cmd/zvol_id/zvol_id_main.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2011, Fajar A. Nugraha.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <linux/ioctl.h>
  31 #include <sys/stat.h>
  32 #include <sys/ioctl.h>
  33 #include <sys/zfs_znode.h>
  34 #include <sys/fs/zfs.h>
  35
  36 int ioctl_get_msg(char *var, int fd)
  37 {
  38         int error = 0;
  39         char msg[ZFS_MAXNAMELEN];
  40
  41         error = ioctl(fd, BLKZNAME, msg);
  42         if (error < 0) {
  43                 printf("ioctl_get_msg failed:%d\n", error);
  44                 return (error);
  45         }
  46
  47         snprintf(var, ZFS_MAXNAMELEN, "%s", msg);
  48         return (error);
  49 }
  50
  51 int main(int argc, char **argv)
  52 {
  53         int fd, error = 0;
  54         char zvol_name[ZFS_MAXNAMELEN], zvol_name_part[ZFS_MAXNAMELEN];
  55         char *dev_name;
  56         struct stat64 statbuf;
  57         int dev_minor, dev_part;
  58
  59         if (argc < 2) {
  60                 printf("Usage: %s /dev/zvol_device_node\n", argv[0]);
  61                 return (EINVAL);
  62         }
  63
  64         dev_name = argv[1];
  65         error = stat64(dev_name, &statbuf);
  66         if (error != 0) {
  67                 printf("Unable to access device file: %s\n", dev_name);
  68                 return (errno);
  69         }
  70
  71         dev_minor = minor(statbuf.st_rdev);
  72         dev_part = dev_minor % ZVOL_MINORS;
  73
  74         fd = open(dev_name, O_RDONLY);
  75         if (fd < 0) {
  76                 printf("Unable to open device file: %s\n", dev_name);
  77                 return (errno);
  78         }
  79
  80         ioctl_get_msg(zvol_name, fd);
  81         if (dev_part > 0)
  82                 snprintf(zvol_name_part, ZFS_MAXNAMELEN, "%s-part%d", zvol_name,
  83                     dev_part);
  84         else
  85                 snprintf(zvol_name_part, ZFS_MAXNAMELEN, "%s", zvol_name);
  86
  87         printf("%s\n", zvol_name_part);
  88         close(fd);
  89         return (error);
  90 }