ramfs_vfsops.c

微内核软实时操作系统

/*
 * Copyright (c) 2006-2007, Kohsuke Ohtani
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of any co-contributors 
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/vnode.h>
#include <sys/mount.h>

#include <errno.h>

#include "ramfs.h"

extern struct vnops ramfs_vnops;

static int ramfs_mount(mount_t mp, char *dev, int flags, void *data);
static int ramfs_unmount(mount_t mp);

/*
 * File system operations
 */
struct vfsops ramfs_vfsops = {
	.mount	 = ramfs_mount,
	.unmount = ramfs_unmount,
	.sync	 = VFS_NULL,
	.vget	 = VFS_NULL,
	.statfs	 = VFS_NULL,
	.vnops	 = &ramfs_vnops,
};

/*
 * Mount a file system.
 */
static int ramfs_mount(mount_t mp, char *dev, int flags, void *data)
{
	struct ramfs_node *node;

	dprintf("ramfs_mount: dev=%s\n", dev);

	/* Create a root node */
	node = ramfs_allocate_node("/", VDIR);
	if (node == NULL)
		return ENOMEM;
	mp->m_root->v_data = node;
	return 0;
}

/*
 * Unmount a file system.
 *
 * NOTE: Currently, we don't support unmounting of the RAMFS. This is
 *       because we have to deallocate all nodes included in all sub
 *       directories, and it requires more work...
 */
static int ramfs_unmount(mount_t mp)
{
	return EBUSY;
}