. If called under either blkcg or queue lock, the iteration | |
548 | * is guaranteed to include all and only online blkgs. The caller may | |
492eb21b | 549 | * update @pos_css by calling css_rightmost_descendant() to skip subtree. |
bd8815a6 | 550 | * @p_blkg is included in the iteration and the first node to be visited. |
dd4a4ffc | 551 | */ |
492eb21b TH |
552 | #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \ |
553 | css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \ | |
554 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
dd4a4ffc TH |
555 | (p_blkg)->q, false))) |
556 | ||
aa539cb3 TH |
557 | /** |
558 | * blkg_for_each_descendant_post - post-order walk of a blkg's descendants | |
559 | * @d_blkg: loop cursor pointing to the current descendant | |
492eb21b | 560 | * @pos_css: used for iteration |
aa539cb3 TH |
561 | * @p_blkg: target blkg to walk descendants of |
562 | * | |
563 | * Similar to blkg_for_each_descendant_pre() but performs post-order | |
bd8815a6 TH |
564 | * traversal instead. Synchronization rules are the same. @p_blkg is |
565 | * included in the iteration and the last node to be visited. | |
aa539cb3 | 566 | */ |
492eb21b TH |
567 | #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \ |
568 | css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \ | |
569 | if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \ | |
aa539cb3 TH |
570 | (p_blkg)->q, false))) |
571 | ||
24bdb8ef | 572 | static inline int blkg_stat_init(struct blkg_stat *stat, gfp_t gfp) |
90d3839b | 573 | { |
24bdb8ef TH |
574 | int ret; |
575 | ||
576 | ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp); | |
577 | if (ret) | |
578 | return ret; | |
579 | ||
e6269c44 | 580 | atomic64_set(&stat->aux_cnt, 0); |
24bdb8ef TH |
581 | return 0; |
582 | } | |
583 | ||
584 | static inline void blkg_stat_exit(struct blkg_stat *stat) | |
585 | { | |
586 | percpu_counter_destroy(&stat->cpu_cnt); | |
90d3839b PZ |
587 | } |
588 | ||
edcb0722 TH |
589 | /** |
590 | * blkg_stat_add - add a value to a blkg_stat | |
591 | * @stat: target blkg_stat | |
592 | * @val: value to add | |
593 | * | |
24bdb8ef TH |
594 | * Add @val to @stat. The caller must ensure that IRQ on the same CPU |
595 | * don't re-enter this function for the same counter. | |
edcb0722 TH |
596 | */ |
597 | static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) | |
598 | { | |
104b4e51 | 599 | percpu_counter_add_batch(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH); |
edcb0722 TH |
600 | } |
601 | ||
602 | /** | |
603 | * blkg_stat_read - read the current value of a blkg_stat | |
604 | * @stat: blkg_stat to read | |
edcb0722 TH |
605 | */ |
606 | static inline uint64_t blkg_stat_read(struct blkg_stat *stat) | |
607 | { | |
24bdb8ef | 608 | return percpu_counter_sum_positive(&stat->cpu_cnt); |
edcb0722 TH |
609 | } |
610 | ||
611 | /** | |
612 | * blkg_stat_reset - reset a blkg_stat | |
613 | * @stat: blkg_stat to reset | |
614 | */ | |
615 | static inline void blkg_stat_reset(struct blkg_stat *stat) | |
616 | { | |
24bdb8ef | 617 | percpu_counter_set(&stat->cpu_cnt, 0); |
e6269c44 | 618 | atomic64_set(&stat->aux_cnt, 0); |
edcb0722 TH |
619 | } |
620 | ||
16b3de66 | 621 | /** |
e6269c44 | 622 | * blkg_stat_add_aux - add a blkg_stat into another's aux count |
16b3de66 TH |
623 | * @to: the destination blkg_stat |
624 | * @from: the source | |
625 | * | |
e6269c44 | 626 | * Add @from's count including the aux one to @to's aux count. |
16b3de66 | 627 | */ |
e6269c44 TH |
628 | static inline void blkg_stat_add_aux(struct blkg_stat *to, |
629 | struct blkg_stat *from) | |
16b3de66 | 630 | { |
e6269c44 TH |
631 | atomic64_add(blkg_stat_read(from) + atomic64_read(&from->aux_cnt), |
632 | &to->aux_cnt); | |
16b3de66 TH |
633 | } |
634 | ||
