[PATCH] erofs-utils: add clusterofs zero check to write_uncompressed_extent()

[Gao Xiang]

On Tue, Aug 17, 2021 at 12:06:04PM +0800, Yue Hu wrote:
> From: Yue Hu <huyue2 at yulong.com>
> 
> No need to reset clusterofs to 0 if it's already 0. Acturally, we also
> observed that case frequently. Let's avoid it.
> 
> Signed-off-by: Yue Hu <huyue2 at yulong.com>

Reviewed-by: Gao Xiang <hsiangkao at linux.alibaba.com>

(btw, also, if compression performance is important for some cases, I'd
 suggest if someone could take some time on multi-threaded mkfs...
 That includes:
  - paralleled compression for different files;
  - paralleled segment compression for one file (the basic principle is
    to deal with a file with sub-files with the same segment size, such
    as 16M, like what I described in the following thread:

 https://lore.kernel.org/r/20200705182049.GA20632@hsiangkao-HP-ZHAN-66-Pro-G1

 That may be quite also useful for LZMA compression later.)
Thanks,
Gao Xiang