xref: /netbsd-src/sys/kern/subr_disk_open.c (revision 0953dc8744b62dfdecb2f203329e730593755659)
1 /*	$NetBSD: subr_disk_open.c,v 1.7 2012/04/07 05:38:07 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: subr_disk_open.c,v 1.7 2012/04/07 05:38:07 christos Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/conf.h>
34 #include <sys/device.h>
35 #include <sys/disk.h>
36 #include <sys/disklabel.h>
37 #include <sys/fcntl.h>
38 #include <sys/kauth.h>
39 #include <sys/vnode.h>
40 #include <miscfs/specfs/specdev.h>
41 
42 struct vnode *
43 opendisk(struct device *dv)
44 {
45 	int bmajor, bminor;
46 	struct vnode *tmpvn;
47 	int error;
48 	dev_t dev;
49 
50 	/*
51 	 * Lookup major number for disk block device.
52 	 */
53 	bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
54 	if (bmajor == -1)
55 		return NULL;
56 
57 	bminor = minor(device_unit(dv));
58 	/*
59 	 * Fake a temporary vnode for the disk, open it, and read
60 	 * and hash the sectors.
61 	 */
62 	dev = device_is_a(dv, "dk") ? makedev(bmajor, bminor) :
63 	    MAKEDISKDEV(bmajor, bminor, RAW_PART);
64 	if (bdevvp(dev, &tmpvn))
65 		panic("%s: can't alloc vnode for %s", __func__,
66 		    device_xname(dv));
67 	error = VOP_OPEN(tmpvn, FREAD | FSILENT, NOCRED);
68 	if (error) {
69 		/*
70 		 * Ignore errors caused by missing device, partition,
71 		 * medium, or busy [presumably because of a wedge covering it]
72 		 */
73 		switch (error) {
74 		case ENXIO:
75 		case ENODEV:
76 		case EBUSY:
77 			break;
78 		default:
79 			printf("%s: can't open dev %s (%d)\n",
80 			    __func__, device_xname(dv), error);
81 			break;
82 		}
83 		vput(tmpvn);
84 		return NULL;
85 	}
86 
87 	return tmpvn;
88 }
89 
90 int
91 getdisksize(struct vnode *vp, uint64_t *numsecp, unsigned *secsizep)
92 {
93 	struct partinfo dpart;
94 	struct dkwedge_info dkw;
95 	struct disk *pdk;
96 	int error;
97 
98 	error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED);
99 	if (error == 0) {
100 		*secsizep = dpart.disklab->d_secsize;
101 		*numsecp  = dpart.part->p_size;
102 		return 0;
103 	}
104 
105 	error = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD, NOCRED);
106 	if (error == 0) {
107 		pdk = disk_find(dkw.dkw_parent);
108 		if (pdk != NULL) {
109 			*secsizep = DEV_BSIZE << pdk->dk_blkshift;
110 			*numsecp  = dkw.dkw_size;
111 		} else
112 			error = ENODEV;
113 	}
114 
115 	return error;
116 }
117 
118 int
119 getdiskinfo(struct vnode *vp, struct dkwedge_info *dkw)
120 {
121 	struct partinfo dpart;
122 	int error;
123 	dev_t dev = vp->v_specnode->sn_rdev;
124 
125 	if (VOP_IOCTL(vp, DIOCGWEDGEINFO, dkw, FREAD, NOCRED) == 0)
126 		return 0;
127 
128 	if ((error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED)) != 0)
129 		return error;
130 
131 	snprintf(dkw->dkw_devname, sizeof(dkw->dkw_devname), "%s%" PRId32 "%c",
132 	    devsw_blk2name(major(dev)), DISKUNIT(dev), (char)DISKPART(dev) +
133 	    'a');
134 
135 	dkw->dkw_wname[0] = '\0';
136 
137 	strlcpy(dkw->dkw_parent, dkw->dkw_devname, sizeof(dkw->dkw_parent));
138 
139 	dkw->dkw_size = dpart.part->p_size;
140 	dkw->dkw_offset = dpart.part->p_offset;
141 
142 	strlcpy(dkw->dkw_ptype, getfstypename(dpart.part->p_fstype),
143 	    sizeof(dkw->dkw_ptype));
144 
145 	return 0;
146 }
147