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 file system extent on disk. 47 */ 48 struct ext4_extent { 49 uint32_t e_blk; /* first logical block */ 50 uint16_t e_len; /* number of blocks */ 51 uint16_t e_start_hi; /* high 16 bits of physical block */ 52 uint32_t e_start_lo; /* low 32 bits of physical block */ 53 }; 54 55 /* 56 * Extent index on disk. 57 */ 58 struct ext4_extent_index { 59 uint32_t ei_blk; /* indexes logical blocks */ 60 uint32_t ei_leaf_lo; /* points to physical block of the 61 * next level */ 62 uint16_t ei_leaf_hi; /* high 16 bits of physical block */ 63 uint16_t ei_unused; 64 }; 65 66 /* 67 * Extent tree header. 68 */ 69 struct ext4_extent_header { 70 uint16_t eh_magic; /* magic number: 0xf30a */ 71 uint16_t eh_ecount; /* number of valid entries */ 72 uint16_t eh_max; /* capacity of store in entries */ 73 uint16_t eh_depth; /* the depth of extent tree */ 74 uint32_t eh_gen; /* generation of extent tree */ 75 }; 76 77 /* 78 * Save cached extent. 79 */ 80 struct ext4_extent_cache { 81 daddr_t ec_start; /* extent start */ 82 uint32_t ec_blk; /* logical block */ 83 uint32_t ec_len; 84 uint32_t ec_type; 85 }; 86 87 /* 88 * Save path to some extent. 89 */ 90 struct ext4_extent_path { 91 int index_count; 92 uint16_t ep_depth; 93 uint64_t ep_blk; 94 char *ep_data; 95 struct ext4_extent *ep_ext; 96 struct ext4_extent_index *ep_index; 97 struct ext4_extent_header *ep_header; 98 }; 99 100 #define EXT_FIRST_EXTENT(hdr) ((struct ext4_extent *)(((char *)(hdr)) + \ 101 sizeof(struct ext4_extent_header))) 102 #define EXT_FIRST_INDEX(hdr) ((struct ext4_extent_index *)(((char *)(hdr)) + \ 103 sizeof(struct ext4_extent_header))) 104 #define EXT_LAST_EXTENT(hdr) (EXT_FIRST_EXTENT((hdr)) + (hdr)->eh_ecount - 1) 105 #define EXT_LAST_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + (hdr)->eh_ecount - 1) 106 #define EXT4_EXTENT_TAIL_OFFSET(hdr) (sizeof(struct ext4_extent_header) + \ 107 (sizeof(struct ext4_extent) * (hdr)->eh_max)) 108 #define EXT_HAS_FREE_INDEX(path) \ 109 ((path)->ep_header->eh_ecount < (path)->ep_header->eh_max) 110 #define EXT_MAX_EXTENT(hdr) (EXT_FIRST_EXTENT(hdr) + ((hdr)->eh_max) - 1) 111 #define EXT_MAX_INDEX(hdr) (EXT_FIRST_INDEX((hdr)) + (hdr)->eh_max - 1) 112 113 struct inode; 114 struct m_ext2fs; 115 void ext4_ext_tree_init(struct inode *ip); 116 int ext4_ext_in_cache(struct inode *, daddr_t, struct ext4_extent *); 117 void ext4_ext_put_cache(struct inode *, struct ext4_extent *, int); 118 int ext4_ext_find_extent(struct inode *, daddr_t, struct ext4_extent_path **); 119 void ext4_ext_path_free(struct ext4_extent_path *path); 120 int ext4_ext_remove_space(struct inode *ip, off_t length, int flags, 121 struct ucred *cred, struct thread *td); 122 int ext4_ext_get_blocks(struct inode *ip, int64_t iblock, 123 unsigned long max_blocks, struct ucred *cred, struct buf **bpp, int *allocate, uint32_t *); 124 #ifdef EXT2FS_DEBUG 125 void ext4_ext_print_extent_tree_status(struct inode * ip); 126 #endif 127 128 #endif /* !_FS_EXT2FS_EXT2_EXTENTS_H_ */ 129