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 /* how to allocate cached pages for a pcluster */ 100 enum z_erofs_cache_alloctype { 101 DONTALLOC, /* don't allocate any cached pages */ 102 /* 103 * try to use cached I/O if page allocation succeeds or fallback 104 * to in-place I/O instead to avoid any direct reclaim. 105 */ 106 TRYALLOC, 107 }; 108 109 /* 110 * tagged pointer with 1-bit tag for all compressed pages 111 * tag 0 - the page is just found with an extra page reference 112 */ 113 typedef tagptr1_t compressed_page_t; 114 115 #define tag_compressed_page_justfound(page) \ 116 tagptr_fold(compressed_page_t, page, 1) 117 118 static struct workqueue_struct *z_erofs_workqueue __read_mostly; 119 120 void z_erofs_exit_zip_subsystem(void) 121 { 122 destroy_workqueue(z_erofs_workqueue); 123 z_erofs_destroy_pcluster_pool(); 124 } 125 126 static inline int z_erofs_init_workqueue(void) 127 { 128 const unsigned int onlinecpus = num_possible_cpus(); 129 130 /* 131 * no need to spawn too many threads, limiting threads could minimum 132 * scheduling overhead, perhaps per-CPU threads should be better? 133 */ 134 z_erofs_workqueue = alloc_workqueue("erofs_unzipd", 135 WQ_UNBOUND | WQ_HIGHPRI, 136 onlinecpus + onlinecpus / 4); 137 return z_erofs_workqueue ? 0 : -ENOMEM; 138 } 139 140 int __init z_erofs_init_zip_subsystem(void) 141 { 142 int err = z_erofs_create_pcluster_pool(); 143 144 if (err) 145 return err; 146 err = z_erofs_init_workqueue(); 147 if (err) 148 z_erofs_destroy_pcluster_pool(); 149 return err; 150 } 151 152 enum z_erofs_collectmode { 153 COLLECT_SECONDARY, 154 COLLECT_PRIMARY, 155 /* 156 * The current collection was the tail of an exist chain, in addition 157 * that the previous processed chained collections are all decided to 158 * be hooked up to it. 159 * A new chain will be created for the remaining collections which are 160 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED, 161 * the next collection cannot reuse the whole page safely in 162 * the following scenario: 163 * ________________________________________________________________ 164 * | tail (partial) page | head (partial) page | 165 * | (belongs to the next cl) | (belongs to the current cl) | 166 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| 167 */ 168 COLLECT_PRIMARY_HOOKED, 169 /* 170 * a weak form of COLLECT_PRIMARY_FOLLOWED, the difference is that it 171 * could be dispatched into bypass queue later due to uptodated managed 172 * pages. All related online pages cannot be reused for inplace I/O (or 173 * pagevec) since it can be directly decoded without I/O submission. 174 */ 175 COLLECT_PRIMARY_FOLLOWED_NOINPLACE, 176 /* 177 * The current collection has been linked with the owned chain, and 178 * could also be linked with the remaining collections, which means 179 * if the processing page is the tail page of the collection, thus 180 * the current collection can safely use the whole page (since 181 * the previous collection is under control) for in-place I/O, as 182 * illustrated below: 183 * ________________________________________________________________ 184 * | tail (partial) page | head (partial) page | 185 * | (of the current cl) | (of the previous collection) | 186 * | PRIMARY_FOLLOWED or | | 187 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| 188 * 189 * [ (*) the above page can be used as inplace I/O. ] 190 */ 191 COLLECT_PRIMARY_FOLLOWED, 192 }; 193 194 struct z_erofs_collector { 195 struct z_erofs_pagevec_ctor vector; 196 197 struct z_erofs_pcluster *pcl, *tailpcl; 198 struct z_erofs_collection *cl; 199 /* a pointer used to pick up inplace I/O pages */ 200 struct page **icpage_ptr; 201 z_erofs_next_pcluster_t owned_head; 202 203 enum z_erofs_collectmode mode; 204 }; 205 206 struct z_erofs_decompress_frontend { 207 struct inode *const inode; 208 209 struct z_erofs_collector clt; 210 struct erofs_map_blocks map; 211 212 bool readahead; 213 /* used for applying cache strategy on the fly */ 214 bool backmost; 215 erofs_off_t headoffset; 216 }; 217 218 #define COLLECTOR_INIT() { \ 219 .owned_head = Z_EROFS_PCLUSTER_TAIL, \ 220 .mode = COLLECT_PRIMARY_FOLLOWED } 221 222 #define DECOMPRESS_FRONTEND_INIT(__i) { \ 223 .inode = __i, .clt = COLLECTOR_INIT(), \ 224 .backmost = true, } 225 226 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES]; 227 static DEFINE_MUTEX(z_pagemap_global_lock); 228 229 static void preload_compressed_pages(struct z_erofs_collector *clt, 230 struct address_space *mc, 231 enum z_erofs_cache_alloctype type, 232 struct page **pagepool) 233 { 234 struct z_erofs_pcluster *pcl = clt->pcl; 235 bool standalone = true; 236 gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | 237 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 238 struct page **pages; 239 pgoff_t index; 240 241 if (clt->mode < COLLECT_PRIMARY_FOLLOWED) 242 return; 243 244 pages = pcl->compressed_pages; 245 index = pcl->obj.index; 246 for (; index < pcl->obj.index + pcl->pclusterpages; ++index, ++pages) { 247 struct page *page; 248 compressed_page_t t; 249 struct page *newpage = NULL; 250 251 /* the compressed page was loaded before */ 252 if (READ_ONCE(*pages)) 253 continue; 254 255 page = find_get_page(mc, index); 256 257 if (page) { 258 t = tag_compressed_page_justfound(page); 259 } else { 260 /* I/O is needed, no possible to decompress directly */ 261 standalone = false; 262 switch (type) { 263 case TRYALLOC: 264 newpage = erofs_allocpage(pagepool, gfp); 265 if (!newpage) 266 continue; 267 set_page_private(newpage, 268 Z_EROFS_PREALLOCATED_PAGE); 269 t = tag_compressed_page_justfound(newpage); 270 break; 271 default: /* DONTALLOC */ 272 continue; 273 } 274 } 275 276 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t))) 277 continue; 278 279 if (page) 280 put_page(page); 281 else if (newpage) 282 erofs_pagepool_add(pagepool, newpage); 283 } 284 285 /* 286 * don't do inplace I/O if all compressed pages are available in 287 * managed cache since it can be moved to the bypass queue instead. 288 */ 289 if (standalone) 290 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE; 291 } 292 293 /* called by erofs_shrinker to get rid of all compressed_pages */ 294 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 295 struct erofs_workgroup *grp) 296 { 297 struct z_erofs_pcluster *const pcl = 298 container_of(grp, struct z_erofs_pcluster, obj); 299 int i; 300 301 /* 302 * refcount of workgroup is now freezed as 1, 303 * therefore no need to worry about available decompression users. 304 */ 305 for (i = 0; i < pcl->pclusterpages; ++i) { 306 struct page *page = pcl->compressed_pages[i]; 307 308 if (!page) 309 continue; 310 311 /* block other users from reclaiming or migrating the page */ 312 if (!trylock_page(page)) 313 return -EBUSY; 314 315 if (!erofs_page_is_managed(sbi, page)) 316 continue; 317 318 /* barrier is implied in the following 'unlock_page' */ 319 WRITE_ONCE(pcl->compressed_pages[i], NULL); 320 detach_page_private(page); 321 unlock_page(page); 322 } 323 return 0; 324 } 325 326 int erofs_try_to_free_cached_page(struct page *page) 327 { 328 struct z_erofs_pcluster *const pcl = (void *)page_private(page); 329 int ret = 0; /* 0 - busy */ 330 331 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) { 332 unsigned int i; 333 334 for (i = 0; i < pcl->pclusterpages; ++i) { 335 if (pcl->compressed_pages[i] == page) { 336 WRITE_ONCE(pcl->compressed_pages[i], NULL); 337 ret = 1; 338 break; 339 } 340 } 341 erofs_workgroup_unfreeze(&pcl->obj, 1); 342 343 if (ret) 344 detach_page_private(page); 345 } 346 return ret; 347 } 348 349 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ 350 static bool z_erofs_try_inplace_io(struct z_erofs_collector *clt, 351 struct page *page) 352 { 353 struct z_erofs_pcluster *const pcl = clt->pcl; 354 355 while (clt->icpage_ptr > pcl->compressed_pages) 356 if (!cmpxchg(--clt->icpage_ptr, NULL, page)) 357 return true; 358 return false; 359 } 360 361 /* callers must be with collection lock held */ 362 static int z_erofs_attach_page(struct z_erofs_collector *clt, 363 struct page *page, enum z_erofs_page_type type, 364 bool pvec_safereuse) 365 { 366 int ret; 367 368 /* give priority for inplaceio */ 369 if (clt->mode >= COLLECT_PRIMARY && 370 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && 371 z_erofs_try_inplace_io(clt, page)) 372 return 0; 373 374 ret = z_erofs_pagevec_enqueue(&clt->vector, page, type, 375 pvec_safereuse); 376 clt->cl->vcnt += (unsigned int)ret; 377 return ret ? 0 : -EAGAIN; 378 } 379 380 static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt) 381 { 382 struct z_erofs_pcluster *pcl = clt->pcl; 383 z_erofs_next_pcluster_t *owned_head = &clt->owned_head; 384 385 /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */ 386 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, 387 *owned_head) == Z_EROFS_PCLUSTER_NIL) { 388 *owned_head = &pcl->next; 389 /* so we can attach this pcluster to our submission chain. */ 390 clt->mode = COLLECT_PRIMARY_FOLLOWED; 391 return; 392 } 393 394 /* 395 * type 2, link to the end of an existing open chain, be careful 396 * that its submission is controlled by the original attached chain. 397 */ 398 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 399 *owned_head) == Z_EROFS_PCLUSTER_TAIL) { 400 *owned_head = Z_EROFS_PCLUSTER_TAIL; 401 clt->mode = COLLECT_PRIMARY_HOOKED; 402 clt->tailpcl = NULL; 403 return; 404 } 405 /* type 3, it belongs to a chain, but it isn't the end of the chain */ 406 clt->mode = COLLECT_PRIMARY; 407 } 408 409 static int z_erofs_lookup_collection(struct z_erofs_collector *clt, 410 struct inode *inode, 411 struct erofs_map_blocks *map) 412 { 413 struct z_erofs_pcluster *pcl = clt->pcl; 414 struct z_erofs_collection *cl; 415 unsigned int length; 416 417 /* to avoid unexpected loop formed by corrupted images */ 418 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) { 419 DBG_BUGON(1); 420 return -EFSCORRUPTED; 421 } 422 423 cl = z_erofs_primarycollection(pcl); 424 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) { 425 DBG_BUGON(1); 426 return -EFSCORRUPTED; 427 } 428 429 length = READ_ONCE(pcl->length); 430 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) { 431 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) { 432 DBG_BUGON(1); 