[PATCH v7 4/4] xfs: xfs_seek_hole() refinement with hole searching from page cache for unwritten extent

[Dave Chinner]

On Mon, Aug 13, 2012 at 09:08:13PM +0800, Jeff Liu wrote:
> Improve xfs_seek_hole() to search hole offset from page cache for unwritten extents.
> 
> Signed-off-by: Jie Liu <jeff.liu at oracle.com>

same as previous patch.

Reviewed-by: Dave Chinner <dchinner at redhat.com>

> +		 */
> +		if (nmap == 1) {
> +			offset = isize;
> +			break;
> +		}
>  
> -	holeoff = XFS_FSB_TO_B(mp, fsbno);
> -	if (holeoff <= start)
> -		offset = start;
> -	else {
>  		/*
> -		 * xfs_bmap_first_unused() could return a value bigger than
> -		 * isize if there are no more holes past the supplied offset.
> +		 * Both mappings contains data, proceed to the next round of
> +		 * search if the current reading offset not beyond or hit EOF.
>  		 */
> -		offset = min_t(loff_t, holeoff, isize);

		ASSERT(i > 1);

> +		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
> +		start = XFS_FSB_TO_B(mp, fsbno);
> +		if (start >= isize) {
> +			offset = isize;
> +			break;
> +		}
>  	}

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com