?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge tag 'regmap-fix-v5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux/fpc-iii.git] / fs / erofs / zdata.c
blob6cb356c4217b26d32c47fda6080b8a47770d3aa5
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2018 HUAWEI, Inc.
4 * https://www.huawei.com/
5 * Created by Gao Xiang <gaoxiang25@huawei.com>
6 */
7 #include "zdata.h"
8 #include "compress.h"
9 #include <linux/prefetch.h>
10
11 #include <trace/events/erofs.h>
12
13 /*
14 * a compressed_pages[] placeholder in order to avoid
15 * being filled with file pages for in-place decompression.
16 */
17 #define PAGE_UNALLOCATED ((void *)0x5F0E4B1D)
18
19 /* how to allocate cached pages for a pcluster */
20 enum z_erofs_cache_alloctype {
21 DONTALLOC, /* don't allocate any cached pages */
22 DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */
23 /*
24 * try to use cached I/O if page allocation succeeds or fallback
25 * to in-place I/O instead to avoid any direct reclaim.
26 */
27 TRYALLOC,
28 };
29
30 /*
31 * tagged pointer with 1-bit tag for all compressed pages
32 * tag 0 - the page is just found with an extra page reference
33 */
34 typedef tagptr1_t compressed_page_t;
35
36 #define tag_compressed_page_justfound(page) \
37 tagptr_fold(compressed_page_t, page, 1)
38
39 static struct workqueue_struct *z_erofs_workqueue __read_mostly;
40 static struct kmem_cache *pcluster_cachep __read_mostly;
41
42 void z_erofs_exit_zip_subsystem(void)
43 {
44 destroy_workqueue(z_erofs_workqueue);
45 kmem_cache_destroy(pcluster_cachep);
46 }
47
48 static inline int z_erofs_init_workqueue(void)
49 {
50 const unsigned int onlinecpus = num_possible_cpus();
51
52 /*
53 * no need to spawn too many threads, limiting threads could minimum
54 * scheduling overhead, perhaps per-CPU threads should be better?
55 */
56 z_erofs_workqueue = alloc_workqueue("erofs_unzipd",
57 WQ_UNBOUND | WQ_HIGHPRI,
58 onlinecpus + onlinecpus / 4);
59 return z_erofs_workqueue ? 0 : -ENOMEM;
60 }
61
62 static void z_erofs_pcluster_init_once(void *ptr)
63 {
64 struct z_erofs_pcluster *pcl = ptr;
65 struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
66 unsigned int i;
67
68 mutex_init(&cl->lock);
69 cl->nr_pages = 0;
70 cl->vcnt = 0;
71 for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i)
72 pcl->compressed_pages[i] = NULL;
73 }
74
75 int __init z_erofs_init_zip_subsystem(void)
76 {
77 pcluster_cachep = kmem_cache_create("erofs_compress",
78 Z_EROFS_WORKGROUP_SIZE, 0,
79 SLAB_RECLAIM_ACCOUNT,
80 z_erofs_pcluster_init_once);
81 if (pcluster_cachep) {
82 if (!z_erofs_init_workqueue())
83 return 0;
84
85 kmem_cache_destroy(pcluster_cachep);
86 }
87 return -ENOMEM;
88 }
89
90 enum z_erofs_collectmode {
91 COLLECT_SECONDARY,
92 COLLECT_PRIMARY,
93 /*
94 * The current collection was the tail of an exist chain, in addition
95 * that the previous processed chained collections are all decided to
96 * be hooked up to it.
97 * A new chain will be created for the remaining collections which are
98 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED,
99 * the next collection cannot reuse the whole page safely in
100 * the following scenario:
101 * ________________________________________________________________
102 * | tail (partial) page | head (partial) page |
103 * | (belongs to the next cl) | (belongs to the current cl) |
104 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
105 */
106 COLLECT_PRIMARY_HOOKED,
107 COLLECT_PRIMARY_FOLLOWED_NOINPLACE,
108 /*
109 * The current collection has been linked with the owned chain, and
110 * could also be linked with the remaining collections, which means
111 * if the processing page is the tail page of the collection, thus
112 * the current collection can safely use the whole page (since
113 * the previous collection is under control) for in-place I/O, as
114 * illustrated below:
115 * ________________________________________________________________
116 * | tail (partial) page | head (partial) page |
117 * | (of the current cl) | (of the previous collection) |
118 * | PRIMARY_FOLLOWED or | |
119 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
120 *
121 * [ (*) the above page can be used as inplace I/O. ]
122 */
123 COLLECT_PRIMARY_FOLLOWED,
124 };
125
126 struct z_erofs_collector {
127 struct z_erofs_pagevec_ctor vector;
128
129 struct z_erofs_pcluster *pcl, *tailpcl;
130 struct z_erofs_collection *cl;
131 struct page **compressedpages;
132 z_erofs_next_pcluster_t owned_head;
133
134 enum z_erofs_collectmode mode;
135 };
136
137 struct z_erofs_decompress_frontend {
138 struct inode *const inode;
139
140 struct z_erofs_collector clt;
141 struct erofs_map_blocks map;
142
143 bool readahead;
144 /* used for applying cache strategy on the fly */
145 bool backmost;
146 erofs_off_t headoffset;
147 };
148
149 #define COLLECTOR_INIT() { \
150 .owned_head = Z_EROFS_PCLUSTER_TAIL, \
151 .mode = COLLECT_PRIMARY_FOLLOWED }
152
153 #define DECOMPRESS_FRONTEND_INIT(__i) { \
154 .inode = __i, .clt = COLLECTOR_INIT(), \
155 .backmost = true, }
156
157 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
158 static DEFINE_MUTEX(z_pagemap_global_lock);
