[mirror_ubuntu-artful-kernel.git] / block / blk-cgroup.h

#ifndef _BLK_CGROUP_H
#define _BLK_CGROUP_H
/*
 * Common Block IO controller cgroup interface
 *
 * Based on ideas and code from CFQ, CFS and BFQ:
 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
 *
 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
 *		      Paolo Valente <paolo.valente@unimore.it>
 *
 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
 * 	              Nauman Rafique <nauman@google.com>
 */

#include <linux/cgroup.h>
#include <linux/u64_stats_sync.h>

enum blkio_policy_id {
	BLKIO_POLICY_PROP = 0,		/* Proportional Bandwidth division */
	BLKIO_POLICY_THROTL,		/* Throttling */

	BLKIO_NR_POLICIES,
};

/* Max limits for throttle policy */
#define THROTL_IOPS_MAX		UINT_MAX

#ifdef CONFIG_BLK_CGROUP

enum stat_type {
	/* Total time spent (in ns) between request dispatch to the driver and
	 * request completion for IOs doen by this cgroup. This may not be
	 * accurate when NCQ is turned on. */
	BLKIO_STAT_SERVICE_TIME = 0,
	/* Total time spent waiting in scheduler queue in ns */
	BLKIO_STAT_WAIT_TIME,
	/* Number of IOs queued up */
	BLKIO_STAT_QUEUED,
	/* All the single valued stats go below this */
	BLKIO_STAT_TIME,
#ifdef CONFIG_DEBUG_BLK_CGROUP
	/* Time not charged to this cgroup */
	BLKIO_STAT_UNACCOUNTED_TIME,
	BLKIO_STAT_AVG_QUEUE_SIZE,
	BLKIO_STAT_IDLE_TIME,
	BLKIO_STAT_EMPTY_TIME,
	BLKIO_STAT_GROUP_WAIT_TIME,
	BLKIO_STAT_DEQUEUE
#endif
};

/* Per cpu stats */
enum stat_type_cpu {
	BLKIO_STAT_CPU_SECTORS,
	/* Total bytes transferred */
	BLKIO_STAT_CPU_SERVICE_BYTES,
	/* Total IOs serviced, post merge */
	BLKIO_STAT_CPU_SERVICED,
	/* Number of IOs merged */
	BLKIO_STAT_CPU_MERGED,
	BLKIO_STAT_CPU_NR
};

enum stat_sub_type {
	BLKIO_STAT_READ = 0,
	BLKIO_STAT_WRITE,
	BLKIO_STAT_SYNC,
	BLKIO_STAT_ASYNC,
	BLKIO_STAT_TOTAL
};

/* blkg state flags */
enum blkg_state_flags {
	BLKG_waiting = 0,
	BLKG_idling,
	BLKG_empty,
};

/* cgroup files owned by proportional weight policy */
enum blkcg_file_name_prop {
	BLKIO_PROP_weight = 1,
	BLKIO_PROP_weight_device,
	BLKIO_PROP_io_service_bytes,
	BLKIO_PROP_io_serviced,
	BLKIO_PROP_time,
	BLKIO_PROP_sectors,
	BLKIO_PROP_unaccounted_time,
	BLKIO_PROP_io_service_time,
	BLKIO_PROP_io_wait_time,
	BLKIO_PROP_io_merged,
	BLKIO_PROP_io_queued,
	BLKIO_PROP_avg_queue_size,
	BLKIO_PROP_group_wait_time,
	BLKIO_PROP_idle_time,
	BLKIO_PROP_empty_time,
	BLKIO_PROP_dequeue,
};

/* cgroup files owned by throttle policy */
enum blkcg_file_name_throtl {
	BLKIO_THROTL_read_bps_device,
	BLKIO_THROTL_write_bps_device,
	BLKIO_THROTL_read_iops_device,
	BLKIO_THROTL_write_iops_device,
	BLKIO_THROTL_io_service_bytes,
	BLKIO_THROTL_io_serviced,
};

struct blkio_cgroup {
	struct cgroup_subsys_state css;
	unsigned int weight;
	spinlock_t lock;
	struct hlist_head blkg_list;
};

struct blkio_group_stats {
	/* total disk time and nr sectors dispatched by this group */
	uint64_t time;
	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
#ifdef CONFIG_DEBUG_BLK_CGROUP
	/* Time not charged to this cgroup */
	uint64_t unaccounted_time;

