blob: 31eef839577436709b1a5261507aff59bcf821d7 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* linux/drivers/staging/erofs/unzip_vle.c
*
* Copyright (C) 2018 HUAWEI, Inc.
* http://www.huawei.com/
* Created by Gao Xiang <gaoxiang25@huawei.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of the Linux
* distribution for more details.
*/
#include "unzip_vle.h"
#include <linux/prefetch.h>
#include <trace/events/erofs.h>
/*
* a compressed_pages[] placeholder in order to avoid
* being filled with file pages for in-place decompression.
*/
#define PAGE_UNALLOCATED ((void *)0x5F0E4B1D)
/* how to allocate cached pages for a workgroup */
enum z_erofs_cache_alloctype {
DONTALLOC, /* don't allocate any cached pages */
DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */
};
/*
* tagged pointer with 1-bit tag for all compressed pages
* tag 0 - the page is just found with an extra page reference
*/
typedef tagptr1_t compressed_page_t;
#define tag_compressed_page_justfound(page) \
tagptr_fold(compressed_page_t, page, 1)
static struct workqueue_struct *z_erofs_workqueue __read_mostly;
static struct kmem_cache *z_erofs_workgroup_cachep __read_mostly;
void z_erofs_exit_zip_subsystem(void)
{
destroy_workqueue(z_erofs_workqueue);
kmem_cache_destroy(z_erofs_workgroup_cachep);
}
static inline int init_unzip_workqueue(void)
{
const unsigned int onlinecpus = num_possible_cpus();
/*
* we don't need too many threads, limiting threads
* could improve scheduling performance.
*/
z_erofs_workqueue =
alloc_workqueue("erofs_unzipd",
WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
onlinecpus + onlinecpus / 4);
return z_erofs_workqueue ? 0 : -ENOMEM;
}
static void init_once(void *ptr)
{
struct z_erofs_vle_workgroup *grp = ptr;
struct z_erofs_vle_work *const work =
z_erofs_vle_grab_primary_work(grp);
unsigned int i;
mutex_init(&work->lock);
work->nr_pages = 0;
work->vcnt = 0;
for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i)
grp->compressed_pages[i] = NULL;
}
static void init_always(struct z_erofs_vle_workgroup *grp)
{
struct z_erofs_vle_work *const work =
z_erofs_vle_grab_primary_work(grp);
atomic_set(&grp->obj.refcount, 1);
grp->flags = 0;
DBG_BUGON(work->nr_pages);
DBG_BUGON(work->vcnt);
}
int __init z_erofs_init_zip_subsystem(void)
{
z_erofs_workgroup_cachep =
kmem_cache_create("erofs_compress",
Z_EROFS_WORKGROUP_SIZE, 0,
SLAB_RECLAIM_ACCOUNT, init_once);
if (z_erofs_workgroup_cachep) {
if (!init_unzip_workqueue())
return 0;
kmem_cache_destroy(z_erofs_workgroup_cachep);
}
return -ENOMEM;
}
enum z_erofs_vle_work_role {
Z_EROFS_VLE_WORK_SECONDARY,
Z_EROFS_VLE_WORK_PRIMARY,
/*
* The current work was the tail of an exist chain, and the previous
* processed chained works are all decided to be hooked up to it.
* A new chain should be created for the remaining unprocessed works,
* therefore different from Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED,
* the next work cannot reuse the whole page in the following scenario:
* ________________________________________________________________
* | tail (partial) page | head (partial) page |
* | (belongs to the next work) | (belongs to the current work) |
* |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
*/
Z_EROFS_VLE_WORK_PRIMARY_HOOKED,
/*
* The current work has been linked with the processed chained works,
* and could be also linked with the potential remaining works, which
* means if the processing page is the tail partial page of the work,
* the current work can safely use the whole page (since the next work
* is under control) for in-place decompression, as illustrated below:
* ________________________________________________________________
* | tail (partial) page | head (partial) page |
* | (of the current work) | (of the previous work) |
* | PRIMARY_FOLLOWED or | |
* |_____PRIMARY_HOOKED____|____________PRIMARY_FOLLOWED____________|
*
* [ (*) the above page can be used for the current work itself. ]
*/
Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED,
Z_EROFS_VLE_WORK_MAX
};
struct z_erofs_vle_work_builder {
enum z_erofs_vle_work_role role;
/*
* 'hosted = false' means that the current workgroup doesn't belong to
* the owned chained workgroups. In the other words, it is none of our
* business to submit this workgroup.
*/
bool hosted;
struct z_erofs_vle_workgroup *grp;
struct z_erofs_vle_work *work;
struct z_erofs_pagevec_ctor vector;
/* pages used for reading the compressed data */
struct page **compressed_pages;
unsigned int compressed_deficit;
};
#define VLE_WORK_BUILDER_INIT() \
{ .work = NULL, .role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED }
#ifdef EROFS_FS_HAS_MANAGED_CACHE
static void preload_compressed_pages(struct z_erofs_vle_work_builder *bl,
struct address_space *mc,
pgoff_t index,
unsigned int clusterpages,
enum z_erofs_cache_alloctype type,
struct list_head *pagepool,
gfp_t gfp)
{
struct page **const pages = bl->compressed_pages;
const unsigned int remaining = bl->compressed_deficit;
bool standalone = true;
unsigned int i, j = 0;
if (bl->role < Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED)
return;
gfp = mapping_gfp_constraint(mc, gfp) & ~__GFP_RECLAIM;
index += clusterpages - remaining;
for (i = 0; i < remaining; ++i) {
struct page *page;
compressed_page_t t;
/* the compressed page was loaded before */
if (READ_ONCE(pages[i]))
continue;
page = find_get_page(mc, index + i);
if (page) {
t = tag_compressed_page_justfound(page);
} else if (type == DELAYEDALLOC) {
t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
} else { /* DONTALLOC */
if (standalone)
j = i;
standalone = false;
continue;
}
if (!cmpxchg_relaxed(&pages[i], NULL, tagptr_cast_ptr(t)))
continue;
if (page)
put_page(page);
}
bl->compressed_pages += j;
bl->compressed_deficit = remaining - j;
if (standalone)
bl->role = Z_EROFS_VLE_WORK_PRIMARY;
}
/* called by erofs_shrinker to get rid of all compressed_pages */
int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
struct erofs_workgroup *egrp)
{
struct z_erofs_vle_workgroup *const grp =
container_of(egrp, struct z_erofs_vle_workgroup, obj);
struct address_space *const mapping = MNGD_MAPPING(sbi);
const int clusterpages = erofs_clusterpages(sbi);
int i;
/*
* refcount of workgroup is now freezed as 1,
* therefore no need to worry about available decompression users.
