1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  linux/fs/hpfs/dnode.c
4 *
5 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6 *
7 *  handling directory dnode tree - adding, deleteing & searching for dirents
8 */
9
10#include "hpfs_fn.h"
11
12static loff_t get_pos(struct dnode *d, struct hpfs_dirent *fde)
13{
14	struct hpfs_dirent *de;
15	struct hpfs_dirent *de_end = dnode_end_de(d);
16	int i = 1;
17	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
18		if (de == fde) return ((loff_t) le32_to_cpu(d->self) << 4) | (loff_t)i;
19		i++;
20	}
21	pr_info("%s(): not_found\n", __func__);
22	return ((loff_t)le32_to_cpu(d->self) << 4) | (loff_t)1;
23}
24
25int hpfs_add_pos(struct inode *inode, loff_t *pos)
26{
27	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
28	int i = 0;
29	loff_t **ppos;
30
31	if (hpfs_inode->i_rddir_off)
32		for (; hpfs_inode->i_rddir_off[i]; i++)
33			if (hpfs_inode->i_rddir_off[i] == pos)
34				return 0;
35	if (!(i&0x0f)) {
36		ppos = kmalloc_array(i + 0x11, sizeof(loff_t *), GFP_NOFS);
37		if (!ppos) {
38			pr_err("out of memory for position list\n");
39			return -ENOMEM;
40		}
41		if (hpfs_inode->i_rddir_off) {
42			memcpy(ppos, hpfs_inode->i_rddir_off, i * sizeof(loff_t));
43			kfree(hpfs_inode->i_rddir_off);
44		}
45		hpfs_inode->i_rddir_off = ppos;
46	}
47	hpfs_inode->i_rddir_off[i] = pos;
48	hpfs_inode->i_rddir_off[i + 1] = NULL;
49	return 0;
50}
51
52void hpfs_del_pos(struct inode *inode, loff_t *pos)
53{
54	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
55	loff_t **i, **j;
56
57	if (!hpfs_inode->i_rddir_off) goto not_f;
58	for (i = hpfs_inode->i_rddir_off; *i; i++) if (*i == pos) goto fnd;
59	goto not_f;
60	fnd:
61	for (j = i + 1; *j; j++) ;
62	*i = *(j - 1);
63	*(j - 1) = NULL;
64	if (j - 1 == hpfs_inode->i_rddir_off) {
65		kfree(hpfs_inode->i_rddir_off);
66		hpfs_inode->i_rddir_off = NULL;
67	}
68	return;
69	not_f:
70	/*pr_warn("position pointer %p->%08x not found\n",
71		  pos, (int)*pos);*/
72	return;
73}
74
75static void for_all_poss(struct inode *inode, void (*f)(loff_t *, loff_t, loff_t),
76			 loff_t p1, loff_t p2)
77{
78	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
79	loff_t **i;
80
81	if (!hpfs_inode->i_rddir_off) return;
82	for (i = hpfs_inode->i_rddir_off; *i; i++) (*f)(*i, p1, p2);
83	return;
84}
85
86static void hpfs_pos_subst(loff_t *p, loff_t f, loff_t t)
87{
88	if (*p == f) *p = t;
89}
90
91/*void hpfs_hpfs_pos_substd(loff_t *p, loff_t f, loff_t t)
92{
93	if ((*p & ~0x3f) == (f & ~0x3f)) *p = (t & ~0x3f) | (*p & 0x3f);
94}*/
95
96static void hpfs_pos_ins(loff_t *p, loff_t d, loff_t c)
97{
98	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
99		int n = (*p & 0x3f) + c;
100		if (n > 0x3f)
101			pr_err("%s(): %08x + %d\n",
102				__func__, (int)*p, (int)c >> 8);
103		else
104			*p = (*p & ~0x3f) | n;
105	}
106}
107
108static void hpfs_pos_del(loff_t *p, loff_t d, loff_t c)
109{
110	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
111		int n = (*p & 0x3f) - c;
112		if (n < 1)
113			pr_err("%s(): %08x - %d\n",
114				__func__, (int)*p, (int)c >> 8);
115		else
116			*p = (*p & ~0x3f) | n;
117	}
118}
119
120static struct hpfs_dirent *dnode_pre_last_de(struct dnode *d)
121{
122	struct hpfs_dirent *de, *de_end, *dee = NULL, *deee = NULL;
123	de_end = dnode_end_de(d);
124	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
125		deee = dee; dee = de;
126	}
127	return deee;
128}
129
130static struct hpfs_dirent *dnode_last_de(struct dnode *d)
131{
132	struct hpfs_dirent *de, *de_end, *dee = NULL;
133	de_end = dnode_end_de(d);
134	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
135		dee = de;
136	}
137	return dee;
138}
139
140static void set_last_pointer(struct super_block *s, struct dnode *d, dnode_secno ptr)
141{
142	struct hpfs_dirent *de;
143	if (!(de = dnode_last_de(d))) {
144		hpfs_error(s, "set_last_pointer: empty dnode %08x", le32_to_cpu(d->self));
145		return;
146	}
147	if (hpfs_sb(s)->sb_chk) {
148		if (de->down) {
149			hpfs_error(s, "set_last_pointer: dnode %08x has already last pointer %08x",
150				le32_to_cpu(d->self), de_down_pointer(de));
151			return;
152		}
153		if (le16_to_cpu(de->length) != 32) {
154			hpfs_error(s, "set_last_pointer: bad last dirent in dnode %08x", le32_to_cpu(d->self));
155			return;
156		}
157	}
158	if (ptr) {
159		le32_add_cpu(&d->first_free, 4);
