/*
* vget: get a particular vnode from the free list, increment its reference
* count and return it.
*
* => Must be called with v_interlock held.
*
* If state is VS_RECLAIMING, the vnode may be eliminated in vcache_reclaim().
* In that case, we cannot grab the vnode, so the process is awakened when
* the transition is completed, and an error returned to indicate that the
* vnode is no longer usable.
*
* If state is VS_LOADING or VS_BLOCKED, wait until the vnode enters a
* stable state (VS_ACTIVE or VS_RECLAIMED).
*/