[PATCH 2/5] jffs2: Add LZO compression support to jffs2
From: Richard Purdie
Date: Fri May 04 2007 - 07:31:52 EST
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@xxxxxxxxxxxxxx>
---
fs/Kconfig | 11 +++++
fs/jffs2/Makefile | 1 +
fs/jffs2/compr.c | 6 +++
fs/jffs2/compr.h | 7 +++-
fs/jffs2/compr_lzo.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/jffs2.h | 1 +
6 files changed, 135 insertions(+), 1 deletions(-)
diff --git a/fs/Kconfig b/fs/Kconfig
index a42f767..421c821 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1310,6 +1310,17 @@ config JFFS2_ZLIB
Say 'Y' if unsure.
+config JFFS2_LZO
+ bool "JFFS2 LZO compression support" if JFFS2_COMPRESSION_OPTIONS
+ select LZO
+ depends on JFFS2_FS
+ default y
+ help
+ LZO based compression. Generally works faster than Zlib with
+ a slightly lower compression ratio.
+
+ Say 'Y' if unsure.
+
config JFFS2_RTIME
bool "JFFS2 RTIME compression support" if JFFS2_COMPRESSION_OPTIONS
depends on JFFS2_FS
diff --git a/fs/jffs2/Makefile b/fs/jffs2/Makefile
index c32b241..60e5d49 100644
--- a/fs/jffs2/Makefile
+++ b/fs/jffs2/Makefile
@@ -17,4 +17,5 @@ jffs2-$(CONFIG_JFFS2_FS_POSIX_ACL) += acl.o
jffs2-$(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
diff --git a/fs/jffs2/compr.c b/fs/jffs2/compr.c
index 485d065..6a23408 100644
--- a/fs/jffs2/compr.c
+++ b/fs/jffs2/compr.c
@@ -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();
diff --git a/fs/jffs2/compr.h b/fs/jffs2/compr.h
index 68cc701..8c6b2af 100644
--- a/fs/jffs2/compr.h
+++ b/fs/jffs2/compr.h
@@ -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 */
@@ -90,5 +91,9 @@ void jffs2_rtime_exit(void);
int jffs2_zlib_init(void);
void jffs2_zlib_exit(void);
#endif
+#ifdef CONFIG_JFFS2_LZO
+int jffs2_lzo_init(void);
+void jffs2_lzo_exit(void);
+#endif
#endif /* __JFFS2_COMPR_H__ */
diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c
new file mode 100644
index 0000000..6396682
--- /dev/null
+++ b/fs/jffs2/compr_lzo.c
@@ -0,0 +1,110 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * LZO Compression Interface
+ *
+ * Copyright © 2007 Nokia Corporation. All rights reserved.
+ *
+ * Created by Richard Purdie <rpurdie@xxxxxxxxxxxxxx>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#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)
+{
+ unsigned long 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)
+{
+ unsigned long dl = destlen;
+ int ret;
+
+ ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl, NULL);
+
+ 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();
+}
diff --git a/include/linux/jffs2.h b/include/linux/jffs2.h
index 840631f..6b563ca 100644
--- a/include/linux/jffs2.h
+++ b/include/linux/jffs2.h
@@ -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
-
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