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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Mikulas Patocka0b697602011-05-08 20:44:26 +020022#if !defined(__LITTLE_ENDIAN) && !defined(__BIG_ENDIAN)
23#error unknown endian
24#endif
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026/* Notation */
27
Mikulas Patockad8785972011-05-08 20:43:34 +020028typedef u32 secno; /* sector number, partition relative */
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30typedef secno dnode_secno; /* sector number of a dnode */
31typedef secno fnode_secno; /* sector number of an fnode */
32typedef secno anode_secno; /* sector number of an anode */
33
34typedef u32 time32_t; /* 32-bit time_t type */
35
36/* sector 0 */
37
38/* The boot block is very like a FAT boot block, except that the
39 29h signature byte is 28h instead, and the ID string is "HPFS". */
40
41#define BB_MAGIC 0xaa55
42
43struct hpfs_boot_block
44{
Mikulas Patockad8785972011-05-08 20:43:34 +020045 u8 jmp[3];
46 u8 oem_id[8];
47 u8 bytes_per_sector[2]; /* 512 */
48 u8 sectors_per_cluster;
49 u8 n_reserved_sectors[2];
50 u8 n_fats;
51 u8 n_rootdir_entries[2];
52 u8 n_sectors_s[2];
53 u8 media_byte;
54 u16 sectors_per_fat;
55 u16 sectors_per_track;
56 u16 heads_per_cyl;
57 u32 n_hidden_sectors;
58 u32 n_sectors_l; /* size of partition */
59 u8 drive_number;
60 u8 mbz;
61 u8 sig_28h; /* 28h */
62 u8 vol_serno[4];
63 u8 vol_label[11];
64 u8 sig_hpfs[8]; /* "HPFS " */
65 u8 pad[448];
66 u16 magic; /* aa55 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070067};
68
69
70/* sector 16 */
71
72/* The super block has the pointer to the root directory. */
73
74#define SB_MAGIC 0xf995e849
75
76struct hpfs_super_block
77{
Mikulas Patockad8785972011-05-08 20:43:34 +020078 u32 magic; /* f995 e849 */
79 u32 magic1; /* fa53 e9c5, more magic? */
80 u8 version; /* version of a filesystem usually 2 */
81 u8 funcversion; /* functional version - oldest version
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 of filesystem that can understand
83 this disk */
Mikulas Patockad8785972011-05-08 20:43:34 +020084 u16 zero; /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 fnode_secno root; /* fnode of root directory */
86 secno n_sectors; /* size of filesystem */
Mikulas Patockad8785972011-05-08 20:43:34 +020087 u32 n_badblocks; /* number of bad blocks */
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 secno bitmaps; /* pointers to free space bit maps */
Mikulas Patockad8785972011-05-08 20:43:34 +020089 u32 zero1; /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 secno badblocks; /* bad block list */
Mikulas Patockad8785972011-05-08 20:43:34 +020091 u32 zero3; /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 time32_t last_chkdsk; /* date last checked, 0 if never */
Mikulas Patockad8785972011-05-08 20:43:34 +020093 time32_t last_optimize; /* date last optimized, 0 if never */
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 secno n_dir_band; /* number of sectors in dir band */
95 secno dir_band_start; /* first sector in dir band */
96 secno dir_band_end; /* last sector in dir band */
97 secno dir_band_bitmap; /* free space map, 1 dnode per bit */
Mikulas Patockad8785972011-05-08 20:43:34 +020098 u8 volume_name[32]; /* not used */
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 secno user_id_table; /* 8 preallocated sectors - user id */
Mikulas Patockad8785972011-05-08 20:43:34 +0200100 u32 zero6[103]; /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101};
102
103
104/* sector 17 */
105
106/* The spare block has pointers to spare sectors. */
