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 5e6a6d379SPhillip Lougher * Phillip Lougher <phillip@lougher.demon.co.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> 29e6a6d379SPhillip Lougher 30e6a6d379SPhillip Lougher #include "squashfs_fs.h" 31e6a6d379SPhillip Lougher #include "squashfs_fs_sb.h" 32e6a6d379SPhillip Lougher #include "squashfs_fs_i.h" 33e6a6d379SPhillip Lougher #include "squashfs.h" 344c0f0bb2SPhillip Lougher #include "decompressor.h" 35e6a6d379SPhillip Lougher 364c0f0bb2SPhillip Lougher static void *zlib_init(struct squashfs_sb_info *dummy) 37f1a40359SPhillip Lougher { 38f1a40359SPhillip Lougher z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); 39f1a40359SPhillip Lougher if (stream == NULL) 40f1a40359SPhillip Lougher goto failed; 41f1a40359SPhillip Lougher stream->workspace = kmalloc(zlib_inflate_workspacesize(), 42f1a40359SPhillip Lougher GFP_KERNEL); 43f1a40359SPhillip Lougher if (stream->workspace == NULL) 44f1a40359SPhillip Lougher goto failed; 45f1a40359SPhillip Lougher 46f1a40359SPhillip Lougher return stream; 47f1a40359SPhillip Lougher 48f1a40359SPhillip Lougher failed: 49f1a40359SPhillip Lougher ERROR("Failed to allocate zlib workspace\n"); 50f1a40359SPhillip Lougher kfree(stream); 51f1a40359SPhillip Lougher return NULL; 52f1a40359SPhillip Lougher } 53f1a40359SPhillip Lougher 54f1a40359SPhillip Lougher 554c0f0bb2SPhillip Lougher static void zlib_free(void *strm) 56f1a40359SPhillip Lougher { 57f1a40359SPhillip Lougher z_stream *stream = strm; 58f1a40359SPhillip Lougher 59f1a40359SPhillip Lougher if (stream) 60f1a40359SPhillip Lougher kfree(stream->workspace); 61f1a40359SPhillip Lougher kfree(stream); 62f1a40359SPhillip Lougher } 63f1a40359SPhillip Lougher 64f1a40359SPhillip Lougher 654c0f0bb2SPhillip Lougher static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer, 66e6a6d379SPhillip Lougher struct buffer_head **bh, int b, int offset, int length, int srclength, 67e6a6d379SPhillip Lougher int pages) 68e6a6d379SPhillip Lougher { 69e6a6d379SPhillip Lougher int zlib_err = 0, zlib_init = 0; 70e6a6d379SPhillip Lougher int avail, bytes, k = 0, page = 0; 71f1a40359SPhillip Lougher z_stream *stream = msblk->stream; 72e6a6d379SPhillip Lougher 73e6a6d379SPhillip Lougher mutex_lock(&msblk->read_data_mutex); 74e6a6d379SPhillip Lougher 75f1a40359SPhillip Lougher stream->avail_out = 0; 76f1a40359SPhillip Lougher stream->avail_in = 0; 77e6a6d379SPhillip Lougher 78e6a6d379SPhillip Lougher bytes = length; 79e6a6d379SPhillip Lougher do { 80f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) { 81e6a6d379SPhillip Lougher avail = min(bytes, msblk->devblksize - offset); 82e6a6d379SPhillip Lougher bytes -= avail; 83e6a6d379SPhillip Lougher wait_on_buffer(bh[k]); 84e6a6d379SPhillip Lougher if (!buffer_uptodate(bh[k])) 85e6a6d379SPhillip Lougher goto release_mutex; 86e6a6d379SPhillip Lougher 87e6a6d379SPhillip Lougher if (avail == 0) { 88e6a6d379SPhillip Lougher