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. 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. > +#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. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
