From e6a6d3795565b8ccb957afc6ca0e50db40b2d899 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Tue, 22 Sep 2009 19:25:24 +0100 Subject: Squashfs: move zlib decompression wrapper code into a separate file Signed-off-by: Phillip Lougher --- fs/squashfs/zlib_wrapper.c | 109 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 fs/squashfs/zlib_wrapper.c (limited to 'fs/squashfs/zlib_wrapper.c') diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c new file mode 100644 index 00000000000..3be99642d6a --- /dev/null +++ b/fs/squashfs/zlib_wrapper.c @@ -0,0 +1,109 @@ +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 + * Phillip Lougher + * + * 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 +#include +#include + +#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; +} -- cgit v1.2.3