vdrop9
Acquire/release a hold on a vnode
Part of vhold(9).
Usage
#include <sys/param.h>
#include <sys/vnode.h>
void
vhold(struct vnode *vp);
void
vholdl(struct vnode *vp);
void
vdrop(struct vnode *vp);
void
vdropl(struct vnode *vp);
Overview
The vhold() and vholdl() functions increment the v_holdcnt of the given vnode. If the vnode has already been added to the free list and is still referenced, it will be removed.
The vdrop() and vdropl() functions decrement the v_holdcnt of the vnode. If the holdcount is less than or equal to zero prior to calling vdrop() or vdropl(), the system will panic. If the vnode is no longer referenced, it will be freed.
vhold() and vdrop() lock the vnode interlock while vholdl() and vdropl() expect the interlock to already be held.
Releases
56 releases since FreeBSD 5.0-RELEASE; the text changed 33 times.