// SPDX-License-Identifier: GPL-2.0 /* * linux/drivers/staging/erofs/unzip_vle.c * * Copyright (C) 2018 HUAWEI, Inc. * http://www.huawei.com/ * Created by Gao Xiang * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of the Linux * distribution for more details. */ #include "unzip_vle.h" #include static struct workqueue_struct *z_erofs_workqueue __read_mostly; static struct kmem_cache *z_erofs_workgroup_cachep __read_mostly; void z_erofs_exit_zip_subsystem(void) { destroy_workqueue(z_erofs_workqueue); kmem_cache_destroy(z_erofs_workgroup_cachep); } static inline int init_unzip_workqueue(void) { const unsigned onlinecpus = num_possible_cpus(); /* * we don't need too many threads, limiting threads * could improve scheduling performance. */ z_erofs_workqueue = alloc_workqueue("erofs_unzipd", WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE, onlinecpus + onlinecpus / 4); return z_erofs_workqueue != NULL ? 0 : -ENOMEM; } int z_erofs_init_zip_subsystem(void) { z_erofs_workgroup_cachep = kmem_cache_create("erofs_compress", Z_EROFS_WORKGROUP_SIZE, 0, SLAB_RECLAIM_ACCOUNT, NULL); if (z_erofs_workgroup_cachep != NULL) { if (!init_unzip_workqueue()) return 0; kmem_cache_destroy(z_erofs_workgroup_cachep); } return -ENOMEM; } enum z_erofs_vle_work_role { Z_EROFS_VLE_WORK_SECONDARY, Z_EROFS_VLE_WORK_PRIMARY, /* * The current work was the tail of an exist chain, and the previous * processed chained works are all decided to be hooked up to it. * A new chain should be created for the remaining unprocessed works, * therefore different from Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED, * the next work cannot reuse the whole page in the following scenario: * ________________________________________________________________ * | tail (partial) page | head (partial) page | * | (belongs to the next work) | (belongs to the current work) | * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| */ Z_EROFS_VLE_WORK_PRIMARY_HOOKED, /* * The current work has been linked with the processed chained works, * and could be also linked with the potential remaining works, which * means if the processing page is the tail partial page of the work, * the current work can safely use the whole page (since the next work * is under control) for in-place decompression, as illustrated below: * ________________________________________________________________ * | tail (partial) page | head (partial) page | * | (of the current work) | (of the previous work) | * | PRIMARY_FOLLOWED or | | * |_____PRIMARY_HOOKED____|____________PRIMARY_FOLLOWED____________| * * [ (*) the above page can be used for the current work itself. ] */ Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED, Z_EROFS_VLE_WORK_MAX }; struct z_erofs_vle_work_builder { enum z_erofs_vle_work_role role; /* * 'hosted = false' means that the current workgroup doesn't belong to * the owned chained workgroups. In the other words, it is none of our * business to submit this workgroup. */ bool hosted; struct z_erofs_vle_workgroup *grp; struct z_erofs_vle_work *work; struct z_erofs_pagevec_ctor vector; /* pages used for reading the compressed data */ struct page **compressed_pages; unsigned compressed_deficit; }; #define VLE_WORK_BUILDER_INIT() \ { .work = NULL, .role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED } #ifdef EROFS_FS_HAS_MANAGED_CACHE static bool grab_managed_cache_pages(struct address_space *mapping, erofs_blk_t start, struct page **compressed_pages, int clusterblks, bool reserve_allocation) { bool noio = true; unsigned int i; /* TODO: optimize by introducing find_get_pages_range */ for (i = 0; i < clusterblks; ++i) { struct page *page, *found; if (READ_ONCE(compressed_pages[i]) != NULL) continue; page = found = find_get_page(mapping, start + i); if (found == NULL) { noio = false; if (!reserve_allocation) continue; page = EROFS_UNALLOCATED_CACHED_PAGE; } if (NULL == cmpxchg(compressed_pages + i, NULL, page)) continue; if (found != NULL) put_page(found); } return noio; } /* 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 *egrp) { struct z_erofs_vle_workgroup *const grp = container_of(egrp, struct z_erofs_vle_workgroup, obj); struct address_space *const mapping = sbi->managed_cache->i_mapping; const int clusterpages = erofs_clusterpages(sbi); int i; /* * refcount of workgroup is now freezed as 1, * therefore no need to worry about available decompression users. */ for (i = 0; i < clusterpages; ++i) { struct page *page = grp->compressed_pages[i]; if (page == NULL || page->mapping != mapping) continue; /* block other users from reclaiming or migrating the page */ if (!trylock_page(page)) return -EBUSY; /* barrier is implied in the following 'unlock_page' */ WRITE_ONCE(grp->compressed_pages[i], NULL); set_page_private(page, 0); ClearPagePrivate(page); unlock_page(page); put_page(page); } return 0; } int erofs_try_to_free_cached_page(struct address_space *mapping, struct page *page) { struct erofs_sb_info *const sbi = EROFS_SB(mapping->host->i_sb); const unsigned int clusterpages = erofs_clusterpages(sbi); struct