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ext4: correct validation check of inode table in ext4_valid_block_bitmap

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1.Last valid cluster of inode table is EXT4_B2C(sbi, offset +
sbi->s_itb_per_group - 1). We should make sure last valid cluster is <
max_bit, i.e., EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) is <
max_bit rather than EXT4_B2C(sbi, offset + sbi->s_itb_per_group) is
< max_bit.

2.Bit search length should be last valid cluster plus 1, i.e.,
EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) + 1 rather than
EXT4_B2C(sbi, offset + sbi->s_itb_per_group).

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Kemeng Shi 2023-02-21 19:59:14 +08:00 committed by Theodore Ts'o
parent b5aa06bfe9
commit 3d61ef10f5
1 changed files with 3 additions and 3 deletions
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6
fs/ext4/balloc.c
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@ -350,13 +350,13 @@ static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
blk = ext4_inode_table(sb, desc);
offset = blk - group_first_block;
if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
EXT4_B2C(sbi, offset + sbi->s_itb_per_group) >= max_bit)
EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) >= max_bit)
return blk;
next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
EXT4_B2C(sbi, offset + sbi->s_itb_per_group),
EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) + 1,
EXT4_B2C(sbi, offset));
if (next_zero_bit <
EXT4_B2C(sbi, offset + sbi->s_itb_per_group))
EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) + 1)
/* bad bitmap for inode tables */
return blk;
return 0;