mirror of
https://github.com/torvalds/linux.git
synced 2024-12-11 05:33:09 +00:00
0cfc11ed45
Oliver Paukstadt from our test department is testing the xip patches in Linus' git-tree. He found a problem that shows when reading a file that contains sparse blocks (holes) on a -o xip mounted ext2 filesystem: the BUG_ON() in fs/ext2/xip.c:40 triggers where it should not. The problem was introduced by a cleanup in my previous patch, this patch fixes it. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
94 lines
2.0 KiB
C
94 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/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);
|
|
}
|
|
|
|
static inline int
|
|
__ext2_get_sector(struct inode *inode, sector_t offset, int create,
|
|
sector_t *result)
|
|
{
|
|
struct buffer_head tmp;
|
|
int rc;
|
|
|
|
memset(&tmp, 0, sizeof(struct buffer_head));
|
|
rc = ext2_get_block(inode, offset/ (PAGE_SIZE/512), &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, int block)
|
|
{
|
|
sector_t sector = block * (PAGE_SIZE/512);
|
|
unsigned long data;
|
|
int rc;
|
|
|
|
rc = __inode_direct_access(inode, sector, &data);
|
|
if (!rc)
|
|
clear_page((void*)data);
|
|
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_warning(sb, __FUNCTION__,
|
|
"ignoring xip option - not supported by bdev");
|
|
}
|
|
}
|
|
|
|
struct page *
|
|
ext2_get_xip_page(struct address_space *mapping, sector_t offset,
|
|
int create)
|
|
{
|
|
int rc;
|
|
unsigned long data;
|
|
sector_t sector;
|
|
|
|
/* first, retrieve the sector number */
|
|
rc = __ext2_get_sector(mapping->host, offset, create, §or);
|
|
if (rc)
|
|
goto error;
|
|
|
|
/* retrieve address of the target data */
|
|
rc = __inode_direct_access
|
|
(mapping->host, sector * (PAGE_SIZE/512), &data);
|
|
if (!rc)
|
|
return virt_to_page(data);
|
|
|
|
error:
|
|
return ERR_PTR(rc);
|
|
}
|