Re: [PATCH v0] mkfs.ubifs: Add support for lz4hc compressor in mkfs.ubifs

[Konstantin Tokarev <annulen@yandex.ru>]

05.10.2013, 17:52, "Konstantin Tokarev" <annulen@yandex.ru>:
> 05.10.2013, 17:25, "Konstantin Tokarev" <annulen@yandex.ru>:
>
>>  05.10.2013, 16:56, "Elie De Brauwer" <eliedebrauwer@gmail.com>:
>>>   That's odd, yesterday I started by cloning mtd-utils.git and when I
>>>   try to repeat my own steps and apply my patch it does seem to work.
>>  I've figured it out: you've included patch into the mail instead of attaching
>>  it as a file, so I copied it, and tab characters got lost. patch -p1 -l
>>  works successfully.
>
> When trying to compress my rootfs, I got message "32866 compression errors occurred".
> Resulting image is much larger than LZO one (133M for lz4hc, 86M for lzo, 79M for zlib)

The next patch over your patch fixes the issue:

diff --git a/mkfs.ubifs/compr.c b/mkfs.ubifs/compr.c
index 2030042..65c7dbe 100644
--- a/mkfs.ubifs/compr.c
+++ b/mkfs.ubifs/compr.c
@@ -109,9 +109,10 @@ static int lz4hc_compress(void *in_buf, size_t in_len, void *out_buf,
            size_t *out_len)
 {
    int ret;
-   ret = LZ4_compressHC_limitedOutput(in_buf, out_buf, in_len, *out_len);
+   ret = LZ4_compressHC(in_buf, out_buf, in_len);
+   *out_len = ret;

-   if (ret != 0) {
+   if (ret == 0) {
        errcnt += 1;
        return -1;
    }


I've replaced LZ4_compressHC_limitedOutput with LZ4_compressHC to match lzo_compress logic which changes out_len instead of limiting it. No errors are reported now. However, result is still larger than LZO (93M).



-- 
Regards,
Konstantin