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 unsigned int pclusterpages = z_erofs_pclusterpages(pcl); 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 (pclusterpages > pcs->maxpages) 92 continue; 93 94 kmem_cache_free(pcs->slab, pcl); 95 return; 96 } 97 DBG_BUGON(1); 98 } 99 100 /* how to allocate cached pages for a pcluster */ 101 enum z_erofs_cache_alloctype { 102 DONTALLOC, /* don't allocate any cached pages */ 103 /* 104 * try to use cached I/O if page allocation succeeds or fallback 105 * to in-place I/O instead to avoid any direct reclaim. 106 */ 107 TRYALLOC, 108 }; 109 110 /* 111 * tagged pointer with 1-bit tag for all compressed pages 112 * tag 0 - the page is just found with an extra page reference 113 */ 114 typedef tagptr1_t compressed_page_t; 115 116 #define tag_compressed_page_justfound(page) \ 117 tagptr_fold(compressed_page_t, page, 1) 118 119 static struct workqueue_struct *z_erofs_workqueue __read_mostly; 120 121 void z_erofs_exit_zip_subsystem(void) 122 { 123 destroy_workqueue(z_erofs_workqueue); 124 z_erofs_destroy_pcluster_pool(); 125 } 126 127 static inline int z_erofs_init_workqueue(void) 128 { 129 const unsigned int onlinecpus = num_possible_cpus(); 130 131 /* 132 * no need to spawn too many threads, limiting threads could minimum 133 * scheduling overhead, perhaps per-CPU threads should be better? 134 */ 135 z_erofs_workqueue = alloc_workqueue("erofs_unzipd", 136 WQ_UNBOUND | WQ_HIGHPRI, 137 onlinecpus + onlinecpus / 4); 138 return z_erofs_workqueue ? 0 : -ENOMEM; 139 } 140 141 int __init z_erofs_init_zip_subsystem(void) 142 { 143 int err = z_erofs_create_pcluster_pool(); 144 145 if (err) 146 return err; 147 err = z_erofs_init_workqueue(); 148 if (err) 149 z_erofs_destroy_pcluster_pool(); 150 return err; 151 } 152 153 enum z_erofs_collectmode { 154 COLLECT_SECONDARY, 155 COLLECT_PRIMARY, 156 /* 157 * The current collection was the tail of an exist chain, in addition 158 * that the previous processed chained collections are all decided to 159 * be hooked up to it. 160 * A new chain will be created for the remaining collections which are 161 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED, 162 * the next collection cannot reuse the whole page safely in 163 * the following scenario: 164 * ________________________________________________________________ 165 * | tail (partial) page | head (partial) page | 166 * | (belongs to the next cl) | (belongs to the current cl) | 167 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| 168 */ 169 COLLECT_PRIMARY_HOOKED, 170 /* 171 * a weak form of COLLECT_PRIMARY_FOLLOWED, the difference is that it 172 * could be dispatched into bypass queue later due to uptodated managed 173 * pages. All related online pages cannot be reused for inplace I/O (or 174 * pagevec) since it can be directly decoded without I/O submission. 175 */ 176 COLLECT_PRIMARY_FOLLOWED_NOINPLACE, 177 /* 178 * The current collection has been linked with the owned chain, and 179 * could also be linked with the remaining collections, which means 180 * if the processing page is the tail page of the collection, thus 181 * the current collection can safely use the whole page (since 182 * the previous collection is under control) for in-place I/O, as 183 * illustrated below: 184 * ________________________________________________________________ 185 * | tail (partial) page | head (partial) page | 186 * | (of the current cl) | (of the previous collection) | 187 * | PRIMARY_FOLLOWED or | | 188 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| 189 * 190 * [ (*) the above page can be used as inplace I/O. ] 191 */ 192 COLLECT_PRIMARY_FOLLOWED, 193 }; 194 195 struct z_erofs_collector { 196 struct z_erofs_pagevec_ctor vector; 197 198 struct z_erofs_pcluster *pcl, *tailpcl; 199 struct z_erofs_collection *cl; 200 /* a pointer used to pick up inplace I/O pages */ 201 struct page **icpage_ptr; 202 z_erofs_next_pcluster_t owned_head; 203 204 enum z_erofs_collectmode mode; 205 }; 206 207 struct z_erofs_decompress_frontend { 208 struct inode *const inode; 209 210 struct z_erofs_collector clt; 211 struct erofs_map_blocks map; 212 213 bool readahead; 214 /* used for applying cache strategy on the fly */ 215 bool backmost; 216 erofs_off_t headoffset; 217 }; 218 219 #define COLLECTOR_INIT() { \ 220 .owned_head = Z_EROFS_PCLUSTER_TAIL, \ 221 .mode = COLLECT_PRIMARY_FOLLOWED } 222 223 #define DECOMPRESS_FRONTEND_INIT(__i) { \ 224 .inode = __i, .clt = COLLECTOR_INIT(), \ 225 .backmost = true, } 226 227 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES]; 228 static DEFINE_MUTEX(z_pagemap_global_lock); 229 230 static void preload_compressed_pages(struct z_erofs_collector *clt, 231 struct address_space *mc, 232 enum z_erofs_cache_alloctype type, 233 struct page **pagepool) 234 { 235 struct z_erofs_pcluster *pcl = clt->pcl; 236 bool standalone = true; 237 gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | 238 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 239 struct page **pages; 240 pgoff_t index; 241 242 if (clt->mode < COLLECT_PRIMARY_FOLLOWED) 243 return; 244 245 pages = pcl->compressed_pages; 246 index = pcl->obj.index; 247 for (; index < pcl->obj.index + pcl->pclusterpages; ++index, ++pages) { 248 struct page *page; 249 compressed_page_t t; 250 struct page *newpage = NULL; 251 252 /* the compressed page was loaded before */ 253 if (READ_ONCE(*pages)) 254 continue; 255 256 page = find_get_page(mc, index); 257 258 if (page) { 259 t = tag_compressed_page_justfound(page); 260 } else { 261 /* I/O is needed, no possible to decompress directly */ 262 standalone = false; 263 switch (type) { 264 case TRYALLOC: 265 newpage = erofs_allocpage(pagepool, gfp); 266 if (!newpage) 267 continue; 268 set_page_private(newpage, 269 Z_EROFS_PREALLOCATED_PAGE); 270 t = tag_compressed_page_justfound(newpage); 271 break; 272 default: /* DONTALLOC */ 273 continue; 274 } 275 } 276 277 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t))) 278 continue; 279 280 if (page) 281 put_page(page); 282 else if (newpage) 283 erofs_pagepool_add(pagepool, newpage); 284 } 285 286 /* 287 * don't do inplace I/O if all compressed pages are available in 288 * managed cache since it can be moved to the bypass queue instead. 