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swapctl.c revision 1.6 
      1 /*	$NetBSD: swapctl.c,v 1.6 1997/09/15 11:22:00 lukem Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1996, 1997 Matthew R. Green
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by Matthew R. Green for
     18  *      The NetBSD Foundation.
     19  * 4. The name of the author may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     30  * 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 /*
     36  * swapctl command:
     37  *	-A		add all devices listed as `sw' in /etc/fstab
     38  *	-t [blk|noblk]	if -A, add either all block device or all non-block
     39  *			devices
     40  *	-a <dev>	add this device
     41  *	-d <dev>	remove this swap device (not supported yet)
     42  *	-l		list swap devices
     43  *	-s		short listing of swap devices
     44  *	-k		use kilobytes
     45  *	-p <pri>	use this priority
     46  *	-c		change priority
     47  *
     48  * or, if invoked as "swapon" (compatibility mode):
     49  *
     50  *	-a		all devices listed as `sw' in /etc/fstab
     51  *	-t		same as -t above (feature not present in old
     52  *			swapon(8) command)
     53  *	<dev>		add this device
     54  */
     55 
     56 #include <sys/param.h>
     57 #include <sys/stat.h>
     58 
     59 #include <vm/vm_swap.h>
     60 
     61 #include <unistd.h>
     62 #include <err.h>
     63 #include <errno.h>
     64 #include <stdio.h>
     65 #include <stdlib.h>
     66 #include <string.h>
     67 #include <fstab.h>
     68 
     69 #include "swapctl.h"
     70 
     71 int	command;
     72 
     73 /*
     74  * Commands for swapctl(8).  These are mutually exclusive.
     75  */
     76 #define	CMD_A		0x01	/* process /etc/fstab */
     77 #define	CMD_a		0x02	/* add a swap file/device */
     78 #define	CMD_c		0x04	/* change priority of a swap file/device */
     79 #define	CMD_d		0x08	/* delete a swap file/device */
     80 #define	CMD_l		0x10	/* list swap files/devices */
     81 #define	CMD_s		0x20	/* summary of swap files/devices */
     82 
     83 #define	SET_COMMAND(cmd) \
     84 do { \
     85 	if (command) \
     86 		usage(); \
     87 	command = (cmd); \
     88 } while (0)
     89 
     90 /*
     91  * Commands that require a "path" argument at the end of the command
     92  * line, and the ones which require that none exist.
     93  */
     94 #define	REQUIRE_PATH	(CMD_a | CMD_c | CMD_d)
     95 #define	REQUIRE_NOPATH	(CMD_A | CMD_l | CMD_s)
     96 
     97 /*
     98  * Option flags, and the commands with which they are valid.
     99  */
    100 int	kflag;		/* display in 1K blocks */
    101 #define	KFLAG_CMDS	(CMD_l | CMD_s)
    102 
    103 int	pflag;		/* priority was specified */
    104 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
    105 
    106 char	*tflag;		/* swap device type (blk or noblk) */
    107 #define	TFLAG_CMDS	(CMD_A)
    108 
    109 int	pri;		/* uses 0 as default pri */
    110 
    111 static	void change_priority __P((char *));
    112 static	void add_swap __P((char *));
    113 static	void del_swap __P((char *));
    114 	int  main __P((int, char *[]));
    115 static	void do_fstab __P((void));
    116 static	void usage __P((void));
    117 static	void swapon_command __P((int, char **));
    118 #if 0
    119 static	void swapoff_command __P((int, char **));
    120 #endif
    121 
    122 extern	char *__progname;	/* from crt0.o */
    123 
    124 int
    125 main(argc, argv)
    126 	int	argc;
    127 	char	*argv[];
    128 {
    129 	int	c;
    130 
    131 	if (strcmp(__progname, "swapon") == 0) {
    132 		swapon_command(argc, argv);
    133 		/* NOTREACHED */
    134 	}
    135 
    136 #if 0
    137 	if (strcmp(__progname, "swapoff") == 0) {
    138 		swapoff_command(argc, argv);
    139 		/* NOTREACHED */
    140 	}
