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 */ 46 struct ext4_extent_tail { 47 uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */ 48 }; 49 50 /* 51 * Ext4 file system extent on disk. 52 */ 53 struct 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 */ 63 struct 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 */ 74 struct 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 */ 85 struct 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 */ 95 struct 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) 117 118 struct inode; 119 struct m_ext2fs; 120 void ext4_ext_tree_init(struct inode *ip); 121 int ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *); 122 void ext4_ext_put_cache(struct inode *, struct ext4_extent *, int); 123 int ext4_ext_find_extent(struct inode *, daddr_t, struct ext4_extent_path **); 124 void ext4_ext_path_free(struct ext4_extent_path *path); 125 int ext4_ext_remove_space(struct inode *ip, off_t length, int flags, 126 struct ucred *cred, struct thread *td); 127 int 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 131 int ext4_ext_walk(struct inode *ip); 132 #endif 133 134 #endif /* !_FS_EXT2FS_EXT2_EXTENTS_H_ */ 135