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
z_erofs_exit_zip_subsystem(void)37 void z_erofs_exit_zip_subsystem(void)
38 {
39 destroy_workqueue(z_erofs_workqueue);
40 kmem_cache_destroy(pcluster_cachep);
41 }
42
z_erofs_init_workqueue(void)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
z_erofs_pcluster_init_once(void * ptr)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
z_erofs_pcluster_init_always(struct z_erofs_pcluster * pcl)70 static void z_erofs_pcluster_init_always(struct z_erofs_pcluster *pcl)
71 {
72 struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
73
74 atomic_set(&pcl->obj.refcount, 1);
75
76 DBG_BUGON(cl->nr_pages);
77 DBG_BUGON(cl->vcnt);
78 }
79
z_erofs_init_zip_subsystem(void)80 int __init z_erofs_init_zip_subsystem(void)
81 {
82 pcluster_cachep = kmem_cache_create("erofs_compress",
83 Z_EROFS_WORKGROUP_SIZE, 0,
84 SLAB_RECLAIM_ACCOUNT,
85 z_erofs_pcluster_init_once);
86 if (pcluster_cachep) {
87 if (!z_erofs_init_workqueue())
88 return 0;
89
90 kmem_cache_destroy(pcluster_cachep);
91 }
92 return -ENOMEM;
93 }
94
95 enum z_erofs_collectmode {
96 COLLECT_SECONDARY,
97 COLLECT_PRIMARY,
98 /*
99 * The current collection was the tail of an exist chain, in addition
100 * that the previous processed chained collections are all decided to
101 * be hooked up to it.
102 * A new chain will be created for the remaining collections which are
103 * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED,
104 * the next collection cannot reuse the whole page safely in
105 * the following scenario:
106 * ________________________________________________________________
107 * | tail (partial) page | head (partial) page |
108 * | (belongs to the next cl) | (belongs to the current cl) |
109 * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
110 */
111 COLLECT_PRIMARY_HOOKED,
112 COLLECT_PRIMARY_FOLLOWED_NOINPLACE,
113 /*
114 * The current collection has been linked with the owned chain, and
115 * could also be linked with the remaining collections, which means
116 * if the processing page is the tail page of the collection, thus
117 * the current collection can safely use the whole page (since
118 * the previous collection is under control) for in-place I/O, as
119 * illustrated below:
120 * ________________________________________________________________
121 * | tail (partial) page | head (partial) page |
122 * | (of the current cl) | (of the previous collection) |
123 * | PRIMARY_FOLLOWED or | |
124 * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
125 *
126 * [ (*) the above page can be used as inplace I/O. ]
127 */
128 COLLECT_PRIMARY_FOLLOWED,
129 };
130
131 struct z_erofs_collector {
132 struct z_erofs_pagevec_ctor vector;
133
134 struct z_erofs_pcluster *pcl, *tailpcl;
135 struct z_erofs_collection *cl;
136 struct page **compressedpages;
137 z_erofs_next_pcluster_t owned_head;
138
139 enum z_erofs_collectmode mode;
140 };
141
142 struct z_erofs_decompress_frontend {
143 struct inode *const inode;
144
145 struct z_erofs_collector clt;
146 struct erofs_map_blocks map;
147
148 /* used for applying cache strategy on the fly */
149 bool backmost;
150 erofs_off_t headoffset;
151 };
152
153 #define COLLECTOR_INIT() { \
154 .owned_head = Z_EROFS_PCLUSTER_TAIL, \
155 .mode = COLLECT_PRIMARY_FOLLOWED }
156
157 #define DECOMPRESS_FRONTEND_INIT(__i) { \
158 .inode = __i, .clt = COLLECTOR_INIT(), \
159 .backmost = true, }
160
161 static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
162 static DEFINE_MUTEX(z_pagemap_global_lock);
163
preload_compressed_pages(struct z_erofs_collector * clt,struct address_space * mc,enum z_erofs_cache_alloctype type,struct list_head * pagepool)164 static void preload_compressed_pages(struct z_erofs_collector *clt,
165 struct address_space *mc,
166 enum z_erofs_cache_alloctype type,
167 struct list_head *pagepool)
168 {
169 const struct z_erofs_pcluster *pcl = clt->pcl;
170 const unsigned int clusterpages = BIT(pcl->clusterbits);
171 struct page **pages = clt->compressedpages;
172 pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages);
173 bool standalone = true;
174
175 if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
176 return;
177
178 for (; pages < pcl->compressed_pages + clusterpages; ++pages) {
179 struct page *page;
180 compressed_page_t t;
181
182 /* the compressed page was loaded before */
183 if (READ_ONCE(*pages))
184 continue;
185
186 page = find_get_page(mc, index);
187
188 if (page) {
189 t = tag_compressed_page_justfound(page);
190 } else if (type == DELAYEDALLOC) {
191 t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
192 } else { /* DONTALLOC */
193 if (standalone)
194 clt->compressedpages = pages;
195 standalone = false;
196 continue;
197 }
198
199 if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
200 continue;
201
202 if (page)
203 put_page(page);
204 }
205
206 if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */
207 clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
208 }
209
210 /* called by erofs_shrinker to get rid of all compressed_pages */
erofs_try_to_free_all_cached_pages(struct erofs_sb_info * sbi,struct erofs_workgroup * grp)211 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
212 struct erofs_workgroup *grp)
213 {
214 struct z_erofs_pcluster *const pcl =
215 container_of(grp, struct z_erofs_pcluster, obj);
216 struct address_space *const mapping = MNGD_MAPPING(sbi);
217 const unsigned int clusterpages = BIT(pcl->clusterbits);
218 int i;
219
220 /*
221 * refcount of workgroup is now freezed as 1,
222 * therefore no need to worry about available decompression users.
