1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2018-2019 HUAWEI, Inc.
4 * https://www.huawei.com/
5 */
6 #include "internal.h"
7 #include <asm/unaligned.h>
8 #include <trace/events/erofs.h>
9
10 struct z_erofs_maprecorder {
11 struct inode *inode;
12 struct erofs_map_blocks *map;
13 void *kaddr;
14
15 unsigned long lcn;
16 /* compression extent information gathered */
17 u8 type, headtype;
18 u16 clusterofs;
19 u16 delta[2];
20 erofs_blk_t pblk, compressedblks;
21 erofs_off_t nextpackoff;
22 bool partialref;
23 };
24
z_erofs_load_full_lcluster(struct z_erofs_maprecorder * m,unsigned long lcn)25 static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
26 unsigned long lcn)
27 {
28 struct inode *const inode = m->inode;
29 struct erofs_inode *const vi = EROFS_I(inode);
30 const erofs_off_t pos = Z_EROFS_FULL_INDEX_ALIGN(erofs_iloc(inode) +
31 vi->inode_isize + vi->xattr_isize) +
32 lcn * sizeof(struct z_erofs_lcluster_index);
33 struct z_erofs_lcluster_index *di;
34 unsigned int advise, type;
35
36 m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
37 erofs_blknr(inode->i_sb, pos), EROFS_KMAP);
38 if (IS_ERR(m->kaddr))
39 return PTR_ERR(m->kaddr);
40
41 m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
42 m->lcn = lcn;
43 di = m->kaddr + erofs_blkoff(inode->i_sb, pos);
44
45 advise = le16_to_cpu(di->di_advise);
46 type = (advise >> Z_EROFS_LI_LCLUSTER_TYPE_BIT) &
47 ((1 << Z_EROFS_LI_LCLUSTER_TYPE_BITS) - 1);
48 switch (type) {
49 case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
50 m->clusterofs = 1 << vi->z_logical_clusterbits;
51 m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
52 if (m->delta[0] & Z_EROFS_LI_D0_CBLKCNT) {
53 if (!(vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 |
54 Z_EROFS_ADVISE_BIG_PCLUSTER_2))) {
55 DBG_BUGON(1);
56 return -EFSCORRUPTED;
57 }
58 m->compressedblks = m->delta[0] &
59 ~Z_EROFS_LI_D0_CBLKCNT;
60 m->delta[0] = 1;
61 }
62 m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
63 break;
64 case Z_EROFS_LCLUSTER_TYPE_PLAIN:
65 case Z_EROFS_LCLUSTER_TYPE_HEAD1:
66 case Z_EROFS_LCLUSTER_TYPE_HEAD2:
67 if (advise & Z_EROFS_LI_PARTIAL_REF)
68 m->partialref = true;
69 m->clusterofs = le16_to_cpu(di->di_clusterofs);
70 if (m->clusterofs >= 1 << vi->z_logical_clusterbits) {
71 DBG_BUGON(1);
72 return -EFSCORRUPTED;
73 }
74 m->pblk = le32_to_cpu(di->di_u.blkaddr);
75 break;
76 default:
77 DBG_BUGON(1);
78 return -EOPNOTSUPP;
79 }
80 m->type = type;
81 return 0;
82 }
83
decode_compactedbits(unsigned int lobits,u8 * in,unsigned int pos,u8 * type)84 static unsigned int decode_compactedbits(unsigned int lobits,
85 u8 *in, unsigned int pos, u8 *type)
86 {
87 const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7);
