1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 */ 6 #include "zdata.h" 7 #include "compress.h" 8 #include <linux/prefetch.h> 9 10 #include <trace/events/erofs.h> 11 12 /* 13 * since pclustersize is variable for big pcluster feature, introduce slab 14 * pools implementation for different pcluster sizes. 15 */ 16 struct z_erofs_pcluster_slab { 17 struct kmem_cache *slab; 18 unsigned int maxpages; 19 char name[48]; 20 }; 21 22 #define _PCLP(n) { .maxpages = n } 23 24 static struct z_erofs_pcluster_slab pcluster_pool[] __read_mostly = { 25 _PCLP(1), _PCLP(4), _PCLP(16), _PCLP(64), _PCLP(128), 26 _PCLP(Z_EROFS_PCLUSTER_MAX_PAGES) 27 }; 28 29 static void z_erofs_destroy_pcluster_pool(void) 30 { 31 int i; 32 33 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 34 if (!pcluster_pool[i].slab) 35 continue; 36 kmem_cache_destroy(pcluster_pool[i].slab); 37 pcluster_pool[i].slab = NULL; 38 } 39 } 40 41 static int z_erofs_create_pcluster_pool(void) 42 { 43 struct z_erofs_pcluster_slab *pcs; 44 struct z_erofs_pcluster *a; 45 unsigned int size; 46 47 for (pcs = pcluster_pool; 48 pcs < pcluster_pool + ARRAY_SIZE(pcluster_pool); ++pcs) { 49 size = struct_size(a, compressed_pages, pcs->maxpages); 50 51 sprintf(pcs->name, "erofs_pcluster-%u", pcs->maxpages); 52 pcs->slab = kmem_cache_create(pcs->name, size, 0, 53 SLAB_RECLAIM_ACCOUNT, NULL); 54 if (pcs->slab) 55 continue; 56 57 z_erofs_destroy_pcluster_pool(); 58 return -ENOMEM; 59 } 60 return 0; 61 } 62 63 static struct z_erofs_pcluster *z_erofs_alloc_pcluster(unsigned int nrpages) 64 { 65 int i; 66 67 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 68 struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; 69 struct z_erofs_pcluster *pcl; 70 71 if (nrpages > pcs->maxpages) 72 continue; 73 74 pcl = kmem_cache_zalloc(pcs->slab, GFP_NOFS); 75 if (!pcl) 76 return ERR_PTR(-ENOMEM); 77 pcl->pclusterpages = nrpages; 78 return pcl; 79 } 80 return ERR_PTR(-EINVAL); 81 } 82 83 static void z_erofs_free_pcluster(struct z_erofs_pcluster *pcl) 84 { 85 int i; 86 87 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 88 struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; 89 90 if (pcl->pclusterpages > pcs->maxpages) 91 continue; 92 93 kmem_cache_free(pcs->slab, pcl); 94 return; 95 } 96 DBG_BUGON(1); 97 } 98 99 /* 100 * a compressed_pages[] placeholder in order to avoid 101 * being filled with file pages for in-place decompression. 102 */ 103 #define PAGE_UNALLOCATED ((void *)0x5F0E4B1D) 104 105 /* how to allocate cached pages for a pcluster */ 106 enum z_erofs_cache_alloctype { 107 DONTALLOC, /* don't allocate any cached pages */ 108 DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */ 109 /* 110 * try to use cached I/O if page allocation succeeds or fallback 111 * to in-place I/O instead to avoid any direct reclaim. 112 */ 113 TRYALLOC, 114 }; 115 116 /* 117 * tagged pointer with 1-bit tag for all compressed pages 118 * tag 0 - the page is just found with an extra page reference 119 */ 120 typedef tagptr1_t compressed_page_t; 121 122 #define tag_compressed_page_justfound(page) \ 123 tagptr_fold(compressed_page_t, page, 1) 124 125 static struct workqueue_struct *z_erofs_workqueue __read_mostly; 126 127 void z_erofs_exit_zip_subsystem(void) 128 { 129 destroy_workqueue(z_erofs_workqueue); 130 z_erofs_destroy_pcluster_pool(); 131 } 132 133 static inline int z_erofs_init_workqueue(void) 134 { 135 const unsigned int onlinecpus = num_possible_cpus(); 136 137 /* 138 * no need to spawn too many threads, limiting threads could minimum 139 * scheduling overhead, perhaps per-CPU threads should be better? 140 */ 141 z_erofs_workqueue = alloc_workqueue("erofs_unzipd", 142 WQ_UNBOUND | WQ_HIGHPRI, 143 onlinecpus + onlinecpus / 4); 144 return z_erofs_workqueue ? 0 : -ENOMEM; 145 } 146 147 int __init z_erofs_init_zip_subsystem(void) 148 { 149 int err = z_erofs_create_pcluster_pool(); 150 151 if (err) 152 return err; 153 err = z_erofs_init_workqueue(); 154 if (err) 155 z_erofs_destroy_pcluster_pool(); 156 return err; 157 } 158 159 enum z_erofs_collectmode { 160 COLLECT_SECONDARY, 161 COLLECT_PRIMARY, 162 /* 163 * The current collection was the tail of an exist chain, in addition 164 * that the previous processed chained collections are all decided to 165 * be hooked up to it. 166 * A new chain will be created for the remaining collections which are 167 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED, 168 * the next collection cannot reuse the whole page safely in 169 * the following scenario: 170 * ________________________________________________________________ 171 * | tail (partial) page | head (partial) page | 172 * | (belongs to the next cl) | (belongs to the current cl) | 173 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| 174 */ 175 COLLECT_PRIMARY_HOOKED, 176 /* 177 * a weak form of COLLECT_PRIMARY_FOLLOWED, the difference is that it 178 * could be dispatched into bypass queue later due to uptodated managed 179 * pages. All related online pages cannot be reused for inplace I/O (or 180 * pagevec) since it can be directly decoded without I/O submission. 