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672fdcf0 ML |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _BLK_CGROUP_PRIVATE_H | |
3 | #define _BLK_CGROUP_PRIVATE_H | |
4 | /* | |
5 | * block cgroup private header | |
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/blk-cgroup.h> | |
c97ab271 CH |
18 | #include <linux/cgroup.h> |
19 | #include <linux/kthread.h> | |
6b2b0459 | 20 | #include <linux/blk-mq.h> |
3b8cc629 | 21 | #include <linux/llist.h> |
672fdcf0 | 22 | |
dec223c9 CH |
23 | struct blkcg_gq; |
24 | struct blkg_policy_data; | |
25 | ||
26 | ||
672fdcf0 ML |
27 | /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ |
28 | #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) | |
29 | ||
30 | #ifdef CONFIG_BLK_CGROUP | |
bbb1ebe7 CH |
31 | |
32 | enum blkg_iostat_type { | |
33 | BLKG_IOSTAT_READ, | |
34 | BLKG_IOSTAT_WRITE, | |
35 | BLKG_IOSTAT_DISCARD, | |
36 | ||
37 | BLKG_IOSTAT_NR, | |
38 | }; | |
39 | ||
40 | struct blkg_iostat { | |
41 | u64 bytes[BLKG_IOSTAT_NR]; | |
42 | u64 ios[BLKG_IOSTAT_NR]; | |
43 | }; | |
44 | ||
45 | struct blkg_iostat_set { | |
46 | struct u64_stats_sync sync; | |
3b8cc629 WL |
47 | struct blkcg_gq *blkg; |
48 | struct llist_node lnode; | |
49 | int lqueued; /* queued in llist */ | |
bbb1ebe7 CH |
50 | struct blkg_iostat cur; |
51 | struct blkg_iostat last; | |
52 | }; | |
53 | ||
54 | /* association between a blk cgroup and a request queue */ | |
55 | struct blkcg_gq { | |
56 | /* Pointer to the associated request_queue */ | |
57 | struct request_queue *q; | |
58 | struct list_head q_node; | |
59 | struct hlist_node blkcg_node; | |
60 | struct blkcg *blkcg; | |
61 | ||
62 | /* all non-root blkcg_gq's are guaranteed to have access to parent */ | |
63 | struct blkcg_gq *parent; | |
64 | ||
65 | /* reference count */ | |
66 | struct percpu_ref refcnt; | |
67 | ||
68 | /* is this blkg online? protected by both blkcg and q locks */ | |
69 | bool online; | |
70 | ||
71 | struct blkg_iostat_set __percpu *iostat_cpu; | |
72 | struct blkg_iostat_set iostat; | |
73 | ||
74 | struct blkg_policy_data *pd[BLKCG_MAX_POLS]; | |
75 | ||
76 | spinlock_t async_bio_lock; | |
77 | struct bio_list async_bios; | |
78 | union { | |
79 | struct work_struct async_bio_work; | |
80 | struct work_struct free_work; | |
81 | }; | |
82 | ||
83 | atomic_t use_delay; | |
84 | atomic64_t delay_nsec; | |
85 | atomic64_t delay_start; | |
86 | u64 last_delay; | |
87 | int last_use; | |
88 | ||
89 | struct rcu_head rcu_head; | |
90 | }; | |
91 | ||
dec223c9 CH |
92 | struct blkcg { |
93 | struct cgroup_subsys_state css; | |
94 | spinlock_t lock; | |
95 | refcount_t online_pin; | |
96 | ||
97 | struct radix_tree_root blkg_tree; | |
98 | struct blkcg_gq __rcu *blkg_hint; | |
99 | struct hlist_head blkg_list; | |
100 | ||
101 | struct blkcg_policy_data *cpd[BLKCG_MAX_POLS]; | |
102 | ||
103 | struct list_head all_blkcgs_node; | |
3b8cc629 WL |
104 | |
105 | /* | |
106 | * List of updated percpu blkg_iostat_set's since the last flush. | |
107 | */ | |
108 | struct llist_head __percpu *lhead; | |
109 | ||
dec223c9 CH |
110 | #ifdef CONFIG_BLK_CGROUP_FC_APPID |
111 | char fc_app_id[FC_APPID_LEN]; | |
112 | #endif | |
113 | #ifdef CONFIG_CGROUP_WRITEBACK | |
114 | struct list_head cgwb_list; | |
115 | #endif | |
116 | }; | |
117 | ||
118 | static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) | |
119 | { | |
120 | return css ? container_of(css, struct blkcg, css) : NULL; | |
121 | } | |
672fdcf0 ML |
122 | |
123 | /* | |
124 | * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a | |
125 | * request_queue (q). This is used by blkcg policies which need to track | |
126 | * information per blkcg - q pair. | |
127 | * | |
128 | * There can be multiple active blkcg policies and each blkg:policy pair is | |
129 | * represented by a blkg_policy_data which is allocated and freed by each | |
130 | * policy's pd_alloc/free_fn() methods. A policy can allocate private data | |
131 | * area by allocating larger data structure which embeds blkg_policy_data | |
