Re: lz4hc compression in UBIFS?

[Konstantin Tokarev <annulen@yandex.ru>]

04.10.2013, 07:09, "Brent Taylor" <motobud@gmail.com>:
> Here is a patch based on linux-3.12-rc3.  I haven't performed any
> performance testing UBIFS using lz4hc, but I can mount UBIFS volumes
> and haven't seen any problems yet.  The only think I know that isn't
> correct about the patch is the description for the Kconfig element for
> select lz4hc as a compression option.  I only copied the description
> from the lzo description.

Hi Brent,

I'm testing your patch on my SH4 device. When I create new partition
with lz4hc compressor, it works fine: I can copy file into it, and
md5sums of original and copy match. However, after reboot I cannot
read the file anymore:

UBIFS error (pid 1101): ubifs_decompress: cannot decompress 934 bytes, compressor lz4hc, error -22
UBIFS error (pid 1101): read_block: bad data node (block 1, inode 65)
UBIFS error (pid 1101): do_readpage: cannot read page 1 of inode 65, error -22

The same error appears if I use lz4hc-compressed ubifs image to flash rootfs
(using patched mkfs.ubifs).

Decompression error occurs in lz4_uncompress() function (lib/lz4/lz4_decompress.c),
on the line 101:

/* Error: offset create reference outside destination buffer */
if (unlikely(ref < (BYTE *const) dest))
    goto _output_error;

Brent: are you able to read data from lz4hc volume on your device?
Anyone: any ideas what may happen here?

-- 
Regards,
Konstantin