	/* Sum of number of IOs queued across all samples */
	uint64_t avg_queue_size_sum;
	/* Count of samples taken for average */
	uint64_t avg_queue_size_samples;
	/* How many times this group has been removed from service tree */
	unsigned long dequeue;

	/* Total time spent waiting for it to be assigned a timeslice. */
	uint64_t group_wait_time;
	uint64_t start_group_wait_time;

	/* Time spent idling for this blkio_group */
	uint64_t idle_time;
	uint64_t start_idle_time;
	/*
	 * Total time when we have requests queued and do not contain the
	 * current active queue.
	 */
	uint64_t empty_time;
	uint64_t start_empty_time;
	uint16_t flags;
#endif
};

/* Per cpu blkio group stats */
struct blkio_group_stats_cpu {
	uint64_t sectors;
	uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
	struct u64_stats_sync syncp;
};

struct blkio_group_conf {
	unsigned int weight;
	unsigned int iops[2];
	u64 bps[2];
};

/* per-blkg per-policy data */
struct blkg_policy_data {
	/* the blkg this per-policy data belongs to */
	struct blkio_group *blkg;

	/* Configuration */
	struct blkio_group_conf conf;

	struct blkio_group_stats stats;
	/* Per cpu stats pointer */
	struct blkio_group_stats_cpu __percpu *stats_cpu;

	/* pol->pdata_size bytes of private data used by policy impl */
	char pdata[] __aligned(__alignof__(unsigned long long));
};

struct blkio_group {
	/* Pointer to the associated request_queue, RCU protected */
	struct request_queue __rcu *q;
	struct list_head q_node[BLKIO_NR_POLICIES];
	struct hlist_node blkcg_node;
	struct blkio_cgroup *blkcg;
	/* Store cgroup path */
	char path[128];
	/* policy which owns this blk group */
	enum blkio_policy_id plid;
	/* reference count */
	int refcnt;

	/* Need to serialize the stats in the case of reset/update */
	spinlock_t stats_lock;
	struct blkg_policy_data *pd[BLKIO_NR_POLICIES];

	struct rcu_head rcu_head;
};

typedef void (blkio_init_group_fn)(struct blkio_group *blkg);
typedef void (blkio_update_group_weight_fn)(struct request_queue *q,
			struct blkio_group *blkg, unsigned int weight);
typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q,
			struct blkio_group *blkg, u64 read_bps);
typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q,
			struct blkio_group *blkg, u64 write_bps);
typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q,
			struct blkio_group *blkg, unsigned int read_iops);
typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q,
			struct blkio_group *blkg, unsigned int write_iops);

struct blkio_policy_ops {
	blkio_init_group_fn *blkio_init_group_fn;
	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
	blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
	blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
	blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
	blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
};

struct blkio_policy_type {
	struct list_head list;
	struct blkio_policy_ops ops;
	enum blkio_policy_id plid;
	size_t pdata_size;		/* policy specific private data size */
};

extern int blkcg_init_queue(struct request_queue *q);
extern void blkcg_drain_queue(struct request_queue *q);
extern void blkcg_exit_queue(struct request_queue *q);

/* Blkio controller policy registration */
extern void blkio_policy_register(struct blkio_policy_type *);
extern void blkio_policy_unregister(struct blkio_policy_type *);
extern void blkg_destroy_all(struct request_queue *q,
			     enum blkio_policy_id plid, bool destroy_root);

/**
 * blkg_to_pdata - get policy private data
 * @blkg: blkg of interest
 * @pol: policy of interest
 *
 * Return pointer to private data associated with the @blkg-@pol pair.
 */
static inline void *blkg_to_pdata(struct blkio_group *blkg,
			      struct blkio_policy_type *pol)
{
	return blkg ? blkg->pd[pol->plid]->pdata : NULL;
}

