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Linux 5.7.6
[linux/fpc-iii.git] / fs / erofs / zdata.c
blobc4b6c9aa87eccecaed8f375c100dbee9625f5772
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2018 HUAWEI, Inc.
4 * http://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
25 /*
26 * tagged pointer with 1-bit tag for all compressed pages
27 * tag 0 - the page is just found with an extra page reference
28 */
29 typedef tagptr1_t compressed_page_t;
30
31 #define tag_compressed_page_justfound(page) \
32 tagptr_fold(compressed_page_t, page, 1)
33
34 static struct workqueue_struct *z_erofs_workqueue __read_mostly;
35 static struct kmem_cache *pcluster_cachep __read_mostly;
36
37 void z_erofs_exit_zip_subsystem(void)
38 {
39 destroy_workqueue(z_erofs_workqueue);
40 kmem_cache_destroy(pcluster_cachep);
41 }
42
43 static inline int z_erofs_init_workqueue(void)
44 {
45 const unsigned int onlinecpus = num_possible_cpus();
46 const unsigned int flags = WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE;
47
48 /*
49 * no need to spawn too many threads, limiting threads could minimum
50 * scheduling overhead, perhaps per-CPU threads should be better?
51 */
52 z_erofs_workqueue = alloc_workqueue("erofs_unzipd", flags,
53 onlinecpus + onlinecpus / 4);
54 return z_erofs_workqueue ? 0 : -ENOMEM;
55 }
56
57 static void z_erofs_pcluster_init_once(void *ptr)
58 {
59 struct z_erofs_pcluster *pcl = ptr;
60 struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
61 unsigned int i;
62
63 mutex_init(&cl->lock);
64 cl->nr_pages = 0;
65 cl->vcnt = 0;
66 for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i)
67 pcl->compressed_pages[i] = NULL;
68 }
69
70 int __init z_erofs_init_zip_subsystem(void)
71 {
72 pcluster_cachep = kmem_cache_create("erofs_compress",
73 Z_EROFS_WORKGROUP_SIZE, 0,
74 SLAB_RECLAIM_ACCOUNT,
75 z_erofs_pcluster_init_once);
76 if (pcluster_cachep) {
77 if (!z_erofs_init_workqueue())
78 return 0;
79
80 kmem_cache_destroy(pcluster_cachep);
81 }
82 return -ENOMEM;
83 }
84
85 enum z_erofs_collectmode {
86 COLLECT_SECONDARY,
87 COLLECT_PRIMARY,
88 /*
89 * The current collection was the tail of an exist chain, in addition
90 * that the previous processed chained collections are all decided to
91 * be hooked up to it.
92 * A new chain will be created for the remaining collections which are
93 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED,
94 * the next collection cannot reuse the whole page safely in
95 * the following scenario:
96 * ________________________________________________________________
97 * | tail (partial) page | head (partial) page |
98 * | (belongs to the next cl) | (belongs to the current cl) |
99 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
100 */
101 COLLECT_PRIMARY_HOOKED,
102 COLLECT_PRIMARY_FOLLOWED_NOINPLACE,
103 /*
104 * The current collection has been linked with the owned chain, and
105 * could also be linked with the remaining collections, which means
106 * if the processing page is the tail page of the collection, thus
107 * the current collection can safely use the whole page (since
108 * the previous collection is under control) for in-place I/O, as
109 * illustrated below:
110 * ________________________________________________________________
111 * | tail (partial) page | head (partial) page |
112 * | (of the current cl) | (of the previous collection) |
113 * | PRIMARY_FOLLOWED or | |
114 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
115 *
116 * [ (*) the above page can be used as inplace I/O. ]
117 */
118 COLLECT_PRIMARY_FOLLOWED,
119 };
120
121 struct z_erofs_collector {
122 struct z_erofs_pagevec_ctor vector;
123
124 struct z_erofs_pcluster *pcl, *tailpcl;
125 struct z_erofs_collection *cl;
126 struct page **compressedpages;
127 z_erofs_next_pcluster_t owned_head;
128
129 enum z_erofs_collectmode mode;
130 };
131
132 struct z_erofs_decompress_frontend {
133 struct inode *const inode;
134
135 struct z_erofs_collector clt;
136 struct erofs_map_blocks map;
137
138 /* used for applying cache strategy on the fly */
139 bool backmost;
140 erofs_off_t headoffset;
141 };
142
143 #define COLLECTOR_INIT() { \
144 .owned_head = Z_EROFS_PCLUSTER_TAIL, \
145 .mode = COLLECT_PRIMARY_FOLLOWED }
146
147 #define DECOMPRESS_FRONTEND_INIT(__i) { \
148 .inode = __i, .clt = COLLECTOR_INIT(), \
149 .backmost = true, }
150
151 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
152 static DEFINE_MUTEX(z_pagemap_global_lock);
153
154 static void preload_compressed_pages(struct z_erofs_collector *clt,
155 struct address_space *mc,
156 enum z_erofs_cache_alloctype type,
157 struct list_head *pagepool)
158 {
159 const struct z_erofs_pcluster *pcl = clt->pcl;
160 const unsigned int clusterpages = BIT(pcl->clusterbits);
161 struct page **pages = clt->compressedpages;
162 pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages);
163 bool standalone = true;
164
165 if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
166 return;
167
168 for (; pages < pcl->compressed_pages + clusterpages; ++pages) {
169 struct page *page;
170 compressed_page_t t;
171
172 /* the compressed page was loaded before */
173 if (READ_ONCE(*pages))
174 continue;
175
176 page = find_get_page(mc, index);
177
178 if (page) {
179 t = tag_compressed_page_justfound(page);
180 } else if (type == DELAYEDALLOC) {
181 t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
182 } else { /* DONTALLOC */
183 if (standalone)
184 clt->compressedpages = pages;
185 standalone = false;
186 continue;
187 }
188
189 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
190 continue;
191
192 if (page)
193 put_page(page);
194 }
195
196 if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */
197 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
198 }
199
200 /* called by erofs_shrinker to get rid of all compressed_pages */
201 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
202 struct erofs_workgroup *grp)
203 {
204 struct z_erofs_pcluster *const pcl =
205 container_of(grp, struct z_erofs_pcluster, obj);
206 struct address_space *const mapping = MNGD_MAPPING(sbi);
207 const unsigned int clusterpages = BIT(pcl->clusterbits);
208 int i;
209
210 /*
211 * refcount of workgroup is now freezed as 1,
212 * therefore no need to worry about available decompression users.
