1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 * Created by Gao Xiang <gaoxiang25@huawei.com> 6 */ 7 #include "zdata.h" 8 #include "compress.h" 9 #include <linux/prefetch.h> 10 11 #include <trace/events/erofs.h> 12 13 /* 14 * since pclustersize is variable for big pcluster feature, introduce slab 15 * pools implementation for different pcluster sizes. 16 */ 17 struct z_erofs_pcluster_slab { 18 struct kmem_cache *slab; 19 unsigned int maxpages; 20 char name[48]; 21 }; 22 23 #define _PCLP(n) { .maxpages = n } 24 25 static struct z_erofs_pcluster_slab pcluster_pool[] __read_mostly = { 26 _PCLP(1), _PCLP(4), _PCLP(16), _PCLP(64), _PCLP(128), 27 _PCLP(Z_EROFS_PCLUSTER_MAX_PAGES) 28 }; 29 30 static void z_erofs_destroy_pcluster_pool(void) 31 { 32 int i; 33 34 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 35 if (!pcluster_pool[i].slab) 36 continue; 37 kmem_cache_destroy(pcluster_pool[i].slab); 38 pcluster_pool[i].slab = NULL; 39 } 40 } 41 42 static int z_erofs_create_pcluster_pool(void) 43 { 44 struct z_erofs_pcluster_slab *pcs; 45 struct z_erofs_pcluster *a; 46 unsigned int size; 47 48 for (pcs = pcluster_pool; 49 pcs < pcluster_pool + ARRAY_SIZE(pcluster_pool); ++pcs) { 50 size = struct_size(a, compressed_pages, pcs->maxpages); 51 52 sprintf(pcs->name, "erofs_pcluster-%u", pcs->maxpages); 53 pcs->slab = kmem_cache_create(pcs->name, size, 0, 54 SLAB_RECLAIM_ACCOUNT, NULL); 55 if (pcs->slab) 56 continue; 57 58 z_erofs_destroy_pcluster_pool(); 59 return -ENOMEM; 60 } 61 return 0; 62 } 63 64 static struct z_erofs_pcluster *z_erofs_alloc_pcluster(unsigned int nrpages) 65 { 66 int i; 67 68 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 69 struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; 70 struct z_erofs_pcluster *pcl; 71 72 if (nrpages > pcs->maxpages) 73 continue; 74 75 pcl = kmem_cache_zalloc(pcs->slab, GFP_NOFS); 76 if (!pcl) 77 return ERR_PTR(-ENOMEM); 78 pcl->pclusterpages = nrpages; 79 return pcl; 80 } 81 return ERR_PTR(-EINVAL); 82 } 83 84 static void z_erofs_free_pcluster(struct z_erofs_pcluster *pcl) 85 { 86 int i; 87 88 for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { 89 struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; 90 91 if (pcl->pclusterpages > pcs->maxpages) 92 continue; 93 94 kmem_cache_free(pcs->slab, pcl); 95 return; 96 } 97 DBG_BUGON(1); 98 } 99 100 /* 101 * a compressed_pages[] placeholder in order to avoid 102 * being filled with file pages for in-place decompression. 103 */ 104 #define PAGE_UNALLOCATED ((void *)0x5F0E4B1D) 105 106 /* how to allocate cached pages for a pcluster */ 107 enum z_erofs_cache_alloctype { 108 DONTALLOC, /* don't allocate any cached pages */ 109 DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */ 110 /* 111 * try to use cached I/O if page allocation succeeds or fallback 112 * to in-place I/O instead to avoid any direct reclaim. 113 */ 114 TRYALLOC, 115 }; 116 117 /* 118 * tagged pointer with 1-bit tag for all compressed pages 119 * tag 0 - the page is just found with an extra page reference 120 */ 121 typedef tagptr1_t compressed_page_t; 122 123 #define tag_compressed_page_justfound(page) \ 124 tagptr_fold(compressed_page_t, page, 1) 125 126 static struct workqueue_struct *z_erofs_workqueue __read_mostly; 127 128 void z_erofs_exit_zip_subsystem(void) 129 { 130 destroy_workqueue(z_erofs_workqueue); 131 z_erofs_destroy_pcluster_pool(); 132 } 133 134 static inline int z_erofs_init_workqueue(void) 135 { 136 const unsigned int onlinecpus = num_possible_cpus(); 137 138 /* 139 * no need to spawn too many threads, limiting threads could minimum 140 * scheduling overhead, perhaps per-CPU threads should be better? 141 */ 142 z_erofs_workqueue = alloc_workqueue("erofs_unzipd", 143 WQ_UNBOUND | WQ_HIGHPRI, 144 onlinecpus + onlinecpus / 4); 145 return z_erofs_workqueue ? 0 : -ENOMEM; 146 } 147 148 int __init z_erofs_init_zip_subsystem(void) 149 { 150 int err = z_erofs_create_pcluster_pool(); 151 152 if (err) 153 return err; 154 err = z_erofs_init_workqueue(); 155 if (err) 156 z_erofs_destroy_pcluster_pool(); 157 return err; 158 } 159 160 enum z_erofs_collectmode { 161 COLLECT_SECONDARY, 162 COLLECT_PRIMARY, 163 /* 164 * The current collection was the tail of an exist chain, in addition 165 * that the previous processed chained collections are all decided to 166 * be hooked up to it. 167 * A new chain will be created for the remaining collections which are 168 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED, 169 * the next collection cannot reuse the whole page safely in 170 * the following scenario: 171 * ________________________________________________________________ 172 * | tail (partial) page | head (partial) page | 173 * | (belongs to the next cl) | (belongs to the current cl) | 174 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| 175 */ 176 COLLECT_PRIMARY_HOOKED, 177 /* 178 * a weak form of COLLECT_PRIMARY_FOLLOWED, the difference is that it 179 * could be dispatched into bypass queue later due to uptodated managed 180 * pages. All related online pages cannot be reused for inplace I/O (or 181 * pagevec) since it can be directly decoded without I/O submission. 