[Ocfs2-devel] [PATCH 1/4] Ocfs2: Optimize truncting codes for ocfs2 to use ocfs2_remove_btree_range instead.

[Joel Becker <Joel.Becker@oracle.com>]

On Thu, May 06, 2010 at 02:50:15PM +0800, Tristan Ye wrote:
> The patch has been tested normally for sanity check, stress tests with heavier workload
> will be expected.

	The patch looks functionally good.  A couple housekeeping
comments.

> +static int ocfs2_reserve_blocks_for_rec_trunc(struct inode *inode,
> +					      struct ocfs2_extent_tree *et,
> +					      u32 extents_to_split,
> +					      struct ocfs2_alloc_context **ac,
> +					      int extra_blocks)
> +{
> +	int ret = 0, num_free_extents, blocks = extra_blocks;
> +	unsigned int max_recs_needed = 2 * extents_to_split;
> +	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
> +
> +	*ac = NULL;
> +
> +	num_free_extents = ocfs2_num_free_extents(osb, et);
> +	if (num_free_extents < 0) {
> +		ret = num_free_extents;
> +		mlog_errno(ret);
> +		goto out;
> +	}
> +
> +	if (!num_free_extents ||
> +	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed))
> +		blocks += ocfs2_extend_meta_needed(et->et_root_el);

	You don't need the blocks variable.  Just use extra_blocks here.
Save us a word on the stack.

>  int ocfs2_remove_btree_range(struct inode *inode,
>  			     struct ocfs2_extent_tree *et,
>  			     u32 cpos, u32 phys_cpos, u32 len,

	Move flags here:     u32 cpos, u32 phys_cpos, u32 len, int flags,

> -			     struct ocfs2_cached_dealloc_ctxt *dealloc)
> +			     struct ocfs2_cached_dealloc_ctxt *dealloc,
> +			     u64 refcount_loc, int flags)

It fits with the tuple representing the extent range.

> diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
> index 33dd2a1..cabdcf8 100644
> --- a/fs/ocfs2/refcounttree.c
> +++ b/fs/ocfs2/refcounttree.c
> @@ -2508,21 +2508,20 @@ out:
>   * we gonna touch and whether we need to create new blocks.
>   *
>   * Normally the refcount blocks store these refcount should be
> - * contiguous also, so that we can get the number easily.
> - * As for meta_ac, we will at most add split 2 refcount record and
> - * 2 more refcount block, so just check it in a rough way.
> + * continguous also, so that we can get the number easily.

	Whoops, you misspelled 'contiguous' here.

Joel

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Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127