88 const unsigned int lo = v & ((1 << lobits) - 1);
89
90 *type = (v >> lobits) & 3;
91 return lo;
92 }
93
get_compacted_la_distance(unsigned int lobits,unsigned int encodebits,unsigned int vcnt,u8 * in,int i)94 static int get_compacted_la_distance(unsigned int lobits,
95 unsigned int encodebits,
96 unsigned int vcnt, u8 *in, int i)
97 {
98 unsigned int lo, d1 = 0;
99 u8 type;
100
101 DBG_BUGON(i >= vcnt);
102
103 do {
104 lo = decode_compactedbits(lobits, in, encodebits * i, &type);
105
106 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD)
107 return d1;
108 ++d1;
109 } while (++i < vcnt);
110
111 /* vcnt - 1 (Z_EROFS_LCLUSTER_TYPE_NONHEAD) item */
112 if (!(lo & Z_EROFS_LI_D0_CBLKCNT))
113 d1 += lo - 1;
114 return d1;
115 }
116
unpack_compacted_index(struct z_erofs_maprecorder * m,unsigned int amortizedshift,erofs_off_t pos,bool lookahead)117 static int unpack_compacted_index(struct z_erofs_maprecorder *m,
118 unsigned int amortizedshift,
119 erofs_off_t pos, bool lookahead)
120 {
121 struct erofs_inode *const vi = EROFS_I(m->inode);
122 const unsigned int lclusterbits = vi->z_logical_clusterbits;
123 unsigned int vcnt, base, lo, lobits, encodebits, nblk, eofs;
124 int i;
125 u8 *in, type;
126 bool big_pcluster;
127
128 if (1 << amortizedshift == 4 && lclusterbits <= 14)
129 vcnt = 2;
130 else if (1 << amortizedshift == 2 && lclusterbits <= 12)
131 vcnt = 16;
132 else
133 return -EOPNOTSUPP;
134
135 /* it doesn't equal to round_up(..) */
136 m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
137 (vcnt << amortizedshift);
138 big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
139 lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
140 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
141 eofs = erofs_blkoff(m->inode->i_sb, pos);
142 base = round_down(eofs, vcnt << amortizedshift);
143 in = m->kaddr + base;
144
145 i = (eofs - base) >> amortizedshift;
146
147 lo = decode_compactedbits(lobits, in, encodebits * i, &type);
148 m->type = type;
149 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
150 m->clusterofs = 1 << lclusterbits;
151
152 /* figure out lookahead_distance: delta[1] if needed */
153 if (lookahead)
154 m->delta[1] = get_compacted_la_distance(lobits,
155 encodebits, vcnt, in, i);
156 if (lo & Z_EROFS_LI_D0_CBLKCNT) {
157 if (!big_pcluster) {
158 DBG_BUGON(1);
159 return -EFSCORRUPTED;
160 }
161 m->compressedblks = lo & ~Z_EROFS_LI_D0_CBLKCNT;
162 m->delta[0] = 1;
163 return 0;
164 } else if (i + 1 != (int)vcnt) {
165 m->delta[0] = lo;
166 return 0;
167 }
168 /*
169 * since the last lcluster in the pack is special,
170 * of which lo saves delta[1] rather than delta[0].
171 * Hence, get delta[0] by the previous lcluster indirectly.
