Filesystems on snapshot volumes are not exported as different NFS volumes

Issue

• Filesystems on snapshot volumes are not exported as different NFS volumes.

# lvs testvg
  LV       VG     Attr       LSize  Pool     Origin Data%  Meta%  Move Log Cpy%Sync Convert
  snap1    testvg swi-aos---  8.00m          testlv 0.93                                   
  snap2    testvg swi-aos---  8.00m          testlv 0.54                                   
  testlv   testvg owi-aotz-- 12.00m thinpool        13.54                                  
  thinpool testvg twi-aotz-- 52.00m                 3.12   0.98                            

# cat /proc/mounts | grep testvg-snap1
/dev/mapper/testvg-snap1 /mnt/snap1 ext4 rw,seclabel,relatime,stripe=64,data=ordered 0 0
# ls /mnt/snap1
file-snap1  file-testlv  lost+found

# cat /proc/mounts | grep testvg-snap2
/dev/mapper/testvg-snap2 /mnt/snap2 ext4 rw,seclabel,relatime,stripe=64,data=ordered 0 0
# ls /mnt/snap2
file-snap2  file-testlv  lost+found

# cat /etc/exports
/mnt/snap1 *(no_root_squash)
/mnt/snap2 *(no_root_squash) 

# mount localhost:/mnt/snap1 /mnt/nfs/snap1
# ls /mnt/nfs/snap1
file-snap1  file-testlv  lost+found

# mount localhost:/mnt/snap2 /mnt/nfs/snap2 
# ls /mnt/nfs/snap2
file-snap1  file-testlv  lost+found