160		if (le32_to_cpu(d->first_free) > 2048) {
161			hpfs_error(s, "set_last_pointer: too long dnode %08x", le32_to_cpu(d->self));
162			le32_add_cpu(&d->first_free, -4);
163			return;
164		}
165		de->length = cpu_to_le16(36);
166		de->down = 1;
167		*(__le32 *)((char *)de + 32) = cpu_to_le32(ptr);
168	}
169}
170
171/* Add an entry to dnode and don't care if it grows over 2048 bytes */
172
173struct hpfs_dirent *hpfs_add_de(struct super_block *s, struct dnode *d,
174				const unsigned char *name,
175				unsigned namelen, secno down_ptr)
176{
177	struct hpfs_dirent *de;
178	struct hpfs_dirent *de_end = dnode_end_de(d);
179	unsigned d_size = de_size(namelen, down_ptr);
180	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
181		int c = hpfs_compare_names(s, name, namelen, de->name, de->namelen, de->last);
182		if (!c) {
183			hpfs_error(s, "name (%c,%d) already exists in dnode %08x", *name, namelen, le32_to_cpu(d->self));
184			return NULL;
185		}
186		if (c < 0) break;
187	}
188	memmove((char *)de + d_size, de, (char *)de_end - (char *)de);
189	memset(de, 0, d_size);
190	if (down_ptr) {
191		*(__le32 *)((char *)de + d_size - 4) = cpu_to_le32(down_ptr);
192		de->down = 1;
193	}
194	de->length = cpu_to_le16(d_size);
195	de->not_8x3 = hpfs_is_name_long(name, namelen);
196	de->namelen = namelen;
197	memcpy(de->name, name, namelen);
198	le32_add_cpu(&d->first_free, d_size);
199	return de;
200}
201
202/* Delete dirent and don't care about its subtree */
203
204static void hpfs_delete_de(struct super_block *s, struct dnode *d,
205			   struct hpfs_dirent *de)
206{
207	if (de->last) {
208		hpfs_error(s, "attempt to delete last dirent in dnode %08x", le32_to_cpu(d->self));
209		return;
210	}
211	d->first_free = cpu_to_le32(le32_to_cpu(d->first_free) - le16_to_cpu(de->length));
212	memmove(de, de_next_de(de), le32_to_cpu(d->first_free) + (char *)d - (char *)de);
213}
214
215static void fix_up_ptrs(struct super_block *s, struct dnode *d)
216{
217	struct hpfs_dirent *de;
218	struct hpfs_dirent *de_end = dnode_end_de(d);
219	dnode_secno dno = le32_to_cpu(d->self);
220	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de))
221		if (de->down) {
222			struct quad_buffer_head qbh;
223			struct dnode *dd;
224			if ((dd = hpfs_map_dnode(s, de_down_pointer(de), &qbh))) {
225				if (le32_to_cpu(dd->up) != dno || dd->root_dnode) {
226					dd->up = cpu_to_le32(dno);
227					dd->root_dnode = 0;
228					hpfs_mark_4buffers_dirty(&qbh);
229				}
230				hpfs_brelse4(&qbh);
231			}
232		}
233}
234
235/* Add an entry to dnode and do dnode splitting if required */
236
237static int hpfs_add_to_dnode(struct inode *i, dnode_secno dno,
238			     const unsigned char *name, unsigned namelen,
239			     struct hpfs_dirent *new_de, dnode_secno down_ptr)
240{
241	struct quad_buffer_head qbh, qbh1, qbh2;
242	struct dnode *d, *ad, *rd, *nd = NULL;
243	dnode_secno adno, rdno;
244	struct hpfs_dirent *de;
245	struct hpfs_dirent nde;
246	unsigned char *nname;
247	int h;
248	int pos;
249	struct buffer_head *bh;
250	struct fnode *fnode;
251	int c1, c2 = 0;
252	if (!(nname = kmalloc(256, GFP_NOFS))) {
253		pr_err("out of memory, can't add to dnode\n");
254		return 1;
255	}
256	go_up:
257	if (namelen >= 256) {
258		hpfs_error(i->i_sb, "%s(): namelen == %d", __func__, namelen);
259		kfree(nd);
260		kfree(nname);
261		return 1;
262	}
263	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) {
264		kfree(nd);
265		kfree(nname);
266		return 1;
267	}
268	go_up_a:
269	if (hpfs_sb(i->i_sb)->sb_chk)
270		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_to_dnode")) {
271			hpfs_brelse4(&qbh);
272			kfree(nd);
273			kfree(nname);
274			return 1;
275		}
276	if (le32_to_cpu(d->first_free) + de_size(namelen, down_ptr) <= 2048) {
277		loff_t t;
278		copy_de(de=hpfs_add_de(i->i_sb, d, name, namelen, down_ptr), new_de);
279		t = get_pos(d, de);
280		for_all_poss(i, hpfs_pos_ins, t, 1);
281		for_all_poss(i, hpfs_pos_subst, 4, t);
282		for_all_poss(i, hpfs_pos_subst, 5, t + 1);
283		hpfs_mark_4buffers_dirty(&qbh);
284		hpfs_brelse4(&qbh);
285		kfree(nd);
286		kfree(nname);
287		return 0;
288	}
289	if (!nd) if (!(nd = kmalloc(0x924, GFP_NOFS))) {
290		/* 0x924 is a max size of dnode after adding a dirent with
291		   max name length. We alloc this only once. There must
292		   not be any error while splitting dnodes, otherwise the
