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 <linux/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 unsigned long lcn;
14 /* compression extent information gathered */
15 u8 type, headtype;
16 u16 clusterofs;
17 u16 delta[2];
18 erofs_blk_t pblk, compressedblks;
19 erofs_off_t nextpackoff;
20 bool partialref, in_mbox;
21 };
22
z_erofs_load_full_lcluster(struct z_erofs_maprecorder * m,unsigned long lcn)23 static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
24 unsigned long lcn)
25 {
26 struct inode *const inode = m->inode;
27 struct erofs_inode *const vi = EROFS_I(inode);
28 const erofs_off_t pos = Z_EROFS_FULL_INDEX_START(erofs_iloc(inode) +
29 vi->inode_isize + vi->xattr_isize) +
30 lcn * sizeof(struct z_erofs_lcluster_index);
31 struct z_erofs_lcluster_index *di;
32 unsigned int advise;
33
34 di = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, m->in_mbox);
35 if (IS_ERR(di))
36 return PTR_ERR(di);
37 m->lcn = lcn;
38 m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
39
40 advise = le16_to_cpu(di->di_advise);
41 m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK;
42 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
43 m->clusterofs = 1 << vi->z_lclusterbits;
44 m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
45 if (m->delta[0] & Z_EROFS_LI_D0_CBLKCNT) {
46 if (!(vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 |
47 Z_EROFS_ADVISE_BIG_PCLUSTER_2))) {
48 DBG_BUGON(1);
49 return -EFSCORRUPTED;
50 }
51 m->compressedblks = m->delta[0] & ~Z_EROFS_LI_D0_CBLKCNT;
52 m->delta[0] = 1;
53 }
54 m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
55 } else {
56 m->partialref = !!(advise & Z_EROFS_LI_PARTIAL_REF);
57 m->clusterofs = le16_to_cpu(di->di_clusterofs);
58 if (m->clusterofs >= 1 << vi->z_lclusterbits) {
59 DBG_BUGON(1);
60 return -EFSCORRUPTED;
61 }
62 m->pblk = le32_to_cpu(di->di_u.blkaddr);
63 }
64 return 0;
65 }
66
decode_compactedbits(unsigned int lobits,u8 * in,unsigned int pos,u8 * type)67 static unsigned int decode_compactedbits(unsigned int lobits,
68 u8 *in, unsigned int pos, u8 *type)
69 {
70 const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7);
71 const unsigned int lo = v & ((1 << lobits) - 1);
72
73 *type = (v >> lobits) & 3;
74 return lo;
75 }
76
get_compacted_la_distance(unsigned int lobits,unsigned int encodebits,unsigned int vcnt,u8 * in,int i)77 static int get_compacted_la_distance(unsigned int lobits,
78 unsigned int encodebits,
79 unsigned int vcnt, u8 *in, int i)
80 {
81 unsigned int lo, d1 = 0;
82 u8 type;
83
84 DBG_BUGON(i >= vcnt);
85
86 do {
87 lo = decode_compactedbits(lobits, in, encodebits * i, &type);
88
89 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD)
90 return d1;
91 ++d1;
92 } while (++i < vcnt);
93
94 /* vcnt - 1 (Z_EROFS_LCLUSTER_TYPE_NONHEAD) item */
95 if (!(lo & Z_EROFS_LI_D0_CBLKCNT))
96 d1 += lo - 1;
97 return d1;
98 }
99
z_erofs_load_compact_lcluster(struct z_erofs_maprecorder * m,unsigned long lcn,bool lookahead)100 static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
101 unsigned long lcn, bool lookahead)
102 {
103 struct inode *const inode = m->inode;
104 struct erofs_inode *const vi = EROFS_I(inode);
105 const erofs_off_t ebase = Z_EROFS_MAP_HEADER_END(erofs_iloc(inode) +
106 vi->inode_isize + vi->xattr_isize);
107 const unsigned int lclusterbits = vi->z_lclusterbits;
108 const unsigned int totalidx = erofs_iblks(inode);
109 unsigned int compacted_4b_initial, compacted_2b, amortizedshift;
110 unsigned int vcnt, lo, lobits, encodebits, nblk, bytes;
