1A DT changeset is a method which allows one to apply changes 2in the live tree in such a way that either the full set of changes 3will be applied, or none of them will be. If an error occurs partway 4through applying the changeset, then the tree will be rolled back to the 5previous state. A changeset can also be removed after it has been 6applied. 7 8When a changeset is applied, all of the changes get applied to the tree 9at once before emitting OF_RECONFIG notifiers. This is so that the 10receiver sees a complete and consistent state of the tree when it 11receives the notifier. 12 13The sequence of a changeset is as follows. 14 151. of_changeset_init() - initializes a changeset 16 172. A number of DT tree change calls, of_changeset_attach_node(), 18of_changeset_detach_node(), of_changeset_add_property(), 19of_changeset_remove_property, of_changeset_update_property() to prepare 20a set of changes. No changes to the active tree are made at this point. 21All the change operations are recorded in the of_changeset 'entries' 22list. 23 243. of_changeset_apply() - Apply the changes to the tree. Either the 25entire changeset will get applied, or if there is an error the tree will 26be restored to the previous state. The core ensures proper serialization 27through locking. An unlocked version __of_changeset_apply is available, 28if needed. 29 30If a successfully applied changeset needs to be removed, it can be done 31with of_changeset_revert(). 32