107
108#define SP_MAGIC 0xf9911849
109
110struct hpfs_spare_block
111{
Mikulas Patockad8785972011-05-08 20:43:34 +0200112 u32 magic; /* f991 1849 */
113 u32 magic1; /* fa52 29c5, more magic? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
Mikulas Patocka0b697602011-05-08 20:44:26 +0200115#ifdef __LITTLE_ENDIAN
116 u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */
117 u8 sparedir_used: 1; /* spare dirblks used */
118 u8 hotfixes_used: 1; /* hotfixes used */
119 u8 bad_sector: 1; /* bad sector, corrupted disk (???) */
120 u8 bad_bitmap: 1; /* bad bitmap */
121 u8 fast: 1; /* partition was fast formatted */
122 u8 old_wrote: 1; /* old version wrote to partion */
123 u8 old_wrote_1: 1; /* old version wrote to partion (?) */
124#else
125 u8 old_wrote_1: 1; /* old version wrote to partion (?) */
126 u8 old_wrote: 1; /* old version wrote to partion */
127 u8 fast: 1; /* partition was fast formatted */
128 u8 bad_bitmap: 1; /* bad bitmap */
129 u8 bad_sector: 1; /* bad sector, corrupted disk (???) */
130 u8 hotfixes_used: 1; /* hotfixes used */
131 u8 sparedir_used: 1; /* spare dirblks used */
132 u8 dirty: 1; /* 0 clean, 1 "improperly stopped" */
133#endif
134
135#ifdef __LITTLE_ENDIAN
136 u8 install_dasd_limits: 1; /* HPFS386 flags */
137 u8 resynch_dasd_limits: 1;
138 u8 dasd_limits_operational: 1;
139 u8 multimedia_active: 1;
140 u8 dce_acls_active: 1;
141 u8 dasd_limits_dirty: 1;
142 u8 flag67: 2;
143#else
144 u8 flag67: 2;
145 u8 dasd_limits_dirty: 1;
146 u8 dce_acls_active: 1;
147 u8 multimedia_active: 1;
148 u8 dasd_limits_operational: 1;
149 u8 resynch_dasd_limits: 1;
150 u8 install_dasd_limits: 1; /* HPFS386 flags */
151#endif
152
Mikulas Patockad8785972011-05-08 20:43:34 +0200153 u8 mm_contlgulty;
154 u8 unused;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 secno hotfix_map; /* info about remapped bad sectors */
Mikulas Patockad8785972011-05-08 20:43:34 +0200157 u32 n_spares_used; /* number of hotfixes */
158 u32 n_spares; /* number of spares in hotfix map */
159 u32 n_dnode_spares_free; /* spare dnodes unused */
160 u32 n_dnode_spares; /* length of spare_dnodes[] list,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 follows in this block*/
162 secno code_page_dir; /* code page directory block */
Mikulas Patockad8785972011-05-08 20:43:34 +0200163 u32 n_code_pages; /* number of code pages */
164 u32 super_crc; /* on HPFS386 and LAN Server this is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 checksum of superblock, on normal
166 OS/2 unused */
Mikulas Patockad8785972011-05-08 20:43:34 +0200167 u32 spare_crc; /* on HPFS386 checksum of spareblock */
168 u32 zero1[15]; /* unused */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 dnode_secno spare_dnodes[100]; /* emergency free dnode list */
Mikulas Patockad8785972011-05-08 20:43:34 +0200170 u32 zero2[1]; /* room for more? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171};
172
173/* The bad block list is 4 sectors long. The first word must be zero,
174 the remaining words give n_badblocks bad block numbers.
175 I bet you can see it coming... */
176
177#define BAD_MAGIC 0
178
179/* The hotfix map is 4 sectors long. It looks like
180
181 secno from[n_spares];
182 secno to[n_spares];
183
184 The to[] list is initialized to point to n_spares preallocated empty
185 sectors. The from[] list contains the sector numbers of bad blocks
186 which have been remapped to corresponding sectors in the to[] list.
187 n_spares_used gives the length of the from[] list. */
188
189
190/* Sectors 18 and 19 are preallocated and unused.
