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authorChan Jeong <chan.jeong@lge.com>2010-08-05 02:29:59 +0100
committerPhillip Lougher <phillip@lougher.demon.co.uk>2010-08-05 02:29:59 +0100
commit79cb8ced7eef53856b5a877db0544acf52e00c80 (patch)
treefd39e0c73f15fd5b86a816a4c6ebc10d12cb6622 /fs/squashfs/lzo_wrapper.c
parent4690148f77f90ec132b5eb780650ba8769b9ed39 (diff)
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Squashfs: Add LZO compression support
Signed-off-by: Chan Jeong <chan.jeong@lge.com> Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Diffstat (limited to 'fs/squashfs/lzo_wrapper.c')
-rw-r--r--fs/squashfs/lzo_wrapper.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
new file mode 100644
index 000000000000..e1f86ded0ee5
--- /dev/null
+++ b/fs/squashfs/lzo_wrapper.c
@@ -0,0 +1,134 @@
+/*
+ * 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)
+{
+ struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+ if (stream == NULL)
+ goto failed;
+ stream->input = vmalloc(msblk->block_size);
+ if (stream->input == NULL)
+ goto failed;
+ stream->output = vmalloc(msblk->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 = msblk->block_size;
+
+ 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
+};