1/* 2 * linux/fs/hpfs/hpfs.h 3 * 4 * HPFS structures by Chris Smith, 1993 5 * 6 * a little bit modified by Mikulas Patocka, 1998-1999 7 */ 8 9/* The paper 10 11 Duncan, Roy 12 Design goals and implementation of the new High Performance File System 13 Microsoft Systems Journal Sept 1989 v4 n5 p1(13) 14 15 describes what HPFS looked like when it was new, and it is the source 16 of most of the information given here. The rest is conjecture. 17 18 For definitive information on the Duncan paper, see it, not this file. 19 For definitive information on HPFS, ask somebody else -- this is guesswork. 20 There are certain to be many mistakes. */ 21 22/* Notation */ 23 24typedef unsigned secno; /* sector number, partition relative */ 25 26typedef secno dnode_secno; /* sector number of a dnode */ 27typedef secno fnode_secno; /* sector number of an fnode */ 28typedef secno anode_secno; /* sector number of an anode */ 29 30typedef u32 time32_t; /* 32-bit time_t type */ 31 32/* sector 0 */ 33 34/* The boot block is very like a FAT boot block, except that the 35 29h signature byte is 28h instead, and the ID string is "HPFS". */ 36 37#define BB_MAGIC 0xaa55 38 39struct hpfs_boot_block 40{ 41 unsigned char jmp[3]; 42 unsigned char oem_id[8]; 43 unsigned char bytes_per_sector[2]; /* 512 */ 44 unsigned char sectors_per_cluster; 45 unsigned char n_reserved_sectors[2]; 46 unsigned char n_fats; 47 unsigned char n_rootdir_entries[2]; 48 unsigned char n_sectors_s[2]; 49 unsigned char media_byte; 50 unsigned short sectors_per_fat; 51 unsigned short sectors_per_track; 52 unsigned short heads_per_cyl; 53 unsigned int n_hidden_sectors; 54 unsigned int n_sectors_l; /* size of partition */ 55 unsigned char drive_number; 56 unsigned char mbz; 57 unsigned char sig_28h; /* 28h */ 58 unsigned char vol_serno[4]; 59 unsigned char vol_label[11]; 60 unsigned char sig_hpfs[8]; /* "HPFS " */ 61 unsigned char pad[448]; 62 unsigned short magic; /* aa55 */ 63}; 64 65 66/* sector 16 */ 67 68/* The super block has the pointer to the root directory. */ 69 70#define SB_MAGIC 0xf995e849 71 72struct hpfs_super_block 73{ 74 unsigned magic; /* f995 e849 */ 75 unsigned magic1; /* fa53 e9c5, more magic? */ 76 /*unsigned huh202;*/ /* ?? 202 = N. of B. in 1.00390625 S.*/ 77 char version; /* version of a filesystem usually 2 */ 78 char funcversion; /* functional version - oldest version 79 of filesystem that can understand 80 this disk */ 81 unsigned short int zero; /* 0 */ 82 fnode_secno root; /* fnode of root directory */ 83 secno n_sectors; /* size of filesystem */ 84 unsigned n_badblocks; /* number of bad blocks */ 85 secno bitmaps; /* pointers to free space bit maps */ 86 unsigned zero1; /* 0 */ 87 secno badblocks; /* bad block list */ 88 unsigned zero3; /* 0 */ 89 time32_t last_chkdsk; /* date last checked, 0 if never */ 90 /*unsigned zero4;*/ /* 0 */ 91 time32_t last_optimize; /* date last optimized, 0 if never */ 92 secno n_dir_band; /* number of sectors in dir band */ 93 secno dir_band_start; /* first sector in dir band */ 94 secno dir_band_end; /* last sector in dir band */ 95 secno dir_band_bitmap; /* free space map, 1 dnode per bit */ 96 char volume_name[32]; /* not used */ 97 secno user_id_table; /* 8 preallocated sectors - user id */ 98 unsigned zero6[103]; /* 0 */ 99}; 100 101 102/* sector 17 */ 103 104/* The spare block has pointers to spare sectors. */ 105 106#define SP_MAGIC 0xf9911849 107 108struct hpfs_spare_block 109{ 110 unsigned magic; /* f991 1849 */ 111 unsigned magic1; /* fa52 29c5, more magic? */ 112 113 unsigned dirty: 