145 lines
3.0 KiB
C
145 lines
3.0 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
||
|
|
/*
|
||
|
|
* Squashfs - a compressed read only filesystem for Linux
|
||
|
|
*
|
||
|
|
* Copyright (c) 2016-present, Facebook, Inc.
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* zstd_wrapper.c
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/mutex.h>
|
||
|
|
#include <linux/bio.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/zstd.h>
|
||
|
|
#include <linux/vmalloc.h>
|
||
|
|
|
||
|
|
#include "squashfs_fs.h"
|
||
|
|
#include "squashfs_fs_sb.h"
|
||
|
|
#include "squashfs.h"
|
||
|
|
#include "decompressor.h"
|
||
|
|
#include "page_actor.h"
|
||
|
|
|
||
|
|
struct workspace {
|
||
|
|
void *mem;
|
||
|
|
size_t mem_size;
|
||
|
|
size_t window_size;
|
||
|
|
};
|
||
|
|
|
||
|
|
static void *zstd_init(struct squashfs_sb_info *msblk, void *buff)
|
||
|
|
{
|
||
|
|
struct workspace *wksp = kmalloc(sizeof(*wksp), GFP_KERNEL);
|
||
|
|
|
||
|
|
if (wksp == NULL)
|
||
|
|
goto failed;
|
||
|
|
wksp->window_size = max_t(size_t,
|
||
|
|
msblk->block_size, SQUASHFS_METADATA_SIZE);
|
||
|
|
wksp->mem_size = zstd_dstream_workspace_bound(wksp->window_size);
|
||
|
|
wksp->mem = vmalloc(wksp->mem_size);
|
||
|
|
if (wksp->mem == NULL)
|
||
|
|
goto failed;
|
||
|
|
|
||
|
|
return wksp;
|
||
|
|
|
||
|
|
failed:
|
||
|
|
ERROR("Failed to allocate zstd workspace\n");
|
||
|
|
kfree(wksp);
|
||
|
|
return ERR_PTR(-ENOMEM);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
static void zstd_free(void *strm)
|
||
|
|
{
|
||
|
|
struct workspace *wksp = strm;
|
||
|
|
|
||
|
|
if (wksp)
|
||
|
|
vfree(wksp->mem);
|
||
|
|
kfree(wksp);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm,
|
||
|
|
struct bio *bio, int offset, int length,
|
||
|
|
struct squashfs_page_actor *output)
|
||
|
|
{
|
||
|
|
struct workspace *wksp = strm;
|
||
|
|
zstd_dstream *stream;
|
||
|
|
size_t total_out = 0;
|
||
|
|
int error = 0;
|
||
|
|
zstd_in_buffer in_buf = { NULL, 0, 0 };
|
||
|
|
zstd_out_buffer out_buf = { NULL, 0, 0 };
|
||
|
|
struct bvec_iter_all iter_all = {};
|
||
|
|
struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
|
||
|
|
|
||
|
|
stream = zstd_init_dstream(wksp->window_size, wksp->mem, wksp->mem_size);
|
||
|
|
|
||
|
|
if (!stream) {
|
||
|
|
ERROR("Failed to initialize zstd decompressor\n");
|
||
|
|
return -EIO;
|
||
|
|
}
|
||
|
|
|
||
|
|
out_buf.size = PAGE_SIZE;
|
||
|
|
out_buf.dst = squashfs_first_page(output);
|
||
|
|
|
||
|
|
for (;;) {
|
||
|
|
size_t zstd_err;
|
||
|
|
|
||
|
|
if (in_buf.pos == in_buf.size) {
|
||
|
|
const void *data;
|
||
|
|
int avail;
|
||
|
|
|
||
|
|
if (!bio_next_segment(bio, &iter_all)) {
|
||
|
|
error = -EIO;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
avail = min(length, ((int)bvec->bv_len) - offset);
|
||
|
|
data = bvec_virt(bvec);
|
||
|
|
length -= avail;
|
||
|
|
in_buf.src = data + offset;
|
||
|
|
in_buf.size = avail;
|
||
|
|
in_buf.pos = 0;
|
||
|
|
offset = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (out_buf.pos == out_buf.size) {
|
||
|
|
out_buf.dst = squashfs_next_page(output);
|
||
|
|
if (out_buf.dst == NULL) {
|
||
|
|
/* Shouldn't run out of pages
|
||
|
|
* before stream is done.
|
||
|
|
*/
|
||
|
|
error = -EIO;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
out_buf.pos = 0;
|
||
|
|
out_buf.size = PAGE_SIZE;
|
||
|
|
}
|
||
|
|
|
||
|
|
total_out -= out_buf.pos;
|
||
|
|
zstd_err = zstd_decompress_stream(stream, &out_buf, &in_buf);
|
||
|
|
total_out += out_buf.pos; /* add the additional data produced */
|
||
|
|
if (zstd_err == 0)
|
||
|
|
break;
|
||
|
|
|
||
|
|
if (zstd_is_error(zstd_err)) {
|
||
|
|
ERROR("zstd decompression error: %d\n",
|
||
|
|
(int)zstd_get_error_code(zstd_err));
|
||
|
|
error = -EIO;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
squashfs_finish_page(output);
|
||
|
|
|
||
|
|
return error ? error : total_out;
|
||
|
|
}
|
||
|
|
|
||
|
|
const struct squashfs_decompressor squashfs_zstd_comp_ops = {
|
||
|
|
.init = zstd_init,
|
||
|
|
.free = zstd_free,
|
||
|
|
.decompress = zstd_uncompress,
|
||
|
|
.id = ZSTD_COMPRESSION,
|
||
|
|
.name = "zstd",
|
||
|
|
.supported = 1
|
||
|
|
};
|