181 */ 182 COLLECT_PRIMARY_FOLLOWED_NOINPLACE, 183 /* 184 * The current collection has been linked with the owned chain, and 185 * could also be linked with the remaining collections, which means 186 * if the processing page is the tail page of the collection, thus 187 * the current collection can safely use the whole page (since 188 * the previous collection is under control) for in-place I/O, as 189 * illustrated below: 190 * ________________________________________________________________ 191 * | tail (partial) page | head (partial) page | 192 * | (of the current cl) | (of the previous collection) | 193 * | PRIMARY_FOLLOWED or | | 194 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| 195 * 196 * [ (*) the above page can be used as inplace I/O. ] 197 */ 198 COLLECT_PRIMARY_FOLLOWED, 199 }; 200 201 struct z_erofs_collector { 202 struct z_erofs_pagevec_ctor vector; 203 204 struct z_erofs_pcluster *pcl, *tailpcl; 205 struct z_erofs_collection *cl; 206 /* a pointer used to pick up inplace I/O pages */ 207 struct page **icpage_ptr; 208 z_erofs_next_pcluster_t owned_head; 209 210 enum z_erofs_collectmode mode; 211 }; 212 213 struct z_erofs_decompress_frontend { 214 struct inode *const inode; 215 216 struct z_erofs_collector clt; 217 struct erofs_map_blocks map; 218 219 bool readahead; 220 /* used for applying cache strategy on the fly */ 221 bool backmost; 222 erofs_off_t headoffset; 223 }; 224 225 #define COLLECTOR_INIT() { \ 226 .owned_head = Z_EROFS_PCLUSTER_TAIL, \ 227 .mode = COLLECT_PRIMARY_FOLLOWED } 228 229 #define DECOMPRESS_FRONTEND_INIT(__i) { \ 230 .inode = __i, .clt = COLLECTOR_INIT(), \ 231 .backmost = true, } 232 233 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES]; 234 static DEFINE_MUTEX(z_pagemap_global_lock); 235 236 static void preload_compressed_pages(struct z_erofs_collector *clt, 237 struct address_space *mc, 238 enum z_erofs_cache_alloctype type, 239 struct list_head *pagepool) 240 { 241 struct z_erofs_pcluster *pcl = clt->pcl; 242 bool standalone = true; 243 gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | 244 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 245 struct page **pages; 246 pgoff_t index; 247 248 if (clt->mode < COLLECT_PRIMARY_FOLLOWED) 249 return; 250 251 pages = pcl->compressed_pages; 252 index = pcl->obj.index; 253 for (; index < pcl->obj.index + pcl->pclusterpages; ++index, ++pages) { 254 struct page *page; 255 compressed_page_t t; 256 struct page *newpage = NULL; 257 258 /* the compressed page was loaded before */ 259 if (READ_ONCE(*pages)) 260 continue; 261 262 page = find_get_page(mc, index); 263 264 if (page) { 265 t = tag_compressed_page_justfound(page); 266 } else { 267 /* I/O is needed, no possible to decompress directly */ 268 standalone = false; 269 switch (type) { 270 case DELAYEDALLOC: 271 t = tagptr_init(compressed_page_t, 272 PAGE_UNALLOCATED); 273 break; 274 case TRYALLOC: 275 newpage = erofs_allocpage(pagepool, gfp); 276 if (!newpage) 277 continue; 278 set_page_private(newpage, 279 Z_EROFS_PREALLOCATED_PAGE); 280 t = tag_compressed_page_justfound(newpage); 281 break; 282 default: /* DONTALLOC */ 283 continue; 284 } 285 } 286 287 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t))) 288 continue; 289 290 if (page) { 291 put_page(page); 292 } else if (newpage) { 293 set_page_private(newpage, 0); 294 list_add(&newpage->lru, pagepool); 295 } 296 } 297 298 /* 299 * don't do inplace I/O if all compressed pages are available in 300 * managed cache since it can be moved to the bypass queue instead. 301 */ 302 if (standalone) 303 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE; 304 } 305 306 /* called by erofs_shrinker to get rid of all compressed_pages */ 307 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 308 struct erofs_workgroup *grp) 309 { 310 struct z_erofs_pcluster *const pcl = 311 container_of(grp, struct z_erofs_pcluster, obj); 312 struct address_space *const mapping = MNGD_MAPPING(sbi); 313 int i; 314 315 /* 316 * refcount of workgroup is now freezed as 1, 317 * therefore no need to worry about available decompression users. 318 */ 319 for (i = 0; i < pcl->pclusterpages; ++i) { 320 struct page *page = pcl->compressed_pages[i]; 321 322 if (!page) 323 continue; 324 325 /* block other users from reclaiming or migrating the page */ 326 if (!trylock_page(page)) 327 return -EBUSY; 328 329 if (page->mapping != mapping) 330 continue; 331 332 /* barrier is implied in the following 'unlock_page' */ 333 WRITE_ONCE(pcl->compressed_pages[i], NULL); 334 detach_page_private(page); 335 unlock_page(page); 336 } 337 return 0; 338 } 339 340 int erofs_try_to_free_cached_page(struct address_space *mapping, 341 struct page *page) 342 { 343 struct z_erofs_pcluster *const pcl = (void *)page_private(page); 344 int ret = 0; /* 0 - busy */ 345 346 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) { 347 unsigned int i; 348 349 for (i = 0; i < pcl->pclusterpages; ++i) { 350 if (pcl->compressed_pages[i] == page) { 351 WRITE_ONCE(pcl->compressed_pages[i], NULL); 352 ret = 1; 353 break; 354 } 355 } 356 erofs_workgroup_unfreeze(&pcl->obj, 1); 357 358 if (ret) 359 detach_page_private(page); 360 } 361 return ret; 362 } 363 364 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ 365 static bool z_erofs_try_inplace_io(struct z_erofs_collector *clt, 366 struct page *page) 367 { 368 struct z_erofs_pcluster *const pcl = clt->pcl; 369 370 while (clt->icpage_ptr > pcl->compressed_pages) 371 if (!cmpxchg(--clt->icpage_ptr, NULL, page)) 372 return true; 373 return false; 374 } 375 376 /* callers must be with collection lock held */ 377 static int z_erofs_attach_page(struct z_erofs_collector *clt, 378 struct page *page, 379 enum z_erofs_page_type type) 380 { 381 int ret; 382 383 /* give priority for inplaceio */ 384 if (clt->mode >= COLLECT_PRIMARY && 385 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && 386 z_erofs_try_inplace_io(clt, page)) 387 return 0; 388 389 ret = z_erofs_pagevec_enqueue(&clt->vector, page, type); 390 clt->cl->vcnt += (unsigned int)ret; 391 392 return ret ? 