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Commit | Line | Data |
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1da177e4 LT |
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 | ||
d878597c | 24 | typedef u32 secno; /* sector number, partition relative */ |
1da177e4 LT |
25 | |
26 | typedef secno dnode_secno; /* sector number of a dnode */ | |
27 | typedef secno fnode_secno; /* sector number of an fnode */ | |
28 | typedef secno anode_secno; /* sector number of an anode */ | |
29 | ||
30 | typedef 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 | ||
39 | struct hpfs_boot_block | |
40 | { | |
d878597c MP |
41 | u8 jmp[3]; |
42 | u8 oem_id[8]; | |
43 | u8 bytes_per_sector[2]; /* 512 */ | |
44 | u8 sectors_per_cluster; | |
45 | u8 n_reserved_sectors[2]; | |
46 | u8 n_fats; | |
47 | u8 n_rootdir_entries[2]; | |
48 | u8 n_sectors_s[2]; | |
49 | u8 media_byte; | |
50 | u16 sectors_per_fat; | |
51 | u16 sectors_per_track; | |
52 | u16 heads_per_cyl; | |
53 | u32 n_hidden_sectors; | |
54 | u32 n_sectors_l; /* size of partition */ | |
55 | u8 drive_number; | |
56 | u8 mbz; | |
57 | u8 sig_28h; /* 28h */ | |
58 | u8 vol_serno[4]; | |
59 | u8 vol_label[11]; | |
60 | u8 sig_hpfs[8]; /* "HPFS " */ | |
61 | u8 pad[448]; | |
62 | u16 magic; /* aa55 */ | |
1da177e4 LT |
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 | ||
72 | struct hpfs_super_block | |
73 | { | |
d878597c MP |
74 | u32 magic; /* f995 e849 */ |
75 | u32 magic1; /* fa53 e9c5, more magic? */ | |
76 | u8 version; /* version of a filesystem usually 2 */ | |
77 | u8 funcversion; /* functional version - oldest version | |
1da177e4 LT |
78 | of filesystem that can understand |
79 | this disk */ | |
d878597c | 80 | u16 zero; /* 0 */ |
1da177e4 LT |
81 | fnode_secno root; /* fnode of root directory */ |
82 | secno n_sectors; /* size of filesystem */ | |
d878597c | 83 | u32 n_badblocks; /* number of bad blocks */ |
1da177e4 | 84 | secno bitmaps; /* pointers to free space bit maps */ |
d878597c | 85 | u32 zero1; /* 0 */ |
1da177e4 | 86 | secno badblocks; /* bad block list */ |
d878597c | 87 | u32 zero3; /* 0 */ |
1da177e4 | 88 | time32_t last_chkdsk; /* date last checked, 0 if never */ |
d878597c MP |
89 | /*u32 zero4;*/ /* 0 */ |
90 | time32_t last_optimize; /* date last optimized, 0 if never */ | |
1da177e4 LT |
91 | secno n_dir_band; /* number of sectors in dir band */ |
92 | secno dir_band_start; /* first sector in dir band */ | |
93 | secno dir_band_end; /* last sector in dir band */ | |
94 | secno dir_band_bitmap; /* free space map, 1 dnode per bit */ | |
d878597c | 95 | u8 volume_name[32]; /* not used */ |
1da177e4 | 96 | secno user_id_table; /* 8 preallocated sectors - user id */ |
d878597c | 97 | u32 zero6[103]; /* 0 */ |
1da177e4 LT |
98 | }; |
99 | ||
100 | ||
101 | /* sector 17 */ | |
102 | ||
103 | /* The spare block has pointers to spare sectors. */ | |
104 | ||
105 | #define SP_MAGIC 0xf9911849 | |
106 | ||
107 | struct hpfs_spare_block | |
108 | { | |
d878597c MP |
109 | u32 magic; /* f991 1849 */ |
110 | u32 magic1; /* fa52 29c5, more magic? */ | |
1da177e4 LT |
111 | |
112 | unsigned dirty: 1; /* 0 clean, 1 "improperly stopped" */ | |
1da177e4 LT |
113 | unsigned sparedir_used: 1; /* spare dirblks used */ |