z_erofs_vle_workgroup *grp; int ret = 0; /* 0 - busy */ /* prevent the workgroup from being freed */ rcu_read_lock(); grp = (void *)page_private(page); if (erofs_workgroup_try_to_freeze(&grp->obj, 1)) { unsigned int i; for (i = 0; i < clusterpages; ++i) { if (grp->compressed_pages[i] == page) { WRITE_ONCE(grp->compressed_pages[i], NULL); ret = 1; break; } } erofs_workgroup_unfreeze(&grp->obj, 1); } rcu_read_unlock(); if (ret) { ClearPagePrivate(page); put_page(page); } return ret; } #endif /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ static inline bool try_to_reuse_as_compressed_page( struct z_erofs_vle_work_builder *b, struct page *page) { while (b->compressed_deficit) { --b->compressed_deficit; if (NULL == cmpxchg(b->compressed_pages++, NULL, page)) return true; } return false; } /* callers must be with work->lock held */ static int z_erofs_vle_work_add_page( struct z_erofs_vle_work_builder *builder, struct page *page, enum z_erofs_page_type type) { int ret; bool occupied; /* give priority for the compressed data storage */ if (builder->role >= Z_EROFS_VLE_WORK_PRIMARY && type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && try_to_reuse_as_compressed_page(builder, page)) return 0; ret = z_erofs_pagevec_ctor_enqueue(&builder->vector, page, type, &occupied); builder->work->vcnt += (unsigned)ret; return ret ? 0 : -EAGAIN; } static enum z_erofs_vle_work_role try_to_claim_workgroup(struct z_erofs_vle_workgroup *grp, z_erofs_vle_owned_workgrp_t *owned_head, bool *hosted) { DBG_BUGON(*hosted == true); /* let's claim these following types of workgroup */ retry: if (grp->next == Z_EROFS_VLE_WORKGRP_NIL) { /* type 1, nil workgroup */ if (Z_EROFS_VLE_WORKGRP_NIL != cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_NIL, *owned_head)) goto retry; *owned_head = grp; *hosted = true; /* lucky, I am the followee :) */ return Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED; } else if (grp->next == Z_EROFS_VLE_WORKGRP_TAIL) { /* * type 2, link to the end of a existing open chain, * be careful that its submission itself is governed * by the original owned chain. */ if (Z_EROFS_VLE_WORKGRP_TAIL != cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL, *owned_head)) goto retry; *owned_head = Z_EROFS_VLE_WORKGRP_TAIL; return Z_EROFS_VLE_WORK_PRIMARY_HOOKED; } return Z_EROFS_VLE_WORK_PRIMARY; /* :( better luck next time */ } static struct z_erofs_vle_work * z_erofs_vle_work_lookup(struct super_block *sb, pgoff_t idx, unsigned pageofs, struct z_erofs_vle_workgroup **grp_ret, enum z_erofs_vle_work_role *role, z_erofs_vle_owned_workgrp_t *owned_head, bool *hosted) { bool tag, primary; struct erofs_workgroup *egrp; struct z_erofs_vle_workgroup *grp; struct z_erofs_vle_work *work; egrp = erofs_find_workgroup(sb, idx, &tag); if (egrp == NULL) { *grp_ret = NULL; return NULL; } *grp_ret = grp = container_of(egrp, struct z_erofs_vle_workgroup, obj); work = z_erofs_vle_grab_work(grp, pageofs); /* if multiref is disabled, `primary' is always true */ primary = true; DBG_BUGON(work->pageofs != pageofs); /* * lock must be taken first to avoid grp->next == NIL between * claiming workgroup and adding pages: * grp->next != NIL * grp->next = NIL * mutex_unlock_all * mutex_lock(&work->lock) * add all pages to pagevec * * [correct locking case 1]: * mutex_lock(grp->work[a]) * ... * mutex_lock(grp->work[b]) mutex_lock(grp->work[c]) * ... *role = SECONDARY * add all pages to pagevec * ... * mutex_unlock(grp->work[c]) * mutex_lock(grp->work[c]) * ... * grp->next = NIL * mutex_unlock_all * * [correct locking case 2]: * mutex_lock(grp->work[b]) * ... * mutex_lock(grp->work[a]) * ... * mutex_lock(grp->work[c]) * ... * grp->next = NIL * mutex_unlock_all * mutex_lock(grp->work[a]) * *role = PRIMARY_OWNER * add all pages to pagevec * ... */ mutex_lock(&work->lock); *hosted = false; if (!primary) *role = Z_EROFS_VLE_WORK_SECONDARY; else /* claim the workgroup if possible */ *role = try_to_claim_workgroup(grp, owned_head, hosted); return work; } static struct z_erofs_vle_work * z_erofs_vle_work_register(struct super_block *sb, struct z_erofs_vle_workgroup **grp_ret, struct erofs_map_blocks *map, pgoff_t index, unsigned pageofs, enum z_erofs_vle_work_role *role, z_erofs_vle_owned_workgrp_t *owned_head, bool *hosted) { bool newgrp = false; struct z_erofs_vle_workgroup *grp = *grp_ret; struct z_erofs_vle_work *work; /* if multiref is disabled, grp should never be nullptr */ if (unlikely(grp)) { DBG_BUGON(1); return ERR_PTR(-EINVAL); } /* no available workgroup, let's allocate one */ grp = kmem_cache_zalloc(z_erofs_workgroup_cachep, GFP_NOFS); if (unlikely(grp == NULL)) return ERR_PTR(-ENOMEM); grp->obj.index = index; grp->llen = map->m_llen; z_erofs_vle_set_workgrp_fmt(grp, (map->m_flags & EROFS_MAP_ZIPPED) ? Z_EROFS_VLE_WORKGRP_FMT_LZ4 : Z_EROFS_VLE_WORKGRP_FMT_PLAIN); atomic_set(&grp->obj.refcount, 1); /* new workgrps have been claimed as type 1 */ WRITE_ONCE(grp->next, *owned_head); /* primary and followed work for all new workgrps */ *role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED; /* it