xref: /linux/fs/hpfs/dnode.c (revision 861e10be08c69808065d755d3e3cab5d520a2d32)
1 /*
2  *  linux/fs/hpfs/dnode.c
3  *
4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5  *
6  *  handling directory dnode tree - adding, deleteing & searching for dirents
7  */
8 
9 #include "hpfs_fn.h"
10 
11 static loff_t get_pos(struct dnode *d, struct hpfs_dirent *fde)
12 {
13 	struct hpfs_dirent *de;
14 	struct hpfs_dirent *de_end = dnode_end_de(d);
15 	int i = 1;
16 	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
17 		if (de == fde) return ((loff_t) le32_to_cpu(d->self) << 4) | (loff_t)i;
18 		i++;
19 	}
20 	printk("HPFS: get_pos: not_found\n");
21 	return ((loff_t)le32_to_cpu(d->self) << 4) | (loff_t)1;
22 }
23 
24 void hpfs_add_pos(struct inode *inode, loff_t *pos)
25 {
26 	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
27 	int i = 0;
28 	loff_t **ppos;
29 
30 	if (hpfs_inode->i_rddir_off)
31 		for (; hpfs_inode->i_rddir_off[i]; i++)
32 			if (hpfs_inode->i_rddir_off[i] == pos) return;
33 	if (!(i&0x0f)) {
34 		if (!(ppos = kmalloc((i+0x11) * sizeof(loff_t*), GFP_NOFS))) {
35 			printk("HPFS: out of memory for position list\n");
36 			return;
37 		}
38 		if (hpfs_inode->i_rddir_off) {
39 			memcpy(ppos, hpfs_inode->i_rddir_off, i * sizeof(loff_t));
40 			kfree(hpfs_inode->i_rddir_off);
41 		}
42 		hpfs_inode->i_rddir_off = ppos;
43 	}
44 	hpfs_inode->i_rddir_off[i] = pos;
45 	hpfs_inode->i_rddir_off[i + 1] = NULL;
46 }
47 
48 void hpfs_del_pos(struct inode *inode, loff_t *pos)
49 {
50 	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
51 	loff_t **i, **j;
52 
53 	if (!hpfs_inode->i_rddir_off) goto not_f;
54 	for (i = hpfs_inode->i_rddir_off; *i; i++) if (*i == pos) goto fnd;
55 	goto not_f;
56 	fnd:
57 	for (j = i + 1; *j; j++) ;
58 	*i = *(j - 1);
59 	*(j - 1) = NULL;
60 	if (j - 1 == hpfs_inode->i_rddir_off) {
61 		kfree(hpfs_inode->i_rddir_off);
62 		hpfs_inode->i_rddir_off = NULL;
63 	}
64 	return;
65 	not_f:
66 	/*printk("HPFS: warning: position pointer %p->%08x not found\n", pos, (int)*pos);*/
67 	return;
68 }
69 
70 static void for_all_poss(struct inode *inode, void (*f)(loff_t *, loff_t, loff_t),
71 			 loff_t p1, loff_t p2)
72 {
73 	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
74 	loff_t **i;
75 
76 	if (!hpfs_inode->i_rddir_off) return;
77 	for (i = hpfs_inode->i_rddir_off; *i; i++) (*f)(*i, p1, p2);
78 	return;
79 }
80 
81 static void hpfs_pos_subst(loff_t *p, loff_t f, loff_t t)
82 {
83 	if (*p == f) *p = t;
84 }
85 
86 /*void hpfs_hpfs_pos_substd(loff_t *p, loff_t f, loff_t t)
87 {
88 	if ((*p & ~0x3f) == (f & ~0x3f)) *p = (t & ~0x3f) | (*p & 0x3f);
89 }*/
90 
91 static void hpfs_pos_ins(loff_t *p, loff_t d, loff_t c)
92 {
93 	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
94 		int n = (*p & 0x3f) + c;
95 		if (n > 0x3f) printk("HPFS: hpfs_pos_ins: %08x + %d\n", (int)*p, (int)c >> 8);
96 		else *p = (*p & ~0x3f) | n;
97 	}
98 }
99 
100 static void hpfs_pos_del(loff_t *p, loff_t d, loff_t c)
101 {
102 	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
103 		int n = (*p & 0x3f) - c;
104 		if (n < 1) printk("HPFS: hpfs_pos_ins: %08x - %d\n", (int)*p, (int)c >> 8);
105 		else *p = (*p & ~0x3f) | n;
106 	}
107 }
108 
109 static struct hpfs_dirent *dnode_pre_last_de(struct dnode *d)
110 {
111 	struct hpfs_dirent *de, *de_end, *dee = NULL, *deee = NULL;
112 	de_end = dnode_end_de(d);
113 	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
114 		deee = dee; dee = de;
115 	}
116 	return deee;
117 }
118 
119 static struct hpfs_dirent *dnode_last_de(struct dnode *d)
120 {
121 	struct hpfs_dirent *de, *de_end, *dee = NULL;
122 	de_end = dnode_end_de(d);
123 	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
124 		dee = de;
125 	}
126 	return dee;
127 }
128 
129 static void set_last_pointer(struct super_block *s, struct dnode *d, dnode_secno ptr)
130 {
131 	struct hpfs_dirent *de;
132 	if (!(de = dnode_last_de(d))) {
133 		hpfs_error(s, "set_last_pointer: empty dnode %08x", le32_to_cpu(d->self));
134 		return;
135 	}
136 	if (hpfs_sb(s)->sb_chk) {
137 		if (de->down) {
138 			hpfs_error(s, "set_last_pointer: dnode %08x has already last pointer %08x",
139 				le32_to_cpu(d->self), de_down_pointer(de));
140 			return;
141 		}
142 		if (le16_to_cpu(de->length) != 32) {
143 			hpfs_error(s, "set_last_pointer: bad last dirent in dnode %08x", le32_to_cpu(d->self));
144 			return;
145 		}
146 	}
147 	if (ptr) {
148 		le32_add_cpu(&d->first_free, 4);
149 		if (le32_to_cpu(d->first_free) > 2048) {