293		   whole directory, not only file we're adding, would
294		   be lost. */
295		pr_err("out of memory for dnode splitting\n");
296		hpfs_brelse4(&qbh);
297		kfree(nname);
298		return 1;
299	}
300	memcpy(nd, d, le32_to_cpu(d->first_free));
301	copy_de(de = hpfs_add_de(i->i_sb, nd, name, namelen, down_ptr), new_de);
302	for_all_poss(i, hpfs_pos_ins, get_pos(nd, de), 1);
303	h = ((char *)dnode_last_de(nd) - (char *)nd) / 2 + 10;
304	if (!(ad = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &adno, &qbh1))) {
305		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
306		hpfs_brelse4(&qbh);
307		kfree(nd);
308		kfree(nname);
309		return 1;
310	}
311	i->i_size += 2048;
312	i->i_blocks += 4;
313	pos = 1;
314	for (de = dnode_first_de(nd); (char *)de_next_de(de) - (char *)nd < h; de = de_next_de(de)) {
315		copy_de(hpfs_add_de(i->i_sb, ad, de->name, de->namelen, de->down ? de_down_pointer(de) : 0), de);
316		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, ((loff_t)adno << 4) | pos);
317		pos++;
318	}
319	copy_de(new_de = &nde, de);
320	memcpy(nname, de->name, de->namelen);
321	name = nname;
322	namelen = de->namelen;
323	for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, 4);
324	down_ptr = adno;
325	set_last_pointer(i->i_sb, ad, de->down ? de_down_pointer(de) : 0);
326	de = de_next_de(de);
327	memmove((char *)nd + 20, de, le32_to_cpu(nd->first_free) + (char *)nd - (char *)de);
328	le32_add_cpu(&nd->first_free, -((char *)de - (char *)nd - 20));
329	memcpy(d, nd, le32_to_cpu(nd->first_free));
330	for_all_poss(i, hpfs_pos_del, (loff_t)dno << 4, pos);
331	fix_up_ptrs(i->i_sb, ad);
332	if (!d->root_dnode) {
333		ad->up = d->up;
334		dno = le32_to_cpu(ad->up);
335		hpfs_mark_4buffers_dirty(&qbh);
336		hpfs_brelse4(&qbh);
337		hpfs_mark_4buffers_dirty(&qbh1);
338		hpfs_brelse4(&qbh1);
339		goto go_up;
340	}
341	if (!(rd = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &rdno, &qbh2))) {
342		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
343		hpfs_brelse4(&qbh);
344		hpfs_brelse4(&qbh1);
345		kfree(nd);
346		kfree(nname);
347		return 1;
348	}
349	i->i_size += 2048;
350	i->i_blocks += 4;
351	rd->root_dnode = 1;
352	rd->up = d->up;
353	if (!(fnode = hpfs_map_fnode(i->i_sb, le32_to_cpu(d->up), &bh))) {
354		hpfs_free_dnode(i->i_sb, rdno);
355		hpfs_brelse4(&qbh);
356		hpfs_brelse4(&qbh1);
357		hpfs_brelse4(&qbh2);
358		kfree(nd);
359		kfree(nname);
360		return 1;
361	}
362	fnode->u.external[0].disk_secno = cpu_to_le32(rdno);
363	mark_buffer_dirty(bh);
364	brelse(bh);
365	hpfs_i(i)->i_dno = rdno;
366	d->up = ad->up = cpu_to_le32(rdno);
367	d->root_dnode = ad->root_dnode = 0;
368	hpfs_mark_4buffers_dirty(&qbh);
369	hpfs_brelse4(&qbh);
370	hpfs_mark_4buffers_dirty(&qbh1);
371	hpfs_brelse4(&qbh1);
372	qbh = qbh2;
373	set_last_pointer(i->i_sb, rd, dno);
374	dno = rdno;
375	d = rd;
376	goto go_up_a;
377}
378
379/*
380 * Add an entry to directory btree.
381 * I hate such crazy directory structure.
382 * It's easy to read but terrible to write.
383 * I wrote this directory code 4 times.
384 * I hope, now it's finally bug-free.
385 */
386
387int hpfs_add_dirent(struct inode *i,
388		    const unsigned char *name, unsigned namelen,
389		    struct hpfs_dirent *new_de)
390{
391	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
392	struct dnode *d;
393	struct hpfs_dirent *de, *de_end;
394	struct quad_buffer_head qbh;
395	dnode_secno dno;
396	int c;
397	int c1, c2 = 0;
398	dno = hpfs_inode->i_dno;
399	down:
400	if (hpfs_sb(i->i_sb)->sb_chk)
401		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_dirent")) return 1;
402	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 1;
403	de_end = dnode_end_de(d);
404	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
405		if (!(c = hpfs_compare_names(i->i_sb, name, namelen, de->name, de->namelen, de->last))) {
406			hpfs_brelse4(&qbh);
407			return -1;
408		}
409		if (c < 0) {
410			if (de->down) {
411				dno = de_down_pointer(de);
412				hpfs_brelse4(&qbh);
413				goto down;
414			}
415			break;
416		}
417	}
418	hpfs_brelse4(&qbh);
419	if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_ADD)) {
420		c = 1;
421		goto ret;
422	}
423	c = hpfs_add_to_dnode(i, dno, name, namelen, new_de, 0);
424	ret:
425	return c;
426}
427
428/*
429 * Find dirent with higher name in 'from' subtree and move it to 'to' dnode.
