| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2018 HUAWEI, Inc. |
| * https://www.huawei.com/ |
| */ |
| #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) |
| }; |
| |
| 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_pages, 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) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(pcluster_pool); ++i) { |
| struct z_erofs_pcluster_slab *pcs = pcluster_pool + i; |
| |
| if (pcl->pclusterpages > pcs->maxpages) |
| continue; |
| |
| kmem_cache_free(pcs->slab, pcl); |
| return; |
| } |
| DBG_BUGON(1); |
| } |
| |
| /* |
| * 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 pcluster */ |
| enum z_erofs_cache_alloctype { |
| DONTALLOC, /* don't allocate any cached pages */ |
| DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */ |
| /* |
| * 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_collectmode { |
| COLLECT_SECONDARY, |
| COLLECT_PRIMARY, |
| /* |
| * The current collection was the tail of an exist chain, in addition |
| * that the previous processed chained collections are all decided to |
| * be hooked up to it. |
| * A new chain will be created for the remaining collections which are |
| * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED, |
| * the next collection cannot reuse the whole page safely in |
| * the following scenario: |
| * ________________________________________________________________ |
| * | tail (partial) page | head (partial) page | |
| * | (belongs to the next cl) | (belongs to the current cl) | |
| * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| |
| */ |
| COLLECT_PRIMARY_HOOKED, |
| /* |
| * a weak form of COLLECT_PRIMARY_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 |
| * pagevec) since it can be directly decoded without I/O submission. |
| */ |
| COLLECT_PRIMARY_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) | |
| * | PRIMARY_FOLLOWED or | | |
| * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________| |
| * |
| * [ (*) the above page can be used as inplace I/O. ] |
| */ |
| COLLECT_PRIMARY_FOLLOWED, |
| }; |
| |
| struct z_erofs_collector { |
| struct z_erofs_pagevec_ctor vector; |
| |
| struct z_erofs_pcluster *pcl, *tailpcl; |
| struct z_erofs_collection *cl; |
| /* a pointer used to pick up inplace I/O pages */ |
| struct page **icpage_ptr; |
| z_erofs_next_pcluster_t owned_head; |
| |
| enum z_erofs_collectmode mode; |
| }; |
| |
| struct z_erofs_decompress_frontend { |
| struct inode *const inode; |
| |
| struct z_erofs_collector clt; |
| struct erofs_map_blocks map; |
| |
| bool readahead; |
| /* used for applying cache strategy on the fly */ |
| bool backmost; |
| erofs_off_t headoffset; |
| }; |
| |
| #define COLLECTOR_INIT() { \ |
| .owned_head = Z_EROFS_PCLUSTER_TAIL, \ |
| .mode = COLLECT_PRIMARY_FOLLOWED } |
| |
| #define DECOMPRESS_FRONTEND_INIT(__i) { \ |
| .inode = __i, .clt = COLLECTOR_INIT(), \ |
| .backmost = true, } |
| |
| static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES]; |
| static DEFINE_MUTEX(z_pagemap_global_lock); |
| |
| static void preload_compressed_pages(struct z_erofs_collector *clt, |
| struct address_space *mc, |
| enum z_erofs_cache_alloctype type, |
| struct list_head *pagepool) |
| { |
| struct z_erofs_pcluster *pcl = clt->pcl; |
| bool standalone = true; |
| gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) | |
| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; |
| struct page **pages; |
| pgoff_t index; |
| |
| if (clt->mode < COLLECT_PRIMARY_FOLLOWED) |
| return; |
| |
| pages = pcl->compressed_pages; |
| index = pcl->obj.index; |
| for (; index < pcl->obj.index + pcl->pclusterpages; ++index, ++pages) { |
| struct page *page; |
| compressed_page_t t; |
| struct page *newpage = NULL; |
| |
| /* the compressed page was loaded before */ |