159
160 static void preload_compressed_pages(struct z_erofs_collector *clt,
161 struct address_space *mc,
162 enum z_erofs_cache_alloctype type,
163 struct list_head *pagepool)
164 {
165 const struct z_erofs_pcluster *pcl = clt->pcl;
166 const unsigned int clusterpages = BIT(pcl->clusterbits);
167 struct page **pages = clt->compressedpages;
168 pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages);
169 bool standalone = true;
170 gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) |
171 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
172
173 if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
174 return;
175
176 for (; pages < pcl->compressed_pages + clusterpages; ++pages) {
177 struct page *page;
178 compressed_page_t t;
179 struct page *newpage = NULL;
180
181 /* the compressed page was loaded before */
182 if (READ_ONCE(*pages))
183 continue;
184
185 page = find_get_page(mc, index);
186
187 if (page) {
188 t = tag_compressed_page_justfound(page);
189 } else if (type == DELAYEDALLOC) {
190 t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
191 } else if (type == TRYALLOC) {
192 newpage = erofs_allocpage(pagepool, gfp);
193 if (!newpage)
194 goto dontalloc;
195
196 set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE);
197 t = tag_compressed_page_justfound(newpage);
198 } else { /* DONTALLOC */
199 dontalloc:
200 if (standalone)
201 clt->compressedpages = pages;
202 standalone = false;
203 continue;
204 }
205
206 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
207 continue;
208
209 if (page) {
210 put_page(page);
211 } else if (newpage) {
212 set_page_private(newpage, 0);
213 list_add(&newpage->lru, pagepool);
214 }
215 }
216
217 if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */
218 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
219 }
220
221 /* called by erofs_shrinker to get rid of all compressed_pages */
222 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
223 struct erofs_workgroup *grp)
224 {
225 struct z_erofs_pcluster *const pcl =
226 container_of(grp, struct z_erofs_pcluster, obj);
227 struct address_space *const mapping = MNGD_MAPPING(sbi);
228 const unsigned int clusterpages = BIT(pcl->clusterbits);
229 int i;
230
231 /*
232 * refcount of workgroup is now freezed as 1,
233 * therefore no need to worry about available decompression users.
234 */
235 for (i = 0; i < clusterpages; ++i) {
236 struct page *page = pcl->compressed_pages[i];
237
238 if (!page)
239 continue;
240
241 /* block other users from reclaiming or migrating the page */
242 if (!trylock_page(page))
243 return -EBUSY;
244
245 if (page->mapping != mapping)
246 continue;
247
248 /* barrier is implied in the following 'unlock_page' */
249 WRITE_ONCE(pcl->compressed_pages[i], NULL);
250 detach_page_private(page);
251 unlock_page(page);
252 }
253 return 0;
254 }
255
256 int erofs_try_to_free_cached_page(struct address_space *mapping,
257 struct page *page)
258 {
259 struct z_erofs_pcluster *const pcl = (void *)page_private(page);
260 const unsigned int clusterpages = BIT(pcl->clusterbits);
261 int ret = 0; /* 0 - busy */
262
263 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) {
264 unsigned int i;
265
266 for (i = 0; i < clusterpages; ++i) {
267 if (pcl->compressed_pages[i] == page) {
268 WRITE_ONCE(pcl->compressed_pages[i], NULL);
269 ret = 1;
270 break;
271 }
272 }
273 erofs_workgroup_unfreeze(&pcl->obj, 1);
274
275 if (ret)
276 detach_page_private(page);
277 }
278 return ret;
279 }
280
281 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
282 static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
283 struct page *page)
284 {
285 struct z_erofs_pcluster *const pcl = clt->pcl;
286 const unsigned int clusterpages = BIT(pcl->clusterbits);
287
288 while (clt->compressedpages < pcl->compressed_pages + clusterpages) {
289 if (!cmpxchg(clt->compressedpages++, NULL, page))
290 return true;
291 }
292 return false;
293 }
294
295 /* callers must be with collection lock held */
296 static int z_erofs_attach_page(struct z_erofs_collector *clt,
297 struct page *page,
298 enum z_erofs_page_type type)
299 {
300 int ret;
301 bool occupied;
302
303 /* give priority for inplaceio */
304 if (clt->mode >= COLLECT_PRIMARY &&
305 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
306 z_erofs_try_inplace_io(clt, page))
307 return 0;
308
309 ret = z_erofs_pagevec_enqueue(&clt->vector,
310 page, type, &occupied);
311 clt->cl->vcnt += (unsigned int)ret;
312
313 return ret ? 0 : -EAGAIN;
314 }
315
316 static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt)
317 {
318 struct z_erofs_pcluster *pcl = clt->pcl;
319 z_erofs_next_pcluster_t *owned_head = &clt->owned_head;
320
321 /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */
322 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
323 *owned_head) == Z_EROFS_PCLUSTER_NIL) {
324 *owned_head = &pcl->next;
325 /* so we can attach this pcluster to our submission chain. */
326 clt->mode = COLLECT_PRIMARY_FOLLOWED;
327 return;
328 }
329
330 /*
331 * type 2, link to the end of an existing open chain, be careful
332 * that its submission is controlled by the original attached chain.