182 */ 183 COLLECT_PRIMARY_FOLLOWED_NOINPLACE, 184 /* 185 * The current collection has been linked with the owned chain, and 186 * could also be linked with the remaining collections, which means 187 * if the processing page is the tail page of the collection, thus 188 * the current collection can safely use the whole page (since 189 * the previous collection is under control) for in-place I/O, as 190 * illustrated below: 191 * ________________________________________________________________ 192 * | tail (partial) page | head (partial) page | 193 * | (of the current cl) | (of the previous collection) | 194 * | PRIMARY_FOLLOWED or | | 195 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| 196 * 197 * [ (*) the above page can be used as inplace I/O. ] 198 */ 199 COLLECT_PRIMARY_FOLLOWED, 200 }; 201 202 struct z_erofs_collector { 203 struct z_erofs_pagevec_ctor vector; 204 205 struct z_erofs_pcluster *pcl, *tailpcl; 206 struct z_erofs_collection *cl; 207 struct page **compressedpages; 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 const struct z_erofs_pcluster *pcl = clt->pcl; 242 struct page **pages = clt->compressedpages; 243 pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages); 244 bool standalone = true; 245 gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | 246 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 247 248 if (clt->mode < COLLECT_PRIMARY_FOLLOWED) 249 return; 250 251 for (; pages < pcl->compressed_pages + pcl->pclusterpages; ++pages) { 252 struct page *page; 253 compressed_page_t t; 254 struct page *newpage = NULL; 255 256 /* the compressed page was loaded before */ 257 if (READ_ONCE(*pages)) 258 continue; 259 260 page = find_get_page(mc, index); 261 262 if (page) { 263 t = tag_compressed_page_justfound(page); 264 } else { 265 /* I/O is needed, no possible to decompress directly */ 266 standalone = false; 267 switch (type) { 268 case DELAYEDALLOC: 269 t = tagptr_init(compressed_page_t, 270 PAGE_UNALLOCATED); 271 break; 272 case TRYALLOC: 273 newpage = erofs_allocpage(pagepool, gfp); 274 if (!newpage) 275 continue; 276 set_page_private(newpage, 277 Z_EROFS_PREALLOCATED_PAGE); 278 t = tag_compressed_page_justfound(newpage); 279 break; 280 default: /* DONTALLOC */ 281 continue; 282 } 283 } 284 285 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t))) 286 continue; 287 288 if (page) { 289 put_page(page); 290 } else if (newpage) { 291 set_page_private(newpage, 0); 292 list_add(&newpage->lru, pagepool); 293 } 294 } 295 296 /* 297 * don't do inplace I/O if all compressed pages are available in 298 * managed cache since it can be moved to the bypass queue instead. 299 */ 300 if (standalone) 301 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE; 302 } 303 304 /* called by erofs_shrinker to get rid of all compressed_pages */ 305 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 306 struct erofs_workgroup *grp) 307 { 308 struct z_erofs_pcluster *const pcl = 309 container_of(grp, struct z_erofs_pcluster, obj); 310 struct address_space *const mapping = MNGD_MAPPING(sbi); 311 int i; 312 313 /* 314 * refcount of workgroup is now freezed as 1, 315 * therefore no need to worry about available decompression users. 316 */ 317 for (i = 0; i < pcl->pclusterpages; ++i) { 318 struct page *page = pcl->compressed_pages[i]; 319 320 if (!page) 321 continue; 322 323 /* block other users from reclaiming or migrating the page */ 324 if (!trylock_page(page)) 325 return -EBUSY; 326 327 if (page->mapping != mapping) 328 continue; 329 330 /* barrier is implied in the following 'unlock_page' */ 331 WRITE_ONCE(pcl->compressed_pages[i], NULL); 332 detach_page_private(page); 333 unlock_page(page); 334 } 335 return 0; 336 } 337 338 int erofs_try_to_free_cached_page(struct address_space *mapping, 339 struct page *page) 340 { 341 struct z_erofs_pcluster *const pcl = (void *)page_private(page); 342 int ret = 0; /* 0 - busy */ 343 344 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) { 345 unsigned int i; 346 347 for (i = 0; i < pcl->pclusterpages; ++i) { 348 if (pcl->compressed_pages[i] == page) { 349 WRITE_ONCE(pcl->compressed_pages[i], NULL); 350 ret = 1; 351 break; 352 } 353 } 354 erofs_workgroup_unfreeze(&pcl->obj, 1); 355 356 if (ret) 357 detach_page_private(page); 358 } 359 return ret; 360 } 361 362 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ 363 static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt, 364 struct page *page) 365 { 366 struct z_erofs_pcluster *const pcl = clt->pcl; 367 368 while (clt->compressedpages < 369 pcl->compressed_pages + pcl->pclusterpages) { 370 if (!cmpxchg(clt->compressedpages++, NULL, page)) 371 return true; 372 } 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 bool occupied; 383 384 /* give priority for inplaceio */ 385 if (clt->mode >= COLLECT_PRIMARY && 386 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && 387 z_erofs_try_inplace_io(clt, page)) 388 return 0; 389 390 ret = z_erofs_pagevec_enqueue(&clt->vector, 391 page, type, &occupied); 392 clt->cl->vcnt += (unsigned int)ret; 393 394 return ret ? 