xref: /openbmc/linux/fs/hpfs/anode.c (revision ab73b751)
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 (bp_internal(btree)) {
24 		for (i = 0; i < btree->n_used_nodes; i++)
25 			if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
26 				a = le32_to_cpu(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 (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
38 		    le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
39 			a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(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 = le32_to_cpu(btree->u.external[i].file_secno);
47 				hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
48 				hpfs_inode->i_n_secs = le32_to_cpu(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 (bp_internal(btree)) {
86 		a = le32_to_cpu(btree->u.internal[n].down);
87 		btree->u.internal[n].file_secno = cpu_to_le32(-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 (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {
98 			hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
99 				le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(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 = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
105 			btree->u.external[n].length = cpu_to_le32(le32_to_cpu(btree->u.external[n].length) + 1);
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))) {
119 		brelse(bh);
120 		return -1;
121 	}
122 	fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);
123 	if (!btree->n_free_nodes) {
124 		up = a != node ? le32_to_cpu(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 = cpu_to_le32(node);
132 			anode->btree.flags |= BP_fnode_parent;
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->flags |= BP_internal;
138 			btree->n_free_nodes = 11;
139 			btree->n_used_nodes = 1;
140 			btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
141 			btree->u.internal[0].file_secno = cpu_to_le32(-1);
142 			btree->u.internal[0].down = cpu_to_le32(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 = cpu_to_le16(le16_to_cpu(btree->first_free) + 12);
157 	btree->u.external[n].disk_secno = cpu_to_le32(se);
158 	btree->u.external[n].file_secno = cpu_to_le32(fs);
159 	btree->u.external[n].length = cpu_to_le32(1);
160 	mark_buffer_dirty(bh);
161 	brelse(bh);
162 	if ((a == node && fnod) || na == -1) return se;
163 	c2 = 0;
164 	while (up != (anode_secno)-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 = cpu_to_le16(le16_to_cpu(btree->first_free) + 8);
178 			btree->u.internal[n].file_secno = cpu_to_le32(-1);
179 			btree->u.internal[n].down = cpu_to_le32(na);
180 			btree->u.internal[n-1].file_secno = cpu_to_le32(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 = cpu_to_le32(up);
187 				if (up == node && fnod)
188 					anode->btree.flags |= BP_fnode_parent;
189 				else
190 					anode->btree.flags &= ~BP_fnode_parent;
191 				mark_buffer_dirty(bh);
192 				brelse(bh);
193 			}
194 			return se;
195 		}
196 		up = up != node ? le32_to_cpu(anode->up) : -1;
197 		btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);
198 		mark_buffer_dirty(bh);
199 		brelse(bh);
200 		a = na;
201 		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
202 			anode = new_anode;
203 			/*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
204 			anode->btree.flags |= BP_internal;
205 			anode->btree.n_used_nodes = 1;
206 			anode->btree.n_free_nodes = 59;
207 			anode->btree.first_free = cpu_to_le16(16);
208 			anode->btree.u.internal[0].down = cpu_to_le32(a);
209 			anode->btree.u.internal[0].file_secno = cpu_to_le32(-1);
210 			mark_buffer_dirty(bh);
211 			brelse(bh);
212 			if ((anode = hpfs_map_anode(s, a, &bh))) {
213 				anode->up = cpu_to_le32(na);
214 				mark_buffer_dirty(bh);
215 				brelse(bh);
216 			}
217 		} else na = a;
218 	}
219 	if ((anode = hpfs_map_anode(s, na, &bh))) {
220 		anode->up = cpu_to_le32(node);
221 		if (fnod)
222 			anode->btree.flags |= BP_fnode_parent;
223 		mark_buffer_dirty(bh);
224 		brelse(bh);
225 	}
226 	if (!fnod) {
227 		if (!(anode = hpfs_map_anode(s, node, &bh))) {
228 			brelse(bh2);
229 			return -1;
230 		}
231 		btree = &anode->btree;
232 	} else {
233 		if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
234 			brelse(bh2);
235 			return -1;
236 		}
