1 /* $NetBSD: ntfs_ihash.c,v 1.11 2015/02/20 17:08:13 maxv Exp $ */
2
3 /*
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
32 * Id: ntfs_ihash.c,v 1.5 1999/05/12 09:42:58 semenu Exp
33 */
34
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: ntfs_ihash.c,v 1.11 2015/02/20 17:08:13 maxv Exp $");
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/mount.h>
44 #include <sys/mallocvar.h>
45
46 #include <fs/ntfs/ntfs.h>
47 #include <fs/ntfs/ntfs_inode.h>
48 #include <fs/ntfs/ntfs_ihash.h>
49
50 /*
51 * Structures associated with inode cacheing.
52 */
53 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
54 static u_long ntfs_nthash; /* size of hash table - 1 */
55 #define NTNOHASH(device, inum) ((minor(device) + (inum)) & ntfs_nthash)
56 static kmutex_t ntfs_nthash_lock;
57 kmutex_t ntfs_hashlock;
58
59 /*
60 * Initialize inode hash table.
61 */
62 void
ntfs_nthashinit(void)63 ntfs_nthashinit(void)
64 {
65 mutex_init(&ntfs_hashlock, MUTEX_DEFAULT, IPL_NONE);
66 mutex_init(&ntfs_nthash_lock, MUTEX_DEFAULT, IPL_NONE);
67 ntfs_nthashtbl = hashinit(desiredvnodes, HASH_LIST, true, &ntfs_nthash);
68 }
69
70 /*
71 * Reinitialize inode hash table.
72 */
73
74 void
ntfs_nthashreinit(void)75 ntfs_nthashreinit(void)
76 {
77 struct ntnode *ip;
78 struct nthashhead *oldhash, *hash;
79 u_long oldmask, mask, val;
80 int i;
81
82 hash = hashinit(desiredvnodes, HASH_LIST, true, &mask);
83
84 mutex_enter(&ntfs_nthash_lock);
85 oldhash = ntfs_nthashtbl;
86 oldmask = ntfs_nthash;
87 ntfs_nthashtbl = hash;
88 ntfs_nthash = mask;
89 for (i = 0; i <= oldmask; i++) {
90 while ((ip = LIST_FIRST(&oldhash[i])) != NULL) {
91 LIST_REMOVE(ip, i_hash);
92 val = NTNOHASH(ip->i_dev, ip->i_number);
93 LIST_INSERT_HEAD(&hash[val], ip, i_hash);
94 }
95 }
96 mutex_exit(&ntfs_nthash_lock);
97 hashdone(oldhash, HASH_LIST, oldmask);
98 }
99
100 /*
101 * Free the inode hash table. Called from ntfs_done(), only needed
102 * on NetBSD.
103 */
104 void
ntfs_nthashdone(void)105 ntfs_nthashdone(void)
106 {
107 hashdone(ntfs_nthashtbl, HASH_LIST, ntfs_nthash);
108 mutex_destroy(&ntfs_hashlock);
109 mutex_destroy(&ntfs_nthash_lock);
110 }
111
112 /*
113 * Use the device/inum pair to find the incore inode, and return a pointer
114 * to it. If it is in core, return it, even if it is locked.
115 */
116 struct ntnode *
ntfs_nthashlookup(dev_t dev,ino_t inum)117 ntfs_nthashlookup(dev_t dev, ino_t inum)
118 {
119 struct ntnode *ip;
120 struct nthashhead *ipp;
121
122 mutex_enter(&ntfs_nthash_lock);
123 ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)];
124 LIST_FOREACH(ip, ipp, i_hash) {
125 if (inum == ip->i_number && dev == ip->i_dev)
126 break;
127 }
128 mutex_exit(&ntfs_nthash_lock);
129
130 return (ip);
131 }
132
133 /*
134 * Insert the ntnode into the hash table.
135 */
136 void
ntfs_nthashins(struct ntnode * ip)137 ntfs_nthashins(struct ntnode *ip)
138 {
139 struct nthashhead *ipp;
140
141 mutex_enter(&ntfs_nthash_lock);
142 ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)];
143 LIST_INSERT_HEAD(ipp, ip, i_hash);
144 ip->i_flag |= IN_HASHED;
145 mutex_exit(&ntfs_nthash_lock);
146 }
147
148 /*
149 * Remove the inode from the hash table.
150 */
151 void
ntfs_nthashrem(struct ntnode * ip)152 ntfs_nthashrem(struct ntnode *ip)
153 {
154 mutex_enter(&ntfs_nthash_lock);
155 if (ip->i_flag & IN_HASHED) {
156 ip->i_flag &= ~IN_HASHED;
157 LIST_REMOVE(ip, i_hash);
158 }
159 mutex_exit(&ntfs_nthash_lock);
160 }
161