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 <ctype.h>
  27 #include <string.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <fcntl.h>
  31 #include <unistd.h>
  32 #include <linux/ioctl.h>
  33 #include <sys/stat.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/zfs_znode.h>
  36 #include <sys/fs/zfs.h>
  37
  38 static int
  39 ioctl_get_msg(char *var, int fd)
  40 {
  41         int error = 0;
  42         char msg[ZFS_MAX_DATASET_NAME_LEN];
  43
  44         error = ioctl(fd, BLKZNAME, msg);
  45         if (error < 0) {
  46                 return (error);
  47         }
  48
  49         snprintf(var, ZFS_MAX_DATASET_NAME_LEN, "%s", msg);
  50         return (error);
  51 }
  52
  53 int
  54 main(int argc, char **argv)
  55 {
  56         int fd, error = 0;
  57         char zvol_name[ZFS_MAX_DATASET_NAME_LEN];
  58         char *zvol_name_part = NULL;
  59         char *dev_name;
  60         struct stat64 statbuf;
  61         int dev_minor, dev_part;
  62         int i;
  63         int rc;
  64
  65         if (argc < 2) {
  66                 printf("Usage: %s /dev/zvol_device_node\n", argv[0]);
  67                 return (EINVAL);
  68         }
  69
  70         dev_name = argv[1];
  71         error = stat64(dev_name, &statbuf);
  72         if (error != 0) {
  73                 printf("Unable to access device file: %s\n", dev_name);
  74                 return (errno);
  75         }
  76
  77         dev_minor = minor(statbuf.st_rdev);
  78         dev_part = dev_minor % ZVOL_MINORS;
  79
  80         fd = open(dev_name, O_RDONLY);
  81         if (fd < 0) {
  82                 printf("Unable to open device file: %s\n", dev_name);
  83                 return (errno);
  84         }
  85
  86         error = ioctl_get_msg(zvol_name, fd);
  87         if (error < 0) {
  88                 printf("ioctl_get_msg failed:%s\n", strerror(errno));
  89                 return (errno);
  90         }
  91         if (dev_part > 0)
  92                 rc = asprintf(&zvol_name_part, "%s-part%d", zvol_name,
  93                     dev_part);
  94         else
  95                 rc = asprintf(&zvol_name_part, "%s", zvol_name);
  96
  97         if (rc == -1 || zvol_name_part == NULL)
  98                 goto error;
  99
 100         for (i = 0; i < strlen(zvol_name_part); i++) {
 101                 if (isblank(zvol_name_part[i]))
 102                         zvol_name_part[i] = '+';
 103         }
 104
 105         printf("%s\n", zvol_name_part);
 106         free(zvol_name_part);
 107 error:
 108         close(fd);
 109         return (error);
 110 }