1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2018 HUAWEI, Inc. 4 * http://www.huawei.com/ 5 * Created by Gao Xiang <gaoxiang25@huawei.com> 6 */ 7 #include "zdata.h" 8 #include "compress.h" 9 #include <linux/prefetch.h> 10 11 #include <trace/events/erofs.h> 12 13 /* 14 * a compressed_pages[] placeholder in order to avoid 15 * being filled with file pages for in-place decompression. 16 */ 17 #define PAGE_UNALLOCATED ((void *)0x5F0E4B1D) 18 19 /* how to allocate cached pages for a pcluster */ 20 enum z_erofs_cache_alloctype { 21 DONTALLOC, /* don't allocate any cached pages */ 22 DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */ 23 }; 24 25 /* 26 * tagged pointer with 1-bit tag for all compressed pages 27 * tag 0 - the page is just found with an extra page reference 28 */ 29 typedef tagptr1_t compressed_page_t; 30 31 #define tag_compressed_page_justfound(page) \ 32 tagptr_fold(compressed_page_t, page, 1) 33 34 static struct workqueue_struct *z_erofs_workqueue __read_mostly; 35 static struct kmem_cache *pcluster_cachep __read_mostly; 36 37 void z_erofs_exit_zip_subsystem(void) 38 { 39 destroy_workqueue(z_erofs_workqueue); 40 kmem_cache_destroy(pcluster_cachep); 41 } 42 43 static inline int z_erofs_init_workqueue(void) 44 { 45 const unsigned int onlinecpus = num_possible_cpus(); 46 const unsigned int flags = WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE; 47 48 /* 49 * no need to spawn too many threads, limiting threads could minimum 50 * scheduling overhead, perhaps per-CPU threads should be better? 51 */ 52 z_erofs_workqueue = alloc_workqueue("erofs_unzipd", flags, 53 onlinecpus + onlinecpus / 4); 54 return z_erofs_workqueue ? 0 : -ENOMEM; 55 } 56 57 static void z_erofs_pcluster_init_once(void *ptr) 58 { 59 struct z_erofs_pcluster *pcl = ptr; 60 struct z_erofs_collection *cl = z_erofs_primarycollection(pcl); 61 unsigned int i; 62 63 mutex_init(&cl->lock); 64 cl->nr_pages = 0; 65 cl->vcnt = 0; 66 for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i) 67 pcl->compressed_pages[i] = NULL; 68 } 69 70 int __init z_erofs_init_zip_subsystem(void) 71 { 72 pcluster_cachep = kmem_cache_create("erofs_compress", 73 Z_EROFS_WORKGROUP_SIZE, 0, 74 SLAB_RECLAIM_ACCOUNT, 75 z_erofs_pcluster_init_once); 76 if (pcluster_cachep) { 77 if (!z_erofs_init_workqueue()) 78 return 0; 79 80 kmem_cache_destroy(pcluster_cachep); 81 } 82 return -ENOMEM; 83 } 84 85 enum z_erofs_collectmode { 86 COLLECT_SECONDARY, 87 COLLECT_PRIMARY, 88 /* 89 * The current collection was the tail of an exist chain, in addition 90 * that the previous processed chained collections are all decided to 91 * be hooked up to it. 92 * A new chain will be created for the remaining collections which are 93 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED, 94 * the next collection cannot reuse the whole page safely in 95 * the following scenario: 96 * ________________________________________________________________ 97 * | tail (partial) page | head (partial) page | 98 * | (belongs to the next cl) | (belongs to the current cl) | 99 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| 100 */ 101 COLLECT_PRIMARY_HOOKED, 102 COLLECT_PRIMARY_FOLLOWED_NOINPLACE, 103 /* 104 * The current collection has been linked with the owned chain, and 105 * could also be linked with the remaining collections, which means 106 * if the processing page is the tail page of the collection, thus 107 * the current collection can safely use the whole page (since 108 * the previous collection is under control) for in-place I/O, as 109 * illustrated below: 110 * ________________________________________________________________ 111 * | tail (partial) page | head (partial) page | 112 * | (of the current cl) | (of the previous collection) | 113 * | PRIMARY_FOLLOWED or | | 114 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| 115 * 116 * [ (*) the above page can be used as inplace I/O. ] 117 */ 118 COLLECT_PRIMARY_FOLLOWED, 119 }; 120 121 struct z_erofs_collector { 122 struct z_erofs_pagevec_ctor vector; 123 124 struct z_erofs_pcluster *pcl, *tailpcl; 125 struct z_erofs_collection *cl; 126 struct page **compressedpages; 127 z_erofs_next_pcluster_t owned_head; 128 129 enum z_erofs_collectmode mode; 130 }; 131 132 struct z_erofs_decompress_frontend { 133 struct inode *const inode; 134 135 struct z_erofs_collector clt; 136 struct erofs_map_blocks map; 137 138 /* used for applying cache strategy on the fly */ 139 bool backmost; 140 erofs_off_t headoffset; 141 }; 142 143 #define COLLECTOR_INIT() { \ 144 .owned_head = Z_EROFS_PCLUSTER_TAIL, \ 145 .mode = COLLECT_PRIMARY_FOLLOWED } 146 147 #define DECOMPRESS_FRONTEND_INIT(__i) { \ 148 .inode = __i, .clt = COLLECTOR_INIT(), \ 149 .backmost = true, } 150 151 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES]; 152 static DEFINE_MUTEX(z_pagemap_global_lock); 153 154 static void preload_compressed_pages(struct z_erofs_collector *clt, 155 struct