mmap.c
2.11 KB
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/*
* fs/sdcardfs/mmap.c
*
* Copyright (c) 2013 Samsung Electronics Co. Ltd
* Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun,
* Sunghwan Yun, Sungjong Seo
*
* This program has been developed as a stackable file system based on
* the WrapFS which written by
*
* Copyright (c) 1998-2011 Erez Zadok
* Copyright (c) 2009 Shrikar Archak
* Copyright (c) 2003-2011 Stony Brook University
* Copyright (c) 2003-2011 The Research Foundation of SUNY
*
* This file is dual licensed. It may be redistributed and/or modified
* under the terms of the Apache 2.0 License OR version 2 of the GNU
* General Public License.
*/
#include "sdcardfs.h"
static int sdcardfs_fault(struct vm_fault *vmf)
{
int err;
struct file *file;
const struct vm_operations_struct *lower_vm_ops;
file = (struct file *)vmf->vma->vm_private_data;
lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
BUG_ON(!lower_vm_ops);
err = lower_vm_ops->fault(vmf);
return err;
}
static void sdcardfs_vm_open(struct vm_area_struct *vma)
{
struct file *file = (struct file *)vma->vm_private_data;
get_file(file);
}
static void sdcardfs_vm_close(struct vm_area_struct *vma)
{
struct file *file = (struct file *)vma->vm_private_data;
fput(file);
}
static int sdcardfs_page_mkwrite(struct vm_fault *vmf)
{
int err = 0;
struct file *file;
const struct vm_operations_struct *lower_vm_ops;
file = (struct file *)vmf->vma->vm_private_data;
lower_vm_ops = SDCARDFS_F(file)->lower_vm_ops;
BUG_ON(!lower_vm_ops);
if (!lower_vm_ops->page_mkwrite)
goto out;
err = lower_vm_ops->page_mkwrite(vmf);
out:
return err;
}
static ssize_t sdcardfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
/*
* This function should never be called directly. We need it
* to exist, to get past a check in open_check_o_direct(),
* which is called from do_last().
*/
return -EINVAL;
}
const struct address_space_operations sdcardfs_aops = {
.direct_IO = sdcardfs_direct_IO,
};
const struct vm_operations_struct sdcardfs_vm_ops = {
.fault = sdcardfs_fault,
.page_mkwrite = sdcardfs_page_mkwrite,
.open = sdcardfs_vm_open,
.close = sdcardfs_vm_close,
};