xref: /netbsd-src/sys/kern/subr_disk_open.c (revision da39824b722dbd84beb9a1ab7e8de6710cc44d4b)
1 /*	$NetBSD: subr_disk_open.c,v 1.11 2012/10/27 17:18:39 chs 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 1.11 2012/10/27 17:18:39 chs 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(device_t dv)
44 {
45 	devmajor_t bmajor;
46 	int unit;
47 	struct vnode *tmpvn;
48 	int error;
49 	dev_t dev;
50 
51 	/*
52 	 * Lookup major number for disk block device.
53 	 */
54 	bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
55 	if (bmajor == -1)
56 		return NULL;
57 
58 	unit = device_unit(dv);
59 	/*
60 	 * Fake a temporary vnode for the disk, open it, and read
61 	 * and hash the sectors.
62 	 */
63 	dev = device_is_a(dv, "dk") ? makedev(bmajor, unit) :
64 	    MAKEDISKDEV(bmajor, unit, RAW_PART);
65 	if (bdevvp(dev, &tmpvn))
66 		panic("%s: can't alloc vnode for %s", __func__,
67 		    device_xname(dv));
68 	error = VOP_OPEN(tmpvn, FREAD | FSILENT, NOCRED);
69 	if (error) {
70 		/*
71 		 * Ignore errors caused by missing device, partition,
72 		 * medium, or busy [presumably because of a wedge covering it]
73 		 */
74 		switch (error) {
75 		case ENXIO:
76 		case ENODEV:
77 		case EBUSY:
78 			break;
79 		default:
80 			printf("%s: can't open dev %s (%d)\n",
81 			    __func__, device_xname(dv), error);
82 			break;
83 		}
84 		vput(tmpvn);
85 		return NULL;
86 	}
87 
88 	return tmpvn;
89 }
90 
91 int
92 getdisksize(struct vnode *vp, uint64_t *numsecp, unsigned int *secsizep)
93 {
94 	struct partinfo dpart;
95 	struct dkwedge_info dkw;
96 	struct disk *pdk;
97 	unsigned int secsize;
98 	uint64_t numsec;
99 	int error;
100 
101 	error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED);
102 	if (error == 0) {
103 		secsize = dpart.disklab->d_secsize;
104 		numsec  = dpart.part->p_size;
105 	} else {
106 		error = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD, NOCRED);
107 		if (error == 0) {
108 			pdk = disk_find(dkw.dkw_parent);
109 			if (pdk != NULL) {
110 				secsize = DEV_BSIZE << pdk->dk_blkshift;
111 				numsec  = dkw.dkw_size;
112 			} else
113 				error = ENODEV;
114 		}
115 	}
116 
117 	if (error == 0 &&
118 	    (secsize == 0 || secsize > MAXBSIZE || !powerof2(secsize) ||
119 	     numsec == 0)) {
120 #ifdef DIAGNOSTIC
121 		printf("%s: %s returns invalid disksize values"
122 		    " (secsize = %u, numsec = %" PRIu64 ")\n",
123 		    __func__,
124 		    devsw_blk2name(major(vp->v_specnode->sn_rdev)),
125 		    secsize, numsec);
126 #endif
127 		error = EINVAL;
128 	}
129 	if (error == 0) {
130 		*secsizep = secsize;
131 		*numsecp  = numsec;
132 	}
133 
134 	return error;
135 }
136 
137 int
138 getdiskinfo(struct vnode *vp, struct dkwedge_info *dkw)
139 {
140 	struct partinfo dpart;
141 	int error;
142 	dev_t dev = vp->v_specnode->sn_rdev;
143 
144 	if (VOP_IOCTL(vp, DIOCGWEDGEINFO, dkw, FREAD, NOCRED) == 0)
145 		return 0;
146 
147 	if ((error = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, NOCRED)) != 0)
148 		return error;
149 
150 	snprintf(dkw->dkw_devname, sizeof(dkw->dkw_devname), "%s%" PRId32 "%c",
151 	    devsw_blk2name(major(dev)), DISKUNIT(dev), (char)DISKPART(dev) +
152 	    'a');
153 
154 	dkw->dkw_wname[0] = '\0';
155 
156 	strlcpy(dkw->dkw_parent, dkw->dkw_devname, sizeof(dkw->dkw_parent));
157 
158 	dkw->dkw_size = dpart.part->p_size;
159 	dkw->dkw_offset = dpart.part->p_offset;
160 
161 	strlcpy(dkw->dkw_ptype, getfstypename(dpart.part->p_fstype),
162 	    sizeof(dkw->dkw_ptype));
163 
164 	return 0;
165 }
166