213 */
214 for (i = 0; i < clusterpages; ++i) {
215 struct page *page = pcl->compressed_pages[i];
216
217 if (!page)
218 continue;
219
220 /* block other users from reclaiming or migrating the page */
221 if (!trylock_page(page))
222 return -EBUSY;
223
224 if (page->mapping != mapping)
225 continue;
226
227 /* barrier is implied in the following 'unlock_page' */
228 WRITE_ONCE(pcl->compressed_pages[i], NULL);
229 set_page_private(page, 0);
230 ClearPagePrivate(page);
231
232 unlock_page(page);
233 put_page(page);
234 }
235 return 0;
236 }
237
238 int erofs_try_to_free_cached_page(struct address_space *mapping,
239 struct page *page)
240 {
241 struct z_erofs_pcluster *const pcl = (void *)page_private(page);
242 const unsigned int clusterpages = BIT(pcl->clusterbits);
243 int ret = 0; /* 0 - busy */
244
245 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) {
246 unsigned int i;
247
248 for (i = 0; i < clusterpages; ++i) {
249 if (pcl->compressed_pages[i] == page) {
250 WRITE_ONCE(pcl->compressed_pages[i], NULL);
251 ret = 1;
252 break;
253 }
254 }
255 erofs_workgroup_unfreeze(&pcl->obj, 1);
256
257 if (ret) {
258 ClearPagePrivate(page);
259 put_page(page);
260 }
261 }
262 return ret;
263 }
264
265 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
266 static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
267 struct page *page)
268 {
269 struct z_erofs_pcluster *const pcl = clt->pcl;
270 const unsigned int clusterpages = BIT(pcl->clusterbits);
271
272 while (clt->compressedpages < pcl->compressed_pages + clusterpages) {
273 if (!cmpxchg(clt->compressedpages++, NULL, page))
274 return true;
275 }
276 return false;
277 }
278
279 /* callers must be with collection lock held */
280 static int z_erofs_attach_page(struct z_erofs_collector *clt,
281 struct page *page,
282 enum z_erofs_page_type type)
283 {
284 int ret;
285 bool occupied;
286
287 /* give priority for inplaceio */
288 if (clt->mode >= COLLECT_PRIMARY &&
289 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
290 z_erofs_try_inplace_io(clt, page))
291 return 0;
292
293 ret = z_erofs_pagevec_enqueue(&clt->vector,
294 page, type, &occupied);
295 clt->cl->vcnt += (unsigned int)ret;
296
297 return ret ? 0 : -EAGAIN;
298 }
299
300 static enum z_erofs_collectmode
301 try_to_claim_pcluster(struct z_erofs_pcluster *pcl,
302 z_erofs_next_pcluster_t *owned_head)
303 {
304 /* let's claim these following types of pclusters */
305 retry:
306 if (pcl->next == Z_EROFS_PCLUSTER_NIL) {
307 /* type 1, nil pcluster */
308 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
309 *owned_head) != Z_EROFS_PCLUSTER_NIL)
310 goto retry;
311
312 *owned_head = &pcl->next;
313 /* lucky, I am the followee :) */
314 return COLLECT_PRIMARY_FOLLOWED;
315 } else if (pcl->next == Z_EROFS_PCLUSTER_TAIL) {
316 /*
317 * type 2, link to the end of a existing open chain,
318 * be careful that its submission itself is governed
319 * by the original owned chain.