address_space *mc, 156 enum z_erofs_cache_alloctype type, 157 struct list_head *pagepool) 158 { 159 const struct z_erofs_pcluster *pcl = clt->pcl; 160 const unsigned int clusterpages = BIT(pcl->clusterbits); 161 struct page **pages = clt->compressedpages; 162 pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages); 163 bool standalone = true; 164 165 if (clt->mode < COLLECT_PRIMARY_FOLLOWED) 166 return; 167 168 for (; pages < pcl->compressed_pages + clusterpages; ++pages) { 169 struct page *page; 170 compressed_page_t t; 171 172 /* the compressed page was loaded before */ 173 if (READ_ONCE(*pages)) 174 continue; 175 176 page = find_get_page(mc, index); 177 178 if (page) { 179 t = tag_compressed_page_justfound(page); 180 } else if (type == DELAYEDALLOC) { 181 t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED); 182 } else { /* DONTALLOC */ 183 if (standalone) 184 clt->compressedpages = pages; 185 standalone = false; 186 continue; 187 } 188 189 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t))) 190 continue; 191 192 if (page) 193 put_page(page); 194 } 195 196 if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */ 197 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE; 198 } 199 200 /* called by erofs_shrinker to get rid of all compressed_pages */ 201 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 202 struct erofs_workgroup *grp) 203 { 204 struct z_erofs_pcluster *const pcl = 205 container_of(grp, struct z_erofs_pcluster, obj); 206 struct address_space *const mapping = MNGD_MAPPING(sbi); 207 const unsigned int clusterpages = BIT(pcl->clusterbits); 208 int i; 209 210 /* 211 * refcount of workgroup is now freezed as 1, 212 * therefore no need to worry about available decompression users. 213 */ 214 for (i = 0; i < clusterpages; ++i) { 215 struct page *page = pcl->compressed_pages[i]; 216 217 if (!page) 218 continue; 219 220 /* block other users from reclaiming or migrating the page */ 221 if (!trylock_page(page)) 222 return -EBUSY; 223 224 if (page->mapping != mapping) 225 continue; 226 227 /* barrier is implied in the following 'unlock_page' */ 228 WRITE_ONCE(pcl->compressed_pages[i], NULL); 229 set_page_private(page, 0); 230 ClearPagePrivate(page); 231 232 unlock_page(page); 233 put_page(page); 234 } 235 return 0; 236 } 237 238 int erofs_try_to_free_cached_page(struct address_space *mapping, 239 struct page *page) 240 { 241 struct z_erofs_pcluster *const pcl = (void *)page_private(page); 242 const unsigned int clusterpages = BIT(pcl->clusterbits); 243 int ret = 0; /* 0 - busy */ 244 245 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) { 246 unsigned int i; 247 248 for (i = 0; i < clusterpages; ++i) { 249 if (pcl->compressed_pages[i] == page) { 250 WRITE_ONCE(pcl->compressed_pages[i], NULL); 251 ret = 1; 252 break; 253 } 254 } 255 erofs_workgroup_unfreeze(&pcl->obj, 1); 256 257 if (ret) { 258 ClearPagePrivate(page); 259 put_page(page); 260 } 261 } 262 return ret; 263 } 264 265 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ 266 static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt, 267 struct page *page) 268 { 269 struct z_erofs_pcluster *const pcl = clt->pcl; 270 const unsigned int clusterpages = BIT(pcl->clusterbits); 271 272 while (clt->compressedpages < pcl->compressed_pages + clusterpages) { 273 if (!cmpxchg(clt->compressedpages++, NULL, page)) 274 return true; 275 } 276 return false; 277 } 278 279 /* callers must be with collection lock held */ 280 static int z_erofs_attach_page(struct z_erofs_collector *clt, 281 struct page *page, 282 enum z_erofs_page_type type) 283 { 284 int ret; 285 bool occupied; 286 287 /* give priority for inplaceio */ 288 if (clt->mode >= COLLECT_PRIMARY && 289 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && 290 z_erofs_try_inplace_io(clt, page)) 291 return 0; 292 293 ret = z_erofs_pagevec_enqueue(&clt->vector, 294 page, type, &occupied); 295 clt->cl->vcnt += (unsigned int)ret; 296 297 return ret ? 0 : -EAGAIN; 298 } 299 300 static enum z_erofs_collectmode 301 try_to_claim_pcluster(struct z_erofs_pcluster *pcl, 302 z_erofs_next_pcluster_t *owned_head) 303 { 304 /* let's claim these following types of pclusters */ 305 retry: 306 if (pcl->next == Z_EROFS_PCLUSTER_NIL) { 307 /* type 1, nil pcluster */ 308 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, 309 *owned_head) != Z_EROFS_PCLUSTER_NIL) 310 goto retry; 311 312 *owned_head = &pcl->next; 313 /* lucky, I am the followee :) */ 314 return COLLECT_PRIMARY_FOLLOWED; 315 } else if (pcl->next == Z_EROFS_PCLUSTER_TAIL) { 316 /* 317 * type 2, link to the end of a existing open chain, 318 * be careful that its submission itself is governed 319 * by the original owned chain. 