0 : -EAGAIN; 393 } 394 395 static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt) 396 { 397 struct z_erofs_pcluster *pcl = clt->pcl; 398 z_erofs_next_pcluster_t *owned_head = &clt->owned_head; 399 400 /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */ 401 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, 402 *owned_head) == Z_EROFS_PCLUSTER_NIL) { 403 *owned_head = &pcl->next; 404 /* so we can attach this pcluster to our submission chain. */ 405 clt->mode = COLLECT_PRIMARY_FOLLOWED; 406 return; 407 } 408 409 /* 410 * type 2, link to the end of an existing open chain, be careful 411 * that its submission is controlled by the original attached chain. 412 */ 413 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 414 *owned_head) == Z_EROFS_PCLUSTER_TAIL) { 415 *owned_head = Z_EROFS_PCLUSTER_TAIL; 416 clt->mode = COLLECT_PRIMARY_HOOKED; 417 clt->tailpcl = NULL; 418 return; 419 } 420 /* type 3, it belongs to a chain, but it isn't the end of the chain */ 421 clt->mode = COLLECT_PRIMARY; 422 } 423 424 static int z_erofs_lookup_collection(struct z_erofs_collector *clt, 425 struct inode *inode, 426 struct erofs_map_blocks *map) 427 { 428 struct z_erofs_pcluster *pcl = clt->pcl; 429 struct z_erofs_collection *cl; 430 unsigned int length; 431 432 /* to avoid unexpected loop formed by corrupted images */ 433 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) { 434 DBG_BUGON(1); 435 return -EFSCORRUPTED; 436 } 437 438 cl = z_erofs_primarycollection(pcl); 439 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) { 440 DBG_BUGON(1); 441 return -EFSCORRUPTED; 442 } 443 444 length = READ_ONCE(pcl->length); 445 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) { 446 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) { 447 DBG_BUGON(1); 448 return -EFSCORRUPTED; 449 } 450 } else { 451 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT; 452 453 if (map->m_flags & EROFS_MAP_FULL_MAPPED) 454 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH; 455 456 while (llen > length && 457 length != cmpxchg_relaxed(&pcl->length, length, llen)) { 458 cpu_relax(); 459 length = READ_ONCE(pcl->length); 460 } 461 } 462 mutex_lock(&cl->lock); 463 /* used to check tail merging loop due to corrupted images */ 464 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 465 clt->tailpcl = pcl; 466 467 z_erofs_try_to_claim_pcluster(clt); 468 clt->cl = cl; 469 return 0; 470 } 471 472 static int z_erofs_register_collection(struct z_erofs_collector *clt, 473 struct inode *inode, 474 struct erofs_map_blocks *map) 475 { 476 struct z_erofs_pcluster *pcl; 477 struct z_erofs_collection *cl; 478 struct erofs_workgroup *grp; 479 int err; 480 481 /* no available pcluster, let's allocate one */ 482 pcl = z_erofs_alloc_pcluster(map->m_plen >> PAGE_SHIFT); 483 if (IS_ERR(pcl)) 484 return PTR_ERR(pcl); 485 486 atomic_set(&pcl->obj.refcount, 1); 487 pcl->obj.index = map->m_pa >> PAGE_SHIFT; 488 489 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) | 490 (map->m_flags & EROFS_MAP_FULL_MAPPED ? 491 Z_EROFS_PCLUSTER_FULL_LENGTH : 0); 492 493 if (map->m_flags & EROFS_MAP_ZIPPED) 494 pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4; 495 else 496 pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED; 497 498 /* new pclusters should be claimed as type 1, primary and followed */ 499 pcl->next = clt->owned_head; 500 clt->mode = COLLECT_PRIMARY_FOLLOWED; 501 502 cl = z_erofs_primarycollection(pcl); 503 cl->pageofs = map->m_la & ~PAGE_MASK; 504 505 /* 506 * lock all primary followed works before visible to others 507 * and mutex_trylock *never* fails for a new pcluster. 508 */ 509 mutex_init(&cl->lock); 510 DBG_BUGON(!mutex_trylock(&cl->lock)); 511 512 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj); 513 if (IS_ERR(grp)) { 514 err = PTR_ERR(grp); 515 goto err_out; 516 } 517 518 if (grp != &pcl->obj) { 519 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 520 err = -EEXIST; 521 goto err_out; 522 } 523 /* used to check tail merging loop due to corrupted images */ 524 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 525 clt->tailpcl = pcl; 526 clt->owned_head = &pcl->next; 527 clt->pcl = pcl; 528 clt->cl = cl; 529 return 0; 530 531 err_out: 532 mutex_unlock(&cl->lock); 533 z_erofs_free_pcluster(pcl); 534 return err; 535 } 536 537 static int z_erofs_collector_begin(struct z_erofs_collector *clt, 538 struct inode *inode, 539 struct erofs_map_blocks *map) 540 { 541 struct erofs_workgroup *grp; 542 int ret; 543 544 DBG_BUGON(clt->cl); 545 546 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */ 547 