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Commit | Line | Data |
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65cb7305 HJ |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | #include "internal.h" | |
3 | ||
4 | int 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 | ||
18 | static 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 | ||
59 | struct z_erofs_maprecorder { | |
60 | struct erofs_inode *inode; | |
61 | struct erofs_map_blocks *map; | |
62 | void *kaddr; | |
63 | ||
64 | unsigned long lcn; | |
65 | /* compression extent information gathered */ | |
66 | u8 type, headtype; | |
67 | u16 clusterofs; | |
68 | u16 delta[2]; | |
69 | erofs_blk_t pblk, compressedlcs; | |
70 | }; | |
71 | ||
72 | static 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 | ||
91 | static 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 | ||
142 | static 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 | ||
153 | static 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 | /* vcnt - 1 (Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) item */ | |
173 | if (!(lo & Z_EROFS_VLE_DI_D0_CBLKCNT)) | |
174 | d1 += lo - 1; | |
175 | return d1; | |
176 | } | |
177 | ||
178 | static 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 | /* figure out lookahead_distance: delta[1] if needed */ | |
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 | * since the last lcluster in the pack is special, | |
229 | * of which lo saves delta[1] rather than delta[0]. | |
230 | * Hence, get delta[0] by the previous lcluster indirectly. | |
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 | /* figout out blkaddr (pblk) for HEAD lclusters */ | |
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 | /* --i; ++nblk; continue; */ | |
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 | ||
284 | static 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 | /* used to align to 32-byte (compacted_2b) alignment */ | |
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; | |
330 | out: | |
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 | ||
339 | static 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 | ||
353 | static 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 | /* load extent head logical cluster if needed */ | |
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 | ||
398 | static 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 | * If the 1st NONHEAD lcluster has already been handled initially w/o | |
425 | * valid compressedlcs, which means at least it mustn't be CBLKCNT, or | |
426 | * an internal implemenatation error is detected. | |
427 | * | |
428 | * The following code can also handle it properly anyway, but let's | |
429 | * BUG_ON in the debugging mode only for developers to notice that. | |
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 | * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type | |
439 | * rather than CBLKCNT, it's a 1 lcluster-sized pcluster. | |
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 | /* fallthrough */ | |
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 | } | |
455 | out: | |
456 | map->m_plen = m->compressedlcs << lclusterbits; | |
457 | return 0; | |
458 | err_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 | ||
465 | static 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 | /* handle the last EOF pcluster (no next HEAD lcluster) */ | |
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 | /* go on until the next HEAD lcluster */ | |
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 | ||
507 | int 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 | /* when trying to read beyond EOF, leave it unmapped */ | |
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 | /* m.lcn should be >= 1 if endoff < m.clusterofs */ | |
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 | /* fallthrough */ | |
563 | case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: | |
564 | /* get the correspoinding first chunk */ | |
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 | ||
594 | out: | |
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 | } |