blob: c02e669945e9279bceb796eb9a1adb938ebf863b [file] [log] [blame]
Vivek Goyal31e4c282009-12-03 12:59:42 -05001#ifndef _BLK_CGROUP_H
2#define _BLK_CGROUP_H
3/*
4 * Common Block IO controller cgroup interface
5 *
6 * Based on ideas and code from CFQ, CFS and BFQ:
7 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
8 *
9 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
10 * Paolo Valente <paolo.valente@unimore.it>
11 *
12 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
13 * Nauman Rafique <nauman@google.com>
14 */
15
16#include <linux/cgroup.h>
Tejun Heo24bdb8e2015-08-18 14:55:22 -070017#include <linux/percpu_counter.h>
Tejun Heo829fdb52012-04-01 14:38:43 -070018#include <linux/seq_file.h>
Tejun Heoa6371202012-04-19 16:29:24 -070019#include <linux/radix-tree.h>
Tejun Heoa0516612012-06-26 15:05:44 -070020#include <linux/blkdev.h>
Tejun Heoa5049a82014-06-19 17:42:57 -040021#include <linux/atomic.h>
Vivek Goyal31e4c282009-12-03 12:59:42 -050022
Tejun Heo24bdb8e2015-08-18 14:55:22 -070023/* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */
24#define BLKG_STAT_CPU_BATCH (INT_MAX / 2)
25
Vivek Goyal9355aed2010-10-01 21:16:41 +020026/* Max limits for throttle policy */
27#define THROTL_IOPS_MAX UINT_MAX
28
Tejun Heof48ec1d2012-04-13 13:11:25 -070029#ifdef CONFIG_BLK_CGROUP
30
Tejun Heoedcb0722012-04-01 14:38:42 -070031enum blkg_rwstat_type {
32 BLKG_RWSTAT_READ,
33 BLKG_RWSTAT_WRITE,
34 BLKG_RWSTAT_SYNC,
35 BLKG_RWSTAT_ASYNC,
36
37 BLKG_RWSTAT_NR,
38 BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
Divyesh Shah303a3ac2010-04-01 15:01:24 -070039};
40
Tejun Heoa6371202012-04-19 16:29:24 -070041struct blkcg_gq;
42
Tejun Heo3c798392012-04-16 13:57:25 -070043struct blkcg {
Tejun Heo36558c82012-04-16 13:57:24 -070044 struct cgroup_subsys_state css;
45 spinlock_t lock;
Tejun Heoa6371202012-04-19 16:29:24 -070046
47 struct radix_tree_root blkg_tree;
48 struct blkcg_gq *blkg_hint;
Tejun Heo36558c82012-04-16 13:57:24 -070049 struct hlist_head blkg_list;
Tejun Heo9a9e8a22012-03-19 15:10:56 -070050
Tejun Heo81437642015-08-18 14:55:15 -070051 struct blkcg_policy_data *cpd[BLKCG_MAX_POLS];
Tejun Heo52ebea72015-05-22 17:13:37 -040052
Tejun Heo7876f932015-07-09 16:39:49 -040053 struct list_head all_blkcgs_node;
Tejun Heo52ebea72015-05-22 17:13:37 -040054#ifdef CONFIG_CGROUP_WRITEBACK
55 struct list_head cgwb_list;
56#endif
Vivek Goyal31e4c282009-12-03 12:59:42 -050057};
58
Tejun Heoe6269c42015-08-18 14:55:21 -070059/*
60 * blkg_[rw]stat->aux_cnt is excluded for local stats but included for
Tejun Heo24bdb8e2015-08-18 14:55:22 -070061 * recursive. Used to carry stats of dead children, and, for blkg_rwstat,
62 * to carry result values from read and sum operations.
Tejun Heoe6269c42015-08-18 14:55:21 -070063 */
Tejun Heoedcb0722012-04-01 14:38:42 -070064struct blkg_stat {
Tejun Heo24bdb8e2015-08-18 14:55:22 -070065 struct percpu_counter cpu_cnt;
Tejun Heoe6269c42015-08-18 14:55:21 -070066 atomic64_t aux_cnt;
Tejun Heoedcb0722012-04-01 14:38:42 -070067};
68
69struct blkg_rwstat {
Tejun Heo24bdb8e2015-08-18 14:55:22 -070070 struct percpu_counter cpu_cnt[BLKG_RWSTAT_NR];
Tejun Heoe6269c42015-08-18 14:55:21 -070071 atomic64_t aux_cnt[BLKG_RWSTAT_NR];
Tejun Heoedcb0722012-04-01 14:38:42 -070072};
73
Tejun Heof95a04a2012-04-16 13:57:26 -070074/*
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.
78 *
Tejun Heo001bea72015-08-18 14:55:11 -070079 * 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
83 * at the beginning.
Tejun Heof95a04a2012-04-16 13:57:26 -070084 */
Tejun Heo03814112012-03-05 13:15:14 -080085struct blkg_policy_data {
Tejun Heob276a872013-01-09 08:05:12 -080086 /* the blkg and policy id this per-policy data belongs to */
Tejun Heo3c798392012-04-16 13:57:25 -070087 struct blkcg_gq *blkg;
Tejun Heob276a872013-01-09 08:05:12 -080088 int plid;
Tejun Heo03814112012-03-05 13:15:14 -080089};
90
Arianna Avanzinie48453c2015-06-05 23:38:42 +020091/*
Tejun Heoe4a9bde2015-08-18 14:55:16 -070092 * 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.