| if (READ_ONCE(*pages)) |
| continue; |
| |
| page = find_get_page(mc, index); |
| |
| if (page) { |
| t = tag_compressed_page_justfound(page); |
| } else { |
| /* I/O is needed, no possible to decompress directly */ |
| standalone = false; |
| switch (type) { |
| case DELAYEDALLOC: |
| t = tagptr_init(compressed_page_t, |
| PAGE_UNALLOCATED); |
| break; |
| 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(pages, NULL, tagptr_cast_ptr(t))) |
| continue; |
| |
| if (page) { |
| put_page(page); |
| } else if (newpage) { |
| set_page_private(newpage, 0); |
| list_add(&newpage->lru, pagepool); |
| } |
| } |
| |
| /* |
| * 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) |
| clt->mode = COLLECT_PRIMARY_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; |
| |
| /* |
| * 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_pages[i]; |
| |
| 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_pages[i], 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 = 0; /* 0 - busy */ |
| |
| if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) { |
| unsigned int i; |
| |
| for (i = 0; i < pcl->pclusterpages; ++i) { |
| if (pcl->compressed_pages[i] == page) { |
| WRITE_ONCE(pcl->compressed_pages[i], NULL); |
| ret = 1; |
| break; |
| } |
| } |
| erofs_workgroup_unfreeze(&pcl->obj, 1); |
| |
| if (ret) |
| detach_page_private(page); |
| } |
| return ret; |
| } |
| |
| /* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */ |
| static bool z_erofs_try_inplace_io(struct z_erofs_collector *clt, |
| struct page *page) |
| { |
| struct z_erofs_pcluster *const pcl = clt->pcl; |
| |
| while (clt->icpage_ptr > pcl->compressed_pages) |
| if (!cmpxchg(--clt->icpage_ptr, NULL, page)) |
| return true; |
| return false; |
| } |
| |
| /* callers must be with collection lock held */ |
| static int z_erofs_attach_page(struct z_erofs_collector *clt, |
| struct page *page, |
| enum z_erofs_page_type type) |
| { |
| int ret; |
| |
| /* give priority for inplaceio */ |
| if (clt->mode >= COLLECT_PRIMARY && |
| type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && |
| z_erofs_try_inplace_io(clt, page)) |
| return 0; |
| |
| ret = z_erofs_pagevec_enqueue(&clt->vector, page, type); |
| clt->cl->vcnt += (unsigned int)ret; |
| |
| return ret ? 0 : -EAGAIN; |
| } |
| |
| static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt) |
| { |
| struct z_erofs_pcluster *pcl = clt->pcl; |
| z_erofs_next_pcluster_t *owned_head = &clt->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. */ |
| clt->mode = COLLECT_PRIMARY_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 (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, |
| *owned_head) == Z_EROFS_PCLUSTER_TAIL) { |
| *owned_head = Z_EROFS_PCLUSTER_TAIL; |
| clt->mode = COLLECT_PRIMARY_HOOKED; |
| clt->tailpcl = NULL; |
| return; |
| } |
| /* type 3, it belongs to a chain, but it isn't the end of the chain */ |
| clt->mode = COLLECT_PRIMARY; |
| } |
| |
| static int z_erofs_lookup_collection(struct z_erofs_collector *clt, |
| struct inode *inode, |
| struct erofs_map_blocks *map) |
| { |
| struct z_erofs_pcluster *pcl = clt->pcl; |
| struct z_erofs_collection *cl; |
| unsigned int length; |
| |
| /* to avoid unexpected loop formed by corrupted images */ |
| if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) { |
| DBG_BUGON(1); |
| return -EFSCORRUPTED; |
| } |
| |
| cl = z_erofs_primarycollection(pcl); |
| if (cl->pageofs != (map->m_la & ~PAGE_MASK)) { |
| DBG_BUGON(1); |
| return -EFSCORRUPTED; |
| } |
| |
| length = READ_ONCE(pcl->length); |
| if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) { |
| if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) { |
| DBG_BUGON(1); |
| return -EFSCORRUPTED; |
| } |
| } else { |
| unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT; |
