mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Fabio M. De Francesco](/assets/img/avatar_default.png)
The use of kmap() is being deprecated in favor of kmap_local_page(). With kmap_local_page(), the mapping is per thread, CPU local and not globally visible. Therefore, use kmap_local_page() / kunmap_local() in zstd.c because in this file the mappings are per thread and are not visible in other contexts. In the meanwhile use plain page_address() on output pages allocated with the GFP_NOFS flag instead of calling kmap*() on them (since they are always allocated from ZONE_NORMAL). Tested with xfstests on QEMU + KVM 32 bits VM with 4GB of RAM, booting a kernel with HIGHMEM64G enabled. Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
703 lines
18 KiB
C
703 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (c) 2016-present, Facebook, Inc.
|
|
* All rights reserved.
|
|
*
|
|
*/
|
|
|
|
#include <linux/bio.h>
|
|
#include <linux/bitmap.h>
|
|
#include <linux/err.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/sched/mm.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/refcount.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/zstd.h>
|
|
#include "misc.h"
|
|
#include "compression.h"
|
|
#include "ctree.h"
|
|
|
|
#define ZSTD_BTRFS_MAX_WINDOWLOG 17
|
|
#define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
|
|
#define ZSTD_BTRFS_DEFAULT_LEVEL 3
|
|
#define ZSTD_BTRFS_MAX_LEVEL 15
|
|
/* 307s to avoid pathologically clashing with transaction commit */
|
|
#define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ)
|
|
|
|
static zstd_parameters zstd_get_btrfs_parameters(unsigned int level,
|
|
size_t src_len)
|
|
{
|
|
zstd_parameters params = zstd_get_params(level, src_len);
|
|
|
|
if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
|
|
params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
|
|
WARN_ON(src_len > ZSTD_BTRFS_MAX_INPUT);
|
|
return params;
|
|
}
|
|
|
|
struct workspace {
|
|
void *mem;
|
|
size_t size;
|
|
char *buf;
|
|
unsigned int level;
|
|
unsigned int req_level;
|
|
unsigned long last_used; /* jiffies */
|
|
struct list_head list;
|
|
struct list_head lru_list;
|
|
zstd_in_buffer in_buf;
|
|
zstd_out_buffer out_buf;
|
|
};
|
|
|
|
/*
|
|
* Zstd Workspace Management
|
|
*
|
|
* Zstd workspaces have different memory requirements depending on the level.
|
|
* The zstd workspaces are managed by having individual lists for each level
|
|
* and a global lru. Forward progress is maintained by protecting a max level
|
|
* workspace.
|
|
*
|
|
* Getting a workspace is done by using the bitmap to identify the levels that
|
|
* have available workspaces and scans up. This lets us recycle higher level
|
|
* workspaces because of the monotonic memory guarantee. A workspace's
|
|
* last_used is only updated if it is being used by the corresponding memory
|
|
* level. Putting a workspace involves adding it back to the appropriate places
|
|
* and adding it back to the lru if necessary.
|
|
*
|
|
* A timer is used to reclaim workspaces if they have not been used for
|
|
* ZSTD_BTRFS_RECLAIM_JIFFIES. This helps keep only active workspaces around.
|
|
* The upper bound is provided by the workqueue limit which is 2 (percpu limit).
|
|
*/
|
|
|
|
struct zstd_workspace_manager {
|
|
const struct btrfs_compress_op *ops;
|
|
spinlock_t lock;
|
|
struct list_head lru_list;
|
|
struct list_head idle_ws[ZSTD_BTRFS_MAX_LEVEL];
|
|
unsigned long active_map;
|
|
wait_queue_head_t wait;
|
|
struct timer_list timer;
|
|
};
|
|
|
|
static struct zstd_workspace_manager wsm;
|
|
|
|
static size_t zstd_ws_mem_sizes[ZSTD_BTRFS_MAX_LEVEL];
|
|
|
|
static inline struct workspace *list_to_workspace(struct list_head *list)
|
|
{
|
|
return container_of(list, struct workspace, list);
|
|
}
|
|
|
|
void zstd_free_workspace(struct list_head *ws);
|
|
struct list_head *zstd_alloc_workspace(unsigned int level);
|
|
|
|
/**
|
|
* Timer callback to free unused workspaces.
