160 lines
5.7 KiB
C
160 lines
5.7 KiB
C
/*
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* file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
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*
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* Copyright (c) 2001-2005 Anton Altaparmakov
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*
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* This program/include file is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as published
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* by the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program/include file is distributed in the hope that it will be
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* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program (in the main directory of the Linux-NTFS
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* distribution in the file COPYING); if not, write to the Free Software
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* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/pagemap.h>
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#include <linux/buffer_head.h>
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#include "inode.h"
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#include "debug.h"
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#include "ntfs.h"
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/**
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* ntfs_file_open - called when an inode is about to be opened
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* @vi: inode to be opened
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* @filp: file structure describing the inode
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*
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* Limit file size to the page cache limit on architectures where unsigned long
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* is 32-bits. This is the most we can do for now without overflowing the page
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* cache page index. Doing it this way means we don't run into problems because
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* of existing too large files. It would be better to allow the user to read
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* the beginning of the file but I doubt very much anyone is going to hit this
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* check on a 32-bit architecture, so there is no point in adding the extra
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* complexity required to support this.
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*
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* On 64-bit architectures, the check is hopefully optimized away by the
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* compiler.
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*
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* After the check passes, just call generic_file_open() to do its work.
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*/
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static int ntfs_file_open(struct inode *vi, struct file *filp)
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{
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if (sizeof(unsigned long) < 8) {
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if (i_size_read(vi) > MAX_LFS_FILESIZE)
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return -EFBIG;
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}
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return generic_file_open(vi, filp);
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}
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#ifdef NTFS_RW
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/**
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* ntfs_file_fsync - sync a file to disk
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* @filp: file to be synced
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* @dentry: dentry describing the file to sync
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* @datasync: if non-zero only flush user data and not metadata
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*
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* Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
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* system calls. This function is inspired by fs/buffer.c::file_fsync().
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*
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* If @datasync is false, write the mft record and all associated extent mft
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* records as well as the $DATA attribute and then sync the block device.
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*
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* If @datasync is true and the attribute is non-resident, we skip the writing
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* of the mft record and all associated extent mft records (this might still
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* happen due to the write_inode_now() call).
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*
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* Also, if @datasync is true, we do not wait on the inode to be written out
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* but we always wait on the page cache pages to be written out.
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*
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* Note: In the past @filp could be NULL so we ignore it as we don't need it
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* anyway.
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*
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* Locking: Caller must hold i_sem on the inode.
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*
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* TODO: We should probably also write all attribute/index inodes associated
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* with this inode but since we have no simple way of getting to them we ignore
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* this problem for now.
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*/
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static int ntfs_file_fsync(struct file *filp, struct dentry *dentry,
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int datasync)
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{
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struct inode *vi = dentry->d_inode;
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int err, ret = 0;
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ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
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BUG_ON(S_ISDIR(vi->i_mode));
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if (!datasync || !NInoNonResident(NTFS_I(vi)))
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ret = ntfs_write_inode(vi, 1);
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write_inode_now(vi, !datasync);
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/*
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* NOTE: If we were to use mapping->private_list (see ext2 and
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* fs/buffer.c) for dirty blocks then we could optimize the below to be
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* sync_mapping_buffers(vi->i_mapping).
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*/
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err = sync_blockdev(vi->i_sb->s_bdev);
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if (unlikely(err && !ret))
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ret = err;
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if (likely(!ret))
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ntfs_debug("Done.");
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else
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ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
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"%u.", datasync ? "data" : "", vi->i_ino, -ret);
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return ret;
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}
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#endif /* NTFS_RW */
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struct file_operations ntfs_file_ops = {
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.llseek = generic_file_llseek, /* Seek inside file. */
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.read = generic_file_read, /* Read from file. */
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.aio_read = generic_file_aio_read, /* Async read from file. */
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.readv = generic_file_readv, /* Read from file. */
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#ifdef NTFS_RW
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.write = generic_file_write, /* Write to file. */
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.aio_write = generic_file_aio_write, /* Async write to file. */
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.writev = generic_file_writev, /* Write to file. */
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/*.release = ,*/ /* Last file is closed. See
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fs/ext2/file.c::
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ext2_release_file() for
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how to use this to discard
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preallocated space for
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write opened files. */
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.fsync = ntfs_file_fsync, /* Sync a file to disk. */
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/*.aio_fsync = ,*/ /* Sync all outstanding async
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i/o operations on a
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kiocb. */
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#endif /* NTFS_RW */
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/*.ioctl = ,*/ /* Perform function on the
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mounted filesystem. */
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.mmap = generic_file_mmap, /* Mmap file. */
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.open = ntfs_file_open, /* Open file. */
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.sendfile = generic_file_sendfile, /* Zero-copy data send with
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the data source being on
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the ntfs partition. We
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do not need to care about
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the data destination. */
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/*.sendpage = ,*/ /* Zero-copy data send with
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the data destination being
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on the ntfs partition. We
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do not need to care about
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the data source. */
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};
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struct inode_operations ntfs_file_inode_ops = {
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#ifdef NTFS_RW
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.truncate = ntfs_truncate_vfs,
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.setattr = ntfs_setattr,
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#endif /* NTFS_RW */
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};
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struct file_operations ntfs_empty_file_ops = {};
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struct inode_operations ntfs_empty_inode_ops = {};
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