1 /* 2 * Copyright 2000-2002 by Hans Reiser, licensing governed by reiserfs/README 3 * 4 * GRUB -- GRand Unified Bootloader 5 * Copyright (C) 2000, 2001 Free Software Foundation, Inc. 6 * 7 * (C) Copyright 2003 - 2004 8 * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com> 9 * 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 */ 25 26 /* An implementation for the ReiserFS filesystem ported from GRUB. 27 * Some parts of this code (mainly the structures and defines) are 28 * from the original reiser fs code, as found in the linux kernel. 29 */ 30 31 #ifndef __BYTE_ORDER 32 #if defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN) 33 #define __BYTE_ORDER __LITTLE_ENDIAN 34 #elif defined(__BIG_ENDIAN) && !defined(__LITTLE_ENDIAN) 35 #define __BYTE_ORDER __BIG_ENDIAN 36 #else 37 #error "unable to define __BYTE_ORDER" 38 #endif 39 #endif /* not __BYTE_ORDER */ 40 41 #define FSYS_BUFLEN 0x8000 42 #define FSYS_BUF fsys_buf 43 44 /* This is the new super block of a journaling reiserfs system */ 45 struct reiserfs_super_block 46 { 47 __u32 s_block_count; /* blocks count */ 48 __u32 s_free_blocks; /* free blocks count */ 49 __u32 s_root_block; /* root block number */ 50 __u32 s_journal_block; /* journal block number */ 51 __u32 s_journal_dev; /* journal device number */ 52 __u32 s_journal_size; /* size of the journal on FS creation. used to make sure they don't overflow it */ 53 __u32 s_journal_trans_max; /* max number of blocks in a transaction. */ 54 __u32 s_journal_magic; /* random value made on fs creation */ 55 __u32 s_journal_max_batch; /* max number of blocks to batch into a trans */ 56 __u32 s_journal_max_commit_age; /* in seconds, how old can an async commit be */ 57 __u32 s_journal_max_trans_age; /* in seconds, how old can a transaction be */ 58 __u16 s_blocksize; /* block size */ 59 __u16 s_oid_maxsize; /* max size of object id array */ 60 __u16 s_oid_cursize; /* current size of object id array */ 61 __u16 s_state; /* valid or error */ 62 char s_magic[16]; /* reiserfs magic string indicates that file system is reiserfs */ 63 __u16 s_tree_height; /* height of disk tree */ 64 __u16 s_bmap_nr; /* amount of bitmap blocks needed to address each block of file system */ 65 __u16 s_version; 66 char s_unused[128]; /* zero filled by mkreiserfs */ 67 }; 68 69 70 #define sb_root_block(sbp) (__le32_to_cpu((sbp)->s_root_block)) 71 #define sb_journal_block(sbp) (__le32_to_cpu((sbp)->s_journal_block)) 72 #define set_sb_journal_block(sbp,v) ((sbp)->s_journal_block = __cpu_to_le32(v)) 73 #define sb_journal_size(sbp) (__le32_to_cpu((sbp)->s_journal_size)) 74 #define sb_blocksize(sbp) (__le16_to_cpu((sbp)->s_blocksize)) 75 #define set_sb_blocksize(sbp,v) ((sbp)->s_blocksize = __cpu_to_le16(v)) 76 #define sb_version(sbp) (__le16_to_cpu((sbp)->s_version)) 77 #define set_sb_version(sbp,v) ((sbp)->s_version = __cpu_to_le16(v)) 78 79 80 #define REISERFS_MAX_SUPPORTED_VERSION 2 81 #define REISERFS_SUPER_MAGIC_STRING "ReIsErFs" 82 #define REISER2FS_SUPER_MAGIC_STRING "ReIsEr2Fs" 83 #define REISER3FS_SUPER_MAGIC_STRING "ReIsEr3Fs" 84 85 #define MAX_HEIGHT 7 86 87 /* must be correct to