[linux-2.6-block.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;

/*
 * 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;
	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 for_kupdate:1;		/* A kupdate writeback */
	unsigned for_background:1;	/* A background writeback */
	unsigned tagged_writepages:1;	/* tag-and-write to avoid livelock */
	unsigned for_reclaim:1;		/* Invoked from the page allocator */
	unsigned range_cyclic:1;	/* range_start is cyclic */
};

/*
 * fs/fs-writeback.c
 */	
struct bdi_writeback;
int inode_wait(void *);
void writeback_inodes_sb(struct super_block *);
void writeback_inodes_sb_nr(struct super_block *, unsigned long nr);
int writeback_inodes_sb_if_idle(struct super_block *);
int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr);
void sync_inodes_sb(struct super_block *);
long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages);
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);
void tag_pages_for_writeback(struct address_space *mapping,
			     pgoff_t start, pgoff_t end);
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;
1da177e4 LT	11
1da177e4 LT	12	/*
	13	* fs/fs-writeback.c
	14	*/
	15	enum writeback_sync_modes {
	16	WB_SYNC_NONE, /* Don't wait on anything */
	17	WB_SYNC_ALL, /* Wait on every mapping */
1da177e4 LT	18	};
	19
	20	/*
	21	* A control structure which tells the writeback code what to do. These are
	22	* always on the stack, and hence need no locking. They are always initialised
	23	* in a manner such that unspecified fields are set to zero.
	24	*/
	25	struct writeback_control {
1da177e4	26	enum writeback_sync_modes sync_mode;
1da177e4 LT	27	long nr_to_write; /* Write this many pages, and decrement
	28	this for each page written */
	29	long pages_skipped; /* Pages which were not written */
	30
	31	/*
	32	* For a_ops->writepages(): is start or end are non-zero then this is
	33	* a hint that the filesystem need only write out the pages inside that
	34	* byterange. The byte at `end' is included in the writeout request.
	35	*/
111ebb6e OH	36	loff_t range_start;
111ebb6e OH	37	loff_t range_end;
1da177e4	38
22905f77	39	unsigned for_kupdate:1; /* A kupdate writeback */
b17621fe	40	unsigned for_background:1; /* A background writeback */
6e6938b6	41	unsigned tagged_writepages:1; /* tag-and-write to avoid livelock */
22905f77	42	unsigned for_reclaim:1; /* Invoked from the page allocator */
111ebb6e	43	unsigned range_cyclic:1; /* range_start is cyclic */
1da177e4 LT	44	};
1da177e4 LT	45
1da177e4 LT	46	/*
	47	* fs/fs-writeback.c
	48	*/
03ba3782	49	struct bdi_writeback;
1da177e4	50	int inode_wait(void *);
b6e51316	51	void writeback_inodes_sb(struct super_block *);
3259f8be	52	void writeback_inodes_sb_nr(struct super_block *, unsigned long nr);
17bd55d0	53	int writeback_inodes_sb_if_idle(struct super_block *);
3259f8be	54	int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr);
b6e51316	55	void sync_inodes_sb(struct super_block *);
d46db3d5	56	long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages);
03ba3782 JA	57	long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
03ba3782 JA	58	void wakeup_flusher_threads(long nr_pages);
1da177e4 LT	59
	60	/* writeback.h requires fs.h; it, too, is not included from here. */
	61	static inline void wait_on_inode(struct inode *inode)
	62	{
	63	might_sleep();
eaff8079	64	wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
1da177e4	65	}
1c0eeaf5 JE	66	static inline void inode_sync_wait(struct inode *inode)
	67	{
	68	might_sleep();
	69	wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
	70	TASK_UNINTERRUPTIBLE);
	71	}
	72
1da177e4 LT	73
	74	/*
	75	* mm/page-writeback.c
	76	*/
c2c4986e	77	#ifdef CONFIG_BLOCK
31373d09	78	void laptop_io_completion(struct backing_dev_info *info);
1da177e4	79	void laptop_sync_completion(void);
31373d09 MG	80	void laptop_mode_sync(struct work_struct *work);
31373d09 MG	81	void laptop_mode_timer_fn(unsigned long data);
c2c4986e JA	82	#else
	83	static inline void laptop_sync_completion(void) { }
	84	#endif
232ea4d6	85	void throttle_vm_writeout(gfp_t gfp_mask);
1da177e4 LT	86
	87	/* These are exported to sysctl. */
	88	extern int dirty_background_ratio;
2da02997	89	extern unsigned long dirty_background_bytes;
1da177e4	90	extern int vm_dirty_ratio;
2da02997	91	extern unsigned long vm_dirty_bytes;
704503d8 AD	92	extern unsigned int dirty_writeback_interval;
704503d8 AD	93	extern unsigned int dirty_expire_interval;
195cf453	94	extern int vm_highmem_is_dirtyable;
1da177e4 LT	95	extern int block_dump;
	96	extern int laptop_mode;
	97
3eefae99 SR	98	extern unsigned long determine_dirtyable_memory(void);
3eefae99 SR	99
2da02997	100	extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
8d65af78	101	void __user buffer, size_t lenp,
2da02997 DR	102	loff_t *ppos);
2da02997 DR	103	extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
8d65af78	104	void __user buffer, size_t lenp,
2da02997	105	loff_t *ppos);
04fbfdc1	106	extern int dirty_ratio_handler(struct ctl_table *table, int write,
8d65af78	107	void __user buffer, size_t lenp,
04fbfdc1	108	loff_t *ppos);
2da02997	109	extern int dirty_bytes_handler(struct ctl_table *table, int write,
8d65af78	110	void __user buffer, size_t lenp,
2da02997	111	loff_t *ppos);
04fbfdc1	112
1da177e4	113	struct ctl_table;
8d65af78	114	int dirty_writeback_centisecs_handler(struct ctl_table *, int,
1da177e4 LT	115	void __user , size_t , loff_t *);
1da177e4 LT	116
16c4042f WF	117	void global_dirty_limits(unsigned long pbackground, unsigned long pdirty);
	118	unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
	119	unsigned long dirty);
cf0ca9fe	120
1da177e4	121	void page_writeback_init(void);
fa5a734e AM	122	void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
	123	unsigned long nr_pages_dirtied);
	124
	125	static inline void
	126	balance_dirty_pages_ratelimited(struct address_space *mapping)
	127	{
	128	balance_dirty_pages_ratelimited_nr(mapping, 1);
	129	}
	130
0ea97180 MS	131	typedef int (writepage_t)(struct page page, struct writeback_control *wbc,
	132	void *data);
	133
0ea97180 MS	134	int generic_writepages(struct address_space *mapping,
0ea97180 MS	135	struct writeback_control *wbc);
5b41d924 ES	136	void tag_pages_for_writeback(struct address_space *mapping,
5b41d924 ES	137	pgoff_t start, pgoff_t end);
0ea97180 MS	138	int write_cache_pages(struct address_space *mapping,
	139	struct writeback_control *wbc, writepage_t writepage,
	140	void *data);
1da177e4	141	int do_writepages(struct address_space mapping, struct writeback_control wbc);
a200ee18	142	void set_page_dirty_balance(struct page *page, int page_mkwrite);
2d1d43f6	143	void writeback_set_ratelimit(void);
92c09c04 NK	144	void tag_pages_for_writeback(struct address_space *mapping,
92c09c04 NK	145	pgoff_t start, pgoff_t end);
1da177e4 LT	146
	147	/* pdflush.c */
	148	extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
	149	read-only. */
	150
	151
	152	#endif /* WRITEBACK_H */