From: Petr Malat <oss@malat.biz>
To: linux-ext4@vger.kernel.org
Cc: adilger.kernel@dilger.ca, tytso@mit.edu, Petr Malat <oss@malat.biz>
Subject: [PATCH] ext4: Do not interpret high bytes if 64bit feature is disabled
Date: Tue, 25 Aug 2020 17:00:16 +0200 [thread overview]
Message-ID: <20200825150016.3363-1-oss@malat.biz> (raw)
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>
---
fs/ext4/ext4.h | 14 ++++++++------
1 file 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,
--
2.20.1
next reply other threads:[~2020-08-25 15:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-25 15:00 Petr Malat [this message]
2020-10-03 4:05 ` [PATCH] ext4: Do not interpret high bytes if 64bit feature is disabled Theodore Y. Ts'o
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