433 return -EFSCORRUPTED; 434 } 435 } else { 436 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT; 437 438 if (map->m_flags & EROFS_MAP_FULL_MAPPED) 439 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH; 440 441 while (llen > length && 442 length != cmpxchg_relaxed(&pcl->length, length, llen)) { 443 cpu_relax(); 444 length = READ_ONCE(pcl->length); 445 } 446 } 447 mutex_lock(&cl->lock); 448 /* used to check tail merging loop due to corrupted images */ 449 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 450 clt->tailpcl = pcl; 451 452 z_erofs_try_to_claim_pcluster(clt); 453 clt->cl = cl; 454 return 0; 455 } 456 457 static int z_erofs_register_collection(struct z_erofs_collector *clt, 458 struct inode *inode, 459 struct erofs_map_blocks *map) 460 { 461 struct z_erofs_pcluster *pcl; 462 struct z_erofs_collection *cl; 463 struct erofs_workgroup *grp; 464 int err; 465 466 if (!(map->m_flags & EROFS_MAP_ENCODED)) { 467 DBG_BUGON(1); 468 return -EFSCORRUPTED; 469 } 470 471 /* no available pcluster, let's allocate one */ 472 pcl = z_erofs_alloc_pcluster(map->m_plen >> PAGE_SHIFT); 473 if (IS_ERR(pcl)) 474 return PTR_ERR(pcl); 475 476 atomic_set(&pcl->obj.refcount, 1); 477 pcl->obj.index = map->m_pa >> PAGE_SHIFT; 478 pcl->algorithmformat = map->m_algorithmformat; 479 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) | 480 (map->m_flags & EROFS_MAP_FULL_MAPPED ? 481 Z_EROFS_PCLUSTER_FULL_LENGTH : 0); 482 483 /* new pclusters should be claimed as type 1, primary and followed */ 484 pcl->next = clt->owned_head; 485 clt->mode = COLLECT_PRIMARY_FOLLOWED; 486 487 cl = z_erofs_primarycollection(pcl); 488 cl->pageofs = map->m_la & ~PAGE_MASK; 489 490 /* 491 * lock all primary followed works before visible to others 492 * and mutex_trylock *never* fails for a new pcluster. 493 */ 494 mutex_init(&cl->lock); 495 DBG_BUGON(!mutex_trylock(&cl->lock)); 496 497 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj); 498 if (IS_ERR(grp)) { 499 err = PTR_ERR(grp); 500 goto err_out; 501 } 502 503 if (grp != &pcl->obj) { 504 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 505 err = -EEXIST; 506 goto err_out; 507 } 508 /* used to check tail merging loop due to corrupted images */ 509 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 510 clt->tailpcl = pcl; 511 clt->owned_head = &pcl->next; 512 clt->pcl = pcl; 513 clt->cl = cl; 514 return 0; 515 516 err_out: 517 mutex_unlock(&cl->lock); 518 z_erofs_free_pcluster(pcl); 519 return err; 520 } 521 522 static int z_erofs_collector_begin(struct z_erofs_collector *clt, 523 struct inode *inode, 524 struct erofs_map_blocks *map) 525 { 526 struct erofs_workgroup *grp; 527 int ret; 528 529 DBG_BUGON(clt->cl); 530 531 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */ 532 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL); 533 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 534 535 if (!PAGE_ALIGNED(map->m_pa)) { 536 DBG_BUGON(1); 537 return -EINVAL; 538 } 539 540 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT); 541 if (grp) { 542 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 543 } else { 544 ret = z_erofs_register_collection(clt, inode, map); 545 546 if (!ret) 547 goto out; 548 if (ret != -EEXIST) 549 return ret; 550 } 551 552 ret = z_erofs_lookup_collection(clt, inode, map); 553 if (ret) { 554 erofs_workgroup_put(&clt->pcl->obj); 555 return ret; 556 } 557 558 out: 559 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS, 560 clt->cl->pagevec, clt->cl->vcnt); 561 562 /* since file-backed online pages are traversed in reverse order */ 563 clt->icpage_ptr = clt->pcl->compressed_pages + clt->pcl->pclusterpages; 564 return 0; 565 } 566 567 /* 568 * keep in mind that no referenced pclusters will be freed 569 * only after a RCU grace period. 570 */ 571 static void z_erofs_rcu_callback(struct rcu_head *head) 572 { 573 struct z_erofs_collection *const cl = 574 container_of(head, struct z_erofs_collection, rcu); 575 576 z_erofs_free_pcluster(container_of(cl, struct z_erofs_pcluster, 577 primary_collection)); 578 } 579 580 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) 581 { 582 struct z_erofs_pcluster *const pcl = 583 container_of(grp, struct z_erofs_pcluster, obj); 584 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl); 585 586 call_rcu(&cl->rcu, z_erofs_rcu_callback); 587 } 588 589 static void z_erofs_collection_put(struct z_erofs_collection *cl) 590 { 591 struct z_erofs_pcluster *const pcl = 592 container_of(cl, struct z_erofs_pcluster, primary_collection); 593 594 erofs_workgroup_put(&pcl->obj); 595 } 596 597 static bool z_erofs_collector_end(struct z_erofs_collector *clt) 598 { 599 struct z_erofs_collection *cl = clt->cl; 600 601 if (!cl) 602 return false; 603 604 z_erofs_pagevec_ctor_exit(&clt->vector, false); 605 mutex_unlock(&cl->lock); 606 607 /* 608 * if all pending pages are added, don't hold its reference 609 * any longer if the pcluster isn't hosted by ourselves. 