ntfs_ihash.c revision 93818 
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 * 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 93818 2002-04-04 21:03:38Z jhb $
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/mount.h>
46#include <sys/mutex.h>
47
48#include <fs/ntfs/ntfs.h>
49#include <fs/ntfs/ntfs_inode.h>
50#include <fs/ntfs/ntfs_ihash.h>
51
52MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
53
54/*
55 * Structures associated with inode cacheing.
56 */
57static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
58static u_long	ntfs_nthash;		/* size of hash table - 1 */
59#define	NTNOHASH(device, inum)	(&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
60static struct mtx ntfs_nthash_mtx;
61struct lock ntfs_hashlock;
62
63/*
64 * Initialize inode hash table.
65 */
66void
67ntfs_nthashinit()
68{
69	lockinit(&ntfs_hashlock, PINOD, "ntfs_nthashlock", 0, 0);
70	ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash);
71	mtx_init(&ntfs_nthash_mtx, "ntfs nthash", NULL, MTX_DEF);
72}
73
74/*
75 * Destroy inode hash table.
76 */
77void
78ntfs_nthashdestroy(void)
79{
80	lockdestroy(&ntfs_hashlock);
81	mtx_destroy(&ntfs_nthash_mtx);
82}
83
84/*
85 * Use the device/inum pair to find the incore inode, and return a pointer
86 * to it. If it is in core, return it, even if it is locked.
87 */
88struct ntnode *
89ntfs_nthashlookup(dev, inum)
90	dev_t dev;
91	ino_t inum;
92{
93	struct ntnode *ip;
94
95	mtx_lock(&ntfs_nthash_mtx);
96	LIST_FOREACH(ip, NTNOHASH(dev, inum), i_hash)
97		if (inum == ip->i_number && dev == ip->i_dev)
98			break;
99	mtx_unlock(&ntfs_nthash_mtx);
100
101	return (ip);
102}
103
104/*
105 * Insert the ntnode into the hash table.
106 */
107void
108ntfs_nthashins(ip)
109	struct ntnode *ip;
110{
111	struct nthashhead *ipp;
112
113	mtx_lock(&ntfs_nthash_mtx);
114	ipp = NTNOHASH(ip->i_dev, ip->i_number);
115	LIST_INSERT_HEAD(ipp, ip, i_hash);
116	ip->i_flag |= IN_HASHED;
117	mtx_unlock(&ntfs_nthash_mtx);
118}
119
120/*
121 * Remove the inode from the hash table.
122 */
123void
124ntfs_nthashrem(ip)
125	struct ntnode *ip;
126{
127	mtx_lock(&ntfs_nthash_mtx);
128	if (ip->i_flag & IN_HASHED) {
129		ip->i_flag &= ~IN_HASHED;
130		LIST_REMOVE(ip, i_hash);
131	}
132	mtx_unlock(&ntfs_nthash_mtx);
133}
134