keep the desc and commit structs at 4k */ 88 #define JOURNAL_TRANS_HALF 1018 89 90 /* first block written in a commit. */ 91 struct reiserfs_journal_desc { 92 __u32 j_trans_id; /* id of commit */ 93 __u32 j_len; /* length of commit. len +1 is the commit block */ 94 __u32 j_mount_id; /* mount id of this trans*/ 95 __u32 j_realblock[JOURNAL_TRANS_HALF]; /* real locations for the first blocks */ 96 char j_magic[12]; 97 }; 98 99 /* last block written in a commit */ 100 struct reiserfs_journal_commit { 101 __u32 j_trans_id; /* must match j_trans_id from the desc block */ 102 __u32 j_len; /* ditto */ 103 __u32 j_realblock[JOURNAL_TRANS_HALF]; /* real locations for the last blocks */ 104 char j_digest[16]; /* md5 sum of all the blocks involved, including desc and commit. not used, kill it */ 105 }; 106 107 /* this header block gets written whenever a transaction is considered 108 fully flushed, and is more recent than the last fully flushed 109 transaction. 110 fully flushed means all the log blocks and all the real blocks are 111 on disk, and this transaction does not need to be replayed. 112 */ 113 struct reiserfs_journal_header { 114 /* id of last fully flushed transaction */ 115 __u32 j_last_flush_trans_id; 116 /* offset in the log of where to start replay after a crash */ 117 __u32 j_first_unflushed_offset; 118 /* mount id to detect very old transactions */ 119 __u32 j_mount_id; 120 }; 121 122 /* magic string to find desc blocks in the journal */ 123 #define JOURNAL_DESC_MAGIC "ReIsErLB" 124 125 126 /* 127 * directories use this key as well as old files 128 */ 129 struct offset_v1 130 { 131 /* 132 * for regular files this is the offset to the first byte of the 133 * body, contained in the object-item, as measured from the start of 134 * the entire body of the object. 135 * 136 * for directory entries, k_offset consists of hash derived from 137 * hashing the name and using few bits (23 or more) of the resulting 138 * hash, and generation number that allows distinguishing names with 139 * hash collisions. If number of collisions overflows generation 140 * number, we return EEXIST. High order bit is 0 always 141 */ 142 __u32 k_offset; 143 __u32 k_uniqueness; 144 }; 145 146 struct offset_v2 { 147 /* 148 * for regular files this is the offset to the first byte of the 149 * body, contained in the object-item, as measured from the start of 150 * the entire body of the object. 151 * 152 * for directory entries, k_offset consists of hash derived from 153 * hashing the name and using few bits (23 or more) of the resulting 154 * hash, and generation number that allows distinguishing names with 155 * hash collisions. If number of collisions overflows generation 156 * number, we return EEXIST. High order bit is 0 always 157 */ 158 159 #if defined(__LITTLE_ENDIAN_BITFIELD) 160 /* little endian version */ 161 __u64 k_offset:60; 162 __u64 k_type: 4; 163 #elif defined(__BIG_ENDIAN_BITFIELD) 164 /* big endian version */ 165 __u64 k_type: 4; 166 __u64 k_offset:60; 167 #else 168 #error "__LITTLE_ENDIAN_BITFIELD or __BIG_ENDIAN_BITFIELD must be defined" 169 #endif 170 } __attribute__ ((__packed__)); 