1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 * Copyright (C) 2022 Alibaba Cloud 6 */ 7 #include "compress.h" 8 #include <linux/prefetch.h> 9 #include <linux/psi.h> 10 #include <linux/cpuhotplug.h> 11 #include <trace/events/erofs.h> 12 13 #define Z_EROFS_PCLUSTER_MAX_PAGES (Z_EROFS_PCLUSTER_MAX_SIZE / PAGE_SIZE) 14 #define Z_EROFS_INLINE_BVECS 2 15 16 /* 17 * let's leave a type here in case of introducing 18 * another tagged pointer later. 19 */ 20 typedef void *z_erofs_next_pcluster_t; 21 22 struct z_erofs_bvec { 23 struct page *page; 24 int offset; 25 unsigned int end; 26 }; 27 28 #define __Z_EROFS_BVSET(name, total) \ 29 struct name { \ 30 /* point to the next page which contains the following bvecs */ \ 31 struct page *nextpage; \ 32 struct z_erofs_bvec bvec[total]; \ 33 } 34 __Z_EROFS_BVSET(z_erofs_bvset,); 35 __Z_EROFS_BVSET(z_erofs_bvset_inline, Z_EROFS_INLINE_BVECS); 36 37 /* 38 * Structure fields follow one of the following exclusion rules. 39 * 40 * I: Modifiable by initialization/destruction paths and read-only 41 * for everyone else; 42 * 43 * L: Field should be protected by the pcluster lock; 44 * 45 * A: Field should be accessed / updated in atomic for parallelized code. 46 */ 47 struct z_erofs_pcluster { 48 struct erofs_workgroup obj; 49 struct mutex lock; 50 51 /* A: point to next chained pcluster or TAILs */ 52 z_erofs_next_pcluster_t next; 53 54 /* L: the maximum decompression size of this round */ 55 unsigned int length; 56 57 /* L: total number of bvecs */ 58 unsigned int vcnt; 59 60 /* I: page offset of start position of decompression */ 61 unsigned short pageofs_out; 62 63 /* I: page offset of inline compressed data */ 64 unsigned short pageofs_in; 65 66 union { 67 /* L: inline a certain number of bvec for bootstrap */ 68 struct z_erofs_bvset_inline bvset; 69 70 /* I: can be used to free the pcluster by RCU. */ 71 struct rcu_head rcu; 72 }; 73 74 union { 75 /* I: physical cluster size in pages */ 76 unsigned short pclusterpages; 77 78 /* I: tailpacking inline compressed size */ 79 unsigned short tailpacking_size; 80 }; 81 82 /* I: compression algorithm format */ 83 unsigned char algorithmformat; 84 85 /* L: whether partial decompression or not */ 86 bool partial; 87 88 /* L: indicate several pageofs_outs or not */ 89 bool multibases; 90 91 /* A: compressed bvecs (can be cached or inplaced pages) */ 92 struct z_erofs_bvec compressed_bvecs[]; 93 }; 94 95 /* let's avoid the valid 32-bit kernel addresses */ 96 97 /* the chained workgroup has't submitted io (still open) */ 98 #define Z_EROFS_PCLUSTER_TAIL ((void *)0x5F0ECAFE) 99 /* the chained workgroup has already submitted io */ 100 #define Z_EROFS_PCLUSTER_TAIL_CLOSED ((void *)0x5F0EDEAD) 101 102 #define Z_EROFS_PCLUSTER_NIL (NULL) 103 104 struct z_erofs_decompressqueue { 105 struct super_block *sb; 106 atomic_t pending_bios; 107 z_erofs_next_pcluster_t head; 108 109 union { 110 struct completion done; 111 struct work_struct work; 112 struct kthread_work kthread_work; 113 } u; 114 bool eio, sync; 115 }; 116 117 static inline bool z_erofs_is_inline_pcluster(struct z_erofs_pcluster *pcl) 118 { 119 return !pcl->obj.index; 120 } 121 122 static inline unsigned int z_erofs_pclusterpages(struct z_erofs_pcluster *pcl) 123 { 124 if (z_erofs_is_inline_pcluster(pcl)) 125 return 1; 126 return pcl->pclusterpages; 127 } 128 129 /* 130 * bit 30: I/O error occurred on this page 131 * bit 0 - 29: remaining parts to complete this page 132 */ 133 #define Z_EROFS_PAGE_EIO (1 << 30) 134 135 static inline void z_erofs_onlinepage_init(struct page *page) 136 { 137 union { 138 atomic_t o; 139 unsigned long v; 140 } u = { .o = ATOMIC_INIT(1) }; 141 142 set_page_private(page, u.v); 143 smp_wmb(); 144 SetPagePrivate(page); 145 } 146 147 static inline void z_erofs_onlinepage_split(struct page *page) 148 { 149 atomic_inc((atomic_t *)&page->private); 150 } 151 152 static inline void z_erofs_page_mark_eio(struct page *page) 153 { 154 int orig; 155 156 do { 157 orig = atomic_read((atomic_t *)&page->private); 158 } while (atomic_cmpxchg((atomic_t *)&page->private, orig, 159 orig | Z_EROFS_PAGE_EIO) != orig); 160 } 161 162 static inline void z_erofs_onlinepage_endio(struct page *page) 163 { 164 unsigned int v; 165 166 DBG_BUGON(!PagePrivate(page)); 167 v = atomic_dec_return((atomic_t *)&page->private); 168 if (!(v & ~Z_EROFS_PAGE_EIO)) { 169 set_page_private(page, 0); 170 ClearPagePrivate(page); 171 if (!(v & Z_EROFS_PAGE_EIO)) 172 SetPageUptodate(page); 173 unlock_page(page); 174 } 175 } 176 177 #define Z_EROFS_ONSTACK_PAGES 32 178 179 /* 180 * since pclustersize is variable for big pcluster feature, introduce slab 181 * pools implementation for different pcluster sizes. 182 */ 183 struct z_erofs_pcluster_slab { 184 struct kmem_cache *slab; 185 unsigned int maxpages; 186 char name[48]; 187 }; 188 189 #define _PCLP(n) { .maxpages = n } 190 191 static struct z_erofs_pcluster_slab pcluster_pool[] __read_mostly = { 192 _PCLP(1), _PCLP(4), _PCLP(16), _PCLP(64), _PCLP(128), 193 _PCLP(Z_EROFS_PCLUSTER_MAX_PAGES) 194 }; 195 196 struct z_erofs_bvec_iter { 197 struct page *bvpage; 198 struct z_erofs_bvset *bvset; 199 unsigned int nr, cur; 200 }; 201 202 static struct page *z_erofs_bvec_iter_end(struct z_erofs_bvec_iter *iter) 203 { 204 if (iter->bvpage) 205 kunmap_local(iter->bvset); 206 return iter->bvpage; 207 } 208 209 static struct page *z_erofs_bvset_flip(struct z_erofs_bvec_iter *iter) 210 { 211 unsigned long base = (unsigned long)((struct z_erofs_bvset *)0)->bvec; 212 /* have to access nextpage in advance, otherwise it will be unmapped */ 213 struct page *nextpage = iter->bvset->nextpage; 214 struct page *oldpage; 215 216 DBG_BUGON(!nextpage); 217 oldpage = z_erofs_bvec_iter_end(iter); 218 iter->bvpage = nextpage; 219 iter->bvset = kmap_local_page(nextpage); 220 iter->nr = (PAGE_SIZE - base) / sizeof(struct z_erofs_bvec); 221 iter->cur = 0; 222 return oldpage; 223 } 224 225 static void z_erofs_bvec_iter_begin(struct z_erofs_bvec_iter *iter, 226 struct z_erofs_bvset_inline *bvset, 227 unsigned int bootstrap_nr, 228 unsigned int cur) 229 { 230 *iter = (struct z_erofs_bvec_iter) { 231 .nr = bootstrap_nr, 232 .bvset = (struct z_erofs_bvset *)bvset, 233 }; 234 235 while (cur > iter->nr) { 236 cur -= iter->nr; 237 z_erofs_bvset_flip(iter); 238 } 239 iter->cur = cur; 240 } 241 242 static int z_erofs_bvec_enqueue(struct z_erofs_bvec_iter *iter, 243 struct z_erofs_bvec *bvec, 244 struct page **candidate_bvpage) 245 { 246 if (iter->cur == iter->nr) { 247 if (!