/**
 * pdata_to_blkg - get blkg associated with policy private data
 * @pdata: policy private data of interest
 * @pol: policy @pdata is for
 *
 * @pdata is policy private data for @pol.  Determine the blkg it's
 * associated with.
 */
static inline struct blkio_group *pdata_to_blkg(void *pdata,
						struct blkio_policy_type *pol)
{
	if (pdata) {
		struct blkg_policy_data *pd =
			container_of(pdata, struct blkg_policy_data, pdata);
		return pd->blkg;
	}
	return NULL;
}

static inline char *blkg_path(struct blkio_group *blkg)
{
	return blkg->path;
}

/**
 * blkg_get - get a blkg reference
 * @blkg: blkg to get
 *
 * The caller should be holding queue_lock and an existing reference.
 */
static inline void blkg_get(struct blkio_group *blkg)
{
	lockdep_assert_held(blkg->q->queue_lock);
	WARN_ON_ONCE(!blkg->refcnt);
	blkg->refcnt++;
}

void __blkg_release(struct blkio_group *blkg);

/**
 * blkg_put - put a blkg reference
 * @blkg: blkg to put
 *
 * The caller should be holding queue_lock.
 */
static inline void blkg_put(struct blkio_group *blkg)
{
	lockdep_assert_held(blkg->q->queue_lock);
	WARN_ON_ONCE(blkg->refcnt <= 0);
	if (!--blkg->refcnt)
		__blkg_release(blkg);
}

#else

struct blkio_group {
};

struct blkio_policy_type {
};

static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
static inline void blkcg_drain_queue(struct request_queue *q) { }
static inline void blkcg_exit_queue(struct request_queue *q) { }
static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
static inline void blkg_destroy_all(struct request_queue *q,
				    enum blkio_policy_id plid,
				    bool destory_root) { }

static inline void *blkg_to_pdata(struct blkio_group *blkg,
				struct blkio_policy_type *pol) { return NULL; }
static inline struct blkio_group *pdata_to_blkg(void *pdata,
				struct blkio_policy_type *pol) { return NULL; }
static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
static inline void blkg_get(struct blkio_group *blkg) { }
static inline void blkg_put(struct blkio_group *blkg) { }

#endif

#define BLKIO_WEIGHT_MIN	10
#define BLKIO_WEIGHT_MAX	1000
#define BLKIO_WEIGHT_DEFAULT	500

#ifdef CONFIG_DEBUG_BLK_CGROUP
void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
					 struct blkio_policy_type *pol);
void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
				  struct blkio_policy_type *pol,
				  unsigned long dequeue);
void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
					struct blkio_policy_type *pol);
void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
				    struct blkio_policy_type *pol);
void blkiocg_set_start_empty_time(struct blkio_group *blkg,
				  struct blkio_policy_type *pol);

#define BLKG_FLAG_FNS(name)						\
static inline void blkio_mark_blkg_##name(				\
		struct blkio_group_stats *stats)			\
{									\
	stats->flags |= (1 << BLKG_##name);				\
}									\
static inline void blkio_clear_blkg_##name(				\
		struct blkio_group_stats *stats)			\
{									\
	stats->flags &= ~(1 << BLKG_##name);				\
}									\
static inline int blkio_blkg_##name(struct blkio_group_stats *stats)	\
{									\
	return (stats->flags & (1 << BLKG_##name)) != 0;		\
}									\

BLKG_FLAG_FNS(waiting)
BLKG_FLAG_FNS(idling)
BLKG_FLAG_FNS(empty)
#undef BLKG_FLAG_FNS
#else
static inline void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol) { }
static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol, unsigned long dequeue) { }
static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol) { }
static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol) { }
static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg,
			struct blkio_policy_type *pol) { }
#endif

