1
2#include "internal.h"
3
4int z_erofs_fill_inode(struct erofs_inode *vi)
5{
6 if (!erofs_sb_has_big_pcluster() &&
7 vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) {
8 vi->z_advise = 0;
9 vi->z_algorithmtype[0] = 0;
10 vi->z_algorithmtype[1] = 0;
11 vi->z_logical_clusterbits = LOG_BLOCK_SIZE;
12
13 vi->flags |= EROFS_I_Z_INITED;
14 }
15 return 0;
16}
17
18static int z_erofs_fill_inode_lazy(struct erofs_inode *vi)
19{
20 int ret;
21 erofs_off_t pos;
22 struct z_erofs_map_header *h;
23 char buf[sizeof(struct z_erofs_map_header)];
24
25 if (vi->flags & EROFS_I_Z_INITED)
26 return 0;
27
28 DBG_BUGON(!erofs_sb_has_big_pcluster() &&
29 vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
30 pos = round_up(iloc(vi->nid) + vi->inode_isize + vi->xattr_isize, 8);
31
32 ret = erofs_dev_read(0, buf, pos, sizeof(buf));
33 if (ret < 0)
34 return -EIO;
35
36 h = (struct z_erofs_map_header *)buf;
37 vi->z_advise = le16_to_cpu(h->h_advise);
38 vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
39 vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
40
41 if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX) {
42 erofs_err("unknown compression format %u for nid %llu",
43 vi->z_algorithmtype[0], (unsigned long long)vi->nid);
44 return -EOPNOTSUPP;
45 }
46
47 vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
48 if (vi->datalayout == EROFS_INODE_FLAT_COMPRESSION &&
49 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
50 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
51 erofs_err("big pcluster head1/2 of compact indexes should be consistent for nid %llu",
52 vi->nid * 1ULL);
53 return -EFSCORRUPTED;
54 }
55 vi->flags |= EROFS_I_Z_INITED;
56 return 0;
57}
58
59struct z_erofs_maprecorder {
60 struct erofs_inode *inode;
61 struct erofs_map_blocks *map;
62 void *kaddr;
63
64 unsigned long lcn;
65
66 u8 type, headtype;
67 u16 clusterofs;
68 u16 delta[2];
69 erofs_blk_t pblk, compressedlcs;
70};
71
72static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
73 erofs_blk_t eblk)
74{
75 int ret;
76 struct erofs_map_blocks *const map = m->map;
77 char *mpage = map->mpage;
78
79 if (map->index == eblk)
80 return 0;
81
82 ret = erofs_blk_read(mpage, eblk, 1);
83 if (ret < 0)
84 return -EIO;
85
86 map->index = eblk;
87
88 return 0;
89}
90
91static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
92 unsigned long lcn)
93{
94 struct erofs_inode *const vi = m->inode;
95 const erofs_off_t ibase = iloc(vi->nid);
96 const erofs_off_t pos =
97 Z_EROFS_VLE_LEGACY_INDEX_ALIGN(ibase + vi->inode_isize +
98 vi->xattr_isize) +
99 lcn * sizeof(struct z_erofs_vle_decompressed_index);
100 struct z_erofs_vle_decompressed_index *di;
101 unsigned int advise, type;
102 int err;
103
104 err = z_erofs_reload_indexes(m, erofs_blknr(pos));
105 if (err)
106 return err;
107
108 m->lcn = lcn;
109 di = m->kaddr + erofs_blkoff(pos);
110
111 advise = le16_to_cpu(di->di_advise);
112 type = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) &
113 ((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1);
114 switch (type) {
115 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
116 m->clusterofs = 1 << vi->z_logical_clusterbits;
117 m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
118 if (m->delta[0] & Z_EROFS_VLE_DI_D0_CBLKCNT) {
119 if (!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
120 DBG_BUGON(1);
121 return -EFSCORRUPTED;
122 }
123 m->compressedlcs = m->delta[0] &
124 ~Z_EROFS_VLE_DI_D0_CBLKCNT;
125 m->delta[0] = 1;
126 }
127 m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
128 break;
129 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
130 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
131 m->clusterofs = le16_to_cpu(di->di_clusterofs);
132 m->pblk = le32_to_cpu(di->di_u.blkaddr);
133 break;
134 default:
135 DBG_BUGON(1);
136 return -EOPNOTSUPP;
137 }
138 m->type = type;
139 return 0;
140}
141
142static unsigned int decode_compactedbits(unsigned int lobits,
143 unsigned int lomask,
144 u8 *in, unsigned int pos, u8 *type)
