1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2018-2019 HUAWEI, Inc.
4 * https://www.huawei.com/
7 #include <asm/unaligned.h>
8 #include <trace/events/erofs.h>
10 int z_erofs_fill_inode(struct inode *inode)
12 struct erofs_inode *const vi = EROFS_I(inode);
13 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
15 if (!erofs_sb_has_big_pcluster(sbi) &&
16 vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) {
18 vi->z_algorithmtype[0] = 0;
19 vi->z_algorithmtype[1] = 0;
20 vi->z_logical_clusterbits = LOG_BLOCK_SIZE;
21 set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
23 inode->i_mapping->a_ops = &z_erofs_aops;
27 static int z_erofs_fill_inode_lazy(struct inode *inode)
29 struct erofs_inode *const vi = EROFS_I(inode);
30 struct super_block *const sb = inode->i_sb;
35 struct z_erofs_map_header *h;
37 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) {
39 * paired with smp_mb() at the end of the function to ensure
40 * fields will only be observed after the bit is set.
46 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE))
50 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags))
53 DBG_BUGON(!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
54 vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
56 pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
58 page = erofs_get_meta_page(sb, erofs_blknr(pos));
64 kaddr = kmap_atomic(page);
66 h = kaddr + erofs_blkoff(pos);
67 vi->z_advise = le16_to_cpu(h->h_advise);
68 vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
69 vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
71 if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX) {
72 erofs_err(sb, "unknown compression format %u for nid %llu, please upgrade kernel",
73 vi->z_algorithmtype[0], vi->nid);
78 vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
79 if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
80 vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 |
81 Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
82 erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu",
87 if (vi->datalayout == EROFS_INODE_FLAT_COMPRESSION &&
88 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
89 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
90 erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu",
95 /* paired with smp_mb() at the beginning of the function */
97 set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
103 clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags);
107 struct z_erofs_maprecorder {
109 struct erofs_map_blocks *map;
113 /* compression extent information gathered */
117 erofs_blk_t pblk, compressedlcs;
120 static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
123 struct super_block *const sb = m->inode->i_sb;
124 struct erofs_map_blocks *const map = m->map;
125 struct page *mpage = map->mpage;
128 if (mpage->index == eblk) {
130 m->kaddr = kmap_atomic(mpage);
135 kunmap_atomic(m->kaddr);
141 mpage = erofs_get_meta_page(sb, eblk);
144 return PTR_ERR(mpage);
146 m->kaddr = kmap_atomic(mpage);
152 static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
155 struct inode *const inode = m->inode;
156 struct erofs_inode *const vi = EROFS_I(inode);
157 const erofs_off_t ibase = iloc(EROFS_I_SB(inode), vi->nid);
158 const erofs_off_t pos =
159 Z_EROFS_VLE_LEGACY_INDEX_ALIGN(ibase + vi->inode_isize +
161 lcn * sizeof(struct z_erofs_vle_decompressed_index);
162 struct z_erofs_vle_decompressed_index *di;
163 unsigned int advise, type;
166 err = z_erofs_reload_indexes(m, erofs_blknr(pos));
171 di = m->kaddr + erofs_blkoff(pos);
173 advise = le16_to_cpu(di->di_advise);
174 type = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) &
175 ((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1);
177 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
178 m->clusterofs = 1 << vi->z_logical_clusterbits;
179 m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
180 if (m->delta[0] & Z_EROFS_VLE_DI_D0_CBLKCNT) {
181 if (!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
183 return -EFSCORRUPTED;
185 m->compressedlcs = m->delta[0] &
186 ~Z_EROFS_VLE_DI_D0_CBLKCNT;
189 m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
191 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
192 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
193 m->clusterofs = le16_to_cpu(di->di_clusterofs);
194 m->pblk = le32_to_cpu(di->di_u.blkaddr);
204 static unsigned int decode_compactedbits(unsigned int lobits,
206 u8 *in, unsigned int pos, u8 *type)
208 const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7);
209 const unsigned int lo = v & lomask;
211 *type = (v >> lobits) & 3;
215 static int unpack_compacted_index(struct z_erofs_maprecorder *m,
216 unsigned int amortizedshift,
219 struct erofs_inode *const vi = EROFS_I(m->inode);
220 const unsigned int lclusterbits = vi->z_logical_clusterbits;
221 const unsigned int lomask = (1 << lclusterbits) - 1;
222 unsigned int vcnt, base, lo, encodebits, nblk;
227 if (1 << amortizedshift == 4)
229 else if (1 << amortizedshift == 2 && lclusterbits == 12)
234 big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
235 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
236 base = round_down(eofs, vcnt << amortizedshift);
237 in = m->kaddr + base;
239 i = (eofs - base) >> amortizedshift;
241 lo = decode_compactedbits(lclusterbits, lomask,
242 in, encodebits * i, &type);
244 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
245 m->clusterofs = 1 << lclusterbits;
246 if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
249 return -EFSCORRUPTED;
251 m->compressedlcs = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
254 } else if (i + 1 != (int)vcnt) {
259 * since the last lcluster in the pack is special,
260 * of which lo saves delta[1] rather than delta[0].
