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 ret;
  42         char msg[ZFS_MAX_DATASET_NAME_LEN];
  43
  44         ret = ioctl(fd, BLKZNAME, msg);
  45         if (ret < 0) {
  46                 return (ret);
  47         }
  48
  49         snprintf(var, ZFS_MAX_DATASET_NAME_LEN, "%s", msg);
  50         return (ret);
  51 }
  52
  53 int
  54 main(int argc, char **argv)
  55 {
  56         int fd = -1, ret = 0, status = EXIT_FAILURE;
  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
  64         if (argc < 2) {
  65                 fprintf(stderr, "Usage: %s /dev/zvol_device_node\n", argv[0]);
  66                 goto fail;
  67         }
  68
  69         dev_name = argv[1];
  70         ret = stat64(dev_name, &statbuf);
  71         if (ret != 0) {
  72                 fprintf(stderr, "Unable to access device file: %s\n", dev_name);
  73                 goto fail;
  74         }
  75
  76         dev_minor = minor(statbuf.st_rdev);
  77         dev_part = dev_minor % ZVOL_MINORS;
  78
  79         fd = open(dev_name, O_RDONLY);
  80         if (fd < 0) {
  81                 fprintf(stderr, "Unable to open device file: %s\n", dev_name);
  82                 goto fail;
  83         }
  84
  85         ret = ioctl_get_msg(zvol_name, fd);
  86         if (ret < 0) {
  87                 fprintf(stderr, "ioctl_get_msg failed: %s\n", strerror(errno));
  88                 goto fail;
  89         }
  90         if (dev_part > 0)
  91                 ret = asprintf(&zvol_name_part, "%s-part%d", zvol_name,
  92                     dev_part);
  93         else
  94                 ret = asprintf(&zvol_name_part, "%s", zvol_name);
  95
  96         if (ret == -1 || zvol_name_part == NULL)
  97                 goto fail;
  98
  99         for (i = 0; i < strlen(zvol_name_part); i++) {
 100                 if (isblank(zvol_name_part[i]))
 101                         zvol_name_part[i] = '+';
 102         }
 103
 104         printf("%s\n", zvol_name_part);
 105         status = EXIT_SUCCESS;
 106
 107 fail:
 108         if (zvol_name_part)
 109                 free(zvol_name_part);
 110         if (fd >= 0)
 111                 close(fd);
 112
 113         return (status);
 114 }