88
/*
* Flush operation. This can be used to invalidate:
* 1) name cache for one node
* 2) name cache for all children
* 3) name cache for the entire mount
* 4) page cache for a set of ranges in one node
* 5) page cache for one entire node
*
* It can be used to flush:
* 1) page cache for a set of ranges in one node
* 2) page cache for one entire node
*/