150 			hpfs_error(s, "set_last_pointer: too long dnode %08x", le32_to_cpu(d->self));
151 			le32_add_cpu(&d->first_free, -4);
152 			return;
153 		}
154 		de->length = cpu_to_le16(36);
155 		de->down = 1;
156 		*(__le32 *)((char *)de + 32) = cpu_to_le32(ptr);
157 	}
158 }
159 
160 /* Add an entry to dnode and don't care if it grows over 2048 bytes */
161 
162 struct hpfs_dirent *hpfs_add_de(struct super_block *s, struct dnode *d,
163 				const unsigned char *name,
164 				unsigned namelen, secno down_ptr)
165 {
166 	struct hpfs_dirent *de;
167 	struct hpfs_dirent *de_end = dnode_end_de(d);
168 	unsigned d_size = de_size(namelen, down_ptr);
169 	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
170 		int c = hpfs_compare_names(s, name, namelen, de->name, de->namelen, de->last);
171 		if (!c) {
172 			hpfs_error(s, "name (%c,%d) already exists in dnode %08x", *name, namelen, le32_to_cpu(d->self));
173 			return NULL;
174 		}
175 		if (c < 0) break;
176 	}
177 	memmove((char *)de + d_size, de, (char *)de_end - (char *)de);
178 	memset(de, 0, d_size);
179 	if (down_ptr) {
180 		*(__le32 *)((char *)de + d_size - 4) = cpu_to_le32(down_ptr);
181 		de->down = 1;
182 	}
183 	de->length = cpu_to_le16(d_size);
184 	de->not_8x3 = hpfs_is_name_long(name, namelen);
185 	de->namelen = namelen;
186 	memcpy(de->name, name, namelen);
187 	le32_add_cpu(&d->first_free, d_size);
188 	return de;
189 }
190 
191 /* Delete dirent and don't care about its subtree */
192 
193 static void hpfs_delete_de(struct super_block *s, struct dnode *d,
194 			   struct hpfs_dirent *de)
195 {
196 	if (de->last) {
197 		hpfs_error(s, "attempt to delete last dirent in dnode %08x", le32_to_cpu(d->self));
198 		return;
199 	}
200 	d->first_free = cpu_to_le32(le32_to_cpu(d->first_free) - le16_to_cpu(de->length));
201 	memmove(de, de_next_de(de), le32_to_cpu(d->first_free) + (char *)d - (char *)de);
202 }
203 
204 static void fix_up_ptrs(struct super_block *s, struct dnode *d)
205 {
206 	struct hpfs_dirent *de;
207 	struct hpfs_dirent *de_end = dnode_end_de(d);
208 	dnode_secno dno = le32_to_cpu(d->self);
209 	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de))
210 		if (de->down) {
211 			struct quad_buffer_head qbh;
212 			struct dnode *dd;
213 			if ((dd = hpfs_map_dnode(s, de_down_pointer(de), &qbh))) {
214 				if (le32_to_cpu(dd->up) != dno || dd->root_dnode) {
215 					dd->up = cpu_to_le32(dno);
216 					dd->root_dnode = 0;
217 					hpfs_mark_4buffers_dirty(&qbh);
218 				}
219 				hpfs_brelse4(&qbh);
220 			}
221 		}
222 }
223 
224 /* Add an entry to dnode and do dnode splitting if required */
225 
226 static int hpfs_add_to_dnode(struct inode *i, dnode_secno dno,
227 			     const unsigned char *name, unsigned namelen,
228 			     struct hpfs_dirent *new_de, dnode_secno down_ptr)
229 {
230 	struct quad_buffer_head qbh, qbh1, qbh2;
231 	struct dnode *d, *ad, *rd, *nd = NULL;
232 	dnode_secno adno, rdno;
233 	struct hpfs_dirent *de;
234 	struct hpfs_dirent nde;
235 	unsigned char *nname;
236 	int h;
237 	int pos;
238 	struct buffer_head *bh;
239 	struct fnode *fnode;
240 	int c1, c2 = 0;
241 	if (!(nname = kmalloc(256, GFP_NOFS))) {
242 		printk("HPFS: out of memory, can't add to dnode\n");
243 		return 1;
244 	}
245 	go_up:
246 	if (namelen >= 256) {
247 		hpfs_error(i->i_sb, "hpfs_add_to_dnode: namelen == %d", namelen);
248 		kfree(nd);
249 		kfree(nname);
250 		return 1;
251 	}
252 	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) {
253 		kfree(nd);
254 		kfree(nname);
255 		return 1;
256 	}
257 	go_up_a:
258 	if (hpfs_sb(i->i_sb)->sb_chk)
259 		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_to_dnode")) {
260 			hpfs_brelse4(&qbh);
261 			kfree(nd);
262 			kfree(nname);
263 			return 1;
264 		}
265 	if (le32_to_cpu(d->first_free) + de_size(namelen, down_ptr) <= 2048) {
266 		loff_t t;
267 		copy_de(de=hpfs_add_de(i->i_sb, d, name, namelen, down_ptr), new_de);
268 		t = get_pos(d, de);
269 		for_all_poss(i, hpfs_pos_ins, t, 1);
270 		for_all_poss(i, hpfs_pos_subst, 4, t);
271 		for_all_poss(i, hpfs_pos_subst, 5, t + 1);
272 		hpfs_mark_4buffers_dirty(&qbh);
273 		hpfs_brelse4(&qbh);
274 		kfree(nd);
275 		kfree(nname);
276 		return 0;
277 	}
278 	if (!nd) if (!(nd = kmalloc(0x924, GFP_NOFS))) {
279 		/* 0x924 is a max size of dnode after adding a dirent with
280 		   max name length. We alloc this only once. There must
281 		   not be any error while splitting dnodes, otherwise the
