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/*
* include/linux/writeback.h.
*/
#ifndef WRITEBACK_H
#define WRITEBACK_H
struct backing_dev_info;
extern spinlock_t inode_lock;
extern struct list_head inode_in_use;
extern struct list_head inode_unused;
/*
* Yes, writeback.h requires sched.h
* No, sched.h is not included from here.
*/
static inline int current_is_pdflush(void)
{
return current->flags & PF_FLUSHER;
}
/*
* fs/fs-writeback.c
*/
enum writeback_sync_modes {
WB_SYNC_NONE, /* Don't wait on anything */
WB_SYNC_ALL, /* Wait on every mapping */
WB_SYNC_HOLD, /* Hold the inode on sb_dirty for sys_sync() */
};
/*
* A control structure which tells the writeback code what to do
*/
struct writeback_control {
struct backing_dev_info *bdi; /* If !NULL, only write back this
queue */
enum writeback_sync_modes sync_mode;
unsigned long *older_than_this; /* If !NULL, only write back inodes
older than this */
long nr_to_write; /* Write this many pages, and decrement
this for each page written */
int nonblocking; /* Don't get stuck on request queues */
int encountered_congestion; /* An output: a queue is full */
int for_kupdate; /* A kupdate writeback */
int for_reclaim; /* Invoked from the page allocator */
};
/*
* ->writepage() return values (make these much larger than a pagesize, in
* case some fs is returning number-of-bytes-written from writepage)
*/
#define WRITEPAGE_ACTIVATE 0x80000 /* IO was not started: activate page */
/*
* fs/fs-writeback.c
*/
void writeback_inodes(struct writeback_control *wbc);
void wake_up_inode(struct inode *inode);
void __wait_on_inode(struct inode * inode);
void sync_inodes_sb(struct super_block *, int wait);
void sync_inodes(int wait);
/* writeback.h requires fs.h; it, too, is not included from here. */
static inline void wait_on_inode(struct inode *inode)
{
if (inode->i_state & I_LOCK)
__wait_on_inode(inode);
}
/*
* mm/page-writeback.c
*/
int wakeup_bdflush(long nr_pages);
/* These 5 are exported to sysctl. */
extern int dirty_background_ratio;
extern int vm_dirty_ratio;
extern int dirty_writeback_centisecs;
extern int dirty_expire_centisecs;
struct ctl_table;
struct file;
int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *,
void __user *, size_t *);
void page_writeback_init(void);
void balance_dirty_pages_ratelimited(struct address_space *mapping);
int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0);
int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
/* pdflush.c */
extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
read-only. */
#endif /* WRITEBACK_H */
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