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![Gao Xiang](/assets/img/avatar_default.png)
Try to forcely switch to inplace I/O under low memory scenario in order to avoid direct memory reclaim due to cached page allocation. Link: https://lore.kernel.org/r/20201209123717.12430-1-hsiangkao@aol.com Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
1390 lines
36 KiB
C
1390 lines
36 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2018 HUAWEI, Inc.
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* https://www.huawei.com/
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* Created by Gao Xiang <gaoxiang25@huawei.com>
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*/
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#include "zdata.h"
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#include "compress.h"
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#include <linux/prefetch.h>
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#include <trace/events/erofs.h>
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/*
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* a compressed_pages[] placeholder in order to avoid
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* being filled with file pages for in-place decompression.
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*/
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#define PAGE_UNALLOCATED ((void *)0x5F0E4B1D)
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/* how to allocate cached pages for a pcluster */
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enum z_erofs_cache_alloctype {
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DONTALLOC, /* don't allocate any cached pages */
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DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */
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/*
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* try to use cached I/O if page allocation succeeds or fallback
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* to in-place I/O instead to avoid any direct reclaim.
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*/
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TRYALLOC,
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};
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/*
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* tagged pointer with 1-bit tag for all compressed pages
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* tag 0 - the page is just found with an extra page reference
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*/
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typedef tagptr1_t compressed_page_t;
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#define tag_compressed_page_justfound(page) \
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tagptr_fold(compressed_page_t, page, 1)
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static struct workqueue_struct *z_erofs_workqueue __read_mostly;
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static struct kmem_cache *pcluster_cachep __read_mostly;
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void z_erofs_exit_zip_subsystem(void)
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{
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destroy_workqueue(z_erofs_workqueue);
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kmem_cache_destroy(pcluster_cachep);
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}
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static inline int z_erofs_init_workqueue(void)
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{
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const unsigned int onlinecpus = num_possible_cpus();
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/*
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* no need to spawn too many threads, limiting threads could minimum
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* scheduling overhead, perhaps per-CPU threads should be better?
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*/
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z_erofs_workqueue = alloc_workqueue("erofs_unzipd",
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WQ_UNBOUND | WQ_HIGHPRI,
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onlinecpus + onlinecpus / 4);
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return z_erofs_workqueue ? 0 : -ENOMEM;
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}
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static void z_erofs_pcluster_init_once(void *ptr)
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{
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struct z_erofs_pcluster *pcl = ptr;
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struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
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unsigned int i;
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mutex_init(&cl->lock);
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cl->nr_pages = 0;
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cl->vcnt = 0;
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for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i)
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pcl->compressed_pages[i] = NULL;
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}
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int __init z_erofs_init_zip_subsystem(void)
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{
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pcluster_cachep = kmem_cache_create("erofs_compress",
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Z_EROFS_WORKGROUP_SIZE, 0,
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SLAB_RECLAIM_ACCOUNT,
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z_erofs_pcluster_init_once);
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if (pcluster_cachep) {
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if (!z_erofs_init_workqueue())
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return 0;
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kmem_cache_destroy(pcluster_cachep);
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}
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return -ENOMEM;
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}
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enum z_erofs_collectmode {
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COLLECT_SECONDARY,
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COLLECT_PRIMARY,
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/*
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* The current collection was the tail of an exist chain, in addition
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* that the previous processed chained collections are all decided to
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* be hooked up to it.