282 		   whole directory, not only file we're adding, would
283 		   be lost. */
284 		printk("HPFS: out of memory for dnode splitting\n");
285 		hpfs_brelse4(&qbh);
286 		kfree(nname);
287 		return 1;
288 	}
289 	memcpy(nd, d, le32_to_cpu(d->first_free));
290 	copy_de(de = hpfs_add_de(i->i_sb, nd, name, namelen, down_ptr), new_de);
291 	for_all_poss(i, hpfs_pos_ins, get_pos(nd, de), 1);
292 	h = ((char *)dnode_last_de(nd) - (char *)nd) / 2 + 10;
293 	if (!(ad = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &adno, &qbh1))) {
294 		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
295 		hpfs_brelse4(&qbh);
296 		kfree(nd);
297 		kfree(nname);
298 		return 1;
299 	}
300 	i->i_size += 2048;
301 	i->i_blocks += 4;
302 	pos = 1;
303 	for (de = dnode_first_de(nd); (char *)de_next_de(de) - (char *)nd < h; de = de_next_de(de)) {
304 		copy_de(hpfs_add_de(i->i_sb, ad, de->name, de->namelen, de->down ? de_down_pointer(de) : 0), de);
305 		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, ((loff_t)adno << 4) | pos);
306 		pos++;
307 	}
308 	copy_de(new_de = &nde, de);
309 	memcpy(nname, de->name, de->namelen);
310 	name = nname;
311 	namelen = de->namelen;
312 	for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, 4);
313 	down_ptr = adno;
314 	set_last_pointer(i->i_sb, ad, de->down ? de_down_pointer(de) : 0);
315 	de = de_next_de(de);
316 	memmove((char *)nd + 20, de, le32_to_cpu(nd->first_free) + (char *)nd - (char *)de);
317 	le32_add_cpu(&nd->first_free, -((char *)de - (char *)nd - 20));
318 	memcpy(d, nd, le32_to_cpu(nd->first_free));
319 	for_all_poss(i, hpfs_pos_del, (loff_t)dno << 4, pos);
320 	fix_up_ptrs(i->i_sb, ad);
321 	if (!d->root_dnode) {
322 		ad->up = d->up;
323 		dno = le32_to_cpu(ad->up);
324 		hpfs_mark_4buffers_dirty(&qbh);
325 		hpfs_brelse4(&qbh);
326 		hpfs_mark_4buffers_dirty(&qbh1);
327 		hpfs_brelse4(&qbh1);
328 		goto go_up;
329 	}
330 	if (!(rd = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &rdno, &qbh2))) {
331 		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
332 		hpfs_brelse4(&qbh);
333 		hpfs_brelse4(&qbh1);
334 		kfree(nd);
335 		kfree(nname);
336 		return 1;
337 	}
338 	i->i_size += 2048;
339 	i->i_blocks += 4;
340 	rd->root_dnode = 1;
341 	rd->up = d->up;
342 	if (!(fnode = hpfs_map_fnode(i->i_sb, le32_to_cpu(d->up), &bh))) {
343 		hpfs_free_dnode(i->i_sb, rdno);
344 		hpfs_brelse4(&qbh);
345 		hpfs_brelse4(&qbh1);
346 		hpfs_brelse4(&qbh2);
347 		kfree(nd);
348 		kfree(nname);
349 		return 1;
350 	}
351 	fnode->u.external[0].disk_secno = cpu_to_le32(rdno);
352 	mark_buffer_dirty(bh);
353 	brelse(bh);
354 	hpfs_i(i)->i_dno = rdno;
355 	d->up = ad->up = cpu_to_le32(rdno);
356 	d->root_dnode = ad->root_dnode = 0;
357 	hpfs_mark_4buffers_dirty(&qbh);
358 	hpfs_brelse4(&qbh);
359 	hpfs_mark_4buffers_dirty(&qbh1);
360 	hpfs_brelse4(&qbh1);
361 	qbh = qbh2;
362 	set_last_pointer(i->i_sb, rd, dno);
363 	dno = rdno;
364 	d = rd;
365 	goto go_up_a;
366 }
367 
368 /*
369  * Add an entry to directory btree.
370  * I hate such crazy directory structure.
371  * It's easy to read but terrible to write.
372  * I wrote this directory code 4 times.
373  * I hope, now it's finally bug-free.
374  */
375 
376 int hpfs_add_dirent(struct inode *i,
377 		    const unsigned char *name, unsigned namelen,
378 		    struct hpfs_dirent *new_de)
379 {
380 	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
381 	struct dnode *d;
382 	struct hpfs_dirent *de, *de_end;
383 	struct quad_buffer_head qbh;
384 	dnode_secno dno;
385 	int c;
386 	int c1, c2 = 0;
387 	dno = hpfs_inode->i_dno;
388 	down:
389 	if (hpfs_sb(i->i_sb)->sb_chk)
390 		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_dirent")) return 1;
391 	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 1;
392 	de_end = dnode_end_de(d);
393 	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
394 		if (!(c = hpfs_compare_names(i->i_sb, name, namelen, de->name, de->namelen, de->last))) {
395 			hpfs_brelse4(&qbh);
396 			return -1;
397 		}
398 		if (c < 0) {
399 			if (de->down) {
400 				dno = de_down_pointer(de);
401 				hpfs_brelse4(&qbh);
402 				goto down;
403 			}
404 			break;
405 		}
406 	}
407 	hpfs_brelse4(&qbh);
408 	if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_ADD)) {
409 		c = 1;
410 		goto ret;
411 	}
412 	i->i_version++;
413 	c = hpfs_add_to_dnode(i, dno, name, namelen, new_de, 0);
414 	ret:
415 	return c;
416 }
417 
418 /*
419  * Find dirent with higher name in 'from' subtree and move it to 'to' dnode.