223 */
224 for (i = 0; i < clusterpages; ++i) {
225 struct page *page = pcl->compressed_pages[i];
226
227 if (!page)
228 continue;
229
230 /* block other users from reclaiming or migrating the page */
231 if (!trylock_page(page))
232 return -EBUSY;
233
234 if (page->mapping != mapping)
235 continue;
236
237 /* barrier is implied in the following 'unlock_page' */
238 WRITE_ONCE(pcl->compressed_pages[i], NULL);
239 set_page_private(page, 0);
240 ClearPagePrivate(page);
241
242 unlock_page(page);
243 put_page(page);
244 }
245 return 0;
246 }
247
erofs_try_to_free_cached_page(struct address_space * mapping,struct page * page)248 int erofs_try_to_free_cached_page(struct address_space *mapping,
249 struct page *page)
250 {
251 struct z_erofs_pcluster *const pcl = (void *)page_private(page);
252 const unsigned int clusterpages = BIT(pcl->clusterbits);
253 int ret = 0; /* 0 - busy */
254
255 if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) {
256 unsigned int i;
257
258 for (i = 0; i < clusterpages; ++i) {
259 if (pcl->compressed_pages[i] == page) {
260 WRITE_ONCE(pcl->compressed_pages[i], NULL);
261 ret = 1;
262 break;
263 }
264 }
265 erofs_workgroup_unfreeze(&pcl->obj, 1);
266
267 if (ret) {
268 ClearPagePrivate(page);
269 put_page(page);
270 }
271 }
272 return ret;
273 }
274
275 /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
z_erofs_try_inplace_io(struct z_erofs_collector * clt,struct page * page)276 static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
277 struct page *page)
278 {
279 struct z_erofs_pcluster *const pcl = clt->pcl;
280 const unsigned int clusterpages = BIT(pcl->clusterbits);
281
282 while (clt->compressedpages < pcl->compressed_pages + clusterpages) {
283 if (!cmpxchg(clt->compressedpages++, NULL, page))
284 return true;
285 }
286 return false;
287 }
288
289 /* callers must be with collection lock held */
z_erofs_attach_page(struct z_erofs_collector * clt,struct page * page,enum z_erofs_page_type type,bool pvec_safereuse)290 static int z_erofs_attach_page(struct z_erofs_collector *clt,
291 struct page *page, enum z_erofs_page_type type,
292 bool pvec_safereuse)
293 {
294 int ret;
295
296 /* give priority for inplaceio */
297 if (clt->mode >= COLLECT_PRIMARY &&
298 type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
299 z_erofs_try_inplace_io(clt, page))
300 return 0;
301
302 ret = z_erofs_pagevec_enqueue(&clt->vector, page, type,
303 pvec_safereuse);
304 clt->cl->vcnt += (unsigned int)ret;
305 return ret ? 0 : -EAGAIN;
306 }
307
308 static enum z_erofs_collectmode
try_to_claim_pcluster(struct z_erofs_pcluster * pcl,z_erofs_next_pcluster_t * owned_head)309 try_to_claim_pcluster(struct z_erofs_pcluster *pcl,
310 z_erofs_next_pcluster_t *owned_head)
311 {
312 /* let's claim these following types of pclusters */
313 retry:
314 if (pcl->next == Z_EROFS_PCLUSTER_NIL) {
315 /* type 1, nil pcluster */
316 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
317 *owned_head) != Z_EROFS_PCLUSTER_NIL)
318 goto retry;
319
320 *owned_head = &pcl->next;
321 /* lucky, I am the followee :) */
322 return COLLECT_PRIMARY_FOLLOWED;
323 } else if (pcl->next == Z_EROFS_PCLUSTER_TAIL) {
324 /*
325 * type 2, link to the end of a existing open chain,
326 * be careful that its submission itself is governed
327 * by the original owned chain.
328 */
329 if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
330 *owned_head) != Z_EROFS_PCLUSTER_TAIL)
331 goto retry;
332 *owned_head = Z_EROFS_PCLUSTER_TAIL;
333 return COLLECT_PRIMARY_HOOKED;
334 }
335 return COLLECT_PRIMARY; /* :( better luck next time */
336 }
337
cllookup(struct z_erofs_collector * clt,struct inode * inode,struct erofs_map_blocks * map)338 static struct z_erofs_collection *cllookup(struct z_erofs_collector *clt,
339 struct inode *inode,
340 struct erofs_map_blocks *map)
341 {
342 struct erofs_workgroup *grp;
343 struct z_erofs_pcluster *pcl;
344 struct z_erofs_collection *cl;
345 unsigned int length;
346 bool tag;
347
348 grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT, &tag);
349 if (!grp)
350 return NULL;
351
352 pcl = container_of(grp, struct z_erofs_pcluster, obj);
353 if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
354 DBG_BUGON(1);
355 erofs_workgroup_put(grp);
356 return ERR_PTR(-EFSCORRUPTED);
357 }
358
359 cl = z_erofs_primarycollection(pcl);
360 if (cl->pageofs != (map->m_la & ~PAGE_MASK)) {
361 DBG_BUGON(1);
362 erofs_workgroup_put(grp);
363 return ERR_PTR(-EFSCORRUPTED);
364 }
365
366 length = READ_ONCE(pcl->length);
367 if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
368 if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
369 DBG_BUGON(1);
370 erofs_workgroup_put(grp);
371 return ERR_PTR(-EFSCORRUPTED);
372 }
373 } else {
374 unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT;
375
376 if (map->m_flags & EROFS_MAP_FULL_MAPPED)
377 llen |= Z_EROFS_PCLUSTER_FULL_LENGTH;
378
379 while (llen > length &&
380 length != cmpxchg_relaxed(&pcl->length, length, llen)) {
381 cpu_relax();
382 length = READ_ONCE(pcl->length);
383 }
384 }
385 mutex_lock(&cl->lock);
386 /* used to check tail merging loop due to corrupted images */
387 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
388 clt->tailpcl = pcl;
389 clt->mode = try_to_claim_pcluster(pcl, &clt->owned_head);
390 /* clean tailpcl if the current owned_head is Z_EROFS_PCLUSTER_TAIL */
391 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
392 clt->tailpcl = NULL;
393 clt->pcl = pcl;
394 clt->cl = cl;
395 return cl;
396 }
397
clregister(struct z_erofs_collector * clt,struct inode * inode,struct erofs_map_blocks * map)398 static struct z_erofs_collection *clregister(struct z_erofs_collector *clt,
399 struct inode *inode,
400 struct erofs_map_blocks *map)
401 {
402 struct z_erofs_pcluster *pcl;
403 struct z_erofs_collection *cl;
404 int err;
405
406 /* no available workgroup, let's allocate one */
407 pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS);
408 if (!pcl)
409 return ERR_PTR(-ENOMEM);
410
411 z_erofs_pcluster_init_always(pcl);
412 pcl->obj.index = map->m_pa >> PAGE_SHIFT;
413
414 pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
415 (map->m_flags & EROFS_MAP_FULL_MAPPED ?