1; /* 0 clean, 1 "improperly stopped" */ 114 /*unsigned flag1234: 4;*/ /* unknown flags */ 115 unsigned sparedir_used: 1; /* spare dirblks used */ 116 unsigned hotfixes_used: 1; /* hotfixes used */ 117 unsigned bad_sector: 1; /* bad sector, corrupted disk (???) */ 118 unsigned bad_bitmap: 1; /* bad bitmap */ 119 unsigned fast: 1; /* partition was fast formatted */ 120 unsigned old_wrote: 1; /* old version wrote to partion */ 121 unsigned old_wrote_1: 1; /* old version wrote to partion (?) */ 122 unsigned install_dasd_limits: 1; /* HPFS386 flags */ 123 unsigned resynch_dasd_limits: 1; 124 unsigned dasd_limits_operational: 1; 125 unsigned multimedia_active: 1; 126 unsigned dce_acls_active: 1; 127 unsigned dasd_limits_dirty: 1; 128 unsigned flag67: 2; 129 unsigned char mm_contlgulty; 130 unsigned char unused; 131 132 secno hotfix_map; /* info about remapped bad sectors */ 133 unsigned n_spares_used; /* number of hotfixes */ 134 unsigned n_spares; /* number of spares in hotfix map */ 135 unsigned n_dnode_spares_free; /* spare dnodes unused */ 136 unsigned n_dnode_spares; /* length of spare_dnodes[] list, 137 follows in this block*/ 138 secno code_page_dir; /* code page directory block */ 139 unsigned n_code_pages; /* number of code pages */ 140 /*unsigned large_numbers[2];*/ /* ?? */ 141 unsigned super_crc; /* on HPFS386 and LAN Server this is 142 checksum of superblock, on normal 143 OS/2 unused */ 144 unsigned spare_crc; /* on HPFS386 checksum of spareblock */ 145 unsigned zero1[15]; /* unused */ 146 dnode_secno spare_dnodes[100]; /* emergency free dnode list */ 147 unsigned zero2[1]; /* room for more? */ 148}; 149 150/* The bad block list is 4 sectors long. The first word must be zero, 151 the remaining words give n_badblocks bad block numbers. 152 I bet you can see it coming... */ 153 154#define BAD_MAGIC 0 155 156/* The hotfix map is 4 sectors long. It looks like 157 158 secno from[n_spares]; 159 secno to[n_spares]; 160 161 The to[] list is initialized to point to n_spares preallocated empty 162 sectors. The from[] list contains the sector numbers of bad blocks 163 which have been remapped to corresponding sectors in the to[] list. 164 n_spares_used gives the length of the from[] list. */ 165 166 167/* Sectors 18 and 19 are preallocated and unused. 168 Maybe they're spares for 16 and 17, but simple substitution fails. */ 169 170 171/* The code page info pointed to by the spare block consists of an index 172 block and blocks containing uppercasing tables. I don't know what 173 these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them 174 itself. Linux doesn't use them either. */ 175 176/* block pointed to by spareblock->code_page_dir */ 177 178#define CP_DIR_MAGIC 0x494521f7 179 180struct code_page_directory 181{ 182 unsigned magic; /* 4945 21f7 */ 183 unsigned n_code_pages; /* number of pointers following */ 184 unsigned zero1[2]; 185 struct { 186 unsigned short ix; /* index */ 187 unsigned short code_page_number; /* code page number */ 188 unsigned bounds; /* matches corresponding word 189 in data block */ 190 secno code_page_data; /* sector number of a code_page_data 191 containing c.p. array */ 192 unsigned short index; /* index in c.p. array in that sector*/ 193 unsigned short unknown; /* some unknown value; usually 0; 194 2 in Japanese version */ 195 } array[31]; /* unknown length */ 196}; 197 198/* blocks pointed to by code_page_directory */ 199 200#define CP_DATA_MAGIC 0x894521f7 201 202struct code_page_data 203{ 204 unsigned magic; /* 8945 21f7 */ 205 unsigned n_used; /* # elements