1 files changed, 155 insertions, 0 deletions

diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
new file mode 100644
index 000000000000..818a5e063faf
--- /dev/null
+++ b/fs/squashfs/zlib_wrapper.c
@@ -0,0 +1,155 @@
+/*
+ * 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.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, zlib_init = 0;
+        int k = 0, page = 0;
+        z_stream *stream = msblk->stream;
+
+        mutex_lock(&msblk->read_data_mutex);
+
+        stream->avail_out = 0;
+        stream->avail_in = 0;
+
+        do {
+                if (stream->avail_in == 0 && k < b) {
+                        int avail = min(length, msblk->devblksize - offset);
+                        length -= 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;
+        }
+
+        if (k < b) {
+                ERROR("zlib_uncompress error, data remaining\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
+};
+