xref: /openbmc/linux/fs/hpfs/anode.c (revision 367b8112)
1 /*
2  *  linux/fs/hpfs/anode.c
3  *
4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5  *
6  *  handling HPFS anode tree that contains file allocation info
7  */
8 
9 #include "hpfs_fn.h"
10 
11 /* Find a sector in allocation tree */
12 
13 secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
14 		   struct bplus_header *btree, unsigned sec,
15 		   struct buffer_head *bh)
16 {
17 	anode_secno a = -1;
18 	struct anode *anode;
19 	int i;
20 	int c1, c2 = 0;
21 	go_down:
22 	if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
23 	if (btree->internal) {
24 		for (i = 0; i < btree->n_used_nodes; i++)
25 			if (btree->u.internal[i].file_secno > sec) {
26 				a = btree->u.internal[i].down;
27 				brelse(bh);
28 				if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
29 				btree = &anode->btree;
30 				goto go_down;
31 			}
32 		hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
33 		brelse(bh);
34 		return -1;
35 	}
36 	for (i = 0; i < btree->n_used_nodes; i++)
37 		if (btree->u.external[i].file_secno <= sec &&
38 		    btree->u.external[i].file_secno + btree->u.external[i].length > sec) {
39 			a = btree->u.external[i].disk_secno + sec - btree->u.external[i].file_secno;
40 			if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
41 				brelse(bh);
42 				return -1;
43 			}
44 			if (inode) {
45 				struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
46 				hpfs_inode->i_file_sec = btree->u.external[i].file_secno;
47 				hpfs_inode->i_disk_sec = btree->u.external[i].disk_secno;
48 				hpfs_inode->i_n_secs = btree->u.external[i].length;
49 			}
50 			brelse(bh);
51 			return a;
52 		}
53 	hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
54 	brelse(bh);
55 	return -1;
56 }
57 
58 /* Add a sector to tree */
59 
60 secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
61 {
62 	struct bplus_header *btree;
63 	struct anode *anode = NULL, *ranode = NULL;
64 	struct fnode *fnode;
65 	anode_secno a, na = -1, ra, up = -1;
66 	secno se;
67 	struct buffer_head *bh, *bh1, *bh2;
68 	int n;
69 	unsigned fs;
70 	int c1, c2 = 0;
71 	if (fnod) {
72 		if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
73 		btree = &fnode->btree;
74 	} else {
75 		if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
76 		btree = &anode->btree;
77 	}
78 	a = node;
79 	go_down:
80 	if ((n = btree->n_used_nodes - 1) < -!!fnod) {
81 		hpfs_error(s, "anode %08x has no entries", a);
82 		brelse(bh);
83 		return -1;
84 	}
85 	if (btree->internal) {
86 		a = btree->u.internal[n].down;
87 		btree->u.internal[n].file_secno = -1;
88 		mark_buffer_dirty(bh);
89 		brelse(bh);
90 		if (hpfs_sb(s)->sb_chk)
91 			if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
92 		if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
93 		btree = &anode->btree;
94 		goto go_down;
95 	}
96 	if (n >= 0) {
97 		if (btree->u.external[n].file_secno + btree->u.external[n].length != fsecno) {
98 			hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
99 				btree->u.external[n].file_secno + btree->u.external[n].length, fsecno,
100 				fnod?'f':'a', node);
101 			brelse(bh);
102 			return -1;
103 		}
104 		if (hpfs_alloc_if_possible(s, se = btree->u.external[n].disk_secno + btree->u.external[n].length)) {
105 			btree->u.external[n].length++;
106 			mark_buffer_dirty(bh);
107 			brelse(bh);
108 			return se;
109 		}
110 	} else {
111 		if (fsecno) {
112 			hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
113 			brelse(bh);
114 			return -1;
115 		}
116 		se = !fnod ? node : (node + 16384) & ~16383;
117 	}
118 	if (!(se = hpfs_alloc_sector(s, se, 1, fsecno*ALLOC_M>ALLOC_FWD_MAX ? ALLOC_FWD_MAX : fsecno*ALLOC_M<ALLOC_FWD_MIN ? ALLOC_FWD_MIN : fsecno*ALLOC_M, 1))) {
119 		brelse(bh);
120 		return -1;
121 	}
122 	fs = n < 0 ? 0 : btree->u.external[n].file_secno + btree->u.external[n].length;
123 	if (!btree->n_free_nodes) {
124 		up = a != node ? anode->up : -1;
125 		if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
126 			brelse(bh);
127 			hpfs_free_sectors(s, se, 1);
128 			return -1;
129 		}
130 		if (a == node && fnod) {
131 			anode->up = node;
132 			anode->btree.fnode_parent = 1;
133 			anode->btree.n_used_nodes = btree->n_used_nodes;
134 			anode->btree.first_free = btree->first_free;
