11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * uncompress.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright 1999 Linus Torvalds 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * cramfs interfaces to the uncompression library. There's really just 71da177e4SLinus Torvalds * three entrypoints: 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * - cramfs_uncompress_init() - called to initialize the thing. 101da177e4SLinus Torvalds * - cramfs_uncompress_exit() - tell me when you're done 111da177e4SLinus Torvalds * - cramfs_uncompress_block() - uncompress a block. 121da177e4SLinus Torvalds * 131da177e4SLinus Torvalds * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We 141da177e4SLinus Torvalds * only have one stream, and we'll initialize it only once even if it 151da177e4SLinus Torvalds * then is used by multiple filesystems. 161da177e4SLinus Torvalds */ 171da177e4SLinus Torvalds 181da177e4SLinus Torvalds #include <linux/kernel.h> 191da177e4SLinus Torvalds #include <linux/errno.h> 201da177e4SLinus Torvalds #include <linux/vmalloc.h> 211da177e4SLinus Torvalds #include <linux/zlib.h> 22*f7f4f4ddSAl Viro #include "internal.h" 231da177e4SLinus Torvalds 241da177e4SLinus Torvalds static z_stream stream; 251da177e4SLinus Torvalds static int initialized; 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds /* Returns length of decompressed data. */ 281da177e4SLinus Torvalds int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen) 291da177e4SLinus Torvalds { 301da177e4SLinus Torvalds int err; 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds stream.next_in = src; 331da177e4SLinus Torvalds stream.avail_in = srclen; 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds stream.next_out = dst; 361da177e4SLinus Torvalds stream.avail_out = dstlen; 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds err = zlib_inflateReset(&stream); 391da177e4SLinus Torvalds if (err != Z_OK) { 401da177e4SLinus Torvalds printk("zlib_inflateReset error %d\n", err); 411da177e4SLinus Torvalds zlib_inflateEnd(&stream); 421da177e4SLinus Torvalds zlib_inflateInit(&stream); 431da177e4SLinus Torvalds } 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds err = zlib_inflate(&stream, Z_FINISH); 461da177e4SLinus Torvalds if (err != Z_STREAM_END) 471da177e4SLinus Torvalds goto err; 481da177e4SLinus Torvalds return stream.total_out; 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds err: 511da177e4SLinus Torvalds printk("Error %d while decompressing!\n", err); 521da177e4SLinus Torvalds printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); 5398310e58SDavid VomLehn return -EIO; 541da177e4SLinus Torvalds } 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds int cramfs_uncompress_init(void) 571da177e4SLinus Torvalds { 581da177e4SLinus Torvalds if (!initialized++) { 591da177e4SLinus Torvalds stream.workspace = vmalloc(zlib_inflate_workspacesize()); 601da177e4SLinus Torvalds if ( !stream.workspace ) { 611da177e4SLinus Torvalds initialized = 0; 621da177e4SLinus Torvalds return -ENOMEM; 631da177e4SLinus Torvalds } 641da177e4SLinus Torvalds stream.next_in = NULL; 651da177e4SLinus Torvalds stream.avail_in = 0; 661da177e4SLinus Torvalds zlib_inflateInit(&stream); 671da177e4SLinus Torvalds } 681da177e4SLinus Torvalds return 0; 691da177e4SLinus Torvalds } 701da177e4SLinus Torvalds 71368bdb3dSAlexey Dobriyan void cramfs_uncompress_exit(void) 721da177e4SLinus Torvalds { 731da177e4SLinus Torvalds if (!--initialized) { 741da177e4SLinus Torvalds zlib_inflateEnd(&stream); 751da177e4SLinus Torvalds vfree(stream.workspace); 761da177e4SLinus Torvalds } 771da177e4SLinus Torvalds } 78