320 */
321 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
322 *owned_head) != Z_EROFS_PCLUSTER_TAIL)
323 goto retry;
324 *owned_head = Z_EROFS_PCLUSTER_TAIL;
325 return COLLECT_PRIMARY_HOOKED;
326 }
327 return COLLECT_PRIMARY; /* :( better luck next time */
328 }
329
330 static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
331 struct inode *inode,
332 struct erofs_map_blocks *map)
333 {
334 struct z_erofs_pcluster *pcl = clt->pcl;
335 struct z_erofs_collection *cl;
336 unsigned int length;
337
338 /* to avoid unexpected loop formed by corrupted images */
339 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
340 DBG_BUGON(1);
341 return -EFSCORRUPTED;
342 }
343
344 cl = z_erofs_primarycollection(pcl);
345 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) {
346 DBG_BUGON(1);
347 return -EFSCORRUPTED;
348 }
349
350 length = READ_ONCE(pcl->length);
351 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
352 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
353 DBG_BUGON(1);
354 return -EFSCORRUPTED;
355 }
356 } else {
357 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT;
358
359 if (map->m_flags & EROFS_MAP_FULL_MAPPED)
360 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH;
361
362 while (llen > length &&
363 length != cmpxchg_relaxed(&pcl->length, length, llen)) {
364 cpu_relax();
365 length = READ_ONCE(pcl->length);
366 }
367 }
368 mutex_lock(&cl->lock);
369 /* used to check tail merging loop due to corrupted images */
370 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
371 clt->tailpcl = pcl;
372 clt->mode = try_to_claim_pcluster(pcl, &clt->owned_head);
373 /* clean tailpcl if the current owned_head is Z_EROFS_PCLUSTER_TAIL */
374 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
375 clt->tailpcl = NULL;
376 clt->cl = cl;
377 return 0;
378 }
379
380 static int z_erofs_register_collection(struct z_erofs_collector *clt,
381 struct inode *inode,
382 struct erofs_map_blocks *map)
383 {
384 struct z_erofs_pcluster *pcl;
385 struct z_erofs_collection *cl;
386 struct erofs_workgroup *grp;
387 int err;
388
389 /* no available workgroup, let's allocate one */
390 pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS);
391 if (!pcl)
392 return -ENOMEM;
393
394 atomic_set(&pcl->obj.refcount, 1);
395 pcl->obj.index = map->m_pa >> PAGE_SHIFT;
396
397 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
398 (map->m_flags & EROFS_MAP_FULL_MAPPED ?
399 Z_EROFS_PCLUSTER_FULL_LENGTH : 0);
400
401 if (map->m_flags & EROFS_MAP_ZIPPED)
402 pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4;
403 else
404 pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
405
406 pcl->clusterbits = EROFS_I(inode)->z_physical_clusterbits[0];
407 pcl->clusterbits -= PAGE_SHIFT;
408
409 /* new pclusters should be claimed as type 1, primary and followed */
410 pcl->next = clt->owned_head;
411 clt->mode = COLLECT_PRIMARY_FOLLOWED;
412
413 cl = z_erofs_primarycollection(pcl);
414
415 /* must be cleaned before freeing to slab */
416 DBG_BUGON(cl->nr_pages);
417 DBG_BUGON(cl->vcnt);
418
419 cl->pageofs = map->m_la & ~PAGE_MASK;
420
421 /*
422 * lock all primary followed works before visible to others
423 * and mutex_trylock *never* fails for a new pcluster.
424 */
425 DBG_BUGON(!mutex_trylock(&cl->lock));
426
427 grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj);
428 if (IS_ERR(grp)) {
429 err = PTR_ERR(grp);
430 goto err_out;
431 }
432
433 if (grp != &pcl->obj) {
434 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
435 err = -EEXIST;
436 goto err_out;
437 }
438 /* used to check tail merging loop due to corrupted images */
439 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
440 clt->tailpcl = pcl;
441 clt->owned_head = &pcl->next;
442 clt->pcl = pcl;
443 clt->cl = cl;
444 return 0;
445
446 err_out:
447 mutex_unlock(&cl->lock);
448 kmem_cache_free(pcluster_cachep, pcl);
449 return err;
450 }
451
452 static int z_erofs_collector_begin(struct z_erofs_collector *clt,
453 struct inode *inode,
454 struct erofs_map_blocks *map)
455 {
456 struct erofs_workgroup *grp;
457 int ret;
458
459 DBG_BUGON(clt->cl);
460
461 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
462 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
463 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
464
465 if (!PAGE_ALIGNED(map->m_pa)) {
466 DBG_BUGON(1);
467 return -EINVAL;
468 }
469
470 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
471 if (grp) {
472 clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
473 } else {
474 ret = z_erofs_register_collection(clt, inode, map);
475
476 if (!ret)
477 goto out;
478 if (ret != -EEXIST)
479 return ret;
480 }
481
482 ret = z_erofs_lookup_collection(clt, inode, map);
483 if (ret) {
484 erofs_workgroup_put(&clt->pcl->obj);
485 return ret;
486 }
487
488 out:
489 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
490 clt->cl->pagevec, clt->cl->vcnt);
491
492 clt->compressedpages = clt->pcl->compressed_pages;
493 if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */
494 clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES;
495 return 0;
496 }
497
498 /*
499 * keep in mind that no referenced pclusters will be freed
500 * only after a RCU grace period.
