mirror of https://gitee.com/openkylin/linux.git
128 lines
2.6 KiB
C
128 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Squashfs - a compressed read only filesystem for Linux
|
|
*
|
|
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
|
|
* Phillip Lougher <phillip@squashfs.org.uk>
|
|
*
|
|
* zlib_wrapper.c
|
|
*/
|
|
|
|
|
|
#include <linux/mutex.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/zlib.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
#include "squashfs_fs.h"
|
|
#include "squashfs_fs_sb.h"
|
|
#include "squashfs.h"
|
|
#include "decompressor.h"
|
|
#include "page_actor.h"
|
|
|
|
static void *zlib_init(struct squashfs_sb_info *dummy, void *buff)
|
|
{
|
|
z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
|
|
if (stream == NULL)
|
|
goto failed;
|
|
stream->workspace = vmalloc(zlib_inflate_workspacesize());
|
|
if (stream->workspace == NULL)
|
|
goto failed;
|
|
|
|
return stream;
|
|
|
|
failed:
|
|
ERROR("Failed to allocate zlib workspace\n");
|
|
kfree(stream);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
|
|
static void zlib_free(void *strm)
|
|
{
|
|
z_stream *stream = strm;
|
|
|
|
if (stream)
|
|
vfree(stream->workspace);
|
|
kfree(stream);
|
|
}
|
|
|
|
|
|
static int zlib_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);
|
|
int zlib_init = 0, error = 0;
|
|
z_stream *stream = strm;
|
|
|
|
stream->avail_out = PAGE_SIZE;
|
|
stream->next_out = squashfs_first_page(output);
|
|
stream->avail_in = 0;
|
|
|
|
for (;;) {
|
|
int zlib_err;
|
|
|
|
if (stream->avail_in == 0) {
|
|
const void *data;
|
|
int avail;
|
|
|
|
if (!bio_next_segment(bio, &iter_all)) {
|
|
/* Z_STREAM_END must be reached. */
|
|
error = -EIO;
|
|
break;
|
|
}
|
|
|
|
avail = min(length, ((int)bvec->bv_len) - offset);
|
|
data = page_address(bvec->bv_page) + bvec->bv_offset;
|
|
length -= avail;
|
|
stream->next_in = data + offset;
|
|
stream->avail_in = avail;
|
|
offset = 0;
|
|
}
|
|
|
|
if (stream->avail_out == 0) {
|
|
stream->next_out = squashfs_next_page(output);
|
|
if (stream->next_out != NULL)
|
|
stream->avail_out = PAGE_SIZE;
|
|
}
|
|
|
|
if (!zlib_init) {
|
|
zlib_err = zlib_inflateInit(stream);
|
|
if (zlib_err != Z_OK) {
|
|
error = -EIO;
|
|
break;
|
|
}
|
|
zlib_init = 1;
|
|
}
|
|
|
|
zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
|
|
if (zlib_err == Z_STREAM_END)
|
|
break;
|
|
if (zlib_err != Z_OK) {
|
|
error = -EIO;
|
|
break;
|
|
}
|
|
}
|
|
|
|
squashfs_finish_page(output);
|
|
|
|
if (!error)
|
|
if (zlib_inflateEnd(stream) != Z_OK)
|
|
error = -EIO;
|
|
|
|
return error ? error : stream->total_out;
|
|
}
|
|
|
|
const struct squashfs_decompressor squashfs_zlib_comp_ops = {
|
|
.init = zlib_init,
|
|
.free = zlib_free,
|
|
.decompress = zlib_uncompress,
|
|
.id = ZLIB_COMPRESSION,
|
|
.name = "zlib",
|
|
.supported = 1
|
|
};
|
|
|