libdisk/lvm.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 <errno.h>
  35 #include <stdlib.h>
  36 #include <unistd.h>
  37 #include <string.h>
  38 #include <sys/stat.h>
  39 #include <sys/types.h>
  40 #include <linux/major.h>
  41 #include <volume.h>
  42
  43 int
  44 mnt_is_lvm_subvol(dev_t dev)
  45 {
  46         if (dev >> 8 == LVM_BLK_MAJOR)
  47                 return 1;
  48         return 0;
  49 }
  50
  51 int
  52 lvm_get_subvol_stripe(
  53         char            *dfile,
  54         sv_type_t       type,
  55         int             *sunit,
  56         int             *swidth,
  57         struct stat64   *sb)
  58 {
  59         int             lvpipe[2], stripes = 0, stripesize = 0;
  60         char            *largv[3], buf[1024];
  61         FILE            *stream;
  62
  63         if (!mnt_is_lvm_subvol(sb->st_rdev))
  64                 return 0;
  65
  66         /* Quest for lvdisplay */
  67         if (!access("/usr/local/sbin/lvdisplay", R_OK|X_OK))
  68                 largv[0] = "/usr/local/sbin/lvdisplay";
  69         else if (!access("/usr/sbin/lvdisplay", R_OK|X_OK))
  70                 largv[0] = "/usr/sbin/lvdisplay";
  71         else if (!access("/sbin/lvdisplay", R_OK|X_OK))
  72                 largv[0] = "/sbin/lvdisplay";
  73         else {
  74                 fprintf(stderr,
  75                         "Warning - LVM device, but no lvdisplay(8) found\n");
  76                 return 0;
  77         }
  78
  79         largv[1] = dfile;
  80         largv[2] = NULL;
  81
  82         /* Open pipe */
  83         if (pipe(lvpipe) < 0) {
  84                 fprintf(stderr, "Could not open pipe\n");
  85                 exit(1);
  86         }
  87
  88         /* Spawn lvdisplay */
  89         switch (fork()) {
  90         case 0:
  91                 /* Plumbing */
  92                 close(lvpipe[0]);
  93
  94                 if (lvpipe[1] != STDOUT_FILENO)
  95                         dup2(lvpipe[1], STDOUT_FILENO);
  96
  97                 execv(largv[0], largv);
  98
  99                 fprintf(stderr, "\nFailed to execute %s\n", largv[0]);
 100                 exit(1);
 101
 102         case -1:
 103                 fprintf(stderr, "Failed forking lvdisplay process\n");
 104                 exit(1);
 105
 106         default:
 107                 break;
 108         }
 109
 110         close(lvpipe[1]);
 111         stream = fdopen(lvpipe[0], "r");
 112
 113         /* Scan stream for keywords */
 114         while (fgets(buf, 1023, stream) != NULL) {
 115
 116                 if (!strncmp(buf, "Stripes", 7))
 117                         sscanf(buf, "Stripes %d", &stripes);
 118
 119                 if (!strncmp(buf, "Stripe size", 11))
 120                         sscanf(buf, "Stripe size (KByte) %d", &stripesize);
 121         }
 122
 123         /* Update sizes */
 124         *sunit = stripesize << 1;
 125         *swidth = (stripes * stripesize) << 1;
 126
 127         fclose(stream);
 128
 129         return 1;
 130 }