416 Z_EROFS_PCLUSTER_FULL_LENGTH : 0);
417
418 if (map->m_flags & EROFS_MAP_ZIPPED)
419 pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4;
420 else
421 pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
422
423 pcl->clusterbits = EROFS_I(inode)->z_physical_clusterbits[0];
424 pcl->clusterbits -= PAGE_SHIFT;
425
426 /* new pclusters should be claimed as type 1, primary and followed */
427 pcl->next = clt->owned_head;
428 clt->mode = COLLECT_PRIMARY_FOLLOWED;
429
430 cl = z_erofs_primarycollection(pcl);
431 cl->pageofs = map->m_la & ~PAGE_MASK;
432
433 /*
434 * lock all primary followed works before visible to others
435 * and mutex_trylock *never* fails for a new pcluster.
436 */
437 mutex_trylock(&cl->lock);
438
439 err = erofs_register_workgroup(inode->i_sb, &pcl->obj, 0);
440 if (err) {
441 mutex_unlock(&cl->lock);
442 kmem_cache_free(pcluster_cachep, pcl);
443 return ERR_PTR(-EAGAIN);
444 }
445 /* used to check tail merging loop due to corrupted images */
446 if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
447 clt->tailpcl = pcl;
448 clt->owned_head = &pcl->next;
449 clt->pcl = pcl;
450 clt->cl = cl;
451 return cl;
452 }
453
z_erofs_collector_begin(struct z_erofs_collector * clt,struct inode * inode,struct erofs_map_blocks * map)454 static int z_erofs_collector_begin(struct z_erofs_collector *clt,
455 struct inode *inode,
456 struct erofs_map_blocks *map)
457 {
458 struct z_erofs_collection *cl;
459
460 DBG_BUGON(clt->cl);
461
462 /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
463 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
464 DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
465
466 if (!PAGE_ALIGNED(map->m_pa)) {
467 DBG_BUGON(1);
468 return -EINVAL;
469 }
470
471 repeat:
472 cl = cllookup(clt, inode, map);
473 if (!cl) {
474 cl = clregister(clt, inode, map);
475
476 if (cl == ERR_PTR(-EAGAIN))
477 goto repeat;
478 }
479
480 if (IS_ERR(cl))
481 return PTR_ERR(cl);
482
483 z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
484 cl->pagevec, cl->vcnt);
485
486 clt->compressedpages = clt->pcl->compressed_pages;
487 if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */
488 clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES;
489 return 0;
490 }
491
492 /*
493 * keep in mind that no referenced pclusters will be freed
494 * only after a RCU grace period.
495 */
z_erofs_rcu_callback(struct rcu_head * head)496 static void z_erofs_rcu_callback(struct rcu_head *head)
497 {
498 struct z_erofs_collection *const cl =
499 container_of(head, struct z_erofs_collection, rcu);
500
501 kmem_cache_free(pcluster_cachep,
502 container_of(cl, struct z_erofs_pcluster,
503 primary_collection));
504 }
505
erofs_workgroup_free_rcu(struct erofs_workgroup * grp)506 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
507 {
508 struct z_erofs_pcluster *const pcl =
509 container_of(grp, struct z_erofs_pcluster, obj);
510 struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl);
511
512 call_rcu(&cl->rcu, z_erofs_rcu_callback);
513 }
514
z_erofs_collection_put(struct z_erofs_collection * cl)515 static void z_erofs_collection_put(struct z_erofs_collection *cl)
516 {
517 struct z_erofs_pcluster *const pcl =
518 container_of(cl, struct z_erofs_pcluster, primary_collection);
519
520 erofs_workgroup_put(&pcl->obj);
521 }
522
z_erofs_collector_end(struct z_erofs_collector * clt)523 static bool z_erofs_collector_end(struct z_erofs_collector *clt)
524 {
525 struct z_erofs_collection *cl = clt->cl;
526
527 if (!cl)
528 return false;
529
530 z_erofs_pagevec_ctor_exit(&clt->vector, false);
531 mutex_unlock(&cl->lock);
532
533 /*
534 * if all pending pages are added, don't hold its reference
535 * any longer if the pcluster isn't hosted by ourselves.