261 * Hence, get delta[0] by the previous lcluster indirectly.
263 lo = decode_compactedbits(lclusterbits, lomask,
264 in, encodebits * (i - 1), &type);
265 if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
267 else if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT)
269 m->delta[0] = lo + 1;
274 /* figout out blkaddr (pblk) for HEAD lclusters */
279 lo = decode_compactedbits(lclusterbits, lomask,
280 in, encodebits * i, &type);
281 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
291 lo = decode_compactedbits(lclusterbits, lomask,
292 in, encodebits * i, &type);
293 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
294 if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
296 nblk += lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
299 /* bigpcluster shouldn't have plain d0 == 1 */
302 return -EFSCORRUPTED;
310 in += (vcnt << amortizedshift) - sizeof(__le32);
311 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
315 static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
318 struct inode *const inode = m->inode;
319 struct erofs_inode *const vi = EROFS_I(inode);
320 const unsigned int lclusterbits = vi->z_logical_clusterbits;
321 const erofs_off_t ebase = ALIGN(iloc(EROFS_I_SB(inode), vi->nid) +
322 vi->inode_isize + vi->xattr_isize, 8) +
323 sizeof(struct z_erofs_map_header);
324 const unsigned int totalidx = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
325 unsigned int compacted_4b_initial, compacted_2b;
326 unsigned int amortizedshift;
330 if (lclusterbits != 12)
337 /* used to align to 32-byte (compacted_2b) alignment */
338 compacted_4b_initial = (32 - ebase % 32) / 4;
339 if (compacted_4b_initial == 32 / 4)
340 compacted_4b_initial = 0;
342 if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
343 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
348 if (lcn < compacted_4b_initial) {
352 pos += compacted_4b_initial * 4;
353 lcn -= compacted_4b_initial;
355 if (lcn < compacted_2b) {
359 pos += compacted_2b * 2;
363 pos += lcn * (1 << amortizedshift);
364 err = z_erofs_reload_indexes(m, erofs_blknr(pos));
367 return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos));
370 static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
373 const unsigned int datamode = EROFS_I(m->inode)->datalayout;
375 if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
376 return legacy_load_cluster_from_disk(m, lcn);
378 if (datamode == EROFS_INODE_FLAT_COMPRESSION)
379 return compacted_load_cluster_from_disk(m, lcn);
384 static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
385 unsigned int lookback_distance)
387 struct erofs_inode *const vi = EROFS_I(m->inode);
388 struct erofs_map_blocks *const map = m->map;
389 const unsigned int lclusterbits = vi->z_logical_clusterbits;
390 unsigned long lcn = m->lcn;
393 if (lcn < lookback_distance) {
394 erofs_err(m->inode->i_sb,
395 "bogus lookback distance @ nid %llu", vi->nid);
397 return -EFSCORRUPTED;
400 /* load extent head logical cluster if needed */
401 lcn -= lookback_distance;
402 err = z_erofs_load_cluster_from_disk(m, lcn);
407 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
409 erofs_err(m->inode->i_sb,
410 "invalid lookback distance 0 @ nid %llu",
413 return -EFSCORRUPTED;
415 return z_erofs_extent_lookback(m, m->delta[0]);
416 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
417 map->m_flags &= ~EROFS_MAP_ZIPPED;
419 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
420 map->m_la = (lcn << lclusterbits) | m->clusterofs;
423 erofs_err(m->inode->i_sb,
424 "unknown type %u @ lcn %lu of nid %llu",
425 m->type, lcn, vi->nid);
432 static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
433 unsigned int initial_lcn)
435 struct erofs_inode *const vi = EROFS_I(m->inode);
436 struct erofs_map_blocks *const map = m->map;
437 const unsigned int lclusterbits = vi->z_logical_clusterbits;
441 DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN &&
442 m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD);
443 if (!(map->m_flags & EROFS_MAP_ZIPPED) ||
444 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
445 map->m_plen = 1 << lclusterbits;
450 if (m->compressedlcs)
453 err = z_erofs_load_cluster_from_disk(m, lcn);
458 * If the 1st NONHEAD lcluster has already been handled initially w/o
459 * valid compressedlcs, which means at least it mustn't be CBLKCNT, or
460 * an internal implemenatation error is detected.
