Re: [PATCH 4/5] xfs: reduce the size of struct xfs_extent_free_item

[Chandan Babu R <chandan.babu@oracle.com>]

On 20 Oct 2021 at 00:22, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
>
> We only use EFIs to free metadata blocks -- not regular data/attr fork
> extents.  Remove all the fields that we never use, for a net reduction
> of 16 bytes.
>

Looks good to me.

Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>

> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  fs/xfs/libxfs/xfs_alloc.c |   25 ++++++++++++++++---------
>  fs/xfs/libxfs/xfs_alloc.h |    8 ++++++--
>  fs/xfs/xfs_extfree_item.c |   13 ++++++++++---
>  3 files changed, 32 insertions(+), 14 deletions(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
> index 9bc1a03a8167..353e53b892e6 100644
> --- a/fs/xfs/libxfs/xfs_alloc.c
> +++ b/fs/xfs/libxfs/xfs_alloc.c
> @@ -2462,12 +2462,11 @@ xfs_defer_agfl_block(
>  	ASSERT(xfs_extfree_item_cache != NULL);
>  	ASSERT(oinfo != NULL);
>  
> -	new = kmem_cache_alloc(xfs_extfree_item_cache,
> +	new = kmem_cache_zalloc(xfs_extfree_item_cache,
>  			       GFP_KERNEL | __GFP_NOFAIL);
>  	new->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno);
>  	new->xefi_blockcount = 1;
> -	new->xefi_oinfo = *oinfo;
> -	new->xefi_skip_discard = false;
> +	new->xefi_owner = oinfo->oi_owner;
>  
>  	trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1);
>  
> @@ -2505,15 +2504,23 @@ __xfs_free_extent_later(
>  #endif
>  	ASSERT(xfs_extfree_item_cache != NULL);
>  
> -	new = kmem_cache_alloc(xfs_extfree_item_cache,
> +	new = kmem_cache_zalloc(xfs_extfree_item_cache,
>  			       GFP_KERNEL | __GFP_NOFAIL);
>  	new->xefi_startblock = bno;
>  	new->xefi_blockcount = (xfs_extlen_t)len;
> -	if (oinfo)
> -		new->xefi_oinfo = *oinfo;
> -	else
> -		new->xefi_oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
> -	new->xefi_skip_discard = skip_discard;
> +	if (skip_discard)
> +		new->xefi_flags |= XFS_EFI_SKIP_DISCARD;
> +	if (oinfo) {
> +		ASSERT(oinfo->oi_offset == 0);
> +
> +		if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK)
> +			new->xefi_flags |= XFS_EFI_ATTR_FORK;
> +		if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK)
> +			new->xefi_flags |= XFS_EFI_BMBT_BLOCK;
> +		new->xefi_owner = oinfo->oi_owner;
> +	} else {
> +		new->xefi_owner = XFS_RMAP_OWN_NULL;
> +	}
>  	trace_xfs_bmap_free_defer(tp->t_mountp,
>  			XFS_FSB_TO_AGNO(tp->t_mountp, bno), 0,
>  			XFS_FSB_TO_AGBNO(tp->t_mountp, bno), len);
> diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
> index b61aeb6fbe32..1c14a0b1abea 100644
> --- a/fs/xfs/libxfs/xfs_alloc.h
> +++ b/fs/xfs/libxfs/xfs_alloc.h
> @@ -258,12 +258,16 @@ void __xfs_free_extent_later(struct xfs_trans *tp, xfs_fsblock_t bno,
>   */
>  struct xfs_extent_free_item {
>  	struct list_head	xefi_list;
> +	uint64_t		xefi_owner;
>  	xfs_fsblock_t		xefi_startblock;/* starting fs block number */
>  	xfs_extlen_t		xefi_blockcount;/* number of blocks in extent */
> -	bool			xefi_skip_discard;
> -	struct xfs_owner_info	xefi_oinfo;	/* extent owner */
> +	unsigned int		xefi_flags;
>  };
>  
> +#define XFS_EFI_SKIP_DISCARD	(1U << 0) /* don't issue discard */
> +#define XFS_EFI_ATTR_FORK	(1U << 1) /* freeing attr fork block */
> +#define XFS_EFI_BMBT_BLOCK	(1U << 2) /* freeing bmap btree block */
> +
>  static inline void
>  xfs_free_extent_later(
>  	struct xfs_trans		*tp,
> diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
> index eb378e345f13..47ef9c9c5c17 100644
> --- a/fs/xfs/xfs_extfree_item.c
> +++ b/fs/xfs/xfs_extfree_item.c
> @@ -474,14 +474,20 @@ xfs_extent_free_finish_item(
>  	struct list_head		*item,
>  	struct xfs_btree_cur		**state)
>  {
> +	struct xfs_owner_info		oinfo = { };
>  	struct xfs_extent_free_item	*free;
>  	int				error;
>  
>  	free = container_of(item, struct xfs_extent_free_item, xefi_list);
> +	oinfo.oi_owner = free->xefi_owner;
> +	if (free->xefi_flags & XFS_EFI_ATTR_FORK)
> +		oinfo.oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
> +	if (free->xefi_flags & XFS_EFI_BMBT_BLOCK)
> +		oinfo.oi_flags |= XFS_OWNER_INFO_BMBT_BLOCK;
>  	error = xfs_trans_free_extent(tp, EFD_ITEM(done),
>  			free->xefi_startblock,
>  			free->xefi_blockcount,
> -			&free->xefi_oinfo, free->xefi_skip_discard);
> +			&oinfo, free->xefi_flags & XFS_EFI_SKIP_DISCARD);
>  	kmem_cache_free(xfs_extfree_item_cache, free);
>  	return error;
>  }
> @@ -525,6 +531,7 @@ xfs_agfl_free_finish_item(
>  	struct list_head		*item,
>  	struct xfs_btree_cur		**state)
>  {
> +	struct xfs_owner_info		oinfo = { };
>  	struct xfs_mount		*mp = tp->t_mountp;
>  	struct xfs_efd_log_item		*efdp = EFD_ITEM(done);
>  	struct xfs_extent_free_item	*free;
> @@ -539,13 +546,13 @@ xfs_agfl_free_finish_item(
>  	ASSERT(free->xefi_blockcount == 1);
>  	agno = XFS_FSB_TO_AGNO(mp, free->xefi_startblock);
>  	agbno = XFS_FSB_TO_AGBNO(mp, free->xefi_startblock);
> +	oinfo.oi_owner = free->xefi_owner;
>  
>  	trace_xfs_agfl_free_deferred(mp, agno, 0, agbno, free->xefi_blockcount);
>  
>  	error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
>  	if (!error)
> -		error = xfs_free_agfl_block(tp, agno, agbno, agbp,
> -					    &free->xefi_oinfo);
> +		error = xfs_free_agfl_block(tp, agno, agbno, agbp, &oinfo);
>  
>  	/*
>  	 * Mark the transaction dirty, even on error. This ensures the


-- 
chandan