used in c_p_data[] */ 206 unsigned bounds[3]; /* looks a bit like 207 (beg1,end1), (beg2,end2) 208 one byte each */ 209 unsigned short offs[3]; /* offsets from start of sector 210 to start of c_p_data[ix] */ 211 struct { 212 unsigned short ix; /* index */ 213 unsigned short code_page_number; /* code page number */ 214 unsigned short unknown; /* the same as in cp directory */ 215 unsigned char map[128]; /* upcase table for chars 80..ff */ 216 unsigned short zero2; 217 } code_page[3]; 218 unsigned char incognita[78]; 219}; 220 221 222/* Free space bitmaps are 4 sectors long, which is 16384 bits. 223 16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap. 224 Bit order in the maps is little-endian. 0 means taken, 1 means free. 225 226 Bit map sectors are marked allocated in the bit maps, and so are sectors 227 off the end of the partition. 228 229 Band 0 is sectors 0-3fff, its map is in sectors 18-1b. 230 Band 1 is 4000-7fff, its map is in 7ffc-7fff. 231 Band 2 is 8000-ffff, its map is in 8000-8003. 232 The remaining bands have maps in their first (even) or last (odd) 4 sectors 233 -- if the last, partial, band is odd its map is in its last 4 sectors. 234 235 The bitmap locations are given in a table pointed to by the super block. 236 No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is 237 just where they usually are. 238 239 The "directory band" is a bunch of sectors preallocated for dnodes. 240 It has a 4-sector free space bitmap of its own. Each bit in the map 241 corresponds to one 4-sector dnode, bit 0 of the map corresponding to 242 the first 4 sectors of the directory band. The entire band is marked 243 allocated in the main bitmap. The super block gives the locations 244 of the directory band and its bitmap. ("band" doesn't mean it is 245 8 meg long; it isn't.) */ 246 247 248/* dnode: directory. 4 sectors long */ 249 250/* A directory is a tree of dnodes. The fnode for a directory 251 contains one pointer, to the root dnode of the tree. The fnode 252 never moves, the dnodes do the B-tree thing, splitting and merging 253 as files are added and removed. */ 254 255#define DNODE_MAGIC 0x77e40aae 256 257struct dnode { 258 unsigned magic; /* 77e4 0aae */ 259 unsigned first_free; /* offset from start of dnode to 260 first free dir entry */ 261 unsigned root_dnode:1; /* Is it root dnode? */ 262 unsigned increment_me:31; /* some kind of activity counter? 263 Neither HPFS.IFS nor CHKDSK cares 264 if you change this word */ 265 secno up; /* (root dnode) directory's fnode 266 (nonroot) parent dnode */ 267 dnode_secno self; /* pointer to this dnode */ 268 unsigned char dirent[2028]; /* one or more dirents */ 269}; 270 271struct hpfs_dirent { 272 unsigned short length; /* offset to next dirent */ 273 unsigned first: 1; /* set on phony ^A^A (".") entry */ 274 unsigned has_acl: 1; 275 unsigned down: 1; /* down pointer present (after name) */ 276 unsigned last: 1; /* set on phony \377 entry */ 277 unsigned has_ea: 1; /* entry has EA */ 278 unsigned has_xtd_perm: 1; /* has extended perm list (???) */ 279 unsigned has_explicit_acl: 1; 280 unsigned has_needea: 1; /* ?? some EA has NEEDEA set 281 I have no idea why this is 282 interesting in a dir entry */ 283 unsigned read_only: 1; /* dos attrib */ 284 unsigned hidden: 1; /* dos attrib */ 285 unsigned system: 1; /* dos attrib */ 286 unsigned flag11: 1; /* would be volume label dos attrib */ 287 unsigned directory: 1; /* dos attrib */ 288 unsigned archive: 1; /* dos attrib */ 289 unsigned not_8x3: 1; /* name is not 8.3 */ 290 unsigned flag15: 