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* A new chain will be created for the remaining collections which are
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* not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED,
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* the next collection cannot reuse the whole page safely in
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* the following scenario:
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* ________________________________________________________________
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* | tail (partial) page | head (partial) page |
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* | (belongs to the next cl) | (belongs to the current cl) |
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* |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
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*/
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COLLECT_PRIMARY_HOOKED,
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COLLECT_PRIMARY_FOLLOWED_NOINPLACE,
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/*
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* The current collection has been linked with the owned chain, and
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* could also be linked with the remaining collections, which means
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* if the processing page is the tail page of the collection, thus
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* the current collection can safely use the whole page (since
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* the previous collection is under control) for in-place I/O, as
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* illustrated below:
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* ________________________________________________________________
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* | tail (partial) page | head (partial) page |
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* | (of the current cl) | (of the previous collection) |
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* | PRIMARY_FOLLOWED or | |
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* |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
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*
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* [ (*) the above page can be used as inplace I/O. ]
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*/
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COLLECT_PRIMARY_FOLLOWED,
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};
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struct z_erofs_collector {
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struct z_erofs_pagevec_ctor vector;
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struct z_erofs_pcluster *pcl, *tailpcl;
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struct z_erofs_collection *cl;
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struct page **compressedpages;
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z_erofs_next_pcluster_t owned_head;
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enum z_erofs_collectmode mode;
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};
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struct z_erofs_decompress_frontend {
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struct inode *const inode;
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struct z_erofs_collector clt;
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struct erofs_map_blocks map;
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bool readahead;
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/* used for applying cache strategy on the fly */
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bool backmost;
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erofs_off_t headoffset;
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};
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#define COLLECTOR_INIT() { \
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.owned_head = Z_EROFS_PCLUSTER_TAIL, \
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.mode = COLLECT_PRIMARY_FOLLOWED }
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#define DECOMPRESS_FRONTEND_INIT(__i) { \
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.inode = __i, .clt = COLLECTOR_INIT(), \
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.backmost = true, }
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static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
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static DEFINE_MUTEX(z_pagemap_global_lock);
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static void preload_compressed_pages(struct z_erofs_collector *clt,
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struct address_space *mc,
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enum z_erofs_cache_alloctype type,
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struct list_head *pagepool)
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{
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const struct z_erofs_pcluster *pcl = clt->pcl;
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const unsigned int clusterpages = BIT(pcl->clusterbits);
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struct page **pages = clt->compressedpages;
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pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages);
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bool standalone = true;
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gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) |
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__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
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if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
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return;
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for (; pages < pcl->compressed_pages + clusterpages; ++pages) {
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struct page *page;
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compressed_page_t t;
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struct page *newpage = NULL;
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/* the compressed page was loaded before */
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if (READ_ONCE(*pages))
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continue;
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page = find_get_page(mc, index);
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if (page) {
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t = tag_compressed_page_justfound(page);
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} else if (type == DELAYEDALLOC) {
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t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
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} else if (type == TRYALLOC) {
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newpage = erofs_allocpage(pagepool, gfp);
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if (!newpage)
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goto dontalloc;
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set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE);
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t = tag_compressed_page_justfound(newpage);
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} else { /* DONTALLOC */
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dontalloc:
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if (standalone)
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clt->compressedpages = pages;
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standalone = false;
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continue;
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}
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if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
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continue;
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if (page) {
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put_page(page);
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} else if (newpage) {
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set_page_private(newpage, 0);
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list_add(&newpage->lru, pagepool);
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}
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}
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if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */
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clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
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}
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/* called by erofs_shrinker to get rid of all compressed_pages */
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int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
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struct erofs_workgroup *grp)
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{
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struct z_erofs_pcluster *const pcl =
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container_of(grp, struct z_erofs_pcluster, obj);
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struct address_space *const mapping = MNGD_MAPPING(sbi);
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const unsigned int clusterpages = BIT(pcl->clusterbits);
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int i;
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/*
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* refcount of workgroup is now freezed as 1,
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* therefore no need to worry about available decompression users.