114 | unsigned hotfixes_used: 1; /* hotfixes used */ | |
115 | unsigned bad_sector: 1; /* bad sector, corrupted disk (???) */ | |
116 | unsigned bad_bitmap: 1; /* bad bitmap */ | |
117 | unsigned fast: 1; /* partition was fast formatted */ | |
118 | unsigned old_wrote: 1; /* old version wrote to partion */ | |
119 | unsigned old_wrote_1: 1; /* old version wrote to partion (?) */ | |
120 | unsigned install_dasd_limits: 1; /* HPFS386 flags */ | |
121 | unsigned resynch_dasd_limits: 1; | |
122 | unsigned dasd_limits_operational: 1; | |
123 | unsigned multimedia_active: 1; | |
124 | unsigned dce_acls_active: 1; | |
125 | unsigned dasd_limits_dirty: 1; | |
126 | unsigned flag67: 2; | |
d878597c MP |
127 | u8 mm_contlgulty; |
128 | u8 unused; | |
1da177e4 LT |
129 | |
130 | secno hotfix_map; /* info about remapped bad sectors */ | |
d878597c MP |
131 | u32 n_spares_used; /* number of hotfixes */ |
132 | u32 n_spares; /* number of spares in hotfix map */ | |
133 | u32 n_dnode_spares_free; /* spare dnodes unused */ | |
134 | u32 n_dnode_spares; /* length of spare_dnodes[] list, | |
1da177e4 LT |
135 | follows in this block*/ |
136 | secno code_page_dir; /* code page directory block */ | |
d878597c MP |
137 | u32 n_code_pages; /* number of code pages */ |
138 | u32 super_crc; /* on HPFS386 and LAN Server this is | |
1da177e4 LT |
139 | checksum of superblock, on normal |
140 | OS/2 unused */ | |
d878597c MP |
141 | u32 spare_crc; /* on HPFS386 checksum of spareblock */ |
142 | u32 zero1[15]; /* unused */ | |
1da177e4 | 143 | dnode_secno spare_dnodes[100]; /* emergency free dnode list */ |
d878597c | 144 | u32 zero2[1]; /* room for more? */ |
1da177e4 LT |
145 | }; |
146 | ||
147 | /* The bad block list is 4 sectors long. The first word must be zero, | |
148 | the remaining words give n_badblocks bad block numbers. | |
149 | I bet you can see it coming... */ | |
150 | ||
151 | #define BAD_MAGIC 0 | |
152 | ||
153 | /* The hotfix map is 4 sectors long. It looks like | |
154 | ||
155 | secno from[n_spares]; | |
156 | secno to[n_spares]; | |
157 | ||
158 | The to[] list is initialized to point to n_spares preallocated empty | |
159 | sectors. The from[] list contains the sector numbers of bad blocks | |
160 | which have been remapped to corresponding sectors in the to[] list. | |
161 | n_spares_used gives the length of the from[] list. */ | |
162 | ||
163 | ||
164 | /* Sectors 18 and 19 are preallocated and unused. | |
165 | Maybe they're spares for 16 and 17, but simple substitution fails. */ | |
166 | ||
167 | ||
168 | /* The code page info pointed to by the spare block consists of an index | |
169 | block and blocks containing uppercasing tables. I don't know what | |
170 | these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them | |
171 | itself. Linux doesn't use them either. */ | |
172 | ||
173 | /* block pointed to by spareblock->code_page_dir */ | |
174 | ||
175 | #define CP_DIR_MAGIC 0x494521f7 | |
176 | ||
177 | struct code_page_directory | |
178 | { | |
d878597c MP |
179 | u32 magic; /* 4945 21f7 */ |
180 | u32 n_code_pages; /* number of pointers following */ | |
181 | u32 zero1[2]; | |
1da177e4 | 182 | struct { |
d878597c MP |
183 | u16 ix; /* index */ |
184 | u16 code_page_number; /* code page number */ | |