Arianna Avanzinie48453c2015-06-05 23:38:42 +020097 */
98struct blkcg_policy_data {
Tejun Heo81437642015-08-18 14:55:15 -070099 /* the blkcg and policy id this per-policy data belongs to */
100 struct blkcg *blkcg;
Arianna Avanzinie48453c2015-06-05 23:38:42 +0200101 int plid;
Arianna Avanzinie48453c2015-06-05 23:38:42 +0200102};
103
Tejun Heo3c798392012-04-16 13:57:25 -0700104/* association between a blk cgroup and a request queue */
105struct blkcg_gq {
Tejun Heoc875f4d2012-03-05 13:15:22 -0800106 /* Pointer to the associated request_queue */
Tejun Heo36558c82012-04-16 13:57:24 -0700107 struct request_queue *q;
108 struct list_head q_node;
109 struct hlist_node blkcg_node;
Tejun Heo3c798392012-04-16 13:57:25 -0700110 struct blkcg *blkcg;
Tejun Heo3c547862013-01-09 08:05:10 -0800111
Tejun Heoce7acfe2015-05-22 17:13:38 -0400112 /*
113 * Each blkg gets congested separately and the congestion state is
114 * propagated to the matching bdi_writeback_congested.
115 */
116 struct bdi_writeback_congested *wb_congested;
117
Tejun Heo3c547862013-01-09 08:05:10 -0800118 /* all non-root blkcg_gq's are guaranteed to have access to parent */
119 struct blkcg_gq *parent;
120
Tejun Heoa0516612012-06-26 15:05:44 -0700121 /* request allocation list for this blkcg-q pair */
122 struct request_list rl;
Tejun Heo3c547862013-01-09 08:05:10 -0800123
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800124 /* reference count */
Tejun Heoa5049a82014-06-19 17:42:57 -0400125 atomic_t refcnt;
Vivek Goyal22084192009-12-03 12:59:49 -0500126
Tejun Heof427d902013-01-09 08:05:12 -0800127 /* is this blkg online? protected by both blkcg and q locks */
128 bool online;
129
Tejun Heo77ea7332015-08-18 14:55:24 -0700130 struct blkg_rwstat stat_bytes;
131 struct blkg_rwstat stat_ios;
132
Tejun Heo36558c82012-04-16 13:57:24 -0700133 struct blkg_policy_data *pd[BLKCG_MAX_POLS];
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800134
Tejun Heo36558c82012-04-16 13:57:24 -0700135 struct rcu_head rcu_head;
Vivek Goyal31e4c282009-12-03 12:59:42 -0500136};
137
Tejun Heoe4a9bde2015-08-18 14:55:16 -0700138typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp);
Tejun Heo81437642015-08-18 14:55:15 -0700139typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
Tejun Heoe4a9bde2015-08-18 14:55:16 -0700140typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd);
Tejun Heo69d7fde2015-08-18 14:55:36 -0700141typedef void (blkcg_pol_bind_cpd_fn)(struct blkcg_policy_data *cpd);
Tejun Heo001bea72015-08-18 14:55:11 -0700142typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
Tejun Heoa9520cd2015-08-18 14:55:14 -0700143typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
144typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
145typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
Tejun Heo001bea72015-08-18 14:55:11 -0700146typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
Tejun Heoa9520cd2015-08-18 14:55:14 -0700147typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
Vivek Goyal3e252062009-12-04 10:36:42 -0500148
Tejun Heo3c798392012-04-16 13:57:25 -0700149struct blkcg_policy {
Tejun Heo36558c82012-04-16 13:57:24 -0700150 int plid;
Tejun Heo36558c82012-04-16 13:57:24 -0700151 /* cgroup files for the policy */
Tejun Heo2ee867dc2015-08-18 14:55:34 -0700152 struct cftype *dfl_cftypes;
Tejun Heo880f50e2015-08-18 14:55:30 -0700153 struct cftype *legacy_cftypes;
Tejun Heof9fcc2d2012-04-16 13:57:27 -0700154
155 /* operations */
Tejun Heoe4a9bde2015-08-18 14:55:16 -0700156 blkcg_pol_alloc_cpd_fn *cpd_alloc_fn;
Arianna Avanzinie48453c2015-06-05 23:38:42 +0200157 blkcg_pol_init_cpd_fn *cpd_init_fn;
Tejun Heoe4a9bde2015-08-18 14:55:16 -0700158 blkcg_pol_free_cpd_fn *cpd_free_fn;
Tejun Heo69d7fde2015-08-18 14:55:36 -0700159 blkcg_pol_bind_cpd_fn *cpd_bind_fn;
Tejun Heoe4a9bde2015-08-18 14:55:16 -0700160
Tejun Heo001bea72015-08-18 14:55:11 -0700161 blkcg_pol_alloc_pd_fn *pd_alloc_fn;
Tejun Heof9fcc2d2012-04-16 13:57:27 -0700162 blkcg_pol_init_pd_fn *pd_init_fn;
Tejun Heof427d902013-01-09 08:05:12 -0800163 blkcg_pol_online_pd_fn *pd_online_fn;
164 blkcg_pol_offline_pd_fn *pd_offline_fn;
Tejun Heo001bea72015-08-18 14:55:11 -0700165 blkcg_pol_free_pd_fn *pd_free_fn;
Tejun Heof9fcc2d2012-04-16 13:57:27 -0700166 blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
Vivek Goyal3e252062009-12-04 10:36:42 -0500167};
168
Tejun Heo3c798392012-04-16 13:57:25 -0700169extern struct blkcg blkcg_root;
Tejun Heo496d5e72015-05-22 17:13:21 -0400170extern struct cgroup_subsys_state * const blkcg_root_css;