1; 291 fnode_secno fnode; /* fnode giving allocation info */ 292 time32_t write_date; /* mtime */ 293 unsigned file_size; /* file length, bytes */ 294 time32_t read_date; /* atime */ 295 time32_t creation_date; /* ctime */ 296 unsigned ea_size; /* total EA length, bytes */ 297 unsigned char no_of_acls : 3; /* number of ACL's */ 298 unsigned char reserver : 5; 299 unsigned char ix; /* code page index (of filename), see 300 struct code_page_data */ 301 unsigned char namelen, name[1]; /* file name */ 302 /* dnode_secno down; btree down pointer, if present, 303 follows name on next word boundary, or maybe it 304 precedes next dirent, which is on a word boundary. */ 305}; 306 307 308/* B+ tree: allocation info in fnodes and anodes */ 309 310/* dnodes point to fnodes which are responsible for listing the sectors 311 assigned to the file. This is done with trees of (length,address) 312 pairs. (Actually triples, of (length, file-address, disk-address) 313 which can represent holes. Find out if HPFS does that.) 314 At any rate, fnodes contain a small tree; if subtrees are needed 315 they occupy essentially a full block in anodes. A leaf-level tree node 316 has 3-word entries giving sector runs, a non-leaf node has 2-word 317 entries giving subtree pointers. A flag in the header says which. */ 318 319struct bplus_leaf_node 320{ 321 unsigned file_secno; /* first file sector in extent */ 322 unsigned length; /* length, sectors */ 323 secno disk_secno; /* first corresponding disk sector */ 324}; 325 326struct bplus_internal_node 327{ 328 unsigned file_secno; /* subtree maps sectors < this */ 329 anode_secno down; /* pointer to subtree */ 330}; 331 332struct bplus_header 333{ 334 unsigned hbff: 1; /* high bit of first free entry offset */ 335 unsigned flag1: 1; 336 unsigned flag2: 1; 337 unsigned flag3: 1; 338 unsigned flag4: 1; 339 unsigned fnode_parent: 1; /* ? we're pointed to by an fnode, 340 the data btree or some ea or the 341 main ea bootage pointer ea_secno */ 342 /* also can get set in fnodes, which 343 may be a chkdsk glitch or may mean 344 this bit is irrelevant in fnodes, 345 or this interpretation is all wet */ 346 unsigned binary_search: 1; /* suggest binary search (unused) */ 347 unsigned internal: 1; /* 1 -> (internal) tree of anodes 348 0 -> (leaf) list of extents */ 349 unsigned char fill[3]; 350 unsigned char n_free_nodes; /* free nodes in following array */ 351 unsigned char n_used_nodes; /* used nodes in following array */ 352 unsigned short first_free; /* offset from start of header to 353 first free node in array */ 354 union { 355 struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving 356 subtree pointers */ 357 struct bplus_leaf_node external[0]; /* (external) 3-word entries giving 358 sector runs */ 359 } u; 360}; 361 362/* fnode: root of allocation b+ tree, and EA's */ 363 364/* Every file and every directory has one fnode, pointed to by the directory 365 entry and pointing to the file's sectors or directory's root dnode. EA's 366 are also stored here, and there are said to be ACL's somewhere here too. */ 367 368#define FNODE_MAGIC 0xf7e40aae 369 370struct fnode 371{ 372 unsigned magic; /* f7e4 0aae */ 373 unsigned zero1[2]; /* read history */ 374 unsigned char len, name[15]; /* true length, truncated name */ 375 fnode_secno up; /* pointer to file's directory fnode */ 376 /*unsigned zero2[3];*/ 377 secno acl_size_l; 378 secno acl_secno; 379 unsigned short acl_size_s; 380 char acl_anode; 381 char zero2; /* history bit count */ 382 unsigned ea_size_l; /* length of