320 */ 321 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 322 *owned_head) != Z_EROFS_PCLUSTER_TAIL) 323 goto retry; 324 *owned_head = Z_EROFS_PCLUSTER_TAIL; 325 return COLLECT_PRIMARY_HOOKED; 326 } 327 return COLLECT_PRIMARY; /* :( better luck next time */ 328 } 329 330 static int z_erofs_lookup_collection(struct z_erofs_collector *clt, 331 struct inode *inode, 332 struct erofs_map_blocks *map) 333 { 334 struct z_erofs_pcluster *pcl = clt->pcl; 335 struct z_erofs_collection *cl; 336 unsigned int length; 337 338 /* to avoid unexpected loop formed by corrupted images */ 339 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) { 340 DBG_BUGON(1); 341 return -EFSCORRUPTED; 342 } 343 344 cl = z_erofs_primarycollection(pcl); 345 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) { 346 DBG_BUGON(1); 347 return -EFSCORRUPTED; 348 } 349 350 length = READ_ONCE(pcl->length); 351 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) { 352 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) { 353 DBG_BUGON(1); 354 return -EFSCORRUPTED; 355 } 356 } else { 357 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT; 358 359 if (map->m_flags & EROFS_MAP_FULL_MAPPED) 360 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH; 361 362 while (llen > length && 363 length != cmpxchg_relaxed(&pcl->length, length, llen)) { 364 cpu_relax(); 365 length = READ_ONCE(pcl->length); 366 } 367 } 368 mutex_lock(&cl->lock); 369 /* used to check tail merging loop due to corrupted images */ 370 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 371 clt->tailpcl = pcl; 372 clt->mode = try_to_claim_pcluster(pcl, &clt->owned_head); 373 /* clean tailpcl if the current owned_head is Z_EROFS_PCLUSTER_TAIL */ 374 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 375 clt->tailpcl = NULL; 376 clt->cl = cl; 377 return 0; 378 } 379 380 static int z_erofs_register_collection(struct z_erofs_collector *clt, 381 struct inode *inode, 382 struct erofs_map_blocks *map) 383 { 384 struct z_erofs_pcluster *pcl; 385 struct z_erofs_collection *cl; 386 struct erofs_workgroup *grp; 387 int err; 388 389 /* no available workgroup, let's allocate one */ 390 pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS); 391 if (!pcl) 392 return -ENOMEM; 393 394 atomic_set(&pcl->obj.refcount, 1); 395 pcl->obj.index = map->m_pa >> PAGE_SHIFT; 396 397 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) | 398 (map->m_flags & EROFS_MAP_FULL_MAPPED ? 399 Z_EROFS_PCLUSTER_FULL_LENGTH : 0); 400 401 if (map->m_flags & EROFS_MAP_ZIPPED) 402 pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4; 403 else 404 pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED; 405 406 pcl->clusterbits = EROFS_I(inode)->z_physical_clusterbits[0]; 407 pcl->clusterbits -= PAGE_SHIFT; 408 409 /* new pclusters should be claimed as type 1, primary and followed */ 410 pcl->next = clt->owned_head; 411 clt->mode = COLLECT_PRIMARY_FOLLOWED; 412 413 cl = z_erofs_primarycollection(pcl); 414 415 /* must be cleaned before freeing to slab */ 416 DBG_BUGON(cl->nr_pages); 417 DBG_BUGON(cl->vcnt); 418 419 cl->pageofs = map->m_la & ~PAGE_MASK; 420 421 /* 422 * lock all primary followed works before visible to others 423 * and mutex_trylock *never* fails for a new pcluster. 424 */ 425 DBG_BUGON(!mutex_trylock(&cl->lock)); 426 427 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj); 428 if (IS_ERR(grp)) { 429 err = PTR_ERR(grp); 430 goto err_out; 431 } 432 433 if (grp != &pcl->obj) { 434 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 435 err = -EEXIST; 436 goto err_out; 437 } 438 /* used to check tail merging loop due to corrupted images */ 439 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 440 clt->tailpcl = pcl; 441 clt->owned_head = &pcl->next; 442 clt->pcl = pcl; 443 clt->cl = cl; 444 return 0; 445 446 err_out: 447 mutex_unlock(&cl->lock); 448 kmem_cache_free(pcluster_cachep, pcl); 449 return err; 450 } 451 452 static int z_erofs_collector_begin(struct z_erofs_collector *clt, 453 struct inode *inode, 454 struct erofs_map_blocks *map) 455 { 456 struct erofs_workgroup *grp; 457 int ret; 458 459 DBG_BUGON(clt->cl); 460 461 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */ 462 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL); 463 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 464 465 if (!PAGE_ALIGNED(map->m_pa)) { 466 DBG_BUGON(1); 467 return -EINVAL; 468 } 469 470 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT); 471 if (grp) { 472 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 473 } else { 474 ret = z_erofs_register_collection(clt, inode, map); 475 476 if (!ret) 477 goto out; 478 if (ret != -EEXIST) 479 return ret; 480 } 481 482 ret = z_erofs_lookup_collection(clt, inode, map); 483 if (ret) { 484 erofs_workgroup_put(&clt->pcl->obj); 485 return ret; 486 } 487 488 out: 489 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS, 490 clt->cl->pagevec, clt->cl->vcnt); 491 492 clt->compressedpages = clt->pcl->compressed_pages; 493 if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */ 494 clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES; 495 return 0; 496 } 497 498 /* 499 * keep in mind that no referenced pclusters will be freed 500 * only after a RCU grace period. 