should be submitted by ourselves */ *hosted = true; newgrp = true; work = z_erofs_vle_grab_primary_work(grp); work->pageofs = pageofs; mutex_init(&work->lock); if (newgrp) { int err = erofs_register_workgroup(sb, &grp->obj, 0); if (err) { kmem_cache_free(z_erofs_workgroup_cachep, grp); return ERR_PTR(-EAGAIN); } } *owned_head = *grp_ret = grp; mutex_lock(&work->lock); return work; } static inline void __update_workgrp_llen(struct z_erofs_vle_workgroup *grp, unsigned int llen) { while (1) { unsigned int orig_llen = grp->llen; if (orig_llen >= llen || orig_llen == cmpxchg(&grp->llen, orig_llen, llen)) break; } } #define builder_is_hooked(builder) \ ((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_HOOKED) #define builder_is_followed(builder) \ ((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED) static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder, struct super_block *sb, struct erofs_map_blocks *map, z_erofs_vle_owned_workgrp_t *owned_head) { const unsigned clusterpages = erofs_clusterpages(EROFS_SB(sb)); const erofs_blk_t index = erofs_blknr(map->m_pa); const unsigned pageofs = map->m_la & ~PAGE_MASK; struct z_erofs_vle_workgroup *grp; struct z_erofs_vle_work *work; DBG_BUGON(builder->work != NULL); /* must be Z_EROFS_WORK_TAIL or the next chained work */ DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_NIL); DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); DBG_BUGON(erofs_blkoff(map->m_pa)); repeat: work = z_erofs_vle_work_lookup(sb, index, pageofs, &grp, &builder->role, owned_head, &builder->hosted); if (work != NULL) { __update_workgrp_llen(grp, map->m_llen); goto got_it; } work = z_erofs_vle_work_register(sb, &grp, map, index, pageofs, &builder->role, owned_head, &builder->hosted); if (unlikely(work == ERR_PTR(-EAGAIN))) goto repeat; if (unlikely(IS_ERR(work))) return PTR_ERR(work); got_it: z_erofs_pagevec_ctor_init(&builder->vector, Z_EROFS_VLE_INLINE_PAGEVECS, work->pagevec, work->vcnt); if (builder->role >= Z_EROFS_VLE_WORK_PRIMARY) { /* enable possibly in-place decompression */ builder->compressed_pages = grp->compressed_pages; builder->compressed_deficit = clusterpages; } else { builder->compressed_pages = NULL; builder->compressed_deficit = 0; } builder->grp = grp; builder->work = work; return 0; } /* * keep in mind that no referenced workgroups will be freed * only after a RCU grace period, so rcu_read_lock() could * prevent a workgroup from being freed. */ static void z_erofs_rcu_callback(struct rcu_head *head) { struct z_erofs_vle_work *work = container_of(head, struct z_erofs_vle_work, rcu); struct z_erofs_vle_workgroup *grp = z_erofs_vle_work_workgroup(work, true); kmem_cache_free(z_erofs_workgroup_cachep, grp); } void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) { struct z_erofs_vle_workgroup *const vgrp = container_of(grp, struct z_erofs_vle_workgroup, obj); struct z_erofs_vle_work *const work = &vgrp->work; call_rcu(&work->rcu, z_erofs_rcu_callback); } static void __z_erofs_vle_work_release(struct z_erofs_vle_workgroup *grp, struct z_erofs_vle_work *work __maybe_unused) { erofs_workgroup_put(&grp->obj); } void z_erofs_vle_work_release(struct z_erofs_vle_work *work) { struct z_erofs_vle_workgroup *grp = z_erofs_vle_work_workgroup(work, true); __z_erofs_vle_work_release(grp, work); } static inline bool z_erofs_vle_work_iter_end(struct z_erofs_vle_work_builder *builder) { struct z_erofs_vle_work *work = builder->work; if (work == NULL) return false; z_erofs_pagevec_ctor_exit(&builder->vector, false); mutex_unlock(&work->lock); /* * if all pending pages are added, don't hold work reference * any longer if the current work isn't hosted by ourselves. */ if (!builder->hosted) __z_erofs_vle_work_release(builder->grp, work); builder->work = NULL; builder->grp = NULL; return true; } static inline struct page *__stagingpage_alloc(struct list_head *pagepool, gfp_t gfp) { struct page *page = erofs_allocpage(pagepool, gfp); if (unlikely(page == NULL)) return NULL; page->mapping = Z_EROFS_MAPPING_STAGING; return page; } struct z_erofs_vle_frontend { struct inode *const inode; struct z_erofs_vle_work_builder builder; struct erofs_map_blocks_iter m_iter; z_erofs_vle_owned_workgrp_t owned_head; bool initial; #if (EROFS_FS_ZIP_CACHE_LVL >= 2) erofs_off_t cachedzone_la; #endif }; #define VLE_FRONTEND_INIT(__i) { \ .inode = __i, \ .m_iter = { \ { .m_llen = 0, .m_plen = 0 }, \ .mpage = NULL \ }, \ .builder = VLE_WORK_BUILDER_INIT(), \ .owned_head = Z_EROFS_VLE_WORKGRP_TAIL, \ .initial = true, } static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe, struct page *page, struct list_head *page_pool) { struct super_block *const sb = fe->inode->i_sb; struct erofs_sb_info *const sbi __maybe_unused = EROFS_SB(sb); struct erofs_map_blocks_iter *const m = &fe->m_iter; struct erofs_map_blocks *const map = &m->map; struct z_erofs_vle_work_builder *const builder = &fe->builder; const loff_t offset = page_offset(page); bool tight = builder_is_hooked(builder); struct z_erofs_vle_work *work = builder->work; #ifdef