Re: [BUG] lib: zram lz4 compression/decompression still broken on big endian

From: Rui Salvaterra
Date: Tue Apr 05 2016 - 12:02:27 EST


2016-04-05 16:34 GMT+01:00 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>:
> On Tue, Apr 05, 2016 at 03:07:48PM +0100, Rui Salvaterra wrote:
>> Hi,
>>
>>
>> I apologise in advance if I've cc'ed too many/the wrong people/lists.
>>
>> Whenever I try to use zram with lz4, on my Power Mac G5 (tested with
>> kernel 4.4.0-16-powerpc64-smp from Ubuntu 16.04 LTS), I get the
>> following on my dmesg:
>>
>> [13150.675820] zram: Added device: zram0
>> [13150.704133] zram0: detected capacity change from 0 to 5131976704
>> [13150.715960] zram: Decompression failed! err=-1, page=0
>> [13150.716008] zram: Decompression failed! err=-1, page=0
>> [13150.716027] zram: Decompression failed! err=-1, page=0
>> [13150.716032] Buffer I/O error on dev zram0, logical block 0, async page read
>>
>> I believe Eunbong Song wrote a patch [1] to fix this (or a very
>> identical) bug on MIPS, but it never got merged (maybe
>> incorrect/incomplete?). Is there any hope of seeing this bug fixed?
>>
>>
>> Thanks,
>>
>> Rui Salvaterra
>>
>>
>> [1] http://comments.gmane.org/gmane.linux.kernel/1752745
>
> For some reason it never got merged, sorry, I don't remember why.
>
> Have you tested this patch? If so, can you resend it with your
> tested-by: line added to it?
>
> thanks,
>
> greg k-h

Hi, Greg


No, I haven't tested the patch at all. I want to do so, and fix if if
necessary, but I still need to learn how to (meaning, I need to watch
your "first kernel patch" presentation again). I'd love to get
involved in kernel development, and this seems to be a good
opportunity, if none of the kernel gods beat me to it (I may need a
month, but then again nobody complained about this bug in almost two
years).


Thanks,

Rui