0 : -EAGAIN; 395 } 396 397 static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt) 398 { 399 struct z_erofs_pcluster *pcl = clt->pcl; 400 z_erofs_next_pcluster_t *owned_head = &clt->owned_head; 401 402 /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */ 403 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, 404 *owned_head) == Z_EROFS_PCLUSTER_NIL) { 405 *owned_head = &pcl->next; 406 /* so we can attach this pcluster to our submission chain. */ 407 clt->mode = COLLECT_PRIMARY_FOLLOWED; 408 return; 409 } 410 411 /* 412 * type 2, link to the end of an existing open chain, be careful 413 * that its submission is controlled by the original attached chain. 414 */ 415 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 416 *owned_head) == Z_EROFS_PCLUSTER_TAIL) { 417 *owned_head = Z_EROFS_PCLUSTER_TAIL; 418 clt->mode = COLLECT_PRIMARY_HOOKED; 419 clt->tailpcl = NULL; 420 return; 421 } 422 /* type 3, it belongs to a chain, but it isn't the end of the chain */ 423 clt->mode = COLLECT_PRIMARY; 424 } 425 426 static int z_erofs_lookup_collection(struct z_erofs_collector *clt, 427 struct inode *inode, 428 struct erofs_map_blocks *map) 429 { 430 struct z_erofs_pcluster *pcl = clt->pcl; 431 struct z_erofs_collection *cl; 432 unsigned int length; 433 434 /* to avoid unexpected loop formed by corrupted images */ 435 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) { 436 DBG_BUGON(1); 437 return -EFSCORRUPTED; 438 } 439 440 cl = z_erofs_primarycollection(pcl); 441 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) { 442 DBG_BUGON(1); 443 return -EFSCORRUPTED; 444 } 445 446 length = READ_ONCE(pcl->length); 447 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) { 448 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) { 449 DBG_BUGON(1); 450 return -EFSCORRUPTED; 451 } 452 } else { 453 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT; 454 455 if (map->m_flags & EROFS_MAP_FULL_MAPPED) 456 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH; 457 458 while (llen > length && 459 length != cmpxchg_relaxed(&pcl->length, length, llen)) { 460 cpu_relax(); 461 length = READ_ONCE(pcl->length); 462 } 463 } 464 mutex_lock(&cl->lock); 465 /* used to check tail merging loop due to corrupted images */ 466 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 467 clt->tailpcl = pcl; 468 469 z_erofs_try_to_claim_pcluster(clt); 470 clt->cl = cl; 471 return 0; 472 } 473 474 static int z_erofs_register_collection(struct z_erofs_collector *clt, 475 struct inode *inode, 476 struct erofs_map_blocks *map) 477 { 478 struct z_erofs_pcluster *pcl; 479 struct z_erofs_collection *cl; 480 struct erofs_workgroup *grp; 481 int err; 482 483 /* no available pcluster, let's allocate one */ 484 pcl = z_erofs_alloc_pcluster(map->m_plen >> PAGE_SHIFT); 485 if (IS_ERR(pcl)) 486 return PTR_ERR(pcl); 487 488 atomic_set(&pcl->obj.refcount, 1); 489 pcl->obj.index = map->m_pa >> PAGE_SHIFT; 490 491 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) | 492 (map->m_flags & EROFS_MAP_FULL_MAPPED ? 493 Z_EROFS_PCLUSTER_FULL_LENGTH : 0); 494 495 if (map->m_flags & EROFS_MAP_ZIPPED) 496 pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4; 497 else 498 pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED; 499 500 /* new pclusters should be claimed as type 1, primary and followed */ 501 pcl->next = clt->owned_head; 502 clt->mode = COLLECT_PRIMARY_FOLLOWED; 503 504 cl = z_erofs_primarycollection(pcl); 505 cl->pageofs = map->m_la & ~PAGE_MASK; 506 507 /* 508 * lock all primary followed works before visible to others 509 * and mutex_trylock *never* fails for a new pcluster. 510 */ 511 mutex_init(&cl->lock); 512 DBG_BUGON(!mutex_trylock(&cl->lock)); 513 514 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj); 515 if (IS_ERR(grp)) { 516 err = PTR_ERR(grp); 517 goto err_out; 518 } 519 520 if (grp != &pcl->obj) { 521 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 522 err = -EEXIST; 523 goto err_out; 524 } 525 /* used to check tail merging loop due to corrupted images */ 526 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 527 clt->tailpcl = pcl; 528 clt->owned_head = &pcl->next; 529 clt->pcl = pcl; 530 clt->cl = cl; 531 return 0; 532 533 err_out: 534 mutex_unlock(&cl->lock); 535 z_erofs_free_pcluster(pcl); 536 return err; 537 } 538 539 static int z_erofs_collector_begin(struct z_erofs_collector *clt, 540 struct inode *inode, 541 struct erofs_map_blocks *map) 542 { 543 struct erofs_workgroup *grp; 544 int ret; 545 546 DBG_BUGON(clt->cl); 547 548 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */ 549 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL); 550 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 551 552 if (!PAGE_ALIGNED(map->m_pa)) { 553 DBG_BUGON(1); 554 return -EINVAL; 555 } 556 557 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT); 558 if (grp) { 559 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 560 } else { 561 ret = z_erofs_register_collection(clt, inode, map); 562 563 if (!ret) 564 goto out; 565 if (ret != -EEXIST) 566 return ret; 567 } 568 569 ret = z_erofs_lookup_collection(clt, inode, map); 570 if (ret) { 571 erofs_workgroup_put(&clt->pcl->obj); 572 return ret; 573 } 574 575 out: 576 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS, 577 clt->cl->pagevec, clt->cl->vcnt); 578 579 clt->compressedpages = clt->pcl->compressed_pages; 580 if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */ 581 clt->compressedpages += clt->pcl->pclusterpages; 582 return 0; 583 } 584 585 /* 586 * keep in mind that no referenced pclusters will be freed 587 * only after a RCU grace period. 