792590c723
Fix locking bug in zlib wrapper introduced by recent decompressor changes. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
153 lines
3.5 KiB
C
153 lines
3.5 KiB
C
/*
|
|
* 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/slab.h>
|
|
#include <linux/zlib.h>
|
|
|
|
#include "squashfs_fs.h"
|
|
#include "squashfs_fs_sb.h"
|
|
#include "squashfs_fs_i.h"
|
|
#include "squashfs.h"
|
|
#include "decompressor.h"
|
|
|
|
static void *zlib_init(struct squashfs_sb_info *dummy)
|
|
{
|
|
z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
|
|
if (stream == NULL)
|
|
goto failed;
|
|
stream->workspace = kmalloc(zlib_inflate_workspacesize(),
|
|
GFP_KERNEL);
|
|
if (stream->workspace == NULL)
|
|
goto failed;
|
|
|
|
return stream;
|
|
|
|
failed:
|
|
ERROR("Failed to allocate zlib workspace\n");
|
|
kfree(stream);
|
|
return NULL;
|
|
}
|
|
|
|
|
|
static void zlib_free(void *strm)
|
|
{
|
|
z_stream *stream = strm;
|
|
|
|
if (stream)
|
|
kfree(stream->workspace);
|
|
kfree(stream);
|
|
}
|
|
|
|
|
|
static int 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;
|
|
z_stream *stream = msblk->stream;
|
|
|
|
mutex_lock(&msblk->read_data_mutex);
|
|
|
|
stream->avail_out = 0;
|
|
stream->avail_in = 0;
|
|
|
|
bytes = length;
|
|
do {
|
|
if (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;
|
|
}
|
|
|
|
stream->next_in = bh[k]->b_data + offset;
|
|
stream->avail_in = avail;
|
|
offset = 0;
|
|
}
|
|
|
|
if (stream->avail_out == 0 && page < pages) {
|
|
stream->next_out = buffer[page++];
|
|
stream->avail_out = PAGE_CACHE_SIZE;
|
|
}
|
|
|
|
if (!zlib_init) {
|
|
zlib_err = zlib_inflateInit(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(stream, Z_SYNC_FLUSH);
|
|
|
|
if (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(stream);
|
|
if (zlib_err != Z_OK) {
|
|
ERROR("zlib_inflate error, data probably corrupt\n");
|
|
goto release_mutex;
|
|
}
|
|
|
|
length = stream->total_out;
|
|
mutex_unlock(&msblk->read_data_mutex);
|
|
return length;
|
|
|
|
release_mutex:
|
|
mutex_unlock(&msblk->read_data_mutex);
|
|
|
|
for (; k < b; k++)
|
|
put_bh(bh[k]);
|
|
|
|
return -EIO;
|
|
}
|
|
|
|
const struct squashfs_decompressor squashfs_zlib_comp_ops = {
|
|
.init = zlib_init,
|
|
.free = zlib_free,
|
|
.decompress = zlib_uncompress,
|
|
.id = ZLIB_COMPRESSION,
|
|
.name = "zlib",
|
|
.supported = 1
|
|
};
|
|
|