132 | * at the beginning. | |
133 | */ | |
134 | struct blkg_policy_data { | |
135 | /* the blkg and policy id this per-policy data belongs to */ | |
136 | struct blkcg_gq *blkg; | |
137 | int plid; | |
138 | }; | |
139 | ||
140 | /* | |
141 | * Policies that need to keep per-blkcg data which is independent from any | |
142 | * request_queue associated to it should implement cpd_alloc/free_fn() | |
143 | * methods. A policy can allocate private data area by allocating larger | |
144 | * data structure which embeds blkcg_policy_data at the beginning. | |
145 | * cpd_init() is invoked to let each policy handle per-blkcg data. | |
146 | */ | |
147 | struct blkcg_policy_data { | |
148 | /* the blkcg and policy id this per-policy data belongs to */ | |
149 | struct blkcg *blkcg; | |
150 | int plid; | |
151 | }; | |
152 | ||
153 | typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp); | |
154 | typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd); | |
155 | typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd); | |
156 | typedef void (blkcg_pol_bind_cpd_fn)(struct blkcg_policy_data *cpd); | |
157 | typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, | |
158 | struct request_queue *q, struct blkcg *blkcg); | |
159 | typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd); | |
160 | typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd); | |
161 | typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd); | |
162 | typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd); | |
163 | typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd); | |
3607849d | 164 | typedef void (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, |
672fdcf0 ML |
165 | struct seq_file *s); |
166 | ||
167 | struct blkcg_policy { | |
168 | int plid; | |
169 | /* cgroup files for the policy */ | |
170 | struct cftype *dfl_cftypes; | |
171 | struct cftype *legacy_cftypes; | |
172 | ||
173 | /* operations */ | |
174 | blkcg_pol_alloc_cpd_fn *cpd_alloc_fn; | |
175 | blkcg_pol_init_cpd_fn *cpd_init_fn; | |
176 | blkcg_pol_free_cpd_fn *cpd_free_fn; | |
177 | blkcg_pol_bind_cpd_fn *cpd_bind_fn; | |
178 | ||
179 | blkcg_pol_alloc_pd_fn *pd_alloc_fn; | |
180 | blkcg_pol_init_pd_fn *pd_init_fn; | |
181 | blkcg_pol_online_pd_fn *pd_online_fn; | |
182 | blkcg_pol_offline_pd_fn *pd_offline_fn; | |
183 | blkcg_pol_free_pd_fn *pd_free_fn; | |
184 | blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; | |
185 | blkcg_pol_stat_pd_fn *pd_stat_fn; | |
186 | }; | |
187 | ||
188 | extern struct blkcg blkcg_root; | |
189 | extern bool blkcg_debug_stats; | |
190 | ||
9823538f CH |
191 | int blkcg_init_disk(struct gendisk *disk); |
192 | void blkcg_exit_disk(struct gendisk *disk); | |
672fdcf0 ML |
193 | |
194 | /* Blkio controller policy registration */ | |
195 | int blkcg_policy_register(struct blkcg_policy *pol); | |
196 | void blkcg_policy_unregister(struct blkcg_policy *pol); | |
197 | int blkcg_activate_policy(struct request_queue *q, | |
198 | const struct blkcg_policy *pol); | |
199 | void blkcg_deactivate_policy(struct request_queue *q, | |
200 | const struct blkcg_policy *pol); | |
201 | ||
202 | const char *blkg_dev_name(struct blkcg_gq *blkg); | |
203 | void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, | |
204 | u64 (*prfill)(struct seq_file *, | |
205 | struct blkg_policy_data *, int), | |
206 | const struct blkcg_policy *pol, int data, | |
207 | bool show_total); | |
208 | u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); | |
209 | ||
210 | struct blkg_conf_ctx { | |
211 | struct block_device *bdev; | |
212 | struct blkcg_gq *blkg; | |
213 | char *body; | |
214 | }; | |
215 | ||
216 | struct block_device *blkcg_conf_open_bdev(char **inputp); | |
217 | int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, | |
218 | char *input, struct blkg_conf_ctx *ctx); | |
219 | void blkg_conf_finish(struct blkg_conf_ctx *ctx); | |
220 | ||
672fdcf0 ML |
221 | /** |
222 | * bio_issue_as_root_blkg - see if this bio needs to be issued as root blkg | |
