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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
30 * $FreeBSD: src/sys/ufs/ufs/ufs_ihash.c,v 1.20 1999/08/28 00:52:29 peter Exp $
31 */
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/vnode.h>
38 #include <sys/malloc.h>
39 #include <sys/proc.h>
40 #include <sys/mount.h>
41
42 #include "quota.h"
43 #include "inode.h"
44 #include "ufs_extern.h"
45 #include "ufsmount.h"
46
47 static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables");
48
49 #define INOHASH(ump, inum) \
50 (&ump->um_ihashtbl[inum & ump->um_ihash])
51
52 /*
53 * Initialize inode hash table.
54 */
55 void
ufs_ihashinit(struct ufsmount * ump)56 ufs_ihashinit(struct ufsmount *ump)
57 {
58 ump->um_ihash = vfs_inodehashsize();
59 ump->um_ihashtbl = kmalloc(sizeof(void *) * ump->um_ihash,
60 M_UFSIHASH,
61 M_WAITOK|M_ZERO);
62 --ump->um_ihash;
63 }
64
65 void
ufs_ihashuninit(struct ufsmount * ump)66 ufs_ihashuninit(struct ufsmount *ump)
67 {
68 if (ump->um_ihashtbl) {
69 kfree(ump->um_ihashtbl, M_UFSIHASH);
70 ump->um_ihashtbl = NULL;
71 }
72 }
73
74 /*
75 * Use the device/inum pair to find the incore inode, and return a pointer
76 * to it. If it is in core, return it, even if it is locked.
77 */
78 struct vnode *
ufs_ihashlookup(struct ufsmount * ump,cdev_t dev,ino_t inum)79 ufs_ihashlookup(struct ufsmount *ump, cdev_t dev, ino_t inum)
80 {
81 struct inode *ip = NULL;
82
83 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) {
84 if (inum == ip->i_number && dev == ip->i_dev)
85 break;
86 }
87 if (ip)
88 return (ITOV(ip));
89 return (NULLVP);
90 }
91
92 /*
93 * Use the device/inum pair to find the incore inode, and return a pointer
94 * to it. If it is in core, but locked, wait for it.
95 *
96 * This subroutine may block.
97 */
98 struct vnode *
ufs_ihashget(struct ufsmount * ump,cdev_t dev,ino_t inum)99 ufs_ihashget(struct ufsmount *ump, cdev_t dev, ino_t inum)
100 {
101 struct inode *ip;
102 struct vnode *vp;
103
104 loop:
105 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) {
106 if (inum != ip->i_number || dev != ip->i_dev)
107 continue;
108 vp = ITOV(ip);
109 if (vget(vp, LK_EXCLUSIVE))
110 goto loop;
111 /*
112 * We must check to see if the inode has been ripped
113 * out from under us after blocking.
114 */
115 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) {
116 if (inum == ip->i_number && dev == ip->i_dev)
117 break;
118 }
119 if (ip == NULL || ITOV(ip) != vp) {
120 vput(vp);
121 goto loop;
122 }
123 return (vp);
124 }
125 return (NULL);
126 }
127
128 /*
129 * Check to see if an inode is in the hash table. This is used to interlock
130 * file free operations to ensure that the vnode is not reused due to a
131 * reallocate of its inode number before we have had a chance to recycle it.
132 */
133 int
ufs_ihashcheck(struct ufsmount * ump,cdev_t dev,ino_t inum)134 ufs_ihashcheck(struct ufsmount *ump, cdev_t dev, ino_t inum)
135 {
136 struct inode *ip;
137
138 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) {
139 if (inum == ip->i_number && dev == ip->i_dev)
140 break;
141 }
142 return(ip ? 1 : 0);
143 }
144
145 /*
146 * Insert the inode into the hash table, and return it locked.
147 */
148 int
ufs_ihashins(struct ufsmount * ump,struct inode * ip)149 ufs_ihashins(struct ufsmount *ump, struct inode *ip)
150 {
151 struct inode **ipp;
152 struct inode *iq;
153
154 KKASSERT((ip->i_flag & IN_HASHED) == 0);
155 ipp = INOHASH(ump, ip->i_number);
156 while ((iq = *ipp) != NULL) {
157 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
158 return(EBUSY);
159 }
160 ipp = &iq->i_next;
161 }
162 ip->i_next = NULL;
163 *ipp = ip;
164 ip->i_flag |= IN_HASHED;
165 return(0);
166 }
167
168 /*
169 * Remove the inode from the hash table.
170 */
171 void
ufs_ihashrem(struct ufsmount * ump,struct inode * ip)172 ufs_ihashrem(struct ufsmount *ump, struct inode *ip)
173 {
174 struct inode **ipp;
175 struct inode *iq;
176
177 if (ip->i_flag & IN_HASHED) {
178 ipp = INOHASH(ump, ip->i_number);
179 while ((iq = *ipp) != NULL) {
180 if (ip == iq)
181 break;
182 ipp = &iq->i_next;
183 }
184 KKASSERT(ip == iq);
185 *ipp = ip->i_next;
186 ip->i_next = NULL;
187 ip->i_flag &= ~IN_HASHED;
188 }
189 }
190
191