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                 return (error);
  44         }
  45
  46         snprintf(var, ZFS_MAXNAMELEN, "%s", msg);
  47         return (error);
  48 }
  49
  50 int main(int argc, char **argv)
  51 {
  52         int fd, error = 0;
  53         char zvol_name[ZFS_MAXNAMELEN], zvol_name_part[ZFS_MAXNAMELEN];
  54         char *dev_name;
  55         struct stat64 statbuf;
  56         int dev_minor, dev_part;
  57
  58         if (argc < 2) {
  59                 printf("Usage: %s /dev/zvol_device_node\n", argv[0]);
  60                 return (EINVAL);
  61         }
  62
  63         dev_name = argv[1];
  64         error = stat64(dev_name, &statbuf);
  65         if (error != 0) {
  66                 printf("Unable to access device file: %s\n", dev_name);
  67                 return (errno);
  68         }
  69
  70         dev_minor = minor(statbuf.st_rdev);
  71         dev_part = dev_minor % ZVOL_MINORS;
  72
  73         fd = open(dev_name, O_RDONLY);
  74         if (fd < 0) {
  75                 printf("Unable to open device file: %s\n", dev_name);
  76                 return (errno);
  77         }
  78
  79         error = ioctl_get_msg(zvol_name, fd);
  80         if (error < 0) {
  81                 printf("ioctl_get_msg failed:%s\n", strerror(errno));
  82                 return (errno);
  83         }
  84         if (dev_part > 0)
  85                 snprintf(zvol_name_part, ZFS_MAXNAMELEN, "%s-part%d", zvol_name,
  86                     dev_part);
  87         else
  88                 snprintf(zvol_name_part, ZFS_MAXNAMELEN, "%s", zvol_name);
  89
  90         printf("%s\n", zvol_name_part);
  91         close(fd);
  92         return (error);
  93 }