Example #1
0
int dm_array_get_value(struct dm_array_info *info, dm_block_t root,
		       uint32_t index, void *value_le)
{
	int r;
	struct dm_block *block;
	struct array_block *ab;
	size_t size_of_block;
	unsigned entry, max_entries;

	size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
	max_entries = calc_max_entries(info->value_type.size, size_of_block);

	r = lookup_ablock(info, root, index / max_entries, &block, &ab);
	if (r)
		return r;

	entry = index % max_entries;
	if (entry >= le32_to_cpu(ab->nr_entries))
		r = -ENODATA;
	else
		memcpy(value_le, element_at(info, ab, entry),
		       info->value_type.size);

	unlock_ablock(info, block);
	return r;
}
Example #2
0
static int array_resize(struct dm_array_info *info, dm_block_t root,
			uint32_t old_size, uint32_t new_size,
			const void *value, dm_block_t *new_root)
{
	int r;
	struct resize resize;

	if (old_size == new_size)
		return 0;

	resize.info = info;
	resize.root = root;
	resize.size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
	resize.max_entries = calc_max_entries(info->value_type.size,
					      resize.size_of_block);

	resize.old_nr_full_blocks = old_size / resize.max_entries;
	resize.old_nr_entries_in_last_block = old_size % resize.max_entries;
	resize.new_nr_full_blocks = new_size / resize.max_entries;
	resize.new_nr_entries_in_last_block = new_size % resize.max_entries;
	resize.value = value;

	r = ((new_size > old_size) ? grow : shrink)(&resize);
	if (r)
		return r;

	*new_root = resize.root;
	return 0;
}
Example #3
0
int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root)
{
	int r;
	struct dm_block *b;
	struct btree_node *n;
	size_t block_size;
	uint32_t max_entries;

	r = new_block(info, &b);
	if (r < 0)
		return r;

	block_size = dm_bm_block_size(dm_tm_get_bm(info->tm));
	max_entries = calc_max_entries(info->value_type.size, block_size);

	n = dm_block_data(b);
	memset(n, 0, block_size);
	n->header.flags = cpu_to_le32(LEAF_NODE);
	n->header.nr_entries = cpu_to_le32(0);
	n->header.max_entries = cpu_to_le32(max_entries);
	n->header.value_size = cpu_to_le32(info->value_type.size);

	*root = dm_block_location(b);
	return unlock_block(info, b);
}
Example #4
0
static void prefetch_children(struct del_stack *s, struct frame *f)
{
	unsigned i;
	struct dm_block_manager *bm = dm_tm_get_bm(s->tm);

	for (i = 0; i < f->nr_children; i++)
		dm_bm_prefetch(bm, value64(f->n, i));
}
static int rebalance_children(struct shadow_spine *s,
			      struct dm_btree_info *info,
			      struct dm_btree_value_type *vt, uint64_t key)
{
	int i, r, has_left_sibling, has_right_sibling;
	uint32_t child_entries;
	struct btree_node *n;

	n = dm_block_data(shadow_current(s));

	if (le32_to_cpu(n->header.nr_entries) == 1) {
		struct dm_block *child;
		dm_block_t b = value64(n, 0);

		r = dm_tm_read_lock(info->tm, b, &btree_node_validator, &child);
		if (r)
			return r;

		memcpy(n, dm_block_data(child),
		       dm_bm_block_size(dm_tm_get_bm(info->tm)));
		r = dm_tm_unlock(info->tm, child);
		if (r)
			return r;

		dm_tm_dec(info->tm, dm_block_location(child));
		return 0;
	}

	i = lower_bound(n, key);
	if (i < 0)
		return -ENODATA;

	r = get_nr_entries(info->tm, value64(n, i), &child_entries);
	if (r)
		return r;

	has_left_sibling = i > 0;
	has_right_sibling = i < (le32_to_cpu(n->header.nr_entries) - 1);

	if (!has_left_sibling)
		r = rebalance2(s, info, vt, i);

	else if (!has_right_sibling)
		r = rebalance2(s, info, vt, i - 1);

	else
		r = rebalance3(s, info, vt, i - 1);

