Andreas Dilger wrote:
On Nov 24, 2006 17:48 +0100, Valerie Clement wrote:
@@ -133,6 +133,9 @@ struct ext4_group_desc
__le32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */
__le32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */
__le32 bg_inode_table_hi; /* Inodes table block MSB */
+ __le16 bg_free_blocks_count_hi; /* Free blocks count MSB */
+ __le16 bg_free_inodes_count_hi; /* Free inodes count MSB */
+ __le16 bg_used_dirs_count_hi; /* Directories count MSB */
};
Does the ext4 code already avoid using "sizeof(struct ext4_group_desc)"
or "sizeof(*gdp)" everywhere? Otherwise this is very dangerous.
Currently, the code doesn't use sizeof of the structure or of a group
descriptor, but do you mean that adding padding to the structure is better?
Also note that the on-disk layout of this struct in e2fsprogs is a bit
incorrect - it has the above 3 __u16, but then immediately __u32 bg_reserved
so those fields are padded incorrectly. I think it isn't a fatal problem,
just something to be aware of and fix.
OK.
+#define EXT4_READ_SPLIT_LE32(__sb, __field) \
+ ((__u32)le16_to_cpu(__field) + \
+ (EXT4_HAS_INCOMPAT_FEATURE((__sb), EXT4_FEATURE_INCOMPAT_64BIT) ? \
+ (__u32)le16_to_cpu(__field##_hi) << 16 : 0))
Is it better to make this INCOMPAT_64BIT or s_desc_size? Does INCOMPAT_64BIT
always imply s_desc_size > 32? Hmm, I guess it does, or we have no place to
store the _hi part of the block addresses for a group.
I prefer using INCOMPAT_64BIT rather than s_desc_size.
Thank you Andreas to point that out, I missed to update my e2fsprogs
version to initialize s_desc_size with the right value in some cases.
Valérie
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