501 */ 502 static void z_erofs_rcu_callback(struct rcu_head *head) 503 { 504 struct z_erofs_collection *const cl = 505 container_of(head, struct z_erofs_collection, rcu); 506 507 kmem_cache_free(pcluster_cachep, 508 container_of(cl, struct z_erofs_pcluster, 509 primary_collection)); 510 } 511 512 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) 513 { 514 struct z_erofs_pcluster *const pcl = 515 container_of(grp, struct z_erofs_pcluster, obj); 516 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl); 517 518 call_rcu(&cl->rcu, z_erofs_rcu_callback); 519 } 520 521 static void z_erofs_collection_put(struct z_erofs_collection *cl) 522 { 523 struct z_erofs_pcluster *const pcl = 524 container_of(cl, struct z_erofs_pcluster, primary_collection); 525 526 erofs_workgroup_put(&pcl->obj); 527 } 528 529 static bool z_erofs_collector_end(struct z_erofs_collector *clt) 530 { 531 struct z_erofs_collection *cl = clt->cl; 532 533 if (!cl) 534 return false; 535 536 z_erofs_pagevec_ctor_exit(&clt->vector, false); 537 mutex_unlock(&cl->lock); 538 539 /* 540 * if all pending pages are added, don't hold its reference 541 * any longer if the pcluster isn't hosted by ourselves. 542 */ 543 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE) 544 z_erofs_collection_put(cl); 545 546 clt->cl = NULL; 547 return true; 548 } 549 550 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe, 551 unsigned int cachestrategy, 552 erofs_off_t la) 553 { 554 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) 555 return false; 556 557 if (fe->backmost) 558 return true; 559 560 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND && 561 la < fe->headoffset; 562 } 563 564 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 565 struct page *page, 566 struct list_head *pagepool) 567 { 568 struct inode *const inode = fe->inode; 569 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 570 struct erofs_map_blocks *const map = &fe->map; 571 struct z_erofs_collector *const clt = &fe->clt; 572 const loff_t offset = page_offset(page); 573 bool tight = true; 574 575 enum z_erofs_cache_alloctype cache_strategy; 576 enum z_erofs_page_type page_type; 577 unsigned int cur, end, spiltted, index; 578 int err = 0; 579 580 /* register locked file pages as online pages in pack */ 581 z_erofs_onlinepage_init(page); 582 583 spiltted = 0; 584 end = PAGE_SIZE; 585 repeat: 586 cur = end - 1; 587 588 /* lucky, within the range of the current map_blocks */ 589 if (offset + cur >= map->m_la && 590 offset + cur < map->m_la + map->m_llen) { 591 /* didn't get a valid collection previously (very rare) */ 592 if (!clt->cl) 593 goto restart_now; 594 goto hitted; 595 } 596 597 /* go ahead the next map_blocks */ 598 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur); 599 600 if (z_erofs_collector_end(clt)) 601 fe->backmost = false; 602 603 map->m_la = offset + cur; 604 map->m_llen = 0; 605 err = z_erofs_map_blocks_iter(inode, map, 0); 606 if (err) 607 goto err_out; 608 609 restart_now: 610 if (!(map->m_flags & EROFS_MAP_MAPPED)) 611 goto hitted; 612 613 err = z_erofs_collector_begin(clt, inode, map); 614 if (err) 615 goto err_out; 616 617 /* preload all compressed pages (maybe downgrade role if necessary) */ 618 if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la)) 619 cache_strategy = DELAYEDALLOC; 620 else 621 cache_strategy = DONTALLOC; 622 623 preload_compressed_pages(clt, MNGD_MAPPING(sbi), 624 cache_strategy, pagepool); 625 626 hitted: 627 /* 628 * Ensure the current partial page belongs to this submit chain rather 629 * than other concurrent submit chains or the noio(bypass) chain since 630 * those chains are handled asynchronously thus the page cannot be used 631 * for inplace I/O or pagevec (should be processed in strict order.) 632 */ 633 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED && 634 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE); 635 636 cur = end - min_t(unsigned int, offset + end - map->m_la, end); 637 if (!(map->m_flags & EROFS_MAP_MAPPED)) { 638 zero_user_segment(page, cur, end); 639 goto next_part; 640 } 641 642 /* let's derive page type */ 643 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD : 644 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 645 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 646 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); 647 648 if (cur) 649 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED); 650 651 retry: 652 err = z_erofs_attach_page(clt, page, page_type); 653 /* should allocate an additional staging page for pagevec */ 654 if (err == -EAGAIN) { 655 struct page *const newpage = 656 erofs_allocpage(pagepool, GFP_NOFS | __GFP_NOFAIL); 657 658 newpage->mapping = Z_EROFS_MAPPING_STAGING; 659 err = z_erofs_attach_page(clt, newpage, 660 Z_EROFS_PAGE_TYPE_EXCLUSIVE); 661 if (!err) 662 goto retry; 