1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/hpfs/anode.c
  4 *
  5 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
  6 *
  7 *  handling HPFS anode tree that contains file allocation info
  8 */
  9
 10#include "hpfs_fn.h"
 11
 12/* Find a sector in allocation tree */
 13
 14secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
 15		   struct bplus_header *btree, unsigned sec,
 16		   struct buffer_head *bh)
 17{
 18	anode_secno a = -1;
 19	struct anode *anode;
 20	int i;
 21	int c1, c2 = 0;
 22	go_down:
 23	if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
 24	if (bp_internal(btree)) {
 25		for (i = 0; i < btree->n_used_nodes; i++)
 26			if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
 27				a = le32_to_cpu(btree->u.internal[i].down);
 28				brelse(bh);
 29				if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
 30				btree = &anode->btree;
 31				goto go_down;
 32			}
 33		hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
 34		brelse(bh);
 35		return -1;
 36	}
 37	for (i = 0; i < btree->n_used_nodes; i++)
 38		if (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
 39		    le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
 40			a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(btree->u.external[i].file_secno);
 41			if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
 42				brelse(bh);
 43				return -1;
 44			}
 45			if (inode) {
 46				struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
 47				hpfs_inode->i_file_sec = le32_to_cpu(btree->u.external[i].file_secno);
 48				hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
 49				hpfs_inode->i_n_secs = le32_to_cpu(btree->u.external[i].length);
 50			}
 51			brelse(bh);
 52			return a;
 53		}
 54	hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
 55	brelse(bh);
 56	return -1;
 57}
 58
 59/* Add a sector to tree */
 60
 61secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
 62{
 63	struct bplus_header *btree;
 64	struct anode *anode = NULL, *ranode = NULL;
 65	struct fnode *fnode;
 66	anode_secno a, na = -1, ra, up = -1;
 67	secno se;
 68	struct buffer_head *bh, *bh1, *bh2;
 69	int n;
 70	unsigned fs;
 71	int c1, c2 = 0;
 72	if (fnod) {
 73		if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
 74		btree = &fnode->btree;
 75	} else {
 76		if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
 77		btree = &anode->btree;
 78	}
 79	a = node;
 80	go_down:
 81	if ((n = btree->n_used_nodes - 1) < -!!fnod) {
 82		hpfs_error(s, "anode %08x has no entries", a);
 83		brelse(bh);
 84		return -1;
 85	}
 86	if (bp_internal(btree)) {
 87		a = le32_to_cpu(btree->u.internal[n].down);
 88		btree->u.internal[n].file_secno = cpu_to_le32(-1);
 89		mark_buffer_dirty(bh);
 90		brelse(bh);
 91		if (hpfs_sb(s)->sb_chk)
 92			if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
 93		if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
 94		btree = &anode->btree;
 95		goto go_down;
 96	}
 97	if (n >= 0) {
 98		if (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {
 99			hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
100				le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length), fsecno,
101				fnod?'f':'a', node);
102			brelse(bh);
103			return -1;
104		}
105		if (hpfs_alloc_if_possible(s, se = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
106			le32_add_cpu(&btree->u.external[n].length, 1);
107			mark_buffer_dirty(bh);
108			brelse(bh);
109			return se;
110		}
111	} else {
112		if (fsecno) {
113			hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
114			brelse(bh);
115			return -1;
116		}
117		se = !fnod ? node : (node + 16384) & ~16383;
118	}	
119	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))) {
120		brelse(bh);
121		return -1;
122	}
123	fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);
124	if (!btree->n_free_nodes) {
125		up = a != node ? le32_to_cpu(anode->up) : -1;
126		if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
127			brelse(bh);
