| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2018 HUAWEI, Inc. |
| * https://www.huawei.com/ |
| * Copyright (C) 2022 Alibaba Cloud |
| */ |
| #include "zdata.h" |
| #include "compress.h" |
| #include <linux/prefetch.h> |
| |
| #include <trace/events/erofs.h> |
| |
| /* |
| * since pclustersize is variable for big pcluster feature, introduce slab |
| * pools implementation for different pcluster sizes. |
| */ |
| struct z_erofs_pcluster_slab { |
| struct kmem_cache *slab; |
| unsigned int maxpages; |
| char name[48]; |
| }; |
| |
| #define _PCLP(n) { .maxpages = n } |
| |
| static struct z_erofs_pcluster_slab pcluster_pool[] __read_mostly = { |
| _PCLP(1), _PCLP(4), _PCLP(16), _PCLP(64), _PCLP(128), |
| _PCLP(Z_EROFS_PCLUSTER_MAX_PAGES) |
| }; |
| |
| struct z_erofs_bvec_iter { |
| struct page *bvpage; |
| struct z_erofs_bvset *bvset; |
| unsigned int nr, cur; |
| }; |
| |
| static struct page *z_erofs_bvec_iter_end(struct z_erofs_bvec_iter *iter) |
| { |
| if (iter->bvpage) |
| kunmap_local(iter->bvset); |
| return iter->bvpage; |
| } |
| |
| static struct page *z_erofs_bvset_flip(struct z_erofs_bvec_iter *iter) |
| { |
| unsigned long base = (unsigned long)((struct z_erofs_bvset *)0)->bvec; |
| /* have to access nextpage in advance, otherwise it will be unmapped */ |
| struct page *nextpage = iter->bvset->nextpage; |
| struct page *oldpage; |
| |
| DBG_BUGON(!nextpage); |
| oldpage = z_erofs_bvec_iter_end(iter); |
| iter->bvpage = nextpage; |
| iter->bvset = kmap_local_page(nextpage); |
| iter->nr = (PAGE_SIZE - base) / sizeof(struct z_erofs_bvec); |
| iter->cur = 0; |
| return oldpage; |
| } |
| |
| static void z_erofs_bvec_iter_begin(struct z_erofs_bvec_iter *iter, |
| struct z_erofs_bvset_inline *bvset, |
| unsigned int bootstrap_nr, |
| unsigned int cur) |
| { |
| *iter = (struct z_erofs_bvec_iter) { |
| .nr = bootstrap_nr, |
| .bvset = (struct z_erofs_bvset *)bvset, |
| }; |
| |
| while (cur > iter->nr) { |
| cur -= iter->nr; |
| z_erofs_bvset_flip(iter); |
| } |
| iter->cur = cur; |
| } |
| |
| static int z_erofs_bvec_enqueue(struct z_erofs_bvec_iter *iter, |
| struct z_erofs_bvec *bvec, |
| struct page **candidate_bvpage) |
| { |
| if (iter->cur == iter->nr) { |
| if (!*candidate_bvpage) |
| return -EAGAIN; |
| |
| DBG_BUGON(iter->bvset->nextpage); |
| iter->bvset->nextpage = *candidate_bvpage; |
| z_erofs_bvset_flip(iter); |
| |
| iter->bvset->nextpage = NULL; |
| *candidate_bvpage = NULL; |
| } |
| iter->bvset->bvec[iter->cur++] = *bvec; |
| return 0; |
| } |
| |
| static void z_erofs_bvec_dequeue(struct z_erofs_bvec_iter *iter, |
| struct z_erofs_bvec *bvec, |
| struct page **old_bvpage) |
| { |
| if (iter->cur == iter->nr) |
| *old_bvpage = z_erofs_bvset_flip(iter); |
| else |
| *old_bvpage = NULL; |
| *bvec = iter->bvset->bvec[iter->cur++]; |
| } |
| |
| static void z_erofs_destroy_pcluster_pool(void) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { |
| if (!pcluster_pool[i].slab) |
| continue; |
| kmem_cache_destroy(pcluster_pool[i].slab); |
| pcluster_pool[i].slab = NULL; |
| } |
| } |
| |
| static int z_erofs_create_pcluster_pool(void) |
| { |
| struct z_erofs_pcluster_slab *pcs; |
| struct z_erofs_pcluster *a; |
| unsigned int size; |
| |
| for (pcs = pcluster_pool; |
| pcs < pcluster_pool + ARRAY_SIZE(pcluster_pool); ++pcs) { |
| size = struct_size(a, compressed_bvecs, pcs->maxpages); |
| |
| sprintf(pcs->name, "erofs_pcluster-%u", pcs->maxpages); |
| pcs->slab = kmem_cache_create(pcs->name, size, 0, |
| SLAB_RECLAIM_ACCOUNT, NULL); |
| if (pcs->slab) |
| continue; |
| |
| z_erofs_destroy_pcluster_pool(); |
| return -ENOMEM; |
| } |
| return 0; |
| } |
| |
| static struct z_erofs_pcluster *z_erofs_alloc_pcluster(unsigned int nrpages) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { |
| struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; |
| struct z_erofs_pcluster *pcl; |
| |
| if (nrpages > pcs->maxpages) |
| continue; |
| |
| pcl = kmem_cache_zalloc(pcs->slab, GFP_NOFS); |
| if (!pcl) |
| return ERR_PTR(-ENOMEM); |
| pcl->pclusterpages = nrpages; |
| return pcl; |
| } |
| return ERR_PTR(-EINVAL); |
| } |
| |
| static void z_erofs_free_pcluster(struct z_erofs_pcluster *pcl) |
| { |
| unsigned int pclusterpages = z_erofs_pclusterpages(pcl); |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { |
| struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; |
| |
| if (pclusterpages > pcs->maxpages) |
| continue; |
| |
| kmem_cache_free(pcs->slab, pcl); |
| return; |
| } |
| DBG_BUGON(1); |
| } |
| |
| /* how to allocate cached pages for a pcluster */ |
| enum z_erofs_cache_alloctype { |
| DONTALLOC, /* don't allocate any cached pages */ |
| /* |
| * try to use cached I/O if page allocation succeeds or fallback |
| * to in-place I/O instead to avoid any direct reclaim. |
| */ |
| TRYALLOC, |
| }; |
| |
| /* |
| * tagged pointer with 1-bit tag for all compressed pages |
| * tag 0 - the page is just found with an extra page reference |
| */ |
| typedef tagptr1_t compressed_page_t; |
| |
| #define tag_compressed_page_justfound(page) \ |
| tagptr_fold(compressed_page_t, page, 1) |
| |
| static struct workqueue_struct *z_erofs_workqueue __read_mostly; |
| |
| void z_erofs_exit_zip_subsystem(void) |
| { |
| destroy_workqueue(z_erofs_workqueue); |
| z_erofs_destroy_pcluster_pool(); |
| } |
| |
| static inline int z_erofs_init_workqueue(void) |
| { |
| const unsigned int onlinecpus = num_possible_cpus(); |
| |
| /* |
| * no need to spawn too many threads, limiting threads could minimum |
| * scheduling overhead, perhaps per-CPU threads should be better? |
| */ |
| z_erofs_workqueue = alloc_workqueue("erofs_unzipd", |
| WQ_UNBOUND | WQ_HIGHPRI, |
| onlinecpus + onlinecpus / 4); |
| return z_erofs_workqueue ? 0 : -ENOMEM; |
| } |
| |
| int __init z_erofs_init_zip_subsystem(void) |
| { |
| int err = z_erofs_create_pcluster_pool(); |
| |
| if (err) |
| return err; |
