Annotation of sys/miscfs/specfs/spec_subr.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: spec_subr.c,v 1.2 2006/06/02 20:49:08 pedro Exp $ */
2:
3: /*
4: * Copyright (c) 2006 Pedro Martelletto <pedro@openbsd.org>
5: * Copyright (c) 2006 Thordur Bjornsson <thib@openbsd.org>
6: *
7: * Permission to use, copy, modify, and distribute this software for any
8: * purpose with or without fee is hereby granted, provided that the above
9: * copyright notice and this permission notice appear in all copies.
10: *
11: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18: */
19:
20: #include <sys/param.h>
21: #include <sys/vnode.h>
22: #include <sys/malloc.h>
23: #include <sys/conf.h>
24: #include <sys/stat.h>
25:
26: #include <miscfs/specfs/specdev.h>
27:
28: int
29: spec_open_clone(struct vop_open_args *ap)
30: {
31: struct vnode *cvp, *vp = ap->a_vp;
32: struct cloneinfo *cip;
33: int error, i;
34:
35: for (i = 1; i < sizeof(vp->v_specbitmap) * NBBY; i++)
36: if (isclr(vp->v_specbitmap, i)) {
37: setbit(vp->v_specbitmap, i);
38: break;
39: }
40:
41: if (i == sizeof(vp->v_specbitmap) * NBBY)
42: return (EBUSY); /* too many open instances */
43:
44: printf("spec_open_clone(): cloning device (%d, %d) for pid %u\n",
45: major(vp->v_rdev), minor(vp->v_rdev), curproc->p_pid);
46:
47: error = cdevvp(makedev(major(vp->v_rdev), i), &cvp);
48: if (error)
49: return (error); /* out of vnodes */
50:
51: VOP_UNLOCK(vp, 0, ap->a_p);
52:
53: error = cdevsw[major(vp->v_rdev)].d_open(cvp->v_rdev, ap->a_mode,
54: S_IFCHR, ap->a_p);
55:
56: vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
57:
58: if (error) {
59: clrbit(vp->v_specbitmap, i);
60: return (error); /* device open failed */
61: }
62:
63: cip = malloc(sizeof(struct cloneinfo), M_TEMP, M_WAITOK);
64: cip->ci_data = vp->v_data;
65: cip->ci_vp = cvp;
66:
67: cvp->v_specparent = vp;
68: vp->v_flag |= VCLONED;
69: vp->v_data = cip;
70:
71: printf("spec_open_clone(): new minor for cloned device is %d\n",
72: minor(cvp->v_rdev));
73:
74: return (0); /* device cloned */
75: }
76:
77: int
78: spec_close_clone(struct vop_close_args *ap)
79: {
80: struct vnode *pvp, *vp = ap->a_vp;
81: int error;
82:
83: error = cdevsw[major(vp->v_rdev)].d_close(vp->v_rdev, ap->a_fflag,
84: S_IFCHR, ap->a_p);
85: if (error)
86: return (error); /* device close failed */
87:
88: pvp = vp->v_specparent; /* get parent device */
89: clrbit(pvp->v_specbitmap, minor(vp->v_rdev));
90:
91: printf("spec_close_clone(): freeing minor %d of dev %d for"
92: " pid %u\n", minor(vp->v_rdev), major(vp->v_rdev), curproc->p_pid);
93:
94: return (0); /* clone closed */
95: }
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