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/fs.h>
28 #include <linux/mm.h>
29 #include <linux/ramfs.h>
30 #include <linux/sched.h>
31
32 #include "internal.h"
33
34 static unsigned long ramfs_mmu_get_unmapped_area(struct file *file,
35 unsigned long addr, unsigned long len, unsigned long pgoff,
36 unsigned long flags)
37 {
38 return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags);
39 }
40
41 const struct file_operations ramfs_file_operations = {
42 .read_iter = generic_file_read_iter,
43 .write_iter = generic_file_write_iter,
44 .mmap = generic_file_mmap,
45 .fsync = noop_fsync,
46 .splice_read = filemap_splice_read,
47 .splice_write = iter_file_splice_write,
48 .llseek = generic_file_llseek,
49 .get_unmapped_area = ramfs_mmu_get_unmapped_area,
50 };
51
52 const struct inode_operations ramfs_file_inode_operations = {
53 .setattr = simple_setattr,
54 .getattr = simple_getattr,
55 };
56
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