24bdb8ef | 635 | static inline int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp) |
90d3839b | 636 | { |
24bdb8ef TH |
637 | int i, ret; |
638 | ||
639 | for (i = 0; i < BLKG_RWSTAT_NR; i++) { | |
640 | ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp); | |
641 | if (ret) { | |
642 | while (--i >= 0) | |
643 | percpu_counter_destroy(&rwstat->cpu_cnt[i]); | |
644 | return ret; | |
645 | } | |
646 | atomic64_set(&rwstat->aux_cnt[i], 0); | |
647 | } | |
648 | return 0; | |
649 | } | |
e6269c44 | 650 | |
24bdb8ef TH |
651 | static inline void blkg_rwstat_exit(struct blkg_rwstat *rwstat) |
652 | { | |
653 | int i; | |
e6269c44 TH |
654 | |
655 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
24bdb8ef | 656 | percpu_counter_destroy(&rwstat->cpu_cnt[i]); |
90d3839b PZ |
657 | } |
658 | ||
edcb0722 TH |
659 | /** |
660 | * blkg_rwstat_add - add a value to a blkg_rwstat | |
661 | * @rwstat: target blkg_rwstat | |
ef295ecf | 662 | * @op: REQ_OP and flags |
edcb0722 TH |
663 | * @val: value to add |
664 | * | |
665 | * Add @val to @rwstat. The counters are chosen according to @rw. The | |
666 | * caller is responsible for synchronizing calls to this function. | |
667 | */ | |
668 | static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, | |
ef295ecf | 669 | unsigned int op, uint64_t val) |
edcb0722 | 670 | { |
24bdb8ef | 671 | struct percpu_counter *cnt; |
edcb0722 | 672 | |
636620b6 TH |
673 | if (op_is_discard(op)) |
674 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_DISCARD]; | |
675 | else if (op_is_write(op)) | |
24bdb8ef | 676 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_WRITE]; |
edcb0722 | 677 | else |
24bdb8ef TH |
678 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ]; |
679 | ||
104b4e51 | 680 | percpu_counter_add_batch(cnt, val, BLKG_STAT_CPU_BATCH); |
24bdb8ef | 681 | |
d71d9ae1 | 682 | if (op_is_sync(op)) |
24bdb8ef | 683 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_SYNC]; |
edcb0722 | 684 | else |
24bdb8ef | 685 | cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_ASYNC]; |
edcb0722 | 686 | |
104b4e51 | 687 | percpu_counter_add_batch(cnt, val, BLKG_STAT_CPU_BATCH); |
edcb0722 TH |
688 | } |
689 | ||
690 | /** | |
691 | * blkg_rwstat_read - read the current values of a blkg_rwstat | |
692 | * @rwstat: blkg_rwstat to read | |
693 | * | |
24bdb8ef | 694 | * Read the current snapshot of @rwstat and return it in the aux counts. |
edcb0722 | 695 | */ |
c94bed89 | 696 | static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) |
edcb0722 | 697 | { |
24bdb8ef TH |
698 | struct blkg_rwstat result; |
699 | int i; | |
edcb0722 | 700 | |
24bdb8ef TH |
701 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
702 | atomic64_set(&result.aux_cnt[i], | |
703 | percpu_counter_sum_positive(&rwstat->cpu_cnt[i])); | |
704 | return result; | |
edcb0722 TH |
705 | } |
706 | ||
707 | /** | |
4d5e80a7 | 708 | * blkg_rwstat_total - read the total count of a blkg_rwstat |
edcb0722 TH |
709 | * @rwstat: blkg_rwstat to read |
710 | * | |
711 | * Return the total count of @rwstat regardless of the IO direction. This | |
712 | * function can be called without synchronization and takes care of u64 | |
713 | * atomicity. | |
714 | */ | |
4d5e80a7 | 715 | static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat) |
edcb0722 TH |
716 | { |
717 | struct blkg_rwstat tmp = blkg_rwstat_read(rwstat); | |
718 | ||
24bdb8ef TH |
719 | return atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + |
720 | atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); | |
edcb0722 TH |
721 | } |
722 | ||
723 | /** | |
724 | * blkg_rwstat_reset - reset a blkg_rwstat | |
725 | * @rwstat: blkg_rwstat to reset | |
726 | */ | |
727 | static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) | |
728 | { | |
e6269c44 TH |
729 | int i; |
