xref: /freebsd/sys/fs/ext2fs/ext2_extents.h (revision 95ee2897)
1d7511a40SPedro F. Giffuni /*-
24d846d26SWarner Losh  * SPDX-License-Identifier: BSD-2-Clause
3d63027b6SPedro F. Giffuni  *
4d7511a40SPedro F. Giffuni  * Copyright (c) 2012, 2010 Zheng Liu <lz@freebsd.org>
5d7511a40SPedro F. Giffuni  * All rights reserved.
6d7511a40SPedro F. Giffuni  *
7d7511a40SPedro F. Giffuni  * Redistribution and use in source and binary forms, with or without
8d7511a40SPedro F. Giffuni  * modification, are permitted provided that the following conditions
9d7511a40SPedro F. Giffuni  * are met:
10d7511a40SPedro F. Giffuni  * 1. Redistributions of source code must retain the above copyright
11d7511a40SPedro F. Giffuni  *    notice, this list of conditions and the following disclaimer.
12d7511a40SPedro F. Giffuni  * 2. Redistributions in binary form must reproduce the above copyright
13d7511a40SPedro F. Giffuni  *    notice, this list of conditions and the following disclaimer in the
14d7511a40SPedro F. Giffuni  *    documentation and/or other materials provided with the distribution.
15d7511a40SPedro F. Giffuni  *
16d7511a40SPedro F. Giffuni  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17d7511a40SPedro F. Giffuni  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18d7511a40SPedro F. Giffuni  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19d7511a40SPedro F. Giffuni  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20d7511a40SPedro F. Giffuni  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21d7511a40SPedro F. Giffuni  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22d7511a40SPedro F. Giffuni  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23d7511a40SPedro F. Giffuni  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24d7511a40SPedro F. Giffuni  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25d7511a40SPedro F. Giffuni  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26d7511a40SPedro F. Giffuni  * SUCH DAMAGE.
27d7511a40SPedro F. Giffuni  */
28d7511a40SPedro F. Giffuni #ifndef _FS_EXT2FS_EXT2_EXTENTS_H_
29d7511a40SPedro F. Giffuni #define	_FS_EXT2FS_EXT2_EXTENTS_H_
30d7511a40SPedro F. Giffuni 
31d7511a40SPedro F. Giffuni #include <sys/types.h>
32d7511a40SPedro F. Giffuni 
33d7511a40SPedro F. Giffuni #define	EXT4_EXT_MAGIC  0xf30a
34b394cd1eSFedor Uporov #define EXT4_MAX_BLOCKS 0xffffffff
35b394cd1eSFedor Uporov #define EXT_INIT_MAX_LEN (1UL << 15)
36b394cd1eSFedor Uporov #define EXT4_MAX_LEN	(EXT_INIT_MAX_LEN - 1)
37b394cd1eSFedor Uporov #define EXT4_EXT_DEPTH_MAX 5
38d7511a40SPedro F. Giffuni 
39d7511a40SPedro F. Giffuni #define	EXT4_EXT_CACHE_NO	0
40d7511a40SPedro F. Giffuni #define	EXT4_EXT_CACHE_GAP	1
41d7511a40SPedro F. Giffuni #define	EXT4_EXT_CACHE_IN	2
42d7511a40SPedro F. Giffuni 
43d7511a40SPedro F. Giffuni /*
44512f29d1SFedor Uporov  * Ext4 extent tail with csum
45512f29d1SFedor Uporov  */
46512f29d1SFedor Uporov struct ext4_extent_tail {
47512f29d1SFedor Uporov 	uint32_t et_checksum;	/* crc32c(uuid+inum+extent_block) */
48512f29d1SFedor Uporov };
49512f29d1SFedor Uporov 
50512f29d1SFedor Uporov /*
51d7511a40SPedro F. Giffuni  * Ext4 file system extent on disk.
52d7511a40SPedro F. Giffuni  */
53d7511a40SPedro F. Giffuni struct ext4_extent {
54d7511a40SPedro F. Giffuni 	uint32_t e_blk;			/* first logical block */
55d7511a40SPedro F. Giffuni 	uint16_t e_len;			/* number of blocks */
56d7511a40SPedro F. Giffuni 	uint16_t e_start_hi;		/* high 16 bits of physical block */
57d7511a40SPedro F. Giffuni 	uint32_t e_start_lo;		/* low 32 bits of physical block */
58d7511a40SPedro F. Giffuni };
59d7511a40SPedro F. Giffuni 
60d7511a40SPedro F. Giffuni /*
61d7511a40SPedro F. Giffuni  * Extent index on disk.
62d7511a40SPedro F. Giffuni  */
63d7511a40SPedro F. Giffuni struct ext4_extent_index {
64d7511a40SPedro F. Giffuni 	uint32_t ei_blk;	/* indexes logical blocks */
65d7511a40SPedro F. Giffuni 	uint32_t ei_leaf_lo;	/* points to physical block of the
66d7511a40SPedro F. Giffuni 				 * next level */
67d7511a40SPedro F. Giffuni 	uint16_t ei_leaf_hi;	/* high 16 bits of physical block */
68d7511a40SPedro F. Giffuni 	uint16_t ei_unused;
69d7511a40SPedro F. Giffuni };
70d7511a40SPedro F. Giffuni 
71d7511a40SPedro F. Giffuni /*
72d7511a40SPedro F. Giffuni  * Extent tree header.
