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 __rcu
*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 void (blkcg_pol_bind_cpd_fn
)(struct blkcg_policy_data
*cpd
);
142 typedef struct blkg_policy_data
*(blkcg_pol_alloc_pd_fn
)(gfp_t gfp
, int node
);
143 typedef void (blkcg_pol_init_pd_fn
)(struct blkg_policy_data
*pd
);
144 typedef void (blkcg_pol_online_pd_fn
)(struct blkg_policy_data
*pd
);
145 typedef void (blkcg_pol_offline_pd_fn
)(struct blkg_policy_data
*pd
);
146 typedef void (blkcg_pol_free_pd_fn
)(struct blkg_policy_data
*pd
);
147 typedef void (blkcg_pol_reset_pd_stats_fn
)(struct blkg_policy_data
*pd
);
149 struct blkcg_policy
{
151 /* cgroup files for the policy */
152 struct cftype
*dfl_cftypes
;
153 struct cftype
*legacy_cftypes
;
156 blkcg_pol_alloc_cpd_fn
*cpd_alloc_fn
;
157 blkcg_pol_init_cpd_fn
*cpd_init_fn
;
158 blkcg_pol_free_cpd_fn
*cpd_free_fn
;
159 blkcg_pol_bind_cpd_fn
*cpd_bind_fn
;
161 blkcg_pol_alloc_pd_fn
*pd_alloc_fn
;
162 blkcg_pol_init_pd_fn
*pd_init_fn
;
163 blkcg_pol_online_pd_fn
*pd_online_fn
;
164 blkcg_pol_offline_pd_fn
*pd_offline_fn
;
165 blkcg_pol_free_pd_fn
*pd_free_fn
;
166 blkcg_pol_reset_pd_stats_fn
*pd_reset_stats_fn
;
169 extern struct blkcg blkcg_root
;
170 extern struct cgroup_subsys_state
* const blkcg_root_css
;
172 struct blkcg_gq
*blkg_lookup_slowpath(struct blkcg
*blkcg
,
173 struct request_queue
*q
, bool update_hint
);
174 struct blkcg_gq
*blkg_lookup_create(struct blkcg
*blkcg
,
175 struct request_queue
*q
);
176 int blkcg_init_queue(struct request_queue
*q
);
177 void blkcg_drain_queue(struct request_queue
*q
);
178 void blkcg_exit_queue(struct request_queue
*q
);
180 /* Blkio controller policy registration */
181 int blkcg_policy_register(struct blkcg_policy
*pol
);
182 void blkcg_policy_unregister(struct blkcg_policy
*pol
);
183 int blkcg_activate_policy(struct request_queue
*q
,
184 const struct blkcg_policy
*pol
);
185 void blkcg_deactivate_policy(struct request_queue
*q
,
186 const struct blkcg_policy
*pol
);
188 const char *blkg_dev_name(struct blkcg_gq
*blkg
);
189 void blkcg_print_blkgs(struct seq_file
*sf
, struct blkcg
*blkcg
,
190 u64 (*prfill
)(struct seq_file
*,
191 struct blkg_policy_data
*, int),
192 const struct blkcg_policy
*pol
, int data
,
194 u64
__blkg_prfill_u64(struct seq_file
*sf
, struct blkg_policy_data
*pd
, u64 v
);
195 u64
__blkg_prfill_rwstat(struct seq_file
*sf
, struct blkg_policy_data
*pd
,
196 const struct blkg_rwstat
*rwstat
);
197 u64
blkg_prfill_stat(struct seq_file
*sf
, struct blkg_policy_data
*pd
, int off
);
198 u64
blkg_prfill_rwstat(struct seq_file
*sf
, struct blkg_policy_data
*pd
,
200 int blkg_print_stat_bytes(struct seq_file
*sf
, void *v
);
201 int blkg_print_stat_ios(struct seq_file
*sf
, void *v
);
202 int blkg_print_stat_bytes_recursive(struct seq_file
*sf
, void *v
);
203 int blkg_print_stat_ios_recursive(struct seq_file
*sf
, void *v
);
205 u64
blkg_stat_recursive_sum(struct blkcg_gq
*blkg
,
206 struct blkcg_policy
*pol
, int off
);
207 struct blkg_rwstat
blkg_rwstat_recursive_sum(struct blkcg_gq
*blkg
,
208 struct blkcg_policy
*pol
, int off
);
210 struct blkg_conf_ctx
{
211 struct gendisk
*disk
;
212 struct blkcg_gq
*blkg
;
216 int blkg_conf_prep(struct blkcg
*blkcg
, const struct blkcg_policy
*pol
,
217 char *input
, struct blkg_conf_ctx
*ctx
);
218 void blkg_conf_finish(struct blkg_conf_ctx
*ctx
);
221 static inline struct blkcg
*css_to_blkcg(struct cgroup_subsys_state
*css
)
223 return css
? container_of(css
, struct blkcg
, css
) : NULL
;
226 static inline struct blkcg
*task_blkcg(struct task_struct
*tsk
)
228 return css_to_blkcg(task_css(tsk
, io_cgrp_id
));
231 static inline struct blkcg
*bio_blkcg(struct bio
*bio
)
233 if (bio
&& bio
->bi_css
)
234 return css_to_blkcg(bio
->bi_css
);
235 return task_blkcg(current
);
238 static inline struct cgroup_subsys_state
*
239 task_get_blkcg_css(struct task_struct
*task
)
241 return task_get_css(task
, io_cgrp_id
);
245 * blkcg_parent - get the parent of a blkcg
246 * @blkcg: blkcg of interest
248 * Return the parent blkcg of @blkcg. Can be called anytime.
