NAME
vput
, vrele
,
vunref
—
decrement the use count for a
vnode
SYNOPSIS
#include
<sys/param.h>
#include <sys/vnode.h>
void
vput
(struct
vnode *vp);
void
vrele
(struct
vnode *vp);
void
vunref
(struct
vnode *vp);
DESCRIPTION
Decrement the v_usecount field of a vnode.- vp
- the vnode to decrement
The
vrele
()
function takes an unlocked vnode and returns with the vnode unlocked.
The
vput
()
function should be given a locked vnode as argument, the vnode is unlocked
after the function returned. The vput
() is
operationally equivalent to calling
VOP_UNLOCK(9) followed by
vrele(9), with less overhead.
The
vunref
()
function takes a locked vnode as argument, and returns with the vnode
locked.
Any code in the system which signified its use of a vnode by usecount should call one of the listed function to decrement use counter. If the v_usecount field of the non-doomed vnode reaches zero, then it will be inactivated and placed on the free list.
The
vrele
()
function may lock the vnode. All three functions may sleep.
The hold count for the vnode is always greater or equal to the usecount. Non-forced unmount fails when mount point owns a vnode that has non-zero usecount, see vflush(9).
SEE ALSO
AUTHORS
This manual page was written by Doug
Rabson and
Konstantin Belousov.