952fc18ef9
Commit f975d6bcc7 introduced bug which caused ext4_statfs() to
miscalculate the number of file system overhead blocks. This causes
the f_blocks field in the statfs structure to be larger than it should
be. This would in turn cause the "df" output to show the number of
data blocks in the file system and the number of data blocks used to
be larger than they should be.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
108 lines
3 KiB
C
108 lines
3 KiB
C
/*
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* linux/fs/ext4/bitmap.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*/
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#include <linux/buffer_head.h>
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#include <linux/jbd2.h>
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#include "ext4.h"
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static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
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unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
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{
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unsigned int i, sum = 0;
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for (i = 0; i < numchars; i++)
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sum += nibblemap[bitmap[i] & 0xf] +
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nibblemap[(bitmap[i] >> 4) & 0xf];
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return sum;
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}
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int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
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struct ext4_group_desc *gdp,
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struct buffer_head *bh, int sz)
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{
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__u32 hi;
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__u32 provided, calculated;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
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EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
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return 1;
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provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
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calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
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if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
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hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
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provided |= (hi << 16);
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} else
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calculated &= 0xFFFF;
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return provided == calculated;
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}
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void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
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struct ext4_group_desc *gdp,
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struct buffer_head *bh, int sz)
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{
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__u32 csum;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
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EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
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return;
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csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
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gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
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if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
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gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
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}
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int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
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struct ext4_group_desc *gdp,
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struct buffer_head *bh, int sz)
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{
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__u32 hi;
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__u32 provided, calculated;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
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EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
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return 1;
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provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
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calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
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if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
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hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
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provided |= (hi << 16);
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} else
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calculated &= 0xFFFF;
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if (provided == calculated)
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return 1;
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ext4_error(sb, "Bad block bitmap checksum: block_group = %u", group);
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return 0;
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}
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void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
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struct ext4_group_desc *gdp,
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struct buffer_head *bh, int sz)
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{
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__u32 csum;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
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EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
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return;
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csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
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gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
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if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
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gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
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}
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