/*
 * Prepares for removal from one level of the hierarchy.  The caller must
 * call delete_at() to remove the entry at index.
 */
static int remove_raw(struct shadow_spine *s, struct dm_btree_info *info,
		      struct dm_btree_value_type *vt, dm_block_t root,
		      uint64_t key, unsigned *index)
{
	int i = *index, r;
	struct btree_node *n;

	for (;;) {
		r = shadow_step(s, root, vt);
		if (r < 0)
			break;

		/*
		 * We have to patch up the parent node, ugly, but I don't
		 * see a way to do this automatically as part of the spine
		 * op.
		 */
		if (shadow_has_parent(s)) {
			__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
			memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
			       &location, sizeof(__le64));
		}

		n = dm_block_data(shadow_current(s));

		if (le32_to_cpu(n->header.flags) & LEAF_NODE)
			return do_leaf(n, key, index);

		r = rebalance_children(s, info, vt, key);
		if (r)
			break;

		n = dm_block_data(shadow_current(s));
		if (le32_to_cpu(n->header.flags) & LEAF_NODE)
			return do_leaf(n, key, index);

		i = lower_bound(n, key);

		/*
		 * We know the key is present, or else
		 * rebalance_children would have returned
		 * -ENODATA
		 */
		root = value64(n, i);
	}

	return r;
}
Esempio n. 2
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static int btree_insert_raw(struct shadow_spine *s, dm_block_t root,
			    struct dm_btree_value_type *vt,
			    uint64_t key, unsigned *index)
{
	int r, i = *index, top = 1;
	struct btree_node *node;

	for (;;) {
		r = shadow_step(s, root, vt);
		if (r < 0)
			return r;

		node = dm_block_data(shadow_current(s));

		/*
		 * We have to patch up the parent node, ugly, but I don't
		 * see a way to do this automatically as part of the spine
		 * op.
		 */
		if (shadow_has_parent(s) && i >= 0) { /* FIXME: second clause unness. */
			__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));

			__dm_bless_for_disk(&location);
			memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i),
				    &location, sizeof(__le64));
		}

		node = dm_block_data(shadow_current(s));

		if (node->header.nr_entries == node->header.max_entries) {
			if (top)
				r = btree_split_beneath(s, key);
			else
				r = btree_split_sibling(s, root, i, key);

			if (r < 0)
				return r;
		}

		node = dm_block_data(shadow_current(s));

		i = lower_bound(node, key);

		if (le32_to_cpu(node->header.flags) & LEAF_NODE)
			break;

		if (i < 0) {
			/* change the bounds on the lowest key */
			node->keys[0] = cpu_to_le64(key);
			i = 0;
		}

		root = value64(node, i);
		top = 0;
	}

	if (i < 0 || le64_to_cpu(node->keys[i]) != key)
		i++;

	*index = i;
	return 0;
}