223 | * @return: true if this bio needs to be submitted with the root blkg context. | |
224 | * | |
225 | * In order to avoid priority inversions we sometimes need to issue a bio as if | |
226 | * it were attached to the root blkg, and then backcharge to the actual owning | |
bbb1ebe7 CH |
227 | * blkg. The idea is we do bio_blkcg_css() to look up the actual context for |
228 | * the bio and attach the appropriate blkg to the bio. Then we call this helper | |
229 | * and if it is true run with the root blkg for that queue and then do any | |
672fdcf0 ML |
230 | * backcharging to the originating cgroup once the io is complete. |
231 | */ | |
232 | static inline bool bio_issue_as_root_blkg(struct bio *bio) | |
233 | { | |
234 | return (bio->bi_opf & (REQ_META | REQ_SWAP)) != 0; | |
235 | } | |
236 | ||
237 | /** | |
4a69f325 | 238 | * blkg_lookup - lookup blkg for the specified blkcg - q pair |
672fdcf0 ML |
239 | * @blkcg: blkcg of interest |
240 | * @q: request_queue of interest | |
672fdcf0 | 241 | * |
4a69f325 CH |
242 | * Lookup blkg for the @blkcg - @q pair. |
243 | ||
244 | * Must be called in a RCU critical section. | |
672fdcf0 | 245 | */ |
4a69f325 CH |
246 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, |
247 | struct request_queue *q) | |
672fdcf0 ML |
248 | { |
249 | struct blkcg_gq *blkg; | |
250 | ||
4a69f325 CH |
251 | WARN_ON_ONCE(!rcu_read_lock_held()); |
252 | ||
672fdcf0 ML |
253 | if (blkcg == &blkcg_root) |
254 | return q->root_blkg; | |
255 | ||
256 | blkg = rcu_dereference(blkcg->blkg_hint); | |
257 | if (blkg && blkg->q == q) | |
258 | return blkg; | |
259 | ||
4a69f325 CH |
260 | blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id); |
261 | if (blkg && blkg->q != q) | |
262 | blkg = NULL; | |
263 | return blkg; | |
672fdcf0 ML |
264 | } |
265 | ||
672fdcf0 ML |
266 | /** |
267 | * blkg_to_pdata - get policy private data | |
268 | * @blkg: blkg of interest | |
269 | * @pol: policy of interest | |
270 | * | |
271 | * Return pointer to private data associated with the @blkg-@pol pair. | |
272 | */ | |
273 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, | |
274 | struct blkcg_policy *pol) | |
275 | { | |
276 | return blkg ? blkg->pd[pol->plid] : NULL; | |
277 | } | |
278 | ||
279 | static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg, | |
280 | struct blkcg_policy *pol) | |
281 | { | |
282 | return blkcg ? blkcg->cpd[pol->plid] : NULL; | |
283 | } | |
284 | ||
285 | /** | |
286 | * pdata_to_blkg - get blkg associated with policy private data | |
287 | * @pd: policy private data of interest | |
288 | * | |
289 | * @pd is policy private data. Determine the blkg it's associated with. | |
290 | */ | |
291 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) | |
292 | { | |
293 | return pd ? pd->blkg : NULL; | |
294 | } | |
295 | ||
296 | static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd) | |
297 | { | |
298 | return cpd ? cpd->blkcg : NULL; | |
299 | } | |
300 | ||
301 | /** | |
302 | * blkg_path - format cgroup path of blkg | |
303 | * @blkg: blkg of interest | |
304 | * @buf: target buffer | |
305 | * @buflen: target buffer length | |
306 | * | |
307 | * Format the path of the cgroup of @blkg into @buf. | |
308 | */ | |
309 | static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen) | |
310 | { | |
311 | return cgroup_path(blkg->blkcg->css.cgroup, buf, buflen); | |
312 | } | |
313 | ||
314 | /** | |
315 | * blkg_get - get a blkg reference | |
316 | * @blkg: blkg to get | |
317 | * | |
318 | * The caller should be holding an existing reference. | |
319 | */ | |
320 | static inline void blkg_get(struct blkcg_gq *blkg) | |
321 | { | |
322 | percpu_ref_get(&blkg->refcnt); | |
323 | } | |
324 | ||
325 | /** | |
326 | * blkg_tryget - try and get a blkg reference | |
327 | * @blkg: blkg to get | |
328 | * | |
329 | * This is for use when doing an RCU lookup of the blkg. We may be in the midst | |
330 | * of freeing this blkg, so we can only use it if the refcnt is not zero. | |
331 | */ | |
