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| author | Petr Malat <oss@malat.biz> | 2020-08-25 17:00:16 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-10-18 10:36:13 -0400 |
| commit | 81e8c3c50352f4eede634a89e018e3b3907c2d44 (patch) | |
| tree | 346f0b060b0af852a3f50915ff3f3ab9014268ce | |
| parent | b483bb77194b4ec462fb23ad3fd6a6b36a635340 (diff) | |
| download | lwn-81e8c3c50352f4eede634a89e018e3b3907c2d44.tar.gz lwn-81e8c3c50352f4eede634a89e018e3b3907c2d44.zip | |
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: Petr Malat <oss@malat.biz>
Link: https://lore.kernel.org/r/20200825150016.3363-1-oss@malat.biz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/ext4.h | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 523e00d7b392..eafb92fe7735 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -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, |