185 | u32 bounds; /* matches corresponding word | |
1da177e4 LT |
186 | in data block */ |
187 | secno code_page_data; /* sector number of a code_page_data | |
188 | containing c.p. array */ | |
d878597c MP |
189 | u16 index; /* index in c.p. array in that sector*/ |
190 | u16 unknown; /* some unknown value; usually 0; | |
1da177e4 LT |
191 | 2 in Japanese version */ |
192 | } array[31]; /* unknown length */ | |
193 | }; | |
194 | ||
195 | /* blocks pointed to by code_page_directory */ | |
196 | ||
197 | #define CP_DATA_MAGIC 0x894521f7 | |
198 | ||
199 | struct code_page_data | |
200 | { | |
d878597c MP |
201 | u32 magic; /* 8945 21f7 */ |
202 | u32 n_used; /* # elements used in c_p_data[] */ | |
203 | u32 bounds[3]; /* looks a bit like | |
1da177e4 LT |
204 | (beg1,end1), (beg2,end2) |
205 | one byte each */ | |
d878597c | 206 | u16 offs[3]; /* offsets from start of sector |
1da177e4 LT |
207 | to start of c_p_data[ix] */ |
208 | struct { | |
d878597c MP |
209 | u16 ix; /* index */ |
210 | u16 code_page_number; /* code page number */ | |
211 | u16 unknown; /* the same as in cp directory */ | |
212 | u8 map[128]; /* upcase table for chars 80..ff */ | |
213 | u16 zero2; | |
1da177e4 | 214 | } code_page[3]; |
d878597c | 215 | u8 incognita[78]; |
1da177e4 LT |
216 | }; |
217 | ||
218 | ||
219 | /* Free space bitmaps are 4 sectors long, which is 16384 bits. | |
220 | 16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap. | |
221 | Bit order in the maps is little-endian. 0 means taken, 1 means free. | |
222 | ||
223 | Bit map sectors are marked allocated in the bit maps, and so are sectors | |
224 | off the end of the partition. | |
225 | ||
226 | Band 0 is sectors 0-3fff, its map is in sectors 18-1b. | |
227 | Band 1 is 4000-7fff, its map is in 7ffc-7fff. | |
228 | Band 2 is 8000-ffff, its map is in 8000-8003. | |
229 | The remaining bands have maps in their first (even) or last (odd) 4 sectors | |
230 | -- if the last, partial, band is odd its map is in its last 4 sectors. | |
231 | ||
232 | The bitmap locations are given in a table pointed to by the super block. | |
233 | No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is | |
234 | just where they usually are. | |
235 | ||
236 | The "directory band" is a bunch of sectors preallocated for dnodes. | |
237 | It has a 4-sector free space bitmap of its own. Each bit in the map | |
238 | corresponds to one 4-sector dnode, bit 0 of the map corresponding to | |
239 | the first 4 sectors of the directory band. The entire band is marked | |
240 | allocated in the main bitmap. The super block gives the locations | |
241 | of the directory band and its bitmap. ("band" doesn't mean it is | |
242 | 8 meg long; it isn't.) */ | |
243 | ||
244 | ||
245 | /* dnode: directory. 4 sectors long */ | |
246 | ||
247 | /* A directory is a tree of dnodes. The fnode for a directory | |
248 | contains one pointer, to the root dnode of the tree. The fnode | |
249 | never moves, the dnodes do the B-tree thing, splitting and merging | |
250 | as files are added and removed. */ | |
251 | ||
252 | #define DNODE_MAGIC 0x77e40aae | |
253 | ||
254 | struct dnode { | |
d878597c MP |
255 | u32 magic; /* 77e4 0aae */ |
256 | u32 first_free; /* offset from start of dnode to | |
1da177e4 LT |
257 | first free dir entry */ |
