Commit 81e8c3c5 authored by Petr Malat's avatar Petr Malat Committed by Theodore Ts'o
Browse files

ext4: do not interpret high bytes if 64bit feature is disabled 



Fields s_free_blocks_count_hi, s_r_blocks_count_hi and s_blocks_count_hi
are not valid if EXT4_FEATURE_INCOMPAT_64BIT is not enabled and should be
treated as zeroes.

Signed-off-by: default avatarPetr Malat <oss@malat.biz>
Link: https://lore.kernel.org/r/20200825150016.3363-1-oss@malat.biz


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent b483bb77

fs/ext4/ext4.h

+8 −6
Original line number Diff line number Diff line
@@ -3012,22 +3012,24 @@ static inline int ext4_has_group_desc_csum(struct super_block *sb) 
	return ext4_has_feature_gdt_csum(sb) || ext4_has_metadata_csum(sb);

}



#define ext4_read_incompat_64bit_val(es, name) \

	(((es)->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT) \

		? (ext4_fsblk_t)le32_to_cpu(es->name##_hi) << 32 : 0) | \

		le32_to_cpu(es->name##_lo))



static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)

{

	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |

		le32_to_cpu(es->s_blocks_count_lo);

	return ext4_read_incompat_64bit_val(es, s_blocks_count);

}



static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)

{

	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |

		le32_to_cpu(es->s_r_blocks_count_lo);

	return ext4_read_incompat_64bit_val(es, s_r_blocks_count);

}



static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)

{

	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |

		le32_to_cpu(es->s_free_blocks_count_lo);

	return ext4_read_incompat_64bit_val(es, s_free_blocks_count);

}



static inline void ext4_blocks_count_set(struct ext4_super_block *es,

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