xref: /freebsd/sys/fs/ext2fs/htree.h (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2010, 2012 Zheng Liu <lz@freebsd.org>
5  * Copyright (c) 2012, Vyacheslav Matyushin
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef _FS_EXT2FS_HTREE_H_
33 #define	_FS_EXT2FS_HTREE_H_
34 
35 /* EXT3 HTree directory indexing */
36 
37 #define	EXT2_HTREE_LEGACY		0
38 #define	EXT2_HTREE_HALF_MD4		1
39 #define	EXT2_HTREE_TEA			2
40 #define	EXT2_HTREE_LEGACY_UNSIGNED	3
41 #define	EXT2_HTREE_HALF_MD4_UNSIGNED	4
42 #define	EXT2_HTREE_TEA_UNSIGNED		5
43 
44 #define	EXT2_HTREE_EOF 0x7FFFFFFF
45 
46 struct ext2fs_fake_direct {
47 	uint32_t e2d_ino;		/* inode number of entry */
48 	uint16_t e2d_reclen;		/* length of this record */
49 	uint8_t	e2d_namlen;		/* length of string in d_name */
50 	uint8_t	e2d_type;		/* file type */
51 };
52 
53 struct ext2fs_htree_count {
54 	uint16_t h_entries_max;
55 	uint16_t h_entries_num;
56 };
57 
58 struct ext2fs_htree_entry {
59 	uint32_t h_hash;
60 	uint32_t h_blk;
61 };
62 
63 /*
64  * This goes at the end of each htree block.
65  */
66 struct ext2fs_htree_tail {
67 	uint32_t ht_reserved;
68 	uint32_t ht_checksum;	/* crc32c(uuid+inum+dirblock) */
69 };
70 
71 struct ext2fs_htree_root_info {
72 	uint32_t h_reserved1;
73 	uint8_t	h_hash_version;
74 	uint8_t	h_info_len;
75 	uint8_t	h_ind_levels;
76 	uint8_t	h_reserved2;
77 };
78 
79 struct ext2fs_htree_root {
80 	struct ext2fs_fake_direct h_dot;
81 	char	h_dot_name[4];
82 	struct ext2fs_fake_direct h_dotdot;
83 	char	h_dotdot_name[4];
84 	struct ext2fs_htree_root_info h_info;
85 	struct ext2fs_htree_entry h_entries[0];
86 };
87 
88 struct ext2fs_htree_node {
89 	struct ext2fs_fake_direct h_fake_dirent;
90 	struct ext2fs_htree_entry h_entries[0];
91 };
92 
93 struct ext2fs_htree_lookup_level {
94 	struct buf *h_bp;
95 	struct ext2fs_htree_entry *h_entries;
96 	struct ext2fs_htree_entry *h_entry;
97 };
98 
99 struct ext2fs_htree_lookup_info {
100 	struct ext2fs_htree_lookup_level h_levels[2];
101 	uint32_t h_levels_num;
102 };
103 
104 struct ext2fs_htree_sort_entry {
105 	uint16_t h_offset;
106 	uint16_t h_size;
107 	uint32_t h_hash;
108 };
109 
110 #endif	/* !_FS_EXT2FS_HTREE_H_ */
111