1 /* $OpenBSD: ntfs_ihash.c,v 1.21 2021/03/11 13:31:35 jsg Exp $ */
2 /* $NetBSD: ntfs_ihash.c,v 1.1 2002/12/23 17:38:32 jdolecek Exp $ */
3
4 /*
5 * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
33 * Id: ntfs_ihash.c,v 1.5 1999/05/12 09:42:58 semenu Exp
34 */
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/rwlock.h>
39 #include <sys/vnode.h>
40 #include <sys/malloc.h>
41 #include <sys/mount.h>
42
43 #include <crypto/siphash.h>
44
45 #include <ntfs/ntfs.h>
46 #include <ntfs/ntfs_inode.h>
47 #include <ntfs/ntfs_ihash.h>
48
49 /*
50 * Structures associated with inode caching.
51 */
52 u_int ntfs_hash(dev_t, ntfsino_t);
53 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
54 static SIPHASH_KEY ntfs_nthashkey;
55 static u_long ntfs_nthash; /* size of hash table - 1 */
56 #define NTNOHASH(device, inum) ntfs_hash((device), (inum))
57 struct rwlock ntfs_hashlock = RWLOCK_INITIALIZER("ntfs_nthashlock");
58
59 /*
60 * Initialize inode hash table.
61 */
62 void
ntfs_nthashinit(void)63 ntfs_nthashinit(void)
64 {
65 u_long nthash;
66 void *nthashtbl;
67
68 if (ntfs_nthashtbl)
69 return;
70
71 nthashtbl = hashinit(initialvnodes, M_NTFSNTHASH, M_WAITOK, &nthash);
72 if (ntfs_nthashtbl) {
73 hashfree(nthashtbl, initialvnodes, M_NTFSNTHASH);
74 return;
75 }
76 ntfs_nthashtbl = nthashtbl;
77 ntfs_nthash = nthash;
78
79 arc4random_buf(&ntfs_nthashkey, sizeof(ntfs_nthashkey));
80 }
81
82 u_int
ntfs_hash(dev_t dev,ntfsino_t inum)83 ntfs_hash(dev_t dev, ntfsino_t inum)
84 {
85 SIPHASH_CTX ctx;
86
87 SipHash24_Init(&ctx, &ntfs_nthashkey);
88 SipHash24_Update(&ctx, &dev, sizeof(dev));
89 SipHash24_Update(&ctx, &inum, sizeof(inum));
90
91 return (SipHash24_End(&ctx) & ntfs_nthash);
92 }
93
94 /*
95 * Use the device/inum pair to find the incore inode, and return a pointer
96 * to it. If it is in core, return it, even if it is locked.
97 */
98 struct ntnode *
ntfs_nthashlookup(dev_t dev,ntfsino_t inum)99 ntfs_nthashlookup(dev_t dev, ntfsino_t inum)
100 {
101 struct ntnode *ip;
102 struct nthashhead *ipp;
103
104 /* XXXLOCKING lock hash list? */
105 ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)];
106 LIST_FOREACH(ip, ipp, i_hash) {
107 if (inum == ip->i_number && dev == ip->i_dev)
108 break;
109 }
110 /* XXXLOCKING unlock hash list? */
111
112 return (ip);
113 }
114
115 /*
116 * Insert the ntnode into the hash table.
117 */
118 void
ntfs_nthashins(struct ntnode * ip)119 ntfs_nthashins(struct ntnode *ip)
120 {
121 struct nthashhead *ipp;
122
123 /* XXXLOCKING lock hash list? */
124 ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)];
125 LIST_INSERT_HEAD(ipp, ip, i_hash);
126 ip->i_flag |= IN_HASHED;
127 /* XXXLOCKING unlock hash list? */
128 }
129
130 /*
131 * Remove the inode from the hash table.
132 */
133 void
ntfs_nthashrem(struct ntnode * ip)134 ntfs_nthashrem(struct ntnode *ip)
135 {
136 /* XXXLOCKING lock hash list? */
137 if (ip->i_flag & IN_HASHED) {
138 ip->i_flag &= ~IN_HASHED;
139 LIST_REMOVE(ip, i_hash);
140 }
141 /* XXXLOCKING unlock hash list? */
142 }
143