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