| David Howells | 642fb4d | 2006-01-06 00:11:41 -0800 | [diff] [blame] | 1 | /* 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 |  | 
 | 27 | #include <linux/module.h> | 
 | 28 | #include <linux/fs.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> | 
 | 36 |  | 
 | 37 | #include <asm/uaccess.h> | 
 | 38 | #include "internal.h" | 
 | 39 |  | 
 | 40 | struct address_space_operations ramfs_aops = { | 
 | 41 | 	.readpage	= simple_readpage, | 
 | 42 | 	.prepare_write	= simple_prepare_write, | 
 | 43 | 	.commit_write	= simple_commit_write | 
 | 44 | }; | 
 | 45 |  | 
 | 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, | 
 | 53 | }; | 
 | 54 |  | 
 | 55 | struct inode_operations ramfs_file_inode_operations = { | 
 | 56 | 	.getattr	= simple_getattr, | 
 | 57 | }; |