| /* |
| * Squashfs - a compressed read only filesystem for Linux |
| * |
| * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
| * Phillip Lougher <phillip@lougher.demon.co.uk> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2, |
| * or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| * |
| * zlib_wrapper.c |
| */ |
| |
| |
| #include <linux/mutex.h> |
| #include <linux/buffer_head.h> |
| #include <linux/zlib.h> |
| |
| #include "squashfs_fs.h" |
| #include "squashfs_fs_sb.h" |
| #include "squashfs_fs_i.h" |
| #include "squashfs.h" |
| |
| int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer, |
| struct buffer_head **bh, int b, int offset, int length, int srclength, |
| int pages) |
| { |
| int zlib_err = 0, zlib_init = 0; |
| int avail, bytes, k = 0, page = 0; |
| |
| mutex_lock(&msblk->read_data_mutex); |
| |
| msblk->stream.avail_out = 0; |
| msblk->stream.avail_in = 0; |
| |
| bytes = length; |
| do { |
| if (msblk->stream.avail_in == 0 && k < b) { |
| avail = min(bytes, msblk->devblksize - offset); |
| bytes -= avail; |
| wait_on_buffer(bh[k]); |
| if (!buffer_uptodate(bh[k])) |
| goto release_mutex; |
| |
| if (avail == 0) { |
| offset = 0; |
| put_bh(bh[k++]); |
| continue; |
| } |
| |
| msblk->stream.next_in = bh[k]->b_data + offset; |
| msblk->stream.avail_in = avail; |
| offset = 0; |
| } |
| |
| if (msblk->stream.avail_out == 0 && page < pages) { |
| msblk->stream.next_out = buffer[page++]; |
| msblk->stream.avail_out = PAGE_CACHE_SIZE; |
| } |
| |
| if (!zlib_init) { |
| zlib_err = zlib_inflateInit(&msblk->stream); |
| if (zlib_err != Z_OK) { |
| ERROR("zlib_inflateInit returned unexpected " |
| "result 0x%x, srclength %d\n", |
| zlib_err, srclength); |
| goto release_mutex; |
| } |
| zlib_init = 1; |
| } |
| |
| zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH); |
| |
| if (msblk->stream.avail_in == 0 && k < b) |
| put_bh(bh[k++]); |
| } while (zlib_err == Z_OK); |
| |
| if (zlib_err != Z_STREAM_END) { |
| ERROR("zlib_inflate error, data probably corrupt\n"); |
| goto release_mutex; |
| } |
| |
| zlib_err = zlib_inflateEnd(&msblk->stream); |
| if (zlib_err != Z_OK) { |
| ERROR("zlib_inflate error, data probably corrupt\n"); |
| goto release_mutex; |
| } |
| |
| mutex_unlock(&msblk->read_data_mutex); |
| return msblk->stream.total_out; |
| |
| release_mutex: |
| mutex_unlock(&msblk->read_data_mutex); |
| |
| for (; k < b; k++) |
| put_bh(bh[k]); |
| |
| return -EIO; |
| } |