*candidate_bvpage) 248 return -EAGAIN; 249 250 DBG_BUGON(iter->bvset->nextpage); 251 iter->bvset->nextpage = *candidate_bvpage; 252 z_erofs_bvset_flip(iter); 253 254 iter->bvset->nextpage = NULL; 255 *candidate_bvpage = NULL; 256 } 257 iter->bvset->bvec[iter->cur++] = *bvec; 258 return 0; 259 } 260 261 static void z_erofs_bvec_dequeue(struct z_erofs_bvec_iter *iter, 262 struct z_erofs_bvec *bvec, 263 struct page **old_bvpage) 264 { 265 if (iter->cur == iter->nr) 266 *old_bvpage = z_erofs_bvset_flip(iter); 267 else 268 *old_bvpage = NULL; 269 *bvec = iter->bvset->bvec[iter->cur++]; 270 } 271 272 static void z_erofs_destroy_pcluster_pool(void) 273 { 274 int i; 275 276 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 277 if (!pcluster_pool[i].slab) 278 continue; 279 kmem_cache_destroy(pcluster_pool[i].slab); 280 pcluster_pool[i].slab = NULL; 281 } 282 } 283 284 static int z_erofs_create_pcluster_pool(void) 285 { 286 struct z_erofs_pcluster_slab *pcs; 287 struct z_erofs_pcluster *a; 288 unsigned int size; 289 290 for (pcs = pcluster_pool; 291 pcs < pcluster_pool + ARRAY_SIZE(pcluster_pool); ++pcs) { 292 size = struct_size(a, compressed_bvecs, pcs->maxpages); 293 294 sprintf(pcs->name, "erofs_pcluster-%u", pcs->maxpages); 295 pcs->slab = kmem_cache_create(pcs->name, size, 0, 296 SLAB_RECLAIM_ACCOUNT, NULL); 297 if (pcs->slab) 298 continue; 299 300 z_erofs_destroy_pcluster_pool(); 301 return -ENOMEM; 302 } 303 return 0; 304 } 305 306 static struct z_erofs_pcluster *z_erofs_alloc_pcluster(unsigned int nrpages) 307 { 308 int i; 309 310 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 311 struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; 312 struct z_erofs_pcluster *pcl; 313 314 if (nrpages > pcs->maxpages) 315 continue; 316 317 pcl = kmem_cache_zalloc(pcs->slab, GFP_NOFS); 318 if (!pcl) 319 return ERR_PTR(-ENOMEM); 320 pcl->pclusterpages = nrpages; 321 return pcl; 322 } 323 return ERR_PTR(-EINVAL); 324 } 325 326 static void z_erofs_free_pcluster(struct z_erofs_pcluster *pcl) 327 { 328 unsigned int pclusterpages = z_erofs_pclusterpages(pcl); 329 int i; 330 331 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 332 struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; 333 334 if (pclusterpages > pcs->maxpages) 335 continue; 336 337 kmem_cache_free(pcs->slab, pcl); 338 return; 339 } 340 DBG_BUGON(1); 341 } 342 343 static struct workqueue_struct *z_erofs_workqueue __read_mostly; 344 345 #ifdef CONFIG_EROFS_FS_PCPU_KTHREAD 346 static struct kthread_worker __rcu **z_erofs_pcpu_workers; 347 348 static void erofs_destroy_percpu_workers(void) 349 { 350 struct kthread_worker *worker; 351 unsigned int cpu; 352 353 for_each_possible_cpu(cpu) { 354 worker = rcu_dereference_protected( 355 z_erofs_pcpu_workers[cpu], 1); 356 rcu_assign_pointer(z_erofs_pcpu_workers[cpu], NULL); 357 if (worker) 358 kthread_destroy_worker(worker); 359 } 360 kfree(z_erofs_pcpu_workers); 361 } 362 363 static struct kthread_worker *erofs_init_percpu_worker(int cpu) 364 { 365 struct kthread_worker *worker = 366 kthread_create_worker_on_cpu(cpu, 0, "erofs_worker/%u", cpu); 367 368 if (IS_ERR(worker)) 369 return worker; 370 if (IS_ENABLED(CONFIG_EROFS_FS_PCPU_KTHREAD_HIPRI)) 371 sched_set_fifo_low(worker->task); 372 return worker; 373 } 374 375 static int erofs_init_percpu_workers(void) 376 { 377 struct kthread_worker *worker; 378 unsigned int cpu; 379 380 z_erofs_pcpu_workers = kcalloc(num_possible_cpus(), 381 sizeof(struct kthread_worker *), GFP_ATOMIC); 382 if (!z_erofs_pcpu_workers) 383 return -ENOMEM; 384 385 for_each_online_cpu(cpu) { /* could miss cpu{off,on}line? */ 386 worker = erofs_init_percpu_worker(cpu); 387 if (!IS_ERR(worker)) 388 rcu_assign_pointer(z_erofs_pcpu_workers[cpu], worker); 389 } 390 return 0; 391 } 392 #else 393 static inline void erofs_destroy_percpu_workers(void) {} 394 static inline int erofs_init_percpu_workers(void) { return 0; } 395 #endif 396 397 #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_EROFS_FS_PCPU_KTHREAD) 398 static DEFINE_SPINLOCK(z_erofs_pcpu_worker_lock); 399 static enum cpuhp_state erofs_cpuhp_state; 400 401 static int erofs_cpu_online(unsigned int cpu) 402 { 403 struct kthread_worker *worker, *old; 404 405 worker = erofs_init_percpu_worker(cpu); 406 if (IS_ERR(worker)) 407 return PTR_ERR(worker); 408 409 spin_lock(&z_erofs_pcpu_worker_lock); 410 old = rcu_dereference_protected(z_erofs_pcpu_workers[cpu], 411 lockdep_is_held(&z_erofs_pcpu_worker_lock)); 412 if (!old) 413 rcu_assign_pointer(z_erofs_pcpu_workers[cpu], worker); 414 spin_unlock(&z_erofs_pcpu_worker_lock); 415 if (old) 416 kthread_destroy_worker(worker); 417 return 0; 418 } 419 420 static int erofs_cpu_offline(unsigned int cpu) 421 { 422 struct kthread_worker *worker; 423 424 spin_lock(&z_erofs_pcpu_worker_lock); 425 worker = rcu_dereference_protected(z_erofs_pcpu_workers[cpu], 426 lockdep_is_held(&z_erofs_pcpu_worker_lock)); 427 rcu_assign_pointer(z_erofs_pcpu_workers[cpu], NULL); 428 spin_unlock(&z_erofs_pcpu_worker_lock); 429 430 synchronize_rcu(); 431 if (worker) 432 kthread_destroy_worker(worker); 433 return 0; 434 } 435 436 static int erofs_cpu_hotplug_init(void) 437 { 438 int state; 439 440 state = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, 441 "fs/erofs:online", erofs_cpu_online, erofs_cpu_offline); 442 if (state < 0) 443 return state; 444 445 erofs_cpuhp_state = state; 446 return 0; 447 } 448 449 static void erofs_cpu_hotplug_destroy(void) 450 { 451 if (erofs_cpuhp_state) 452 cpuhp_remove_state_nocalls(erofs_cpuhp_state); 453 } 454 #else /* !CONFIG_HOTPLUG_CPU || !CONFIG_EROFS_FS_PCPU_KTHREAD */ 455 static inline int erofs_cpu_hotplug_init(void) { return 0; } 456 static inline void erofs_cpu_hotplug_destroy(void) {} 457 #endif 458 459 void z_erofs_exit_zip_subsystem(void) 460 { 461 erofs_cpu_hotplug_destroy(); 462 erofs_destroy_percpu_workers(); 463 destroy_workqueue(z_erofs_workqueue); 464 z_erofs_destroy_pcluster_pool(); 465 } 466 467 int __init z_erofs_init_zip_subsystem(void) 468 { 469 int err = z_erofs_create_pcluster_pool(); 470 471 if (err) 472 goto out_error_pcluster_pool; 473 474 z_erofs_workqueue = alloc_workqueue("erofs_worker", 475 WQ_UNBOUND | WQ_HIGHPRI, num_possible_cpus()); 476 if (!z_erofs_workqueue) { 477 err = -ENOMEM; 478 goto out_error_workqueue_init; 479 } 480 481 err = erofs_init_percpu_workers(); 482 if (err) 483 goto out_error_pcpu_worker; 484 485 err = erofs_cpu_hotplug_init(); 486 if (err < 0) 487 goto out_error_cpuhp_init; 488 return err; 489 490 out_error_cpuhp_init: 491 erofs_destroy_percpu_workers(); 492 out_error_pcpu_worker: 493 destroy_workqueue(z_erofs_workqueue); 494 out_error_workqueue_init: 495 z_erofs_destroy_pcluster_pool(); 496 out_error_pcluster_pool: 497 return err; 498 } 499 500 enum z_erofs_pclustermode { 501 Z_EROFS_PCLUSTER_INFLIGHT, 502 /* 503 * The current pclusters was the tail of an exist chain, in addition 504 * that the previous processed chained pclusters are all decided to 505 * be hooked up to it. 506 * A new chain will be created for the remaining pclusters which are 507 * not processed yet, so different from Z_EROFS_PCLUSTER_FOLLOWED, 508 * the next pcluster cannot reuse the whole page safely for inplace I/O 509 * in the following scenario: 510 * ________________________________________________________________ 511 * | tail (partial) page | head (partial) page | 512 * | (belongs to the next pcl) | (belongs to the current pcl) | 513 * |_______PCLUSTER_FOLLOWED______|________PCLUSTER_HOOKED__________| 514 */ 515 Z_EROFS_PCLUSTER_HOOKED, 516 /* 517 * a weak form of Z_EROFS_PCLUSTER_FOLLOWED, the difference is that it 518 * could be dispatched into bypass queue later due to uptodated managed 519 * pages. All related online pages cannot be reused for inplace I/O (or 520 * bvpage) since it can be directly decoded without I/O submission. 