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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/*
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}