333 */
334 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
335 *owned_head) == Z_EROFS_PCLUSTER_TAIL) {
336 *owned_head = Z_EROFS_PCLUSTER_TAIL;
337 clt->mode = COLLECT_PRIMARY_HOOKED;
338 clt->tailpcl = NULL;
339 return;
340 }
341 /* type 3, it belongs to a chain, but it isn't the end of the chain */
342 clt->mode = COLLECT_PRIMARY;
343 }
344
345 static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
346 struct inode *inode,
347 struct erofs_map_blocks *map)
348 {
349 struct z_erofs_pcluster *pcl = clt->pcl;
350 struct z_erofs_collection *cl;
351 unsigned int length;
352
353 /* to avoid unexpected loop formed by corrupted images */
354 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
355 DBG_BUGON(1);
356 return -EFSCORRUPTED;
357 }
358
359 cl = z_erofs_primarycollection(pcl);
360 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) {
361 DBG_BUGON(1);
362 return -EFSCORRUPTED;
363 }
364
365 length = READ_ONCE(pcl->length);
366 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
367 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
368 DBG_BUGON(1);
369 return -EFSCORRUPTED;
370 }
371 } else {
372 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT;
373
374 if (map->m_flags & EROFS_MAP_FULL_MAPPED)
375 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH;
376
377 while (llen > length &&
378 length != cmpxchg_relaxed(&pcl->length, length, llen)) {
379 cpu_relax();
380 length = READ_ONCE(pcl->length);
381 }
382 }
383 mutex_lock(&cl->lock);
384 /* used to check tail merging loop due to corrupted images */
385 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
386 clt->tailpcl = pcl;
387
388 z_erofs_try_to_claim_pcluster(clt);
389 clt->cl = cl;
390 return 0;
391 }
392
393 static int z_erofs_register_collection(struct z_erofs_collector *clt,
394 struct inode *inode,
395 struct erofs_map_blocks *map)
396 {
397 struct z_erofs_pcluster *pcl;
398 struct z_erofs_collection *cl;
399 struct erofs_workgroup *grp;
400 int err;
401
402 /* no available workgroup, let's allocate one */
403 pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS);
404 if (!pcl)
405 return -ENOMEM;
406
407 atomic_set(&pcl->obj.refcount, 1);
408 pcl->obj.index = map->m_pa >> PAGE_SHIFT;
409
410 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
411 (map->m_flags & EROFS_MAP_FULL_MAPPED ?
412 Z_EROFS_PCLUSTER_FULL_LENGTH : 0);
413
414 if (map->m_flags & EROFS_MAP_ZIPPED)
415 pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4;
416 else
417 pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
418
419 pcl->clusterbits = EROFS_I(inode)->z_physical_clusterbits[0];
420 pcl->clusterbits -= PAGE_SHIFT;
421
422 /* new pclusters should be claimed as type 1, primary and followed */
423 pcl->next = clt->owned_head;
424 clt->mode = COLLECT_PRIMARY_FOLLOWED;
425
426 cl = z_erofs_primarycollection(pcl);
427
428 /* must be cleaned before freeing to slab */
429 DBG_BUGON(cl->nr_pages);
430 DBG_BUGON(cl->vcnt);
431
432 cl->pageofs = map->m_la & ~PAGE_MASK;
433
434 /*
435 * lock all primary followed works before visible to others
436 * and mutex_trylock *never* fails for a new pcluster.
437 */
438 DBG_BUGON(!mutex_trylock(&cl->lock));
439
440 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj);
441 if (IS_ERR(grp)) {
442 err = PTR_ERR(grp);
443 goto err_out;
444 }
445
446 if (grp != &pcl->obj) {
447 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
448 err = -EEXIST;
449 goto err_out;
450 }
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 clt->owned_head = &pcl->next;
455 clt->pcl = pcl;
456 clt->cl = cl;
457 return 0;
458
459 err_out:
460 mutex_unlock(&cl->lock);
461 kmem_cache_free(pcluster_cachep, pcl);
462 return err;
463 }
464
465 static int z_erofs_collector_begin(struct z_erofs_collector *clt,
466 struct inode *inode,
467 struct erofs_map_blocks *map)
468 {
469 struct erofs_workgroup *grp;
470 int ret;
471
472 DBG_BUGON(clt->cl);
473
474 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
475 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
476 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
477
478 if (!PAGE_ALIGNED(map->m_pa)) {
479 DBG_BUGON(1);
480 return -EINVAL;
481 }
482
483 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
484 if (grp) {
485 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
486 } else {
487 ret = z_erofs_register_collection(clt, inode, map);
488
489 if (!ret)
490 goto out;
491 if (ret != -EEXIST)
492 return ret;
493 }
494
495 ret = z_erofs_lookup_collection(clt, inode, map);
496 if (ret) {
497 erofs_workgroup_put(&clt->pcl->obj);
498 return ret;
499 }
500
501 out:
502 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
503 clt->cl->pagevec, clt->cl->vcnt);
504
505 clt->compressedpages = clt->pcl->compressed_pages;
506 if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */
507 clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES;
508 return 0;
509 }
510
511 /*
512 * keep in mind that no referenced pclusters will be freed
513 * only after a RCU grace period.