332 | static inline bool blkg_tryget(struct blkcg_gq *blkg) | |
333 | { | |
334 | return blkg && percpu_ref_tryget(&blkg->refcnt); | |
335 | } | |
336 | ||
337 | /** | |
338 | * blkg_put - put a blkg reference | |
339 | * @blkg: blkg to put | |
340 | */ | |
341 | static inline void blkg_put(struct blkcg_gq *blkg) | |
342 | { | |
343 | percpu_ref_put(&blkg->refcnt); | |
344 | } | |
345 | ||
346 | /** | |
347 | * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants | |
348 | * @d_blkg: loop cursor pointing to the current descendant | |
349 | * @pos_css: used for iteration | |
350 | * @p_blkg: target blkg to walk descendants of | |
351 | * | |
352 | * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU | |
353 | * read locked. If called under either blkcg or queue lock, the iteration | |
354 | * is guaranteed to include all and only online blkgs. The caller may | |
355 | * update @pos_css by calling css_rightmost_descendant() to skip subtree. | |
356 | * @p_blkg is included in the iteration and the first node to be visited. | |
357 | */ | |
358 | #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \ | |
359 | css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \ | |
79fcc5be CH |
360 | if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css), \ |
361 | (p_blkg)->q))) | |
672fdcf0 ML |
362 | |
363 | /** | |
364 | * blkg_for_each_descendant_post - post-order walk of a blkg's descendants | |
365 | * @d_blkg: loop cursor pointing to the current descendant | |
366 | * @pos_css: used for iteration | |
367 | * @p_blkg: target blkg to walk descendants of | |
368 | * | |
369 | * Similar to blkg_for_each_descendant_pre() but performs post-order | |
370 | * traversal instead. Synchronization rules are the same. @p_blkg is | |
371 | * included in the iteration and the last node to be visited. | |
372 | */ | |
373 | #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \ | |
374 | css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \ | |
79fcc5be CH |
375 | if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css), \ |
376 | (p_blkg)->q))) | |
672fdcf0 ML |
377 | |
378 | bool __blkcg_punt_bio_submit(struct bio *bio); | |
379 | ||
380 | static inline bool blkcg_punt_bio_submit(struct bio *bio) | |
381 | { | |
382 | if (bio->bi_opf & REQ_CGROUP_PUNT) | |
383 | return __blkcg_punt_bio_submit(bio); | |
384 | else | |
385 | return false; | |
386 | } | |
387 | ||
388 | static inline void blkcg_bio_issue_init(struct bio *bio) | |
389 | { | |
390 | bio_issue_init(&bio->bi_issue, bio_sectors(bio)); | |
391 | } | |
392 | ||
393 | static inline void blkcg_use_delay(struct blkcg_gq *blkg) | |
394 | { | |
395 | if (WARN_ON_ONCE(atomic_read(&blkg->use_delay) < 0)) | |
396 | return; | |
397 | if (atomic_add_return(1, &blkg->use_delay) == 1) | |
398 | atomic_inc(&blkg->blkcg->css.cgroup->congestion_count); | |
399 | } | |
400 | ||
401 | static inline int blkcg_unuse_delay(struct blkcg_gq *blkg) | |
402 | { | |
403 | int old = atomic_read(&blkg->use_delay); | |
404 | ||
405 | if (WARN_ON_ONCE(old < 0)) | |
406 | return 0; | |
407 | if (old == 0) | |
408 | return 0; | |
409 | ||
410 | /* | |
411 | * We do this song and dance because we can race with somebody else | |
412 | * adding or removing delay. If we just did an atomic_dec we'd end up | |
413 | * negative and we'd already be in trouble. We need to subtract 1 and | |
414 | * then check to see if we were the last delay so we can drop the | |
415 | * congestion count on the cgroup. | |
416 | */ | |
96388f57 UB |
417 | while (old && !atomic_try_cmpxchg(&blkg->use_delay, &old, old - 1)) |
418 | ; | |
672fdcf0 ML |
419 | |
420 | if (old == 0) | |
421 | return 0; | |
422 | if (old == 1) | |
423 | atomic_dec(&blkg->blkcg->css.cgroup->congestion_count); | |
424 | return 1; | |
425 | } | |
426 | ||
427 | /** | |
428 | * blkcg_set_delay - Enable allocator delay mechanism with the specified delay amount | |
429 | * @blkg: target blkg | |
430 | * @delay: delay duration in nsecs | |
431 | * | |
