// 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 #include /* * a compressed_pages[] placeholder in order to avoid * being filled with file pages for in-place decompression. */ #define PAGE_UNALLOCATED ((void *)0x5F0E4B1D) /* how to allocate cached pages for a workgroup */ enum z_erofs_cache_alloctype { DONTALLOC, /* don't allocate any cached pages */ DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */ }; /* * 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; 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 int 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 ? 0 : -ENOMEM; } static void init_once(void *ptr) { struct z_erofs_vle_workgroup *grp = ptr; struct z_erofs_vle_work *const work = z_erofs_vle_grab_primary_work(grp); unsigned int i; mutex_init(&work->lock); work->nr_pages = 0; work->vcnt = 0; for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i) grp->compressed_pages[i] = NULL; } static void init_always(struct z_erofs_vle_workgroup *grp) { struct z_erofs_vle_work *const work = z_erofs_vle_grab_primary_work(grp); atomic_set(&grp->obj.refcount, 1); grp->flags = 0; DBG_BUGON(work->nr_pages); DBG_BUGON(work->vcnt); } int __init z_erofs_init_zip_subsystem(void) { z_erofs_workgroup_cachep = kmem_cache_create("erofs_compress", Z_EROFS_WORKGROUP_SIZE, 0, SLAB_RECLAIM_ACCOUNT, init_once); if (z_erofs_workgroup_cachep) { 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 int compressed_deficit; }; #define VLE_WORK_BUILDER_INIT() \ { .work = NULL, .role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED } #ifdef EROFS_FS_HAS_MANAGED_CACHE static void preload_compressed_pages(struct z_erofs_vle_work_builder *bl, struct address_space *mc, pgoff_t index, unsigned int clusterpages, enum z_erofs_cache_alloctype type, struct list_head *pagepool, gfp_t gfp) { struct page **const pages = bl->compressed_pages; const unsigned int remaining = bl->compressed_deficit; bool standalone = true; unsigned int i, j = 0; if (bl->role < Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED) return; gfp = mapping_gfp_constraint(mc, gfp) & ~__GFP_RECLAIM; index += clusterpages - remaining; for (i = 0; i < remaining; ++i) { struct page *page; compressed_page_t t; /* the compressed page was loaded before */ if (READ_ONCE(pages[i])) continue; page = find_get_page(mc, index + i); if (page) { t = tag_compressed_page_justfound(page); } else if (type == DELAYEDALLOC) { t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED); } else { /* DONTALLOC */ if (standalone) j = i; standalone = false; continue; } if (!cmpxchg_relaxed(&pages[i], NULL, tagptr_cast_ptr(t))) continue; if (page) put_page(page); } bl->compressed_pages += j; bl->compressed_deficit = remaining - j; if (standalone) bl->role = Z_EROFS_VLE_WORK_PRIMARY; } /* 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 = MNGD_MAPPING(sbi); 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 || 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 *const grp = (void *)page_private(page); int ret = 0; /* 0 - busy */ 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); if (ret) { ClearPagePrivate(page); put_page(page); } } return ret; } #else static void preload_compressed_pages(struct z_erofs_vle_work_builder *bl, struct address_space *mc, pgoff_t index, unsigned int clusterpages, enum z_erofs_cache_alloctype type, struct list_head *pagepool, gfp_t gfp) { /* nowhere to load compressed pages from */ } #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 (!