Squashfs: move zlib decompression wrapper code into a separate file

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

1 files changed, 109 insertions, 0 deletions

diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 000000000000..3be99642d6af
--- /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 <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;
+}