4 * Common Block IO controller cgroup interface
6 * Based on ideas and code from CFQ, CFS and BFQ:
7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
9 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
10 * Paolo Valente <paolo.valente@unimore.it>
12 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
13 * Nauman Rafique <nauman@google.com>
16 #include <linux/cgroup.h>
17 #include <linux/percpu_counter.h>
18 #include <linux/seq_file.h>
19 #include <linux/radix-tree.h>
20 #include <linux/blkdev.h>
21 #include <linux/atomic.h>
23 /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */
24 #define BLKG_STAT_CPU_BATCH (INT_MAX / 2)
26 /* Max limits for throttle policy */
27 #define THROTL_IOPS_MAX UINT_MAX
29 #ifdef CONFIG_BLK_CGROUP
31 enum blkg_rwstat_type {
38 BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
44 struct cgroup_subsys_state css;
47 struct radix_tree_root blkg_tree;
48 struct blkcg_gq *blkg_hint;
49 struct hlist_head blkg_list;
51 struct blkcg_policy_data *cpd[BLKCG_MAX_POLS];
53 struct list_head all_blkcgs_node;
54 #ifdef CONFIG_CGROUP_WRITEBACK
55 struct list_head cgwb_list;
60 * blkg_[rw]stat->aux_cnt is excluded for local stats but included for
61 * recursive. Used to carry stats of dead children, and, for blkg_rwstat,
62 * to carry result values from read and sum operations.
65 struct percpu_counter cpu_cnt;
70 struct percpu_counter cpu_cnt[BLKG_RWSTAT_NR];
71 atomic64_t aux_cnt[BLKG_RWSTAT_NR];
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.
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
85 struct blkg_policy_data {
86 /* the blkg and policy id this per-policy data belongs to */
87 struct blkcg_gq *blkg;
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.
98 struct blkcg_policy_data {
99 /* the blkcg and policy id this per-policy data belongs to */
104 /* association between a blk cgroup and a request queue */
106 /* Pointer to the associated request_queue */
107 struct request_queue *q;
108 struct list_head q_node;
109 struct hlist_node blkcg_node;
113 * Each blkg gets congested separately and the congestion state is
114 * propagated to the matching bdi_writeback_congested.
116 struct bdi_writeback_congested *wb_congested;
118 /* all non-root blkcg_gq's are guaranteed to have access to parent */
119 struct blkcg_gq *parent;
121 /* request allocation list for this blkcg-q pair */
122 struct request_list rl;
124 /* reference count */
127 /* is this blkg online? protected by both blkcg and q locks */
130 struct blkg_rwstat stat_bytes;
131 struct blkg_rwstat stat_ios;
133 struct blkg_policy_data *pd[BLKCG_MAX_POLS];
135 struct rcu_head rcu_head;
138 typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp);
139 typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
140 typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd);
141 typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
142 typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
143 typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
144 typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
145 typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
146 typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
148 struct blkcg_policy {
150 /* cgroup files for the policy */
151 struct cftype *legacy_cftypes;
154 blkcg_pol_alloc_cpd_fn *cpd_alloc_fn;
155 blkcg_pol_init_cpd_fn *cpd_init_fn;
156 blkcg_pol_free_cpd_fn *cpd_free_fn;
158 blkcg_pol_alloc_pd_fn *pd_alloc_fn;
159 blkcg_pol_init_pd_fn *pd_init_fn;
160 blkcg_pol_online_pd_fn *pd_online_fn;
161 blkcg_pol_offline_pd_fn *pd_offline_fn;
162 blkcg_pol_free_pd_fn *pd_free_fn;
163 blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
166 extern struct blkcg blkcg_root;
167 extern struct cgroup_subsys_state * const blkcg_root_css;
169 struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
170 struct request_queue *q, bool update_hint);
171 struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
172 struct request_queue *q);
173 int blkcg_init_queue(struct request_queue *q);
174 void blkcg_drain_queue(struct request_queue *q);
175 void blkcg_exit_queue(struct request_queue *q);
177 /* Blkio controller policy registration */
178 int blkcg_policy_register(struct blkcg_policy *pol);
179 void blkcg_policy_unregister(struct blkcg_policy *pol);
180 int blkcg_activate_policy(struct request_queue *q,
181 const struct blkcg_policy *pol);
182 void blkcg_deactivate_policy(struct request_queue *q,
183 const struct blkcg_policy *pol);
185 void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
186 u64 (*prfill)(struct seq_file *,
187 struct blkg_policy_data *, int),
188 const struct blkcg_policy *pol, int data,
190 u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v);
191 u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
192 const struct blkg_rwstat *rwstat);
193 u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off);
194 u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
196 int blkg_print_stat_bytes(struct seq_file *sf, void *v);
197 int blkg_print_stat_ios(struct seq_file *sf, void *v);
198 int blkg_print_stat_bytes_recursive(struct seq_file *sf, void *v);
199 int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v);
201 u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
202 struct blkcg_policy *pol, int off);
203 struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
204 struct blkcg_policy *pol, int off);
206 struct blkg_conf_ctx {
207 struct gendisk *disk;
208 struct blkcg_gq *blkg;
212 int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
213 char *input, struct blkg_conf_ctx *ctx);
214 void blkg_conf_finish(struct blkg_conf_ctx *ctx);
217 static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)
219 return css ? container_of(css, struct blkcg, css) : NULL;
222 static inline struct blkcg *task_blkcg(struct task_struct *tsk)
224 return css_to_blkcg(task_css(tsk, io_cgrp_id));
227 static inline struct blkcg *bio_blkcg(struct bio *bio)
229 if (bio && bio->bi_css)
230 return css_to_blkcg(bio->bi_css);
231 return task_blkcg(current);
234 static inline struct cgroup_subsys_state *
235 task_get_blkcg_css(struct task_struct *task)
237 return task_get_css(task, io_cgrp_id);
241 * blkcg_parent - get the parent of a blkcg
242 * @blkcg: blkcg of interest
244 * Return the parent blkcg of @blkcg. Can be called anytime.
