185 lines
5.9 KiB
C
185 lines
5.9 KiB
C
/*
|
|
* include/linux/writeback.h
|
|
*/
|
|
#ifndef WRITEBACK_H
|
|
#define WRITEBACK_H
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/fs.h>
|
|
|
|
DECLARE_PER_CPU(int, dirty_throttle_leaks);
|
|
|
|
/*
|
|
* The 1/4 region under the global dirty thresh is for smooth dirty throttling:
|
|
*
|
|
* (thresh - thresh/DIRTY_FULL_SCOPE, thresh)
|
|
*
|
|
* Further beyond, all dirtier tasks will enter a loop waiting (possibly long
|
|
* time) for the dirty pages to drop, unless written enough pages.
|
|
*
|
|
* The global dirty threshold is normally equal to the global dirty limit,
|
|
* except when the system suddenly allocates a lot of anonymous memory and
|
|
* knocks down the global dirty threshold quickly, in which case the global
|
|
* dirty limit will follow down slowly to prevent livelocking all dirtier tasks.
|
|
*/
|
|
#define DIRTY_SCOPE 8
|
|
#define DIRTY_FULL_SCOPE (DIRTY_SCOPE / 2)
|
|
|
|
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 */
|
|
};
|
|
|
|
/*
|
|
* why some writeback work was initiated
|
|
*/
|
|
enum wb_reason {
|
|
WB_REASON_BACKGROUND,
|
|
WB_REASON_TRY_TO_FREE_PAGES,
|
|
WB_REASON_SYNC,
|
|
WB_REASON_PERIODIC,
|
|
WB_REASON_LAPTOP_TIMER,
|
|
WB_REASON_FREE_MORE_MEM,
|
|
WB_REASON_FS_FREE_SPACE,
|
|
WB_REASON_FORKER_THREAD,
|
|
|
|
WB_REASON_MAX,
|
|
};
|
|
extern const char *wb_reason_name[];
|
|
|
|
/*
|
|
* 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 {
|
|
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(): if 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;
|
|
|
|
enum writeback_sync_modes sync_mode;
|
|
|
|
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 *, enum wb_reason reason);
|
|
void writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
|
|
enum wb_reason reason);
|
|
int try_to_writeback_inodes_sb(struct super_block *, enum wb_reason reason);
|
|
int try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
|
|
enum wb_reason reason);
|
|
void sync_inodes_sb(struct super_block *);
|
|
long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages,
|
|
enum wb_reason reason);
|
|
long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
|
|
void wakeup_flusher_threads(long nr_pages, enum wb_reason reason);
|
|
void inode_wait_for_writeback(struct inode *inode);
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
bool zone_dirty_ok(struct zone *zone);
|
|
|
|
extern unsigned long global_dirty_limit;
|
|
|
|
/* 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 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 __bdi_update_bandwidth(struct backing_dev_info *bdi,
|
|
unsigned long thresh,
|
|
unsigned long bg_thresh,
|
|
unsigned long dirty,
|
|
unsigned long bdi_thresh,
|
|
unsigned long bdi_dirty,
|
|
unsigned long start_time);
|
|
|
|
void page_writeback_init(void);
|
|
void balance_dirty_pages_ratelimited(struct address_space *mapping);
|
|
|
|
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);
|
|
|
|
void account_page_redirty(struct page *page);
|
|
|
|
#endif /* WRITEBACK_H */
|