1 files changed, 136 insertions, 0 deletions

diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
new file mode 100644
index 000000000000..5d87789bf1c1
--- /dev/null
+++ b/fs/squashfs/lzo_wrapper.c
@@ -0,0 +1,136 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2010 LG Electronics
+ * Chan Jeong <chan.jeong@lge.com>
+ *
+ * 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.
+ *
+ * lzo_wrapper.c
+ */
+
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/lzo.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "decompressor.h"
+
+struct squashfs_lzo {
+        void    *input;
+        void    *output;
+};
+
+static void *lzo_init(struct squashfs_sb_info *msblk)
+{
+        int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
+
+        struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+        if (stream == NULL)
+                goto failed;
+        stream->input = vmalloc(block_size);
+        if (stream->input == NULL)
+                goto failed;
+        stream->output = vmalloc(block_size);
+        if (stream->output == NULL)
+                goto failed2;
+
+        return stream;
+
+failed2:
+        vfree(stream->input);
+failed:
+        ERROR("Failed to allocate lzo workspace\n");
+        kfree(stream);
+        return NULL;
+}
+
+
+static void lzo_free(void *strm)
+{
+        struct squashfs_lzo *stream = strm;
+
+        if (stream) {
+                vfree(stream->input);
+                vfree(stream->output);
+        }
+        kfree(stream);
+}
+
+
+static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer,
+        struct buffer_head **bh, int b, int offset, int length, int srclength,
+        int pages)
+{
+        struct squashfs_lzo *stream = msblk->stream;
+        void *buff = stream->input;
+        int avail, i, bytes = length, res;
+        size_t out_len = srclength;
+
+        mutex_lock(&msblk->read_data_mutex);
+
+        for (i = 0; i < b; i++) {
+                wait_on_buffer(bh[i]);
+                if (!buffer_uptodate(bh[i]))
+                        goto block_release;
+
+                avail = min(bytes, msblk->devblksize - offset);
+                memcpy(buff, bh[i]->b_data + offset, avail);
+                buff += avail;
+                bytes -= avail;
+                offset = 0;
+                put_bh(bh[i]);
+        }
+
+        res = lzo1x_decompress_safe(stream->input, (size_t)length,
+                                        stream->output, &out_len);
+        if (res != LZO_E_OK)
+                goto failed;
+
+        res = bytes = (int)out_len;
+        for (i = 0, buff = stream->output; bytes && i < pages; i++) {
+                avail = min_t(int, bytes, PAGE_CACHE_SIZE);
+                memcpy(buffer[i], buff, avail);
+                buff += avail;
+                bytes -= avail;
+        }
+
+        mutex_unlock(&msblk->read_data_mutex);
+        return res;
+
+block_release:
+        for (; i < b; i++)
+                put_bh(bh[i]);
+
+failed:
+        mutex_unlock(&msblk->read_data_mutex);
+
+        ERROR("lzo decompression failed, data probably corrupt\n");
+        return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_lzo_comp_ops = {
+        .init = lzo_init,
+        .free = lzo_free,
+        .decompress = lzo_uncompress,
+        .id = LZO_COMPRESSION,
+        .name = "lzo",
+        .supported = 1
+};