289 */ 290 if (standalone) 291 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE; 292 } 293 294 /* called by erofs_shrinker to get rid of all compressed_pages */ 295 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 296 struct erofs_workgroup *grp) 297 { 298 struct z_erofs_pcluster *const pcl = 299 container_of(grp, struct z_erofs_pcluster, obj); 300 int i; 301 302 DBG_BUGON(z_erofs_is_inline_pcluster(pcl)); 303 /* 304 * refcount of workgroup is now freezed as 1, 305 * therefore no need to worry about available decompression users. 306 */ 307 for (i = 0; i < pcl->pclusterpages; ++i) { 308 struct page *page = pcl->compressed_pages[i]; 309 310 if (!page) 311 continue; 312 313 /* block other users from reclaiming or migrating the page */ 314 if (!trylock_page(page)) 315 return -EBUSY; 316 317 if (!erofs_page_is_managed(sbi, page)) 318 continue; 319 320 /* barrier is implied in the following 'unlock_page' */ 321 WRITE_ONCE(pcl->compressed_pages[i], NULL); 322 detach_page_private(page); 323 unlock_page(page); 324 } 325 return 0; 326 } 327 328 int erofs_try_to_free_cached_page(struct page *page) 329 { 330 struct z_erofs_pcluster *const pcl = (void *)page_private(page); 331 int ret = 0; /* 0 - busy */ 332 333 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) { 334 unsigned int i; 335 336 DBG_BUGON(z_erofs_is_inline_pcluster(pcl)); 337 for (i = 0; i < pcl->pclusterpages; ++i) { 338 if (pcl->compressed_pages[i] == page) { 339 WRITE_ONCE(pcl->compressed_pages[i], NULL); 340 ret = 1; 341 break; 342 } 343 } 344 erofs_workgroup_unfreeze(&pcl->obj, 1); 345 346 if (ret) 347 detach_page_private(page); 348 } 349 return ret; 350 } 351 352 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ 353 static bool z_erofs_try_inplace_io(struct z_erofs_collector *clt, 354 struct page *page) 355 { 356 struct z_erofs_pcluster *const pcl = clt->pcl; 357 358 while (clt->icpage_ptr > pcl->compressed_pages) 359 if (!cmpxchg(--clt->icpage_ptr, NULL, page)) 360 return true; 361 return false; 362 } 363 364 /* callers must be with collection lock held */ 365 static int z_erofs_attach_page(struct z_erofs_collector *clt, 366 struct page *page, enum z_erofs_page_type type, 367 bool pvec_safereuse) 368 { 369 int ret; 370 371 /* give priority for inplaceio */ 372 if (clt->mode >= COLLECT_PRIMARY && 373 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && 374 z_erofs_try_inplace_io(clt, page)) 375 return 0; 376 377 ret = z_erofs_pagevec_enqueue(&clt->vector, page, type, 378 pvec_safereuse); 379 clt->cl->vcnt += (unsigned int)ret; 380 return ret ? 0 : -EAGAIN; 381 } 382 383 static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt) 384 { 385 struct z_erofs_pcluster *pcl = clt->pcl; 386 z_erofs_next_pcluster_t *owned_head = &clt->owned_head; 387 388 /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */ 389 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, 390 *owned_head) == Z_EROFS_PCLUSTER_NIL) { 391 *owned_head = &pcl->next; 392 /* so we can attach this pcluster to our submission chain. */ 393 clt->mode = COLLECT_PRIMARY_FOLLOWED; 394 return; 395 } 396 397 /* 398 * type 2, link to the end of an existing open chain, be careful 399 * that its submission is controlled by the original attached chain. 400 */ 401 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 402 *owned_head) == Z_EROFS_PCLUSTER_TAIL) { 403 *owned_head = Z_EROFS_PCLUSTER_TAIL; 404 clt->mode = COLLECT_PRIMARY_HOOKED; 405 clt->tailpcl = NULL; 406 return; 407 } 408 /* type 3, it belongs to a chain, but it isn't the end of the chain */ 409 clt->mode = COLLECT_PRIMARY; 410 } 411 412 static int z_erofs_lookup_collection(struct z_erofs_collector *clt, 413 struct inode *inode, 414 struct erofs_map_blocks *map) 415 { 416 struct z_erofs_pcluster *pcl = clt->pcl; 417 struct z_erofs_collection *cl; 418 unsigned int length; 419 420 /* to avoid unexpected loop formed by corrupted images */ 421 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) { 422 DBG_BUGON(1); 423 return -EFSCORRUPTED; 424 } 425 426 cl = z_erofs_primarycollection(pcl); 427 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) { 428 DBG_BUGON(1); 429 return -EFSCORRUPTED; 430 } 431 432 length = READ_ONCE(pcl->length); 433 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) { 434 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) { 435 DBG_BUGON(1); 436 return -EFSCORRUPTED; 437 } 438 } else { 439 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT; 440 441 if (map->m_flags & EROFS_MAP_FULL_MAPPED) 442 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH; 443 444 while (llen > length && 445 length != cmpxchg_relaxed(&pcl->length, length, llen)) { 446 cpu_relax(); 447 length = READ_ONCE(pcl->length); 448 } 449 } 450 mutex_lock(&cl->lock); 451 /* used to check tail merging loop due to corrupted images */ 452 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 453 clt->tailpcl = pcl; 454 455 z_erofs_try_to_claim_pcluster(clt); 456 clt->cl = cl; 457 return 0; 458 } 459 460 static int z_erofs_register_collection(struct z_erofs_collector *clt, 461 struct inode *inode, 462 struct erofs_map_blocks *map) 463 { 464 bool ztailpacking = map->m_flags & EROFS_MAP_META; 465 struct z_erofs_pcluster *pcl; 466 struct z_erofs_collection *cl; 467 struct erofs_workgroup *grp; 468 int err; 469 470 if (!