*/
for (i = 0; i < clusterpages; ++i) {
struct page *page = grp->compressed_pages[i];
if (!page || page->mapping != mapping)
continue;
/* block other users from reclaiming or migrating the page */
if (!trylock_page(page))
return -EBUSY;
/* barrier is implied in the following 'unlock_page' */
WRITE_ONCE(grp->compressed_pages[i], NULL);
set_page_private(page, 0);
ClearPagePrivate(page);
unlock_page(page);
put_page(page);
}
return 0;
}
int erofs_try_to_free_cached_page(struct address_space *mapping,
struct page *page)
{
struct erofs_sb_info *const sbi = EROFS_SB(mapping->host->i_sb);
const unsigned int clusterpages = erofs_clusterpages(sbi);
struct z_erofs_vle_workgroup *const grp = (void *)page_private(page);
int ret = 0; /* 0 - busy */
if (erofs_workgroup_try_to_freeze(&grp->obj, 1)) {
unsigned int i;
for (i = 0; i < clusterpages; ++i) {
if (grp->compressed_pages[i] == page) {
WRITE_ONCE(grp->compressed_pages[i], NULL);
ret = 1;
break;
}
}
erofs_workgroup_unfreeze(&grp->obj, 1);
if (ret) {
ClearPagePrivate(page);
put_page(page);
}
}
return ret;
}
#else
static void preload_compressed_pages(struct z_erofs_vle_work_builder *bl,
struct address_space *mc,
pgoff_t index,
unsigned int clusterpages,
enum z_erofs_cache_alloctype type,
struct list_head *pagepool,
gfp_t gfp)
{
/* nowhere to load compressed pages from */
}
#endif
/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
static inline bool try_to_reuse_as_compressed_page(
struct z_erofs_vle_work_builder *b,
struct page *page)
{
while (b->compressed_deficit) {
--b->compressed_deficit;
if (!cmpxchg(b->compressed_pages++, NULL, page))
return true;
}
return false;
}
/* callers must be with work->lock held */
static int z_erofs_vle_work_add_page(
struct z_erofs_vle_work_builder *builder,
struct page *page,
enum z_erofs_page_type type)
{
int ret;
bool occupied;
/* give priority for the compressed data storage */
if (builder->role >= Z_EROFS_VLE_WORK_PRIMARY &&
type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
try_to_reuse_as_compressed_page(builder, page))
return 0;
ret = z_erofs_pagevec_ctor_enqueue(&builder->vector,
page, type, &occupied);
builder->work->vcnt += (unsigned int)ret;
return ret ? 0 : -EAGAIN;
}
static enum z_erofs_vle_work_role
try_to_claim_workgroup(struct z_erofs_vle_workgroup *grp,
z_erofs_vle_owned_workgrp_t *owned_head,
bool *hosted)
{
DBG_BUGON(*hosted == true);
/* let's claim these following types of workgroup */
retry:
if (grp->next == Z_EROFS_VLE_WORKGRP_NIL) {
/* type 1, nil workgroup */
if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_NIL,
*owned_head) != Z_EROFS_VLE_WORKGRP_NIL)
goto retry;
*owned_head = &grp->next;
*hosted = true;
/* lucky, I am the followee :) */
return Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
} else if (grp->next == Z_EROFS_VLE_WORKGRP_TAIL) {
/*
* type 2, link to the end of a existing open chain,
* be careful that its submission itself is governed
* by the original owned chain.
*/
if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL,
*owned_head) != Z_EROFS_VLE_WORKGRP_TAIL)
goto retry;
*owned_head = Z_EROFS_VLE_WORKGRP_TAIL;
return Z_EROFS_VLE_WORK_PRIMARY_HOOKED;
}
return Z_EROFS_VLE_WORK_PRIMARY; /* :( better luck next time */
}
struct z_erofs_vle_work_finder {
struct super_block *sb;
pgoff_t idx;
unsigned int pageofs;
struct z_erofs_vle_workgroup **grp_ret;
enum z_erofs_vle_work_role *role;
z_erofs_vle_owned_workgrp_t *owned_head;
bool *hosted;
};
static struct z_erofs_vle_work *
z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f)
{
bool tag, primary;
struct erofs_workgroup *egrp;
struct z_erofs_vle_workgroup *grp;
struct z_erofs_vle_work *work;
egrp = erofs_find_workgroup(f->sb, f->idx, &tag);
if (!egrp) {
*f->grp_ret = NULL;
return NULL;
}
grp = container_of(egrp, struct z_erofs_vle_workgroup, obj);
*f->grp_ret = grp;
work = z_erofs_vle_grab_work(grp, f->pageofs);
/* if multiref is disabled, `primary' is always true */
primary = true;
DBG_BUGON(work->pageofs != f->pageofs);
/*
* lock must be taken first to avoid grp->next == NIL between
* claiming workgroup and adding pages:
* grp->next != NIL
* grp->next = NIL
* mutex_unlock_all
* mutex_lock(&work->lock)
* add all pages to pagevec
*
* [correct locking case 1]:
* mutex_lock(grp->work[a])
* ...
* mutex_lock(grp->work[b]) mutex_lock(grp->work[c])
* ... *role = SECONDARY
* add all pages to pagevec
* ...
* mutex_unlock(grp->work[c])
* mutex_lock(grp->work[c])
* ...
* grp->next = NIL
* mutex_unlock_all
*
* [correct locking case 2]:
* mutex_lock(grp->work[b])
* ...
* mutex_lock(grp->work[a])
* ...
* mutex_lock(grp->work[c])
* ...
* grp->next = NIL
* mutex_unlock_all
* mutex_lock(grp->work[a])
* *role = PRIMARY_OWNER
* add all pages to pagevec
* ...
*/
mutex_lock(&work->lock);
*f->hosted = false;
if (!primary)
*f->role = Z_EROFS_VLE_WORK_SECONDARY;
else /* claim the workgroup if possible */
*f->role = try_to_claim_workgroup(grp, f->owned_head,
f->hosted);
return work;
}
static struct z_erofs_vle_work *
z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f,
struct erofs_map_blocks *map)
{
bool gnew = false;
struct z_erofs_vle_workgroup *grp = *f->grp_ret;
struct z_erofs_vle_work *work;
/* if multiref is disabled, grp should never be nullptr */
if (unlikely(grp)) {
DBG_BUGON(1);
return ERR_PTR(-EINVAL);
}
/* no available workgroup, let's allocate one */
grp = kmem_cache_alloc(z_erofs_workgroup_cachep, GFP_NOFS);
if (unlikely(!grp))
return ERR_PTR(-ENOMEM);
init_always(grp);
grp->obj.index = f->idx;
grp->llen = map->m_llen;
z_erofs_vle_set_workgrp_fmt(grp,
(map->m_flags & EROFS_MAP_ZIPPED) ?