| |
| if (map->m_flags & EROFS_MAP_FULL_MAPPED) |
| llen |= Z_EROFS_PCLUSTER_FULL_LENGTH; |
| |
| while (llen > length && |
| length != cmpxchg_relaxed(&pcl->length, length, llen)) { |
| cpu_relax(); |
| length = READ_ONCE(pcl->length); |
| } |
| } |
| mutex_lock(&cl->lock); |
| /* used to check tail merging loop due to corrupted images */ |
| if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) |
| clt->tailpcl = pcl; |
| |
| z_erofs_try_to_claim_pcluster(clt); |
| clt->cl = cl; |
| return 0; |
| } |
| |
| static int z_erofs_register_collection(struct z_erofs_collector *clt, |
| struct inode *inode, |
| struct erofs_map_blocks *map) |
| { |
| struct z_erofs_pcluster *pcl; |
| struct z_erofs_collection *cl; |
| struct erofs_workgroup *grp; |
| int err; |
| |
| /* no available pcluster, let's allocate one */ |
| pcl = z_erofs_alloc_pcluster(map->m_plen >> PAGE_SHIFT); |
| if (IS_ERR(pcl)) |
| return PTR_ERR(pcl); |
| |
| atomic_set(&pcl->obj.refcount, 1); |
| pcl->obj.index = map->m_pa >> PAGE_SHIFT; |
| |
| pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) | |
| (map->m_flags & EROFS_MAP_FULL_MAPPED ? |
| Z_EROFS_PCLUSTER_FULL_LENGTH : 0); |
| |
| if (map->m_flags & EROFS_MAP_ZIPPED) |
| pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4; |
| else |
| pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED; |
| |
| /* new pclusters should be claimed as type 1, primary and followed */ |
| pcl->next = clt->owned_head; |
| clt->mode = COLLECT_PRIMARY_FOLLOWED; |
| |
| cl = z_erofs_primarycollection(pcl); |
| cl->pageofs = map->m_la & ~PAGE_MASK; |
| |
| /* |
| * lock all primary followed works before visible to others |
| * and mutex_trylock *never* fails for a new pcluster. |
| */ |
| mutex_init(&cl->lock); |
| DBG_BUGON(!mutex_trylock(&cl->lock)); |
| |
| grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj); |
| if (IS_ERR(grp)) { |
| err = PTR_ERR(grp); |
| goto err_out; |
| } |
| |
| if (grp != &pcl->obj) { |
| clt->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 (clt->owned_head == Z_EROFS_PCLUSTER_TAIL) |
| clt->tailpcl = pcl; |
| clt->owned_head = &pcl->next; |
| clt->pcl = pcl; |
| clt->cl = cl; |
| return 0; |
| |
| err_out: |
| mutex_unlock(&cl->lock); |
| z_erofs_free_pcluster(pcl); |
| return err; |
| } |
| |
| static int z_erofs_collector_begin(struct z_erofs_collector *clt, |
| struct inode *inode, |
| struct erofs_map_blocks *map) |
| { |
| struct erofs_workgroup *grp; |
| int ret; |
| |
| DBG_BUGON(clt->cl); |
| |
| /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */ |
| DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL); |
| DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| |
| if (!PAGE_ALIGNED(map->m_pa)) { |
| DBG_BUGON(1); |
| return -EINVAL; |
| } |
| |
| grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT); |
| if (grp) { |
| clt->pcl = container_of(grp, struct z_erofs_pcluster, obj); |
| } else { |
| ret = z_erofs_register_collection(clt, inode, map); |
| |
| if (!ret) |
| goto out; |
| if (ret != -EEXIST) |
| return ret; |
| } |
| |
| ret = z_erofs_lookup_collection(clt, inode, map); |
| if (ret) { |
| erofs_workgroup_put(&clt->pcl->obj); |
| return ret; |
| } |
| |
| out: |
| z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS, |
| clt->cl->pagevec, clt->cl->vcnt); |
| |
| /* since file-backed online pages are traversed in reverse order */ |
| clt->icpage_ptr = clt->pcl->compressed_pages + clt->pcl->pclusterpages; |
| 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) |
| { |
| struct z_erofs_collection *const cl = |
| container_of(head, struct z_erofs_collection, rcu); |
| |
| z_erofs_free_pcluster(container_of(cl, struct z_erofs_pcluster, |
| primary_collection)); |
| } |
| |
| void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) |