172 */
173 lo = decode_compactedbits(lobits, in,
174 encodebits * (i - 1), &type);
175 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD)
176 lo = 0;
177 else if (lo & Z_EROFS_LI_D0_CBLKCNT)
178 lo = 1;
179 m->delta[0] = lo + 1;
180 return 0;
181 }
182 m->clusterofs = lo;
183 m->delta[0] = 0;
184 /* figout out blkaddr (pblk) for HEAD lclusters */
185 if (!big_pcluster) {
186 nblk = 1;
187 while (i > 0) {
188 --i;
189 lo = decode_compactedbits(lobits, in,
190 encodebits * i, &type);
191 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD)
192 i -= lo;
193
194 if (i >= 0)
195 ++nblk;
196 }
197 } else {
198 nblk = 0;
199 while (i > 0) {
200 --i;
201 lo = decode_compactedbits(lobits, in,
202 encodebits * i, &type);
203 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
204 if (lo & Z_EROFS_LI_D0_CBLKCNT) {
205 --i;
206 nblk += lo & ~Z_EROFS_LI_D0_CBLKCNT;
207 continue;
208 }
209 /* bigpcluster shouldn't have plain d0 == 1 */
210 if (lo <= 1) {
211 DBG_BUGON(1);
212 return -EFSCORRUPTED;
213 }
214 i -= lo - 2;
215 continue;
216 }
217 ++nblk;
218 }
219 }
220 in += (vcnt << amortizedshift) - sizeof(__le32);
221 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
222 return 0;
223 }
224
z_erofs_load_compact_lcluster(struct z_erofs_maprecorder * m,unsigned long lcn,bool lookahead)225 static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
226 unsigned long lcn, bool lookahead)
227 {
228 struct inode *const inode = m->inode;
229 struct erofs_inode *const vi = EROFS_I(inode);
230 const erofs_off_t ebase = sizeof(struct z_erofs_map_header) +
231 ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8);
232 unsigned int totalidx = erofs_iblks(inode);
233 unsigned int compacted_4b_initial, compacted_2b;
234 unsigned int amortizedshift;
235 erofs_off_t pos;
236
237 if (lcn >= totalidx)
238 return -EINVAL;
239
240 m->lcn = lcn;
241 /* used to align to 32-byte (compacted_2b) alignment */
242 compacted_4b_initial = (32 - ebase % 32) / 4;
243 if (compacted_4b_initial == 32 / 4)
244 compacted_4b_initial = 0;
245
246 if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
247 compacted_4b_initial < totalidx)
248 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
249 else
250 compacted_2b = 0;
251
252 pos = ebase;
253 if (lcn < compacted_4b_initial) {
254 amortizedshift = 2;
255 goto out;
256 }
257 pos += compacted_4b_initial * 4;
258 lcn -= compacted_4b_initial;
259
260 if (lcn < compacted_2b) {
261 amortizedshift = 1;
262 goto out;
263 }
264 pos += compacted_2b * 2;
265 lcn -= compacted_2b;
266 amortizedshift = 2;
267 out:
268 pos += lcn * (1 << amortizedshift);
269 m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
270 erofs_blknr(inode->i_sb, pos), EROFS_KMAP);
271 if (IS_ERR(m->kaddr))
272 return PTR_ERR(m->kaddr);
273 return unpack_compacted_index(m, amortizedshift, pos, lookahead);
274 }
275
z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder * m,unsigned int lcn,bool lookahead)276 static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m,
277 unsigned int lcn, bool lookahead)
278 {
279 switch (EROFS_I(m->inode)->datalayout) {
280 case EROFS_INODE_COMPRESSED_FULL:
281 return z_erofs_load_full_lcluster(m, lcn);
282 case EROFS_INODE_COMPRESSED_COMPACT:
283 return z_erofs_load_compact_lcluster(m, lcn, lookahead);
284 default:
285 return -EINVAL;
286 }
287 }
288
z_erofs_extent_lookback(struct z_erofs_maprecorder * m,unsigned int lookback_distance)289 static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
290 unsigned int lookback_distance)
291 {
292 struct super_block *sb = m->inode->i_sb;
293 struct erofs_inode *const vi = EROFS_I(m->inode);
294 const unsigned int lclusterbits = vi->z_logical_clusterbits;
295
296 while (m->lcn >= lookback_distance) {
297 unsigned long lcn = m->lcn - lookback_distance;
298 int err;
299
300 err = z_erofs_load_lcluster_from_disk(m, lcn, false);
301 if (err)
302 return err;
303
304 switch (m->type) {