521 */ 522 Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE, 523 /* 524 * The current collection has been linked with the owned chain, and 525 * could also be linked with the remaining collections, which means 526 * if the processing page is the tail page of the collection, thus 527 * the current collection can safely use the whole page (since 528 * the previous collection is under control) for in-place I/O, as 529 * illustrated below: 530 * ________________________________________________________________ 531 * | tail (partial) page | head (partial) page | 532 * | (of the current cl) | (of the previous collection) | 533 * | PCLUSTER_FOLLOWED or | | 534 * |_____PCLUSTER_HOOKED__|___________PCLUSTER_FOLLOWED____________| 535 * 536 * [ (*) the above page can be used as inplace I/O. ] 537 */ 538 Z_EROFS_PCLUSTER_FOLLOWED, 539 }; 540 541 struct z_erofs_decompress_frontend { 542 struct inode *const inode; 543 struct erofs_map_blocks map; 544 struct z_erofs_bvec_iter biter; 545 546 struct page *candidate_bvpage; 547 struct z_erofs_pcluster *pcl, *tailpcl; 548 z_erofs_next_pcluster_t owned_head; 549 enum z_erofs_pclustermode mode; 550 551 bool readahead; 552 /* used for applying cache strategy on the fly */ 553 bool backmost; 554 erofs_off_t headoffset; 555 556 /* a pointer used to pick up inplace I/O pages */ 557 unsigned int icur; 558 }; 559 560 #define DECOMPRESS_FRONTEND_INIT(__i) { \ 561 .inode = __i, .owned_head = Z_EROFS_PCLUSTER_TAIL, \ 562 .mode = Z_EROFS_PCLUSTER_FOLLOWED, .backmost = true } 563 564 static bool z_erofs_should_alloc_cache(struct z_erofs_decompress_frontend *fe) 565 { 566 unsigned int cachestrategy = EROFS_I_SB(fe->inode)->opt.cache_strategy; 567 568 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) 569 return false; 570 571 if (fe->backmost) 572 return true; 573 574 if (cachestrategy >= EROFS_ZIP_CACHE_READAROUND && 575 fe->map.m_la < fe->headoffset) 576 return true; 577 578 return false; 579 } 580 581 static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe, 582 struct page **pagepool) 583 { 584 struct address_space *mc = MNGD_MAPPING(EROFS_I_SB(fe->inode)); 585 struct z_erofs_pcluster *pcl = fe->pcl; 586 bool shouldalloc = z_erofs_should_alloc_cache(fe); 587 bool standalone = true; 588 /* 589 * optimistic allocation without direct reclaim since inplace I/O 590 * can be used if low memory otherwise. 591 */ 592 gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | 593 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 594 unsigned int i; 595 596 if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED) 597 return; 598 599 for (i = 0; i < pcl->pclusterpages; ++i) { 600 struct page *page; 601 void *t; /* mark pages just found for debugging */ 602 struct page *newpage = NULL; 603 604 /* the compressed page was loaded before */ 605 if (READ_ONCE(pcl->compressed_bvecs[i].page)) 606 continue; 607 608 page = find_get_page(mc, pcl->obj.index + i); 609 610 if (page) { 611 t = (void *)((unsigned long)page | 1); 612 } else { 613 /* I/O is needed, no possible to decompress directly */ 614 standalone = false; 615 if (!shouldalloc) 616 continue; 617 618 /* 619 * try to use cached I/O if page allocation 620 * succeeds or fallback to in-place I/O instead 621 * to avoid any direct reclaim. 622 */ 623 newpage = erofs_allocpage(pagepool, gfp); 624 if (!newpage) 625 continue; 626 set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE); 627 t = (void *)((unsigned long)newpage | 1); 628 } 629 630 if (!cmpxchg_relaxed(&pcl->compressed_bvecs[i].page, NULL, t)) 631 continue; 632 633 if (page) 634 put_page(page); 635 else if (newpage) 636 erofs_pagepool_add(pagepool, newpage); 637 } 638 639 /* 640 * don't do inplace I/O if all compressed pages are available in 641 * managed cache since it can be moved to the bypass queue instead. 642 */ 643 if (standalone) 644 fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE; 645 } 646 647 /* called by erofs_shrinker to get rid of all compressed_pages */ 648 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 649 struct erofs_workgroup *grp) 650 { 651 struct z_erofs_pcluster *const pcl = 652 container_of(grp, struct z_erofs_pcluster, obj); 653 int i; 654 655 DBG_BUGON(z_erofs_is_inline_pcluster(pcl)); 656 /* 657 * refcount of workgroup is now freezed as 1, 658 * therefore no need to worry about available decompression users. 659 */ 660 for (i = 0; i < pcl->pclusterpages; ++i) { 661 struct page *page = pcl->compressed_bvecs[i].page; 662 663 if (!page) 664 continue; 665 666 /* block other users from reclaiming or migrating the page */ 667 if (!trylock_page(page)) 668 return -EBUSY; 669 670 if (!erofs_page_is_managed(sbi, page)) 671 continue; 672 673 /* barrier is implied in the following 'unlock_page' */ 674 WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); 675 detach_page_private(page); 676 unlock_page(page); 677 } 678 return 0; 679 } 680 681 int erofs_try_to_free_cached_page(struct page *page) 682 { 683 struct z_erofs_pcluster *const pcl = (void *)page_private(page); 684 int ret, i; 685 686 if (!erofs_workgroup_try_to_freeze(&pcl->obj, 1)) 687 return 0; 688 689 ret = 0; 690 DBG_BUGON(z_erofs_is_inline_pcluster(pcl)); 691 for (i = 0; i < pcl->pclusterpages; ++i) { 692 if (pcl->compressed_bvecs[i].page == page) { 693 WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); 694 ret = 1; 695 break; 696 } 697 } 698 erofs_workgroup_unfreeze(&pcl->obj, 1); 699 if (ret) 700 detach_page_private(page); 701 return ret; 702 } 703 704 static bool z_erofs_try_inplace_io(struct z_erofs_decompress_frontend *fe, 705 struct z_erofs_bvec *bvec) 706 { 707 struct z_erofs_pcluster *const pcl = fe->pcl; 708 709 while (fe->icur > 0) { 710 if (!cmpxchg(&pcl->compressed_bvecs[--fe->icur].page, 711 NULL, bvec->page)) { 712 pcl->compressed_bvecs[fe->icur] = *bvec; 713 return true; 714 } 715 } 716 return false; 717 } 718 719 /* callers must be with pcluster lock held */ 720 static int z_erofs_attach_page(struct z_erofs_decompress_frontend *fe, 721 struct z_erofs_bvec *bvec, bool exclusive) 722 { 723 int ret; 724 725 if (exclusive) { 726 /* give priority for inplaceio to use file pages first */ 727 if (z_erofs_try_inplace_io(fe, bvec)) 728 return 0; 729 /* otherwise, check if it can be used as a bvpage */ 730 if (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED && 731 !fe->candidate_bvpage) 732 fe->candidate_bvpage = bvec->page; 733 } 734 ret = z_erofs_bvec_enqueue(&fe->biter, bvec, &fe->candidate_bvpage); 735 fe->pcl->vcnt += (ret >= 0); 736 return ret; 737 } 738 739 static void z_erofs_try_to_claim_pcluster(struct z_erofs_decompress_frontend *f) 740 { 741 struct z_erofs_pcluster *pcl = f->pcl; 742 z_erofs_next_pcluster_t *owned_head = &f->owned_head; 743 744 /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */ 745 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, 746 *owned_head) == Z_EROFS_PCLUSTER_NIL) { 747 *owned_head = &pcl->next; 748 /* so we can attach this pcluster to our submission chain. */ 749 f->mode = Z_EROFS_PCLUSTER_FOLLOWED; 750 return; 751 } 752 753 /* 754 * type 2, link to the end of an existing open chain, be careful 755 * that its submission is controlled by the original attached chain. 