src/lib/fs_simfs.c

/*
 *  Copyright (C) 2000-2009, Parallels, Inc. All rights reserved.
 *
 *  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 <stdlib.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdio.h>
#include <limits.h>

#include "types.h"
#include "fs.h"
#include "logger.h"
#include "vzerror.h"

/*  Check is fs mounted
 *  return: 1 - yes
 *	    0 - no
 *	  < 0 - error
 */
int vz_fs_is_mounted(const char *target)
{
	struct stat st1, st2;
	char parent[PATH_MAX];

	if (stat(target, &st1)) {
		logger(-1, errno, "stat(%s)", target);
		return -1;
	}

	snprintf(parent, sizeof(parent), "%s/..", target);
	if (stat(parent, &st2)) {
		logger(-1, errno, "stat(%s)", parent);
		return -1;
	}

	return (st1.st_dev != st2.st_dev);
}

static char *fs_name = "simfs";
const char *vz_fs_get_name()
{
	return fs_name;
}

int vz_mount(fs_param *fs, int flags)
{
	int mntopt = fs->flags | flags;
	const int remount = flags & MS_REMOUNT;

	logger(2, 0,  "Mounting root: %s %s", fs->root, fs->private);
	if (mount(fs->private, fs->root, "simfs", mntopt,
			remount ? "" : fs->private) < 0)
	{
		logger(-1, errno, "Can't mount: %s %s", fs->root, fs->private);
		if (errno == ENODEV)
			logger(-1, 0, "Kernel lacks simfs support. Please "
				"compile it in, or load simfs module.");
		return VZ_FS_CANTMOUNT;
	}
	return 0;
}