237 		btree = &fnode->btree;
238 	}
239 	ranode->up = cpu_to_le32(node);
240 	memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
241 	if (fnod)
242 		ranode->btree.flags |= BP_fnode_parent;
243 	ranode->btree.n_free_nodes = (bp_internal(&ranode->btree) ? 60 : 40) - ranode->btree.n_used_nodes;
244 	if (bp_internal(&ranode->btree)) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
245 		struct anode *unode;
246 		if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
247 			unode->up = cpu_to_le32(ra);
248 			unode->btree.flags &= ~BP_fnode_parent;
249 			mark_buffer_dirty(bh1);
250 			brelse(bh1);
251 		}
252 	}
253 	btree->flags |= BP_internal;
254 	btree->n_free_nodes = fnod ? 10 : 58;
255 	btree->n_used_nodes = 2;
256 	btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
257 	btree->u.internal[0].file_secno = cpu_to_le32(fs);
258 	btree->u.internal[0].down = cpu_to_le32(ra);
259 	btree->u.internal[1].file_secno = cpu_to_le32(-1);
260 	btree->u.internal[1].down = cpu_to_le32(na);
261 	mark_buffer_dirty(bh);
262 	brelse(bh);
263 	mark_buffer_dirty(bh2);
264 	brelse(bh2);
265 	return se;
266 }
267 
268 /*
269  * Remove allocation tree. Recursion would look much nicer but
270  * I want to avoid it because it can cause stack overflow.
271  */
272 
273 void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
274 {
275 	struct bplus_header *btree1 = btree;
276 	struct anode *anode = NULL;
277 	anode_secno ano = 0, oano;
278 	struct buffer_head *bh;
279 	int level = 0;
280 	int pos = 0;
281 	int i;
282 	int c1, c2 = 0;
283 	int d1, d2;
284 	go_down:
285 	d2 = 0;
286 	while (bp_internal(btree1)) {
287 		ano = le32_to_cpu(btree1->u.internal[pos].down);
288 		if (level) brelse(bh);
289 		if (hpfs_sb(s)->sb_chk)
290 			if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
291 				return;
292 		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
293 		btree1 = &anode->btree;
294 		level++;
295 		pos = 0;
296 	}
297 	for (i = 0; i < btree1->n_used_nodes; i++)
298 		hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));
299 	go_up:
300 	if (!level) return;
301 	brelse(bh);
302 	if (hpfs_sb(s)->sb_chk)
303 		if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
304 	hpfs_free_sectors(s, ano, 1);
305 	oano = ano;
306 	ano = le32_to_cpu(anode->up);
307 	if (--level) {
308 		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
309 		btree1 = &anode->btree;
310 	} else btree1 = btree;
311 	for (i = 0; i < btree1->n_used_nodes; i++) {
312 		if (le32_to_cpu(btree1->u.internal[i].down) == oano) {
313 			if ((pos = i + 1) < btree1->n_used_nodes)
314 				goto go_down;
315 			else
316 				goto go_up;
317 		}
318 	}
319 	hpfs_error(s,
320 		   "reference to anode %08x not found in anode %08x "
321 		   "(probably bad up pointer)",
322 		   oano, level ? ano : -1);
323 	if (level)
324 		brelse(bh);
325 }
326 
327 /* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
328 
329 static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
330 {
331 	struct anode *anode;
332 	struct buffer_head *bh;
333 	if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
334 	return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
335 }
336 
337 int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
338 	    unsigned len, char *buf)
339 {
340 	struct buffer_head *bh;
341 	char *data;
342 	secno sec;
343 	unsigned l;
344 	while (len) {
345 		if (ano) {
346 			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
347 				return -1;
348 		} else sec = a + (pos >> 9);
349 		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
350 		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
351 			return -1;
352 		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
353 		memcpy(buf, data + (pos & 0x1ff), l);
354 		brelse(bh);
355 		buf += l; pos += l; len -= l;
356 	}
357 	return 0;
358 }
359 
360 int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
361 	     unsigned len, const char *buf)
362 {
363 	struct buffer_head *bh;
364 	char *data;
365 	secno sec;
366 	unsigned l;
367 	while (len) {
368 		if (ano) {
369 			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
370 				return -1;
371 		} else sec = a + (pos >> 9);
372 		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
373 		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