258 | unsigned root_dnode:1; /* Is it root dnode? */ | |
259 | unsigned increment_me:31; /* some kind of activity counter? | |
260 | Neither HPFS.IFS nor CHKDSK cares | |
261 | if you change this word */ | |
262 | secno up; /* (root dnode) directory's fnode | |
263 | (nonroot) parent dnode */ | |
264 | dnode_secno self; /* pointer to this dnode */ | |
d878597c | 265 | u8 dirent[2028]; /* one or more dirents */ |
1da177e4 LT |
266 | }; |
267 | ||
268 | struct hpfs_dirent { | |
d878597c | 269 | u16 length; /* offset to next dirent */ |
1da177e4 LT |
270 | unsigned first: 1; /* set on phony ^A^A (".") entry */ |
271 | unsigned has_acl: 1; | |
272 | unsigned down: 1; /* down pointer present (after name) */ | |
273 | unsigned last: 1; /* set on phony \377 entry */ | |
274 | unsigned has_ea: 1; /* entry has EA */ | |
275 | unsigned has_xtd_perm: 1; /* has extended perm list (???) */ | |
276 | unsigned has_explicit_acl: 1; | |
277 | unsigned has_needea: 1; /* ?? some EA has NEEDEA set | |
278 | I have no idea why this is | |
279 | interesting in a dir entry */ | |
280 | unsigned read_only: 1; /* dos attrib */ | |
281 | unsigned hidden: 1; /* dos attrib */ | |
282 | unsigned system: 1; /* dos attrib */ | |
283 | unsigned flag11: 1; /* would be volume label dos attrib */ | |
284 | unsigned directory: 1; /* dos attrib */ | |
285 | unsigned archive: 1; /* dos attrib */ | |
286 | unsigned not_8x3: 1; /* name is not 8.3 */ | |
287 | unsigned flag15: 1; | |
288 | fnode_secno fnode; /* fnode giving allocation info */ | |
289 | time32_t write_date; /* mtime */ | |
d878597c | 290 | u32 file_size; /* file length, bytes */ |
1da177e4 LT |
291 | time32_t read_date; /* atime */ |
292 | time32_t creation_date; /* ctime */ | |
d878597c | 293 | u32 ea_size; /* total EA length, bytes */ |
1da177e4 LT |
294 | unsigned char no_of_acls : 3; /* number of ACL's */ |
295 | unsigned char reserver : 5; | |
d878597c | 296 | u8 ix; /* code page index (of filename), see |
1da177e4 | 297 | struct code_page_data */ |
d878597c | 298 | u8 namelen, name[1]; /* file name */ |
1da177e4 LT |
299 | /* dnode_secno down; btree down pointer, if present, |
300 | follows name on next word boundary, or maybe it | |
301 | precedes next dirent, which is on a word boundary. */ | |
302 | }; | |
303 | ||
304 | ||
305 | /* B+ tree: allocation info in fnodes and anodes */ | |
306 | ||
307 | /* dnodes point to fnodes which are responsible for listing the sectors | |
308 | assigned to the file. This is done with trees of (length,address) | |
309 | pairs. (Actually triples, of (length, file-address, disk-address) | |
310 | which can represent holes. Find out if HPFS does that.) | |
311 | At any rate, fnodes contain a small tree; if subtrees are needed | |
312 | they occupy essentially a full block in anodes. A leaf-level tree node | |
313 | has 3-word entries giving sector runs, a non-leaf node has 2-word | |
314 | entries giving subtree pointers. A flag in the header says which. */ | |
315 | ||
316 | struct bplus_leaf_node | |
317 | { | |
d878597c MP |
318 | u32 file_secno; /* first file sector in extent */ |
319 | u32 length; /* length, sectors */ | |
1da177e4 LT |
320 | secno disk_secno; /* first corresponding disk sector */ |
321 | }; | |
322 | ||
323 | struct bplus_internal_node | |