Tejun Heo36558c82012-04-16 13:57:24 -0700171
Tejun Heo24f29042015-08-18 14:55:17 -0700172struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
173 struct request_queue *q, bool update_hint);
Tejun Heo3c798392012-04-16 13:57:25 -0700174struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
175 struct request_queue *q);
Tejun Heo36558c82012-04-16 13:57:24 -0700176int blkcg_init_queue(struct request_queue *q);
177void blkcg_drain_queue(struct request_queue *q);
178void blkcg_exit_queue(struct request_queue *q);
Tejun Heo5efd6112012-03-05 13:15:12 -0800179
Vivek Goyal3e252062009-12-04 10:36:42 -0500180/* Blkio controller policy registration */
Jens Axboed5bf0292014-06-22 16:31:56 -0600181int blkcg_policy_register(struct blkcg_policy *pol);
Tejun Heo3c798392012-04-16 13:57:25 -0700182void blkcg_policy_unregister(struct blkcg_policy *pol);
Tejun Heo36558c82012-04-16 13:57:24 -0700183int blkcg_activate_policy(struct request_queue *q,
Tejun Heo3c798392012-04-16 13:57:25 -0700184 const struct blkcg_policy *pol);
Tejun Heo36558c82012-04-16 13:57:24 -0700185void blkcg_deactivate_policy(struct request_queue *q,
Tejun Heo3c798392012-04-16 13:57:25 -0700186 const struct blkcg_policy *pol);
Vivek Goyal3e252062009-12-04 10:36:42 -0500187
Tejun Heodd165eb2015-08-18 14:55:33 -0700188const char *blkg_dev_name(struct blkcg_gq *blkg);
Tejun Heo3c798392012-04-16 13:57:25 -0700189void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
Tejun Heof95a04a2012-04-16 13:57:26 -0700190 u64 (*prfill)(struct seq_file *,
191 struct blkg_policy_data *, int),
Tejun Heo3c798392012-04-16 13:57:25 -0700192 const struct blkcg_policy *pol, int data,
Tejun Heoec399342012-04-13 13:11:27 -0700193 bool show_total);
Tejun Heof95a04a2012-04-16 13:57:26 -0700194u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v);
195u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
Tejun Heo829fdb52012-04-01 14:38:43 -0700196 const struct blkg_rwstat *rwstat);
Tejun Heof95a04a2012-04-16 13:57:26 -0700197u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off);
198u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
199 int off);
Tejun Heo77ea7332015-08-18 14:55:24 -0700200int blkg_print_stat_bytes(struct seq_file *sf, void *v);
201int blkg_print_stat_ios(struct seq_file *sf, void *v);
202int blkg_print_stat_bytes_recursive(struct seq_file *sf, void *v);
203int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v);
Tejun Heo829fdb52012-04-01 14:38:43 -0700204
Tejun Heof12c74c2015-08-18 14:55:23 -0700205u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
206 struct blkcg_policy *pol, int off);
207struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
208 struct blkcg_policy *pol, int off);
Tejun Heo16b3de62013-01-09 08:05:12 -0800209
Tejun Heo829fdb52012-04-01 14:38:43 -0700210struct blkg_conf_ctx {
Tejun Heo36558c82012-04-16 13:57:24 -0700211 struct gendisk *disk;
Tejun Heo3c798392012-04-16 13:57:25 -0700212 struct blkcg_gq *blkg;
Tejun Heo36aa9e52015-08-18 14:55:31 -0700213 char *body;
Tejun Heo829fdb52012-04-01 14:38:43 -0700214};
215
Tejun Heo3c798392012-04-16 13:57:25 -0700216int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
Tejun Heo36aa9e52015-08-18 14:55:31 -0700217 char *input, struct blkg_conf_ctx *ctx);
Tejun Heo829fdb52012-04-01 14:38:43 -0700218void blkg_conf_finish(struct blkg_conf_ctx *ctx);
219
220
Tejun Heoa7c6d552013-08-08 20:11:23 -0400221static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)
222{
223 return css ? container_of(css, struct blkcg, css) : NULL;
224}
225
Tejun Heob1208b52012-06-04 20:40:57 -0700226static inline struct blkcg *task_blkcg(struct task_struct *tsk)
227{
Tejun Heoc165b3e2015-08-18 14:55:29 -0700228 return css_to_blkcg(task_css(tsk, io_cgrp_id));
Tejun Heob1208b52012-06-04 20:40:57 -0700229}
230
231static inline struct blkcg *bio_blkcg(struct bio *bio)
232{
233 if (bio && bio->bi_css)
Tejun Heoa7c6d552013-08-08 20:11:23 -0400234 return css_to_blkcg(bio->bi_css);
Tejun Heob1208b52012-06-04 20:40:57 -0700235 return task_blkcg(current);
236}
237
Tejun Heofd383c22015-05-22 17:13:23 -0400238static inline struct cgroup_subsys_state *
239task_get_blkcg_css(struct task_struct *task)
240{
Tejun Heoc165b3e2015-08-18 14:55:29 -0700241 return task_get_css(task, io_cgrp_id);
Tejun Heofd383c22015-05-22 17:13:23 -0400242}
243
Tejun Heo03814112012-03-05 13:15:14 -0800244/**
Tejun Heo3c547862013-01-09 08:05:10 -0800245 * blkcg_parent - get the parent of a blkcg
246 * @blkcg: blkcg of interest
247 *
248 * Return the parent blkcg of @blkcg. Can be called anytime.