514 */
515 static void z_erofs_rcu_callback(struct rcu_head *head)
516 {
517 struct z_erofs_collection *const cl =
518 container_of(head, struct z_erofs_collection, rcu);
519
520 kmem_cache_free(pcluster_cachep,
521 container_of(cl, struct z_erofs_pcluster,
522 primary_collection));
523 }
524
525 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
526 {
527 struct z_erofs_pcluster *const pcl =
528 container_of(grp, struct z_erofs_pcluster, obj);
529 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl);
530
531 call_rcu(&cl->rcu, z_erofs_rcu_callback);
532 }
533
534 static void z_erofs_collection_put(struct z_erofs_collection *cl)
535 {
536 struct z_erofs_pcluster *const pcl =
537 container_of(cl, struct z_erofs_pcluster, primary_collection);
538
539 erofs_workgroup_put(&pcl->obj);
540 }
541
542 static bool z_erofs_collector_end(struct z_erofs_collector *clt)
543 {
544 struct z_erofs_collection *cl = clt->cl;
545
546 if (!cl)
547 return false;
548
549 z_erofs_pagevec_ctor_exit(&clt->vector, false);
550 mutex_unlock(&cl->lock);
551
552 /*
553 * if all pending pages are added, don't hold its reference
554 * any longer if the pcluster isn't hosted by ourselves.
555 */
556 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
557 z_erofs_collection_put(cl);
558
559 clt->cl = NULL;
560 return true;
561 }
562
563 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
564 unsigned int cachestrategy,
565 erofs_off_t la)
566 {
567 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
568 return false;
569
570 if (fe->backmost)
571 return true;
572
573 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
574 la < fe->headoffset;
575 }
576
577 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
578 struct page *page, struct list_head *pagepool)
579 {
580 struct inode *const inode = fe->inode;
581 struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
582 struct erofs_map_blocks *const map = &fe->map;
583 struct z_erofs_collector *const clt = &fe->clt;
584 const loff_t offset = page_offset(page);
585 bool tight = true;
586
587 enum z_erofs_cache_alloctype cache_strategy;
588 enum z_erofs_page_type page_type;
589 unsigned int cur, end, spiltted, index;
590 int err = 0;
591
592 /* register locked file pages as online pages in pack */
593 z_erofs_onlinepage_init(page);
594
595 spiltted = 0;
596 end = PAGE_SIZE;
597 repeat:
598 cur = end - 1;
599
600 /* lucky, within the range of the current map_blocks */
601 if (offset + cur >= map->m_la &&
602 offset + cur < map->m_la + map->m_llen) {
603 /* didn't get a valid collection previously (very rare) */
604 if (!clt->cl)
605 goto restart_now;
606 goto hitted;
607 }
608
609 /* go ahead the next map_blocks */
610 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur);
611
612 if (z_erofs_collector_end(clt))
613 fe->backmost = false;
614
615 map->m_la = offset + cur;
616 map->m_llen = 0;
617 err = z_erofs_map_blocks_iter(inode, map, 0);
618 if (err)
619 goto err_out;
620
621 restart_now:
622 if (!(map->m_flags & EROFS_MAP_MAPPED))
623 goto hitted;
624
625 err = z_erofs_collector_begin(clt, inode, map);
626 if (err)
627 goto err_out;
628
629 /* preload all compressed pages (maybe downgrade role if necessary) */
630 if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la))
631 cache_strategy = TRYALLOC;
632 else
633 cache_strategy = DONTALLOC;
634
635 preload_compressed_pages(clt, MNGD_MAPPING(sbi),
636 cache_strategy, pagepool);
637
638 hitted:
639 /*
640 * Ensure the current partial page belongs to this submit chain rather
641 * than other concurrent submit chains or the noio(bypass) chain since
642 * those chains are handled asynchronously thus the page cannot be used
643 * for inplace I/O or pagevec (should be processed in strict order.)