501 */
502 static void z_erofs_rcu_callback(struct rcu_head *head)
503 {
504 struct z_erofs_collection *const cl =
505 container_of(head, struct z_erofs_collection, rcu);
506
507 kmem_cache_free(pcluster_cachep,
508 container_of(cl, struct z_erofs_pcluster,
509 primary_collection));
510 }
511
512 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
513 {
514 struct z_erofs_pcluster *const pcl =
515 container_of(grp, struct z_erofs_pcluster, obj);
516 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl);
517
518 call_rcu(&cl->rcu, z_erofs_rcu_callback);
519 }
520
521 static void z_erofs_collection_put(struct z_erofs_collection *cl)
522 {
523 struct z_erofs_pcluster *const pcl =
524 container_of(cl, struct z_erofs_pcluster, primary_collection);
525
526 erofs_workgroup_put(&pcl->obj);
527 }
528
529 static bool z_erofs_collector_end(struct z_erofs_collector *clt)
530 {
531 struct z_erofs_collection *cl = clt->cl;
532
533 if (!cl)
534 return false;
535
536 z_erofs_pagevec_ctor_exit(&clt->vector, false);
537 mutex_unlock(&cl->lock);
538
539 /*
540 * if all pending pages are added, don't hold its reference
541 * any longer if the pcluster isn't hosted by ourselves.
542 */
543 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
544 z_erofs_collection_put(cl);
545
546 clt->cl = NULL;
547 return true;
548 }
549
550 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
551 unsigned int cachestrategy,
552 erofs_off_t la)
553 {
554 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
555 return false;
556
557 if (fe->backmost)
558 return true;
559
560 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
561 la < fe->headoffset;
562 }
563
564 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
565 struct page *page,
566 struct list_head *pagepool)
567 {
568 struct inode *const inode = fe->inode;
569 struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
570 struct erofs_map_blocks *const map = &fe->map;
571 struct z_erofs_collector *const clt = &fe->clt;
572 const loff_t offset = page_offset(page);
573 bool tight = true;
574
575 enum z_erofs_cache_alloctype cache_strategy;
576 enum z_erofs_page_type page_type;
577 unsigned int cur, end, spiltted, index;
578 int err = 0;
579
580 /* register locked file pages as online pages in pack */
581 z_erofs_onlinepage_init(page);
582
583 spiltted = 0;
584 end = PAGE_SIZE;
585 repeat:
586 cur = end - 1;
587
588 /* lucky, within the range of the current map_blocks */
589 if (offset + cur >= map->m_la &&
590 offset + cur < map->m_la + map->m_llen) {
591 /* didn't get a valid collection previously (very rare) */
592 if (!clt->cl)
593 goto restart_now;
594 goto hitted;
595 }
596
597 /* go ahead the next map_blocks */
598 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur);
599
600 if (z_erofs_collector_end(clt))
601 fe->backmost = false;
602
603 map->m_la = offset + cur;
604 map->m_llen = 0;
605 err = z_erofs_map_blocks_iter(inode, map, 0);
606 if (err)
607 goto err_out;
608
609 restart_now:
610 if (!(map->m_flags & EROFS_MAP_MAPPED))
611 goto hitted;
612
613 err = z_erofs_collector_begin(clt, inode, map);
614 if (err)
615 goto err_out;
616
617 /* preload all compressed pages (maybe downgrade role if necessary) */
618 if (should_alloc_managed_pages(fe, sbi->cache_strategy, map->m_la))
619 cache_strategy = DELAYEDALLOC;
620 else
621 cache_strategy = DONTALLOC;
622
623 preload_compressed_pages(clt, MNGD_MAPPING(sbi),
624 cache_strategy, pagepool);
625
626 hitted:
627 /*
628 * Ensure the current partial page belongs to this submit chain rather
629 * than other concurrent submit chains or the noio(bypass) chain since
630 * those chains are handled asynchronously thus the page cannot be used
631 * for inplace I/O or pagevec (should be processed in strict order.)
632 */
633 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED &&
634 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);
635
636 cur = end - min_t(unsigned int, offset + end - map->m_la, end);
637 if (!(map->m_flags & EROFS_MAP_MAPPED)) {
638 zero_user_segment(page, cur, end);
639 goto next_part;
640 }
641
642 /* let's derive page type */
643 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
644 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
645 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
646 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
647
648 if (cur)
649 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
650
651 retry:
652 err = z_erofs_attach_page(clt, page, page_type);
653 /* should allocate an additional staging page for pagevec */
654 if (err == -EAGAIN) {
655 struct page *const newpage =
656 erofs_allocpage(pagepool, GFP_NOFS | __GFP_NOFAIL);
657
658 newpage->mapping = Z_EROFS_MAPPING_STAGING;
659 err = z_erofs_attach_page(clt, newpage,
660 Z_EROFS_PAGE_TYPE_EXCLUSIVE);
661 if (!err)
662 goto retry;
663 }
664
665 if (err)
666 goto err_out;
667
668 index = page->index - (map->m_la >> PAGE_SHIFT);
669
670 z_erofs_onlinepage_fixup(page, index, true);
671
672 /* bump up the number of spiltted parts of a page */
