On Tue, Apr 30, 2024 at 02:49:21PM +0200, Christoph Hellwig wrote:
> Add a common helper for the calculation of the overhead when converting
> a shortform to block format directory.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/xfs/libxfs/xfs_dir2_block.c | 4 ++--
> fs/xfs/libxfs/xfs_dir2_priv.h | 12 ++++++++++++
> fs/xfs/libxfs/xfs_dir2_sf.c | 12 ++++--------
> 3 files changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_dir2_block.c b/fs/xfs/libxfs/xfs_dir2_block.c
> index 378d3aefdd9ced..a19744cb43ca0c 100644
> --- a/fs/xfs/libxfs/xfs_dir2_block.c
> +++ b/fs/xfs/libxfs/xfs_dir2_block.c
> @@ -1109,8 +1109,8 @@ xfs_dir2_sf_to_block(
> /*
> * Compute size of block "tail" area.
> */
> - i = (uint)sizeof(*btp) +
> - (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t);
> + i = xfs_dir2_block_overhead(sfp->count);
> +
> /*
> * The whole thing is initialized to free by the init routine.
> * Say we're using the leaf and tail area.
> diff --git a/fs/xfs/libxfs/xfs_dir2_priv.h b/fs/xfs/libxfs/xfs_dir2_priv.h
> index 1e4401f9ec936e..bfbc73251f275a 100644
> --- a/fs/xfs/libxfs/xfs_dir2_priv.h
> +++ b/fs/xfs/libxfs/xfs_dir2_priv.h
> @@ -205,4 +205,16 @@ xfs_dahash_t xfs_dir2_hashname(struct xfs_mount *mp,
> enum xfs_dacmp xfs_dir2_compname(struct xfs_da_args *args,
> const unsigned char *name, int len);
>
> +/*
> + * Overhead if we converted a shortform directory to block format.
> + *
> + * The extra two entries are because "." and ".." don't have real entries in
> + * the shortform format.
> + */
> +static inline unsigned int xfs_dir2_block_overhead(unsigned int count)
> +{
> + return (count + 2) * sizeof(struct xfs_dir2_leaf_entry) +
> + sizeof(struct xfs_dir2_block_tail);
I could've sworn there's a helper to compute this, but as I cannot find
it I guess I'll let that go.
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> +}
> +
> #endif /* __XFS_DIR2_PRIV_H__ */
> diff --git a/fs/xfs/libxfs/xfs_dir2_sf.c b/fs/xfs/libxfs/xfs_dir2_sf.c
> index 21e04594606b89..1e1dcdf83b8f95 100644
> --- a/fs/xfs/libxfs/xfs_dir2_sf.c
> +++ b/fs/xfs/libxfs/xfs_dir2_sf.c
> @@ -629,9 +629,7 @@ xfs_dir2_sf_addname_pick(
> * Calculate data bytes used excluding the new entry, if this
> * was a data block (block form directory).
> */
> - used = offset +
> - (sfp->count + 3) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
> - (uint)sizeof(xfs_dir2_block_tail_t);
> + used = offset + xfs_dir2_block_overhead(sfp->count + 1);
> /*
> * If it won't fit in a block form then we can't insert it,
> * we'll go back, convert to block, then try the insert and convert
> @@ -691,9 +689,7 @@ xfs_dir2_sf_check(
> }
> ASSERT(i8count == sfp->i8count);
> ASSERT((char *)sfep - (char *)sfp == dp->i_disk_size);
> - ASSERT(offset +
> - (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
> - (uint)sizeof(xfs_dir2_block_tail_t) <= args->geo->blksize);
> + ASSERT(offset + xfs_dir2_block_overhead(sfp->count));
> }
> #endif /* DEBUG */
>
> @@ -782,8 +778,8 @@ xfs_dir2_sf_verify(
> return __this_address;
>
> /* Make sure this whole thing ought to be in local format. */
> - if (offset + (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
> - (uint)sizeof(xfs_dir2_block_tail_t) > mp->m_dir_geo->blksize)
> + if (offset + xfs_dir2_block_overhead(sfp->count) >
> + mp->m_dir_geo->blksize)
> return __this_address;
>
> return NULL;
> --
> 2.39.2
>
>