756 */ 757 if (*owned_head != &pcl->next && pcl != f->tailpcl && 758 cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 759 *owned_head) == Z_EROFS_PCLUSTER_TAIL) { 760 *owned_head = Z_EROFS_PCLUSTER_TAIL; 761 f->mode = Z_EROFS_PCLUSTER_HOOKED; 762 f->tailpcl = NULL; 763 return; 764 } 765 /* type 3, it belongs to a chain, but it isn't the end of the chain */ 766 f->mode = Z_EROFS_PCLUSTER_INFLIGHT; 767 } 768 769 static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe) 770 { 771 struct erofs_map_blocks *map = &fe->map; 772 bool ztailpacking = map->m_flags & EROFS_MAP_META; 773 struct z_erofs_pcluster *pcl; 774 struct erofs_workgroup *grp; 775 int err; 776 777 if (!(map->m_flags & EROFS_MAP_ENCODED) || 778 (!ztailpacking && !(map->m_pa >> PAGE_SHIFT))) { 779 DBG_BUGON(1); 780 return -EFSCORRUPTED; 781 } 782 783 /* no available pcluster, let's allocate one */ 784 pcl = z_erofs_alloc_pcluster(ztailpacking ? 1 : 785 map->m_plen >> PAGE_SHIFT); 786 if (IS_ERR(pcl)) 787 return PTR_ERR(pcl); 788 789 atomic_set(&pcl->obj.refcount, 1); 790 pcl->algorithmformat = map->m_algorithmformat; 791 pcl->length = 0; 792 pcl->partial = true; 793 794 /* new pclusters should be claimed as type 1, primary and followed */ 795 pcl->next = fe->owned_head; 796 pcl->pageofs_out = map->m_la & ~PAGE_MASK; 797 fe->mode = Z_EROFS_PCLUSTER_FOLLOWED; 798 799 /* 800 * lock all primary followed works before visible to others 801 * and mutex_trylock *never* fails for a new pcluster. 802 */ 803 mutex_init(&pcl->lock); 804 DBG_BUGON(!mutex_trylock(&pcl->lock)); 805 806 if (ztailpacking) { 807 pcl->obj.index = 0; /* which indicates ztailpacking */ 808 pcl->pageofs_in = erofs_blkoff(fe->inode->i_sb, map->m_pa); 809 pcl->tailpacking_size = map->m_plen; 810 } else { 811 pcl->obj.index = map->m_pa >> PAGE_SHIFT; 812 813 grp = erofs_insert_workgroup(fe->inode->i_sb, &pcl->obj); 814 if (IS_ERR(grp)) { 815 err = PTR_ERR(grp); 816 goto err_out; 817 } 818 819 if (grp != &pcl->obj) { 820 fe->pcl = container_of(grp, 821 struct z_erofs_pcluster, obj); 822 err = -EEXIST; 823 goto err_out; 824 } 825 } 826 /* used to check tail merging loop due to corrupted images */ 827 if (fe->owned_head == Z_EROFS_PCLUSTER_TAIL) 828 fe->tailpcl = pcl; 829 fe->owned_head = &pcl->next; 830 fe->pcl = pcl; 831 return 0; 832 833 err_out: 834 mutex_unlock(&pcl->lock); 835 z_erofs_free_pcluster(pcl); 836 return err; 837 } 838 839 static int z_erofs_collector_begin(struct z_erofs_decompress_frontend *fe) 840 { 841 struct erofs_map_blocks *map = &fe->map; 842 struct erofs_workgroup *grp = NULL; 843 int ret; 844 845 DBG_BUGON(fe->pcl); 846 847 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous pcluster */ 848 DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_NIL); 849 DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 850 851 if (!(map->m_flags & EROFS_MAP_META)) { 852 grp = erofs_find_workgroup(fe->inode->i_sb, 853 map->m_pa >> PAGE_SHIFT); 854 } else if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) { 855 DBG_BUGON(1); 856 return -EFSCORRUPTED; 857 } 858 859 if (grp) { 860 fe->pcl = container_of(grp, struct z_erofs_pcluster, obj); 861 ret = -EEXIST; 862 } else { 863 ret = z_erofs_register_pcluster(fe); 864 } 865 866 if (ret == -EEXIST) { 867 mutex_lock(&fe->pcl->lock); 868 /* used to check tail merging loop due to corrupted images */ 869 if (fe->owned_head == Z_EROFS_PCLUSTER_TAIL) 870 fe->tailpcl = fe->pcl; 871 872 z_erofs_try_to_claim_pcluster(fe); 873 } else if (ret) { 874 return ret; 875 } 876 z_erofs_bvec_iter_begin(&fe->biter, &fe->pcl->bvset, 877 Z_EROFS_INLINE_BVECS, fe->pcl->vcnt); 878 /* since file-backed online pages are traversed in reverse order */ 879 fe->icur = z_erofs_pclusterpages(fe->pcl); 880 return 0; 881 } 882 883 /* 884 * keep in mind that no referenced pclusters will be freed 885 * only after a RCU grace period. 886 */ 887 static void z_erofs_rcu_callback(struct rcu_head *head) 888 { 889 z_erofs_free_pcluster(container_of(head, 890 struct z_erofs_pcluster, rcu)); 891 } 892 893 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) 894 { 895 struct z_erofs_pcluster *const pcl = 896 container_of(grp, struct z_erofs_pcluster, obj); 897 898 call_rcu(&pcl->rcu, z_erofs_rcu_callback); 899 } 900 901 static bool z_erofs_collector_end(struct z_erofs_decompress_frontend *fe) 902 { 903 struct z_erofs_pcluster *pcl = fe->pcl; 904 905 if (!pcl) 906 return false; 907 908 z_erofs_bvec_iter_end(&fe->biter); 909 mutex_unlock(&pcl->lock); 910 911 if (fe->candidate_bvpage) { 912 DBG_BUGON(z_erofs_is_shortlived_page(fe->candidate_bvpage)); 913 fe->candidate_bvpage = NULL; 914 } 915 916 /* 917 * if all pending pages are added, don't hold its reference 918 * any longer if the pcluster isn't hosted by ourselves. 919 */ 920 if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE) 921 erofs_workgroup_put(&pcl->obj); 922 923 fe->pcl = NULL; 924 return true; 925 } 926 927 static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos, 928 struct page *page, unsigned int pageofs, 929 unsigned int len) 930 { 931 struct super_block *sb = inode->i_sb; 932 struct inode *packed_inode = EROFS_I_SB(inode)->packed_inode; 933 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 934 u8 *src, *dst; 935 unsigned int i, cnt; 936 937 if (!packed_inode) 938 return -EFSCORRUPTED; 939 940 buf.inode = packed_inode; 941 pos += EROFS_I(inode)->z_fragmentoff; 942 for (i = 0; i < len; i += cnt) { 943 cnt = min_t(unsigned int, len - i, 944 sb->s_blocksize - erofs_blkoff(sb, pos)); 945 src = erofs_bread(&buf, erofs_blknr(sb, pos), EROFS_KMAP); 946 if (IS_ERR(src)) { 947 erofs_put_metabuf(&buf); 948 return PTR_ERR(src); 949 } 950 951 dst = kmap_local_page(page); 952 memcpy(dst + pageofs + i, src + erofs_blkoff(sb, pos), cnt); 953 kunmap_local(dst); 954 pos += cnt; 955 } 956 erofs_put_metabuf(&buf); 957 return 0; 958 } 959 960 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 961 struct page *page, struct page **pagepool) 962 { 963 struct inode *const inode = fe->inode; 964 struct erofs_map_blocks *const map = &fe->map; 965 const loff_t offset = page_offset(page); 966 bool tight = true, exclusive; 967 unsigned int cur, end, spiltted; 968 int err = 0; 969 970 /* register locked file pages as online pages in pack */ 971 z_erofs_onlinepage_init(page); 972 973 spiltted = 0; 974 end = PAGE_SIZE; 975 repeat: 976 cur = end - 1; 977 978 if (offset + cur < map->m_la || 979 offset + cur >= map->m_la + map->m_llen) { 980 if (z_erofs_collector_end(fe)) 981 fe->backmost = false; 982 map->m_la = offset + cur; 983 map->m_llen = 0; 984 err = z_erofs_map_blocks_iter(inode, map, 0); 985 if (err) 986 goto out; 987 } else { 988 if (fe->pcl) 989 goto hitted; 990 /* didn't get a valid pcluster previously (very rare) */ 991 } 992 993 if (!