99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* linux/fs/ext4/bitmap.c
|
||
|
|
*
|
||
|
|
* Copyright (C) 1992, 1993, 1994, 1995
|
||
|
|
* Remy Card (card@masi.ibp.fr)
|
||
|
|
* Laboratoire MASI - Institut Blaise Pascal
|
||
|
|
* Universite Pierre et Marie Curie (Paris VI)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/buffer_head.h>
|
||
|
|
#include "ext4.h"
|
||
|
|
|
||
|
|
unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
|
||
|
|
{
|
||
|
|
return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
|
||
|
|
}
|
||
|
|
|
||
|
|
int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
|
||
|
|
struct ext4_group_desc *gdp,
|
||
|
|
struct buffer_head *bh, int sz)
|
||
|
|
{
|
||
|
|
__u32 hi;
|
||
|
|
__u32 provided, calculated;
|
||
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
||
|
|
|
||
|
|
if (!ext4_has_metadata_csum(sb))
|
||
|
|
return 1;
|
||
|
|
|
||
|
|
provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
|
||
|
|
calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
|
||
|
|
if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
|
||
|
|
hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
|
||
|
|
provided |= (hi << 16);
|
||
|
|
} else
|
||
|
|
calculated &= 0xFFFF;
|
||
|
|
|
||
|
|
return provided == calculated;
|
||
|
|
}
|
||
|
|
|
||
|
|
void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
|
||
|
|
struct ext4_group_desc *gdp,
|
||
|
|
struct buffer_head *bh, int sz)
|
||
|
|
{
|
||
|
|
__u32 csum;
|
||
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
||
|
|
|
||
|
|
if (!ext4_has_metadata_csum(sb))
|
||
|
|
return;
|
||
|
|
|
||
|
|
csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
|
||
|
|
gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
|
||
|
|
if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
|
||
|
|
gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
|
||
|
|
}
|
||
|
|
|
||
|
|
int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
|
||
|
|
struct ext4_group_desc *gdp,
|
||
|
|
struct buffer_head *bh)
|
||
|
|
{
|
||
|
|
__u32 hi;
|
||
|
|
__u32 provided, calculated;
|
||
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
||
|
|
int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
|
||
|
|
|
||
|
|
if (!ext4_has_metadata_csum(sb))
|
||
|
|
return 1;
|
||
|
|
|
||
|
|
provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
|
||
|
|
calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
|
||
|
|
if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
|
||
|
|
hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
|
||
|
|
provided |= (hi << 16);
|
||
|
|
} else
|
||
|
|
calculated &= 0xFFFF;
|
||
|
|
|
||
|
|
if (provided == calculated)
|
||
|
|
return 1;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
|
||
|
|
struct ext4_group_desc *gdp,
|
||
|
|
struct buffer_head *bh)
|
||
|
|
{
|
||
|
|
int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
|
||
|
|
__u32 csum;
|
||
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
||
|
|
|
||
|
|
if (!ext4_has_metadata_csum(sb))
|
||
|
|
return;
|
||
|
|
|
||
|
|
csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
|
||
|
|
gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
|
||
|
|
if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
|
||
|
|
gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
|
||
|
|
}
|