128			hpfs_free_sectors(s, se, 1);
129			return -1;
130		}
131		if (a == node && fnod) {
132			anode->up = cpu_to_le32(node);
133			anode->btree.flags |= BP_fnode_parent;
134			anode->btree.n_used_nodes = btree->n_used_nodes;
135			anode->btree.first_free = btree->first_free;
136			anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
137			memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
138			btree->flags |= BP_internal;
139			btree->n_free_nodes = 11;
140			btree->n_used_nodes = 1;
141			btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
142			btree->u.internal[0].file_secno = cpu_to_le32(-1);
143			btree->u.internal[0].down = cpu_to_le32(na);
144			mark_buffer_dirty(bh);
145		} else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
146			brelse(bh);
147			brelse(bh1);
148			hpfs_free_sectors(s, se, 1);
149			hpfs_free_sectors(s, na, 1);
150			return -1;
151		}
152		brelse(bh);
153		bh = bh1;
154		btree = &anode->btree;
155	}
156	btree->n_free_nodes--; n = btree->n_used_nodes++;
157	le16_add_cpu(&btree->first_free, 12);
158	btree->u.external[n].disk_secno = cpu_to_le32(se);
159	btree->u.external[n].file_secno = cpu_to_le32(fs);
160	btree->u.external[n].length = cpu_to_le32(1);
161	mark_buffer_dirty(bh);
162	brelse(bh);
163	if ((a == node && fnod) || na == -1) return se;
164	c2 = 0;
165	while (up != (anode_secno)-1) {
166		struct anode *new_anode;
167		if (hpfs_sb(s)->sb_chk)
168			if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
169		if (up != node || !fnod) {
170			if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
171			btree = &anode->btree;
172		} else {
173			if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
174			btree = &fnode->btree;
175		}
176		if (btree->n_free_nodes) {
177			btree->n_free_nodes--; n = btree->n_used_nodes++;
178			le16_add_cpu(&btree->first_free, 8);
179			btree->u.internal[n].file_secno = cpu_to_le32(-1);
180			btree->u.internal[n].down = cpu_to_le32(na);
181			btree->u.internal[n-1].file_secno = cpu_to_le32(fs);
182			mark_buffer_dirty(bh);
183			brelse(bh);
184			brelse(bh2);
185			hpfs_free_sectors(s, ra, 1);
186			if ((anode = hpfs_map_anode(s, na, &bh))) {
187				anode->up = cpu_to_le32(up);
188				if (up == node && fnod)
189					anode->btree.flags |= BP_fnode_parent;
190				else
191					anode->btree.flags &= ~BP_fnode_parent;
192				mark_buffer_dirty(bh);
193				brelse(bh);
194			}
195			return se;
196		}
197		up = up != node ? le32_to_cpu(anode->up) : -1;
198		btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);
199		mark_buffer_dirty(bh);
200		brelse(bh);
201		a = na;
202		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
203			anode = new_anode;
204			/*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
205			anode->btree.flags |= BP_internal;
206			anode->btree.n_used_nodes = 1;
207			anode->btree.n_free_nodes = 59;
208			anode->btree.first_free = cpu_to_le16(16);
209			anode->btree.u.internal[0].down = cpu_to_le32(a);
210			anode->btree.u.internal[0].file_secno = cpu_to_le32(-1);
211			mark_buffer_dirty(bh);
212			brelse(bh);
213			if ((anode = hpfs_map_anode(s, a, &bh))) {
214				anode->up = cpu_to_le32(na);
215				mark_buffer_dirty(bh);
216				brelse(bh);
217			}
218		} else na = a;
219	}
220	if ((anode = hpfs_map_anode(s, na, &bh))) {
221		anode->up = cpu_to_le32(node);
222		if (fnod)
223			anode->btree.flags |= BP_fnode_parent;
224		mark_buffer_dirty(bh);
225		brelse(bh);
226	}
227	if (!fnod) {
228		if (!(anode = hpfs_map_anode(s, node, &bh))) {
229			brelse(bh2);
230			return -1;
231		}
232		btree = &anode->btree;
233	} else {
234		if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
235			brelse(bh2);
236			return -1;
237		}
238		btree = &fnode->btree;
239	}
240	ranode->up = cpu_to_le32(node);
241	memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
242	if (fnod)
243		ranode->btree.flags |= BP_fnode_parent;
244	ranode->btree.n_free_nodes = (bp_internal(&ranode->btree) ? 60 : 40) - ranode->btree.n_used_nodes;