offset = 0; 89e6a6d379SPhillip Lougher put_bh(bh[k++]); 90e6a6d379SPhillip Lougher continue; 91e6a6d379SPhillip Lougher } 92e6a6d379SPhillip Lougher 93f1a40359SPhillip Lougher stream->next_in = bh[k]->b_data + offset; 94f1a40359SPhillip Lougher stream->avail_in = avail; 95e6a6d379SPhillip Lougher offset = 0; 96e6a6d379SPhillip Lougher } 97e6a6d379SPhillip Lougher 98f1a40359SPhillip Lougher if (stream->avail_out == 0 && page < pages) { 99f1a40359SPhillip Lougher stream->next_out = buffer[page++]; 100f1a40359SPhillip Lougher stream->avail_out = PAGE_CACHE_SIZE; 101e6a6d379SPhillip Lougher } 102e6a6d379SPhillip Lougher 103e6a6d379SPhillip Lougher if (!zlib_init) { 104f1a40359SPhillip Lougher zlib_err = zlib_inflateInit(stream); 105e6a6d379SPhillip Lougher if (zlib_err != Z_OK) { 106e6a6d379SPhillip Lougher ERROR("zlib_inflateInit returned unexpected " 107e6a6d379SPhillip Lougher "result 0x%x, srclength %d\n", 108e6a6d379SPhillip Lougher zlib_err, srclength); 109e6a6d379SPhillip Lougher goto release_mutex; 110e6a6d379SPhillip Lougher } 111e6a6d379SPhillip Lougher zlib_init = 1; 112e6a6d379SPhillip Lougher } 113e6a6d379SPhillip Lougher 114f1a40359SPhillip Lougher zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); 115e6a6d379SPhillip Lougher 116f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) 117e6a6d379SPhillip Lougher put_bh(bh[k++]); 118e6a6d379SPhillip Lougher } while (zlib_err == Z_OK); 119e6a6d379SPhillip Lougher 120e6a6d379SPhillip Lougher if (zlib_err != Z_STREAM_END) { 121e6a6d379SPhillip Lougher ERROR("zlib_inflate error, data probably corrupt\n"); 122e6a6d379SPhillip Lougher goto release_mutex; 123e6a6d379SPhillip Lougher } 124e6a6d379SPhillip Lougher 125f1a40359SPhillip Lougher zlib_err = zlib_inflateEnd(stream); 126e6a6d379SPhillip Lougher if (zlib_err != Z_OK) { 127e6a6d379SPhillip Lougher ERROR("zlib_inflate error, data probably corrupt\n"); 128e6a6d379SPhillip Lougher goto release_mutex; 129e6a6d379SPhillip Lougher } 130e6a6d379SPhillip Lougher 131e6a6d379SPhillip Lougher mutex_unlock(&msblk->read_data_mutex); 132f1a40359SPhillip Lougher return stream->total_out; 133e6a6d379SPhillip Lougher 134e6a6d379SPhillip Lougher release_mutex: 135e6a6d379SPhillip Lougher mutex_unlock(&msblk->read_data_mutex); 136e6a6d379SPhillip Lougher 137e6a6d379SPhillip Lougher for (; k < b; k++) 138e6a6d379SPhillip Lougher put_bh(bh[k]); 139e6a6d379SPhillip Lougher 140e6a6d379SPhillip Lougher return -EIO; 141e6a6d379SPhillip Lougher } 1424c0f0bb2SPhillip Lougher 1434c0f0bb2SPhillip Lougher const struct squashfs_decompressor squashfs_zlib_comp_ops = { 1444c0f0bb2SPhillip Lougher .init = zlib_init, 1454c0f0bb2SPhillip Lougher .free = zlib_free, 1464c0f0bb2SPhillip Lougher .decompress = zlib_uncompress, 1474c0f0bb2SPhillip Lougher .id = ZLIB_COMPRESSION, 1484c0f0bb2SPhillip Lougher .name = "zlib", 1494c0f0bb2SPhillip Lougher .supported = 1 1504c0f0bb2SPhillip Lougher }; 1514c0f0bb2SPhillip Lougher 152