| err = z_erofs_init_workqueue(); |
| if (err) |
| z_erofs_destroy_pcluster_pool(); |
| return err; |
| } |
| |
| enum z_erofs_pclustermode { |
| Z_EROFS_PCLUSTER_INFLIGHT, |
| /* |
| * The current pclusters was the tail of an exist chain, in addition |
| * that the previous processed chained pclusters are all decided to |
| * be hooked up to it. |
| * A new chain will be created for the remaining pclusters which are |
| * not processed yet, so different from Z_EROFS_PCLUSTER_FOLLOWED, |
| * the next pcluster cannot reuse the whole page safely for inplace I/O |
| * in the following scenario: |
| * ________________________________________________________________ |
| * | tail (partial) page | head (partial) page | |
| * | (belongs to the next pcl) | (belongs to the current pcl) | |
| * |_______PCLUSTER_FOLLOWED______|________PCLUSTER_HOOKED__________| |
| */ |
| Z_EROFS_PCLUSTER_HOOKED, |
| /* |
| * a weak form of Z_EROFS_PCLUSTER_FOLLOWED, the difference is that it |
| * could be dispatched into bypass queue later due to uptodated managed |
| * pages. All related online pages cannot be reused for inplace I/O (or |
| * bvpage) since it can be directly decoded without I/O submission. |
| */ |
| Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE, |
| /* |
| * The current collection has been linked with the owned chain, and |
| * could also be linked with the remaining collections, which means |
| * if the processing page is the tail page of the collection, thus |
| * the current collection can safely use the whole page (since |
| * the previous collection is under control) for in-place I/O, as |
| * illustrated below: |
| * ________________________________________________________________ |
| * | tail (partial) page | head (partial) page | |
| * | (of the current cl) | (of the previous collection) | |
| * | PCLUSTER_FOLLOWED or | | |
| * |_____PCLUSTER_HOOKED__|___________PCLUSTER_FOLLOWED____________| |
| * |
| * [ (*) the above page can be used as inplace I/O. ] |
| */ |
| Z_EROFS_PCLUSTER_FOLLOWED, |
| }; |
| |
| struct z_erofs_decompress_frontend { |
| struct inode *const inode; |
| struct erofs_map_blocks map; |
| struct z_erofs_bvec_iter biter; |
| |
| struct page *candidate_bvpage; |
| struct z_erofs_pcluster *pcl, *tailpcl; |
| z_erofs_next_pcluster_t owned_head; |
| enum z_erofs_pclustermode mode; |
| |
| bool readahead; |
| /* used for applying cache strategy on the fly */ |
| bool backmost; |
| erofs_off_t headoffset; |
| |
| /* a pointer used to pick up inplace I/O pages */ |
| unsigned int icur; |
| }; |
| |
| #define DECOMPRESS_FRONTEND_INIT(__i) { \ |
| .inode = __i, .owned_head = Z_EROFS_PCLUSTER_TAIL, \ |
| .mode = Z_EROFS_PCLUSTER_FOLLOWED, .backmost = true } |
| |
| static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe, |
| enum z_erofs_cache_alloctype type, |
| struct page **pagepool) |
| { |
| struct address_space *mc = MNGD_MAPPING(EROFS_I_SB(fe->inode)); |
| struct z_erofs_pcluster *pcl = fe->pcl; |
| bool standalone = true; |
| /* |
| * optimistic allocation without direct reclaim since inplace I/O |
| * can be used if low memory otherwise. |
| */ |
| gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | |
| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; |
| unsigned int i; |
| |
| if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED) |
| return; |
| |
| for (i = 0; i < pcl->pclusterpages; ++i) { |
| struct page *page; |
| compressed_page_t t; |
| struct page *newpage = NULL; |
| |
| /* the compressed page was loaded before */ |
| if (READ_ONCE(pcl->compressed_bvecs[i].page)) |
| continue; |
| |
| page = find_get_page(mc, pcl->obj.index + i); |
| |
| if (page) { |
| t = tag_compressed_page_justfound(page); |
| } else { |
| /* I/O is needed, no possible to decompress directly */ |
| standalone = false; |
| switch (type) { |
| case TRYALLOC: |
| newpage = erofs_allocpage(pagepool, gfp); |
| if (!newpage) |
| continue; |
| set_page_private(newpage, |
| Z_EROFS_PREALLOCATED_PAGE); |
| t = tag_compressed_page_justfound(newpage); |
| break; |
| default: /* DONTALLOC */ |
| continue; |
| } |
| } |
| |
| if (!cmpxchg_relaxed(&pcl->compressed_bvecs[i].page, NULL, |
| tagptr_cast_ptr(t))) |
| continue; |
| |
| if (page) |
| put_page(page); |
| else if (newpage) |
| erofs_pagepool_add(pagepool, newpage); |
| } |
| |
| /* |
| * don't do inplace I/O if all compressed pages are available in |
| * managed cache since it can be moved to the bypass queue instead. |
| */ |
| if (standalone) |
| fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE; |
| } |
| |
| /* called by erofs_shrinker to get rid of all compressed_pages */ |
| int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, |
| struct erofs_workgroup *grp) |
| { |
| struct z_erofs_pcluster *const pcl = |
| container_of(grp, struct z_erofs_pcluster, obj); |
| int i; |
| |
| DBG_BUGON(z_erofs_is_inline_pcluster(pcl)); |
| /* |
| * refcount of workgroup is now freezed as 1, |
| * therefore no need to worry about available decompression users. |
| */ |
| for (i = 0; i < pcl->pclusterpages; ++i) { |
| struct page *page = pcl->compressed_bvecs[i].page; |
| |
| if (!page) |
| continue; |
| |
| /* block other users from reclaiming or migrating the page */ |
| if (!trylock_page(page)) |
| return -EBUSY; |
| |
| if (!erofs_page_is_managed(sbi, page)) |
| continue; |
| |
| /* barrier is implied in the following 'unlock_page' */ |
| WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); |
| detach_page_private(page); |
| unlock_page(page); |
| } |
| return 0; |
| } |
| |
| int erofs_try_to_free_cached_page(struct page *page) |
| { |
| struct z_erofs_pcluster *const pcl = (void *)page_private(page); |
| int ret, i; |
| |
| if (!erofs_workgroup_try_to_freeze(&pcl->obj, 1)) |
| return 0; |
| |
| ret = 0; |
| DBG_BUGON(z_erofs_is_inline_pcluster(pcl)); |
| for (i = 0; i < pcl->pclusterpages; ++i) { |
| if (pcl->compressed_bvecs[i].page == page) { |
| WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); |
| ret = 1; |
| break; |
| } |
| } |
| erofs_workgroup_unfreeze(&pcl->obj, 1); |
| if (ret) |
| detach_page_private(page); |
| return ret; |
| } |
| |
| static bool z_erofs_try_inplace_io(struct z_erofs_decompress_frontend *fe, |
| struct z_erofs_bvec *bvec) |
| { |
| struct z_erofs_pcluster *const pcl = fe->pcl; |
| |
| while (fe->icur > 0) { |
| if (!cmpxchg(&pcl->compressed_bvecs[--fe->icur].page, |
| NULL, bvec->page)) { |
| pcl->compressed_bvecs[fe->icur] = *bvec; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /* callers must be with pcluster lock held */ |
| static int z_erofs_attach_page(struct z_erofs_decompress_frontend *fe, |
| struct z_erofs_bvec *bvec, bool exclusive) |
| { |
| int ret; |
| |
| if (exclusive) { |
| /* give priority for inplaceio to use file pages first */ |
| if (z_erofs_try_inplace_io(fe, bvec)) |
| return 0; |
| /* otherwise, check if it can be used as a bvpage */ |
| if (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED && |
| !fe->candidate_bvpage) |
| fe->candidate_bvpage = bvec->page; |
| } |
| ret = z_erofs_bvec_enqueue(&fe->biter, bvec, &fe->candidate_bvpage); |
| fe->pcl->vcnt += (ret >= 0); |
| return ret; |
| } |
| |
| static void z_erofs_try_to_claim_pcluster(struct z_erofs_decompress_frontend *f) |
| { |
| struct z_erofs_pcluster *pcl = f->pcl; |
| z_erofs_next_pcluster_t *owned_head = &f->owned_head; |
| |
| /* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */ |
| if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL, |
| *owned_head) == Z_EROFS_PCLUSTER_NIL) { |
| *owned_head = &pcl->next; |
| /* so we can attach this pcluster to our submission chain. */ |
| f->mode = Z_EROFS_PCLUSTER_FOLLOWED; |
| return; |
| } |
| |
| /* |
| * type 2, link to the end of an existing open chain, be careful |
| * that its submission is controlled by the original attached chain. |
| */ |
| if (*owned_head != &pcl->next && pcl != f->tailpcl && |
| cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, |
| *owned_head) == Z_EROFS_PCLUSTER_TAIL) { |
| *owned_head = Z_EROFS_PCLUSTER_TAIL; |
| f->mode = Z_EROFS_PCLUSTER_HOOKED; |
| f->tailpcl = NULL; |
| return; |
| } |
| /* type 3, it belongs to a chain, but it isn't the end of the chain */ |
| f->mode = Z_EROFS_PCLUSTER_INFLIGHT; |
| } |
| |
| static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe) |
| { |
| struct erofs_map_blocks *map = &fe->map; |
| bool ztailpacking = map->m_flags & EROFS_MAP_META; |
| struct z_erofs_pcluster *pcl; |
| struct erofs_workgroup *grp; |
| int err; |
| |
| if (!(map->m_flags & EROFS_MAP_ENCODED)) { |
| DBG_BUGON(1); |
| return -EFSCORRUPTED; |
| } |
| |
| /* no available pcluster, let's allocate one */ |
| pcl = z_erofs_alloc_pcluster(ztailpacking ? 1 : |
| map->m_plen >> PAGE_SHIFT); |
| if (IS_ERR(pcl)) |
| return PTR_ERR(pcl); |
| |
| atomic_set(&pcl->obj.refcount, 1); |
| pcl->algorithmformat = map->m_algorithmformat; |
| pcl->length = 0; |
| pcl->partial = true; |
| |
| /* new pclusters should be claimed as type 1, primary and followed */ |
| pcl->next = fe->owned_head; |
| pcl->pageofs_out = map->m_la & ~PAGE_MASK; |
| fe->mode = Z_EROFS_PCLUSTER_FOLLOWED; |
| |
| /* |
| * lock all primary followed works before visible to others |
| * and mutex_trylock *never* fails for a new pcluster. |
| */ |
| mutex_init(&pcl->lock); |
| DBG_BUGON(!mutex_trylock(&pcl->lock)); |
| |
| if (ztailpacking) { |
| pcl->obj.index = 0; /* which indicates ztailpacking */ |
| pcl->pageofs_in = erofs_blkoff(map->m_pa); |
| pcl->tailpacking_size = map->m_plen; |
| } else { |
| pcl->obj.index = map->m_pa >> PAGE_SHIFT; |
| |
| grp = erofs_insert_workgroup(fe->inode->i_sb, &pcl->obj); |
| if (IS_ERR(grp)) { |
| err = PTR_ERR(grp); |
| goto err_out; |
| } |
| |
| if (grp != &pcl->obj) { |
| fe->pcl = container_of(grp, |
| struct z_erofs_pcluster, obj); |
| err = -EEXIST; |
| goto err_out; |
| } |
| } |
| /* used to check tail merging loop due to corrupted images */ |
| if (fe->owned_head == Z_EROFS_PCLUSTER_TAIL) |
| fe->tailpcl = pcl; |
| fe->owned_head = &pcl->next; |
| fe->pcl = pcl; |
| return 0; |
| |
| err_out: |
| mutex_unlock(&pcl->lock); |
| z_erofs_free_pcluster(pcl); |
| return err; |
| } |
| |
| static int z_erofs_collector_begin(struct z_erofs_decompress_frontend *fe) |
| { |
| struct erofs_map_blocks *map = &fe->map; |
| struct erofs_workgroup *grp = NULL; |
| int ret; |
| |
| DBG_BUGON(fe->pcl); |
| |
| /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous pcluster */ |
| DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_NIL); |
| DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| |
| if (!(map->m_flags & EROFS_MAP_META)) { |
| grp = erofs_find_workgroup(fe->inode->i_sb, |
| map->m_pa >> PAGE_SHIFT); |
| } else if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) { |
| DBG_BUGON(1); |
| return -EFSCORRUPTED; |
| } |
| |
| if (grp) { |
| fe->pcl = container_of(grp, struct z_erofs_pcluster, obj); |
| ret = -EEXIST; |
| } else { |
| ret = z_erofs_register_pcluster(fe); |
| } |
| |
| if (ret == -EEXIST) { |
| mutex_lock(&fe->pcl->lock); |
| /* used to check tail merging loop due to corrupted images */ |
| if (fe->owned_head == Z_EROFS_PCLUSTER_TAIL) |
| fe->tailpcl = fe->pcl; |
| |
| z_erofs_try_to_claim_pcluster(fe); |
| } else if (ret) { |
| return ret; |
| } |
| z_erofs_bvec_iter_begin(&fe->biter, &fe->pcl->bvset, |
| Z_EROFS_INLINE_BVECS, fe->pcl->vcnt); |
| /* since file-backed online pages are traversed in reverse order */ |
| fe->icur = z_erofs_pclusterpages(fe->pcl); |
| return 0; |
| } |
| |
| /* |
| * keep in mind that no referenced pclusters will be freed |
| * only after a RCU grace period. |
| */ |
| static void z_erofs_rcu_callback(struct rcu_head *head) |
| { |
| z_erofs_free_pcluster(container_of(head, |
| struct z_erofs_pcluster, rcu)); |
| } |
| |
| void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) |
