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