430 * Return the dnode we moved from (to be checked later if it's empty)
431 */
432
433static secno move_to_top(struct inode *i, dnode_secno from, dnode_secno to)
434{
435	dnode_secno dno, ddno;
436	dnode_secno chk_up = to;
437	struct dnode *dnode;
438	struct quad_buffer_head qbh;
439	struct hpfs_dirent *de, *nde;
440	int a;
441	loff_t t;
442	int c1, c2 = 0;
443	dno = from;
444	while (1) {
445		if (hpfs_sb(i->i_sb)->sb_chk)
446			if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "move_to_top"))
447				return 0;
448		if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 0;
449		if (hpfs_sb(i->i_sb)->sb_chk) {
450			if (le32_to_cpu(dnode->up) != chk_up) {
451				hpfs_error(i->i_sb, "move_to_top: up pointer from %08x should be %08x, is %08x",
452					dno, chk_up, le32_to_cpu(dnode->up));
453				hpfs_brelse4(&qbh);
454				return 0;
455			}
456			chk_up = dno;
457		}
458		if (!(de = dnode_last_de(dnode))) {
459			hpfs_error(i->i_sb, "move_to_top: dnode %08x has no last de", dno);
460			hpfs_brelse4(&qbh);
461			return 0;
462		}
463		if (!de->down) break;
464		dno = de_down_pointer(de);
465		hpfs_brelse4(&qbh);
466	}
467	while (!(de = dnode_pre_last_de(dnode))) {
468		dnode_secno up = le32_to_cpu(dnode->up);
469		hpfs_brelse4(&qbh);
470		hpfs_free_dnode(i->i_sb, dno);
471		i->i_size -= 2048;
472		i->i_blocks -= 4;
473		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, 5);
474		if (up == to) return to;
475		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return 0;
476		if (dnode->root_dnode) {
477			hpfs_error(i->i_sb, "move_to_top: got to root_dnode while moving from %08x to %08x", from, to);
478			hpfs_brelse4(&qbh);
479			return 0;
480		}
481		de = dnode_last_de(dnode);
482		if (!de || !de->down) {
483			hpfs_error(i->i_sb, "move_to_top: dnode %08x doesn't point down to %08x", up, dno);
484			hpfs_brelse4(&qbh);
485			return 0;
486		}
487		le32_add_cpu(&dnode->first_free, -4);
488		le16_add_cpu(&de->length, -4);
489		de->down = 0;
490		hpfs_mark_4buffers_dirty(&qbh);
491		dno = up;
492	}
493	t = get_pos(dnode, de);
494	for_all_poss(i, hpfs_pos_subst, t, 4);
495	for_all_poss(i, hpfs_pos_subst, t + 1, 5);
496	if (!(nde = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
497		hpfs_error(i->i_sb, "out of memory for dirent - directory will be corrupted");
498		hpfs_brelse4(&qbh);
499		return 0;
500	}
501	memcpy(nde, de, le16_to_cpu(de->length));
502	ddno = de->down ? de_down_pointer(de) : 0;
503	hpfs_delete_de(i->i_sb, dnode, de);
504	set_last_pointer(i->i_sb, dnode, ddno);
505	hpfs_mark_4buffers_dirty(&qbh);
506	hpfs_brelse4(&qbh);
507	a = hpfs_add_to_dnode(i, to, nde->name, nde->namelen, nde, from);
508	kfree(nde);
509	if (a) return 0;
510	return dno;
511}
512
513/*
514 * Check if a dnode is empty and delete it from the tree
515 * (chkdsk doesn't like empty dnodes)
516 */
517
518static void delete_empty_dnode(struct inode *i, dnode_secno dno)
519{
520	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
521	struct quad_buffer_head qbh;
522	struct dnode *dnode;
523	dnode_secno down, up, ndown;
524	int p;
525	struct hpfs_dirent *de;
526	int c1, c2 = 0;
527	try_it_again:
528	if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "delete_empty_dnode")) return;
529	if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return;
530	if (le32_to_cpu(dnode->first_free) > 56) goto end;
531	if (le32_to_cpu(dnode->first_free) == 52 || le32_to_cpu(dnode->first_free) == 56) {
532		struct hpfs_dirent *de_end;
533		int root = dnode->root_dnode;
534		up = le32_to_cpu(dnode->up);
535		de = dnode_first_de(dnode);
536		down = de->down ? de_down_pointer(de) : 0;
537		if (hpfs_sb(i->i_sb)->sb_chk) if (root && !down) {
538			hpfs_error(i->i_sb, "delete_empty_dnode: root dnode %08x is empty", dno);
539			goto end;
540		}
541		hpfs_brelse4(&qbh);
542		hpfs_free_dnode(i->i_sb, dno);
543		i->i_size -= 2048;
544		i->i_blocks -= 4;
545		if (root) {
546			struct fnode *fnode;
547			struct buffer_head *bh;
548			struct dnode *d1;
549			struct quad_buffer_head qbh1;
550			if (hpfs_sb(i->i_sb)->sb_chk)
551				if (up != i->i_ino) {
552					hpfs_error(i->i_sb,
553						   "bad pointer to fnode, dnode %08x, pointing to %08x, should be %08lx",
554						   dno, up,
555						   (unsigned long)i->i_ino);
556					return;
557				}
