138514Sdfr// SPDX-License-Identifier: GPL-2.0 238514Sdfr/* 338514Sdfr * uncompress.c 438514Sdfr * 538514Sdfr * (C) Copyright 1999 Linus Torvalds 638514Sdfr * 738514Sdfr * cramfs interfaces to the uncompression library. There's really just 838514Sdfr * three entrypoints: 938514Sdfr * 1038514Sdfr * - cramfs_uncompress_init() - called to initialize the thing. 1138514Sdfr * - cramfs_uncompress_exit() - tell me when you're done 1238514Sdfr * - cramfs_uncompress_block() - uncompress a block. 1338514Sdfr * 1438514Sdfr * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We 1538514Sdfr * only have one stream, and we'll initialize it only once even if it 1638514Sdfr * then is used by multiple filesystems. 1738514Sdfr */ 1838514Sdfr 1938514Sdfr#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 2038514Sdfr 2138514Sdfr#include <linux/kernel.h> 2238514Sdfr#include <linux/errno.h> 2338514Sdfr#include <linux/vmalloc.h> 2438514Sdfr#include <linux/zlib.h> 2538514Sdfr#include "internal.h" 2650477Speter 2738514Sdfrstatic z_stream stream; 2838514Sdfrstatic int initialized; 2938514Sdfr 3038514Sdfr/* Returns length of decompressed data. */ 3138514Sdfrint cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen) 3238514Sdfr{ 3338514Sdfr int err; 3438514Sdfr 3538514Sdfr stream.next_in = src; 3638514Sdfr stream.avail_in = srclen; 3738514Sdfr 3838514Sdfr stream.next_out = dst; 3938514Sdfr stream.avail_out = dstlen; 4039071Sdfr 4152128Speter err = zlib_inflateReset(&stream); 4252128Speter if (err != Z_OK) { 4339071Sdfr pr_err("zlib_inflateReset error %d\n", err); 4439071Sdfr zlib_inflateEnd(&stream); 4552128Speter zlib_inflateInit(&stream); 4639071Sdfr } 4739071Sdfr 4839071Sdfr err = zlib_inflate(&stream, Z_FINISH); 4952128Speter if (err != Z_STREAM_END) 5039071Sdfr goto err; 5139071Sdfr return stream.total_out; 5239071Sdfr 5340156Spetererr: 5438514Sdfr pr_err("Error %d while decompressing!\n", err); 5538514Sdfr pr_err("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); 5643301Sdillon return -EIO; 5743309Sdillon} 5838514Sdfr 5943301Sdillonint cramfs_uncompress_init(void) 6038514Sdfr{ 6140156Speter if (!initialized++) { 6240156Speter stream.workspace = vmalloc(zlib_inflate_workspacesize()); 6338514Sdfr if (!stream.workspace) { 6438514Sdfr initialized = 0; 6540156Speter return -ENOMEM; 6638514Sdfr } 6738514Sdfr stream.next_in = NULL; 6838514Sdfr stream.avail_in = 0; 6938514Sdfr zlib_inflateInit(&stream); 7038514Sdfr } 7138514Sdfr return 0; 7240156Speter} 7338514Sdfr 7438514Sdfrvoid cramfs_uncompress_exit(void) 7540156Speter{ 7640156Speter if (!--initialized) { 7740156Speter zlib_inflateEnd(&stream); 7840156Speter vfree(stream.workspace); 7940156Speter } 8040156Speter} 8138514Sdfr