305 case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
306 lookback_distance = m->delta[0];
307 if (!lookback_distance)
308 goto err_bogus;
309 continue;
310 case Z_EROFS_LCLUSTER_TYPE_PLAIN:
311 case Z_EROFS_LCLUSTER_TYPE_HEAD1:
312 case Z_EROFS_LCLUSTER_TYPE_HEAD2:
313 m->headtype = m->type;
314 m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
315 return 0;
316 default:
317 erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu",
318 m->type, lcn, vi->nid);
319 DBG_BUGON(1);
320 return -EOPNOTSUPP;
321 }
322 }
323 err_bogus:
324 erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu",
325 lookback_distance, m->lcn, vi->nid);
326 DBG_BUGON(1);
327 return -EFSCORRUPTED;
328 }
329
z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder * m,unsigned int initial_lcn)330 static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
331 unsigned int initial_lcn)
332 {
333 struct super_block *sb = m->inode->i_sb;
334 struct erofs_inode *const vi = EROFS_I(m->inode);
335 struct erofs_map_blocks *const map = m->map;
336 const unsigned int lclusterbits = vi->z_logical_clusterbits;
337 unsigned long lcn;
338 int err;
339
340 DBG_BUGON(m->type != Z_EROFS_LCLUSTER_TYPE_PLAIN &&
341 m->type != Z_EROFS_LCLUSTER_TYPE_HEAD1 &&
342 m->type != Z_EROFS_LCLUSTER_TYPE_HEAD2);
343 DBG_BUGON(m->type != m->headtype);
344
345 if (m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN ||
346 ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1) &&
347 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) ||
348 ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) &&
349 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2))) {
350 map->m_plen = 1ULL << lclusterbits;
351 return 0;
352 }
353 lcn = m->lcn + 1;
354 if (m->compressedblks)
355 goto out;
356
357 err = z_erofs_load_lcluster_from_disk(m, lcn, false);
358 if (err)
359 return err;
360
361 /*
362 * If the 1st NONHEAD lcluster has already been handled initially w/o
363 * valid compressedblks, which means at least it mustn't be CBLKCNT, or
364 * an internal implemenatation error is detected.
365 *
366 * The following code can also handle it properly anyway, but let's
367 * BUG_ON in the debugging mode only for developers to notice that.
368 */
369 DBG_BUGON(lcn == initial_lcn &&
370 m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD);
371
372 switch (m->type) {
373 case Z_EROFS_LCLUSTER_TYPE_PLAIN:
374 case Z_EROFS_LCLUSTER_TYPE_HEAD1:
375 case Z_EROFS_LCLUSTER_TYPE_HEAD2:
376 /*
377 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
378 * rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
379 */
380 m->compressedblks = 1 << (lclusterbits - sb->s_blocksize_bits);
381 break;
382 case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
383 if (m->delta[0] != 1)
384 goto err_bonus_cblkcnt;
385 if (m->compressedblks)
386 break;
387 fallthrough;
388 default:
389 erofs_err(sb, "cannot found CBLKCNT @ lcn %lu of nid %llu", lcn,
390 vi->nid);
391 DBG_BUGON(1);
392 return -EFSCORRUPTED;
393 }
394 out:
395 map->m_plen = erofs_pos(sb, m->compressedblks);
396 return 0;
397 err_bonus_cblkcnt:
398 erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid);
399 DBG_BUGON(1);
400 return -EFSCORRUPTED;
401 }
402
z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder * m)403 static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
404 {
405 struct inode *inode = m->inode;
406 struct erofs_inode *vi = EROFS_I(inode);
407 struct erofs_map_blocks *map = m->map;
408 unsigned int lclusterbits = vi->z_logical_clusterbits;
409 u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits;
410 int err;
411
412 do {
413 /* handle the last EOF pcluster (no next HEAD lcluster) */
414 if ((lcn << lclusterbits) >= inode->i_size) {
415 map->m_llen = inode->i_size - map->m_la;
416 return 0;
417 }
418
419 err = z_erofs_load_lcluster_from_disk(m, lcn, true);
420 if (err)
421 return err;
422
423 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
