1*b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * uncompress.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * cramfs interfaces to the uncompression library. There's really just 81da177e4SLinus Torvalds * three entrypoints: 91da177e4SLinus Torvalds * 101da177e4SLinus Torvalds * - cramfs_uncompress_init() - called to initialize the thing. 111da177e4SLinus Torvalds * - cramfs_uncompress_exit() - tell me when you're done 121da177e4SLinus Torvalds * - cramfs_uncompress_block() - uncompress a block. 131da177e4SLinus Torvalds * 141da177e4SLinus Torvalds * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We 151da177e4SLinus Torvalds * only have one stream, and we'll initialize it only once even if it 161da177e4SLinus Torvalds * then is used by multiple filesystems. 171da177e4SLinus Torvalds */ 181da177e4SLinus Torvalds 194f21e1eaSFabian Frederick #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 204f21e1eaSFabian Frederick 211da177e4SLinus Torvalds #include <linux/kernel.h> 221da177e4SLinus Torvalds #include <linux/errno.h> 231da177e4SLinus Torvalds #include <linux/vmalloc.h> 241da177e4SLinus Torvalds #include <linux/zlib.h> 25f7f4f4ddSAl Viro #include "internal.h" 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds static z_stream stream; 281da177e4SLinus Torvalds static int initialized; 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds /* Returns length of decompressed data. */ 311da177e4SLinus Torvalds int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen) 321da177e4SLinus Torvalds { 331da177e4SLinus Torvalds int err; 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds stream.next_in = src; 361da177e4SLinus Torvalds stream.avail_in = srclen; 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds stream.next_out = dst; 391da177e4SLinus Torvalds stream.avail_out = dstlen; 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds err = zlib_inflateReset(&stream); 421da177e4SLinus Torvalds if (err != Z_OK) { 43f175ff81SFabian Frederick pr_err("zlib_inflateReset error %d\n", err); 441da177e4SLinus Torvalds zlib_inflateEnd(&stream); 451da177e4SLinus Torvalds zlib_inflateInit(&stream); 461da177e4SLinus Torvalds } 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds err = zlib_inflate(&stream, Z_FINISH); 491da177e4SLinus Torvalds if (err != Z_STREAM_END) 501da177e4SLinus Torvalds goto err; 511da177e4SLinus Torvalds return stream.total_out; 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds err: 54f175ff81SFabian Frederick pr_err("Error %d while decompressing!\n", err); 55f175ff81SFabian Frederick pr_err("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); 5698310e58SDavid VomLehn return -EIO; 571da177e4SLinus Torvalds } 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds int cramfs_uncompress_init(void) 601da177e4SLinus Torvalds { 611da177e4SLinus Torvalds if (!initialized++) { 621da177e4SLinus Torvalds stream.workspace = vmalloc(zlib_inflate_workspacesize()); 631da177e4SLinus Torvalds if (!stream.workspace) { 641da177e4SLinus Torvalds initialized = 0; 651da177e4SLinus Torvalds return -ENOMEM; 661da177e4SLinus Torvalds } 671da177e4SLinus Torvalds stream.next_in = NULL; 681da177e4SLinus Torvalds stream.avail_in = 0; 691da177e4SLinus Torvalds zlib_inflateInit(&stream); 701da177e4SLinus Torvalds } 711da177e4SLinus Torvalds return 0; 721da177e4SLinus Torvalds } 731da177e4SLinus Torvalds 74368bdb3dSAlexey Dobriyan void cramfs_uncompress_exit(void) 751da177e4SLinus Torvalds { 761da177e4SLinus Torvalds if (!--initialized) { 771da177e4SLinus Torvalds zlib_inflateEnd(&stream); 781da177e4SLinus Torvalds vfree(stream.workspace); 791da177e4SLinus Torvalds } 801da177e4SLinus Torvalds } 81