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authorRichard Purdie <rpurdie@openedhand.com>2007-07-10 10:28:36 +0100
committerDavid Woodhouse <dwmw2@infradead.org>2007-07-11 15:03:53 +0100
commitc799aca31bfe61ba3a91133acf5a13a0773087d4 (patch)
treed05f44fbec08e26fd52b8b1f4c7b5d162cfe3c31 /fs/jffs2/compr_lzo.c
parent8691a729a2a3d739ee40a577053157393450aabd (diff)
downloadlinux-linaro-c799aca31bfe61ba3a91133acf5a13a0773087d4.tar.gz
[JFFS2] Add LZO compression support.
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@openedhand.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'fs/jffs2/compr_lzo.c')
-rw-r--r--fs/jffs2/compr_lzo.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c
new file mode 100644
index 00000000000..47b045797e4
--- /dev/null
+++ b/fs/jffs2/compr_lzo.c
@@ -0,0 +1,108 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2007 Nokia Corporation. All rights reserved.
+ *
+ * Created by Richard Purdie <rpurdie@openedhand.com>
+ *
+ * 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)
+{
+ 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();
+}