588 */ 589 static void z_erofs_rcu_callback(struct rcu_head *head) 590 { 591 struct z_erofs_collection *const cl = 592 container_of(head, struct z_erofs_collection, rcu); 593 594 z_erofs_free_pcluster(container_of(cl, struct z_erofs_pcluster, 595 primary_collection)); 596 } 597 598 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) 599 { 600 struct z_erofs_pcluster *const pcl = 601 container_of(grp, struct z_erofs_pcluster, obj); 602 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl); 603 604 call_rcu(&cl->rcu, z_erofs_rcu_callback); 605 } 606 607 static void z_erofs_collection_put(struct z_erofs_collection *cl) 608 { 609 struct z_erofs_pcluster *const pcl = 610 container_of(cl, struct z_erofs_pcluster, primary_collection); 611 612 erofs_workgroup_put(&pcl->obj); 613 } 614 615 static bool z_erofs_collector_end(struct z_erofs_collector *clt) 616 { 617 struct z_erofs_collection *cl = clt->cl; 618 619 if (!cl) 620 return false; 621 622 z_erofs_pagevec_ctor_exit(&clt->vector, false); 623 mutex_unlock(&cl->lock); 624 625 /* 626 * if all pending pages are added, don't hold its reference 627 * any longer if the pcluster isn't hosted by ourselves. 628 */ 629 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE) 630 z_erofs_collection_put(cl); 631 632 clt->cl = NULL; 633 return true; 634 } 635 636 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe, 637 unsigned int cachestrategy, 638 erofs_off_t la) 639 { 640 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) 641 return false; 642 643 if (fe->backmost) 644 return true; 645 646 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND && 647 la < fe->headoffset; 648 } 649 650 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 651 struct page *page, struct list_head *pagepool) 652 { 653 struct inode *const inode = fe->inode; 654 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 655 struct erofs_map_blocks *const map = &fe->map; 656 struct z_erofs_collector *const clt = &fe->clt; 657 const loff_t offset = page_offset(page); 658 bool tight = true; 659 660 enum z_erofs_cache_alloctype cache_strategy; 661 enum z_erofs_page_type page_type; 662 unsigned int cur, end, spiltted, index; 663 int err = 0; 664 665 /* register locked file pages as online pages in pack */ 666 z_erofs_onlinepage_init(page); 667 668 spiltted = 0; 669 end = PAGE_SIZE; 670 repeat: 671 cur = end - 1; 672 673 /* lucky, within the range of the current map_blocks */ 674 if (offset + cur >= map->m_la && 675 offset + cur < map->m_la + map->m_llen) { 676 /* didn't get a valid collection previously (very rare) */ 677 if (!clt->cl) 678 goto restart_now; 679 goto hitted; 680 } 681 682 /* go ahead the next map_blocks */ 683 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur); 684 685 if (z_erofs_collector_end(clt)) 686 fe->backmost = false; 687 688 map->m_la = offset + cur; 689 map->m_llen = 0; 690 err = z_erofs_map_blocks_iter(inode, map, 0); 691 if (err) 692 goto err_out; 693 694 restart_now: 695 if (!(map->m_flags & EROFS_MAP_MAPPED)) 696 goto hitted; 697 698 err = z_erofs_collector_begin(clt, inode, map); 699 if (err) 700 goto err_out; 701 702 /* preload all compressed pages (maybe downgrade role if necessary) */ 703 if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la)) 704 cache_strategy = TRYALLOC; 705 else 706 cache_strategy = DONTALLOC; 707 708 preload_compressed_pages(clt, MNGD_MAPPING(sbi), 709 cache_strategy, pagepool); 710 711 hitted: 712 /* 713 * Ensure the current partial page belongs to this submit chain rather 714 * than other concurrent submit chains or the noio(bypass) chain since 715 * those chains are handled asynchronously thus the page cannot be used 716 * for inplace I/O or pagevec (should be processed in strict order.) 717 */ 718 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED && 719 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE); 720 721 cur = end - min_t(unsigned int, offset + end - map->m_la, end); 722 if (!