libdisk/xvm.c

   1 /*
   2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32
  33 #include <stdio.h>
  34 #include <fcntl.h>
  35 #include <unistd.h>
  36 #include <sys/stat.h>
  37 #include <sys/ioctl.h>
  38 #include <volume.h>
  39 #include "xvm.h"
  40
  41 int
  42 mnt_is_xvm_subvol(dev_t dev)
  43 {
  44         if (major(dev) == get_driver_block_major("xvm"))
  45                 return 1;
  46         return 0;
  47 }
  48
  49 /*
  50  * If the logical device is a xvm striped volume, then it returns the
  51  * stripe unit and stripe width information.
  52  * Input parameters:    the logical volume
  53  *                      the subvolume type - (SVTYPE_RT or
  54  *                                            SVTYPE_DATA)
  55  * Output parameters:   the stripe unit and width in 512 byte blocks
  56  *                      true/false - was this device an XVM volume?
  57  */
  58 int
  59 xvm_get_subvol_stripe(
  60         char            *dev,
  61         sv_type_t       type,
  62         int             *sunit,
  63         int             *swidth,
  64         struct stat64   *sb)
  65 {
  66         int fd;
  67         xvm_getdev_t getdev;
  68         xvm_subvol_stripe_t subvol_stripe;
  69
  70         if (!mnt_is_xvm_subvol(sb->st_rdev))
  71                 return 0;
  72
  73         /*
  74          * This will actually open the data subvolume.
  75          */
  76         if ((fd = open(dev, O_RDONLY)) < 0)
  77                 return 0;
  78
  79         /*
  80          * Go and get the the information for the correct
  81          * subvolume.
  82          */
  83         if (ioctl(fd, DIOCGETVOLDEV, &getdev) < 0) {
  84                 close(fd);
  85                 return 0;
  86         }
  87         if ( (type == SVTYPE_RT) && (getdev.rt_subvol_dev) )
  88                 subvol_stripe.dev = getdev.rt_subvol_dev;
  89         else if ( (type == SVTYPE_DATA) && (getdev.data_subvol_dev) )
  90                 subvol_stripe.dev = getdev.data_subvol_dev;
  91         else {
  92                 close(fd);
  93                 return 0;
  94         }
  95
  96         if (ioctl(fd, DIOCGETVOLSTRIPE, &subvol_stripe) < 0) {
  97                 close(fd);
  98                 return 0;
  99         }
 100
 101         *sunit = subvol_stripe.unit_size;
 102         *swidth = *sunit * subvol_stripe.width_size;
 103         close(fd);
 104         return 1;
 105 }