Btrfs: Commenting/cleanup

	}

}

/*

 * The leaf data grows from end-to-front in the node.

 * this returns the address of the start of the last item,

 * which is the stop of the leaf data stack

 */

static inline unsigned int leaf_data_end(struct leaf *leaf)

{

	unsigned int nr = leaf->header.nritems;

	return leaf->items[nr-1].offset;

}

/*

 * The space between the end of the leaf items and

 * the start of the leaf data.  IOW, how much room

 * the leaf has left for both items and data

 */

static inline int leaf_free_space(struct leaf *leaf)

{

	int data_end = leaf_data_end(leaf);

	return (char *)(leaf->data + data_end) - (char *)items_end;

}

/*

 * compare two keys in a memcmp fashion

 */

int comp_keys(struct key *k1, struct key *k2)

{

	if (k1->objectid > k2->objectid)

		return -1;

	return 0;

}

/*

 * search for key in the array p.  items p are item_size apart

 * and there are 'max' items in p

 * the slot in the array is returned via slot, and it points to

 * the place where you would insert key if it is not found in

 * the array.

 *

 * slot may point to max if the key is bigger than all of the keys

 */

int generic_bin_search(char *p, int item_size, struct key *key,

		       int max, int *slot)

{

	return -1;

}

/*

 * look for key in the tree.  path is filled in with nodes along the way

 * if key is found, we return zero and you can find the item in the leaf

 * level of the path (level 0)

 *

 * If the key isn't found, the path points to the slot where it should

 * be inserted.

 */

int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p)

{

	struct tree_buffer *b = root->node;

	return -1;

}

/*

 * adjust the pointers going up the tree, starting at level

 * making sure the right key of each node is points to 'key'.

 * This is used after shifting pointers to the left, so it stops

 * fixing up pointers when a given leaf/node is not in slot 0 of the

 * higher levels

 */

static void fixup_low_keys(struct ctree_root *root,

			   struct ctree_path *path, struct key *key,

			   int level)

{

	int i;

	/* adjust the pointers going up the tree */

	for (i = level; i < MAX_LEVEL; i++) {

		struct node *t;

		int tslot = path->slots[i];

	}

}

int __insert_ptr(struct ctree_root *root,

		struct ctree_path *path, struct key *key,

		u64 blocknr, int slot, int level)

{

	struct node *c;

	struct node *lower;

	struct key *lower_key;

	int nritems;

	/* need a new root */

	if (!path->nodes[level]) {

		struct tree_buffer *t;

		t = alloc_free_block(root);

		c = &t->node;

		memset(c, 0, sizeof(c));

		c->header.nritems = 2;

		c->header.flags = node_level(level);

		c->header.blocknr = t->blocknr;

		lower = &path->nodes[level-1]->node;

		if (is_leaf(lower->header.flags))

			lower_key = &((struct leaf *)lower)->items[0].key;

		else

			lower_key = lower->keys;

		memcpy(c->keys, lower_key, sizeof(struct key));

		memcpy(c->keys + 1, key, sizeof(struct key));

		c->blockptrs[0] = path->nodes[level-1]->blocknr;

		c->blockptrs[1] = blocknr;

		/* the path has an extra ref to root->node */

		tree_block_release(root, root->node);

		root->node = t;

		t->count++;

		write_tree_block(root, t);

		path->nodes[level] = t;

		path->slots[level] = 0;

		if (c->keys[1].objectid == 0)

			BUG();

		return 0;

	}

	lower = &path->nodes[level]->node;

	nritems = lower->header.nritems;

	if (slot > nritems)

		BUG();

	if (nritems == NODEPTRS_PER_BLOCK)

		BUG();

	if (slot != nritems) {

		memmove(lower->keys + slot + 1, lower->keys + slot,

			(nritems - slot) * sizeof(struct key));

		memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot,

			(nritems - slot) * sizeof(u64));

	}

	memcpy(lower->keys + slot, key, sizeof(struct key));

	lower->blockptrs[slot] = blocknr;

	lower->header.nritems++;

	if (lower->keys[1].objectid == 0)

			BUG();

	write_tree_block(root, path->nodes[level]);

	return 0;

}

/*

 * try to push data from one node into the next node left in the

 * tree.  The src node is found at specified level in the path.

