[JFFS2] Add LZO compression support.

[firefly-linux-kernel-4.4.55.git] / fs / jffs2 / compr_lzo.c

diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c
new file mode 100644 (file)
index 0000000..47b0457
--- /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();
+}