|
|
*
|
|
* @t: timer
|
|
*
|
|
* This scans the lru_list and attempts to reclaim any workspace that hasn't
|
|
* been used for ZSTD_BTRFS_RECLAIM_JIFFIES.
|
|
*
|
|
* The context is softirq and does not need the _bh locking primitives.
|
|
*/
|
|
static void zstd_reclaim_timer_fn(struct timer_list *timer)
|
|
{
|
|
unsigned long reclaim_threshold = jiffies - ZSTD_BTRFS_RECLAIM_JIFFIES;
|
|
struct list_head *pos, *next;
|
|
|
|
spin_lock(&wsm.lock);
|
|
|
|
if (list_empty(&wsm.lru_list)) {
|
|
spin_unlock(&wsm.lock);
|
|
return;
|
|
}
|
|
|
|
list_for_each_prev_safe(pos, next, &wsm.lru_list) {
|
|
struct workspace *victim = container_of(pos, struct workspace,
|
|
lru_list);
|
|
unsigned int level;
|
|
|
|
if (time_after(victim->last_used, reclaim_threshold))
|
|
break;
|
|
|
|
/* workspace is in use */
|
|
if (victim->req_level)
|
|
continue;
|
|
|
|
level = victim->level;
|
|
list_del(&victim->lru_list);
|
|
list_del(&victim->list);
|
|
zstd_free_workspace(&victim->list);
|
|
|
|
if (list_empty(&wsm.idle_ws[level - 1]))
|
|
clear_bit(level - 1, &wsm.active_map);
|
|
|
|
}
|
|
|
|
if (!list_empty(&wsm.lru_list))
|
|
mod_timer(&wsm.timer, jiffies + ZSTD_BTRFS_RECLAIM_JIFFIES);
|
|
|
|
spin_unlock(&wsm.lock);
|
|
}
|
|
|
|
/*
|
|
* zstd_calc_ws_mem_sizes - calculate monotonic memory bounds
|
|
*
|
|
* It is possible based on the level configurations that a higher level
|
|
* workspace uses less memory than a lower level workspace. In order to reuse
|
|
* workspaces, this must be made a monotonic relationship. This precomputes
|
|
* the required memory for each level and enforces the monotonicity between
|
|
* level and memory required.
|
|
*/
|
|
static void zstd_calc_ws_mem_sizes(void)
|
|
{
|
|
size_t max_size = 0;
|
|
unsigned int level;
|
|
|
|
for (level = 1; level <= ZSTD_BTRFS_MAX_LEVEL; level++) {
|
|
zstd_parameters params =
|
|
zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT);
|
|
size_t level_size =
|
|
max_t(size_t,
|
|
zstd_cstream_workspace_bound(¶ms.cParams),
|
|
zstd_dstream_workspace_bound(ZSTD_BTRFS_MAX_INPUT));
|
|
|
|
max_size = max_t(size_t, max_size, level_size);
|
|
zstd_ws_mem_sizes[level - 1] = max_size;
|
|
}
|
|
}
|
|
|
|
void zstd_init_workspace_manager(void)
|
|
{
|
|
struct list_head *ws;
|
|
int i;
|
|
|
|
zstd_calc_ws_mem_sizes();
|
|
|
|
wsm.ops = &btrfs_zstd_compress;
|
|
spin_lock_init(&wsm.lock);
|
|
init_waitqueue_head(&wsm.wait);
|
|
timer_setup(&wsm.timer, zstd_reclaim_timer_fn, 0);
|
|
|
|
INIT_LIST_HEAD(&wsm.lru_list);
|
|
for (i = 0; i < ZSTD_BTRFS_MAX_LEVEL; i++)