245	if (bp_internal(&ranode->btree)) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
246		struct anode *unode;
247		if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
248			unode->up = cpu_to_le32(ra);
249			unode->btree.flags &= ~BP_fnode_parent;
250			mark_buffer_dirty(bh1);
251			brelse(bh1);
252		}
253	}
254	btree->flags |= BP_internal;
255	btree->n_free_nodes = fnod ? 10 : 58;
256	btree->n_used_nodes = 2;
257	btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
258	btree->u.internal[0].file_secno = cpu_to_le32(fs);
259	btree->u.internal[0].down = cpu_to_le32(ra);
260	btree->u.internal[1].file_secno = cpu_to_le32(-1);
261	btree->u.internal[1].down = cpu_to_le32(na);
262	mark_buffer_dirty(bh);
263	brelse(bh);
264	mark_buffer_dirty(bh2);
265	brelse(bh2);
266	return se;
267}
268
269/*
270 * Remove allocation tree. Recursion would look much nicer but
271 * I want to avoid it because it can cause stack overflow.
272 */
273
274void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
275{
276	struct bplus_header *btree1 = btree;
277	struct anode *anode = NULL;
278	anode_secno ano = 0, oano;
279	struct buffer_head *bh;
280	int level = 0;
281	int pos = 0;
282	int i;
283	int c1, c2 = 0;
284	int d1, d2;
285	go_down:
286	d2 = 0;
287	while (bp_internal(btree1)) {
288		ano = le32_to_cpu(btree1->u.internal[pos].down);
289		if (level) brelse(bh);
290		if (hpfs_sb(s)->sb_chk)
291			if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
292				return;
293		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
294		btree1 = &anode->btree;
295		level++;
296		pos = 0;
297	}
298	for (i = 0; i < btree1->n_used_nodes; i++)
299		hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));
300	go_up:
301	if (!level) return;
302	brelse(bh);
303	if (hpfs_sb(s)->sb_chk)
304		if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
305	hpfs_free_sectors(s, ano, 1);
306	oano = ano;
307	ano = le32_to_cpu(anode->up);
308	if (--level) {
309		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
310		btree1 = &anode->btree;
311	} else btree1 = btree;
312	for (i = 0; i < btree1->n_used_nodes; i++) {
313		if (le32_to_cpu(btree1->u.internal[i].down) == oano) {
314			if ((pos = i + 1) < btree1->n_used_nodes)
315				goto go_down;
316			else
317				goto go_up;
318		}
319	}
320	hpfs_error(s,
321		   "reference to anode %08x not found in anode %08x "
322		   "(probably bad up pointer)",
323		   oano, level ? ano : -1);
324	if (level)
325		brelse(bh);
326}
327
328/* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
329
330static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
331{
332	struct anode *anode;
333	struct buffer_head *bh;
334	if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
335	return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
336}
337
338int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
339	    unsigned len, char *buf)
340{
341	struct buffer_head *bh;
342	char *data;
343	secno sec;
344	unsigned l;
345	while (len) {
346		if (ano) {
347			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
348				return -1;
349		} else sec = a + (pos >> 9);
350		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
351		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
352			return -1;
353		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
354		memcpy(buf, data + (pos & 0x1ff), l);
355		brelse(bh);
356		buf += l; pos += l; len -= l;
357	}
358	return 0;
359}
360
361int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
362	     unsigned len, const char *buf)
363{
364	struct buffer_head *bh;
365	char *data;
366	secno sec;
367	unsigned l;
368	while (len) {
369		if (ano) {
370			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
371				return -1;
372		} else sec = a + (pos >> 9);
373		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
374		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
375			return -1;
376		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
377		memcpy(data + (pos & 0x1ff), buf, l);
378		mark_buffer_dirty(bh);
