1/*	$NetBSD: ntfs_ihash.c,v 1.5 1999/09/30 16:56:40 jdolecek 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 * 4. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)ufs_ihash.c	8.7 (Berkeley) 5/17/95
32 * $FreeBSD$
33 */
34
35#include <sys/param.h>
36#include <sys/systm.h>
37#include <sys/kernel.h>
38#include <sys/lock.h>
39#include <sys/vnode.h>
40#include <sys/malloc.h>
41#include <sys/mount.h>
42#include <sys/mutex.h>
43
44#include <fs/ntfs/ntfs.h>
45#include <fs/ntfs/ntfs_inode.h>
46#include <fs/ntfs/ntfs_ihash.h>
47
48MALLOC_DEFINE(M_NTFSNTHASH, "ntfs_nthash", "NTFS ntnode hash tables");
49
50/*
51 * Structures associated with inode cacheing.
52 */
53static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
54static u_long	ntfs_nthash;		/* size of hash table - 1 */
55#define	NTNOHASH(inum)	(&ntfs_nthashtbl[(inum) & ntfs_nthash])
56static struct mtx ntfs_nthash_mtx;
57struct lock ntfs_hashlock;
58
59/*
60 * Initialize inode hash table.
61 */
62void
63ntfs_nthashinit()
64{
65	lockinit(&ntfs_hashlock, PINOD, "ntfs_nthashlock", 0, 0);
66	ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash);
67	mtx_init(&ntfs_nthash_mtx, "ntfs nthash", NULL, MTX_DEF);
68}
69
70/*
71 * Destroy inode hash table.
72 */
73void
74ntfs_nthashdestroy(void)
75{
76	hashdestroy(ntfs_nthashtbl, M_NTFSNTHASH, ntfs_nthash);
77	lockdestroy(&ntfs_hashlock);
78	mtx_destroy(&ntfs_nthash_mtx);
79}
80
81/*
82 * Use the device/inum pair to find the incore inode, and return a pointer
83 * to it. If it is in core, return it, even if it is locked.
84 */
85struct ntnode *
86ntfs_nthashlookup(dev, inum)
87	struct cdev *dev;
88	ino_t inum;
89{
90	struct ntnode *ip;
91
92	mtx_lock(&ntfs_nthash_mtx);
93	LIST_FOREACH(ip, NTNOHASH(inum), i_hash)
94		if (inum == ip->i_number && dev == ip->i_dev)
95			break;
96	mtx_unlock(&ntfs_nthash_mtx);
97
98	return (ip);
99}
100
101/*
102 * Insert the ntnode into the hash table.
103 */
104void
105ntfs_nthashins(ip)
106	struct ntnode *ip;
107{
108	struct nthashhead *ipp;
109
110	mtx_lock(&ntfs_nthash_mtx);
111	ipp = NTNOHASH(ip->i_number);
112	LIST_INSERT_HEAD(ipp, ip, i_hash);
113	ip->i_flag |= IN_HASHED;
114	mtx_unlock(&ntfs_nthash_mtx);
115}
116
117/*
118 * Remove the inode from the hash table.
119 */
120void
121ntfs_nthashrem(ip)
122	struct ntnode *ip;
123{
124	mtx_lock(&ntfs_nthash_mtx);
125	if (ip->i_flag & IN_HASHED) {
126		ip->i_flag &= ~IN_HASHED;
127		LIST_REMOVE(ip, i_hash);
128	}
129	mtx_unlock(&ntfs_nthash_mtx);
130}
131