246 static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
248 return css_to_blkcg(blkcg->css.parent);
252 * __blkg_lookup - internal version of blkg_lookup()
253 * @blkcg: blkcg of interest
254 * @q: request_queue of interest
255 * @update_hint: whether to update lookup hint with the result or not
257 * This is internal version and shouldn't be used by policy
258 * implementations. Looks up blkgs for the @blkcg - @q pair regardless of
259 * @q's bypass state. If @update_hint is %true, the caller should be
260 * holding @q->queue_lock and lookup hint is updated on success.
262 static inline struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
263 struct request_queue *q,
266 struct blkcg_gq *blkg;
268 if (blkcg == &blkcg_root)
271 blkg = rcu_dereference(blkcg->blkg_hint);
272 if (blkg && blkg->q == q)
275 return blkg_lookup_slowpath(blkcg, q, update_hint);
279 * blkg_lookup - lookup blkg for the specified blkcg - q pair
280 * @blkcg: blkcg of interest
281 * @q: request_queue of interest
283 * Lookup blkg for the @blkcg - @q pair. This function should be called
284 * under RCU read lock and is guaranteed to return %NULL if @q is bypassing
285 * - see blk_queue_bypass_start() for details.
287 static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
288 struct request_queue *q)
290 WARN_ON_ONCE(!rcu_read_lock_held());
292 if (unlikely(blk_queue_bypass(q)))
294 return __blkg_lookup(blkcg, q, false);
298 * blkg_to_pdata - get policy private data
299 * @blkg: blkg of interest
300 * @pol: policy of interest
302 * Return pointer to private data associated with the @blkg-@pol pair.
304 static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
305 struct blkcg_policy *pol)
307 return blkg ? blkg->pd[pol->plid] : NULL;
310 static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
311 struct blkcg_policy *pol)
313 return blkcg ? blkcg->cpd[pol->plid] : NULL;
317 * pdata_to_blkg - get blkg associated with policy private data
318 * @pd: policy private data of interest
320 * @pd is policy private data. Determine the blkg it's associated with.
322 static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
324 return pd ? pd->blkg : NULL;
327 static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
329 return cpd ? cpd->blkcg : NULL;
333 * blkg_path - format cgroup path of blkg
334 * @blkg: blkg of interest
335 * @buf: target buffer
336 * @buflen: target buffer length
338 * Format the path of the cgroup of @blkg into @buf.
340 static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
344 p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
346 strncpy(buf, "<unavailable>", buflen);
347 return -ENAMETOOLONG;
350 memmove(buf, p, buf + buflen - p);
355 * blkg_get - get a blkg reference
358 * The caller should be holding an existing reference.
360 static inline void blkg_get(struct blkcg_gq *blkg)
362 WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0);
363 atomic_inc(&blkg->refcnt);
366 void __blkg_release_rcu(struct rcu_head *rcu);
369 * blkg_put - put a blkg reference
372 static inline void blkg_put(struct blkcg_gq *blkg)
374 WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0);
375 if (atomic_dec_and_test(&blkg->refcnt))
376 call_rcu(&blkg->rcu_head, __blkg_release_rcu);
380 * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
381 * @d_blkg: loop cursor pointing to the current descendant
382 * @pos_css: used for iteration
383 * @p_blkg: target blkg to walk descendants of
385 * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
386 * read locked. If called under either blkcg or queue lock, the iteration
387 * is guaranteed to include all and only online blkgs. The caller may
388 * update @pos_css by calling css_rightmost_descendant() to skip subtree.