424 DBG_BUGON(!m->delta[1] &&
425 m->clusterofs != 1 << lclusterbits);
426 } else if (m->type == Z_EROFS_LCLUSTER_TYPE_PLAIN ||
427 m->type == Z_EROFS_LCLUSTER_TYPE_HEAD1 ||
428 m->type == Z_EROFS_LCLUSTER_TYPE_HEAD2) {
429 /* go on until the next HEAD lcluster */
430 if (lcn != headlcn)
431 break;
432 m->delta[1] = 1;
433 } else {
434 erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu",
435 m->type, lcn, vi->nid);
436 DBG_BUGON(1);
437 return -EOPNOTSUPP;
438 }
439 lcn += m->delta[1];
440 } while (m->delta[1]);
441
442 map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la;
443 return 0;
444 }
445
z_erofs_do_map_blocks(struct inode * inode,struct erofs_map_blocks * map,int flags)446 static int z_erofs_do_map_blocks(struct inode *inode,
447 struct erofs_map_blocks *map, int flags)
448 {
449 struct erofs_inode *const vi = EROFS_I(inode);
450 bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
451 bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
452 struct z_erofs_maprecorder m = {
453 .inode = inode,
454 .map = map,
455 };
456 int err = 0;
457 unsigned int lclusterbits, endoff, afmt;
458 unsigned long initial_lcn;
459 unsigned long long ofs, end;
460
461 lclusterbits = vi->z_logical_clusterbits;
462 ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la;
463 initial_lcn = ofs >> lclusterbits;
464 endoff = ofs & ((1 << lclusterbits) - 1);
465
466 err = z_erofs_load_lcluster_from_disk(&m, initial_lcn, false);
467 if (err)
468 goto unmap_out;
469
470 if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL))
471 vi->z_idataoff = m.nextpackoff;
472
473 map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
474 end = (m.lcn + 1ULL) << lclusterbits;
475
476 switch (m.type) {
477 case Z_EROFS_LCLUSTER_TYPE_PLAIN:
478 case Z_EROFS_LCLUSTER_TYPE_HEAD1:
479 case Z_EROFS_LCLUSTER_TYPE_HEAD2:
480 if (endoff >= m.clusterofs) {
481 m.headtype = m.type;
482 map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
483 /*
484 * For ztailpacking files, in order to inline data more
485 * effectively, special EOF lclusters are now supported
486 * which can have three parts at most.
487 */
488 if (ztailpacking && end > inode->i_size)
489 end = inode->i_size;
490 break;
491 }
492 /* m.lcn should be >= 1 if endoff < m.clusterofs */
493 if (!m.lcn) {
494 erofs_err(inode->i_sb,
495 "invalid logical cluster 0 at nid %llu",
496 vi->nid);
497 err = -EFSCORRUPTED;
498 goto unmap_out;
499 }
500 end = (m.lcn << lclusterbits) | m.clusterofs;
501 map->m_flags |= EROFS_MAP_FULL_MAPPED;
502 m.delta[0] = 1;
503 fallthrough;
504 case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
505 /* get the corresponding first chunk */
506 err = z_erofs_extent_lookback(&m, m.delta[0]);
507 if (err)
508 goto unmap_out;
509 break;
510 default:
511 erofs_err(inode->i_sb,
512 "unknown type %u @ offset %llu of nid %llu",
513 m.type, ofs, vi->nid);
514 err = -EOPNOTSUPP;
515 goto unmap_out;
516 }
517 if (m.partialref)
518 map->m_flags |= EROFS_MAP_PARTIAL_REF;
519 map->m_llen = end - map->m_la;
520
521 if (flags & EROFS_GET_BLOCKS_FINDTAIL) {
522 vi->z_tailextent_headlcn = m.lcn;
523 /* for non-compact indexes, fragmentoff is 64 bits */
524 if (fragment && vi->datalayout == EROFS_INODE_COMPRESSED_FULL)
525 vi->z_fragmentoff |= (u64)m.pblk << 32;
526 }
527 if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
528 map->m_flags |= EROFS_MAP_META;
529 map->m_pa = vi->z_idataoff;
530 map->m_plen = vi->z_idata_size;
531 } else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
532 map->m_flags |= EROFS_MAP_FRAGMENT;
533 } else {
534 map->m_pa = erofs_pos(inode->i_sb, m.pblk);
535 err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
536 if (err)
537 goto unmap_out;
538 }
539
540 if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) {
541 if (map->m_llen > map->m_plen) {
542 DBG_BUGON(1);
543 err = -EFSCORRUPTED;
544 goto unmap_out;
545 }
546 afmt = vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER ?
