Re: [PATCH 08/14] xfs: support embedded dfops in transaction

[Christoph Hellwig <hch@infradead.org>]

> +/*
> + * Move state from one xfs_defer_ops to another and reset the source to initial
> + * state. This is primarily used to carry state forward across transaction rolls
> + * with internal dfops.
> + */

> +void
> +xfs_defer_move(
> +	struct xfs_defer_ops	*dst,
> +	struct xfs_defer_ops	*src)
> +{
> +	int			i;
> +
> +	ASSERT(dst != src);
> +
> +	list_splice_init(&src->dop_intake, &dst->dop_intake);
> +	list_splice_init(&src->dop_pending, &dst->dop_pending);
> +
> +	for (i = 0; i < XFS_DEFER_OPS_NR_INODES; i++) {
> +		if (!src->dop_inodes[i])
> +			break;
> +		dst->dop_inodes[i] = src->dop_inodes[i];
> +	}
> +	for (i = 0; i< XFS_DEFER_OPS_NR_BUFS; i++) {
> +		if (!src->dop_bufs[i])
> +			break;
> +		dst->dop_bufs[i] = src->dop_bufs[i];
> +	}

I suspect simply memcpy()ing the state over would be faster..