1e6a6d379SPhillip Lougher /* 2e6a6d379SPhillip Lougher * Squashfs - a compressed read only filesystem for Linux 3e6a6d379SPhillip Lougher * 4e6a6d379SPhillip Lougher * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 5d7f2ff67SPhillip Lougher * Phillip Lougher <phillip@squashfs.org.uk> 6e6a6d379SPhillip Lougher * 7e6a6d379SPhillip Lougher * This program is free software; you can redistribute it and/or 8e6a6d379SPhillip Lougher * modify it under the terms of the GNU General Public License 9e6a6d379SPhillip Lougher * as published by the Free Software Foundation; either version 2, 10e6a6d379SPhillip Lougher * or (at your option) any later version. 11e6a6d379SPhillip Lougher * 12e6a6d379SPhillip Lougher * This program is distributed in the hope that it will be useful, 13e6a6d379SPhillip Lougher * but WITHOUT ANY WARRANTY; without even the implied warranty of 14e6a6d379SPhillip Lougher * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15e6a6d379SPhillip Lougher * GNU General Public License for more details. 16e6a6d379SPhillip Lougher * 17e6a6d379SPhillip Lougher * You should have received a copy of the GNU General Public License 18e6a6d379SPhillip Lougher * along with this program; if not, write to the Free Software 19e6a6d379SPhillip Lougher * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20e6a6d379SPhillip Lougher * 21e6a6d379SPhillip Lougher * zlib_wrapper.c 22e6a6d379SPhillip Lougher */ 23e6a6d379SPhillip Lougher 24e6a6d379SPhillip Lougher 25e6a6d379SPhillip Lougher #include <linux/mutex.h> 26e6a6d379SPhillip Lougher #include <linux/buffer_head.h> 275a0e3ad6STejun Heo #include <linux/slab.h> 28e6a6d379SPhillip Lougher #include <linux/zlib.h> 29117a91e0SPhillip Lougher #include <linux/vmalloc.h> 30e6a6d379SPhillip Lougher 31e6a6d379SPhillip Lougher #include "squashfs_fs.h" 32e6a6d379SPhillip Lougher #include "squashfs_fs_sb.h" 33e6a6d379SPhillip Lougher #include "squashfs.h" 344c0f0bb2SPhillip Lougher #include "decompressor.h" 35e6a6d379SPhillip Lougher 369508c6b9SPhillip Lougher static void *zlib_init(struct squashfs_sb_info *dummy, void *buff) 37f1a40359SPhillip Lougher { 38f1a40359SPhillip Lougher z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); 39f1a40359SPhillip Lougher if (stream == NULL) 40f1a40359SPhillip Lougher goto failed; 41117a91e0SPhillip Lougher stream->workspace = vmalloc(zlib_inflate_workspacesize()); 42f1a40359SPhillip Lougher if (stream->workspace == NULL) 43f1a40359SPhillip Lougher goto failed; 44f1a40359SPhillip Lougher 45f1a40359SPhillip Lougher return stream; 46f1a40359SPhillip Lougher 47f1a40359SPhillip Lougher failed: 48f1a40359SPhillip Lougher ERROR("Failed to allocate zlib workspace\n"); 49f1a40359SPhillip Lougher kfree(stream); 50b7fc0ff0SPhillip Lougher return ERR_PTR(-ENOMEM); 51f1a40359SPhillip Lougher } 52f1a40359SPhillip Lougher 53f1a40359SPhillip Lougher 544c0f0bb2SPhillip Lougher static void zlib_free(void *strm) 55f1a40359SPhillip Lougher { 56f1a40359SPhillip Lougher z_stream *stream = strm; 57f1a40359SPhillip Lougher 58f1a40359SPhillip Lougher if (stream) 59117a91e0SPhillip Lougher vfree(stream->workspace); 60f1a40359SPhillip