1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/hpfs/alloc.c
4 *
5 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6 *
7 * HPFS bitmap operations
8 */
9
10 #include "hpfs_fn.h"
11
12 static void hpfs_claim_alloc(struct super_block *s, secno sec)
13 {
14 struct hpfs_sb_info *sbi = hpfs_sb(s);
15 if (sbi->sb_n_free != (unsigned)-1) {
16 if (unlikely(!sbi->sb_n_free)) {
17 hpfs_error(s, "free count underflow, allocating sector %08x", sec);
18 sbi->sb_n_free = -1;
19 return;
20 }
21 sbi->sb_n_free--;
22 }
23 }
24
25 static void hpfs_claim_free(struct super_block *s, secno sec)
26 {
27 struct hpfs_sb_info *sbi = hpfs_sb(s);
28 if (sbi->sb_n_free != (unsigned)-1) {
29 if (unlikely(sbi->sb_n_free >= sbi->sb_fs_size)) {
30 hpfs_error(s, "free count overflow, freeing sector %08x", sec);
31 sbi->sb_n_free = -1;
32 return;
33 }
34 sbi->sb_n_free++;
35 }
36 }
37
38 static void hpfs_claim_dirband_alloc(struct super_block *s, secno sec)
39 {
40 struct hpfs_sb_info *sbi = hpfs_sb(s);
41 if (sbi->sb_n_free_dnodes != (unsigned)-1) {
42 if (unlikely(!sbi->sb_n_free_dnodes)) {
43 hpfs_error(s, "dirband free count underflow, allocating sector %08x", sec);
44 sbi->sb_n_free_dnodes = -1;
45 return;
46 }
47 sbi->sb_n_free_dnodes--;
48 }
49 }
50
51 static void hpfs_claim_dirband_free(struct super_block *s, secno sec)
52 {
53 struct hpfs_sb_info *sbi = hpfs_sb(s);
54 if (sbi->sb_n_free_dnodes != (unsigned)-1) {
55 if (unlikely(sbi->sb_n_free_dnodes >= sbi->sb_dirband_size / 4)) {
56 hpfs_error(s, "dirband free count overflow, freeing sector %08x", sec);
57 sbi->sb_n_free_dnodes = -1;
58 return;
59 }
60 sbi->sb_n_free_dnodes++;
61 }
62 }
63
64 /*
65 * Check if a sector is allocated in bitmap
66 * This is really slow. Turned on only if chk==2
67 */
68
69 static int chk_if_allocated(struct super_block *s, secno sec, char *msg)
70 {
71 struct quad_buffer_head qbh;
72 __le32 *bmp;
73 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;
74 if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f)) & 1) {
75 hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec);
76 goto fail1;
77 }
78 hpfs_brelse4(&qbh);
79 if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
80 unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4;
81 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail;
82 if ((le32_to_cpu(bmp[ssec >> 5]) >> (ssec & 0x1f)) & 1) {
83 hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec);
84 goto fail1;
85 }
86 hpfs_brelse4(&qbh);
87 }
88 return 0;
89 fail1:
90 hpfs_brelse4(&qbh);
91 fail:
92 return 1;
93 }
94
95 /*
96 * Check if sector(s) have proper number and additionally check if they're
97 * allocated in bitmap.
98 */
99
100 int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg)
101 {
102 if (start + len < start || start < 0x12 ||
103 start + len > hpfs_sb(s)->sb_fs_size) {
104 hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);
105 return 1;
106 }
107 if (hpfs_sb(s)->sb_chk>=2) {
108 int i;
109 for (i = 0; i < len; i++)
110 if (chk_if_allocated(s, start + i, msg)) return 1;
111 }
112 return 0;
113 }
114
115 static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward)
116 {
117 struct quad_buffer_head qbh;
118 __le32 *bmp;
119 unsigned bs = near & ~0x3fff;
120 unsigned nr = (near & 0x3fff) & ~(n - 1);
121 /*unsigned mnr;*/
122 unsigned i, q;
123 int a, b;
124 secno ret = 0;
125 if (n != 1 && n != 4) {
126 hpfs_error(s, "Bad allocation size: %d", n);
127 return 0;
128 }
129 if (bs != ~0x3fff) {
130 if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls;
131 } else {
132 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls;
133 }
134 if (!tstbits(bmp, nr, n + forward)) {
135 ret = bs + nr;
136 goto rt;
137 }
138 q = nr + n; b = 0;
139 while ((a = tstbits(bmp, q, n + forward)) != 0) {
140 q += a;
141 if (n != 1) q = ((q-1)&~(n-1))+n;
142 if (!b) {
143 if (q>>5 != nr>>5) {
144 b = 1;
145 q = nr & 0x1f;
146 }
