File:  [DragonFly] / src / sys / vfs / ntfs / ntfs_ihash.c
Revision 1.8: download - view: text, annotated - select for diffs
Mon Mar 1 06:33:22 2004 UTC (10 years, 8 months ago) by dillon
Branches: MAIN
CVS tags: HEAD
Newtoken commit.  Change the token implementation as follows:  (1) Obtaining
a token no longer enters a critical section.  (2) tokens can be held through
schedular switches and blocking conditions and are effectively released and
reacquired on resume.  Thus tokens serialize access only while the thread
is actually running.  Serialization is not broken by preemptive interrupts.
That is, interrupt threads which preempt do no release the preempted thread's
tokens.  (3) Unlike spl's, tokens will interlock w/ interrupt threads on
the same or on a different cpu.

The vnode interlock code has been rewritten and the API has changed.  The
mountlist vnode scanning code has been consolidated and all known races have
been fixed.  The vnode interlock is now a pool token.

The code that frees unreferenced vnodes whos last VM page has been freed has
been moved out of the low level vm_page_free() code and moved to the
periodic filesystem sycer code in vfs_msycn().

The SMP startup code and the IPI code has been cleaned up considerably.
Certain early token interactions on AP cpus have been moved to the BSP.

The LWKT rwlock API has been cleaned up and turned on.

Major testing by: David Rhodus

/*	$NetBSD: ntfs_ihash.c,v 1.5 1999/09/30 16:56:40 jdolecek Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ufs_ihash.c	8.7 (Berkeley) 5/17/95
 * $FreeBSD: src/sys/ntfs/ntfs_ihash.c,v 1.7 1999/12/03 20:37:39 semenu Exp $
 * $DragonFly: src/sys/vfs/ntfs/ntfs_ihash.c,v 1.8 2004/03/01 06:33:22 dillon Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/mount.h>

#include "ntfs.h"
#include "ntfs_inode.h"
#include "ntfs_ihash.h"

MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");

/*
 * Structures associated with inode cacheing.
 */
static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
static u_long	ntfs_nthash;		/* size of hash table - 1 */
#define	NTNOHASH(device, inum)	(&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
static struct lwkt_token ntfs_nthash_slock;
struct lock ntfs_hashlock;

/*
 * Initialize inode hash table.
 */
void
ntfs_nthashinit()
{
	lockinit(&ntfs_hashlock, 0, "ntfs_nthashlock", 0, 0);
	ntfs_nthashtbl = HASHINIT(desiredvnodes, M_NTFSNTHASH, M_WAITOK,
	    &ntfs_nthash);
	lwkt_token_init(&ntfs_nthash_slock);
}

/*
 * Free the inode hash table.
 */
int
ntfs_nthash_uninit(struct vfsconf *vfc)
{
	lwkt_tokref ilock;

	lwkt_gettoken(&ilock, &ntfs_nthash_slock);
	if (ntfs_nthashtbl)
		free(ntfs_nthashtbl, M_NTFSNTHASH);
	lwkt_reltoken(&ilock);

	return 0;
}

/*
 * Use the device/inum pair to find the incore inode, and return a pointer
 * to it. If it is in core, return it, even if it is locked.
 */
struct ntnode *
ntfs_nthashlookup(dev, inum)
	dev_t dev;
	ino_t inum;
{
	struct ntnode *ip;
	lwkt_tokref ilock;

	lwkt_gettoken(&ilock, &ntfs_nthash_slock);
	for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
		if (inum == ip->i_number && dev == ip->i_dev)
			break;
	}
	lwkt_reltoken(&ilock);

	return (ip);
}

/*
 * Insert the ntnode into the hash table.
 */
void
ntfs_nthashins(ip)
	struct ntnode *ip;
{
	struct nthashhead *ipp;
	lwkt_tokref ilock;

	lwkt_gettoken(&ilock, &ntfs_nthash_slock);
	ipp = NTNOHASH(ip->i_dev, ip->i_number);
	LIST_INSERT_HEAD(ipp, ip, i_hash);
	ip->i_flag |= IN_HASHED;
	lwkt_reltoken(&ilock);
}

/*
 * Remove the inode from the hash table.
 */
void
ntfs_nthashrem(ip)
	struct ntnode *ip;
{
	lwkt_tokref ilock;

	lwkt_gettoken(&ilock, &ntfs_nthash_slock);
	if (ip->i_flag & IN_HASHED) {
		ip->i_flag &= ~IN_HASHED;
		LIST_REMOVE(ip, i_hash);
#ifdef DIAGNOSTIC
		ip->i_hash.le_next = NULL;
		ip->i_hash.le_prev = NULL;
#endif
	}
	lwkt_reltoken(&ilock);
}