1 /* file-mmu.c: ramfs MMU-based file operations
3 * Resizable simple ram filesystem for Linux.
5 * Copyright (C) 2000 Linus Torvalds.
8 * Usage limits added by David Gibson, Linuxcare Australia.
9 * This file is released under the GPL.
13 * NOTE! This filesystem is probably most useful
14 * not as a real filesystem, but as an example of
15 * how virtual filesystems can be written.
17 * It doesn't get much simpler than this. Consider
18 * that this file implements the full semantics of
19 * a POSIX-compliant read-write filesystem.
21 * Note in particular how the filesystem does not
22 * need to implement any data structures of its own
23 * to keep track of the virtual data: using the VFS
24 * caches is sufficient.
27 #include <linux/module.h>
29 #include <linux/pagemap.h>
30 #include <linux/highmem.h>
31 #include <linux/init.h>
32 #include <linux/string.h>
33 #include <linux/smp_lock.h>
34 #include <linux/backing-dev.h>
35 #include <linux/ramfs.h>
37 #include <asm/uaccess.h>
40 struct address_space_operations ramfs_aops
= {
41 .readpage
= simple_readpage
,
42 .prepare_write
= simple_prepare_write
,
43 .commit_write
= simple_commit_write
46 struct file_operations ramfs_file_operations
= {
47 .read
= generic_file_read
,
48 .write
= generic_file_write
,
49 .mmap
= generic_file_mmap
,
50 .fsync
= simple_sync_file
,
51 .sendfile
= generic_file_sendfile
,
52 .llseek
= generic_file_llseek
,
55 struct inode_operations ramfs_file_inode_operations
= {
56 .getattr
= simple_getattr
,