663 } 664 665 if (err) 666 goto err_out; 667 668 index = page->index - (map->m_la >> PAGE_SHIFT); 669 670 z_erofs_onlinepage_fixup(page, index, true); 671 672 /* bump up the number of spiltted parts of a page */ 673 ++spiltted; 674 /* also update nr_pages */ 675 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1); 676 next_part: 677 /* can be used for verification */ 678 map->m_llen = offset + cur - map->m_la; 679 680 end = cur; 681 if (end > 0) 682 goto repeat; 683 684 out: 685 z_erofs_onlinepage_endio(page); 686 687 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu", 688 __func__, page, spiltted, map->m_llen); 689 return err; 690 691 /* if some error occurred while processing this page */ 692 err_out: 693 SetPageError(page); 694 goto out; 695 } 696 697 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, 698 bool sync, int bios) 699 { 700 /* wake up the caller thread for sync decompression */ 701 if (sync) { 702 unsigned long flags; 703 704 spin_lock_irqsave(&io->u.wait.lock, flags); 705 if (!atomic_add_return(bios, &io->pending_bios)) 706 wake_up_locked(&io->u.wait); 707 spin_unlock_irqrestore(&io->u.wait.lock, flags); 708 return; 709 } 710 711 if (!atomic_add_return(bios, &io->pending_bios)) 712 queue_work(z_erofs_workqueue, &io->u.work); 713 } 714 715 static void z_erofs_decompressqueue_endio(struct bio *bio) 716 { 717 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private); 718 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t); 719 blk_status_t err = bio->bi_status; 720 struct bio_vec *bvec; 721 struct bvec_iter_all iter_all; 722 723 bio_for_each_segment_all(bvec, bio, iter_all) { 724 struct page *page = bvec->bv_page; 725 726 DBG_BUGON(PageUptodate(page)); 727 DBG_BUGON(!page->mapping); 728 729 if (err) 730 SetPageError(page); 731 732 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { 733 if (!err) 734 SetPageUptodate(page); 735 unlock_page(page); 736 } 737 } 738 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); 739 bio_put(bio); 740 } 741 742 static int z_erofs_decompress_pcluster(struct super_block *sb, 743 struct z_erofs_pcluster *pcl, 744 struct list_head *pagepool) 745 { 746 struct erofs_sb_info *const sbi = EROFS_SB(sb); 747 const unsigned int clusterpages = BIT(pcl->clusterbits); 748 struct z_erofs_pagevec_ctor ctor; 749 unsigned int i, outputsize, llen, nr_pages; 750 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES]; 751 struct page **pages, **compressed_pages, *page; 752 753 enum z_erofs_page_type page_type; 754 bool overlapped, partial; 755 struct z_erofs_collection *cl; 756 int err; 757 758 might_sleep(); 759 cl = z_erofs_primarycollection(pcl); 760 DBG_BUGON(!READ_ONCE(cl->nr_pages)); 761 762 mutex_lock(&cl->lock); 763 nr_pages = cl->nr_pages; 764 765 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) { 766 pages = pages_onstack; 767 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES && 768 mutex_trylock(&z_pagemap_global_lock)) { 769 pages = z_pagemap_global; 770 } else { 771 gfp_t gfp_flags = GFP_KERNEL; 772 773 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES) 774 gfp_flags |= __GFP_NOFAIL; 775 776 pages = kvmalloc_array(nr_pages, sizeof(struct page *), 777 gfp_flags); 778 779 /* fallback to global pagemap for the lowmem scenario */ 780 if (!pages) { 781 mutex_lock(&z_pagemap_global_lock); 782 pages = z_pagemap_global; 783 } 784 } 785 786 for (i = 0; i < nr_pages; ++i) 787 pages[i] = NULL; 788 789 err = 0; 790 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, 791 cl->pagevec, 0); 792 793 for (i = 0; i < cl->vcnt; ++i) { 794 unsigned int pagenr; 795 796 page = z_erofs_pagevec_dequeue(&ctor, &page_type); 797 798 /* all pages in pagevec ought to be valid */ 799 DBG_BUGON(!page); 800 DBG_BUGON(!page->mapping); 801 802 if (z_erofs_put_stagingpage(pagepool, page)) 803 continue; 804 805 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD) 806 pagenr = 0; 807 else 808 pagenr = z_erofs_onlinepage_index(page); 809 810 DBG_BUGON(pagenr >= nr_pages); 811 812 /* 813 * currently EROFS doesn't support multiref(dedup), 814 * so here erroring out one multiref page. 815 */ 816 if (pages[pagenr]) { 817 DBG_BUGON(1); 818 SetPageError(pages[pagenr]); 819 z_erofs_onlinepage_endio(pages[pagenr]); 820 err = -EFSCORRUPTED; 821 } 822 pages[pagenr] = page; 823 } 824 z_erofs_pagevec_ctor_exit(&ctor, true); 825 826 overlapped = false; 827 compressed_pages = pcl->compressed_pages; 828 829 for (i = 0; i < clusterpages; ++i) { 830 unsigned int pagenr; 831 832 page = compressed_pages[i]; 833 834 /* all compressed pages ought to be valid */ 835 DBG_BUGON(!page); 836 DBG_BUGON(!page->mapping); 837 838 if (!z_erofs_page_is_staging(page)) { 839 if (erofs_page_is_managed(sbi, page)) { 840 if (!PageUptodate(page)) 841 err = -EIO; 842 continue; 843 } 844 845 /* 846 * only if non-head page can be selected 847 * for inplace decompression 848 */ 849 pagenr = z_erofs_onlinepage_index(page); 