ACFS mounting read-only

I have a problem with my ACFS file systems being unwriteable. This is 12.1.0.2 on OEL6.6. Here is an example:

[oracle@madrid1 ~]$

[oracle@madrid1 ~]$ sqlplus / as sysasm

SQL*Plus: Release 12.1.0.2.0 Production on Wed Feb 3 09:49:08 2016

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to:

Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production

With the Real Application Clusters and Automatic Storage Management options

+ASM1> select group_number,name,state from v$asm_diskgroup;

GROUP_NUMBER NAME                           STATE

------------ ------------------------------ -----------

           2 G2                             MOUNTED

           1 CWFILES                        MOUNTED

           3 G3                             MOUNTED

+ASM1> alter diskgroup g2 add volume src size 4200m;

Diskgroup altered.

+ASM1> select group_number,volume_name,state from v$asm_volume;