| { |
| struct z_erofs_pcluster *const pcl = |
| container_of(grp, struct z_erofs_pcluster, obj); |
| struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl); |
| |
| call_rcu(&cl->rcu, z_erofs_rcu_callback); |
| } |
| |
| static void z_erofs_collection_put(struct z_erofs_collection *cl) |
| { |
| struct z_erofs_pcluster *const pcl = |
| container_of(cl, struct z_erofs_pcluster, primary_collection); |
| |
| erofs_workgroup_put(&pcl->obj); |
| } |
| |
| static bool z_erofs_collector_end(struct z_erofs_collector *clt) |
| { |
| struct z_erofs_collection *cl = clt->cl; |
| |
| if (!cl) |
| return false; |
| |
| z_erofs_pagevec_ctor_exit(&clt->vector, false); |
| mutex_unlock(&cl->lock); |
| |
| /* |
| * if all pending pages are added, don't hold its reference |
| * any longer if the pcluster isn't hosted by ourselves. |
| */ |
| if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE) |
| z_erofs_collection_put(cl); |
| |
| clt->cl = 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 list_head *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; |
| struct z_erofs_collector *const clt = &fe->clt; |
| const loff_t offset = page_offset(page); |
| bool tight = true; |
| |
| 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 collection previously (very rare) */ |
| if (!clt->cl) |
| goto restart_now; |
| goto hitted; |
| } |
| |
| /* go ahead the next map_blocks */ |
| erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur); |
| |
| if (z_erofs_collector_end(clt)) |
| fe->backmost = false; |
| |
| map->m_la = offset + cur; |
| map->m_llen = 0; |
| err = z_erofs_map_blocks_iter(inode, map, 0); |
| if (err) |
| goto err_out; |
| |
| restart_now: |
| if (!(map->m_flags & EROFS_MAP_MAPPED)) |
| goto hitted; |
| |
| err = z_erofs_collector_begin(clt, inode, map); |
| if (err) |
| goto err_out; |
| |
| /* preload all compressed pages (maybe downgrade role if necessary) */ |
| if (should_alloc_managed_pages(fe, sbi->ctx.cache_strategy, map->m_la)) |
| cache_strategy = TRYALLOC; |
| else |
| cache_strategy = DONTALLOC; |
| |
| preload_compressed_pages(clt, MNGD_MAPPING(sbi), |
| 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 pagevec (should be processed in strict order.) |
| */ |
| tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED && |
| clt->mode != COLLECT_PRIMARY_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; |
| } |
| |
| /* 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 &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED); |
| |
| retry: |
| err = z_erofs_attach_page(clt, page, page_type); |
| /* should allocate an additional short-lived page for pagevec */ |
| if (err == -EAGAIN) { |
| struct page *const newpage = |
| alloc_page(GFP_NOFS | __GFP_NOFAIL); |
| |
| set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); |
| err = z_erofs_attach_page(clt, newpage, |
| Z_EROFS_PAGE_TYPE_EXCLUSIVE); |
| if (!err) |
| goto retry; |
| } |
| |
| if (err) |
| goto err_out; |
| |
| index = page->index - (map->m_la >> PAGE_SHIFT); |
| |
| z_erofs_onlinepage_fixup(page, index, true); |
| |
| /* bump up the number of spiltted parts of a page */ |
| ++spiltted; |
| /* also update nr_pages */ |
| clt->cl->nr_pages = max_t(pgoff_t, clt->cl->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: |
| 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; |
| |
| /* if some error occurred while processing this page */ |
| err_out: |
| SetPageError(page); |
| goto out; |
| } |
| |
| static void z_erofs_decompressqueue_work(struct work_struct *work); |
| 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) { |
| 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)) |
| return; |
| /* Use workqueue and sync decompression for atomic contexts only */ |
| if (in_atomic() || irqs_disabled()) { |