558			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
559				d1->up = cpu_to_le32(up);
560				d1->root_dnode = 1;
561				hpfs_mark_4buffers_dirty(&qbh1);
562				hpfs_brelse4(&qbh1);
563			}
564			if ((fnode = hpfs_map_fnode(i->i_sb, up, &bh))) {
565				fnode->u.external[0].disk_secno = cpu_to_le32(down);
566				mark_buffer_dirty(bh);
567				brelse(bh);
568			}
569			hpfs_inode->i_dno = down;
570			for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, (loff_t) 12);
571			return;
572		}
573		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return;
574		p = 1;
575		de_end = dnode_end_de(dnode);
576		for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de), p++)
577			if (de->down) if (de_down_pointer(de) == dno) goto fnd;
578		hpfs_error(i->i_sb, "delete_empty_dnode: pointer to dnode %08x not found in dnode %08x", dno, up);
579		goto end;
580		fnd:
581		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, ((loff_t)up << 4) | p);
582		if (!down) {
583			de->down = 0;
584			le16_add_cpu(&de->length, -4);
585			le32_add_cpu(&dnode->first_free, -4);
586			memmove(de_next_de(de), (char *)de_next_de(de) + 4,
587				(char *)dnode + le32_to_cpu(dnode->first_free) - (char *)de_next_de(de));
588		} else {
589			struct dnode *d1;
590			struct quad_buffer_head qbh1;
591			*(dnode_secno *) ((void *) de + le16_to_cpu(de->length) - 4) = down;
592			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
593				d1->up = cpu_to_le32(up);
594				hpfs_mark_4buffers_dirty(&qbh1);
595				hpfs_brelse4(&qbh1);
596			}
597		}
598	} else {
599		hpfs_error(i->i_sb, "delete_empty_dnode: dnode %08x, first_free == %03x", dno, le32_to_cpu(dnode->first_free));
600		goto end;
601	}
602
603	if (!de->last) {
604		struct hpfs_dirent *de_next = de_next_de(de);
605		struct hpfs_dirent *de_cp;
606		struct dnode *d1;
607		struct quad_buffer_head qbh1;
608		if (!de_next->down) goto endm;
609		ndown = de_down_pointer(de_next);
610		if (!(de_cp = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
611			pr_err("out of memory for dtree balancing\n");
612			goto endm;
613		}
614		memcpy(de_cp, de, le16_to_cpu(de->length));
615		hpfs_delete_de(i->i_sb, dnode, de);
616		hpfs_mark_4buffers_dirty(&qbh);
617		hpfs_brelse4(&qbh);
618		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, 4);
619		for_all_poss(i, hpfs_pos_del, ((loff_t)up << 4) | p, 1);
620		if (de_cp->down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de_cp), &qbh1))) {
621			d1->up = cpu_to_le32(ndown);
622			hpfs_mark_4buffers_dirty(&qbh1);
623			hpfs_brelse4(&qbh1);
624		}
625		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, de_cp->down ? de_down_pointer(de_cp) : 0);
626		/*pr_info("UP-TO-DNODE: %08x (ndown = %08x, down = %08x, dno = %08x)\n",
627		  up, ndown, down, dno);*/
628		dno = up;
629		kfree(de_cp);
630		goto try_it_again;
631	} else {
632		struct hpfs_dirent *de_prev = dnode_pre_last_de(dnode);
633		struct hpfs_dirent *de_cp;
634		struct dnode *d1;
635		struct quad_buffer_head qbh1;
636		dnode_secno dlp;
637		if (!de_prev) {
638			hpfs_error(i->i_sb, "delete_empty_dnode: empty dnode %08x", up);
639			hpfs_mark_4buffers_dirty(&qbh);
640			hpfs_brelse4(&qbh);
641			dno = up;
642			goto try_it_again;
643		}
644		if (!de_prev->down) goto endm;
645		ndown = de_down_pointer(de_prev);
646		if ((d1 = hpfs_map_dnode(i->i_sb, ndown, &qbh1))) {
647			struct hpfs_dirent *del = dnode_last_de(d1);
648			dlp = del->down ? de_down_pointer(del) : 0;
649			if (!dlp && down) {
650				if (le32_to_cpu(d1->first_free) > 2044) {
651					if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
652						pr_err("unbalanced dnode tree, see hpfs.txt 4 more info\n");
653						pr_err("terminating balancing operation\n");
654					}
655					hpfs_brelse4(&qbh1);
656					goto endm;
657				}
658				if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
659					pr_err("unbalanced dnode tree, see hpfs.txt 4 more info\n");
660					pr_err("goin'on\n");
661				}
662				le16_add_cpu(&del->length, 4);
663				del->down = 1;
664				le32_add_cpu(&d1->first_free, 4);
665			}
666			if (dlp && !down) {
667				le16_add_cpu(&del->length, -4);
668				del->down = 0;
669				le32_add_cpu(&d1->first_free, -4);
670			} else if (down)
671				*(__le32 *) ((void *) del + le16_to_cpu(del->length) - 4) = cpu_to_le32(down);
672		} else goto endm;