Z_EROFS_VLE_WORKGRP_FMT_LZ4 :
Z_EROFS_VLE_WORKGRP_FMT_PLAIN);
/* new workgrps have been claimed as type 1 */
WRITE_ONCE(grp->next, *f->owned_head);
/* primary and followed work for all new workgrps */
*f->role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
/* it should be submitted by ourselves */
*f->hosted = true;
gnew = true;
work = z_erofs_vle_grab_primary_work(grp);
work->pageofs = f->pageofs;
/*
* lock all primary followed works before visible to others
* and mutex_trylock *never* fails for a new workgroup.
*/
mutex_trylock(&work->lock);
if (gnew) {
int err = erofs_register_workgroup(f->sb, &grp->obj, 0);
if (err) {
mutex_unlock(&work->lock);
kmem_cache_free(z_erofs_workgroup_cachep, grp);
return ERR_PTR(-EAGAIN);
}
}
*f->owned_head = &grp->next;
*f->grp_ret = grp;
return work;
}
#define builder_is_hooked(builder) \
((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_HOOKED)
#define builder_is_followed(builder) \
((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED)
static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder,
struct super_block *sb,
struct erofs_map_blocks *map,
z_erofs_vle_owned_workgrp_t *owned_head)
{
const unsigned int clusterpages = erofs_clusterpages(EROFS_SB(sb));
struct z_erofs_vle_workgroup *grp;
const struct z_erofs_vle_work_finder finder = {
.sb = sb,
.idx = erofs_blknr(map->m_pa),
.pageofs = map->m_la & ~PAGE_MASK,
.grp_ret = &grp,
.role = &builder->role,
.owned_head = owned_head,
.hosted = &builder->hosted
};
struct z_erofs_vle_work *work;
DBG_BUGON(builder->work);
/* must be Z_EROFS_WORK_TAIL or the next chained work */
DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_NIL);
DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
DBG_BUGON(erofs_blkoff(map->m_pa));
repeat:
work = z_erofs_vle_work_lookup(&finder);
if (work) {
unsigned int orig_llen;
/* increase workgroup `llen' if needed */
while ((orig_llen = READ_ONCE(grp->llen)) < map->m_llen &&
orig_llen != cmpxchg_relaxed(&grp->llen,
orig_llen, map->m_llen))
cpu_relax();
goto got_it;
}
work = z_erofs_vle_work_register(&finder, map);
if (unlikely(work == ERR_PTR(-EAGAIN)))
goto repeat;
if (IS_ERR(work))
return PTR_ERR(work);
got_it:
z_erofs_pagevec_ctor_init(&builder->vector,
Z_EROFS_VLE_INLINE_PAGEVECS, work->pagevec, work->vcnt);
if (builder->role >= Z_EROFS_VLE_WORK_PRIMARY) {
/* enable possibly in-place decompression */
builder->compressed_pages = grp->compressed_pages;
builder->compressed_deficit = clusterpages;
} else {
builder->compressed_pages = NULL;
builder->compressed_deficit = 0;
}
builder->grp = grp;
builder->work = work;
return 0;
}
/*
* keep in mind that no referenced workgroups will be freed
* only after a RCU grace period, so rcu_read_lock() could
* prevent a workgroup from being freed.
*/
static void z_erofs_rcu_callback(struct rcu_head *head)
{
struct z_erofs_vle_work *work = container_of(head,
struct z_erofs_vle_work, rcu);
struct z_erofs_vle_workgroup *grp =
z_erofs_vle_work_workgroup(work, true);
kmem_cache_free(z_erofs_workgroup_cachep, grp);
}
void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
{
struct z_erofs_vle_workgroup *const vgrp = container_of(grp,
struct z_erofs_vle_workgroup, obj);
struct z_erofs_vle_work *const work = &vgrp->work;
call_rcu(&work->rcu, z_erofs_rcu_callback);
}
static void __z_erofs_vle_work_release(struct z_erofs_vle_workgroup *grp,
struct z_erofs_vle_work *work __maybe_unused)
{
erofs_workgroup_put(&grp->obj);
}
static void z_erofs_vle_work_release(struct z_erofs_vle_work *work)
{
struct z_erofs_vle_workgroup *grp =
z_erofs_vle_work_workgroup(work, true);
__z_erofs_vle_work_release(grp, work);
}
static inline bool
z_erofs_vle_work_iter_end(struct z_erofs_vle_work_builder *builder)
{
struct z_erofs_vle_work *work = builder->work;
if (!work)
return false;
z_erofs_pagevec_ctor_exit(&builder->vector, false);
mutex_unlock(&work->lock);
/*
* if all pending pages are added, don't hold work reference
* any longer if the current work isn't hosted by ourselves.
*/
if (!builder->hosted)
__z_erofs_vle_work_release(builder->grp, work);
builder->work = NULL;
builder->grp = NULL;
return true;
}
static inline struct page *__stagingpage_alloc(struct list_head *pagepool,
gfp_t gfp)
{
struct page *page = erofs_allocpage(pagepool, gfp);
if (unlikely(!page))
return NULL;
page->mapping = Z_EROFS_MAPPING_STAGING;
return page;
}
struct z_erofs_vle_frontend {
struct inode *const inode;
struct z_erofs_vle_work_builder builder;
struct erofs_map_blocks map;
z_erofs_vle_owned_workgrp_t owned_head;
/* used for applying cache strategy on the fly */
bool backmost;
erofs_off_t headoffset;
};
#define VLE_FRONTEND_INIT(__i) { \
.inode = __i, \
.map = { \
.m_llen = 0, \
.m_plen = 0, \
.mpage = NULL \
}, \
.builder = VLE_WORK_BUILDER_INIT(), \
.owned_head = Z_EROFS_VLE_WORKGRP_TAIL, \
.backmost = true, }
#ifdef EROFS_FS_HAS_MANAGED_CACHE
static inline bool
should_alloc_managed_pages(struct z_erofs_vle_frontend *fe, erofs_off_t la)
{
if (fe->backmost)
return true;
if (EROFS_FS_ZIP_CACHE_LVL >= 2)
return la < fe->headoffset;
return false;
}
#else
static inline bool
should_alloc_managed_pages(struct z_erofs_vle_frontend *fe, erofs_off_t la)
{
return false;
}
#endif
static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
struct page *page,
struct list_head *page_pool)
{
struct super_block *const sb = fe->inode->i_sb;
struct erofs_sb_info *const sbi __maybe_unused = EROFS_SB(sb);
struct erofs_map_blocks *const map = &fe->map;
struct z_erofs_vle_work_builder *const builder = &fe->builder;
const loff_t offset = page_offset(page);
bool tight = builder_is_hooked(builder);
struct z_erofs_vle_work *work = builder->work;
