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 struct bplus_header
398 {
399   u8 flags;				/* bit 0 - high bit of first free entry offset
400 					   bit 5 - we're pointed to by an fnode,
401 					   the data btree or some ea or the
402 					   main ea bootage pointer ea_secno
403 					   bit 6 - suggest binary search (unused)
404 					   bit 7 - 1 -> (internal) tree of anodes
405 						   0 -> (leaf) list of extents */
406   u8 fill[3];
407   u8 n_free_nodes;			/* free nodes in following array */
408   u8 n_used_nodes;			/* used nodes in following array */
409   __le16 first_free;			/* offset from start of header to
410 					   first free node in array */
411   union {
412     struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
413 					       subtree pointers */
414     struct bplus_leaf_node external[0];	    /* (external) 3-word entries giving
415 					       sector runs */
416   } u;
417 };
418 
bp_internal(struct bplus_header * bp)419 static inline bool bp_internal(struct bplus_header *bp)
420 {
421 	return bp->flags & BP_internal;
422 }
423 
bp_fnode_parent(struct bplus_header * bp)424 static inline bool bp_fnode_parent(struct bplus_header *bp)
425 {
426 	return bp->flags & BP_fnode_parent;
427 }
428 
429 /* fnode: root of allocation b+ tree, and EA's */
430 
431 /* Every file and every directory has one fnode, pointed to by the directory
432    entry and pointing to the file's sectors or directory's root dnode.  EA's
433    are also stored here, and there are said to be ACL's somewhere here too. */
434 
435 #define FNODE_MAGIC 0xf7e40aae
436 
437 enum {FNODE_anode = cpu_to_le16(2), FNODE_dir = cpu_to_le16(256)};
438 struct fnode
439 {
440   __le32 magic;				/* f7e4 0aae */
441   __le32 zero1[2];			/* read history */
442   u8 len, name[15];			/* true length, truncated name */
443   __le32 up;				/* pointer to file's directory fnode */
444   __le32 acl_size_l;
445   __le32 acl_secno;
446   __le16 acl_size_s;
447   u8 acl_anode;
448   u8 zero2;				/* history bit count */
449   __le32 ea_size_l;			/* length of disk-resident ea's */
450   __le32 ea_secno;			/* first sector of disk-resident ea's*/
451   __le16 ea_size_s;			/* length of fnode-resident ea's */
452 
453   __le16 flags;				/* bit 1 set -> ea_secno is an anode */
454 					/* bit 8 set -> directory.  first & only extent
455 					   points to dnode. */
456   struct bplus_header btree;		/* b+ tree, 8 extents or 12 subtrees */
457   union {
458     struct bplus_leaf_node external[8];
459     struct bplus_internal_node internal[12];
460   } u;
461 
462   __le32 file_size;			/* file length, bytes */
463   __le32 n_needea;			/* number of EA's with NEEDEA set */
464   u8 user_id[16];			/* unused */
465   __le16 ea_offs;			/* offset from start of fnode
466 					   to first fnode-resident ea */
467   u8 dasd_limit_treshhold;
468   u8 dasd_limit_delta;
469   __le32 dasd_limit;
470   __le32 dasd_usage;
471   u8 ea[316];				/* zero or more EA's, packed together
472 					   with no alignment padding.
473 					   (Do not use this name, get here
474 					   via fnode + ea_offs. I think.) */
475 };
476 
fnode_in_anode(struct fnode * p)477 static inline bool fnode_in_anode(struct fnode *p)
478 {
479 	return (p->flags & FNODE_anode) != 0;
480 }
481 
fnode_is_dir(struct fnode * p)482 static inline bool fnode_is_dir(struct fnode *p)
483 {
484 	return (p->flags & FNODE_dir) != 0;
485 }
486 
487 
488 /* anode: 99.44% pure allocation tree */
489 
490 #define ANODE_MAGIC 0x37e40aae
491 
492 struct anode
493 {
494   __le32 magic;				/* 37e4 0aae */
495   __le32 self;				/* pointer to this anode */
496   __le32 up;				/* parent anode or fnode */
497 
498   struct bplus_header btree;		/* b+tree, 40 extents or 60 subtrees */
499   union {
500     struct bplus_leaf_node external[40];
501     struct bplus_internal_node internal[60];
502   } u;
503 
504   __le32 fill[3];			/* unused */
505 };
506 
507 
508 /* extended attributes.
509 
510    A file's EA info is stored as a list of (name,value) pairs.  It is
511    usually in the fnode, but (if it's large) it is moved to a single
512    sector run outside the fnode, or to multiple runs with an anode tree
513    that points to them.
514 
515    The value of a single EA is stored along with the name, or (if large)
516    it is moved to a single sector run, or multiple runs pointed to by an
517    anode tree, pointed to by the value field of the (name,value) pair.
518 
519    Flags in the EA tell whether the value is immediate, in a single sector
520    run, or in multiple runs.  Flags in the fnode tell whether the EA list
521    is immediate, in a single run, or in multiple runs. */
522 
523 enum {EA_indirect = 1, EA_anode = 2, EA_needea = 128 };
524 struct extended_attribute
525 {
526   u8 flags;				/* bit 0 set -> value gives sector number
527 					   where real value starts */
528 					/* bit 1 set -> sector is an anode
529 					   that points to fragmented value */
530 					/* bit 7 set -> required ea */
531   u8 namelen;				/* length of name, bytes */
532   u8 valuelen_lo;			/* length of value, bytes */
533   u8 valuelen_hi;			/* length of value, bytes */
534   u8 name[];
535   /*
536     u8 name[namelen];			ascii attrib name
537     u8 nul;				terminating '\0', not counted
538     u8 value[valuelen];			value, arbitrary
539       if this.flags & 1, valuelen is 8 and the value is
540         u32 length;			real length of value, bytes
541         secno secno;			sector address where it starts
542       if this.anode, the above sector number is the root of an anode tree
543         which points to the value.
544   */
545 };
546 
ea_indirect(struct extended_attribute * ea)547 static inline bool ea_indirect(struct extended_attribute *ea)
548 {
549 	return ea->flags & EA_indirect;
550 }
551 
ea_in_anode(struct extended_attribute * ea)552 static inline bool ea_in_anode(struct extended_attribute *ea)
553 {
554 	return ea->flags & EA_anode;
555 }
556 
557 /*
558    Local Variables:
559    comment-column: 40
560    End:
561 */
562