536 */
537 if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
538 z_erofs_collection_put(cl);
539
540 clt->cl = NULL;
541 return true;
542 }
543
__stagingpage_alloc(struct list_head * pagepool,gfp_t gfp)544 static inline struct page *__stagingpage_alloc(struct list_head *pagepool,
545 gfp_t gfp)
546 {
547 struct page *page = erofs_allocpage(pagepool, gfp, true);
548
549 page->mapping = Z_EROFS_MAPPING_STAGING;
550 return page;
551 }
552
should_alloc_managed_pages(struct z_erofs_decompress_frontend * fe,unsigned int cachestrategy,erofs_off_t la)553 static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
554 unsigned int cachestrategy,
555 erofs_off_t la)
556 {
557 if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
558 return false;
559
560 if (fe->backmost)
561 return true;
562
563 return cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
564 la < fe->headoffset;
565 }
566
z_erofs_do_read_page(struct z_erofs_decompress_frontend * fe,struct page * page,struct list_head * pagepool)567 static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
568 struct page *page,
569 struct list_head *pagepool)
570 {
571 struct inode *const inode = fe->inode;
572 struct erofs_sb_info *const sbi __maybe_unused = EROFS_I_SB(inode);
573 struct erofs_map_blocks *const map = &fe->map;
574 struct z_erofs_collector *const clt = &fe->clt;
575 const loff_t offset = page_offset(page);
576 bool tight = true;
577
578 enum z_erofs_cache_alloctype cache_strategy;
579 enum z_erofs_page_type page_type;
580 unsigned int cur, end, spiltted, index;
581 int err = 0;
582
583 /* register locked file pages as online pages in pack */
584 z_erofs_onlinepage_init(page);
585
586 spiltted = 0;
587 end = PAGE_SIZE;
588 repeat:
589 cur = end - 1;
590
591 /* lucky, within the range of the current map_blocks */
592 if (offset + cur >= map->m_la &&
593 offset + cur < map->m_la + map->m_llen) {
594 /* didn't get a valid collection previously (very rare) */
595 if (!clt->cl)
596 goto restart_now;
597 goto hitted;
598 }
599
600 /* go ahead the next map_blocks */
601 erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur);
602
603 if (z_erofs_collector_end(clt))
604 fe->backmost = false;
605
606 map->m_la = offset + cur;
607 map->m_llen = 0;
608 err = z_erofs_map_blocks_iter(inode, map, 0);
609 if (err)
610 goto err_out;
611
612 restart_now:
613 if (!(map->m_flags & EROFS_MAP_MAPPED))
614 goto hitted;
615
616 err = z_erofs_collector_begin(clt, inode, map);
617 if (err)
618 goto err_out;
619
620 /* preload all compressed pages (maybe downgrade role if necessary) */
621 if (should_alloc_managed_pages(fe, sbi->cache_strategy, map->m_la))
622 cache_strategy = DELAYEDALLOC;
623 else
624 cache_strategy = DONTALLOC;
625
626 preload_compressed_pages(clt, MNGD_MAPPING(sbi),
627 cache_strategy, pagepool);
628
629 hitted:
630 /*
631 * Ensure the current partial page belongs to this submit chain rather
632 * than other concurrent submit chains or the noio(bypass) chain since
633 * those chains are handled asynchronously thus the page cannot be used
634 * for inplace I/O or pagevec (should be processed in strict order.)
635 */
636 tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED &&
637 clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);
638
639 cur = end - min_t(erofs_off_t, offset + end - map->m_la, end);
640 if (!(map->m_flags & EROFS_MAP_MAPPED)) {
641 zero_user_segment(page, cur, end);
642 ++spiltted;
643 tight = false;
644 goto next_part;
645 }
646
647 /* let's derive page type */
648 page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
649 (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
650 (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
651 Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
652
653 if (cur)
654 tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
655
656 retry:
657 err = z_erofs_attach_page(clt, page, page_type,
658 clt->mode >= COLLECT_PRIMARY_FOLLOWED);
659 /* should allocate an additional staging page for pagevec */
660 if (err == -EAGAIN) {
661 struct page *const newpage =
662 __stagingpage_alloc(pagepool, GFP_NOFS);
663
664 err = z_erofs_attach_page(clt, newpage,
665 Z_EROFS_PAGE_TYPE_EXCLUSIVE, true);
666 if (!err)
667 goto retry;
668 }
669
670 if (err)
671 goto err_out;
672
673 index = page->index - (map->m_la >> PAGE_SHIFT);
674
675 z_erofs_onlinepage_fixup(page, index, true);
676
677 /* bump up the number of spiltted parts of a page */
678 ++spiltted;
679 /* also update nr_pages */
680 clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1);
681 next_part:
682 /* can be used for verification */
683 map->m_llen = offset + cur - map->m_la;
684
685 end = cur;
686 if (end > 0)
687 goto repeat;
688
689 out:
690 z_erofs_onlinepage_endio(page);
691
692 erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu",
693 __func__, page, spiltted, map->m_llen);
694 return err;
695
696 /* if some error occurred while processing this page */
697 err_out:
698 SetPageError(page);
699 goto out;
700 }
701
z_erofs_vle_unzip_kickoff(void * ptr,int bios)702 static void z_erofs_vle_unzip_kickoff(void *ptr, int bios)
