[PATCH 1/3] jffs2: Add LZO compression support to jffs2
Richard Purdie
rpurdie at openedhand.com
Tue Jul 10 04:38:39 EDT 2007
Add LZO1X compression/decompression support to jffs2.
LZO's interface doesn't entirely match that required by jffs2 so a
buffer and memcpy is unavoidable.
Signed-off-by: Richard Purdie <rpurdie at openedhand.com>
---
fs/Kconfig | 11 ++++
fs/jffs2/Makefile | 1
fs/jffs2/compr.c | 6 ++
fs/jffs2/compr.h | 3 -
fs/jffs2/compr_lzo.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/jffs2.h | 1
6 files changed, 141 insertions(+), 1 deletion(-)
Index: linux-2.6.21/fs/Kconfig
===================================================================
--- linux-2.6.21.orig/fs/Kconfig 2007-07-01 18:20:47.000000000 +0100
+++ linux-2.6.21/fs/Kconfig 2007-07-01 18:25:31.000000000 +0100
@@ -1306,6 +1306,17 @@ config JFFS2_ZLIB
Say 'Y' if unsure.
+config JFFS2_LZO
+ bool "JFFS2 LZO compression support" if JFFS2_COMPRESSION_OPTIONS
+ select LZO_COMPRESS
+ select LZO_DECOMPRESS
+ depends on JFFS2_FS
+ default y
+ help
+ minilzo-based compression. Generally works better than Zlib.
+
+ Say 'Y' if unsure.
+
config JFFS2_RTIME
bool "JFFS2 RTIME compression support" if JFFS2_COMPRESSION_OPTIONS
depends on JFFS2_FS
Index: linux-2.6.21/fs/jffs2/Makefile
===================================================================
--- linux-2.6.21.orig/fs/jffs2/Makefile 2007-07-01 18:20:48.000000000 +0100
+++ linux-2.6.21/fs/jffs2/Makefile 2007-07-01 18:24:32.000000000 +0100
@@ -17,4 +17,5 @@ jffs2-$(CONFIG_JFFS2_FS_POSIX_ACL) += ac
jffs2-$(CONFIG_JFFS2_RUBIN) += compr_rubin.o
jffs2-$(CONFIG_JFFS2_RTIME) += compr_rtime.o
jffs2-$(CONFIG_JFFS2_ZLIB) += compr_zlib.o
+jffs2-$(CONFIG_JFFS2_LZO) += compr_lzo.o
jffs2-$(CONFIG_JFFS2_SUMMARY) += summary.o
Index: linux-2.6.21/fs/jffs2/compr.c
===================================================================
--- linux-2.6.21.orig/fs/jffs2/compr.c 2007-07-01 18:20:48.000000000 +0100
+++ linux-2.6.21/fs/jffs2/compr.c 2007-07-01 18:24:32.000000000 +0100
@@ -285,6 +285,9 @@ int __init jffs2_compressors_init(void)
jffs2_rubinmips_init();
jffs2_dynrubin_init();
#endif
+#ifdef CONFIG_JFFS2_LZO
+ jffs2_lzo_init();
+#endif
/* Setting default compression mode */
#ifdef CONFIG_JFFS2_CMODE_NONE
jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
@@ -303,6 +306,9 @@ int __init jffs2_compressors_init(void)
int jffs2_compressors_exit(void)
{
/* Unregistering compressors */
+#ifdef CONFIG_JFFS2_LZO
+ jffs2_lzo_exit();
+#endif
#ifdef CONFIG_JFFS2_RUBIN
jffs2_dynrubin_exit();
jffs2_rubinmips_exit();
Index: linux-2.6.21/fs/jffs2/compr_lzo.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.21/fs/jffs2/compr_lzo.c 2007-07-01 18:24:32.000000000 +0100
@@ -0,0 +1,120 @@
+/*
+ * JFFS2 LZO Compression Interface
+ *
+ * Copyright (C) 2007 Nokia Corporation. All rights reserved.
