[net-next-2.6.git] / include / linux / writeback.h

/*
 * include/linux/writeback.h
 */
#ifndef WRITEBACK_H
#define WRITEBACK_H

#include <linux/sched.h>
#include <linux/fs.h>

struct backing_dev_info;

extern spinlock_t inode_lock;
extern struct list_head inode_in_use;
extern struct list_head inode_unused;

/*
 * fs/fs-writeback.c
 */
enum writeback_sync_modes {
	WB_SYNC_NONE,	/* Don't wait on anything */
	WB_SYNC_ALL,	/* Wait on every mapping */
};

/*
 * A control structure which tells the writeback code what to do.  These are
 * always on the stack, and hence need no locking.  They are always initialised
 * in a manner such that unspecified fields are set to zero.
 */
struct writeback_control {
	enum writeback_sync_modes sync_mode;
	unsigned long *older_than_this;	/* If !NULL, only write back inodes
					   older than this */
	unsigned long wb_start;         /* Time writeback_inodes_wb was
					   called. This is needed to avoid
					   extra jobs and livelock */
	long nr_to_write;		/* Write this many pages, and decrement
					   this for each page written */
	long pages_skipped;		/* Pages which were not written */

	/*
	 * For a_ops->writepages(): is start or end are non-zero then this is
	 * a hint that the filesystem need only write out the pages inside that
	 * byterange.  The byte at `end' is included in the writeout request.
	 */
	loff_t range_start;
	loff_t range_end;

	unsigned nonblocking:1;		/* Don't get stuck on request queues */
	unsigned encountered_congestion:1; /* An output: a queue is full */
	unsigned for_kupdate:1;		/* A kupdate writeback */
	unsigned for_background:1;	/* A background writeback */
	unsigned for_reclaim:1;		/* Invoked from the page allocator */
	unsigned range_cyclic:1;	/* range_start is cyclic */
	unsigned more_io:1;		/* more io to be dispatched */
};

/*
 * fs/fs-writeback.c
 */	
struct bdi_writeback;
int inode_wait(void *);
void writeback_inodes_sb(struct super_block *);
int writeback_inodes_sb_if_idle(struct super_block *);
void sync_inodes_sb(struct super_block *);
void writeback_inodes_wb(struct bdi_writeback *wb,
		struct writeback_control *wbc);
long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
void wakeup_flusher_threads(long nr_pages);

/* writeback.h requires fs.h; it, too, is not included from here. */
static inline void wait_on_inode(struct inode *inode)
{
	might_sleep();
	wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
}
static inline void inode_sync_wait(struct inode *inode)
{
	might_sleep();
	wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
							TASK_UNINTERRUPTIBLE);
}


/*
 * mm/page-writeback.c
 */
#ifdef CONFIG_BLOCK
void laptop_io_completion(struct backing_dev_info *info);
void laptop_sync_completion(void);
void laptop_mode_sync(struct work_struct *work);
void laptop_mode_timer_fn(unsigned long data);
#else
static inline void laptop_sync_completion(void) { }
#endif
void throttle_vm_writeout(gfp_t gfp_mask);

/* These are exported to sysctl. */
extern int dirty_background_ratio;
extern unsigned long dirty_background_bytes;
extern int vm_dirty_ratio;
extern unsigned long vm_dirty_bytes;
extern unsigned int dirty_writeback_interval;
extern unsigned int dirty_expire_interval;
extern int vm_highmem_is_dirtyable;
extern int block_dump;
extern int laptop_mode;

extern unsigned long determine_dirtyable_memory(void);

extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos);
extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos);
extern int dirty_ratio_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos);
extern int dirty_bytes_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos);

struct ctl_table;
int dirty_writeback_centisecs_handler(struct ctl_table *, int,
				      void __user *, size_t *, loff_t *);

void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
			       unsigned long dirty);

void page_writeback_init(void);
void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
					unsigned long nr_pages_dirtied);

static inline void
balance_dirty_pages_ratelimited(struct address_space *mapping)
{
	balance_dirty_pages_ratelimited_nr(mapping, 1);
}

typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
				void *data);

int generic_writepages(struct address_space *mapping,
		       struct writeback_control *wbc);
int write_cache_pages(struct address_space *mapping,
		      struct writeback_control *wbc, writepage_t writepage,
		      void *data);
int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
void set_page_dirty_balance(struct page *page, int page_mkwrite);
void writeback_set_ratelimit(void);
void tag_pages_for_writeback(struct address_space *mapping,
			     pgoff_t start, pgoff_t end);

