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 <linux/jbd2.h>
12#include "ext4.h"
13
14static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
15
16unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
17{
18 unsigned int i, sum = 0;
19
20 for (i = 0; i < numchars; i++)
21 sum += nibblemap[bitmap[i] & 0xf] +
22 nibblemap[(bitmap[i] >> 4) & 0xf];
23 return sum;
24}
25
26int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
27 struct ext4_group_desc *gdp,
28 struct buffer_head *bh, int sz)
29{
30 __u32 hi;
31 __u32 provided, calculated;
32 struct ext4_sb_info *sbi = EXT4_SB(sb);
33
34 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
35 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
36 return 1;
37
38 provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
39 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
40 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
41 hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
42 provided |= (hi << 16);
43 } else
44 calculated &= 0xFFFF;
45
46 return provided == calculated;
47}
48
49void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
50 struct ext4_group_desc *gdp,
51 struct buffer_head *bh, int sz)
52{
53 __u32 csum;
54 struct ext4_sb_info *sbi = EXT4_SB(sb);
55
56 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
57 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
58 return;
59
60 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
61 gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
62 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
63 gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
64}
65
66int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
67 struct ext4_group_desc *gdp,
68 struct buffer_head *bh, int sz)
69{
70 __u32 hi;
71 __u32 provided, calculated;
72 struct ext4_sb_info *sbi = EXT4_SB(sb);
73
74 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
75 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
76 return 1;
77
78 provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
79 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
80 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
81 hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
82 provided |= (hi << 16);
83 } else
84 calculated &= 0xFFFF;
85
86 if (provided == calculated)
87 return 1;
88
89 return 0;
90}
91
92void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
93 struct ext4_group_desc *gdp,
94 struct buffer_head *bh, int sz)
95{
96 __u32 csum;
97 struct ext4_sb_info *sbi = EXT4_SB(sb);
98
99 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
100 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
101 return;
102
103 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
104 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
105 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
106 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
107}
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,
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,
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,
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 return provided == calculated;
78}
79
80void ext4_block_bitmap_csum_set(struct super_block *sb,
81 struct ext4_group_desc *gdp,
82 struct buffer_head *bh)
83{
84 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
85 __u32 csum;
86 struct ext4_sb_info *sbi = EXT4_SB(sb);
87
88 if (!ext4_has_metadata_csum(sb))
89 return;
90
91 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
92 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
93 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
94 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
95}