|
|
INIT_LIST_HEAD(&wsm.idle_ws[i]);
|
|
|
|
ws = zstd_alloc_workspace(ZSTD_BTRFS_MAX_LEVEL);
|
|
if (IS_ERR(ws)) {
|
|
pr_warn(
|
|
"BTRFS: cannot preallocate zstd compression workspace\n");
|
|
} else {
|
|
set_bit(ZSTD_BTRFS_MAX_LEVEL - 1, &wsm.active_map);
|
|
list_add(ws, &wsm.idle_ws[ZSTD_BTRFS_MAX_LEVEL - 1]);
|
|
}
|
|
}
|
|
|
|
void zstd_cleanup_workspace_manager(void)
|
|
{
|
|
struct workspace *workspace;
|
|
int i;
|
|
|
|
spin_lock_bh(&wsm.lock);
|
|
for (i = 0; i < ZSTD_BTRFS_MAX_LEVEL; i++) {
|
|
while (!list_empty(&wsm.idle_ws[i])) {
|
|
workspace = container_of(wsm.idle_ws[i].next,
|
|
struct workspace, list);
|
|
list_del(&workspace->list);
|
|
list_del(&workspace->lru_list);
|
|
zstd_free_workspace(&workspace->list);
|
|
}
|
|
}
|
|
spin_unlock_bh(&wsm.lock);
|
|
|
|
del_timer_sync(&wsm.timer);
|
|
}
|
|
|
|
/*
|
|
* zstd_find_workspace - find workspace
|
|
* @level: compression level
|
|
*
|
|
* This iterates over the set bits in the active_map beginning at the requested
|
|
* compression level. This lets us utilize already allocated workspaces before
|
|
* allocating a new one. If the workspace is of a larger size, it is used, but
|
|
* the place in the lru_list and last_used times are not updated. This is to
|
|
* offer the opportunity to reclaim the workspace in favor of allocating an
|
|
* appropriately sized one in the future.
|
|
*/
|
|
static struct list_head *zstd_find_workspace(unsigned int level)
|
|
{
|
|
struct list_head *ws;
|
|
struct workspace *workspace;
|
|
int i = level - 1;
|
|
|
|
spin_lock_bh(&wsm.lock);
|
|
for_each_set_bit_from(i, &wsm.active_map, ZSTD_BTRFS_MAX_LEVEL) {
|
|
if (!list_empty(&wsm.idle_ws[i])) {
|
|
ws = wsm.idle_ws[i].next;
|
|
workspace = list_to_workspace(ws);
|
|
list_del_init(ws);
|
|
/* keep its place if it's a lower level using this */
|
|
workspace->req_level = level;
|
|
if (level == workspace->level)
|
|
list_del(&workspace->lru_list);
|
|
if (list_empty(&wsm.idle_ws[i]))
|
|
clear_bit(i, &wsm.active_map);
|
|
spin_unlock_bh(&wsm.lock);
|
|
return ws;
|
|
}
|
|
}
|
|
spin_unlock_bh(&wsm.lock);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* zstd_get_workspace - zstd's get_workspace
|
|
* @level: compression level
|
|
*
|
|
* If @level is 0, then any compression level can be used. Therefore, we begin
|
|
* scanning from 1. We first scan through possible workspaces and then after
|
|
* attempt to allocate a new workspace. If we fail to allocate one due to
|
|
* memory pressure, go to sleep waiting for the max level workspace to free up.
