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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*/
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-25 07:12:30 -0500