389 * @p_blkg is included in the iteration and the first node to be visited.
391 #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \
392 css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \
393 if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
394 (p_blkg)->q, false)))
397 * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
398 * @d_blkg: loop cursor pointing to the current descendant
399 * @pos_css: used for iteration
400 * @p_blkg: target blkg to walk descendants of
402 * Similar to blkg_for_each_descendant_pre() but performs post-order
403 * traversal instead. Synchronization rules are the same. @p_blkg is
404 * included in the iteration and the last node to be visited.
406 #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \
407 css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \
408 if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
409 (p_blkg)->q, false)))
412 * blk_get_rl - get request_list to use
413 * @q: request_queue of interest
414 * @bio: bio which will be attached to the allocated request (may be %NULL)
416 * The caller wants to allocate a request from @q to use for @bio. Find
417 * the request_list to use and obtain a reference on it. Should be called
418 * under queue_lock. This function is guaranteed to return non-%NULL
421 static inline struct request_list *blk_get_rl(struct request_queue *q,
425 struct blkcg_gq *blkg;
429 blkcg = bio_blkcg(bio);
431 /* bypass blkg lookup and use @q->root_rl directly for root */
432 if (blkcg == &blkcg_root)
436 * Try to use blkg->rl. blkg lookup may fail under memory pressure
437 * or if either the blkcg or queue is going away. Fall back to
438 * root_rl in such cases.
440 blkg = blkg_lookup(blkcg, q);
453 * blk_put_rl - put request_list
454 * @rl: request_list to put
456 * Put the reference acquired by blk_get_rl(). Should be called under
459 static inline void blk_put_rl(struct request_list *rl)
461 if (rl->blkg->blkcg != &blkcg_root)
466 * blk_rq_set_rl - associate a request with a request_list
467 * @rq: request of interest
468 * @rl: target request_list
470 * Associate @rq with @rl so that accounting and freeing can know the
471 * request_list @rq came from.
473 static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl)
479 * blk_rq_rl - return the request_list a request came from
480 * @rq: request of interest
482 * Return the request_list @rq is allocated from.
484 static inline struct request_list *blk_rq_rl(struct request *rq)
489 struct request_list *__blk_queue_next_rl(struct request_list *rl,
490 struct request_queue *q);
492 * blk_queue_for_each_rl - iterate through all request_lists of a request_queue
494 * Should be used under queue_lock.
496 #define blk_queue_for_each_rl(rl, q) \
497 for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q)))
499 static inline int blkg_stat_init(struct blkg_stat *stat, gfp_t gfp)
503 ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp);
507 atomic64_set(&stat->aux_cnt, 0);
511 static inline void blkg_stat_exit(struct blkg_stat *stat)
513 percpu_counter_destroy(&stat->cpu_cnt);
517 * blkg_stat_add - add a value to a blkg_stat
518 * @stat: target blkg_stat
521 * Add @val to @stat. The caller must ensure that IRQ on the same CPU
522 * don't re-enter this function for the same counter.
524 static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val)
526 __percpu_counter_add(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH);
530 * blkg_stat_read - read the current value of a blkg_stat
531 * @stat: blkg_stat to read
533 static inline uint64_t blkg_stat_read(struct blkg_stat *stat)
535 return percpu_counter_sum_positive(&stat->cpu_cnt);
539 * blkg_stat_reset - reset a blkg_stat
540 * @stat: blkg_stat to reset
542 static inline void blkg_stat_reset(struct blkg_stat *stat)
544 percpu_counter_set(&stat->cpu_cnt, 0);
545 atomic64_set(&stat->aux_cnt, 0);
549 * blkg_stat_add_aux - add a blkg_stat into another's aux count
550 * @to: the destination blkg_stat
553 * Add @from's count including the aux one to @to's aux count.
555 static inline void blkg_stat_add_aux(struct blkg_stat *to,
556 struct blkg_stat *from)
558 atomic64_add(blkg_stat_read(from) + atomic64_read(&from->aux_cnt),
562 static inline int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp)
566 for (i = 0; i < BLKG_RWSTAT_NR; i++) {
567 ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp);
570 percpu_counter_destroy(&rwstat->cpu_cnt[i]);
573 atomic64_set(&rwstat->aux_cnt[i], 0);
578 static inline void blkg_rwstat_exit(struct blkg_rwstat *rwstat)
582 for (i = 0; i < BLKG_RWSTAT_NR; i++)
583 percpu_counter_destroy(&rwstat->cpu_cnt[i]);
587 * blkg_rwstat_add - add a value to a blkg_rwstat
588 * @rwstat: target blkg_rwstat
589 * @rw: mask of REQ_{WRITE|SYNC}
592 * Add @val to @rwstat. The counters are chosen according to @rw. The
593 * caller is responsible for synchronizing calls to this function.
