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/* $OpenBSD: spec_subr.c,v 1.4 2008/04/08 14:46:45 thib Exp $ */
/*
* Copyright (c) 2006 Pedro Martelletto <pedro@ambientworks.net>
* Copyright (c) 2006 Thordur Bjornsson <thib@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <miscfs/specfs/specdev.h>
#ifdef CLONE_DEBUG
#define DNPRINTF(m...) do { printf(m); } while (0)
#else
#define DNPRINTF(m...) /* nothing */
#endif
int
spec_open_clone(struct vop_open_args *ap)
{
struct vnode *cvp, *vp = ap->a_vp;
struct cloneinfo *cip;
int error, i;
DNPRINTF("cloning vnode\n");
for (i = 1; i < sizeof(vp->v_specbitmap) * NBBY; i++)
if (isclr(vp->v_specbitmap, i)) {
setbit(vp->v_specbitmap, i);
break;
}
if (i == sizeof(vp->v_specbitmap) * NBBY)
return (EBUSY); /* too many open instances */
error = cdevvp(makedev(major(vp->v_rdev), i), &cvp);
if (error)
return (error); /* out of vnodes */
VOP_UNLOCK(vp, 0, ap->a_p);
error = cdevsw[major(vp->v_rdev)].d_open(cvp->v_rdev, ap->a_mode,
S_IFCHR, ap->a_p);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
if (error) {
clrbit(vp->v_specbitmap, i);
return (error); /* device open failed */
}
cvp->v_flag |= VCLONE;
cip = malloc(sizeof(struct cloneinfo), M_TEMP, M_WAITOK);
cip->ci_data = vp->v_data;
cip->ci_vp = cvp;
cvp->v_specparent = vp;
vp->v_flag |= VCLONED;
vp->v_data = cip;
DNPRINTF("clone of vnode %p is vnode %p\n", vp, cvp);
return (0); /* device cloned */
}
int
spec_close_clone(struct vop_close_args *ap)
{
struct vnode *pvp, *vp = ap->a_vp;
int error;
error = cdevsw[major(vp->v_rdev)].d_close(vp->v_rdev, ap->a_fflag,
S_IFCHR, ap->a_p);
if (error)
return (error); /* device close failed */
pvp = vp->v_specparent; /* get parent device */
clrbit(pvp->v_specbitmap, minor(vp->v_rdev));
vrele(pvp);
return (0); /* clone closed */
}
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