73d7511a40SPedro F. Giffuni  */
74d7511a40SPedro F. Giffuni struct ext4_extent_header {
75d7511a40SPedro F. Giffuni 	uint16_t eh_magic;		/* magic number: 0xf30a */
76d7511a40SPedro F. Giffuni 	uint16_t eh_ecount;		/* number of valid entries */
77d7511a40SPedro F. Giffuni 	uint16_t eh_max;		/* capacity of store in entries */
78d7511a40SPedro F. Giffuni 	uint16_t eh_depth;		/* the depth of extent tree */
79d7511a40SPedro F. Giffuni 	uint32_t eh_gen;		/* generation of extent tree */
80d7511a40SPedro F. Giffuni };
81d7511a40SPedro F. Giffuni 
82d7511a40SPedro F. Giffuni /*
83d7511a40SPedro F. Giffuni  * Save cached extent.
84d7511a40SPedro F. Giffuni  */
85d7511a40SPedro F. Giffuni struct ext4_extent_cache {
86d7511a40SPedro F. Giffuni 	daddr_t	ec_start;		/* extent start */
87d7511a40SPedro F. Giffuni 	uint32_t ec_blk;		/* logical block */
88d7511a40SPedro F. Giffuni 	uint32_t ec_len;
89d7511a40SPedro F. Giffuni 	uint32_t ec_type;
90d7511a40SPedro F. Giffuni };
91d7511a40SPedro F. Giffuni 
92d7511a40SPedro F. Giffuni /*
93d7511a40SPedro F. Giffuni  * Save path to some extent.
94d7511a40SPedro F. Giffuni  */
95d7511a40SPedro F. Giffuni struct ext4_extent_path {
96b394cd1eSFedor Uporov 	int index_count;
97d7511a40SPedro F. Giffuni 	uint16_t ep_depth;
98b394cd1eSFedor Uporov 	uint64_t ep_blk;
99b394cd1eSFedor Uporov 	char *ep_data;
100d7511a40SPedro F. Giffuni 	struct ext4_extent *ep_ext;
101d7511a40SPedro F. Giffuni 	struct ext4_extent_index *ep_index;
102d7511a40SPedro F. Giffuni 	struct ext4_extent_header *ep_header;
103d7511a40SPedro F. Giffuni };
104d7511a40SPedro F. Giffuni 
105b394cd1eSFedor Uporov #define EXT_FIRST_EXTENT(hdr) ((struct ext4_extent *)(((char *)(hdr)) + \
106b394cd1eSFedor Uporov     sizeof(struct ext4_extent_header)))
107b394cd1eSFedor Uporov #define EXT_FIRST_INDEX(hdr) ((struct ext4_extent_index *)(((char *)(hdr)) + \
108b394cd1eSFedor Uporov     sizeof(struct ext4_extent_header)))
109cd3acfe7SFedor Uporov #define EXT_LAST_EXTENT(hdr) (EXT_FIRST_EXTENT((hdr)) + le16toh((hdr)->eh_ecount) - 1)
110cd3acfe7SFedor Uporov #define EXT_LAST_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_ecount) - 1)
111b394cd1eSFedor Uporov #define EXT4_EXTENT_TAIL_OFFSET(hdr) (sizeof(struct ext4_extent_header) + \
112cd3acfe7SFedor Uporov     (sizeof(struct ext4_extent) * le16toh((hdr)->eh_max)))
113b394cd1eSFedor Uporov #define EXT_HAS_FREE_INDEX(path) \
114cd3acfe7SFedor Uporov     (le16toh((path)->ep_header->eh_ecount) < le16toh((path)->ep_header->eh_max))
115cd3acfe7SFedor Uporov #define EXT_MAX_EXTENT(hdr) (EXT_FIRST_EXTENT(hdr) + le16toh((hdr)->eh_max) - 1)
116cd3acfe7SFedor Uporov #define EXT_MAX_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_max) - 1)
117b394cd1eSFedor Uporov 
118d7511a40SPedro F. Giffuni struct inode;
119d7511a40SPedro F. Giffuni struct m_ext2fs;
120b394cd1eSFedor Uporov void	ext4_ext_tree_init(struct inode *ip);
121d7511a40SPedro F. Giffuni int	ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
122d7511a40SPedro F. Giffuni void	ext4_ext_put_cache(struct inode *, struct ext4_extent *, int);
123b394cd1eSFedor Uporov int	ext4_ext_find_extent(struct inode *, daddr_t, struct ext4_extent_path **);
124b394cd1eSFedor Uporov void	ext4_ext_path_free(struct ext4_extent_path *path);
125b394cd1eSFedor Uporov int	ext4_ext_remove_space(struct inode *ip, off_t length, int flags,
126b394cd1eSFedor Uporov     struct ucred *cred, struct thread *td);
127b394cd1eSFedor Uporov int	ext4_ext_get_blocks(struct inode *ip, int64_t iblock,
1283acd9182SFedor Uporov     unsigned long max_blocks, struct ucred *cred, struct buf **bpp,
1293acd9182SFedor Uporov     int *allocate, daddr_t *);
130ebc94b66SFedor Uporov #ifdef EXT2FS_PRINT_EXTENTS
1315679656eSFedor Uporov int	ext4_ext_walk(struct inode *ip);
132b394cd1eSFedor Uporov #endif
133d7511a40SPedro F. Giffuni 
134d7511a40SPedro F. Giffuni #endif	/* !_FS_EXT2FS_EXT2_EXTENTS_H_ */
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