ntfs_ihash.c revision 50477 
1/*	$NetBSD: ntfs_ihash.c,v 1.2 1999/05/06 15:43:19 christos Exp $	*/
2
3/*
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	@(#)ufs_ihash.c	8.7 (Berkeley) 5/17/95
36 * $FreeBSD: head/sys/fs/ntfs/ntfs_ihash.c 50477 1999-08-28 01:08:13Z peter $
37 */
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/kernel.h>
42#include <sys/lock.h>
43#include <sys/vnode.h>
44#include <sys/malloc.h>
45#include <sys/proc.h>
46
47#include <ntfs/ntfs.h>
48#include <ntfs/ntfs_inode.h>
49#include <ntfs/ntfs_ihash.h>
50
51MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
52
53/*
54 * Structures associated with inode cacheing.
55 */
56static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
57static u_long	ntfs_nthash;		/* size of hash table - 1 */
58#define	NTNOHASH(device, inum)	(&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
59#ifndef NULL_SIMPLELOCKS
60static struct simplelock ntfs_nthash_slock;
61#endif
62
63/*
64 * Initialize inode hash table.
65 */
66void
67ntfs_nthashinit()
68{
69
70	ntfs_nthashtbl = HASHINIT(desiredvnodes, M_NTFSNTHASH, M_WAITOK,
71	    &ntfs_nthash);
72	simple_lock_init(&ntfs_nthash_slock);
73}
74
75/*
76 * Use the device/inum pair to find the incore inode, and return a pointer
77 * to it. If it is in core, return it, even if it is locked.
78 */
79struct ntnode *
80ntfs_nthashlookup(dev, inum)
81	dev_t dev;
82	ino_t inum;
83{
84	struct ntnode *ip;
85
86	simple_lock(&ntfs_nthash_slock);
87	for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next)
88		if (inum == ip->i_number && dev == ip->i_dev)
89			break;
90	simple_unlock(&ntfs_nthash_slock);
91
92	return (ip);
93}
94
95/*
96 * Insert the ntnode into the hash table.
97 */
98void
99ntfs_nthashins(ip)
100	struct ntnode *ip;
101{
102	struct nthashhead *ipp;
103
104	simple_lock(&ntfs_nthash_slock);
105	ipp = NTNOHASH(ip->i_dev, ip->i_number);
106	LIST_INSERT_HEAD(ipp, ip, i_hash);
107	ip->i_flag |= IN_HASHED;
108	simple_unlock(&ntfs_nthash_slock);
109}
110
111/*
112 * Remove the inode from the hash table.
113 */
114void
115ntfs_nthashrem(ip)
116	struct ntnode *ip;
117{
118	simple_lock(&ntfs_nthash_slock);
119	if (ip->i_flag & IN_HASHED) {
120		ip->i_flag &= ~IN_HASHED;
121		LIST_REMOVE(ip, i_hash);
122#ifdef DIAGNOSTIC
123		ip->i_hash.le_next = NULL;
124		ip->i_hash.le_prev = NULL;
125#endif
126	}
127	simple_unlock(&ntfs_nthash_slock);
128}
129