420  * Return the dnode we moved from (to be checked later if it's empty)
421  */
422 
423 static secno move_to_top(struct inode *i, dnode_secno from, dnode_secno to)
424 {
425 	dnode_secno dno, ddno;
426 	dnode_secno chk_up = to;
427 	struct dnode *dnode;
428 	struct quad_buffer_head qbh;
429 	struct hpfs_dirent *de, *nde;
430 	int a;
431 	loff_t t;
432 	int c1, c2 = 0;
433 	dno = from;
434 	while (1) {
435 		if (hpfs_sb(i->i_sb)->sb_chk)
436 			if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "move_to_top"))
437 				return 0;
438 		if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 0;
439 		if (hpfs_sb(i->i_sb)->sb_chk) {
440 			if (le32_to_cpu(dnode->up) != chk_up) {
441 				hpfs_error(i->i_sb, "move_to_top: up pointer from %08x should be %08x, is %08x",
442 					dno, chk_up, le32_to_cpu(dnode->up));
443 				hpfs_brelse4(&qbh);
444 				return 0;
445 			}
446 			chk_up = dno;
447 		}
448 		if (!(de = dnode_last_de(dnode))) {
449 			hpfs_error(i->i_sb, "move_to_top: dnode %08x has no last de", dno);
450 			hpfs_brelse4(&qbh);
451 			return 0;
452 		}
453 		if (!de->down) break;
454 		dno = de_down_pointer(de);
455 		hpfs_brelse4(&qbh);
456 	}
457 	while (!(de = dnode_pre_last_de(dnode))) {
458 		dnode_secno up = le32_to_cpu(dnode->up);
459 		hpfs_brelse4(&qbh);
460 		hpfs_free_dnode(i->i_sb, dno);
461 		i->i_size -= 2048;
462 		i->i_blocks -= 4;
463 		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, 5);
464 		if (up == to) return to;
465 		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return 0;
466 		if (dnode->root_dnode) {
467 			hpfs_error(i->i_sb, "move_to_top: got to root_dnode while moving from %08x to %08x", from, to);
468 			hpfs_brelse4(&qbh);
469 			return 0;
470 		}
471 		de = dnode_last_de(dnode);
472 		if (!de || !de->down) {
473 			hpfs_error(i->i_sb, "move_to_top: dnode %08x doesn't point down to %08x", up, dno);
474 			hpfs_brelse4(&qbh);
475 			return 0;
476 		}
477 		le32_add_cpu(&dnode->first_free, -4);
478 		le16_add_cpu(&de->length, -4);
479 		de->down = 0;
480 		hpfs_mark_4buffers_dirty(&qbh);
481 		dno = up;
482 	}
483 	t = get_pos(dnode, de);
484 	for_all_poss(i, hpfs_pos_subst, t, 4);
485 	for_all_poss(i, hpfs_pos_subst, t + 1, 5);
486 	if (!(nde = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
487 		hpfs_error(i->i_sb, "out of memory for dirent - directory will be corrupted");
488 		hpfs_brelse4(&qbh);
489 		return 0;
490 	}
491 	memcpy(nde, de, le16_to_cpu(de->length));
492 	ddno = de->down ? de_down_pointer(de) : 0;
493 	hpfs_delete_de(i->i_sb, dnode, de);
494 	set_last_pointer(i->i_sb, dnode, ddno);
495 	hpfs_mark_4buffers_dirty(&qbh);
496 	hpfs_brelse4(&qbh);
497 	a = hpfs_add_to_dnode(i, to, nde->name, nde->namelen, nde, from);
498 	kfree(nde);
499 	if (a) return 0;
500 	return dno;
501 }
502 
503 /*
504  * Check if a dnode is empty and delete it from the tree
505  * (chkdsk doesn't like empty dnodes)
506  */
507 
508 static void delete_empty_dnode(struct inode *i, dnode_secno dno)
509 {
510 	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
511 	struct quad_buffer_head qbh;
512 	struct dnode *dnode;
513 	dnode_secno down, up, ndown;
514 	int p;
515 	struct hpfs_dirent *de;
516 	int c1, c2 = 0;
517 	try_it_again:
518 	if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "delete_empty_dnode")) return;
519 	if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return;
520 	if (le32_to_cpu(dnode->first_free) > 56) goto end;
521 	if (le32_to_cpu(dnode->first_free) == 52 || le32_to_cpu(dnode->first_free) == 56) {
522 		struct hpfs_dirent *de_end;
523 		int root = dnode->root_dnode;
524 		up = le32_to_cpu(dnode->up);
525 		de = dnode_first_de(dnode);
526 		down = de->down ? de_down_pointer(de) : 0;
527 		if (hpfs_sb(i->i_sb)->sb_chk) if (root && !down) {
528 			hpfs_error(i->i_sb, "delete_empty_dnode: root dnode %08x is empty", dno);
529 			goto end;
530 		}
531 		hpfs_brelse4(&qbh);
532 		hpfs_free_dnode(i->i_sb, dno);
533 		i->i_size -= 2048;
534 		i->i_blocks -= 4;
535 		if (root) {
536 			struct fnode *fnode;
537 			struct buffer_head *bh;
538 			struct dnode *d1;
539 			struct quad_buffer_head qbh1;
540 			if (hpfs_sb(i->i_sb)->sb_chk)
541 			    if (up != i->i_ino) {
542 				hpfs_error(i->i_sb,
543 					"bad pointer to fnode, dnode %08x, pointing to %08x, should be %08lx",
544 					dno, up, (unsigned long)i->i_ino);
545 				return;
546 			    }
547 			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