#ifdef CONFIG_BLK_CGROUP
extern struct blkio_cgroup blkio_root_cgroup;
extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
				       struct request_queue *q,
				       enum blkio_policy_id plid);
struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
				       struct request_queue *q,
				       enum blkio_policy_id plid,
				       bool for_root);
void blkiocg_update_timeslice_used(struct blkio_group *blkg,
				   struct blkio_policy_type *pol,
				   unsigned long time,
				   unsigned long unaccounted_time);
void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
				   struct blkio_policy_type *pol,
				   uint64_t bytes, bool direction, bool sync);
void blkiocg_update_completion_stats(struct blkio_group *blkg,
				     struct blkio_policy_type *pol,
				     uint64_t start_time,
				     uint64_t io_start_time, bool direction,
				     bool sync);
void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
				    struct blkio_policy_type *pol,
				    bool direction, bool sync);
void blkiocg_update_io_add_stats(struct blkio_group *blkg,
				 struct blkio_policy_type *pol,
				 struct blkio_group *curr_blkg, bool direction,
				 bool sync);
void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
				    struct blkio_policy_type *pol,
				    bool direction, bool sync);
#else
struct cgroup;
static inline struct blkio_cgroup *
cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
static inline struct blkio_cgroup *
task_blkio_cgroup(struct task_struct *tsk) { return NULL; }

