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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 "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,
20 struct ext4_group_desc *gdp,
21 struct buffer_head *bh)
22{
23 __u32 hi;
24 __u32 provided, calculated;
25 struct ext4_sb_info *sbi = EXT4_SB(sb);
26 int sz;
27
28 if (!ext4_has_metadata_csum(sb))
29 return 1;
30
31 sz = EXT4_INODES_PER_GROUP(sb) >> 3;
32 provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
33 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
34 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
35 hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
36 provided |= (hi << 16);
37 } else
38 calculated &= 0xFFFF;
39
40 return provided == calculated;
41}
42
43void ext4_inode_bitmap_csum_set(struct super_block *sb,
44 struct ext4_group_desc *gdp,
45 struct buffer_head *bh)
46{
47 __u32 csum;
48 struct ext4_sb_info *sbi = EXT4_SB(sb);
49 int sz;
50
51 if (!ext4_has_metadata_csum(sb))
52 return;
53
54 sz = EXT4_INODES_PER_GROUP(sb) >> 3;
55 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
56 gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
57 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
58 gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
59}
60
61int ext4_block_bitmap_csum_verify(struct super_block *sb,
62 struct ext4_group_desc *gdp,
63 struct buffer_head *bh)
64{
65 __u32 hi;
66 __u32 provided, calculated;
67 struct ext4_sb_info *sbi = EXT4_SB(sb);
68 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
69
70 if (!ext4_has_metadata_csum(sb))
71 return 1;
72
73 provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
74 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
75 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
76 hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
77 provided |= (hi << 16);
78 } else
79 calculated &= 0xFFFF;
80
81 return provided == calculated;
82}
83
84void ext4_block_bitmap_csum_set(struct super_block *sb,
85 struct ext4_group_desc *gdp,
86 struct buffer_head *bh)
87{
88 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
89 __u32 csum;
90 struct ext4_sb_info *sbi = EXT4_SB(sb);
91
92 if (!ext4_has_metadata_csum(sb))
93 return;
94
95 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
96 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
97 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
98 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
99}