1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * linux/fs/hpfs/hpfs.h
4 *
5 * HPFS structures by Chris Smith, 1993
6 *
7 * a little bit modified by Mikulas Patocka, 1998-1999
8 */
9
10 /* The paper
11
12 Duncan, Roy
13 Design goals and implementation of the new High Performance File System
14 Microsoft Systems Journal Sept 1989 v4 n5 p1(13)
15
16 describes what HPFS looked like when it was new, and it is the source
17 of most of the information given here. The rest is conjecture.
18
19 For definitive information on the Duncan paper, see it, not this file.
20 For definitive information on HPFS, ask somebody else -- this is guesswork.
21 There are certain to be many mistakes. */
22
23 #if !defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN)
24 #error unknown endian
25 #endif
26
27 /* Notation */
28
29 typedef u32 secno; /* sector number, partition relative */
30
31 typedef secno dnode_secno; /* sector number of a dnode */
32 typedef secno fnode_secno; /* sector number of an fnode */
33 typedef secno anode_secno; /* sector number of an anode */
34
35 typedef u32 time32_t; /* 32-bit time_t type */
36
37 /* sector 0 */
38
39 /* The boot block is very like a FAT boot block, except that the
40 29h signature byte is 28h instead, and the ID string is "HPFS". */
41
42 #define BB_MAGIC 0xaa55
43
44 struct hpfs_boot_block
45 {
46 u8 jmp[3];
47 u8 oem_id[8];
48 u8 bytes_per_sector[2]; /* 512 */
49 u8 sectors_per_cluster;
50 u8 n_reserved_sectors[2];
51 u8 n_fats;
52 u8 n_rootdir_entries[2];
53 u8 n_sectors_s[2];
54 u8 media_byte;
55 __le16 sectors_per_fat;
56 __le16 sectors_per_track;
57 __le16 heads_per_cyl;
58 __le32 n_hidden_sectors;
59 __le32 n_sectors_l; /* size of partition */
60 u8 drive_number;
61 u8 mbz;
62 u8 sig_28h; /* 28h */
63 u8 vol_serno[4];
64 u8 vol_label[11];
65 u8 sig_hpfs[8]; /* "HPFS " */
66 u8 pad[448];
67 __le16 magic; /* aa55 */
68 };
69
70
71 /* sector 16 */
72
73 /* The super block has the pointer to the root directory. */
74
75 #define SB_MAGIC 0xf995e849
76
77 struct hpfs_super_block
78 {
79 __le32 magic; /* f995 e849 */
80 __le32 magic1; /* fa53 e9c5, more magic? */
81 u8 version; /* version of a filesystem usually 2 */
82 u8 funcversion; /* functional version - oldest version
83 of filesystem that can understand
84 this disk */
85 __le16 zero; /* 0 */
86 __le32 root; /* fnode of root directory */
87 __le32 n_sectors; /* size of filesystem */
88 __le32 n_badblocks; /* number of bad blocks */
89 __le32 bitmaps; /* pointers to free space bit maps */
90 __le32 zero1; /* 0 */
91 __le32 badblocks; /* bad block list */
92 __le32 zero3; /* 0 */
93 __le32 last_chkdsk; /* date last checked, 0 if never */
94 __le32 last_optimize; /* date last optimized, 0 if never */
95 __le32 n_dir_band; /* number of sectors in dir band */
96 __le32 dir_band_start; /* first sector in dir band */
97 __le32 dir_band_end; /* last sector in dir band */
98 __le32 dir_band_bitmap; /* free space map, 1 dnode per bit */
99 u8 volume_name[32]; /* not used */
100 __le32 user_id_table; /* 8 preallocated sectors - user id */
101 u32 zero6[103]; /* 0 */
102 };
103
104
105 /* sector 17 */
106
107 /* The spare block has pointers to spare sectors. */
108
109 #define SP_MAGIC 0xf9911849
110
111 struct hpfs_spare_block
112 {
113 __le32 magic; /* f991 1849 */
114 __le32 magic1; /* fa52 29c5, more magic? */
115
116 #ifdef __LITTLE_ENDIAN
117 u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */
118 u8 sparedir_used: 1; /* spare dirblks used */
119 u8 hotfixes_used: 1; /* hotfixes used */
120 u8 bad_sector: 1; /* bad sector, corrupted disk (???) */
121 u8 bad_bitmap: 1; /* bad bitmap */
122 u8 fast: 1; /* partition was fast formatted */
123 u8 old_wrote: 1; /* old version wrote to partition */
124 u8 old_wrote_1: 1; /* old version wrote to partition (?) */
125 #else
126 u8 old_wrote_1: 1; /* old version wrote to partition (?) */
127 u8 old_wrote: 1; /* old version wrote to partition */
128 u8 fast: 1; /* partition was fast formatted */
