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
13secno 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
60secno 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
268void 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
324static 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
332int 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
355int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
356	     unsigned len, const 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
379void 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
393void 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
475void 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