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/*
* linux/fs/ext2/xip.c
*
* Copyright (C) 2005 IBM Corporation
* Author: Carsten Otte (cotte@de.ibm.com)
*/
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/buffer_head.h>
#include <linux/ext2_fs_sb.h>
#include <linux/ext2_fs.h>
#include "ext2.h"
#include "xip.h"
static inline int
__inode_direct_access(struct inode *inode, sector_t sector, unsigned long *data) {
BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access);
return inode->i_sb->s_bdev->bd_disk->fops
->direct_access(inode->i_sb->s_bdev,sector,data);
}
int
ext2_clear_xip_target(struct inode *inode, int block) {
sector_t sector = block*(PAGE_SIZE/512);
unsigned long data;
int rc;
rc = __inode_direct_access(inode, sector, &data);
if (rc)
return rc;
clear_page((void*)data);
return 0;
}
void ext2_xip_verify_sb(struct super_block *sb)
{
struct ext2_sb_info *sbi = EXT2_SB(sb);
if ((sbi->s_mount_opt & EXT2_MOUNT_XIP)) {
if ((sb->s_bdev == NULL) ||
sb->s_bdev->bd_disk == NULL ||
sb->s_bdev->bd_disk->fops == NULL ||
sb->s_bdev->bd_disk->fops->direct_access == NULL) {
sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
ext2_warning(sb, __FUNCTION__,
"ignoring xip option - not supported by bdev");
}
}
}
struct page*
ext2_get_xip_page(struct address_space *mapping, sector_t blockno,
int create)
{
int rc;
unsigned long data;
struct buffer_head tmp;
tmp.b_state = 0;
tmp.b_blocknr = 0;
rc = ext2_get_block(mapping->host, blockno/(PAGE_SIZE/512) , &tmp,
create);
if (rc)
return ERR_PTR(rc);
if (tmp.b_blocknr == 0) {
/* SPARSE block */
BUG_ON(create);
return ERR_PTR(-ENODATA);
}
rc = __inode_direct_access
(mapping->host,tmp.b_blocknr*(PAGE_SIZE/512) ,&data);
if (rc)
return ERR_PTR(rc);
SetPageUptodate(virt_to_page(data));
return virt_to_page(data);
}
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