703 {
704 tagptr1_t t = tagptr_init(tagptr1_t, ptr);
705 struct z_erofs_unzip_io *io = tagptr_unfold_ptr(t);
706 bool background = tagptr_unfold_tags(t);
707
708 if (!background) {
709 unsigned long flags;
710
711 spin_lock_irqsave(&io->u.wait.lock, flags);
712 if (!atomic_add_return(bios, &io->pending_bios))
713 wake_up_locked(&io->u.wait);
714 spin_unlock_irqrestore(&io->u.wait.lock, flags);
715 return;
716 }
717
718 if (!atomic_add_return(bios, &io->pending_bios))
719 queue_work(z_erofs_workqueue, &io->u.work);
720 }
721
z_erofs_vle_read_endio(struct bio * bio)722 static inline void z_erofs_vle_read_endio(struct bio *bio)
723 {
724 struct erofs_sb_info *sbi = NULL;
725 blk_status_t err = bio->bi_status;
726 struct bio_vec *bvec;
727 struct bvec_iter_all iter_all;
728
729 bio_for_each_segment_all(bvec, bio, iter_all) {
730 struct page *page = bvec->bv_page;
731 bool cachemngd = false;
732
733 DBG_BUGON(PageUptodate(page));
734 DBG_BUGON(!page->mapping);
735
736 if (!sbi && !z_erofs_page_is_staging(page))
737 sbi = EROFS_SB(page->mapping->host->i_sb);
738
739 /* sbi should already be gotten if the page is managed */
740 if (sbi)
741 cachemngd = erofs_page_is_managed(sbi, page);
742
743 if (err)
744 SetPageError(page);
745 else if (cachemngd)
746 SetPageUptodate(page);
747
748 if (cachemngd)
749 unlock_page(page);
750 }
751
752 z_erofs_vle_unzip_kickoff(bio->bi_private, -1);
753 bio_put(bio);
754 }
755
z_erofs_decompress_pcluster(struct super_block * sb,struct z_erofs_pcluster * pcl,struct list_head * pagepool)756 static int z_erofs_decompress_pcluster(struct super_block *sb,
757 struct z_erofs_pcluster *pcl,
758 struct list_head *pagepool)
759 {
760 struct erofs_sb_info *const sbi = EROFS_SB(sb);
761 const unsigned int clusterpages = BIT(pcl->clusterbits);
762 struct z_erofs_pagevec_ctor ctor;
763 unsigned int i, outputsize, llen, nr_pages;
764 struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES];
765 struct page **pages, **compressed_pages, *page;
766
767 enum z_erofs_page_type page_type;
768 bool overlapped, partial;
769 struct z_erofs_collection *cl;
770 int err;
771
772 might_sleep();
773 cl = z_erofs_primarycollection(pcl);
774 DBG_BUGON(!READ_ONCE(cl->nr_pages));
775
776 mutex_lock(&cl->lock);
777 nr_pages = cl->nr_pages;
778
779 if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) {
780 pages = pages_onstack;
781 } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES &&
782 mutex_trylock(&z_pagemap_global_lock)) {
783 pages = z_pagemap_global;
784 } else {
785 gfp_t gfp_flags = GFP_KERNEL;
786
787 if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES)
788 gfp_flags |= __GFP_NOFAIL;
789
790 pages = kvmalloc_array(nr_pages, sizeof(struct page *),
791 gfp_flags);
792
793 /* fallback to global pagemap for the lowmem scenario */
794 if (!pages) {
795 mutex_lock(&z_pagemap_global_lock);
796 pages = z_pagemap_global;
797 }
798 }
799
800 for (i = 0; i < nr_pages; ++i)
801 pages[i] = NULL;
802
803 err = 0;
804 z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS,
805 cl->pagevec, 0);
806
807 for (i = 0; i < cl->vcnt; ++i) {
808 unsigned int pagenr;
809
810 page = z_erofs_pagevec_dequeue(&ctor, &page_type);
811
812 /* all pages in pagevec ought to be valid */
813 DBG_BUGON(!page);
814 DBG_BUGON(!page->mapping);
815
816 if (z_erofs_put_stagingpage(pagepool, page))
817 continue;
818
819 if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
820 pagenr = 0;
821 else
822 pagenr = z_erofs_onlinepage_index(page);
823
824 DBG_BUGON(pagenr >= nr_pages);
825
826 /*
827 * currently EROFS doesn't support multiref(dedup),
828 * so here erroring out one multiref page.
829 */
830 if (pages[pagenr]) {
831 DBG_BUGON(1);
832 SetPageError(pages[pagenr]);
833 z_erofs_onlinepage_endio(pages[pagenr]);
834 err = -EFSCORRUPTED;
835 }
836 pages[pagenr] = page;
837 }
838 z_erofs_pagevec_ctor_exit(&ctor, true);
839
840 overlapped = false;
841 compressed_pages = pcl->compressed_pages;
842
843 for (i = 0; i < clusterpages; ++i) {
844 unsigned int pagenr;
845
846 page = compressed_pages[i];
847
848 /* all compressed pages ought to be valid */
849 DBG_BUGON(!page);
850 DBG_BUGON(!page->mapping);
851
852 if (!z_erofs_page_is_staging(page)) {
853 if (erofs_page_is_managed(sbi, page)) {
854 if (!PageUptodate(page))
855 err = -EIO;
856 continue;
857 }
858
859 /*
860 * only if non-head page can be selected
861 * for inplace decompression
862 */
863 pagenr = z_erofs_onlinepage_index(page);
864
865 DBG_BUGON(pagenr >= nr_pages);
866 if (pages[pagenr]) {
867 DBG_BUGON(1);
868 SetPageError(pages[pagenr]);
869 z_erofs_onlinepage_endio(pages[pagenr]);
870 err = -EFSCORRUPTED;
871 }
872 pages[pagenr] = page;
873
874 overlapped = true;
875 }
876
877 /* PG_error needs checking for inplaced and staging pages */
878 if (PageError(page)) {
879 DBG_BUGON(PageUptodate(page));
880 err = -EIO;
881 }
882 }
883
884 if (err)
885 goto out;
886
887 llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT;
888 if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) {
889 outputsize = llen;