129 u8 bad_bitmap: 1; /* bad bitmap */
130 u8 bad_sector: 1; /* bad sector, corrupted disk (???) */
131 u8 hotfixes_used: 1; /* hotfixes used */
132 u8 sparedir_used: 1; /* spare dirblks used */
133 u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */
134 #endif
135
136 #ifdef __LITTLE_ENDIAN
137 u8 install_dasd_limits: 1; /* HPFS386 flags */
138 u8 resynch_dasd_limits: 1;
139 u8 dasd_limits_operational: 1;
140 u8 multimedia_active: 1;
141 u8 dce_acls_active: 1;
142 u8 dasd_limits_dirty: 1;
143 u8 flag67: 2;
144 #else
145 u8 flag67: 2;
146 u8 dasd_limits_dirty: 1;
147 u8 dce_acls_active: 1;
148 u8 multimedia_active: 1;
149 u8 dasd_limits_operational: 1;
150 u8 resynch_dasd_limits: 1;
151 u8 install_dasd_limits: 1; /* HPFS386 flags */
152 #endif
153
154 u8 mm_contlgulty;
155 u8 unused;
156
157 __le32 hotfix_map; /* info about remapped bad sectors */
158 __le32 n_spares_used; /* number of hotfixes */
159 __le32 n_spares; /* number of spares in hotfix map */
160 __le32 n_dnode_spares_free; /* spare dnodes unused */
161 __le32 n_dnode_spares; /* length of spare_dnodes[] list,
162 follows in this block*/
163 __le32 code_page_dir; /* code page directory block */
164 __le32 n_code_pages; /* number of code pages */
165 __le32 super_crc; /* on HPFS386 and LAN Server this is
166 checksum of superblock, on normal
167 OS/2 unused */
168 __le32 spare_crc; /* on HPFS386 checksum of spareblock */
169 __le32 zero1[15]; /* unused */
170 __le32 spare_dnodes[100]; /* emergency free dnode list */
171 __le32 zero2[1]; /* room for more? */
172 };
173
174 /* The bad block list is 4 sectors long. The first word must be zero,
175 the remaining words give n_badblocks bad block numbers.
176 I bet you can see it coming... */
177
178 #define BAD_MAGIC 0
179
180 /* The hotfix map is 4 sectors long. It looks like
181
182 secno from[n_spares];
183 secno to[n_spares];
184
185 The to[] list is initialized to point to n_spares preallocated empty
186 sectors. The from[] list contains the sector numbers of bad blocks
187 which have been remapped to corresponding sectors in the to[] list.
188 n_spares_used gives the length of the from[] list. */
189
190
191 /* Sectors 18 and 19 are preallocated and unused.
192 Maybe they're spares for 16 and 17, but simple substitution fails. */
193
194
195 /* The code page info pointed to by the spare block consists of an index
196 block and blocks containing uppercasing tables. I don't know what
197 these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them
198 itself. Linux doesn't use them either. */
199
200 /* block pointed to by spareblock->code_page_dir */
201
202 #define CP_DIR_MAGIC 0x494521f7
203
204 struct code_page_directory
205 {
206 __le32 magic; /* 4945 21f7 */
207 __le32 n_code_pages; /* number of pointers following */
208 __le32 zero1[2];
209 struct {
210 __le16 ix; /* index */
211 __le16 code_page_number; /* code page number */
212 __le32 bounds; /* matches corresponding word
213 in data block */
214 __le32 code_page_data; /* sector number of a code_page_data
215 containing c.p. array */
216 __le16 index; /* index in c.p. array in that sector*/
217 __le16 unknown; /* some unknown value; usually 0;
218 2 in Japanese version */
219 } array[31]; /* unknown length */
220 };
221
222 /* blocks pointed to by code_page_directory */
223
224 #define CP_DATA_MAGIC 0x894521f7
225
226 struct code_page_data
227 {
228 __le32 magic; /* 8945 21f7 */
229 __le32 n_used; /* # elements used in c_p_data[] */
230 __le32 bounds[3]; /* looks a bit like
231 (beg1,end1), (beg2,end2)
232 one byte each */
233 __le16 offs[3]; /* offsets from start of sector
234 to start of c_p_data[ix] */
235 struct {
236 __le16 ix; /* index */
237 __le16 code_page_number; /* code page number */
238 __le16 unknown; /* the same as in cp directory */
239 u8 map[128]; /* upcase table for chars 80..ff */
240 __le16 zero2;
241 } code_page[3];
242 u8 incognita[78];
243 };
244
245
246 /* Free space bitmaps are 4 sectors long, which is 16384 bits.
