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-rw-r--r--fs/squashfs/zlib_wrapper.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 00000000000..15a03d0fb9f
--- /dev/null
+++ b/fs/squashfs/zlib_wrapper.c
@@ -0,0 +1,151 @@
+/*
+ * 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;
+ }
+
+ mutex_unlock(&msblk->read_data_mutex);
+ return stream->total_out;
+
+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
+};
+