disk-resident ea's */ 383 secno ea_secno; /* first sector of disk-resident ea's*/ 384 unsigned short ea_size_s; /* length of fnode-resident ea's */ 385 386 unsigned flag0: 1; 387 unsigned ea_anode: 1; /* 1 -> ea_secno is an anode */ 388 unsigned flag2: 1; 389 unsigned flag3: 1; 390 unsigned flag4: 1; 391 unsigned flag5: 1; 392 unsigned flag6: 1; 393 unsigned flag7: 1; 394 unsigned dirflag: 1; /* 1 -> directory. first & only extent 395 points to dnode. */ 396 unsigned flag9: 1; 397 unsigned flag10: 1; 398 unsigned flag11: 1; 399 unsigned flag12: 1; 400 unsigned flag13: 1; 401 unsigned flag14: 1; 402 unsigned flag15: 1; 403 404 struct bplus_header btree; /* b+ tree, 8 extents or 12 subtrees */ 405 union { 406 struct bplus_leaf_node external[8]; 407 struct bplus_internal_node internal[12]; 408 } u; 409 410 unsigned file_size; /* file length, bytes */ 411 unsigned n_needea; /* number of EA's with NEEDEA set */ 412 char user_id[16]; /* unused */ 413 unsigned short ea_offs; /* offset from start of fnode 414 to first fnode-resident ea */ 415 char dasd_limit_treshhold; 416 char dasd_limit_delta; 417 unsigned dasd_limit; 418 unsigned dasd_usage; 419 /*unsigned zero5[2];*/ 420 unsigned char ea[316]; /* zero or more EA's, packed together 421 with no alignment padding. 422 (Do not use this name, get here 423 via fnode + ea_offs. I think.) */ 424}; 425 426 427/* anode: 99.44% pure allocation tree */ 428 429#define ANODE_MAGIC 0x37e40aae 430 431struct anode 432{ 433 unsigned magic; /* 37e4 0aae */ 434 anode_secno self; /* pointer to this anode */ 435 secno up; /* parent anode or fnode */ 436 437 struct bplus_header btree; /* b+tree, 40 extents or 60 subtrees */ 438 union { 439 struct bplus_leaf_node external[40]; 440 struct bplus_internal_node internal[60]; 441 } u; 442 443 unsigned fill[3]; /* unused */ 444}; 445 446 447/* extended attributes. 448 449 A file's EA info is stored as a list of (name,value) pairs. It is 450 usually in the fnode, but (if it's large) it is moved to a single 451 sector run outside the fnode, or to multiple runs with an anode tree 452 that points to them. 453 454 The value of a single EA is stored along with the name, or (if large) 455 it is moved to a single sector run, or multiple runs pointed to by an 456 anode tree, pointed to by the value field of the (name,value) pair. 457 458 Flags in the EA tell whether the value is immediate, in a single sector 459 run, or in multiple runs. Flags in the fnode tell whether the EA list 460 is immediate, in a single run, or in multiple runs. */ 461 462struct extended_attribute 463{ 464 unsigned indirect: 1; /* 1 -> value gives sector number 465 where real value starts */ 466 unsigned anode: 1; /* 1 -> sector is an anode 467 that points to fragmented value */ 468 unsigned flag2: 1; 469 unsigned flag3: 1; 470 unsigned flag4: 1; 471 unsigned flag5: 1; 472 unsigned flag6: 1; 473 unsigned needea: 1; /* required ea */ 474 unsigned char namelen; /* length of name, bytes */ 475 unsigned short valuelen; /* length of value, bytes */ 476 unsigned char name[0]; 477 /* 478 unsigned char name[namelen]; ascii attrib name 479 unsigned char nul; terminating '\0', not counted 480 unsigned char value[valuelen]; value, arbitrary 481 if this.indirect, valuelen is 8 and the value is 482 unsigned length; real length of value, bytes 483 secno secno; sector address where it starts 484 if this.anode, the above sector number is the root of an anode tree 485 which points to the value. 486 */ 487}; 488 489/* 490 Local Variables: 491 comment-column: 40 492 End: 493*/ 494