| { |
| struct z_erofs_pcluster *const pcl = |
| container_of(grp, struct z_erofs_pcluster, obj); |
| |
| call_rcu(&pcl->rcu, z_erofs_rcu_callback); |
| } |
| |
| static bool z_erofs_collector_end(struct z_erofs_decompress_frontend *fe) |
| { |
| struct z_erofs_pcluster *pcl = fe->pcl; |
| |
| if (!pcl) |
| return false; |
| |
| z_erofs_bvec_iter_end(&fe->biter); |
| mutex_unlock(&pcl->lock); |
| |
| if (fe->candidate_bvpage) { |
| DBG_BUGON(z_erofs_is_shortlived_page(fe->candidate_bvpage)); |
| fe->candidate_bvpage = NULL; |
| } |
| |
| /* |
| * if all pending pages are added, don't hold its reference |
| * any longer if the pcluster isn't hosted by ourselves. |
| */ |
| if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE) |
| erofs_workgroup_put(&pcl->obj); |
| |
| fe->pcl = NULL; |
| return true; |
| } |
| |
| static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe, |
| unsigned int cachestrategy, |
| erofs_off_t la) |
| { |
| if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED) |
| return false; |
| |
| if (fe->backmost) |
| return true; |
| |
| return cachestrategy >= EROFS_ZIP_CACHE_READAROUND && |
| la < fe->headoffset; |
| } |
| |
| static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, |
| struct page *page, struct page **pagepool) |
| { |
| struct inode *const inode = fe->inode; |
| struct erofs_sb_info *const sbi = EROFS_I_SB(inode); |
| struct erofs_map_blocks *const map = &fe->map; |
| const loff_t offset = page_offset(page); |
| bool tight = true, exclusive; |
| |
| enum z_erofs_cache_alloctype cache_strategy; |
| unsigned int cur, end, spiltted; |
| int err = 0; |
| |
| /* register locked file pages as online pages in pack */ |
| z_erofs_onlinepage_init(page); |
| |
| spiltted = 0; |
| end = PAGE_SIZE; |
| repeat: |
| cur = end - 1; |
| |
| if (offset + cur < map->m_la || |
| offset + cur >= map->m_la + map->m_llen) { |
| erofs_dbg("out-of-range map @ pos %llu", offset + cur); |
| |
| if (z_erofs_collector_end(fe)) |
| fe->backmost = false; |
| map->m_la = offset + cur; |
| map->m_llen = 0; |
| err = z_erofs_map_blocks_iter(inode, map, 0); |
| if (err) |
| goto out; |
| } else { |
| if (fe->pcl) |
| goto hitted; |
| /* didn't get a valid pcluster previously (very rare) */ |
| } |
| |
| if (!(map->m_flags & EROFS_MAP_MAPPED)) |
| goto hitted; |
| |
| err = z_erofs_collector_begin(fe); |
| if (err) |
| goto out; |
| |
| if (z_erofs_is_inline_pcluster(fe->pcl)) { |
| void *mp; |
| |
| mp = erofs_read_metabuf(&fe->map.buf, inode->i_sb, |
| erofs_blknr(map->m_pa), EROFS_NO_KMAP); |
| if (IS_ERR(mp)) { |
| err = PTR_ERR(mp); |
| erofs_err(inode->i_sb, |
| "failed to get inline page, err %d", err); |
| goto out; |
| } |
| get_page(fe->map.buf.page); |
| WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, |
| fe->map.buf.page); |
| fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE; |
| } else { |
| /* bind cache first when cached decompression is preferred */ |
| if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy, |
| map->m_la)) |
| cache_strategy = TRYALLOC; |
| else |
| cache_strategy = DONTALLOC; |
| |
| z_erofs_bind_cache(fe, cache_strategy, pagepool); |
| } |
| hitted: |
| /* |
| * Ensure the current partial page belongs to this submit chain rather |
| * than other concurrent submit chains or the noio(bypass) chain since |
| * those chains are handled asynchronously thus the page cannot be used |
| * for inplace I/O or bvpage (should be processed in a strict order.) |
| */ |
| tight &= (fe->mode >= Z_EROFS_PCLUSTER_HOOKED && |
| fe->mode != Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE); |
| |
| cur = end - min_t(unsigned int, offset + end - map->m_la, end); |
| if (!(map->m_flags & EROFS_MAP_MAPPED)) { |
| zero_user_segment(page, cur, end); |
| goto next_part; |
| } |
| |
| exclusive = (!cur && (!spiltted || tight)); |
| if (cur) |
| tight &= (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED); |
| |
| retry: |
| err = z_erofs_attach_page(fe, &((struct z_erofs_bvec) { |
| .page = page, |
| .offset = offset - map->m_la, |
| .end = end, |
| }), exclusive); |
| /* should allocate an additional short-lived page for bvset */ |
| if (err == -EAGAIN && !fe->candidate_bvpage) { |
| fe->candidate_bvpage = alloc_page(GFP_NOFS | __GFP_NOFAIL); |
| set_page_private(fe->candidate_bvpage, |
| Z_EROFS_SHORTLIVED_PAGE); |
| goto retry; |
| } |
| |
| if (err) { |
| DBG_BUGON(err == -EAGAIN && fe->candidate_bvpage); |
| goto out; |
| } |
| |
| z_erofs_onlinepage_split(page); |
| /* bump up the number of spiltted parts of a page */ |
| ++spiltted; |
| if (fe->pcl->pageofs_out != (map->m_la & ~PAGE_MASK)) |
| fe->pcl->multibases = true; |
| |
| if ((map->m_flags & EROFS_MAP_FULL_MAPPED) && |
| fe->pcl->length == map->m_llen) |
| fe->pcl->partial = false; |
| if (fe->pcl->length < offset + end - map->m_la) { |
| fe->pcl->length = offset + end - map->m_la; |
| fe->pcl->pageofs_out = map->m_la & ~PAGE_MASK; |
| } |
| next_part: |
| /* shorten the remaining extent to update progress */ |
| map->m_llen = offset + cur - map->m_la; |
| map->m_flags &= ~EROFS_MAP_FULL_MAPPED; |
| |
| end = cur; |
| if (end > 0) |
| goto repeat; |
| |
| out: |
| if (err) |
| z_erofs_page_mark_eio(page); |
| z_erofs_onlinepage_endio(page); |
| |
| erofs_dbg("%s, finish page: %pK spiltted: %u map->m_llen %llu", |
| __func__, page, spiltted, map->m_llen); |
| return err; |
| } |
| |
| static bool z_erofs_get_sync_decompress_policy(struct erofs_sb_info *sbi, |
| unsigned int readahead_pages) |
| { |
| /* auto: enable for read_folio, disable for readahead */ |
| if ((sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) && |
| !readahead_pages) |
| return true; |
| |
| if ((sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_FORCE_ON) && |
| (readahead_pages <= sbi->opt.max_sync_decompress_pages)) |
| return true; |
| |
| return false; |
| } |
| |