147 } else if (q > nr) break;
148 }
149 if (!a) {
150 ret = bs + q;
151 goto rt;
152 }
153 nr >>= 5;
154 /*for (i = nr + 1; i != nr; i++, i &= 0x1ff) */
155 i = nr;
156 do {
157 if (!le32_to_cpu(bmp[i])) goto cont;
158 if (n + forward >= 0x3f && le32_to_cpu(bmp[i]) != 0xffffffff) goto cont;
159 q = i<<5;
160 if (i > 0) {
161 unsigned k = le32_to_cpu(bmp[i-1]);
162 while (k & 0x80000000) {
163 q--; k <<= 1;
164 }
165 }
166 if (n != 1) q = ((q-1)&~(n-1))+n;
167 while ((a = tstbits(bmp, q, n + forward)) != 0) {
168 q += a;
169 if (n != 1) q = ((q-1)&~(n-1))+n;
170 if (q>>5 > i) break;
171 }
172 if (!a) {
173 ret = bs + q;
174 goto rt;
175 }
176 cont:
177 i++, i &= 0x1ff;
178 } while (i != nr);
179 rt:
180 if (ret) {
181 if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (le32_to_cpu(bmp[(ret & 0x3fff) >> 5]) | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) {
182 hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret);
183 ret = 0;
184 goto b;
185 }
186 bmp[(ret & 0x3fff) >> 5] &= cpu_to_le32(~(((1 << n) - 1) << (ret & 0x1f)));
187 hpfs_mark_4buffers_dirty(&qbh);
188 }
189 b:
190 hpfs_brelse4(&qbh);
191 uls:
192 return ret;
193 }
194
195 /*
196 * Allocation strategy: 1) search place near the sector specified
197 * 2) search bitmap where free sectors last found
198 * 3) search all bitmaps
199 * 4) search all bitmaps ignoring number of pre-allocated
200 * sectors
201 */
202
203 secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward)
204 {
205 secno sec;
206 int i;
207 unsigned n_bmps;
208 struct hpfs_sb_info *sbi = hpfs_sb(s);
209 int f_p = 0;
210 int near_bmp;
211 if (forward < 0) {
212 forward = -forward;
213 f_p = 1;
214 }
215 n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14;
216 if (near && near < sbi->sb_fs_size) {
217 if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;
218 near_bmp = near >> 14;
219 } else near_bmp = n_bmps / 2;
220 /*
221 if (b != -1) {
222 if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) {
223 b &= 0x0fffffff;
224 goto ret;
225 }
226 if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret;
227 */
228 if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc;
229 less_fwd:
230 for (i = 0; i < n_bmps; i++) {
231 if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) {
232 sbi->sb_c_bitmap = near_bmp+i;
233 goto ret;
234 }
235 if (!forward) {
236 if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) {
237 sbi->sb_c_bitmap = near_bmp-i-1;
238 goto ret;
239 }
240 } else {
241 if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) {
242 sbi->sb_c_bitmap = near_bmp+i-n_bmps;
243 goto ret;
244 }
245 }
246 if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) {
247 goto ret;
248 }
249 }
250 if (!f_p) {
251 if (forward) {
252 sbi->sb_max_fwd_alloc = forward * 3 / 4;
253 forward /= 2;
254 goto less_fwd;
255 }
256 }
257 sec = 0;
258 ret:
259 if (sec) {
260 i = 0;
261 do
262 hpfs_claim_alloc(s, sec + i);
263 while (unlikely(++i < n));
264 }
265 if (sec && f_p) {
266 for (i = 0; i < forward; i++) {
267 if (!hpfs_alloc_if_possible(s, sec + n + i)) {
268 hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i);
269 sec = 0;
270 break;
271 }
272 }
273 }
274 return sec;
275 }
276
277 static secno alloc_in_dirband(struct super_block *s, secno near)
278 {
279 unsigned nr = near;
280 secno sec;
281 struct hpfs_sb_info *sbi = hpfs_sb(s);
282 if (nr < sbi->sb_dirband_start)
283 nr = sbi->sb_dirband_start;
284 if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size)
285 nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4;
286 nr -= sbi->sb_dirband_start;
287 nr >>= 2;
288 sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0);
289 if (!sec) return 0;
290 hpfs_claim_dirband_alloc(s, sec);
291 return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start;
292 }
293
294 /* Alloc sector if it's free */
295
296 int hpfs_alloc_if_possible(struct super_block *s, secno sec)
297 {