    141 #endif
    142 
    143 	while ((c = getopt(argc, argv, "Aacdlkp:st:")) != -1) {
    144 		switch (c) {
    145 		case 'A':
    146 			SET_COMMAND(CMD_A);
    147 			break;
    148 
    149 		case 'a':
    150 			SET_COMMAND(CMD_a);
    151 			break;
    152 
    153 		case 'c':
    154 			SET_COMMAND(CMD_c);
    155 			break;
    156 
    157 		case 'd':
    158 			SET_COMMAND(CMD_d);
    159 			break;
    160 
    161 		case 'l':
    162 			SET_COMMAND(CMD_l);
    163 			break;
    164 
    165 		case 'k':
    166 			kflag = 1;
    167 			break;
    168 
    169 		case 'p':
    170 			pflag = 1;
    171 			/* XXX strtol() */
    172 			pri = atoi(optarg);
    173 			break;
    174 
    175 		case 's':
    176 			SET_COMMAND(CMD_s);
    177 			break;
    178 
    179 		case 't':
    180 			if (tflag != NULL)
    181 				usage();
    182 			tflag = optarg;
    183 			break;
    184 
    185 		default:
    186 			usage();
    187 			/* NOTREACHED */
    188 		}
    189 	}
    190 
    191 	/* Did the user specify a command? */
    192 	if (command == 0)
    193 		usage();
    194 
    195 	argv += optind;
    196 	argc -= optind;
    197 
    198 	switch (argc) {
    199 	case 0:
    200 		if (command & REQUIRE_PATH)
    201 			usage();
    202 		break;
    203 
    204 	case 1:
    205 		if (command & REQUIRE_NOPATH)
    206 			usage();
    207 		break;
    208 
    209 	default:
    210 		usage();
    211 	}
    212 
    213 	/* To change priority, you have to specify one. */
    214 	if ((command == CMD_c) && pflag == 0)
    215 		usage();
    216 
    217 	/* Sanity-check -t */
    218 	if (tflag != NULL) {
    219 		if (command != CMD_A)
    220 			usage();
    221 		if (strcmp(tflag, "blk") != 0 &&
    222 		    strcmp(tflag, "noblk") != 0)
    223 			usage();
    224 	}
    225 
    226 	/* Dispatch the command. */
    227 	switch (command) {
    228 	case CMD_l:
    229 		list_swap(pri, kflag, pflag, 0, 1);
    230 		break;
    231 
    232 	case CMD_s:
    233 		list_swap(pri, kflag, pflag, 0, 0);
    234 		break;
    235 
    236 	case CMD_c:
    237 		change_priority(argv[0]);
    238 		break;
    239 
    240 	case CMD_a:
    241 		add_swap(argv[0]);
    242 		break;
    243 
    244 	case CMD_d:
    245 		del_swap(argv[0]);
    246 		break;
    247 
    248 	case CMD_A:
    249 		do_fstab();
    250 		break;
    251 	}
    252 
    253 	exit(0);
    254 }
    255 
    256 /*
    257  * swapon_command: emulate the old swapon(8) program.
    258  */
    259 void
    260 swapon_command(argc, argv)
    261 	int argc;
    262 	char **argv;
    263 {
    264 	int ch, fiztab = 0;
    265 
    266 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    267 		switch (ch) {
    268 		case 'a':
    269 			fiztab = 1;
    270 			break;
    271 		case 't':
    272 			if (tflag != NULL)
    273 				usage();
    274 			tflag = optarg;
    275 			break;
    276 		default:
    277 			goto swapon_usage;
    278 		}
    279 	}
    280 	argc -= optind;
    281 	argv += optind;
    282 
    283 	if (fiztab) {
    284 		if (argc)
    285 			goto swapon_usage;
    286 		/* Sanity-check -t */
    287 		if (tflag != NULL) {
    288 			if (strcmp(tflag, "blk") != 0 &&
    289 			    strcmp(tflag, "noblk") != 0)
    290 				usage();
    291 		}
    292 		do_fstab();
    293 		exit(0);
    294 	} else if (argc == 0 || tflag != NULL)
    295 		goto swapon_usage;
    296 
    297 	while (argc) {
    298 		add_swap(argv[0]);
    299 		argc--;
    300 		argv++;
    301 	}
    302 	exit(0);
    303 	/* NOTREACHED */
    304 
    305  swapon_usage:
    306 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", __progname);
    307 	fprintf(stderr, "       %s <path> ...\n", __progname);
    308 	exit(1);
    309 }
    310 
    311 /*
    312  * change_priority:  change the priority of a swap device.