135 			anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
136 			memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
137 			btree->internal = 1;
138 			btree->n_free_nodes = 11;
139 			btree->n_used_nodes = 1;
140 			btree->first_free = (char *)&(btree->u.internal[1]) - (char *)btree;
141 			btree->u.internal[0].file_secno = -1;
142 			btree->u.internal[0].down = na;
143 			mark_buffer_dirty(bh);
144 		} else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
145 			brelse(bh);
146 			brelse(bh1);
147 			hpfs_free_sectors(s, se, 1);
148 			hpfs_free_sectors(s, na, 1);
149 			return -1;
150 		}
151 		brelse(bh);
152 		bh = bh1;
153 		btree = &anode->btree;
154 	}
155 	btree->n_free_nodes--; n = btree->n_used_nodes++;
156 	btree->first_free += 12;
157 	btree->u.external[n].disk_secno = se;
158 	btree->u.external[n].file_secno = fs;
159 	btree->u.external[n].length = 1;
160 	mark_buffer_dirty(bh);
161 	brelse(bh);
162 	if ((a == node && fnod) || na == -1) return se;
163 	c2 = 0;
164 	while (up != -1) {
165 		struct anode *new_anode;
166 		if (hpfs_sb(s)->sb_chk)
167 			if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
168 		if (up != node || !fnod) {
169 			if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
170 			btree = &anode->btree;
171 		} else {
172 			if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
173 			btree = &fnode->btree;
174 		}
175 		if (btree->n_free_nodes) {
176 			btree->n_free_nodes--; n = btree->n_used_nodes++;
177 			btree->first_free += 8;
178 			btree->u.internal[n].file_secno = -1;
179 			btree->u.internal[n].down = na;
180 			btree->u.internal[n-1].file_secno = fs;
181 			mark_buffer_dirty(bh);
182 			brelse(bh);
183 			brelse(bh2);
184 			hpfs_free_sectors(s, ra, 1);
185 			if ((anode = hpfs_map_anode(s, na, &bh))) {
186 				anode->up = up;
187 				anode->btree.fnode_parent = up == node && fnod;
188 				mark_buffer_dirty(bh);
189 				brelse(bh);
190 			}
191 			return se;
192 		}
193 		up = up != node ? anode->up : -1;
194 		btree->u.internal[btree->n_used_nodes - 1].file_secno = /*fs*/-1;
195 		mark_buffer_dirty(bh);
196 		brelse(bh);
197 		a = na;
198 		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
199 			anode = new_anode;
200 			/*anode->up = up != -1 ? up : ra;*/
201 			anode->btree.internal = 1;
202 			anode->btree.n_used_nodes = 1;
203 			anode->btree.n_free_nodes = 59;
204 			anode->btree.first_free = 16;
205 			anode->btree.u.internal[0].down = a;
206 			anode->btree.u.internal[0].file_secno = -1;
207 			mark_buffer_dirty(bh);
208 			brelse(bh);
209 			if ((anode = hpfs_map_anode(s, a, &bh))) {
210 				anode->up = na;
211 				mark_buffer_dirty(bh);
212 				brelse(bh);
213 			}
214 		} else na = a;
215 	}
216 	if ((anode = hpfs_map_anode(s, na, &bh))) {
217 		anode->up = node;
218 		if (fnod) anode->btree.fnode_parent = 1;
219 		mark_buffer_dirty(bh);
220 		brelse(bh);
221 	}
222 	if (!fnod) {
223 		if (!(anode = hpfs_map_anode(s, node, &bh))) {
224 			brelse(bh2);
225 			return -1;
226 		}
227 		btree = &anode->btree;
228 	} else {
229 		if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
230 			brelse(bh2);
231 			return -1;
232 		}
233 		btree = &fnode->btree;
234 	}
235 	ranode->up = node;
236 	memcpy(&ranode->btree, btree, btree->first_free);
237 	if (fnod) ranode->btree.fnode_parent = 1;
238 	ranode->btree.n_free_nodes = (ranode->btree.internal ? 60 : 40) - ranode->btree.n_used_nodes;
239 	if (ranode->btree.internal) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
240 		struct anode *unode;
241 		if ((unode = hpfs_map_anode(s, ranode->u.internal[n].down, &bh1))) {
242 			unode->up = ra;
243 			unode->btree.fnode_parent = 0;
244 			mark_buffer_dirty(bh1);
245 			brelse(bh1);
246 		}
247 	}
248 	btree->internal = 1;
249 	btree->n_free_nodes = fnod ? 10 : 58;
250 	btree->n_used_nodes = 2;
251 	btree->first_free = (char *)&btree->u.internal[2] - (char *)btree;
252 	btree->u.internal[0].file_secno = fs;
253 	btree->u.internal[0].down = ra;
254 	btree->u.internal[1].file_secno = -1;
255 	btree->u.internal[1].down = na;
256 	mark_buffer_dirty(bh);
257 	brelse(bh);
258 	mark_buffer_dirty(bh2);
259 	brelse(bh2);
260 	return se;
261 }
262 
263 /*
264  * Remove allocation tree. Recursion would look much nicer but
265  * I want to avoid it because it can cause stack overflow.