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 int)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 (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_NIL, *owned_head) != Z_EROFS_VLE_WORKGRP_NIL) goto retry; *owned_head = &grp->next; *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 (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL, *owned_head) != Z_EROFS_VLE_WORKGRP_TAIL) 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 */ } struct z_erofs_vle_work_finder { struct super_block *sb; pgoff_t idx; unsigned int 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; }; static struct z_erofs_vle_work * z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f) { bool tag, primary; struct erofs_workgroup *egrp; struct z_erofs_vle_workgroup *grp; struct z_erofs_vle_work *work; egrp = erofs_find_workgroup(f->sb, f->idx, &tag); if (!egrp) { *f->grp_ret = NULL; return NULL; } grp = container_of(egrp, struct z_erofs_vle_workgroup, obj); *f->grp_ret = grp; work = z_erofs_vle_grab_work(grp, f->pageofs); /* if multiref is disabled, `primary' is always true */ primary = true; DBG_BUGON(work->pageofs != f->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); *f->hosted = false; if (!primary) *f->role = Z_EROFS_VLE_WORK_SECONDARY; else /* claim the workgroup if possible */ *f->role = try_to_claim_workgroup(grp, f->owned_head, f->hosted); return work; } static struct z_erofs_vle_work * z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f, struct erofs_map_blocks *map) { bool gnew = false; struct z_erofs_vle_workgroup *grp = *f->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_alloc(z_erofs_workgroup_cachep, GFP_NOFS); if (unlikely(!grp)) return ERR_PTR(-ENOMEM); init_always(grp); grp->obj.index = f->idx; 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); /* new workgrps have been claimed as type 1 */ WRITE_ONCE(grp->next, *f->owned_head); /* primary and followed work for all new workgrps */ *f->role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED; /* it should be submitted by ourselves */ *f->hosted = true; gnew = true; work = z_erofs_vle_grab_primary_work(grp); work->pageofs = f->pageofs; /* * lock all primary followed works before visible to others * and mutex_trylock *never* fails for a new workgroup. */ mutex_trylock(&work->lock); if (gnew) { int err = erofs_register_workgroup(f->sb, &grp->obj, 0); if (err) { mutex_unlock(&work->lock); kmem_cache_free(z_erofs_workgroup_cachep, grp); return ERR_PTR(-EAGAIN); } } *f->owned_head = &grp->next; *f->grp_ret = grp; return work; } #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 int clusterpages = erofs_clusterpages(EROFS_SB(sb)); struct z_erofs_vle_workgroup *grp; const struct z_erofs_vle_work_finder finder = { .sb = sb, .idx = erofs_blknr(map->m_pa), .pageofs = map->m_la & ~PAGE_MASK, .grp_ret = &grp, .role = &builder->role, .owned_head = owned_head, .hosted = &builder->hosted }; struct z_erofs_vle_work *work; DBG_BUGON(builder->work); /* 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(&finder); if (work) { unsigned int orig_llen; /* increase workgroup `llen' if needed */ while ((orig_llen = READ_ONCE(grp->llen)) < map->m_llen && orig_llen != cmpxchg_relaxed(&grp->llen, orig_llen, map->m_llen)) cpu_relax(); goto got_it; } work = z_erofs_vle_work_register(&finder, map); if (unlikely(work == ERR_PTR(-EAGAIN))) goto repeat; if (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); } static 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) 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)) 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 map; z_erofs_vle_owned_workgrp_t owned_head; /* used for applying cache strategy on the fly */ bool backmost; erofs_off_t headoffset; }; #define VLE_FRONTEND_INIT(__i) { \ .inode = __i, \ .map = { \ .m_llen = 0, \ .m_plen = 0, \ .mpage = NULL \ }, \ .builder = VLE_WORK_BUILDER_INIT(), \ .owned_head = Z_EROFS_VLE_WORKGRP_TAIL, \ .backmost = true, } #ifdef EROFS_FS_HAS_MANAGED_CACHE static inline bool should_alloc_managed_pages(struct z_erofs_vle_frontend *fe, erofs_off_t la) { if (fe->backmost) return true; if (EROFS_FS_ZIP_CACHE_LVL >= 2) return la < fe->headoffset; return false; } #else static inline bool should_alloc_managed_pages(struct z_erofs_vle_frontend *fe, erofs_off_t la) { return false; } #endif 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 *const map = &fe->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; enum z_erofs_cache_alloctype