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Commit | Line | Data |
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ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/bitmap.c |
ac27a0ec DK |
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> | |
dab291af | 11 | #include <linux/jbd2.h> |
3dcf5451 | 12 | #include "ext4.h" |
ac27a0ec | 13 | |
f6fb99ca | 14 | unsigned int ext4_count_free(char *bitmap, unsigned int numchars) |
ac27a0ec | 15 | { |
6017b485 | 16 | return numchars * BITS_PER_BYTE - memweight(bitmap, numchars); |
ac27a0ec DK |
17 | } |
18 | ||
41a246d1 DW |
19 | int 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_RO_COMPAT_FEATURE(sb, | |
28 | EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) | |
29 | return 1; | |
30 | ||
31 | provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo); | |
32 | calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz); | |
33 | if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) { | |
34 | hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi); | |
35 | provided |= (hi << 16); | |
36 | } else | |
37 | calculated &= 0xFFFF; | |
38 | ||
39 | return provided == calculated; | |
40 | } | |
41 | ||
42 | void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group, | |
43 | struct ext4_group_desc *gdp, | |
44 | struct buffer_head *bh, int sz) | |
45 | { | |
46 | __u32 csum; | |
47 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
48 | ||
49 | if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, | |
50 | EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) | |
51 | return; | |
52 | ||
53 | csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz); | |
54 | gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF); | |
55 | if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) | |
56 | gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16); | |
57 | } | |
fa77dcfa DW |
58 | |
59 | int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group, | |
60 | struct ext4_group_desc *gdp, | |
79f1ba49 | 61 | struct buffer_head *bh) |
fa77dcfa DW |
62 | { |
63 | __u32 hi; | |
64 | __u32 provided, calculated; | |
65 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
79f1ba49 | 66 | int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8; |
fa77dcfa DW |
67 | |
68 | if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, | |
69 | EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) | |
70 | return 1; | |
71 | ||
72 | provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo); | |
73 | calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz); | |
74 | if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) { | |
75 | hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi); | |
76 | provided |= (hi << 16); | |
77 | } else | |
78 | calculated &= 0xFFFF; | |
79 | ||
80 | if (provided == calculated) | |
81 | return 1; | |
82 | ||
fa77dcfa DW |
83 | return 0; |
84 | } | |
85 | ||
86 | void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group, | |
87 | struct ext4_group_desc *gdp, | |
79f1ba49 | 88 | struct buffer_head *bh) |
fa77dcfa | 89 | { |
79f1ba49 | 90 | int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8; |
fa77dcfa DW |
91 | __u32 csum; |
92 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
93 | ||
94 | if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, | |
95 | EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) | |
96 | return; | |
97 | ||
98 | csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz); | |
99 | gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF); | |
100 | if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) | |
101 | gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16); | |
102 | } |