| queue_work(z_erofs_workqueue, &io->u.work); |
| sbi->ctx.readahead_sync_decompress = true; |
| return; |
| } |
| z_erofs_decompressqueue_work(&io->u.work); |
| } |
| |
| static bool z_erofs_page_is_invalidated(struct page *page) |
| { |
| return !page->mapping && !z_erofs_is_shortlived_page(page); |
| } |
| |
| 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 (err) |
| SetPageError(page); |
| |
| if (erofs_page_is_managed(EROFS_SB(q->sb), page)) { |
| if (!err) |
| SetPageUptodate(page); |
| unlock_page(page); |
| } |
| } |
| z_erofs_decompress_kickoff(q, tagptr_unfold_tags(t), -1); |
| bio_put(bio); |
| } |
| |
| static int z_erofs_decompress_pcluster(struct super_block *sb, |
| struct z_erofs_pcluster *pcl, |
| struct list_head *pagepool) |
| { |
| struct erofs_sb_info *const sbi = EROFS_SB(sb); |
| struct z_erofs_pagevec_ctor ctor; |
| unsigned int i, inputsize, outputsize, llen, nr_pages; |
| struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES]; |
| struct page **pages, **compressed_pages, *page; |
| |
| enum z_erofs_page_type page_type; |
| bool overlapped, partial; |
| struct z_erofs_collection *cl; |
| int err; |
| |
| might_sleep(); |
| cl = z_erofs_primarycollection(pcl); |
| DBG_BUGON(!READ_ONCE(cl->nr_pages)); |
| |
| mutex_lock(&cl->lock); |
| nr_pages = cl->nr_pages; |
| |
| if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) { |
| pages = pages_onstack; |
| } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES && |
| mutex_trylock(&z_pagemap_global_lock)) { |
| pages = z_pagemap_global; |
| } else { |
| gfp_t gfp_flags = GFP_KERNEL; |
| |
| if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES) |
| gfp_flags |= __GFP_NOFAIL; |
| |
| pages = kvmalloc_array(nr_pages, sizeof(struct page *), |
| gfp_flags); |
| |
| /* fallback to global pagemap for the lowmem scenario */ |
| if (!pages) { |
| mutex_lock(&z_pagemap_global_lock); |
| pages = z_pagemap_global; |
| } |
| } |
| |
| for (i = 0; i < nr_pages; ++i) |
| pages[i] = NULL; |
| |
| err = 0; |
| z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, |
| cl->pagevec, 0); |
| |
| for (i = 0; i < cl->vcnt; ++i) { |
| unsigned int pagenr; |
| |
| page = z_erofs_pagevec_dequeue(&ctor, &page_type); |
| |
| /* all pages in pagevec ought to be valid */ |
| DBG_BUGON(!page); |
| DBG_BUGON(z_erofs_page_is_invalidated(page)); |
| |
| if (z_erofs_put_shortlivedpage(pagepool, 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); |
| |
| /* |
| * currently EROFS doesn't support multiref(dedup), |
| * so here erroring out one multiref page. |
| */ |
| if (pages[pagenr]) { |
| DBG_BUGON(1); |
| SetPageError(pages[pagenr]); |
| z_erofs_onlinepage_endio(pages[pagenr]); |
| err = -EFSCORRUPTED; |
| } |
| pages[pagenr] = page; |
| } |
| z_erofs_pagevec_ctor_exit(&ctor, true); |
| |
| overlapped = false; |
| compressed_pages = pcl->compressed_pages; |
| |
| for (i = 0; i < pcl->pclusterpages; ++i) { |
| unsigned int pagenr; |
| |
| page = compressed_pages[i]; |
| |
| /* all compressed pages ought to be valid */ |
| DBG_BUGON(!page); |
| DBG_BUGON(z_erofs_page_is_invalidated(page)); |
| |
| if (!z_erofs_is_shortlived_page(page)) { |
| if (erofs_page_is_managed(sbi, page)) { |
| if (!PageUptodate(page)) |
| err = -EIO; |
| continue; |
| } |
| |
| /* |
| * only if non-head page can be selected |
| * for inplace decompression |
| */ |
| pagenr = z_erofs_onlinepage_index(page); |
| |
| DBG_BUGON(pagenr >= nr_pages); |
| if (pages[pagenr]) { |
| DBG_BUGON(1); |
| SetPageError(pages[pagenr]); |
| z_erofs_onlinepage_endio(pages[pagenr]); |
| err = -EFSCORRUPTED; |
| } |
| pages[pagenr] = page; |
| |
| overlapped = true; |
| } |
| |
| /* PG_error needs checking for all non-managed pages */ |
| if (PageError(page)) { |
| DBG_BUGON(PageUptodate(page)); |
| err = -EIO; |