595 static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
596 int rw, uint64_t val)
598 struct percpu_counter *cnt;
601 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_WRITE];
603 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ];
605 __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH);
608 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_SYNC];
610 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_ASYNC];
612 __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH);
616 * blkg_rwstat_read - read the current values of a blkg_rwstat
617 * @rwstat: blkg_rwstat to read
619 * Read the current snapshot of @rwstat and return it in the aux counts.
621 static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
623 struct blkg_rwstat result;
626 for (i = 0; i < BLKG_RWSTAT_NR; i++)
627 atomic64_set(&result.aux_cnt[i],
628 percpu_counter_sum_positive(&rwstat->cpu_cnt[i]));
633 * blkg_rwstat_total - read the total count of a blkg_rwstat
634 * @rwstat: blkg_rwstat to read
636 * Return the total count of @rwstat regardless of the IO direction. This
637 * function can be called without synchronization and takes care of u64
640 static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat)
642 struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
644 return atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
645 atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);
649 * blkg_rwstat_reset - reset a blkg_rwstat
650 * @rwstat: blkg_rwstat to reset
652 static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
656 for (i = 0; i < BLKG_RWSTAT_NR; i++) {
657 percpu_counter_set(&rwstat->cpu_cnt[i], 0);
658 atomic64_set(&rwstat->aux_cnt[i], 0);
663 * blkg_rwstat_add_aux - add a blkg_rwstat into another's aux count
664 * @to: the destination blkg_rwstat
667 * Add @from's count including the aux one to @to's aux count.
669 static inline void blkg_rwstat_add_aux(struct blkg_rwstat *to,
670 struct blkg_rwstat *from)
672 struct blkg_rwstat v = blkg_rwstat_read(from);
675 for (i = 0; i < BLKG_RWSTAT_NR; i++)
676 atomic64_add(atomic64_read(&v.aux_cnt[i]) +
677 atomic64_read(&from->aux_cnt[i]),
681 #ifdef CONFIG_BLK_DEV_THROTTLING
682 extern bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
685 static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
686 struct bio *bio) { return false; }
689 static inline bool blkcg_bio_issue_check(struct request_queue *q,
693 struct blkcg_gq *blkg;
697 blkcg = bio_blkcg(bio);
699 blkg = blkg_lookup(blkcg, q);
700 if (unlikely(!blkg)) {
701 spin_lock_irq(q->queue_lock);
702 blkg = blkg_lookup_create(blkcg, q);
705 spin_unlock_irq(q->queue_lock);
708 throtl = blk_throtl_bio(q, blkg, bio);
711 blkg = blkg ?: q->root_blkg;
712 blkg_rwstat_add(&blkg->stat_bytes, bio->bi_flags,
713 bio->bi_iter.bi_size);
714 blkg_rwstat_add(&blkg->stat_ios, bio->bi_flags, 1);
721 #else /* CONFIG_BLK_CGROUP */
726 struct blkg_policy_data {
729 struct blkcg_policy_data {
735 struct blkcg_policy {
738 #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
740 static inline struct cgroup_subsys_state *
741 task_get_blkcg_css(struct task_struct *task)
748 static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
749 static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
750 static inline void blkcg_drain_queue(struct request_queue *q) { }
751 static inline void blkcg_exit_queue(struct request_queue *q) { }
752 static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
753 static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
754 static inline int blkcg_activate_policy(struct request_queue *q,
755 const struct blkcg_policy *pol) { return 0; }
756 static inline void blkcg_deactivate_policy(struct request_queue *q,
757 const struct blkcg_policy *pol) { }
759 static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
761 static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
762 struct blkcg_policy *pol) { return NULL; }
763 static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
764 static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
765 static inline void blkg_get(struct blkcg_gq *blkg) { }
766 static inline void blkg_put(struct blkcg_gq *blkg) { }
768 static inline struct request_list *blk_get_rl(struct request_queue *q,
769 struct bio *bio) { return &q->root_rl; }
770 static inline void blk_put_rl(struct request_list *rl) { }
771 static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { }
772 static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; }
774 static inline bool blkcg_bio_issue_check(struct request_queue *q,
775 struct bio *bio) { return true; }
777 #define blk_queue_for_each_rl(rl, q) \
778 for ((rl) = &(q)->root_rl; (rl); (rl) = NULL)
780 #endif /* CONFIG_BLOCK */
781 #endif /* CONFIG_BLK_CGROUP */
782 #endif /* _BLK_CGROUP_H */