Hi,

It seems more fixes are needed.

when compare btrfs subvol with xfs crossmnt, we found out
a new feature difference.

/mnt/test		xfs
/mnt/text/xfs2	 another xfs(crossmnt)
nfsd4_encode_dirent_fattr() report "/mnt/test/xfs2" + "/";


but 
/mnt/test		btrfs
/mnt/test/sub1	 btrfs subvol
nfsd4_encode_dirent_fattr() report "/mnt/test/" + "sub1";

for '/mnt/test/sub1',  nfsd should treat the mountpoint as
'/mn/test/sub1', rather than '/mnt/test'?

I'm sorry that yet no patch is avaliable, kernel source is quite
difficult for me.

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2021/06/20