(map->m_flags & EROFS_MAP_ENCODED)) { 471 DBG_BUGON(1); 472 return -EFSCORRUPTED; 473 } 474 475 /* no available pcluster, let's allocate one */ 476 pcl = z_erofs_alloc_pcluster(ztailpacking ? 1 : 477 map->m_plen >> PAGE_SHIFT); 478 if (IS_ERR(pcl)) 479 return PTR_ERR(pcl); 480 481 atomic_set(&pcl->obj.refcount, 1); 482 pcl->algorithmformat = map->m_algorithmformat; 483 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) | 484 (map->m_flags & EROFS_MAP_FULL_MAPPED ? 485 Z_EROFS_PCLUSTER_FULL_LENGTH : 0); 486 487 /* new pclusters should be claimed as type 1, primary and followed */ 488 pcl->next = clt->owned_head; 489 clt->mode = COLLECT_PRIMARY_FOLLOWED; 490 491 cl = z_erofs_primarycollection(pcl); 492 cl->pageofs = map->m_la & ~PAGE_MASK; 493 494 /* 495 * lock all primary followed works before visible to others 496 * and mutex_trylock *never* fails for a new pcluster. 497 */ 498 mutex_init(&cl->lock); 499 DBG_BUGON(!mutex_trylock(&cl->lock)); 500 501 if (ztailpacking) { 502 pcl->obj.index = 0; /* which indicates ztailpacking */ 503 pcl->pageofs_in = erofs_blkoff(map->m_pa); 504 pcl->tailpacking_size = map->m_plen; 505 } else { 506 pcl->obj.index = map->m_pa >> PAGE_SHIFT; 507 508 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj); 509 if (IS_ERR(grp)) { 510 err = PTR_ERR(grp); 511 goto err_out; 512 } 513 514 if (grp != &pcl->obj) { 515 clt->pcl = container_of(grp, 516 struct z_erofs_pcluster, obj); 517 err = -EEXIST; 518 goto err_out; 519 } 520 } 521 /* used to check tail merging loop due to corrupted images */ 522 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) 523 clt->tailpcl = pcl; 524 clt->owned_head = &pcl->next; 525 clt->pcl = pcl; 526 clt->cl = cl; 527 return 0; 528 529 err_out: 530 mutex_unlock(&cl->lock); 531 z_erofs_free_pcluster(pcl); 532 return err; 533 } 534 535 static int z_erofs_collector_begin(struct z_erofs_collector *clt, 536 struct inode *inode, 537 struct erofs_map_blocks *map) 538 { 539 struct erofs_workgroup *grp; 540 int ret; 541 542 DBG_BUGON(clt->cl); 543 544 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */ 545 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL); 546 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 547 548 if (map->m_flags & EROFS_MAP_META) { 549 if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) { 550 DBG_BUGON(1); 551 return -EFSCORRUPTED; 552 } 553 goto tailpacking; 554 } 555 556 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT); 557 if (grp) { 558 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); 559 } else { 560 tailpacking: 561 ret = z_erofs_register_collection(clt, inode, map); 562 if (!ret) 563 goto out; 564 if (ret != -EEXIST) 565 return ret; 566 } 567 568 ret = z_erofs_lookup_collection(clt, inode, map); 569 if (ret) { 570 erofs_workgroup_put(&clt->pcl->obj); 571 return ret; 572 } 573 574 out: 575 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS, 576 clt->cl->pagevec, clt->cl->vcnt); 577 /* since file-backed online pages are traversed in reverse order */ 578 clt->icpage_ptr = clt->pcl->compressed_pages + 579 z_erofs_pclusterpages(clt->pcl); 580 return 0; 581 } 582 583 /* 584 * keep in mind that no referenced pclusters will be freed 585 * only after a RCU grace period. 586 */ 587 static void z_erofs_rcu_callback(struct rcu_head *head) 588 { 589 struct z_erofs_collection *const cl = 590 container_of(head, struct z_erofs_collection, rcu); 591 592 z_erofs_free_pcluster(container_of(cl, struct z_erofs_pcluster, 593 primary_collection)); 594 } 595 596 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) 597 { 598 struct z_erofs_pcluster *const pcl = 599 container_of(grp, struct z_erofs_pcluster, obj); 600 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl); 601 602 call_rcu(&cl->rcu, z_erofs_rcu_callback); 603 } 604 605 static void z_erofs_collection_put(struct z_erofs_collection *cl) 606 { 607 struct z_erofs_pcluster *const pcl = 608 container_of(cl, struct z_erofs_pcluster, primary_collection); 609 610 erofs_workgroup_put(&pcl->obj); 611 } 612 613 static bool z_erofs_collector_end(struct z_erofs_collector *clt) 614 { 615 struct z_erofs_collection *cl = clt->cl; 616 617 if (!cl) 618 return false; 619 620 z_erofs_pagevec_ctor_exit(&clt->vector, false); 621 mutex_unlock(&cl->lock); 622 623 /* 624 * if all pending pages are added, don't hold its reference 625 * any longer if the pcluster isn't hosted by ourselves. 