Re: [RFC][PATCH 6/12] handling of 64-bit block counts in e2fsprofs

Andreas Dilger
2007-06-12T10:02:22Z

On Jun 11, 2007 18:42 +0200, Valerie Clement wrote:
> +#ifdef _EXT4FS_
> +#define EXT2_BLOCKS_PER_GROUP(s) ((__u64)EXT2_SB(s)->s_blocks_per_group)
> +#else
> #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group)
> +#endif

Are there actually plans for s_blocks_per_group > 2^32? We can already handle
up to 2^32 groups, so we have plenty of room to spare.

> @@ -573,6 +577,54 @@ struct ext2_super_block {
> __u32 s_reserved[167]; /* Padding to the end of the block */
> };
>
> +#ifdef _EXT4FS_
> +#define EXT2_BLOCKS_COUNT(s) \
> + ((s)->s_blocks_count + ((__u64)(s)->s_blocks_count_hi << 32))
> +
> +#define EXT2_BLOCKS_COUNT_SET(s, v) \
> + do { \
> + (s)->s_blocks_count = (v); \
> + (s)->s_blocks_count_hi = (v) >> 32; \
> + } while (0)
> +
> +#define EXT2_R_BLOCKS_COUNT(s) \
> + ((s)->s_r_blocks_count + ((__u64)(s)->s_r_blocks_count_hi << 32))
> +
> +#define EXT2_R_BLOCKS_COUNT_SET(s, v) \
> + do { \
> + (s)->s_r_blocks_count = (v); \
> + (s)->s_r_blocks_count_hi = (v) >> 32; \
> + } while (0)
> +
> +#define EXT2_FREE_BLOCKS_COUNT(s) \
> + ((s)->s_free_blocks_count + ((__u64)(s)->s_free_blocks_hi << 32))
> +
> +#define EXT2_FREE_BLOCKS_COUNT_SET(s, v) \
> + do { \
> + (s)->s_free_blocks_count = (v); \
> + (s)->s_free_blocks_hi = (v) >> 32; \
> + } while (0)
> +#else
> +#define EXT2_BLOCKS_COUNT(s) ((s)->s_blocks_count)
> +#define EXT2_R_BLOCKS_COUNT(s) ((s)->s_r_blocks_count)
> +#define EXT2_FREE_BLOCKS_COUNT(s) ((s)->s_free_blocks_count)

I don't think any of this (above or in most/all of the rest of this patch)
should be conditional upon #ifdef _EXT4FS_. Instead, it should depend on
INCOMPAT_64BIT being set in the superblock. I don't think it introduces
any compatibility issues by itself.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.