xref: /freebsd/sbin/nfsiod/nfsiod.c (revision 6bfca4dcab07dad45a805879d954876b353c0810)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Rick Macklem at The University of Guelph.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/syslog.h>
37 #include <sys/wait.h>
38 #include <sys/linker.h>
39 #include <sys/mount.h>
40 #include <sys/sysctl.h>
41 
42 #include <err.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 
47 #define	MAXNFSDCNT      20
48 
49 static void
50 usage(void)
51 {
52 	(void)fprintf(stderr, "usage: nfsiod [-n num_servers]\n");
53 	exit(1);
54 }
55 
56 int
57 main(int argc, char *argv[])
58 {
59 	int ch;
60 	struct xvfsconf vfc;
61 	int error;
62 	unsigned int iodmin, iodmax, num_servers;
63 	size_t len;
64 
65 	error = getvfsbyname("nfs", &vfc);
66 	if (error) {
67 		if (kldload("nfs") == -1)
68 			err(1, "kldload(nfs)");
69 		error = getvfsbyname("nfs", &vfc);
70 	}
71 	if (error)
72 		errx(1, "NFS support is not available in the running kernel");
73 
74 	num_servers = 0;
75 	while ((ch = getopt(argc, argv, "n:")) != -1)
76 		switch (ch) {
77 		case 'n':
78 			num_servers = atoi(optarg);
79 			if (num_servers < 1) {
80 				warnx("nfsiod count %u; reset to %d",
81 				    num_servers, 1);
82 				num_servers = 1;
83 			}
84 			if (num_servers > MAXNFSDCNT) {
85 				warnx("nfsiod count %u; reset to %d",
86 				    num_servers, MAXNFSDCNT);
87 				num_servers = MAXNFSDCNT;
88 			}
89 			break;
90 		case '?':
91 		default:
92 			usage();
93 		}
94 	argc -= optind;
95 	argv += optind;
96 
97 	if (argc > 0)
98 		usage();
99 
100 	len = sizeof iodmin;
101 	error = sysctlbyname("vfs.nfs.iodmin", &iodmin, &len, NULL, 0);
102 	if (error < 0)
103 		err(1, "sysctlbyname(\"vfs.nfs.iodmin\")");
104 	len = sizeof iodmax;
105 	error = sysctlbyname("vfs.nfs.iodmax", &iodmax, &len, NULL, 0);
106 	if (error < 0)
107 		err(1, "sysctlbyname(\"vfs.nfs.iodmax\")");
108 	if (num_servers == 0) {		/* no change */
109 		printf("vfs.nfs.iodmin=%u\nvfs.nfs.iodmax=%u\n",
110 		    iodmin, iodmax);
111 		exit(0);
112 	}
113 	/* Catch the case where we're lowering num_servers below iodmin */
114 	if (iodmin > num_servers) {
115 		iodmin = num_servers;
116 		error = sysctlbyname("vfs.nfs.iodmin", NULL, 0, &iodmin,
117 		    sizeof iodmin);
118 		if (error < 0)
119 			err(1, "sysctlbyname(\"vfs.nfs.iodmin\")");
120 	}
121 	iodmax = num_servers;
122 	error = sysctlbyname("vfs.nfs.iodmax", NULL, 0, &iodmax, sizeof iodmax);
123 	if (error < 0)
124 		err(1, "sysctlbyname(\"vfs.nfs.iodmax\")");
125 	exit (0);
126 }
127 
128