626 */ 627 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE) 628 z_erofs_collection_put(cl); 629 630 clt->cl = NULL; 631 return true; 632 } 633 634 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe, 635 unsigned int cachestrategy, 636 erofs_off_t la) 637 { 638 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) 639 return false; 640 641 if (fe->backmost) 642 return true; 643 644 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND && 645 la < fe->headoffset; 646 } 647 648 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 649 struct page *page, struct page **pagepool) 650 { 651 struct inode *const inode = fe->inode; 652 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 653 struct erofs_map_blocks *const map = &fe->map; 654 struct z_erofs_collector *const clt = &fe->clt; 655 const loff_t offset = page_offset(page); 656 bool tight = true; 657 658 enum z_erofs_cache_alloctype cache_strategy; 659 enum z_erofs_page_type page_type; 660 unsigned int cur, end, spiltted, index; 661 int err = 0; 662 663 /* register locked file pages as online pages in pack */ 664 z_erofs_onlinepage_init(page); 665 666 spiltted = 0; 667 end = PAGE_SIZE; 668 repeat: 669 cur = end - 1; 670 671 /* lucky, within the range of the current map_blocks */ 672 if (offset + cur >= map->m_la && 673 offset + cur < map->m_la + map->m_llen) { 674 /* didn't get a valid collection previously (very rare) */ 675 if (!clt->cl) 676 goto restart_now; 677 goto hitted; 678 } 679 680 /* go ahead the next map_blocks */ 681 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur); 682 683 if (z_erofs_collector_end(clt)) 684 fe->backmost = false; 685 686 map->m_la = offset + cur; 687 map->m_llen = 0; 688 err = z_erofs_map_blocks_iter(inode, map, 0); 689 if (err) 690 goto err_out; 691 692 restart_now: 693 if (!(map->m_flags & EROFS_MAP_MAPPED)) 694 goto hitted; 695 696 err = z_erofs_collector_begin(clt, inode, map); 697 if (err) 698 goto err_out; 699 700 if (z_erofs_is_inline_pcluster(clt->pcl)) { 701 void *mp; 702 703 mp = erofs_read_metabuf(&fe->map.buf, inode->i_sb, 704 erofs_blknr(map->m_pa), EROFS_NO_KMAP); 705 if (IS_ERR(mp)) { 706 err = PTR_ERR(mp); 707 erofs_err(inode->i_sb, 708 "failed to get inline page, err %d", err); 709 goto err_out; 710 } 711 get_page(fe->map.buf.page); 712 WRITE_ONCE(clt->pcl->compressed_pages[0], fe->map.buf.page); 713 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE; 714 } else { 715 /* preload all compressed pages (can change mode if needed) */ 716 if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy, 717 map->m_la)) 718 cache_strategy = TRYALLOC; 719 else 720 cache_strategy = DONTALLOC; 721 722 preload_compressed_pages(clt, MNGD_MAPPING(sbi), 723 cache_strategy, pagepool); 724 } 725 726 hitted: 727 /* 728 * Ensure the current partial page belongs to this submit chain rather 729 * than other concurrent submit chains or the noio(bypass) chain since 730 * those chains are handled asynchronously thus the page cannot be used 731 * for inplace I/O or pagevec (should be processed in strict order.) 732 */ 733 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED && 734 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE); 735 736 cur = end - min_t(unsigned int, offset + end - map->m_la, end); 737 if (!(map->m_flags & EROFS_MAP_MAPPED)) { 738 zero_user_segment(page, cur, end); 739 goto next_part; 740 } 741 742 /* let's derive page type */ 743 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD : 744 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 745 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : 746 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); 747 748 if (cur) 749 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED); 750 751 retry: 752 err = z_erofs_attach_page(clt, page, page_type, 753 clt->mode >= COLLECT_PRIMARY_FOLLOWED); 754 /* should allocate an additional short-lived page for pagevec */ 755 if (err == -EAGAIN) { 756 struct page *const newpage = 757 alloc_page(GFP_NOFS | __GFP_NOFAIL); 758 759 set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); 760 err = z_erofs_attach_page(clt, newpage, 761 Z_EROFS_PAGE_TYPE_EXCLUSIVE, true); 762 if (!err) 763 goto retry; 764 } 765 766 if (err) 767 goto err_out; 768 769 index = page->index - (map->m_la >> PAGE_SHIFT); 770 771 z_erofs_onlinepage_fixup(page, index, true); 772 773 /* bump up the number of spiltted parts of a page */ 774 ++spiltted; 775 /* also update nr_pages */ 776 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1); 777 next_part: 778 /* can be used for verification */ 779 map->m_llen = offset + cur - map->m_la; 780 781 end = cur; 782 if (end > 0) 783 goto repeat; 784 785 out: 786 z_erofs_onlinepage_endio(page); 787 788 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu", 789 __func__, page, spiltted, map->m_llen); 790 return err; 791 792 /* if some error occurred while processing this page */ 793 err_out: 794 SetPageError(page); 795 goto out; 796 } 797 798 static bool z_erofs_get_sync_decompress_policy(struct erofs_sb_info *sbi, 799 unsigned int readahead_pages) 800 { 801 /* auto: enable for readpage, disable for readahead */ 802 if ((sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) && 803 !readahead_pages) 804 return true; 805 806 if ((sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_FORCE_ON) && 807 (readahead_pages <= sbi->opt.max_sync_decompress_pages)) 808 return true; 809 810 return false; 811 } 812 813 static bool z_erofs_page_is_invalidated(struct page *page) 814 { 815 return !page->mapping && !z_erofs_is_shortlived_page(page); 816 } 817 818 static int z_erofs_decompress_pcluster(struct super_block *sb, 819 struct z_erofs_pcluster *pcl, 820 struct page **pagepool) 821 { 822 struct erofs_sb_info *const sbi = EROFS_SB(sb); 823 unsigned