610 */ 611 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE) 612 z_erofs_collection_put(cl); 613 614 clt->cl = NULL; 615 return true; 616 } 617 618 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe, 619 unsigned int cachestrategy, 620 erofs_off_t la) 621 { 622 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) 623 return false; 624 625 if (fe->backmost) 626 return true; 627 628 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND && 629 la < fe->headoffset; 630 } 631 632 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 633 struct page *page, struct page **pagepool) 634 { 635 struct inode *const inode = fe->inode; 636 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 637 struct erofs_map_blocks *const map = &fe->map; 638 struct z_erofs_collector *const clt = &fe->clt; 639 const loff_t offset = page_offset(page); 640 bool tight = true; 641 642 enum z_erofs_cache_alloctype cache_strategy; 643 enum z_erofs_page_type page_type; 644 unsigned int cur, end, spiltted, index; 645 int err = 0; 646 647 /* register locked file pages as online pages in pack */ 648 z_erofs_onlinepage_init(page); 649 650 spiltted = 0; 651 end = PAGE_SIZE; 652 repeat: 653 cur = end - 1; 654 655 /* lucky, within the range of the current map_blocks */ 656 if (offset + cur >= map->m_la && 657 offset + cur < map->m_la + map->m_llen) { 658 /* didn't get a valid collection previously (very rare) */ 659 if (!clt->cl) 660 goto restart_now; 661 goto hitted; 662 } 663 664 /* go ahead the next map_blocks */ 665 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur); 666 667 if (z_erofs_collector_end(clt)) 668 fe->backmost = false; 669 670 map->m_la = offset + cur; 671 map->m_llen = 0; 672 err = z_erofs_map_blocks_iter(inode, map, 0); 673 if (err) 674 goto err_out; 675 676 restart_now: 677 if (!(map->m_flags & EROFS_MAP_MAPPED)) 678 goto hitted; 679 680 err = z_erofs_collector_begin(clt, inode, map); 681 if (err) 682 goto err_out; 683 684 /* preload all compressed pages (maybe downgrade role if necessary) */ 685 if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy, map->m_la)) 686 cache_strategy = TRYALLOC; 687 else 688 cache_strategy = DONTALLOC; 689 690 preload_compressed_pages(clt, MNGD_MAPPING(sbi), 691 cache_strategy, pagepool); 692 693 hitted: 694 /* 695 * Ensure the current partial page belongs to this submit chain rather 696 * than other concurrent submit chains or the noio(bypass) chain since 697 * those chains are handled asynchronously thus the page cannot be used 698 * for inplace I/O or pagevec (should be processed in strict order.) 699 */ 700 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED && 701 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE); 702 703 cur = end - min_t(unsigned int, offset + end - map->m_la, end); 704 if (!(map->m_flags & EROFS_MAP_MAPPED)) { 705 zero_user_segment(page, cur, end); 706 goto next_part; 707 } 708 709 /* let's derive page type */ 710 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD : 711 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 712 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 713 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); 714 715 if (cur) 716 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED); 717 718 retry: 719 err = z_erofs_attach_page(clt, page, page_type, 720 clt->mode >= COLLECT_PRIMARY_FOLLOWED); 721 /* should allocate an additional short-lived page for pagevec */ 722 if (err == -EAGAIN) { 723 struct page *const newpage = 724 alloc_page(GFP_NOFS | __GFP_NOFAIL); 725 726 set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); 727 err = z_erofs_attach_page(clt, newpage, 728 Z_EROFS_PAGE_TYPE_EXCLUSIVE, true); 729 if (!err) 730 goto retry; 731 } 732 733 if (err) 734 goto err_out; 735 736 index = page->index - (map->m_la >> PAGE_SHIFT); 737 738 z_erofs_onlinepage_fixup(page, index, true); 739 740 /* bump up the number of spiltted parts of a page */ 741 ++spiltted; 742 /* also update nr_pages */ 743 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1); 744 next_part: 745 /* can be used for verification */ 746 map->m_llen = offset + cur - map->m_la; 747 748 end = cur; 749 if (end > 0) 750 goto repeat; 751 752 out: 753 z_erofs_onlinepage_endio(page); 754 755 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu", 756 __func__, page, spiltted, map->m_llen); 757 return err; 758 759 /* if some error occurred while processing this page */ 760 err_out: 761 SetPageError(page); 762 goto out; 763 } 764 765 static void z_erofs_decompressqueue_work(struct work_struct *work); 766 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, 767 bool sync, int bios) 768 { 769 struct erofs_sb_info *const sbi = EROFS_SB(io->sb); 770 771 /* wake up the caller thread for sync decompression */ 772 if (sync) { 773 unsigned long flags; 774 775 spin_lock_irqsave(&io->u.wait.lock, flags); 776 if (!atomic_add_return(bios, &io->pending_bios)) 777 wake_up_locked(&io->u.wait); 778 spin_unlock_irqrestore(&io->u.wait.lock, flags); 779 return; 780 } 781 782 if (atomic_add_return(bios, &io->pending_bios)) 783 return; 784 /* Use workqueue and sync decompression for atomic contexts only */ 785 if (in_atomic() || irqs_disabled()) { 786 queue_work(z_erofs_workqueue, &io->u.work); 787 sbi->opt.readahead_sync_decompress = true; 788 return; 