[PATCH v2 resend] erofs: make filesystem exportable

[Chao Yu]

On 2022/4/25 12:07, Hongnan Li wrote:
> Implement export operations in order to make EROFS support accessing
> inodes with filehandles so that it can be exported via NFS and used
> by overlayfs.
> 
> Without this patch, 'exportfs -rv' will report:
> exportfs: /root/erofs_mp does not support NFS export
> 
> Also tested with unionmount-testsuite and the testcase below passes now:
> ./run --ov --erofs --verify hard-link
> 
> For more details about the testcase, see:
> https://github.com/amir73il/unionmount-testsuite/pull/6
> 
> Signed-off-by: Hongnan Li <hongnan.li at linux.alibaba.com>

Reviewed-by: Chao Yu <chao at kernel.org>

Thanks,