mirror of
https://github.com/torvalds/linux.git
synced 2024-12-23 19:31:53 +00:00
91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
/*
|
|
* 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/blkdev.h>
|
|
#include "ext2.h"
|
|
#include "xip.h"
|
|
|
|
static inline int
|
|
__inode_direct_access(struct inode *inode, sector_t block,
|
|
void **kaddr, unsigned long *pfn)
|
|
{
|
|
struct block_device *bdev = inode->i_sb->s_bdev;
|
|
const struct block_device_operations *ops = bdev->bd_disk->fops;
|
|
sector_t sector;
|
|
|
|
sector = block * (PAGE_SIZE / 512); /* ext2 block to bdev sector */
|
|
|
|
BUG_ON(!ops->direct_access);
|
|
return ops->direct_access(bdev, sector, kaddr, pfn);
|
|
}
|
|
|
|
static inline int
|
|
__ext2_get_block(struct inode *inode, pgoff_t pgoff, int create,
|
|
sector_t *result)
|
|
{
|
|
struct buffer_head tmp;
|
|
int rc;
|
|
|
|
memset(&tmp, 0, sizeof(struct buffer_head));
|
|
rc = ext2_get_block(inode, pgoff, &tmp, create);
|
|
*result = tmp.b_blocknr;
|
|
|
|
/* did we get a sparse block (hole in the file)? */
|
|
if (!tmp.b_blocknr && !rc) {
|
|
BUG_ON(create);
|
|
rc = -ENODATA;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
int
|
|
ext2_clear_xip_target(struct inode *inode, sector_t block)
|
|
{
|
|
void *kaddr;
|
|
unsigned long pfn;
|
|
int rc;
|
|
|
|
rc = __inode_direct_access(inode, block, &kaddr, &pfn);
|
|
if (!rc)
|
|
clear_page(kaddr);
|
|
return rc;
|
|
}
|
|
|
|
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) &&
|
|
!sb->s_bdev->bd_disk->fops->direct_access) {
|
|
sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
|
|
ext2_msg(sb, KERN_WARNING,
|
|
"warning: ignoring xip option - "
|
|
"not supported by bdev");
|
|
}
|
|
}
|
|
|
|
int ext2_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create,
|
|
void **kmem, unsigned long *pfn)
|
|
{
|
|
int rc;
|
|
sector_t block;
|
|
|
|
/* first, retrieve the sector number */
|
|
rc = __ext2_get_block(mapping->host, pgoff, create, &block);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/* retrieve address of the target data */
|
|
rc = __inode_direct_access(mapping->host, block, kmem, pfn);
|
|
return rc;
|
|
}
|