SVCPLAN-2782: Support no_gpfs/no_lustre block files during maintenance

[billglick]

Add maintenance postscripts that allow us to support service block files like the following:

• /root/no_gpfs
• /root/no_lustre

This is being tested on mg-adm01 & mgtest05.

[jlong1s]

Functionally, everything looks good.

I was wondering about whether or not we wanted to allow a list of lock_files to be passed to the maintenance_begin script. However, that might open us up to typo errors when setting up for maintenance. Hard coding the lock_files as it is now is probably the better way to go. Then we can just throw an exit at the top of the script when maintenance is completed to force a NO-OP. That would be less prone to mistakes. I think I like things they way they are currently written.

[billglick]

Would we want to add/remove /etc/nologin by default?

Or any other similar files?

[billglick]

To answer a few issues/questions brought up in comments:

• We updated maintenance_end to support multiple files/globs. These are supplied as a space separated parameter (2nd field), e.g. maintenance_end 30 "/root/no_* /etc/no_gpfs" 0
• We opted to not add /etc/nologin to the default block files to check for in maintenance_end. There are multiple use cases where we would not want to let users login yet at the point that maintenance_end would run.