summaryrefslogtreecommitdiffstats
path: root/fs/ntfs/file.c
blob: be9fd1dd423d18de8bab0c320f52af5d5ba48392 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * file.c - NTFS kernel file operations.  Part of the Linux-NTFS project.
 *
 * Copyright (c) 2001-2005 Anton Altaparmakov
 *
 * This program/include file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program/include file is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/pagemap.h>
#include <linux/buffer_head.h>

#include "inode.h"
#include "debug.h"
#include "ntfs.h"

/**
 * ntfs_file_open - called when an inode is about to be opened
 * @vi:		inode to be opened
 * @filp:	file structure describing the inode
 *
 * Limit file size to the page cache limit on architectures where unsigned long
 * is 32-bits. This is the most we can do for now without overflowing the page
 * cache page index. Doing it this way means we don't run into problems because
 * of existing too large files. It would be better to allow the user to read
 * the beginning of the file but I doubt very much anyone is going to hit this
 * check on a 32-bit architecture, so there is no point in adding the extra
 * complexity required to support this.
 *
 * On 64-bit architectures, the check is hopefully optimized away by the
 * compiler.
 *
 * After the check passes, just call generic_file_open() to do its work.
 */
static int ntfs_file_open(struct inode *vi, struct file *filp)
{
	if (sizeof(unsigned long) < 8) {
		if (i_size_read(vi) > MAX_LFS_FILESIZE)
			return -EFBIG;
	}
	return generic_file_open(vi, filp);
}

#ifdef NTFS_RW

/**
 * ntfs_file_fsync - sync a file to disk
 * @filp:	file to be synced
 * @dentry:	dentry describing the file to sync
 * @datasync:	if non-zero only flush user data and not metadata
 *
 * Data integrity sync of a file to disk.  Used for fsync, fdatasync, and msync
 * system calls.  This function is inspired by fs/buffer.c::file_fsync().
 *
 * If @datasync is false, write the mft record and all associated extent mft
 * records as well as the $DATA attribute and then sync the block device.
 *
 * If @datasync is true and the attribute is non-resident, we skip the writing
 * of the mft record and all associated extent mft records (this might still
 * happen due to the write_inode_now() call).
 *
 * Also, if @datasync is true, we do not wait on the inode to be written out
 * but we always wait on the page cache pages to be written out.
 *
 * Note: In the past @filp could be NULL so we ignore it as we don't need it
 * anyway.
 *
 * Locking: Caller must hold i_sem on the inode.
 *
 * TODO: We should probably also write all attribute/index inodes associated
 * with this inode but since we have no simple way of getting to them we ignore
 * this problem for now.
 */
static int ntfs_file_fsync(struct file *filp, struct dentry *dentry,
		int datasync)
{
	struct inode *vi = dentry->d_inode;
	int err, ret = 0;

	ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
	BUG_ON(S_ISDIR(vi->i_mode));
	if (!datasync || !NInoNonResident(NTFS_I(vi)))
		ret = ntfs_write_inode(vi, 1);
	write_inode_now(vi, !datasync);
	/*
	 * NOTE: If we were to use mapping->private_list (see ext2 and
	 * fs/buffer.c) for dirty blocks then we could optimize the below to be
	 * sync_mapping_buffers(vi->i_mapping).
	 */
	err = sync_blockdev(vi->i_sb->s_bdev);
	if (unlikely(err && !ret))
		ret = err;
	if (likely(!ret))
		ntfs_debug("Done.");
	else
		ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx.  Error "
				"%u.", datasync ? "data" : "", vi->i_ino, -ret);
	return ret;
}

#endif /* NTFS_RW */

struct file_operations ntfs_file_ops = {
	.llseek		= generic_file_llseek,	  /* Seek inside file. */
	.read		= generic_file_read,	  /* Read from file. */
	.aio_read	= generic_file_aio_read,  /* Async read from file. */
	.readv		= generic_file_readv,	  /* Read from file. */
#ifdef NTFS_RW
	.write		= generic_file_write,	  /* Write to file. */
	.aio_write	= generic_file_aio_write, /* Async write to file. */
	.writev		= generic_file_writev,	  /* Write to file. */
	/*.release	= ,*/			  /* Last file is closed.  See
						     fs/ext2/file.c::
						     ext2_release_file() for
						     how to use this to discard
						     preallocated space for
						     write opened files. */
	.fsync		= ntfs_file_fsync,	  /* Sync a file to disk. */
	/*.aio_fsync	= ,*/			  /* Sync all outstanding async
						     i/o operations on a
						     kiocb. */
#endif /* NTFS_RW */
	/*.ioctl	= ,*/			  /* Perform function on the
						     mounted filesystem. */
	.mmap		= generic_file_mmap,	  /* Mmap file. */
	.open		= ntfs_file_open,	  /* Open file. */
	.sendfile	= generic_file_sendfile,  /* Zero-copy data send with
						     the data source being on
						     the ntfs partition.  We
						     do not need to care about
						     the data destination. */
	/*.sendpage	= ,*/			  /* Zero-copy data send with
						     the data destination being
						     on the ntfs partition.  We
						     do not need to care about
						     the data source. */
};

struct inode_operations ntfs_file_inode_ops = {
#ifdef NTFS_RW
	.truncate	= ntfs_truncate_vfs,
	.setattr	= ntfs_setattr,
#endif /* NTFS_RW */
};

struct file_operations ntfs_empty_file_ops = {};

struct inode_operations ntfs_empty_inode_ops = {};