nilfs2: file operations

/*

 * file.c - NILFS regular file handling primitives including fsync().

 *

 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.

 *

 * This program 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 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; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * Written by Amagai Yoshiji <amagai@osrg.net>,

 *            Ryusuke Konishi <ryusuke@osrg.net>

 */

#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/writeback.h>

#include "nilfs.h"

#include "segment.h"

int nilfs_sync_file(struct file *file, struct dentry *dentry, int datasync)

{

	/*

	 * Called from fsync() system call

	 * This is the only entry point that can catch write and synch

	 * timing for both data blocks and intermediate blocks.

	 *

	 * This function should be implemented when the writeback function

	 * will be implemented.

	 */

	struct inode *inode = dentry->d_inode;

	int err;

	if (!nilfs_inode_dirty(inode))

		return 0;

	if (datasync)

		err = nilfs_construct_dsync_segment(inode->i_sb, inode);

	else

		err = nilfs_construct_segment(inode->i_sb);

	return err;

}

static ssize_t

nilfs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,

		     unsigned long nr_segs, loff_t pos)

{

	struct file *file = iocb->ki_filp;

	struct inode *inode = file->f_dentry->d_inode;

	ssize_t ret;

	ret = generic_file_aio_write(iocb, iov, nr_segs, pos);

	if (ret <= 0)

		return ret;

	if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {

		int err;

		err = nilfs_construct_dsync_segment(inode->i_sb, inode);

		if (unlikely(err))

			return err;

	}

	return ret;

}

static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)

{

	if (!(vma->vm_flags & (VM_WRITE | VM_MAYWRITE)))

		return -EPERM;

	SetPageChecked(page);

	wait_on_page_writeback(page);

	return 0;

}

struct vm_operations_struct nilfs_file_vm_ops = {

	.fault		= filemap_fault,

	.page_mkwrite	= nilfs_page_mkwrite,

};

static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)

{

	file_accessed(file);

	vma->vm_ops = &nilfs_file_vm_ops;

	vma->vm_flags |= VM_CAN_NONLINEAR;

	return 0;

}

/*

 * We have mostly NULL's here: the current defaults are ok for

 * the nilfs filesystem.

 */

struct file_operations nilfs_file_operations = {

	.llseek		= generic_file_llseek,

	.read		= do_sync_read,

	.write		= do_sync_write,

	.aio_read	= generic_file_aio_read,

	.aio_write	= nilfs_file_aio_write,

	.ioctl		= nilfs_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl	= nilfs_compat_ioctl,

#endif	/* CONFIG_COMPAT */

	.mmap		= nilfs_file_mmap,

	.open		= generic_file_open,

	/* .release	= nilfs_release_file, */

	.fsync		= nilfs_sync_file,

	.splice_read	= generic_file_splice_read,

};

struct inode_operations nilfs_file_inode_operations = {

	.truncate	= nilfs_truncate,

	.setattr	= nilfs_setattr,

	.permission     = nilfs_permission,

};

/* end of file */