/*
* 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;
}