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*/
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for (i = 0; i < clusterpages; ++i) {
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struct page *page = pcl->compressed_pages[i];
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if (!page)
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continue;
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/* block other users from reclaiming or migrating the page */
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if (!trylock_page(page))
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return -EBUSY;
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if (page->mapping != mapping)
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continue;
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/* barrier is implied in the following 'unlock_page' */
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WRITE_ONCE(pcl->compressed_pages[i], NULL);
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detach_page_private(page);
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unlock_page(page);
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}
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return 0;
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}
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int erofs_try_to_free_cached_page(struct address_space *mapping,
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struct page *page)
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{
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struct z_erofs_pcluster *const pcl = (void *)page_private(page);
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const unsigned int clusterpages = BIT(pcl->clusterbits);
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int ret = 0; /* 0 - busy */
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if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) {
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unsigned int i;
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for (i = 0; i < clusterpages; ++i) {
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if (pcl->compressed_pages[i] == page) {
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WRITE_ONCE(pcl->compressed_pages[i], NULL);
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ret = 1;
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break;
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}
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}
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erofs_workgroup_unfreeze(&pcl->obj, 1);
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if (ret)
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detach_page_private(page);
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}
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return ret;
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}
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/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
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static inline bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
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struct page *page)
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{
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struct z_erofs_pcluster *const pcl = clt->pcl;
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const unsigned int clusterpages = BIT(pcl->clusterbits);
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while (clt->compressedpages < pcl->compressed_pages + clusterpages) {
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if (!cmpxchg(clt->compressedpages++, NULL, page))
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return true;
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}
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return false;
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}
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/* callers must be with collection lock held */
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static int z_erofs_attach_page(struct z_erofs_collector *clt,
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struct page *page,
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enum z_erofs_page_type type)
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{
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int ret;
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bool occupied;
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/* give priority for inplaceio */
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if (clt->mode >= COLLECT_PRIMARY &&
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type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
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z_erofs_try_inplace_io(clt, page))
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return 0;
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ret = z_erofs_pagevec_enqueue(&clt->vector,
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page, type, &occupied);
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clt->cl->vcnt += (unsigned int)ret;
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return ret ? 0 : -EAGAIN;
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}
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static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt)
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{
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struct z_erofs_pcluster *pcl = clt->pcl;
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z_erofs_next_pcluster_t *owned_head = &clt->owned_head;
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/* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */
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if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
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*owned_head) == Z_EROFS_PCLUSTER_NIL) {
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*owned_head = &pcl->next;
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/* so we can attach this pcluster to our submission chain. */
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clt->mode = COLLECT_PRIMARY_FOLLOWED;
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return;
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}
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/*
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* type 2, link to the end of an existing open chain, be careful
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* that its submission is controlled by the original attached chain.
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*/
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if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
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*owned_head) == Z_EROFS_PCLUSTER_TAIL) {
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*owned_head = Z_EROFS_PCLUSTER_TAIL;
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clt->mode = COLLECT_PRIMARY_HOOKED;
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clt->tailpcl = NULL;
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return;
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}
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/* type 3, it belongs to a chain, but it isn't the end of the chain */
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clt->mode = COLLECT_PRIMARY;
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}
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static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
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struct inode *inode,
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struct erofs_map_blocks *map)
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{
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struct z_erofs_pcluster *pcl = clt->pcl;
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struct z_erofs_collection *cl;
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unsigned int length;
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/* to avoid unexpected loop formed by corrupted images */
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if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
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DBG_BUGON(1);
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return -EFSCORRUPTED;
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}
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cl = z_erofs_primarycollection(pcl);
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if (cl->pageofs != (map->m_la & ~PAGE_MASK)) {
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DBG_BUGON(1);
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return -EFSCORRUPTED;
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}
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length = READ_ONCE(pcl->length);
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if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
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if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
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DBG_BUGON(1);
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return -EFSCORRUPTED;
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}
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} else {
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unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT;
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if (map->m_flags & EROFS_MAP_FULL_MAPPED)
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llen |= Z_EROFS_PCLUSTER_FULL_LENGTH;
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while (llen > length &&
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length != cmpxchg_relaxed(&pcl->length, length, llen)) {
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cpu_relax();
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length = READ_ONCE(pcl->length);
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}
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}
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mutex_lock(&cl->lock);
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/* used to check tail merging loop due to corrupted images */
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if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
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clt->tailpcl = pcl;
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z_erofs_try_to_claim_pcluster(clt);
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clt->cl = cl;
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return 0;
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}
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static int z_erofs_register_collection(struct z_erofs_collector *clt,
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struct inode *inode,
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struct erofs_map_blocks *map)
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{
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struct z_erofs_pcluster *pcl;
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struct z_erofs_collection *cl;
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struct erofs_workgroup *grp;
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int err;
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/* no available workgroup, let's allocate one */
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pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS);
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if (!pcl)
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return -ENOMEM;
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atomic_set(&pcl->obj.refcount, 1);
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pcl->obj.index = map->m_pa >> PAGE_SHIFT;
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pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
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(map->m_flags & EROFS_MAP_FULL_MAPPED ?