673 ++spiltted;
674 /* also update nr_pages */
675 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1);
676 next_part:
677 /* can be used for verification */
678 map->m_llen = offset + cur - map->m_la;
679
680 end = cur;
681 if (end > 0)
682 goto repeat;
683
684 out:
685 z_erofs_onlinepage_endio(page);
686
687 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu",
688 __func__, page, spiltted, map->m_llen);
689 return err;
690
691 /* if some error occurred while processing this page */
692 err_out:
693 SetPageError(page);
694 goto out;
695 }
696
697 static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io,
698 bool sync, int bios)
699 {
700 /* wake up the caller thread for sync decompression */
701 if (sync) {
702 unsigned long flags;
703
704 spin_lock_irqsave(&io->u.wait.lock, flags);
705 if (!atomic_add_return(bios, &io->pending_bios))
706 wake_up_locked(&io->u.wait);
707 spin_unlock_irqrestore(&io->u.wait.lock, flags);
708 return;
709 }
710
711 if (!atomic_add_return(bios, &io->pending_bios))
712 queue_work(z_erofs_workqueue, &io->u.work);
713 }
714
715 static void z_erofs_decompressqueue_endio(struct bio *bio)
716 {
717 tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private);
718 struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t);
719 blk_status_t err = bio->bi_status;
720 struct bio_vec *bvec;
721 struct bvec_iter_all iter_all;
722
723 bio_for_each_segment_all(bvec, bio, iter_all) {
724 struct page *page = bvec->bv_page;
725
726 DBG_BUGON(PageUptodate(page));
727 DBG_BUGON(!page->mapping);
728
729 if (err)
730 SetPageError(page);
731
732 if (erofs_page_is_managed(EROFS_SB(q->sb), page)) {
733 if (!err)
734 SetPageUptodate(page);
735 unlock_page(page);
736 }
737 }
738 z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1);
739 bio_put(bio);
740 }
741
742 static int z_erofs_decompress_pcluster(struct super_block *sb,
743 struct z_erofs_pcluster *pcl,
744 struct list_head *pagepool)
745 {
746 struct erofs_sb_info *const sbi = EROFS_SB(sb);
747 const unsigned int clusterpages = BIT(pcl->clusterbits);
748 struct z_erofs_pagevec_ctor ctor;
749 unsigned int i, outputsize, llen, nr_pages;
750 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES];
751 struct page **pages, **compressed_pages, *page;
752
753 enum z_erofs_page_type page_type;
754 bool overlapped, partial;
755 struct z_erofs_collection *cl;
756 int err;
757
758 might_sleep();
759 cl = z_erofs_primarycollection(pcl);
760 DBG_BUGON(!READ_ONCE(cl->nr_pages));
761
762 mutex_lock(&cl->lock);
763 nr_pages = cl->nr_pages;
764
765 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) {
766 pages = pages_onstack;
767 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES &&
768 mutex_trylock(&z_pagemap_global_lock)) {
769 pages = z_pagemap_global;
770 } else {
771 gfp_t gfp_flags = GFP_KERNEL;
772
773 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES)
774 gfp_flags |= __GFP_NOFAIL;
775
776 pages = kvmalloc_array(nr_pages, sizeof(struct page *),
777 gfp_flags);
778
779 /* fallback to global pagemap for the lowmem scenario */
780 if (!pages) {
781 mutex_lock(&z_pagemap_global_lock);
782 pages = z_pagemap_global;
783 }
784 }
785
786 for (i = 0; i < nr_pages; ++i)
787 pages[i] = NULL;
788
789 err = 0;
790 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS,
791 cl->pagevec, 0);
792
793 for (i = 0; i < cl->vcnt; ++i) {
794 unsigned int pagenr;
795
796 page = z_erofs_pagevec_dequeue(&ctor, &page_type);
797
798 /* all pages in pagevec ought to be valid */
799 DBG_BUGON(!page);
800 DBG_BUGON(!page->mapping);
801
802 if (z_erofs_put_stagingpage(pagepool, page))
803 continue;
804
805 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
806 pagenr = 0;
807 else
808 pagenr = z_erofs_onlinepage_index(page);
809
810 DBG_BUGON(pagenr >= nr_pages);
811
812 /*
813 * currently EROFS doesn't support multiref(dedup),
814 * so here erroring out one multiref page.
815 */
816 if (pages[pagenr]) {
817 DBG_BUGON(1);
818 SetPageError(pages[pagenr]);
819 z_erofs_onlinepage_endio(pages[pagenr]);
820 err = -EFSCORRUPTED;
821 }
822 pages[pagenr] = page;
823 }
824 z_erofs_pagevec_ctor_exit(&ctor, true);
825
826 overlapped = false;
827 compressed_pages = pcl->compressed_pages;
828
829 for (i = 0; i < clusterpages; ++i) {
830 unsigned int pagenr;
831
832 page = compressed_pages[i];
833
834 /* all compressed pages ought to be valid */
835 DBG_BUGON(!page);
836 DBG_BUGON(!page->mapping);
837
838 if (!z_erofs_page_is_staging(page)) {
839 if (erofs_page_is_managed(sbi, page)) {
840 if (!PageUptodate(page))
841 err = -EIO;
842 continue;
843 }
844
845 /*
846 * only if non-head page can be selected
847 * for inplace decompression
848 */
849 pagenr = z_erofs_onlinepage_index(page);
850
851 DBG_BUGON(pagenr >= nr_pages);
852 if (pages[pagenr]) {
853 DBG_BUGON(1);
854 SetPageError(pages[pagenr]);
855 z_erofs_onlinepage_endio(pages[pagenr]);
856 err = -EFSCORRUPTED;
857 }
858 pages[pagenr] = page;
859
860 overlapped = true;
861 }
862
863 /* PG_error needs checking for inplaced and staging pages */