191 Maybe they're spares for 16 and 17, but simple substitution fails. */
192
193
194/* The code page info pointed to by the spare block consists of an index
195 block and blocks containing uppercasing tables. I don't know what
196 these are for (CHKDSK, maybe?) -- OS/2 does not seem to use them
197 itself. Linux doesn't use them either. */
198
199/* block pointed to by spareblock->code_page_dir */
200
201#define CP_DIR_MAGIC 0x494521f7
202
203struct code_page_directory
204{
Mikulas Patockad8785972011-05-08 20:43:34 +0200205 u32 magic; /* 4945 21f7 */
206 u32 n_code_pages; /* number of pointers following */
207 u32 zero1[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 struct {
Mikulas Patockad8785972011-05-08 20:43:34 +0200209 u16 ix; /* index */
210 u16 code_page_number; /* code page number */
211 u32 bounds; /* matches corresponding word
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 in data block */
213 secno code_page_data; /* sector number of a code_page_data
214 containing c.p. array */
Mikulas Patockad8785972011-05-08 20:43:34 +0200215 u16 index; /* index in c.p. array in that sector*/
216 u16 unknown; /* some unknown value; usually 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 2 in Japanese version */
218 } array[31]; /* unknown length */
219};
220
221/* blocks pointed to by code_page_directory */
222
223#define CP_DATA_MAGIC 0x894521f7
224
225struct code_page_data
226{
Mikulas Patockad8785972011-05-08 20:43:34 +0200227 u32 magic; /* 8945 21f7 */
228 u32 n_used; /* # elements used in c_p_data[] */
229 u32 bounds[3]; /* looks a bit like
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 (beg1,end1), (beg2,end2)
231 one byte each */
Mikulas Patockad8785972011-05-08 20:43:34 +0200232 u16 offs[3]; /* offsets from start of sector
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 to start of c_p_data[ix] */
234 struct {
Mikulas Patockad8785972011-05-08 20:43:34 +0200235 u16 ix; /* index */
236 u16 code_page_number; /* code page number */
237 u16 unknown; /* the same as in cp directory */
238 u8 map[128]; /* upcase table for chars 80..ff */
239 u16 zero2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 } code_page[3];
Mikulas Patockad8785972011-05-08 20:43:34 +0200241 u8 incognita[78];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242};
243
244
245/* Free space bitmaps are 4 sectors long, which is 16384 bits.
246 16384 sectors is 8 meg, and each 8 meg band has a 4-sector bitmap.
247 Bit order in the maps is little-endian. 0 means taken, 1 means free.
248
249 Bit map sectors are marked allocated in the bit maps, and so are sectors
250 off the end of the partition.
251
252 Band 0 is sectors 0-3fff, its map is in sectors 18-1b.
253 Band 1 is 4000-7fff, its map is in 7ffc-7fff.
254 Band 2 is 8000-ffff, its map is in 8000-8003.
255 The remaining bands have maps in their first (even) or last (odd) 4 sectors
256 -- if the last, partial, band is odd its map is in its last 4 sectors.
257
258 The bitmap locations are given in a table pointed to by the super block.
259 No doubt they aren't constrained to be at 18, 7ffc, 8000, ...; that is
260 just where they usually are.
261
262 The "directory band" is a bunch of sectors preallocated for dnodes.
263 It has a 4-sector free space bitmap of its own. Each bit in the map
264 corresponds to one 4-sector dnode, bit 0 of the map corresponding to
265 the first 4 sectors of the directory band. The entire band is marked
266 allocated in the main bitmap. The super block gives the locations
267 of the directory band and its bitmap. ("band" doesn't mean it is
268 8 meg long; it isn't.) */
269
270
271/* dnode: directory. 4 sectors long */
272
273/* A directory is a tree of dnodes. The fnode for a directory
274 contains one pointer, to the root dnode of the tree. The fnode
275 never moves, the dnodes do the B-tree thing, splitting and merging
276 as files are added and removed. */
277
278#define DNODE_MAGIC 0x77e40aae
279
280struct dnode {
Mikulas Patockad8785972011-05-08 20:43:34 +0200281 u32 magic; /* 77e4 0aae */