145{
146 const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7);
147 const unsigned int lo = v & lomask;
148
149 *type = (v >> lobits) & 3;
150 return lo;
151}
152
153static int get_compacted_la_distance(unsigned int lclusterbits,
154 unsigned int encodebits,
155 unsigned int vcnt, u8 *in, int i)
156{
157 const unsigned int lomask = (1 << lclusterbits) - 1;
158 unsigned int lo, d1 = 0;
159 u8 type;
160
161 DBG_BUGON(i >= vcnt);
162
163 do {
164 lo = decode_compactedbits(lclusterbits, lomask,
165 in, encodebits * i, &type);
166
167 if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
168 return d1;
169 ++d1;
170 } while (++i < vcnt);
171
172
173 if (!(lo & Z_EROFS_VLE_DI_D0_CBLKCNT))
174 d1 += lo - 1;
175 return d1;
176}
177
178static int unpack_compacted_index(struct z_erofs_maprecorder *m,
179 unsigned int amortizedshift,
180 unsigned int eofs, bool lookahead)
181{
182 struct erofs_inode *const vi = m->inode;
183 const unsigned int lclusterbits = vi->z_logical_clusterbits;
184 const unsigned int lomask = (1 << lclusterbits) - 1;
185 unsigned int vcnt, base, lo, encodebits, nblk;
186 int i;
187 u8 *in, type;
188 bool big_pcluster;
189
190 if (1 << amortizedshift == 4)
191 vcnt = 2;
192 else if (1 << amortizedshift == 2 && lclusterbits == 12)
193 vcnt = 16;
194 else
195 return -EOPNOTSUPP;
196
197 big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
198 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
199 base = round_down(eofs, vcnt << amortizedshift);
200 in = m->kaddr + base;
201
202 i = (eofs - base) >> amortizedshift;
203
204 lo = decode_compactedbits(lclusterbits, lomask,
205 in, encodebits * i, &type);
206 m->type = type;
207 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
208 m->clusterofs = 1 << lclusterbits;
209
210
211 if (lookahead)
212 m->delta[1] = get_compacted_la_distance(lclusterbits,
213 encodebits,
214 vcnt, in, i);
215 if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
216 if (!big_pcluster) {
217 DBG_BUGON(1);
218 return -EFSCORRUPTED;
219 }
220 m->compressedlcs = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
221 m->delta[0] = 1;
222 return 0;
223 } else if (i + 1 != (int)vcnt) {
224 m->delta[0] = lo;
225 return 0;
226 }
227
228
229
230
231
232 lo = decode_compactedbits(lclusterbits, lomask,
233 in, encodebits * (i - 1), &type);
234 if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
235 lo = 0;
236 else if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT)
237 lo = 1;
238 m->delta[0] = lo + 1;
239 return 0;
240 }
241 m->clusterofs = lo;
242 m->delta[0] = 0;
243
244 if (!big_pcluster) {
245 nblk = 1;
246 while (i > 0) {
247 --i;
248 lo = decode_compactedbits(lclusterbits, lomask,
249 in, encodebits * i, &type);
250 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
251 i -= lo;
252
253 if (i >= 0)
254 ++nblk;
255 }
256 } else {
257 nblk = 0;
258 while (i > 0) {
259 --i;
260 lo = decode_compactedbits(lclusterbits, lomask,
261 in, encodebits * i, &type);
262 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
263 if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
264 --i;
265 nblk += lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
266 continue;
267 }
268 if (lo == 1) {
269 DBG_BUGON(1);
270
271 return -EFSCORRUPTED;
272 }
273 i -= lo - 2;
274 continue;
275 }
276 ++nblk;
277 }
278 }
279 in += (vcnt << amortizedshift) - sizeof(__le32);
280 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
281 return 0;
282}
283
284static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
285 unsigned long lcn, bool lookahead)
286{
287 struct erofs_inode *const vi = m->inode;
288 const unsigned int lclusterbits = vi->z_logical_clusterbits;
289 const erofs_off_t ebase = round_up(iloc(vi->nid) + vi->inode_isize +
290 vi->xattr_isize, 8) +
291 sizeof(struct z_erofs_map_header);
292 const unsigned int totalidx = DIV_ROUND_UP(vi->i_size, EROFS_BLKSIZ);
293 unsigned int compacted_4b_initial, compacted_2b;
294 unsigned int amortizedshift;
295 erofs_off_t pos;
296 int err;
