[PATCH 1/5] fs: squashfs: port lzo compression support from kernel
Enrico Jorns
ejo at pengutronix.de
Tue Oct 4 03:10:44 PDT 2016
This ports lzo_wrapper from kernel code and adds some minimal adaptions
to make squashfs lzo compression work in barebox.
Signed-off-by: Enrico Jorns <ejo at pengutronix.de>
---
fs/squashfs/Kconfig | 14 +++++
fs/squashfs/Makefile | 1 +
fs/squashfs/lzo_wrapper.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/lzo.h | 47 +++++++++++++++++
4 files changed, 190 insertions(+)
create mode 100644 fs/squashfs/lzo_wrapper.c
create mode 100644 include/linux/lzo.h
diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index dc25d93..d8ee554 100644
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -17,6 +17,20 @@ menuconfig FS_SQUASHFS
embedded systems where low overhead is needed. Further information
and tools are available from http://squashfs.sourceforge.net.
+config SQUASHFS_LZO
+ bool "Include support for LZO compressed file systems"
+ default y
+ depends on FS_SQUASHFS
+ select LZO_DECOMPRESS
+ help
+ Saying Y here includes support for reading Squashfs file systems
+ compressed with LZO compression. LZO compression is mainly
+ aimed at embedded systems with slower CPUs where the overheads
+ of zlib are too high.
+
+ LZO is not the standard compression used in Squashfs and so most
+ file systems will be readable without selecting this option.
+
config SQUASHFS_XZ
bool "Include support for XZ compressed file systems"
default y
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index c0d024c..447e15e 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -11,3 +11,4 @@ obj-y += inode.o
obj-y += namei.o
obj-y += super.o
obj-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
+obj-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
new file mode 100644
index 0000000..b457955
--- /dev/null
+++ b/fs/squashfs/lzo_wrapper.c
@@ -0,0 +1,128 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2010 LG Electronics
+ * Chan Jeong <chan.jeong at 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/lzo.h>
+#include <types.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,
+ char **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] + offset, avail);
+ buff += avail;
+ bytes -= avail;
+ offset = 0;
+ kfree(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
+};
diff --git a/include/linux/lzo.h b/include/linux/lzo.h
new file mode 100644
index 0000000..ae52d79
--- /dev/null
+++ b/include/linux/lzo.h
@@ -0,0 +1,47 @@
+#ifndef __LZO_H__
+#define __LZO_H__
+/*
+ * LZO Public Kernel Interface
+ * A mini subset of the LZO real-time data compression library
+ *
+ * Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus at oberhumer.com>
+ *
+ * The full LZO package can be found at:
+ * http://www.oberhumer.com/opensource/lzo/
+ *
+ * Changed for Linux kernel use by:
+ * Nitin Gupta <nitingupta910 at gmail.com>
+ * Richard Purdie <rpurdie at openedhand.com>
+ */
+
+#include <types.h>
+
+#define LZO1X_1_MEM_COMPRESS (8192 * sizeof(unsigned short))
+#define LZO1X_MEM_COMPRESS LZO1X_1_MEM_COMPRESS
+
+#define lzo1x_worst_compress(x) ((x) + ((x) / 16) + 64 + 3)
+
+/* This requires 'wrkmem' of size LZO1X_1_MEM_COMPRESS */
+int lzo1x_1_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem);
+
+/* safe decompression with overrun testing */
+int lzo1x_decompress_safe(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len);
+
+/*
+ * Return values (< 0 = Error)
+ */
+#define LZO_E_OK 0
+#define LZO_E_ERROR (-1)
+#define LZO_E_OUT_OF_MEMORY (-2)
+#define LZO_E_NOT_COMPRESSIBLE (-3)
+#define LZO_E_INPUT_OVERRUN (-4)
+#define LZO_E_OUTPUT_OVERRUN (-5)
+#define LZO_E_LOOKBEHIND_OVERRUN (-6)
+#define LZO_E_EOF_NOT_FOUND (-7)
+#define LZO_E_INPUT_NOT_CONSUMED (-8)
+#define LZO_E_NOT_YET_IMPLEMENTED (-9)
+#define LZO_E_INVALID_ARGUMENT (-10)
+
+#endif
--
2.9.3
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