171 172 #define TYPE_MAXTYPE 3 173 #define TYPE_ANY 15 174 175 #if (__BYTE_ORDER == __BIG_ENDIAN) 176 typedef union { 177 struct offset_v2 offset_v2; 178 __u64 linear; 179 } __attribute__ ((__packed__)) offset_v2_esafe_overlay; 180 181 static inline __u16 offset_v2_k_type( const struct offset_v2 *v2 ) 182 { 183 offset_v2_esafe_overlay tmp = *(const offset_v2_esafe_overlay *)v2; 184 tmp.linear = __le64_to_cpu( tmp.linear ); 185 return (tmp.offset_v2.k_type <= TYPE_MAXTYPE)?tmp.offset_v2.k_type:TYPE_ANY; 186 } 187 188 static inline loff_t offset_v2_k_offset( const struct offset_v2 *v2 ) 189 { 190 offset_v2_esafe_overlay tmp = *(const offset_v2_esafe_overlay *)v2; 191 tmp.linear = __le64_to_cpu( tmp.linear ); 192 return tmp.offset_v2.k_offset; 193 } 194 #elif (__BYTE_ORDER == __LITTLE_ENDIAN) 195 # define offset_v2_k_type(v2) ((v2)->k_type) 196 # define offset_v2_k_offset(v2) ((v2)->k_offset) 197 #else 198 #error "__BYTE_ORDER must be __LITTLE_ENDIAN or __BIG_ENDIAN" 199 #endif 200 201 struct key 202 { 203 /* packing locality: by default parent directory object id */ 204 __u32 k_dir_id; 205 /* object identifier */ 206 __u32 k_objectid; 207 /* the offset and node type (old and new form) */ 208 union 209 { 210 struct offset_v1 v1; 211 struct offset_v2 v2; 212 } 213 u; 214 }; 215 216 #define KEY_SIZE (sizeof (struct key)) 217 218 /* Header of a disk block. More precisely, header of a formatted leaf 219 or internal node, and not the header of an unformatted node. */ 220 struct block_head 221 { 222 __u16 blk_level; /* Level of a block in the tree. */ 223 __u16 blk_nr_item; /* Number of keys/items in a block. */ 224 __u16 blk_free_space; /* Block free space in bytes. */ 225 struct key blk_right_delim_key; /* Right delimiting key for this block (supported for leaf level nodes 226 only) */ 227 }; 228 #define BLKH_SIZE (sizeof (struct block_head)) 229 #define DISK_LEAF_NODE_LEVEL 1 /* Leaf node level. */ 230 231 struct item_head 232 { 233 /* Everything in the tree is found by searching for it based on 234 * its key.*/ 235 struct key ih_key; 236 union { 237 /* The free space in the last unformatted node of an 238 indirect item if this is an indirect item. This 239 equals 0xFFFF iff this is a direct item or stat data 240 item. Note that the key, not this field, is used to 241 determine the item type, and thus which field this 242 union contains. */ 243 __u16 ih_free_space; 244 /* Iff this is a directory item, this field equals the 245 number of directory entries in the directory item. */ 246 __u16 ih_entry_count; 247 } __attribute__ ((__packed__)) u; 248 __u16 ih_item_len; /* total size of the item body */ 249 __u16 ih_item_location; /* an offset to the item body 250 * within the block */ 251 __u16 ih_version; /* 0 for all old items, 2 for new 252 ones. Highest bit is set by fsck 253 temporary, cleaned after all 254 done */ 255 } __attribute__ ((__packed__)); 256 257 /* size of item header */ 258 #define IH_SIZE (sizeof (struct item_head)) 259 260 #define ITEM_VERSION_1 0 261 #define ITEM_VERSION_2 1 262 263 #define ih_version(ih) (__le16_to_cpu((ih)->ih_version)) 264 265 #define