(map->m_flags & EROFS_MAP_MAPPED)) { 723 zero_user_segment(page, cur, end); 724 goto next_part; 725 } 726 727 /* let's derive page type */ 728 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD : 729 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 730 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 731 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); 732 733 if (cur) 734 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED); 735 736 retry: 737 err = z_erofs_attach_page(clt, page, page_type); 738 /* should allocate an additional short-lived page for pagevec */ 739 if (err == -EAGAIN) { 740 struct page *const newpage = 741 alloc_page(GFP_NOFS | __GFP_NOFAIL); 742 743 set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); 744 err = z_erofs_attach_page(clt, newpage, 745 Z_EROFS_PAGE_TYPE_EXCLUSIVE); 746 if (!err) 747 goto retry; 748 } 749 750 if (err) 751 goto err_out; 752 753 index = page->index - (map->m_la >> PAGE_SHIFT); 754 755 z_erofs_onlinepage_fixup(page, index, true); 756 757 /* bump up the number of spiltted parts of a page */ 758 ++spiltted; 759 /* also update nr_pages */ 760 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1); 761 next_part: 762 /* can be used for verification */ 763 map->m_llen = offset + cur - map->m_la; 764 765 end = cur; 766 if (end > 0) 767 goto repeat; 768 769 out: 770 z_erofs_onlinepage_endio(page); 771 772 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu", 773 __func__, page, spiltted, map->m_llen); 774 return err; 775 776 /* if some error occurred while processing this page */ 777 err_out: 778 SetPageError(page); 779 goto out; 780 } 781 782 static void z_erofs_decompressqueue_work(struct work_struct *work); 783 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, 784 bool sync, int bios) 785 { 786 struct erofs_sb_info *const sbi = EROFS_SB(io->sb); 787 788 /* wake up the caller thread for sync decompression */ 789 if (sync) { 790 unsigned long flags; 791 792 spin_lock_irqsave(&io->u.wait.lock, flags); 793 if (!atomic_add_return(bios, &io->pending_bios)) 794 wake_up_locked(&io->u.wait); 795 spin_unlock_irqrestore(&io->u.wait.lock, flags); 796 return; 797 } 798 799 if (atomic_add_return(bios, &io->pending_bios)) 800 return; 801 /* Use workqueue and sync decompression for atomic contexts only */ 802 if (in_atomic() || irqs_disabled()) { 803 queue_work(z_erofs_workqueue, &io->u.work); 804 sbi->ctx.readahead_sync_decompress = true; 805 return; 806 } 807 z_erofs_decompressqueue_work(&io->u.work); 808 } 809 810 static bool z_erofs_page_is_invalidated(struct page *page) 811 { 812 return !page->mapping && !z_erofs_is_shortlived_page(page); 813 } 814 815 static void z_erofs_decompressqueue_endio(struct bio *bio) 816 { 817 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private); 818 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t); 819 blk_status_t err = bio->bi_status; 820 struct bio_vec *bvec; 821 struct bvec_iter_all iter_all; 822 823 bio_for_each_segment_all(bvec, bio, iter_all) { 824 struct page *page = bvec->bv_page; 825 826 DBG_BUGON(PageUptodate(page)); 827 DBG_BUGON(z_erofs_page_is_invalidated(page)); 828 829 if (err) 830 SetPageError(page); 831 832 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { 833 if (!err) 834 SetPageUptodate(page); 835 unlock_page(page); 836 } 837 } 838 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); 839 bio_put(bio); 840 } 841 842 static int z_erofs_decompress_pcluster(struct super_block *sb, 843 struct z_erofs_pcluster *pcl, 844 struct list_head *pagepool) 845 { 846 struct erofs_sb_info *const sbi = EROFS_SB(sb); 847 struct z_erofs_pagevec_ctor ctor; 848 unsigned int i, inputsize, outputsize, llen, nr_pages; 849 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES]; 850 struct page **pages, **compressed_pages, *page; 851 852 enum z_erofs_page_type page_type; 853 bool overlapped, partial; 854 struct z_erofs_collection *cl; 855 int err; 856 857 might_sleep(); 858 cl = z_erofs_primarycollection(pcl); 859 DBG_BUGON(!READ_ONCE(cl->nr_pages)); 860 861 mutex_lock(&cl->lock); 862 nr_pages = cl->nr_pages; 863 864 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) { 865 pages = pages_onstack; 866 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES && 867 mutex_trylock(&z_pagemap_global_lock)) { 868 pages = z_pagemap_global; 869 } else { 870 gfp_t gfp_flags = GFP_KERNEL; 871 872 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES) 873 gfp_flags |= __GFP_NOFAIL; 874 875 pages = kvmalloc_array(nr_pages, sizeof(struct page *), 876 gfp_flags); 877 878 /* fallback to global pagemap for the lowmem scenario */ 879 if (!pages) { 880 mutex_lock(&z_pagemap_global_lock); 881 pages = z_pagemap_global; 882 } 883 } 884 885 for (i = 0; i < nr_pages; ++i) 886 pages[i] = NULL; 887 888 err = 0; 889 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, 890 cl->pagevec, 0); 891 892 for (i = 0; i < cl->vcnt; ++i) { 893 unsigned int pagenr; 894 895 page = z_erofs_pagevec_dequeue(&ctor, &page_type); 896 897 /* all pages in pagevec ought to be valid */ 898 DBG_BUGON(!page); 899 DBG_BUGON(z_erofs_page_is_invalidated(page)); 900 901 if (z_erofs_put_shortlivedpage(pagepool, page)) 902 continue; 903 904 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD) 905 pagenr = 0; 906 else 907 pagenr = z_erofs_onlinepage_index(page); 908 909 DBG_BUGON(pagenr >= nr_pages); 910 911 /* 912 * currently EROFS doesn't support multiref(dedup), 913 * so here erroring out one multiref page. 914 */ 915 if (pages[pagenr]) { 916 DBG_BUGON(1); 917 SetPageError(pages[pagenr]); 918 z_erofs_onlinepage_endio(pages[pagenr]); 919 err = -EFSCORRUPTED; 920 } 921 pages[pagenr] = page; 922 } 923 z_erofs_pagevec_ctor_exit(&ctor, true); 924 925 overlapped = false; 926 compressed_pages = pcl->compressed_pages; 927 928 for (i = 0; i < pcl->pclusterpages; ++i) { 929 unsigned int pagenr; 930 931 