864 if (PageError(page)) {
865 DBG_BUGON(PageUptodate(page));
866 err = -EIO;
867 }
868 }
869
870 if (err)
871 goto out;
872
873 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT;
874 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) {
875 outputsize = llen;
876 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH);
877 } else {
878 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs;
879 partial = true;
880 }
881
882 err = z_erofs_decompress(&(struct z_erofs_decompress_req) {
883 .sb = sb,
884 .in = compressed_pages,
885 .out = pages,
886 .pageofs_out = cl->pageofs,
887 .inputsize = PAGE_SIZE,
888 .outputsize = outputsize,
889 .alg = pcl->algorithmformat,
890 .inplace_io = overlapped,
891 .partial_decoding = partial
892 }, pagepool);
893
894 out:
895 /* must handle all compressed pages before endding pages */
896 for (i = 0; i < clusterpages; ++i) {
897 page = compressed_pages[i];
898
899 if (erofs_page_is_managed(sbi, page))
900 continue;
901
902 /* recycle all individual staging pages */
903 (void)z_erofs_put_stagingpage(pagepool, page);
904
905 WRITE_ONCE(compressed_pages[i], NULL);
906 }
907
908 for (i = 0; i < nr_pages; ++i) {
909 page = pages[i];
910 if (!page)
911 continue;
912
913 DBG_BUGON(!page->mapping);
914
915 /* recycle all individual staging pages */
916 if (z_erofs_put_stagingpage(pagepool, page))
917 continue;
918
919 if (err < 0)
920 SetPageError(page);
921
922 z_erofs_onlinepage_endio(page);
923 }
924
925 if (pages == z_pagemap_global)
926 mutex_unlock(&z_pagemap_global_lock);
927 else if (pages != pages_onstack)
928 kvfree(pages);
929
930 cl->nr_pages = 0;
931 cl->vcnt = 0;
932
933 /* all cl locks MUST be taken before the following line */
934 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL);
935
936 /* all cl locks SHOULD be released right now */
937 mutex_unlock(&cl->lock);
938
939 z_erofs_collection_put(cl);
940 return err;
941 }
942
943 static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io,
944 struct list_head *pagepool)
945 {
946 z_erofs_next_pcluster_t owned = io->head;
947
948 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) {
949 struct z_erofs_pcluster *pcl;
950
951 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
952 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL);
953
954 /* no possible that 'owned' equals NULL */
955 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL);
956
957 pcl = container_of(owned, struct z_erofs_pcluster, next);
958 owned = READ_ONCE(pcl->next);
959
960 z_erofs_decompress_pcluster(io->sb, pcl, pagepool);
961 }
962 }
963
964 static void z_erofs_decompressqueue_work(struct work_struct *work)
965 {
966 struct z_erofs_decompressqueue *bgq =
967 container_of(work, struct z_erofs_decompressqueue, u.work);
968 LIST_HEAD(pagepool);
969
970 DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
971 z_erofs_decompress_queue(bgq, &pagepool);
972
973 put_pages_list(&pagepool);
974 kvfree(bgq);
975 }
976
977 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
978 unsigned int nr,
979 struct list_head *pagepool,
980 struct address_space *mc,
981 gfp_t gfp)
982 {
983 const pgoff_t index = pcl->obj.index;
984 bool tocache = false;
985
986 struct address_space *mapping;
987 struct page *oldpage, *page;
988
989 compressed_page_t t;
990 int justfound;
991
992 repeat:
993 page = READ_ONCE(pcl->compressed_pages[nr]);
994 oldpage = page;
995
996 if (!page)
997 goto out_allocpage;
998
999 /*
1000 * the cached page has not been allocated and
1001 * an placeholder is out there, prepare it now.
1002 */
1003 if (page == PAGE_UNALLOCATED) {
1004 tocache = true;
1005 goto out_allocpage;
1006 }
1007
1008 /* process the target tagged pointer */
1009 t = tagptr_init(compressed_page_t, page);
1010 justfound = tagptr_unfold_tags(t);
1011 page = tagptr_unfold_ptr(t);
1012
1013 mapping = READ_ONCE(page->mapping);
1014
1015 /*
1016 * unmanaged (file) pages are all locked solidly,
1017 * therefore it is impossible for `mapping' to be NULL.
1018 */
1019 if (mapping && mapping != mc)
1020 /* ought to be unmanaged pages */
1021 goto out;
1022
1023 lock_page(page);
1024
1025 /* only true if page reclaim goes wrong, should never happen */
1026 DBG_BUGON(justfound && PagePrivate(page));
1027
1028 /* the page is still in manage cache */
1029 if (page->mapping == mc) {
1030 WRITE_ONCE(pcl->compressed_pages[nr], page);
1031
1032 ClearPageError(page);
1033 if (!PagePrivate(page)) {
1034 /*
1035 * impossible to be !PagePrivate(page) for
1036 * the current restriction as well if
1037 * the page is already in compressed_pages[].
1038 */
1039 DBG_BUGON(!justfound);
1040
1041 justfound = 0;
1042 set_page_private(page, (unsigned long)pcl);
1043 SetPagePrivate(page);
1044 }
1045
1046 /* no need to submit io if it is already up-to-date */
1047 if (PageUptodate(page)) {
1048 unlock_page(page);
1049 page = NULL;
1050 }
1051 goto out;
1052 }
1053
1054 /*
1055 * the managed page has been truncated, it's unsafe to
1056 * reuse this one, let's allocate a new cache-managed page.
