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 | }; |