page = compressed_pages[i]; 932 933 /* all compressed pages ought to be valid */ 934 DBG_BUGON(!page); 935 DBG_BUGON(z_erofs_page_is_invalidated(page)); 936 937 if (!z_erofs_is_shortlived_page(page)) { 938 if (erofs_page_is_managed(sbi, page)) { 939 if (!PageUptodate(page)) 940 err = -EIO; 941 continue; 942 } 943 944 /* 945 * only if non-head page can be selected 946 * for inplace decompression 947 */ 948 pagenr = z_erofs_onlinepage_index(page); 949 950 DBG_BUGON(pagenr >= nr_pages); 951 if (pages[pagenr]) { 952 DBG_BUGON(1); 953 SetPageError(pages[pagenr]); 954 z_erofs_onlinepage_endio(pages[pagenr]); 955 err = -EFSCORRUPTED; 956 } 957 pages[pagenr] = page; 958 959 overlapped = true; 960 } 961 962 /* PG_error needs checking for all non-managed pages */ 963 if (PageError(page)) { 964 DBG_BUGON(PageUptodate(page)); 965 err = -EIO; 966 } 967 } 968 969 if (err) 970 goto out; 971 972 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT; 973 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) { 974 outputsize = llen; 975 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH); 976 } else { 977 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs; 978 partial = true; 979 } 980 981 inputsize = pcl->pclusterpages * PAGE_SIZE; 982 err = z_erofs_decompress(&(struct z_erofs_decompress_req) { 983 .sb = sb, 984 .in = compressed_pages, 985 .out = pages, 986 .pageofs_out = cl->pageofs, 987 .inputsize = inputsize, 988 .outputsize = outputsize, 989 .alg = pcl->algorithmformat, 990 .inplace_io = overlapped, 991 .partial_decoding = partial 992 }, pagepool); 993 994 out: 995 /* must handle all compressed pages before ending pages */ 996 for (i = 0; i < pcl->pclusterpages; ++i) { 997 page = compressed_pages[i]; 998 999 if (erofs_page_is_managed(sbi, page)) 1000 continue; 1001 1002 /* recycle all individual short-lived pages */ 1003 (void)z_erofs_put_shortlivedpage(pagepool, page); 1004 1005 WRITE_ONCE(compressed_pages[i], NULL); 1006 } 1007 1008 for (i = 0; i < nr_pages; ++i) { 1009 page = pages[i]; 1010 if (!page) 1011 continue; 1012 1013 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1014 1015 /* recycle all individual short-lived pages */ 1016 if (z_erofs_put_shortlivedpage(pagepool, page)) 1017 continue; 1018 1019 if (err < 0) 1020 SetPageError(page); 1021 1022 z_erofs_onlinepage_endio(page); 1023 } 1024 1025 if (pages == z_pagemap_global) 1026 mutex_unlock(&z_pagemap_global_lock); 1027 else if (pages != pages_onstack) 1028 kvfree(pages); 1029 1030 cl->nr_pages = 0; 1031 cl->vcnt = 0; 1032 1033 /* all cl locks MUST be taken before the following line */ 1034 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); 1035 1036 /* all cl locks SHOULD be released right now */ 1037 mutex_unlock(&cl->lock); 1038 1039 z_erofs_collection_put(cl); 1040 return err; 1041 } 1042 1043 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, 1044 struct list_head *pagepool) 1045 { 1046 z_erofs_next_pcluster_t owned = io->head; 1047 1048 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { 1049 struct z_erofs_pcluster *pcl; 1050 1051 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ 1052 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); 1053 1054 /* no possible that 'owned' equals NULL */ 1055 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); 1056 1057 pcl = container_of(owned, struct z_erofs_pcluster, next); 1058 owned = READ_ONCE(pcl->next); 1059 1060 z_erofs_decompress_pcluster(io->sb, pcl, pagepool); 1061 } 1062 } 1063 1064 static void z_erofs_decompressqueue_work(struct work_struct *work) 1065 { 1066 struct z_erofs_decompressqueue *bgq = 1067 container_of(work, struct z_erofs_decompressqueue, u.work); 1068 LIST_HEAD(pagepool); 1069 1070 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1071 z_erofs_decompress_queue(bgq, &pagepool); 1072 1073 put_pages_list(&pagepool); 1074 kvfree(bgq); 1075 } 1076 1077 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 1078 unsigned int nr, 1079 struct list_head *pagepool, 1080 struct address_space *mc, 1081 gfp_t gfp) 1082 { 1083 const pgoff_t index = pcl->obj.index; 1084 bool tocache = false; 1085 1086 struct address_space *mapping; 1087 struct page *oldpage, *page; 1088 1089 compressed_page_t t; 1090 int justfound; 1091 1092 repeat: 1093 page = READ_ONCE(pcl->compressed_pages[nr]); 1094 oldpage = page; 1095 1096 if (!page) 1097 goto out_allocpage; 1098 1099 /* 1100 * the cached page has not been allocated and 1101 * an placeholder is out there, prepare it now. 1102 */ 1103 if (page == PAGE_UNALLOCATED) { 1104 tocache = true; 1105 goto out_allocpage; 1106 } 1107 1108 /* process the target tagged pointer */ 1109 t = tagptr_init(compressed_page_t, page); 1110 justfound = tagptr_unfold_tags(t); 1111 page = tagptr_unfold_ptr(t); 1112 1113 /* 1114 * preallocated cached pages, which is used to avoid direct reclaim 1115 * otherwise, it will go inplace I/O path instead. 