mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
143 lines
2.9 KiB
143 lines
2.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Copyright (c) 2013, 2014 |
|
* Phillip Lougher <[email protected]> |
|
*/ |
|
|
|
#include <linux/bio.h> |
|
#include <linux/mutex.h> |
|
#include <linux/slab.h> |
|
#include <linux/vmalloc.h> |
|
#include <linux/lz4.h> |
|
|
|
#include "squashfs_fs.h" |
|
#include "squashfs_fs_sb.h" |
|
#include "squashfs.h" |
|
#include "decompressor.h" |
|
#include "page_actor.h" |
|
|
|
#define LZ4_LEGACY 1 |
|
|
|
struct lz4_comp_opts { |
|
__le32 version; |
|
__le32 flags; |
|
}; |
|
|
|
struct squashfs_lz4 { |
|
void *input; |
|
void *output; |
|
}; |
|
|
|
|
|
static void *lz4_comp_opts(struct squashfs_sb_info *msblk, |
|
void *buff, int len) |
|
{ |
|
struct lz4_comp_opts *comp_opts = buff; |
|
|
|
/* LZ4 compressed filesystems always have compression options */ |
|
if (comp_opts == NULL || len < sizeof(*comp_opts)) |
|
return ERR_PTR(-EIO); |
|
|
|
if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) { |
|
/* LZ4 format currently used by the kernel is the 'legacy' |
|
* format */ |
|
ERROR("Unknown LZ4 version\n"); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
|
|
static void *lz4_init(struct squashfs_sb_info *msblk, void *buff) |
|
{ |
|
int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); |
|
struct squashfs_lz4 *stream; |
|
|
|
stream = kzalloc(sizeof(*stream), GFP_KERNEL); |
|
if (stream == NULL) |
|
goto failed; |
|
stream->input = vmalloc(block_size); |
|
if (stream->input == NULL) |
|
goto failed2; |
|
stream->output = vmalloc(block_size); |
|
if (stream->output == NULL) |
|
goto failed3; |
|
|
|
return stream; |
|
|
|
failed3: |
|
vfree(stream->input); |
|
failed2: |
|
kfree(stream); |
|
failed: |
|
ERROR("Failed to initialise LZ4 decompressor\n"); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
|
|
|
|
static void lz4_free(void *strm) |
|
{ |
|
struct squashfs_lz4 *stream = strm; |
|
|
|
if (stream) { |
|
vfree(stream->input); |
|
vfree(stream->output); |
|
} |
|
kfree(stream); |
|
} |
|
|
|
|
|
static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, |
|
struct bio *bio, int offset, int length, |
|
struct squashfs_page_actor *output) |
|
{ |
|
struct bvec_iter_all iter_all = {}; |
|
struct bio_vec *bvec = bvec_init_iter_all(&iter_all); |
|
struct squashfs_lz4 *stream = strm; |
|
void *buff = stream->input, *data; |
|
int bytes = length, res; |
|
|
|
while (bio_next_segment(bio, &iter_all)) { |
|
int avail = min(bytes, ((int)bvec->bv_len) - offset); |
|
|
|
data = bvec_virt(bvec); |
|
memcpy(buff, data + offset, avail); |
|
buff += avail; |
|
bytes -= avail; |
|
offset = 0; |
|
} |
|
|
|
res = LZ4_decompress_safe(stream->input, stream->output, |
|
length, output->length); |
|
|
|
if (res < 0) |
|
return -EIO; |
|
|
|
bytes = res; |
|
data = squashfs_first_page(output); |
|
buff = stream->output; |
|
while (data) { |
|
if (bytes <= PAGE_SIZE) { |
|
memcpy(data, buff, bytes); |
|
break; |
|
} |
|
memcpy(data, buff, PAGE_SIZE); |
|
buff += PAGE_SIZE; |
|
bytes -= PAGE_SIZE; |
|
data = squashfs_next_page(output); |
|
} |
|
squashfs_finish_page(output); |
|
|
|
return res; |
|
} |
|
|
|
const struct squashfs_decompressor squashfs_lz4_comp_ops = { |
|
.init = lz4_init, |
|
.comp_opts = lz4_comp_opts, |
|
.free = lz4_free, |
|
.decompress = lz4_uncompress, |
|
.id = LZ4_COMPRESSION, |
|
.name = "lz4", |
|
.supported = 1 |
|
};
|
|
|