850 851 DBG_BUGON(pagenr >= nr_pages); 852 if (pages[pagenr]) { 853 DBG_BUGON(1); 854 SetPageError(pages[pagenr]); 855 z_erofs_onlinepage_endio(pages[pagenr]); 856 err = -EFSCORRUPTED; 857 } 858 pages[pagenr] = page; 859 860 overlapped = true; 861 } 862 863 /* PG_error needs checking for inplaced and staging pages */ 864 if (PageError(page)) { 865 DBG_BUGON(PageUptodate(page)); 866 err = -EIO; 867 } 868 } 869 870 if (err) 871 goto out; 872 873 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT; 874 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) { 875 outputsize = llen; 876 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH); 877 } else { 878 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs; 879 partial = true; 880 } 881 882 err = z_erofs_decompress(&(struct z_erofs_decompress_req) { 883 .sb = sb, 884 .in = compressed_pages, 885 .out = pages, 886 .pageofs_out = cl->pageofs, 887 .inputsize = PAGE_SIZE, 888 .outputsize = outputsize, 889 .alg = pcl->algorithmformat, 890 .inplace_io = overlapped, 891 .partial_decoding = partial 892 }, pagepool); 893 894 out: 895 /* must handle all compressed pages before endding pages */ 896 for (i = 0; i < clusterpages; ++i) { 897 page = compressed_pages[i]; 898 899 if (erofs_page_is_managed(sbi, page)) 900 continue; 901 902 /* recycle all individual staging pages */ 903 (void)z_erofs_put_stagingpage(pagepool, page); 904 905 WRITE_ONCE(compressed_pages[i], NULL); 906 } 907 908 for (i = 0; i < nr_pages; ++i) { 909 page = pages[i]; 910 if (!page) 911 continue; 912 913 DBG_BUGON(!page->mapping); 914 915 /* recycle all individual staging pages */ 916 if (z_erofs_put_stagingpage(pagepool, page)) 917 continue; 918 919 if (err < 0) 920 SetPageError(page); 921 922 z_erofs_onlinepage_endio(page); 923 } 924 925 if (pages == z_pagemap_global) 926 mutex_unlock(&z_pagemap_global_lock); 927 else if (pages != pages_onstack) 928 kvfree(pages); 929 930 cl->nr_pages = 0; 931 cl->vcnt = 0; 932 933 /* all cl locks MUST be taken before the following line */ 934 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); 935 936 /* all cl locks SHOULD be released right now */ 937 mutex_unlock(&cl->lock); 938 939 z_erofs_collection_put(cl); 940 return err; 941 } 942 943 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, 944 struct list_head *pagepool) 945 { 946 z_erofs_next_pcluster_t owned = io->head; 947 948 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { 949 struct z_erofs_pcluster *pcl; 950 951 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ 952 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); 953 954 /* no possible that 'owned' equals NULL */ 955 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); 956 957 pcl = container_of(owned, struct z_erofs_pcluster, next); 958 owned = READ_ONCE(pcl->next); 959 960 z_erofs_decompress_pcluster(io->sb, pcl, pagepool); 961 } 962 } 963 964 static void z_erofs_decompressqueue_work(struct work_struct *work) 965 { 966 struct z_erofs_decompressqueue *bgq = 967 container_of(work, struct z_erofs_decompressqueue, u.work); 968 LIST_HEAD(pagepool); 969 970 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 971 z_erofs_decompress_queue(bgq, &pagepool); 972 973 put_pages_list(&pagepool); 974 kvfree(bgq); 975 } 976 977 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 978 unsigned int nr, 979 struct list_head *pagepool, 980 struct address_space *mc, 981 gfp_t gfp) 982 { 983 const pgoff_t index = pcl->obj.index; 984 bool tocache = false; 985 986 struct address_space *mapping; 987 struct page *oldpage, *page; 988 989 compressed_page_t t; 990 int justfound; 991 992 repeat: 993 page = READ_ONCE(pcl->compressed_pages[nr]); 994 oldpage = page; 995 996 if (!page) 997 goto out_allocpage; 998 999 /* 1000 * the cached page has not been allocated and 1001 * an placeholder is out there, prepare it now. 1002 */ 1003 if (page == PAGE_UNALLOCATED) { 1004 tocache = true; 1005 goto out_allocpage; 1006 } 1007 1008 /* process the target tagged pointer */ 1009 t = tagptr_init(compressed_page_t, page); 1010 justfound = tagptr_unfold_tags(t); 1011 page = tagptr_unfold_ptr(t); 1012 1013 mapping = READ_ONCE(page->mapping); 1014 1015 /* 1016 * unmanaged (file) pages are all locked solidly, 1017 * therefore it is impossible for `mapping' to be NULL. 1018 */ 1019 if (mapping && mapping != mc) 1020 /* ought to be unmanaged pages */ 1021 goto out; 1022 1023 lock_page(page); 1024 1025 /* only true if page reclaim goes wrong, should never happen */ 1026 DBG_BUGON(justfound && PagePrivate(page)); 1027 1028 /* the page is still in manage cache */ 1029 if (page->mapping == mc) { 1030 WRITE_ONCE(pcl->compressed_pages[nr], page); 1031 1032 ClearPageError(page); 1033 if (!PagePrivate(page)) { 1034 /* 1035 * impossible to be !PagePrivate(page) for 1036 * the current restriction as well if 1037 * the page is already in compressed_pages[]. 