673		if (!(de_cp = kmalloc(le16_to_cpu(de_prev->length), GFP_NOFS))) {
674			pr_err("out of memory for dtree balancing\n");
675			hpfs_brelse4(&qbh1);
676			goto endm;
677		}
678		hpfs_mark_4buffers_dirty(&qbh1);
679		hpfs_brelse4(&qbh1);
680		memcpy(de_cp, de_prev, le16_to_cpu(de_prev->length));
681		hpfs_delete_de(i->i_sb, dnode, de_prev);
682		if (!de_prev->down) {
683			le16_add_cpu(&de_prev->length, 4);
684			de_prev->down = 1;
685			le32_add_cpu(&dnode->first_free, 4);
686		}
687		*(__le32 *) ((void *) de_prev + le16_to_cpu(de_prev->length) - 4) = cpu_to_le32(ndown);
688		hpfs_mark_4buffers_dirty(&qbh);
689		hpfs_brelse4(&qbh);
690		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | (p - 1), 4);
691		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, ((loff_t)up << 4) | (p - 1));
692		if (down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de), &qbh1))) {
693			d1->up = cpu_to_le32(ndown);
694			hpfs_mark_4buffers_dirty(&qbh1);
695			hpfs_brelse4(&qbh1);
696		}
697		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, dlp);
698		dno = up;
699		kfree(de_cp);
700		goto try_it_again;
701	}
702	endm:
703	hpfs_mark_4buffers_dirty(&qbh);
704	end:
705	hpfs_brelse4(&qbh);
706}
707
708
709/* Delete dirent from directory */
710
711int hpfs_remove_dirent(struct inode *i, dnode_secno dno, struct hpfs_dirent *de,
712		       struct quad_buffer_head *qbh, int depth)
713{
714	struct dnode *dnode = qbh->data;
715	dnode_secno down = 0;
716	loff_t t;
717	if (de->first || de->last) {
718		hpfs_error(i->i_sb, "hpfs_remove_dirent: attempt to delete first or last dirent in dnode %08x", dno);
719		hpfs_brelse4(qbh);
720		return 1;
721	}
722	if (de->down) down = de_down_pointer(de);
723	if (depth && (de->down || (de == dnode_first_de(dnode) && de_next_de(de)->last))) {
724		if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_DEL)) {
725			hpfs_brelse4(qbh);
726			return 2;
727		}
728	}
729	for_all_poss(i, hpfs_pos_del, (t = get_pos(dnode, de)) + 1, 1);
730	hpfs_delete_de(i->i_sb, dnode, de);
731	hpfs_mark_4buffers_dirty(qbh);
732	hpfs_brelse4(qbh);
733	if (down) {
734		dnode_secno a = move_to_top(i, down, dno);
735		for_all_poss(i, hpfs_pos_subst, 5, t);
736		if (a) delete_empty_dnode(i, a);
737		return !a;
738	}
739	delete_empty_dnode(i, dno);
740	return 0;
741}
742
743void hpfs_count_dnodes(struct super_block *s, dnode_secno dno, int *n_dnodes,
744		       int *n_subdirs, int *n_items)
745{
746	struct dnode *dnode;
747	struct quad_buffer_head qbh;
748	struct hpfs_dirent *de;
749	dnode_secno ptr, odno = 0;
750	int c1, c2 = 0;
751	int d1, d2 = 0;
752	go_down:
753	if (n_dnodes) (*n_dnodes)++;
754	if (hpfs_sb(s)->sb_chk)
755		if (hpfs_stop_cycles(s, dno, &c1, &c2, "hpfs_count_dnodes #1")) return;
756	ptr = 0;
757	go_up:
758	if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
759	if (hpfs_sb(s)->sb_chk) if (odno && odno != -1 && le32_to_cpu(dnode->up) != odno)
760		hpfs_error(s, "hpfs_count_dnodes: bad up pointer; dnode %08x, down %08x points to %08x", odno, dno, le32_to_cpu(dnode->up));
761	de = dnode_first_de(dnode);
762	if (ptr) while(1) {
763		if (de->down) if (de_down_pointer(de) == ptr) goto process_de;
764		if (de->last) {
765			hpfs_brelse4(&qbh);
766			hpfs_error(s, "hpfs_count_dnodes: pointer to dnode %08x not found in dnode %08x, got here from %08x",
767				ptr, dno, odno);
768			return;
769		}
770		de = de_next_de(de);
771	}
772	next_de:
773	if (de->down) {
774		odno = dno;
775		dno = de_down_pointer(de);
776		hpfs_brelse4(&qbh);
777		goto go_down;
778	}
779	process_de:
780	if (!de->first && !de->last && de->directory && n_subdirs) (*n_subdirs)++;
781	if (!de->first && !de->last && n_items) (*n_items)++;
782	if ((de = de_next_de(de)) < dnode_end_de(dnode)) goto next_de;
783	ptr = dno;
784	dno = le32_to_cpu(dnode->up);
785	if (dnode->root_dnode) {
786		hpfs_brelse4(&qbh);
787		return;
788	}
789	hpfs_brelse4(&qbh);
790	if (hpfs_sb(s)->sb_chk)
791		if (hpfs_stop_cycles(s, ptr, &d1, &d2, "hpfs_count_dnodes #2")) return;
792	odno = -1;
793	goto go_up;
794}
795
796static struct hpfs_dirent *map_nth_dirent(struct super_block *s, dnode_secno dno, int n,
797					  struct quad_buffer_head *qbh, struct dnode **dn)
798{
799	int i;
800	struct hpfs_dirent *de, *de_end;
801	struct dnode *dnode;
802	dnode = hpfs_map_dnode(s, dno, qbh);
