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 get_compacted_la_distance(unsigned int lclusterbits,
216 unsigned int encodebits,
217 unsigned int vcnt, u8 *in, int i)
219 const unsigned int lomask = (1 << lclusterbits) - 1;
220 unsigned int lo, d1 = 0;
223 DBG_BUGON(i >= vcnt);
226 lo = decode_compactedbits(lclusterbits, lomask,
227 in, encodebits * i, &type);
229 if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
232 } while (++i < vcnt);
234 /* vcnt - 1 (Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) item */
235 if (!(lo & Z_EROFS_VLE_DI_D0_CBLKCNT))
240 static int unpack_compacted_index(struct z_erofs_maprecorder *m,
241 unsigned int amortizedshift,
242 unsigned int eofs, bool lookahead)
244 struct erofs_inode *const vi = EROFS_I(m->inode);
245 const unsigned int lclusterbits = vi->z_logical_clusterbits;
246 const unsigned int lomask = (1 << lclusterbits) - 1;
247 unsigned int vcnt, base, lo, encodebits, nblk;
252 if (1 << amortizedshift == 4)
254 else if (1 << amortizedshift == 2 && lclusterbits == 12)
259 big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
260 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
261 base = round_down(eofs, vcnt << amortizedshift);
262 in = m->kaddr + base;
264 i = (eofs - base) >> amortizedshift;
266 lo = decode_compactedbits(lclusterbits, lomask,
267 in, encodebits * i, &type);
269 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
270 m->clusterofs = 1 << lclusterbits;
272 /* figure out lookahead_distance: delta[1] if needed */
274 m->delta[1] = get_compacted_la_distance(lclusterbits,
275 encodebits, vcnt, in, i);
276 if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
279 return -EFSCORRUPTED;
281 m->compressedlcs = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
284 } else if (i + 1 != (int)vcnt) {
289 * since the last lcluster in the pack is special,
290 * of which lo saves delta[1] rather than delta[0].
291 * Hence, get delta[0] by the previous lcluster indirectly.
293 lo = decode_compactedbits(lclusterbits, lomask,
294 in, encodebits * (i - 1), &type);
295 if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
297 else if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT)
299 m->delta[0] = lo + 1;
304 /* figout out blkaddr (pblk) for HEAD lclusters */
309 lo = decode_compactedbits(lclusterbits, lomask,
310 in, encodebits * i, &type);
311 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
321 lo = decode_compactedbits(lclusterbits, lomask,
322 in, encodebits * i, &type);
323 if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
324 if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
326 nblk += lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
329 /* bigpcluster shouldn't have plain d0 == 1 */
332 return -EFSCORRUPTED;
340 in += (vcnt << amortizedshift) - sizeof(__le32);
341 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
345 static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
346 unsigned long lcn, bool lookahead)
348 struct inode *const inode = m->inode;
349 struct erofs_inode *const vi = EROFS_I(inode);
350 const unsigned int lclusterbits = vi->z_logical_clusterbits;
351 const erofs_off_t ebase = ALIGN(iloc(EROFS_I_SB(inode), vi->nid) +
352 vi->inode_isize + vi->xattr_isize, 8) +
353 sizeof(struct z_erofs_map_header);
354 const unsigned int totalidx = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
355 unsigned int compacted_4b_initial, compacted_2b;
356 unsigned int amortizedshift;
360 if (lclusterbits != 12)
367 /* used to align to 32-byte (compacted_2b) alignment */
368 compacted_4b_initial = (32 - ebase % 32) / 4;
369 if (compacted_4b_initial == 32 / 4)
370 compacted_4b_initial = 0;
372 if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
373 compacted_4b_initial < totalidx)
374 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
379 if (lcn < compacted_4b_initial) {
383 pos += compacted_4b_initial * 4;
384 lcn -= compacted_4b_initial;
386 if (lcn < compacted_2b) {
390 pos += compacted_2b * 2;
394 pos += lcn * (1 << amortizedshift);
395 err = z_erofs_reload_indexes(m, erofs_blknr(pos));
398 return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos),
402 static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
403 unsigned int lcn, bool lookahead)
405 const unsigned int datamode = EROFS_I(m->inode)->datalayout;
407 if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
408 return legacy_load_cluster_from_disk(m, lcn);
410 if (datamode == EROFS_INODE_FLAT_COMPRESSION)
411 return compacted_load_cluster_from_disk(m, lcn, lookahead);
416 static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
417 unsigned int lookback_distance)
419 struct erofs_inode *const vi = EROFS_I(m->inode);
420 struct erofs_map_blocks *const map = m->map;
421 const unsigned int lclusterbits = vi->z_logical_clusterbits;
422 unsigned long lcn = m->lcn;
425 if (lcn < lookback_distance) {
426 erofs_err(m->inode->i_sb,
427 "bogus lookback distance @ nid %llu", vi->nid);
429 return -EFSCORRUPTED;
432 /* load extent head logical cluster if needed */
433 lcn -= lookback_distance;
434 err = z_erofs_load_cluster_from_disk(m, lcn, false);
439 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
441 erofs_err(m->inode->i_sb,
442 "invalid lookback distance 0 @ nid %llu",
445 return -EFSCORRUPTED;
447 return z_erofs_extent_lookback(m, m->delta[0]);
448 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
449 map->m_flags &= ~EROFS_MAP_ZIPPED;
451 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
452 map->m_la = (lcn << lclusterbits) | m->clusterofs;
455 erofs_err(m->inode->i_sb,
456 "unknown type %u @ lcn %lu of nid %llu",
457 m->type, lcn, vi->nid);
464 static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
465 unsigned int initial_lcn)
467 struct erofs_inode *const vi = EROFS_I(m->inode);
468 struct erofs_map_blocks *const map = m->map;
469 const unsigned int lclusterbits = vi->z_logical_clusterbits;
473 DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN &&
474 m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD);
475 if (!(map->m_flags & EROFS_MAP_ZIPPED) ||
476 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
477 map->m_plen = 1 << lclusterbits;
482 if (m->compressedlcs)
485 err = z_erofs_load_cluster_from_disk(m, lcn, false);
490 * If the 1st NONHEAD lcluster has already been handled initially w/o
491 * valid compressedlcs, which means at least it mustn't be CBLKCNT, or
492 * an internal implemenatation error is detected.