|
|
*/
|
|
struct list_head *zstd_get_workspace(unsigned int level)
|
|
{
|
|
struct list_head *ws;
|
|
unsigned int nofs_flag;
|
|
|
|
/* level == 0 means we can use any workspace */
|
|
if (!level)
|
|
level = 1;
|
|
|
|
again:
|
|
ws = zstd_find_workspace(level);
|
|
if (ws)
|
|
return ws;
|
|
|
|
nofs_flag = memalloc_nofs_save();
|
|
ws = zstd_alloc_workspace(level);
|
|
memalloc_nofs_restore(nofs_flag);
|
|
|
|
if (IS_ERR(ws)) {
|
|
DEFINE_WAIT(wait);
|
|
|
|
prepare_to_wait(&wsm.wait, &wait, TASK_UNINTERRUPTIBLE);
|
|
schedule();
|
|
finish_wait(&wsm.wait, &wait);
|
|
|
|
goto again;
|
|
}
|
|
|
|
return ws;
|
|
}
|
|
|
|
/*
|
|
* zstd_put_workspace - zstd put_workspace
|
|
* @ws: list_head for the workspace
|
|
*
|
|
* When putting back a workspace, we only need to update the LRU if we are of
|
|
* the requested compression level. Here is where we continue to protect the
|
|
* max level workspace or update last_used accordingly. If the reclaim timer
|
|
* isn't set, it is also set here. Only the max level workspace tries and wakes
|
|
* up waiting workspaces.
|
|
*/
|
|
void zstd_put_workspace(struct list_head *ws)
|
|
{
|
|
struct workspace *workspace = list_to_workspace(ws);
|
|
|
|
spin_lock_bh(&wsm.lock);
|
|
|
|
/* A node is only taken off the lru if we are the corresponding level */
|
|
if (workspace->req_level == workspace->level) {
|
|
/* Hide a max level workspace from reclaim */
|
|
if (list_empty(&wsm.idle_ws[ZSTD_BTRFS_MAX_LEVEL - 1])) {
|
|
INIT_LIST_HEAD(&workspace->lru_list);
|
|
} else {
|
|
workspace->last_used = jiffies;
|
|
list_add(&workspace->lru_list, &wsm.lru_list);
|
|
if (!timer_pending(&wsm.timer))
|
|
mod_timer(&wsm.timer,
|
|
jiffies + ZSTD_BTRFS_RECLAIM_JIFFIES);
|
|
}
|
|
}
|
|
|
|
set_bit(workspace->level - 1, &wsm.active_map);
|
|
list_add(&workspace->list, &wsm.idle_ws[workspace->level - 1]);
|
|
workspace->req_level = 0;
|
|
|
|
spin_unlock_bh(&wsm.lock);
|
|
|
|
if (workspace->level == ZSTD_BTRFS_MAX_LEVEL)
|
|
cond_wake_up(&wsm.wait);
|
|
}
|
|
|
|
void zstd_free_workspace(struct list_head *ws)
|
|
{
|
|
struct workspace *workspace = list_entry(ws, struct workspace, list);
|
|
|
|
kvfree(workspace->mem);
|
|
kfree(workspace->buf);
|
|
kfree(workspace);
|
|
}
|
|
|
|
struct list_head *zstd_alloc_workspace(unsigned int level)
|
|
{
|
|
struct workspace *workspace;
|
|
|
|
workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
|
|
if (!workspace)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
workspace->size = zstd_ws_mem_sizes[level - 1];
|
|
workspace->level = level;
|
|
workspace->req_level = level;
|
|
workspace->last_used = jiffies;
|
|
workspace->mem = kvmalloc(workspace->size, GFP_KERNEL);
|
|
workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!workspace->mem || !workspace->buf)
|
|
goto fail;
|
|
|
|
INIT_LIST_HEAD(&workspace->list);
|
|
INIT_LIST_HEAD(&workspace->lru_list);
|
|
|
|
return &workspace->list;
|
|
fail:
|
|
zstd_free_workspace(&workspace->list);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
|
|