111 bool big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
112 erofs_off_t pos;
113 u8 *in, type;
114 int i;
115
116 if (lcn >= totalidx || lclusterbits > 14)
117 return -EINVAL;
118
119 m->lcn = lcn;
120 /* used to align to 32-byte (compacted_2b) alignment */
121 compacted_4b_initial = ((32 - ebase % 32) / 4) & 7;
122 compacted_2b = 0;
123 if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
124 compacted_4b_initial < totalidx)
125 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
126
127 pos = ebase;
128 amortizedshift = 2; /* compact_4b */
129 if (lcn >= compacted_4b_initial) {
130 pos += compacted_4b_initial * 4;
131 lcn -= compacted_4b_initial;
132 if (lcn < compacted_2b) {
133 amortizedshift = 1;
134 } else {
135 pos += compacted_2b * 2;
136 lcn -= compacted_2b;
137 }
138 }
139 pos += lcn * (1 << amortizedshift);
140
141 /* figure out the lcluster count in this pack */
142 if (1 << amortizedshift == 4 && lclusterbits <= 14)
143 vcnt = 2;
144 else if (1 << amortizedshift == 2 && lclusterbits <= 12)
145 vcnt = 16;
146 else
147 return -EOPNOTSUPP;
148
149 in = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, m->in_mbox);
150 if (IS_ERR(in))
151 return PTR_ERR(in);
152
153 /* it doesn't equal to round_up(..) */
154 m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
155 (vcnt << amortizedshift);
156 lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
157 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
158 bytes = pos & ((vcnt << amortizedshift) - 1);
159 in -= bytes;
160 i = bytes >> amortizedshift;
161
162 lo = decode_compactedbits(lobits, in, encodebits * i, &type);
163 m->type = type;
164 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
165 m->clusterofs = 1 << lclusterbits;
166
167 /* figure out lookahead_distance: delta[1] if needed */
168 if (lookahead)
169 m->delta[1] = get_compacted_la_distance(lobits,
170 encodebits, vcnt, in, i);
171 if (lo & Z_EROFS_LI_D0_CBLKCNT) {
172 if (!big_pcluster) {
173 DBG_BUGON(1);
174 return -EFSCORRUPTED;
175 }
176 m->compressedblks = lo & ~Z_EROFS_LI_D0_CBLKCNT;
177 m->delta[0] = 1;
178 return 0;
179 } else if (i + 1 != (int)vcnt) {
180 m->delta[0] = lo;
181 return 0;
182 }
183 /*
184 * since the last lcluster in the pack is special,
185 * of which lo saves delta[1] rather than delta[0].
186 * Hence, get delta[0] by the previous lcluster indirectly.
187 */
188 lo = decode_compactedbits(lobits, in,
189 encodebits * (i - 1), &type);
190 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD)
191 lo = 0;
192 else if (lo & Z_EROFS_LI_D0_CBLKCNT)
193 lo = 1;
194 m->delta[0] = lo + 1;
195 return 0;
196 }
197 m->clusterofs = lo;
198 m->delta[0] = 0;
199 /* figout out blkaddr (pblk) for HEAD lclusters */
200 if (!big_pcluster) {
201 nblk = 1;
202 while (i > 0) {
203 --i;
204 lo = decode_compactedbits(lobits, in,
205 encodebits * i, &type);
206 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD)
207 i -= lo;
208
209 if (i >= 0)
210 ++nblk;
211 }
212 } else {
213 nblk = 0;
214 while (i > 0) {
215 --i;
216 lo = decode_compactedbits(lobits, in,
217 encodebits * i, &type);
218 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
219 if (lo & Z_EROFS_LI_D0_CBLKCNT) {
220 --i;
221 nblk += lo & ~Z_EROFS_LI_D0_CBLKCNT;
222 continue;
223 }
224 /* bigpcluster shouldn't have plain d0 == 1 */
225 if (lo <= 1) {
226 DBG_BUGON(1);
227 return -EFSCORRUPTED;
228 }
229 i -= lo - 2;
230 continue;
231 }
232 ++nblk;
233 }
234 }
235 in += (vcnt << amortizedshift) - sizeof(__le32);
236 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
237 return 0;
238 }