297
298 if (lclusterbits != 12)
299 return -EOPNOTSUPP;
300
301 if (lcn >= totalidx)
302 return -EINVAL;
303
304 m->lcn = lcn;
305
306 compacted_4b_initial = (32 - ebase % 32) / 4;
307 if (compacted_4b_initial == 32 / 4)
308 compacted_4b_initial = 0;
309
310 if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
311 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
312 else
313 compacted_2b = 0;
314
315 pos = ebase;
316 if (lcn < compacted_4b_initial) {
317 amortizedshift = 2;
318 goto out;
319 }
320 pos += compacted_4b_initial * 4;
321 lcn -= compacted_4b_initial;
322
323 if (lcn < compacted_2b) {
324 amortizedshift = 1;
325 goto out;
326 }
327 pos += compacted_2b * 2;
328 lcn -= compacted_2b;
329 amortizedshift = 2;
330out:
331 pos += lcn * (1 << amortizedshift);
332 err = z_erofs_reload_indexes(m, erofs_blknr(pos));
333 if (err)
334 return err;
335 return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos),
336 lookahead);
337}
338
339static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
340 unsigned int lcn, bool lookahead)
341{
342 const unsigned int datamode = m->inode->datalayout;
343
344 if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
345 return legacy_load_cluster_from_disk(m, lcn);
346
347 if (datamode == EROFS_INODE_FLAT_COMPRESSION)
348 return compacted_load_cluster_from_disk(m, lcn, lookahead);
349
350 return -EINVAL;
351}
352
353static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
354 unsigned int lookback_distance)
355{
356 struct erofs_inode *const vi = m->inode;
357 struct erofs_map_blocks *const map = m->map;
358 const unsigned int lclusterbits = vi->z_logical_clusterbits;
359 unsigned long lcn = m->lcn;
360 int err;
361
362 if (lcn < lookback_distance) {
363 erofs_err("bogus lookback distance @ nid %llu",
364 (unsigned long long)vi->nid);
365 DBG_BUGON(1);
366 return -EFSCORRUPTED;
367 }
368
369
370 lcn -= lookback_distance;
371 err = z_erofs_load_cluster_from_disk(m, lcn, false);
372 if (err)
373 return err;
374
375 switch (m->type) {
376 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
377 if (!m->delta[0]) {
378 erofs_err("invalid lookback distance 0 @ nid %llu",
379 (unsigned long long)vi->nid);
380 DBG_BUGON(1);
381 return -EFSCORRUPTED;
382 }
383 return z_erofs_extent_lookback(m, m->delta[0]);
384 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
385 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
386 m->headtype = m->type;
387 map->m_la = (lcn << lclusterbits) | m->clusterofs;
388 break;
389 default:
390 erofs_err("unknown type %u @ lcn %lu of nid %llu",
391 m->type, lcn, (unsigned long long)vi->nid);
392 DBG_BUGON(1);
393 return -EOPNOTSUPP;
394 }
395 return 0;
396}
397
398static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
399 unsigned int initial_lcn)
400{
401 struct erofs_inode *const vi = m->inode;
402 struct erofs_map_blocks *const map = m->map;
403 const unsigned int lclusterbits = vi->z_logical_clusterbits;
404 unsigned long lcn;
405 int err;
406
407 DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN &&
408 m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD);
409 if (m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
410 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
411 map->m_plen = 1 << lclusterbits;
412 return 0;
413 }
414
415 lcn = m->lcn + 1;
416 if (m->compressedlcs)
417 goto out;
418
419 err = z_erofs_load_cluster_from_disk(m, lcn, false);
420 if (err)
421 return err;
422
423
424
425
426
427
428
429
430
431 DBG_BUGON(lcn == initial_lcn &&
432 m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD);
433
434 switch (m->type) {
435 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
436 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
437
438
439
440
441 m->compressedlcs = 1;
442 break;
443 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
444 if (m->delta[0] != 1)
445 goto err_bonus_cblkcnt;
446 if (m->compressedlcs)
447 break;
448
449 default:
450 erofs_err("cannot found CBLKCNT @ lcn %lu of nid %llu",