266  */
267 
268 void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
269 {
270 	struct bplus_header *btree1 = btree;
271 	struct anode *anode = NULL;
272 	anode_secno ano = 0, oano;
273 	struct buffer_head *bh;
274 	int level = 0;
275 	int pos = 0;
276 	int i;
277 	int c1, c2 = 0;
278 	int d1, d2;
279 	go_down:
280 	d2 = 0;
281 	while (btree1->internal) {
282 		ano = btree1->u.internal[pos].down;
283 		if (level) brelse(bh);
284 		if (hpfs_sb(s)->sb_chk)
285 			if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
286 				return;
287 		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
288 		btree1 = &anode->btree;
289 		level++;
290 		pos = 0;
291 	}
292 	for (i = 0; i < btree1->n_used_nodes; i++)
293 		hpfs_free_sectors(s, btree1->u.external[i].disk_secno, btree1->u.external[i].length);
294 	go_up:
295 	if (!level) return;
296 	brelse(bh);
297 	if (hpfs_sb(s)->sb_chk)
298 		if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
299 	hpfs_free_sectors(s, ano, 1);
300 	oano = ano;
301 	ano = anode->up;
302 	if (--level) {
303 		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
304 		btree1 = &anode->btree;
305 	} else btree1 = btree;
306 	for (i = 0; i < btree1->n_used_nodes; i++) {
307 		if (btree1->u.internal[i].down == oano) {
308 			if ((pos = i + 1) < btree1->n_used_nodes)
309 				goto go_down;
310 			else
311 				goto go_up;
312 		}
313 	}
314 	hpfs_error(s,
315 		   "reference to anode %08x not found in anode %08x "
316 		   "(probably bad up pointer)",
317 		   oano, level ? ano : -1);
318 	if (level)
319 		brelse(bh);
320 }
321 
322 /* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
323 
324 static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
325 {
326 	struct anode *anode;
327 	struct buffer_head *bh;
328 	if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
329 	return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
330 }
331 
332 int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
333 	    unsigned len, char *buf)
334 {
335 	struct buffer_head *bh;
336 	char *data;
337 	secno sec;
338 	unsigned l;
339 	while (len) {
340 		if (ano) {
341 			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
342 				return -1;
343 		} else sec = a + (pos >> 9);
344 		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
345 		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
346 			return -1;
347 		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
348 		memcpy(buf, data + (pos & 0x1ff), l);
349 		brelse(bh);
350 		buf += l; pos += l; len -= l;
351 	}
352 	return 0;
353 }
354 
355 int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
356 	     unsigned len, char *buf)
357 {
358 	struct buffer_head *bh;
359 	char *data;
360 	secno sec;
361 	unsigned l;
362 	while (len) {
363 		if (ano) {
364 			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
365 				return -1;
366 		} else sec = a + (pos >> 9);
367 		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
368 		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
369 			return -1;
370 		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
371 		memcpy(data + (pos & 0x1ff), buf, l);
372 		mark_buffer_dirty(bh);
373 		brelse(bh);
374 		buf += l; pos += l; len -= l;
375 	}
376 	return 0;
377 }
378 
379 void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
380 {
381 	struct anode *anode;
382 	struct buffer_head *bh;
383 	if (ano) {
384 		if (!(anode = hpfs_map_anode(s, a, &bh))) return;
385 		hpfs_remove_btree(s, &anode->btree);
386 		brelse(bh);
387 		hpfs_free_sectors(s, a, 1);
388 	} else hpfs_free_sectors(s, a, (len + 511) >> 9);
389 }
390 
391 /* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