282 u32 first_free; /* offset from start of dnode to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 first free dir entry */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200284#ifdef __LITTLE_ENDIAN
285 u8 root_dnode: 1; /* Is it root dnode? */
286 u8 increment_me: 7; /* some kind of activity counter? */
287 /* Neither HPFS.IFS nor CHKDSK cares
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 if you change this word */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200289#else
290 u8 increment_me: 7; /* some kind of activity counter? */
291 /* Neither HPFS.IFS nor CHKDSK cares
292 if you change this word */
293 u8 root_dnode: 1; /* Is it root dnode? */
294#endif
295 u8 increment_me2[3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 secno up; /* (root dnode) directory's fnode
297 (nonroot) parent dnode */
298 dnode_secno self; /* pointer to this dnode */
Mikulas Patockad8785972011-05-08 20:43:34 +0200299 u8 dirent[2028]; /* one or more dirents */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300};
301
302struct hpfs_dirent {
Mikulas Patocka0b697602011-05-08 20:44:26 +0200303 u16 length; /* offset to next dirent */
304
305#ifdef __LITTLE_ENDIAN
306 u8 first: 1; /* set on phony ^A^A (".") entry */
307 u8 has_acl: 1;
308 u8 down: 1; /* down pointer present (after name) */
309 u8 last: 1; /* set on phony \377 entry */
310 u8 has_ea: 1; /* entry has EA */
311 u8 has_xtd_perm: 1; /* has extended perm list (???) */
312 u8 has_explicit_acl: 1;
313 u8 has_needea: 1; /* ?? some EA has NEEDEA set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 I have no idea why this is
315 interesting in a dir entry */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200316#else
317 u8 has_needea: 1; /* ?? some EA has NEEDEA set
318 I have no idea why this is
319 interesting in a dir entry */
320 u8 has_explicit_acl: 1;
321 u8 has_xtd_perm: 1; /* has extended perm list (???) */
322 u8 has_ea: 1; /* entry has EA */
323 u8 last: 1; /* set on phony \377 entry */
324 u8 down: 1; /* down pointer present (after name) */
325 u8 has_acl: 1;
326 u8 first: 1; /* set on phony ^A^A (".") entry */
327#endif
328
329#ifdef __LITTLE_ENDIAN
330 u8 read_only: 1; /* dos attrib */
331 u8 hidden: 1; /* dos attrib */
332 u8 system: 1; /* dos attrib */
333 u8 flag11: 1; /* would be volume label dos attrib */
334 u8 directory: 1; /* dos attrib */
335 u8 archive: 1; /* dos attrib */
336 u8 not_8x3: 1; /* name is not 8.3 */
337 u8 flag15: 1;
338#else
339 u8 flag15: 1;
340 u8 not_8x3: 1; /* name is not 8.3 */
341 u8 archive: 1; /* dos attrib */
342 u8 directory: 1; /* dos attrib */
343 u8 flag11: 1; /* would be volume label dos attrib */
344 u8 system: 1; /* dos attrib */
345 u8 hidden: 1; /* dos attrib */
346 u8 read_only: 1; /* dos attrib */
347#endif
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 fnode_secno fnode; /* fnode giving allocation info */
350 time32_t write_date; /* mtime */
Mikulas Patockad8785972011-05-08 20:43:34 +0200351 u32 file_size; /* file length, bytes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 time32_t read_date; /* atime */
353 time32_t creation_date; /* ctime */
Mikulas Patockad8785972011-05-08 20:43:34 +0200354 u32 ea_size; /* total EA length, bytes */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200355 u8 no_of_acls; /* number of ACL's (low 3 bits) */
Mikulas Patockad8785972011-05-08 20:43:34 +0200356 u8 ix; /* code page index (of filename), see
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 struct code_page_data */
Mikulas Patockad8785972011-05-08 20:43:34 +0200358 u8 namelen, name[1]; /* file name */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 /* dnode_secno down; btree down pointer, if present,
360 follows name on next word boundary, or maybe it
361 precedes next dirent, which is on a word boundary. */
362};
363
364
365/* B+ tree: allocation info in fnodes and anodes */
366
367/* dnodes point to fnodes which are responsible for listing the sectors
368 assigned to the file. This is done with trees of (length,address)
369 pairs. (Actually triples, of (length, file-address, disk-address)
370 which can represent holes. Find out if HPFS does that.)