239
z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder * m,unsigned int lcn,bool lookahead)240 static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m,
241 unsigned int lcn, bool lookahead)
242 {
243 if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) {
244 erofs_err(m->inode->i_sb, "unknown type %u @ lcn %u of nid %llu",
245 m->type, lcn, EROFS_I(m->inode)->nid);
246 DBG_BUGON(1);
247 return -EOPNOTSUPP;
248 }
249
250 switch (EROFS_I(m->inode)->datalayout) {
251 case EROFS_INODE_COMPRESSED_FULL:
252 return z_erofs_load_full_lcluster(m, lcn);
253 case EROFS_INODE_COMPRESSED_COMPACT:
254 return z_erofs_load_compact_lcluster(m, lcn, lookahead);
255 default:
256 return -EINVAL;
257 }
258 }
259
z_erofs_extent_lookback(struct z_erofs_maprecorder * m,unsigned int lookback_distance)260 static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
261 unsigned int lookback_distance)
262 {
263 struct super_block *sb = m->inode->i_sb;
264 struct erofs_inode *const vi = EROFS_I(m->inode);
265 const unsigned int lclusterbits = vi->z_lclusterbits;
266
267 while (m->lcn >= lookback_distance) {
268 unsigned long lcn = m->lcn - lookback_distance;
269 int err;
270
271 err = z_erofs_load_lcluster_from_disk(m, lcn, false);
272 if (err)
273 return err;
274
275 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
276 lookback_distance = m->delta[0];
277 if (!lookback_distance)
278 break;
279 continue;
280 } else {
281 m->headtype = m->type;
282 m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
283 return 0;
284 }
285 }
286 erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu",
287 lookback_distance, m->lcn, vi->nid);
288 DBG_BUGON(1);
289 return -EFSCORRUPTED;
290 }
291
z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder * m,unsigned int initial_lcn)292 static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
293 unsigned int initial_lcn)
294 {
295 struct inode *inode = m->inode;
296 struct super_block *sb = inode->i_sb;
297 struct erofs_inode *vi = EROFS_I(inode);
298 bool bigpcl1 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
299 bool bigpcl2 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2;
300 unsigned long lcn = m->lcn + 1;
301 int err;
302
303 DBG_BUGON(m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD);
304 DBG_BUGON(m->type != m->headtype);
305
306 if ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1 && !bigpcl1) ||
307 ((m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN ||
308 m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) && !bigpcl2) ||
309 (lcn << vi->z_lclusterbits) >= inode->i_size)
310 m->compressedblks = 1;
311
312 if (m->compressedblks)
313 goto out;
314
315 err = z_erofs_load_lcluster_from_disk(m, lcn, false);
316 if (err)
317 return err;
318
319 /*
320 * If the 1st NONHEAD lcluster has already been handled initially w/o
321 * valid compressedblks, which means at least it mustn't be CBLKCNT, or
322 * an internal implemenatation error is detected.
323 *
324 * The following code can also handle it properly anyway, but let's
325 * BUG_ON in the debugging mode only for developers to notice that.
326 */
327 DBG_BUGON(lcn == initial_lcn &&
328 m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD);
329
330 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD && m->delta[0] != 1) {
331 erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid);
332 DBG_BUGON(1);
333 return -EFSCORRUPTED;
334 }
335
336 /*
337 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type rather
338 * than CBLKCNT, it's a 1 block-sized pcluster.