u64 start, struct page **pages, unsigned long *out_pages,
|
|
unsigned long *total_in, unsigned long *total_out)
|
|
{
|
|
struct workspace *workspace = list_entry(ws, struct workspace, list);
|
|
zstd_cstream *stream;
|
|
int ret = 0;
|
|
int nr_pages = 0;
|
|
struct page *in_page = NULL; /* The current page to read */
|
|
struct page *out_page = NULL; /* The current page to write to */
|
|
unsigned long tot_in = 0;
|
|
unsigned long tot_out = 0;
|
|
unsigned long len = *total_out;
|
|
const unsigned long nr_dest_pages = *out_pages;
|
|
unsigned long max_out = nr_dest_pages * PAGE_SIZE;
|
|
zstd_parameters params = zstd_get_btrfs_parameters(workspace->req_level,
|
|
len);
|
|
|
|
*out_pages = 0;
|
|
*total_out = 0;
|
|
*total_in = 0;
|
|
|
|
/* Initialize the stream */
|
|
stream = zstd_init_cstream(¶ms, len, workspace->mem,
|
|
workspace->size);
|
|
if (!stream) {
|
|
pr_warn("BTRFS: zstd_init_cstream failed\n");
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
/* map in the first page of input data */
|
|
in_page = find_get_page(mapping, start >> PAGE_SHIFT);
|
|
workspace->in_buf.src = kmap_local_page(in_page);
|
|
workspace->in_buf.pos = 0;
|
|
workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
|
|
|
|
|
|
/* Allocate and map in the output buffer */
|
|
out_page = alloc_page(GFP_NOFS);
|
|
if (out_page == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
pages[nr_pages++] = out_page;
|
|
workspace->out_buf.dst = page_address(out_page);
|
|
workspace->out_buf.pos = 0;
|
|
workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
|
|
|
|
while (1) {
|
|
size_t ret2;
|
|
|
|
ret2 = zstd_compress_stream(stream, &workspace->out_buf,
|
|
&workspace->in_buf);
|
|
if (zstd_is_error(ret2)) {
|
|
pr_debug("BTRFS: zstd_compress_stream returned %d\n",
|
|
zstd_get_error_code(ret2));
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
/* Check to see if we are making it bigger */
|
|
if (tot_in + workspace->in_buf.pos > 8192 &&
|
|
tot_in + workspace->in_buf.pos <
|
|
tot_out + workspace->out_buf.pos) {
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
|
|
/* We've reached the end of our output range */
|
|
if (workspace->out_buf.pos >= max_out) {
|
|
tot_out += workspace->out_buf.pos;
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
|
|
/* Check if we need more output space */
|
|
if (workspace->out_buf.pos == workspace->out_buf.size) {
|
|
tot_out += PAGE_SIZE;
|
|
max_out -= PAGE_SIZE;
|
|
if (nr_pages == nr_dest_pages) {
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
out_page = alloc_page(GFP_NOFS);
|
|
if (out_page == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
pages[nr_pages++] = out_page;
|
|
workspace->out_buf.dst = page_address(out_page);
|
|
workspace->out_buf.pos = 0;
|
|
workspace->out_buf.size = min_t(size_t, max_out,
|
|
PAGE_SIZE);
|
|
}
|
|
|
|
/* We've reached the end of the input */
|
|
if (workspace->in_buf.pos >= len) {
|
|
tot_in += workspace->in_buf.pos;
|
|
break;
|
|
}
|
|
|
|
/* Check if we need more input */
|
|
if (workspace->in_buf.pos == workspace->in_buf.size) {