250 static inline struct blkcg
*blkcg_parent(struct blkcg
*blkcg
)
252 return css_to_blkcg(blkcg
->css
.parent
);
256 * __blkg_lookup - internal version of blkg_lookup()
257 * @blkcg: blkcg of interest
258 * @q: request_queue of interest
259 * @update_hint: whether to update lookup hint with the result or not
261 * This is internal version and shouldn't be used by policy
262 * implementations. Looks up blkgs for the @blkcg - @q pair regardless of
263 * @q's bypass state. If @update_hint is %true, the caller should be
264 * holding @q->queue_lock and lookup hint is updated on success.
266 static inline struct blkcg_gq
*__blkg_lookup(struct blkcg
*blkcg
,
267 struct request_queue
*q
,
270 struct blkcg_gq
*blkg
;
272 if (blkcg
== &blkcg_root
)
275 blkg
= rcu_dereference(blkcg
->blkg_hint
);
276 if (blkg
&& blkg
->q
== q
)
279 return blkg_lookup_slowpath(blkcg
, q
, update_hint
);
283 * blkg_lookup - lookup blkg for the specified blkcg - q pair
284 * @blkcg: blkcg of interest
285 * @q: request_queue of interest
287 * Lookup blkg for the @blkcg - @q pair. This function should be called
288 * under RCU read lock and is guaranteed to return %NULL if @q is bypassing
289 * - see blk_queue_bypass_start() for details.
291 static inline struct blkcg_gq
*blkg_lookup(struct blkcg
*blkcg
,
292 struct request_queue
*q
)
294 WARN_ON_ONCE(!rcu_read_lock_held());
296 if (unlikely(blk_queue_bypass(q
)))
298 return __blkg_lookup(blkcg
, q
, false);
302 * blkg_to_pdata - get policy private data
303 * @blkg: blkg of interest
304 * @pol: policy of interest
306 * Return pointer to private data associated with the @blkg-@pol pair.
308 static inline struct blkg_policy_data
*blkg_to_pd(struct blkcg_gq
*blkg
,
309 struct blkcg_policy
*pol
)
311 return blkg
? blkg
->pd
[pol
->plid
] : NULL
;
314 static inline struct blkcg_policy_data
*blkcg_to_cpd(struct blkcg
*blkcg
,
315 struct blkcg_policy
*pol
)
317 return blkcg
? blkcg
->cpd
[pol
->plid
] : NULL
;
321 * pdata_to_blkg - get blkg associated with policy private data
322 * @pd: policy private data of interest
324 * @pd is policy private data. Determine the blkg it's associated with.
326 static inline struct blkcg_gq
*pd_to_blkg(struct blkg_policy_data
*pd
)
328 return pd
? pd
->blkg
: NULL
;
331 static inline struct blkcg
*cpd_to_blkcg(struct blkcg_policy_data
*cpd
)
333 return cpd
? cpd
->blkcg
: NULL
;
337 * blkg_path - format cgroup path of blkg
338 * @blkg: blkg of interest
339 * @buf: target buffer
340 * @buflen: target buffer length
342 * Format the path of the cgroup of @blkg into @buf.
344 static inline int blkg_path(struct blkcg_gq
*blkg
, char *buf
, int buflen
)
346 return cgroup_path(blkg
->blkcg
->css
.cgroup
, buf
, buflen
);
350 * blkg_get - get a blkg reference
353 * The caller should be holding an existing reference.