392 
393 void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
394 {
395 	struct fnode *fnode;
396 	struct anode *anode;
397 	struct buffer_head *bh;
398 	struct bplus_header *btree;
399 	anode_secno node = f;
400 	int i, j, nodes;
401 	int c1, c2 = 0;
402 	if (fno) {
403 		if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
404 		btree = &fnode->btree;
405 	} else {
406 		if (!(anode = hpfs_map_anode(s, f, &bh))) return;
407 		btree = &anode->btree;
408 	}
409 	if (!secs) {
410 		hpfs_remove_btree(s, btree);
411 		if (fno) {
412 			btree->n_free_nodes = 8;
413 			btree->n_used_nodes = 0;
414 			btree->first_free = 8;
415 			btree->internal = 0;
416 			mark_buffer_dirty(bh);
417 		} else hpfs_free_sectors(s, f, 1);
418 		brelse(bh);
419 		return;
420 	}
421 	while (btree->internal) {
422 		nodes = btree->n_used_nodes + btree->n_free_nodes;
423 		for (i = 0; i < btree->n_used_nodes; i++)
424 			if (btree->u.internal[i].file_secno >= secs) goto f;
425 		brelse(bh);
426 		hpfs_error(s, "internal btree %08x doesn't end with -1", node);
427 		return;
428 		f:
429 		for (j = i + 1; j < btree->n_used_nodes; j++)
430 			hpfs_ea_remove(s, btree->u.internal[j].down, 1, 0);
431 		btree->n_used_nodes = i + 1;
432 		btree->n_free_nodes = nodes - btree->n_used_nodes;
433 		btree->first_free = 8 + 8 * btree->n_used_nodes;
434 		mark_buffer_dirty(bh);
435 		if (btree->u.internal[i].file_secno == secs) {
436 			brelse(bh);
437 			return;
438 		}
439 		node = btree->u.internal[i].down;
440 		brelse(bh);
441 		if (hpfs_sb(s)->sb_chk)
442 			if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
443 				return;
444 		if (!(anode = hpfs_map_anode(s, node, &bh))) return;
445 		btree = &anode->btree;
446 	}
447 	nodes = btree->n_used_nodes + btree->n_free_nodes;
448 	for (i = 0; i < btree->n_used_nodes; i++)
449 		if (btree->u.external[i].file_secno + btree->u.external[i].length >= secs) goto ff;
450 	brelse(bh);
451 	return;
452 	ff:
453 	if (secs <= btree->u.external[i].file_secno) {
454 		hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
455 		if (i) i--;
456 	}
457 	else if (btree->u.external[i].file_secno + btree->u.external[i].length > secs) {
458 		hpfs_free_sectors(s, btree->u.external[i].disk_secno + secs -
459 			btree->u.external[i].file_secno, btree->u.external[i].length
460 			- secs + btree->u.external[i].file_secno); /* I hope gcc optimizes this :-) */
461 		btree->u.external[i].length = secs - btree->u.external[i].file_secno;
462 	}
463 	for (j = i + 1; j < btree->n_used_nodes; j++)
464 		hpfs_free_sectors(s, btree->u.external[j].disk_secno, btree->u.external[j].length);
465 	btree->n_used_nodes = i + 1;
466 	btree->n_free_nodes = nodes - btree->n_used_nodes;
467 	btree->first_free = 8 + 12 * btree->n_used_nodes;
468 	mark_buffer_dirty(bh);
469 	brelse(bh);
470 }
471 
472 /* Remove file or directory and it's eas - note that directory must
473    be empty when this is called. */
474 
475 void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
476 {
477 	struct buffer_head *bh;
478 	struct fnode *fnode;
479 	struct extended_attribute *ea;
480 	struct extended_attribute *ea_end;
481 	if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
482 	if (!fnode->dirflag) hpfs_remove_btree(s, &fnode->btree);
483 	else hpfs_remove_dtree(s, fnode->u.external[0].disk_secno);
484 	ea_end = fnode_end_ea(fnode);
485 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
486 		if (ea->indirect)
487 			hpfs_ea_remove(s, ea_sec(ea), ea->anode, ea_len(ea));
488 	hpfs_ea_ext_remove(s, fnode->ea_secno, fnode->ea_anode, fnode->ea_size_l);
489 	brelse(bh);
490 	hpfs_free_sectors(s, fno, 1);
491 }
492