static inline int
blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }

static inline struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
					      void *key) { return NULL; }
static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
			struct blkio_policy_type *pol, unsigned long time,
			unsigned long unaccounted_time) { }
static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol, uint64_t bytes,
			bool direction, bool sync) { }
static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol, uint64_t start_time,
			uint64_t io_start_time, bool direction, bool sync) { }
static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol, bool direction,
			bool sync) { }
static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol,
			struct blkio_group *curr_blkg, bool direction,
			bool sync) { }
static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
			struct blkio_policy_type *pol, bool direction,
			bool sync) { }
#endif
#endif /* _BLK_CGROUP_H */
Commit	Line	Data
31e4c28d VG	1	#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>
575969a0	17	#include <linux/u64_stats_sync.h>
31e4c28d	18
062a644d VG	19	enum blkio_policy_id {
062a644d VG	20	BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
4c9eefa1	21	BLKIO_POLICY_THROTL, /* Throttling */
035d10b2 TH	22
035d10b2 TH	23	BLKIO_NR_POLICIES,
062a644d VG	24	};
062a644d VG	25
9355aede VG	26	/* Max limits for throttle policy */
	27	#define THROTL_IOPS_MAX UINT_MAX
	28
32e380ae	29	#ifdef CONFIG_BLK_CGROUP
2f5ea477	30
84c124da DS	31	enum stat_type {
	32	/* Total time spent (in ns) between request dispatch to the driver and
	33	* request completion for IOs doen by this cgroup. This may not be
	34	* accurate when NCQ is turned on. */
	35	BLKIO_STAT_SERVICE_TIME = 0,
84c124da DS	36	/* Total time spent waiting in scheduler queue in ns */
84c124da DS	37	BLKIO_STAT_WAIT_TIME,
cdc1184c DS	38	/* Number of IOs queued up */
cdc1184c DS	39	BLKIO_STAT_QUEUED,
84c124da DS	40	/* All the single valued stats go below this */
84c124da DS	41	BLKIO_STAT_TIME,
a23e6869	42	#ifdef CONFIG_DEBUG_BLK_CGROUP
167400d3 JT	43	/* Time not charged to this cgroup */
167400d3 JT	44	BLKIO_STAT_UNACCOUNTED_TIME,
cdc1184c	45	BLKIO_STAT_AVG_QUEUE_SIZE,
812df48d DS	46	BLKIO_STAT_IDLE_TIME,
	47	BLKIO_STAT_EMPTY_TIME,
	48	BLKIO_STAT_GROUP_WAIT_TIME,
84c124da DS	49	BLKIO_STAT_DEQUEUE
	50	#endif
	51	};
	52
5624a4e4 VG	53	/* Per cpu stats */
	54	enum stat_type_cpu {
	55	BLKIO_STAT_CPU_SECTORS,
	56	/* Total bytes transferred */
	57	BLKIO_STAT_CPU_SERVICE_BYTES,
	58	/* Total IOs serviced, post merge */
	59	BLKIO_STAT_CPU_SERVICED,
317389a7 VG	60	/* Number of IOs merged */
317389a7 VG	61	BLKIO_STAT_CPU_MERGED,
5624a4e4 VG	62	BLKIO_STAT_CPU_NR
	63	};
	64
84c124da DS	65	enum stat_sub_type {
	66	BLKIO_STAT_READ = 0,
	67	BLKIO_STAT_WRITE,
	68	BLKIO_STAT_SYNC,
	69	BLKIO_STAT_ASYNC,
	70	BLKIO_STAT_TOTAL
303a3acb DS	71	};
303a3acb DS	72
812df48d DS	73	/* blkg state flags */
	74	enum blkg_state_flags {
	75	BLKG_waiting = 0,
	76	BLKG_idling,
	77	BLKG_empty,
	78	};
	79
062a644d VG	80	/* cgroup files owned by proportional weight policy */
	81	enum blkcg_file_name_prop {
	82	BLKIO_PROP_weight = 1,
	83	BLKIO_PROP_weight_device,
	84	BLKIO_PROP_io_service_bytes,
	85	BLKIO_PROP_io_serviced,
	86	BLKIO_PROP_time,
	87	BLKIO_PROP_sectors,
167400d3	88	BLKIO_PROP_unaccounted_time,
062a644d VG	89	BLKIO_PROP_io_service_time,
	90	BLKIO_PROP_io_wait_time,
	91	BLKIO_PROP_io_merged,
	92	BLKIO_PROP_io_queued,
	93	BLKIO_PROP_avg_queue_size,
	94	BLKIO_PROP_group_wait_time,
	95	BLKIO_PROP_idle_time,
	96	BLKIO_PROP_empty_time,
	97	BLKIO_PROP_dequeue,
	98	};
	99
4c9eefa1 VG	100	/* cgroup files owned by throttle policy */
	101	enum blkcg_file_name_throtl {
	102	BLKIO_THROTL_read_bps_device,
	103	BLKIO_THROTL_write_bps_device,
7702e8f4 VG	104	BLKIO_THROTL_read_iops_device,
7702e8f4 VG	105	BLKIO_THROTL_write_iops_device,
4c9eefa1 VG	106	BLKIO_THROTL_io_service_bytes,
	107	BLKIO_THROTL_io_serviced,
	108	};
	109
31e4c28d VG	110	struct blkio_cgroup {
	111	struct cgroup_subsys_state css;
	112	unsigned int weight;
	113	spinlock_t lock;
	114	struct hlist_head blkg_list;
	115	};
	116
303a3acb DS	117	struct blkio_group_stats {
	118	/* total disk time and nr sectors dispatched by this group */
	119	uint64_t time;
cdc1184c	120	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