EROFS_FS_HAS_MANAGED_CACHE struct address_space *const mngda = sbi->managed_cache->i_mapping; struct z_erofs_vle_workgroup *grp; bool noio_outoforder; #endif enum z_erofs_page_type page_type; unsigned cur, end, spiltted, index; 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; /* lucky, within the range of the current map_blocks */ if (offset + cur >= map->m_la && offset + cur < map->m_la + map->m_llen) { /* didn't get a valid unzip work previously (very rare) */ if (!builder->work) goto restart_now; goto hitted; } /* go ahead the next map_blocks */ debugln("%s: [out-of-range] pos %llu", __func__, offset + cur); if (z_erofs_vle_work_iter_end(builder)) fe->initial = false; map->m_la = offset + cur; map->m_llen = 0; err = erofs_map_blocks_iter(fe->inode, map, &m->mpage, 0); if (unlikely(err)) goto err_out; restart_now: if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED))) goto hitted; DBG_BUGON(map->m_plen != 1 << sbi->clusterbits); DBG_BUGON(erofs_blkoff(map->m_pa)); err = z_erofs_vle_work_iter_begin(builder, sb, map, &fe->owned_head); if (unlikely(err)) goto err_out; #ifdef EROFS_FS_HAS_MANAGED_CACHE grp = fe->builder.grp; /* let's do out-of-order decompression for noio */ noio_outoforder = grab_managed_cache_pages(mngda, erofs_blknr(map->m_pa), grp->compressed_pages, erofs_blknr(map->m_plen), /* compressed page caching selection strategy */ fe->initial | (EROFS_FS_ZIP_CACHE_LVL >= 2 ? map->m_la < fe->cachedzone_la : 0)); if (noio_outoforder && builder_is_followed(builder)) builder->role = Z_EROFS_VLE_WORK_PRIMARY; #endif tight &= builder_is_hooked(builder); work = builder->work; hitted: cur = end - min_t(unsigned, offset + end - map->m_la, end); if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED))) { zero_user_segment(page, cur, end); goto next_part; } /* let's derive page type */ page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD : (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); if (cur) tight &= builder_is_followed(builder); retry: err = z_erofs_vle_work_add_page(builder, page, page_type); /* should allocate an additional staging page for pagevec */ if (err == -EAGAIN) { struct page *const newpage = __stagingpage_alloc(page_pool, GFP_NOFS); err = z_erofs_vle_work_add_page(builder, newpage, Z_EROFS_PAGE_TYPE_EXCLUSIVE); if (likely(!err)) goto retry; } if (unlikely(err)) goto err_out; index = page->index - map->m_la / PAGE_SIZE; /* FIXME! avoid the last relundant fixup & endio */ z_erofs_onlinepage_fixup(page, index, true); /* bump up the number of spiltted parts of a page */ ++spiltted; /* also update nr_pages */ work->nr_pages = max_t(pgoff_t, work->nr_pages, index + 1); next_part: /* can be used for verification */ map->m_llen = offset + cur - map->m_la; end = cur; if (end > 0) goto repeat; out: /* FIXME! avoid the last relundant fixup & endio */ z_erofs_onlinepage_endio(page); debugln("%s, finish page: %pK spiltted: %u map->m_llen %llu", __func__, page, spiltted, map->m_llen); return err; /* if some error occurred while processing this page */ err_out: SetPageError(page); goto out; } static void z_erofs_vle_unzip_kickoff(void *ptr, int bios) { tagptr1_t t = tagptr_init(tagptr1_t, ptr); struct z_erofs_vle_unzip_io *io = tagptr_unfold_ptr(t); bool background = tagptr_unfold_tags(t); if (!background) { unsigned long flags; spin_lock_irqsave(&io->u.wait.lock, flags); if (!atomic_add_return(bios, &io->pending_bios)) wake_up_locked(&io->u.wait); spin_unlock_irqrestore(&io->u.wait.lock, flags); return; } if (!atomic_add_return(bios, &io->pending_bios)) queue_work(z_erofs_workqueue, &io->u.work); } static inline void z_erofs_vle_read_endio(struct bio *bio) { const blk_status_t err = bio->bi_status; unsigned i; struct bio_vec *bvec; #ifdef EROFS_FS_HAS_MANAGED_CACHE struct address_space *mngda = NULL; #endif bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; bool cachemngd = false; DBG_BUGON(PageUptodate(page)); DBG_BUGON(!page->mapping); #ifdef EROFS_FS_HAS_MANAGED_CACHE if (unlikely(mngda == NULL && !z_erofs_is_stagingpage(page))) { struct inode *const inode = page->mapping->host; struct super_block *const sb = inode->i_sb; mngda = EROFS_SB(sb)->managed_cache->i_mapping; } /* * If mngda has not gotten, it equals NULL, * however, page->mapping never be NULL if working properly. */ cachemngd = (page->mapping == mngda); #endif if (unlikely(err)) SetPageError(page); else if (cachemngd) SetPageUptodate(page); if (cachemngd) unlock_page(page); } z_erofs_vle_unzip_kickoff(bio->bi_private, -1); bio_put(bio); } static struct page *z_pagemap_global[Z_EROFS_VLE_VMAP_GLOBAL_PAGES]; static DEFINE_MUTEX(z_pagemap_global_lock); static int z_erofs_vle_unzip(struct super_block *sb, struct z_erofs_vle_workgroup *grp, struct list_head *page_pool) { struct erofs_sb_info *const sbi = EROFS_SB(sb); #ifdef EROFS_FS_HAS_MANAGED_CACHE struct address_space *const mngda = sbi->managed_cache->i_mapping; #endif const unsigned clusterpages = erofs_clusterpages(sbi); struct z_erofs_pagevec_ctor ctor; unsigned int nr_pages; unsigned int sparsemem_pages = 