1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * NILFS B-tree.
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Koji Sato.
8 */
9
10#ifndef _NILFS_BTREE_H
11#define _NILFS_BTREE_H
12
13#include <linux/types.h>
14#include <linux/buffer_head.h>
15#include <linux/list.h>
16#include <linux/nilfs2_ondisk.h>	/* nilfs_btree_node */
17#include "btnode.h"
18#include "bmap.h"
19
20/**
21 * struct nilfs_btree_path - A path on which B-tree operations are executed
22 * @bp_bh: buffer head of node block
23 * @bp_sib_bh: buffer head of sibling node block
24 * @bp_index: index of child node
25 * @bp_oldreq: ptr end request for old ptr
26 * @bp_newreq: ptr alloc request for new ptr
27 * @bp_op: rebalance operation
28 */
29struct nilfs_btree_path {
30	struct buffer_head *bp_bh;
31	struct buffer_head *bp_sib_bh;
32	int bp_index;
33	union nilfs_bmap_ptr_req bp_oldreq;
34	union nilfs_bmap_ptr_req bp_newreq;
35	struct nilfs_btnode_chkey_ctxt bp_ctxt;
36	void (*bp_op)(struct nilfs_bmap *, struct nilfs_btree_path *,
37		      int, __u64 *, __u64 *);
38};
39
40#define NILFS_BTREE_ROOT_SIZE		NILFS_BMAP_SIZE
41#define NILFS_BTREE_ROOT_NCHILDREN_MAX					\
42	((NILFS_BTREE_ROOT_SIZE - sizeof(struct nilfs_btree_node)) /	\
43	 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
44#define NILFS_BTREE_ROOT_NCHILDREN_MIN	0
45#define NILFS_BTREE_NODE_EXTRA_PAD_SIZE	(sizeof(__le64))
46#define NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize)			\
47	(((nodesize) - sizeof(struct nilfs_btree_node) -		\
48		NILFS_BTREE_NODE_EXTRA_PAD_SIZE) /			\
49	 (sizeof(__le64 /* dkey */) + sizeof(__le64 /* dptr */)))
50#define NILFS_BTREE_NODE_NCHILDREN_MIN(nodesize)			\
51	((NILFS_BTREE_NODE_NCHILDREN_MAX(nodesize) - 1) / 2 + 1)
52#define NILFS_BTREE_KEY_MIN	((__u64)0)
53#define NILFS_BTREE_KEY_MAX	(~(__u64)0)
54
55extern struct kmem_cache *nilfs_btree_path_cache;
56
57int nilfs_btree_init(struct nilfs_bmap *);
58int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
59				   const __u64 *, const __u64 *, int);
60void nilfs_btree_init_gc(struct nilfs_bmap *);
61
62int nilfs_btree_broken_node_block(struct buffer_head *bh);
63
64#endif	/* _NILFS_BTREE_H */
65