247 16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap.
248 Bit order in the maps is little-endian. 0 means taken, 1 means free.
249
250 Bit map sectors are marked allocated in the bit maps, and so are sectors
251 off the end of the partition.
252
253 Band 0 is sectors 0-3fff, its map is in sectors 18-1b.
254 Band 1 is 4000-7fff, its map is in 7ffc-7fff.
255 Band 2 is 8000-ffff, its map is in 8000-8003.
256 The remaining bands have maps in their first (even) or last (odd) 4 sectors
257 -- if the last, partial, band is odd its map is in its last 4 sectors.
258
259 The bitmap locations are given in a table pointed to by the super block.
260 No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is
261 just where they usually are.
262
263 The "directory band" is a bunch of sectors preallocated for dnodes.
264 It has a 4-sector free space bitmap of its own. Each bit in the map
265 corresponds to one 4-sector dnode, bit 0 of the map corresponding to
266 the first 4 sectors of the directory band. The entire band is marked
267 allocated in the main bitmap. The super block gives the locations
268 of the directory band and its bitmap. ("band" doesn't mean it is
269 8 meg long; it isn't.) */
270
271
272 /* dnode: directory. 4 sectors long */
273
274 /* A directory is a tree of dnodes. The fnode for a directory
275 contains one pointer, to the root dnode of the tree. The fnode
276 never moves, the dnodes do the B-tree thing, splitting and merging
277 as files are added and removed. */
278
279 #define DNODE_MAGIC 0x77e40aae
280
281 struct dnode {
282 __le32 magic; /* 77e4 0aae */
283 __le32 first_free; /* offset from start of dnode to
284 first free dir entry */
285 #ifdef __LITTLE_ENDIAN
286 u8 root_dnode: 1; /* Is it root dnode? */
287 u8 increment_me: 7; /* some kind of activity counter? */
288 /* Neither HPFS.IFS nor CHKDSK cares
289 if you change this word */
290 #else
291 u8 increment_me: 7; /* some kind of activity counter? */
292 /* Neither HPFS.IFS nor CHKDSK cares
293 if you change this word */
294 u8 root_dnode: 1; /* Is it root dnode? */
295 #endif
296 u8 increment_me2[3];
297 __le32 up; /* (root dnode) directory's fnode
298 (nonroot) parent dnode */
299 __le32 self; /* pointer to this dnode */
300 u8 dirent[2028]; /* one or more dirents */
301 };
302
303 struct hpfs_dirent {
304 __le16 length; /* offset to next dirent */
305
306 #ifdef __LITTLE_ENDIAN
307 u8 first: 1; /* set on phony ^A^A (".") entry */
308 u8 has_acl: 1;
309 u8 down: 1; /* down pointer present (after name) */
310 u8 last: 1; /* set on phony \377 entry */
311 u8 has_ea: 1; /* entry has EA */
312 u8 has_xtd_perm: 1; /* has extended perm list (???) */
313 u8 has_explicit_acl: 1;
314 u8 has_needea: 1; /* ?? some EA has NEEDEA set
315 I have no idea why this is
316 interesting in a dir entry */
317 #else
318 u8 has_needea: 1; /* ?? some EA has NEEDEA set
319 I have no idea why this is
320 interesting in a dir entry */
321 u8 has_explicit_acl: 1;
322 u8 has_xtd_perm: 1; /* has extended perm list (???) */
323 u8 has_ea: 1; /* entry has EA */
324 u8 last: 1; /* set on phony \377 entry */
325 u8 down: 1; /* down pointer present (after name) */
326 u8 has_acl: 1;
327 u8 first: 1; /* set on phony ^A^A (".") entry */
328 #endif
329
330 #ifdef __LITTLE_ENDIAN
331 u8 read_only: 1; /* dos attrib */
332 u8 hidden: 1; /* dos attrib */
333 u8 system: 1; /* dos attrib */
334 u8 flag11: 1; /* would be volume label dos attrib */
335 u8 directory: 1; /* dos attrib */
336 u8 archive: 1; /* dos attrib */
337 u8 not_8x3: 1; /* name is not 8.3 */
338 u8 flag15: 1;
339 #else
340 u8 flag15: 1;
341 u8 not_8x3: 1; /* name is not 8.3 */
342 u8 archive: 1; /* dos attrib */
343 u8 directory: 1; /* dos attrib */
344 u8 flag11: 1; /* would be volume label dos attrib */
345 u8 system: 1; /* dos attrib */
346 u8 hidden: 1; /* dos attrib */
347 u8 read_only: 1; /* dos attrib */
348 #endif
349
350 __le32 fnode; /* fnode giving allocation info */
351 __le32 write_date; /* mtime */
352 __le32 file_size; /* file length, bytes */
353 __le32 read_date; /* atime */
354 __le32 creation_date; /* ctime */
355 __le32 ea_size; /* total EA length, bytes */
356 u8 no_of_acls; /* number of ACL's (low 3 bits) */
357 u8 ix; /* code page index (of filename), see
358 struct code_page_data */
359 u8 namelen; /* file name length */
360 u8 name[]; /* file name */
361 /* dnode_secno down; btree down pointer, if present,
362 follows name on next word boundary, or maybe it
363 precedes next dirent, which is on a word boundary. */
364 };
365
366
367 /* B+ tree: allocation info in fnodes and anodes */
368
369 /* dnodes point to fnodes which are responsible for listing the sectors
370 assigned to the file. This is done with trees of (length,address)
371 pairs. (Actually triples, of (length, file-address, disk-address)
372 which can represent holes. Find out if HPFS does that.)