(map->m_flags & EROFS_MAP_MAPPED) || 994 map->m_flags & EROFS_MAP_FRAGMENT) 995 goto hitted; 996 997 err = z_erofs_collector_begin(fe); 998 if (err) 999 goto out; 1000 1001 if (z_erofs_is_inline_pcluster(fe->pcl)) { 1002 void *mp; 1003 1004 mp = erofs_read_metabuf(&fe->map.buf, inode->i_sb, 1005 erofs_blknr(inode->i_sb, map->m_pa), 1006 EROFS_NO_KMAP); 1007 if (IS_ERR(mp)) { 1008 err = PTR_ERR(mp); 1009 erofs_err(inode->i_sb, 1010 "failed to get inline page, err %d", err); 1011 goto out; 1012 } 1013 get_page(fe->map.buf.page); 1014 WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, 1015 fe->map.buf.page); 1016 fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE; 1017 } else { 1018 /* bind cache first when cached decompression is preferred */ 1019 z_erofs_bind_cache(fe, pagepool); 1020 } 1021 hitted: 1022 /* 1023 * Ensure the current partial page belongs to this submit chain rather 1024 * than other concurrent submit chains or the noio(bypass) chain since 1025 * those chains are handled asynchronously thus the page cannot be used 1026 * for inplace I/O or bvpage (should be processed in a strict order.) 1027 */ 1028 tight &= (fe->mode >= Z_EROFS_PCLUSTER_HOOKED && 1029 fe->mode != Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE); 1030 1031 cur = end - min_t(unsigned int, offset + end - map->m_la, end); 1032 if (!(map->m_flags & EROFS_MAP_MAPPED)) { 1033 zero_user_segment(page, cur, end); 1034 goto next_part; 1035 } 1036 if (map->m_flags & EROFS_MAP_FRAGMENT) { 1037 unsigned int pageofs, skip, len; 1038 1039 if (offset > map->m_la) { 1040 pageofs = 0; 1041 skip = offset - map->m_la; 1042 } else { 1043 pageofs = map->m_la & ~PAGE_MASK; 1044 skip = 0; 1045 } 1046 len = min_t(unsigned int, map->m_llen - skip, end - cur); 1047 err = z_erofs_read_fragment(inode, skip, page, pageofs, len); 1048 if (err) 1049 goto out; 1050 ++spiltted; 1051 tight = false; 1052 goto next_part; 1053 } 1054 1055 exclusive = (!cur && (!spiltted || tight)); 1056 if (cur) 1057 tight &= (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED); 1058 1059 retry: 1060 err = z_erofs_attach_page(fe, &((struct z_erofs_bvec) { 1061 .page = page, 1062 .offset = offset - map->m_la, 1063 .end = end, 1064 }), exclusive); 1065 /* should allocate an additional short-lived page for bvset */ 1066 if (err == -EAGAIN && !fe->candidate_bvpage) { 1067 fe->candidate_bvpage = alloc_page(GFP_NOFS | __GFP_NOFAIL); 1068 set_page_private(fe->candidate_bvpage, 1069 Z_EROFS_SHORTLIVED_PAGE); 1070 goto retry; 1071 } 1072 1073 if (err) { 1074 DBG_BUGON(err == -EAGAIN && fe->candidate_bvpage); 1075 goto out; 1076 } 1077 1078 z_erofs_onlinepage_split(page); 1079 /* bump up the number of spiltted parts of a page */ 1080 ++spiltted; 1081 if (fe->pcl->pageofs_out != (map->m_la & ~PAGE_MASK)) 1082 fe->pcl->multibases = true; 1083 if (fe->pcl->length < offset + end - map->m_la) { 1084 fe->pcl->length = offset + end - map->m_la; 1085 fe->pcl->pageofs_out = map->m_la & ~PAGE_MASK; 1086 } 1087 if ((map->m_flags & EROFS_MAP_FULL_MAPPED) && 1088 !(map->m_flags & EROFS_MAP_PARTIAL_REF) && 1089 fe->pcl->length == map->m_llen) 1090 fe->pcl->partial = false; 1091 next_part: 1092 /* shorten the remaining extent to update progress */ 1093 map->m_llen = offset + cur - map->m_la; 1094 map->m_flags &= ~EROFS_MAP_FULL_MAPPED; 1095 1096 end = cur; 1097 if (end > 0) 1098 goto repeat; 1099 1100 out: 1101 if (err) 1102 z_erofs_page_mark_eio(page); 1103 z_erofs_onlinepage_endio(page); 1104 return err; 1105 } 1106 1107 static bool z_erofs_get_sync_decompress_policy(struct erofs_sb_info *sbi, 1108 unsigned int readahead_pages) 1109 { 1110 /* auto: enable for read_folio, disable for readahead */ 1111 if ((sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) && 1112 !readahead_pages) 1113 return true; 1114 1115 if ((sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_FORCE_ON) && 1116 (readahead_pages <= sbi->opt.max_sync_decompress_pages)) 1117 return true; 1118 1119 return false; 1120 } 1121 1122 static bool z_erofs_page_is_invalidated(struct page *page) 1123 { 1124 return !page->mapping && !z_erofs_is_shortlived_page(page); 1125 } 1126 1127 struct z_erofs_decompress_backend { 1128 struct page *onstack_pages[Z_EROFS_ONSTACK_PAGES]; 1129 struct super_block *sb; 1130 struct z_erofs_pcluster *pcl; 1131 1132 /* pages with the longest decompressed length for deduplication */ 1133 struct page **decompressed_pages; 1134 /* pages to keep the compressed data */ 1135 struct page **compressed_pages; 1136 1137 struct list_head decompressed_secondary_bvecs; 1138 struct page **pagepool; 1139 unsigned int onstack_used, nr_pages; 1140 }; 1141 1142 struct z_erofs_bvec_item { 1143 struct z_erofs_bvec bvec; 1144 struct list_head list; 1145 }; 1146 1147 static void z_erofs_do_decompressed_bvec(struct z_erofs_decompress_backend *be, 1148 struct z_erofs_bvec *bvec) 1149 { 1150 struct z_erofs_bvec_item *item; 1151 1152 if (!((bvec->offset + be->pcl->pageofs_out) & ~PAGE_MASK)) { 1153 unsigned int pgnr; 1154 1155 pgnr = (bvec->offset + be->pcl->pageofs_out) >> PAGE_SHIFT; 1156 DBG_BUGON(pgnr >= be->nr_pages); 1157 if (!be->decompressed_pages[pgnr]) { 1158 be->decompressed_pages[pgnr] = bvec->page; 1159 return; 1160 } 1161 } 1162 1163 /* (cold path) one pcluster is requested multiple times */ 1164 item = kmalloc(sizeof(*item), GFP_KERNEL | __GFP_NOFAIL); 1165 item->bvec = *bvec; 1166 list_add(&item->list, &be->decompressed_secondary_bvecs); 1167 } 1168 1169 static void z_erofs_fill_other_copies(struct z_erofs_decompress_backend *be, 1170 int err) 1171 { 1172 unsigned int off0 = be->pcl->pageofs_out; 1173 struct list_head *p, *n; 1174 1175 list_for_each_safe(p, n, &be->decompressed_secondary_bvecs) { 1176 struct z_erofs_bvec_item *bvi; 1177 unsigned int end, cur; 1178 void *dst, *src; 1179 1180 bvi = container_of(p, struct z_erofs_bvec_item, list); 1181 cur = bvi->bvec.offset < 0 ? -bvi->bvec.offset : 0; 1182 end = min_t(unsigned int, be->pcl->length - bvi->bvec.offset, 1183 bvi->bvec.end); 1184 dst = kmap_local_page(bvi->bvec.page); 1185 while (cur < end) { 1186 unsigned int pgnr, scur, len; 1187 1188 pgnr = (bvi->bvec.offset + cur + off0) >> PAGE_SHIFT; 1189 DBG_BUGON(pgnr >= be->nr_pages); 1190 1191 scur = bvi->bvec.offset + cur - 1192 ((pgnr << PAGE_SHIFT) - off0); 1193 len = min_t(unsigned int, end - cur, PAGE_SIZE - scur); 1194 if (!be->decompressed_pages[pgnr]) { 1195 err = -EFSCORRUPTED; 1196 cur += len; 1197 continue; 1198 } 1199 src = kmap_local_page(be->decompressed_pages[pgnr]); 1200 memcpy(dst + cur, src + scur, len); 1201 kunmap_local(src); 1202 cur += len; 1203 } 1204 kunmap_local(dst); 1205 if (err) 1206 z_erofs_page_mark_eio(bvi->bvec.page); 1207 z_erofs_onlinepage_endio(bvi->bvec.page); 1208 list_del(p); 1209 kfree(bvi); 1210 } 1211 } 1212 1213 static void z_erofs_parse_out_bvecs(struct z_erofs_decompress_backend *be) 1214 { 1215 struct z_erofs_pcluster *pcl = be->pcl; 1216 struct z_erofs_bvec_iter biter; 1217 struct page *old_bvpage; 1218 int i; 1219 1220 z_erofs_bvec_iter_begin(&biter, &pcl->bvset, Z_EROFS_INLINE_BVECS, 0); 1221 for (i = 0; i < pcl->vcnt; ++i) { 1222 struct z_erofs_bvec bvec; 1223 1224 z_erofs_bvec_dequeue(&biter, &bvec, &old_bvpage); 1225 1226 if (old_bvpage) 1227 z_erofs_put_shortlivedpage(be->pagepool, old_bvpage); 1228 1229 DBG_BUGON(z_erofs_page_is_invalidated(bvec.page)); 1230 z_erofs_do_decompressed_bvec(be, &bvec); 1231 } 1232 1233 old_bvpage = z_erofs_bvec_iter_end(&biter); 1234 if (old_bvpage) 1235 z_erofs_put_shortlivedpage(be->pagepool, old_bvpage); 1236 } 1237 1238 static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be, 