1 /* $NetBSD: subr_disk_open.c,v 1.15 2020/02/29 14:44:44 mlelstv 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 1.15 2020/02/29 14:44:44 mlelstv 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 *
opendisk(device_t dv)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 vn_lock(tmpvn, LK_EXCLUSIVE | LK_RETRY);
69 error = VOP_OPEN(tmpvn, FREAD | FSILENT, NOCRED);
70 if (error) {
71 /*
72 * Ignore errors caused by missing device, partition,
73 * medium, or busy [presumably because of a wedge covering it]
74 */
75 switch (error) {
76 case ENXIO:
77 case ENODEV:
78 case EBUSY:
79 break;
80 default:
81 printf("%s: can't open dev %s (%d)\n",
82 __func__, device_xname(dv), error);
83 break;
84 }
85 vput(tmpvn);
86 return NULL;
87 }
88
89 return tmpvn;
90 }
91
92 int
getdisksize(struct vnode * vp,uint64_t * numsecp,unsigned int * secsizep)93 getdisksize(struct vnode *vp, uint64_t *numsecp, unsigned int *secsizep)
94 {
95 struct partinfo pi;
96 struct dkwedge_info dkw;
97 struct disk *pdk;
98 unsigned int secsize;
99 uint64_t numsec;
100 int error;
101
102 /*
103 * We attempt to get the wedge information first if it exists,
104 * because the label does not support larger size disks.
105 */
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 if (error) {
117 error = VOP_IOCTL(vp, DIOCGPARTINFO, &pi, FREAD, NOCRED);
118 if (error == 0) {
119 secsize = pi.pi_secsize;
120 numsec = pi.pi_size;
121 }
122 }
123
124 if (error == 0 &&
125 (secsize == 0 || secsize > MAXBSIZE || !powerof2(secsize) ||
126 numsec == 0)) {
127 #ifdef DIAGNOSTIC
128 printf("%s: %s returns invalid disksize values"
129 " (secsize = %u, numsec = %" PRIu64 ")\n",
130 __func__,
131 devsw_blk2name(major(vp->v_specnode->sn_rdev)),
132 secsize, numsec);
133 #endif
134 error = EINVAL;
135 }
136 if (error == 0) {
137 *secsizep = secsize;
138 *numsecp = numsec;
139 }
140
141 return error;
142 }
143
144 int
getdiskinfo(struct vnode * vp,struct dkwedge_info * dkw)145 getdiskinfo(struct vnode *vp, struct dkwedge_info *dkw)
146 {
147 struct partinfo pi;
148 int error;
149 dev_t dev = vp->v_specnode->sn_rdev;
150
151 if (VOP_IOCTL(vp, DIOCGWEDGEINFO, dkw, FREAD, NOCRED) == 0)
152 return 0;
153
154 if ((error = VOP_IOCTL(vp, DIOCGPARTINFO, &pi, FREAD, NOCRED)) != 0)
155 return error;
156
157 snprintf(dkw->dkw_devname, sizeof(dkw->dkw_devname), "%s%" PRId32 "%c",
158 devsw_blk2name(major(dev)), DISKUNIT(dev), (char)DISKPART(dev) +
159 'a');
160
161 dkw->dkw_wname[0] = '\0';
162
163 snprintf(dkw->dkw_parent, sizeof(dkw->dkw_parent), "%s%" PRId32,
164 devsw_blk2name(major(dev)), DISKUNIT(dev));
165
166 dkw->dkw_size = pi.pi_size;
167 dkw->dkw_offset = pi.pi_offset;
168 strlcpy(dkw->dkw_ptype, getfstypename(pi.pi_fstype),
169 sizeof(dkw->dkw_ptype));
170
171 return 0;
172 }
173