789 } 790 z_erofs_decompressqueue_work(&io->u.work); 791 } 792 793 static bool z_erofs_page_is_invalidated(struct page *page) 794 { 795 return !page->mapping && !z_erofs_is_shortlived_page(page); 796 } 797 798 static void z_erofs_decompressqueue_endio(struct bio *bio) 799 { 800 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private); 801 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t); 802 blk_status_t err = bio->bi_status; 803 struct bio_vec *bvec; 804 struct bvec_iter_all iter_all; 805 806 bio_for_each_segment_all(bvec, bio, iter_all) { 807 struct page *page = bvec->bv_page; 808 809 DBG_BUGON(PageUptodate(page)); 810 DBG_BUGON(z_erofs_page_is_invalidated(page)); 811 812 if (err) 813 SetPageError(page); 814 815 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { 816 if (!err) 817 SetPageUptodate(page); 818 unlock_page(page); 819 } 820 } 821 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); 822 bio_put(bio); 823 } 824 825 static int z_erofs_decompress_pcluster(struct super_block *sb, 826 struct z_erofs_pcluster *pcl, 827 struct page **pagepool) 828 { 829 struct erofs_sb_info *const sbi = EROFS_SB(sb); 830 struct z_erofs_pagevec_ctor ctor; 831 unsigned int i, inputsize, outputsize, llen, nr_pages; 832 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES]; 833 struct page **pages, **compressed_pages, *page; 834 835 enum z_erofs_page_type page_type; 836 bool overlapped, partial; 837 struct z_erofs_collection *cl; 838 int err; 839 840 might_sleep(); 841 cl = z_erofs_primarycollection(pcl); 842 DBG_BUGON(!READ_ONCE(cl->nr_pages)); 843 844 mutex_lock(&cl->lock); 845 nr_pages = cl->nr_pages; 846 847 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) { 848 pages = pages_onstack; 849 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES && 850 mutex_trylock(&z_pagemap_global_lock)) { 851 pages = z_pagemap_global; 852 } else { 853 gfp_t gfp_flags = GFP_KERNEL; 854 855 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES) 856 gfp_flags |= __GFP_NOFAIL; 857 858 pages = kvmalloc_array(nr_pages, sizeof(struct page *), 859 gfp_flags); 860 861 /* fallback to global pagemap for the lowmem scenario */ 862 if (!pages) { 863 mutex_lock(&z_pagemap_global_lock); 864 pages = z_pagemap_global; 865 } 866 } 867 868 for (i = 0; i < nr_pages; ++i) 869 pages[i] = NULL; 870 871 err = 0; 872 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, 873 cl->pagevec, 0); 874 875 for (i = 0; i < cl->vcnt; ++i) { 876 unsigned int pagenr; 877 878 page = z_erofs_pagevec_dequeue(&ctor, &page_type); 879 880 /* all pages in pagevec ought to be valid */ 881 DBG_BUGON(!page); 882 DBG_BUGON(z_erofs_page_is_invalidated(page)); 883 884 if (z_erofs_put_shortlivedpage(pagepool, page)) 885 continue; 886 887 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD) 888 pagenr = 0; 889 else 890 pagenr = z_erofs_onlinepage_index(page); 891 892 DBG_BUGON(pagenr >= nr_pages); 893 894 /* 895 * currently EROFS doesn't support multiref(dedup), 896 * so here erroring out one multiref page. 897 */ 898 if (pages[pagenr]) { 899 DBG_BUGON(1); 900 SetPageError(pages[pagenr]); 901 z_erofs_onlinepage_endio(pages[pagenr]); 902 err = -EFSCORRUPTED; 903 } 904 pages[pagenr] = page; 905 } 906 z_erofs_pagevec_ctor_exit(&ctor, true); 907 908 overlapped = false; 909 compressed_pages = pcl->compressed_pages; 910 911 for (i = 0; i < pcl->pclusterpages; ++i) { 912 unsigned int pagenr; 913 914 page = compressed_pages[i]; 915 916 /* all compressed pages ought to be valid */ 917 DBG_BUGON(!page); 918 DBG_BUGON(z_erofs_page_is_invalidated(page)); 919 920 if (!z_erofs_is_shortlived_page(page)) { 921 if (erofs_page_is_managed(sbi, page)) { 922 if (!PageUptodate(page)) 923 err = -EIO; 924 continue; 925 } 926 927 /* 928 * only if non-head page can be selected 929 * for inplace decompression 930 */ 931 pagenr = z_erofs_onlinepage_index(page); 932 933 DBG_BUGON(pagenr >= nr_pages); 934 if (pages[pagenr]) { 935 DBG_BUGON(1); 936 SetPageError(pages[pagenr]); 937 z_erofs_onlinepage_endio(pages[pagenr]); 938 err = -EFSCORRUPTED; 939 } 940 pages[pagenr] = page; 941 942 overlapped = true; 943 } 944 945 /* PG_error needs checking for all non-managed pages */ 946 if (PageError(page)) { 947 DBG_BUGON(PageUptodate(page)); 948 err = -EIO; 949 } 950 } 951 952 if (err) 953 goto out; 954 955 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT; 956 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) { 957 outputsize = llen; 958 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH); 959 } else { 960 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs; 961 partial = true; 962 } 963 964 inputsize = pcl->pclusterpages * PAGE_SIZE; 965 err = z_erofs_decompress(&(struct z_erofs_decompress_req) { 966 .sb = sb, 967 .in = compressed_pages, 968 .out = pages, 969 .pageofs_out = cl->pageofs, 970 .inputsize = inputsize, 971 .outputsize = outputsize, 972 .alg = pcl->algorithmformat, 973 .inplace_io = overlapped, 974 .partial_decoding = partial 975 }, pagepool); 976 977 out: 978 /* must handle all compressed pages before ending pages */ 979 for (i = 0; i < pcl->pclusterpages; ++i) { 980 page = compressed_pages[i]; 