    313  */
    314 void
    315 change_priority(path)
    316 	char	*path;
    317 {
    318 
    319 	if (swapctl(SWAP_CTL, path, pri) < 0)
    320 		warn("%s", path);
    321 }
    322 
    323 /*
    324  * add_swap:  add the pathname to the list of swap devices.
    325  */
    326 void
    327 add_swap(path)
    328 	char *path;
    329 {
    330 
    331 	if (swapctl(SWAP_ON, path, pri) < 0)
    332 		err(1, "%s", path);
    333 }
    334 
    335 /*
    336  * del_swap:  remove the pathname to the list of swap devices.
    337  */
    338 void
    339 del_swap(path)
    340 	char *path;
    341 {
    342 
    343 	if (swapctl(SWAP_OFF, path, pri) < 0)
    344 		err(1, "%s", path);
    345 }
    346 
    347 void
    348 do_fstab()
    349 {
    350 	struct	fstab *fp;
    351 	char	*s;
    352 	long	priority;
    353 	struct	stat st;
    354 	int	isblk;
    355 
    356 #define PRIORITYEQ	"priority="
    357 #define NFSMNTPT	"nfsmntpt="
    358 #define PATH_MOUNT	"/sbin/mount_nfs"
    359 	while ((fp = getfsent()) != NULL) {
    360 		char *spec;
    361 
    362 		if (strcmp(fp->fs_type, "sw") != 0)
    363 			continue;
    364 
    365 		spec = fp->fs_spec;
    366 		isblk = 0;
    367 
    368 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    369 			s += sizeof(PRIORITYEQ) - 1;
    370 			priority = atol(s);
    371 		} else
    372 			priority = pri;
    373 
    374 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    375 			char *t, cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    376 
    377 			/*
    378 			 * Skip this song and dance if we're only
    379 			 * doing block devices.
    380 			 */
    381 			if (tflag != NULL &&
    382 			    strcmp(tflag, "blk") == 0)
    383 				continue;
    384 
    385 			t = strpbrk(s, ",");
    386 			if (t != 0)
    387 				*t = '\0';
    388 			spec = strdup(s + strlen(NFSMNTPT));
    389 			if (t != 0)
    390 				*t = ',';
    391 
    392 			if (spec == NULL)
    393 				errx(1, "Out of memory");
    394 
    395 			if (strlen(spec) == 0) {
    396 				warnx("empty mountpoint");
    397 				free(spec);
    398 				continue;
    399 			}
    400 			snprintf(cmd, sizeof(cmd), "%s %s %s",
    401 				PATH_MOUNT, fp->fs_spec, spec);
    402 			if (system(cmd) != 0) {
    403 				warnx("%s: mount failed", fp->fs_spec);
    404 				continue;
    405 			}
    406 		} else {
    407 			/*
    408 			 * Determine blk-ness.
    409 			 */
    410 			if (stat(spec, &st) < 0) {
    411 				warn(spec);
    412 				continue;
    413 			}
    414 			if (S_ISBLK(st.st_mode))
    415 				isblk = 1;
    416 		}
    417 
    418 		/*
    419 		 * Skip this type if we're told to.
    420 		 */
    421 		if (tflag != NULL) {
    422 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    423 				continue;
    424 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    425 				continue;
    426 		}
    427 
    428 		if (swapctl(SWAP_ON, spec, (int)priority) < 0)
    429 			warn("%s", spec);
    430 		else
    431 			printf("%s: adding %s as swap device at priority %d\n",
    432 			    __progname, fp->fs_spec, (int)priority);
    433 
    434 		if (spec != fp->fs_spec)
    435 			free(spec);
    436 	}
    437 }
    438 
    439 void
    440 usage()
    441 {
    442 
    443 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    444 	    __progname);
    445 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
    446 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
    447 	fprintf(stderr, "       %s -d path\n", __progname);
    448 	fprintf(stderr, "       %s -l | -s [-k]\n", __progname);
    449 	exit(1);
    450 }
    451