1239 bool *overlapped) 1240 { 1241 struct z_erofs_pcluster *pcl = be->pcl; 1242 unsigned int pclusterpages = z_erofs_pclusterpages(pcl); 1243 int i, err = 0; 1244 1245 *overlapped = false; 1246 for (i = 0; i < pclusterpages; ++i) { 1247 struct z_erofs_bvec *bvec = &pcl->compressed_bvecs[i]; 1248 struct page *page = bvec->page; 1249 1250 /* compressed pages ought to be present before decompressing */ 1251 if (!page) { 1252 DBG_BUGON(1); 1253 continue; 1254 } 1255 be->compressed_pages[i] = page; 1256 1257 if (z_erofs_is_inline_pcluster(pcl)) { 1258 if (!PageUptodate(page)) 1259 err = -EIO; 1260 continue; 1261 } 1262 1263 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1264 if (!z_erofs_is_shortlived_page(page)) { 1265 if (erofs_page_is_managed(EROFS_SB(be->sb), page)) { 1266 if (!PageUptodate(page)) 1267 err = -EIO; 1268 continue; 1269 } 1270 z_erofs_do_decompressed_bvec(be, bvec); 1271 *overlapped = true; 1272 } 1273 } 1274 1275 if (err) 1276 return err; 1277 return 0; 1278 } 1279 1280 static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be, 1281 int err) 1282 { 1283 struct erofs_sb_info *const sbi = EROFS_SB(be->sb); 1284 struct z_erofs_pcluster *pcl = be->pcl; 1285 unsigned int pclusterpages = z_erofs_pclusterpages(pcl); 1286 const struct z_erofs_decompressor *decompressor = 1287 &erofs_decompressors[pcl->algorithmformat]; 1288 unsigned int i, inputsize; 1289 int err2; 1290 struct page *page; 1291 bool overlapped; 1292 1293 mutex_lock(&pcl->lock); 1294 be->nr_pages = PAGE_ALIGN(pcl->length + pcl->pageofs_out) >> PAGE_SHIFT; 1295 1296 /* allocate (de)compressed page arrays if cannot be kept on stack */ 1297 be->decompressed_pages = NULL; 1298 be->compressed_pages = NULL; 1299 be->onstack_used = 0; 1300 if (be->nr_pages <= Z_EROFS_ONSTACK_PAGES) { 1301 be->decompressed_pages = be->onstack_pages; 1302 be->onstack_used = be->nr_pages; 1303 memset(be->decompressed_pages, 0, 1304 sizeof(struct page *) * be->nr_pages); 1305 } 1306 1307 if (pclusterpages + be->onstack_used <= Z_EROFS_ONSTACK_PAGES) 1308 be->compressed_pages = be->onstack_pages + be->onstack_used; 1309 1310 if (!be->decompressed_pages) 1311 be->decompressed_pages = 1312 kvcalloc(be->nr_pages, sizeof(struct page *), 1313 GFP_KERNEL | __GFP_NOFAIL); 1314 if (!be->compressed_pages) 1315 be->compressed_pages = 1316 kvcalloc(pclusterpages, sizeof(struct page *), 1317 GFP_KERNEL | __GFP_NOFAIL); 1318 1319 z_erofs_parse_out_bvecs(be); 1320 err2 = z_erofs_parse_in_bvecs(be, &overlapped); 1321 if (err2) 1322 err = err2; 1323 if (err) 1324 goto out; 1325 1326 if (z_erofs_is_inline_pcluster(pcl)) 1327 inputsize = pcl->tailpacking_size; 1328 else 1329 inputsize = pclusterpages * PAGE_SIZE; 1330 1331 err = decompressor->decompress(&(struct z_erofs_decompress_req) { 1332 .sb = be->sb, 1333 .in = be->compressed_pages, 1334 .out = be->decompressed_pages, 1335 .pageofs_in = pcl->pageofs_in, 1336 .pageofs_out = pcl->pageofs_out, 1337 .inputsize = inputsize, 1338 .outputsize = pcl->length, 1339 .alg = pcl->algorithmformat, 1340 .inplace_io = overlapped, 1341 .partial_decoding = pcl->partial, 1342 .fillgaps = pcl->multibases, 1343 }, be->pagepool); 1344 1345 out: 1346 /* must handle all compressed pages before actual file pages */ 1347 if (z_erofs_is_inline_pcluster(pcl)) { 1348 page = pcl->compressed_bvecs[0].page; 1349 WRITE_ONCE(pcl->compressed_bvecs[0].page, NULL); 1350 put_page(page); 1351 } else { 1352 for (i = 0; i < pclusterpages; ++i) { 1353 page = pcl->compressed_bvecs[i].page; 1354 1355 if (erofs_page_is_managed(sbi, page)) 1356 continue; 1357 1358 /* recycle all individual short-lived pages */ 1359 (void)z_erofs_put_shortlivedpage(be->pagepool, page); 1360 WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); 1361 } 1362 } 1363 if (be->compressed_pages < be->onstack_pages || 1364 be->compressed_pages >= be->onstack_pages + Z_EROFS_ONSTACK_PAGES) 1365 kvfree(be->compressed_pages); 1366 z_erofs_fill_other_copies(be, err); 1367 1368 for (i = 0; i < be->nr_pages; ++i) { 1369 page = be->decompressed_pages[i]; 1370 if (!page) 1371 continue; 1372 1373 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1374 1375 /* recycle all individual short-lived pages */ 1376 if (z_erofs_put_shortlivedpage(be->pagepool, page)) 1377 continue; 1378 if (err) 1379 z_erofs_page_mark_eio(page); 1380 z_erofs_onlinepage_endio(page); 1381 } 1382 1383 if (be->decompressed_pages != be->onstack_pages) 1384 kvfree(be->decompressed_pages); 1385 1386 pcl->length = 0; 1387 pcl->partial = true; 1388 pcl->multibases = false; 1389 pcl->bvset.nextpage = NULL; 1390 pcl->vcnt = 0; 1391 1392 /* pcluster lock MUST be taken before the following line */ 1393 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); 1394 mutex_unlock(&pcl->lock); 1395 return err; 1396 } 1397 1398 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, 1399 struct page **pagepool) 1400 { 1401 struct z_erofs_decompress_backend be = { 1402 .sb = io->sb, 1403 .pagepool = pagepool, 1404 .decompressed_secondary_bvecs = 1405 LIST_HEAD_INIT(be.decompressed_secondary_bvecs), 1406 }; 1407 z_erofs_next_pcluster_t owned = io->head; 1408 1409 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { 1410 /* impossible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ 1411 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); 1412 /* impossible that 'owned' equals Z_EROFS_PCLUSTER_NIL */ 1413 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); 1414 1415 be.pcl = container_of(owned, struct z_erofs_pcluster, next); 1416 owned = READ_ONCE(be.pcl->next); 1417 1418 z_erofs_decompress_pcluster(&be, io->eio ? -EIO : 0); 1419 erofs_workgroup_put(&be.pcl->obj); 1420 } 1421 } 1422 1423 static void z_erofs_decompressqueue_work(struct work_struct *work) 1424 { 1425 struct z_erofs_decompressqueue *bgq = 1426 container_of(work, struct z_erofs_decompressqueue, u.work); 1427 struct page *pagepool = NULL; 1428 1429 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1430 z_erofs_decompress_queue(bgq, &pagepool); 1431 erofs_release_pages(&pagepool); 1432 kvfree(bgq); 1433 } 1434 1435 #ifdef CONFIG_EROFS_FS_PCPU_KTHREAD 1436 static void z_erofs_decompressqueue_kthread_work(struct kthread_work *work) 1437 { 1438 z_erofs_decompressqueue_work((struct work_struct *)work); 1439 } 1440 #endif 1441 1442 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, 1443 int bios) 1444 { 1445 struct erofs_sb_info *const sbi = EROFS_SB(io->sb); 1446 1447 /* wake up the caller thread for sync decompression */ 1448 if (io->sync) { 1449 if (!atomic_add_return(bios, &io->pending_bios)) 1450 complete(&io->u.done); 1451 return; 1452 } 1453 1454 if (atomic_add_return(bios, &io->pending_bios)) 1455 return; 1456 /* Use (kthread_)work and sync decompression for atomic contexts only */ 1457 if (in_atomic() || irqs_disabled()) { 1458 #ifdef CONFIG_EROFS_FS_PCPU_KTHREAD 1459 struct kthread_worker *worker; 1460 1461 rcu_read_lock(); 1462 worker = rcu_dereference( 1463 z_erofs_pcpu_workers[raw_smp_processor_id()]); 1464 if (!worker) { 1465 INIT_WORK(&io->u.work, z_erofs_decompressqueue_work); 1466 queue_work(z_erofs_workqueue, &io->u.work); 1467 } else { 1468 kthread_queue_work(worker, &io->u.kthread_work); 