libdisk/xvm.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18
  19 #include <stdio.h>
  20 #include <fcntl.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <sys/stat.h>
  24 #include <sys/ioctl.h>
  25 #include <disk/volume.h>
  26 #include "xvm.h"
  27
  28 int
  29 mnt_is_xvm_subvol(
  30         dev_t           dev)
  31 {
  32         return get_driver_block_major("xvm", major(dev));
  33 }
  34
  35 /*
  36  * If the logical device is a xvm striped volume, then it returns the
  37  * stripe unit and stripe width information.
  38  * Input parameters:    the logical volume
  39  *                      the subvolume type - (SVTYPE_RT or
  40  *                                            SVTYPE_DATA)
  41  * Output parameters:   the stripe unit and width in 512 byte blocks
  42  *                      true/false - was this device an XVM volume?
  43  */
  44 int
  45 xvm_get_subvol_stripe(
  46         char            *dev,
  47         sv_type_t       type,
  48         int             *sunit,
  49         int             *swidth,
  50         int             *sectalign,
  51         struct stat64   *sb)
  52 {
  53         int fd;
  54         xvm_getdev_t getdev;
  55         xvm_subvol_stripe_t subvol_stripe;
  56
  57         if (!mnt_is_xvm_subvol(sb->st_rdev))
  58                 return 0;
  59
  60         /*
  61          * This will actually open the data subvolume.
  62          */
  63         if ((fd = open(dev, O_RDONLY)) < 0)
  64                 return 0;
  65
  66         /*
  67          * Go and get the the information for the correct
  68          * subvolume.
  69          */
  70         if (ioctl(fd, DIOCGETVOLDEV, &getdev) < 0) {
  71                 close(fd);
  72                 return 0;
  73         }
  74         if ( (type == SVTYPE_RT) && (getdev.rt_subvol_dev) )
  75                 subvol_stripe.dev = getdev.rt_subvol_dev;
  76         else if ( (type == SVTYPE_DATA) && (getdev.data_subvol_dev) )
  77                 subvol_stripe.dev = getdev.data_subvol_dev;
  78         else {
  79                 close(fd);
  80                 return 0;
  81         }
  82
  83         if (ioctl(fd, DIOCGETVOLSTRIPE, &subvol_stripe) < 0) {
  84                 close(fd);
  85                 return 0;
  86         }
  87
  88         *sunit = subvol_stripe.unit_size;
  89         *swidth = *sunit * subvol_stripe.width_size;
  90         *sectalign = 0;
  91         close(fd);
  92         return 1;
  93 }