379		brelse(bh);
380		buf += l; pos += l; len -= l;
381	}
382	return 0;
383}
384
385void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
386{
387	struct anode *anode;
388	struct buffer_head *bh;
389	if (ano) {
390		if (!(anode = hpfs_map_anode(s, a, &bh))) return;
391		hpfs_remove_btree(s, &anode->btree);
392		brelse(bh);
393		hpfs_free_sectors(s, a, 1);
394	} else hpfs_free_sectors(s, a, (len + 511) >> 9);
395}
396
397/* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
398
399void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
400{
401	struct fnode *fnode;
402	struct anode *anode;
403	struct buffer_head *bh;
404	struct bplus_header *btree;
405	anode_secno node = f;
406	int i, j, nodes;
407	int c1, c2 = 0;
408	if (fno) {
409		if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
410		btree = &fnode->btree;
411	} else {
412		if (!(anode = hpfs_map_anode(s, f, &bh))) return;
413		btree = &anode->btree;
414	}
415	if (!secs) {
416		hpfs_remove_btree(s, btree);
417		if (fno) {
418			btree->n_free_nodes = 8;
419			btree->n_used_nodes = 0;
420			btree->first_free = cpu_to_le16(8);
421			btree->flags &= ~BP_internal;
422			mark_buffer_dirty(bh);
423		} else hpfs_free_sectors(s, f, 1);
424		brelse(bh);
425		return;
426	}
427	while (bp_internal(btree)) {
428		nodes = btree->n_used_nodes + btree->n_free_nodes;
429		for (i = 0; i < btree->n_used_nodes; i++)
430			if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;
431		brelse(bh);
432		hpfs_error(s, "internal btree %08x doesn't end with -1", node);
433		return;
434		f:
435		for (j = i + 1; j < btree->n_used_nodes; j++)
436			hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);
437		btree->n_used_nodes = i + 1;
438		btree->n_free_nodes = nodes - btree->n_used_nodes;
439		btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);
440		mark_buffer_dirty(bh);
441		if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {
442			brelse(bh);
443			return;
444		}
445		node = le32_to_cpu(btree->u.internal[i].down);
446		brelse(bh);
447		if (hpfs_sb(s)->sb_chk)
448			if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
449				return;
450		if (!(anode = hpfs_map_anode(s, node, &bh))) return;
451		btree = &anode->btree;
452	}	
453	nodes = btree->n_used_nodes + btree->n_free_nodes;
454	for (i = 0; i < btree->n_used_nodes; i++)
455		if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;
456	brelse(bh);
457	return;
458	ff:
459	if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {
460		hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
461		if (i) i--;
462	}
463	else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
464		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
465			le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
466			- secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
467		btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));
468	}
469	for (j = i + 1; j < btree->n_used_nodes; j++)
470		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));
471	btree->n_used_nodes = i + 1;
472	btree->n_free_nodes = nodes - btree->n_used_nodes;
473	btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);
474	mark_buffer_dirty(bh);
475	brelse(bh);
476}
477
478/* Remove file or directory and it's eas - note that directory must
479   be empty when this is called. */
480
481void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
482{
483	struct buffer_head *bh;
484	struct fnode *fnode;
485	struct extended_attribute *ea;
486	struct extended_attribute *ea_end;
487	if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
488	if (!fnode_is_dir(fnode)) hpfs_remove_btree(s, &fnode->btree);
489	else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));
490	ea_end = fnode_end_ea(fnode);
491	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
492		if (ea_indirect(ea))
493			hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
494	hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l));
495	brelse(bh);
496	hpfs_free_sectors(s, fno, 1);
497}