451 lcn, vi->nid | 0ULL);
452 DBG_BUGON(1);
453 return -EFSCORRUPTED;
454 }
455out:
456 map->m_plen = m->compressedlcs << lclusterbits;
457 return 0;
458err_bonus_cblkcnt:
459 erofs_err("bogus CBLKCNT @ lcn %lu of nid %llu",
460 lcn, vi->nid | 0ULL);
461 DBG_BUGON(1);
462 return -EFSCORRUPTED;
463}
464
465static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
466{
467 struct erofs_inode *const vi = m->inode;
468 struct erofs_map_blocks *map = m->map;
469 unsigned int lclusterbits = vi->z_logical_clusterbits;
470 u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits;
471 int err;
472
473 do {
474
475 if ((lcn << lclusterbits) >= vi->i_size) {
476 map->m_llen = vi->i_size - map->m_la;
477 return 0;
478 }
479
480 err = z_erofs_load_cluster_from_disk(m, lcn, true);
481 if (err)
482 return err;
483
484 if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
485 DBG_BUGON(!m->delta[1] &&
486 m->clusterofs != 1 << lclusterbits);
487 } else if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
488 m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD) {
489
490 if (lcn != headlcn)
491 break;
492 m->delta[1] = 1;
493 } else {
494 erofs_err("unknown type %u @ lcn %llu of nid %llu",
495 m->type, lcn | 0ULL,
496 (unsigned long long)vi->nid);
497 DBG_BUGON(1);
498 return -EOPNOTSUPP;
499 }
500 lcn += m->delta[1];
501 } while (m->delta[1]);
502
503 map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la;
504 return 0;
505}
506
507int z_erofs_map_blocks_iter(struct erofs_inode *vi,
508 struct erofs_map_blocks *map,
509 int flags)
510{
511 struct z_erofs_maprecorder m = {
512 .inode = vi,
513 .map = map,
514 .kaddr = map->mpage,
515 };
516 int err = 0;
517 unsigned int lclusterbits, endoff;
518 unsigned long initial_lcn;
519 unsigned long long ofs, end;
520
521
522 if (map->m_la >= vi->i_size) {
523 map->m_llen = map->m_la + 1 - vi->i_size;
524 map->m_la = vi->i_size;
525 map->m_flags = 0;
526 goto out;
527 }
528
529 err = z_erofs_fill_inode_lazy(vi);
530 if (err)
531 goto out;
532
533 lclusterbits = vi->z_logical_clusterbits;
534 ofs = map->m_la;
535 initial_lcn = ofs >> lclusterbits;
536 endoff = ofs & ((1 << lclusterbits) - 1);
537
538 err = z_erofs_load_cluster_from_disk(&m, initial_lcn, false);
539 if (err)
540 goto out;
541
542 map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
543 end = (m.lcn + 1ULL) << lclusterbits;
544 switch (m.type) {
545 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
546 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
547 if (endoff >= m.clusterofs) {
548 m.headtype = m.type;
549 map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
550 break;
551 }
552
553 if (!m.lcn) {
554 erofs_err("invalid logical cluster 0 at nid %llu",
555 (unsigned long long)vi->nid);
556 err = -EFSCORRUPTED;
557 goto out;
558 }
559 end = (m.lcn << lclusterbits) | m.clusterofs;
560 map->m_flags |= EROFS_MAP_FULL_MAPPED;
561 m.delta[0] = 1;
562
563 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
564
565 err = z_erofs_extent_lookback(&m, m.delta[0]);
566 if (err)
567 goto out;
568 break;
569 default:
570 erofs_err("unknown type %u @ offset %llu of nid %llu",
571 m.type, ofs, (unsigned long long)vi->nid);
572 err = -EOPNOTSUPP;
573 goto out;
574 }
575
576 map->m_llen = end - map->m_la;
577 map->m_pa = blknr_to_addr(m.pblk);
578
579 err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
580 if (err)
581 goto out;
582
583 if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN)
584 map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
585 else
586 map->m_algorithmformat = vi->z_algorithmtype[0];
587
588 if (flags & EROFS_GET_BLOCKS_FIEMAP) {
589 err = z_erofs_get_extent_decompressedlen(&m);
590 if (!err)
591 map->m_flags |= EROFS_MAP_FULL_MAPPED;
592 }
593
594out:
595 erofs_dbg("m_la %" PRIu64 " m_pa %" PRIu64 " m_llen %" PRIu64 " m_plen %" PRIu64 " m_flags 0%o",
596 map->m_la, map->m_pa,
597 map->m_llen, map->m_plen, map->m_flags);
598
599 DBG_BUGON(err < 0 && err != -ENOMEM);
600 return err;
601}
602
