xref: /openbmc/linux/fs/nilfs2/btree.h (revision 1cc1e4c8)
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  */
29 struct 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 
55 extern struct kmem_cache *nilfs_btree_path_cache;
56 
57 int nilfs_btree_init(struct nilfs_bmap *);
58 int nilfs_btree_convert_and_insert(struct nilfs_bmap *, __u64, __u64,
59 				   const __u64 *, const __u64 *, int);
60 void nilfs_btree_init_gc(struct nilfs_bmap *);
61 
62 int nilfs_btree_broken_node_block(struct buffer_head *bh);
63 
64 #endif	/* _NILFS_BTREE_H */
65