IH_KEY_OFFSET(ih) (ih_version(ih) == ITEM_VERSION_1 \ 266 ? __le32_to_cpu((ih)->ih_key.u.v1.k_offset) \ 267 : offset_v2_k_offset(&((ih)->ih_key.u.v2))) 268 269 #define IH_KEY_ISTYPE(ih, type) (ih_version(ih) == ITEM_VERSION_1 \ 270 ? __le32_to_cpu((ih)->ih_key.u.v1.k_uniqueness) == V1_##type \ 271 : offset_v2_k_type(&((ih)->ih_key.u.v2)) == V2_##type) 272 273 /***************************************************************************/ 274 /* DISK CHILD */ 275 /***************************************************************************/ 276 /* Disk child pointer: The pointer from an internal node of the tree 277 to a node that is on disk. */ 278 struct disk_child { 279 __u32 dc_block_number; /* Disk child's block number. */ 280 __u16 dc_size; /* Disk child's used space. */ 281 __u16 dc_reserved; 282 }; 283 284 #define DC_SIZE (sizeof(struct disk_child)) 285 #define dc_block_number(dc_p) (__le32_to_cpu((dc_p)->dc_block_number)) 286 287 288 /* 289 * old stat data is 32 bytes long. We are going to distinguish new one by 290 * different size 291 */ 292 struct stat_data_v1 293 { 294 __u16 sd_mode; /* file type, permissions */ 295 __u16 sd_nlink; /* number of hard links */ 296 __u16 sd_uid; /* owner */ 297 __u16 sd_gid; /* group */ 298 __u32 sd_size; /* file size */ 299 __u32 sd_atime; /* time of last access */ 300 __u32 sd_mtime; /* time file was last modified */ 301 __u32 sd_ctime; /* time inode (stat data) was last changed (except changes to sd_atime and sd_mtime) */ 302 union { 303 __u32 sd_rdev; 304 __u32 sd_blocks; /* number of blocks file uses */ 305 } __attribute__ ((__packed__)) u; 306 __u32 sd_first_direct_byte; /* first byte of file which is stored 307 in a direct item: except that if it 308 equals 1 it is a symlink and if it 309 equals ~(__u32)0 there is no 310 direct item. The existence of this 311 field really grates on me. Let's 312 replace it with a macro based on 313 sd_size and our tail suppression 314 policy. Someday. -Hans */ 315 } __attribute__ ((__packed__)); 316 317 #define stat_data_v1(ih) (ih_version(ih) == ITEM_VERSION_1) 318 #define sd_v1_mode(sdp) ((sdp)->sd_mode) 319 #define sd_v1_nlink(sdp) (__le16_to_cpu((sdp)->sd_nlink)) 320 #define sd_v1_uid(sdp) (__le16_to_cpu((sdp)->sd_uid)) 321 #define sd_v1_gid(sdp) (__le16_to_cpu((sdp)->sd_gid)) 322 #define sd_v1_size(sdp) (__le32_to_cpu((sdp)->sd_size)) 323 #define sd_v1_mtime(sdp) (__le32_to_cpu((sdp)->sd_mtime)) 324 325 /* Stat Data on disk (reiserfs version of UFS disk inode minus the 326 address blocks) */ 327 struct stat_data { 328 __u16 sd_mode; /* file type, permissions */ 329 __u16 sd_attrs; /* persistent inode flags */ 330 __u32 sd_nlink; /* number of hard links */ 331 __u64 sd_size; /* file size */ 332 __u32 sd_uid; /* owner */ 333 __u32 sd_gid; /* group */ 334 __u32 sd_atime; /* time of last access */ 335 __u32 sd_mtime; /* time file was last modified */ 336 __u32 sd_ctime; /* time inode (stat data) was last changed (except changes to sd_atime and sd_mtime) */ 337 __u32 sd_blocks; 338 union { 339 __u32 sd_rdev; 340 __u32 sd_generation; 341 /*__u32 sd_first_direct_byte; */ 342 /* first byte of file