| static bool z_erofs_page_is_invalidated(struct page *page) |
| { |
| return !page->mapping && !z_erofs_is_shortlived_page(page); |
| } |
| |
| struct z_erofs_decompress_backend { |
| struct page *onstack_pages[Z_EROFS_ONSTACK_PAGES]; |
| struct super_block *sb; |
| struct z_erofs_pcluster *pcl; |
| |
| /* pages with the longest decompressed length for deduplication */ |
| struct page **decompressed_pages; |
| /* pages to keep the compressed data */ |
| struct page **compressed_pages; |
| |
| struct list_head decompressed_secondary_bvecs; |
| struct page **pagepool; |
| unsigned int onstack_used, nr_pages; |
| }; |
| |
| struct z_erofs_bvec_item { |
| struct z_erofs_bvec bvec; |
| struct list_head list; |
| }; |
| |
| static void z_erofs_do_decompressed_bvec(struct z_erofs_decompress_backend *be, |
| struct z_erofs_bvec *bvec) |
| { |
| struct z_erofs_bvec_item *item; |
| |
| if (!((bvec->offset + be->pcl->pageofs_out) & ~PAGE_MASK)) { |
| unsigned int pgnr; |
| struct page *oldpage; |
| |
| pgnr = (bvec->offset + be->pcl->pageofs_out) >> PAGE_SHIFT; |
| DBG_BUGON(pgnr >= be->nr_pages); |
| oldpage = be->decompressed_pages[pgnr]; |
| be->decompressed_pages[pgnr] = bvec->page; |
| |
| if (!oldpage) |
| return; |
| } |
| |
| /* (cold path) one pcluster is requested multiple times */ |
| item = kmalloc(sizeof(*item), GFP_KERNEL | __GFP_NOFAIL); |
| item->bvec = *bvec; |
| list_add(&item->list, &be->decompressed_secondary_bvecs); |
| } |
| |
| static void z_erofs_fill_other_copies(struct z_erofs_decompress_backend *be, |
| int err) |
| { |
| unsigned int off0 = be->pcl->pageofs_out; |
| struct list_head *p, *n; |
| |
| list_for_each_safe(p, n, &be->decompressed_secondary_bvecs) { |
| struct z_erofs_bvec_item *bvi; |
| unsigned int end, cur; |
| void *dst, *src; |
| |
| bvi = container_of(p, struct z_erofs_bvec_item, list); |
| cur = bvi->bvec.offset < 0 ? -bvi->bvec.offset : 0; |
| end = min_t(unsigned int, be->pcl->length - bvi->bvec.offset, |
| bvi->bvec.end); |
| dst = kmap_local_page(bvi->bvec.page); |
| while (cur < end) { |
| unsigned int pgnr, scur, len; |
| |
| pgnr = (bvi->bvec.offset + cur + off0) >> PAGE_SHIFT; |
| DBG_BUGON(pgnr >= be->nr_pages); |
| |
| scur = bvi->bvec.offset + cur - |
| ((pgnr << PAGE_SHIFT) - off0); |
| len = min_t(unsigned int, end - cur, PAGE_SIZE - scur); |
| if (!be->decompressed_pages[pgnr]) { |
| err = -EFSCORRUPTED; |
| cur += len; |
| continue; |
| } |
| src = kmap_local_page(be->decompressed_pages[pgnr]); |
| memcpy(dst + cur, src + scur, len); |
| kunmap_local(src); |
| cur += len; |
| } |
| kunmap_local(dst); |
| if (err) |
| z_erofs_page_mark_eio(bvi->bvec.page); |
| z_erofs_onlinepage_endio(bvi->bvec.page); |
| list_del(p); |
| kfree(bvi); |
| } |
| } |
| |
| static void z_erofs_parse_out_bvecs(struct z_erofs_decompress_backend *be) |
| { |
| struct z_erofs_pcluster *pcl = be->pcl; |
| struct z_erofs_bvec_iter biter; |
| struct page *old_bvpage; |
| int i; |
| |
| z_erofs_bvec_iter_begin(&biter, &pcl->bvset, Z_EROFS_INLINE_BVECS, 0); |
| for (i = 0; i < pcl->vcnt; ++i) { |
| struct z_erofs_bvec bvec; |
| |
| z_erofs_bvec_dequeue(&biter, &bvec, &old_bvpage); |
| |
| if (old_bvpage) |
| z_erofs_put_shortlivedpage(be->pagepool, old_bvpage); |
| |
| DBG_BUGON(z_erofs_page_is_invalidated(bvec.page)); |
| z_erofs_do_decompressed_bvec(be, &bvec); |
| } |
| |
| old_bvpage = z_erofs_bvec_iter_end(&biter); |
| if (old_bvpage) |
| z_erofs_put_shortlivedpage(be->pagepool, old_bvpage); |
| } |
| |
| static int z_erofs_parse_in_bvecs(struct z_erofs_decompress_backend *be, |
| bool *overlapped) |
| { |
| struct z_erofs_pcluster *pcl = be->pcl; |
| unsigned int pclusterpages = z_erofs_pclusterpages(pcl); |
| int i, err = 0; |
| |
| *overlapped = false; |
| for (i = 0; i < pclusterpages; ++i) { |
| struct z_erofs_bvec *bvec = &pcl->compressed_bvecs[i]; |
| struct page *page = bvec->page; |
| |
| /* compressed pages ought to be present before decompressing */ |
| if (!page) { |
| DBG_BUGON(1); |
| continue; |
| } |
| be->compressed_pages[i] = page; |
| |
| if (z_erofs_is_inline_pcluster(pcl)) { |
| if (!PageUptodate(page)) |
| err = -EIO; |
| continue; |
| } |
| |
| DBG_BUGON(z_erofs_page_is_invalidated(page)); |
| if (!z_erofs_is_shortlived_page(page)) { |
| if (erofs_page_is_managed(EROFS_SB(be->sb), page)) { |
| if (!PageUptodate(page)) |
| err = -EIO; |
| continue; |
| } |
| z_erofs_do_decompressed_bvec(be, bvec); |
| *overlapped = true; |
| } |
| } |
| |
| if (err) |
| return err; |
| return 0; |
| } |
| |
| static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be, |
| int err) |
| { |
| struct erofs_sb_info *const sbi = EROFS_SB(be->sb); |
| struct z_erofs_pcluster *pcl = be->pcl; |
| unsigned int pclusterpages = z_erofs_pclusterpages(pcl); |
| unsigned int i, inputsize; |
| int err2; |
| struct page *page; |
| bool overlapped; |
| |
| mutex_lock(&pcl->lock); |
| be->nr_pages = PAGE_ALIGN(pcl->length + pcl->pageofs_out) >> PAGE_SHIFT; |
| |
| /* allocate (de)compressed page arrays if cannot be kept on stack */ |
| be->decompressed_pages = NULL; |
| be->compressed_pages = NULL; |
| be->onstack_used = 0; |
| if (be->nr_pages <= Z_EROFS_ONSTACK_PAGES) { |
| be->decompressed_pages = be->onstack_pages; |
| be->onstack_used = be->nr_pages; |
| memset(be->decompressed_pages, 0, |
| sizeof(struct page *) * be->nr_pages); |
| } |
| |
| if (pclusterpages + be->onstack_used <= Z_EROFS_ONSTACK_PAGES) |
| be->compressed_pages = be->onstack_pages + be->onstack_used; |
| |
| if (!be->decompressed_pages) |
| be->decompressed_pages = |
| kvcalloc(be->nr_pages, sizeof(struct page *), |
| GFP_KERNEL | __GFP_NOFAIL); |
| if (!be->compressed_pages) |
| be->compressed_pages = |
| kvcalloc(pclusterpages, sizeof(struct page *), |
| GFP_KERNEL | __GFP_NOFAIL); |
| |
| z_erofs_parse_out_bvecs(be); |
| err2 = z_erofs_parse_in_bvecs(be, &overlapped); |
| if (err2) |
| err = err2; |
| if (err) |
| goto out; |
| |