cache_strategy; enum z_erofs_page_type page_type; unsigned int 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->backmost = false; map->m_la = offset + cur; map->m_llen = 0; err = z_erofs_map_blocks_iter(fe->inode, map, 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; /* preload all compressed pages (maybe downgrade role if necessary) */ if (should_alloc_managed_pages(fe, map->m_la)) cache_strategy = DELAYEDALLOC; else cache_strategy = DONTALLOC; preload_compressed_pages(builder, MNGD_MAPPING(sbi), map->m_pa / PAGE_SIZE, map->m_plen / PAGE_SIZE, cache_strategy, page_pool, GFP_KERNEL); tight &= builder_is_hooked(builder); work = builder->work; hitted: cur = end - min_t(unsigned int, 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 int i; struct bio_vec *bvec; #ifdef EROFS_FS_HAS_MANAGED_CACHE struct address_space *mc = NULL; #endif struct bvec_iter_all iter_all; bio_for_each_segment_all(bvec, bio, i, iter_all) { 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(!mc && !z_erofs_is_stagingpage(page))) { struct inode *const inode = page->mapping->host; struct super_block *const sb = inode->i_sb; mc = MNGD_MAPPING(EROFS_SB(sb)); } /* * If mc has not gotten, it equals NULL, * however, page->mapping never be NULL if working properly. */ cachemngd = (page->mapping == mc); #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); const unsigned int 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 int 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)) { 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 int pagenr; page = z_erofs_pagevec_ctor_dequeue(&ctor, &page_type); /* all pages in pagevec ought to be valid */ DBG_BUGON(!page); DBG_BUGON(!page->mapping); 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 int pagenr; page = compressed_pages[i]; /* all compressed pages ought to be valid */ DBG_BUGON(!page); DBG_BUGON(!page->mapping); if (!z_erofs_is_stagingpage(page)) { #ifdef EROFS_FS_HAS_MANAGED_CACHE if (page->mapping == MNGD_MAPPING(sbi)) { 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]) 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 == MNGD_MAPPING(sbi)) 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); /* 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 = container_of(owned, struct z_erofs_vle_workgroup, next); 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 struct page * pickup_page_for_submission(struct z_erofs_vle_workgroup *grp, unsigned int nr, struct list_head *pagepool, struct address_space *mc, gfp_t gfp) { /* determined at compile time to avoid too many #ifdefs */ const bool nocache = __builtin_constant_p(mc) ? !mc : false; const pgoff_t index = grp->obj.index; bool tocache = false; struct address_space *mapping; struct page *oldpage, *page; compressed_page_t t; int justfound; repeat: page = READ_ONCE(grp->compressed_pages[nr]); oldpage = page; if (!page) goto out_allocpage; /* * the cached page has not been allocated and * an placeholder is out there, prepare it now. */ if (!nocache && page == PAGE_UNALLOCATED) { tocache = true; 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); mapping = READ_ONCE(page->mapping); /* * if managed cache is disabled, it's no way to * get such a cached-like page. */ if (nocache) { /* if managed cache is disabled, it is impossible `justfound' */ DBG_BUGON(justfound); /* and it should be locked, not uptodate, and not truncated */ DBG_BUGON(!PageLocked(page)); DBG_BUGON(PageUptodate(page)); DBG_BUGON(!mapping); goto out; } /* * unmanaged (file) pages are all locked solidly, * therefore it is impossible for `mapping' to be NULL. */ if (mapping && mapping != mc) /* ought to be unmanaged pages */ 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(grp->compressed_pages[nr], page); ClearPageError(page); if (!PagePrivate(page)) { /* * impossible to be !PagePrivate(page) for * the current restriction as well if * the page is already in compressed_pages[]. */ DBG_BUGON(!justfound); justfound = 