1038 */ 1039 DBG_BUGON(!justfound); 1040 1041 justfound = 0; 1042 set_page_private(page, (unsigned long)pcl); 1043 SetPagePrivate(page); 1044 } 1045 1046 /* no need to submit io if it is already up-to-date */ 1047 if (PageUptodate(page)) { 1048 unlock_page(page); 1049 page = NULL; 1050 } 1051 goto out; 1052 } 1053 1054 /* 1055 * the managed page has been truncated, it's unsafe to 1056 * reuse this one, let's allocate a new cache-managed page. 1057 */ 1058 DBG_BUGON(page->mapping); 1059 DBG_BUGON(!justfound); 1060 1061 tocache = true; 1062 unlock_page(page); 1063 put_page(page); 1064 out_allocpage: 1065 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); 1066 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { 1067 /* non-LRU / non-movable temporary page is needed */ 1068 page->mapping = Z_EROFS_MAPPING_STAGING; 1069 tocache = false; 1070 } 1071 1072 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) { 1073 if (tocache) { 1074 /* since it added to managed cache successfully */ 1075 unlock_page(page); 1076 put_page(page); 1077 } else { 1078 list_add(&page->lru, pagepool); 1079 } 1080 cond_resched(); 1081 goto repeat; 1082 } 1083 set_page_private(page, (unsigned long)pcl); 1084 SetPagePrivate(page); 1085 out: /* the only exit (for tracing and debugging) */ 1086 return page; 1087 } 1088 1089 static struct z_erofs_decompressqueue * 1090 jobqueue_init(struct super_block *sb, 1091 struct z_erofs_decompressqueue *fgq, bool *fg) 1092 { 1093 struct z_erofs_decompressqueue *q; 1094 1095 if (fg && !*fg) { 1096 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); 1097 if (!q) { 1098 *fg = true; 1099 goto fg_out; 1100 } 1101 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); 1102 } else { 1103 fg_out: 1104 q = fgq; 1105 init_waitqueue_head(&fgq->u.wait); 1106 atomic_set(&fgq->pending_bios, 0); 1107 } 1108 q->sb = sb; 1109 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1110 return q; 1111 } 1112 1113 /* define decompression jobqueue types */ 1114 enum { 1115 JQ_BYPASS, 1116 JQ_SUBMIT, 1117 NR_JOBQUEUES, 1118 }; 1119 1120 static void *jobqueueset_init(struct super_block *sb, 1121 struct z_erofs_decompressqueue *q[], 1122 struct z_erofs_decompressqueue *fgq, bool *fg) 1123 { 1124 /* 1125 * if managed cache is enabled, bypass jobqueue is needed, 1126 * no need to read from device for all pclusters in this queue. 1127 */ 1128 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); 1129 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg); 1130 1131 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg)); 1132 } 1133 1134 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 1135 z_erofs_next_pcluster_t qtail[], 1136 z_erofs_next_pcluster_t owned_head) 1137 { 1138 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; 1139 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; 1140 1141 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1142 if (owned_head == Z_EROFS_PCLUSTER_TAIL) 1143 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1144 1145 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); 1146 1147 WRITE_ONCE(*submit_qtail, owned_head); 1148 WRITE_ONCE(*bypass_qtail, &pcl->next); 1149 1150 qtail[JQ_BYPASS] = &pcl->next; 1151 } 1152 1153 static void z_erofs_submit_queue(struct super_block *sb, 1154 z_erofs_next_pcluster_t owned_head, 1155 struct list_head *pagepool, 1156 struct z_erofs_decompressqueue *fgq, 1157 bool *force_fg) 1158 { 1159 struct erofs_sb_info *const sbi = EROFS_SB(sb); 1160 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; 1161 struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; 1162 void *bi_private; 1163 /* since bio will be NULL, no need to initialize last_index */ 1164 pgoff_t uninitialized_var(last_index); 1165 unsigned int nr_bios = 0; 1166 struct bio *bio = NULL; 1167 1168 bi_private = jobqueueset_init(sb, q, fgq, force_fg); 1169 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; 1170 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; 1171 1172 /* by default, all need io submission */ 1173 q[JQ_SUBMIT]->head = owned_head; 1174 1175 do { 1176 struct z_erofs_pcluster *pcl; 1177 pgoff_t cur, end; 1178 unsigned int i = 0; 1179 bool bypass = true; 1180 1181 /* no possible 'owned_head' equals the following */ 1182 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1183 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); 1184 1185 pcl = container_of(owned_head, struct z_erofs_pcluster, next); 1186 1187 cur = pcl->obj.index; 1188 end = cur + BIT(pcl->clusterbits); 1189 1190 /* close the main owned chain at first */ 1191 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 1192 Z_EROFS_PCLUSTER_TAIL_CLOSED); 1193 1194 do { 1195 struct page *page; 1196 int err; 1197 1198 page = pickup_page_for_submission(pcl, i++, pagepool, 1199 MNGD_MAPPING(sbi), 1200 GFP_NOFS); 1201 if (!page) 1202 continue; 1203 1204 if (bio && cur != last_index + 1) { 1205 submit_bio_retry: 1206 submit_bio(bio); 1207 bio = NULL; 1208 } 1209 