339 */
340 if (m->type != Z_EROFS_LCLUSTER_TYPE_NONHEAD || !m->compressedblks)
341 m->compressedblks = 1;
342 out:
343 m->map->m_plen = erofs_pos(sb, m->compressedblks);
344 return 0;
345 }
346
z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder * m)347 static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
348 {
349 struct inode *inode = m->inode;
350 struct erofs_inode *vi = EROFS_I(inode);
351 struct erofs_map_blocks *map = m->map;
352 unsigned int lclusterbits = vi->z_lclusterbits;
353 u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits;
354 int err;
355
356 while (1) {
357 /* handle the last EOF pcluster (no next HEAD lcluster) */
358 if ((lcn << lclusterbits) >= inode->i_size) {
359 map->m_llen = inode->i_size - map->m_la;
360 return 0;
361 }
362
363 err = z_erofs_load_lcluster_from_disk(m, lcn, true);
364 if (err)
365 return err;
366
367 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
368 /* work around invalid d1 generated by pre-1.0 mkfs */
369 if (unlikely(!m->delta[1])) {
370 m->delta[1] = 1;
371 DBG_BUGON(1);
372 }
373 } else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) {
374 if (lcn != headlcn)
375 break; /* ends at the next HEAD lcluster */
376 m->delta[1] = 1;
377 }
378 lcn += m->delta[1];
379 }
380 map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la;
381 return 0;
382 }
383
z_erofs_map_blocks_fo(struct inode * inode,struct erofs_map_blocks * map,int flags)384 static int z_erofs_map_blocks_fo(struct inode *inode,
385 struct erofs_map_blocks *map, int flags)
386 {
387 struct erofs_inode *vi = EROFS_I(inode);
388 struct super_block *sb = inode->i_sb;
389 bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
390 bool ztailpacking = vi->z_idata_size;
391 unsigned int lclusterbits = vi->z_lclusterbits;
392 struct z_erofs_maprecorder m = {
393 .inode = inode,
394 .map = map,
395 .in_mbox = erofs_inode_in_metabox(inode),
396 };
397 unsigned int endoff;
398 unsigned long initial_lcn;
399 unsigned long long ofs, end;
400 int err;
401
402 ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la;
403 if (fragment && !(flags & EROFS_GET_BLOCKS_FINDTAIL) &&
404 !vi->z_tailextent_headlcn) {
405 map->m_la = 0;
406 map->m_llen = inode->i_size;
407 map->m_flags = EROFS_MAP_FRAGMENT;
408 return 0;
409 }
410 initial_lcn = ofs >> lclusterbits;
411 endoff = ofs & ((1 << lclusterbits) - 1);
412
413 err = z_erofs_load_lcluster_from_disk(&m, initial_lcn, false);
414 if (err)
415 goto unmap_out;
416
417 if ((flags & EROFS_GET_BLOCKS_FINDTAIL) && ztailpacking)
418 vi->z_fragmentoff = m.nextpackoff;
419 map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
420 end = (m.lcn + 1ULL) << lclusterbits;
421
422 if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD && endoff >= m.clusterofs) {
423 m.headtype = m.type;
424 map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
425 /*
426 * For ztailpacking files, in order to inline data more
427 * effectively, special EOF lclusters are now supported
428 * which can have three parts at most.
429 */
430 if (ztailpacking && end > inode->i_size)
431 end = inode->i_size;
432 } else {
433 if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
434 /* m.lcn should be >= 1 if endoff < m.clusterofs */
435 if (!m.lcn) {
436 erofs_err(sb, "invalid logical cluster 0 at nid %llu",
437 vi->nid);
438 err = -EFSCORRUPTED;
439 goto unmap_out;
440 }
441 end = (m.lcn << lclusterbits) | m.clusterofs;
442 map->m_flags |= EROFS_MAP_FULL_MAPPED;
443 m.delta[0] = 1;
444 }
445 /* get the corresponding first chunk */
446 err = z_erofs_extent_lookback(&m, m.delta[0]);
447 if (err)
448 goto unmap_out;
449 }
450 if (m.partialref)
451 map->m_flags |= EROFS_MAP_PARTIAL_REF;
452 map->m_llen = end - map->m_la;
453
454 if (flags & EROFS_GET_BLOCKS_FINDTAIL) {
455 vi->z_tailextent_headlcn = m.lcn;
456 /* for non-compact indexes, fragmentoff is 64 bits */
457 if (fragment && vi->datalayout == EROFS_INODE_COMPRESSED_FULL)
458 vi->z_fragmentoff |= (u64)m.pblk << 32;