374 			return -1;
375 		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
376 		memcpy(data + (pos & 0x1ff), buf, l);
377 		mark_buffer_dirty(bh);
378 		brelse(bh);
379 		buf += l; pos += l; len -= l;
380 	}
381 	return 0;
382 }
383 
384 void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
385 {
386 	struct anode *anode;
387 	struct buffer_head *bh;
388 	if (ano) {
389 		if (!(anode = hpfs_map_anode(s, a, &bh))) return;
390 		hpfs_remove_btree(s, &anode->btree);
391 		brelse(bh);
392 		hpfs_free_sectors(s, a, 1);
393 	} else hpfs_free_sectors(s, a, (len + 511) >> 9);
394 }
395 
396 /* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
397 
398 void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
399 {
400 	struct fnode *fnode;
401 	struct anode *anode;
402 	struct buffer_head *bh;
403 	struct bplus_header *btree;
404 	anode_secno node = f;
405 	int i, j, nodes;
406 	int c1, c2 = 0;
407 	if (fno) {
408 		if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
409 		btree = &fnode->btree;
410 	} else {
411 		if (!(anode = hpfs_map_anode(s, f, &bh))) return;
412 		btree = &anode->btree;
413 	}
414 	if (!secs) {
415 		hpfs_remove_btree(s, btree);
416 		if (fno) {
417 			btree->n_free_nodes = 8;
418 			btree->n_used_nodes = 0;
419 			btree->first_free = cpu_to_le16(8);
420 			btree->flags &= ~BP_internal;
421 			mark_buffer_dirty(bh);
422 		} else hpfs_free_sectors(s, f, 1);
423 		brelse(bh);
424 		return;
425 	}
426 	while (bp_internal(btree)) {
427 		nodes = btree->n_used_nodes + btree->n_free_nodes;
428 		for (i = 0; i < btree->n_used_nodes; i++)
429 			if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;
430 		brelse(bh);
431 		hpfs_error(s, "internal btree %08x doesn't end with -1", node);
432 		return;
433 		f:
434 		for (j = i + 1; j < btree->n_used_nodes; j++)
435 			hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);
436 		btree->n_used_nodes = i + 1;
437 		btree->n_free_nodes = nodes - btree->n_used_nodes;
438 		btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);
439 		mark_buffer_dirty(bh);
440 		if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {
441 			brelse(bh);
442 			return;
443 		}
444 		node = le32_to_cpu(btree->u.internal[i].down);
445 		brelse(bh);
446 		if (hpfs_sb(s)->sb_chk)
447 			if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
448 				return;
449 		if (!(anode = hpfs_map_anode(s, node, &bh))) return;
450 		btree = &anode->btree;
451 	}
452 	nodes = btree->n_used_nodes + btree->n_free_nodes;
453 	for (i = 0; i < btree->n_used_nodes; i++)
454 		if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;
455 	brelse(bh);
456 	return;
457 	ff:
458 	if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {
459 		hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
460 		if (i) i--;
461 	}
462 	else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
463 		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
464 			le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
465 			- secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
466 		btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));
467 	}
468 	for (j = i + 1; j < btree->n_used_nodes; j++)
469 		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));
470 	btree->n_used_nodes = i + 1;
471 	btree->n_free_nodes = nodes - btree->n_used_nodes;
472 	btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);
473 	mark_buffer_dirty(bh);
474 	brelse(bh);
475 }
476 
477 /* Remove file or directory and it's eas - note that directory must
478    be empty when this is called. */
479 
480 void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
481 {
482 	struct buffer_head *bh;
483 	struct fnode *fnode;
484 	struct extended_attribute *ea;
485 	struct extended_attribute *ea_end;
486 	if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
487 	if (!fnode_is_dir(fnode)) hpfs_remove_btree(s, &fnode->btree);
488 	else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));
489 	ea_end = fnode_end_ea(fnode);
490 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
491 		if (ea_indirect(ea))
492 			hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
493 	hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l));
494 	brelse(bh);
495 	hpfs_free_sectors(s, fno, 1);
496 }
497