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Holding a DLM lock protects a range of the key space. The DLM locks span inodes or regions of inodes. We need the sort order in LSM items to match the DLM range keys so that we can read all the items covered by a lock into the cache from a region of LSM segments. If their orders differered then we'd have to jump around segments to find all the items covered by a given DLM lock. Previously we were sorting by type then, within types, by inode. Now we want to sort by inode then by type. But there are structures which previously had a type but weren't then sorted by inode. We introduce zones as the primary sort key. Inode index and node zones are sorted by the inode fields and node ids respectively. Then comes the fs zone first sorted by inode then the type of the key. The bulk of this is the mechanical introduction of the zone field to the keys, moving the type field down, and a bulk rename of _KEY to _TYPE. But there are some more substantial changes. The orphan keys needed to be put in a zone. They fit in the NODE zone which is all about resources that nodes hold and would need to be cleaned up if the node went away. The key formatting is significantly changed to match the new formatting. Formatted keys are now generally of the form "zone.primary.type..." And finally with the keys now properly sorted by inodes we can correctly construct a single range of item cache keys to invalidate when unlocking the inode group locks. Signed-off-by: Zach Brown <zab@versity.com>