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL); 548 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 549 550 if (!PAGE_ALIGNED(map->m_pa)) { 551 DBG_BUGON(1); 552 return -EINVAL; 553 } 554 555 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT); 556 if (grp) { 557 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 558 } else { 559 ret = z_erofs_register_collection(clt, inode, map); 560 561 if (!ret) 562 goto out; 563 if (ret != -EEXIST) 564 return ret; 565 } 566 567 ret = z_erofs_lookup_collection(clt, inode, map); 568 if (ret) { 569 erofs_workgroup_put(&clt->pcl->obj); 570 return ret; 571 } 572 573 out: 574 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS, 575 clt->cl->pagevec, clt->cl->vcnt); 576 577 /* since file-backed online pages are traversed in reverse order */ 578 clt->icpage_ptr = clt->pcl->compressed_pages + clt->pcl->pclusterpages; 579 return 0; 580 } 581 582 /* 583 * keep in mind that no referenced pclusters will be freed 584 * only after a RCU grace period. 585 */ 586 static void z_erofs_rcu_callback(struct rcu_head *head) 587 { 588 struct z_erofs_collection *const cl = 589 container_of(head, struct z_erofs_collection, rcu); 590 591 z_erofs_free_pcluster(container_of(cl, struct z_erofs_pcluster, 592 primary_collection)); 593 } 594 595 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) 596 { 597 struct z_erofs_pcluster *const pcl = 598 container_of(grp, struct z_erofs_pcluster, obj); 599 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl); 600 601 call_rcu(&cl->rcu, z_erofs_rcu_callback); 602 } 603 604 static void z_erofs_collection_put(struct z_erofs_collection *cl) 605 { 606 struct z_erofs_pcluster *const pcl = 607 container_of(cl, struct z_erofs_pcluster, primary_collection); 608 609 erofs_workgroup_put(&pcl->obj); 610 } 611 612 static bool z_erofs_collector_end(struct z_erofs_collector *clt) 613 { 614 struct z_erofs_collection *cl = clt->cl; 615 616 if (!cl) 617 return false; 618 619 z_erofs_pagevec_ctor_exit(&clt->vector, false); 620 mutex_unlock(&cl->lock); 621 622 /* 623 * if all pending pages are added, don't hold its reference 624 * any longer if the pcluster isn't hosted by ourselves. 625 */ 626 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE) 627 z_erofs_collection_put(cl); 628 629 clt->cl = NULL; 630 return true; 631 } 632 633 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe, 634 unsigned int cachestrategy, 635 erofs_off_t la) 636 { 637 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) 638 return false; 639 640 if (fe->backmost) 641 return true; 642 643 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND && 644 la < fe->headoffset; 645 } 646 647 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 648 struct page *page, struct list_head *pagepool) 649 { 650 struct inode *const inode = fe->inode; 651 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 652 struct erofs_map_blocks *const map = &fe->map; 653 struct z_erofs_collector *const clt = &fe->clt; 654 const loff_t offset = page_offset(page); 655 bool tight = true; 656 657 enum z_erofs_cache_alloctype cache_strategy; 658 enum z_erofs_page_type page_type; 659 unsigned int cur, end, spiltted, index; 660 int err = 0; 661 662 /* register locked file pages as online pages in pack */ 663 z_erofs_onlinepage_init(page); 664 665 spiltted = 0; 666 end = PAGE_SIZE; 667 repeat: 668 cur = end - 1; 669 670 /* lucky, within the range of the current map_blocks */ 671 if (offset + cur >= map->m_la && 672 offset + cur < map->m_la + map->m_llen) { 673 /* didn't get a valid collection previously (very rare) */ 674 if (!clt->cl) 675 goto restart_now; 676 goto hitted; 677 } 678 679 /* go ahead the next map_blocks */ 680 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur); 681 682 if (z_erofs_collector_end(clt)) 683 fe->backmost = false; 684 685 map->m_la = offset + cur; 686 map->m_llen = 0; 687 err = z_erofs_map_blocks_iter(inode, map, 0); 688 if (err) 689 goto err_out; 690 691 restart_now: 692 if (!(map->m_flags & EROFS_MAP_MAPPED)) 693 goto hitted; 694 695 err = z_erofs_collector_begin(clt, inode, map); 696 if (err) 697 goto err_out; 698 699 /* preload all compressed pages (maybe downgrade role if necessary) */ 700 if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la)) 701 cache_strategy = TRYALLOC; 702 else 703 cache_strategy = DONTALLOC; 704 705 preload_compressed_pages(clt, MNGD_MAPPING(sbi), 706 cache_strategy, pagepool); 707 708 hitted: 709 /* 710 * Ensure the current partial page belongs to this submit chain rather 711 * than other concurrent submit chains or the noio(bypass) chain since 712 * those chains are handled asynchronously thus the page cannot be used 713 * for inplace I/O or pagevec (should be processed in strict order.) 714 */ 715 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED && 716 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE); 717 718 cur = end - min_t(unsigned int, offset + end - map->m_la, end); 719 if (!