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author | Richard Purdie <rpurdie@openedhand.com> | 2007-07-10 11:28:36 +0200 |
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committer | David Woodhouse <dwmw2@infradead.org> | 2007-07-11 16:03:53 +0200 |
commit | c799aca31bfe61ba3a91133acf5a13a0773087d4 (patch) | |
tree | d05f44fbec08e26fd52b8b1f4c7b5d162cfe3c31 /fs/jffs2/compr_lzo.c | |
parent | [MTD] Add sync/unblank function to mtdoops (diff) | |
download | linux-c799aca31bfe61ba3a91133acf5a13a0773087d4.tar.xz linux-c799aca31bfe61ba3a91133acf5a13a0773087d4.zip |
[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.c | 108 |
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 000000000000..47b045797e42 --- /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(); +} |