[PATCH] NOMMU: Provide shared-writable mmap support on ramfs

[deliverable/linux.git] / fs / ramfs / file-mmu.c

/* file-mmu.c: ramfs MMU-based file operations
 *
 * Resizable simple ram filesystem for Linux.
 *
 * Copyright (C) 2000 Linus Torvalds.
 *               2000 Transmeta Corp.
 *
 * Usage limits added by David Gibson, Linuxcare Australia.
 * This file is released under the GPL.
 */

/*
 * NOTE! This filesystem is probably most useful
 * not as a real filesystem, but as an example of
 * how virtual filesystems can be written.
 *
 * It doesn't get much simpler than this. Consider
 * that this file implements the full semantics of
 * a POSIX-compliant read-write filesystem.
 *
 * Note in particular how the filesystem does not
 * need to implement any data structures of its own
 * to keep track of the virtual data: using the VFS
 * caches is sufficient.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <linux/ramfs.h>

#include <asm/uaccess.h>
#include "internal.h"

struct address_space_operations ramfs_aops = {
	.readpage	= simple_readpage,
	.prepare_write	= simple_prepare_write,
	.commit_write	= simple_commit_write
};

struct file_operations ramfs_file_operations = {
	.read		= generic_file_read,
	.write		= generic_file_write,
	.mmap		= generic_file_mmap,
	.fsync		= simple_sync_file,
	.sendfile	= generic_file_sendfile,
	.llseek		= generic_file_llseek,
};

struct inode_operations ramfs_file_inode_operations = {
	.getattr	= simple_getattr,
};