xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_extents.h (revision a24efa7dea9f1f56c3bdb15a927d3516792ace1c)
1 /*	$NetBSD: ext2fs_extents.h,v 1.1 2016/06/03 15:35:48 christos 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 #include <ufs/ufs/inode.h>
36 #define	EXT4_EXT_MAGIC  0xf30a
37 
38 #define	EXT4_EXT_CACHE_NO	0
39 #define	EXT4_EXT_CACHE_GAP	1
40 #define	EXT4_EXT_CACHE_IN	2
41 
42 /*
43  * Ext4 file system extent on disk.
44  */
45 struct ext4_extent {
46 	uint32_t e_blk;		/* first logical block */
47 	uint16_t e_len;		/* number of blocks */
48 	uint16_t e_start_hi;	/* high 16 bits of physical block */
49 	uint32_t e_start_lo;	/* low 32 bits of physical block */
50 };
51 
52 /*
53  * Extent index on disk.
54  */
55 struct ext4_extent_index {
56 	uint32_t ei_blk;	/* indexes logical blocks */
57 	uint32_t ei_leaf_lo;	/* points to physical block of the
58 				 * next level */
59 	uint16_t ei_leaf_hi;	/* high 16 bits of physical block */
60 	uint16_t ei_unused;
61 };
62 
63 /*
64  * Extent tree header.
65  */
66 struct ext4_extent_header {
67 	uint16_t eh_magic;	/* magic number: 0xf30a */
68 	uint16_t eh_ecount;	/* number of valid entries */
69 	uint16_t eh_max;	/* capacity of store in entries */
70 	uint16_t eh_depth;	/* the depth of extent tree */
71 	uint32_t eh_gen;	/* generation of extent tree */
72 };
73 
74 /*
75  * Save cached extent.
76  */
77 struct ext4_extent_cache {
78 	daddr_t	ec_start;	/* extent start */
79 	uint32_t ec_blk;	/* logical block */
80 	uint32_t ec_len;
81 	uint32_t ec_type;
82 };
83 
84 /*
85  * Save path to some extent.
86  */
87 struct ext4_extent_path {
88 	uint16_t ep_depth;
89 	struct buf *ep_bp;
90 	bool ep_is_sparse;
91 	union {
92 		struct ext4_extent ep_sparse_ext;
93 		struct ext4_extent *ep_ext;
94 	};
95 	struct ext4_extent_index *ep_index;
96 	struct ext4_extent_header *ep_header;
97 };
98 
99 struct inode;
100 struct m_ext2fs;
101 
102 int	ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
103 void	ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
104 struct ext4_extent_path *ext4_ext_find_extent(struct m_ext2fs *fs,
105     struct inode *, daddr_t, struct ext4_extent_path *);
106 
107 #endif /* !_UFS_EXT2FS_EXT2FS_EXTENTS_H_ */
108