432 | * When enabled with this function, the delay is not decayed and must be | |
433 | * explicitly cleared with blkcg_clear_delay(). Must not be mixed with | |
434 | * blkcg_[un]use_delay() and blkcg_add_delay() usages. | |
435 | */ | |
436 | static inline void blkcg_set_delay(struct blkcg_gq *blkg, u64 delay) | |
437 | { | |
438 | int old = atomic_read(&blkg->use_delay); | |
439 | ||
440 | /* We only want 1 person setting the congestion count for this blkg. */ | |
96388f57 | 441 | if (!old && atomic_try_cmpxchg(&blkg->use_delay, &old, -1)) |
672fdcf0 ML |
442 | atomic_inc(&blkg->blkcg->css.cgroup->congestion_count); |
443 | ||
444 | atomic64_set(&blkg->delay_nsec, delay); | |
445 | } | |
446 | ||
447 | /** | |
448 | * blkcg_clear_delay - Disable allocator delay mechanism | |
449 | * @blkg: target blkg | |
450 | * | |
451 | * Disable use_delay mechanism. See blkcg_set_delay(). | |
452 | */ | |
453 | static inline void blkcg_clear_delay(struct blkcg_gq *blkg) | |
454 | { | |
455 | int old = atomic_read(&blkg->use_delay); | |
456 | ||
457 | /* We only want 1 person clearing the congestion count for this blkg. */ | |
96388f57 | 458 | if (old && atomic_try_cmpxchg(&blkg->use_delay, &old, 0)) |
672fdcf0 ML |
459 | atomic_dec(&blkg->blkcg->css.cgroup->congestion_count); |
460 | } | |
461 | ||
6b2b0459 TH |
462 | /** |
463 | * blk_cgroup_mergeable - Determine whether to allow or disallow merges | |
464 | * @rq: request to merge into | |
465 | * @bio: bio to merge | |
466 | * | |
467 | * @bio and @rq should belong to the same cgroup and their issue_as_root should | |
468 | * match. The latter is necessary as we don't want to throttle e.g. a metadata | |
469 | * update because it happens to be next to a regular IO. | |
470 | */ | |
471 | static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) | |
472 | { | |
473 | return rq->bio->bi_blkg == bio->bi_blkg && | |
474 | bio_issue_as_root_blkg(rq->bio) == bio_issue_as_root_blkg(bio); | |
475 | } | |
476 | ||
672fdcf0 ML |
477 | void blk_cgroup_bio_start(struct bio *bio); |
478 | void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta); | |
479 | #else /* CONFIG_BLK_CGROUP */ | |
480 | ||
481 | struct blkg_policy_data { | |
482 | }; | |
483 | ||
484 | struct blkcg_policy_data { | |
485 | }; | |
486 | ||
487 | struct blkcg_policy { | |
488 | }; | |
489 | ||
bbb1ebe7 CH |
490 | struct blkcg { |
491 | }; | |
492 | ||
672fdcf0 | 493 | static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } |
9823538f CH |
494 | static inline int blkcg_init_disk(struct gendisk *disk) { return 0; } |
495 | static inline void blkcg_exit_disk(struct gendisk *disk) { } | |
672fdcf0 ML |
496 | static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } |
497 | static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } | |
498 | static inline int blkcg_activate_policy(struct request_queue *q, | |
499 | const struct blkcg_policy *pol) { return 0; } | |
500 | static inline void blkcg_deactivate_policy(struct request_queue *q, | |
501 | const struct blkcg_policy *pol) { } | |
502 | ||
672fdcf0 ML |
503 | static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, |
504 | struct blkcg_policy *pol) { return NULL; } | |
505 | static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } | |
506 | static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } | |
507 | static inline void blkg_get(struct blkcg_gq *blkg) { } | |
508 | static inline void blkg_put(struct blkcg_gq *blkg) { } | |
509 | ||
510 | static inline bool blkcg_punt_bio_submit(struct bio *bio) { return false; } | |
511 | static inline void blkcg_bio_issue_init(struct bio *bio) { } | |
512 | static inline void blk_cgroup_bio_start(struct bio *bio) { } | |
6b2b0459 | 513 | static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) { return true; } |
672fdcf0 ML |
514 | |
515 | #define blk_queue_for_each_rl(rl, q) \ | |
516 | for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) | |
517 | ||
672fdcf0 ML |
518 | #endif /* CONFIG_BLK_CGROUP */ |
519 | ||
520 | #endif /* _BLK_CGROUP_PRIVATE_H */ |