303a3acb	121	#ifdef CONFIG_DEBUG_BLK_CGROUP
a23e6869 VG	122	/* Time not charged to this cgroup */
	123	uint64_t unaccounted_time;
	124
cdc1184c DS	125	/* Sum of number of IOs queued across all samples */
	126	uint64_t avg_queue_size_sum;
	127	/* Count of samples taken for average */
	128	uint64_t avg_queue_size_samples;
303a3acb DS	129	/* How many times this group has been removed from service tree */
303a3acb DS	130	unsigned long dequeue;
812df48d DS	131
	132	/* Total time spent waiting for it to be assigned a timeslice. */
	133	uint64_t group_wait_time;
	134	uint64_t start_group_wait_time;
	135
	136	/* Time spent idling for this blkio_group */
	137	uint64_t idle_time;
	138	uint64_t start_idle_time;
	139	/*
	140	* Total time when we have requests queued and do not contain the
	141	* current active queue.
	142	*/
	143	uint64_t empty_time;
	144	uint64_t start_empty_time;
	145	uint16_t flags;
303a3acb DS	146	#endif
	147	};
	148
5624a4e4 VG	149	/* Per cpu blkio group stats */
	150	struct blkio_group_stats_cpu {
	151	uint64_t sectors;
	152	uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
575969a0	153	struct u64_stats_sync syncp;
5624a4e4 VG	154	};
5624a4e4 VG	155
e56da7e2 TH	156	struct blkio_group_conf {
	157	unsigned int weight;
	158	unsigned int iops[2];
	159	u64 bps[2];
	160	};
	161
0381411e TH	162	/* per-blkg per-policy data */
	163	struct blkg_policy_data {
	164	/* the blkg this per-policy data belongs to */
	165	struct blkio_group *blkg;
	166
549d3aa8 TH	167	/* Configuration */
	168	struct blkio_group_conf conf;
	169
	170	struct blkio_group_stats stats;
	171	/* Per cpu stats pointer */
	172	struct blkio_group_stats_cpu __percpu *stats_cpu;
	173
0381411e TH	174	/* pol->pdata_size bytes of private data used by policy impl */
	175	char pdata[] __aligned(__alignof__(unsigned long long));
	176	};
	177
31e4c28d	178	struct blkio_group {
ca32aefc TH	179	/* Pointer to the associated request_queue, RCU protected */
ca32aefc TH	180	struct request_queue __rcu *q;
4eef3049	181	struct list_head q_node[BLKIO_NR_POLICIES];
31e4c28d	182	struct hlist_node blkcg_node;
7ee9c562	183	struct blkio_cgroup *blkcg;
2868ef7b VG	184	/* Store cgroup path */
2868ef7b VG	185	char path[128];
062a644d VG	186	/* policy which owns this blk group */
062a644d VG	187	enum blkio_policy_id plid;
1adaf3dd TH	188	/* reference count */
1adaf3dd TH	189	int refcnt;
22084190	190
303a3acb DS	191	/* Need to serialize the stats in the case of reset/update */
303a3acb DS	192	spinlock_t stats_lock;
549d3aa8	193	struct blkg_policy_data *pd[BLKIO_NR_POLICIES];
1adaf3dd TH	194
1adaf3dd TH	195	struct rcu_head rcu_head;
31e4c28d VG	196	};
31e4c28d VG	197
0381411e	198	typedef void (blkio_init_group_fn)(struct blkio_group *blkg);
ca32aefc	199	typedef void (blkio_update_group_weight_fn)(struct request_queue *q,
fe071437	200	struct blkio_group *blkg, unsigned int weight);
ca32aefc	201	typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q,
fe071437	202	struct blkio_group *blkg, u64 read_bps);
ca32aefc	203	typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q,
fe071437	204	struct blkio_group *blkg, u64 write_bps);
ca32aefc	205	typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q,
fe071437	206	struct blkio_group *blkg, unsigned int read_iops);
ca32aefc	207	typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q,
fe071437	208	struct blkio_group *blkg, unsigned int write_iops);
3e252066 VG	209
3e252066 VG	210	struct blkio_policy_ops {
0381411e	211	blkio_init_group_fn *blkio_init_group_fn;
3e252066	212	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
4c9eefa1 VG	213	blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
4c9eefa1 VG	214	blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
7702e8f4 VG	215	blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
7702e8f4 VG	216	blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
3e252066 VG	217	};
	218
	219	struct blkio_policy_type {
	220	struct list_head list;
	221	struct blkio_policy_ops ops;
062a644d	222	enum blkio_policy_id plid;
0381411e	223	size_t pdata_size; /* policy specific private data size */
3e252066 VG	224	};
3e252066 VG	225
5efd6113 TH	226	extern int blkcg_init_queue(struct request_queue *q);
	227	extern void blkcg_drain_queue(struct request_queue *q);
	228	extern void blkcg_exit_queue(struct request_queue *q);
	229
3e252066 VG	230	/* Blkio controller policy registration */