355 static inline void blkg_get(struct blkcg_gq
*blkg
)
357 WARN_ON_ONCE(atomic_read(&blkg
->refcnt
) <= 0);
358 atomic_inc(&blkg
->refcnt
);
361 void __blkg_release_rcu(struct rcu_head
*rcu
);
364 * blkg_put - put a blkg reference
367 static inline void blkg_put(struct blkcg_gq
*blkg
)
369 WARN_ON_ONCE(atomic_read(&blkg
->refcnt
) <= 0);
370 if (atomic_dec_and_test(&blkg
->refcnt
))
371 call_rcu(&blkg
->rcu_head
, __blkg_release_rcu
);
375 * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
376 * @d_blkg: loop cursor pointing to the current descendant
377 * @pos_css: used for iteration
378 * @p_blkg: target blkg to walk descendants of
380 * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
381 * read locked. If called under either blkcg or queue lock, the iteration
382 * is guaranteed to include all and only online blkgs. The caller may
383 * update @pos_css by calling css_rightmost_descendant() to skip subtree.
384 * @p_blkg is included in the iteration and the first node to be visited.
386 #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \
387 css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \
388 if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
389 (p_blkg)->q, false)))
392 * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
393 * @d_blkg: loop cursor pointing to the current descendant
394 * @pos_css: used for iteration
395 * @p_blkg: target blkg to walk descendants of
397 * Similar to blkg_for_each_descendant_pre() but performs post-order
398 * traversal instead. Synchronization rules are the same. @p_blkg is
399 * included in the iteration and the last node to be visited.
401 #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \
402 css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \
403 if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
404 (p_blkg)->q, false)))
407 * blk_get_rl - get request_list to use
408 * @q: request_queue of interest
409 * @bio: bio which will be attached to the allocated request (may be %NULL)
411 * The caller wants to allocate a request from @q to use for @bio. Find
412 * the request_list to use and obtain a reference on it. Should be called
413 * under queue_lock. This function is guaranteed to return non-%NULL
416 static inline struct request_list
*blk_get_rl(struct request_queue
*q
,
420 struct blkcg_gq
*blkg
;
424 blkcg
= bio_blkcg(bio
);
426 /* bypass blkg lookup and use @q->root_rl directly for root */
427 if (blkcg
== &blkcg_root
)
431 * Try to use blkg->rl. blkg lookup may fail under memory pressure
432 * or if either the blkcg or queue is going away. Fall back to
433 * root_rl in such cases.
435 blkg
= blkg_lookup(blkcg
, q
);
448 * blk_put_rl - put request_list
449 * @rl: request_list to put
451 * Put the reference acquired by blk_get_rl(). Should be called under
454 static inline void blk_put_rl(struct request_list
*rl
)
456 if (rl
->blkg
->blkcg
!= &blkcg_root
)
461 * blk_rq_set_rl - associate a request with a request_list
462 * @rq: request of interest
463 * @rl: target request_list
465 * Associate @rq with @rl so that accounting and freeing can know the
466 * request_list @rq came from.
468 static inline void blk_rq_set_rl(struct request
*rq
, struct request_list
*rl
)
474 * blk_rq_rl - return the request_list a request came from
475 * @rq: request of interest
477 * Return the request_list @rq is allocated from.
479 static inline struct request_list
*blk_rq_rl(struct request
*rq
)
484 struct request_list
*__blk_queue_next_rl(struct request_list
*rl
,
485 struct request_queue
*q
);
487 * blk_queue_for_each_rl - iterate through all request_lists of a request_queue
489 * Should be used under queue_lock.
491 #define blk_queue_for_each_rl(rl, q) \
492 for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q)))
494 static inline int blkg_stat_init(struct blkg_stat
*stat
, gfp_t gfp
)
498 ret
= percpu_counter_init(&stat
->cpu_cnt
, 0, gfp
);
502 atomic64_set(&stat
->aux_cnt
, 0);
506 static inline void blkg_stat_exit(struct blkg_stat
*stat
)
508 percpu_counter_destroy(&stat
->cpu_cnt
);
512 * blkg_stat_add - add a value to a blkg_stat
513 * @stat: target blkg_stat
516 * Add @val to @stat. The caller must ensure that IRQ on the same CPU
517 * don't re-enter this function for the same counter.