0; struct page *pages_onstack[Z_EROFS_VLE_VMAP_ONSTACK_PAGES]; struct page **pages, **compressed_pages, *page; unsigned i, llen; enum z_erofs_page_type page_type; bool overlapped; struct z_erofs_vle_work *work; void *vout; int err; might_sleep(); work = z_erofs_vle_grab_primary_work(grp); DBG_BUGON(!READ_ONCE(work->nr_pages)); mutex_lock(&work->lock); nr_pages = work->nr_pages; if (likely(nr_pages <= Z_EROFS_VLE_VMAP_ONSTACK_PAGES)) pages = pages_onstack; else if (nr_pages <= Z_EROFS_VLE_VMAP_GLOBAL_PAGES && mutex_trylock(&z_pagemap_global_lock)) pages = z_pagemap_global; else { repeat: pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); /* fallback to global pagemap for the lowmem scenario */ if (unlikely(pages == NULL)) { if (nr_pages > Z_EROFS_VLE_VMAP_GLOBAL_PAGES) goto repeat; else { mutex_lock(&z_pagemap_global_lock); pages = z_pagemap_global; } } } for (i = 0; i < nr_pages; ++i) pages[i] = NULL; z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_VLE_INLINE_PAGEVECS, work->pagevec, 0); for (i = 0; i < work->vcnt; ++i) { unsigned pagenr; page = z_erofs_pagevec_ctor_dequeue(&ctor, &page_type); /* all pages in pagevec ought to be valid */ DBG_BUGON(page == NULL); DBG_BUGON(page->mapping == NULL); if (z_erofs_gather_if_stagingpage(page_pool, page)) continue; if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD) pagenr = 0; else pagenr = z_erofs_onlinepage_index(page); DBG_BUGON(pagenr >= nr_pages); DBG_BUGON(pages[pagenr]); pages[pagenr] = page; } sparsemem_pages = i; z_erofs_pagevec_ctor_exit(&ctor, true); overlapped = false; compressed_pages = grp->compressed_pages; err = 0; for (i = 0; i < clusterpages; ++i) { unsigned pagenr; page = compressed_pages[i]; /* all compressed pages ought to be valid */ DBG_BUGON(page == NULL); DBG_BUGON(page->mapping == NULL); if (!z_erofs_is_stagingpage(page)) { #ifdef EROFS_FS_HAS_MANAGED_CACHE if (page->mapping == mngda) { if (unlikely(!PageUptodate(page))) err = -EIO; continue; } #endif /* * only if non-head page can be selected * for inplace decompression */ pagenr = z_erofs_onlinepage_index(page); DBG_BUGON(pagenr >= nr_pages); DBG_BUGON(pages[pagenr]); ++sparsemem_pages; pages[pagenr] = page; overlapped = true; } /* PG_error needs checking for inplaced and staging pages */ if (unlikely(PageError(page))) { DBG_BUGON(PageUptodate(page)); err = -EIO; } } if (unlikely(err)) goto out; llen = (nr_pages << PAGE_SHIFT) - work->pageofs; if (z_erofs_vle_workgrp_fmt(grp) == Z_EROFS_VLE_WORKGRP_FMT_PLAIN) { err = z_erofs_vle_plain_copy(compressed_pages, clusterpages, pages, nr_pages, work->pageofs); goto out; } if (llen > grp->llen) llen = grp->llen; err = z_erofs_vle_unzip_fast_percpu(compressed_pages, clusterpages, pages, llen, work->pageofs); if (err != -ENOTSUPP) goto out; if (sparsemem_pages >= nr_pages) goto skip_allocpage; for (i = 0; i < nr_pages; ++i) { if (pages[i] != NULL) continue; pages[i] = __stagingpage_alloc(page_pool, GFP_NOFS); } skip_allocpage: vout = erofs_vmap(pages, nr_pages); if (!vout) { err = -ENOMEM; goto out; } err = z_erofs_vle_unzip_vmap(compressed_pages, clusterpages, vout, llen, work->pageofs, overlapped); erofs_vunmap(vout, nr_pages); out: /* must handle all compressed pages before endding pages */ for (i = 0; i < clusterpages; ++i) { page = compressed_pages[i]; #ifdef EROFS_FS_HAS_MANAGED_CACHE if (page->mapping == mngda) continue; #endif /* recycle all individual staging pages */ (void)z_erofs_gather_if_stagingpage(page_pool, page); WRITE_ONCE(compressed_pages[i], NULL); } for (i = 0; i < nr_pages; ++i) { page = pages[i]; if (!page) continue; DBG_BUGON(page->mapping == NULL); /* recycle all individual staging pages */ if (z_erofs_gather_if_stagingpage(page_pool, page)) continue; if (unlikely(err < 0)) SetPageError(page); z_erofs_onlinepage_endio(page); } if (pages == z_pagemap_global) mutex_unlock(&z_pagemap_global_lock); else if (unlikely(pages != pages_onstack)) kvfree(pages); work->nr_pages = 0; work->vcnt = 0; /* all work locks MUST be taken before the following line */ WRITE_ONCE(grp->next, Z_EROFS_VLE_WORKGRP_NIL); /* all work locks SHOULD be released right now */ mutex_unlock(&work->lock); z_erofs_vle_work_release(work); return err; } static void z_erofs_vle_unzip_all(struct super_block *sb, struct z_erofs_vle_unzip_io *io, struct list_head *page_pool) { z_erofs_vle_owned_workgrp_t owned = io->head; while (owned != Z_EROFS_VLE_WORKGRP_TAIL_CLOSED) { struct z_erofs_vle_workgroup *grp; /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ DBG_BUGON(owned == Z_EROFS_VLE_WORKGRP_TAIL); /* no possible that 'owned' equals NULL */ DBG_BUGON(owned == Z_EROFS_VLE_WORKGRP_NIL); grp = owned; owned = READ_ONCE(grp->next); z_erofs_vle_unzip(sb, grp, page_pool); } } static void z_erofs_vle_unzip_wq(struct work_struct *work) { struct z_erofs_vle_unzip_io_sb *iosb = container_of(work, struct z_erofs_vle_unzip_io_sb, io.u.work); LIST_HEAD(page_pool); DBG_BUGON(iosb->io.head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); z_erofs_vle_unzip_all(iosb->sb, &iosb->io, &page_pool); put_pages_list(&page_pool); kvfree(iosb); } static