(map->m_flags & EROFS_MAP_MAPPED)) { 720 zero_user_segment(page, cur, end); 721 goto next_part; 722 } 723 724 /* let's derive page type */ 725 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD : 726 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 727 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 728 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); 729 730 if (cur) 731 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED); 732 733 retry: 734 err = z_erofs_attach_page(clt, page, page_type); 735 /* should allocate an additional short-lived page for pagevec */ 736 if (err == -EAGAIN) { 737 struct page *const newpage = 738 alloc_page(GFP_NOFS | __GFP_NOFAIL); 739 740 set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); 741 err = z_erofs_attach_page(clt, newpage, 742 Z_EROFS_PAGE_TYPE_EXCLUSIVE); 743 if (!err) 744 goto retry; 745 } 746 747 if (err) 748 goto err_out; 749 750 index = page->index - (map->m_la >> PAGE_SHIFT); 751 752 z_erofs_onlinepage_fixup(page, index, true); 753 754 /* bump up the number of spiltted parts of a page */ 755 ++spiltted; 756 /* also update nr_pages */ 757 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1); 758 next_part: 759 /* can be used for verification */ 760 map->m_llen = offset + cur - map->m_la; 761 762 end = cur; 763 if (end > 0) 764 goto repeat; 765 766 out: 767 z_erofs_onlinepage_endio(page); 768 769 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu", 770 __func__, page, spiltted, map->m_llen); 771 return err; 772 773 /* if some error occurred while processing this page */ 774 err_out: 775 SetPageError(page); 776 goto out; 777 } 778 779 static void z_erofs_decompressqueue_work(struct work_struct *work); 780 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, 781 bool sync, int bios) 782 { 783 struct erofs_sb_info *const sbi = EROFS_SB(io->sb); 784 785 /* wake up the caller thread for sync decompression */ 786 if (sync) { 787 unsigned long flags; 788 789 spin_lock_irqsave(&io->u.wait.lock, flags); 790 if (!atomic_add_return(bios, &io->pending_bios)) 791 wake_up_locked(&io->u.wait); 792 spin_unlock_irqrestore(&io->u.wait.lock, flags); 793 return; 794 } 795 796 if (atomic_add_return(bios, &io->pending_bios)) 797 return; 798 /* Use workqueue and sync decompression for atomic contexts only */ 799 if (in_atomic() || irqs_disabled()) { 800 queue_work(z_erofs_workqueue, &io->u.work); 801 sbi->ctx.readahead_sync_decompress = true; 802 return; 803 } 804 z_erofs_decompressqueue_work(&io->u.work); 805 } 806 807 static bool z_erofs_page_is_invalidated(struct page *page) 808 { 809 return !page->mapping && !z_erofs_is_shortlived_page(page); 810 } 811 812 static void z_erofs_decompressqueue_endio(struct bio *bio) 813 { 814 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private); 815 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t); 816 blk_status_t err = bio->bi_status; 817 struct bio_vec *bvec; 818 struct bvec_iter_all iter_all; 819 820 bio_for_each_segment_all(bvec, bio, iter_all) { 821 struct page *page = bvec->bv_page; 822 823 DBG_BUGON(PageUptodate(page)); 824 DBG_BUGON(z_erofs_page_is_invalidated(page)); 825 826 if (err) 827 SetPageError(page); 828 829 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { 830 if (!err) 831 SetPageUptodate(page); 832 unlock_page(page); 833 } 834 } 835 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); 836 bio_put(bio); 837 } 838 839 static int z_erofs_decompress_pcluster(struct super_block *sb, 840 struct z_erofs_pcluster *pcl, 841 struct list_head *pagepool) 842 { 843 struct erofs_sb_info *const sbi = EROFS_SB(sb); 844 struct z_erofs_pagevec_ctor ctor; 845 unsigned int i, inputsize, outputsize, llen, nr_pages; 846 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES]; 847 struct page **pages, **compressed_pages, *page; 848 849 enum z_erofs_page_type page_type; 850 bool overlapped, partial; 851 struct z_erofs_collection *cl; 852 int err; 853 854 might_sleep(); 855 cl = z_erofs_primarycollection(pcl); 856 DBG_BUGON(!READ_ONCE(cl->nr_pages)); 857 858 mutex_lock(&cl->lock); 859 nr_pages = cl->nr_pages; 860 861 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) { 862 pages = pages_onstack; 863 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES && 864 mutex_trylock(&z_pagemap_global_lock)) { 865 pages = z_pagemap_global; 866 } else { 867 gfp_t gfp_flags = GFP_KERNEL; 868 869 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES) 870 gfp_flags |= __GFP_NOFAIL; 871 872 pages = kvmalloc_array(nr_pages, sizeof(struct page *), 873 gfp_flags); 874 875 /* fallback to global pagemap for the lowmem scenario */ 876 if (!pages) { 877 mutex_lock(&z_pagemap_global_lock); 878 pages = z_pagemap_global; 879 } 880 } 881 882 for (i = 0; i < nr_pages; ++i) 883 pages[i] = NULL; 884 885 err = 0; 886 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, 887 cl->pagevec, 0); 888 889 for (i = 0; i < cl->vcnt; ++i) { 890 unsigned int pagenr; 891 892 page = z_erofs_pagevec_dequeue(&ctor, &page_type); 893 894 /* all pages in pagevec ought to be valid */ 895 DBG_BUGON(!page); 896 DBG_BUGON(z_erofs_page_is_invalidated(page)); 897 898 if (z_erofs_put_shortlivedpage(pagepool, page)) 899 continue; 900 901 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD) 902 pagenr = 0; 903 else 904 pagenr = z_erofs_onlinepage_index(page); 905 906 DBG_BUGON(pagenr >= nr_pages); 907 908 /* 909 * currently EROFS doesn't support multiref(dedup), 910 * so here erroring out one multiref page. 911 */ 912 if (pages[pagenr]) { 913 DBG_BUGON(1); 