[PATCH 11/71] xfs: define the on-disk refcount btree format

[Christoph Hellwig]

On Thu, Aug 25, 2016 at 04:33:09PM -0700, Darrick J. Wong wrote:
> [hch: allocate the cursor with KM_NOFS to quiet lockdep]
> Signed-off-by: Christoph Hellwig <hch at lst.de>

feel free to drop mentioning this little fixlet..

> +/* Per-AG btree private information. */
> +union xfs_btree_cur_private {
> +	struct {
> +		unsigned long	nr_ops;		/* # record updates */
> +		int		shape_changes;	/* # of extent splits */
> +	} refc;
>  };
>  
>  /*
> @@ -247,6 +258,7 @@ typedef struct xfs_btree_cur
>  			struct xfs_buf	*agbp;	/* agf/agi buffer pointer */
>  			struct xfs_defer_ops *dfops;	/* deferred updates */
>  			xfs_agnumber_t	agno;	/* ag number */
> +			union xfs_btree_cur_private	priv;
>  		} a;

So we have a struct in a union in a struct in a union in a struct.
But I don't really see a good way around this..

But in general this looks fine:

Reviewed-by: Christoph Hellwig <hch at lst.de>