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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	opera-
       tion 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.

FreeBSD	14.3		       January 18, 2016			       VREF(9)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=vref&sektion=9&manpath=FreeBSD+14.3-RELEASE+and+Ports>

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