inline struct z_erofs_vle_unzip_io * prepare_io_handler(struct super_block *sb, struct z_erofs_vle_unzip_io *io, bool background) { struct z_erofs_vle_unzip_io_sb *iosb; if (!background) { /* waitqueue available for foreground io */ BUG_ON(io == NULL); init_waitqueue_head(&io->u.wait); atomic_set(&io->pending_bios, 0); goto out; } if (io != NULL) BUG(); else { /* allocate extra io descriptor for background io */ iosb = kvzalloc(sizeof(struct z_erofs_vle_unzip_io_sb), GFP_KERNEL | __GFP_NOFAIL); BUG_ON(iosb == NULL); io = &iosb->io; } iosb->sb = sb; INIT_WORK(&io->u.work, z_erofs_vle_unzip_wq); out: io->head = Z_EROFS_VLE_WORKGRP_TAIL_CLOSED; return io; } #ifdef EROFS_FS_HAS_MANAGED_CACHE /* true - unlocked (noio), false - locked (need submit io) */ static inline bool recover_managed_page(struct z_erofs_vle_workgroup *grp, struct page *page) { wait_on_page_locked(page); if (PagePrivate(page) && PageUptodate(page)) return true; lock_page(page); ClearPageError(page); if (unlikely(!PagePrivate(page))) { set_page_private(page, (unsigned long)grp); SetPagePrivate(page); } if (unlikely(PageUptodate(page))) { unlock_page(page); return true; } return false; } #define __FSIO_1 1 #else #define __FSIO_1 0 #endif static bool z_erofs_vle_submit_all(struct super_block *sb, z_erofs_vle_owned_workgrp_t owned_head, struct list_head *pagepool, struct z_erofs_vle_unzip_io *fg_io, bool force_fg) { struct erofs_sb_info *const sbi = EROFS_SB(sb); const unsigned clusterpages = erofs_clusterpages(sbi); const gfp_t gfp = GFP_NOFS; #ifdef EROFS_FS_HAS_MANAGED_CACHE struct address_space *const mngda = sbi->managed_cache->i_mapping; struct z_erofs_vle_workgroup *lstgrp_noio = NULL, *lstgrp_io = NULL; #endif struct z_erofs_vle_unzip_io *ios[1 + __FSIO_1]; struct bio *bio; tagptr1_t bi_private; /* since bio will be NULL, no need to initialize last_index */ pgoff_t uninitialized_var(last_index); bool force_submit = false; unsigned nr_bios; if (unlikely(owned_head == Z_EROFS_VLE_WORKGRP_TAIL)) return false; /* * force_fg == 1, (io, fg_io[0]) no io, (io, fg_io[1]) need submit io * force_fg == 0, (io, fg_io[0]) no io; (io[1], bg_io) need submit io */ #ifdef EROFS_FS_HAS_MANAGED_CACHE ios[0] = prepare_io_handler(sb, fg_io + 0, false); #endif if (force_fg) { ios[__FSIO_1] = prepare_io_handler(sb, fg_io + __FSIO_1, false); bi_private = tagptr_fold(tagptr1_t, ios[__FSIO_1], 0); } else { ios[__FSIO_1] = prepare_io_handler(sb, NULL, true); bi_private = tagptr_fold(tagptr1_t, ios[__FSIO_1], 1); } nr_bios = 0; force_submit = false; bio = NULL; /* by default, all need io submission */ ios[__FSIO_1]->head = owned_head; do { struct z_erofs_vle_workgroup *grp; struct page **compressed_pages, *oldpage, *page; pgoff_t first_index; unsigned i = 0; #ifdef EROFS_FS_HAS_MANAGED_CACHE unsigned int noio = 0; bool cachemngd; #endif int err; /* no possible 'owned_head' equals the following */ DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_NIL); grp = owned_head; /* close the main owned chain at first */ owned_head = cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL, Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); first_index = grp->obj.index; compressed_pages = grp->compressed_pages; force_submit |= (first_index != last_index + 1); repeat: /* fulfill all compressed pages */ oldpage = page = READ_ONCE(compressed_pages[i]); #ifdef EROFS_FS_HAS_MANAGED_CACHE cachemngd = false; if (page == EROFS_UNALLOCATED_CACHED_PAGE) { cachemngd = true; goto do_allocpage; } else if (page != NULL) { if (page->mapping != mngda) BUG_ON(PageUptodate(page)); else if (recover_managed_page(grp, page)) { /* page is uptodate, skip io submission */ force_submit = true; ++noio; goto skippage; } } else { do_allocpage: #else if (page != NULL) BUG_ON(PageUptodate(page)); else { #endif page = __stagingpage_alloc(pagepool, gfp); if (oldpage != cmpxchg(compressed_pages + i, oldpage, page)) { list_add(&page->lru, pagepool); goto repeat; #ifdef EROFS_FS_HAS_MANAGED_CACHE } else if (cachemngd && !add_to_page_cache_lru(page, mngda, first_index + i, gfp)) { set_page_private(page, (unsigned long)grp); SetPagePrivate(page); #endif } } if (bio != NULL && force_submit) { submit_bio_retry: __submit_bio(bio, REQ_OP_READ, 0); bio = NULL; } if (bio == NULL) { bio = prepare_bio(sb, first_index + i, BIO_MAX_PAGES, z_erofs_vle_read_endio); bio->bi_private = tagptr_cast_ptr(bi_private); ++nr_bios; } err = bio_add_page(bio, page, PAGE_SIZE, 0); if (err < PAGE_SIZE) goto submit_bio_retry; force_submit = false; last_index = first_index + i; #ifdef EROFS_FS_HAS_MANAGED_CACHE skippage: #endif if (++i < clusterpages) goto repeat; #ifdef EROFS_FS_HAS_MANAGED_CACHE if (noio < clusterpages) { lstgrp_io = grp; } else { z_erofs_vle_owned_workgrp_t iogrp_next = owned_head == Z_EROFS_VLE_WORKGRP_TAIL ? Z_EROFS_VLE_WORKGRP_TAIL_CLOSED : owned_head; if (lstgrp_io == NULL) ios[1]->head = iogrp_next; else WRITE_ONCE(lstgrp_io->next, iogrp_next); if (lstgrp_noio == NULL) ios[0]->head = grp; else WRITE_ONCE(lstgrp_noio->next, grp); lstgrp_noio = grp; } #endif } while (owned_head != Z_EROFS_VLE_WORKGRP_TAIL); if (bio != NULL) __submit_bio(bio, REQ_OP_READ, 0); #ifndef EROFS_FS_HAS_MANAGED_CACHE BUG_ON(!nr_bios); #else if (lstgrp_noio != NULL) WRITE_ONCE(lstgrp_noio->next, Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); if (!force_fg && !nr_bios) { kvfree(container_of(ios[1], struct z_erofs_vle_unzip_io_sb, io)); return true; } #endif z_erofs_vle_unzip_kickoff(tagptr_cast_ptr(bi_private), nr_bios); return true; } static void z_erofs_submit_and_unzip(struct z_erofs_vle_frontend *f, struct list_head *pagepool, bool force_fg) { struct super_block *sb = f->inode->i_sb; struct z_erofs_vle_unzip_io io[1 + __FSIO_1]; if (!z_erofs_vle_submit_all(sb, f->owned_head, pagepool, io, force_fg)) return; #ifdef EROFS_FS_HAS_MANAGED_CACHE z_erofs_vle_unzip_all(sb, &io[0], pagepool); #endif if (!force_fg) return; /* wait until all bios are completed */ wait_event(io[__FSIO_1].u.wait, !atomic_read(&io[__FSIO_1].pending_bios)); /* let's synchronous decompression */ z_erofs_vle_unzip_all(sb, &io[__FSIO_1], pagepool); } static int z_erofs_vle_normalaccess_readpage(struct file *file, struct page *page) { struct inode *const inode = page->mapping->host; struct z_erofs_vle_frontend f = VLE_FRONTEND_INIT(inode); int err; LIST_HEAD(pagepool); #if (EROFS_FS_ZIP_CACHE_LVL >= 2) f.cachedzone_la = page->index << PAGE_SHIFT; #endif err = z_erofs_do_read_page(&f, page, &pagepool); (void)z_erofs_vle_work_iter_end(&f.builder); if (err) { errln("%s, failed to read, err [%d]", __func__, err); goto out; } z_erofs_submit_and_unzip(&f, &pagepool, true); out: if (f.m_iter.mpage != NULL) put_page(f.m_iter.mpage); /* clean up the remaining free pages */ put_pages_list(&pagepool); return 0; } static inline int __z_erofs_vle_normalaccess_readpages( struct file *filp, struct address_space *mapping, struct list_head *pages, unsigned nr_pages, bool sync) { struct inode *const inode = mapping->host; struct z_erofs_vle_frontend f = VLE_FRONTEND_INIT(inode); gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL); struct page *head = NULL; LIST_HEAD(pagepool); #if (EROFS_FS_ZIP_CACHE_LVL >= 2) f.cachedzone_la = lru_to_page(pages)->index << PAGE_SHIFT; #endif for (; nr_pages; --nr_pages) { struct page *page = lru_to_page(pages); prefetchw(&page->flags); list_del(&page->lru); if (add_to_page_cache_lru(page, mapping, page->index, gfp)) { list_add(&page->lru, &pagepool); continue; } set_page_private(page, (unsigned long)head); head = page; } while (head != NULL) { 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) { struct erofs_vnode *vi = EROFS_V(inode); errln("%s, readahead error at page %lu of nid %llu", __func__, page->index, vi->nid); } put_page(page); } (void)z_erofs_vle_work_iter_end(&f.builder); z_erofs_submit_and_unzip(&f, &pagepool, sync); if (f.m_iter.mpage != NULL) put_page(f.m_iter.mpage); /* clean up the remaining free pages */ put_pages_list(&pagepool); return 0; } static int z_erofs_vle_normalaccess_readpages( struct file *filp, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { return __z_erofs_vle_normalaccess_readpages(filp, mapping, pages, nr_pages, nr_pages < 4 /* sync */); } const struct address_space_operations z_erofs_vle_normalaccess_aops = { .readpage = z_erofs_vle_normalaccess_readpage, .readpages = z_erofs_vle_normalaccess_readpages, }; #define __vle_cluster_advise(x, bit, bits) \ ((le16_to_cpu(x) >> (bit)) & ((1 << (bits)) - 1)) #define __vle_cluster_type(advise) __vle_cluster_advise(advise, \ Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT, Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) enum { Z_EROFS_VLE_CLUSTER_TYPE_PLAIN, Z_EROFS_VLE_CLUSTER_TYPE_HEAD, Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD, Z_EROFS_VLE_CLUSTER_TYPE_RESERVED, Z_EROFS_VLE_CLUSTER_TYPE_MAX }; #define vle_cluster_type(di) \ __vle_cluster_type((di)->di_advise) static inline unsigned vle_compressed_index_clusterofs(unsigned clustersize, struct z_erofs_vle_decompressed_index *di) { debugln("%s, vle=%pK, advise=%x (type %u), clusterofs=%x blkaddr=%x", __func__, di, di->di_advise, vle_cluster_type(di), di->di_clusterofs, di->di_u.blkaddr); switch (vle_cluster_type(di)) { case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: break; case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: return di->di_clusterofs; default: BUG_ON(1); } return clustersize; } static inline erofs_blk_t vle_extent_blkaddr(struct inode *inode, pgoff_t index) { struct erofs_sb_info *sbi = EROFS_I_SB(inode); struct erofs_vnode *vi = EROFS_V(inode); unsigned ofs = Z_EROFS_VLE_EXTENT_ALIGN(vi->inode_isize + vi->xattr_isize) + sizeof(struct erofs_extent_header) + index * sizeof(struct z_erofs_vle_decompressed_index); return erofs_blknr(iloc(sbi, vi->nid) + ofs); } static inline unsigned int vle_extent_blkoff(struct inode *inode, pgoff_t index) { struct erofs_sb_info *sbi = EROFS_I_SB(inode); struct erofs_vnode *vi = EROFS_V(inode); unsigned ofs = Z_EROFS_VLE_EXTENT_ALIGN(vi->inode_isize + vi->xattr_isize) + sizeof(struct erofs_extent_header) + index * sizeof(struct z_erofs_vle_decompressed_index); return erofs_blkoff(iloc(sbi, vi->nid) + ofs); } /* * Variable-sized Logical Extent (Fixed Physical Cluster) Compression Mode * --- * VLE compression mode attempts to compress a number of logical data into * a physical cluster with a fixed size. * VLE compression mode uses "struct z_erofs_vle_decompressed_index". */ static erofs_off_t vle_get_logical_extent_head( struct inode *inode, struct page **page_iter, void **kaddr_iter, unsigned lcn, /* logical cluster number */ erofs_blk_t *pcn, unsigned *flags) { /* for extent meta */ struct page *page = *page_iter; erofs_blk_t blkaddr = vle_extent_blkaddr(inode, lcn); struct z_erofs_vle_decompressed_index *di; unsigned long long ofs; const unsigned int clusterbits = EROFS_SB(inode->i_sb)->clusterbits; const unsigned int clustersize = 1 << clusterbits; unsigned int delta0; if (page->index != blkaddr) { kunmap_atomic(*kaddr_iter); unlock_page(page); put_page(page); *page_iter = page = erofs_get_meta_page(inode->i_sb, blkaddr, false); *kaddr_iter = kmap_atomic(page); } di = *kaddr_iter + vle_extent_blkoff(inode, lcn); switch (vle_cluster_type(di)) { case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: delta0 = le16_to_cpu(di->di_u.delta[0]); DBG_BUGON(!delta0); DBG_BUGON(lcn < delta0); ofs = vle_get_logical_extent_head(inode, page_iter, kaddr_iter, lcn - delta0, pcn, flags); break; case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: *flags ^= EROFS_MAP_ZIPPED; case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: /* clustersize should be a power of two */ ofs = ((unsigned long long)lcn << clusterbits) + (le16_to_cpu(di->di_clusterofs) & (clustersize - 1)); *pcn = le32_to_cpu(di->di_u.blkaddr); break; default: BUG_ON(1); } return ofs; } int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, struct page **mpage_ret, int flags) { /* logicial extent (start, end) offset */ unsigned long long ofs, end; struct z_erofs_vle_decompressed_index *di; erofs_blk_t e_blkaddr, pcn; unsigned lcn, logical_cluster_ofs, cluster_type; u32 ofs_rem; struct page *mpage = *mpage_ret; void *kaddr; bool initial; const unsigned int clusterbits = EROFS_SB(inode->i_sb)->clusterbits; const unsigned int clustersize = 1 << clusterbits; int err = 0; /* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */ initial = !map->m_llen; /* when trying to read beyond EOF, leave it unmapped */ if (unlikely(map->m_la >= inode->i_size)) { BUG_ON(!initial); map->m_llen = map->m_la + 1 - inode->i_size; map->m_la = inode->i_size - 1; map->m_flags = 0; goto out; } debugln("%s, m_la %llu m_llen %llu --- start", __func__, map->m_la, map->m_llen); ofs = map->m_la + map->m_llen; /* clustersize should be power of two */ lcn = ofs >> clusterbits; ofs_rem = ofs & (clustersize - 1); e_blkaddr = vle_extent_blkaddr(inode, lcn); if (mpage == NULL || mpage->index != e_blkaddr) { if (mpage != NULL) put_page(mpage); mpage = erofs_get_meta_page(inode->i_sb, e_blkaddr, false); *mpage_ret = mpage; } else { lock_page(mpage); DBG_BUGON(!PageUptodate(mpage)); } kaddr = kmap_atomic(mpage); di = kaddr + vle_extent_blkoff(inode, lcn); debugln("%s, lcn %u e_blkaddr %u e_blkoff %u", __func__, lcn, e_blkaddr, vle_extent_blkoff(inode, lcn)); logical_cluster_ofs = vle_compressed_index_clusterofs(clustersize, di); if (!initial) { /* [walking mode] 'map' has been already initialized */ map->m_llen += logical_cluster_ofs; goto unmap_out; } /* by default, compressed */ map->m_flags |= EROFS_MAP_ZIPPED; end = (u64)(lcn + 1) * clustersize; cluster_type = vle_cluster_type(di); switch (cluster_type) { case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: if (ofs_rem >= logical_cluster_ofs) map->m_flags ^= EROFS_MAP_ZIPPED; /* fallthrough */ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: if (ofs_rem == logical_cluster_ofs) { pcn = le32_to_cpu(di->di_u.blkaddr); goto exact_hitted; } if (ofs_rem > logical_cluster_ofs) { ofs = lcn * clustersize | logical_cluster_ofs; pcn = le32_to_cpu(di->di_u.blkaddr); break; } /* logical cluster number should be >= 1 */ if (unlikely(!lcn)) { errln("invalid logical cluster 0 at nid %llu", EROFS_V(inode)->nid); err = -EIO; goto unmap_out; } end = (lcn-- * clustersize) | logical_cluster_ofs; /* fallthrough */ case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: /* get the correspoinding first chunk */ ofs = vle_get_logical_extent_head(inode, mpage_ret, &kaddr, lcn, &pcn, &map->m_flags); mpage = *mpage_ret; break; default: errln("unknown cluster type %u at offset %llu of nid %llu", cluster_type, ofs, EROFS_V(inode)->nid); err = -EIO; goto unmap_out; } map->m_la = ofs; exact_hitted: map->m_llen = end - ofs; map->m_plen = clustersize; map->m_pa = blknr_to_addr(pcn); map->m_flags |= EROFS_MAP_MAPPED; unmap_out: kunmap_atomic(kaddr); unlock_page(mpage); out: debugln("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o", __func__, map->m_la, map->m_pa, map->m_llen, map->m_plen, map->m_flags); /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */ DBG_BUGON(err < 0); return err; }