730 | ||
24bdb8ef TH |
731 | for (i = 0; i < BLKG_RWSTAT_NR; i++) { |
732 | percpu_counter_set(&rwstat->cpu_cnt[i], 0); | |
e6269c44 | 733 | atomic64_set(&rwstat->aux_cnt[i], 0); |
24bdb8ef | 734 | } |
edcb0722 TH |
735 | } |
736 | ||
16b3de66 | 737 | /** |
e6269c44 | 738 | * blkg_rwstat_add_aux - add a blkg_rwstat into another's aux count |
16b3de66 TH |
739 | * @to: the destination blkg_rwstat |
740 | * @from: the source | |
741 | * | |
e6269c44 | 742 | * Add @from's count including the aux one to @to's aux count. |
16b3de66 | 743 | */ |
e6269c44 TH |
744 | static inline void blkg_rwstat_add_aux(struct blkg_rwstat *to, |
745 | struct blkg_rwstat *from) | |
16b3de66 | 746 | { |
ddc21231 | 747 | u64 sum[BLKG_RWSTAT_NR]; |
16b3de66 TH |
748 | int i; |
749 | ||
16b3de66 | 750 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
ddc21231 AB |
751 | sum[i] = percpu_counter_sum_positive(&from->cpu_cnt[i]); |
752 | ||
753 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
754 | atomic64_add(sum[i] + atomic64_read(&from->aux_cnt[i]), | |
e6269c44 | 755 | &to->aux_cnt[i]); |
16b3de66 TH |
756 | } |
757 | ||
ae118896 TH |
758 | #ifdef CONFIG_BLK_DEV_THROTTLING |
759 | extern bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, | |
760 | struct bio *bio); | |
761 | #else | |
762 | static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, | |
763 | struct bio *bio) { return false; } | |
764 | #endif | |
765 | ||
e439bedf DZ |
766 | |
767 | static inline void blkcg_bio_issue_init(struct bio *bio) | |
768 | { | |
769 | bio_issue_init(&bio->bi_issue, bio_sectors(bio)); | |
770 | } | |
771 | ||
ae118896 TH |
772 | static inline bool blkcg_bio_issue_check(struct request_queue *q, |
773 | struct bio *bio) | |
774 | { | |
ae118896 TH |
775 | struct blkcg_gq *blkg; |
776 | bool throtl = false; | |
777 | ||
4705de73 DZ |
778 | rcu_read_lock(); |
779 | ||
5cdf2e3f DZ |
780 | if (!bio->bi_blkg) { |
781 | char b[BDEVNAME_SIZE]; | |
782 | ||
783 | WARN_ONCE(1, | |
784 | "no blkg associated for bio on block-device: %s\n", | |
785 | bio_devname(bio, b)); | |
786 | bio_associate_blkg(bio); | |
787 | } | |
b5f2954d | 788 | |
5cdf2e3f | 789 | blkg = bio->bi_blkg; |
ae118896 TH |
790 | |
791 | throtl = blk_throtl_bio(q, blkg, bio); | |
792 | ||
77ea7338 | 793 | if (!throtl) { |
c454edc2 JB |
794 | /* |
795 | * If the bio is flagged with BIO_QUEUE_ENTERED it means this | |
796 | * is a split bio and we would have already accounted for the | |
797 | * size of the bio. | |
798 | */ | |
799 | if (!bio_flagged(bio, BIO_QUEUE_ENTERED)) | |
800 | blkg_rwstat_add(&blkg->stat_bytes, bio->bi_opf, | |
801 | bio->bi_iter.bi_size); | |
ef295ecf | 802 | blkg_rwstat_add(&blkg->stat_ios, bio->bi_opf, 1); |
77ea7338 TH |
803 | } |
804 | ||
e439bedf DZ |
805 | blkcg_bio_issue_init(bio); |
806 | ||
4705de73 | 807 | rcu_read_unlock(); |
ae118896 TH |
808 | return !throtl; |
809 | } | |
810 | ||
d09d8df3 JB |
811 | static inline void blkcg_use_delay(struct blkcg_gq *blkg) |
812 | { | |
813 | if (atomic_add_return(1, &blkg->use_delay) == 1) | |
814 | atomic_inc(&blkg->blkcg->css.cgroup->congestion_count); | |
815 | } | |
816 | ||
817 | static inline int blkcg_unuse_delay(struct blkcg_gq *blkg) | |
818 | { | |
819 | int old = atomic_read(&blkg->use_delay); | |
820 | ||
821 | if (old == 0) | |
822 | return 0; | |
823 | ||
824 | /* | |
825 | * We do this song and dance because we can race with somebody else | |
826 | * adding or removing delay. If we just did an atomic_dec we'd end up | |
827 | * negative and we'd already be in trouble. We need to subtract 1 and | |
828 | * then check to see if we were the last delay so we can drop the | |
829 | * congestion count on the cgroup. | |
830 | */ | |
831 | while (old) { | |
832 | int cur = atomic_cmpxchg(&blkg->use_delay, old, old - 1); | |