 * If some bytes were pushed, return 0, otherwise return 1.

 *

 * Lower nodes/leaves in the path are not touched, higher nodes may

 * be modified to reflect the push.

 *

 * The path is altered to reflect the push.

 */

int push_node_left(struct ctree_root *root, struct ctree_path *path, int level)

{

	int slot;

	return 0;

}

/*

 * try to push data from one node into the next node right in the

 * tree.  The src node is found at specified level in the path.

 * If some bytes were pushed, return 0, otherwise return 1.

 *

 * Lower nodes/leaves in the path are not touched, higher nodes may

 * be modified to reflect the push.

 *

 * The path is altered to reflect the push.

 */

int push_node_right(struct ctree_root *root, struct ctree_path *path, int level)

{

	int slot;

	int dst_nritems;

	int src_nritems;

	/* can't push from the root */

	if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0)

		return 1;

	/* only try to push inside the node higher up */

	slot = path->slots[level + 1];

	if (slot == NODEPTRS_PER_BLOCK - 1)

		return 1;

	write_tree_block(root, t);

	write_tree_block(root, src_buffer);

	/* then fixup the leaf pointer in the path */

	/* then fixup the pointers in the path */

	if (path->slots[level] >= src->header.nritems) {

		path->slots[level] -= src->header.nritems;

		tree_block_release(root, path->nodes[level]);

	return 0;

}

/*

 * worker function to insert a single pointer in a node.

 * the node should have enough room for the pointer already

 * slot and level indicate where you want the key to go, and

 * blocknr is the block the key points to.

 */

int __insert_ptr(struct ctree_root *root,

		struct ctree_path *path, struct key *key,

		u64 blocknr, int slot, int level)

{

	struct node *c;

	struct node *lower;

	struct key *lower_key;

	int nritems;

	/* need a new root */

	if (!path->nodes[level]) {

		struct tree_buffer *t;

		t = alloc_free_block(root);

		c = &t->node;

		memset(c, 0, sizeof(c));

		c->header.nritems = 2;

		c->header.flags = node_level(level);

		c->header.blocknr = t->blocknr;

		lower = &path->nodes[level-1]->node;

		if (is_leaf(lower->header.flags))

			lower_key = &((struct leaf *)lower)->items[0].key;

		else

			lower_key = lower->keys;

		memcpy(c->keys, lower_key, sizeof(struct key));

		memcpy(c->keys + 1, key, sizeof(struct key));

		c->blockptrs[0] = path->nodes[level-1]->blocknr;

		c->blockptrs[1] = blocknr;

		/* the path has an extra ref to root->node */

		tree_block_release(root, root->node);

		root->node = t;

		t->count++;

		write_tree_block(root, t);

		path->nodes[level] = t;

		path->slots[level] = 0;

		if (c->keys[1].objectid == 0)

			BUG();

		return 0;

	}

	lower = &path->nodes[level]->node;

	nritems = lower->header.nritems;

	if (slot > nritems)

		BUG();

	if (nritems == NODEPTRS_PER_BLOCK)

		BUG();

	if (slot != nritems) {

		memmove(lower->keys + slot + 1, lower->keys + slot,

			(nritems - slot) * sizeof(struct key));

		memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot,

			(nritems - slot) * sizeof(u64));

	}

	memcpy(lower->keys + slot, key, sizeof(struct key));

	lower->blockptrs[slot] = blocknr;

	lower->header.nritems++;

	if (lower->keys[1].objectid == 0)

			BUG();

	write_tree_block(root, path->nodes[level]);

	return 0;

}

/*

 * insert a key,blocknr pair into the tree at a given level

 * If the node at that level in the path doesn't have room,

 * it is split or shifted as appropriate.

 */

int insert_ptr(struct ctree_root *root,

		struct ctree_path *path, struct key *key,

		u64 blocknr, int level)

	int mid;

	int bal_start = -1;

	/*

	 * check to see if we need to make room in the node for this

	 * pointer.  If we do, keep walking the tree, making sure there

	 * is enough room in each level for the required insertions.

	 *

	 * The bal array is filled in with any nodes to be inserted

	 * due to splitting.  Once we've done all the splitting required

	 * do the inserts based on the data in the bal array.

