Provided by: freebsd-manpages_8.2-1_all
vput, vrele, vunref — decrement the use count for a vnode
vput(struct vnode *vp);
vrele(struct vnode *vp);
vunref(struct vnode *vp);
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
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
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. Since the functions might need
to call VOPs for the vnode, the Giant mutex should be conditionally
locked around the call.
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).
vget(9), vnode(9), vref(9), vrefcnt(9)
This manual page was written by Doug Rabson and