xref: /titanic_41/usr/src/lib/lvm/libmeta/common/meta_admin.c (revision 80ab886d233f514d54c2a6bdeb9fdfd951bd6881)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 
30 /*
31  * miscellaneous utilities
32  */
33 
34 #include <meta.h>
35 #include <zone.h>
36 
37 static	int	meta_fd = -1;
38 static	major_t	meta_major;
39 
40 /*
41  * open administrative device
42  */
43 int
44 open_admin(
45 	md_error_t	*ep
46 )
47 {
48 	struct stat	buf;
49 
50 	/* if not already open */
51 	if (meta_fd < 0) {
52 		ulong_t	dversion = 0;
53 
54 		/* try read/write fall back to readonly */
55 		if ((meta_fd = open(ADMSPECIAL, O_RDWR, 0)) < 0) {
56 			if (errno == ENOENT && getzoneid() != GLOBAL_ZONEID)
57 				return (mderror(ep, MDE_ZONE_ADMIN, NULL));
58 			if (errno != EACCES)
59 				return (mdsyserror(ep, errno, ADMSPECIAL));
60 			if ((meta_fd = open(ADMSPECIAL, O_RDONLY, 0)) < 0)
61 				return (mdsyserror(ep, errno, ADMSPECIAL));
62 		}
63 
64 		/* get major */
65 		if (fstat(meta_fd, &buf) != 0)
66 			return (mdsyserror(ep, errno, ADMSPECIAL));
67 		meta_major = major(buf.st_rdev);
68 
69 		/* check driver version */
70 		if (metaioctl(MD_IOCGVERSION, &dversion, ep, NULL) != 0)
71 			return (-1);
72 		if (dversion != MD_DVERSION)
73 			return (mderror(ep, MDE_DVERSION, NULL));
74 	}
75 
76 	/* return fd */
77 	return (meta_fd);
78 }
79 
80 int
81 close_admin(
82 	md_error_t	*ep
83 )
84 {
85 	if (meta_fd >= 0) {
86 		if (close(meta_fd) == -1)
87 			return (mdsyserror(ep, errno, ADMSPECIAL));
88 		meta_fd = -1;
89 	}
90 
91 	return (0);
92 }
93 
94 /*
95  * Returns True if the md_dev64_t passed in is a metadevice.
96  * Else it returns False.
97  */
98 int
99 meta_dev_ismeta(
100 	md_dev64_t	dev
101 )
102 {
103 	int		fd;
104 	md_error_t	status = mdnullerror;
105 
106 	fd = open_admin(&status);
107 	assert(fd >= 0);
108 	return (meta_getmajor(dev) == meta_major);
109 }
110 
111 
112 int
113 meta_get_nunits(md_error_t *ep)
114 {
115 
116 	static set_t		max_nunits = 0;
117 
118 	if (max_nunits == 0)
119 		if (metaioctl(MD_IOCGETNUNITS, &max_nunits, ep, NULL) != 0)
120 			return (-1);
121 
122 	return (max_nunits);
123 }
124 
125 md_dev64_t
126 metamakedev(minor_t mnum)
127 {
128 	int		fd;
129 	md_error_t	status = mdnullerror;
130 
131 	fd = open_admin(&status);
132 
133 	assert(fd >= 0);
134 
135 	return (((md_dev64_t)meta_major << NBITSMINOR64) | mnum);
136 }
137