644 */
645 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED &&
646 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);
647
648 cur = end - min_t(unsigned int, offset + end - map->m_la, end);
649 if (!(map->m_flags & EROFS_MAP_MAPPED)) {
650 zero_user_segment(page, cur, end);
651 goto next_part;
652 }
653
654 /* let's derive page type */
655 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
656 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
657 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
658 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
659
660 if (cur)
661 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
662
663 retry:
664 err = z_erofs_attach_page(clt, page, page_type);
665 /* should allocate an additional short-lived page for pagevec */
666 if (err == -EAGAIN) {
667 struct page *const newpage =
668 alloc_page(GFP_NOFS | __GFP_NOFAIL);
669
670 set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE);
671 err = z_erofs_attach_page(clt, newpage,
672 Z_EROFS_PAGE_TYPE_EXCLUSIVE);
673 if (!err)
674 goto retry;
675 }
676
677 if (err)
678 goto err_out;
679
680 index = page->index - (map->m_la >> PAGE_SHIFT);
681
682 z_erofs_onlinepage_fixup(page, index, true);
683
684 /* bump up the number of spiltted parts of a page */
685 ++spiltted;
686 /* also update nr_pages */
687 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1);
688 next_part:
689 /* can be used for verification */
690 map->m_llen = offset + cur - map->m_la;
691
692 end = cur;
693 if (end > 0)
694 goto repeat;
695
696 out:
697 z_erofs_onlinepage_endio(page);
698
699 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu",
700 __func__, page, spiltted, map->m_llen);
701 return err;
702
703 /* if some error occurred while processing this page */
704 err_out:
705 SetPageError(page);
706 goto out;
707 }
708
709 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io,
710 bool sync, int bios)
711 {
712 /* wake up the caller thread for sync decompression */
713 if (sync) {
714 unsigned long flags;
715
716 spin_lock_irqsave(&io->u.wait.lock, flags);
717 if (!atomic_add_return(bios, &io->pending_bios))
718 wake_up_locked(&io->u.wait);
719 spin_unlock_irqrestore(&io->u.wait.lock, flags);
720 return;
721 }
722
723 if (!atomic_add_return(bios, &io->pending_bios))
724 queue_work(z_erofs_workqueue, &io->u.work);
725 }
726
727 static bool z_erofs_page_is_invalidated(struct page *page)
728 {
729 return !page->mapping && !z_erofs_is_shortlived_page(page);
730 }
731
732 static void z_erofs_decompressqueue_endio(struct bio *bio)
733 {
734 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private);
735 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t);
736 blk_status_t err = bio->bi_status;
737 struct bio_vec *bvec;
738 struct bvec_iter_all iter_all;
739
740 bio_for_each_segment_all(bvec, bio, iter_all) {
741 struct page *page = bvec->bv_page;
742
743 DBG_BUGON(PageUptodate(page));
744 DBG_BUGON(z_erofs_page_is_invalidated(page));
745
746 if (err)
747 SetPageError(page);
748
749 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) {
750 if (!err)
751 SetPageUptodate(page);
752 unlock_page(page);
753 }
754 }
755 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1);
756 bio_put(bio);
757 }
758
759 static int z_erofs_decompress_pcluster(struct super_block *sb,
760 struct z_erofs_pcluster *pcl,
761 struct list_head *pagepool)
762 {
763 struct erofs_sb_info *const sbi = EROFS_SB(sb);
764 const unsigned int clusterpages = BIT(pcl->clusterbits);
765 struct z_erofs_pagevec_ctor ctor;
766 unsigned int i, outputsize, llen, nr_pages;
767 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES];
768 struct page **pages, **compressed_pages, *page;
769
770 enum z_erofs_page_type page_type;
771 bool overlapped, partial;
772 struct z_erofs_collection *cl;
773 int err;
774
775 might_sleep();
776 cl = z_erofs_primarycollection(pcl);
777 DBG_BUGON(!READ_ONCE(cl->nr_pages));
778
779 mutex_lock(&cl->lock);
780 nr_pages = cl->nr_pages;
781
782 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) {
783 pages = pages_onstack;
784 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES &&
785 mutex_trylock(&z_pagemap_global_lock)) {
786 pages = z_pagemap_global;
787 } else {
788 gfp_t gfp_flags = GFP_KERNEL;
789
790 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES)
791 gfp_flags |= __GFP_NOFAIL;
792
793 pages = kvmalloc_array(nr_pages, sizeof(struct page *),
794 gfp_flags);
795
796 /* fallback to global pagemap for the lowmem scenario */
797 if (!pages) {
798 mutex_lock(&z_pagemap_global_lock);
799 pages = z_pagemap_global;
800 }
801 }
802
803 for (i = 0; i < nr_pages; ++i)
804 pages[i] = NULL;
805
806 err = 0;
807 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS,
808 cl->pagevec, 0);
809
810 for (i = 0; i < cl->vcnt; ++i) {
811 unsigned int pagenr;
812
813 page = z_erofs_pagevec_dequeue(&ctor, &page_type);
814
815 /* all pages in pagevec ought to be valid */
816 DBG_BUGON(!page);
817 DBG_BUGON(z_erofs_page_is_invalidated(page));
818
819 if (z_erofs_put_shortlivedpage(pagepool, page))
820 continue;
821
822 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
823 pagenr = 0;
824 else
825 pagenr = z_erofs_onlinepage_index(page);
826
827 DBG_BUGON(pagenr >= nr_pages);
828
829 /*
830 * currently EROFS doesn't support multiref(dedup),
831 * so here erroring out one multiref page.