|
|
tot_in += PAGE_SIZE;
|
|
kunmap_local(workspace->in_buf.src);
|
|
put_page(in_page);
|
|
start += PAGE_SIZE;
|
|
len -= PAGE_SIZE;
|
|
in_page = find_get_page(mapping, start >> PAGE_SHIFT);
|
|
workspace->in_buf.src = kmap_local_page(in_page);
|
|
workspace->in_buf.pos = 0;
|
|
workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
|
|
}
|
|
}
|
|
while (1) {
|
|
size_t ret2;
|
|
|
|
ret2 = zstd_end_stream(stream, &workspace->out_buf);
|
|
if (zstd_is_error(ret2)) {
|
|
pr_debug("BTRFS: zstd_end_stream returned %d\n",
|
|
zstd_get_error_code(ret2));
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
if (ret2 == 0) {
|
|
tot_out += workspace->out_buf.pos;
|
|
break;
|
|
}
|
|
if (workspace->out_buf.pos >= max_out) {
|
|
tot_out += workspace->out_buf.pos;
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
|
|
tot_out += PAGE_SIZE;
|
|
max_out -= PAGE_SIZE;
|
|
if (nr_pages == nr_dest_pages) {
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
out_page = alloc_page(GFP_NOFS);
|
|
if (out_page == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
pages[nr_pages++] = out_page;
|
|
workspace->out_buf.dst = page_address(out_page);
|
|
workspace->out_buf.pos = 0;
|
|
workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
|
|
}
|
|
|
|
if (tot_out >= tot_in) {
|
|
ret = -E2BIG;
|
|
goto out;
|
|
}
|
|
|
|
ret = 0;
|
|
*total_in = tot_in;
|
|
*total_out = tot_out;
|
|
out:
|
|
*out_pages = nr_pages;
|
|
if (workspace->in_buf.src) {
|
|
kunmap_local(workspace->in_buf.src);
|
|
put_page(in_page);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
|
|
{
|
|
struct workspace *workspace = list_entry(ws, struct workspace, list);
|
|
struct page **pages_in = cb->compressed_pages;
|
|
size_t srclen = cb->compressed_len;
|
|
zstd_dstream *stream;
|
|
int ret = 0;
|
|
unsigned long page_in_index = 0;
|
|
unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
|
|
unsigned long buf_start;
|
|
unsigned long total_out = 0;
|
|
|
|
stream = zstd_init_dstream(
|
|
ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
|
|
if (!stream) {
|
|
pr_debug("BTRFS: zstd_init_dstream failed\n");
|
|
ret = -EIO;
|
|
goto done;
|
|
}
|
|
|
|
workspace->in_buf.src = kmap_local_page(pages_in[page_in_index]);
|
|
workspace->in_buf.pos = 0;
|
|
workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
|
|
|
|
workspace->out_buf.dst = workspace->buf;
|
|
workspace->out_buf.pos = 0;
|
|
workspace->out_buf.size = PAGE_SIZE;
|
|
|
|
while (1) {
|
|
size_t ret2;
|
|
|
|
ret2 = zstd_decompress_stream(stream, &workspace->out_buf,
|
|
&workspace->in_buf);
|
|
if (zstd_is_error(ret2)) {
|
|
pr_debug("BTRFS: zstd_decompress_stream returned %d\n",
|
|
zstd_get_error_code(ret2));
|
|
ret = -EIO;
|
|
goto done;
|
|
}
|
|
buf_start = total_out;
|
|
total_out += workspace->out_buf.pos;
|
|
workspace->out_buf.pos = 0;
|
|
|
|
ret = btrfs_decompress_buf2page(workspace->out_buf.dst,
|
|
total_out - buf_start, cb, buf_start);
|
|
if (ret == 0)
|
|
break;
|
|
|
|
if (workspace->in_buf.pos >= srclen)
|
|
break;
|
|
|
|
