mirror of https://gitee.com/openkylin/linux.git
156 lines
5.5 KiB
C
156 lines
5.5 KiB
C
/*
|
|
* file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
|
|
*
|
|
* Copyright (c) 2001-2004 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);
|
|
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 = {};
|