| } |
| } |
| |
| if (err) |
| goto out; |
| |
| llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT; |
| if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) { |
| outputsize = llen; |
| partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH); |
| } else { |
| outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs; |
| partial = true; |
| } |
| |
| inputsize = pcl->pclusterpages * PAGE_SIZE; |
| err = z_erofs_decompress(&(struct z_erofs_decompress_req) { |
| .sb = sb, |
| .in = compressed_pages, |
| .out = pages, |
| .pageofs_out = cl->pageofs, |
| .inputsize = inputsize, |
| .outputsize = outputsize, |
| .alg = pcl->algorithmformat, |
| .inplace_io = overlapped, |
| .partial_decoding = partial |
| }, pagepool); |
| |
| out: |
| /* must handle all compressed pages before ending pages */ |
| for (i = 0; i < pcl->pclusterpages; ++i) { |
| page = compressed_pages[i]; |
| |
| if (erofs_page_is_managed(sbi, page)) |
| continue; |
| |
| /* recycle all individual short-lived pages */ |
| (void)z_erofs_put_shortlivedpage(pagepool, page); |
| |
| WRITE_ONCE(compressed_pages[i], NULL); |
| } |
| |
| for (i = 0; i < nr_pages; ++i) { |
| page = pages[i]; |
| if (!page) |
| continue; |
| |
| DBG_BUGON(z_erofs_page_is_invalidated(page)); |
| |
| /* recycle all individual short-lived pages */ |
| if (z_erofs_put_shortlivedpage(pagepool, page)) |
| continue; |
| |
| if (err < 0) |
| SetPageError(page); |
| |
| z_erofs_onlinepage_endio(page); |
| } |
| |
| if (pages == z_pagemap_global) |
| mutex_unlock(&z_pagemap_global_lock); |
| else if (pages != pages_onstack) |
| kvfree(pages); |
| |
| cl->nr_pages = 0; |
| cl->vcnt = 0; |
| |
| /* all cl locks MUST be taken before the following line */ |
| WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL); |
| |
| /* all cl locks SHOULD be released right now */ |
| mutex_unlock(&cl->lock); |
| |
| z_erofs_collection_put(cl); |
| return err; |
| } |
| |
| static void z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io, |
| struct list_head *pagepool) |
| { |
| z_erofs_next_pcluster_t owned = io->head; |
| |
| while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) { |
| struct z_erofs_pcluster *pcl; |
| |
| /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */ |
| DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL); |
| |
| /* no possible that 'owned' equals NULL */ |
| DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL); |
| |
| pcl = container_of(owned, struct z_erofs_pcluster, next); |
| owned = READ_ONCE(pcl->next); |
| |
| z_erofs_decompress_pcluster(io->sb, pcl, pagepool); |
| } |
| } |
| |
| static void z_erofs_decompressqueue_work(struct work_struct *work) |
| { |
| struct z_erofs_decompressqueue *bgq = |
| container_of(work, struct z_erofs_decompressqueue, u.work); |
| LIST_HEAD(pagepool); |
| |
| DBG_BUGON(bgq->head == Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| z_erofs_decompress_queue(bgq, &pagepool); |
| |
| put_pages_list(&pagepool); |
| kvfree(bgq); |
| } |
| |
| static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl, |
| unsigned int nr, |
| struct list_head *pagepool, |
| struct address_space *mc, |
| gfp_t gfp) |
| { |
| const pgoff_t index = pcl->obj.index; |
| bool tocache = false; |
| |
| struct address_space *mapping; |
| struct page *oldpage, *page; |
| |
| compressed_page_t t; |
| int justfound; |
| |
| repeat: |
| page = READ_ONCE(pcl->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 (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); |
| |
| /* |
| * 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_pages[nr], 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_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)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_pages[nr], oldpage, page)) { |