914 SetPageError(pages[pagenr]); 915 z_erofs_onlinepage_endio(pages[pagenr]); 916 err = -EFSCORRUPTED; 917 } 918 pages[pagenr] = page; 919 } 920 z_erofs_pagevec_ctor_exit(&ctor, true); 921 922 overlapped = false; 923 compressed_pages = pcl->compressed_pages; 924 925 for (i = 0; i < pcl->pclusterpages; ++i) { 926 unsigned int pagenr; 927 928 page = compressed_pages[i]; 929 930 /* all compressed pages ought to be valid */ 931 DBG_BUGON(!page); 932 DBG_BUGON(z_erofs_page_is_invalidated(page)); 933 934 if (!z_erofs_is_shortlived_page(page)) { 935 if (erofs_page_is_managed(sbi, page)) { 936 if (!PageUptodate(page)) 937 err = -EIO; 938 continue; 939 } 940 941 /* 942 * only if non-head page can be selected 943 * for inplace decompression 944 */ 945 pagenr = z_erofs_onlinepage_index(page); 946 947 DBG_BUGON(pagenr >= nr_pages); 948 if (pages[pagenr]) { 949 DBG_BUGON(1); 950 SetPageError(pages[pagenr]); 951 z_erofs_onlinepage_endio(pages[pagenr]); 952 err = -EFSCORRUPTED; 953 } 954 pages[pagenr] = page; 955 956 overlapped = true; 957 } 958 959 /* PG_error needs checking for all non-managed pages */ 960 if (PageError(page)) { 961 DBG_BUGON(PageUptodate(page)); 962 err = -EIO; 963 } 964 } 965 966 if (err) 967 goto out; 968 969 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT; 970 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) { 971 outputsize = llen; 972 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH); 973 } else { 974 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs; 975 partial = true; 976 } 977 978 inputsize = pcl->pclusterpages * PAGE_SIZE; 979 err = z_erofs_decompress(&(struct z_erofs_decompress_req) { 980 .sb = sb, 981 .in = compressed_pages, 982 .out = pages, 983 .pageofs_out = cl->pageofs, 984 .inputsize = inputsize, 985 .outputsize = outputsize, 986 .alg = pcl->algorithmformat, 987 .inplace_io = overlapped, 988 .partial_decoding = partial 989 }, pagepool); 990 991 out: 992 /* must handle all compressed pages before ending pages */ 993 for (i = 0; i < pcl->pclusterpages; ++i) { 994 page = compressed_pages[i]; 995 996 if (erofs_page_is_managed(sbi, page)) 997 continue; 998 999 /* recycle all individual short-lived pages */ 1000 (void)z_erofs_put_shortlivedpage(pagepool, page); 1001 1002 WRITE_ONCE(compressed_pages[i], NULL); 1003 } 1004 1005 for (i = 0; i < nr_pages; ++i) { 1006 page = pages[i]; 1007 if (!page) 1008 continue; 1009 1010 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1011 1012 /* recycle all individual short-lived pages */ 1013 if (z_erofs_put_shortlivedpage(pagepool, page)) 1014 continue; 1015 1016 if (err < 0) 1017 SetPageError(page); 1018 1019 z_erofs_onlinepage_endio(page); 1020 } 1021 1022 if (pages == z_pagemap_global) 1023 mutex_unlock(&z_pagemap_global_lock); 1024 else if (pages != pages_onstack) 1025 kvfree(pages); 1026 1027 cl->nr_pages = 0; 1028 cl->vcnt = 0; 1029 1030 /* all cl locks MUST be taken before the following line */ 1031 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); 1032 1033 /* all cl locks SHOULD be released right now */ 1034 mutex_unlock(&cl->lock); 1035 1036 z_erofs_collection_put(cl); 1037 return err; 1038 } 1039 1040 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, 1041 struct list_head *pagepool) 1042 { 1043 z_erofs_next_pcluster_t owned = io->head; 1044 1045 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { 1046 struct z_erofs_pcluster *pcl; 1047 1048 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ 1049 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); 1050 1051 /* no possible that 'owned' equals NULL */ 1052 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); 1053 1054 pcl = container_of(owned, struct z_erofs_pcluster, next); 1055 owned = READ_ONCE(pcl->next); 1056 1057 z_erofs_decompress_pcluster(io->sb, pcl, pagepool); 1058 } 1059 } 1060 1061 static void z_erofs_decompressqueue_work(struct work_struct *work) 1062 { 1063 struct z_erofs_decompressqueue *bgq = 1064 container_of(work, struct z_erofs_decompressqueue, u.work); 1065 LIST_HEAD(pagepool); 1066 1067 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1068 z_erofs_decompress_queue(bgq, &pagepool); 1069 1070 put_pages_list(&pagepool); 1071 kvfree(bgq); 1072 } 1073 1074 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 1075 unsigned int nr, 1076 struct list_head *pagepool, 1077 struct address_space *mc, 1078 gfp_t gfp) 1079 { 1080 const pgoff_t index = pcl->obj.index; 1081 bool tocache = false; 1082 1083 struct address_space *mapping; 1084 struct page *oldpage, *page; 1085 1086 compressed_page_t t; 1087 int justfound; 1088 1089 repeat: 1090 page = READ_ONCE(pcl->compressed_pages[nr]); 1091 oldpage = page; 1092 1093 if (!page) 1094 goto out_allocpage; 1095 1096 /* 1097 * the cached page has not been allocated and 1098 * an placeholder is out there, prepare it now. 1099 */ 1100 if (page == PAGE_UNALLOCATED) { 1101 tocache = true; 1102 goto out_allocpage; 1103 } 1104 1105 /* process the target tagged pointer */ 1106 t = tagptr_init(compressed_page_t, page); 1107 justfound = tagptr_unfold_tags(t); 1108 page = tagptr_unfold_ptr(t); 1109 1110 /* 1111 * preallocated cached pages, which is used to avoid direct reclaim 1112 * otherwise, it will go inplace I/O path instead. 