371 At any rate, fnodes contain a small tree; if subtrees are needed
372 they occupy essentially a full block in anodes. A leaf-level tree node
373 has 3-word entries giving sector runs, a non-leaf node has 2-word
374 entries giving subtree pointers. A flag in the header says which. */
375
376struct bplus_leaf_node
377{
Mikulas Patockad8785972011-05-08 20:43:34 +0200378 u32 file_secno; /* first file sector in extent */
379 u32 length; /* length, sectors */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 secno disk_secno; /* first corresponding disk sector */
381};
382
383struct bplus_internal_node
384{
Mikulas Patockad8785972011-05-08 20:43:34 +0200385 u32 file_secno; /* subtree maps sectors < this */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 anode_secno down; /* pointer to subtree */
387};
388
389struct bplus_header
390{
Mikulas Patocka0b697602011-05-08 20:44:26 +0200391#ifdef __LITTLE_ENDIAN
392 u8 hbff: 1; /* high bit of first free entry offset */
393 u8 flag1234: 4;
394 u8 fnode_parent: 1; /* ? we're pointed to by an fnode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 the data btree or some ea or the
396 main ea bootage pointer ea_secno */
397 /* also can get set in fnodes, which
398 may be a chkdsk glitch or may mean
399 this bit is irrelevant in fnodes,
400 or this interpretation is all wet */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200401 u8 binary_search: 1; /* suggest binary search (unused) */
402 u8 internal: 1; /* 1 -> (internal) tree of anodes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 0 -> (leaf) list of extents */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200404#else
405 u8 internal: 1; /* 1 -> (internal) tree of anodes
406 0 -> (leaf) list of extents */
407 u8 binary_search: 1; /* suggest binary search (unused) */
408 u8 fnode_parent: 1; /* ? we're pointed to by an fnode,
409 the data btree or some ea or the
410 main ea bootage pointer ea_secno */
411 /* also can get set in fnodes, which
412 may be a chkdsk glitch or may mean
413 this bit is irrelevant in fnodes,
414 or this interpretation is all wet */
415 u8 flag1234: 4;
416 u8 hbff: 1; /* high bit of first free entry offset */
417#endif
Mikulas Patockad8785972011-05-08 20:43:34 +0200418 u8 fill[3];
419 u8 n_free_nodes; /* free nodes in following array */
420 u8 n_used_nodes; /* used nodes in following array */
421 u16 first_free; /* offset from start of header to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 first free node in array */
423 union {
424 struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
425 subtree pointers */
426 struct bplus_leaf_node external[0]; /* (external) 3-word entries giving
427 sector runs */
428 } u;
429};
430
431/* fnode: root of allocation b+ tree, and EA's */
432
433/* Every file and every directory has one fnode, pointed to by the directory
434 entry and pointing to the file's sectors or directory's root dnode. EA's
435 are also stored here, and there are said to be ACL's somewhere here too. */
436
437#define FNODE_MAGIC 0xf7e40aae
438
439struct fnode
440{
Mikulas Patockad8785972011-05-08 20:43:34 +0200441 u32 magic; /* f7e4 0aae */
442 u32 zero1[2]; /* read history */
443 u8 len, name[15]; /* true length, truncated name */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 fnode_secno up; /* pointer to file's directory fnode */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 secno acl_size_l;
446 secno acl_secno;
Mikulas Patockad8785972011-05-08 20:43:34 +0200447 u16 acl_size_s;
448 u8 acl_anode;
449 u8 zero2; /* history bit count */
450 u32 ea_size_l; /* length of disk-resident ea's */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 secno ea_secno; /* first sector of disk-resident ea's*/
Mikulas Patockad8785972011-05-08 20:43:34 +0200452 u16 ea_size_s; /* length of fnode-resident ea's */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453
Mikulas Patocka0b697602011-05-08 20:44:26 +0200454#ifdef __LITTLE_ENDIAN
455 u8 flag0: 1;
456 u8 ea_anode: 1; /* 1 -> ea_secno is an anode */
457 u8 flag234567: 6;
458#else
459 u8 flag234567: 6;
460 u8 ea_anode: 1; /* 1 -> ea_secno is an anode */
461 u8 flag0: 1;
462#endif
463
464#ifdef __LITTLE_ENDIAN
465 u8 dirflag: 1; /* 1 -> directory. first & only extent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 points to dnode. */
Mikulas Patocka0b697602011-05-08 20:44:26 +0200467 u8 flag9012345: 7;
468#else
469 u8 flag9012345: 7;
470 u8 dirflag: 1; /* 1 -> directory. first & only extent
471 points to dnode. */
472#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
474 struct bplus_header 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
Mikulas Patockad8785972011-05-08 20:43:34 +0200480 u32 file_size; /* file length, bytes */
481 u32 n_needea; /* number of EA's with NEEDEA set */
482 u8 user_id[16]; /* unused */
483 u16 ea_offs; /* offset from start of fnode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 to first fnode-resident ea */
Mikulas Patockad8785972011-05-08 20:43:34 +0200485 u8 dasd_limit_treshhold;
486 u8 dasd_limit_delta;
487 u32 dasd_limit;
488 u32 dasd_usage;
489 u8 ea[316]; /* zero or more EA's, packed together
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 with no alignment padding.