enum z_erofs_cache_alloctype cache_strategy;
enum z_erofs_page_type page_type;
unsigned int cur, end, spiltted, index;
int err = 0;
/* register locked file pages as online pages in pack */
z_erofs_onlinepage_init(page);
spiltted = 0;
end = PAGE_SIZE;
repeat:
cur = end - 1;
/* lucky, within the range of the current map_blocks */
if (offset + cur >= map->m_la &&
offset + cur < map->m_la + map->m_llen) {
/* didn't get a valid unzip work previously (very rare) */
if (!builder->work)
goto restart_now;
goto hitted;
}
/* go ahead the next map_blocks */
debugln("%s: [out-of-range] pos %llu", __func__, offset + cur);
if (z_erofs_vle_work_iter_end(builder))
fe->backmost = false;
map->m_la = offset + cur;
map->m_llen = 0;
err = z_erofs_map_blocks_iter(fe->inode, map, 0);
if (unlikely(err))
goto err_out;
restart_now:
if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED)))
goto hitted;
DBG_BUGON(map->m_plen != 1 << sbi->clusterbits);
DBG_BUGON(erofs_blkoff(map->m_pa));
err = z_erofs_vle_work_iter_begin(builder, sb, map, &fe->owned_head);
if (unlikely(err))
goto err_out;
/* preload all compressed pages (maybe downgrade role if necessary) */
if (should_alloc_managed_pages(fe, map->m_la))
cache_strategy = DELAYEDALLOC;
else
cache_strategy = DONTALLOC;
preload_compressed_pages(builder, MNGD_MAPPING(sbi),
map->m_pa / PAGE_SIZE,
map->m_plen / PAGE_SIZE,
cache_strategy, page_pool, GFP_KERNEL);
tight &= builder_is_hooked(builder);
work = builder->work;
hitted:
cur = end - min_t(unsigned int, offset + end - map->m_la, end);
if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED))) {
zero_user_segment(page, cur, end);
goto next_part;
}
/* let's derive page type */
page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
(!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
(tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
if (cur)
tight &= builder_is_followed(builder);
retry:
err = z_erofs_vle_work_add_page(builder, page, page_type);
/* should allocate an additional staging page for pagevec */
if (err == -EAGAIN) {
struct page *const newpage =
__stagingpage_alloc(page_pool, GFP_NOFS);
err = z_erofs_vle_work_add_page(builder,
newpage, Z_EROFS_PAGE_TYPE_EXCLUSIVE);
if (likely(!err))
goto retry;
}
if (unlikely(err))
goto err_out;
index = page->index - map->m_la / PAGE_SIZE;
/* FIXME! avoid the last relundant fixup & endio */
z_erofs_onlinepage_fixup(page, index, true);
/* bump up the number of spiltted parts of a page */
++spiltted;
/* also update nr_pages */
work->nr_pages = max_t(pgoff_t, work->nr_pages, index + 1);
next_part:
/* can be used for verification */
map->m_llen = offset + cur - map->m_la;
end = cur;
if (end > 0)
goto repeat;
out:
/* FIXME! avoid the last relundant fixup & endio */
z_erofs_onlinepage_endio(page);
debugln("%s, finish page: %pK spiltted: %u map->m_llen %llu",
__func__, page, spiltted, map->m_llen);
return err;
/* if some error occurred while processing this page */
err_out:
SetPageError(page);
goto out;
}
static void z_erofs_vle_unzip_kickoff(void *ptr, int bios)
{
tagptr1_t t = tagptr_init(tagptr1_t, ptr);
struct z_erofs_vle_unzip_io *io = tagptr_unfold_ptr(t);
bool background = tagptr_unfold_tags(t);
if (!background) {
unsigned long flags;
spin_lock_irqsave(&io->u.wait.lock, flags);
if (!atomic_add_return(bios, &io->pending_bios))
wake_up_locked(&io->u.wait);
spin_unlock_irqrestore(&io->u.wait.lock, flags);
return;
}
if (!atomic_add_return(bios, &io->pending_bios))
queue_work(z_erofs_workqueue, &io->u.work);
}
static inline void z_erofs_vle_read_endio(struct bio *bio)
{
const blk_status_t err = bio->bi_status;
unsigned int i;
struct bio_vec *bvec;
#ifdef EROFS_FS_HAS_MANAGED_CACHE
struct address_space *mc = NULL;
#endif
struct bvec_iter_all iter_all;
bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
bool cachemngd = false;
DBG_BUGON(PageUptodate(page));
DBG_BUGON(!page->mapping);
#ifdef EROFS_FS_HAS_MANAGED_CACHE
if (unlikely(!mc && !z_erofs_is_stagingpage(page))) {
struct inode *const inode = page->mapping->host;
struct super_block *const sb = inode->i_sb;
mc = MNGD_MAPPING(EROFS_SB(sb));
}
/*
* If mc has not gotten, it equals NULL,
* however, page->mapping never be NULL if working properly.
*/
cachemngd = (page->mapping == mc);
#endif
if (unlikely(err))
SetPageError(page);
else if (cachemngd)
SetPageUptodate(page);
if (cachemngd)
unlock_page(page);
}
z_erofs_vle_unzip_kickoff(bio->bi_private, -1);
bio_put(bio);
}
static struct page *z_pagemap_global[Z_EROFS_VLE_VMAP_GLOBAL_PAGES];
static DEFINE_MUTEX(z_pagemap_global_lock);
static int z_erofs_vle_unzip(struct super_block *sb,
struct z_erofs_vle_workgroup *grp,
struct list_head *page_pool)
{
struct erofs_sb_info *const sbi = EROFS_SB(sb);
const unsigned int clusterpages = erofs_clusterpages(sbi);
struct z_erofs_pagevec_ctor ctor;
unsigned int nr_pages;
unsigned int sparsemem_pages = 0;
struct page *pages_onstack[Z_EROFS_VLE_VMAP_ONSTACK_PAGES];
struct page **pages, **compressed_pages, *page;
unsigned int i, llen;
enum z_erofs_page_type page_type;
bool overlapped;
struct z_erofs_vle_work *work;
void *vout;
int err;
might_sleep();
work = z_erofs_vle_grab_primary_work(grp);
DBG_BUGON(!READ_ONCE(work->nr_pages));
mutex_lock(&work->lock);
nr_pages = work->nr_pages;
if (likely(nr_pages <= Z_EROFS_VLE_VMAP_ONSTACK_PAGES))
pages = pages_onstack;
else if (nr_pages <= Z_EROFS_VLE_VMAP_GLOBAL_PAGES &&
mutex_trylock(&z_pagemap_global_lock))
pages = z_pagemap_global;
else {
repeat:
pages = kvmalloc_array(nr_pages,
sizeof(struct page *), GFP_KERNEL);
/* fallback to global pagemap for the lowmem scenario */
if (unlikely(!pages)) {
if (nr_pages > Z_EROFS_VLE_VMAP_GLOBAL_PAGES)
goto repeat;
