161 lines
		
	
	
		
			5.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			161 lines
		
	
	
		
			5.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * include/linux/writeback.h
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 */
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#ifndef WRITEBACK_H
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#define WRITEBACK_H
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#include <linux/sched.h>
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#include <linux/fs.h>
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struct backing_dev_info;
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extern spinlock_t inode_lock;
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extern struct list_head inode_in_use;
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extern struct list_head inode_unused;
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/*
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 * fs/fs-writeback.c
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 */
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enum writeback_sync_modes {
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	WB_SYNC_NONE,	/* Don't wait on anything */
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	WB_SYNC_ALL,	/* Wait on every mapping */
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};
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/*
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 * A control structure which tells the writeback code what to do.  These are
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 * always on the stack, and hence need no locking.  They are always initialised
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 * in a manner such that unspecified fields are set to zero.
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 */
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struct writeback_control {
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	struct backing_dev_info *bdi;	/* If !NULL, only write back this
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					   queue */
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	struct super_block *sb;		/* if !NULL, only write inodes from
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					   this super_block */
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	enum writeback_sync_modes sync_mode;
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	unsigned long *older_than_this;	/* If !NULL, only write back inodes
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					   older than this */
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	long nr_to_write;		/* Write this many pages, and decrement
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					   this for each page written */
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	long pages_skipped;		/* Pages which were not written */
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	/*
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	 * For a_ops->writepages(): is start or end are non-zero then this is
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	 * a hint that the filesystem need only write out the pages inside that
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	 * byterange.  The byte at `end' is included in the writeout request.
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	 */
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	loff_t range_start;
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	loff_t range_end;
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	unsigned nonblocking:1;		/* Don't get stuck on request queues */
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	unsigned encountered_congestion:1; /* An output: a queue is full */
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	unsigned for_kupdate:1;		/* A kupdate writeback */
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	unsigned for_reclaim:1;		/* Invoked from the page allocator */
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	unsigned range_cyclic:1;	/* range_start is cyclic */
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	unsigned more_io:1;		/* more io to be dispatched */
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	/*
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	 * write_cache_pages() won't update wbc->nr_to_write and
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	 * mapping->writeback_index if no_nrwrite_index_update
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	 * is set.  write_cache_pages() may write more than we
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	 * requested and we want to make sure nr_to_write and
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	 * writeback_index are updated in a consistent manner
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	 * so we use a single control to update them
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	 */
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	unsigned no_nrwrite_index_update:1;
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};
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/*
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 * fs/fs-writeback.c
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 */	
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struct bdi_writeback;
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int inode_wait(void *);
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void writeback_inodes_sb(struct super_block *);
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int writeback_inodes_sb_if_idle(struct super_block *);
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void sync_inodes_sb(struct super_block *);
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void writeback_inodes_wbc(struct writeback_control *wbc);
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long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
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void wakeup_flusher_threads(long nr_pages);
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/* writeback.h requires fs.h; it, too, is not included from here. */
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static inline void wait_on_inode(struct inode *inode)
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{
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	might_sleep();
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	wait_on_bit(&inode->i_state, __I_LOCK, inode_wait,
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							TASK_UNINTERRUPTIBLE);
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}
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static inline void inode_sync_wait(struct inode *inode)
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{
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	might_sleep();
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	wait_on_bit(&inode->i_state, __I_SYNC, inode_wait,
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							TASK_UNINTERRUPTIBLE);
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}
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/*
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 * mm/page-writeback.c
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 */
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void laptop_io_completion(void);
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void laptop_sync_completion(void);
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void throttle_vm_writeout(gfp_t gfp_mask);
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/* These are exported to sysctl. */
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extern int dirty_background_ratio;
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extern unsigned long dirty_background_bytes;
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extern int vm_dirty_ratio;
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extern unsigned long vm_dirty_bytes;
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extern unsigned int dirty_writeback_interval;
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extern unsigned int dirty_expire_interval;
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extern int vm_highmem_is_dirtyable;
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extern int block_dump;
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extern int laptop_mode;
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extern unsigned long determine_dirtyable_memory(void);
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extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
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		void __user *buffer, size_t *lenp,
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		loff_t *ppos);
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extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
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		void __user *buffer, size_t *lenp,
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		loff_t *ppos);
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extern int dirty_ratio_handler(struct ctl_table *table, int write,
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		void __user *buffer, size_t *lenp,
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		loff_t *ppos);
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extern int dirty_bytes_handler(struct ctl_table *table, int write,
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		void __user *buffer, size_t *lenp,
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		loff_t *ppos);
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struct ctl_table;
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int dirty_writeback_centisecs_handler(struct ctl_table *, int,
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				      void __user *, size_t *, loff_t *);
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void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
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		      unsigned long *pbdi_dirty, struct backing_dev_info *bdi);
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void page_writeback_init(void);
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void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
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					unsigned long nr_pages_dirtied);
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static inline void
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balance_dirty_pages_ratelimited(struct address_space *mapping)
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{
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	balance_dirty_pages_ratelimited_nr(mapping, 1);
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}
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typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
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				void *data);
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int generic_writepages(struct address_space *mapping,
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		       struct writeback_control *wbc);
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int write_cache_pages(struct address_space *mapping,
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		      struct writeback_control *wbc, writepage_t writepage,
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		      void *data);
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int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
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void set_page_dirty_balance(struct page *page, int page_mkwrite);
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void writeback_set_ratelimit(void);
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/* pdflush.c */
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extern int nr_pdflush_threads;	/* Global so it can be exported to sysctl
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				   read-only. */
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#endif		/* WRITEBACK_H */
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