459 }
460 if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
461 map->m_flags |= EROFS_MAP_META;
462 map->m_pa = vi->z_fragmentoff;
463 map->m_plen = vi->z_idata_size;
464 if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) {
465 erofs_err(sb, "invalid tail-packing pclustersize %llu",
466 map->m_plen);
467 err = -EFSCORRUPTED;
468 goto unmap_out;
469 }
470 } else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
471 map->m_flags = EROFS_MAP_FRAGMENT;
472 } else {
473 map->m_pa = erofs_pos(sb, m.pblk);
474 err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
475 if (err)
476 goto unmap_out;
477 }
478
479 if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) {
480 if (map->m_llen > map->m_plen) {
481 DBG_BUGON(1);
482 err = -EFSCORRUPTED;
483 goto unmap_out;
484 }
485 if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
486 map->m_algorithmformat = Z_EROFS_COMPRESSION_INTERLACED;
487 else
488 map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
489 } else if (m.headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) {
490 map->m_algorithmformat = vi->z_algorithmtype[1];
491 } else {
492 map->m_algorithmformat = vi->z_algorithmtype[0];
493 }
494
495 if ((flags & EROFS_GET_BLOCKS_FIEMAP) ||
496 ((flags & EROFS_GET_BLOCKS_READMORE) &&
497 (map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA ||
498 map->m_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE ||
499 map->m_algorithmformat == Z_EROFS_COMPRESSION_ZSTD) &&
500 map->m_llen >= i_blocksize(inode))) {
501 err = z_erofs_get_extent_decompressedlen(&m);
502 if (!err)
503 map->m_flags |= EROFS_MAP_FULL_MAPPED;
504 }
505
506 unmap_out:
507 erofs_unmap_metabuf(&m.map->buf);
508 return err;
509 }
510
z_erofs_map_blocks_ext(struct inode * inode,struct erofs_map_blocks * map,int flags)511 static int z_erofs_map_blocks_ext(struct inode *inode,
512 struct erofs_map_blocks *map, int flags)
513 {
514 struct erofs_inode *vi = EROFS_I(inode);
515 struct super_block *sb = inode->i_sb;
516 bool interlaced = vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER;
517 unsigned int recsz = z_erofs_extent_recsize(vi->z_advise);
518 erofs_off_t pos = round_up(Z_EROFS_MAP_HEADER_END(erofs_iloc(inode) +
519 vi->inode_isize + vi->xattr_isize), recsz);
520 bool in_mbox = erofs_inode_in_metabox(inode);
521 erofs_off_t lend = inode->i_size;
522 erofs_off_t l, r, mid, pa, la, lstart;
523 struct z_erofs_extent *ext;
524 unsigned int fmt;
525 bool last;
526
527 map->m_flags = 0;
528 if (recsz <= offsetof(struct z_erofs_extent, pstart_hi)) {
529 if (recsz <= offsetof(struct z_erofs_extent, pstart_lo)) {
530 ext = erofs_read_metabuf(&map->buf, sb, pos, in_mbox);
531 if (IS_ERR(ext))
532 return PTR_ERR(ext);
533 pa = le64_to_cpu(*(__le64 *)ext);
534 pos += sizeof(__le64);
535 lstart = 0;
536 } else {
537 lstart = round_down(map->m_la, 1 << vi->z_lclusterbits);
538 pos += (lstart >> vi->z_lclusterbits) * recsz;
539 pa = EROFS_NULL_ADDR;
540 }
541
542 for (; lstart <= map->m_la; lstart += 1 << vi->z_lclusterbits) {
543 ext = erofs_read_metabuf(&map->buf, sb, pos, in_mbox);
544 if (IS_ERR(ext))
545 return PTR_ERR(ext);
546 map->m_plen = le32_to_cpu(ext->plen);
547 if (pa != EROFS_NULL_ADDR) {
548 map->m_pa = pa;
549 pa += map->m_plen & Z_EROFS_EXTENT_PLEN_MASK;
550 } else {
551 map->m_pa = le32_to_cpu(ext->pstart_lo);
552 }
553 pos += recsz;
554 }
555 last = (lstart >= round_up(lend, 1 << vi->z_lclusterbits));
556 lend = min(lstart, lend);
557 lstart -= 1 << vi->z_lclusterbits;
558 } else {
559 lstart = lend;
560 for (l = 0, r = vi->z_extents; l < r; ) {
561 mid = l + (r - l) / 2;
562 ext = erofs_read_metabuf(&map->buf, sb,
563 pos + mid * recsz, in_mbox);
564 if (IS_ERR(ext))
565 return PTR_ERR(ext);
566
567 la = le32_to_cpu(ext->lstart_lo);
568 pa = le32_to_cpu(ext->pstart_lo) |
569 (u64)le32_to_cpu(ext->pstart_hi) << 32;
570 if (recsz > offsetof(struct z_erofs_extent, lstart_hi))
571 la |= (u64)le32_to_cpu(ext->lstart_hi) << 32;