	231	extern void blkio_policy_register(struct blkio_policy_type *);
	232	extern void blkio_policy_unregister(struct blkio_policy_type *);
03aa264a TH	233	extern void blkg_destroy_all(struct request_queue *q,
03aa264a TH	234	enum blkio_policy_id plid, bool destroy_root);
3e252066	235
0381411e TH	236	/**
	237	* blkg_to_pdata - get policy private data
	238	* @blkg: blkg of interest
	239	* @pol: policy of interest
	240	*
	241	* Return pointer to private data associated with the @blkg-@pol pair.
	242	*/
	243	static inline void blkg_to_pdata(struct blkio_group blkg,
	244	struct blkio_policy_type *pol)
	245	{
549d3aa8	246	return blkg ? blkg->pd[pol->plid]->pdata : NULL;
0381411e TH	247	}
	248
	249	/**
	250	* pdata_to_blkg - get blkg associated with policy private data
	251	* @pdata: policy private data of interest
	252	* @pol: policy @pdata is for
	253	*
	254	* @pdata is policy private data for @pol. Determine the blkg it's
	255	* associated with.
	256	*/
	257	static inline struct blkio_group pdata_to_blkg(void pdata,
	258	struct blkio_policy_type *pol)
	259	{
	260	if (pdata) {
	261	struct blkg_policy_data *pd =
	262	container_of(pdata, struct blkg_policy_data, pdata);
	263	return pd->blkg;
	264	}
	265	return NULL;
	266	}
	267
afc24d49 VG	268	static inline char blkg_path(struct blkio_group blkg)
	269	{
	270	return blkg->path;
	271	}
	272
1adaf3dd TH	273	/**
	274	* blkg_get - get a blkg reference
	275	* @blkg: blkg to get
	276	*
	277	* The caller should be holding queue_lock and an existing reference.
	278	*/
	279	static inline void blkg_get(struct blkio_group *blkg)
	280	{
	281	lockdep_assert_held(blkg->q->queue_lock);
	282	WARN_ON_ONCE(!blkg->refcnt);
	283	blkg->refcnt++;
	284	}
	285
	286	void __blkg_release(struct blkio_group *blkg);
	287
	288	/**
	289	* blkg_put - put a blkg reference
	290	* @blkg: blkg to put
	291	*
	292	* The caller should be holding queue_lock.
	293	*/
	294	static inline void blkg_put(struct blkio_group *blkg)
	295	{
	296	lockdep_assert_held(blkg->q->queue_lock);
	297	WARN_ON_ONCE(blkg->refcnt <= 0);
	298	if (!--blkg->refcnt)
	299	__blkg_release(blkg);
	300	}
	301
2f5ea477 JA	302	#else
	303
	304	struct blkio_group {
	305	};
	306
3e252066 VG	307	struct blkio_policy_type {
	308	};
	309
5efd6113 TH	310	static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
	311	static inline void blkcg_drain_queue(struct request_queue *q) { }
	312	static inline void blkcg_exit_queue(struct request_queue *q) { }
3e252066 VG	313	static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
3e252066 VG	314	static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
03aa264a TH	315	static inline void blkg_destroy_all(struct request_queue *q,
	316	enum blkio_policy_id plid,
	317	bool destory_root) { }
3e252066	318
0381411e TH	319	static inline void blkg_to_pdata(struct blkio_group blkg,
	320	struct blkio_policy_type *pol) { return NULL; }
	321	static inline struct blkio_group pdata_to_blkg(void pdata,
	322	struct blkio_policy_type *pol) { return NULL; }
afc24d49	323	static inline char blkg_path(struct blkio_group blkg) { return NULL; }
1adaf3dd TH	324	static inline void blkg_get(struct blkio_group *blkg) { }
1adaf3dd TH	325	static inline void blkg_put(struct blkio_group *blkg) { }
afc24d49	326
2f5ea477 JA	327	#endif
2f5ea477 JA	328
df457f84	329	#define BLKIO_WEIGHT_MIN 10
31e4c28d VG	330	#define BLKIO_WEIGHT_MAX 1000
	331	#define BLKIO_WEIGHT_DEFAULT 500
	332
2868ef7b	333	#ifdef CONFIG_DEBUG_BLK_CGROUP
c1768268 TH	334	void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
c1768268 TH	335	struct blkio_policy_type *pol);
9195291e	336	void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
c1768268 TH	337	struct blkio_policy_type *pol,
	338	unsigned long dequeue);
	339	void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
	340	struct blkio_policy_type *pol);
	341	void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
	342	struct blkio_policy_type *pol);
	343	void blkiocg_set_start_empty_time(struct blkio_group *blkg,
	344	struct blkio_policy_type *pol);
812df48d DS	345
	346	#define BLKG_FLAG_FNS(name) \
	347	static inline void blkio_mark_blkg_##name( \
	348	struct blkio_group_stats *stats) \
	349	{ \
	350	stats->flags \|= (1 << BLKG_##name); \
	351	} \
	352	static inline void blkio_clear_blkg_##name( \
	353	struct blkio_group_stats *stats) \
	354	{ \