981 982 if (erofs_page_is_managed(sbi, page)) 983 continue; 984 985 /* recycle all individual short-lived pages */ 986 (void)z_erofs_put_shortlivedpage(pagepool, page); 987 988 WRITE_ONCE(compressed_pages[i], NULL); 989 } 990 991 for (i = 0; i < nr_pages; ++i) { 992 page = pages[i]; 993 if (!page) 994 continue; 995 996 DBG_BUGON(z_erofs_page_is_invalidated(page)); 997 998 /* recycle all individual short-lived pages */ 999 if (z_erofs_put_shortlivedpage(pagepool, page)) 1000 continue; 1001 1002 if (err < 0) 1003 SetPageError(page); 1004 1005 z_erofs_onlinepage_endio(page); 1006 } 1007 1008 if (pages == z_pagemap_global) 1009 mutex_unlock(&z_pagemap_global_lock); 1010 else if (pages != pages_onstack) 1011 kvfree(pages); 1012 1013 cl->nr_pages = 0; 1014 cl->vcnt = 0; 1015 1016 /* all cl locks MUST be taken before the following line */ 1017 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); 1018 1019 /* all cl locks SHOULD be released right now */ 1020 mutex_unlock(&cl->lock); 1021 1022 z_erofs_collection_put(cl); 1023 return err; 1024 } 1025 1026 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, 1027 struct page **pagepool) 1028 { 1029 z_erofs_next_pcluster_t owned = io->head; 1030 1031 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { 1032 struct z_erofs_pcluster *pcl; 1033 1034 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ 1035 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); 1036 1037 /* no possible that 'owned' equals NULL */ 1038 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); 1039 1040 pcl = container_of(owned, struct z_erofs_pcluster, next); 1041 owned = READ_ONCE(pcl->next); 1042 1043 z_erofs_decompress_pcluster(io->sb, pcl, pagepool); 1044 } 1045 } 1046 1047 static void z_erofs_decompressqueue_work(struct work_struct *work) 1048 { 1049 struct z_erofs_decompressqueue *bgq = 1050 container_of(work, struct z_erofs_decompressqueue, u.work); 1051 struct page *pagepool = NULL; 1052 1053 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1054 z_erofs_decompress_queue(bgq, &pagepool); 1055 1056 erofs_release_pages(&pagepool); 1057 kvfree(bgq); 1058 } 1059 1060 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 1061 unsigned int nr, 1062 struct page **pagepool, 1063 struct address_space *mc, 1064 gfp_t gfp) 1065 { 1066 const pgoff_t index = pcl->obj.index; 1067 bool tocache = false; 1068 1069 struct address_space *mapping; 1070 struct page *oldpage, *page; 1071 1072 compressed_page_t t; 1073 int justfound; 1074 1075 repeat: 1076 page = READ_ONCE(pcl->compressed_pages[nr]); 1077 oldpage = page; 1078 1079 if (!page) 1080 goto out_allocpage; 1081 1082 /* process the target tagged pointer */ 1083 t = tagptr_init(compressed_page_t, page); 1084 justfound = tagptr_unfold_tags(t); 1085 page = tagptr_unfold_ptr(t); 1086 1087 /* 1088 * preallocated cached pages, which is used to avoid direct reclaim 1089 * otherwise, it will go inplace I/O path instead. 1090 */ 1091 if (page->private == Z_EROFS_PREALLOCATED_PAGE) { 1092 WRITE_ONCE(pcl->compressed_pages[nr], page); 1093 set_page_private(page, 0); 1094 tocache = true; 1095 goto out_tocache; 1096 } 1097 mapping = READ_ONCE(page->mapping); 1098 1099 /* 1100 * file-backed online pages in plcuster are all locked steady, 1101 * therefore it is impossible for `mapping' to be NULL. 1102 */ 1103 if (mapping && mapping != mc) 1104 /* ought to be unmanaged pages */ 1105 goto out; 1106 1107 /* directly return for shortlived page as well */ 1108 if (z_erofs_is_shortlived_page(page)) 1109 goto out; 1110 1111 lock_page(page); 1112 1113 /* only true if page reclaim goes wrong, should never happen */ 1114 DBG_BUGON(justfound && PagePrivate(page)); 1115 1116 /* the page is still in manage cache */ 1117 if (page->mapping == mc) { 1118 WRITE_ONCE(pcl->compressed_pages[nr], page); 1119 1120 ClearPageError(page); 1121 if (!PagePrivate(page)) { 1122 /* 1123 * impossible to be !PagePrivate(page) for 1124 * the current restriction as well if 1125 * the page is already in compressed_pages[]. 1126 */ 1127 DBG_BUGON(!justfound); 1128 1129 justfound = 0; 1130 set_page_private(page, (unsigned long)pcl); 1131 SetPagePrivate(page); 1132 } 1133 1134 /* no need to submit io if it is already up-to-date */ 1135 if (PageUptodate(page)) { 1136 unlock_page(page); 1137 page = NULL; 1138 } 1139 goto out; 1140 } 1141 1142 /* 1143 * the managed page has been truncated, it's unsafe to 1144 * reuse this one, let's allocate a new cache-managed page. 1145 */ 1146 DBG_BUGON(page->mapping); 1147 DBG_BUGON(!justfound); 1148 1149 tocache = true; 1150 unlock_page(page); 1151 put_page(page); 1152 out_allocpage: 1153 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); 1154 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) { 1155 erofs_pagepool_add(pagepool, page); 1156 cond_resched(); 1157 goto repeat; 1158 } 1159 out_tocache: 1160 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { 1161 /* turn into temporary page if fails (1 ref) */ 1162 set_page_private(page, Z_EROFS_SHORTLIVED_PAGE); 1163 goto out; 1164 } 1165 attach_page_private(page, pcl); 1166 /* drop a refcount added by allocpage (then we have 2 refs here) */ 1167 put_page(page); 1168 1169 out: /* the only exit (for tracing and debugging) */ 1170 return page; 1171 } 1172 1173 static struct z_erofs_decompressqueue * 1174 jobqueue_init(struct super_block *sb, 1175 struct z_erofs_decompressqueue *fgq, bool *fg) 1176 { 1177 struct z_erofs_decompressqueue *q; 1178 1179 if (fg && !