491 (Do not use this name, get here
492 via fnode + ea_offs. I think.) */
493};
494
495
496/* anode: 99.44% pure allocation tree */
497
498#define ANODE_MAGIC 0x37e40aae
499
500struct anode
501{
Mikulas Patockad8785972011-05-08 20:43:34 +0200502 u32 magic; /* 37e4 0aae */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 anode_secno self; /* pointer to this anode */
504 secno up; /* parent anode or fnode */
505
506 struct bplus_header btree; /* b+tree, 40 extents or 60 subtrees */
507 union {
508 struct bplus_leaf_node external[40];
509 struct bplus_internal_node internal[60];
510 } u;
511
Mikulas Patockad8785972011-05-08 20:43:34 +0200512 u32 fill[3]; /* unused */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513};
514
515
516/* extended attributes.
517
518 A file's EA info is stored as a list of (name,value) pairs. It is
519 usually in the fnode, but (if it's large) it is moved to a single
520 sector run outside the fnode, or to multiple runs with an anode tree
521 that points to them.
522
523 The value of a single EA is stored along with the name, or (if large)
524 it is moved to a single sector run, or multiple runs pointed to by an
525 anode tree, pointed to by the value field of the (name,value) pair.
526
527 Flags in the EA tell whether the value is immediate, in a single sector
528 run, or in multiple runs. Flags in the fnode tell whether the EA list
529 is immediate, in a single run, or in multiple runs. */
530
Al Viro4085e152012-04-06 13:21:09 -0400531enum {EA_indirect = 1, EA_anode = 2, EA_needea = 128 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532struct extended_attribute
533{
Al Viro4085e152012-04-06 13:21:09 -0400534 u8 flags; /* bit 0 set -> value gives sector number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 where real value starts */
Al Viro4085e152012-04-06 13:21:09 -0400536 /* bit 1 set -> sector is an anode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 that points to fragmented value */
Al Viro4085e152012-04-06 13:21:09 -0400538 /* bit 7 set -> required ea */
Mikulas Patockad8785972011-05-08 20:43:34 +0200539 u8 namelen; /* length of name, bytes */
Mikulas Patockad0969d12011-05-08 20:44:32 +0200540 u8 valuelen_lo; /* length of value, bytes */
541 u8 valuelen_hi; /* length of value, bytes */
Al Viro4085e152012-04-06 13:21:09 -0400542 u8 name[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 /*
Mikulas Patockad8785972011-05-08 20:43:34 +0200544 u8 name[namelen]; ascii attrib name
545 u8 nul; terminating '\0', not counted
546 u8 value[valuelen]; value, arbitrary
Al Viro4085e152012-04-06 13:21:09 -0400547 if this.flags & 1, valuelen is 8 and the value is
Mikulas Patockad8785972011-05-08 20:43:34 +0200548 u32 length; real length of value, bytes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 secno secno; sector address where it starts
550 if this.anode, the above sector number is the root of an anode tree
551 which points to the value.
552 */
553};
554
Al Viro4085e152012-04-06 13:21:09 -0400555static inline bool ea_indirect(struct extended_attribute *ea)
556{
557 return ea->flags & EA_indirect;
558}
559
560static inline bool ea_in_anode(struct extended_attribute *ea)
561{
562 return ea->flags & EA_anode;
563}
564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565/*
566 Local Variables:
567 comment-column: 40
568 End:
569*/