Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / squashfs / lzo_wrapper.c

diff --git a/kernel/fs/squashfs/lzo_wrapper.c b/kernel/fs/squashfs/lzo_wrapper.c
new file mode 100644 (file)
index 0000000..244b9fb
--- /dev/null
+++ b/kernel/fs/squashfs/lzo_wrapper.c
@@ -0,0 +1,130 @@
+/*
+ * 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.h"
+#include "decompressor.h"
+#include "page_actor.h"
+
+struct squashfs_lzo {
+       void    *input;
+       void    *output;
+};
+
+static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
+{
+       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 ERR_PTR(-ENOMEM);
+}
+
+
+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 *strm,
+       struct buffer_head **bh, int b, int offset, int length,
+       struct squashfs_page_actor *output)
+{
+       struct squashfs_lzo *stream = strm;
+       void *buff = stream->input, *data;
+       int avail, i, bytes = length, res;
+       size_t out_len = output->length;
+
+       for (i = 0; i < b; i++) {
+               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;
+       data = squashfs_first_page(output);
+       buff = stream->output;
+       while (data) {
+               if (bytes <= PAGE_CACHE_SIZE) {
+                       memcpy(data, buff, bytes);
+                       break;
+               } else {
+                       memcpy(data, buff, PAGE_CACHE_SIZE);
+                       buff += PAGE_CACHE_SIZE;
+                       bytes -= PAGE_CACHE_SIZE;
+                       data = squashfs_next_page(output);
+               }
+       }
+       squashfs_finish_page(output);
+
+       return res;
+
+failed:
+       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
+};