833 | if (cur == old) | |
834 | break; | |
835 | old = cur; | |
836 | } | |
837 | ||
838 | if (old == 0) | |
839 | return 0; | |
840 | if (old == 1) | |
841 | atomic_dec(&blkg->blkcg->css.cgroup->congestion_count); | |
842 | return 1; | |
843 | } | |
844 | ||
845 | static inline void blkcg_clear_delay(struct blkcg_gq *blkg) | |
846 | { | |
847 | int old = atomic_read(&blkg->use_delay); | |
848 | if (!old) | |
849 | return; | |
850 | /* We only want 1 person clearing the congestion count for this blkg. */ | |
851 | while (old) { | |
852 | int cur = atomic_cmpxchg(&blkg->use_delay, old, 0); | |
853 | if (cur == old) { | |
854 | atomic_dec(&blkg->blkcg->css.cgroup->congestion_count); | |
855 | break; | |
856 | } | |
857 | old = cur; | |
858 | } | |
859 | } | |
860 | ||
861 | void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta); | |
862 | void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay); | |
863 | void blkcg_maybe_throttle_current(void); | |
36558c8a TH |
864 | #else /* CONFIG_BLK_CGROUP */ |
865 | ||
efa7d1c7 TH |
866 | struct blkcg { |
867 | }; | |
2f5ea477 | 868 | |
f95a04af TH |
869 | struct blkg_policy_data { |
870 | }; | |
871 | ||
e48453c3 AA |
872 | struct blkcg_policy_data { |
873 | }; | |
874 | ||
3c798398 | 875 | struct blkcg_gq { |
2f5ea477 JA |
876 | }; |
877 | ||
3c798398 | 878 | struct blkcg_policy { |
3e252066 VG |
879 | }; |
880 | ||
496d5e75 TH |
881 | #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL)) |
882 | ||
d09d8df3 JB |
883 | static inline void blkcg_maybe_throttle_current(void) { } |
884 | static inline bool blk_cgroup_congested(void) { return false; } | |
885 | ||
efa7d1c7 TH |
886 | #ifdef CONFIG_BLOCK |
887 | ||
d09d8df3 JB |
888 | static inline void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { } |
889 | ||
3c798398 | 890 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } |
b86d865c BVA |
891 | static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q) |
892 | { return NULL; } | |
5efd6113 TH |
893 | static inline int blkcg_init_queue(struct request_queue *q) { return 0; } |
894 | static inline void blkcg_drain_queue(struct request_queue *q) { } | |
895 | static inline void blkcg_exit_queue(struct request_queue *q) { } | |
d5bf0291 | 896 | static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } |
3c798398 | 897 | static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } |
a2b1693b | 898 | static inline int blkcg_activate_policy(struct request_queue *q, |
3c798398 | 899 | const struct blkcg_policy *pol) { return 0; } |
a2b1693b | 900 | static inline void blkcg_deactivate_policy(struct request_queue *q, |
3c798398 TH |
901 | const struct blkcg_policy *pol) { } |
902 | ||
0fe061b9 | 903 | static inline struct blkcg *__bio_blkcg(struct bio *bio) { return NULL; } |
b1208b56 | 904 | static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } |
a051661c | 905 | |
f95a04af TH |
906 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
907 | struct blkcg_policy *pol) { return NULL; } | |
908 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } | |
3c798398 TH |
909 | static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } |
910 | static inline void blkg_get(struct blkcg_gq *blkg) { } | |
911 | static inline void blkg_put(struct blkcg_gq *blkg) { } | |
afc24d49 | 912 | |
e439bedf | 913 | static inline void blkcg_bio_issue_init(struct bio *bio) { } |
ae118896 TH |
914 | static inline bool blkcg_bio_issue_check(struct request_queue *q, |
915 | struct bio *bio) { return true; } | |
916 | ||
a051661c TH |
917 | #define blk_queue_for_each_rl(rl, q) \ |
918 | for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) | |
919 | ||
efa7d1c7 | 920 | #endif /* CONFIG_BLOCK */ |
36558c8a TH |
921 | #endif /* CONFIG_BLK_CGROUP */ |
922 | #endif /* _BLK_CGROUP_H */ |