547 Z_EROFS_COMPRESSION_INTERLACED :
548 Z_EROFS_COMPRESSION_SHIFTED;
549 } else {
550 afmt = m.headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2 ?
551 vi->z_algorithmtype[1] : vi->z_algorithmtype[0];
552 if (!(EROFS_I_SB(inode)->available_compr_algs & (1 << afmt))) {
553 erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu",
554 afmt, vi->nid);
555 err = -EFSCORRUPTED;
556 goto unmap_out;
557 }
558 }
559 map->m_algorithmformat = afmt;
560
561 if ((flags & EROFS_GET_BLOCKS_FIEMAP) ||
562 ((flags & EROFS_GET_BLOCKS_READMORE) &&
563 (map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA ||
564 map->m_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE) &&
565 map->m_llen >= i_blocksize(inode))) {
566 err = z_erofs_get_extent_decompressedlen(&m);
567 if (!err)
568 map->m_flags |= EROFS_MAP_FULL_MAPPED;
569 }
570
571 unmap_out:
572 erofs_unmap_metabuf(&m.map->buf);
573 return err;
574 }
575
z_erofs_fill_inode_lazy(struct inode * inode)576 static int z_erofs_fill_inode_lazy(struct inode *inode)
577 {
578 struct erofs_inode *const vi = EROFS_I(inode);
579 struct super_block *const sb = inode->i_sb;
580 int err, headnr;
581 erofs_off_t pos;
582 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
583 void *kaddr;
584 struct z_erofs_map_header *h;
585
586 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) {
587 /*
588 * paired with smp_mb() at the end of the function to ensure
589 * fields will only be observed after the bit is set.
590 */
591 smp_mb();
592 return 0;
593 }
594
595 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE))
596 return -ERESTARTSYS;
597
598 err = 0;
599 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags))
600 goto out_unlock;
601
602 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8);
603 kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(sb, pos), EROFS_KMAP);
604 if (IS_ERR(kaddr)) {
605 err = PTR_ERR(kaddr);
606 goto out_unlock;
607 }
608
609 h = kaddr + erofs_blkoff(sb, pos);
610 /*
611 * if the highest bit of the 8-byte map header is set, the whole file
612 * is stored in the packed inode. The rest bits keeps z_fragmentoff.
613 */
614 if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) {
615 vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
616 vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
617 vi->z_tailextent_headlcn = 0;
618 goto done;
619 }
620 vi->z_advise = le16_to_cpu(h->h_advise);
621 vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
622 vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
623
624 headnr = 0;
625 if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX ||
626 vi->z_algorithmtype[++headnr] >= Z_EROFS_COMPRESSION_MAX) {
627 erofs_err(sb, "unknown HEAD%u format %u for nid %llu, please upgrade kernel",
628 headnr + 1, vi->z_algorithmtype[headnr], vi->nid);
629 err = -EOPNOTSUPP;
630 goto out_put_metabuf;
631 }
632
633 vi->z_logical_clusterbits = sb->s_blocksize_bits + (h->h_clusterbits & 7);
634 if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
635 vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 |
636 Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
637 erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu",
638 vi->nid);
639 err = -EFSCORRUPTED;
640 goto out_put_metabuf;
641 }
642 if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT &&
643 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
644 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
645 erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu",
646 vi->nid);
647 err = -EFSCORRUPTED;
648 goto out_put_metabuf;
649 }
650
651 if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
652 struct erofs_map_blocks map = {