/* pdflush.c */
extern int nr_pdflush_threads;	/* Global so it can be exported to sysctl
				   read-only. */


#endif		/* WRITEBACK_H */
Commit	Line	Data
1da177e4	1	/*
f30c2269	2	* include/linux/writeback.h
1da177e4 LT	3	*/
	4	#ifndef WRITEBACK_H
	5	#define WRITEBACK_H
	6
e8edc6e0	7	#include <linux/sched.h>
f5ff8422	8	#include <linux/fs.h>
e8edc6e0	9
1da177e4 LT	10	struct backing_dev_info;
	11
	12	extern spinlock_t inode_lock;
	13	extern struct list_head inode_in_use;
	14	extern struct list_head inode_unused;
	15
1da177e4 LT	16	/*
	17	* fs/fs-writeback.c
	18	*/
	19	enum writeback_sync_modes {
	20	WB_SYNC_NONE, /* Don't wait on anything */
	21	WB_SYNC_ALL, /* Wait on every mapping */
1da177e4 LT	22	};
	23
	24	/*
	25	* A control structure which tells the writeback code what to do. These are
	26	* always on the stack, and hence need no locking. They are always initialised
	27	* in a manner such that unspecified fields are set to zero.
	28	*/
	29	struct writeback_control {
1da177e4 LT	30	enum writeback_sync_modes sync_mode;
	31	unsigned long older_than_this; / If !NULL, only write back inodes
	32	older than this */
f11c9c5c ES	33	unsigned long wb_start; /* Time writeback_inodes_wb was
	34	called. This is needed to avoid
	35	extra jobs and livelock */
1da177e4 LT	36	long nr_to_write; /* Write this many pages, and decrement
	37	this for each page written */
	38	long pages_skipped; /* Pages which were not written */
	39
	40	/*
	41	* For a_ops->writepages(): is start or end are non-zero then this is
	42	* a hint that the filesystem need only write out the pages inside that
	43	* byterange. The byte at `end' is included in the writeout request.
	44	*/
111ebb6e OH	45	loff_t range_start;
111ebb6e OH	46	loff_t range_end;
1da177e4	47
22905f77 AM	48	unsigned nonblocking:1; /* Don't get stuck on request queues */
	49	unsigned encountered_congestion:1; /* An output: a queue is full */
	50	unsigned for_kupdate:1; /* A kupdate writeback */
b17621fe	51	unsigned for_background:1; /* A background writeback */
22905f77	52	unsigned for_reclaim:1; /* Invoked from the page allocator */
111ebb6e	53	unsigned range_cyclic:1; /* range_start is cyclic */
8bc3be27	54	unsigned more_io:1; /* more io to be dispatched */
1da177e4 LT	55	};
1da177e4 LT	56
1da177e4 LT	57	/*
	58	* fs/fs-writeback.c
	59	*/
03ba3782	60	struct bdi_writeback;
1da177e4	61	int inode_wait(void *);
b6e51316	62	void writeback_inodes_sb(struct super_block *);
17bd55d0	63	int writeback_inodes_sb_if_idle(struct super_block *);
b6e51316	64	void sync_inodes_sb(struct super_block *);
9c3a8ee8 CH	65	void writeback_inodes_wb(struct bdi_writeback *wb,
9c3a8ee8 CH	66	struct writeback_control *wbc);
03ba3782 JA	67	long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
03ba3782 JA	68	void wakeup_flusher_threads(long nr_pages);
1da177e4 LT	69
	70	/* writeback.h requires fs.h; it, too, is not included from here. */
	71	static inline void wait_on_inode(struct inode *inode)
	72	{
	73	might_sleep();
eaff8079	74	wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
1da177e4	75	}
1c0eeaf5 JE	76	static inline void inode_sync_wait(struct inode *inode)
	77	{
	78	might_sleep();
	79	wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
	80	TASK_UNINTERRUPTIBLE);
