xref: /freebsd/sys/contrib/openzfs/tests/zfs-tests/cmd/getversion.c (revision 780f28929782a104eefbc81f031836bf1febb6de)
1 /*
2  * This file and its contents are supplied under the terms of the
3  * Common Development and Distribution License ("CDDL"), version 1.0.
4  * You may only use this file in accordance with the terms of version
5  * 1.0 of the CDDL.
6  *
7  * A full copy of the text of the CDDL should have accompanied this
8  * source.  A copy of the CDDL is also available via the Internet at
9  * http://www.illumos.org/license/CDDL.
10  */
11 
12 /*
13  * Copyright 2021 iXsystems, Inc.
14  */
15 
16 /*
17  * FreeBSD and macOS expose file generation number through stat(2) and stat(1).
18  * Linux exposes it instead through an ioctl.
19  */
20 
21 #include <sys/ioctl.h>
22 #include <linux/fs.h>
23 #include <err.h>
24 #include <fcntl.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 
29 int
30 main(int argc, const char * const argv[])
31 {
32 	if (argc != 2)
33 		errx(EXIT_FAILURE, "usage: %s filename", argv[0]);
34 
35 	int fd = open(argv[1], O_RDONLY);
36 	if (fd == -1)
37 		err(EXIT_FAILURE, "failed to open %s", argv[1]);
38 
39 	int gen = 0;
40 	if (ioctl(fd, FS_IOC_GETVERSION, &gen) == -1)
41 		err(EXIT_FAILURE, "FS_IOC_GETVERSION failed");
42 
43 	(void) close(fd);
44 
45 	(void) printf("%d\n", gen);
46 
47 	return (EXIT_SUCCESS);
48 }
49