548 				d1->up = cpu_to_le32(up);
549 				d1->root_dnode = 1;
550 				hpfs_mark_4buffers_dirty(&qbh1);
551 				hpfs_brelse4(&qbh1);
552 			}
553 			if ((fnode = hpfs_map_fnode(i->i_sb, up, &bh))) {
554 				fnode->u.external[0].disk_secno = cpu_to_le32(down);
555 				mark_buffer_dirty(bh);
556 				brelse(bh);
557 			}
558 			hpfs_inode->i_dno = down;
559 			for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, (loff_t) 12);
560 			return;
561 		}
562 		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return;
563 		p = 1;
564 		de_end = dnode_end_de(dnode);
565 		for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de), p++)
566 			if (de->down) if (de_down_pointer(de) == dno) goto fnd;
567 		hpfs_error(i->i_sb, "delete_empty_dnode: pointer to dnode %08x not found in dnode %08x", dno, up);
568 		goto end;
569 		fnd:
570 		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, ((loff_t)up << 4) | p);
571 		if (!down) {
572 			de->down = 0;
573 			le16_add_cpu(&de->length, -4);
574 			le32_add_cpu(&dnode->first_free, -4);
575 			memmove(de_next_de(de), (char *)de_next_de(de) + 4,
576 				(char *)dnode + le32_to_cpu(dnode->first_free) - (char *)de_next_de(de));
577 		} else {
578 			struct dnode *d1;
579 			struct quad_buffer_head qbh1;
580 			*(dnode_secno *) ((void *) de + le16_to_cpu(de->length) - 4) = down;
581 			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
582 				d1->up = cpu_to_le32(up);
583 				hpfs_mark_4buffers_dirty(&qbh1);
584 				hpfs_brelse4(&qbh1);
585 			}
586 		}
587 	} else {
588 		hpfs_error(i->i_sb, "delete_empty_dnode: dnode %08x, first_free == %03x", dno, le32_to_cpu(dnode->first_free));
589 		goto end;
590 	}
591 
592 	if (!de->last) {
593 		struct hpfs_dirent *de_next = de_next_de(de);
594 		struct hpfs_dirent *de_cp;
595 		struct dnode *d1;
596 		struct quad_buffer_head qbh1;
597 		if (!de_next->down) goto endm;
598 		ndown = de_down_pointer(de_next);
599 		if (!(de_cp = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
600 			printk("HPFS: out of memory for dtree balancing\n");
601 			goto endm;
602 		}
603 		memcpy(de_cp, de, le16_to_cpu(de->length));
604 		hpfs_delete_de(i->i_sb, dnode, de);
605 		hpfs_mark_4buffers_dirty(&qbh);
606 		hpfs_brelse4(&qbh);
607 		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, 4);
608 		for_all_poss(i, hpfs_pos_del, ((loff_t)up << 4) | p, 1);
609 		if (de_cp->down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de_cp), &qbh1))) {
610 			d1->up = cpu_to_le32(ndown);
611 			hpfs_mark_4buffers_dirty(&qbh1);
612 			hpfs_brelse4(&qbh1);
613 		}
614 		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, de_cp->down ? de_down_pointer(de_cp) : 0);
615 		/*printk("UP-TO-DNODE: %08x (ndown = %08x, down = %08x, dno = %08x)\n", up, ndown, down, dno);*/
616 		dno = up;
617 		kfree(de_cp);
618 		goto try_it_again;
619 	} else {
620 		struct hpfs_dirent *de_prev = dnode_pre_last_de(dnode);
621 		struct hpfs_dirent *de_cp;
622 		struct dnode *d1;
623 		struct quad_buffer_head qbh1;
624 		dnode_secno dlp;
625 		if (!de_prev) {
626 			hpfs_error(i->i_sb, "delete_empty_dnode: empty dnode %08x", up);
627 			hpfs_mark_4buffers_dirty(&qbh);
628 			hpfs_brelse4(&qbh);
629 			dno = up;
630 			goto try_it_again;
631 		}
632 		if (!de_prev->down) goto endm;
633 		ndown = de_down_pointer(de_prev);
634 		if ((d1 = hpfs_map_dnode(i->i_sb, ndown, &qbh1))) {
635 			struct hpfs_dirent *del = dnode_last_de(d1);
636 			dlp = del->down ? de_down_pointer(del) : 0;
637 			if (!dlp && down) {
638 				if (le32_to_cpu(d1->first_free) > 2044) {
639 					if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
640 						printk("HPFS: warning: unbalanced dnode tree, see hpfs.txt 4 more info\n");
641 						printk("HPFS: warning: terminating balancing operation\n");
642 					}
643 					hpfs_brelse4(&qbh1);
644 					goto endm;
645 				}
646 				if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
647 					printk("HPFS: warning: unbalanced dnode tree, see hpfs.txt 4 more info\n");
648 					printk("HPFS: warning: goin'on\n");
649 				}
650 				le16_add_cpu(&del->length, 4);
651 				del->down = 1;
652 				le32_add_cpu(&d1->first_free, 4);
653 			}
654 			if (dlp && !down) {
655 				le16_add_cpu(&del->length, -4);
656 				del->down = 0;
657 				le32_add_cpu(&d1->first_free, -4);
658 			} else if (down)
659 				*(__le32 *) ((void *) del + le16_to_cpu(del->length) - 4) = cpu_to_le32(down);