	return r;
}
Example #6
0
static int array_set_value(struct dm_array_info *info, dm_block_t root,
			   uint32_t index, const void *value, dm_block_t *new_root)
{
	int r;
	struct dm_block *block;
	struct array_block *ab;
	size_t size_of_block;
	unsigned max_entries;
	unsigned entry;
	void *old_value;
	struct dm_btree_value_type *vt = &info->value_type;

	size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
	max_entries = calc_max_entries(info->value_type.size, size_of_block);

	r = shadow_ablock(info, &root, index / max_entries, &block, &ab);
	if (r)
		return r;
	*new_root = root;

	entry = index % max_entries;
	if (entry >= le32_to_cpu(ab->nr_entries)) {
		r = -ENODATA;
		goto out;
	}

	old_value = element_at(info, ab, entry);
	if (vt->dec &&
	    (!vt->equal || !vt->equal(vt->context, old_value, value))) {
		vt->dec(vt->context, old_value);
		if (vt->inc)
			vt->inc(vt->context, value);
	}

	memcpy(old_value, value, info->value_type.size);

out:
	unlock_ablock(info, block);
	return r;
}
Example #7
0
/*
 * Splits a node by creating two new children beneath the given node.
 *
 * Before:
 *	  +----------+
 *	  | A ++++++ |
 *	  +----------+
 *
 *
 * After:
 *	+------------+
 *	| A (shadow) |
 *	+------------+
 *	    |	|
 *   +------+	+----+
 *   |		     |
 *   v		     v
 * +-------+	 +-------+
 * | B +++ |	 | C +++ |
 * +-------+	 +-------+
 */
static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
{
	int r;
	size_t size;
	unsigned nr_left, nr_right;
	struct dm_block *left, *right, *new_parent;
	struct btree_node *pn, *ln, *rn;
	__le64 val;

	new_parent = shadow_current(s);

	r = new_block(s->info, &left);
	if (r < 0)
		return r;

	r = new_block(s->info, &right);
	if (r < 0) {
		/* FIXME: put left */
		return r;
	}

	pn = dm_block_data(new_parent);
	ln = dm_block_data(left);
	rn = dm_block_data(right);

	nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
	nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left;

	ln->header.flags = pn->header.flags;
	ln->header.nr_entries = cpu_to_le32(nr_left);
	ln->header.max_entries = pn->header.max_entries;
	ln->header.value_size = pn->header.value_size;

	rn->header.flags = pn->header.flags;
	rn->header.nr_entries = cpu_to_le32(nr_right);
	rn->header.max_entries = pn->header.max_entries;
	rn->header.value_size = pn->header.value_size;

	memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
	memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0]));

	size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
		sizeof(__le64) : s->info->value_type.size;
	memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
	memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left),
	       nr_right * size);

	/* new_parent should just point to l and r now */
	pn->header.flags = cpu_to_le32(INTERNAL_NODE);
	pn->header.nr_entries = cpu_to_le32(2);
	pn->header.max_entries = cpu_to_le32(
		calc_max_entries(sizeof(__le64),
				 dm_bm_block_size(
					 dm_tm_get_bm(s->info->tm))));
	pn->header.value_size = cpu_to_le32(sizeof(__le64));

	val = cpu_to_le64(dm_block_location(left));
	__dm_bless_for_disk(&val);
	pn->keys[0] = ln->keys[0];
	memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64));

	val = cpu_to_le64(dm_block_location(right));
	__dm_bless_for_disk(&val);
	pn->keys[1] = rn->keys[0];
	memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64));

	/*
	 * rejig the spine.  This is ugly, since it knows too
	 * much about the spine
	 */
	if (s->nodes[0] != new_parent) {
		unlock_block(s->info, s->nodes[0]);
		s->nodes[0] = new_parent;
	}
	if (key < le64_to_cpu(rn->keys[0])) {
		unlock_block(s->info, right);
		s->nodes[1] = left;
	} else {
		unlock_block(s->info, left);
		s->nodes[1] = right;
	}
	s->count = 2;

	return 0;
}