which is stored in a 343 direct item: except that if it equals 1 344 it is a symlink and if it equals 345 ~(__u32)0 there is no direct item. The 346 existence of this field really grates 347 on me. Let's replace it with a macro 348 based on sd_size and our tail 349 suppression policy? */ 350 } __attribute__ ((__packed__)) u; 351 } __attribute__ ((__packed__)); 352 353 #define stat_data_v2(ih) (ih_version(ih) == ITEM_VERSION_2) 354 #define sd_v2_mode(sdp) (__le16_to_cpu((sdp)->sd_mode)) 355 #define sd_v2_nlink(sdp) (__le32_to_cpu((sdp)->sd_nlink)) 356 #define sd_v2_size(sdp) (__le64_to_cpu((sdp)->sd_size)) 357 #define sd_v2_uid(sdp) (__le32_to_cpu((sdp)->sd_uid)) 358 #define sd_v2_gid(sdp) (__le32_to_cpu((sdp)->sd_gid)) 359 #define sd_v2_mtime(sdp) (__le32_to_cpu((sdp)->sd_mtime)) 360 361 #define sd_mode(sdp) (__le16_to_cpu((sdp)->sd_mode)) 362 #define sd_size(sdp) (__le32_to_cpu((sdp)->sd_size)) 363 #define sd_size_hi(sdp) (__le32_to_cpu((sdp)->sd_size_hi)) 364 365 struct reiserfs_de_head 366 { 367 __u32 deh_offset; /* third component of the directory entry key */ 368 __u32 deh_dir_id; /* objectid of the parent directory of the 369 object, that is referenced by directory entry */ 370 __u32 deh_objectid;/* objectid of the object, that is referenced by 371 directory entry */ 372 __u16 deh_location;/* offset of name in the whole item */ 373 __u16 deh_state; /* whether 1) entry contains stat data (for 374 future), and 2) whether entry is hidden 375 (unlinked) */ 376 }; 377 378 #define DEH_SIZE (sizeof (struct reiserfs_de_head)) 379 #define deh_offset(p_deh) (__le32_to_cpu((p_deh)->deh_offset)) 380 #define deh_dir_id(p_deh) (__le32_to_cpu((p_deh)->deh_dir_id)) 381 #define deh_objectid(p_deh) (__le32_to_cpu((p_deh)->deh_objectid)) 382 #define deh_location(p_deh) (__le16_to_cpu((p_deh)->deh_location)) 383 #define deh_state(p_deh) (__le16_to_cpu((p_deh)->deh_state)) 384 385 386 #define DEH_Statdata (1 << 0) /* not used now */ 387 #define DEH_Visible (1 << 2) 388 389 #define SD_OFFSET 0 390 #define SD_UNIQUENESS 0 391 #define DOT_OFFSET 1 392 #define DOT_DOT_OFFSET 2 393 #define DIRENTRY_UNIQUENESS 500 394 395 #define V1_TYPE_STAT_DATA 0x0 396 #define V1_TYPE_DIRECT 0xffffffff 397 #define V1_TYPE_INDIRECT 0xfffffffe 398 #define V1_TYPE_DIRECTORY_MAX 0xfffffffd 399 #define V2_TYPE_STAT_DATA 0 400 #define V2_TYPE_INDIRECT 1 401 #define V2_TYPE_DIRECT 2 402 #define V2_TYPE_DIRENTRY 3 403 404 #define REISERFS_ROOT_OBJECTID 2 405 #define REISERFS_ROOT_PARENT_OBJECTID 1 406 #define REISERFS_DISK_OFFSET_IN_BYTES (64 * 1024) 407 /* the spot for the super in versions 3.5 - 3.5.11 (inclusive) */ 408 #define REISERFS_OLD_DISK_OFFSET_IN_BYTES (8 * 1024) 409 #define REISERFS_OLD_BLOCKSIZE 4096 410 411 #define S_ISREG(mode) (((mode) & 0170000) == 0100000) 412 #define S_ISDIR(mode) (((mode) & 0170000) == 0040000) 413 #define S_ISLNK(mode) (((mode) & 0170000) == 0120000) 414 415 #define PATH_MAX 1024 /* include/linux/limits.h */ 416 #define MAX_LINK_COUNT 5 /* number of symbolic links to follow */ 417 418 /* The size of the node cache */ 419 #define FSYSREISER_CACHE_SIZE 24*1024 420 #define