Re: btrfs development - question about crypto api integration

[Nikolay Borisov <nborisov@suse.com>]

On 30.11.18 г. 17:22 ч., Chris Mason wrote:
> On 29 Nov 2018, at 12:37, Nikolay Borisov wrote:
> 
>> On 29.11.18 г. 18:43 ч., Jean Fobe wrote:
>>> Hi all,
>>>     I've been studying LZ4 and other compression algorithms on the
>>> kernel, and seen other projects such as zram and ubifs using the
>>> crypto api. Is there a technical reason for not using the crypto api
>>> for compression (and possibly for encryption) in btrfs?
>>>     I did not find any design/technical implementation choices in
>>> btrfs development in the developer's FAQ on the wiki. If I completely
>>> missed it, could someone point me in the right direction?
>>>     Lastly, if there is no technical reason for this, would it be
>>> something interesting to have implemented?
>>
>> I personally think it would be better if btrfs' exploited the generic
>> framework. And in fact when you look at zstd, btrfs does use the
>> generic, low-level ZSTD routines but not the crypto library wrappers. 
>> If
>> I were I'd try and convert zstd (since it's the most recently added
>> algorithm) to using the crypto layer to see if there are any lurking
>> problems.
> 
> Back when I first added the zlib support, the zlib API was both easier 
> to use and a better fit for our async worker threads.  That doesn't mean 
> we shouldn't switch, it's just how we got to step one ;)

And what about zstd? WHy is it also using the low level api and not the
crypto wrappers?

> 
> -chris
>