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David Howells642fb4d2006-01-06 00:11:41 -08001/* file-mmu.c: ramfs MMU-based file operations
2 *
3 * Resizable simple ram filesystem for Linux.
4 *
5 * Copyright (C) 2000 Linus Torvalds.
6 * 2000 Transmeta Corp.
7 *
8 * Usage limits added by David Gibson, Linuxcare Australia.
9 * This file is released under the GPL.
10 */
11
12/*
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.
16 *
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.
20 *
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.
25 */
26
David Howells642fb4d2006-01-06 00:11:41 -080027#include <linux/fs.h>
Dimitri Gorokhovik131612d2006-12-29 16:48:24 -080028#include <linux/mm.h>
Adrian Bunk4488c592008-04-29 00:58:51 -070029#include <linux/ramfs.h>
30
31#include "internal.h"
David Howells642fb4d2006-01-06 00:11:41 -080032
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070033const struct address_space_operations ramfs_aops = {
David Howells642fb4d2006-01-06 00:11:41 -080034 .readpage = simple_readpage,
Nick Piggin800d15a2007-10-16 01:25:03 -070035 .write_begin = simple_write_begin,
36 .write_end = simple_write_end,
Ken Chen46626292007-02-10 01:43:17 -080037 .set_page_dirty = __set_page_dirty_no_writeback,
David Howells642fb4d2006-01-06 00:11:41 -080038};
39
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080040const struct file_operations ramfs_file_operations = {
Badari Pulavarty543ade12006-09-30 23:28:48 -070041 .read = do_sync_read,
42 .aio_read = generic_file_aio_read,
43 .write = do_sync_write,
44 .aio_write = generic_file_aio_write,
David Howells642fb4d2006-01-06 00:11:41 -080045 .mmap = generic_file_mmap,
Christoph Hellwig1b061d92010-05-26 17:53:41 +020046 .fsync = noop_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020047 .splice_read = generic_file_splice_read,
Octavian Purdila8b3d3562008-07-04 09:33:33 +020048 .splice_write = generic_file_splice_write,
David Howells642fb4d2006-01-06 00:11:41 -080049 .llseek = generic_file_llseek,
50};
51
Arjan van de Venc5ef1c42007-02-12 00:55:40 -080052const struct inode_operations ramfs_file_inode_operations = {
Nick Piggin3322e792010-05-27 22:42:19 +100053 .setattr = simple_setattr,
David Howells642fb4d2006-01-06 00:11:41 -080054 .getattr = simple_getattr,
55};