1469 } 1470 rcu_read_unlock(); 1471 #else 1472 queue_work(z_erofs_workqueue, &io->u.work); 1473 #endif 1474 /* enable sync decompression for readahead */ 1475 if (sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) 1476 sbi->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_FORCE_ON; 1477 return; 1478 } 1479 z_erofs_decompressqueue_work(&io->u.work); 1480 } 1481 1482 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 1483 unsigned int nr, 1484 struct page **pagepool, 1485 struct address_space *mc) 1486 { 1487 const pgoff_t index = pcl->obj.index; 1488 gfp_t gfp = mapping_gfp_mask(mc); 1489 bool tocache = false; 1490 1491 struct address_space *mapping; 1492 struct page *oldpage, *page; 1493 int justfound; 1494 1495 repeat: 1496 page = READ_ONCE(pcl->compressed_bvecs[nr].page); 1497 oldpage = page; 1498 1499 if (!page) 1500 goto out_allocpage; 1501 1502 justfound = (unsigned long)page & 1UL; 1503 page = (struct page *)((unsigned long)page & ~1UL); 1504 1505 /* 1506 * preallocated cached pages, which is used to avoid direct reclaim 1507 * otherwise, it will go inplace I/O path instead. 1508 */ 1509 if (page->private == Z_EROFS_PREALLOCATED_PAGE) { 1510 WRITE_ONCE(pcl->compressed_bvecs[nr].page, page); 1511 set_page_private(page, 0); 1512 tocache = true; 1513 goto out_tocache; 1514 } 1515 mapping = READ_ONCE(page->mapping); 1516 1517 /* 1518 * file-backed online pages in plcuster are all locked steady, 1519 * therefore it is impossible for `mapping' to be NULL. 1520 */ 1521 if (mapping && mapping != mc) 1522 /* ought to be unmanaged pages */ 1523 goto out; 1524 1525 /* directly return for shortlived page as well */ 1526 if (z_erofs_is_shortlived_page(page)) 1527 goto out; 1528 1529 lock_page(page); 1530 1531 /* only true if page reclaim goes wrong, should never happen */ 1532 DBG_BUGON(justfound && PagePrivate(page)); 1533 1534 /* the page is still in manage cache */ 1535 if (page->mapping == mc) { 1536 WRITE_ONCE(pcl->compressed_bvecs[nr].page, page); 1537 1538 if (!PagePrivate(page)) { 1539 /* 1540 * impossible to be !PagePrivate(page) for 1541 * the current restriction as well if 1542 * the page is already in compressed_bvecs[]. 1543 */ 1544 DBG_BUGON(!justfound); 1545 1546 justfound = 0; 1547 set_page_private(page, (unsigned long)pcl); 1548 SetPagePrivate(page); 1549 } 1550 1551 /* no need to submit io if it is already up-to-date */ 1552 if (PageUptodate(page)) { 1553 unlock_page(page); 1554 page = NULL; 1555 } 1556 goto out; 1557 } 1558 1559 /* 1560 * the managed page has been truncated, it's unsafe to 1561 * reuse this one, let's allocate a new cache-managed page. 1562 */ 1563 DBG_BUGON(page->mapping); 1564 DBG_BUGON(!justfound); 1565 1566 tocache = true; 1567 unlock_page(page); 1568 put_page(page); 1569 out_allocpage: 1570 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); 1571 if (oldpage != cmpxchg(&pcl->compressed_bvecs[nr].page, 1572 oldpage, page)) { 1573 erofs_pagepool_add(pagepool, page); 1574 cond_resched(); 1575 goto repeat; 1576 } 1577 out_tocache: 1578 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { 1579 /* turn into temporary page if fails (1 ref) */ 1580 set_page_private(page, Z_EROFS_SHORTLIVED_PAGE); 1581 goto out; 1582 } 1583 attach_page_private(page, pcl); 1584 /* drop a refcount added by allocpage (then we have 2 refs here) */ 1585 put_page(page); 1586 1587 out: /* the only exit (for tracing and debugging) */ 1588 return page; 1589 } 1590 1591 static struct z_erofs_decompressqueue *jobqueue_init(struct super_block *sb, 1592 struct z_erofs_decompressqueue *fgq, bool *fg) 1593 { 1594 struct z_erofs_decompressqueue *q; 1595 1596 if (fg && !*fg) { 1597 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); 1598 if (!q) { 1599 *fg = true; 1600 goto fg_out; 1601 } 1602 #ifdef CONFIG_EROFS_FS_PCPU_KTHREAD 1603 kthread_init_work(&q->u.kthread_work, 1604 z_erofs_decompressqueue_kthread_work); 1605 #else 1606 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); 1607 #endif 1608 } else { 1609 fg_out: 1610 q = fgq; 1611 init_completion(&fgq->u.done); 1612 atomic_set(&fgq->pending_bios, 0); 1613 q->eio = false; 1614 q->sync = true; 1615 } 1616 q->sb = sb; 1617 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1618 return q; 1619 } 1620 1621 /* define decompression jobqueue types */ 1622 enum { 1623 JQ_BYPASS, 1624 JQ_SUBMIT, 1625 NR_JOBQUEUES, 1626 }; 1627 1628 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 1629 z_erofs_next_pcluster_t qtail[], 1630 z_erofs_next_pcluster_t owned_head) 1631 { 1632 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; 1633 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; 1634 1635 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1636 if (owned_head == Z_EROFS_PCLUSTER_TAIL) 1637 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1638 1639 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); 1640 1641 WRITE_ONCE(*submit_qtail, owned_head); 1642 WRITE_ONCE(*bypass_qtail, &pcl->next); 1643 1644 qtail[JQ_BYPASS] = &pcl->next; 1645 } 1646 1647 static void z_erofs_decompressqueue_endio(struct bio *bio) 1648 { 1649 struct z_erofs_decompressqueue *q = bio->bi_private; 1650 blk_status_t err = bio->bi_status; 1651 struct bio_vec *bvec; 1652 struct bvec_iter_all iter_all; 1653 1654 bio_for_each_segment_all(bvec, bio, iter_all) { 1655 struct page *page = bvec->bv_page; 1656 1657 DBG_BUGON(PageUptodate(page)); 1658 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1659 1660 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { 1661 if (!err) 1662 SetPageUptodate(page); 1663 unlock_page(page); 1664 } 1665 } 1666 if (err) 1667 q->eio = true; 1668 z_erofs_decompress_kickoff(q, -1); 1669 bio_put(bio); 1670 } 1671 1672 static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, 1673 struct page **pagepool, 1674 struct z_erofs_decompressqueue *fgq, 1675 bool *force_fg) 1676 { 1677 struct super_block *sb = f->inode->i_sb; 1678 struct address_space *mc = MNGD_MAPPING(EROFS_SB(sb)); 1679 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; 1680 struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; 1681 z_erofs_next_pcluster_t owned_head = f->owned_head; 1682 /* bio is NULL initially, so no need to initialize last_{index,bdev} */ 1683 pgoff_t last_index; 1684 struct block_device *last_bdev; 1685 unsigned int nr_bios = 0; 1686 struct bio *bio = NULL; 1687 unsigned long pflags; 1688 int memstall = 0; 1689 1690 /* 1691 * if managed cache is enabled, bypass jobqueue is needed, 1692 * no need to read from device for all pclusters in this queue. 