freebsd man page for count_dev

VCOUNT(9)						   BSD Kernel Developer's Manual						 VCOUNT(9)

NAME
     vcount, count_dev -- get total number of references to a device

SYNOPSIS
     #include <sys/param.h>
     #include <sys/time.h>
     #include <sys/conf.h>
     #include <sys/vnode.h>

     int
     vcount(struct vnode *vp);

     int
     count_dev(struct cdev *dev);

DESCRIPTION
     vcount() is used to get the number of references to a particular device.  It allows for the fact that multiple vnodes may reference the same
     device.  count_dev() does the same thing as vcount(), but takes a struct cdev rather than a struct vnode pointer as an argument.

RETURN VALUES
     vcount() and count_dev() both return the number of references to the device.

SEE ALSO
     VFS(9), vnode(9)

AUTHORS
     This manual page was written by Andrew Stevenson.

BSD
								 January 19, 2012							       BSD