660 		} else goto endm;
661 		if (!(de_cp = kmalloc(le16_to_cpu(de_prev->length), GFP_NOFS))) {
662 			printk("HPFS: out of memory for dtree balancing\n");
663 			hpfs_brelse4(&qbh1);
664 			goto endm;
665 		}
666 		hpfs_mark_4buffers_dirty(&qbh1);
667 		hpfs_brelse4(&qbh1);
668 		memcpy(de_cp, de_prev, le16_to_cpu(de_prev->length));
669 		hpfs_delete_de(i->i_sb, dnode, de_prev);
670 		if (!de_prev->down) {
671 			le16_add_cpu(&de_prev->length, 4);
672 			de_prev->down = 1;
673 			le32_add_cpu(&dnode->first_free, 4);
674 		}
675 		*(__le32 *) ((void *) de_prev + le16_to_cpu(de_prev->length) - 4) = cpu_to_le32(ndown);
676 		hpfs_mark_4buffers_dirty(&qbh);
677 		hpfs_brelse4(&qbh);
678 		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | (p - 1), 4);
679 		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, ((loff_t)up << 4) | (p - 1));
680 		if (down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de), &qbh1))) {
681 			d1->up = cpu_to_le32(ndown);
682 			hpfs_mark_4buffers_dirty(&qbh1);
683 			hpfs_brelse4(&qbh1);
684 		}
685 		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, dlp);
686 		dno = up;
687 		kfree(de_cp);
688 		goto try_it_again;
689 	}
690 	endm:
691 	hpfs_mark_4buffers_dirty(&qbh);
692 	end:
693 	hpfs_brelse4(&qbh);
694 }
695 
696 
697 /* Delete dirent from directory */
698 
699 int hpfs_remove_dirent(struct inode *i, dnode_secno dno, struct hpfs_dirent *de,
700 		       struct quad_buffer_head *qbh, int depth)
701 {
702 	struct dnode *dnode = qbh->data;
703 	dnode_secno down = 0;
704 	loff_t t;
705 	if (de->first || de->last) {
706 		hpfs_error(i->i_sb, "hpfs_remove_dirent: attempt to delete first or last dirent in dnode %08x", dno);
707 		hpfs_brelse4(qbh);
708 		return 1;
709 	}
710 	if (de->down) down = de_down_pointer(de);
711 	if (depth && (de->down || (de == dnode_first_de(dnode) && de_next_de(de)->last))) {
712 		if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_DEL)) {
713 			hpfs_brelse4(qbh);
714 			return 2;
715 		}
716 	}
717 	i->i_version++;
718 	for_all_poss(i, hpfs_pos_del, (t = get_pos(dnode, de)) + 1, 1);
719 	hpfs_delete_de(i->i_sb, dnode, de);
720 	hpfs_mark_4buffers_dirty(qbh);
721 	hpfs_brelse4(qbh);
722 	if (down) {
723 		dnode_secno a = move_to_top(i, down, dno);
724 		for_all_poss(i, hpfs_pos_subst, 5, t);
725 		if (a) delete_empty_dnode(i, a);
726 		return !a;
727 	}
728 	delete_empty_dnode(i, dno);
729 	return 0;
730 }
731 
732 void hpfs_count_dnodes(struct super_block *s, dnode_secno dno, int *n_dnodes,
733 		       int *n_subdirs, int *n_items)
734 {
735 	struct dnode *dnode;
736 	struct quad_buffer_head qbh;
737 	struct hpfs_dirent *de;
738 	dnode_secno ptr, odno = 0;
739 	int c1, c2 = 0;
740 	int d1, d2 = 0;
741 	go_down:
742 	if (n_dnodes) (*n_dnodes)++;
743 	if (hpfs_sb(s)->sb_chk)
744 		if (hpfs_stop_cycles(s, dno, &c1, &c2, "hpfs_count_dnodes #1")) return;
745 	ptr = 0;
746 	go_up:
747 	if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
748 	if (hpfs_sb(s)->sb_chk) if (odno && odno != -1 && le32_to_cpu(dnode->up) != odno)
749 		hpfs_error(s, "hpfs_count_dnodes: bad up pointer; dnode %08x, down %08x points to %08x", odno, dno, le32_to_cpu(dnode->up));
750 	de = dnode_first_de(dnode);
751 	if (ptr) while(1) {
752 		if (de->down) if (de_down_pointer(de) == ptr) goto process_de;
753 		if (de->last) {
754 			hpfs_brelse4(&qbh);
755 			hpfs_error(s, "hpfs_count_dnodes: pointer to dnode %08x not found in dnode %08x, got here from %08x",
756 				ptr, dno, odno);
757 			return;
758 		}
759 		de = de_next_de(de);
760 	}
761 	next_de:
762 	if (de->down) {
763 		odno = dno;
764 		dno = de_down_pointer(de);
765 		hpfs_brelse4(&qbh);
766 		goto go_down;
767 	}
768 	process_de:
769 	if (!de->first && !de->last && de->directory && n_subdirs) (*n_subdirs)++;
770 	if (!de->first && !de->last && n_items) (*n_items)++;
771 	if ((de = de_next_de(de)) < dnode_end_de(dnode)) goto next_de;
772 	ptr = dno;
773 	dno = le32_to_cpu(dnode->up);
774 	if (dnode->root_dnode) {
775 		hpfs_brelse4(&qbh);
776 		return;
777 	}
778 	hpfs_brelse4(&qbh);
779 	if (hpfs_sb(s)->sb_chk)
780 		if (hpfs_stop_cycles(s, ptr, &d1, &d2, "hpfs_count_dnodes #2")) return;
781 	odno = -1;
782 	goto go_up;
783 }
784 
785 static struct hpfs_dirent *map_nth_dirent(struct super_block *s, dnode_secno dno, int n,
786 					  struct quad_buffer_head *qbh, struct dnode **dn)
787 {
788 	int i;
789 	struct hpfs_dirent *de, *de_end;