	355	stats->flags &= ~(1 << BLKG_##name); \
	356	} \
	357	static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
	358	{ \
	359	return (stats->flags & (1 << BLKG_##name)) != 0; \
	360	} \
	361
	362	BLKG_FLAG_FNS(waiting)
	363	BLKG_FLAG_FNS(idling)
	364	BLKG_FLAG_FNS(empty)
	365	#undef BLKG_FLAG_FNS
2868ef7b	366	#else
c1768268 TH	367	static inline void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
c1768268 TH	368	struct blkio_policy_type *pol) { }
9195291e	369	static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
c1768268 TH	370	struct blkio_policy_type *pol, unsigned long dequeue) { }
	371	static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
	372	struct blkio_policy_type *pol) { }
	373	static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
	374	struct blkio_policy_type *pol) { }
	375	static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg,
	376	struct blkio_policy_type *pol) { }
2868ef7b VG	377	#endif
2868ef7b VG	378
32e380ae	379	#ifdef CONFIG_BLK_CGROUP
31e4c28d VG	380	extern struct blkio_cgroup blkio_root_cgroup;
31e4c28d VG	381	extern struct blkio_cgroup cgroup_to_blkio_cgroup(struct cgroup cgroup);
70087dc3	382	extern struct blkio_cgroup task_blkio_cgroup(struct task_struct tsk);
31e4c28d	383	extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
cd1604fa TH	384	extern struct blkio_group blkg_lookup(struct blkio_cgroup blkcg,
	385	struct request_queue *q,
	386	enum blkio_policy_id plid);
	387	struct blkio_group blkg_lookup_create(struct blkio_cgroup blkcg,
	388	struct request_queue *q,
	389	enum blkio_policy_id plid,
	390	bool for_root);
303a3acb	391	void blkiocg_update_timeslice_used(struct blkio_group *blkg,
c1768268 TH	392	struct blkio_policy_type *pol,
	393	unsigned long time,
	394	unsigned long unaccounted_time);
	395	void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
	396	struct blkio_policy_type *pol,
	397	uint64_t bytes, bool direction, bool sync);
84c124da	398	void blkiocg_update_completion_stats(struct blkio_group *blkg,
c1768268 TH	399	struct blkio_policy_type *pol,
	400	uint64_t start_time,
	401	uint64_t io_start_time, bool direction,
	402	bool sync);
	403	void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
	404	struct blkio_policy_type *pol,
	405	bool direction, bool sync);
a11cdaa7	406	void blkiocg_update_io_add_stats(struct blkio_group *blkg,
c1768268 TH	407	struct blkio_policy_type *pol,
	408	struct blkio_group *curr_blkg, bool direction,
	409	bool sync);
a11cdaa7	410	void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
c1768268 TH	411	struct blkio_policy_type *pol,
c1768268 TH	412	bool direction, bool sync);
31e4c28d	413	#else
2f5ea477	414	struct cgroup;
31e4c28d VG	415	static inline struct blkio_cgroup *
31e4c28d VG	416	cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
70087dc3 VG	417	static inline struct blkio_cgroup *
70087dc3 VG	418	task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
31e4c28d	419
31e4c28d VG	420	static inline int
	421	blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
	422
cd1604fa TH	423	static inline struct blkio_group blkg_lookup(struct blkio_cgroup blkcg,
cd1604fa TH	424	void *key) { return NULL; }
303a3acb	425	static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
c1768268 TH	426	struct blkio_policy_type *pol, unsigned long time,
c1768268 TH	427	unsigned long unaccounted_time) { }
84c124da	428	static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
c1768268 TH	429	struct blkio_policy_type *pol, uint64_t bytes,
c1768268 TH	430	bool direction, bool sync) { }
84c124da	431	static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
c1768268 TH	432	struct blkio_policy_type *pol, uint64_t start_time,
c1768268 TH	433	uint64_t io_start_time, bool direction, bool sync) { }
812d4026	434	static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
c1768268 TH	435	struct blkio_policy_type *pol, bool direction,
c1768268 TH	436	bool sync) { }
a11cdaa7	437	static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
c1768268 TH	438	struct blkio_policy_type *pol,
	439	struct blkio_group *curr_blkg, bool direction,
	440	bool sync) { }
a11cdaa7	441	static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
c1768268 TH	442	struct blkio_policy_type *pol, bool direction,
c1768268 TH	443	bool sync) { }
31e4c28d VG	444	#endif
31e4c28d VG	445	#endif /* _BLK_CGROUP_H */