/*
* 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/module.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/freezer.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/tracepoint.h>
#include "internal.h"
/*
* 4MB minimal write chunk size
*/
#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10))
/*
* 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;
enum wb_reason reason; /* why was writeback initiated? */
struct list_head list; /* pending work list */
struct completion *done; /* set if the caller waits */
};
/*
* We don't actually have pdflush, but this one is exported though /proc...
*/
int nr_pdflush_threads;
/**
* writeback_in_progress - determine whether there is writeback in progress
* @bdi: the device's backing_dev_info structure.
*
* Determine whether there is writeback waiting to be handled against a
* backing device.
*/
int writeback_in_progress(struct backing_dev_info *bdi)
{
return test_bit(BDI_writeback_running, &bdi->state);
}
static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
if (strcmp(sb->s_type->name, 