572
573 if (la > map->m_la) {
574 r = mid;
575 if (la > lend) {
576 DBG_BUGON(1);
577 return -EFSCORRUPTED;
578 }
579 lend = la;
580 } else {
581 l = mid + 1;
582 if (map->m_la == la)
583 r = min(l + 1, r);
584 lstart = la;
585 map->m_plen = le32_to_cpu(ext->plen);
586 map->m_pa = pa;
587 }
588 }
589 last = (l >= vi->z_extents);
590 }
591
592 if (lstart < lend) {
593 map->m_la = lstart;
594 if (last && (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) {
595 map->m_flags = EROFS_MAP_FRAGMENT;
596 vi->z_fragmentoff = map->m_plen;
597 if (recsz > offsetof(struct z_erofs_extent, pstart_lo))
598 vi->z_fragmentoff |= map->m_pa << 32;
599 } else if (map->m_plen) {
600 map->m_flags |= EROFS_MAP_MAPPED |
601 EROFS_MAP_FULL_MAPPED | EROFS_MAP_ENCODED;
602 fmt = map->m_plen >> Z_EROFS_EXTENT_PLEN_FMT_BIT;
603 if (fmt)
604 map->m_algorithmformat = fmt - 1;
605 else if (interlaced && !erofs_blkoff(sb, map->m_pa))
606 map->m_algorithmformat =
607 Z_EROFS_COMPRESSION_INTERLACED;
608 else
609 map->m_algorithmformat =
610 Z_EROFS_COMPRESSION_SHIFTED;
611 if (map->m_plen & Z_EROFS_EXTENT_PLEN_PARTIAL)
612 map->m_flags |= EROFS_MAP_PARTIAL_REF;
613 map->m_plen &= Z_EROFS_EXTENT_PLEN_MASK;
614 }
615 }
616 map->m_llen = lend - map->m_la;
617 return 0;
618 }
619
z_erofs_fill_inode(struct inode * inode,struct erofs_map_blocks * map)620 static int z_erofs_fill_inode(struct inode *inode, struct erofs_map_blocks *map)
621 {
622 struct erofs_inode *const vi = EROFS_I(inode);
623 struct super_block *const sb = inode->i_sb;
624 struct z_erofs_map_header *h;
625 erofs_off_t pos;
626 int err = 0;
627
628 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) {
629 /*
630 * paired with smp_mb() at the end of the function to ensure
631 * fields will only be observed after the bit is set.
632 */
633 smp_mb();
634 return 0;
635 }
636
637 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE))
638 return -ERESTARTSYS;
639
640 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags))
641 goto out_unlock;
642
643 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8);
644 h = erofs_read_metabuf(&map->buf, sb, pos, erofs_inode_in_metabox(inode));
645 if (IS_ERR(h)) {
646 err = PTR_ERR(h);
647 goto out_unlock;
648 }
649
650 /*
651 * if the highest bit of the 8-byte map header is set, the whole file
652 * is stored in the packed inode. The rest bits keeps z_fragmentoff.
653 */
654 if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) {
655 vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
656 vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
657 vi->z_tailextent_headlcn = 0;
658 goto done;
659 }
660 vi->z_advise = le16_to_cpu(h->h_advise);
661 vi->z_lclusterbits = sb->s_blocksize_bits + (h->h_clusterbits & 15);
662 if (vi->datalayout == EROFS_INODE_COMPRESSED_FULL &&
663 (vi->z_advise & Z_EROFS_ADVISE_EXTENTS)) {
664 vi->z_extents = le32_to_cpu(h->h_extents_lo) |
665 ((u64)le16_to_cpu(h->h_extents_hi) << 32);
666 goto done;
667 }
668
669 vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
670 vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
671 if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)
672 vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
673 else if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER)
674 vi->z_idata_size = le16_to_cpu(h->h_idata_size);
675
676 if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
677 vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 |
678 Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
679 erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu",
680 vi->nid);
681 err = -EFSCORRUPTED;
682 goto out_unlock;
683 }
684 if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT &&
685 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
686 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
687 erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu",
688 vi->nid);
689 err = -EFSCORRUPTED;
690 goto out_unlock;
691 }
692