int pclusterpages = z_erofs_pclusterpages(pcl); 824 struct z_erofs_pagevec_ctor ctor; 825 unsigned int i, inputsize, outputsize, llen, nr_pages; 826 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES]; 827 struct page **pages, **compressed_pages, *page; 828 829 enum z_erofs_page_type page_type; 830 bool overlapped, partial; 831 struct z_erofs_collection *cl; 832 int err; 833 834 might_sleep(); 835 cl = z_erofs_primarycollection(pcl); 836 DBG_BUGON(!READ_ONCE(cl->nr_pages)); 837 838 mutex_lock(&cl->lock); 839 nr_pages = cl->nr_pages; 840 841 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) { 842 pages = pages_onstack; 843 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES && 844 mutex_trylock(&z_pagemap_global_lock)) { 845 pages = z_pagemap_global; 846 } else { 847 gfp_t gfp_flags = GFP_KERNEL; 848 849 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES) 850 gfp_flags |= __GFP_NOFAIL; 851 852 pages = kvmalloc_array(nr_pages, sizeof(struct page *), 853 gfp_flags); 854 855 /* fallback to global pagemap for the lowmem scenario */ 856 if (!pages) { 857 mutex_lock(&z_pagemap_global_lock); 858 pages = z_pagemap_global; 859 } 860 } 861 862 for (i = 0; i < nr_pages; ++i) 863 pages[i] = NULL; 864 865 err = 0; 866 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, 867 cl->pagevec, 0); 868 869 for (i = 0; i < cl->vcnt; ++i) { 870 unsigned int pagenr; 871 872 page = z_erofs_pagevec_dequeue(&ctor, &page_type); 873 874 /* all pages in pagevec ought to be valid */ 875 DBG_BUGON(!page); 876 DBG_BUGON(z_erofs_page_is_invalidated(page)); 877 878 if (z_erofs_put_shortlivedpage(pagepool, page)) 879 continue; 880 881 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD) 882 pagenr = 0; 883 else 884 pagenr = z_erofs_onlinepage_index(page); 885 886 DBG_BUGON(pagenr >= nr_pages); 887 888 /* 889 * currently EROFS doesn't support multiref(dedup), 890 * so here erroring out one multiref page. 891 */ 892 if (pages[pagenr]) { 893 DBG_BUGON(1); 894 SetPageError(pages[pagenr]); 895 z_erofs_onlinepage_endio(pages[pagenr]); 896 err = -EFSCORRUPTED; 897 } 898 pages[pagenr] = page; 899 } 900 z_erofs_pagevec_ctor_exit(&ctor, true); 901 902 overlapped = false; 903 compressed_pages = pcl->compressed_pages; 904 905 for (i = 0; i < pclusterpages; ++i) { 906 unsigned int pagenr; 907 908 page = compressed_pages[i]; 909 /* all compressed pages ought to be valid */ 910 DBG_BUGON(!page); 911 912 if (z_erofs_is_inline_pcluster(pcl)) { 913 if (!PageUptodate(page)) 914 err = -EIO; 915 continue; 916 } 917 918 DBG_BUGON(z_erofs_page_is_invalidated(page)); 919 if (!z_erofs_is_shortlived_page(page)) { 920 if (erofs_page_is_managed(sbi, page)) { 921 if (!PageUptodate(page)) 922 err = -EIO; 923 continue; 924 } 925 926 /* 927 * only if non-head page can be selected 928 * for inplace decompression 929 */ 930 pagenr = z_erofs_onlinepage_index(page); 931 932 DBG_BUGON(pagenr >= nr_pages); 933 if (pages[pagenr]) { 934 DBG_BUGON(1); 935 SetPageError(pages[pagenr]); 936 z_erofs_onlinepage_endio(pages[pagenr]); 937 err = -EFSCORRUPTED; 938 } 939 pages[pagenr] = page; 940 941 overlapped = true; 942 } 943 944 /* PG_error needs checking for all non-managed pages */ 945 if (PageError(page)) { 946 DBG_BUGON(PageUptodate(page)); 947 err = -EIO; 948 } 949 } 950 951 if (err) 952 goto out; 953 954 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT; 955 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) { 956 outputsize = llen; 957 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH); 958 } else { 959 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs; 960 partial = true; 961 } 962 963 if (z_erofs_is_inline_pcluster(pcl)) 964 inputsize = pcl->tailpacking_size; 965 else 966 inputsize = pclusterpages * PAGE_SIZE; 967 968 err = z_erofs_decompress(&(struct z_erofs_decompress_req) { 969 .sb = sb, 970 .in = compressed_pages, 971 .out = pages, 972 .pageofs_in = pcl->pageofs_in, 973 .pageofs_out = cl->pageofs, 974 .inputsize = inputsize, 975 .outputsize = outputsize, 976 .alg = pcl->algorithmformat, 977 .inplace_io = overlapped, 978 .partial_decoding = partial 979 }, pagepool); 980 981 out: 982 /* must handle all compressed pages before actual file pages */ 983 if (z_erofs_is_inline_pcluster(pcl)) { 984 page = compressed_pages[0]; 985 WRITE_ONCE(compressed_pages[0], NULL); 986 put_page(page); 987 } else { 988 for (i = 0; i < pclusterpages; ++i) { 989 page = compressed_pages[i]; 990 991 if (erofs_page_is_managed(sbi, page)) 992 continue; 993 994 /* recycle all individual short-lived pages */ 995 (void)z_erofs_put_shortlivedpage(pagepool, page); 996 WRITE_ONCE(compressed_pages[i], NULL); 997 } 998 } 999 1000 for (i = 0; i < nr_pages; ++i) { 1001 page = pages[i]; 1002 if (!page) 1003 continue; 1004 1005 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1006 1007 /* recycle all individual short-lived pages */ 1008 if (z_erofs_put_shortlivedpage(pagepool, page)) 1009 continue; 1010 1011 if (err < 0) 1012 SetPageError(page); 1013 1014 z_erofs_onlinepage_endio(page); 1015 } 1016 1017 if (pages == z_pagemap_global) 1018 mutex_unlock(&z_pagemap_global_lock); 1019 else if (pages != pages_onstack) 1020 kvfree(pages); 1021 1022 cl->nr_pages = 0; 1023 cl->vcnt = 0; 1024 1025 /* all cl locks MUST be taken before the following line */ 1026 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); 1027 1028 /* all cl locks SHOULD be released right now */ 1029 mutex_unlock(&cl->lock); 