1210 if (!bio) { 1211 bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES); 1212 1213 bio->bi_end_io = z_erofs_decompressqueue_endio; 1214 bio_set_dev(bio, sb->s_bdev); 1215 bio->bi_iter.bi_sector = (sector_t)cur << 1216 LOG_SECTORS_PER_BLOCK; 1217 bio->bi_private = bi_private; 1218 bio->bi_opf = REQ_OP_READ; 1219 ++nr_bios; 1220 } 1221 1222 err = bio_add_page(bio, page, PAGE_SIZE, 0); 1223 if (err < PAGE_SIZE) 1224 goto submit_bio_retry; 1225 1226 last_index = cur; 1227 bypass = false; 1228 } while (++cur < end); 1229 1230 if (!bypass) 1231 qtail[JQ_SUBMIT] = &pcl->next; 1232 else 1233 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1234 } while (owned_head != Z_EROFS_PCLUSTER_TAIL); 1235 1236 if (bio) 1237 submit_bio(bio); 1238 1239 /* 1240 * although background is preferred, no one is pending for submission. 1241 * don't issue workqueue for decompression but drop it directly instead. 1242 */ 1243 if (!*force_fg && !nr_bios) { 1244 kvfree(q[JQ_SUBMIT]); 1245 return; 1246 } 1247 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios); 1248 } 1249 1250 static void z_erofs_runqueue(struct super_block *sb, 1251 struct z_erofs_collector *clt, 1252 struct list_head *pagepool, bool force_fg) 1253 { 1254 struct z_erofs_decompressqueue io[NR_JOBQUEUES]; 1255 1256 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 1257 return; 1258 z_erofs_submit_queue(sb, clt->owned_head, pagepool, io, &force_fg); 1259 1260 /* handle bypass queue (no i/o pclusters) immediately */ 1261 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); 1262 1263 if (!force_fg) 1264 return; 1265 1266 /* wait until all bios are completed */ 1267 io_wait_event(io[JQ_SUBMIT].u.wait, 1268 !atomic_read(&io[JQ_SUBMIT].pending_bios)); 1269 1270 /* handle synchronous decompress queue in the caller context */ 1271 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); 1272 } 1273 1274 static int z_erofs_readpage(struct file *file, struct page *page) 1275 { 1276 struct inode *const inode = page->mapping->host; 1277 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1278 int err; 1279 LIST_HEAD(pagepool); 1280 1281 trace_erofs_readpage(page, false); 1282 1283 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 1284 1285 err = z_erofs_do_read_page(&f, page, &pagepool); 1286 (void)z_erofs_collector_end(&f.clt); 1287 1288 /* if some compressed cluster ready, need submit them anyway */ 1289 z_erofs_runqueue(inode->i_sb, &f.clt, &pagepool, true); 1290 1291 if (err) 1292 erofs_err(inode->i_sb, "failed to read, err [%d]", err); 1293 1294 if (f.map.mpage) 1295 put_page(f.map.mpage); 1296 1297 /* clean up the remaining free pages */ 1298 put_pages_list(&pagepool); 1299 return err; 1300 } 1301 1302 static bool should_decompress_synchronously(struct erofs_sb_info *sbi, 1303 unsigned int nr) 1304 { 1305 return nr <= sbi->ctx.max_sync_decompress_pages; 1306 } 1307 1308 static int z_erofs_readpages(struct file *filp, struct address_space *mapping, 1309 struct list_head *pages, unsigned int nr_pages) 1310 { 1311 struct inode *const inode = mapping->host; 1312 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1313 1314 bool sync = should_decompress_synchronously(sbi, nr_pages); 1315 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1316 gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL); 1317 struct page *head = NULL; 1318 LIST_HEAD(pagepool); 1319 1320 trace_erofs_readpages(mapping->host, lru_to_page(pages), 1321 nr_pages, false); 1322 1323 f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT; 1324 1325 for (; nr_pages; --nr_pages) { 1326 struct page *page = lru_to_page(pages); 1327 1328 prefetchw(&page->flags); 1329 list_del(&page->lru); 1330 1331 /* 1332 * A pure asynchronous readahead is indicated if 1333 * a PG_readahead marked page is hitted at first. 1334 * Let's also do asynchronous decompression for this case. 1335 */ 1336 sync &= !(PageReadahead(page) && !head); 1337 1338 if (add_to_page_cache_lru(page, mapping, page->index, gfp)) { 1339 list_add(&page->lru, &pagepool); 1340 continue; 1341 } 1342 1343 set_page_private(page, (unsigned long)head); 1344 head = page; 1345 } 1346 1347 while (head) { 1348 struct page *page = head; 1349 int err; 1350 1351 /* traversal in reverse order */ 1352 head = (void *)page_private(page); 1353 1354 err = z_erofs_do_read_page(&f, page, &pagepool); 1355 if (err) 1356 erofs_err(inode->i_sb, 1357 "readahead error at page %lu @ nid %llu", 1358 page->index, EROFS_I(inode)->nid); 1359 put_page(page); 1360 } 1361 1362 (void)z_erofs_collector_end(&f.clt); 1363 1364 z_erofs_runqueue(inode->i_sb, &f.clt, &pagepool, sync); 1365 1366 if (f.map.mpage) 1367 put_page(f.map.mpage); 1368 1369 /* clean up the remaining free pages */ 1370 put_pages_list(&pagepool); 1371 return 0; 1372 } 1373 1374 const struct address_space_operations z_erofs_aops = { 1375 .readpage = z_erofs_readpage, 1376 .readpages = z_erofs_readpages, 1377 }; 1378 1379