693 if (vi->z_idata_size ||
694 (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) {
695 struct erofs_map_blocks tm = {
696 .buf = __EROFS_BUF_INITIALIZER
697 };
698
699 err = z_erofs_map_blocks_fo(inode, &tm,
700 EROFS_GET_BLOCKS_FINDTAIL);
701 erofs_put_metabuf(&tm.buf);
702 if (err < 0)
703 goto out_unlock;
704 }
705 done:
706 /* paired with smp_mb() at the beginning of the function */
707 smp_mb();
708 set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
709 out_unlock:
710 clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags);
711 return err;
712 }
713
z_erofs_map_sanity_check(struct inode * inode,struct erofs_map_blocks * map)714 static int z_erofs_map_sanity_check(struct inode *inode,
715 struct erofs_map_blocks *map)
716 {
717 struct erofs_sb_info *sbi = EROFS_I_SB(inode);
718
719 if (!(map->m_flags & EROFS_MAP_ENCODED))
720 return 0;
721 if (unlikely(map->m_algorithmformat >= Z_EROFS_COMPRESSION_RUNTIME_MAX)) {
722 erofs_err(inode->i_sb, "unknown algorithm %d @ pos %llu for nid %llu, please upgrade kernel",
723 map->m_algorithmformat, map->m_la, EROFS_I(inode)->nid);
724 return -EOPNOTSUPP;
725 }
726 if (unlikely(map->m_algorithmformat < Z_EROFS_COMPRESSION_MAX &&
727 !(sbi->available_compr_algs & (1 << map->m_algorithmformat)))) {
728 erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu",
729 map->m_algorithmformat, EROFS_I(inode)->nid);
730 return -EFSCORRUPTED;
731 }
732 if (unlikely(map->m_plen > Z_EROFS_PCLUSTER_MAX_SIZE ||
733 map->m_llen > Z_EROFS_PCLUSTER_MAX_DSIZE))
734 return -EOPNOTSUPP;
735 return 0;
736 }
737
z_erofs_map_blocks_iter(struct inode * inode,struct erofs_map_blocks * map,int flags)738 int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map,
739 int flags)
740 {
741 struct erofs_inode *const vi = EROFS_I(inode);
742 int err = 0;
743
744 trace_erofs_map_blocks_enter(inode, map, flags);
745 if (map->m_la >= inode->i_size) { /* post-EOF unmapped extent */
746 map->m_llen = map->m_la + 1 - inode->i_size;
747 map->m_la = inode->i_size;
748 map->m_flags = 0;
749 } else {
750 err = z_erofs_fill_inode(inode, map);
751 if (!err) {
752 if (vi->datalayout == EROFS_INODE_COMPRESSED_FULL &&
753 (vi->z_advise & Z_EROFS_ADVISE_EXTENTS))
754 err = z_erofs_map_blocks_ext(inode, map, flags);
755 else
756 err = z_erofs_map_blocks_fo(inode, map, flags);
757 }
758 if (!err)
759 err = z_erofs_map_sanity_check(inode, map);
760 if (err)
761 map->m_llen = 0;
762 }
763 trace_erofs_map_blocks_exit(inode, map, flags, err);
764 return err;
765 }
766
z_erofs_iomap_begin_report(struct inode * inode,loff_t offset,loff_t length,unsigned int flags,struct iomap * iomap,struct iomap * srcmap)767 static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
768 loff_t length, unsigned int flags,
769 struct iomap *iomap, struct iomap *srcmap)
770 {
771 int ret;
772 struct erofs_map_blocks map = { .m_la = offset };
773
774 ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP);
775 erofs_put_metabuf(&map.buf);
776 if (ret < 0)
777 return ret;
778
779 iomap->bdev = inode->i_sb->s_bdev;
780 iomap->offset = map.m_la;
781 iomap->length = map.m_llen;
782 if (map.m_flags & EROFS_MAP_MAPPED) {
783 iomap->type = IOMAP_MAPPED;
784 iomap->addr = map.m_flags & __EROFS_MAP_FRAGMENT ?
785 IOMAP_NULL_ADDR : map.m_pa;
786 } else {
787 iomap->type = IOMAP_HOLE;
788 iomap->addr = IOMAP_NULL_ADDR;
789 /*
790 * No strict rule on how to describe extents for post EOF, yet
791 * we need to do like below. Otherwise, iomap itself will get
792 * into an endless loop on post EOF.
793 *
794 * Calculate the effective offset by subtracting extent start
795 * (map.m_la) from the requested offset, and add it to length.
796 * (NB: offset >= map.m_la always)
797 */
798 if (iomap->offset >= inode->i_size)
799 iomap->length = length + offset - map.m_la;
800 }
801 iomap->flags = 0;
802 return 0;
803 }
804
805 const struct iomap_ops z_erofs_iomap_report_ops = {
806 .iomap_begin = z_erofs_iomap_begin_report,
807 };
808