1030 1031 z_erofs_collection_put(cl); 1032 return err; 1033 } 1034 1035 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, 1036 struct page **pagepool) 1037 { 1038 z_erofs_next_pcluster_t owned = io->head; 1039 1040 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { 1041 struct z_erofs_pcluster *pcl; 1042 1043 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ 1044 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); 1045 1046 /* no possible that 'owned' equals NULL */ 1047 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); 1048 1049 pcl = container_of(owned, struct z_erofs_pcluster, next); 1050 owned = READ_ONCE(pcl->next); 1051 1052 z_erofs_decompress_pcluster(io->sb, pcl, pagepool); 1053 } 1054 } 1055 1056 static void z_erofs_decompressqueue_work(struct work_struct *work) 1057 { 1058 struct z_erofs_decompressqueue *bgq = 1059 container_of(work, struct z_erofs_decompressqueue, u.work); 1060 struct page *pagepool = NULL; 1061 1062 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1063 z_erofs_decompress_queue(bgq, &pagepool); 1064 1065 erofs_release_pages(&pagepool); 1066 kvfree(bgq); 1067 } 1068 1069 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, 1070 bool sync, int bios) 1071 { 1072 struct erofs_sb_info *const sbi = EROFS_SB(io->sb); 1073 1074 /* wake up the caller thread for sync decompression */ 1075 if (sync) { 1076 unsigned long flags; 1077 1078 spin_lock_irqsave(&io->u.wait.lock, flags); 1079 if (!atomic_add_return(bios, &io->pending_bios)) 1080 wake_up_locked(&io->u.wait); 1081 spin_unlock_irqrestore(&io->u.wait.lock, flags); 1082 return; 1083 } 1084 1085 if (atomic_add_return(bios, &io->pending_bios)) 1086 return; 1087 /* Use workqueue and sync decompression for atomic contexts only */ 1088 if (in_atomic() || irqs_disabled()) { 1089 queue_work(z_erofs_workqueue, &io->u.work); 1090 /* enable sync decompression for readahead */ 1091 if (sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) 1092 sbi->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_FORCE_ON; 1093 return; 1094 } 1095 z_erofs_decompressqueue_work(&io->u.work); 1096 } 1097 1098 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, 1099 unsigned int nr, 1100 struct page **pagepool, 1101 struct address_space *mc, 1102 gfp_t gfp) 1103 { 1104 const pgoff_t index = pcl->obj.index; 1105 bool tocache = false; 1106 1107 struct address_space *mapping; 1108 struct page *oldpage, *page; 1109 1110 compressed_page_t t; 1111 int justfound; 1112 1113 repeat: 1114 page = READ_ONCE(pcl->compressed_pages[nr]); 1115 oldpage = page; 1116 1117 if (!page) 1118 goto out_allocpage; 1119 1120 /* process the target tagged pointer */ 1121 t = tagptr_init(compressed_page_t, page); 1122 justfound = tagptr_unfold_tags(t); 1123 page = tagptr_unfold_ptr(t); 1124 1125 /* 1126 * preallocated cached pages, which is used to avoid direct reclaim 1127 * otherwise, it will go inplace I/O path instead. 1128 */ 1129 if (page->private == Z_EROFS_PREALLOCATED_PAGE) { 1130 WRITE_ONCE(pcl->compressed_pages[nr], page); 1131 set_page_private(page, 0); 1132 tocache = true; 1133 goto out_tocache; 1134 } 1135 mapping = READ_ONCE(page->mapping); 1136 1137 /* 1138 * file-backed online pages in plcuster are all locked steady, 1139 * therefore it is impossible for `mapping' to be NULL. 1140 */ 1141 if (mapping && mapping != mc) 1142 /* ought to be unmanaged pages */ 1143 goto out; 1144 1145 /* directly return for shortlived page as well */ 1146 if (z_erofs_is_shortlived_page(page)) 1147 goto out; 1148 1149 lock_page(page); 1150 1151 /* only true if page reclaim goes wrong, should never happen */ 1152 DBG_BUGON(justfound && PagePrivate(page)); 1153 1154 /* the page is still in manage cache */ 1155 if (page->mapping == mc) { 1156 WRITE_ONCE(pcl->compressed_pages[nr], page); 1157 1158 ClearPageError(page); 1159 if (!PagePrivate(page)) { 1160 /* 1161 * impossible to be !PagePrivate(page) for 1162 * the current restriction as well if 1163 * the page is already in compressed_pages[]. 1164 */ 1165 DBG_BUGON(!justfound); 1166 1167 justfound = 0; 1168 set_page_private(page, (unsigned long)pcl); 1169 SetPagePrivate(page); 1170 } 1171 1172 /* no need to submit io if it is already up-to-date */ 1173 if (PageUptodate(page)) { 1174 unlock_page(page); 1175 page = NULL; 1176 } 1177 goto out; 1178 } 1179 1180 /* 1181 * the managed page has been truncated, it's unsafe to 1182 * reuse this one, let's allocate a new cache-managed page. 1183 */ 1184 DBG_BUGON(page->mapping); 1185 DBG_BUGON(!justfound); 1186 1187 tocache = true; 1188 unlock_page(page); 1189 put_page(page); 1190 out_allocpage: 1191 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); 1192 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) { 1193 erofs_pagepool_add(pagepool, page); 1194 cond_resched(); 1195 goto repeat; 1196 } 1197 out_tocache: 1198 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { 1199 /* turn into temporary page if fails (1 ref) */ 1200 set_page_private(page, Z_EROFS_SHORTLIVED_PAGE); 1201 goto out; 1202 } 1203 attach_page_private(page, pcl); 1204 /* drop a refcount added by allocpage (then we have 2 refs here) */ 1205 put_page(page); 1206 1207 out: /* the only exit (for tracing and debugging) */ 1208 return page; 1209 } 1210 1211 static struct z_erofs_decompressqueue * 1212 jobqueue_init(struct super_block *sb, 1213 struct z_erofs_decompressqueue *fgq, bool *fg) 1214 { 1215 struct z_erofs_decompressqueue *q; 1216 1217 if (fg && !