890 partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH);
891 } else {
892 outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs;
893 partial = true;
894 }
895
896 err = z_erofs_decompress(&(struct z_erofs_decompress_req) {
897 .sb = sb,
898 .in = compressed_pages,
899 .out = pages,
900 .pageofs_out = cl->pageofs,
901 .inputsize = PAGE_SIZE,
902 .outputsize = outputsize,
903 .alg = pcl->algorithmformat,
904 .inplace_io = overlapped,
905 .partial_decoding = partial
906 }, pagepool);
907
908 out:
909 /* must handle all compressed pages before endding pages */
910 for (i = 0; i < clusterpages; ++i) {
911 page = compressed_pages[i];
912
913 if (erofs_page_is_managed(sbi, page))
914 continue;
915
916 /* recycle all individual staging pages */
917 (void)z_erofs_put_stagingpage(pagepool, page);
918
919 WRITE_ONCE(compressed_pages[i], NULL);
920 }
921
922 for (i = 0; i < nr_pages; ++i) {
923 page = pages[i];
924 if (!page)
925 continue;
926
927 DBG_BUGON(!page->mapping);
928
929 /* recycle all individual staging pages */
930 if (z_erofs_put_stagingpage(pagepool, page))
931 continue;
932
933 if (err < 0)
934 SetPageError(page);
935
936 z_erofs_onlinepage_endio(page);
937 }
938
939 if (pages == z_pagemap_global)
940 mutex_unlock(&z_pagemap_global_lock);
941 else if (pages != pages_onstack)
942 kvfree(pages);
943
944 cl->nr_pages = 0;
945 cl->vcnt = 0;
946
947 /* all cl locks MUST be taken before the following line */
948 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL);
949
950 /* all cl locks SHOULD be released right now */
951 mutex_unlock(&cl->lock);
952
953 z_erofs_collection_put(cl);
954 return err;
955 }
956
z_erofs_vle_unzip_all(struct super_block * sb,struct z_erofs_unzip_io * io,struct list_head * pagepool)957 static void z_erofs_vle_unzip_all(struct super_block *sb,
958 struct z_erofs_unzip_io *io,
959 struct list_head *pagepool)
960 {
961 z_erofs_next_pcluster_t owned = io->head;
962
963 while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) {
964 struct z_erofs_pcluster *pcl;
965
966 /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
967 DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL);
968
969 /* no possible that 'owned' equals NULL */
970 DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL);
971
972 pcl = container_of(owned, struct z_erofs_pcluster, next);
973 owned = READ_ONCE(pcl->next);
974
975 z_erofs_decompress_pcluster(sb, pcl, pagepool);
976 }
977 }
978
z_erofs_vle_unzip_wq(struct work_struct * work)979 static void z_erofs_vle_unzip_wq(struct work_struct *work)
980 {
981 struct z_erofs_unzip_io_sb *iosb =
982 container_of(work, struct z_erofs_unzip_io_sb, io.u.work);
983 LIST_HEAD(pagepool);
984
985 DBG_BUGON(iosb->io.head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
986 z_erofs_vle_unzip_all(iosb->sb, &iosb->io, &pagepool);
987
988 put_pages_list(&pagepool);
989 kvfree(iosb);
990 }
991
pickup_page_for_submission(struct z_erofs_pcluster * pcl,unsigned int nr,struct list_head * pagepool,struct address_space * mc,gfp_t gfp)992 static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
993 unsigned int nr,
994 struct list_head *pagepool,
995 struct address_space *mc,
996 gfp_t gfp)
997 {
998 /* determined at compile time to avoid too many #ifdefs */
999 const bool nocache = __builtin_constant_p(mc) ? !mc : false;
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 (!nocache && 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 mapping = READ_ONCE(page->mapping);
1031
1032 /*
1033 * if managed cache is disabled, it's no way to
1034 * get such a cached-like page.
1035 */
1036 if (nocache) {
1037 /* if managed cache is disabled, it is impossible `justfound' */
1038 DBG_BUGON(justfound);
1039
1040 /* and it should be locked, not uptodate, and not truncated */
1041 DBG_BUGON(!PageLocked(page));
1042 DBG_BUGON(PageUptodate(page));
1043 DBG_BUGON(!mapping);
1044 goto out;
1045 }
1046
1047 /*
1048 * unmanaged (file) pages are all locked solidly,
1049 * therefore it is impossible for `mapping' to be NULL.
1050 */
1051 if (mapping && mapping != mc)
1052 /* ought to be unmanaged pages */
1053 goto out;
1054
1055 lock_page(page);
1056
1057 /* only true if page reclaim goes wrong, should never happen */
1058 DBG_BUGON(justfound && PagePrivate(page));
1059
1060 /* the page is still in manage cache */
1061 if (page->mapping == mc) {
1062 WRITE_ONCE(pcl->compressed_pages[nr], page);
1063
1064 ClearPageError(page);
1065 if (!PagePrivate(page)) {
1066 /*
1067 * impossible to be !PagePrivate(page) for
1068 * the current restriction as well if
1069 * the page is already in compressed_pages[].
1070 */
1071 DBG_BUGON(!justfound);
1072
1073 justfound = 0;
1074 set_page_private(page, (unsigned long)pcl);
1075 SetPagePrivate(page);
1076 }
1077
1078 /* no need to submit io if it is already up-to-date */
1079 if (PageUptodate(page)) {
1080 unlock_page(page);
1081 page = NULL;
1082 }
1083 goto out;
1084 }
1085
1086 /*
1087 * the managed page has been truncated, it's unsafe to
1088 * reuse this one, let's allocate a new cache-managed page.