519 static inline void blkg_stat_add(struct blkg_stat
*stat
, uint64_t val
)
521 __percpu_counter_add(&stat
->cpu_cnt
, val
, BLKG_STAT_CPU_BATCH
);
525 * blkg_stat_read - read the current value of a blkg_stat
526 * @stat: blkg_stat to read
528 static inline uint64_t blkg_stat_read(struct blkg_stat
*stat
)
530 return percpu_counter_sum_positive(&stat
->cpu_cnt
);
534 * blkg_stat_reset - reset a blkg_stat
535 * @stat: blkg_stat to reset
537 static inline void blkg_stat_reset(struct blkg_stat
*stat
)
539 percpu_counter_set(&stat
->cpu_cnt
, 0);
540 atomic64_set(&stat
->aux_cnt
, 0);
544 * blkg_stat_add_aux - add a blkg_stat into another's aux count
545 * @to: the destination blkg_stat
548 * Add @from's count including the aux one to @to's aux count.
550 static inline void blkg_stat_add_aux(struct blkg_stat
*to
,
551 struct blkg_stat
*from
)
553 atomic64_add(blkg_stat_read(from
) + atomic64_read(&from
->aux_cnt
),
557 static inline int blkg_rwstat_init(struct blkg_rwstat
*rwstat
, gfp_t gfp
)
561 for (i
= 0; i
< BLKG_RWSTAT_NR
; i
++) {
562 ret
= percpu_counter_init(&rwstat
->cpu_cnt
[i
], 0, gfp
);
565 percpu_counter_destroy(&rwstat
->cpu_cnt
[i
]);
568 atomic64_set(&rwstat
->aux_cnt
[i
], 0);
573 static inline void blkg_rwstat_exit(struct blkg_rwstat
*rwstat
)
577 for (i
= 0; i
< BLKG_RWSTAT_NR
; i
++)
578 percpu_counter_destroy(&rwstat
->cpu_cnt
[i
]);
582 * blkg_rwstat_add - add a value to a blkg_rwstat
583 * @rwstat: target blkg_rwstat
584 * @op: REQ_OP and flags
587 * Add @val to @rwstat. The counters are chosen according to @rw. The
588 * caller is responsible for synchronizing calls to this function.
590 static inline void blkg_rwstat_add(struct blkg_rwstat
*rwstat
,
591 unsigned int op
, uint64_t val
)
593 struct percpu_counter
*cnt
;
596 cnt
= &rwstat
->cpu_cnt
[BLKG_RWSTAT_WRITE
];
598 cnt
= &rwstat
->cpu_cnt
[BLKG_RWSTAT_READ
];
600 __percpu_counter_add(cnt
, val
, BLKG_STAT_CPU_BATCH
);
603 cnt
= &rwstat
->cpu_cnt
[BLKG_RWSTAT_SYNC
];
605 cnt
= &rwstat
->cpu_cnt
[BLKG_RWSTAT_ASYNC
];
607 __percpu_counter_add(cnt
, val
, BLKG_STAT_CPU_BATCH
);
611 * blkg_rwstat_read - read the current values of a blkg_rwstat
612 * @rwstat: blkg_rwstat to read
614 * Read the current snapshot of @rwstat and return it in the aux counts.
616 static inline struct blkg_rwstat
blkg_rwstat_read(struct blkg_rwstat
*rwstat
)
618 struct blkg_rwstat result
;
621 for (i
= 0; i
< BLKG_RWSTAT_NR
; i
++)
622 atomic64_set(&result
.aux_cnt
[i
],
623 percpu_counter_sum_positive(&rwstat
->cpu_cnt
[i
]));
628 * blkg_rwstat_total - read the total count of a blkg_rwstat
629 * @rwstat: blkg_rwstat to read
631 * Return the total count of @rwstat regardless of the IO direction. This
632 * function can be called without synchronization and takes care of u64
635 static inline uint64_t blkg_rwstat_total(struct blkg_rwstat
*rwstat
)
637 struct blkg_rwstat tmp
= blkg_rwstat_read(rwstat
);
639 return atomic64_read(&tmp
.aux_cnt
[BLKG_RWSTAT_READ
]) +
640 atomic64_read(&tmp
.aux_cnt
[BLKG_RWSTAT_WRITE
]);
644 * blkg_rwstat_reset - reset a blkg_rwstat
645 * @rwstat: blkg_rwstat to reset
647 static inline void blkg_rwstat_reset(struct blkg_rwstat
*rwstat
)
651 for (i
= 0; i
< BLKG_RWSTAT_NR
; i
++) {
652 percpu_counter_set(&rwstat
->cpu_cnt
[i
], 0);
653 atomic64_set(&rwstat
->aux_cnt
[i
], 0);
658 * blkg_rwstat_add_aux - add a blkg_rwstat into another's aux count
659 * @to: the destination blkg_rwstat
662 * Add @from's count including the aux one to @to's aux count.
