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> 27e6a6d379SPhillip Lougher #include <linux/zlib.h> 28e6a6d379SPhillip Lougher 29e6a6d379SPhillip Lougher #include "squashfs_fs.h" 30e6a6d379SPhillip Lougher #include "squashfs_fs_sb.h" 31e6a6d379SPhillip Lougher #include "squashfs_fs_i.h" 32e6a6d379SPhillip Lougher #include "squashfs.h" 33e6a6d379SPhillip Lougher 34e6a6d379SPhillip Lougher int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer, 35e6a6d379SPhillip Lougher struct buffer_head **bh, int b, int offset, int length, int srclength, 36e6a6d379SPhillip Lougher int pages) 37e6a6d379SPhillip Lougher { 38e6a6d379SPhillip Lougher int zlib_err = 0, zlib_init = 0; 39e6a6d379SPhillip Lougher int avail, bytes, k = 0, page = 0; 40e6a6d379SPhillip Lougher 41e6a6d379SPhillip Lougher mutex_lock(&msblk->read_data_mutex); 42e6a6d379SPhillip Lougher 43e6a6d379SPhillip Lougher msblk->stream.avail_out = 0; 44e6a6d379SPhillip Lougher msblk->stream.avail_in = 0; 45e6a6d379SPhillip Lougher 46e6a6d379SPhillip Lougher bytes = length; 47e6a6d379SPhillip Lougher do { 48e6a6d379SPhillip Lougher if (msblk->stream.avail_in == 0 && k < b) { 49e6a6d379SPhillip Lougher avail = min(bytes, msblk->devblksize - offset); 50e6a6d379SPhillip Lougher bytes -= avail; 51e6a6d379SPhillip Lougher wait_on_buffer(bh[k]); 52e6a6d379SPhillip Lougher if (!buffer_uptodate(bh[k])) 53e6a6d379SPhillip Lougher goto release_mutex; 54e6a6d379SPhillip Lougher 55e6a6d379SPhillip Lougher if (avail == 0) { 56e6a6d379SPhillip Lougher offset = 0; 57e6a6d379SPhillip Lougher put_bh(bh[k++]); 58e6a6d379SPhillip Lougher continue; 59e6a6d379SPhillip Lougher } 60e6a6d379SPhillip Lougher 61e6a6d379SPhillip Lougher msblk->stream.next_in = bh[k]->b_data + offset; 62e6a6d379SPhillip Lougher msblk->stream.avail_in = avail; 63e6a6d379SPhillip Lougher offset = 0; 64e6a6d379SPhillip Lougher } 65e6a6d379SPhillip Lougher 66e6a6d379SPhillip Lougher if (msblk->stream.avail_out == 0 && page < pages) { 67e6a6d379SPhillip Lougher msblk->stream.next_out = buffer[page++]; 68e6a6d379SPhillip Lougher msblk->stream.avail_out = PAGE_CACHE_SIZE; 69e6a6d379SPhillip Lougher } 70e6a6d379SPhillip Lougher 71e6a6d379SPhillip Lougher if (!zlib_init) { 72e6a6d379SPhillip Lougher zlib_err = zlib_inflateInit(&msblk->stream); 73e6a6d379SPhillip Lougher if (zlib_err != Z_OK) { 74e6a6d379SPhillip Lougher ERROR("zlib_inflateInit returned unexpected " 75e6a6d379SPhillip Lougher "result 0x%x, srclength %d\n", 76e6a6d379SPhillip Lougher zlib_err, srclength); 77e6a6d379SPhillip Lougher goto release_mutex; 78e6a6d379SPhillip Lougher } 79e6a6d379SPhillip Lougher zlib_init = 1; 80e6a6d379SPhillip Lougher } 81e6a6d379SPhillip Lougher 82e6a6d379SPhillip Lougher zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH); 83e6a6d379SPhillip Lougher 84e6a6d379SPhillip Lougher if (msblk->stream.avail_in == 0 && k < b) 85e6a6d379SPhillip Lougher put_bh(bh[k++]); 86e6a6d379SPhillip Lougher } while (zlib_err == Z_OK); 87e6a6d379SPhillip Lougher 88e6a6d379SPhillip Lougher if (zlib_err != Z_STREAM_END) { 89e6a6d379SPhillip Lougher ERROR("zlib_inflate error, data probably corrupt\n"); 90e6a6d379SPhillip Lougher goto release_mutex; 91e6a6d379SPhillip Lougher } 92e6a6d379SPhillip Lougher 93e6a6d379SPhillip Lougher zlib_err = zlib_inflateEnd(&msblk->stream); 94e6a6d379SPhillip Lougher if (zlib_err != Z_OK) { 95e6a6d379SPhillip Lougher ERROR("zlib_inflate error, data probably corrupt\n"); 96e6a6d379SPhillip Lougher goto release_mutex; 97e6a6d379SPhillip Lougher } 98e6a6d379SPhillip Lougher 99e6a6d379SPhillip Lougher mutex_unlock(&msblk->read_data_mutex); 100e6a6d379SPhillip Lougher return msblk->stream.total_out; 101e6a6d379SPhillip Lougher 102e6a6d379SPhillip Lougher release_mutex: 103e6a6d379SPhillip Lougher mutex_unlock(&msblk->read_data_mutex); 104e6a6d379SPhillip Lougher 105e6a6d379SPhillip Lougher for (; k < b; k++) 106e6a6d379SPhillip Lougher put_bh(bh[k]); 107e6a6d379SPhillip Lougher 108e6a6d379SPhillip Lougher return -EIO; 109e6a6d379SPhillip Lougher } 110