jenkinsci/jenkins — comment on commit e38e687d5b66238f406d1e3642a3d5f6a02aaeb2
File: core/src/main/java/hudson/node_monitors/AbstractDiskSpaceMonitor.java line 49
By kohsuke:

This is problematic. Slaves can be marked temporarily offline for a number of reasons, such as administrator manually making it offline, or from other NodeMonitors.

To correctly do this, we need to remember a set of causes for blockage and only when all of them are removed bring it back online.

I'm rolling back this change for now.