Lougher kfree(stream); 61f1a40359SPhillip Lougher } 62f1a40359SPhillip Lougher 63f1a40359SPhillip Lougher 649508c6b9SPhillip Lougher static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm, 659508c6b9SPhillip Lougher void **buffer, struct buffer_head **bh, int b, int offset, int length, 669508c6b9SPhillip Lougher int srclength, int pages) 67e6a6d379SPhillip Lougher { 68170cf021SPhillip Lougher int zlib_err, zlib_init = 0; 69170cf021SPhillip Lougher int k = 0, page = 0; 709508c6b9SPhillip Lougher z_stream *stream = strm; 71e6a6d379SPhillip Lougher 72f1a40359SPhillip Lougher stream->avail_out = 0; 73f1a40359SPhillip Lougher stream->avail_in = 0; 74e6a6d379SPhillip Lougher 75e6a6d379SPhillip Lougher do { 76f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) { 77170cf021SPhillip Lougher int avail = min(length, msblk->devblksize - offset); 78170cf021SPhillip Lougher length -= avail; 79f1a40359SPhillip Lougher stream->next_in = bh[k]->b_data + offset; 80f1a40359SPhillip Lougher stream->avail_in = avail; 81e6a6d379SPhillip Lougher offset = 0; 82e6a6d379SPhillip Lougher } 83e6a6d379SPhillip Lougher 84f1a40359SPhillip Lougher if (stream->avail_out == 0 && page < pages) { 85f1a40359SPhillip Lougher stream->next_out = buffer[page++]; 86f1a40359SPhillip Lougher stream->avail_out = PAGE_CACHE_SIZE; 87e6a6d379SPhillip Lougher } 88e6a6d379SPhillip Lougher 89e6a6d379SPhillip Lougher if (!zlib_init) { 90f1a40359SPhillip Lougher zlib_err = zlib_inflateInit(stream); 919508c6b9SPhillip Lougher if (zlib_err != Z_OK) 929508c6b9SPhillip Lougher goto out; 93e6a6d379SPhillip Lougher zlib_init = 1; 94e6a6d379SPhillip Lougher } 95e6a6d379SPhillip Lougher 96f1a40359SPhillip Lougher zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); 97e6a6d379SPhillip Lougher 98f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) 99e6a6d379SPhillip Lougher put_bh(bh[k++]); 100e6a6d379SPhillip Lougher } while (zlib_err == Z_OK); 101e6a6d379SPhillip Lougher 1029508c6b9SPhillip Lougher if (zlib_err != Z_STREAM_END) 1039508c6b9SPhillip Lougher goto out; 104e6a6d379SPhillip Lougher 105f1a40359SPhillip Lougher zlib_err = zlib_inflateEnd(stream); 1069508c6b9SPhillip Lougher if (zlib_err != Z_OK) 1079508c6b9SPhillip Lougher goto out; 108e6a6d379SPhillip Lougher 1099508c6b9SPhillip Lougher if (k < b) 1109508c6b9SPhillip Lougher goto out; 111e7ee11f0SPhillip Lougher 1129508c6b9SPhillip Lougher return stream->total_out; 113e6a6d379SPhillip Lougher 1149508c6b9SPhillip Lougher out: 115e6a6d379SPhillip Lougher for (; k < b; k++) 116e6a6d379SPhillip Lougher put_bh(bh[k]); 117e6a6d379SPhillip Lougher 118e6a6d379SPhillip Lougher return -EIO; 119e6a6d379SPhillip Lougher } 1204c0f0bb2SPhillip Lougher 1214c0f0bb2SPhillip Lougher const struct squashfs_decompressor squashfs_zlib_comp_ops = { 1224c0f0bb2SPhillip Lougher .init = zlib_init, 1234c0f0bb2SPhillip Lougher .free = zlib_free, 1244c0f0bb2SPhillip Lougher .decompress = zlib_uncompress, 1254c0f0bb2SPhillip Lougher .id = ZLIB_COMPRESSION, 1264c0f0bb2SPhillip Lougher .name = "zlib", 1274c0f0bb2SPhillip Lougher .supported = 1 1284c0f0bb2SPhillip Lougher }; 1294c0f0bb2SPhillip Lougher 130