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VREF(9) 		    Kernel Developer's Manual			 VREF(9)

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 al-
     ready be held.

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

AUTHORS
     This manual page was written by Doug Rabson.

FreeBSD ports 15.quarterly	January 18, 2016			 VREF(9)

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