| if (z_erofs_is_inline_pcluster(pcl)) |
| inputsize = pcl->tailpacking_size; |
| else |
| inputsize = pclusterpages * PAGE_SIZE; |
| |
| err = z_erofs_decompress(&(struct z_erofs_decompress_req) { |
| .sb = be->sb, |
| .in = be->compressed_pages, |
| .out = be->decompressed_pages, |
| .pageofs_in = pcl->pageofs_in, |
| .pageofs_out = pcl->pageofs_out, |
| .inputsize = inputsize, |
| .outputsize = pcl->length, |
| .alg = pcl->algorithmformat, |
| .inplace_io = overlapped, |
| .partial_decoding = pcl->partial, |
| .fillgaps = pcl->multibases, |
| }, be->pagepool); |
| |
| out: |
| /* must handle all compressed pages before actual file pages */ |
| if (z_erofs_is_inline_pcluster(pcl)) { |
| page = pcl->compressed_bvecs[0].page; |
| WRITE_ONCE(pcl->compressed_bvecs[0].page, NULL); |
| put_page(page); |
| } else { |
| for (i = 0; i < pclusterpages; ++i) { |
| page = pcl->compressed_bvecs[i].page; |
| |
| if (erofs_page_is_managed(sbi, page)) |
| continue; |
| |
| /* recycle all individual short-lived pages */ |
| (void)z_erofs_put_shortlivedpage(be->pagepool, page); |
| WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL); |
| } |
| } |
| if (be->compressed_pages < be->onstack_pages || |
| be->compressed_pages >= be->onstack_pages + Z_EROFS_ONSTACK_PAGES) |
| kvfree(be->compressed_pages); |
| z_erofs_fill_other_copies(be, err); |
| |
| for (i = 0; i < be->nr_pages; ++i) { |
| page = be->decompressed_pages[i]; |
| if (!page) |
| continue; |
| |
| DBG_BUGON(z_erofs_page_is_invalidated(page)); |
| |
| /* recycle all individual short-lived pages */ |
| if (z_erofs_put_shortlivedpage(be->pagepool, page)) |
| continue; |
| if (err) |
| z_erofs_page_mark_eio(page); |
| z_erofs_onlinepage_endio(page); |
| } |
| |
| if (be->decompressed_pages != be->onstack_pages) |
| kvfree(be->decompressed_pages); |
| |
| pcl->length = 0; |
| pcl->partial = true; |
| pcl->multibases = false; |
| pcl->bvset.nextpage = NULL; |
| pcl->vcnt = 0; |
| |
| /* pcluster lock MUST be taken before the following line */ |
| WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); |
| mutex_unlock(&pcl->lock); |
| return err; |
| } |
| |
| static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, |
| struct page **pagepool) |
| { |
| struct z_erofs_decompress_backend be = { |
| .sb = io->sb, |
| .pagepool = pagepool, |
| .decompressed_secondary_bvecs = |
| LIST_HEAD_INIT(be.decompressed_secondary_bvecs), |
| }; |
| z_erofs_next_pcluster_t owned = io->head; |
| |
| while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { |
| /* impossible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ |
| DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); |
| /* impossible that 'owned' equals Z_EROFS_PCLUSTER_NIL */ |
| DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); |
| |
| be.pcl = container_of(owned, struct z_erofs_pcluster, next); |
| owned = READ_ONCE(be.pcl->next); |
| |
| z_erofs_decompress_pcluster(&be, io->eio ? -EIO : 0); |
| erofs_workgroup_put(&be.pcl->obj); |
| } |
| } |
| |
| static void z_erofs_decompressqueue_work(struct work_struct *work) |
| { |
| struct z_erofs_decompressqueue *bgq = |
| container_of(work, struct z_erofs_decompressqueue, u.work); |
| struct page *pagepool = NULL; |
| |
| DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| z_erofs_decompress_queue(bgq, &pagepool); |
| |
| erofs_release_pages(&pagepool); |
| kvfree(bgq); |
| } |
| |
| static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, |
| bool sync, int bios) |
| { |
| struct erofs_sb_info *const sbi = EROFS_SB(io->sb); |
| |
| /* wake up the caller thread for sync decompression */ |
| if (sync) { |
| if (!atomic_add_return(bios, &io->pending_bios)) |
| complete(&io->u.done); |
| return; |
| } |
| |
| if (atomic_add_return(bios, &io->pending_bios)) |
| return; |
| /* Use workqueue and sync decompression for atomic contexts only */ |
| if (in_atomic() || irqs_disabled()) { |
| queue_work(z_erofs_workqueue, &io->u.work); |
| /* enable sync decompression for readahead */ |
| if (sbi->opt.sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) |
| sbi->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_FORCE_ON; |
| return; |
| } |
| z_erofs_decompressqueue_work(&io->u.work); |
| } |
| |
| static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, |
| unsigned int nr, |
| struct page **pagepool, |
| struct address_space *mc) |
| { |
| const pgoff_t index = pcl->obj.index; |
| gfp_t gfp = mapping_gfp_mask(mc); |
| bool tocache = false; |
| |
| struct address_space *mapping; |
| struct page *oldpage, *page; |
| |
| compressed_page_t t; |
| int justfound; |
| |
| repeat: |
| page = READ_ONCE(pcl->compressed_bvecs[nr].page); |
| oldpage = page; |
| |
| if (!page) |
| goto out_allocpage; |
| |
| /* process the target tagged pointer */ |
| t = tagptr_init(compressed_page_t, page); |
| justfound = tagptr_unfold_tags(t); |
| page = tagptr_unfold_ptr(t); |
| |
| /* |
| * preallocated cached pages, which is used to avoid direct reclaim |
| * otherwise, it will go inplace I/O path instead. |
| */ |
| if (page->private == Z_EROFS_PREALLOCATED_PAGE) { |
| WRITE_ONCE(pcl->compressed_bvecs[nr].page, page); |
| set_page_private(page, 0); |
| tocache = true; |
| goto out_tocache; |
| } |
| mapping = READ_ONCE(page->mapping); |
| |
| /* |
| * file-backed online pages in plcuster are all locked steady, |
| * therefore it is impossible for `mapping' to be NULL. |
| */ |
| if (mapping && mapping != mc) |
| /* ought to be unmanaged pages */ |
| goto out; |
| |
| /* directly return for shortlived page as well */ |
| if (z_erofs_is_shortlived_page(page)) |
| goto out; |
| |
| lock_page(page); |
| |
| /* only true if page reclaim goes wrong, should never happen */ |
| DBG_BUGON(justfound && PagePrivate(page)); |
| |
| /* the page is still in manage cache */ |
| if (page->mapping == mc) { |
| WRITE_ONCE(pcl->compressed_bvecs[nr].page, page); |
| |
| if (!PagePrivate(page)) { |
| /* |
