mft.h

linux 内核源代码

/*
 * mft.h - Defines for mft record handling in NTFS Linux kernel driver.
 *	   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
 */

#ifndef _LINUX_NTFS_MFT_H
#define _LINUX_NTFS_MFT_H

#include <linux/fs.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>

#include "inode.h"

extern MFT_RECORD *map_mft_record(ntfs_inode *ni);
extern void unmap_mft_record(ntfs_inode *ni);

extern MFT_RECORD *map_extent_mft_record(ntfs_inode *base_ni, MFT_REF mref,
		ntfs_inode **ntfs_ino);

static inline void unmap_extent_mft_record(ntfs_inode *ni)
{
	unmap_mft_record(ni);
	return;
}

#ifdef NTFS_RW

/**
 * flush_dcache_mft_record_page - flush_dcache_page() for mft records
 * @ni:		ntfs inode structure of mft record
 *
 * Call flush_dcache_page() for the page in which an mft record resides.
 *
 * This must be called every time an mft record is modified, just after the
 * modification.
 */
static inline void flush_dcache_mft_record_page(ntfs_inode *ni)
{
	flush_dcache_page(ni->page);
}

extern void __mark_mft_record_dirty(ntfs_inode *ni);

/**
 * mark_mft_record_dirty - set the mft record and the page containing it dirty
 * @ni:		ntfs inode describing the mapped mft record
 *
 * Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni,
 * as well as the page containing the mft record, dirty.  Also, mark the base
 * vfs inode dirty.  This ensures that any changes to the mft record are
 * written out to disk.
 *
 * NOTE:  Do not do anything if the mft record is already marked dirty.
 */
static inline void mark_mft_record_dirty(ntfs_inode *ni)
{
	if (!NInoTestSetDirty(ni))
		__mark_mft_record_dirty(ni);
}

extern int ntfs_sync_mft_mirror(ntfs_volume *vol, const unsigned long mft_no,
		MFT_RECORD *m, int sync);

extern int write_mft_record_nolock(ntfs_inode *ni, MFT_RECORD *m, int sync);

/**
 * write_mft_record - write out a mapped (extent) mft record
 * @ni:		ntfs inode describing the mapped (extent) mft record
 * @m:		mapped (extent) mft record to write
 * @sync:	if true, wait for i/o completion
 *
 * This is just a wrapper for write_mft_record_nolock() (see mft.c), which
 * locks the page for the duration of the write.  This ensures that there are
 * no race conditions between writing the mft record via the dirty inode code
 * paths and via the page cache write back code paths or between writing
 * neighbouring mft records residing in the same page.
 *
 * Locking the page also serializes us against ->readpage() if the page is not
 * uptodate.
 *
 * On success, clean the mft record and return 0.  On error, leave the mft
 * record dirty and return -errno.
 */
static inline int write_mft_record(ntfs_inode *ni, MFT_RECORD *m, int sync)
{
	struct page *page = ni->page;
	int err;

	BUG_ON(!page);
	lock_page(page);
	err = write_mft_record_nolock(ni, m, sync);
	unlock_page(page);
	return err;
}

extern bool ntfs_may_write_mft_record(ntfs_volume *vol,
		const unsigned long mft_no, const MFT_RECORD *m,
		ntfs_inode **locked_ni);

extern ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, const int mode,
		ntfs_inode *base_ni, MFT_RECORD **mrec);
extern int ntfs_extent_mft_record_free(ntfs_inode *ni, MFT_RECORD *m);

#endif /* NTFS_RW */

#endif /* _LINUX_NTFS_MFT_H */