249 */
250static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
251{
Tejun Heo5c9d5352014-05-16 13:22:48 -0400252 return css_to_blkcg(blkcg->css.parent);
Tejun Heo3c547862013-01-09 08:05:10 -0800253}
254
255/**
Tejun Heo24f29042015-08-18 14:55:17 -0700256 * __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
260 *
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.
265 */
266static inline struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
267 struct request_queue *q,
268 bool update_hint)
269{
270 struct blkcg_gq *blkg;
271
Tejun Heo85b6bc92015-08-18 14:55:18 -0700272 if (blkcg == &blkcg_root)
273 return q->root_blkg;
274
Tejun Heo24f29042015-08-18 14:55:17 -0700275 blkg = rcu_dereference(blkcg->blkg_hint);
276 if (blkg && blkg->q == q)
277 return blkg;
278
279 return blkg_lookup_slowpath(blkcg, q, update_hint);
280}
281
282/**
283 * blkg_lookup - lookup blkg for the specified blkcg - q pair
284 * @blkcg: blkcg of interest
285 * @q: request_queue of interest
286 *
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.
290 */
291static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
292 struct request_queue *q)
293{
294 WARN_ON_ONCE(!rcu_read_lock_held());
295
296 if (unlikely(blk_queue_bypass(q)))
297 return NULL;
298 return __blkg_lookup(blkcg, q, false);
299}
300
301/**
Tejun Heo03814112012-03-05 13:15:14 -0800302 * blkg_to_pdata - get policy private data
303 * @blkg: blkg of interest
304 * @pol: policy of interest
305 *
306 * Return pointer to private data associated with the @blkg-@pol pair.
307 */
Tejun Heof95a04a2012-04-16 13:57:26 -0700308static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
309 struct blkcg_policy *pol)
Tejun Heo03814112012-03-05 13:15:14 -0800310{
Tejun Heof95a04a2012-04-16 13:57:26 -0700311 return blkg ? blkg->pd[pol->plid] : NULL;
Tejun Heo03814112012-03-05 13:15:14 -0800312}
313
Arianna Avanzinie48453c2015-06-05 23:38:42 +0200314static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
315 struct blkcg_policy *pol)
316{
Tejun Heo81437642015-08-18 14:55:15 -0700317 return blkcg ? blkcg->cpd[pol->plid] : NULL;
Arianna Avanzinie48453c2015-06-05 23:38:42 +0200318}
319
Tejun Heo03814112012-03-05 13:15:14 -0800320/**
321 * pdata_to_blkg - get blkg associated with policy private data
Tejun Heof95a04a2012-04-16 13:57:26 -0700322 * @pd: policy private data of interest
Tejun Heo03814112012-03-05 13:15:14 -0800323 *
Tejun Heof95a04a2012-04-16 13:57:26 -0700324 * @pd is policy private data. Determine the blkg it's associated with.
Tejun Heo03814112012-03-05 13:15:14 -0800325 */
Tejun Heof95a04a2012-04-16 13:57:26 -0700326static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
Tejun Heo03814112012-03-05 13:15:14 -0800327{
Tejun Heof95a04a2012-04-16 13:57:26 -0700328 return pd ? pd->blkg : NULL;
Tejun Heo03814112012-03-05 13:15:14 -0800329}
330
Tejun Heo81437642015-08-18 14:55:15 -0700331static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
332{
333 return cpd ? cpd->blkcg : NULL;
334}
335
Tejun Heo54e7ed12012-04-16 13:57:23 -0700336/**
337 * blkg_path - format cgroup path of blkg
338 * @blkg: blkg of interest
339 * @buf: target buffer
340 * @buflen: target buffer length
341 *
342 * Format the path of the cgroup of @blkg into @buf.
343 */
Tejun Heo3c798392012-04-16 13:57:25 -0700344static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
Vivek Goyalafc24d42010-04-26 19:27:56 +0200345{
Tejun Heoe61734c2014-02-12 09:29:50 -0500346 char *p;
Tejun Heo54e7ed12012-04-16 13:57:23 -0700347
Tejun Heoe61734c2014-02-12 09:29:50 -0500348 p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
349 if (!p) {
Tejun Heo54e7ed12012-04-16 13:57:23 -0700350 strncpy(buf, "<unavailable>", buflen);
Tejun Heoe61734c2014-02-12 09:29:50 -0500351 return -ENAMETOOLONG;
352 }
353
354 memmove(buf, p, buf + buflen - p);
355 return 0;
Vivek Goyalafc24d42010-04-26 19:27:56 +0200356}
357
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800358/**
359 * blkg_get - get a blkg reference
360 * @blkg: blkg to get
361 *
Tejun Heoa5049a82014-06-19 17:42:57 -0400362 * The caller should be holding an existing reference.
