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