else {
mutex_lock(&z_pagemap_global_lock);
pages = z_pagemap_global;
}
}
}
for (i = 0; i < nr_pages; ++i)
pages[i] = NULL;
z_erofs_pagevec_ctor_init(&ctor,
Z_EROFS_VLE_INLINE_PAGEVECS, work->pagevec, 0);
for (i = 0; i < work->vcnt; ++i) {
unsigned int pagenr;
page = z_erofs_pagevec_ctor_dequeue(&ctor, &page_type);
/* all pages in pagevec ought to be valid */
DBG_BUGON(!page);
DBG_BUGON(!page->mapping);
if (z_erofs_gather_if_stagingpage(page_pool, page))
continue;
if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
pagenr = 0;
else
pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages);
DBG_BUGON(pages[pagenr]);
pages[pagenr] = page;
}
sparsemem_pages = i;
z_erofs_pagevec_ctor_exit(&ctor, true);
overlapped = false;
compressed_pages = grp->compressed_pages;
err = 0;
for (i = 0; i < clusterpages; ++i) {
unsigned int pagenr;
page = compressed_pages[i];
/* all compressed pages ought to be valid */
DBG_BUGON(!page);
DBG_BUGON(!page->mapping);
if (!z_erofs_is_stagingpage(page)) {
#ifdef EROFS_FS_HAS_MANAGED_CACHE
if (page->mapping == MNGD_MAPPING(sbi)) {
if (unlikely(!PageUptodate(page)))
err = -EIO;
continue;
}
#endif
/*
* only if non-head page can be selected
* for inplace decompression
*/
pagenr = z_erofs_onlinepage_index(page);
DBG_BUGON(pagenr >= nr_pages);
DBG_BUGON(pages[pagenr]);
++sparsemem_pages;
pages[pagenr] = page;
overlapped = true;
}
/* PG_error needs checking for inplaced and staging pages */
if (unlikely(PageError(page))) {
DBG_BUGON(PageUptodate(page));
err = -EIO;
}
}
if (unlikely(err))
goto out;
llen = (nr_pages << PAGE_SHIFT) - work->pageofs;
if (z_erofs_vle_workgrp_fmt(grp) == Z_EROFS_VLE_WORKGRP_FMT_PLAIN) {
err = z_erofs_vle_plain_copy(compressed_pages, clusterpages,
pages, nr_pages, work->pageofs);
goto out;
}
if (llen > grp->llen)
llen = grp->llen;
err = z_erofs_vle_unzip_fast_percpu(compressed_pages, clusterpages,
pages, llen, work->pageofs);
if (err != -ENOTSUPP)
goto out;
if (sparsemem_pages >= nr_pages)
goto skip_allocpage;
for (i = 0; i < nr_pages; ++i) {
if (pages[i])
continue;
pages[i] = __stagingpage_alloc(page_pool, GFP_NOFS);
}
skip_allocpage:
vout = erofs_vmap(pages, nr_pages);
if (!vout) {
err = -ENOMEM;
goto out;
}
err = z_erofs_vle_unzip_vmap(compressed_pages,
clusterpages, vout, llen, work->pageofs, overlapped);
erofs_vunmap(vout, nr_pages);
out:
/* must handle all compressed pages before endding pages */
for (i = 0; i < clusterpages; ++i) {
page = compressed_pages[i];
#ifdef EROFS_FS_HAS_MANAGED_CACHE
if (page->mapping == MNGD_MAPPING(sbi))
continue;
#endif
/* recycle all individual staging pages */
(void)z_erofs_gather_if_stagingpage(page_pool, page);
WRITE_ONCE(compressed_pages[i], NULL);
}
for (i = 0; i < nr_pages; ++i) {
page = pages[i];
if (!page)
continue;
DBG_BUGON(!page->mapping);
/* recycle all individual staging pages */
if (z_erofs_gather_if_stagingpage(page_pool, page))
continue;
if (unlikely(err < 0))
SetPageError(page);
z_erofs_onlinepage_endio(page);
}
if (pages == z_pagemap_global)
mutex_unlock(&z_pagemap_global_lock);
else if (unlikely(pages != pages_onstack))
kvfree(pages);
work->nr_pages = 0;
work->vcnt = 0;
/* all work locks MUST be taken before the following line */
WRITE_ONCE(grp->next, Z_EROFS_VLE_WORKGRP_NIL);
/* all work locks SHOULD be released right now */
mutex_unlock(&work->lock);
z_erofs_vle_work_release(work);
return err;
}
static void z_erofs_vle_unzip_all(struct super_block *sb,
struct z_erofs_vle_unzip_io *io,
struct list_head *page_pool)
{
z_erofs_vle_owned_workgrp_t owned = io->head;
while (owned != Z_EROFS_VLE_WORKGRP_TAIL_CLOSED) {
struct z_erofs_vle_workgroup *grp;
/* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
DBG_BUGON(owned == Z_EROFS_VLE_WORKGRP_TAIL);
/* no possible that 'owned' equals NULL */
DBG_BUGON(owned == Z_EROFS_VLE_WORKGRP_NIL);
grp = container_of(owned, struct z_erofs_vle_workgroup, next);
owned = READ_ONCE(grp->next);
z_erofs_vle_unzip(sb, grp, page_pool);
}
}
static void z_erofs_vle_unzip_wq(struct work_struct *work)
{
struct z_erofs_vle_unzip_io_sb *iosb = container_of(work,
struct z_erofs_vle_unzip_io_sb, io.u.work);
LIST_HEAD(page_pool);
DBG_BUGON(iosb->io.head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
z_erofs_vle_unzip_all(iosb->sb, &iosb->io, &page_pool);
put_pages_list(&page_pool);
kvfree(iosb);
}
static struct page *
pickup_page_for_submission(struct z_erofs_vle_workgroup *grp,
unsigned int nr,
struct list_head *pagepool,
struct address_space *mc,
gfp_t gfp)
{
/* determined at compile time to avoid too many #ifdefs */
const bool nocache = __builtin_constant_p(mc) ? !mc : false;
const pgoff_t index = grp->obj.index;
bool tocache = false;
struct address_space *mapping;
struct page *oldpage, *page;
compressed_page_t t;
int justfound;
repeat:
page = READ_ONCE(grp->compressed_pages[nr]);
oldpage = page;
if (!page)
goto out_allocpage;
/*
* the cached page has not been allocated and
* an placeholder is out there, prepare it now.
*/
if (!nocache && page == PAGE_UNALLOCATED) {
tocache = true;
goto out_allocpage;
}
/* process the target tagged pointer */
t = tagptr_init(compressed_page_t, page);
justfound = tagptr_unfold_tags(t);
page = tagptr_unfold_ptr(t);
mapping = READ_ONCE(page->mapping);
/*
* if managed cache is disabled, it's no way to
* get such a cached-like page.
*/
if (nocache) {
/* if managed cache is disabled, it is impossible `justfound' */
DBG_BUGON(justfound);
/* and it should be locked, not uptodate, and not truncated */
DBG_BUGON(!PageLocked(page));
DBG_BUGON(PageUptodate(page));
DBG_BUGON(!mapping);
goto out;
}
/*
* unmanaged (file) pages are all locked solidly,
* therefore it is impossible for `mapping' to be NULL.