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800363 */
Tejun Heo3c798392012-04-16 13:57:25 -0700364static inline void blkg_get(struct blkcg_gq *blkg)
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800365{
Tejun Heoa5049a82014-06-19 17:42:57 -0400366 WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0);
367 atomic_inc(&blkg->refcnt);
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800368}
369
Tejun Heo2a4fd072013-05-14 13:52:31 -0700370void __blkg_release_rcu(struct rcu_head *rcu);
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800371
372/**
373 * blkg_put - put a blkg reference
374 * @blkg: blkg to put
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800375 */
Tejun Heo3c798392012-04-16 13:57:25 -0700376static inline void blkg_put(struct blkcg_gq *blkg)
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800377{
Tejun Heoa5049a82014-06-19 17:42:57 -0400378 WARN_ON_ONCE(atomic_read(&blkg->refcnt) <= 0);
379 if (atomic_dec_and_test(&blkg->refcnt))
Tejun Heo2a4fd072013-05-14 13:52:31 -0700380 call_rcu(&blkg->rcu_head, __blkg_release_rcu);
Tejun Heo1adaf3d2012-03-05 13:15:15 -0800381}
382
Tejun Heodd4a4ff2013-05-14 13:52:30 -0700383/**
384 * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
385 * @d_blkg: loop cursor pointing to the current descendant
Tejun Heo492eb212013-08-08 20:11:25 -0400386 * @pos_css: used for iteration
Tejun Heodd4a4ff2013-05-14 13:52:30 -0700387 * @p_blkg: target blkg to walk descendants of
388 *
389 * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
390 * read locked. If called under either blkcg or queue lock, the iteration
391 * is guaranteed to include all and only online blkgs. The caller may
Tejun Heo492eb212013-08-08 20:11:25 -0400392 * update @pos_css by calling css_rightmost_descendant() to skip subtree.
Tejun Heobd8815a2013-08-08 20:11:27 -0400393 * @p_blkg is included in the iteration and the first node to be visited.
Tejun Heodd4a4ff2013-05-14 13:52:30 -0700394 */
Tejun Heo492eb212013-08-08 20:11:25 -0400395#define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \
396 css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \
397 if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
Tejun Heodd4a4ff2013-05-14 13:52:30 -0700398 (p_blkg)->q, false)))
399
Tejun Heoedcb0722012-04-01 14:38:42 -0700400/**
Tejun Heoaa539cb2013-05-14 13:52:31 -0700401 * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
402 * @d_blkg: loop cursor pointing to the current descendant
Tejun Heo492eb212013-08-08 20:11:25 -0400403 * @pos_css: used for iteration
Tejun Heoaa539cb2013-05-14 13:52:31 -0700404 * @p_blkg: target blkg to walk descendants of
405 *
406 * Similar to blkg_for_each_descendant_pre() but performs post-order
Tejun Heobd8815a2013-08-08 20:11:27 -0400407 * traversal instead. Synchronization rules are the same. @p_blkg is
408 * included in the iteration and the last node to be visited.
Tejun Heoaa539cb2013-05-14 13:52:31 -0700409 */
Tejun Heo492eb212013-08-08 20:11:25 -0400410#define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \
411 css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \
412 if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
Tejun Heoaa539cb2013-05-14 13:52:31 -0700413 (p_blkg)->q, false)))
414
415/**
Tejun Heoa0516612012-06-26 15:05:44 -0700416 * blk_get_rl - get request_list to use
417 * @q: request_queue of interest
418 * @bio: bio which will be attached to the allocated request (may be %NULL)
419 *
420 * The caller wants to allocate a request from @q to use for @bio. Find
421 * the request_list to use and obtain a reference on it. Should be called
422 * under queue_lock. This function is guaranteed to return non-%NULL
423 * request_list.
424 */
425static inline struct request_list *blk_get_rl(struct request_queue *q,
426 struct bio *bio)
427{
428 struct blkcg *blkcg;
429 struct blkcg_gq *blkg;
430
431 rcu_read_lock();
432
433 blkcg = bio_blkcg(bio);
434
435 /* bypass blkg lookup and use @q->root_rl directly for root */
436 if (blkcg == &blkcg_root)
437 goto root_rl;
438
439 /*
440 * Try to use blkg->rl. blkg lookup may fail under memory pressure
441 * or if either the blkcg or queue is going away. Fall back to
442 * root_rl in such cases.
443 */
Tejun Heoae118892015-08-18 14:55:20 -0700444 blkg = blkg_lookup(blkcg, q);
445 if (unlikely(!blkg))
Tejun Heoa0516612012-06-26 15:05:44 -0700446 goto root_rl;
447
448 blkg_get(blkg);
449 rcu_read_unlock();
450 return &blkg->rl;
451root_rl:
452 rcu_read_unlock();
453 return &q->root_rl;
454}
455
456/**
457 * blk_put_rl - put request_list
458 * @rl: request_list to put
459 *
460 * Put the reference acquired by blk_get_rl(). Should be called under
461 * queue_lock.
