xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_extents.h (revision 9bd4ba417d045dba399c191a33f736de4600c34b)
1 /*	$NetBSD: ext2fs_extents.h,v 1.5 2023/08/26 05:22:50 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2012, 2010 Zheng Liu <lz@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD: head/sys/fs/ext2fs/ext2_extents.h 295523 2016-02-11 15:27:14Z pfg $
29  */
30 
31 #ifndef _UFS_EXT2FS_EXT2FS_EXTENTS_H_
32 #define	_UFS_EXT2FS_EXT2FS_EXTENTS_H_
33 
34 #include <sys/types.h>
35 #ifndef _KERNEL
36 #include <stdbool.h>
37 #endif
38 
39 #include <ufs/ufs/inode.h>
40 #define	EXT4_EXT_MAGIC  0xf30a
41 
42 #define	EXT4_EXT_CACHE_NO	0
43 #define	EXT4_EXT_CACHE_GAP	1
44 #define	EXT4_EXT_CACHE_IN	2
45 
46 /*
47  * Ext4 file system extent on disk.
48  */
49 struct ext4_extent {
50 	uint32_t e_blk;		/* first logical block */
51 	uint16_t e_len;		/* number of blocks */
52 	uint16_t e_start_hi;	/* high 16 bits of physical block */
53 	uint32_t e_start_lo;	/* low 32 bits of physical block */
54 };
55 
56 /*
57  * Extent index on disk.
58  */
59 struct ext4_extent_index {
60 	uint32_t ei_blk;	/* indexes logical blocks */
61 	uint32_t ei_leaf_lo;	/* points to physical block of the
62 				 * next level */
63 	uint16_t ei_leaf_hi;	/* high 16 bits of physical block */
64 	uint16_t ei_unused;
65 };
66 
67 /*
68  * Extent tree header.
69  */
70 struct ext4_extent_header {
71 	uint16_t eh_magic;	/* magic number: 0xf30a */
72 	uint16_t eh_ecount;	/* number of valid entries */
73 	uint16_t eh_max;	/* capacity of store in entries */
74 	uint16_t eh_depth;	/* the depth of extent tree */
75 	uint32_t eh_gen;	/* generation of extent tree */
76 };
77 
78 /*
79  * Save cached extent.
80  */
81 struct ext4_extent_cache {
82 	daddr_t	ec_start;	/* extent start */
83 	uint32_t ec_blk;	/* logical block */
84 	uint32_t ec_len;
85 	uint32_t ec_type;
86 };
87 
88 /*
89  * Save path to some extent.
90  */
91 struct ext4_extent_path {
92 	uint16_t ep_depth;
93 	struct buf *ep_bp;
94 	bool ep_is_sparse;
95 	union {
96 		struct ext4_extent ep_sparse_ext;
97 		struct ext4_extent *ep_ext;
98 	};
99 	struct ext4_extent_index *ep_index;
100 	struct ext4_extent_header *ep_header;
101 };
102 
103 struct inode;
104 struct m_ext2fs;
105 
106 int	ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
107 void	ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
108 struct ext4_extent_path *ext4_ext_find_extent(struct m_ext2fs *fs,
109     struct inode *, daddr_t, struct ext4_extent_path *);
110 
111 #endif /* !_UFS_EXT2FS_EXT2FS_EXTENTS_H_ */
112