298 struct quad_buffer_head qbh;
299 __le32 *bmp;
300 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;
301 if (le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) & (1 << (sec & 0x1f))) {
302 bmp[(sec & 0x3fff) >> 5] &= cpu_to_le32(~(1 << (sec & 0x1f)));
303 hpfs_mark_4buffers_dirty(&qbh);
304 hpfs_brelse4(&qbh);
305 hpfs_claim_alloc(s, sec);
306 return 1;
307 }
308 hpfs_brelse4(&qbh);
309 end:
310 return 0;
311 }
312
313 /* Free sectors in bitmaps */
314
315 void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
316 {
317 struct quad_buffer_head qbh;
318 __le32 *bmp;
319 struct hpfs_sb_info *sbi = hpfs_sb(s);
320 /*pr_info("2 - ");*/
321 if (!n) return;
322 if (sec < 0x12) {
323 hpfs_error(s, "Trying to free reserved sector %08x", sec);
324 return;
325 }
326 sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n;
327 if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff;
328 new_map:
329 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {
330 return;
331 }
332 new_tst:
333 if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f) & 1)) {
334 hpfs_error(s, "sector %08x not allocated", sec);
335 hpfs_brelse4(&qbh);
336 return;
337 }
338 bmp[(sec & 0x3fff) >> 5] |= cpu_to_le32(1 << (sec & 0x1f));
339 hpfs_claim_free(s, sec);
340 if (!--n) {
341 hpfs_mark_4buffers_dirty(&qbh);
342 hpfs_brelse4(&qbh);
343 return;
344 }
345 if (!(++sec & 0x3fff)) {
346 hpfs_mark_4buffers_dirty(&qbh);
347 hpfs_brelse4(&qbh);
348 goto new_map;
349 }
350 goto new_tst;
351 }
352
353 /*
354 * Check if there are at least n free dnodes on the filesystem.
355 * Called before adding to dnode. If we run out of space while
356 * splitting dnodes, it would corrupt dnode tree.
357 */
358
359 int hpfs_check_free_dnodes(struct super_block *s, int n)
360 {
361 int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14;
362 int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff;
363 int i, j;
364 __le32 *bmp;
365 struct quad_buffer_head qbh;
366 if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
367 for (j = 0; j < 512; j++) {
368 unsigned k;
369 if (!le32_to_cpu(bmp[j])) continue;
370 for (k = le32_to_cpu(bmp[j]); k; k >>= 1) if (k & 1) if (!--n) {
371 hpfs_brelse4(&qbh);
372 return 0;
373 }
374 }
375 }
376 hpfs_brelse4(&qbh);
377 i = 0;
378 if (hpfs_sb(s)->sb_c_bitmap != -1) {
379 bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1");
380 goto chk_bmp;
381 }
382 chk_next:
383 if (i == b) i++;
384 if (i >= n_bmps) return 1;
385 bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2");
386 chk_bmp:
387 if (bmp) {
388 for (j = 0; j < 512; j++) {
389 u32 k;
390 if (!le32_to_cpu(bmp[j])) continue;
391 for (k = 0xf; k; k <<= 4)
392 if ((le32_to_cpu(bmp[j]) & k) == k) {
393 if (!--n) {
394 hpfs_brelse4(&qbh);
395 return 0;
396 }
397 }
398 }
399 hpfs_brelse4(&qbh);
400 }
401 i++;
402 goto chk_next;
403 }
404
405 void hpfs_free_dnode(struct super_block *s, dnode_secno dno)
406 {
407 if (hpfs_sb(s)->sb_chk) if (dno & 3) {
408 hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);
409 return;
410 }
411 if (dno < hpfs_sb(s)->sb_dirband_start ||
412 dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
413 hpfs_free_sectors(s, dno, 4);
414 } else {
415 struct quad_buffer_head qbh;
416 __le32 *bmp;
417 unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4;
418 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
419 return;
420 }
421 bmp[ssec >> 5] |= cpu_to_le32(1 << (ssec & 0x1f));
422 hpfs_mark_4buffers_dirty(&qbh);
423 hpfs_brelse4(&qbh);
424 hpfs_claim_dirband_free(s, dno);
425 }
426 }
427
428 struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
429 dnode_secno *dno, struct quad_buffer_head *qbh)
430 {
431 struct dnode *d;
432 if (hpfs_get_free_dnodes(s) > FREE_DNODES_ADD) {
433 if (!(*dno = alloc_in_dirband(s, near)))
434 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) return NULL;
435 } else {
436 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0)))
