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  
hpfs_bplus_lookup(struct super_block * s,struct inode * inode,struct bplus_header * btree,unsigned sec,struct buffer_head * bh)14  secno 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  
hpfs_add_sector_to_btree(struct super_block * s,secno node,int fnod,unsigned fsecno)61  secno 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  
hpfs_remove_btree(struct super_block * s,struct bplus_header * btree)274  void 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  
anode_lookup(struct super_block * s,anode_secno a,unsigned sec)330  static 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  
hpfs_ea_read(struct super_block * s,secno a,int ano,unsigned pos,unsigned len,char * buf)338  int 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  
hpfs_ea_write(struct super_block * s,secno a,int ano,unsigned pos,unsigned len,const char * buf)361  int 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  
hpfs_ea_remove(struct super_block * s,secno a,int ano,unsigned len)385  void 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  
hpfs_truncate_btree(struct super_block * s,secno f,int fno,unsigned secs)399  void 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  
hpfs_remove_fnode(struct super_block * s,fnode_secno fno)481  void 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  }
498