	81	}
	82
1da177e4 LT	83
	84	/*
	85	* mm/page-writeback.c
	86	*/
c2c4986e	87	#ifdef CONFIG_BLOCK
31373d09	88	void laptop_io_completion(struct backing_dev_info *info);
1da177e4	89	void laptop_sync_completion(void);
31373d09 MG	90	void laptop_mode_sync(struct work_struct *work);
31373d09 MG	91	void laptop_mode_timer_fn(unsigned long data);
c2c4986e JA	92	#else
	93	static inline void laptop_sync_completion(void) { }
	94	#endif
232ea4d6	95	void throttle_vm_writeout(gfp_t gfp_mask);
1da177e4 LT	96
	97	/* These are exported to sysctl. */
	98	extern int dirty_background_ratio;
2da02997	99	extern unsigned long dirty_background_bytes;
1da177e4	100	extern int vm_dirty_ratio;
2da02997	101	extern unsigned long vm_dirty_bytes;
704503d8 AD	102	extern unsigned int dirty_writeback_interval;
704503d8 AD	103	extern unsigned int dirty_expire_interval;
195cf453	104	extern int vm_highmem_is_dirtyable;
1da177e4 LT	105	extern int block_dump;
	106	extern int laptop_mode;
	107
3eefae99 SR	108	extern unsigned long determine_dirtyable_memory(void);
3eefae99 SR	109
2da02997	110	extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
8d65af78	111	void __user buffer, size_t lenp,
2da02997 DR	112	loff_t *ppos);
2da02997 DR	113	extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
8d65af78	114	void __user buffer, size_t lenp,
2da02997	115	loff_t *ppos);
04fbfdc1	116	extern int dirty_ratio_handler(struct ctl_table *table, int write,
8d65af78	117	void __user buffer, size_t lenp,
04fbfdc1	118	loff_t *ppos);
2da02997	119	extern int dirty_bytes_handler(struct ctl_table *table, int write,
8d65af78	120	void __user buffer, size_t lenp,
2da02997	121	loff_t *ppos);
04fbfdc1	122
1da177e4	123	struct ctl_table;
8d65af78	124	int dirty_writeback_centisecs_handler(struct ctl_table *, int,
1da177e4 LT	125	void __user , size_t , loff_t *);
1da177e4 LT	126
16c4042f WF	127	void global_dirty_limits(unsigned long pbackground, unsigned long pdirty);
	128	unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
	129	unsigned long dirty);
cf0ca9fe	130
1da177e4	131	void page_writeback_init(void);
fa5a734e AM	132	void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
	133	unsigned long nr_pages_dirtied);
	134
	135	static inline void
	136	balance_dirty_pages_ratelimited(struct address_space *mapping)
	137	{
	138	balance_dirty_pages_ratelimited_nr(mapping, 1);
	139	}
	140
0ea97180 MS	141	typedef int (writepage_t)(struct page page, struct writeback_control *wbc,
	142	void *data);
	143
0ea97180 MS	144	int generic_writepages(struct address_space *mapping,
	145	struct writeback_control *wbc);
	146	int write_cache_pages(struct address_space *mapping,
	147	struct writeback_control *wbc, writepage_t writepage,
	148	void *data);
1da177e4	149	int do_writepages(struct address_space mapping, struct writeback_control wbc);
a200ee18	150	void set_page_dirty_balance(struct page *page, int page_mkwrite);
2d1d43f6	151	void writeback_set_ratelimit(void);
92c09c04 NK	152	void tag_pages_for_writeback(struct address_space *mapping,
92c09c04 NK	153	pgoff_t start, pgoff_t end);
1da177e4 LT	154
	155	/* pdflush.c */
	156	extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
	157	read-only. */
	158
	159
	160	#endif /* WRITEBACK_H */