*fg) { 1180 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); 1181 if (!q) { 1182 *fg = true; 1183 goto fg_out; 1184 } 1185 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); 1186 } else { 1187 fg_out: 1188 q = fgq; 1189 init_waitqueue_head(&fgq->u.wait); 1190 atomic_set(&fgq->pending_bios, 0); 1191 } 1192 q->sb = sb; 1193 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1194 return q; 1195 } 1196 1197 /* define decompression jobqueue types */ 1198 enum { 1199 JQ_BYPASS, 1200 JQ_SUBMIT, 1201 NR_JOBQUEUES, 1202 }; 1203 1204 static void *jobqueueset_init(struct super_block *sb, 1205 struct z_erofs_decompressqueue *q[], 1206 struct z_erofs_decompressqueue *fgq, bool *fg) 1207 { 1208 /* 1209 * if managed cache is enabled, bypass jobqueue is needed, 1210 * no need to read from device for all pclusters in this queue. 1211 */ 1212 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); 1213 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg); 1214 1215 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg)); 1216 } 1217 1218 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 1219 z_erofs_next_pcluster_t qtail[], 1220 z_erofs_next_pcluster_t owned_head) 1221 { 1222 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; 1223 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; 1224 1225 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1226 if (owned_head == Z_EROFS_PCLUSTER_TAIL) 1227 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1228 1229 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); 1230 1231 WRITE_ONCE(*submit_qtail, owned_head); 1232 WRITE_ONCE(*bypass_qtail, &pcl->next); 1233 1234 qtail[JQ_BYPASS] = &pcl->next; 1235 } 1236 1237 static void z_erofs_submit_queue(struct super_block *sb, 1238 struct z_erofs_decompress_frontend *f, 1239 struct page **pagepool, 1240 struct z_erofs_decompressqueue *fgq, 1241 bool *force_fg) 1242 { 1243 struct erofs_sb_info *const sbi = EROFS_SB(sb); 1244 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; 1245 struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; 1246 void *bi_private; 1247 z_erofs_next_pcluster_t owned_head = f->clt.owned_head; 1248 /* bio is NULL initially, so no need to initialize last_{index,bdev} */ 1249 pgoff_t last_index; 1250 struct block_device *last_bdev; 1251 unsigned int nr_bios = 0; 1252 struct bio *bio = NULL; 1253 1254 bi_private = jobqueueset_init(sb, q, fgq, force_fg); 1255 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; 1256 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; 1257 1258 /* by default, all need io submission */ 1259 q[JQ_SUBMIT]->head = owned_head; 1260 1261 do { 1262 struct erofs_map_dev mdev; 1263 struct z_erofs_pcluster *pcl; 1264 pgoff_t cur, end; 1265 unsigned int i = 0; 1266 bool bypass = true; 1267 1268 /* no possible 'owned_head' equals the following */ 1269 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1270 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); 1271 1272 pcl = container_of(owned_head, struct z_erofs_pcluster, next); 1273 1274 /* no device id here, thus it will always succeed */ 1275 mdev = (struct erofs_map_dev) { 1276 .m_pa = blknr_to_addr(pcl->obj.index), 1277 }; 1278 (void)erofs_map_dev(sb, &mdev); 1279 1280 cur = erofs_blknr(mdev.m_pa); 1281 end = cur + pcl->pclusterpages; 1282 1283 /* close the main owned chain at first */ 1284 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 1285 Z_EROFS_PCLUSTER_TAIL_CLOSED); 1286 1287 do { 1288 struct page *page; 1289 1290 page = pickup_page_for_submission(pcl, i++, pagepool, 1291 MNGD_MAPPING(sbi), 1292 GFP_NOFS); 1293 if (!page) 1294 continue; 1295 1296 if (bio && (cur != last_index + 1 || 1297 last_bdev != mdev.m_bdev)) { 1298 submit_bio_retry: 1299 submit_bio(bio); 1300 bio = NULL; 1301 } 1302 1303 if (!bio) { 1304 bio = bio_alloc(GFP_NOIO, BIO_MAX_VECS); 1305 bio->bi_end_io = z_erofs_decompressqueue_endio; 1306 1307 bio_set_dev(bio, mdev.m_bdev); 1308 last_bdev = mdev.m_bdev; 1309 bio->bi_iter.bi_sector = (sector_t)cur << 1310 LOG_SECTORS_PER_BLOCK; 1311 bio->bi_private = bi_private; 1312 bio->bi_opf = REQ_OP_READ; 1313 if (f->readahead) 1314 bio->bi_opf |= REQ_RAHEAD; 1315 ++nr_bios; 1316 } 1317 1318 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) 1319 goto submit_bio_retry; 1320 1321 last_index = cur; 1322 bypass = false; 1323 } while (++cur < end); 1324 1325 if (!bypass) 1326 qtail[JQ_SUBMIT] = &pcl->next; 1327 else 1328 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1329 } while (owned_head != Z_EROFS_PCLUSTER_TAIL); 1330 1331 if (bio) 1332 submit_bio(bio); 1333 1334 /* 1335 * although background is preferred, no one is pending for submission. 1336 * don't issue workqueue for decompression but drop it directly instead. 1337 */ 1338 if (!