437 if (!(*dno = alloc_in_dirband(s, near))) return NULL;
438 }
439 if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {
440 hpfs_free_dnode(s, *dno);
441 return NULL;
442 }
443 memset(d, 0, 2048);
444 d->magic = cpu_to_le32(DNODE_MAGIC);
445 d->first_free = cpu_to_le32(52);
446 d->dirent[0] = 32;
447 d->dirent[2] = 8;
448 d->dirent[30] = 1;
449 d->dirent[31] = 255;
450 d->self = cpu_to_le32(*dno);
451 return d;
452 }
453
454 struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno,
455 struct buffer_head **bh)
456 {
457 struct fnode *f;
458 if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD))) return NULL;
459 if (!(f = hpfs_get_sector(s, *fno, bh))) {
460 hpfs_free_sectors(s, *fno, 1);
461 return NULL;
462 }
463 memset(f, 0, 512);
464 f->magic = cpu_to_le32(FNODE_MAGIC);
465 f->ea_offs = cpu_to_le16(0xc4);
466 f->btree.n_free_nodes = 8;
467 f->btree.first_free = cpu_to_le16(8);
468 return f;
469 }
470
471 struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano,
472 struct buffer_head **bh)
473 {
474 struct anode *a;
475 if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD))) return NULL;
476 if (!(a = hpfs_get_sector(s, *ano, bh))) {
477 hpfs_free_sectors(s, *ano, 1);
478 return NULL;
479 }
480 memset(a, 0, 512);
481 a->magic = cpu_to_le32(ANODE_MAGIC);
482 a->self = cpu_to_le32(*ano);
483 a->btree.n_free_nodes = 40;
484 a->btree.n_used_nodes = 0;
485 a->btree.first_free = cpu_to_le16(8);
486 return a;
487 }
488
489 static unsigned find_run(__le32 *bmp, unsigned *idx)
490 {
491 unsigned len;
492 while (tstbits(bmp, *idx, 1)) {
493 (*idx)++;
494 if (unlikely(*idx >= 0x4000))
495 return 0;
496 }
497 len = 1;
498 while (!tstbits(bmp, *idx + len, 1))
499 len++;
500 return len;
501 }
502
503 static int do_trim(struct super_block *s, secno start, unsigned len, secno limit_start, secno limit_end, unsigned minlen, unsigned *result)
504 {
505 int err;
506 secno end;
507 if (fatal_signal_pending(current))
508 return -EINTR;
509 end = start + len;
510 if (start < limit_start)
511 start = limit_start;
512 if (end > limit_end)
513 end = limit_end;
514 if (start >= end)
515 return 0;
516 if (end - start < minlen)
517 return 0;
518 err = sb_issue_discard(s, start, end - start, GFP_NOFS, 0);
519 if (err)
520 return err;
521 *result += end - start;
522 return 0;
523 }
524
525 int hpfs_trim_fs(struct super_block *s, u64 start, u64 end, u64 minlen, unsigned *result)
526 {
527 int err = 0;
528 struct hpfs_sb_info *sbi = hpfs_sb(s);
529 unsigned idx, len, start_bmp, end_bmp;
530 __le32 *bmp;
531 struct quad_buffer_head qbh;
532
533 *result = 0;
534 if (!end || end > sbi->sb_fs_size)
535 end = sbi->sb_fs_size;
536 if (start >= sbi->sb_fs_size)
537 return 0;
538 if (minlen > 0x4000)
539 return 0;
540 if (start < sbi->sb_dirband_start + sbi->sb_dirband_size && end > sbi->sb_dirband_start) {
541 hpfs_lock(s);
542 if (sb_rdonly(s)) {
543 err = -EROFS;
544 goto unlock_1;
545 }
546 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
547 err = -EIO;
548 goto unlock_1;
549 }
550 idx = 0;
551 while ((len = find_run(bmp, &idx)) && !err) {
552 err = do_trim(s, sbi->sb_dirband_start + idx * 4, len * 4, start, end, minlen, result);
553 idx += len;
554 }
555 hpfs_brelse4(&qbh);
556 unlock_1:
557 hpfs_unlock(s);
558 }
559 start_bmp = start >> 14;
560 end_bmp = (end + 0x3fff) >> 14;
561 while (start_bmp < end_bmp && !err) {
562 hpfs_lock(s);
563 if (sb_rdonly(s)) {
564 err = -EROFS;
565 goto unlock_2;
566 }
567 if (!(bmp = hpfs_map_bitmap(s, start_bmp, &qbh, "trim"))) {
568 err = -EIO;
569 goto unlock_2;
570 }
571 idx = 0;
572 while ((len = find_run(bmp, &idx)) && !err) {
573 err = do_trim(s, (start_bmp << 14) + idx, len, start, end, minlen, result);
574 idx += len;
575 }
576 hpfs_brelse4(&qbh);
577 unlock_2:
578 hpfs_unlock(s);
579 start_bmp++;
580 }
581 return err;
582 }
583
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