Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / vfs / ufs / ufs_ihash.c
CommitLineData
984263bc
MD
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 * $FreeBSD: src/sys/ufs/ufs/ufs_ihash.c,v 1.20 1999/08/28 00:52:29 peter 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 <ufs/ufs/quota.h>
46#include <ufs/ufs/inode.h>
47#include <ufs/ufs/ufs_extern.h>
48
49static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables");
50/*
51 * Structures associated with inode cacheing.
52 */
53static LIST_HEAD(ihashhead, inode) *ihashtbl;
54static u_long ihash; /* size of hash table - 1 */
55#define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash])
56#ifndef NULL_SIMPLELOCKS
57static struct simplelock ufs_ihash_slock;
58#endif
59
60/*
61 * Initialize inode hash table.
62 */
63void
64ufs_ihashinit()
65{
66
67 ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &ihash);
68 simple_lock_init(&ufs_ihash_slock);
69}
70
71/*
72 * Use the device/inum pair to find the incore inode, and return a pointer
73 * to it. If it is in core, return it, even if it is locked.
74 */
75struct vnode *
76ufs_ihashlookup(dev, inum)
77 dev_t dev;
78 ino_t inum;
79{
80 struct inode *ip;
81
82 simple_lock(&ufs_ihash_slock);
83 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next)
84 if (inum == ip->i_number && dev == ip->i_dev)
85 break;
86 simple_unlock(&ufs_ihash_slock);
87
88 if (ip)
89 return (ITOV(ip));
90 return (NULLVP);
91}
92
93/*
94 * Use the device/inum pair to find the incore inode, and return a pointer
95 * to it. If it is in core, but locked, wait for it.
96 */
97struct vnode *
98ufs_ihashget(dev, inum)
99 dev_t dev;
100 ino_t inum;
101{
102 struct proc *p = curproc; /* XXX */
103 struct inode *ip;
104 struct vnode *vp;
105
106loop:
107 simple_lock(&ufs_ihash_slock);
108 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
109 if (inum == ip->i_number && dev == ip->i_dev) {
110 vp = ITOV(ip);
111 simple_lock(&vp->v_interlock);
112 simple_unlock(&ufs_ihash_slock);
113 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))
114 goto loop;
115 return (vp);
116 }
117 }
118 simple_unlock(&ufs_ihash_slock);
119 return (NULL);
120}
121
122/*
123 * Insert the inode into the hash table, and return it locked.
124 */
125void
126ufs_ihashins(ip)
127 struct inode *ip;
128{
129 struct proc *p = curproc; /* XXX */
130 struct ihashhead *ipp;
131
132 /* lock the inode, then put it on the appropriate hash list */
133 lockmgr(&ip->i_lock, LK_EXCLUSIVE, (struct simplelock *)0, p);
134
135 simple_lock(&ufs_ihash_slock);
136 ipp = INOHASH(ip->i_dev, ip->i_number);
137 LIST_INSERT_HEAD(ipp, ip, i_hash);
138 ip->i_flag |= IN_HASHED;
139 simple_unlock(&ufs_ihash_slock);
140}
141
142/*
143 * Remove the inode from the hash table.
144 */
145void
146ufs_ihashrem(ip)
147 struct inode *ip;
148{
149 simple_lock(&ufs_ihash_slock);
150 if (ip->i_flag & IN_HASHED) {
151 ip->i_flag &= ~IN_HASHED;
152 LIST_REMOVE(ip, i_hash);
153#ifdef DIAGNOSTIC
154 ip->i_hash.le_next = NULL;
155 ip->i_hash.le_prev = NULL;
156#endif
157 }
158 simple_unlock(&ufs_ihash_slock);
159}