653 .buf = __EROFS_BUF_INITIALIZER
654 };
655
656 vi->z_idata_size = le16_to_cpu(h->h_idata_size);
657 err = z_erofs_do_map_blocks(inode, &map,
658 EROFS_GET_BLOCKS_FINDTAIL);
659 erofs_put_metabuf(&map.buf);
660
661 if (!map.m_plen ||
662 erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) {
663 erofs_err(sb, "invalid tail-packing pclustersize %llu",
664 map.m_plen);
665 err = -EFSCORRUPTED;
666 }
667 if (err < 0)
668 goto out_put_metabuf;
669 }
670
671 if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
672 !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) {
673 struct erofs_map_blocks map = {
674 .buf = __EROFS_BUF_INITIALIZER
675 };
676
677 vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
678 err = z_erofs_do_map_blocks(inode, &map,
679 EROFS_GET_BLOCKS_FINDTAIL);
680 erofs_put_metabuf(&map.buf);
681 if (err < 0)
682 goto out_put_metabuf;
683 }
684 done:
685 /* paired with smp_mb() at the beginning of the function */
686 smp_mb();
687 set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
688 out_put_metabuf:
689 erofs_put_metabuf(&buf);
690 out_unlock:
691 clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags);
692 return err;
693 }
694
z_erofs_map_blocks_iter(struct inode * inode,struct erofs_map_blocks * map,int flags)695 int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map,
696 int flags)
697 {
698 struct erofs_inode *const vi = EROFS_I(inode);
699 int err = 0;
700
701 trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
702
703 /* when trying to read beyond EOF, leave it unmapped */
704 if (map->m_la >= inode->i_size) {
705 map->m_llen = map->m_la + 1 - inode->i_size;
706 map->m_la = inode->i_size;
707 map->m_flags = 0;
708 goto out;
709 }
710
711 err = z_erofs_fill_inode_lazy(inode);
712 if (err)
713 goto out;
714
715 if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) &&
716 !vi->z_tailextent_headlcn) {
717 map->m_la = 0;
718 map->m_llen = inode->i_size;
719 map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_FULL_MAPPED |
720 EROFS_MAP_FRAGMENT;
721 goto out;
722 }
723
724 err = z_erofs_do_map_blocks(inode, map, flags);
725 out:
726 trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
727 return err;
728 }
729
z_erofs_iomap_begin_report(struct inode * inode,loff_t offset,loff_t length,unsigned int flags,struct iomap * iomap,struct iomap * srcmap)730 static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
731 loff_t length, unsigned int flags,
732 struct iomap *iomap, struct iomap *srcmap)
733 {
734 int ret;
735 struct erofs_map_blocks map = { .m_la = offset };
736
737 ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP);
738 erofs_put_metabuf(&map.buf);
739 if (ret < 0)
740 return ret;
741
742 iomap->bdev = inode->i_sb->s_bdev;
743 iomap->offset = map.m_la;
744 iomap->length = map.m_llen;
745 if (map.m_flags & EROFS_MAP_MAPPED) {
746 iomap->type = IOMAP_MAPPED;
747 iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ?
748 IOMAP_NULL_ADDR : map.m_pa;
749 } else {
750 iomap->type = IOMAP_HOLE;
751 iomap->addr = IOMAP_NULL_ADDR;
752 /*
753 * No strict rule on how to describe extents for post EOF, yet
754 * we need to do like below. Otherwise, iomap itself will get
755 * into an endless loop on post EOF.
756 *
757 * Calculate the effective offset by subtracting extent start
758 * (map.m_la) from the requested offset, and add it to length.
759 * (NB: offset >= map.m_la always)
760 */
761 if (iomap->offset >= inode->i_size)
762 iomap->length = length + offset - map.m_la;
763 }
764 iomap->flags = 0;
765 return 0;
766 }
767
768 const struct iomap_ops z_erofs_iomap_report_ops = {
769 .iomap_begin = z_erofs_iomap_begin_report,
770 };
771