On Thu, Jul 24, 2014 at 10:22:55AM -0400, Brian Foster wrote:
> Sparse inode chunks allow the traditional inode btree record format to
> describe an inode chunk that is not fully allocated and/or contiguous.
> Define a couple constants that set requirements for allocation and
> management of such chunks. Also define a helper to easily detect sparse
> inode chunks.
>
> The granularity of a sparse chunk is defined by the the 16-bit holemask
> field in the inode record. Assuming 64 inodes per full chunk, a single
> holemask bit accounts for 4 inodes. The minimum allocation requirement
> for a sparse inode chunk is defined as the minimum number of blocks
> required to meet the 4 inode granularity.
>
> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
> ---
> fs/xfs/libxfs/xfs_format.h | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> index 39022d9..0baad50 100644
> --- a/fs/xfs/libxfs/xfs_format.h
> +++ b/fs/xfs/libxfs/xfs_format.h
> @@ -211,6 +211,11 @@ typedef __uint64_t xfs_inofree_t;
> #define XFS_INOBT_ALL_FREE ((xfs_inofree_t)-1)
> #define XFS_INOBT_MASK(i) ((xfs_inofree_t)1 << (i))
>
> +#define XFS_INODES_PER_SPCHUNK \
> + (XFS_INODES_PER_CHUNK / (NBBY * sizeof(__uint16_t)))
> +#define XFS_INOBT_MIN_SPCHUNKLEN(sb) \
> + (roundup(XFS_INODES_PER_SPCHUNK, sb.sb_inopblock) / sb.sb_inopblock)
static inline.
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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