linux-imx

/*

 * fs/fs-writeback.c

 *

 * Copyright (C) 2002, Linus Torvalds.

 *

 * Contains all the functions related to writing back and waiting

 * upon dirty inodes against superblocks, and writing back dirty

 * pages against inodes.  ie: data writeback.  Writeout of the

 * inode itself is not handled here.

 *

 * 10Apr2002    Andrew Morton

 *      Split out of fs/inode.c

 *      Additions for address_space-based writeback

 */

​

#include <linux/kernel.h>

#include <linux/export.h>

#include <linux/spinlock.h>

#include <linux/slab.h>

#include <linux/sched.h>

#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/pagemap.h>

#include <linux/kthread.h>

#include <linux/writeback.h>

#include <linux/blkdev.h>

#include <linux/backing-dev.h>

#include <linux/tracepoint.h>

#include <linux/device.h>

#include <linux/memcontrol.h>

#include "internal.h"

​

/*

 * 4MB minimal write chunk size

 */

#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_SHIFT - 10))

​

struct wb_completion {

    atomic_t        cnt;

};

​

/*

 * Passed into wb_writeback(), essentially a subset of writeback_control

 */

struct wb_writeback_work {

    long nr_pages;

    struct super_block *sb;

    unsigned long *older_than_this;

    enum writeback_sync_modes sync_mode;

    unsigned int tagged_writepages:1;

    unsigned int for_kupdate:1;

    unsigned int range_cyclic:1;

    unsigned int for_background:1;

    unsigned int for_sync:1;    /* sync(2) WB_SYNC_ALL writeback */

    unsigned int auto_free:1;   /* free on completion */

    enum wb_reason reason;      /* why was writeback initiated? */

​

    struct list_head list;      /* pending work list */

    struct wb_completion *done; /* set if the caller waits */

};

​

/*

 * If one wants to wait for one or more wb_writeback_works, each work's