[deliverable/linux.git] / include / linux / iocontext.h

#ifndef IOCONTEXT_H
#define IOCONTEXT_H

#include <linux/radix-tree.h>
#include <linux/rcupdate.h>

struct cfq_queue;
struct cfq_ttime {
	unsigned long last_end_request;

	unsigned long ttime_total;
	unsigned long ttime_samples;
	unsigned long ttime_mean;
};

enum {
	CIC_IOPRIO_CHANGED,
	CIC_CGROUP_CHANGED,
};

struct cfq_io_context {
	void *key;
	struct request_queue *q;

	struct cfq_queue *cfqq[2];

	struct io_context *ioc;

	struct cfq_ttime ttime;

	struct list_head queue_list;
	struct hlist_node cic_list;

	unsigned long changed;

	void (*dtor)(struct io_context *); /* destructor */
	void (*exit)(struct io_context *); /* called on task exit */

	struct rcu_head rcu_head;
};

/*
 * I/O subsystem state of the associated processes.  It is refcounted
 * and kmalloc'ed. These could be shared between processes.
 */
struct io_context {
	atomic_long_t refcount;
	atomic_t nr_tasks;

	/* all the fields below are protected by this lock */
	spinlock_t lock;

	unsigned short ioprio;

	/*
	 * For request batching
	 */
	int nr_batch_requests;     /* Number of requests left in the batch */
	unsigned long last_waited; /* Time last woken after wait for request */

	struct radix_tree_root radix_root;
	struct hlist_head cic_list;
	void __rcu *ioc_data;
};

static inline struct io_context *ioc_task_link(struct io_context *ioc)
{
	/*
	 * if ref count is zero, don't allow sharing (ioc is going away, it's
	 * a race).
	 */
	if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
		atomic_inc(&ioc->nr_tasks);
		return ioc;
	}

	return NULL;
}

struct task_struct;
#ifdef CONFIG_BLOCK
void put_io_context(struct io_context *ioc);
void exit_io_context(struct task_struct *task);
struct io_context *get_task_io_context(struct task_struct *task,
				       gfp_t gfp_flags, int node);
void ioc_ioprio_changed(struct io_context *ioc, int ioprio);
void ioc_cgroup_changed(struct io_context *ioc);
#else
struct io_context;
static inline void put_io_context(struct io_context *ioc) { }
static inline void exit_io_context(struct task_struct *task) { }
#endif

#endif
Commit	Line	Data
fd0928df JA	1	#ifndef IOCONTEXT_H
	2	#define IOCONTEXT_H
	3
4ac845a2	4	#include <linux/radix-tree.h>
34e6bbf2	5	#include <linux/rcupdate.h>
4ac845a2	6
fd0928df	7	struct cfq_queue;
383cd721 SL	8	struct cfq_ttime {
	9	unsigned long last_end_request;
	10
	11	unsigned long ttime_total;
	12	unsigned long ttime_samples;
	13	unsigned long ttime_mean;
	14	};
	15
dc86900e TH	16	enum {
	17	CIC_IOPRIO_CHANGED,
	18	CIC_CGROUP_CHANGED,
	19	};
	20
fd0928df	21	struct cfq_io_context {
fd0928df	22	void *key;
283287a5	23	struct request_queue *q;
fd0928df JA	24
	25	struct cfq_queue *cfqq[2];
	26
	27	struct io_context *ioc;
	28
383cd721	29	struct cfq_ttime ttime;
fd0928df	30
fd0928df	31	struct list_head queue_list;
ffc4e759	32	struct hlist_node cic_list;
fd0928df	33
dc86900e TH	34	unsigned long changed;
dc86900e TH	35
fd0928df JA	36	void (dtor)(struct io_context ); /* destructor */
fd0928df JA	37	void (exit)(struct io_context ); /* called on task exit */
34e6bbf2 FC	38
34e6bbf2 FC	39	struct rcu_head rcu_head;
fd0928df JA	40	};
	41
	42	/*
d38ecf93 JA	43	* I/O subsystem state of the associated processes. It is refcounted
d38ecf93 JA	44	* and kmalloc'ed. These could be shared between processes.
fd0928df JA	45	*/
fd0928df JA	46	struct io_context {
d9c7d394	47	atomic_long_t refcount;
d38ecf93 JA	48	atomic_t nr_tasks;
	49
	50	/* all the fields below are protected by this lock */
	51	spinlock_t lock;
fd0928df JA	52
fd0928df JA	53	unsigned short ioprio;
31e4c28d	54
fd0928df JA	55	/*
	56	* For request batching
	57	*/
fd0928df	58	int nr_batch_requests; /* Number of requests left in the batch */
58c24a61	59	unsigned long last_waited; /* Time last woken after wait for request */
fd0928df	60
4ac845a2	61	struct radix_tree_root radix_root;
ffc4e759	62	struct hlist_head cic_list;
4d2deb40	63	void __rcu *ioc_data;
fd0928df JA	64	};
fd0928df JA	65
d38ecf93 JA	66	static inline struct io_context ioc_task_link(struct io_context ioc)
	67	{
	68	/*
	69	* if ref count is zero, don't allow sharing (ioc is going away, it's
	70	* a race).
	71	*/
d9c7d394	72	if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
cbb4f264	73	atomic_inc(&ioc->nr_tasks);
d38ecf93	74	return ioc;
d237e5c7	75	}
d38ecf93 JA	76
	77	return NULL;
	78	}
	79
b69f2292	80	struct task_struct;
da9cbc87	81	#ifdef CONFIG_BLOCK
42ec57a8	82	void put_io_context(struct io_context *ioc);
b69f2292	83	void exit_io_context(struct task_struct *task);
6e736be7 TH	84	struct io_context get_task_io_context(struct task_struct task,
6e736be7 TH	85	gfp_t gfp_flags, int node);
dc86900e TH	86	void ioc_ioprio_changed(struct io_context *ioc, int ioprio);
dc86900e TH	87	void ioc_cgroup_changed(struct io_context *ioc);
da9cbc87	88	#else
da9cbc87	89	struct io_context;
42ec57a8 TH	90	static inline void put_io_context(struct io_context *ioc) { }
42ec57a8 TH	91	static inline void exit_io_context(struct task_struct *task) { }
da9cbc87 JA	92	#endif
da9cbc87 JA	93
fd0928df	94	#endif