494 * The following code can also handle it properly anyway, but let's
495 * BUG_ON in the debugging mode only for developers to notice that.
497 DBG_BUGON(lcn == initial_lcn &&
498 m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD);
501 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
502 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
504 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
505 * rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
507 m->compressedlcs = 1;
509 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
510 if (m->delta[0] != 1)
511 goto err_bonus_cblkcnt;
512 if (m->compressedlcs)
516 erofs_err(m->inode->i_sb,
517 "cannot found CBLKCNT @ lcn %lu of nid %llu",
520 return -EFSCORRUPTED;
523 map->m_plen = m->compressedlcs << lclusterbits;
526 erofs_err(m->inode->i_sb,
527 "bogus CBLKCNT @ lcn %lu of nid %llu",
530 return -EFSCORRUPTED;
533 static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
535 struct inode *inode = m->inode;
536 struct erofs_inode *vi = EROFS_I(inode);
537 struct erofs_map_blocks *map = m->map;
538 unsigned int lclusterbits = vi->z_logical_clusterbits;
539 u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits;
543 /* handle the last EOF pcluster (no next HEAD lcluster) */
544 if ((lcn << lclusterbits) >= inode->i_size) {
545 map->m_llen = inode->i_size - map->m_la;
549 err = z_erofs_load_cluster_from_disk(m, lcn, true);
553 if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
554 DBG_BUGON(!m->delta[1] &&
555 m->clusterofs != 1 << lclusterbits);
556 } else if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
557 m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD) {
558 /* go on until the next HEAD lcluster */
563 erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu",
564 m->type, lcn, vi->nid);
569 } while (m->delta[1]);
571 map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la;
575 int z_erofs_map_blocks_iter(struct inode *inode,
576 struct erofs_map_blocks *map,
579 struct erofs_inode *const vi = EROFS_I(inode);
580 struct z_erofs_maprecorder m = {
585 unsigned int lclusterbits, endoff;
586 unsigned long initial_lcn;
587 unsigned long long ofs, end;
589 trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
591 /* when trying to read beyond EOF, leave it unmapped */
592 if (map->m_la >= inode->i_size) {
593 map->m_llen = map->m_la + 1 - inode->i_size;
594 map->m_la = inode->i_size;
599 err = z_erofs_fill_inode_lazy(inode);
603 lclusterbits = vi->z_logical_clusterbits;
605 initial_lcn = ofs >> lclusterbits;
606 endoff = ofs & ((1 << lclusterbits) - 1);
608 err = z_erofs_load_cluster_from_disk(&m, initial_lcn, false);
612 map->m_flags = EROFS_MAP_ZIPPED; /* by default, compressed */
613 end = (m.lcn + 1ULL) << lclusterbits;
616 case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
617 if (endoff >= m.clusterofs)
618 map->m_flags &= ~EROFS_MAP_ZIPPED;
620 case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
621 if (endoff >= m.clusterofs) {
622 map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
625 /* m.lcn should be >= 1 if endoff < m.clusterofs */
627 erofs_err(inode->i_sb,
628 "invalid logical cluster 0 at nid %llu",
633 end = (m.lcn << lclusterbits) | m.clusterofs;
634 map->m_flags |= EROFS_MAP_FULL_MAPPED;
637 case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
638 /* get the corresponding first chunk */
639 err = z_erofs_extent_lookback(&m, m.delta[0]);
644 erofs_err(inode->i_sb,
645 "unknown type %u @ offset %llu of nid %llu",
646 m.type, ofs, vi->nid);
651 map->m_llen = end - map->m_la;
652 map->m_pa = blknr_to_addr(m.pblk);
653 map->m_flags |= EROFS_MAP_MAPPED;
655 err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
659 if (flags & EROFS_GET_BLOCKS_FIEMAP) {
660 err = z_erofs_get_extent_decompressedlen(&m);
662 map->m_flags |= EROFS_MAP_FULL_MAPPED;
666 kunmap_atomic(m.kaddr);
669 erofs_dbg("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
670 __func__, map->m_la, map->m_pa,
671 map->m_llen, map->m_plen, map->m_flags);
673 trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
675 /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
676 DBG_BUGON(err < 0 && err != -ENOMEM);
680 static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
681 loff_t length, unsigned int flags,
682 struct iomap *iomap, struct iomap *srcmap)
685 struct erofs_map_blocks map = { .m_la = offset };
687 ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP);
693 iomap->bdev = inode->i_sb->s_bdev;
694 iomap->offset = map.m_la;
695 iomap->length = map.m_llen;
696 if (map.m_flags & EROFS_MAP_MAPPED) {
697 iomap->type = IOMAP_MAPPED;
698 iomap->addr = map.m_pa;
700 iomap->type = IOMAP_HOLE;
701 iomap->addr = IOMAP_NULL_ADDR;
703 * No strict rule how to describe extents for post EOF, yet
704 * we need do like below. Otherwise, iomap itself will get
705 * into an endless loop on post EOF.
707 if (iomap->offset >= inode->i_size)
708 iomap->length = length + map.m_la - offset;
714 const struct iomap_ops z_erofs_iomap_report_ops = {
715 .iomap_begin = z_erofs_iomap_begin_report,