*fg) { 1218 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); 1219 if (!q) { 1220 *fg = true; 1221 goto fg_out; 1222 } 1223 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); 1224 } else { 1225 fg_out: 1226 q = fgq; 1227 init_waitqueue_head(&fgq->u.wait); 1228 atomic_set(&fgq->pending_bios, 0); 1229 } 1230 q->sb = sb; 1231 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1232 return q; 1233 } 1234 1235 /* define decompression jobqueue types */ 1236 enum { 1237 JQ_BYPASS, 1238 JQ_SUBMIT, 1239 NR_JOBQUEUES, 1240 }; 1241 1242 static void *jobqueueset_init(struct super_block *sb, 1243 struct z_erofs_decompressqueue *q[], 1244 struct z_erofs_decompressqueue *fgq, bool *fg) 1245 { 1246 /* 1247 * if managed cache is enabled, bypass jobqueue is needed, 1248 * no need to read from device for all pclusters in this queue. 1249 */ 1250 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); 1251 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg); 1252 1253 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg)); 1254 } 1255 1256 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, 1257 z_erofs_next_pcluster_t qtail[], 1258 z_erofs_next_pcluster_t owned_head) 1259 { 1260 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; 1261 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; 1262 1263 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1264 if (owned_head == Z_EROFS_PCLUSTER_TAIL) 1265 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; 1266 1267 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); 1268 1269 WRITE_ONCE(*submit_qtail, owned_head); 1270 WRITE_ONCE(*bypass_qtail, &pcl->next); 1271 1272 qtail[JQ_BYPASS] = &pcl->next; 1273 } 1274 1275 static void z_erofs_decompressqueue_endio(struct bio *bio) 1276 { 1277 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private); 1278 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t); 1279 blk_status_t err = bio->bi_status; 1280 struct bio_vec *bvec; 1281 struct bvec_iter_all iter_all; 1282 1283 bio_for_each_segment_all(bvec, bio, iter_all) { 1284 struct page *page = bvec->bv_page; 1285 1286 DBG_BUGON(PageUptodate(page)); 1287 DBG_BUGON(z_erofs_page_is_invalidated(page)); 1288 1289 if (err) 1290 SetPageError(page); 1291 1292 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { 1293 if (!err) 1294 SetPageUptodate(page); 1295 unlock_page(page); 1296 } 1297 } 1298 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); 1299 bio_put(bio); 1300 } 1301 1302 static void z_erofs_submit_queue(struct super_block *sb, 1303 struct z_erofs_decompress_frontend *f, 1304 struct page **pagepool, 1305 struct z_erofs_decompressqueue *fgq, 1306 bool *force_fg) 1307 { 1308 struct erofs_sb_info *const sbi = EROFS_SB(sb); 1309 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; 1310 struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; 1311 void *bi_private; 1312 z_erofs_next_pcluster_t owned_head = f->clt.owned_head; 1313 /* bio is NULL initially, so no need to initialize last_{index,bdev} */ 1314 pgoff_t last_index; 1315 struct block_device *last_bdev; 1316 unsigned int nr_bios = 0; 1317 struct bio *bio = NULL; 1318 1319 bi_private = jobqueueset_init(sb, q, fgq, force_fg); 1320 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; 1321 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; 1322 1323 /* by default, all need io submission */ 1324 q[JQ_SUBMIT]->head = owned_head; 1325 1326 do { 1327 struct erofs_map_dev mdev; 1328 struct z_erofs_pcluster *pcl; 1329 pgoff_t cur, end; 1330 unsigned int i = 0; 1331 bool bypass = true; 1332 1333 /* no possible 'owned_head' equals the following */ 1334 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); 1335 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); 1336 1337 pcl = container_of(owned_head, struct z_erofs_pcluster, next); 1338 1339 /* close the main owned chain at first */ 1340 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, 1341 Z_EROFS_PCLUSTER_TAIL_CLOSED); 1342 if (z_erofs_is_inline_pcluster(pcl)) { 1343 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1344 continue; 1345 } 1346 1347 /* no device id here, thus it will always succeed */ 1348 mdev = (struct erofs_map_dev) { 1349 .m_pa = blknr_to_addr(pcl->obj.index), 1350 }; 1351 (void)erofs_map_dev(sb, &mdev); 1352 1353 cur = erofs_blknr(mdev.m_pa); 1354 end = cur + pcl->pclusterpages; 1355 1356 do { 1357 struct page *page; 1358 1359 page = pickup_page_for_submission(pcl, i++, pagepool, 1360 MNGD_MAPPING(sbi), 1361 GFP_NOFS); 1362 if (!page) 1363 continue; 1364 1365 if (bio && (cur != last_index + 1 || 1366 last_bdev != mdev.m_bdev)) { 1367 submit_bio_retry: 1368 submit_bio(bio); 1369 bio = NULL; 1370 } 1371 1372 if (!bio) { 1373 bio = bio_alloc(GFP_NOIO, BIO_MAX_VECS); 1374 bio->bi_end_io = z_erofs_decompressqueue_endio; 1375 1376 bio_set_dev(bio, mdev.m_bdev); 1377 last_bdev = mdev.m_bdev; 1378 bio->bi_iter.bi_sector = (sector_t)cur << 1379 LOG_SECTORS_PER_BLOCK; 1380 bio->bi_private = bi_private; 1381 bio->bi_opf = REQ_OP_READ; 1382 if (f->readahead) 1383 bio->bi_opf |= REQ_RAHEAD; 1384 ++nr_bios; 1385 } 1386 1387 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) 1388 goto submit_bio_retry; 1389 1390 last_index = cur; 1391 bypass = false; 1392 } while (++cur < end); 1393 1394 if (!bypass) 1395 qtail[JQ_SUBMIT] = &pcl->next; 1396 else 1397 move_to_bypass_jobqueue(pcl, qtail, owned_head); 1398 } while (owned_head != Z_EROFS_PCLUSTER_TAIL); 1399 1400 if (bio) 1401 submit_bio(bio); 1402 1403 /* 1404 * although background is preferred, no one is pending for submission. 