*/
if (mapping && mapping != mc)
/* ought to be unmanaged pages */
goto out;
lock_page(page);
/* only true if page reclaim goes wrong, should never happen */
DBG_BUGON(justfound && PagePrivate(page));
/* the page is still in manage cache */
if (page->mapping == mc) {
WRITE_ONCE(grp->compressed_pages[nr], page);
ClearPageError(page);
if (!PagePrivate(page)) {
/*
* impossible to be !PagePrivate(page) for
* the current restriction as well if
* the page is already in compressed_pages[].
*/
DBG_BUGON(!justfound);
justfound = 0;
set_page_private(page, (unsigned long)grp);
SetPagePrivate(page);
}
/* no need to submit io if it is already up-to-date */
if (PageUptodate(page)) {
unlock_page(page);
page = NULL;
}
goto out;
}
/*
* the managed page has been truncated, it's unsafe to
* reuse this one, let's allocate a new cache-managed page.
*/
DBG_BUGON(page->mapping);
DBG_BUGON(!justfound);
tocache = true;
unlock_page(page);
put_page(page);
out_allocpage:
page = __stagingpage_alloc(pagepool, gfp);
if (oldpage != cmpxchg(&grp->compressed_pages[nr], oldpage, page)) {
list_add(&page->lru, pagepool);
cpu_relax();
goto repeat;
}
if (nocache || !tocache)
goto out;
if (add_to_page_cache_lru(page, mc, index + nr, gfp)) {
page->mapping = Z_EROFS_MAPPING_STAGING;
goto out;
}
set_page_private(page, (unsigned long)grp);
SetPagePrivate(page);
out: /* the only exit (for tracing and debugging) */
return page;
}
static struct z_erofs_vle_unzip_io *
jobqueue_init(struct super_block *sb,
struct z_erofs_vle_unzip_io *io,
bool foreground)
{
struct z_erofs_vle_unzip_io_sb *iosb;
if (foreground) {
/* waitqueue available for foreground io */
DBG_BUGON(!io);
init_waitqueue_head(&io->u.wait);
atomic_set(&io->pending_bios, 0);
goto out;
}
iosb = kvzalloc(sizeof(struct z_erofs_vle_unzip_io_sb),
GFP_KERNEL | __GFP_NOFAIL);
DBG_BUGON(!iosb);
/* initialize fields in the allocated descriptor */
io = &iosb->io;
iosb->sb = sb;
INIT_WORK(&io->u.work, z_erofs_vle_unzip_wq);
out:
io->head = Z_EROFS_VLE_WORKGRP_TAIL_CLOSED;
return io;
}
/* define workgroup jobqueue types */
enum {
#ifdef EROFS_FS_HAS_MANAGED_CACHE
JQ_BYPASS,
#endif
JQ_SUBMIT,
NR_JOBQUEUES,
};
static void *jobqueueset_init(struct super_block *sb,
z_erofs_vle_owned_workgrp_t qtail[],
struct z_erofs_vle_unzip_io *q[],
struct z_erofs_vle_unzip_io *fgq,
bool forcefg)
{
#ifdef EROFS_FS_HAS_MANAGED_CACHE
/*
* if managed cache is enabled, bypass jobqueue is needed,
* no need to read from device for all workgroups in this queue.
*/
q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, true);
qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head;
#endif
q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, forcefg);
qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head;
return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], !forcefg));
}
#ifdef EROFS_FS_HAS_MANAGED_CACHE
static void move_to_bypass_jobqueue(struct z_erofs_vle_workgroup *grp,
z_erofs_vle_owned_workgrp_t qtail[],
z_erofs_vle_owned_workgrp_t owned_head)
{
z_erofs_vle_owned_workgrp_t *const submit_qtail = qtail[JQ_SUBMIT];
z_erofs_vle_owned_workgrp_t *const bypass_qtail = qtail[JQ_BYPASS];
DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
if (owned_head == Z_EROFS_VLE_WORKGRP_TAIL)
owned_head = Z_EROFS_VLE_WORKGRP_TAIL_CLOSED;
WRITE_ONCE(grp->next, Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
WRITE_ONCE(*submit_qtail, owned_head);
WRITE_ONCE(*bypass_qtail, &grp->next);
qtail[JQ_BYPASS] = &grp->next;
}
static bool postsubmit_is_all_bypassed(struct z_erofs_vle_unzip_io *q[],
unsigned int nr_bios,
bool force_fg)
{
/*
* although background is preferred, no one is pending for submission.
* don't issue workqueue for decompression but drop it directly instead.
*/
if (force_fg || nr_bios)
return false;
kvfree(container_of(q[JQ_SUBMIT],
struct z_erofs_vle_unzip_io_sb,
io));
return true;
}
#else
static void move_to_bypass_jobqueue(struct z_erofs_vle_workgroup *grp,
z_erofs_vle_owned_workgrp_t qtail[],
z_erofs_vle_owned_workgrp_t owned_head)
{
/* impossible to bypass submission for managed cache disabled */
DBG_BUGON(1);
}
static bool postsubmit_is_all_bypassed(struct z_erofs_vle_unzip_io *q[],
unsigned int nr_bios,
bool force_fg)
{
/* bios should be >0 if managed cache is disabled */
DBG_BUGON(!nr_bios);
return false;
}
#endif
static bool z_erofs_vle_submit_all(struct super_block *sb,
z_erofs_vle_owned_workgrp_t owned_head,
struct list_head *pagepool,
struct z_erofs_vle_unzip_io *fgq,
bool force_fg)
{
struct erofs_sb_info *const sbi = EROFS_SB(sb);
const unsigned int clusterpages = erofs_clusterpages(sbi);
const gfp_t gfp = GFP_NOFS;
z_erofs_vle_owned_workgrp_t qtail[NR_JOBQUEUES];
struct z_erofs_vle_unzip_io *q[NR_JOBQUEUES];
struct bio *bio;
void *bi_private;
/* since bio will be NULL, no need to initialize last_index */
pgoff_t uninitialized_var(last_index);
bool force_submit = false;
unsigned int nr_bios;
if (unlikely(owned_head == Z_EROFS_VLE_WORKGRP_TAIL))
return false;
force_submit = false;