462 */
463static inline void blk_put_rl(struct request_list *rl)
464{
Tejun Heo401efbf2015-08-18 14:55:06 -0700465 if (rl->blkg->blkcg != &blkcg_root)
Tejun Heoa0516612012-06-26 15:05:44 -0700466 blkg_put(rl->blkg);
467}
468
469/**
470 * blk_rq_set_rl - associate a request with a request_list
471 * @rq: request of interest
472 * @rl: target request_list
473 *
474 * Associate @rq with @rl so that accounting and freeing can know the
475 * request_list @rq came from.
476 */
477static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl)
478{
479 rq->rl = rl;
480}
481
482/**
483 * blk_rq_rl - return the request_list a request came from
484 * @rq: request of interest
485 *
486 * Return the request_list @rq is allocated from.
487 */
488static inline struct request_list *blk_rq_rl(struct request *rq)
489{
490 return rq->rl;
491}
492
493struct request_list *__blk_queue_next_rl(struct request_list *rl,
494 struct request_queue *q);
495/**
496 * blk_queue_for_each_rl - iterate through all request_lists of a request_queue
497 *
498 * Should be used under queue_lock.
499 */
500#define blk_queue_for_each_rl(rl, q) \
501 for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q)))
502
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700503static inline int blkg_stat_init(struct blkg_stat *stat, gfp_t gfp)
Peter Zijlstra90d38392013-11-12 19:42:14 -0800504{
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700505 int ret;
506
507 ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp);
508 if (ret)
509 return ret;
510
Tejun Heoe6269c42015-08-18 14:55:21 -0700511 atomic64_set(&stat->aux_cnt, 0);
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700512 return 0;
513}
514
515static inline void blkg_stat_exit(struct blkg_stat *stat)
516{
517 percpu_counter_destroy(&stat->cpu_cnt);
Peter Zijlstra90d38392013-11-12 19:42:14 -0800518}
519
Tejun Heoa0516612012-06-26 15:05:44 -0700520/**
Tejun Heoedcb0722012-04-01 14:38:42 -0700521 * blkg_stat_add - add a value to a blkg_stat
522 * @stat: target blkg_stat
523 * @val: value to add
524 *
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700525 * Add @val to @stat. The caller must ensure that IRQ on the same CPU
526 * don't re-enter this function for the same counter.
Tejun Heoedcb0722012-04-01 14:38:42 -0700527 */
528static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val)
529{
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700530 __percpu_counter_add(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH);
Tejun Heoedcb0722012-04-01 14:38:42 -0700531}
532
533/**
534 * blkg_stat_read - read the current value of a blkg_stat
535 * @stat: blkg_stat to read
Tejun Heoedcb0722012-04-01 14:38:42 -0700536 */
537static inline uint64_t blkg_stat_read(struct blkg_stat *stat)
538{
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700539 return percpu_counter_sum_positive(&stat->cpu_cnt);
Tejun Heoedcb0722012-04-01 14:38:42 -0700540}
541
542/**
543 * blkg_stat_reset - reset a blkg_stat
544 * @stat: blkg_stat to reset
545 */
546static inline void blkg_stat_reset(struct blkg_stat *stat)
547{
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700548 percpu_counter_set(&stat->cpu_cnt, 0);
Tejun Heoe6269c42015-08-18 14:55:21 -0700549 atomic64_set(&stat->aux_cnt, 0);
Tejun Heoedcb0722012-04-01 14:38:42 -0700550}
551
552/**
Tejun Heoe6269c42015-08-18 14:55:21 -0700553 * blkg_stat_add_aux - add a blkg_stat into another's aux count
Tejun Heo16b3de62013-01-09 08:05:12 -0800554 * @to: the destination blkg_stat
555 * @from: the source
556 *
Tejun Heoe6269c42015-08-18 14:55:21 -0700557 * Add @from's count including the aux one to @to's aux count.
Tejun Heo16b3de62013-01-09 08:05:12 -0800558 */
Tejun Heoe6269c42015-08-18 14:55:21 -0700559static inline void blkg_stat_add_aux(struct blkg_stat *to,
560 struct blkg_stat *from)
Tejun Heo16b3de62013-01-09 08:05:12 -0800561{
Tejun Heoe6269c42015-08-18 14:55:21 -0700562 atomic64_add(blkg_stat_read(from) + atomic64_read(&from->aux_cnt),
563 &to->aux_cnt);
Tejun Heo16b3de62013-01-09 08:05:12 -0800564}
565
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700566static inline int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp)
567{
568 int i, ret;
569
570 for (i = 0; i < BLKG_RWSTAT_NR; i++) {
571 ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp);
572 if (ret) {
573 while (--i >= 0)
574 percpu_counter_destroy(&rwstat->cpu_cnt[i]);
575 return ret;
576 }
577 atomic64_set(&rwstat->aux_cnt[i], 0);
578 }
579 return 0;
580}
581
582static inline void blkg_rwstat_exit(struct blkg_rwstat *rwstat)
Peter Zijlstra90d38392013-11-12 19:42:14 -0800583{
Tejun Heoe6269c42015-08-18 14:55:21 -0700584 int i;
585
Tejun Heoe6269c42015-08-18 14:55:21 -0700586 for (i = 0; i < BLKG_RWSTAT_NR; i++)
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700587 percpu_counter_destroy(&rwstat->cpu_cnt[i]);
Peter Zijlstra90d38392013-11-12 19:42:14 -0800588}
589
Tejun Heo16b3de62013-01-09 08:05:12 -0800590/**
Tejun Heoedcb0722012-04-01 14:38:42 -0700591 * blkg_rwstat_add - add a value to a blkg_rwstat
592 * @rwstat: target blkg_rwstat
593 * @rw: mask of REQ_{WRITE|SYNC}
594 * @val: value to add
595 *
596 * Add @val to @rwstat. The counters are chosen according to @rw. The
597 * caller is responsible for synchronizing calls to this function.