832 */
833 if (pages[pagenr]) {
834 DBG_BUGON(1);
835 SetPageError(pages[pagenr]);
836 z_erofs_onlinepage_endio(pages[pagenr]);
837 err = -EFSCORRUPTED;
838 }
839 pages[pagenr] = page;
840 }
841 z_erofs_pagevec_ctor_exit(&ctor, true);
842
843 overlapped = false;
844 compressed_pages = pcl->compressed_pages;
845
846 for (i = 0; i < clusterpages; ++i) {
847 unsigned int pagenr;
848
849 page = compressed_pages[i];
850
851 /* all compressed pages ought to be valid */
852 DBG_BUGON(!page);
853 DBG_BUGON(z_erofs_page_is_invalidated(page));
854
855 if (!z_erofs_is_shortlived_page(page)) {
856 if (erofs_page_is_managed(sbi, page)) {
857 if (!PageUptodate(page))
858 err = -EIO;
859 continue;
860 }
861
862 /*
863 * only if non-head page can be selected
864 * for inplace decompression
865 */
866 pagenr = z_erofs_onlinepage_index(page);
867
868 DBG_BUGON(pagenr >= nr_pages);
869 if (pages[pagenr]) {
870 DBG_BUGON(1);
871 SetPageError(pages[pagenr]);
872 z_erofs_onlinepage_endio(pages[pagenr]);
873 err = -EFSCORRUPTED;
874 }
875 pages[pagenr] = page;
876
877 overlapped = true;
878 }
879
880 /* PG_error needs checking for all non-managed pages */
881 if (PageError(page)) {
882 DBG_BUGON(PageUptodate(page));
883 err = -EIO;
884 }
885 }
886
887 if (err)
888 goto out;
889
890 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT;
891 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) {
892 outputsize = llen;
893 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH);
894 } else {
895 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs;
896 partial = true;
897 }
898
899 err = z_erofs_decompress(&(struct z_erofs_decompress_req) {
900 .sb = sb,
901 .in = compressed_pages,
902 .out = pages,
903 .pageofs_out = cl->pageofs,
904 .inputsize = PAGE_SIZE,
905 .outputsize = outputsize,
906 .alg = pcl->algorithmformat,
907 .inplace_io = overlapped,
908 .partial_decoding = partial
909 }, pagepool);
910
911 out:
912 /* must handle all compressed pages before endding pages */
913 for (i = 0; i < clusterpages; ++i) {
914 page = compressed_pages[i];
915
916 if (erofs_page_is_managed(sbi, page))
917 continue;
918
919 /* recycle all individual short-lived pages */
920 (void)z_erofs_put_shortlivedpage(pagepool, page);
921
922 WRITE_ONCE(compressed_pages[i], NULL);
923 }
924
925 for (i = 0; i < nr_pages; ++i) {
926 page = pages[i];
927 if (!page)
928 continue;
929
930 DBG_BUGON(z_erofs_page_is_invalidated(page));
931
932 /* recycle all individual short-lived pages */
933 if (z_erofs_put_shortlivedpage(pagepool, page))
934 continue;
935
936 if (err < 0)
937 SetPageError(page);
938
939 z_erofs_onlinepage_endio(page);
940 }
941
942 if (pages == z_pagemap_global)
943 mutex_unlock(&z_pagemap_global_lock);
944 else if (pages != pages_onstack)
945 kvfree(pages);
946
947 cl->nr_pages = 0;
948 cl->vcnt = 0;
949
950 /* all cl locks MUST be taken before the following line */
951 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL);
952
953 /* all cl locks SHOULD be released right now */
954 mutex_unlock(&cl->lock);
955
956 z_erofs_collection_put(cl);
957 return err;
958 }
959
960 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io,
961 struct list_head *pagepool)
962 {
963 z_erofs_next_pcluster_t owned = io->head;
964
965 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) {
966 struct z_erofs_pcluster *pcl;
967
968 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
969 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL);
970
971 /* no possible that 'owned' equals NULL */
972 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL);
973
974 pcl = container_of(owned, struct z_erofs_pcluster, next);
975 owned = READ_ONCE(pcl->next);
976
977 z_erofs_decompress_pcluster(io->sb, pcl, pagepool);
978 }
979 }
980
981 static void z_erofs_decompressqueue_work(struct work_struct *work)
982 {
983 struct z_erofs_decompressqueue *bgq =
984 container_of(work, struct z_erofs_decompressqueue, u.work);
985 LIST_HEAD(pagepool);
986
987 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
988 z_erofs_decompress_queue(bgq, &pagepool);
989
990 put_pages_list(&pagepool);
991 kvfree(bgq);
992 }
993
994 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
995 unsigned int nr,
996 struct list_head *pagepool,
997 struct address_space *mc,
998 gfp_t gfp)
999 {
1000 const pgoff_t index = pcl->obj.index;
1001 bool tocache = false;
1002
1003 struct address_space *mapping;
1004 struct page *oldpage, *page;
1005
1006 compressed_page_t t;
1007 int justfound;
1008
1009 repeat:
1010 page = READ_ONCE(pcl->compressed_pages[nr]);
1011 oldpage = page;
1012
1013 if (!page)
1014 goto out_allocpage;
1015
1016 /*
1017 * the cached page has not been allocated and
1018 * an placeholder is out there, prepare it now.
1019 */
1020 if (page == PAGE_UNALLOCATED) {
1021 tocache = true;
1022 goto out_allocpage;
1023 }
1024
1025 /* process the target tagged pointer */
1026 t = tagptr_init(compressed_page_t, page);
1027 justfound = tagptr_unfold_tags(t);
1028 page = tagptr_unfold_ptr(t);
1029
1030 /*
1031 * preallocated cached pages, which is used to avoid direct reclaim
1032 * otherwise, it will go inplace I/O path instead.
1033 */
1034 if (page->private == Z_EROFS_PREALLOCATED_PAGE) {
1035 WRITE_ONCE(pcl->compressed_pages[nr], page);
1036 set_page_private(page, 0);
1037 tocache = true;
1038 goto out_tocache;
1039 }
1040 mapping = READ_ONCE(page->mapping);
1041
1042 /*
1043 * file-backed online pages in plcuster are all locked steady,
1044 * therefore it is impossible for `mapping' to be NULL.
1045 */
1046 if (mapping && mapping != mc)
1047 /* ought to be unmanaged pages */
1048 goto out;
1049
1050 /* directly return for shortlived page as well */
1051 if (z_erofs_is_shortlived_page(page))
1052 goto out;
1053
1054 lock_page(page);
1055
1056 /* only true if page reclaim goes wrong, should never happen */
1057 DBG_BUGON(justfound && PagePrivate(page));
1058
1059 /* the page is still in manage cache */
1060 if (page->mapping == mc) {
1061 WRITE_ONCE(pcl->compressed_pages[nr], page);
1062
1063 ClearPageError(page);
1064 if (!PagePrivate(page)) {
1065 /*
1066 * impossible to be !PagePrivate(page) for
1067 * the current restriction as well if
1068 * the page is already in compressed_pages[].