1405 * don't issue workqueue for decompression but drop it directly instead. 1406 */ 1407 if (!*force_fg && !nr_bios) { 1408 kvfree(q[JQ_SUBMIT]); 1409 return; 1410 } 1411 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios); 1412 } 1413 1414 static void z_erofs_runqueue(struct super_block *sb, 1415 struct z_erofs_decompress_frontend *f, 1416 struct page **pagepool, bool force_fg) 1417 { 1418 struct z_erofs_decompressqueue io[NR_JOBQUEUES]; 1419 1420 if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL) 1421 return; 1422 z_erofs_submit_queue(sb, f, pagepool, io, &force_fg); 1423 1424 /* handle bypass queue (no i/o pclusters) immediately */ 1425 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); 1426 1427 if (!force_fg) 1428 return; 1429 1430 /* wait until all bios are completed */ 1431 io_wait_event(io[JQ_SUBMIT].u.wait, 1432 !atomic_read(&io[JQ_SUBMIT].pending_bios)); 1433 1434 /* handle synchronous decompress queue in the caller context */ 1435 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); 1436 } 1437 1438 /* 1439 * Since partial uptodate is still unimplemented for now, we have to use 1440 * approximate readmore strategies as a start. 1441 */ 1442 static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f, 1443 struct readahead_control *rac, 1444 erofs_off_t end, 1445 struct page **pagepool, 1446 bool backmost) 1447 { 1448 struct inode *inode = f->inode; 1449 struct erofs_map_blocks *map = &f->map; 1450 erofs_off_t cur; 1451 int err; 1452 1453 if (backmost) { 1454 map->m_la = end; 1455 err = z_erofs_map_blocks_iter(inode, map, 1456 EROFS_GET_BLOCKS_READMORE); 1457 if (err) 1458 return; 1459 1460 /* expend ra for the trailing edge if readahead */ 1461 if (rac) { 1462 loff_t newstart = readahead_pos(rac); 1463 1464 cur = round_up(map->m_la + map->m_llen, PAGE_SIZE); 1465 readahead_expand(rac, newstart, cur - newstart); 1466 return; 1467 } 1468 end = round_up(end, PAGE_SIZE); 1469 } else { 1470 end = round_up(map->m_la, PAGE_SIZE); 1471 1472 if (!map->m_llen) 1473 return; 1474 } 1475 1476 cur = map->m_la + map->m_llen - 1; 1477 while (cur >= end) { 1478 pgoff_t index = cur >> PAGE_SHIFT; 1479 struct page *page; 1480 1481 page = erofs_grab_cache_page_nowait(inode->i_mapping, index); 1482 if (!page) 1483 goto skip; 1484 1485 if (PageUptodate(page)) { 1486 unlock_page(page); 1487 put_page(page); 1488 goto skip; 1489 } 1490 1491 err = z_erofs_do_read_page(f, page, pagepool); 1492 if (err) 1493 erofs_err(inode->i_sb, 1494 "readmore error at page %lu @ nid %llu", 1495 index, EROFS_I(inode)->nid); 1496 put_page(page); 1497 skip: 1498 if (cur < PAGE_SIZE) 1499 break; 1500 cur = (index << PAGE_SHIFT) - 1; 1501 } 1502 } 1503 1504 static int z_erofs_readpage(struct file *file, struct page *page) 1505 { 1506 struct inode *const inode = page->mapping->host; 1507 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1508 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1509 struct page *pagepool = NULL; 1510 int err; 1511 1512 trace_erofs_readpage(page, false); 1513 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 1514 1515 z_erofs_pcluster_readmore(&f, NULL, f.headoffset + PAGE_SIZE - 1, 1516 &pagepool, true); 1517 err = z_erofs_do_read_page(&f, page, &pagepool); 1518 z_erofs_pcluster_readmore(&f, NULL, 0, &pagepool, false); 1519 1520 (void)z_erofs_collector_end(&f.clt); 1521 1522 /* if some compressed cluster ready, need submit them anyway */ 1523 z_erofs_runqueue(inode->i_sb, &f, &pagepool, 1524 z_erofs_get_sync_decompress_policy(sbi, 0)); 1525 1526 if (err) 1527 erofs_err(inode->i_sb, "failed to read, err [%d]", err); 1528 1529 erofs_put_metabuf(&f.map.buf); 1530 erofs_release_pages(&pagepool); 1531 return err; 1532 } 1533 1534 static void z_erofs_readahead(struct readahead_control *rac) 1535 { 1536 struct inode *const inode = rac->mapping->host; 1537 struct erofs_sb_info *const sbi = EROFS_I_SB(inode); 1538 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); 1539 struct page *pagepool = NULL, *head = NULL, *page; 1540 unsigned int nr_pages; 1541 1542 f.readahead = true; 1543 f.headoffset = readahead_pos(rac); 1544 1545 z_erofs_pcluster_readmore(&f, rac, f.headoffset + 1546 readahead_length(rac) - 1, &pagepool, true); 1547 nr_pages = readahead_count(rac); 1548 trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); 1549 1550 while ((page = readahead_page(rac))) { 1551 set_page_private(page, (unsigned long)head); 1552 head = page; 1553 } 1554 1555 while (head) { 1556 struct page *page = head; 1557 int err; 1558 1559 /* traversal in reverse order */ 1560 head = (void *)page_private(page); 1561 1562 err = z_erofs_do_read_page(&f, page, &pagepool); 1563 if (err) 1564 erofs_err(inode->i_sb, 1565 "readahead error at page %lu @ nid %llu", 1566 page->index, EROFS_I(inode)->nid); 1567 put_page(page); 1568 } 1569 z_erofs_pcluster_readmore(&f, rac, 0, &pagepool, false); 1570 (void)z_erofs_collector_end(&f.clt); 1571 1572 z_erofs_runqueue(inode->i_sb, &f, &pagepool, 1573 z_erofs_get_sync_decompress_policy(sbi, nr_pages)); 1574 erofs_put_metabuf(&f.map.buf); 1575 erofs_release_pages(&pagepool); 1576 } 1577 1578 const struct address_space_operations z_erofs_aops = { 1579 .readpage = z_erofs_readpage, 1580 .readahead = z_erofs_readahead, 1581 }; 1582