803	if (!dnode) return NULL;
804	if (dn) *dn=dnode;
805	de = dnode_first_de(dnode);
806	de_end = dnode_end_de(dnode);
807	for (i = 1; de < de_end; i++, de = de_next_de(de)) {
808		if (i == n) {
809			return de;
810		}
811		if (de->last) break;
812	}
813	hpfs_brelse4(qbh);
814	hpfs_error(s, "map_nth_dirent: n too high; dnode = %08x, requested %08x", dno, n);
815	return NULL;
816}
817
818dnode_secno hpfs_de_as_down_as_possible(struct super_block *s, dnode_secno dno)
819{
820	struct quad_buffer_head qbh;
821	dnode_secno d = dno;
822	dnode_secno up = 0;
823	struct hpfs_dirent *de;
824	int c1, c2 = 0;
825
826	again:
827	if (hpfs_sb(s)->sb_chk)
828		if (hpfs_stop_cycles(s, d, &c1, &c2, "hpfs_de_as_down_as_possible"))
829			return d;
830	if (!(de = map_nth_dirent(s, d, 1, &qbh, NULL))) return dno;
831	if (hpfs_sb(s)->sb_chk)
832		if (up && le32_to_cpu(((struct dnode *)qbh.data)->up) != up)
833			hpfs_error(s, "hpfs_de_as_down_as_possible: bad up pointer; dnode %08x, down %08x points to %08x", up, d, le32_to_cpu(((struct dnode *)qbh.data)->up));
834	if (!de->down) {
835		hpfs_brelse4(&qbh);
836		return d;
837	}
838	up = d;
839	d = de_down_pointer(de);
840	hpfs_brelse4(&qbh);
841	goto again;
842}
843
844struct hpfs_dirent *map_pos_dirent(struct inode *inode, loff_t *posp,
845				   struct quad_buffer_head *qbh)
846{
847	loff_t pos;
848	unsigned c;
849	dnode_secno dno;
850	struct hpfs_dirent *de, *d;
851	struct hpfs_dirent *up_de;
852	struct hpfs_dirent *end_up_de;
853	struct dnode *dnode;
854	struct dnode *up_dnode;
855	struct quad_buffer_head qbh0;
856
857	pos = *posp;
858	dno = pos >> 6 << 2;
859	pos &= 077;
860	if (!(de = map_nth_dirent(inode->i_sb, dno, pos, qbh, &dnode)))
861		goto bail;
862
863	/* Going to the next dirent */
864	if ((d = de_next_de(de)) < dnode_end_de(dnode)) {
865		if (!(++*posp & 077)) {
866			hpfs_error(inode->i_sb,
867				"map_pos_dirent: pos crossed dnode boundary; pos = %08llx",
868				(unsigned long long)*posp);
869			goto bail;
870		}
871		/* We're going down the tree */
872		if (d->down) {
873			*posp = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, de_down_pointer(d)) << 4) + 1;
874		}
875
876		return de;
877	}
878
879	/* Going up */
880	if (dnode->root_dnode) goto bail;
881
882	if (!(up_dnode = hpfs_map_dnode(inode->i_sb, le32_to_cpu(dnode->up), &qbh0)))
883		goto bail;
884
885	end_up_de = dnode_end_de(up_dnode);
886	c = 0;
887	for (up_de = dnode_first_de(up_dnode); up_de < end_up_de;
888	     up_de = de_next_de(up_de)) {
889		if (!(++c & 077)) hpfs_error(inode->i_sb,
890			"map_pos_dirent: pos crossed dnode boundary; dnode = %08x", le32_to_cpu(dnode->up));
891		if (up_de->down && de_down_pointer(up_de) == dno) {
892			*posp = ((loff_t) le32_to_cpu(dnode->up) << 4) + c;
893			hpfs_brelse4(&qbh0);
894			return de;
895		}
896	}
897
898	hpfs_error(inode->i_sb, "map_pos_dirent: pointer to dnode %08x not found in parent dnode %08x",
899		dno, le32_to_cpu(dnode->up));
900	hpfs_brelse4(&qbh0);
901
902	bail:
903	*posp = 12;
904	return de;
905}
906
907/* Find a dirent in tree */
908
909struct hpfs_dirent *map_dirent(struct inode *inode, dnode_secno dno,
910			       const unsigned char *name, unsigned len,
911			       dnode_secno *dd, struct quad_buffer_head *qbh)
912{
913	struct dnode *dnode;
914	struct hpfs_dirent *de;
915	struct hpfs_dirent *de_end;
916	int c1, c2 = 0;
917
918	if (!S_ISDIR(inode->i_mode)) hpfs_error(inode->i_sb, "map_dirent: not a directory\n");
919	again:
920	if (hpfs_sb(inode->i_sb)->sb_chk)
921		if (hpfs_stop_cycles(inode->i_sb, dno, &c1, &c2, "map_dirent")) return NULL;
922	if (!(dnode = hpfs_map_dnode(inode->i_sb, dno, qbh))) return NULL;
923
924	de_end = dnode_end_de(dnode);
925	for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de)) {
926		int t = hpfs_compare_names(inode->i_sb, name, len, de->name, de->namelen, de->last);
927		if (!t) {
928			if (dd) *dd = dno;
929			return de;
930		}
931		if (t < 0) {
932			if (de->down) {
933				dno = de_down_pointer(de);
934				hpfs_brelse4(qbh);
935				goto again;
936			}
937		break;
938		}
939	}
940	hpfs_brelse4(qbh);
941	return NULL;
942}
943
944/*
945 * Remove empty directory. In normal cases it is only one dnode with two
946 * entries, but we must handle also such obscure cases when it's a tree
947 * of empty dnodes.
