1 /*
2 * fs/sdcardfs/mmap.c
3 *
4 * Copyright (c) 2013 Samsung Electronics Co. Ltd
5 * Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun,
6 * Sunghwan Yun, Sungjong Seo
7 *
8 * This program has been developed as a stackable file system based on
9 * the WrapFS which written by
10 *
11 * Copyright (c) 1998-2011 Erez Zadok
12 * Copyright (c) 2009 Shrikar Archak
13 * Copyright (c) 2003-2011 Stony Brook University
14 * Copyright (c) 2003-2011 The Research Foundation of SUNY
15 *
16 * This file is dual licensed. It may be redistributed and/or modified
17 * under the terms of the Apache 2.0 License OR version 2 of the GNU
18 * General Public License.
19 */
20
21 #include "sdcardfs.h"
22
sdcardfs_fault(struct vm_area_struct * vma,struct vm_fault * vmf)23 static int sdcardfs_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
24 {
25 int err;
26 struct file *file;
27 const struct vm_operations_struct *lower_vm_ops;
28
29 file = (struct file *)vma->vm_private_data;
30 lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
31 BUG_ON(!lower_vm_ops);
32
33 err = lower_vm_ops->fault(vma, vmf);
34 return err;
35 }
36
sdcardfs_vm_open(struct vm_area_struct * vma)37 static void sdcardfs_vm_open(struct vm_area_struct *vma)
38 {
39 struct file *file = (struct file *)vma->vm_private_data;
40
41 get_file(file);
42 }
43
sdcardfs_vm_close(struct vm_area_struct * vma)44 static void sdcardfs_vm_close(struct vm_area_struct *vma)
45 {
46 struct file *file = (struct file *)vma->vm_private_data;
47
48 fput(file);
49 }
50
sdcardfs_page_mkwrite(struct vm_area_struct * vma,struct vm_fault * vmf)51 static int sdcardfs_page_mkwrite(struct vm_area_struct *vma,
52 struct vm_fault *vmf)
53 {
54 int err = 0;
55 struct file *file;
56 const struct vm_operations_struct *lower_vm_ops;
57
58 file = (struct file *)vma->vm_private_data;
59 lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
60 BUG_ON(!lower_vm_ops);
61 if (!lower_vm_ops->page_mkwrite)
62 goto out;
63
64 err = lower_vm_ops->page_mkwrite(vma, vmf);
65 out:
66 return err;
67 }
68
sdcardfs_direct_IO(struct kiocb * iocb,struct iov_iter * iter)69 static ssize_t sdcardfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
70 {
71 /*
72 * This function should never be called directly. We need it
73 * to exist, to get past a check in open_check_o_direct(),
74 * which is called from do_last().
75 */
76 return -EINVAL;
77 }
78
79 const struct address_space_operations sdcardfs_aops = {
80 .direct_IO = sdcardfs_direct_IO,
81 };
82
83 const struct vm_operations_struct sdcardfs_vm_ops = {
84 .fault = sdcardfs_fault,
85 .page_mkwrite = sdcardfs_page_mkwrite,
86 .open = sdcardfs_vm_open,
87 .close = sdcardfs_vm_close,
88 };
89