[PATCH] erofs-utils: add preliminary zstd support

[Gao Xiang]

On 2024/5/9 17:53, Yifan Zhao wrote:
> Hi Gao,
> 
> I found this zstd implementation failed in my smoking test[1] with -Eall-fragments and -Eztailpacking enabled. You could reproduce it with enwik8 workload.
> 
> After a galance I notice that libzstd_compress_destsize() may return a value larger than `dstsize`. I mark it in the code below.

That is expected.

> 
> I believe this will break the assumption in its caller and lead to broken image.
> 
> However I'm not an expert of zstd algorithms, could you please take a look at it?
> 
> 
> [1] https://github.com/SToPire/erofsnightly/actions/runs/9004052391
> 

I will look into that, thanks!

Thanks,
Gao Xiang