[net-next-2.6.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_io_context {
	void *key;

	struct cfq_queue *cfqq[2];

	struct io_context *ioc;

	unsigned long last_end_request;

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

	struct list_head queue_list;
	struct hlist_node cic_list;

	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;
	unsigned short ioprio_changed;

#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
	unsigned short cgroup_changed;
#endif

	/*
	 * 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
int put_io_context(struct io_context *ioc);
void exit_io_context(struct task_struct *task);
struct io_context *get_io_context(gfp_t gfp_flags, int node);
struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
#else
static inline void exit_io_context(struct task_struct *task)
{
}

struct io_context;
static inline int put_io_context(struct io_context *ioc)
{
	return 1;
}
#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 JA	7	struct cfq_queue;
fd0928df JA	8	struct cfq_io_context {
fd0928df JA	9	void *key;
	10
	11	struct cfq_queue *cfqq[2];
	12
	13	struct io_context *ioc;
	14
	15	unsigned long last_end_request;
fd0928df JA	16
	17	unsigned long ttime_total;
	18	unsigned long ttime_samples;
	19	unsigned long ttime_mean;
	20
fd0928df	21	struct list_head queue_list;
ffc4e759	22	struct hlist_node cic_list;
fd0928df JA	23
	24	void (dtor)(struct io_context ); /* destructor */
	25	void (exit)(struct io_context ); /* called on task exit */
34e6bbf2 FC	26
34e6bbf2 FC	27	struct rcu_head rcu_head;
fd0928df JA	28	};
	29
	30	/*
d38ecf93 JA	31	* I/O subsystem state of the associated processes. It is refcounted
d38ecf93 JA	32	* and kmalloc'ed. These could be shared between processes.
fd0928df JA	33	*/
fd0928df JA	34	struct io_context {
d9c7d394	35	atomic_long_t refcount;
d38ecf93 JA	36	atomic_t nr_tasks;
	37
	38	/* all the fields below are protected by this lock */
	39	spinlock_t lock;
fd0928df JA	40
	41	unsigned short ioprio;
	42	unsigned short ioprio_changed;
	43
67523c48	44	#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
31e4c28d VG	45	unsigned short cgroup_changed;
	46	#endif
	47
fd0928df JA	48	/*
	49	* For request batching
	50	*/
fd0928df	51	int nr_batch_requests; /* Number of requests left in the batch */
58c24a61	52	unsigned long last_waited; /* Time last woken after wait for request */
fd0928df	53
4ac845a2	54	struct radix_tree_root radix_root;
ffc4e759	55	struct hlist_head cic_list;
4d2deb40	56	void __rcu *ioc_data;
fd0928df JA	57	};
fd0928df JA	58
d38ecf93 JA	59	static inline struct io_context ioc_task_link(struct io_context ioc)
	60	{
	61	/*
	62	* if ref count is zero, don't allow sharing (ioc is going away, it's
	63	* a race).
	64	*/
d9c7d394	65	if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
cbb4f264	66	atomic_inc(&ioc->nr_tasks);
d38ecf93	67	return ioc;
d237e5c7	68	}
d38ecf93 JA	69
	70	return NULL;
	71	}
	72
b69f2292	73	struct task_struct;
da9cbc87 JA	74	#ifdef CONFIG_BLOCK
da9cbc87 JA	75	int put_io_context(struct io_context *ioc);
b69f2292	76	void exit_io_context(struct task_struct *task);
da9cbc87 JA	77	struct io_context *get_io_context(gfp_t gfp_flags, int node);
da9cbc87 JA	78	struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
da9cbc87	79	#else
b69f2292	80	static inline void exit_io_context(struct task_struct *task)
da9cbc87 JA	81	{
	82	}
	83
	84	struct io_context;
	85	static inline int put_io_context(struct io_context *ioc)
	86	{
	87	return 1;
	88	}
	89	#endif
	90
fd0928df	91	#endif