+ *
+ * Author: Richard Purdie <rpurdie at openedhand.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/lzo.h>
+#include "compr.h"
+
+static void *lzo_mem;
+static void *lzo_compress_buf;
+static DEFINE_MUTEX(deflate_mutex);
+
+static void free_workspace(void)
+{
+ vfree(lzo_mem);
+ vfree(lzo_compress_buf);
+}
+
+static int __init alloc_workspace(void)
+{
+ lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
+ lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
+
+ if (!lzo_mem || !lzo_compress_buf) {
+ printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n");
+ free_workspace();
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
+ uint32_t *sourcelen, uint32_t *dstlen, void *model)
+{
+ size_t compress_size;
+ int ret;
+
+ mutex_lock(&deflate_mutex);
+ ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
+ mutex_unlock(&deflate_mutex);
+
+ if (ret != LZO_E_OK)
+ return -1;
+
+ if (compress_size > *dstlen)
+ return -1;
+
+ memcpy(cpage_out, lzo_compress_buf, compress_size);
+ *dstlen = compress_size;
+
+ return 0;
+}
+
+static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
+ uint32_t srclen, uint32_t destlen, void *model)
+{
+ size_t dl = destlen;
+ int ret;
+
+ ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
+
+ if (ret != LZO_E_OK || dl != destlen)
+ return -1;
+
+ return 0;
+}
+
+static struct jffs2_compressor jffs2_lzo_comp = {
+ .priority = JFFS2_LZO_PRIORITY,
+ .name = "lzo",
+ .compr = JFFS2_COMPR_LZO,
+ .compress = &jffs2_lzo_compress,
+ .decompress = &jffs2_lzo_decompress,
+ .disabled = 0,
+};
+
+int __init jffs2_lzo_init(void)
+{
+ int ret;
+
+ ret = alloc_workspace();
+ if (ret < 0)
+ return ret;
+
+ ret = jffs2_register_compressor(&jffs2_lzo_comp);
+ if (ret)
+ free_workspace();
+
+ return ret;
+}
+
+void jffs2_lzo_exit(void)
+{
+ jffs2_unregister_compressor(&jffs2_lzo_comp);
+ free_workspace();
+}
Index: linux-2.6.21/include/linux/jffs2.h
===================================================================
--- linux-2.6.21.orig/include/linux/jffs2.h 2007-07-01 18:15:10.000000000 +0100
+++ linux-2.6.21/include/linux/jffs2.h 2007-07-01 18:24:32.000000000 +0100
@@ -46,6 +46,7 @@
#define JFFS2_COMPR_COPY 0x04
#define JFFS2_COMPR_DYNRUBIN 0x05
#define JFFS2_COMPR_ZLIB 0x06
+#define JFFS2_COMPR_LZO 0x07
/* Compatibility flags. */
#define JFFS2_COMPAT_MASK 0xc000 /* What do to if an unknown nodetype is found */
#define JFFS2_NODE_ACCURATE 0x2000
Index: linux-2.6.21/fs/jffs2/compr.h
===================================================================
--- linux-2.6.21.orig/fs/jffs2/compr.h 2007-07-01 18:20:48.000000000 +0100
+++ linux-2.6.21/fs/jffs2/compr.h 2007-07-01 18:24:32.000000000 +0100
@@ -27,9 +27,10 @@
#define JFFS2_RUBINMIPS_PRIORITY 10
#define JFFS2_DYNRUBIN_PRIORITY 20
#define JFFS2_LZARI_PRIORITY 30
-#define JFFS2_LZO_PRIORITY 40
#define JFFS2_RTIME_PRIORITY 50
#define JFFS2_ZLIB_PRIORITY 60
+#define JFFS2_LZO_PRIORITY 80
+
#define JFFS2_RUBINMIPS_DISABLED /* RUBINs will be used only */
#define JFFS2_DYNRUBIN_DISABLED /* for decompression */
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