1116 */ 1117 if (page->private == Z_EROFS_PREALLOCATED_PAGE) { 1118 WRITE_ONCE(pcl->compressed_pages[nr], page); 1119 set_page_private(page, 0); 1120 tocache = true; 1121 goto out_tocache; 1122 } 1123 mapping = READ_ONCE(page->mapping); 1124 1125 /* 1126 * file-backed online pages in plcuster are all locked steady, 1127 * therefore it is impossible for `mapping' to be NULL. 1128 */ 1129 if (mapping && mapping != mc) 1130 /* ought to be unmanaged pages */ 1131 goto out; 1132 1133 /* directly return for shortlived page as well */ 1134 if (z_erofs_is_shortlived_page(page)) 1135 goto out; 1136 1137 lock_page(page); 1138 1139 /* only true if page reclaim goes wrong, should never happen */ 1140 DBG_BUGON(justfound && PagePrivate(page)); 1141 1142 /* the page is still in manage cache */ 1143 if (page->mapping == mc) { 1144 WRITE_ONCE(pcl->compressed_pages[nr], page); 1145 1146 ClearPageError(page); 1147 if (!PagePrivate(page)) { 1148 /* 1149 * impossible to be !PagePrivate(page) for 1150 * the current restriction as well if 1151 * the page is already in compressed_pages[]. 1152 */ 1153 DBG_BUGON(!justfound); 1154 1155 justfound = 0; 1156 set_page_private(page, (unsigned long)pcl); 1157 SetPagePrivate(page); 1158 } 1159 1160 /* no need to submit io if it is already up-to-date */ 1161 if (PageUptodate(page)) { 1162 unlock_page(page); 1163 page = NULL; 1164 } 1165 goto out; 1166 } 1167 1168 /* 1169 * the managed page has been truncated, it's unsafe to 1170 * reuse this one, let's allocate a new cache-managed page. 1171 */ 1172 DBG_BUGON(page->mapping); 1173 DBG_BUGON(!justfound); 1174 1175 tocache = true; 1176 unlock_page(page); 1177 put_page(page); 1178 out_allocpage: 1179 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); 1180 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) { 1181 list_add(&page->lru, pagepool); 1182 cond_resched(); 1183 goto repeat; 1184 } 1185 out_tocache: 1186 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { 1187 /* turn into temporary page if fails (1 ref) */ 1188 set_page_private(page, Z_EROFS_SHORTLIVED_PAGE); 1189 goto out; 1190 } 1191 attach_page_private(page, pcl); 1192 /* drop a refcount added by allocpage (then we have 2 refs here) */ 1193 put_page(page); 1194 1195 out: /* the only exit (for tracing and debugging) */ 1196 return page; 1197 } 1198 1199 static struct z_erofs_decompressqueue * 1200 jobqueue_init(struct super_block *sb, 1201 struct z_erofs_decompressqueue *fgq, bool *fg) 1202 { 1203 struct z_erofs_decompressqueue *q; 1204 1205 if (fg && !*fg) { 1206 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); 1207 if (!q) { 1208 *fg = true; 1209 goto fg_out; 1210 } 1211 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); 1212 } else { 1213 fg_out: 1214 q = fgq; 1215 init_waitqueue_head(&fgq->u.wait); 1216 atomic_set(&fgq->pending_bios, 0); 1217 } 1218 q->sb = sb; 1219 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1220 return q; 1221 } 1222 1223 /* define decompression jobqueue types */ 1224 enum { 1225 JQ_BYPASS, 1226 JQ_SUBMIT, 1227 NR_JOBQUEUES, 1228 }; 1229 1230 static void *jobqueueset_init(struct super_block *sb, 1231 struct z_erofs_decompressqueue *q[], 1232 struct z_erofs_decompressqueue *fgq, bool *fg) 1233 { 1234 /* 1235 * if managed cache is enabled, bypass jobqueue is needed, 1236 * no need to read from device for all pclusters in this queue. 1237 */ 1238 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); 1239 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg); 1240 1241 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg)); 1242 } 1243 1244 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 1245 z_erofs_next_pcluster_t qtail[], 1246 z_erofs_next_pcluster_t owned_head) 1247 { 1248 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; 1249 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; 1250 1251 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1252 if (owned_head == Z_EROFS_PCLUSTER_TAIL) 1253 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1254 1255 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); 1256 1257 WRITE_ONCE(*submit_qtail, owned_head); 1258 WRITE_ONCE(*bypass_qtail, &pcl->next); 1259 1260 qtail[JQ_BYPASS] = &pcl->next; 1261 } 1262 1263 static void z_erofs_submit_queue(struct super_block *sb, 1264 struct z_erofs_decompress_frontend *f, 1265 struct list_head *pagepool, 1266 struct z_erofs_decompressqueue *fgq, 1267 bool *force_fg) 1268 { 1269 struct erofs_sb_info *const sbi = EROFS_SB(sb); 1270 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; 1271 struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; 1272 void *bi_private; 1273 z_erofs_next_pcluster_t owned_head = f->clt.owned_head; 1274 /* since bio will be NULL, no need to initialize last_index */ 1275 pgoff_t last_index; 1276 unsigned int nr_bios = 0; 1277 struct bio *bio = NULL; 1278 1279 bi_private = jobqueueset_init(sb, q, fgq, force_fg); 1280 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; 1281 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; 1282 1283 /* by default, all need io submission */ 1284 q[JQ_SUBMIT]->head = owned_head; 1285 1286 do { 1287 struct z_erofs_pcluster *pcl; 1288 pgoff_t cur, end; 1289 unsigned int i = 0; 1290 bool bypass = true; 1291 1292 /* no possible 'owned_head' equals the following */ 1293 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1294 