All nodemaps on MDS fileset will be cleared when do these operations. (nodemap_add/nodemap_del, nodemap_activate, nodemap_add_range/nodemap_del_range ,nodemap_add_idmap/nodemap_del_idmap)

But the  admin_nodemap will not be cleared in the same case.

Test steps,

Step1. ON MGS NODE:
lctl nodemap_add user1
lctl set_param -P nodemap.user1.admin_nodemap=1

sleep 10

lctl set_param -P nodemap.user1.fileset=/user1

Step2. ON MDS NODE:
lctl get_param nodemap.user1.*
...
nodemap.user1.admin_nodemap=1
nodemap.user1.fileset=/user1
..

Step3.ON MGS NODE:
lctl nodemap_add user2

//check user1 nodemap is normal in MGS
lctl get_param nodemap.user1.*
...
nodemap.user1.admin_nodemap=1
nodemap.user1.fileset=/user1
...

Step4.ON MDS NODE:
lctl get_param nodemap.user1.*
...
nodemap.user1.admin_nodemap=1
nodemap.user1.fileset=           //fileset missing
...