790 	struct dnode *dnode;
791 	dnode = hpfs_map_dnode(s, dno, qbh);
792 	if (!dnode) return NULL;
793 	if (dn) *dn=dnode;
794 	de = dnode_first_de(dnode);
795 	de_end = dnode_end_de(dnode);
796 	for (i = 1; de < de_end; i++, de = de_next_de(de)) {
797 		if (i == n) {
798 			return de;
799 		}
800 		if (de->last) break;
801 	}
802 	hpfs_brelse4(qbh);
803 	hpfs_error(s, "map_nth_dirent: n too high; dnode = %08x, requested %08x", dno, n);
804 	return NULL;
805 }
806 
807 dnode_secno hpfs_de_as_down_as_possible(struct super_block *s, dnode_secno dno)
808 {
809 	struct quad_buffer_head qbh;
810 	dnode_secno d = dno;
811 	dnode_secno up = 0;
812 	struct hpfs_dirent *de;
813 	int c1, c2 = 0;
814 
815 	again:
816 	if (hpfs_sb(s)->sb_chk)
817 		if (hpfs_stop_cycles(s, d, &c1, &c2, "hpfs_de_as_down_as_possible"))
818 			return d;
819 	if (!(de = map_nth_dirent(s, d, 1, &qbh, NULL))) return dno;
820 	if (hpfs_sb(s)->sb_chk)
821 		if (up && le32_to_cpu(((struct dnode *)qbh.data)->up) != up)
822 			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));
823 	if (!de->down) {
824 		hpfs_brelse4(&qbh);
825 		return d;
826 	}
827 	up = d;
828 	d = de_down_pointer(de);
829 	hpfs_brelse4(&qbh);
830 	goto again;
831 }
832 
833 struct hpfs_dirent *map_pos_dirent(struct inode *inode, loff_t *posp,
834 				   struct quad_buffer_head *qbh)
835 {
836 	loff_t pos;
837 	unsigned c;
838 	dnode_secno dno;
839 	struct hpfs_dirent *de, *d;
840 	struct hpfs_dirent *up_de;
841 	struct hpfs_dirent *end_up_de;
842 	struct dnode *dnode;
843 	struct dnode *up_dnode;
844 	struct quad_buffer_head qbh0;
845 
846 	pos = *posp;
847 	dno = pos >> 6 << 2;
848 	pos &= 077;
849 	if (!(de = map_nth_dirent(inode->i_sb, dno, pos, qbh, &dnode)))
850 		goto bail;
851 
852 	/* Going to the next dirent */
853 	if ((d = de_next_de(de)) < dnode_end_de(dnode)) {
854 		if (!(++*posp & 077)) {
855 			hpfs_error(inode->i_sb,
856 				"map_pos_dirent: pos crossed dnode boundary; pos = %08llx",
857 				(unsigned long long)*posp);
858 			goto bail;
859 		}
860 		/* We're going down the tree */
861 		if (d->down) {
862 			*posp = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, de_down_pointer(d)) << 4) + 1;
863 		}
864 
865 		return de;
866 	}
867 
868 	/* Going up */
869 	if (dnode->root_dnode) goto bail;
870 
871 	if (!(up_dnode = hpfs_map_dnode(inode->i_sb, le32_to_cpu(dnode->up), &qbh0)))
872 		goto bail;
873 
874 	end_up_de = dnode_end_de(up_dnode);
875 	c = 0;
876 	for (up_de = dnode_first_de(up_dnode); up_de < end_up_de;
877 	     up_de = de_next_de(up_de)) {
878 		if (!(++c & 077)) hpfs_error(inode->i_sb,
879 			"map_pos_dirent: pos crossed dnode boundary; dnode = %08x", le32_to_cpu(dnode->up));
880 		if (up_de->down && de_down_pointer(up_de) == dno) {
881 			*posp = ((loff_t) le32_to_cpu(dnode->up) << 4) + c;
882 			hpfs_brelse4(&qbh0);
883 			return de;
884 		}
885 	}
886 
887 	hpfs_error(inode->i_sb, "map_pos_dirent: pointer to dnode %08x not found in parent dnode %08x",
888 		dno, le32_to_cpu(dnode->up));
889 	hpfs_brelse4(&qbh0);
890 
891 	bail:
892 	*posp = 12;
893 	return de;
894 }
895 
896 /* Find a dirent in tree */
897 
898 struct hpfs_dirent *map_dirent(struct inode *inode, dnode_secno dno,
899 			       const unsigned char *name, unsigned len,
900 			       dnode_secno *dd, struct quad_buffer_head *qbh)
901 {
902 	struct dnode *dnode;
903 	struct hpfs_dirent *de;
904 	struct hpfs_dirent *de_end;
905 	int c1, c2 = 0;
906 
907 	if (!S_ISDIR(inode->i_mode)) hpfs_error(inode->i_sb, "map_dirent: not a directory\n");
908 	again:
909 	if (hpfs_sb(inode->i_sb)->sb_chk)
910 		if (hpfs_stop_cycles(inode->i_sb, dno, &c1, &c2, "map_dirent")) return NULL;
911 	if (!(dnode = hpfs_map_dnode(inode->i_sb, dno, qbh))) return NULL;
912 
913 	de_end = dnode_end_de(dnode);
914 	for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de)) {
915 		int t = hpfs_compare_names(inode->i_sb, name, len, de->name, de->namelen, de->last);
916 		if (!t) {
917 			if (dd) *dd = dno;
918 			return de;
919 		}
920 		if (t < 0) {
921 			if (de->down) {
922 				dno = de_down_pointer(de);
923 				hpfs_brelse4(qbh);
924 				goto again;
925 			}
926 		break;
927 		}
928 	}
929 	hpfs_brelse4(qbh);
930 	return NULL;
931 }
932 
933 /*
934  * Remove empty directory. In normal cases it is only one dnode with two
935  * entries, but we must handle also such obscure cases when it's a tree
936  * of empty dnodes.