373 At any rate, fnodes contain a small tree; if subtrees are needed
374 they occupy essentially a full block in anodes. A leaf-level tree node
375 has 3-word entries giving sector runs, a non-leaf node has 2-word
376 entries giving subtree pointers. A flag in the header says which. */
377
378 struct bplus_leaf_node
379 {
380 __le32 file_secno; /* first file sector in extent */
381 __le32 length; /* length, sectors */
382 __le32 disk_secno; /* first corresponding disk sector */
383 };
384
385 struct bplus_internal_node
386 {
387 __le32 file_secno; /* subtree maps sectors < this */
388 __le32 down; /* pointer to subtree */
389 };
390
391 enum {
392 BP_hbff = 1,
393 BP_fnode_parent = 0x20,
394 BP_binary_search = 0x40,
395 BP_internal = 0x80
396 };
397
398 /**
399 * GET_BTREE_PTR() - Get a pointer to struct bplus_header
400 *
401 * Wrapper around container_of() to retrieve a pointer to struct
402 * bplus_header from a pointer to struct bplus_header_fixed.
403 *
404 * @ptr: Pointer to struct bplus_header_fixed.
405 *
406 */
407 #define GET_BTREE_PTR(ptr) \
408 container_of(ptr, struct bplus_header, __hdr)
409
410 struct bplus_header
411 {
412 /* New members MUST be added within the struct_group() macro below. */
413 struct_group_tagged(bplus_header_fixed, __hdr,
414 u8 flags; /* bit 0 - high bit of first free entry offset
415 bit 5 - we're pointed to by an fnode,
416 the data btree or some ea or the
417 main ea bootage pointer ea_secno
418 bit 6 - suggest binary search (unused)
419 bit 7 - 1 -> (internal) tree of anodes
420 0 -> (leaf) list of extents */
421 u8 fill[3];
422 u8 n_free_nodes; /* free nodes in following array */
423 u8 n_used_nodes; /* used nodes in following array */
424 __le16 first_free; /* offset from start of header to
425 first free node in array */
426 );
427 union {
428 /* (internal) 2-word entries giving subtree pointers */
429 DECLARE_FLEX_ARRAY(struct bplus_internal_node, internal);
430 /* (external) 3-word entries giving sector runs */
431 DECLARE_FLEX_ARRAY(struct bplus_leaf_node, external);
432 } u;
433 };
434 static_assert(offsetof(struct bplus_header, u.internal) == sizeof(struct bplus_header_fixed),
435 "struct member likely outside of struct_group_tagged()");
436
bp_internal(struct bplus_header * bp)437 static inline bool bp_internal(struct bplus_header *bp)
438 {
439 return bp->flags & BP_internal;
440 }
441
bp_fnode_parent(struct bplus_header * bp)442 static inline bool bp_fnode_parent(struct bplus_header *bp)
443 {
444 return bp->flags & BP_fnode_parent;
445 }
446
447 /* fnode: root of allocation b+ tree, and EA's */
448
449 /* Every file and every directory has one fnode, pointed to by the directory
450 entry and pointing to the file's sectors or directory's root dnode. EA's
451 are also stored here, and there are said to be ACL's somewhere here too. */
452
453 #define FNODE_MAGIC 0xf7e40aae
454
455 enum {FNODE_anode = cpu_to_le16(2), FNODE_dir = cpu_to_le16(256)};
456 struct fnode
457 {
458 __le32 magic; /* f7e4 0aae */
459 __le32 zero1[2]; /* read history */
460 u8 len, name[15]; /* true length, truncated name */
461 __le32 up; /* pointer to file's directory fnode */
462 __le32 acl_size_l;
463 __le32 acl_secno;
464 __le16 acl_size_s;
465 u8 acl_anode;
466 u8 zero2; /* history bit count */
467 __le32 ea_size_l; /* length of disk-resident ea's */
468 __le32 ea_secno; /* first sector of disk-resident ea's*/
469 __le16 ea_size_s; /* length of fnode-resident ea's */
470
471 __le16 flags; /* bit 1 set -> ea_secno is an anode */