324 | { | |
d878597c | 325 | u32 file_secno; /* subtree maps sectors < this */ |
1da177e4 LT |
326 | anode_secno down; /* pointer to subtree */ |
327 | }; | |
328 | ||
329 | struct bplus_header | |
330 | { | |
331 | unsigned hbff: 1; /* high bit of first free entry offset */ | |
332 | unsigned flag1: 1; | |
333 | unsigned flag2: 1; | |
334 | unsigned flag3: 1; | |
335 | unsigned flag4: 1; | |
336 | unsigned fnode_parent: 1; /* ? we're pointed to by an fnode, | |
337 | the data btree or some ea or the | |
338 | main ea bootage pointer ea_secno */ | |
339 | /* also can get set in fnodes, which | |
340 | may be a chkdsk glitch or may mean | |
341 | this bit is irrelevant in fnodes, | |
342 | or this interpretation is all wet */ | |
343 | unsigned binary_search: 1; /* suggest binary search (unused) */ | |
344 | unsigned internal: 1; /* 1 -> (internal) tree of anodes | |
345 | 0 -> (leaf) list of extents */ | |
d878597c MP |
346 | u8 fill[3]; |
347 | u8 n_free_nodes; /* free nodes in following array */ | |
348 | u8 n_used_nodes; /* used nodes in following array */ | |
349 | u16 first_free; /* offset from start of header to | |
1da177e4 LT |
350 | first free node in array */ |
351 | union { | |
352 | struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving | |
353 | subtree pointers */ | |
354 | struct bplus_leaf_node external[0]; /* (external) 3-word entries giving | |
355 | sector runs */ | |
356 | } u; | |
357 | }; | |
358 | ||
359 | /* fnode: root of allocation b+ tree, and EA's */ | |
360 | ||
361 | /* Every file and every directory has one fnode, pointed to by the directory | |
362 | entry and pointing to the file's sectors or directory's root dnode. EA's | |
363 | are also stored here, and there are said to be ACL's somewhere here too. */ | |
364 | ||
365 | #define FNODE_MAGIC 0xf7e40aae | |
366 | ||
367 | struct fnode | |
368 | { | |
d878597c MP |
369 | u32 magic; /* f7e4 0aae */ |
370 | u32 zero1[2]; /* read history */ | |
371 | u8 len, name[15]; /* true length, truncated name */ | |
1da177e4 | 372 | fnode_secno up; /* pointer to file's directory fnode */ |
1da177e4 LT |
373 | secno acl_size_l; |
374 | secno acl_secno; | |
d878597c MP |
375 | u16 acl_size_s; |
376 | u8 acl_anode; | |
377 | u8 zero2; /* history bit count */ | |
378 | u32 ea_size_l; /* length of disk-resident ea's */ | |
1da177e4 | 379 | secno ea_secno; /* first sector of disk-resident ea's*/ |
d878597c | 380 | u16 ea_size_s; /* length of fnode-resident ea's */ |
1da177e4 LT |
381 | |
382 | unsigned flag0: 1; | |
383 | unsigned ea_anode: 1; /* 1 -> ea_secno is an anode */ | |
384 | unsigned flag2: 1; | |
385 | unsigned flag3: 1; | |
386 | unsigned flag4: 1; | |
387 | unsigned flag5: 1; | |
388 | unsigned flag6: 1; | |
389 | unsigned flag7: 1; | |
390 | unsigned dirflag: 1; /* 1 -> directory. first & only extent | |
391 | points to dnode. */ | |
392 | unsigned flag9: 1; | |
393 | unsigned flag10: 1; | |
394 | unsigned flag11: 1; | |
395 | unsigned flag12: 1; | |
396 | unsigned flag13: 1; | |
397 | unsigned flag14: 1; | |
398 | unsigned flag15: 1; | |
399 | ||
400 | struct bplus_header btree; /* b+ tree, 8 extents or 12 subtrees */ | |
401 | union { | |
402 | struct bplus_leaf_node external[8]; | |
403 | struct bplus_internal_node internal[12]; | |