| list_add(&page->lru, pagepool); |
| 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_waitqueue_head(&fgq->u.wait); |
| atomic_set(&fgq->pending_bios, 0); |
| } |
| 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_submit_queue(struct super_block *sb, |
| struct z_erofs_decompress_frontend *f, |
| struct list_head *pagepool, |
| struct z_erofs_decompressqueue *fgq, |
| bool *force_fg) |
| { |
| struct erofs_sb_info *const sbi = 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->clt.owned_head; |
| /* since bio will be NULL, no need to initialize last_index */ |
| pgoff_t last_index; |
| 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 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); |
| |
| cur = pcl->obj.index; |
| end = cur + pcl->pclusterpages; |
| |
| /* close the main owned chain at first */ |
| owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL, |
| Z_EROFS_PCLUSTER_TAIL_CLOSED); |
| |
| do { |
| struct page *page; |
| |
| page = pickup_page_for_submission(pcl, i++, pagepool, |
| MNGD_MAPPING(sbi), |
| GFP_NOFS); |
| if (!page) |
| continue; |
| |
| if (bio && cur != last_index + 1) { |
| submit_bio_retry: |
| submit_bio(bio); |
| bio = NULL; |
| } |
| |
| if (!bio) { |
| bio = bio_alloc(GFP_NOIO, BIO_MAX_VECS); |
| |
| bio->bi_end_io = z_erofs_decompressqueue_endio; |
| bio_set_dev(bio, sb->s_bdev); |
| bio->bi_iter.bi_sector = (sector_t)cur << |
| LOG_SECTORS_PER_BLOCK; |
| bio->bi_private = bi_private; |
| bio->bi_opf = REQ_OP_READ; |
| 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 super_block *sb, |
| struct z_erofs_decompress_frontend *f, |
| struct list_head *pagepool, bool force_fg) |
| { |
| struct z_erofs_decompressqueue io[NR_JOBQUEUES]; |
| |
| if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL) |
| return; |
| z_erofs_submit_queue(sb, 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 */ |
| io_wait_event(io[JQ_SUBMIT].u.wait, |
| !atomic_read(&io[JQ_SUBMIT].pending_bios)); |
| |
| /* handle synchronous decompress queue in the caller context */ |
| z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool); |
| } |
| |
| static int z_erofs_readpage(struct file *file, struct page *page) |
| { |
| struct inode *const inode = page->mapping->host; |
| struct z_erofs_decompress_frontend f = DECOMPRESS_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_collector_end(&f.clt); |
| |
| /* if some compressed cluster ready, need submit them anyway */ |
| z_erofs_runqueue(inode->i_sb, &f, &pagepool, true); |
| |
| if (err) |
| erofs_err(inode->i_sb, "failed to read, err [%d]", err); |
| |
| if (f.map.mpage) |
| put_page(f.map.mpage); |
| |
| /* clean up the remaining free pages */ |
| put_pages_list(&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); |
| |
| unsigned int nr_pages = readahead_count(rac); |
| bool sync = (sbi->ctx.readahead_sync_decompress && |
| nr_pages <= sbi->ctx.max_sync_decompress_pages); |
| struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode); |
| struct page *page, *head = NULL; |
| LIST_HEAD(pagepool); |
| |
| trace_erofs_readpages(inode, readahead_index(rac), nr_pages, false); |
| |
| f.readahead = true; |
| f.headoffset = readahead_pos(rac); |
| |
| while ((page = readahead_page(rac))) { |
| prefetchw(&page->flags); |
| |
| /* |
| * 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); |
| |
| 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); |
| } |
| |
| (void)z_erofs_collector_end(&f.clt); |
| |
| z_erofs_runqueue(inode->i_sb, &f, &pagepool, sync); |
| |
| if (f.map.mpage) |
| put_page(f.map.mpage); |
| |
| /* clean up the remaining free pages */ |
| put_pages_list(&pagepool); |
| } |
| |
| const struct address_space_operations z_erofs_aops = { |
| .readpage = z_erofs_readpage, |
| .readahead = z_erofs_readahead, |
| }; |