598 */
599static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
600 int rw, uint64_t val)
601{
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700602 struct percpu_counter *cnt;
Tejun Heoedcb0722012-04-01 14:38:42 -0700603
604 if (rw & REQ_WRITE)
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700605 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_WRITE];
Tejun Heoedcb0722012-04-01 14:38:42 -0700606 else
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700607 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ];
Tejun Heoedcb0722012-04-01 14:38:42 -0700608
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700609 __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH);
610
611 if (rw & REQ_SYNC)
612 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_SYNC];
613 else
614 cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_ASYNC];
615
616 __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH);
Tejun Heoedcb0722012-04-01 14:38:42 -0700617}
618
619/**
620 * blkg_rwstat_read - read the current values of a blkg_rwstat
621 * @rwstat: blkg_rwstat to read
622 *
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700623 * Read the current snapshot of @rwstat and return it in the aux counts.
Tejun Heoedcb0722012-04-01 14:38:42 -0700624 */
Tejun Heoc94bed892012-04-16 13:57:22 -0700625static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
Tejun Heoedcb0722012-04-01 14:38:42 -0700626{
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700627 struct blkg_rwstat result;
628 int i;
Tejun Heoedcb0722012-04-01 14:38:42 -0700629
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700630 for (i = 0; i < BLKG_RWSTAT_NR; i++)
631 atomic64_set(&result.aux_cnt[i],
632 percpu_counter_sum_positive(&rwstat->cpu_cnt[i]));
633 return result;
Tejun Heoedcb0722012-04-01 14:38:42 -0700634}
635
636/**
Tejun Heo4d5e80a2013-01-09 08:05:12 -0800637 * blkg_rwstat_total - read the total count of a blkg_rwstat
Tejun Heoedcb0722012-04-01 14:38:42 -0700638 * @rwstat: blkg_rwstat to read
639 *
640 * Return the total count of @rwstat regardless of the IO direction. This
641 * function can be called without synchronization and takes care of u64
642 * atomicity.
643 */
Tejun Heo4d5e80a2013-01-09 08:05:12 -0800644static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat)
Tejun Heoedcb0722012-04-01 14:38:42 -0700645{
646 struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
647
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700648 return atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
649 atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);
Tejun Heoedcb0722012-04-01 14:38:42 -0700650}
651
652/**
653 * blkg_rwstat_reset - reset a blkg_rwstat
654 * @rwstat: blkg_rwstat to reset
655 */
656static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
657{
Tejun Heoe6269c42015-08-18 14:55:21 -0700658 int i;
659
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700660 for (i = 0; i < BLKG_RWSTAT_NR; i++) {
661 percpu_counter_set(&rwstat->cpu_cnt[i], 0);
Tejun Heoe6269c42015-08-18 14:55:21 -0700662 atomic64_set(&rwstat->aux_cnt[i], 0);
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700663 }
Tejun Heoedcb0722012-04-01 14:38:42 -0700664}
665
Tejun Heo16b3de62013-01-09 08:05:12 -0800666/**
Tejun Heoe6269c42015-08-18 14:55:21 -0700667 * blkg_rwstat_add_aux - add a blkg_rwstat into another's aux count
Tejun Heo16b3de62013-01-09 08:05:12 -0800668 * @to: the destination blkg_rwstat
669 * @from: the source
670 *
Tejun Heoe6269c42015-08-18 14:55:21 -0700671 * Add @from's count including the aux one to @to's aux count.