0; set_page_private(page, (unsigned long)grp); 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 = __stagingpage_alloc(pagepool, gfp); if (oldpage != cmpxchg(&grp->compressed_pages[nr], oldpage, page)) { list_add(&page->lru, pagepool); cpu_relax(); goto repeat; } if (nocache || !tocache) goto out; if (add_to_page_cache_lru(page, mc, index + nr, gfp)) { page->mapping = Z_EROFS_MAPPING_STAGING; goto out; } set_page_private(page, (unsigned long)grp); SetPagePrivate(page); out: /* the only exit (for tracing and debugging) */ return page; } static struct z_erofs_vle_unzip_io * jobqueue_init(struct super_block *sb, struct z_erofs_vle_unzip_io *io, bool foreground) { struct z_erofs_vle_unzip_io_sb *iosb; if (foreground) { /* waitqueue available for foreground io */ DBG_BUGON(!io); init_waitqueue_head(&io->u.wait); atomic_set(&io->pending_bios, 0); goto out; } iosb = kvzalloc(sizeof(struct z_erofs_vle_unzip_io_sb), GFP_KERNEL | __GFP_NOFAIL); DBG_BUGON(!iosb); /* initialize fields in the allocated descriptor */ 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; } /* define workgroup jobqueue types */ enum { #ifdef EROFS_FS_HAS_MANAGED_CACHE JQ_BYPASS, #endif JQ_SUBMIT, NR_JOBQUEUES, }; static void *jobqueueset_init(struct super_block *sb, z_erofs_vle_owned_workgrp_t qtail[], struct z_erofs_vle_unzip_io *q[], struct z_erofs_vle_unzip_io *fgq, bool forcefg) { #ifdef EROFS_FS_HAS_MANAGED_CACHE /* * if managed cache is enabled, bypass jobqueue is needed, * no need to read from device for all workgroups in this queue. */ q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, true); qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; #endif q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, forcefg); qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head; return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], !forcefg)); } #ifdef EROFS_FS_HAS_MANAGED_CACHE static void move_to_bypass_jobqueue(struct z_erofs_vle_workgroup *grp, z_erofs_vle_owned_workgrp_t qtail[], z_erofs_vle_owned_workgrp_t owned_head) { z_erofs_vle_owned_workgrp_t *const submit_qtail = qtail[JQ_SUBMIT]; z_erofs_vle_owned_workgrp_t *const bypass_qtail = qtail[JQ_BYPASS]; DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); if (owned_head == Z_EROFS_VLE_WORKGRP_TAIL) owned_head = Z_EROFS_VLE_WORKGRP_TAIL_CLOSED; WRITE_ONCE(grp->next, Z_EROFS_VLE_WORKGRP_TAIL_CLOSED); WRITE_ONCE(*submit_qtail, owned_head); WRITE_ONCE(*bypass_qtail, &grp->next); qtail[JQ_BYPASS] = &grp->next; } static bool postsubmit_is_all_bypassed(struct z_erofs_vle_unzip_io *q[], unsigned int nr_bios, bool force_fg) { /* * 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) return false; kvfree(container_of(q[JQ_SUBMIT], struct z_erofs_vle_unzip_io_sb, io)); return true; } #else static void move_to_bypass_jobqueue(struct z_erofs_vle_workgroup *grp, z_erofs_vle_owned_workgrp_t qtail[], z_erofs_vle_owned_workgrp_t owned_head) { /* impossible to bypass submission for managed cache disabled */ DBG_BUGON(1); } static bool postsubmit_is_all_bypassed(struct z_erofs_vle_unzip_io *q[], unsigned int nr_bios, bool force_fg) { /* bios should be >0 if managed cache is disabled */ DBG_BUGON(!nr_bios); return false; } #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 *fgq, bool force_fg) { struct erofs_sb_info *const sbi = EROFS_SB(sb); const unsigned int clusterpages = erofs_clusterpages(sbi); const gfp_t gfp = GFP_NOFS; z_erofs_vle_owned_workgrp_t qtail[NR_JOBQUEUES]; struct z_erofs_vle_unzip_io *q[NR_JOBQUEUES]; struct bio *bio; void *bi_private; /* since bio will be NULL, no need to initialize last_index */ pgoff_t uninitialized_var(last_index); bool force_submit = false; unsigned int nr_bios; if (unlikely(owned_head == Z_EROFS_VLE_WORKGRP_TAIL)) return false; force_submit = false; bio = NULL; nr_bios = 0; bi_private = jobqueueset_init(sb, qtail, q, fgq, force_fg); /* by default, all need io submission */ q[JQ_SUBMIT]->head = owned_head; do { struct z_erofs_vle_workgroup *grp; pgoff_t first_index; struct page *page; unsigned int i = 0, bypass = 0; 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 = container_of(owned_head, struct z_erofs_vle_workgroup, next); /* 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; force_submit |= (first_index != last_index + 1); repeat: page = pickup_page_for_submission(grp, i, pagepool, MNGD_MAPPING(sbi), gfp); if (!page) { force_submit = true; ++bypass; goto skippage; } if (bio && force_submit) { submit_bio_retry: __submit_bio(bio, REQ_OP_READ, 0); bio = NULL; } if (!bio) { bio = erofs_grab_bio(sb, first_index + i, BIO_MAX_PAGES, z_erofs_vle_read_endio, true); bio->bi_private = 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; skippage: if (++i < clusterpages) goto repeat; if (bypass < clusterpages) qtail[JQ_SUBMIT] = &grp->next; else move_to_bypass_jobqueue(grp, qtail, owned_head); } while (owned_head != Z_EROFS_VLE_WORKGRP_TAIL); if (bio) __submit_bio(bio, REQ_OP_READ, 0); if (postsubmit_is_all_bypassed(q, nr_bios, force_fg)) return true; z_erofs_vle_unzip_kickoff(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[NR_JOBQUEUES]; 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[JQ_BYPASS], pagepool); #endif if (!force_fg) return; /* wait until all bios are completed */ wait_event(io[JQ_SUBMIT].u.wait, !atomic_read(&io[JQ_SUBMIT].pending_bios)); /* let's synchronous decompression */ z_erofs_vle_unzip_all(sb, &io[JQ_SUBMIT], 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); trace_erofs_readpage(page, false); f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT; 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.map.mpage) put_page(f.map.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 int nr_pages) { struct inode *const inode = mapping->host; struct erofs_sb_info *const sbi = EROFS_I_SB(inode); bool sync = __should_decompress_synchronously(sbi, nr_pages); 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); trace_erofs_readpages(mapping->host, lru_to_page(pages), nr_pages, false); f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT; for (; nr_pages; --nr_pages) { struct page *page = lru_to_page(pages); prefetchw(&page->flags); list_del(&page->lru); /* * A pure asynchronous readahead is indicated if * a PG_readahead marked page is hitted at first. * Let's also do asynchronous decompression for this case. */ sync &= !(PageReadahead(page) && !head); 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) { 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.map.mpage) put_page(f.map.mpage); /* clean up the remaining free pages */ put_pages_list(&pagepool); return 0; } const struct address_space_operations z_erofs_vle_normalaccess_aops = { .readpage = z_erofs_vle_normalaccess_readpage, .readpages = z_erofs_vle_normalaccess_readpages, }; /* * 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". */ #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) #define vle_cluster_type(di) \ __vle_cluster_type((di)->di_advise) static int vle_decompressed_index_clusterofs(unsigned int *clusterofs, unsigned int clustersize, struct z_erofs_vle_decompressed_index *di) { switch (vle_cluster_type(di)) { case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: *clusterofs = clustersize; break; case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: *clusterofs = le16_to_cpu(di->di_clusterofs); break; default: DBG_BUGON(1); return -EIO; } return 0; } 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 int 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 int 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); } struct vle_map_blocks_iter_ctx { struct inode *inode; struct super_block *sb; unsigned int clusterbits; struct page **mpage_ret; void **kaddr_ret; }; static int vle_get_logical_extent_head(const struct vle_map_blocks_iter_ctx *ctx, unsigned int lcn, /* logical cluster number */ unsigned long long *ofs, erofs_blk_t *pblk, unsigned int *flags) { const unsigned int clustersize = 1 << ctx->clusterbits; const