Loading...
1/*
2 * linux/fs/ext4/bitmap.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 */
9
10#include <linux/buffer_head.h>
11#include "ext4.h"
12
13unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
14{
15 return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
16}
17
18int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
19 struct ext4_group_desc *gdp,
20 struct buffer_head *bh, int sz)
21{
22 __u32 hi;
23 __u32 provided, calculated;
24 struct ext4_sb_info *sbi = EXT4_SB(sb);
25
26 if (!ext4_has_metadata_csum(sb))
27 return 1;
28
29 provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
30 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
31 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
32 hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
33 provided |= (hi << 16);
34 } else
35 calculated &= 0xFFFF;
36
37 return provided == calculated;
38}
39
40void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
41 struct ext4_group_desc *gdp,
42 struct buffer_head *bh, int sz)
43{
44 __u32 csum;
45 struct ext4_sb_info *sbi = EXT4_SB(sb);
46
47 if (!ext4_has_metadata_csum(sb))
48 return;
49
50 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
51 gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
52 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
53 gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
54}
55
56int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
57 struct ext4_group_desc *gdp,
58 struct buffer_head *bh)
59{
60 __u32 hi;
61 __u32 provided, calculated;
62 struct ext4_sb_info *sbi = EXT4_SB(sb);
63 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
64
65 if (!ext4_has_metadata_csum(sb))
66 return 1;
67
68 provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
69 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
70 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
71 hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
72 provided |= (hi << 16);
73 } else
74 calculated &= 0xFFFF;
75
76 if (provided == calculated)
77 return 1;
78
79 return 0;
80}
81
82void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
83 struct ext4_group_desc *gdp,
84 struct buffer_head *bh)
85{
86 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
87 __u32 csum;
88 struct ext4_sb_info *sbi = EXT4_SB(sb);
89
90 if (!ext4_has_metadata_csum(sb))
91 return;
92
93 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
94 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
95 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
96 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
97}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext4/bitmap.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 */
10
11#include <linux/buffer_head.h>
12#include "ext4.h"
13
14unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
15{
16 return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
17}
18
19int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
20 struct ext4_group_desc *gdp,
21 struct buffer_head *bh, int sz)
22{
23 __u32 hi;
24 __u32 provided, calculated;
25 struct ext4_sb_info *sbi = EXT4_SB(sb);
26
27 if (!ext4_has_metadata_csum(sb))
28 return 1;
29
30 provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
31 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
32 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
33 hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
34 provided |= (hi << 16);
35 } else
36 calculated &= 0xFFFF;
37
38 return provided == calculated;
39}
40
41void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
42 struct ext4_group_desc *gdp,
43 struct buffer_head *bh, int sz)
44{
45 __u32 csum;
46 struct ext4_sb_info *sbi = EXT4_SB(sb);
47
48 if (!ext4_has_metadata_csum(sb))
49 return;
50
51 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
52 gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
53 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
54 gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
55}
56
57int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
58 struct ext4_group_desc *gdp,
59 struct buffer_head *bh)
60{
61 __u32 hi;
62 __u32 provided, calculated;
63 struct ext4_sb_info *sbi = EXT4_SB(sb);
64 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
65
66 if (!ext4_has_metadata_csum(sb))
67 return 1;
68
69 provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
70 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
71 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
72 hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
73 provided |= (hi << 16);
74 } else
75 calculated &= 0xFFFF;
76
77 if (provided == calculated)
78 return 1;
79
80 return 0;
81}
82
83void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
84 struct ext4_group_desc *gdp,
85 struct buffer_head *bh)
86{
87 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
88 __u32 csum;
89 struct ext4_sb_info *sbi = EXT4_SB(sb);
90
91 if (!ext4_has_metadata_csum(sb))
92 return;
93
94 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
95 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
96 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
97 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
98}