1113 */ 1114 if (page->private == Z_EROFS_PREALLOCATED_PAGE) { 1115 WRITE_ONCE(pcl->compressed_pages[nr], page); 1116 set_page_private(page, 0); 1117 tocache = true; 1118 goto out_tocache; 1119 } 1120 mapping = READ_ONCE(page->mapping); 1121 1122 /* 1123 * file-backed online pages in plcuster are all locked steady, 1124 * therefore it is impossible for `mapping' to be NULL. 1125 */ 1126 if (mapping && mapping != mc) 1127 /* ought to be unmanaged pages */ 1128 goto out; 1129 1130 /* directly return for shortlived page as well */ 1131 if (z_erofs_is_shortlived_page(page)) 1132 goto out; 1133 1134 lock_page(page); 1135 1136 /* only true if page reclaim goes wrong, should never happen */ 1137 DBG_BUGON(justfound && PagePrivate(page)); 1138 1139 /* the page is still in manage cache */ 1140 if (page->mapping == mc) { 1141 WRITE_ONCE(pcl->compressed_pages[nr], page); 1142 1143 ClearPageError(page); 1144 if (!PagePrivate(page)) { 1145 /* 1146 * impossible to be !PagePrivate(page) for 1147 * the current restriction as well if 1148 * the page is already in compressed_pages[]. 1149 */ 1150 DBG_BUGON(!justfound); 1151 1152 justfound = 0; 1153 set_page_private(page, (unsigned long)pcl); 1154 SetPagePrivate(page); 1155 } 1156 1157 /* no need to submit io if it is already up-to-date */ 1158 if (PageUptodate(page)) { 1159 unlock_page(page); 1160 page = NULL; 1161 } 1162 goto out; 1163 } 1164 1165 /* 1166 * the managed page has been truncated, it's unsafe to 1167 * reuse this one, let's allocate a new cache-managed page. 1168 */ 1169 DBG_BUGON(page->mapping); 1170 DBG_BUGON(!justfound); 1171 1172 tocache = true; 1173 unlock_page(page); 1174 put_page(page); 1175 out_allocpage: 1176 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); 1177 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) { 1178 list_add(&page->lru, pagepool); 1179 cond_resched(); 1180 goto repeat; 1181 } 1182 out_tocache: 1183 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { 1184 /* turn into temporary page if fails (1 ref) */ 1185 set_page_private(page, Z_EROFS_SHORTLIVED_PAGE); 1186 goto out; 1187 } 1188 attach_page_private(page, pcl); 1189 /* drop a refcount added by allocpage (then we have 2 refs here) */ 1190 put_page(page); 1191 1192 out: /* the only exit (for tracing and debugging) */ 1193 return page; 1194 } 1195 1196 static struct z_erofs_decompressqueue * 1197 jobqueue_init(struct super_block *sb, 1198 struct z_erofs_decompressqueue *fgq, bool *fg) 1199 { 1200 struct z_erofs_decompressqueue *q; 1201 1202 if (fg && !*fg) { 1203 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); 1204 if (!q) { 1205 *fg = true; 1206 goto fg_out; 1207 } 1208 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); 1209 } else { 1210 fg_out: 1211 q = fgq; 1212 init_waitqueue_head(&fgq->u.wait); 1213 atomic_set(&fgq->pending_bios, 0); 1214 } 1215 q->sb = sb; 1216 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1217 return q; 1218 } 1219 1220 /* define decompression jobqueue types */ 1221 enum { 1222 JQ_BYPASS, 1223 JQ_SUBMIT, 1224 NR_JOBQUEUES, 1225 }; 1226 1227 static void *jobqueueset_init(struct super_block *sb, 1228 struct z_erofs_decompressqueue *q[], 1229 struct z_erofs_decompressqueue *fgq, bool *fg) 1230 { 1231 /* 1232 * if managed cache is enabled, bypass jobqueue is needed, 1233 * no need to read from device for all pclusters in this queue. 1234 */ 1235 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); 1236 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg); 1237 1238 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg)); 1239 } 1240 1241 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 1242 z_erofs_next_pcluster_t qtail[], 1243 z_erofs_next_pcluster_t owned_head) 1244 { 1245 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; 1246 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; 1247 1248 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1249 if (owned_head == Z_EROFS_PCLUSTER_TAIL) 1250 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1251 1252 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); 1253 1254 WRITE_ONCE(*submit_qtail, owned_head); 1255 WRITE_ONCE(*bypass_qtail, &pcl->next); 1256 1257 qtail[JQ_BYPASS] = &pcl->next; 1258 } 1259 1260 static void z_erofs_submit_queue(struct super_block *sb, 1261 struct z_erofs_decompress_frontend *f, 1262 struct list_head *pagepool, 1263 struct z_erofs_decompressqueue *fgq, 1264 bool *force_fg) 1265 { 1266 struct erofs_sb_info *const sbi = EROFS_SB(sb); 1267 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; 1268 struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; 1269 void *bi_private; 1270 z_erofs_next_pcluster_t owned_head = f->clt.owned_head; 1271 /* since bio will be NULL, no need to initialize last_index */ 1272 pgoff_t last_index; 1273 unsigned int nr_bios = 0; 1274 struct bio *bio = NULL; 1275 1276 bi_private = jobqueueset_init(sb, q, fgq, force_fg); 1277 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; 1278 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; 1279 1280 /* by default, all need io submission */ 1281 q[JQ_SUBMIT]->head = owned_head; 1282 1283 do { 1284 struct z_erofs_pcluster *pcl; 1285 pgoff_t cur, end; 1286 unsigned int i = 0; 1287 bool bypass = true; 1288 1289 /* no