bio = NULL;
nr_bios = 0;
bi_private = jobqueueset_init(sb, qtail, q, fgq, force_fg);
/* by default, all need io submission */
q[JQ_SUBMIT]->head = owned_head;
do {
struct z_erofs_vle_workgroup *grp;
pgoff_t first_index;
struct page *page;
unsigned int i = 0, bypass = 0;
int err;
/* no possible 'owned_head' equals the following */
DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
DBG_BUGON(owned_head == Z_EROFS_VLE_WORKGRP_NIL);
grp = container_of(owned_head,
struct z_erofs_vle_workgroup, next);
/* close the main owned chain at first */
owned_head = cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL,
Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
first_index = grp->obj.index;
force_submit |= (first_index != last_index + 1);
repeat:
page = pickup_page_for_submission(grp, i, pagepool,
MNGD_MAPPING(sbi), gfp);
if (!page) {
force_submit = true;
++bypass;
goto skippage;
}
if (bio && force_submit) {
submit_bio_retry:
__submit_bio(bio, REQ_OP_READ, 0);
bio = NULL;
}
if (!bio) {
bio = erofs_grab_bio(sb, first_index + i,
BIO_MAX_PAGES,
z_erofs_vle_read_endio, true);
bio->bi_private = bi_private;
++nr_bios;
}
err = bio_add_page(bio, page, PAGE_SIZE, 0);
if (err < PAGE_SIZE)
goto submit_bio_retry;
force_submit = false;
last_index = first_index + i;
skippage:
if (++i < clusterpages)
goto repeat;
if (bypass < clusterpages)
qtail[JQ_SUBMIT] = &grp->next;
else
move_to_bypass_jobqueue(grp, qtail, owned_head);
} while (owned_head != Z_EROFS_VLE_WORKGRP_TAIL);
if (bio)
__submit_bio(bio, REQ_OP_READ, 0);
if (postsubmit_is_all_bypassed(q, nr_bios, force_fg))
return true;
z_erofs_vle_unzip_kickoff(bi_private, nr_bios);
return true;
}
static void z_erofs_submit_and_unzip(struct z_erofs_vle_frontend *f,
struct list_head *pagepool,
bool force_fg)
{
struct super_block *sb = f->inode->i_sb;
struct z_erofs_vle_unzip_io io[NR_JOBQUEUES];
if (!z_erofs_vle_submit_all(sb, f->owned_head, pagepool, io, force_fg))
return;
#ifdef EROFS_FS_HAS_MANAGED_CACHE
z_erofs_vle_unzip_all(sb, &io[JQ_BYPASS], pagepool);
#endif
if (!force_fg)
return;
/* wait until all bios are completed */
wait_event(io[JQ_SUBMIT].u.wait,
!atomic_read(&io[JQ_SUBMIT].pending_bios));
/* let's synchronous decompression */
z_erofs_vle_unzip_all(sb, &io[JQ_SUBMIT], pagepool);
}
static int z_erofs_vle_normalaccess_readpage(struct file *file,
struct page *page)
{
struct inode *const inode = page->mapping->host;
struct z_erofs_vle_frontend f = VLE_FRONTEND_INIT(inode);
int err;
LIST_HEAD(pagepool);
trace_erofs_readpage(page, false);
f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT;
err = z_erofs_do_read_page(&f, page, &pagepool);
(void)z_erofs_vle_work_iter_end(&f.builder);
if (err) {
errln("%s, failed to read, err [%d]", __func__, err);
goto out;
}
z_erofs_submit_and_unzip(&f, &pagepool, true);
out:
if (f.map.mpage)
put_page(f.map.mpage);
/* clean up the remaining free pages */
put_pages_list(&pagepool);
return 0;
}
static int z_erofs_vle_normalaccess_readpages(struct file *filp,
struct address_space *mapping,
struct list_head *pages,
unsigned int nr_pages)
{
struct inode *const inode = mapping->host;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
bool sync = __should_decompress_synchronously(sbi, nr_pages);
struct z_erofs_vle_frontend f = VLE_FRONTEND_INIT(inode);
gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
struct page *head = NULL;
LIST_HEAD(pagepool);
trace_erofs_readpages(mapping->host, lru_to_page(pages),
nr_pages, false);
f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
for (; nr_pages; --nr_pages) {
struct page *page = lru_to_page(pages);
prefetchw(&page->flags);
list_del(&page->lru);
/*
* A pure asynchronous readahead is indicated if
* a PG_readahead marked page is hitted at first.
* Let's also do asynchronous decompression for this case.
*/
sync &= !(PageReadahead(page) && !head);
if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
list_add(&page->lru, &pagepool);
continue;
}
set_page_private(page, (unsigned long)head);
head = page;
}
while (head) {
struct page *page = head;
int err;
/* traversal in reverse order */
head = (void *)page_private(page);
err = z_erofs_do_read_page(&f, page, &pagepool);
if (err) {
struct erofs_vnode *vi = EROFS_V(inode);
errln("%s, readahead error at page %lu of nid %llu",
__func__, page->index, vi->nid);
}
put_page(page);
}
(void)z_erofs_vle_work_iter_end(&f.builder);
z_erofs_submit_and_unzip(&f, &pagepool, sync);
if (f.map.mpage)
put_page(f.map.mpage);
/* clean up the remaining free pages */
put_pages_list(&pagepool);
return 0;
}
const struct address_space_operations z_erofs_vle_normalaccess_aops = {
.readpage = z_erofs_vle_normalaccess_readpage,
.readpages = z_erofs_vle_normalaccess_readpages,
};
/*
* Variable-sized Logical Extent (Fixed Physical Cluster) Compression Mode
* ---
* VLE compression mode attempts to compress a number of logical data into
* a physical cluster with a fixed size.
* VLE compression mode uses "struct z_erofs_vle_decompressed_index".
