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// 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;
if (IS_ERR(stream->next_out)) {
error = PTR_ERR(stream->next_out);
goto finish;
}
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 = bvec_virt(bvec);
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 (IS_ERR(stream->next_out)) {
error = PTR_ERR(stream->next_out);
break;
} else 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;
}
}
finish:
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",
.alloc_buffer = 1,
.supported = 1
};
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