/* Check if we've hit the end of a frame */
|
|
if (ret2 == 0)
|
|
break;
|
|
|
|
if (workspace->in_buf.pos == workspace->in_buf.size) {
|
|
kunmap_local(workspace->in_buf.src);
|
|
page_in_index++;
|
|
if (page_in_index >= total_pages_in) {
|
|
workspace->in_buf.src = NULL;
|
|
ret = -EIO;
|
|
goto done;
|
|
}
|
|
srclen -= PAGE_SIZE;
|
|
workspace->in_buf.src = kmap_local_page(pages_in[page_in_index]);
|
|
workspace->in_buf.pos = 0;
|
|
workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
|
|
}
|
|
}
|
|
ret = 0;
|
|
zero_fill_bio(cb->orig_bio);
|
|
done:
|
|
if (workspace->in_buf.src)
|
|
kunmap_local(workspace->in_buf.src);
|
|
return ret;
|
|
}
|
|
|
|
int zstd_decompress(struct list_head *ws, unsigned char *data_in,
|
|
struct page *dest_page, unsigned long start_byte, size_t srclen,
|
|
size_t destlen)
|
|
{
|
|
struct workspace *workspace = list_entry(ws, struct workspace, list);
|
|
zstd_dstream *stream;
|
|
int ret = 0;
|
|
size_t ret2;
|
|
unsigned long total_out = 0;
|
|
unsigned long pg_offset = 0;
|
|
|
|
stream = zstd_init_dstream(
|
|
ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
|
|
if (!stream) {
|
|
pr_warn("BTRFS: zstd_init_dstream failed\n");
|
|
ret = -EIO;
|
|
goto finish;
|
|
}
|
|
|
|
destlen = min_t(size_t, destlen, PAGE_SIZE);
|
|
|
|
workspace->in_buf.src = data_in;
|
|
workspace->in_buf.pos = 0;
|
|
workspace->in_buf.size = srclen;
|
|
|
|
workspace->out_buf.dst = workspace->buf;
|
|
workspace->out_buf.pos = 0;
|
|
workspace->out_buf.size = PAGE_SIZE;
|
|
|
|
ret2 = 1;
|
|
while (pg_offset < destlen
|
|
&& workspace->in_buf.pos < workspace->in_buf.size) {
|
|
unsigned long buf_start;
|
|
unsigned long buf_offset;
|
|
unsigned long bytes;
|
|
|
|
/* Check if the frame is over and we still need more input */
|
|
if (ret2 == 0) {
|
|
pr_debug("BTRFS: zstd_decompress_stream ended early\n");
|
|
ret = -EIO;
|
|
goto finish;
|
|
}
|
|
ret2 = zstd_decompress_stream(stream, &workspace->out_buf,
|
|
&workspace->in_buf);
|
|
if (zstd_is_error(ret2)) {
|
|
pr_debug("BTRFS: zstd_decompress_stream returned %d\n",
|
|
zstd_get_error_code(ret2));
|
|
ret = -EIO;
|
|
goto finish;
|
|
}
|
|
|
|
buf_start = total_out;
|
|
total_out += workspace->out_buf.pos;
|
|
workspace->out_buf.pos = 0;
|
|
|
|
if (total_out <= start_byte)
|
|
continue;
|
|
|
|
if (total_out > start_byte && buf_start < start_byte)
|
|
buf_offset = start_byte - buf_start;
|
|
else
|
|
buf_offset = 0;
|
|
|
|
bytes = min_t(unsigned long, destlen - pg_offset,
|
|
workspace->out_buf.size - buf_offset);
|
|
|
|
memcpy_to_page(dest_page, pg_offset,
|
|
workspace->out_buf.dst + buf_offset, bytes);
|
|
|
|
pg_offset += bytes;
|
|
}
|
|
ret = 0;
|
|
finish:
|
|
if (pg_offset < destlen) {
|
|
memzero_page(dest_page, pg_offset, destlen - pg_offset);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
const struct btrfs_compress_op btrfs_zstd_compress = {
|
|
/* ZSTD uses own workspace manager */
|
|
.workspace_manager = NULL,
|
|
.max_level = ZSTD_BTRFS_MAX_LEVEL,
|
|
.default_level = ZSTD_BTRFS_DEFAULT_LEVEL,
|
|
};
|