/*
* 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 = {};