948 */
949
950void hpfs_remove_dtree(struct super_block *s, dnode_secno dno)
951{
952	struct quad_buffer_head qbh;
953	struct dnode *dnode;
954	struct hpfs_dirent *de;
955	dnode_secno d1, d2, rdno = dno;
956	while (1) {
957		if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
958		de = dnode_first_de(dnode);
959		if (de->last) {
960			if (de->down) d1 = de_down_pointer(de);
961			else goto error;
962			hpfs_brelse4(&qbh);
963			hpfs_free_dnode(s, dno);
964			dno = d1;
965		} else break;
966	}
967	if (!de->first) goto error;
968	d1 = de->down ? de_down_pointer(de) : 0;
969	de = de_next_de(de);
970	if (!de->last) goto error;
971	d2 = de->down ? de_down_pointer(de) : 0;
972	hpfs_brelse4(&qbh);
973	hpfs_free_dnode(s, dno);
974	do {
975		while (d1) {
976			if (!(dnode = hpfs_map_dnode(s, dno = d1, &qbh))) return;
977			de = dnode_first_de(dnode);
978			if (!de->last) goto error;
979			d1 = de->down ? de_down_pointer(de) : 0;
980			hpfs_brelse4(&qbh);
981			hpfs_free_dnode(s, dno);
982		}
983		d1 = d2;
984		d2 = 0;
985	} while (d1);
986	return;
987	error:
988	hpfs_brelse4(&qbh);
989	hpfs_free_dnode(s, dno);
990	hpfs_error(s, "directory %08x is corrupted or not empty", rdno);
991}
992
993/*
994 * Find dirent for specified fnode. Use truncated 15-char name in fnode as
995 * a help for searching.
996 */
997
998struct hpfs_dirent *map_fnode_dirent(struct super_block *s, fnode_secno fno,
999				     struct fnode *f, struct quad_buffer_head *qbh)
1000{
1001	unsigned char *name1;
1002	unsigned char *name2;
1003	int name1len, name2len;
1004	struct dnode *d;
1005	dnode_secno dno, downd;
1006	struct fnode *upf;
1007	struct buffer_head *bh;
1008	struct hpfs_dirent *de, *de_end;
1009	int c;
1010	int c1, c2 = 0;
1011	int d1, d2 = 0;
1012	name1 = f->name;
1013	if (!(name2 = kmalloc(256, GFP_NOFS))) {
1014		pr_err("out of memory, can't map dirent\n");
1015		return NULL;
1016	}
1017	if (f->len <= 15)
1018		memcpy(name2, name1, name1len = name2len = f->len);
1019	else {
1020		memcpy(name2, name1, 15);
1021		memset(name2 + 15, 0xff, 256 - 15);
1022		/*name2[15] = 0xff;*/
1023		name1len = 15; name2len = 256;
1024	}
1025	if (!(upf = hpfs_map_fnode(s, le32_to_cpu(f->up), &bh))) {
1026		kfree(name2);
1027		return NULL;
1028	}
1029	if (!fnode_is_dir(upf)) {
1030		brelse(bh);
1031		hpfs_error(s, "fnode %08x has non-directory parent %08x", fno, le32_to_cpu(f->up));
1032		kfree(name2);
1033		return NULL;
1034	}
1035	dno = le32_to_cpu(upf->u.external[0].disk_secno);
1036	brelse(bh);
1037	go_down:
1038	downd = 0;
1039	go_up:
1040	if (!(d = hpfs_map_dnode(s, dno, qbh))) {
1041		kfree(name2);
1042		return NULL;
1043	}
1044	de_end = dnode_end_de(d);
1045	de = dnode_first_de(d);
1046	if (downd) {
1047		while (de < de_end) {
1048			if (de->down) if (de_down_pointer(de) == downd) goto f;
1049			de = de_next_de(de);
1050		}
1051		hpfs_error(s, "pointer to dnode %08x not found in dnode %08x", downd, dno);
1052		hpfs_brelse4(qbh);
1053		kfree(name2);
1054		return NULL;
1055	}
1056	next_de:
1057	if (le32_to_cpu(de->fnode) == fno) {
1058		kfree(name2);
1059		return de;
1060	}
1061	c = hpfs_compare_names(s, name1, name1len, de->name, de->namelen, de->last);
1062	if (c < 0 && de->down) {
1063		dno = de_down_pointer(de);
1064		hpfs_brelse4(qbh);
1065		if (hpfs_sb(s)->sb_chk)
1066			if (hpfs_stop_cycles(s, dno, &c1, &c2, "map_fnode_dirent #1")) {
1067				kfree(name2);
1068				return NULL;
1069		}
1070		goto go_down;
1071	}
1072	f:
1073	if (le32_to_cpu(de->fnode) == fno) {
1074		kfree(name2);
1075		return de;
1076	}
1077	c = hpfs_compare_names(s, name2, name2len, de->name, de->namelen, de->last);
1078	if (c < 0 && !de->last) goto not_found;
1079	if ((de = de_next_de(de)) < de_end) goto next_de;
1080	if (d->root_dnode) goto not_found;
1081	downd = dno;
1082	dno = le32_to_cpu(d->up);
1083	hpfs_brelse4(qbh);
1084	if (hpfs_sb(s)->sb_chk)
1085		if (hpfs_stop_cycles(s, downd, &d1, &d2, "map_fnode_dirent #2")) {
1086			kfree(name2);
1087			return NULL;
1088		}
1089	goto go_up;
1090	not_found:
1091	hpfs_brelse4(qbh);
1092	hpfs_error(s, "dirent for fnode %08x not found", fno);
1093	kfree(name2);
1094	return NULL;
1095}
1096