util-linux/swaponoff.c

/* vi: set sw=4 ts=4: */
/*
 * Mini swapon/swapoff implementation for busybox
 *
 * Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen
 * Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <stdio.h>
#include <mntent.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <sys/mount.h>

#if __GNU_LIBRARY__ < 5
/* libc5 doesn't have sys/swap.h, define these here. */ 
extern int swapon (__const char *__path, int __flags);
extern int swapoff (__const char *__path);
#else
#include <sys/swap.h>
#endif

#include "busybox.h"

static int whichApp;    /* default SWAPON_APP */

static const int SWAPON_APP = 0;
static const int SWAPOFF_APP = 1;


static int swap_enable_disable(const char *device)
{
	int status;
	struct stat st;

	if (stat(device, &st) < 0) {
		bb_perror_msg_and_die("cannot stat %s", device);
	}

	/* test for holes */
	if (S_ISREG(st.st_mode)) {
		if (st.st_blocks * 512 < st.st_size) {
			bb_error_msg_and_die("swap file has holes");
		}
	}

	if (whichApp == SWAPON_APP)
		status = swapon(device, 0);
	else
		status = swapoff(device);

	if (status != 0) {
		bb_perror_msg("%s", device);
		return EXIT_FAILURE;
	}
	return EXIT_SUCCESS;
}

static int do_em_all(void)
{
	struct mntent *m;
	FILE *f = setmntent("/etc/fstab", "r");
	int err = 0;

	if (f == NULL)
		bb_perror_msg_and_die("/etc/fstab");
	while ((m = getmntent(f)) != NULL) {
		if (strcmp(m->mnt_type, MNTTYPE_SWAP)==0) {
			if(swap_enable_disable(m->mnt_fsname) == EXIT_FAILURE)
				err++;
		}
	}
	endmntent(f);
	return err;
}


extern int swap_on_off_main(int argc, char **argv)
{
	if (bb_applet_name[5] == 'f') { /* "swapoff" */
		whichApp = SWAPOFF_APP;
	}

	if (argc != 2) {
		goto usage_and_exit;
	}
	argc--;
	argv++;

	/* Parse any options */
	while (**argv == '-') {
		while (*++(*argv))
			switch (**argv) {
			case 'a':
				{
					struct stat statBuf;

					if (stat("/etc/fstab", &statBuf) < 0)
						bb_error_msg_and_die("/etc/fstab file missing");
				}
				return do_em_all();
				break;
			default:
				goto usage_and_exit;
			}
	}
	return swap_enable_disable(*argv);

  usage_and_exit:
	bb_show_usage();
}