usr/src/lib/lvm/libmeta/common/meta_admin.c

   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 }