1089 */
1090 DBG_BUGON(page->mapping);
1091 DBG_BUGON(!justfound);
1092
1093 tocache = true;
1094 unlock_page(page);
1095 put_page(page);
1096 out_allocpage:
1097 page = __stagingpage_alloc(pagepool, gfp);
1098 if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) {
1099 list_add(&page->lru, pagepool);
1100 cpu_relax();
1101 goto repeat;
1102 }
1103 if (nocache || !tocache)
1104 goto out;
1105 if (add_to_page_cache_lru(page, mc, index + nr, gfp)) {
1106 page->mapping = Z_EROFS_MAPPING_STAGING;
1107 goto out;
1108 }
1109
1110 set_page_private(page, (unsigned long)pcl);
1111 SetPagePrivate(page);
1112 out: /* the only exit (for tracing and debugging) */
1113 return page;
1114 }
1115
jobqueue_init(struct super_block * sb,struct z_erofs_unzip_io * io,bool foreground)1116 static struct z_erofs_unzip_io *jobqueue_init(struct super_block *sb,
1117 struct z_erofs_unzip_io *io,
1118 bool foreground)
1119 {
1120 struct z_erofs_unzip_io_sb *iosb;
1121
1122 if (foreground) {
1123 /* waitqueue available for foreground io */
1124 DBG_BUGON(!io);
1125
1126 init_waitqueue_head(&io->u.wait);
1127 atomic_set(&io->pending_bios, 0);
1128 goto out;
1129 }
1130
1131 iosb = kvzalloc(sizeof(*iosb), GFP_KERNEL | __GFP_NOFAIL);
1132 DBG_BUGON(!iosb);
1133
1134 /* initialize fields in the allocated descriptor */
1135 io = &iosb->io;
1136 iosb->sb = sb;
1137 INIT_WORK(&io->u.work, z_erofs_vle_unzip_wq);
1138 out:
1139 io->head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
1140 return io;
1141 }
1142
1143 /* define decompression jobqueue types */
1144 enum {
1145 JQ_BYPASS,
1146 JQ_SUBMIT,
1147 NR_JOBQUEUES,
1148 };
1149
jobqueueset_init(struct super_block * sb,z_erofs_next_pcluster_t qtail[],struct z_erofs_unzip_io * q[],struct z_erofs_unzip_io * fgq,bool forcefg)1150 static void *jobqueueset_init(struct super_block *sb,
1151 z_erofs_next_pcluster_t qtail[],
1152 struct z_erofs_unzip_io *q[],
1153 struct z_erofs_unzip_io *fgq,
1154 bool forcefg)
1155 {
1156 /*
1157 * if managed cache is enabled, bypass jobqueue is needed,
1158 * no need to read from device for all pclusters in this queue.
1159 */
1160 q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, true);
1161 qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head;
1162
1163 q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, forcefg);
1164 qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head;
1165
1166 return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], !forcefg));
1167 }
1168
move_to_bypass_jobqueue(struct z_erofs_pcluster * pcl,z_erofs_next_pcluster_t qtail[],z_erofs_next_pcluster_t owned_head)1169 static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
1170 z_erofs_next_pcluster_t qtail[],
1171 z_erofs_next_pcluster_t owned_head)
1172 {
1173 z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT];
1174 z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS];
1175
1176 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
1177 if (owned_head == Z_EROFS_PCLUSTER_TAIL)
1178 owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
1179
1180 WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED);
1181
1182 WRITE_ONCE(*submit_qtail, owned_head);
1183 WRITE_ONCE(*bypass_qtail, &pcl->next);
1184
1185 qtail[JQ_BYPASS] = &pcl->next;
1186 }
1187
postsubmit_is_all_bypassed(struct z_erofs_unzip_io * q[],unsigned int nr_bios,bool force_fg)1188 static bool postsubmit_is_all_bypassed(struct z_erofs_unzip_io *q[],
1189 unsigned int nr_bios,
1190 bool force_fg)
1191 {
1192 /*
1193 * although background is preferred, no one is pending for submission.
1194 * don't issue workqueue for decompression but drop it directly instead.
1195 */
1196 if (force_fg || nr_bios)
1197 return false;
1198
1199 kvfree(container_of(q[JQ_SUBMIT], struct z_erofs_unzip_io_sb, io));
1200 return true;
1201 }
1202
z_erofs_vle_submit_all(struct super_block * sb,z_erofs_next_pcluster_t owned_head,struct list_head * pagepool,struct z_erofs_unzip_io * fgq,bool force_fg)1203 static bool z_erofs_vle_submit_all(struct super_block *sb,
1204 z_erofs_next_pcluster_t owned_head,
1205 struct list_head *pagepool,
1206 struct z_erofs_unzip_io *fgq,
1207 bool force_fg)
1208 {
1209 struct erofs_sb_info *const sbi __maybe_unused = EROFS_SB(sb);
1210 z_erofs_next_pcluster_t qtail[NR_JOBQUEUES];
1211 struct z_erofs_unzip_io *q[NR_JOBQUEUES];
1212 struct bio *bio;
1213 void *bi_private;
1214 /* since bio will be NULL, no need to initialize last_index */
1215 pgoff_t uninitialized_var(last_index);
1216 bool force_submit = false;
1217 unsigned int nr_bios;
1218
1219 if (owned_head == Z_EROFS_PCLUSTER_TAIL)
1220 return false;
1221
1222 force_submit = false;
1223 bio = NULL;
1224 nr_bios = 0;
1225 bi_private = jobqueueset_init(sb, qtail, q, fgq, force_fg);
1226
1227 /* by default, all need io submission */
1228 q[JQ_SUBMIT]->head = owned_head;
1229
1230 do {
1231 struct z_erofs_pcluster *pcl;
1232 unsigned int clusterpages;
1233 pgoff_t first_index;
1234 struct page *page;
1235 unsigned int i = 0, bypass = 0;
1236 int err;
1237
1238 /* no possible 'owned_head' equals the following */
1239 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
1240 DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL);
1241
1242 pcl = container_of(owned_head, struct z_erofs_pcluster, next);
1243
1244 clusterpages = BIT(pcl->clusterbits);
1245
1246 /* close the main owned chain at first */
1247 owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
1248 Z_EROFS_PCLUSTER_TAIL_CLOSED);
1249
1250 first_index = pcl->obj.index;
1251 force_submit |= (first_index != last_index + 1);