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); 1295 1296 pcl = container_of(owned_head, struct z_erofs_pcluster, next); 1297 1298 cur = pcl->obj.index; 1299 end = cur + pcl->pclusterpages; 1300 1301 /* close the main owned chain at first */ 1302 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 1303 Z_EROFS_PCLUSTER_TAIL_CLOSED); 1304 1305 do { 1306 struct page *page; 1307 1308 page = pickup_page_for_submission(pcl, i++, pagepool, 1309 MNGD_MAPPING(sbi), 1310 GFP_NOFS); 1311 if (!page) 1312 continue; 1313 1314 if (bio && cur != last_index + 1) { 1315 submit_bio_retry: 1316 submit_bio(bio); 1317 bio = NULL; 1318 } 1319 1320 if (!bio) { 1321 bio = bio_alloc(GFP_NOIO, BIO_MAX_VECS); 1322 1323 bio->bi_end_io = z_erofs_decompressqueue_endio; 1324 bio_set_dev(bio, sb->s_bdev); 1325 bio->bi_iter.bi_sector = (sector_t)cur << 1326 LOG_SECTORS_PER_BLOCK; 1327 bio->bi_private = bi_private; 1328 bio->bi_opf = REQ_OP_READ; 1329 if (f->readahead) 1330 bio->bi_opf |= REQ_RAHEAD; 1331 ++nr_bios; 1332 } 1333 1334 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) 1335 goto submit_bio_retry; 1336 1337 last_index = cur; 1338 bypass = false; 1339 } while (++cur < end); 1340 1341 if (!bypass) 1342 qtail[JQ_SUBMIT] = &pcl->next; 1343 else 1344 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1345 } while (owned_head != Z_EROFS_PCLUSTER_TAIL); 1346 1347 if (bio) 1348 submit_bio(bio); 1349 1350 /* 1351 * although background is preferred, no one is pending for submission. 1352 * don't issue workqueue for decompression but drop it directly instead. 1353 */ 1354 if (!*force_fg && !nr_bios) { 1355 kvfree(q[JQ_SUBMIT]); 1356 return; 1357 } 1358 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios); 1359 } 1360 1361 static void z_erofs_runqueue(struct super_block *sb, 1362 struct z_erofs_decompress_frontend *f, 1363 struct list_head *pagepool, bool force_fg) 1364 { 1365 struct z_erofs_decompressqueue io[NR_JOBQUEUES]; 1366 1367 if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL) 1368 return; 1369 z_erofs_submit_queue(sb, f, pagepool, io, &force_fg); 1370 1371 /* handle bypass queue (no i/o pclusters) immediately */ 1372 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); 1373 1374 if (!force_fg) 1375 return; 1376 1377 /* wait until all bios are completed */ 1378 io_wait_event(io[JQ_SUBMIT].u.wait, 1379 !atomic_read(&io[JQ_SUBMIT].pending_bios)); 1380 1381 /* handle synchronous decompress queue in the caller context */ 1382 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); 1383 } 1384 1385 static int z_erofs_readpage(struct file *file, struct page *page) 1386 { 1387 struct inode *const inode = page->mapping->host; 1388 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1389 int err; 1390 LIST_HEAD(pagepool); 1391 1392 trace_erofs_readpage(page, false); 1393 1394 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 1395 1396 err = z_erofs_do_read_page(&f, page, &pagepool); 1397 (void)z_erofs_collector_end(&f.clt); 1398 1399 /* if some compressed cluster ready, need submit them anyway */ 1400 z_erofs_runqueue(inode->i_sb, &f, &pagepool, true); 1401 1402 if (err) 1403 erofs_err(inode->i_sb, "failed to read, err [%d]", err); 1404 1405 if (f.map.mpage) 1406 put_page(f.map.mpage); 1407 1408 /* clean up the remaining free pages */ 1409 put_pages_list(&pagepool); 1410 return err; 1411 } 1412 1413 static void z_erofs_readahead(struct readahead_control *rac) 1414 { 1415 struct inode *const inode = rac->mapping->host; 1416 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1417 1418 unsigned int nr_pages = readahead_count(rac); 1419 bool sync = (sbi->ctx.readahead_sync_decompress && 1420 nr_pages <= sbi->ctx.max_sync_decompress_pages); 1421 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1422 struct page *page, *head = NULL; 1423 LIST_HEAD(pagepool); 1424 1425 trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); 1426 1427 f.readahead = true; 1428 f.headoffset = readahead_pos(rac); 1429 1430 while ((page = readahead_page(rac))) { 1431 prefetchw(&page->flags); 1432 1433 /* 1434 * A pure asynchronous readahead is indicated if 1435 * a PG_readahead marked page is hitted at first. 1436 * Let's also do asynchronous decompression for this case. 1437 */ 1438 sync &= !(PageReadahead(page) && !head); 1439 1440 set_page_private(page, (unsigned long)head); 1441 head = page; 1442 } 1443 1444 while (head) { 1445 struct page *page = head; 1446 int err; 1447 1448 /* traversal in reverse order */ 1449 head = (void *)page_private(page); 1450 1451 err = z_erofs_do_read_page(&f, page, &pagepool); 1452 if (err) 1453 erofs_err(inode->i_sb, 1454 "readahead error at page %lu @ nid %llu", 1455 page->index, EROFS_I(inode)->nid); 1456 put_page(page); 1457 } 1458 1459 (void)z_erofs_collector_end(&f.clt); 1460 1461 z_erofs_runqueue(inode->i_sb, &f, &pagepool, sync); 1462 1463 if (f.map.mpage) 1464 put_page(f.map.mpage); 1465 1466 /* clean up the remaining free pages */ 1467 put_pages_list(&pagepool); 1468 } 1469 1470 const struct address_space_operations z_erofs_aops = { 1471 .readpage = z_erofs_readpage, 1472 .readahead = z_erofs_readahead, 1473 }; 1474 1475