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Z_EROFS_PCLUSTER_FULL_LENGTH : 0);
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if (map->m_flags & EROFS_MAP_ZIPPED)
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pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4;
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else
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pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
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pcl->clusterbits = EROFS_I(inode)->z_physical_clusterbits[0];
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pcl->clusterbits -= PAGE_SHIFT;
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/* new pclusters should be claimed as type 1, primary and followed */
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pcl->next = clt->owned_head;
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clt->mode = COLLECT_PRIMARY_FOLLOWED;
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cl = z_erofs_primarycollection(pcl);
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|
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/* must be cleaned before freeing to slab */
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DBG_BUGON(cl->nr_pages);
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DBG_BUGON(cl->vcnt);
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|
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cl->pageofs = map->m_la & ~PAGE_MASK;
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|
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/*
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* lock all primary followed works before visible to others
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* and mutex_trylock *never* fails for a new pcluster.
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*/
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DBG_BUGON(!mutex_trylock(&cl->lock));
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grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj);
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if (IS_ERR(grp)) {
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err = PTR_ERR(grp);
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goto err_out;
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}
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|
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if (grp != &pcl->obj) {
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clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
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err = -EEXIST;
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goto err_out;
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}
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/* used to check tail merging loop due to corrupted images */
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if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
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clt->tailpcl = pcl;
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clt->owned_head = &pcl->next;
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clt->pcl = pcl;
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clt->cl = cl;
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return 0;
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err_out:
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mutex_unlock(&cl->lock);
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kmem_cache_free(pcluster_cachep, pcl);
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return err;
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}
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|
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static int z_erofs_collector_begin(struct z_erofs_collector *clt,
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struct inode *inode,
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struct erofs_map_blocks *map)
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{
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struct erofs_workgroup *grp;
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int ret;
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DBG_BUGON(clt->cl);
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/* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
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DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
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DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
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|
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if (!PAGE_ALIGNED(map->m_pa)) {
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DBG_BUGON(1);
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return -EINVAL;
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}
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|
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grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
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|
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);
|
|
|
|
clt->compressedpages = clt->pcl->compressed_pages;
|
|
if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */
|
|
clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES;
|
|
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);
|
|
|
|
kmem_cache_free(pcluster_cachep,
|
|
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_decompress_kickoff(struct z_erofs_decompressqueue *io,
|
|
bool sync, int bios)
|
|
{
|
|
/* 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))
|
|
queue_work(z_erofs_workqueue, &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);
|
|
const unsigned int clusterpages = BIT(pcl->clusterbits);
|
|
struct z_erofs_pagevec_ctor ctor;
|
|
unsigned int i, 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 < clusterpages; ++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;
|
|
}
|
|
|
|
err = z_erofs_decompress(&(struct z_erofs_decompress_req) {
|
|
.sb = sb,
|
|
.in = compressed_pages,
|
|
.out = pages,
|
|
.pageofs_out = cl->pageofs,
|
|
.inputsize = PAGE_SIZE,
|
|
.outputsize = outputsize,
|
|
.alg = pcl->algorithmformat,
|
|
.inplace_io = overlapped,
|
|
.partial_decoding = partial
|
|
}, pagepool);
|
|
|
|
out:
|
|
/* must handle all compressed pages before endding pages */
|
|
for (i = 0; i < clusterpages; ++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 + BIT(pcl->clusterbits);
|
|
|
|
/* 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_PAGES);
|
|
|
|
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 = (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,
|
|
};
|
|
|