Change the kernel dev_t, representing a pointer to a specinfo structure,
[dragonfly.git] / sys / vfs / gnu / ext2fs / ext2_ihash.c
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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 $
b13267a5 35 * $DragonFly: src/sys/vfs/gnu/ext2fs/ext2_ihash.c,v 1.4 2006/09/10 01:26:40 dillon Exp $
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36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/kernel.h>
41#include <sys/lock.h>
42#include <sys/vnode.h>
43#include <sys/malloc.h>
44#include <sys/proc.h>
45
46#include "quota.h"
47#include "dinode.h"
48#include "inode.h"
49#include "ext2_extern.h"
50
51static MALLOC_DEFINE(M_EXT2IHASH, "EXT2 ihash", "EXT2 Inode hash tables");
52/*
53 * Structures associated with inode cacheing.
54 */
55static struct inode **ext2_ihashtbl;
56static u_long ext2_ihash; /* size of hash table - 1 */
57static struct lwkt_token ext2_ihash_token;
58
59#define INOHASH(device, inum) (&ext2_ihashtbl[(minor(device) + (inum)) & ext2_ihash])
60
61/*
62 * Initialize inode hash table.
63 */
64void
65ext2_ihashinit(void)
66{
67 ext2_ihash = 16;
68 while (ext2_ihash < desiredvnodes)
69 ext2_ihash <<= 1;
efda3bd0 70 ext2_ihashtbl = kmalloc(sizeof(void *) * ext2_ihash, M_EXT2IHASH, M_WAITOK|M_ZERO);
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71 --ext2_ihash;
72 lwkt_token_init(&ext2_ihash_token);
73}
74
75int
76ext2_uninit(struct vfsconf *vfc)
77{
78 lwkt_tokref ilock;
79
80 lwkt_gettoken(&ilock, &ext2_ihash_token);
81 if (ext2_ihashtbl)
efda3bd0 82 kfree(ext2_ihashtbl, M_EXT2IHASH);
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83 lwkt_reltoken(&ilock);
84
85 return (0);
86}
87/*
88 * Use the device/inum pair to find the incore inode, and return a pointer
89 * to it. If it is in core, return it, even if it is locked.
90 */
91struct vnode *
b13267a5 92ext2_ihashlookup(cdev_t dev, ino_t inum)
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93{
94 struct inode *ip;
95 lwkt_tokref ilock;
96
97 lwkt_gettoken(&ilock, &ext2_ihash_token);
98 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
99 if (inum == ip->i_number && dev == ip->i_dev)
100 break;
101 }
102 lwkt_reltoken(&ilock);
103 if (ip)
104 return (ITOV(ip));
105 return (NULLVP);
106}
107
108/*
109 * Use the device/inum pair to find the incore inode, and return a pointer
110 * to it. If it is in core, but locked, wait for it.
111 *
112 * Note that the serializing tokens do not prevent other processes from
113 * playing with the data structure being protected while we are blocked.
114 * They do protect us from preemptive interrupts which might try to
115 * play with the protected data structure.
116 */
117struct vnode *
b13267a5 118ext2_ihashget(cdev_t dev, ino_t inum)
1f1db49f 119{
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120 lwkt_tokref ilock;
121 struct inode *ip;
122 struct vnode *vp;
123
124 lwkt_gettoken(&ilock, &ext2_ihash_token);
125loop:
126 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
127 if (inum != ip->i_number || dev != ip->i_dev)
128 continue;
129 vp = ITOV(ip);
87de5057 130 if (vget(vp, LK_EXCLUSIVE))
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131 goto loop;
132 /*
133 * We must check to see if the inode has been ripped
134 * out from under us after blocking.
135 */
136 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
137 if (inum == ip->i_number && dev == ip->i_dev)
138 break;
139 }
140 if (ip == NULL || ITOV(ip) != vp) {
141 vput(vp);
142 goto loop;
143 }
144 lwkt_reltoken(&ilock);
145 return (vp);
146 }
147 lwkt_reltoken(&ilock);
148 return (NULL);
149}
150
151/*
152 * Check to see if an inode is in the hash table. This is used to interlock
153 * file free operations to ensure that the vnode is not reused due to a
154 * reallocate of its inode number before we have had a chance to recycle it.
155 */
156int
b13267a5 157ext2_ihashcheck(cdev_t dev, ino_t inum)
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158{
159 lwkt_tokref ilock;
160 struct inode *ip;
161
162 lwkt_gettoken(&ilock, &ext2_ihash_token);
163 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
164 if (inum == ip->i_number && dev == ip->i_dev) {
165 if (ip->i_vnode) {
166 printf("conflict with vnode %p", ip->i_vnode);
167 if (TAILQ_FIRST(&ip->i_vnode->v_namecache))
168 printf(" ncp %s", TAILQ_FIRST(&ip->i_vnode->v_namecache)->nc_name);
169 printf("\n");
170 }
171 break;
172 }
173 }
174 lwkt_reltoken(&ilock);
175 return(ip ? 1 : 0);
176}
177
178/*
179 * Insert the inode into the hash table, and return it locked.
180 */
181int
182ext2_ihashins(struct inode *ip)
183{
184 struct inode **ipp;
185 struct inode *iq;
186 lwkt_tokref ilock;
187
188 KKASSERT((ip->i_flag & IN_HASHED) == 0);
189 lwkt_gettoken(&ilock, &ext2_ihash_token);
190 ipp = INOHASH(ip->i_dev, ip->i_number);
191 while ((iq = *ipp) != NULL) {
192 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
193 lwkt_reltoken(&ilock);
194 return(EBUSY);
195 }
196 ipp = &iq->i_next;
197 }
198 ip->i_next = NULL;
199 *ipp = ip;
200 ip->i_flag |= IN_HASHED;
201 lwkt_reltoken(&ilock);
202 return(0);
203}
204
205/*
206 * Remove the inode from the hash table.
207 */
208void
209ext2_ihashrem(struct inode *ip)
210{
211 lwkt_tokref ilock;
212 struct inode **ipp;
213 struct inode *iq;
214
215 lwkt_gettoken(&ilock, &ext2_ihash_token);
216 if (ip->i_flag & IN_HASHED) {
217 ipp = INOHASH(ip->i_dev, ip->i_number);
218 while ((iq = *ipp) != NULL) {
219 if (ip == iq)
220 break;
221 ipp = &iq->i_next;
222 }
223 KKASSERT(ip == iq);
224 *ipp = ip->i_next;
225 ip->i_next = NULL;
226 ip->i_flag &= ~IN_HASHED;
227 }
228 lwkt_reltoken(&ilock);
229}
230