xref: /freebsd/sys/fs/ext2fs/ext2_dir.h (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 2009 Aditya Sarawgi
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _FS_EXT2FS_EXT2_DIR_H_
30 #define	_FS_EXT2FS_EXT2_DIR_H_
31 
32 /*
33  * Structure of a directory entry
34  */
35 #define	EXT2FS_MAXNAMLEN	255
36 
37 struct ext2fs_direct {
38 	uint32_t e2d_ino;		/* inode number of entry */
39 	uint16_t e2d_reclen;		/* length of this record */
40 	uint16_t e2d_namlen;		/* length of string in e2d_name */
41 	char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
42 };
43 
44 enum slotstatus {
45 	NONE,
46 	COMPACT,
47 	FOUND
48 };
49 
50 struct ext2fs_searchslot {
51 	enum slotstatus slotstatus;
52 	doff_t	slotoffset;		/* offset of area with free space */
53 	int	slotsize;		/* size of area at slotoffset */
54 	int	slotfreespace;		/* amount of space free in slot */
55 	int	slotneeded;		/* sizeof the entry we are seeking */
56 };
57 
58 /*
59  * The new version of the directory entry.  Since EXT2 structures are
60  * stored in intel byte order, and the name_len field could never be
61  * bigger than 255 chars, it's safe to reclaim the extra byte for the
62  * file_type field.
63  */
64 struct ext2fs_direct_2 {
65 	uint32_t e2d_ino;		/* inode number of entry */
66 	uint16_t e2d_reclen;		/* length of this record */
67 	uint8_t	e2d_namlen;		/* length of string in e2d_name */
68 	uint8_t	e2d_type;		/* file type */
69 	char	e2d_name[EXT2FS_MAXNAMLEN];	/* name with
70 						 * length<=EXT2FS_MAXNAMLEN */
71 };
72 
73 /*
74  * Maximal count of links to a file
75  */
76 #define	EXT2_LINK_MAX	32000
77 #define	EXT4_LINK_MAX	65000
78 
79 /*
80  * Ext2 directory file types.  Only the low 3 bits are used.  The
81  * other bits are reserved for now.
82  */
83 #define	EXT2_FT_UNKNOWN		0
84 #define	EXT2_FT_REG_FILE	1
85 #define	EXT2_FT_DIR		2
86 #define	EXT2_FT_CHRDEV		3
87 #define	EXT2_FT_BLKDEV 		4
88 #define	EXT2_FT_FIFO		5
89 #define	EXT2_FT_SOCK		6
90 #define	EXT2_FT_SYMLINK		7
91 #define	EXT2_FT_MAX		8
92 
93 /*
94  * EXT2_DIR_PAD defines the directory entries boundaries
95  *
96  * NOTE: It must be a multiple of 4
97  */
98 #define	EXT2_DIR_PAD		 	4
99 #define	EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
100 #define	EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
101 					 ~EXT2_DIR_ROUND)
102 #endif	/* !_FS_EXT2FS_EXT2_DIR_H_ */
103