| * impossible to be !PagePrivate(page) for |
| * the current restriction as well if |
| * the page is already in compressed_bvecs[]. |
| */ |
| DBG_BUGON(!justfound); |
| |
| justfound = 0; |
| set_page_private(page, (unsigned long)pcl); |
| SetPagePrivate(page); |
| } |
| |
| /* no need to submit io if it is already up-to-date */ |
| if (PageUptodate(page)) { |
| unlock_page(page); |
| page = NULL; |
| } |
| goto out; |
| } |
| |
| /* |
| * the managed page has been truncated, it's unsafe to |
| * reuse this one, let's allocate a new cache-managed page. |
| */ |
| DBG_BUGON(page->mapping); |
| DBG_BUGON(!justfound); |
| |
| tocache = true; |
| unlock_page(page); |
| put_page(page); |
| out_allocpage: |
| page = erofs_allocpage(pagepool, gfp | __GFP_NOFAIL); |
| if (oldpage != cmpxchg(&pcl->compressed_bvecs[nr].page, |
| oldpage, page)) { |
| erofs_pagepool_add(pagepool, page); |
| cond_resched(); |
| goto repeat; |
| } |
| out_tocache: |
| if (!tocache || add_to_page_cache_lru(page, mc, index + nr, gfp)) { |
| /* turn into temporary page if fails (1 ref) */ |
| set_page_private(page, Z_EROFS_SHORTLIVED_PAGE); |
| goto out; |
| } |
| attach_page_private(page, pcl); |
| /* drop a refcount added by allocpage (then we have 2 refs here) */ |
| put_page(page); |
| |
| out: /* the only exit (for tracing and debugging) */ |
| return page; |
| } |
| |
| static struct z_erofs_decompressqueue * |
| jobqueue_init(struct super_block *sb, |
| struct z_erofs_decompressqueue *fgq, bool *fg) |
| { |
| struct z_erofs_decompressqueue *q; |
| |
| if (fg && !*fg) { |
| q = kvzalloc(sizeof(*q), GFP_KERNEL | __GFP_NOWARN); |
| if (!q) { |
| *fg = true; |
| goto fg_out; |
| } |
| INIT_WORK(&q->u.work, z_erofs_decompressqueue_work); |
| } else { |
| fg_out: |
| q = fgq; |
| init_completion(&fgq->u.done); |
| atomic_set(&fgq->pending_bios, 0); |
| q->eio = false; |
| } |
| q->sb = sb; |
| q->head = Z_EROFS_PCLUSTER_TAIL_CLOSED; |
| return q; |
| } |
| |
| /* define decompression jobqueue types */ |
| enum { |
| JQ_BYPASS, |
| JQ_SUBMIT, |
| NR_JOBQUEUES, |
| }; |
| |
| static void *jobqueueset_init(struct super_block *sb, |
| struct z_erofs_decompressqueue *q[], |
| struct z_erofs_decompressqueue *fgq, bool *fg) |
| { |
| /* |
| * if managed cache is enabled, bypass jobqueue is needed, |
| * no need to read from device for all pclusters in this queue. |
| */ |
| q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, NULL); |
| q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, fg); |
| |
| return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], *fg)); |
| } |
| |
| static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl, |
| z_erofs_next_pcluster_t qtail[], |
| z_erofs_next_pcluster_t owned_head) |
| { |
| z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT]; |
| z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS]; |
| |
| DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| if (owned_head == Z_EROFS_PCLUSTER_TAIL) |
| owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED; |
| |
| WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| |
| WRITE_ONCE(*submit_qtail, owned_head); |
| WRITE_ONCE(*bypass_qtail, &pcl->next); |
| |
| qtail[JQ_BYPASS] = &pcl->next; |
| } |
| |
| static void z_erofs_decompressqueue_endio(struct bio *bio) |
| { |
| tagptr1_t t = tagptr_init(tagptr1_t, bio->bi_private); |
| struct z_erofs_decompressqueue *q = tagptr_unfold_ptr(t); |
| blk_status_t err = bio->bi_status; |
| struct bio_vec *bvec; |
| struct bvec_iter_all iter_all; |
| |
| bio_for_each_segment_all(bvec, bio, iter_all) { |
| struct page *page = bvec->bv_page; |
| |
| DBG_BUGON(PageUptodate(page)); |
| DBG_BUGON(z_erofs_page_is_invalidated(page)); |
| |
| if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { |
| if (!err) |
| SetPageUptodate(page); |
| unlock_page(page); |
| } |
| } |
| if (err) |
| q->eio = true; |
| z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); |
| bio_put(bio); |
| } |
| |
| static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, |
| struct page **pagepool, |
| struct z_erofs_decompressqueue *fgq, |
| bool *force_fg) |
| { |
| struct super_block *sb = f->inode->i_sb; |
| struct address_space *mc = MNGD_MAPPING(EROFS_SB(sb)); |
| z_erofs_next_pcluster_t qtail[NR_JOBQUEUES]; |
| struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; |
| void *bi_private; |
| z_erofs_next_pcluster_t owned_head = f->owned_head; |
| /* bio is NULL initially, so no need to initialize last_{index,bdev} */ |
| pgoff_t last_index; |
| struct block_device *last_bdev; |
| unsigned int nr_bios = 0; |
| struct bio *bio = NULL; |
| |
| bi_private = jobqueueset_init(sb, q, fgq, force_fg); |
| qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; |
| qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; |
| |
| /* by default, all need io submission */ |
| q[JQ_SUBMIT]->head = owned_head; |
| |
| do { |
| struct erofs_map_dev mdev; |
| struct z_erofs_pcluster *pcl; |
| pgoff_t cur, end; |
| unsigned int i = 0; |
| bool bypass = true; |
| |
| /* no possible 'owned_head' equals the following */ |
| DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL); |
| |
| pcl = container_of(owned_head, struct z_erofs_pcluster, next); |
| |
| /* close the main owned chain at first */ |
| owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, |
| Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| if (z_erofs_is_inline_pcluster(pcl)) { |
| move_to_bypass_jobqueue(pcl, qtail, owned_head); |
| continue; |
| } |
| |
| /* no device id here, thus it will always succeed */ |
| mdev = (struct erofs_map_dev) { |
| .m_pa = blknr_to_addr(pcl->obj.index), |
| }; |
| (void)erofs_map_dev(sb, &mdev); |
| |
| cur = erofs_blknr(mdev.m_pa); |
| end = cur + pcl->pclusterpages; |
| |
| do { |
| struct page *page; |
| |
| page = pickup_page_for_submission(pcl, i++, pagepool, |
| mc); |
| if (!page) |
| continue; |
| |
