1 /* 2 * Copyright (c) 2003,2004 Cluster File Systems, Inc, info (at) clusterfs.com 3 * Written by Alex Tomas <alex (at) clusterfs.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public Licens 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- 17 */ 18 19 #ifndef _LINUX_EXT3_EXTENTS 20 #define _LINUX_EXT3_EXTENTS 21 22 /* 23 * with AGRESSIVE_TEST defined capacity of index/leaf blocks 24 * become very little, so index split, in-depth growing and 25 * other hard changes happens much more often 26 * this is for debug purposes only 27 */ 28 #define AGRESSIVE_TEST_ 29 30 /* 31 * if CHECK_BINSEARCH defined, then results of binary search 32 * will be checked by linear search 33 */ 34 #define CHECK_BINSEARCH_ 35 36 /* 37 * if EXT_DEBUG is defined you can use 'extdebug' mount option 38 * to get lots of info what's going on 39 */ 40 //#define EXT_DEBUG 41 #ifdef EXT_DEBUG 42 #define ext_debug(tree,fmt,a...) \ 43 do { \ 44 if (test_opt((tree)->inode->i_sb, EXTDEBUG)) \ 45 printk(fmt, ##a); \ 46 } while (0); 47 #else 48 #define ext_debug(tree,fmt,a...) 49 #endif 50 51 /* 52 * if EXT_STATS is defined then stats numbers are collected 53 * these number will be displayed at umount time 54 */ 55 #define EXT_STATS_ 56 57 58 #define EXT3_ALLOC_NEEDED 3 /* block bitmap + group desc. + sb */ 59 60 /* 61 * ext3_inode has i_block array (total 60 bytes) 62 * first 4 bytes are used to store: 63 * - tree depth (0 mean there is no tree yet. all extents in the inode) 64 * - number of alive extents in the inode 65 */ 66 67 /* 68 * this is extent on-disk structure 69 * it's used at the bottom of the tree 70 */ 71 struct ext3_extent { 72 __u32 ee_block; /* first logical block extent covers */ 73 __u16 ee_len; /* number of blocks covered by extent */ 74 __u16 ee_start_hi; /* high 16 bits of physical block */ 75 __u32 ee_start; /* low 32 bigs of physical block */ 76 }; 77 78 /* 79 * this is index on-disk structure 80 * it's used at all the levels, but the bottom 81 */ 82 struct ext3_extent_idx { 83 __u32 ei_block; /* index covers logical blocks from 'block' */ 84 __u32 ei_leaf; /* pointer to the physical block of the next * 85 * level. leaf or next index could bet here */ 86 __u16 ei_leaf_hi; /* high 16 bits of physical block */ 87 __u16 ei_unused; 88 }; 89 90 /* 91 * each block (leaves and indexes), even inode-stored has header 92 */ 93 struct ext3_extent_header { 94 __u16 eh_magic; /* probably will support different formats */ 95 __u16 eh_entries; /* number of valid entries */ 96 __u16 eh_max; /* capacity of store in entries */ 97 __u16 eh_depth; /* has tree real underlaying blocks? */ 98 __u32 eh_generation; /* generation of the tree */ 99 }; 100 101 #define EXT3_EXT_MAGIC 0xf30a 102 103 /* 104 * array of ext3_ext_path contains path to some extent 105 * creation/lookup routines use it for traversal/splitting/etc 106 * truncate uses it to simulate recursive walking 107 */ 108 struct ext3_ext_path { 109 __u32 p_block; 110 __u16 p_depth; 111 struct ext3_extent *p_ext; 112 struct ext3_extent_idx *p_idx; 113 struct ext3_extent_header *p_hdr; 114 struct buffer_head *p_bh; 115 }; 116 117 /* 118 * structure for external API 119 */ 120 121 #define EXT_CONTINUE 0 122 #define EXT_BREAK 1 123 #define EXT_REPEAT 2 124 125 126 #define EXT_MAX_BLOCK 0xffffffff 127 #define EXT_CACHE_MARK 0xffff 128 129 130 #define EXT_FIRST_EXTENT(__hdr__) \ 131 ((struct ext3_extent *) (((char *) (__hdr__)) + \ 132 sizeof(struct ext3_extent_header))) 133 #define EXT_FIRST_INDEX(__hdr__) \ 134 ((struct ext3_extent_idx *) (((char *) (__hdr__)) + \ 135 sizeof(struct ext3_extent_header))) 136 #define EXT_HAS_FREE_INDEX(__path__) \ 137 ((__path__)->p_hdr->eh_entries < (__path__)->p_hdr->eh_max) 138 #define EXT_LAST_EXTENT(__hdr__) \ 139 (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_entries - 1) 140 #define EXT_LAST_INDEX(__hdr__) \ 141 (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_entries - 1) 142 #define EXT_MAX_EXTENT(__hdr__) \ 143 (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_max - 1) 144 #define EXT_MAX_INDEX(__hdr__) \ 145 (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_max - 1) 146 147 #define EXT_ROOT_HDR(tree) \ 148 ((struct ext3_extent_header *) (tree)->root) 149 #define EXT_BLOCK_HDR(bh) \ 150 ((struct ext3_extent_header *) (bh)->b_data) 151 #define EXT_DEPTH(_t_) \ 152 (((struct ext3_extent_header *)((_t_)->root))->eh_depth) 153 #define EXT_GENERATION(_t_) \ 154 (((struct ext3_extent_header *)((_t_)->root))->eh_generation) 155 156 157 #define EXT_ASSERT(__x__) if (!(__x__)) BUG(); 158 159 160 /* 161 * this structure is used to gather extents from the tree via ioctl 162 */ 163 struct ext3_extent_buf { 164 unsigned long start; 165 int buflen; 166 void *buffer; 167 void *cur; 168 int err; 169 }; 170 171 /* 172 * this structure is used to collect stats info about the tree 173 */ 174 struct ext3_extent_tree_stats { 175 int depth; 176 int extents_num; 177 int leaf_num; 178 }; 179 180 #ifdef __KERNEL__ 181 /* 182 * ext3_extents_tree is used to pass initial information 183 * to top-level extents API 184 */ 185 struct ext3_extents_helpers; 186 struct ext3_extents_tree { 187 struct inode *inode; /* inode which tree belongs to */ 188 void *root; /* ptr to data top of tree resides at */ 189 void *buffer; /* will be passed as arg to ^^ routines */ 190 int buffer_len; 191 void *private; 192 struct ext3_extent *cex;/* last found extent */ 193 struct ext3_extents_helpers *ops; 194 }; 195 196 struct ext3_extents_helpers { 197 int (*get_write_access)(handle_t *h, void *buffer); 198 int (*mark_buffer_dirty)(handle_t *h, void *buffer); 199 int (*mergable)(struct ext3_extent *ex1, struct ext3_extent *ex2); 200 int (*remove_extent_credits)(struct ext3_extents_tree *, 201 struct ext3_extent *, unsigned long, 202 unsigned long); 203 int (*remove_extent)(struct ext3_extents_tree *, 204 struct ext3_extent *, unsigned long, 205 unsigned long); 206 int (*new_block)(handle_t *, struct ext3_extents_tree *, 207 struct ext3_ext_path *, struct ext3_extent *, 208 int *); 209 }; 210 211 /* 212 * to be called by ext3_ext_walk_space() 213 * negative retcode - error 214 * positive retcode - signal for ext3_ext_walk_space(), see below 215 * callback must return valid extent (passed or newly created) 216 */ 217 typedef int (*ext_prepare_callback)(struct ext3_extents_tree *, 218 struct ext3_ext_path *, 219 struct ext3_extent *, int); 220 void ext3_init_tree_desc(struct ext3_extents_tree *, struct inode *); 221 extern int ext3_extent_tree_init(handle_t *, struct ext3_extents_tree *); 222 extern int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *, struct ext3_ext_path *); 223 extern int ext3_ext_insert_extent(handle_t *, struct ext3_extents_tree *, struct ext3_ext_path *, struct ext3_extent *); 224 extern int ext3_ext_walk_space(struct ext3_extents_tree *, unsigned long, unsigned long, ext_prepare_callback); 225 extern int ext3_ext_remove_space(struct ext3_extents_tree *, unsigned long, unsigned long); 226 extern struct ext3_ext_path * ext3_ext_find_extent(struct ext3_extents_tree *, int, struct ext3_ext_path *); 227 228 static inline void 229 ext3_ext_invalidate_cache(struct ext3_extents_tree *tree) 230 { 231 if (tree->cex) 232 tree->cex->ee_len = 0; 233 } 234 #endif /* __KERNEL__ */ 235 236 237 #endif /* _LINUX_EXT3_EXTENTS */ 238 239
