2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2012, 2010 Zheng Liu <lz@freebsd.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
30 #ifndef _FS_EXT2FS_EXT2_EXTENTS_H_
31 #define _FS_EXT2FS_EXT2_EXTENTS_H_
33 #include <sys/types.h>
35 #define EXT4_EXT_MAGIC 0xf30a
36 #define EXT4_MAX_BLOCKS 0xffffffff
37 #define EXT_INIT_MAX_LEN (1UL << 15)
38 #define EXT4_MAX_LEN (EXT_INIT_MAX_LEN - 1)
39 #define EXT4_EXT_DEPTH_MAX 5
41 #define EXT4_EXT_CACHE_NO 0
42 #define EXT4_EXT_CACHE_GAP 1
43 #define EXT4_EXT_CACHE_IN 2
46 * Ext4 extent tail with csum
48 struct ext4_extent_tail {
49 uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */
53 * Ext4 file system extent on disk.
56 uint32_t e_blk; /* first logical block */
57 uint16_t e_len; /* number of blocks */
58 uint16_t e_start_hi; /* high 16 bits of physical block */
59 uint32_t e_start_lo; /* low 32 bits of physical block */
63 * Extent index on disk.
65 struct ext4_extent_index {
66 uint32_t ei_blk; /* indexes logical blocks */
67 uint32_t ei_leaf_lo; /* points to physical block of the
69 uint16_t ei_leaf_hi; /* high 16 bits of physical block */
76 struct ext4_extent_header {
77 uint16_t eh_magic; /* magic number: 0xf30a */
78 uint16_t eh_ecount; /* number of valid entries */
79 uint16_t eh_max; /* capacity of store in entries */
80 uint16_t eh_depth; /* the depth of extent tree */
81 uint32_t eh_gen; /* generation of extent tree */
87 struct ext4_extent_cache {
88 daddr_t ec_start; /* extent start */
89 uint32_t ec_blk; /* logical block */
95 * Save path to some extent.
97 struct ext4_extent_path {
102 struct ext4_extent *ep_ext;
103 struct ext4_extent_index *ep_index;
104 struct ext4_extent_header *ep_header;
107 #define EXT_FIRST_EXTENT(hdr) ((struct ext4_extent *)(((char *)(hdr)) + \
108 sizeof(struct ext4_extent_header)))
109 #define EXT_FIRST_INDEX(hdr) ((struct ext4_extent_index *)(((char *)(hdr)) + \
110 sizeof(struct ext4_extent_header)))
111 #define EXT_LAST_EXTENT(hdr) (EXT_FIRST_EXTENT((hdr)) + le16toh((hdr)->eh_ecount) - 1)
112 #define EXT_LAST_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_ecount) - 1)
113 #define EXT4_EXTENT_TAIL_OFFSET(hdr) (sizeof(struct ext4_extent_header) + \
114 (sizeof(struct ext4_extent) * le16toh((hdr)->eh_max)))
115 #define EXT_HAS_FREE_INDEX(path) \
116 (le16toh((path)->ep_header->eh_ecount) < le16toh((path)->ep_header->eh_max))
117 #define EXT_MAX_EXTENT(hdr) (EXT_FIRST_EXTENT(hdr) + le16toh((hdr)->eh_max) - 1)
118 #define EXT_MAX_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + le16toh((hdr)->eh_max) - 1)
122 void ext4_ext_tree_init(struct inode *ip);
123 int ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *);
124 int ext4_ext_find_extent(struct inode *, daddr_t, struct ext4_extent_path **);
125 void ext4_ext_path_free(struct ext4_extent_path *path);
126 int ext4_ext_remove_space(struct inode *ip, off_t length, int flags,
127 struct ucred *cred, struct thread *td);
128 int ext4_ext_get_blocks(struct inode *ip, int64_t iblock,
129 unsigned long max_blocks, struct ucred *cred, struct buf **bpp,
130 int *allocate, daddr_t *);
131 #ifdef EXT2FS_PRINT_EXTENTS
132 void ext4_ext_print_extent_tree_status(struct inode *ip);
135 #endif /* !_FS_EXT2FS_EXT2_EXTENTS_H_ */