ntfs_ihash.c revision 44142 
1/*
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)ufs_ihash.c	8.7 (Berkeley) 5/17/95
34 * $Id: ntfs_ihash.c,v 1.2 1999/01/02 01:17:38 semen Exp $
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <sys/lock.h>
41#include <sys/vnode.h>
42#include <sys/malloc.h>
43#include <sys/proc.h>
44
45#include <ntfs/ntfs.h>
46#include <ntfs/ntfs_inode.h>
47#include <ntfs/ntfs_ihash.h>
48
49MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
50
51/*
52 * Structures associated with inode cacheing.
53 */
54static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
55static u_long	ntfs_nthash;		/* size of hash table - 1 */
56#define	NTNOHASH(device, inum)	(&ntfs_nthashtbl[((device) + (inum)) & ntfs_nthash])
57#ifndef NULL_SIMPLELOCKS
58static struct simplelock ntfs_nthash_slock;
59#endif
60
61/*
62 * Initialize inode hash table.
63 */
64void
65ntfs_nthashinit()
66{
67
68	ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash);
69	simple_lock_init(&ntfs_nthash_slock);
70}
71
72/*
73 * Use the device/inum pair to find the incore inode, and return a pointer
74 * to it. If it is in core, return it, even if it is locked.
75 */
76struct ntnode *
77ntfs_nthashlookup(dev, inum)
78	dev_t dev;
79	ino_t inum;
80{
81	struct ntnode *ip;
82
83	simple_lock(&ntfs_nthash_slock);
84	for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next)
85		if (inum == ip->i_number && dev == ip->i_dev)
86			break;
87	simple_unlock(&ntfs_nthash_slock);
88
89	return (ip);
90}
91
92/*
93 * Insert the ntnode into the hash table.
94 */
95void
96ntfs_nthashins(ip)
97	struct ntnode *ip;
98{
99	struct nthashhead *ipp;
100
101	simple_lock(&ntfs_nthash_slock);
102	ipp = NTNOHASH(ip->i_dev, ip->i_number);
103	LIST_INSERT_HEAD(ipp, ip, i_hash);
104	ip->i_flag |= IN_HASHED;
105	simple_unlock(&ntfs_nthash_slock);
106}
107
108/*
109 * Remove the inode from the hash table.
110 */
111void
112ntfs_nthashrem(ip)
113	struct ntnode *ip;
114{
115	simple_lock(&ntfs_nthash_slock);
116	if (ip->i_flag & IN_HASHED) {
117		ip->i_flag &= ~IN_HASHED;
118		LIST_REMOVE(ip, i_hash);
119#ifdef DIAGNOSTIC
120		ip->i_hash.le_next = NULL;
121		ip->i_hash.le_prev = NULL;
122#endif
123	}
124	simple_unlock(&ntfs_nthash_slock);
125}
126