462 * The following code can also handle it properly anyway, but let's
463 * BUG_ON in the debugging mode only for developers to notice that.
465 DBG_BUGON(lcn == initial_lcn &&
466 m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD);
469 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
470 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
472 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
473 * rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
475 m->compressedlcs = 1;
477 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
478 if (m->delta[0] != 1)
479 goto err_bonus_cblkcnt;
480 if (m->compressedlcs)
484 erofs_err(m->inode->i_sb,
485 "cannot found CBLKCNT @ lcn %lu of nid %llu",
488 return -EFSCORRUPTED;
491 map->m_plen = m->compressedlcs << lclusterbits;
494 erofs_err(m->inode->i_sb,
495 "bogus CBLKCNT @ lcn %lu of nid %llu",
498 return -EFSCORRUPTED;
501 int z_erofs_map_blocks_iter(struct inode *inode,
502 struct erofs_map_blocks *map,
505 struct erofs_inode *const vi = EROFS_I(inode);
506 struct z_erofs_maprecorder m = {
511 unsigned int lclusterbits, endoff;
512 unsigned long initial_lcn;
513 unsigned long long ofs, end;
515 trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
517 /* when trying to read beyond EOF, leave it unmapped */
518 if (map->m_la >= inode->i_size) {
519 map->m_llen = map->m_la + 1 - inode->i_size;
520 map->m_la = inode->i_size;
525 err = z_erofs_fill_inode_lazy(inode);
529 lclusterbits = vi->z_logical_clusterbits;
531 initial_lcn = ofs >> lclusterbits;
532 endoff = ofs & ((1 << lclusterbits) - 1);
534 err = z_erofs_load_cluster_from_disk(&m, initial_lcn);
538 map->m_flags = EROFS_MAP_ZIPPED; /* by default, compressed */
539 end = (m.lcn + 1ULL) << lclusterbits;
542 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
543 if (endoff >= m.clusterofs)
544 map->m_flags &= ~EROFS_MAP_ZIPPED;
546 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
547 if (endoff >= m.clusterofs) {
548 map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
551 /* m.lcn should be >= 1 if endoff < m.clusterofs */
553 erofs_err(inode->i_sb,
554 "invalid logical cluster 0 at nid %llu",
559 end = (m.lcn << lclusterbits) | m.clusterofs;
560 map->m_flags |= EROFS_MAP_FULL_MAPPED;
563 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
564 /* get the corresponding first chunk */
565 err = z_erofs_extent_lookback(&m, m.delta[0]);
570 erofs_err(inode->i_sb,
571 "unknown type %u @ offset %llu of nid %llu",
572 m.type, ofs, vi->nid);
577 map->m_llen = end - map->m_la;
578 map->m_pa = blknr_to_addr(m.pblk);
579 map->m_flags |= EROFS_MAP_MAPPED;
581 err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
586 kunmap_atomic(m.kaddr);
589 erofs_dbg("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
590 __func__, map->m_la, map->m_pa,
591 map->m_llen, map->m_plen, map->m_flags);
593 trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
595 /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
596 DBG_BUGON(err < 0 && err != -ENOMEM);