1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 29 */ 30 #ifndef _FS_EXT2FS_EXT2_EXTENTS_H_ 31 #define _FS_EXT2FS_EXT2_EXTENTS_H_ 32 33 #include <sys/types.h> 34 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 40 41 #define EXT4_EXT_CACHE_NO 0 42 #define EXT4_EXT_CACHE_GAP 1 43 #define EXT4_EXT_CACHE_IN 2 44 45 /* 46 * Ext4 extent tail with csum 47 */ 48 struct ext4_extent_tail { 49 uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */ 50 }; 51 52 /* 53 * Ext4 file system extent on disk. 54 */ 55 struct ext4_extent { 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 */ 60 }; 61 62 /* 63 * Extent index on disk. 64 */ 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 68 * next level */ 69 uint16_t ei_leaf_hi; /* high 16 bits of physical block */ 70 uint16_t ei_unused; 71 }; 72 73 /* 74 * Extent tree header. 75 */ 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 */ 82 }; 83 84 /* 85 * Save cached extent. 86 */ 87 struct ext4_extent_cache { 88 daddr_t ec_start; /* extent start */ 89 uint32_t ec_blk; /* logical block */ 90 uint32_t ec_len; 91 uint32_t ec_type; 92 }; 93 94 /* 95 * Save path to some extent. 96 */ 97 struct ext4_extent_path { 98 int index_count; 99 uint16_t ep_depth; 100 uint64_t ep_blk; 101 char *ep_data; 102 struct ext4_extent *ep_ext; 103 struct ext4_extent_index *ep_index; 104 struct ext4_extent_header *ep_header; 105 }; 106 107 #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) 119 120 struct inode; 121 struct m_ext2fs; 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); 133 #endif 134 135 #endif /* !_FS_EXT2FS_EXT2_EXTENTS_H_ */ 136