| | 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 | |
| | 13 | unsigned int ext4_count_free(char *bitmap, unsigned int numchars) |
| | 14 | { |
| | 15 | return numchars * BITS_PER_BYTE - memweight(bitmap, numchars); |
| | 16 | } |
| | 17 | |
| | 18 | int 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 | |
| | 40 | void 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 | |
| | 56 | int 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 | |
| | 82 | void 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 | } |
projects / mirror_ubuntu-artful-kernel.git / blame_incremental