664 static inline void blkg_rwstat_add_aux(struct blkg_rwstat
*to
,
665 struct blkg_rwstat
*from
)
667 struct blkg_rwstat v
= blkg_rwstat_read(from
);
670 for (i
= 0; i
< BLKG_RWSTAT_NR
; i
++)
671 atomic64_add(atomic64_read(&v
.aux_cnt
[i
]) +
672 atomic64_read(&from
->aux_cnt
[i
]),
676 #ifdef CONFIG_BLK_DEV_THROTTLING
677 extern bool blk_throtl_bio(struct request_queue
*q
, struct blkcg_gq
*blkg
,
680 static inline bool blk_throtl_bio(struct request_queue
*q
, struct blkcg_gq
*blkg
,
681 struct bio
*bio
) { return false; }
684 static inline bool blkcg_bio_issue_check(struct request_queue
*q
,
688 struct blkcg_gq
*blkg
;
692 blkcg
= bio_blkcg(bio
);
694 blkg
= blkg_lookup(blkcg
, q
);
695 if (unlikely(!blkg
)) {
696 spin_lock_irq(q
->queue_lock
);
697 blkg
= blkg_lookup_create(blkcg
, q
);
700 spin_unlock_irq(q
->queue_lock
);
703 throtl
= blk_throtl_bio(q
, blkg
, bio
);
706 blkg
= blkg
?: q
->root_blkg
;
707 blkg_rwstat_add(&blkg
->stat_bytes
, bio
->bi_opf
,
708 bio
->bi_iter
.bi_size
);
709 blkg_rwstat_add(&blkg
->stat_ios
, bio
->bi_opf
, 1);
716 #else /* CONFIG_BLK_CGROUP */
721 struct blkg_policy_data
{
724 struct blkcg_policy_data
{
730 struct blkcg_policy
{
733 #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
735 static inline struct cgroup_subsys_state
*
736 task_get_blkcg_css(struct task_struct
*task
)
743 static inline struct blkcg_gq
*blkg_lookup(struct blkcg
*blkcg
, void *key
) { return NULL
; }
744 static inline int blkcg_init_queue(struct request_queue
*q
) { return 0; }
745 static inline void blkcg_drain_queue(struct request_queue
*q
) { }
746 static inline void blkcg_exit_queue(struct request_queue
*q
) { }
747 static inline int blkcg_policy_register(struct blkcg_policy
*pol
) { return 0; }
748 static inline void blkcg_policy_unregister(struct blkcg_policy
*pol
) { }
749 static inline int blkcg_activate_policy(struct request_queue
*q
,
750 const struct blkcg_policy
*pol
) { return 0; }
751 static inline void blkcg_deactivate_policy(struct request_queue
*q
,
752 const struct blkcg_policy
*pol
) { }
754 static inline struct blkcg
*bio_blkcg(struct bio
*bio
) { return NULL
; }
756 static inline struct blkg_policy_data
*blkg_to_pd(struct blkcg_gq
*blkg
,
757 struct blkcg_policy
*pol
) { return NULL
; }
758 static inline struct blkcg_gq
*pd_to_blkg(struct blkg_policy_data
*pd
) { return NULL
; }
759 static inline char *blkg_path(struct blkcg_gq
*blkg
) { return NULL
; }
760 static inline void blkg_get(struct blkcg_gq
*blkg
) { }
761 static inline void blkg_put(struct blkcg_gq
*blkg
) { }
763 static inline struct request_list
*blk_get_rl(struct request_queue
*q
,
764 struct bio
*bio
) { return &q
->root_rl
; }
765 static inline void blk_put_rl(struct request_list
*rl
) { }
766 static inline void blk_rq_set_rl(struct request
*rq
, struct request_list
*rl
) { }
767 static inline struct request_list
*blk_rq_rl(struct request
*rq
) { return &rq
->q
->root_rl
; }
769 static inline bool blkcg_bio_issue_check(struct request_queue
*q
,
770 struct bio
*bio
) { return true; }
772 #define blk_queue_for_each_rl(rl, q) \
773 for ((rl) = &(q)->root_rl; (rl); (rl) = NULL)
775 #endif /* CONFIG_BLOCK */
776 #endif /* CONFIG_BLK_CGROUP */
777 #endif /* _BLK_CGROUP_H */