/*
* FIXME: We shouldn't use a recursive algorithm when we have limited stack
* space. Also this only works for single level trees.
*/
static int walk_node(struct dm_btree_info *info, dm_block_t block,
int (*fn)(void *context, uint64_t *keys, void *leaf),
void *context)
{
int r;
unsigned i, nr;
struct dm_block *node;
struct btree_node *n;
uint64_t keys;
r = bn_read_lock(info, block, &node);
if (r)
return r;
n = dm_block_data(node);
nr = le32_to_cpu(n->header.nr_entries);
for (i = 0; i < nr; i++) {
if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) {
r = walk_node(info, value64(n, i), fn, context);
if (r)
goto out;
} else {
keys = le64_to_cpu(*key_ptr(n, i));
r = fn(context, &keys, value_ptr(n, i));
if (r)
goto out;
}
}
out:
dm_tm_unlock(info->tm, node);
return r;
}
static void pop_frame(struct del_stack *s)
{
struct frame *f = s->spine + s->top--;
dm_tm_dec(s->tm, dm_block_location(f->b));
dm_tm_unlock(s->tm, f->b);
}
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;
}
static int get_nr_entries(struct dm_transaction_manager *tm,
dm_block_t b, uint32_t *result)
{
int r;
struct dm_block *block;
struct btree_node *n;
r = dm_tm_read_lock(tm, b, &btree_node_validator, &block);
if (r)
return r;
n = dm_block_data(block);
*result = le32_to_cpu(n->header.nr_entries);
return dm_tm_unlock(tm, block);
}
int unlock_block(struct dm_btree_info *info, struct dm_block *b)
{
return dm_tm_unlock(info->tm, b);
}
/*
* Unlocks an array block.
*/
static int unlock_ablock(struct dm_array_info *info, struct dm_block *block)
{
return dm_tm_unlock(info->btree_info.tm, block);
}
static int exit_child(struct dm_btree_info *info, struct child *c)
{
return dm_tm_unlock(info->tm, c->block);
}