1057 */
1058 DBG_BUGON(page->mapping);
1059 DBG_BUGON(!justfound);
1060
1061 tocache = true;
1062 unlock_page(page);
1063 put_page(page);
1064 out_allocpage:
1065 page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL);
1066 if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) {
1067 /* non-LRU / non-movable temporary page is needed */
1068 page->mapping = Z_EROFS_MAPPING_STAGING;
1069 tocache = false;
1070 }
1071
1072 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) {
1073 if (tocache) {
1074 /* since it added to managed cache successfully */
1075 unlock_page(page);
1076 put_page(page);
1077 } else {
1078 list_add(&page->lru, pagepool);
1079 }
1080 cond_resched();
1081 goto repeat;
1082 }
1083 set_page_private(page, (unsigned long)pcl);
1084 SetPagePrivate(page);
1085 out: /* the only exit (for tracing and debugging) */
1086 return page;
1087 }
1088
1089 static struct z_erofs_decompressqueue *
1090 jobqueue_init(struct super_block *sb,
1091 struct z_erofs_decompressqueue *fgq, bool *fg)
1092 {
1093 struct z_erofs_decompressqueue *q;
1094
1095 if (fg && !*fg) {
1096 q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN);
1097 if (!q) {
1098 *fg = true;
1099 goto fg_out;
1100 }
1101 INIT_WORK(&q->u.work, z_erofs_decompressqueue_work);
1102 } else {
1103 fg_out:
1104 q = fgq;
1105 init_waitqueue_head(&fgq->u.wait);
1106 atomic_set(&fgq->pending_bios, 0);
1107 }
1108 q->sb = sb;
1109 q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
1110 return q;
1111 }
1112
1113 /* define decompression jobqueue types */
1114 enum {
1115 JQ_BYPASS,
1116 JQ_SUBMIT,
1117 NR_JOBQUEUES,
1118 };
1119
1120 static void *jobqueueset_init(struct super_block *sb,
1121 struct z_erofs_decompressqueue *q[],
1122 struct z_erofs_decompressqueue *fgq, bool *fg)
1123 {
1124 /*
1125 * if managed cache is enabled, bypass jobqueue is needed,
1126 * no need to read from device for all pclusters in this queue.
1127 */
1128 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL);
1129 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg);
1130
1131 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg));
1132 }
1133
1134 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
1135 z_erofs_next_pcluster_t qtail[],
1136 z_erofs_next_pcluster_t owned_head)
1137 {
1138 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT];
1139 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS];
1140
1141 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
1142 if (owned_head == Z_EROFS_PCLUSTER_TAIL)
1143 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
1144
1145 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED);
1146
1147 WRITE_ONCE(*submit_qtail, owned_head);
1148 WRITE_ONCE(*bypass_qtail, &pcl->next);
1149
1150 qtail[JQ_BYPASS] = &pcl->next;
1151 }
1152
1153 static void z_erofs_submit_queue(struct super_block *sb,
1154 z_erofs_next_pcluster_t owned_head,
1155 struct list_head *pagepool,
1156 struct z_erofs_decompressqueue *fgq,
1157 bool *force_fg)
1158 {
1159 struct erofs_sb_info *const sbi = EROFS_SB(sb);
1160 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES];
1161 struct z_erofs_decompressqueue *q[NR_JOBQUEUES];
1162 void *bi_private;
1163 /* since bio will be NULL, no need to initialize last_index */
1164 pgoff_t uninitialized_var(last_index);
1165 unsigned int nr_bios = 0;
1166 struct bio *bio = NULL;
1167
1168 bi_private = jobqueueset_init(sb, q, fgq, force_fg);
1169 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head;
1170 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head;
1171
1172 /* by default, all need io submission */
1173 q[JQ_SUBMIT]->head = owned_head;
1174
1175 do {
1176 struct z_erofs_pcluster *pcl;
1177 pgoff_t cur, end;
1178 unsigned int i = 0;
1179 bool bypass = true;
1180
1181 /* no possible 'owned_head' equals the following */
1182 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
1183 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL);
1184
1185 pcl = container_of(owned_head, struct z_erofs_pcluster, next);
1186
1187 cur = pcl->obj.index;
1188 end = cur + BIT(pcl->clusterbits);
1189
1190 /* close the main owned chain at first */
1191 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
1192 Z_EROFS_PCLUSTER_TAIL_CLOSED);
1193
1194 do {
1195 struct page *page;
1196 int err;
1197
1198 page = pickup_page_for_submission(pcl, i++, pagepool,
1199 MNGD_MAPPING(sbi),
1200 GFP_NOFS);
1201 if (!page)
1202 continue;
1203
1204 if (bio && cur != last_index + 1) {
1205 submit_bio_retry:
1206 submit_bio(bio);
1207 bio = NULL;
1208 }
1209
1210 if (!bio) {
1211 bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);
1212
1213 bio->bi_end_io = z_erofs_decompressqueue_endio;
1214 bio_set_dev(bio, sb->s_bdev);
1215 bio->bi_iter.bi_sector = (sector_t)cur <<
1216 LOG_SECTORS_PER_BLOCK;
1217 bio->bi_private = bi_private;
1218 bio->bi_opf = REQ_OP_READ;
1219 ++nr_bios;
1220 }
1221
1222 err = bio_add_page(bio, page, PAGE_SIZE, 0);
1223 if (err < PAGE_SIZE)
1224 goto submit_bio_retry;
1225
1226 last_index = cur;
1227 bypass = false;
1228 } while (++cur < end);
1229
1230 if (!bypass)
1231 qtail[JQ_SUBMIT] = &pcl->next;
1232 else
1233 move_to_bypass_jobqueue(pcl, qtail, owned_head);
1234 } while (owned_head != Z_EROFS_PCLUSTER_TAIL);
1235
1236 if (bio)
1237 submit_bio(bio);
1238
1239 /*
1240 * although background is preferred, no one is pending for submission.