1069 */
1070 DBG_BUGON(!justfound);
1071
1072 justfound = 0;
1073 set_page_private(page, (unsigned long)pcl);
1074 SetPagePrivate(page);
1075 }
1076
1077 /* no need to submit io if it is already up-to-date */
1078 if (PageUptodate(page)) {
1079 unlock_page(page);
1080 page = NULL;
1081 }
1082 goto out;
1083 }
1084
1085 /*
1086 * the managed page has been truncated, it's unsafe to
1087 * reuse this one, let's allocate a new cache-managed page.
1088 */
1089 DBG_BUGON(page->mapping);
1090 DBG_BUGON(!justfound);
1091
1092 tocache = true;
1093 unlock_page(page);
1094 put_page(page);
1095 out_allocpage:
1096 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL);
1097 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) {
1098 list_add(&page->lru, pagepool);
1099 cond_resched();
1100 goto repeat;
1101 }
1102 out_tocache:
1103 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) {
1104 /* turn into temporary page if fails (1 ref) */
1105 set_page_private(page, Z_EROFS_SHORTLIVED_PAGE);
1106 goto out;
1107 }
1108 attach_page_private(page, pcl);
1109 /* drop a refcount added by allocpage (then we have 2 refs here) */
1110 put_page(page);
1111
1112 out: /* the only exit (for tracing and debugging) */
1113 return page;
1114 }
1115
1116 static struct z_erofs_decompressqueue *
1117 jobqueue_init(struct super_block *sb,
1118 struct z_erofs_decompressqueue *fgq, bool *fg)
1119 {
1120 struct z_erofs_decompressqueue *q;
1121
1122 if (fg && !*fg) {
1123 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN);
1124 if (!q) {
1125 *fg = true;
1126 goto fg_out;
1127 }
1128 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work);
1129 } else {
1130 fg_out:
1131 q = fgq;
1132 init_waitqueue_head(&fgq->u.wait);
1133 atomic_set(&fgq->pending_bios, 0);
1134 }
1135 q->sb = sb;
1136 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
1137 return q;
1138 }
1139
1140 /* define decompression jobqueue types */
1141 enum {
1142 JQ_BYPASS,
1143 JQ_SUBMIT,
1144 NR_JOBQUEUES,
1145 };
1146
1147 static void *jobqueueset_init(struct super_block *sb,
1148 struct z_erofs_decompressqueue *q[],
1149 struct z_erofs_decompressqueue *fgq, bool *fg)
1150 {
1151 /*
1152 * if managed cache is enabled, bypass jobqueue is needed,
1153 * no need to read from device for all pclusters in this queue.
1154 */
1155 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL);
1156 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg);
1157
1158 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg));
1159 }
1160
1161 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
1162 z_erofs_next_pcluster_t qtail[],
1163 z_erofs_next_pcluster_t owned_head)
1164 {
1165 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT];
1166 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS];
1167
1168 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
1169 if (owned_head == Z_EROFS_PCLUSTER_TAIL)
1170 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
1171
1172 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED);
1173
1174 WRITE_ONCE(*submit_qtail, owned_head);
1175 WRITE_ONCE(*bypass_qtail, &pcl->next);
1176
1177 qtail[JQ_BYPASS] = &pcl->next;
1178 }
1179
1180 static void z_erofs_submit_queue(struct super_block *sb,
1181 struct z_erofs_decompress_frontend *f,
1182 struct list_head *pagepool,
1183 struct z_erofs_decompressqueue *fgq,
1184 bool *force_fg)
1185 {
1186 struct erofs_sb_info *const sbi = EROFS_SB(sb);
1187 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES];
1188 struct z_erofs_decompressqueue *q[NR_JOBQUEUES];
1189 void *bi_private;
1190 z_erofs_next_pcluster_t owned_head = f->clt.owned_head;
1191 /* since bio will be NULL, no need to initialize last_index */
1192 pgoff_t last_index;
1193 unsigned int nr_bios = 0;
1194 struct bio *bio = NULL;
1195
1196 bi_private = jobqueueset_init(sb, q, fgq, force_fg);
1197 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head;
1198 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head;
1199
1200 /* by default, all need io submission */
1201 q[JQ_SUBMIT]->head = owned_head;
1202
1203 do {
1204 struct z_erofs_pcluster *pcl;
1205 pgoff_t cur, end;
1206 unsigned int i = 0;
1207 bool bypass = true;
1208
1209 /* no possible 'owned_head' equals the following */
1210 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
1211 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL);
1212
1213 pcl = container_of(owned_head, struct z_erofs_pcluster, next);
1214
1215 cur = pcl->obj.index;
1216 end = cur + BIT(pcl->clusterbits);
1217
1218 /* close the main owned chain at first */
1219 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
1220 Z_EROFS_PCLUSTER_TAIL_CLOSED);
1221
1222 do {
1223 struct page *page;
1224
1225 page = pickup_page_for_submission(pcl, i++, pagepool,
1226 MNGD_MAPPING(sbi),
1227 GFP_NOFS);
1228 if (!page)
1229 continue;
1230
1231 if (bio && cur != last_index + 1) {
1232 submit_bio_retry:
1233 submit_bio(bio);
1234 bio = NULL;
1235 }
1236
1237 if (!bio) {
1238 bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);
1239
1240 bio->bi_end_io = z_erofs_decompressqueue_endio;
1241 bio_set_dev(bio, sb->s_bdev);
1242 bio->bi_iter.bi_sector = (sector_t)cur <<
1243 LOG_SECTORS_PER_BLOCK;
1244 bio->bi_private = bi_private;
1245 bio->bi_opf = REQ_OP_READ;
1246 if (f->readahead)
1247 bio->bi_opf |= REQ_RAHEAD;
1248 ++nr_bios;
1249 }
1250
1251 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
1252 goto submit_bio_retry;
1253
1254 last_index = cur;
1255 bypass = false;
1256 } while (++cur < end);
1257
1258 if (!bypass)
1259 qtail[JQ_SUBMIT] = &pcl->next;
1260 else
1261 move_to_bypass_jobqueue(pcl, qtail, owned_head);
1262 } while (owned_head != Z_EROFS_PCLUSTER_TAIL);
1263
1264 if (bio)
1265 submit_bio(bio);
1266
1267 /*
1268 * although background is preferred, no one is pending for submission.