erofs_blk_t mblk = vle_extent_blkaddr(ctx->inode, lcn); struct page *mpage = *ctx->mpage_ret; /* extent metapage */ struct z_erofs_vle_decompressed_index *di; unsigned int cluster_type, delta0; if (mpage->index != mblk) { kunmap_atomic(*ctx->kaddr_ret); unlock_page(mpage); put_page(mpage); mpage = erofs_get_meta_page(ctx->sb, mblk, false); if (IS_ERR(mpage)) { *ctx->mpage_ret = NULL; return PTR_ERR(mpage); } *ctx->mpage_ret = mpage; *ctx->kaddr_ret = kmap_atomic(mpage); } di = *ctx->kaddr_ret + vle_extent_blkoff(ctx->inode, lcn); cluster_type = vle_cluster_type(di); switch (cluster_type) { case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: delta0 = le16_to_cpu(di->di_u.delta[0]); if (unlikely(!delta0 || delta0 > lcn)) { errln("invalid NONHEAD dl0 %u at lcn %u of nid %llu", delta0, lcn, EROFS_V(ctx->inode)->nid); DBG_BUGON(1); return -EIO; } return vle_get_logical_extent_head(ctx, lcn - delta0, ofs, pblk, flags); case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: *flags ^= EROFS_MAP_ZIPPED; /* fallthrough */ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD: /* clustersize should be a power of two */ *ofs = ((u64)lcn << ctx->clusterbits) + (le16_to_cpu(di->di_clusterofs) & (clustersize - 1)); *pblk = le32_to_cpu(di->di_u.blkaddr); break; default: errln("unknown cluster type %u at lcn %u of nid %llu", cluster_type, lcn, EROFS_V(ctx->inode)->nid); DBG_BUGON(1); return -EIO; } return 0; } int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, int flags) { void *kaddr; const struct vle_map_blocks_iter_ctx ctx = { .inode = inode, .sb = inode->i_sb, .clusterbits = EROFS_I_SB(inode)->clusterbits, .mpage_ret = &map->mpage, .kaddr_ret = &kaddr }; const unsigned int clustersize = 1 << ctx.clusterbits; /* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */ const bool initial = !map->m_llen; /* logicial extent (start, end) offset */ unsigned long long ofs, end; unsigned int lcn; u32 ofs_rem; /* initialize `pblk' to keep gcc from printing foolish warnings */ erofs_blk_t mblk, pblk = 0; struct page *mpage = map->mpage; struct z_erofs_vle_decompressed_index *di; unsigned int cluster_type, logical_cluster_ofs; int err = 0; trace_z_erofs_map_blocks_iter_enter(inode, map, flags); /* when trying to read beyond EOF, leave it unmapped */ if (unlikely(map->m_la >= inode->i_size)) { DBG_BUGON(!initial); map->m_llen = map->m_la + 1 - inode->i_size; map->m_la = inode->i_size; 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 >> ctx.clusterbits; ofs_rem = ofs & (clustersize - 1); mblk = vle_extent_blkaddr(inode, lcn); if (!mpage || mpage->index != mblk) { if (mpage) put_page(mpage); mpage = erofs_get_meta_page(ctx.sb, mblk, false); if (IS_ERR(mpage)) { err = PTR_ERR(mpage); goto out; } map->mpage = mpage; } else { lock_page(mpage); DBG_BUGON(!PageUptodate(mpage)); } kaddr = kmap_atomic(mpage); di = kaddr + vle_extent_blkoff(inode, lcn); debugln("%s, lcn %u mblk %u e_blkoff %u", __func__, lcn, mblk, vle_extent_blkoff(inode, lcn)); err = vle_decompressed_index_clusterofs(&logical_cluster_ofs, clustersize, di); if (unlikely(err)) goto unmap_out; 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) { pblk = le32_to_cpu(di->di_u.blkaddr); goto exact_hitted; } if (ofs_rem > logical_cluster_ofs) { ofs = (u64)lcn * clustersize | logical_cluster_ofs; pblk = 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 = ((u64)lcn-- * clustersize) | logical_cluster_ofs; /* fallthrough */ case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: /* get the correspoinding first chunk */ err = vle_get_logical_extent_head(&ctx, lcn, &ofs, &pblk, &map->m_flags); mpage = map->mpage; if (unlikely(err)) { if (mpage) goto unmap_out; goto out; } 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(pblk); 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); trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err); /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */ DBG_BUGON(err < 0 && err != -ENOMEM); return err; }