937  */
938 
939 void hpfs_remove_dtree(struct super_block *s, dnode_secno dno)
940 {
941 	struct quad_buffer_head qbh;
942 	struct dnode *dnode;
943 	struct hpfs_dirent *de;
944 	dnode_secno d1, d2, rdno = dno;
945 	while (1) {
946 		if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
947 		de = dnode_first_de(dnode);
948 		if (de->last) {
949 			if (de->down) d1 = de_down_pointer(de);
950 			else goto error;
951 			hpfs_brelse4(&qbh);
952 			hpfs_free_dnode(s, dno);
953 			dno = d1;
954 		} else break;
955 	}
956 	if (!de->first) goto error;
957 	d1 = de->down ? de_down_pointer(de) : 0;
958 	de = de_next_de(de);
959 	if (!de->last) goto error;
960 	d2 = de->down ? de_down_pointer(de) : 0;
961 	hpfs_brelse4(&qbh);
962 	hpfs_free_dnode(s, dno);
963 	do {
964 		while (d1) {
965 			if (!(dnode = hpfs_map_dnode(s, dno = d1, &qbh))) return;
966 			de = dnode_first_de(dnode);
967 			if (!de->last) goto error;
968 			d1 = de->down ? de_down_pointer(de) : 0;
969 			hpfs_brelse4(&qbh);
970 			hpfs_free_dnode(s, dno);
971 		}
972 		d1 = d2;
973 		d2 = 0;
974 	} while (d1);
975 	return;
976 	error:
977 	hpfs_brelse4(&qbh);
978 	hpfs_free_dnode(s, dno);
979 	hpfs_error(s, "directory %08x is corrupted or not empty", rdno);
980 }
981 
982 /*
983  * Find dirent for specified fnode. Use truncated 15-char name in fnode as
984  * a help for searching.
985  */
986 
987 struct hpfs_dirent *map_fnode_dirent(struct super_block *s, fnode_secno fno,
988 				     struct fnode *f, struct quad_buffer_head *qbh)
989 {
990 	unsigned char *name1;
991 	unsigned char *name2;
992 	int name1len, name2len;
993 	struct dnode *d;
994 	dnode_secno dno, downd;
995 	struct fnode *upf;
996 	struct buffer_head *bh;
997 	struct hpfs_dirent *de, *de_end;
998 	int c;
999 	int c1, c2 = 0;
1000 	int d1, d2 = 0;
1001 	name1 = f->name;
1002 	if (!(name2 = kmalloc(256, GFP_NOFS))) {
1003 		printk("HPFS: out of memory, can't map dirent\n");
1004 		return NULL;
1005 	}
1006 	if (f->len <= 15)
1007 		memcpy(name2, name1, name1len = name2len = f->len);
1008 	else {
1009 		memcpy(name2, name1, 15);
1010 		memset(name2 + 15, 0xff, 256 - 15);
1011 		/*name2[15] = 0xff;*/
1012 		name1len = 15; name2len = 256;
1013 	}
1014 	if (!(upf = hpfs_map_fnode(s, le32_to_cpu(f->up), &bh))) {
1015 		kfree(name2);
1016 		return NULL;
1017 	}
1018 	if (!fnode_is_dir(upf)) {
1019 		brelse(bh);
1020 		hpfs_error(s, "fnode %08x has non-directory parent %08x", fno, le32_to_cpu(f->up));
1021 		kfree(name2);
1022 		return NULL;
1023 	}
1024 	dno = le32_to_cpu(upf->u.external[0].disk_secno);
1025 	brelse(bh);
1026 	go_down:
1027 	downd = 0;
1028 	go_up:
1029 	if (!(d = hpfs_map_dnode(s, dno, qbh))) {
1030 		kfree(name2);
1031 		return NULL;
1032 	}
1033 	de_end = dnode_end_de(d);
1034 	de = dnode_first_de(d);
1035 	if (downd) {
1036 		while (de < de_end) {
1037 			if (de->down) if (de_down_pointer(de) == downd) goto f;
1038 			de = de_next_de(de);
1039 		}
1040 		hpfs_error(s, "pointer to dnode %08x not found in dnode %08x", downd, dno);
1041 		hpfs_brelse4(qbh);
1042 		kfree(name2);
1043 		return NULL;
1044 	}
1045 	next_de:
1046 	if (le32_to_cpu(de->fnode) == fno) {
1047 		kfree(name2);
1048 		return de;
1049 	}
1050 	c = hpfs_compare_names(s, name1, name1len, de->name, de->namelen, de->last);
1051 	if (c < 0 && de->down) {
1052 		dno = de_down_pointer(de);
1053 		hpfs_brelse4(qbh);
1054 		if (hpfs_sb(s)->sb_chk)
1055 			if (hpfs_stop_cycles(s, dno, &c1, &c2, "map_fnode_dirent #1")) {
1056 			kfree(name2);
1057 			return NULL;
1058 		}
1059 		goto go_down;
1060 	}
1061 	f:
1062 	if (le32_to_cpu(de->fnode) == fno) {
1063 		kfree(name2);
1064 		return de;
1065 	}
1066 	c = hpfs_compare_names(s, name2, name2len, de->name, de->namelen, de->last);
1067 	if (c < 0 && !de->last) goto not_found;
1068 	if ((de = de_next_de(de)) < de_end) goto next_de;
1069 	if (d->root_dnode) goto not_found;
1070 	downd = dno;
1071 	dno = le32_to_cpu(d->up);
1072 	hpfs_brelse4(qbh);
1073 	if (hpfs_sb(s)->sb_chk)
1074 		if (hpfs_stop_cycles(s, downd, &d1, &d2, "map_fnode_dirent #2")) {
1075 			kfree(name2);
1076 			return NULL;
1077 		}
1078 	goto go_up;
1079 	not_found:
1080 	hpfs_brelse4(qbh);
1081 	hpfs_error(s, "dirent for fnode %08x not found", fno);
1082 	kfree(name2);
1083 	return NULL;
1084 }
1085