Ocfs2/move_extents: lock allocators and reserve metadata blocks and data...

	struct ocfs2_alloc_context *data_ac;

	struct ocfs2_cached_dealloc_ctxt dealloc;

};

/*

 * lock allocators, and reserving appropriate number of bits for

 * meta blocks and data clusters.

 *

 * in some cases, we don't need to reserve clusters, just let data_ac

 * be NULL.

 */

static int ocfs2_lock_allocators_move_extents(struct inode *inode,

					struct ocfs2_extent_tree *et,

					u32 clusters_to_move,

					u32 extents_to_split,

					struct ocfs2_alloc_context **meta_ac,

					struct ocfs2_alloc_context **data_ac,

					int extra_blocks,

					int *credits)

{

	int ret, num_free_extents;

	unsigned int max_recs_needed = 2 * extents_to_split + clusters_to_move;

	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	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))

		extra_blocks += ocfs2_extend_meta_needed(et->et_root_el);

	ret = ocfs2_reserve_new_metadata_blocks(osb, extra_blocks, meta_ac);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}

	if (data_ac) {

		ret = ocfs2_reserve_clusters(osb, clusters_to_move, data_ac);

		if (ret) {

			mlog_errno(ret);

			goto out;

		}

	}

	*credits += ocfs2_calc_extend_credits(osb->sb, et->et_root_el,

					      clusters_to_move + 2);

	mlog(0, "reserve metadata_blocks: %d, data_clusters: %u, credits: %d\n",

	     extra_blocks, clusters_to_move, *credits);

out:

	if (ret) {

		if (*meta_ac) {

			ocfs2_free_alloc_context(*meta_ac);

			*meta_ac = NULL;

		}

	}

	return ret;

}