404 | } u; | |
405 | ||
d878597c MP |
406 | u32 file_size; /* file length, bytes */ |
407 | u32 n_needea; /* number of EA's with NEEDEA set */ | |
408 | u8 user_id[16]; /* unused */ | |
409 | u16 ea_offs; /* offset from start of fnode | |
1da177e4 | 410 | to first fnode-resident ea */ |
d878597c MP |
411 | u8 dasd_limit_treshhold; |
412 | u8 dasd_limit_delta; | |
413 | u32 dasd_limit; | |
414 | u32 dasd_usage; | |
415 | u8 ea[316]; /* zero or more EA's, packed together | |
1da177e4 LT |
416 | with no alignment padding. |
417 | (Do not use this name, get here | |
418 | via fnode + ea_offs. I think.) */ | |
419 | }; | |
420 | ||
421 | ||
422 | /* anode: 99.44% pure allocation tree */ | |
423 | ||
424 | #define ANODE_MAGIC 0x37e40aae | |
425 | ||
426 | struct anode | |
427 | { | |
d878597c | 428 | u32 magic; /* 37e4 0aae */ |
1da177e4 LT |
429 | anode_secno self; /* pointer to this anode */ |
430 | secno up; /* parent anode or fnode */ | |
431 | ||
432 | struct bplus_header btree; /* b+tree, 40 extents or 60 subtrees */ | |
433 | union { | |
434 | struct bplus_leaf_node external[40]; | |
435 | struct bplus_internal_node internal[60]; | |
436 | } u; | |
437 | ||
d878597c | 438 | u32 fill[3]; /* unused */ |
1da177e4 LT |
439 | }; |
440 | ||
441 | ||
442 | /* extended attributes. | |
443 | ||
444 | A file's EA info is stored as a list of (name,value) pairs. It is | |
445 | usually in the fnode, but (if it's large) it is moved to a single | |
446 | sector run outside the fnode, or to multiple runs with an anode tree | |
447 | that points to them. | |
448 | ||
449 | The value of a single EA is stored along with the name, or (if large) | |
450 | it is moved to a single sector run, or multiple runs pointed to by an | |
451 | anode tree, pointed to by the value field of the (name,value) pair. | |
452 | ||
453 | Flags in the EA tell whether the value is immediate, in a single sector | |
454 | run, or in multiple runs. Flags in the fnode tell whether the EA list | |
455 | is immediate, in a single run, or in multiple runs. */ | |
456 | ||
457 | struct extended_attribute | |
458 | { | |
459 | unsigned indirect: 1; /* 1 -> value gives sector number | |
460 | where real value starts */ | |
461 | unsigned anode: 1; /* 1 -> sector is an anode | |
462 | that points to fragmented value */ | |
463 | unsigned flag2: 1; | |
464 | unsigned flag3: 1; | |
465 | unsigned flag4: 1; | |
466 | unsigned flag5: 1; | |
467 | unsigned flag6: 1; | |
468 | unsigned needea: 1; /* required ea */ | |
d878597c MP |
469 | u8 namelen; /* length of name, bytes */ |
470 | u16 valuelen; /* length of value, bytes */ | |
471 | u8 name[0]; | |
1da177e4 | 472 | /* |
d878597c MP |
473 | u8 name[namelen]; ascii attrib name |
474 | u8 nul; terminating '\0', not counted | |
475 | u8 value[valuelen]; value, arbitrary | |
1da177e4 | 476 | if this.indirect, valuelen is 8 and the value is |
d878597c | 477 | u32 length; real length of value, bytes |
1da177e4 LT |
478 | secno secno; sector address where it starts |
479 | if this.anode, the above sector number is the root of an anode tree | |
480 | which points to the value. | |
481 | */ | |
482 | }; | |
483 | ||
484 | /* | |
485 | Local Variables: | |
486 | comment-column: 40 | |
487 | End: | |
488 | */ |