FSYSREISER_MIN_BLOCKSIZE SECTOR_SIZE 421 #define FSYSREISER_MAX_BLOCKSIZE FSYSREISER_CACHE_SIZE / 3 422 423 /* Info about currently opened file */ 424 struct fsys_reiser_fileinfo 425 { 426 __u32 k_dir_id; 427 __u32 k_objectid; 428 }; 429 430 /* In memory info about the currently mounted filesystem */ 431 struct fsys_reiser_info 432 { 433 /* The last read item head */ 434 struct item_head *current_ih; 435 /* The last read item */ 436 char *current_item; 437 /* The information for the currently opened file */ 438 struct fsys_reiser_fileinfo fileinfo; 439 /* The start of the journal */ 440 __u32 journal_block; 441 /* The size of the journal */ 442 __u32 journal_block_count; 443 /* The first valid descriptor block in journal 444 (relative to journal_block) */ 445 __u32 journal_first_desc; 446 447 /* The ReiserFS version. */ 448 __u16 version; 449 /* The current depth of the reiser tree. */ 450 __u16 tree_depth; 451 /* SECTOR_SIZE << blocksize_shift == blocksize. */ 452 __u8 blocksize_shift; 453 /* 1 << full_blocksize_shift == blocksize. */ 454 __u8 fullblocksize_shift; 455 /* The reiserfs block size (must be a power of 2) */ 456 __u16 blocksize; 457 /* The number of cached tree nodes */ 458 __u16 cached_slots; 459 /* The number of valid transactions in journal */ 460 __u16 journal_transactions; 461 462 unsigned int blocks[MAX_HEIGHT]; 463 unsigned int next_key_nr[MAX_HEIGHT]; 464 }; 465 466 /* The cached s+tree blocks in FSYS_BUF, see below 467 * for a more detailed description. 468 */ 469 #define ROOT ((char *) ((int) FSYS_BUF)) 470 #define CACHE(i) (ROOT + ((i) << INFO->fullblocksize_shift)) 471 #define LEAF CACHE (DISK_LEAF_NODE_LEVEL) 472 473 #define BLOCKHEAD(cache) ((struct block_head *) cache) 474 #define ITEMHEAD ((struct item_head *) ((int) LEAF + BLKH_SIZE)) 475 #define KEY(cache) ((struct key *) ((int) cache + BLKH_SIZE)) 476 #define DC(cache) ((struct disk_child *) \ 477 ((int) cache + BLKH_SIZE + KEY_SIZE * nr_item)) 478 /* The fsys_reiser_info block. 479 */ 480 #define INFO \ 481 ((struct fsys_reiser_info *) ((int) FSYS_BUF + FSYSREISER_CACHE_SIZE)) 482 /* 483 * The journal cache. For each transaction it contains the number of 484 * blocks followed by the real block numbers of this transaction. 485 * 486 * If the block numbers of some transaction won't fit in this space, 487 * this list is stopped with a 0xffffffff marker and the remaining 488 * uncommitted transactions aren't cached. 489 */ 490 #define JOURNAL_START ((__u32 *) (INFO + 1)) 491 #define JOURNAL_END ((__u32 *) (FSYS_BUF + FSYS_BUFLEN)) 492 493 494 static __inline__ unsigned long 495 log2 (unsigned long word) 496 { 497 #ifdef __I386__ 498 __asm__ ("bsfl %1,%0" 499 : "=r" (word) 500 : "r" (word)); 501 return word; 502 #else 503 int i; 504 505 for(i=0; i<(8*sizeof(word)); i++) 506 if ((1<<i) & word) 507 return i; 508 509 return 0; 510 #endif 511 } 512 513 static __inline__ int 514 is_power_of_two (unsigned long word) 515 { 516 return (word & -word) == word; 517 } 518 519 extern const char *bb_mode_string(int mode); 520 extern int reiserfs_devread (int sector, int byte_offset, int byte_len, char *buf); 521