possible 'owned_head' equals the following */ 1290 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1291 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); 1292 1293 pcl = container_of(owned_head, struct z_erofs_pcluster, next); 1294 1295 cur = pcl->obj.index; 1296 end = cur + pcl->pclusterpages; 1297 1298 /* close the main owned chain at first */ 1299 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 1300 Z_EROFS_PCLUSTER_TAIL_CLOSED); 1301 1302 do { 1303 struct page *page; 1304 1305 page = pickup_page_for_submission(pcl, i++, pagepool, 1306 MNGD_MAPPING(sbi), 1307 GFP_NOFS); 1308 if (!page) 1309 continue; 1310 1311 if (bio && cur != last_index + 1) { 1312 submit_bio_retry: 1313 submit_bio(bio); 1314 bio = NULL; 1315 } 1316 1317 if (!bio) { 1318 bio = bio_alloc(GFP_NOIO, BIO_MAX_VECS); 1319 1320 bio->bi_end_io = z_erofs_decompressqueue_endio; 1321 bio_set_dev(bio, sb->s_bdev); 1322 bio->bi_iter.bi_sector = (sector_t)cur << 1323 LOG_SECTORS_PER_BLOCK; 1324 bio->bi_private = bi_private; 1325 bio->bi_opf = REQ_OP_READ; 1326 if (f->readahead) 1327 bio->bi_opf |= REQ_RAHEAD; 1328 ++nr_bios; 1329 } 1330 1331 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) 1332 goto submit_bio_retry; 1333 1334 last_index = cur; 1335 bypass = false; 1336 } while (++cur < end); 1337 1338 if (!bypass) 1339 qtail[JQ_SUBMIT] = &pcl->next; 1340 else 1341 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1342 } while (owned_head != Z_EROFS_PCLUSTER_TAIL); 1343 1344 if (bio) 1345 submit_bio(bio); 1346 1347 /* 1348 * although background is preferred, no one is pending for submission. 1349 * don't issue workqueue for decompression but drop it directly instead. 1350 */ 1351 if (!*force_fg && !nr_bios) { 1352 kvfree(q[JQ_SUBMIT]); 1353 return; 1354 } 1355 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios); 1356 } 1357 1358 static void z_erofs_runqueue(struct super_block *sb, 1359 struct z_erofs_decompress_frontend *f, 1360 struct list_head *pagepool, bool force_fg) 1361 { 1362 struct z_erofs_decompressqueue io[NR_JOBQUEUES]; 1363 1364 if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL) 1365 return; 1366 z_erofs_submit_queue(sb, f, pagepool, io, &force_fg); 1367 1368 /* handle bypass queue (no i/o pclusters) immediately */ 1369 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); 1370 1371 if (!force_fg) 1372 return; 1373 1374 /* wait until all bios are completed */ 1375 io_wait_event(io[JQ_SUBMIT].u.wait, 1376 !atomic_read(&io[JQ_SUBMIT].pending_bios)); 1377 1378 /* handle synchronous decompress queue in the caller context */ 1379 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); 1380 } 1381 1382 static int z_erofs_readpage(struct file *file, struct page *page) 1383 { 1384 struct inode *const inode = page->mapping->host; 1385 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1386 int err; 1387 LIST_HEAD(pagepool); 1388 1389 trace_erofs_readpage(page, false); 1390 1391 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 1392 1393 err = z_erofs_do_read_page(&f, page, &pagepool); 1394 (void)z_erofs_collector_end(&f.clt); 1395 1396 /* if some compressed cluster ready, need submit them anyway */ 1397 z_erofs_runqueue(inode->i_sb, &f, &pagepool, true); 1398 1399 if (err) 1400 erofs_err(inode->i_sb, "failed to read, err [%d]", err); 1401 1402 if (f.map.mpage) 1403 put_page(f.map.mpage); 1404 1405 /* clean up the remaining free pages */ 1406 put_pages_list(&pagepool); 1407 return err; 1408 } 1409 1410 static void z_erofs_readahead(struct readahead_control *rac) 1411 { 1412 struct inode *const inode = rac->mapping->host; 1413 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1414 1415 unsigned int nr_pages = readahead_count(rac); 1416 bool sync = (sbi->ctx.readahead_sync_decompress && 1417 nr_pages <= sbi->ctx.max_sync_decompress_pages); 1418 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1419 struct page *page, *head = NULL; 1420 LIST_HEAD(pagepool); 1421 1422 trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); 1423 1424 f.readahead = true; 1425 f.headoffset = readahead_pos(rac); 1426 1427 while ((page = readahead_page(rac))) { 1428 prefetchw(&page->flags); 1429 1430 /* 1431 * A pure asynchronous readahead is indicated if 1432 * a PG_readahead marked page is hitted at first. 1433 * Let's also do asynchronous decompression for this case. 1434 */ 1435 sync &= !(PageReadahead(page) && !head); 1436 1437 set_page_private(page, (unsigned long)head); 1438 head = page; 1439 } 1440 1441 while (head) { 1442 struct page *page = head; 1443 int err; 1444 1445 /* traversal in reverse order */ 1446 head = (void *)page_private(page); 1447 1448 err = z_erofs_do_read_page(&f, page, &pagepool); 1449 if (err) 1450 erofs_err(inode->i_sb, 1451 "readahead error at page %lu @ nid %llu", 1452 page->index, EROFS_I(inode)->nid); 1453 put_page(page); 1454 } 1455 1456 (void)z_erofs_collector_end(&f.clt); 1457 1458 z_erofs_runqueue(inode->i_sb, &f, &pagepool, sync); 1459 1460 if (f.map.mpage) 1461 put_page(f.map.mpage); 1462 1463 /* clean up the remaining free pages */ 1464 put_pages_list(&pagepool); 1465 } 1466 1467 const struct address_space_operations z_erofs_aops = { 1468 .readpage = z_erofs_readpage, 1469 .readahead = z_erofs_readahead, 1470 }; 1471