Re: [PATCH 5/7] xfs: add a xfs_efi_item_sizeof helper

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Apr 19, 2021 at 10:28:02AM +0200, Christoph Hellwig wrote:
> Add a helper to calculate the size of an xfs_efi_log_item structure
> the specified number of extents.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Function name questions notwithstanding, this is a nice cleanup.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_extfree_item.c | 10 +++-------
>  fs/xfs/xfs_extfree_item.h |  6 ++++++
>  fs/xfs/xfs_super.c        |  6 ++----
>  3 files changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
> index f15d6cfca6e2f1..afd568d426c1f1 100644
> --- a/fs/xfs/xfs_extfree_item.c
> +++ b/fs/xfs/xfs_extfree_item.c
> @@ -153,17 +153,13 @@ xfs_efi_init(
>  
>  {
>  	struct xfs_efi_log_item	*efip;
> -	uint			size;
>  
>  	ASSERT(nextents > 0);
> -	if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
> -		size = (uint)(sizeof(struct xfs_efi_log_item) +
> -			((nextents - 1) * sizeof(struct xfs_extent)));
> -		efip = kmem_zalloc(size, 0);
> -	} else {
> +	if (nextents > XFS_EFI_MAX_FAST_EXTENTS)
> +		efip = kmem_zalloc(xfs_efi_item_sizeof(nextents), 0);
> +	else
>  		efip = kmem_cache_zalloc(xfs_efi_zone,
>  					 GFP_KERNEL | __GFP_NOFAIL);
> -	}
>  
>  	xfs_log_item_init(mp, &efip->efi_item, XFS_LI_EFI, &xfs_efi_item_ops);
>  	efip->efi_format.efi_nextents = nextents;
> diff --git a/fs/xfs/xfs_extfree_item.h b/fs/xfs/xfs_extfree_item.h
> index e09afd0f63ff59..d2577d872de771 100644
> --- a/fs/xfs/xfs_extfree_item.h
> +++ b/fs/xfs/xfs_extfree_item.h
> @@ -52,6 +52,12 @@ struct xfs_efi_log_item {
>  	struct xfs_efi_log_format efi_format;
>  };
>  
> +static inline int xfs_efi_item_sizeof(unsigned int nextents)
> +{
> +	return sizeof(struct xfs_efi_log_item) +
> +		(nextents - 1) * sizeof(struct xfs_extent);
> +}
> +
>  /*
>   * This is the "extent free done" log item.  It is used to log
>   * the fact that some extents earlier mentioned in an efi item
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index a2dab05332ac27..c93710cb5ce3f0 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1961,10 +1961,8 @@ xfs_init_zones(void)
>  		goto out_destroy_buf_item_zone;
>  
>  	xfs_efi_zone = kmem_cache_create("xfs_efi_item",
> -					 (sizeof(struct xfs_efi_log_item) +
> -					 (XFS_EFI_MAX_FAST_EXTENTS - 1) *
> -					 sizeof(struct xfs_extent)),
> -					 0, 0, NULL);
> +			xfs_efi_item_sizeof(XFS_EFI_MAX_FAST_EXTENTS),
> +			0, 0, NULL);
>  	if (!xfs_efi_zone)
>  		goto out_destroy_efd_zone;
>  
> -- 
> 2.30.1
>