472 /* bit 8 set -> directory. first & only extent
473 points to dnode. */
474 struct bplus_header_fixed btree; /* b+ tree, 8 extents or 12 subtrees */
475 union {
476 struct bplus_leaf_node external[8];
477 struct bplus_internal_node internal[12];
478 } u;
479
480 __le32 file_size; /* file length, bytes */
481 __le32 n_needea; /* number of EA's with NEEDEA set */
482 u8 user_id[16]; /* unused */
483 __le16 ea_offs; /* offset from start of fnode
484 to first fnode-resident ea */
485 u8 dasd_limit_treshhold;
486 u8 dasd_limit_delta;
487 __le32 dasd_limit;
488 __le32 dasd_usage;
489 u8 ea[316]; /* zero or more EA's, packed together
490 with no alignment padding.
491 (Do not use this name, get here
492 via fnode + ea_offs. I think.) */
493 };
494
fnode_in_anode(struct fnode * p)495 static inline bool fnode_in_anode(struct fnode *p)
496 {
497 return (p->flags & FNODE_anode) != 0;
498 }
499
fnode_is_dir(struct fnode * p)500 static inline bool fnode_is_dir(struct fnode *p)
501 {
502 return (p->flags & FNODE_dir) != 0;
503 }
504
505
506 /* anode: 99.44% pure allocation tree */
507
508 #define ANODE_MAGIC 0x37e40aae
509
510 struct anode
511 {
512 __le32 magic; /* 37e4 0aae */
513 __le32 self; /* pointer to this anode */
514 __le32 up; /* parent anode or fnode */
515
516 struct bplus_header_fixed btree; /* b+tree, 40 extents or 60 subtrees */
517 union {
518 struct bplus_leaf_node external[40];
519 struct bplus_internal_node internal[60];
520 } u;
521
522 __le32 fill[3]; /* unused */
523 };
524
525
526 /* extended attributes.
527
528 A file's EA info is stored as a list of (name,value) pairs. It is
529 usually in the fnode, but (if it's large) it is moved to a single
530 sector run outside the fnode, or to multiple runs with an anode tree
531 that points to them.
532
533 The value of a single EA is stored along with the name, or (if large)
534 it is moved to a single sector run, or multiple runs pointed to by an
535 anode tree, pointed to by the value field of the (name,value) pair.
536
537 Flags in the EA tell whether the value is immediate, in a single sector
538 run, or in multiple runs. Flags in the fnode tell whether the EA list
539 is immediate, in a single run, or in multiple runs. */
540
541 enum {EA_indirect = 1, EA_anode = 2, EA_needea = 128 };
542 struct extended_attribute
543 {
544 u8 flags; /* bit 0 set -> value gives sector number
545 where real value starts */
546 /* bit 1 set -> sector is an anode
547 that points to fragmented value */
548 /* bit 7 set -> required ea */
549 u8 namelen; /* length of name, bytes */
550 u8 valuelen_lo; /* length of value, bytes */
551 u8 valuelen_hi; /* length of value, bytes */
552 u8 name[];
553 /*
554 u8 name[namelen]; ascii attrib name
555 u8 nul; terminating '\0', not counted
556 u8 value[valuelen]; value, arbitrary
557 if this.flags & 1, valuelen is 8 and the value is
558 u32 length; real length of value, bytes
559 secno secno; sector address where it starts
560 if this.anode, the above sector number is the root of an anode tree
561 which points to the value.
562 */
563 };
564
ea_indirect(struct extended_attribute * ea)565 static inline bool ea_indirect(struct extended_attribute *ea)
566 {
567 return ea->flags & EA_indirect;
568 }
569
ea_in_anode(struct extended_attribute * ea)570 static inline bool ea_in_anode(struct extended_attribute *ea)
571 {
572 return ea->flags & EA_anode;
573 }
574
575 /*
576 Local Variables:
577 comment-column: 40
578 End:
579 */
580