	 */

	memset(bal, 0, ARRAY_SIZE(bal));

	while(t && t->node.header.nritems == NODEPTRS_PER_BLOCK) {

		c = &t->node;

		bal_level += 1;

		t = path->nodes[bal_level];

	}

	/*

	 * bal_start tells us the first level in the tree that needed to

	 * be split.  Go through the bal array inserting the new nodes

	 * as needed.  The path is fixed as we go.

	 */

	while(bal_start > 0) {

		b_buffer = bal[bal_start];

		c = &path->nodes[bal_start]->node;

		if (!bal[bal_start])

			break;

	}

	/* Now that the tree has room, insert the requested pointer */

	return __insert_ptr(root, path, key, blocknr, path->slots[level] + 1,

			    level);

}

/*

 * how many bytes are required to store the items in a leaf.  start

 * and nr indicate which items in the leaf to check.  This totals up the

 * space used both by the item structs and the item data

 */

int leaf_space_used(struct leaf *l, int start, int nr)

{

	int data_len;

	return data_len;

}

/*

 * push some data in the path leaf to the left, trying to free up at

 * least data_size bytes.  returns zero if the push worked, nonzero otherwise

 */

int push_leaf_left(struct ctree_root *root, struct ctree_path *path,

		   int data_size)

{

	return 0;

}

/*

 * split the path's leaf in two, making sure there is at least data_size

 * available for the resulting leaf level of the path.

 */

int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size)

{

	struct tree_buffer *l_buf = path->nodes[0];

	       l->data + leaf_data_end(l), data_copy_size);

	rt_data_off = LEAF_DATA_SIZE -

		     (l->items[mid].offset + l->items[mid].size);

	for (i = 0; i < right->header.nritems; i++) {

	for (i = 0; i < right->header.nritems; i++)

		right->items[i].offset += rt_data_off;

	}

	l->header.nritems = mid;

	ret = insert_ptr(root, path, &right->items[0].key,

			  right_buffer->blocknr, 1);

	return ret;

}

/*

 * Given a key and some data, insert an item into the tree.

 * This does all the path init required, making room in the tree if needed.

 */

int insert_item(struct ctree_root *root, struct key *key,

			  void *data, int data_size)

{

	unsigned int data_end;

	struct ctree_path path;

	/* create a root if there isn't one */

	if (!root->node) {

		struct tree_buffer *t;

		t = alloc_free_block(root);

	slot_orig = path.slots[0];

	leaf_buf = path.nodes[0];

	leaf = &leaf_buf->leaf;

	/* make room if needed */

	if (leaf_free_space(leaf) <  sizeof(struct item) + data_size) {

		split_leaf(root, &path, data_size);

		leaf_buf = path.nodes[0];

		        data_end, old_data - data_end);

		data_end = old_data;

	}

	/* copy the new data in */

	memcpy(&leaf->items[slot].key, key, sizeof(struct key));

	leaf->items[slot].offset = data_end - data_size;

	leaf->items[slot].size = data_size;

	return 0;

}

/*

 * delete the pointer from a given level in the path.  The path is not

 * fixed up, so after calling this it is not valid at that level.

 *

 * If the delete empties a node, the node is removed from the tree,

 * continuing all the way the root if required.  The root is converted into

 * a leaf if all the nodes are emptied.

 */

int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)

{

	int slot;

	return 0;

}

/*

 * delete the item at the leaf level in path.  If that empties

 * the leaf, remove it from the tree

 */

int del_item(struct ctree_root *root, struct ctree_path *path)

{

	int slot;

			(leaf->header.nritems - slot - 1));

	}

	leaf->header.nritems -= 1;

	/* delete the leaf if we've emptied it */

	if (leaf->header.nritems == 0) {

		if (leaf_buf == root->node) {

			leaf->header.flags = node_level(0);

		if (slot == 0)

			fixup_low_keys(root, path, &leaf->items[0].key, 1);

		write_tree_block(root, leaf_buf);

		/* delete the leaf if it is mostly empty */

		if (leaf_space_used(leaf, 0, leaf->header.nritems) <

		    LEAF_DATA_SIZE / 4) {

			/* push_leaf_left fixes the path.

	int i;

	int num;

	int ret;

	int run_size = 1000000;

	int run_size = 25000;

	int max_key = 100000000;

	int tree_size = 0;

	struct ctree_path path;