readahead.c File Reference

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/pagevec.h>
#include <linux/pagemap.h>
#include <linux/syscalls.h>
#include <linux/file.h>

Go to the source code of this file.

Macros
#define	list_to_page(head)   (list_entry((head)->prev, struct page, lru))

Functions
void	file_ra_state_init (struct file_ra_state *ra, struct address_space *mapping)
	EXPORT_SYMBOL_GPL (file_ra_state_init)
int	read_cache_pages (struct address_space *mapping, struct list_head *pages, int(*filler)(void *, struct page *), void *data)
	EXPORT_SYMBOL (read_cache_pages)
int	force_page_cache_readahead (struct address_space *mapping, struct file *filp, pgoff_t offset, unsigned long nr_to_read)
unsigned long	max_sane_readahead (unsigned long nr)
unsigned long	ra_submit (struct file_ra_state *ra, struct address_space *mapping, struct file *filp)
void	page_cache_sync_readahead (struct address_space *mapping, struct file_ra_state *ra, struct file *filp, pgoff_t offset, unsigned long req_size)
	EXPORT_SYMBOL_GPL (page_cache_sync_readahead)
void	page_cache_async_readahead (struct address_space *mapping, struct file_ra_state *ra, struct file *filp, struct page *page, pgoff_t offset, unsigned long req_size)
	EXPORT_SYMBOL_GPL (page_cache_async_readahead)
SYSCALL_DEFINE()	readahead (int fd, loff_t offset, size_t count)

Macro Definition Documentation

#define list_to_page

(

head

)

(list_entry((head)->prev, struct page, lru))

Definition at line 35 of file readahead.c.

Function Documentation

EXPORT_SYMBOL

(

read_cache_pages

)

EXPORT_SYMBOL_GPL

(

file_ra_state_init

)

EXPORT_SYMBOL_GPL

(

page_cache_sync_readahead

)

EXPORT_SYMBOL_GPL

(

page_cache_async_readahead

)

void file_ra_state_init	(	struct file_ra_state *	ra,
		struct address_space *	mapping
	)

Definition at line 28 of file readahead.c.

int force_page_cache_readahead	(	struct address_space *	mapping,
		struct file *	filp,
		pgoff_t	offset,
		unsigned long	nr_to_read
	)

Definition at line 211 of file readahead.c.

unsigned long max_sane_readahead

(

unsigned long

nr

)

Definition at line 244 of file readahead.c.

void page_cache_async_readahead	(	struct address_space *	mapping,
		struct file_ra_state *	ra,
		struct file *	filp,
		struct page *	page,
		pgoff_t	offset,
		unsigned long	req_size
	)

Definition at line 540 of file readahead.c.

void page_cache_sync_readahead	(	struct address_space *	mapping,
		struct file_ra_state *	ra,
		struct file *	filp,
		pgoff_t	offset,
		unsigned long	req_size
	)

page_cache_sync_readahead - generic file readahead : address_space which holds the pagecache and I/O vectors : file_ra_state which holds the readahead state : passed on to ->readpage() and ->readpages() : start offset into , in pagecache page-sized units : hint: total size of the read which the caller is performing in pagecache pages

page_cache_sync_readahead() should be called when a cache miss happened: it will submit the read. The readahead logic may decide to piggyback more pages onto the read request if access patterns suggest it will improve performance.

Definition at line 505 of file readahead.c.

unsigned long ra_submit	(	struct file_ra_state *	ra,
		struct address_space *	mapping,
		struct file *	filp
	)

Definition at line 253 of file readahead.c.

int read_cache_pages	(	struct address_space *	mapping,
		struct list_head *	pages,
		int(*)(void *, struct page *)	filler,
		void *	data
	)

read_cache_pages - populate an address space with some pages & start reads against them : the address_space : The address of a list_head which contains the target pages. These pages have their ->index populated and are otherwise uninitialised. : callback routine for filling a single page. : private data for the callback routine.

Hides the details of the LRU cache etc from the filesystems.

Definition at line 83 of file readahead.c.

SYSCALL_DEFINE() readahead	(	int	fd,
		loff_t	offset,
		size_t	count
	)

Definition at line 579 of file readahead.c.