Tejun Heo16b3de62013-01-09 08:05:12 -0800672 */
Tejun Heoe6269c42015-08-18 14:55:21 -0700673static inline void blkg_rwstat_add_aux(struct blkg_rwstat *to,
674 struct blkg_rwstat *from)
Tejun Heo16b3de62013-01-09 08:05:12 -0800675{
676 struct blkg_rwstat v = blkg_rwstat_read(from);
677 int i;
678
Tejun Heo16b3de62013-01-09 08:05:12 -0800679 for (i = 0; i < BLKG_RWSTAT_NR; i++)
Tejun Heo24bdb8e2015-08-18 14:55:22 -0700680 atomic64_add(atomic64_read(&v.aux_cnt[i]) +
681 atomic64_read(&from->aux_cnt[i]),
Tejun Heoe6269c42015-08-18 14:55:21 -0700682 &to->aux_cnt[i]);
Tejun Heo16b3de62013-01-09 08:05:12 -0800683}
684
Tejun Heoae118892015-08-18 14:55:20 -0700685#ifdef CONFIG_BLK_DEV_THROTTLING
686extern bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
687 struct bio *bio);
688#else
689static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
690 struct bio *bio) { return false; }
691#endif
692
693static inline bool blkcg_bio_issue_check(struct request_queue *q,
694 struct bio *bio)
695{
696 struct blkcg *blkcg;
697 struct blkcg_gq *blkg;
698 bool throtl = false;
699
700 rcu_read_lock();
701 blkcg = bio_blkcg(bio);
702
703 blkg = blkg_lookup(blkcg, q);
704 if (unlikely(!blkg)) {
705 spin_lock_irq(q->queue_lock);
706 blkg = blkg_lookup_create(blkcg, q);
707 if (IS_ERR(blkg))
708 blkg = NULL;
709 spin_unlock_irq(q->queue_lock);
710 }
711
712 throtl = blk_throtl_bio(q, blkg, bio);
713
Tejun Heo77ea7332015-08-18 14:55:24 -0700714 if (!throtl) {
715 blkg = blkg ?: q->root_blkg;
Tejun Heo174fd8d2015-10-22 09:27:12 +0900716 blkg_rwstat_add(&blkg->stat_bytes, bio->bi_rw,
Tejun Heo77ea7332015-08-18 14:55:24 -0700717 bio->bi_iter.bi_size);
Tejun Heo174fd8d2015-10-22 09:27:12 +0900718 blkg_rwstat_add(&blkg->stat_ios, bio->bi_rw, 1);
Tejun Heo77ea7332015-08-18 14:55:24 -0700719 }
720
Tejun Heoae118892015-08-18 14:55:20 -0700721 rcu_read_unlock();
722 return !throtl;
723}
724
Tejun Heo36558c82012-04-16 13:57:24 -0700725#else /* CONFIG_BLK_CGROUP */
726
Tejun Heoefa7d1c2015-05-22 17:13:18 -0400727struct blkcg {
728};
Jens Axboe2f5ea472009-12-03 21:06:43 +0100729
Tejun Heof95a04a2012-04-16 13:57:26 -0700730struct blkg_policy_data {
731};
732
Arianna Avanzinie48453c2015-06-05 23:38:42 +0200733struct blkcg_policy_data {
734};
735
Tejun Heo3c798392012-04-16 13:57:25 -0700736struct blkcg_gq {
Jens Axboe2f5ea472009-12-03 21:06:43 +0100737};
738
Tejun Heo3c798392012-04-16 13:57:25 -0700739struct blkcg_policy {
Vivek Goyal3e252062009-12-04 10:36:42 -0500740};
741
Tejun Heo496d5e72015-05-22 17:13:21 -0400742#define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
743
Tejun Heofd383c22015-05-22 17:13:23 -0400744static inline struct cgroup_subsys_state *
745task_get_blkcg_css(struct task_struct *task)
746{
747 return NULL;
748}
749
Tejun Heoefa7d1c2015-05-22 17:13:18 -0400750#ifdef CONFIG_BLOCK
751
Tejun Heo3c798392012-04-16 13:57:25 -0700752static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
Tejun Heo5efd6112012-03-05 13:15:12 -0800753static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
754static inline void blkcg_drain_queue(struct request_queue *q) { }
755static inline void blkcg_exit_queue(struct request_queue *q) { }
Jens Axboed5bf0292014-06-22 16:31:56 -0600756static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
Tejun Heo3c798392012-04-16 13:57:25 -0700757static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
Tejun Heoa2b16932012-04-13 13:11:33 -0700758static inline int blkcg_activate_policy(struct request_queue *q,
Tejun Heo3c798392012-04-16 13:57:25 -0700759 const struct blkcg_policy *pol) { return 0; }
Tejun Heoa2b16932012-04-13 13:11:33 -0700760static inline void blkcg_deactivate_policy(struct request_queue *q,
Tejun Heo3c798392012-04-16 13:57:25 -0700761 const struct blkcg_policy *pol) { }
Vivek Goyal3e252062009-12-04 10:36:42 -0500762
Tejun Heob1208b52012-06-04 20:40:57 -0700763static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
Tejun Heoa0516612012-06-26 15:05:44 -0700764
Tejun Heof95a04a2012-04-16 13:57:26 -0700765static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
766 struct blkcg_policy *pol) { return NULL; }
767static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
Tejun Heo3c798392012-04-16 13:57:25 -0700768static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
769static inline void blkg_get(struct blkcg_gq *blkg) { }
770static inline void blkg_put(struct blkcg_gq *blkg) { }
Vivek Goyalafc24d42010-04-26 19:27:56 +0200771
Tejun Heoa0516612012-06-26 15:05:44 -0700772static inline struct request_list *blk_get_rl(struct request_queue *q,
773 struct bio *bio) { return &q->root_rl; }
774static inline void blk_put_rl(struct request_list *rl) { }
775static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { }
776static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; }
777
Tejun Heoae118892015-08-18 14:55:20 -0700778static inline bool blkcg_bio_issue_check(struct request_queue *q,
779 struct bio *bio) { return true; }
780
Tejun Heoa0516612012-06-26 15:05:44 -0700781#define blk_queue_for_each_rl(rl, q) \
782 for ((rl) = &(q)->root_rl; (rl); (rl) = NULL)
783
Tejun Heoefa7d1c2015-05-22 17:13:18 -0400784#endif /* CONFIG_BLOCK */
Tejun Heo36558c82012-04-16 13:57:24 -0700785#endif /* CONFIG_BLK_CGROUP */
786#endif /* _BLK_CGROUP_H */