| if (bio && (cur != last_index + 1 || |
| last_bdev != mdev.m_bdev)) { |
| submit_bio_retry: |
| submit_bio(bio); |
| bio = NULL; |
| } |
| |
| if (!bio) { |
| bio = bio_alloc(mdev.m_bdev, BIO_MAX_VECS, |
| REQ_OP_READ, GFP_NOIO); |
| bio->bi_end_io = z_erofs_decompressqueue_endio; |
| |
| last_bdev = mdev.m_bdev; |
| bio->bi_iter.bi_sector = (sector_t)cur << |
| LOG_SECTORS_PER_BLOCK; |
| bio->bi_private = bi_private; |
| if (f->readahead) |
| bio->bi_opf |= REQ_RAHEAD; |
| ++nr_bios; |
| } |
| |
| if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) |
| goto submit_bio_retry; |
| |
| last_index = cur; |
| bypass = false; |
| } while (++cur < end); |
| |
| if (!bypass) |
| qtail[JQ_SUBMIT] = &pcl->next; |
| else |
| move_to_bypass_jobqueue(pcl, qtail, owned_head); |
| } while (owned_head != Z_EROFS_PCLUSTER_TAIL); |
| |
| if (bio) |
| submit_bio(bio); |
| |
| /* |
| * although background is preferred, no one is pending for submission. |
| * don't issue workqueue for decompression but drop it directly instead. |
| */ |
| if (!*force_fg && !nr_bios) { |
| kvfree(q[JQ_SUBMIT]); |
| return; |
| } |
| z_erofs_decompress_kickoff(q[JQ_SUBMIT], *force_fg, nr_bios); |
| } |
| |
| static void z_erofs_runqueue(struct z_erofs_decompress_frontend *f, |
| struct page **pagepool, bool force_fg) |
| { |
| struct z_erofs_decompressqueue io[NR_JOBQUEUES]; |
| |
| if (f->owned_head == Z_EROFS_PCLUSTER_TAIL) |
| return; |
| z_erofs_submit_queue(f, pagepool, io, &force_fg); |
| |
| /* handle bypass queue (no i/o pclusters) immediately */ |
| z_erofs_decompress_queue(&io[JQ_BYPASS], pagepool); |
| |
| if (!force_fg) |
| return; |
| |
| /* wait until all bios are completed */ |
| wait_for_completion_io(&io[JQ_SUBMIT].u.done); |
| |
| /* handle synchronous decompress queue in the caller context */ |
| z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); |
| } |
| |
| /* |
| * Since partial uptodate is still unimplemented for now, we have to use |
| * approximate readmore strategies as a start. |
| */ |
| static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f, |
| struct readahead_control *rac, |
| erofs_off_t end, |
| struct page **pagepool, |
| bool backmost) |
| { |
| struct inode *inode = f->inode; |
| struct erofs_map_blocks *map = &f->map; |
| erofs_off_t cur; |
| int err; |
| |
| if (backmost) { |
| map->m_la = end; |
| err = z_erofs_map_blocks_iter(inode, map, |
| EROFS_GET_BLOCKS_READMORE); |
| if (err) |
| return; |
| |
| /* expend ra for the trailing edge if readahead */ |
| if (rac) { |
| loff_t newstart = readahead_pos(rac); |
| |
| cur = round_up(map->m_la + map->m_llen, PAGE_SIZE); |
| readahead_expand(rac, newstart, cur - newstart); |
| return; |
| } |
| end = round_up(end, PAGE_SIZE); |
| } else { |
| end = round_up(map->m_la, PAGE_SIZE); |
| |
| if (!map->m_llen) |
| return; |
| } |
| |
| cur = map->m_la + map->m_llen - 1; |
| while (cur >= end) { |
| pgoff_t index = cur >> PAGE_SHIFT; |
| struct page *page; |
| |
| page = erofs_grab_cache_page_nowait(inode->i_mapping, index); |
| if (page) { |
| if (PageUptodate(page)) { |
| unlock_page(page); |
| } else { |
| err = z_erofs_do_read_page(f, page, pagepool); |
| if (err) |
| erofs_err(inode->i_sb, |
| "readmore error at page %lu @ nid %llu", |
| index, EROFS_I(inode)->nid); |
| } |
| put_page(page); |
| } |
| |
| if (cur < PAGE_SIZE) |
| break; |
| cur = (index << PAGE_SHIFT) - 1; |
| } |
| } |
| |
| static int z_erofs_read_folio(struct file *file, struct folio *folio) |
| { |
| struct page *page = &folio->page; |
| struct inode *const inode = page->mapping->host; |
| struct erofs_sb_info *const sbi = EROFS_I_SB(inode); |
| struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); |
| struct page *pagepool = NULL; |
| int err; |
| |
| trace_erofs_readpage(page, false); |
| f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; |
| |
| z_erofs_pcluster_readmore(&f, NULL, f.headoffset + PAGE_SIZE - 1, |
| &pagepool, true); |
| err = z_erofs_do_read_page(&f, page, &pagepool); |
| z_erofs_pcluster_readmore(&f, NULL, 0, &pagepool, false); |
| |
| (void)z_erofs_collector_end(&f); |
| |
| /* if some compressed cluster ready, need submit them anyway */ |
| z_erofs_runqueue(&f, &pagepool, |
| z_erofs_get_sync_decompress_policy(sbi, 0)); |
| |
| if (err) |
| erofs_err(inode->i_sb, "failed to read, err [%d]", err); |
| |
| erofs_put_metabuf(&f.map.buf); |
| erofs_release_pages(&pagepool); |
| return err; |
| } |
| |
| static void z_erofs_readahead(struct readahead_control *rac) |
| { |
| struct inode *const inode = rac->mapping->host; |
| struct erofs_sb_info *const sbi = EROFS_I_SB(inode); |
| struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); |
| struct page *pagepool = NULL, *head = NULL, *page; |
| unsigned int nr_pages; |
| |
| f.readahead = true; |
| f.headoffset = readahead_pos(rac); |
| |
| z_erofs_pcluster_readmore(&f, rac, f.headoffset + |
| readahead_length(rac) - 1, &pagepool, true); |
| nr_pages = readahead_count(rac); |
| trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); |
| |
| while ((page = readahead_page(rac))) { |
| set_page_private(page, (unsigned long)head); |
| head = page; |
| } |
| |
| while (head) { |
| struct page *page = head; |
| int err; |
| |
| /* traversal in reverse order */ |
| head = (void *)page_private(page); |
| |
| err = z_erofs_do_read_page(&f, page, &pagepool); |
| if (err) |
| erofs_err(inode->i_sb, |
| "readahead error at page %lu @ nid %llu", |
| page->index, EROFS_I(inode)->nid); |
| put_page(page); |
| } |
| z_erofs_pcluster_readmore(&f, rac, 0, &pagepool, false); |
| (void)z_erofs_collector_end(&f); |
| |
| z_erofs_runqueue(&f, &pagepool, |
| z_erofs_get_sync_decompress_policy(sbi, nr_pages)); |
| erofs_put_metabuf(&f.map.buf); |
| erofs_release_pages(&pagepool); |
| } |
| |
| const struct address_space_operations z_erofs_aops = { |
| .read_folio = z_erofs_read_folio, |
| .readahead = z_erofs_readahead, |
| }; |