kernel: Move GPL'd kernel files to sys/gnu to have them all in one place.
[dragonfly.git] / sys / gnu / vfs / ext2fs / ext2_ihash.c
CommitLineData
1f1db49f
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 $
1f1db49f
MD
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 "quota.h"
46#include "dinode.h"
47#include "inode.h"
48#include "ext2_extern.h"
49
50static MALLOC_DEFINE(M_EXT2IHASH, "EXT2 ihash", "EXT2 Inode hash tables");
51/*
52 * Structures associated with inode cacheing.
53 */
54static struct inode **ext2_ihashtbl;
55static u_long ext2_ihash; /* size of hash table - 1 */
56static struct lwkt_token ext2_ihash_token;
57
58#define INOHASH(device, inum) (&ext2_ihashtbl[(minor(device) + (inum)) & ext2_ihash])
59
60/*
61 * Initialize inode hash table.
62 */
63void
64ext2_ihashinit(void)
65{
66 ext2_ihash = 16;
67 while (ext2_ihash < desiredvnodes)
68 ext2_ihash <<= 1;
efda3bd0 69 ext2_ihashtbl = kmalloc(sizeof(void *) * ext2_ihash, M_EXT2IHASH, M_WAITOK|M_ZERO);
1f1db49f 70 --ext2_ihash;
a3c18566 71 lwkt_token_init(&ext2_ihash_token, "ext2ihash");
1f1db49f
MD
72}
73
74int
75ext2_uninit(struct vfsconf *vfc)
76{
3b998fa9 77 lwkt_gettoken(&ext2_ihash_token);
1f1db49f 78 if (ext2_ihashtbl)
efda3bd0 79 kfree(ext2_ihashtbl, M_EXT2IHASH);
3b998fa9 80 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
81
82 return (0);
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 vnode *
b13267a5 89ext2_ihashlookup(cdev_t dev, ino_t inum)
1f1db49f
MD
90{
91 struct inode *ip;
1f1db49f 92
3b998fa9 93 lwkt_gettoken(&ext2_ihash_token);
1f1db49f
MD
94 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
95 if (inum == ip->i_number && dev == ip->i_dev)
96 break;
97 }
3b998fa9 98 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
99 if (ip)
100 return (ITOV(ip));
101 return (NULLVP);
102}
103
104/*
105 * Use the device/inum pair to find the incore inode, and return a pointer
106 * to it. If it is in core, but locked, wait for it.
107 *
108 * Note that the serializing tokens do not prevent other processes from
109 * playing with the data structure being protected while we are blocked.
110 * They do protect us from preemptive interrupts which might try to
111 * play with the protected data structure.
112 */
113struct vnode *
b13267a5 114ext2_ihashget(cdev_t dev, ino_t inum)
1f1db49f 115{
1f1db49f
MD
116 struct inode *ip;
117 struct vnode *vp;
118
3b998fa9 119 lwkt_gettoken(&ext2_ihash_token);
1f1db49f
MD
120loop:
121 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
122 if (inum != ip->i_number || dev != ip->i_dev)
123 continue;
124 vp = ITOV(ip);
87de5057 125 if (vget(vp, LK_EXCLUSIVE))
1f1db49f
MD
126 goto loop;
127 /*
128 * We must check to see if the inode has been ripped
129 * out from under us after blocking.
130 */
131 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
132 if (inum == ip->i_number && dev == ip->i_dev)
133 break;
134 }
135 if (ip == NULL || ITOV(ip) != vp) {
136 vput(vp);
137 goto loop;
138 }
3b998fa9 139 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
140 return (vp);
141 }
3b998fa9 142 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
143 return (NULL);
144}
145
146/*
147 * Check to see if an inode is in the hash table. This is used to interlock
148 * file free operations to ensure that the vnode is not reused due to a
149 * reallocate of its inode number before we have had a chance to recycle it.
150 */
151int
b13267a5 152ext2_ihashcheck(cdev_t dev, ino_t inum)
1f1db49f 153{
1f1db49f
MD
154 struct inode *ip;
155
3b998fa9 156 lwkt_gettoken(&ext2_ihash_token);
1f1db49f 157 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
f3dc9d06 158 if (inum == ip->i_number && dev == ip->i_dev)
1f1db49f 159 break;
1f1db49f 160 }
3b998fa9 161 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
162 return(ip ? 1 : 0);
163}
164
165/*
166 * Insert the inode into the hash table, and return it locked.
167 */
168int
169ext2_ihashins(struct inode *ip)
170{
171 struct inode **ipp;
172 struct inode *iq;
1f1db49f
MD
173
174 KKASSERT((ip->i_flag & IN_HASHED) == 0);
3b998fa9 175 lwkt_gettoken(&ext2_ihash_token);
1f1db49f
MD
176 ipp = INOHASH(ip->i_dev, ip->i_number);
177 while ((iq = *ipp) != NULL) {
178 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
3b998fa9 179 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
180 return(EBUSY);
181 }
182 ipp = &iq->i_next;
183 }
184 ip->i_next = NULL;
185 *ipp = ip;
186 ip->i_flag |= IN_HASHED;
3b998fa9 187 lwkt_reltoken(&ext2_ihash_token);
1f1db49f
MD
188 return(0);
189}
190
191/*
192 * Remove the inode from the hash table.
193 */
194void
195ext2_ihashrem(struct inode *ip)
196{
1f1db49f
MD
197 struct inode **ipp;
198 struct inode *iq;
199
3b998fa9 200 lwkt_gettoken(&ext2_ihash_token);
1f1db49f
MD
201 if (ip->i_flag & IN_HASHED) {
202 ipp = INOHASH(ip->i_dev, ip->i_number);
203 while ((iq = *ipp) != NULL) {
204 if (ip == iq)
205 break;
206 ipp = &iq->i_next;
207 }
208 KKASSERT(ip == iq);
209 *ipp = ip->i_next;
210 ip->i_next = NULL;
211 ip->i_flag &= ~IN_HASHED;
212 }
3b998fa9 213 lwkt_reltoken(&ext2_ihash_token);
1f1db49f 214}