1241 * don't issue workqueue for decompression but drop it directly instead.
1242 */
1243 if (!*force_fg && !nr_bios) {
1244 kvfree(q[JQ_SUBMIT]);
1245 return;
1246 }
1247 z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios);
1248 }
1249
1250 static void z_erofs_runqueue(struct super_block *sb,
1251 struct z_erofs_collector *clt,
1252 struct list_head *pagepool, bool force_fg)
1253 {
1254 struct z_erofs_decompressqueue io[NR_JOBQUEUES];
1255
1256 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
1257 return;
1258 z_erofs_submit_queue(sb, clt->owned_head, pagepool, io, &force_fg);
1259
1260 /* handle bypass queue (no i/o pclusters) immediately */
1261 z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool);
1262
1263 if (!force_fg)
1264 return;
1265
1266 /* wait until all bios are completed */
1267 io_wait_event(io[JQ_SUBMIT].u.wait,
1268 !atomic_read(&io[JQ_SUBMIT].pending_bios));
1269
1270 /* handle synchronous decompress queue in the caller context */
1271 z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool);
1272 }
1273
1274 static int z_erofs_readpage(struct file *file, struct page *page)
1275 {
1276 struct inode *const inode = page->mapping->host;
1277 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
1278 int err;
1279 LIST_HEAD(pagepool);
1280
1281 trace_erofs_readpage(page, false);
1282
1283 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT;
1284
1285 err = z_erofs_do_read_page(&f, page, &pagepool);
1286 (void)z_erofs_collector_end(&f.clt);
1287
1288 /* if some compressed cluster ready, need submit them anyway */
1289 z_erofs_runqueue(inode->i_sb, &f.clt, &pagepool, true);
1290
1291 if (err)
1292 erofs_err(inode->i_sb, "failed to read, err [%d]", err);
1293
1294 if (f.map.mpage)
1295 put_page(f.map.mpage);
1296
1297 /* clean up the remaining free pages */
1298 put_pages_list(&pagepool);
1299 return err;
1300 }
1301
1302 static bool should_decompress_synchronously(struct erofs_sb_info *sbi,
1303 unsigned int nr)
1304 {
1305 return nr <= sbi->max_sync_decompress_pages;
1306 }
1307
1308 static int z_erofs_readpages(struct file *filp, struct address_space *mapping,
1309 struct list_head *pages, unsigned int nr_pages)
1310 {
1311 struct inode *const inode = mapping->host;
1312 struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
1313
1314 bool sync = should_decompress_synchronously(sbi, nr_pages);
1315 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
1316 gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
1317 struct page *head = NULL;
1318 LIST_HEAD(pagepool);
1319
1320 trace_erofs_readpages(mapping->host, lru_to_page(pages),
1321 nr_pages, false);
1322
1323 f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
1324
1325 for (; nr_pages; --nr_pages) {
1326 struct page *page = lru_to_page(pages);
1327
1328 prefetchw(&page->flags);
1329 list_del(&page->lru);
1330
1331 /*
1332 * A pure asynchronous readahead is indicated if
1333 * a PG_readahead marked page is hitted at first.
1334 * Let's also do asynchronous decompression for this case.
1335 */
1336 sync &= !(PageReadahead(page) && !head);
1337
1338 if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
1339 list_add(&page->lru, &pagepool);
1340 continue;
1341 }
1342
1343 set_page_private(page, (unsigned long)head);
1344 head = page;
1345 }
1346
1347 while (head) {
1348 struct page *page = head;
1349 int err;
1350
1351 /* traversal in reverse order */
1352 head = (void *)page_private(page);
1353
1354 err = z_erofs_do_read_page(&f, page, &pagepool);
1355 if (err)
1356 erofs_err(inode->i_sb,
1357 "readahead error at page %lu @ nid %llu",
1358 page->index, EROFS_I(inode)->nid);
1359 put_page(page);
1360 }
1361
1362 (void)z_erofs_collector_end(&f.clt);
1363
1364 z_erofs_runqueue(inode->i_sb, &f.clt, &pagepool, sync);
1365
1366 if (f.map.mpage)
1367 put_page(f.map.mpage);
1368
1369 /* clean up the remaining free pages */
1370 put_pages_list(&pagepool);
1371 return 0;
1372 }
1373
1374 const struct address_space_operations z_erofs_aops = {
1375 .readpage = z_erofs_readpage,
1376 .readpages = z_erofs_readpages,
1377 };
1378
Linux with added FPC-III support