*force_fg && !nr_bios) { 1339 kvfree(q[JQ_SUBMIT]); 1340 return; 1341 } 1342 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios); 1343 } 1344 1345 static void z_erofs_runqueue(struct super_block *sb, 1346 struct z_erofs_decompress_frontend *f, 1347 struct page **pagepool, bool force_fg) 1348 { 1349 struct z_erofs_decompressqueue io[NR_JOBQUEUES]; 1350 1351 if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL) 1352 return; 1353 z_erofs_submit_queue(sb, f, pagepool, io, &force_fg); 1354 1355 /* handle bypass queue (no i/o pclusters) immediately */ 1356 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); 1357 1358 if (!force_fg) 1359 return; 1360 1361 /* wait until all bios are completed */ 1362 io_wait_event(io[JQ_SUBMIT].u.wait, 1363 !atomic_read(&io[JQ_SUBMIT].pending_bios)); 1364 1365 /* handle synchronous decompress queue in the caller context */ 1366 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); 1367 } 1368 1369 /* 1370 * Since partial uptodate is still unimplemented for now, we have to use 1371 * approximate readmore strategies as a start. 1372 */ 1373 static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f, 1374 struct readahead_control *rac, 1375 erofs_off_t end, 1376 struct page **pagepool, 1377 bool backmost) 1378 { 1379 struct inode *inode = f->inode; 1380 struct erofs_map_blocks *map = &f->map; 1381 erofs_off_t cur; 1382 int err; 1383 1384 if (backmost) { 1385 map->m_la = end; 1386 err = z_erofs_map_blocks_iter(inode, map, 1387 EROFS_GET_BLOCKS_READMORE); 1388 if (err) 1389 return; 1390 1391 /* expend ra for the trailing edge if readahead */ 1392 if (rac) { 1393 loff_t newstart = readahead_pos(rac); 1394 1395 cur = round_up(map->m_la + map->m_llen, PAGE_SIZE); 1396 readahead_expand(rac, newstart, cur - newstart); 1397 return; 1398 } 1399 end = round_up(end, PAGE_SIZE); 1400 } else { 1401 end = round_up(map->m_la, PAGE_SIZE); 1402 1403 if (!map->m_llen) 1404 return; 1405 } 1406 1407 cur = map->m_la + map->m_llen - 1; 1408 while (cur >= end) { 1409 pgoff_t index = cur >> PAGE_SHIFT; 1410 struct page *page; 1411 1412 page = erofs_grab_cache_page_nowait(inode->i_mapping, index); 1413 if (!page) 1414 goto skip; 1415 1416 if (PageUptodate(page)) { 1417 unlock_page(page); 1418 put_page(page); 1419 goto skip; 1420 } 1421 1422 err = z_erofs_do_read_page(f, page, pagepool); 1423 if (err) 1424 erofs_err(inode->i_sb, 1425 "readmore error at page %lu @ nid %llu", 1426 index, EROFS_I(inode)->nid); 1427 put_page(page); 1428 skip: 1429 if (cur < PAGE_SIZE) 1430 break; 1431 cur = (index << PAGE_SHIFT) - 1; 1432 } 1433 } 1434 1435 static int z_erofs_readpage(struct file *file, struct page *page) 1436 { 1437 struct inode *const inode = page->mapping->host; 1438 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1439 struct page *pagepool = NULL; 1440 int err; 1441 1442 trace_erofs_readpage(page, false); 1443 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 1444 1445 z_erofs_pcluster_readmore(&f, NULL, f.headoffset + PAGE_SIZE - 1, 1446 &pagepool, true); 1447 err = z_erofs_do_read_page(&f, page, &pagepool); 1448 z_erofs_pcluster_readmore(&f, NULL, 0, &pagepool, false); 1449 1450 (void)z_erofs_collector_end(&f.clt); 1451 1452 /* if some compressed cluster ready, need submit them anyway */ 1453 z_erofs_runqueue(inode->i_sb, &f, &pagepool, true); 1454 1455 if (err) 1456 erofs_err(inode->i_sb, "failed to read, err [%d]", err); 1457 1458 if (f.map.mpage) 1459 put_page(f.map.mpage); 1460 1461 erofs_release_pages(&pagepool); 1462 return err; 1463 } 1464 1465 static void z_erofs_readahead(struct readahead_control *rac) 1466 { 1467 struct inode *const inode = rac->mapping->host; 1468 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1469 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1470 struct page *pagepool = NULL, *head = NULL, *page; 1471 unsigned int nr_pages; 1472 1473 f.readahead = true; 1474 f.headoffset = readahead_pos(rac); 1475 1476 z_erofs_pcluster_readmore(&f, rac, f.headoffset + 1477 readahead_length(rac) - 1, &pagepool, true); 1478 nr_pages = readahead_count(rac); 1479 trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); 1480 1481 while ((page = readahead_page(rac))) { 1482 set_page_private(page, (unsigned long)head); 1483 head = page; 1484 } 1485 1486 while (head) { 1487 struct page *page = head; 1488 int err; 1489 1490 /* traversal in reverse order */ 1491 head = (void *)page_private(page); 1492 1493 err = z_erofs_do_read_page(&f, page, &pagepool); 1494 if (err) 1495 erofs_err(inode->i_sb, 1496 "readahead error at page %lu @ nid %llu", 1497 page->index, EROFS_I(inode)->nid); 1498 put_page(page); 1499 } 1500 z_erofs_pcluster_readmore(&f, rac, 0, &pagepool, false); 1501 (void)z_erofs_collector_end(&f.clt); 1502 1503 z_erofs_runqueue(inode->i_sb, &f, &pagepool, 1504 sbi->opt.readahead_sync_decompress && 1505 nr_pages <= sbi->opt.max_sync_decompress_pages); 1506 if (f.map.mpage) 1507 put_page(f.map.mpage); 1508 erofs_release_pages(&pagepool); 1509 } 1510 1511 const struct address_space_operations z_erofs_aops = { 1512 .readpage = z_erofs_readpage, 1513 .readahead = z_erofs_readahead, 1514 }; 1515