1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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#ifndef _FS_EXT2FS_EXT2_EXTENTS_H_
29#define	_FS_EXT2FS_EXT2_EXTENTS_H_
30
31#include <sys/types.h>
32
33#define	EXT4_EXT_MAGIC  0xf30a
34#define EXT4_MAX_BLOCKS 0xffffffff
35#define EXT_INIT_MAX_LEN (1UL << 15)
36#define EXT4_MAX_LEN	(EXT_INIT_MAX_LEN - 1)
37#define EXT4_EXT_DEPTH_MAX 5
38
39#define	EXT4_EXT_CACHE_NO	0
40#define	EXT4_EXT_CACHE_GAP	1
41#define	EXT4_EXT_CACHE_IN	2
42
43/*
44 * Ext4 extent tail with csum
45 */
46struct ext4_extent_tail {
47	uint32_t et_checksum;	/* crc32c(uuid+inum+extent_block) */
48};
49
50/*
51 * Ext4 file system extent on disk.
52 */
53struct ext4_extent {
54	uint32_t e_blk;			/* first logical block */
55	uint16_t e_len;			/* number of blocks */
56	uint16_t e_start_hi;		/* high 16 bits of physical block */
57	uint32_t e_start_lo;		/* low 32 bits of physical block */
58};
59
60/*
61 * Extent index on disk.
62 */
63struct ext4_extent_index {
64	uint32_t ei_blk;	/* indexes logical blocks */
65	uint32_t ei_leaf_lo;	/* points to physical block of the
66				 * next level */
67	uint16_t ei_leaf_hi;	/* high 16 bits of physical block */
68	uint16_t ei_unused;
69};
70
71/*
72 * Extent tree header.
73 */
74struct ext4_extent_header {
75	uint16_t eh_magic;		/* magic number: 0xf30a */
76	uint16_t eh_ecount;		/* number of valid entries */
77	uint16_t eh_max;		/* capacity of store in entries */
78	uint16_t eh_depth;		/* the depth of extent tree */
79	uint32_t eh_gen;		/* generation of extent tree */
80};
81
82/*
83 * Save cached extent.
84 */
85struct ext4_extent_cache {
86	daddr_t	ec_start;		/* extent start */
87	uint32_t ec_blk;		/* logical block */
88	uint32_t ec_len;
89	uint32_t ec_type;
90};
91
92/*
93 * Save path to some extent.
94 */
95struct ext4_extent_path {
96	int index_count;
97	uint16_t ep_depth;
98	uint64_t ep_blk;
99	char *ep_data;
100	struct ext4_extent *ep_ext;
101	struct ext4_extent_index *ep_index;
102	struct ext4_extent_header *ep_header;
103};
104
105#define EXT_FIRST_EXTENT(hdr) ((struct ext4_extent *)(((char *)(hdr)) + \
106    sizeof(struct ext4_extent_header)))
107#define EXT_FIRST_INDEX(hdr) ((struct ext4_extent_index *)(((char *)(hdr)) + \
108    sizeof(struct ext4_extent_header)))
109#define EXT_LAST_EXTENT(hdr) (EXT_FIRST_EXTENT((hdr)) + le16toh((hdr)->eh_ecount) - 1)
110#define EXT_LAST_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_ecount) - 1)
111#define EXT4_EXTENT_TAIL_OFFSET(hdr) (sizeof(struct ext4_extent_header) + \
112    (sizeof(struct ext4_extent) * le16toh((hdr)->eh_max)))
113#define EXT_HAS_FREE_INDEX(path) \
114    (le16toh((path)->ep_header->eh_ecount) < le16toh((path)->ep_header->eh_max))
115#define EXT_MAX_EXTENT(hdr) (EXT_FIRST_EXTENT(hdr) + le16toh((hdr)->eh_max) - 1)
116#define EXT_MAX_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_max) - 1)
117
118struct inode;
119struct m_ext2fs;
120void	ext4_ext_tree_init(struct inode *ip);
121int	ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
122void	ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
123int	ext4_ext_find_extent(struct inode *, daddr_t, struct ext4_extent_path **);
124void	ext4_ext_path_free(struct ext4_extent_path *path);
125int	ext4_ext_remove_space(struct inode *ip, off_t length, int flags,
126    struct ucred *cred, struct thread *td);
127int	ext4_ext_get_blocks(struct inode *ip, int64_t iblock,
128    unsigned long max_blocks, struct ucred *cred, struct buf **bpp,
129    int *allocate, daddr_t *);
130#ifdef EXT2FS_PRINT_EXTENTS
131int	ext4_ext_walk(struct inode *ip);
132#endif
133
134#endif	/* !_FS_EXT2FS_EXT2_EXTENTS_H_ */
135