1252
1253 repeat:
1254 page = pickup_page_for_submission(pcl, i, pagepool,
1255 MNGD_MAPPING(sbi),
1256 GFP_NOFS);
1257 if (!page) {
1258 force_submit = true;
1259 ++bypass;
1260 goto skippage;
1261 }
1262
1263 if (bio && force_submit) {
1264 submit_bio_retry:
1265 submit_bio(bio);
1266 bio = NULL;
1267 }
1268
1269 if (!bio) {
1270 bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);
1271
1272 bio->bi_end_io = z_erofs_vle_read_endio;
1273 bio_set_dev(bio, sb->s_bdev);
1274 bio->bi_iter.bi_sector = (sector_t)(first_index + i) <<
1275 LOG_SECTORS_PER_BLOCK;
1276 bio->bi_private = bi_private;
1277 bio->bi_opf = REQ_OP_READ;
1278
1279 ++nr_bios;
1280 }
1281
1282 err = bio_add_page(bio, page, PAGE_SIZE, 0);
1283 if (err < PAGE_SIZE)
1284 goto submit_bio_retry;
1285
1286 force_submit = false;
1287 last_index = first_index + i;
1288 skippage:
1289 if (++i < clusterpages)
1290 goto repeat;
1291
1292 if (bypass < clusterpages)
1293 qtail[JQ_SUBMIT] = &pcl->next;
1294 else
1295 move_to_bypass_jobqueue(pcl, qtail, owned_head);
1296 } while (owned_head != Z_EROFS_PCLUSTER_TAIL);
1297
1298 if (bio)
1299 submit_bio(bio);
1300
1301 if (postsubmit_is_all_bypassed(q, nr_bios, force_fg))
1302 return true;
1303
1304 z_erofs_vle_unzip_kickoff(bi_private, nr_bios);
1305 return true;
1306 }
1307
z_erofs_submit_and_unzip(struct super_block * sb,struct z_erofs_collector * clt,struct list_head * pagepool,bool force_fg)1308 static void z_erofs_submit_and_unzip(struct super_block *sb,
1309 struct z_erofs_collector *clt,
1310 struct list_head *pagepool,
1311 bool force_fg)
1312 {
1313 struct z_erofs_unzip_io io[NR_JOBQUEUES];
1314
1315 if (!z_erofs_vle_submit_all(sb, clt->owned_head,
1316 pagepool, io, force_fg))
1317 return;
1318
1319 /* decompress no I/O pclusters immediately */
1320 z_erofs_vle_unzip_all(sb, &io[JQ_BYPASS], pagepool);
1321
1322 if (!force_fg)
1323 return;
1324
1325 /* wait until all bios are completed */
1326 wait_event(io[JQ_SUBMIT].u.wait,
1327 !atomic_read(&io[JQ_SUBMIT].pending_bios));
1328
1329 /* let's synchronous decompression */
1330 z_erofs_vle_unzip_all(sb, &io[JQ_SUBMIT], pagepool);
1331 }
1332
z_erofs_vle_normalaccess_readpage(struct file * file,struct page * page)1333 static int z_erofs_vle_normalaccess_readpage(struct file *file,
1334 struct page *page)
1335 {
1336 struct inode *const inode = page->mapping->host;
1337 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
1338 int err;
1339 LIST_HEAD(pagepool);
1340
1341 trace_erofs_readpage(page, false);
1342
1343 f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT;
1344
1345 err = z_erofs_do_read_page(&f, page, &pagepool);
1346 (void)z_erofs_collector_end(&f.clt);
1347
1348 /* if some compressed cluster ready, need submit them anyway */
1349 z_erofs_submit_and_unzip(inode->i_sb, &f.clt, &pagepool, true);
1350
1351 if (err)
1352 erofs_err(inode->i_sb, "failed to read, err [%d]", err);
1353
1354 if (f.map.mpage)
1355 put_page(f.map.mpage);
1356
1357 /* clean up the remaining free pages */
1358 put_pages_list(&pagepool);
1359 return err;
1360 }
1361
should_decompress_synchronously(struct erofs_sb_info * sbi,unsigned int nr)1362 static bool should_decompress_synchronously(struct erofs_sb_info *sbi,
1363 unsigned int nr)
1364 {
1365 return nr <= sbi->max_sync_decompress_pages;
1366 }
1367
z_erofs_vle_normalaccess_readpages(struct file * filp,struct address_space * mapping,struct list_head * pages,unsigned int nr_pages)1368 static int z_erofs_vle_normalaccess_readpages(struct file *filp,
1369 struct address_space *mapping,
1370 struct list_head *pages,
1371 unsigned int nr_pages)
1372 {
1373 struct inode *const inode = mapping->host;
1374 struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
1375
1376 bool sync = should_decompress_synchronously(sbi, nr_pages);
1377 struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
1378 gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
1379 struct page *head = NULL;
1380 LIST_HEAD(pagepool);
1381
1382 trace_erofs_readpages(mapping->host, lru_to_page(pages),
1383 nr_pages, false);
1384
1385 f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
1386
1387 for (; nr_pages; --nr_pages) {
1388 struct page *page = lru_to_page(pages);
1389
1390 prefetchw(&page->flags);
1391 list_del(&page->lru);
1392
1393 /*
1394 * A pure asynchronous readahead is indicated if
1395 * a PG_readahead marked page is hitted at first.
1396 * Let's also do asynchronous decompression for this case.
1397 */
1398 sync &= !(PageReadahead(page) && !head);
1399
1400 if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
1401 list_add(&page->lru, &pagepool);
1402 continue;
1403 }
1404
1405 set_page_private(page, (unsigned long)head);
1406 head = page;
1407 }
1408
1409 while (head) {
1410 struct page *page = head;
1411 int err;
1412
1413 /* traversal in reverse order */
1414 head = (void *)page_private(page);
1415
1416 err = z_erofs_do_read_page(&f, page, &pagepool);
1417 if (err)
1418 erofs_err(inode->i_sb,
1419 "readahead error at page %lu @ nid %llu",
1420 page->index, EROFS_I(inode)->nid);
1421 put_page(page);
1422 }
1423
1424 (void)z_erofs_collector_end(&f.clt);
1425
1426 z_erofs_submit_and_unzip(inode->i_sb, &f.clt, &pagepool, sync);
1427
1428 if (f.map.mpage)
1429 put_page(f.map.mpage);
1430
1431 /* clean up the remaining free pages */
1432 put_pages_list(&pagepool);
1433 return 0;
1434 }
1435
1436 const struct address_space_operations z_erofs_vle_normalaccess_aops = {
1437 .readpage = z_erofs_vle_normalaccess_readpage,
1438 .readpages = z_erofs_vle_normalaccess_readpages,
1439 };
1440
1441