1693 */ 1694 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); 1695 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, force_fg); 1696 1697 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; 1698 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; 1699 1700 /* by default, all need io submission */ 1701 q[JQ_SUBMIT]->head = owned_head; 1702 1703 do { 1704 struct erofs_map_dev mdev; 1705 struct z_erofs_pcluster *pcl; 1706 pgoff_t cur, end; 1707 unsigned int i = 0; 1708 bool bypass = true; 1709 1710 /* no possible 'owned_head' equals the following */ 1711 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1712 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); 1713 1714 pcl = container_of(owned_head, struct z_erofs_pcluster, next); 1715 1716 /* close the main owned chain at first */ 1717 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 1718 Z_EROFS_PCLUSTER_TAIL_CLOSED); 1719 if (z_erofs_is_inline_pcluster(pcl)) { 1720 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1721 continue; 1722 } 1723 1724 /* no device id here, thus it will always succeed */ 1725 mdev = (struct erofs_map_dev) { 1726 .m_pa = erofs_pos(sb, pcl->obj.index), 1727 }; 1728 (void)erofs_map_dev(sb, &mdev); 1729 1730 cur = erofs_blknr(sb, mdev.m_pa); 1731 end = cur + pcl->pclusterpages; 1732 1733 do { 1734 struct page *page; 1735 1736 page = pickup_page_for_submission(pcl, i++, pagepool, 1737 mc); 1738 if (!page) 1739 continue; 1740 1741 if (bio && (cur != last_index + 1 || 1742 last_bdev != mdev.m_bdev)) { 1743 submit_bio_retry: 1744 submit_bio(bio); 1745 if (memstall) { 1746 psi_memstall_leave(&pflags); 1747 memstall = 0; 1748 } 1749 bio = NULL; 1750 } 1751 1752 if (unlikely(PageWorkingset(page)) && !memstall) { 1753 psi_memstall_enter(&pflags); 1754 memstall = 1; 1755 } 1756 1757 if (!bio) { 1758 bio = bio_alloc(mdev.m_bdev, BIO_MAX_VECS, 1759 REQ_OP_READ, GFP_NOIO); 1760 bio->bi_end_io = z_erofs_decompressqueue_endio; 1761 1762 last_bdev = mdev.m_bdev; 1763 bio->bi_iter.bi_sector = (sector_t)cur << 1764 (sb->s_blocksize_bits - 9); 1765 bio->bi_private = q[JQ_SUBMIT]; 1766 if (f->readahead) 1767 bio->bi_opf |= REQ_RAHEAD; 1768 ++nr_bios; 1769 } 1770 1771 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) 1772 goto submit_bio_retry; 1773 1774 last_index = cur; 1775 bypass = false; 1776 } while (++cur < end); 1777 1778 if (!bypass) 1779 qtail[JQ_SUBMIT] = &pcl->next; 1780 else 1781 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1782 } while (owned_head != Z_EROFS_PCLUSTER_TAIL); 1783 1784 if (bio) { 1785 submit_bio(bio); 1786 if (memstall) 1787 psi_memstall_leave(&pflags); 1788 } 1789 1790 /* 1791 * although background is preferred, no one is pending for submission. 1792 * don't issue decompression but drop it directly instead. 1793 */ 1794 if (!*force_fg && !nr_bios) { 1795 kvfree(q[JQ_SUBMIT]); 1796 return; 1797 } 1798 z_erofs_decompress_kickoff(q[JQ_SUBMIT], nr_bios); 1799 } 1800 1801 static void z_erofs_runqueue(struct z_erofs_decompress_frontend *f, 1802 struct page **pagepool, bool force_fg) 1803 { 1804 struct z_erofs_decompressqueue io[NR_JOBQUEUES]; 1805 1806 if (f->owned_head == Z_EROFS_PCLUSTER_TAIL) 1807 return; 1808 z_erofs_submit_queue(f, pagepool, io, &force_fg); 1809 1810 /* handle bypass queue (no i/o pclusters) immediately */ 1811 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); 1812 1813 if (!force_fg) 1814 return; 1815 1816 /* wait until all bios are completed */ 1817 wait_for_completion_io(&io[JQ_SUBMIT].u.done); 1818 1819 /* handle synchronous decompress queue in the caller context */ 1820 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); 1821 } 1822 1823 /* 1824 * Since partial uptodate is still unimplemented for now, we have to use 1825 * approximate readmore strategies as a start. 1826 */ 1827 static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f, 1828 struct readahead_control *rac, 1829 erofs_off_t end, 1830 struct page **pagepool, 1831 bool backmost) 1832 { 1833 struct inode *inode = f->inode; 1834 struct erofs_map_blocks *map = &f->map; 1835 erofs_off_t cur; 1836 int err; 1837 1838 if (backmost) { 1839 map->m_la = end; 1840 err = z_erofs_map_blocks_iter(inode, map, 1841 EROFS_GET_BLOCKS_READMORE); 1842 if (err) 1843 return; 1844 1845 /* expend ra for the trailing edge if readahead */ 1846 if (rac) { 1847 loff_t newstart = readahead_pos(rac); 1848 1849 cur = round_up(map->m_la + map->m_llen, PAGE_SIZE); 1850 readahead_expand(rac, newstart, cur - newstart); 1851 return; 1852 } 1853 end = round_up(end, PAGE_SIZE); 1854 } else { 1855 end = round_up(map->m_la, PAGE_SIZE); 1856 1857 if (!map->m_llen) 1858 return; 1859 } 1860 1861 cur = map->m_la + map->m_llen - 1; 1862 while (cur >= end) { 1863 pgoff_t index = cur >> PAGE_SHIFT; 1864 struct page *page; 1865 1866 page = erofs_grab_cache_page_nowait(inode->i_mapping, index); 1867 if (page) { 1868 if (PageUptodate(page)) { 1869 unlock_page(page); 1870 } else { 1871 err = z_erofs_do_read_page(f, page, pagepool); 1872 if (err) 1873 erofs_err(inode->i_sb, 1874 "readmore error at page %lu @ nid %llu", 1875 index, EROFS_I(inode)->nid); 1876 } 1877 put_page(page); 1878 } 1879 1880 if (cur < PAGE_SIZE) 1881 break; 1882 cur = (index << PAGE_SHIFT) - 1; 1883 } 1884 } 1885 1886 static int z_erofs_read_folio(struct file *file, struct folio *folio) 1887 { 1888 struct page *page = &folio->page; 1889 struct inode *const inode = page->mapping->host; 1890 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1891 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1892 struct page *pagepool = NULL; 1893 int err; 1894 1895 trace_erofs_readpage(page, false); 1896 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 1897 1898 z_erofs_pcluster_readmore(&f, NULL, f.headoffset + PAGE_SIZE - 1, 1899 &pagepool, true); 1900 err = z_erofs_do_read_page(&f, page, &pagepool); 1901 z_erofs_pcluster_readmore(&f, NULL, 0, &pagepool, false); 1902 1903 (void)z_erofs_collector_end(&f); 1904 1905 /* if some compressed cluster ready, need submit them anyway */ 1906 z_erofs_runqueue(&f, &pagepool, 1907 z_erofs_get_sync_decompress_policy(sbi, 0)); 1908 1909 if (err) 1910 erofs_err(inode->i_sb, "failed to read, err [%d]", err); 1911 1912 erofs_put_metabuf(&f.map.buf); 1913 erofs_release_pages(&pagepool); 1914 return err; 1915 } 1916 1917 static void z_erofs_readahead(struct readahead_control *rac) 1918 { 1919 struct inode *const inode = rac->mapping->host; 1920 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1921 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1922 struct page *pagepool = NULL, *head = NULL, *page; 1923 unsigned int nr_pages; 1924 1925 f.readahead = true; 1926 f.headoffset = readahead_pos(rac); 1927 1928 z_erofs_pcluster_readmore(&f, rac, f.headoffset + 1929 readahead_length(rac) - 1, &pagepool, true); 1930 nr_pages = readahead_count(rac); 1931 trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); 1932 1933 while ((page = readahead_page(rac))) { 1934 set_page_private(page, (unsigned long)head); 1935 head = page; 1936 } 1937 1938 while (head) { 1939 struct page *page = head; 1940 int err; 1941 1942 /* traversal in reverse order */ 1943 head = (void *)page_private(page); 1944 1945 err = z_erofs_do_read_page(&f, page, &pagepool); 1946 if (err) 1947 erofs_err(inode->i_sb, 1948 "readahead error at page %lu @ nid %llu", 1949 page->index, EROFS_I(inode)->nid); 1950 put_page(page); 1951 } 1952 z_erofs_pcluster_readmore(&f, rac, 0, &pagepool, false); 1953 (void)z_erofs_collector_end(&f); 1954 1955 z_erofs_runqueue(&f, &pagepool, 1956 z_erofs_get_sync_decompress_policy(sbi, nr_pages)); 1957 erofs_put_metabuf(&f.map.buf); 1958 erofs_release_pages(&pagepool); 1959 } 1960 1961 const struct address_space_operations z_erofs_aops = { 1962 .read_folio = z_erofs_read_folio, 1963 .readahead = z_erofs_readahead, 1964 }; 1965