1269 * don't issue workqueue for decompression but drop it directly instead.
1270 */
1271 if (!*force_fg && !nr_bios) {
1272 kvfree(q[JQ_SUBMIT]);
1273 return;
1274 }
1275 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios);
1276 }
1277
1278 static void z_erofs_runqueue(struct super_block *sb,
1279 struct z_erofs_decompress_frontend *f,
1280 struct list_head *pagepool, bool force_fg)
1281 {
1282 struct z_erofs_decompressqueue io[NR_JOBQUEUES];
1283
1284 if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL)
1285 return;
1286 z_erofs_submit_queue(sb, f, pagepool, io, &force_fg);
1287
1288 /* handle bypass queue (no i/o pclusters) immediately */
1289 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool);
1290
1291 if (!force_fg)
1292 return;
1293
1294 /* wait until all bios are completed */
1295 io_wait_event(io[JQ_SUBMIT].u.wait,
1296 !atomic_read(&io[JQ_SUBMIT].pending_bios));
1297
1298 /* handle synchronous decompress queue in the caller context */
1299 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool);
1300 }
1301
1302 static int z_erofs_readpage(struct file *file, struct page *page)
1303 {
1304 struct inode *const inode = page->mapping->host;
1305 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
1306 int err;
1307 LIST_HEAD(pagepool);
1308
1309 trace_erofs_readpage(page, false);
1310
1311 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT;
1312
1313 err = z_erofs_do_read_page(&f, page, &pagepool);
1314 (void)z_erofs_collector_end(&f.clt);
1315
1316 /* if some compressed cluster ready, need submit them anyway */
1317 z_erofs_runqueue(inode->i_sb, &f, &pagepool, true);
1318
1319 if (err)
1320 erofs_err(inode->i_sb, "failed to read, err [%d]", err);
1321
1322 if (f.map.mpage)
1323 put_page(f.map.mpage);
1324
1325 /* clean up the remaining free pages */
1326 put_pages_list(&pagepool);
1327 return err;
1328 }
1329
1330 static void z_erofs_readahead(struct readahead_control *rac)
1331 {
1332 struct inode *const inode = rac->mapping->host;
1333 struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
1334
1335 unsigned int nr_pages = readahead_count(rac);
1336 bool sync = (nr_pages <= sbi->ctx.max_sync_decompress_pages);
1337 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
1338 struct page *page, *head = NULL;
1339 LIST_HEAD(pagepool);
1340
1341 trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false);
1342
1343 f.readahead = true;
1344 f.headoffset = readahead_pos(rac);
1345
1346 while ((page = readahead_page(rac))) {
1347 prefetchw(&page->flags);
1348
1349 /*
1350 * A pure asynchronous readahead is indicated if
1351 * a PG_readahead marked page is hitted at first.
1352 * Let's also do asynchronous decompression for this case.
1353 */
1354 sync &= !(PageReadahead(page) && !head);
1355
1356 set_page_private(page, (unsigned long)head);
1357 head = page;
1358 }
1359
1360 while (head) {
1361 struct page *page = head;
1362 int err;
1363
1364 /* traversal in reverse order */
1365 head = (void *)page_private(page);
1366
1367 err = z_erofs_do_read_page(&f, page, &pagepool);
1368 if (err)
1369 erofs_err(inode->i_sb,
1370 "readahead error at page %lu @ nid %llu",
1371 page->index, EROFS_I(inode)->nid);
1372 put_page(page);
1373 }
1374
1375 (void)z_erofs_collector_end(&f.clt);
1376
1377 z_erofs_runqueue(inode->i_sb, &f, &pagepool, sync);
1378
1379 if (f.map.mpage)
1380 put_page(f.map.mpage);
1381
1382 /* clean up the remaining free pages */
1383 put_pages_list(&pagepool);
1384 }
1385
1386 const struct address_space_operations z_erofs_aops = {
1387 .readpage = z_erofs_readpage,
1388 .readahead = z_erofs_readahead,
1389 };
1390
Linux with added FPC-III support