focal (9) VREF.9freebsd.gz

NAME

     vref, vrefl — increment the use count for a vnode

SYNOPSIS

     #include <sys/param.h>
     #include <sys/vnode.h>

     void
     vref(struct vnode *vp);

     void
     vrefl(struct vnode *vp);

DESCRIPTION

     Increment the v_usecount field of a vnode.

     vp  the vnode to increment

     Each vnode maintains a reference count of how many parts of the system are using the vnode.  This allows
     the system to detect when a vnode is no longer being used and can be safely recycled for a different file.

     Any code in the system which is using a vnode (e.g. during the operation of some algorithm or to store in a
     data structure) should call vref() or vrefl().

     vref() locks the vnode interlock while vrefl() expects the interlock to already be held.

SEE ALSO

     vget(9), vnode(9), vput(9), vrefcnt(9), vrele(9)

AUTHORS

     This manual page was written by Doug Rabson.