*/
#define __vle_cluster_advise(x, bit, bits) \
((le16_to_cpu(x) >> (bit)) & ((1 << (bits)) - 1))
#define __vle_cluster_type(advise) __vle_cluster_advise(advise, \
Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT, Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS)
#define vle_cluster_type(di) \
__vle_cluster_type((di)->di_advise)
static int
vle_decompressed_index_clusterofs(unsigned int *clusterofs,
unsigned int clustersize,
struct z_erofs_vle_decompressed_index *di)
{
switch (vle_cluster_type(di)) {
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
*clusterofs = clustersize;
break;
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
*clusterofs = le16_to_cpu(di->di_clusterofs);
break;
default:
DBG_BUGON(1);
return -EIO;
}
return 0;
}
static inline erofs_blk_t
vle_extent_blkaddr(struct inode *inode, pgoff_t index)
{
struct erofs_sb_info *sbi = EROFS_I_SB(inode);
struct erofs_vnode *vi = EROFS_V(inode);
unsigned int ofs = Z_EROFS_VLE_EXTENT_ALIGN(vi->inode_isize +
vi->xattr_isize) + sizeof(struct erofs_extent_header) +
index * sizeof(struct z_erofs_vle_decompressed_index);
return erofs_blknr(iloc(sbi, vi->nid) + ofs);
}
static inline unsigned int
vle_extent_blkoff(struct inode *inode, pgoff_t index)
{
struct erofs_sb_info *sbi = EROFS_I_SB(inode);
struct erofs_vnode *vi = EROFS_V(inode);
unsigned int ofs = Z_EROFS_VLE_EXTENT_ALIGN(vi->inode_isize +
vi->xattr_isize) + sizeof(struct erofs_extent_header) +
index * sizeof(struct z_erofs_vle_decompressed_index);
return erofs_blkoff(iloc(sbi, vi->nid) + ofs);
}
struct vle_map_blocks_iter_ctx {
struct inode *inode;
struct super_block *sb;
unsigned int clusterbits;
struct page **mpage_ret;
void **kaddr_ret;
};
static int
vle_get_logical_extent_head(const struct vle_map_blocks_iter_ctx *ctx,
unsigned int lcn, /* logical cluster number */
unsigned long long *ofs,
erofs_blk_t *pblk,
unsigned int *flags)
{
const unsigned int clustersize = 1 << ctx->clusterbits;
const erofs_blk_t mblk = vle_extent_blkaddr(ctx->inode, lcn);
struct page *mpage = *ctx->mpage_ret; /* extent metapage */
struct z_erofs_vle_decompressed_index *di;
unsigned int cluster_type, delta0;
if (mpage->index != mblk) {
kunmap_atomic(*ctx->kaddr_ret);
unlock_page(mpage);
put_page(mpage);
mpage = erofs_get_meta_page(ctx->sb, mblk, false);
if (IS_ERR(mpage)) {
*ctx->mpage_ret = NULL;
return PTR_ERR(mpage);
}
*ctx->mpage_ret = mpage;
*ctx->kaddr_ret = kmap_atomic(mpage);
}
di = *ctx->kaddr_ret + vle_extent_blkoff(ctx->inode, lcn);
cluster_type = vle_cluster_type(di);
switch (cluster_type) {
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
delta0 = le16_to_cpu(di->di_u.delta[0]);
if (unlikely(!delta0 || delta0 > lcn)) {
errln("invalid NONHEAD dl0 %u at lcn %u of nid %llu",
delta0, lcn, EROFS_V(ctx->inode)->nid);
DBG_BUGON(1);
return -EIO;
}
return vle_get_logical_extent_head(ctx,
lcn - delta0, ofs, pblk, flags);
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
*flags ^= EROFS_MAP_ZIPPED;
/* fallthrough */
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
/* clustersize should be a power of two */
*ofs = ((u64)lcn << ctx->clusterbits) +
(le16_to_cpu(di->di_clusterofs) & (clustersize - 1));
*pblk = le32_to_cpu(di->di_u.blkaddr);
break;
default:
errln("unknown cluster type %u at lcn %u of nid %llu",
cluster_type, lcn, EROFS_V(ctx->inode)->nid);
DBG_BUGON(1);
return -EIO;
}
return 0;
}
int z_erofs_map_blocks_iter(struct inode *inode,
struct erofs_map_blocks *map,
int flags)
{
void *kaddr;
const struct vle_map_blocks_iter_ctx ctx = {
.inode = inode,
.sb = inode->i_sb,
.clusterbits = EROFS_I_SB(inode)->clusterbits,
.mpage_ret = &map->mpage,
.kaddr_ret = &kaddr
};
const unsigned int clustersize = 1 << ctx.clusterbits;
/* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */
const bool initial = !map->m_llen;
/* logicial extent (start, end) offset */
unsigned long long ofs, end;
unsigned int lcn;
u32 ofs_rem;
/* initialize `pblk' to keep gcc from printing foolish warnings */
erofs_blk_t mblk, pblk = 0;
struct page *mpage = map->mpage;
struct z_erofs_vle_decompressed_index *di;
unsigned int cluster_type, logical_cluster_ofs;
int err = 0;
trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
/* when trying to read beyond EOF, leave it unmapped */
if (unlikely(map->m_la >= inode->i_size)) {
DBG_BUGON(!initial);
map->m_llen = map->m_la + 1 - inode->i_size;
map->m_la = inode->i_size;
map->m_flags = 0;
goto out;
}
debugln("%s, m_la %llu m_llen %llu --- start", __func__,
map->m_la, map->m_llen);
ofs = map->m_la + map->m_llen;
/* clustersize should be power of two */
lcn = ofs >> ctx.clusterbits;
ofs_rem = ofs & (clustersize - 1);
mblk = vle_extent_blkaddr(inode, lcn);
if (!mpage || mpage->index != mblk) {
if (mpage)
put_page(mpage);
mpage = erofs_get_meta_page(ctx.sb, mblk, false);
if (IS_ERR(mpage)) {
err = PTR_ERR(mpage);
goto out;
}
map->mpage = mpage;
} else {
lock_page(mpage);
DBG_BUGON(!PageUptodate(mpage));
}
kaddr = kmap_atomic(mpage);
di = kaddr + vle_extent_blkoff(inode, lcn);
debugln("%s, lcn %u mblk %u e_blkoff %u", __func__, lcn,
mblk, vle_extent_blkoff(inode, lcn));
err = vle_decompressed_index_clusterofs(&logical_cluster_ofs,
clustersize, di);
if (unlikely(err))
goto unmap_out;
if (!initial) {
/* [walking mode] 'map' has been already initialized */
map->m_llen += logical_cluster_ofs;
goto unmap_out;
}
/* by default, compressed */
map->m_flags |= EROFS_MAP_ZIPPED;
end = ((u64)lcn + 1) * clustersize;
cluster_type = vle_cluster_type(di);
switch (cluster_type) {
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
if (ofs_rem >= logical_cluster_ofs)
map->m_flags ^= EROFS_MAP_ZIPPED;
/* fallthrough */
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
if (ofs_rem == logical_cluster_ofs) {
pblk = le32_to_cpu(di->di_u.blkaddr);
goto exact_hitted;
}
if (ofs_rem > logical_cluster_ofs) {
ofs = (u64)lcn * clustersize | logical_cluster_ofs;
pblk = le32_to_cpu(di->di_u.blkaddr);
break;
}
/* logical cluster number should be >= 1 */
if (unlikely(!lcn)) {
errln("invalid logical cluster 0 at nid %llu",
EROFS_V(inode)->nid);
err = -EIO;
goto unmap_out;
}
end = ((u64)lcn-- * clustersize) | logical_cluster_ofs;
/* fallthrough */
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
/* get the correspoinding first chunk */
err = vle_get_logical_extent_head(&ctx, lcn, &ofs,
&pblk, &map->m_flags);
mpage = map->mpage;
if (unlikely(err)) {
if (mpage)
goto unmap_out;
goto out;
}
break;
default:
errln("unknown cluster type %u at offset %llu of nid %llu",
cluster_type, ofs, EROFS_V(inode)->nid);
err = -EIO;
goto unmap_out;
}
map->m_la = ofs;
exact_hitted:
map->m_llen = end - ofs;
map->m_plen = clustersize;
map->m_pa = blknr_to_addr(pblk);
map->m_flags |= EROFS_MAP_MAPPED;
unmap_out:
kunmap_atomic(kaddr);
unlock_page(mpage);
out:
debugln("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
__func__, map->m_la, map->m_pa,
map->m_llen, map->m_plen, map->m_flags);
trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
/* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
DBG_BUGON(err < 0 && err != -ENOMEM);
return err;
}