1 /* $OpenBSD: ntfs_ihash.c,v 1.22 2025/01/13 13:58:41 claudio 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 58 /* 59 * Initialize inode hash table. 60 */ 61 void 62 ntfs_nthashinit(void) 63 { 64 u_long nthash; 65 void *nthashtbl; 66 67 if (ntfs_nthashtbl) 68 return; 69 70 nthashtbl = hashinit(initialvnodes, M_NTFSNTHASH, M_WAITOK, &nthash); 71 if (ntfs_nthashtbl) { 72 hashfree(nthashtbl, initialvnodes, M_NTFSNTHASH); 73 return; 74 } 75 ntfs_nthashtbl = nthashtbl; 76 ntfs_nthash = nthash; 77 78 arc4random_buf(&ntfs_nthashkey, sizeof(ntfs_nthashkey)); 79 } 80 81 u_int 82 ntfs_hash(dev_t dev, ntfsino_t inum) 83 { 84 SIPHASH_CTX ctx; 85 86 SipHash24_Init(&ctx, &ntfs_nthashkey); 87 SipHash24_Update(&ctx, &dev, sizeof(dev)); 88 SipHash24_Update(&ctx, &inum, sizeof(inum)); 89 90 return (SipHash24_End(&ctx) & ntfs_nthash); 91 } 92 93 /* 94 * Use the device/inum pair to find the incore inode, and return a pointer 95 * to it. If it is in core, return it, even if it is locked. 96 */ 97 struct ntnode * 98 ntfs_nthashlookup(dev_t dev, ntfsino_t inum) 99 { 100 struct ntnode *ip; 101 struct nthashhead *ipp; 102 103 /* XXXLOCKING lock hash list? */ 104 ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)]; 105 LIST_FOREACH(ip, ipp, i_hash) { 106 if (inum == ip->i_number && dev == ip->i_dev) 107 break; 108 } 109 /* XXXLOCKING unlock hash list? */ 110 111 return (ip); 112 } 113 114 /* 115 * Insert the ntnode into the hash table. 116 */ 117 int 118 ntfs_nthashins(struct ntnode *ip) 119 { 120 struct nthashhead *ipp; 121 struct ntnode *curip; 122 123 /* XXXLOCKING lock hash list? */ 124 ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)]; 125 LIST_FOREACH(curip, ipp, i_hash) { 126 if (ip->i_number == curip->i_number && 127 ip->i_dev == curip->i_dev) 128 return (EEXIST); 129 } 130 131 ip->i_flag |= IN_HASHED; 132 LIST_INSERT_HEAD(ipp, ip, i_hash); 133 /* XXXLOCKING unlock hash list? */ 134 135 return (0); 136 } 137 138 /* 139 * Remove the inode from the hash table. 140 */ 141 void 142 ntfs_nthashrem(struct ntnode *ip) 143 { 144 /* XXXLOCKING lock hash list? */ 145 if (ip->i_flag & IN_HASHED) { 146 ip->i_flag &= ~IN_HASHED; 147 LIST_REMOVE(ip, i_hash); 148 } 149 /* XXXLOCKING unlock hash list? */ 150 } 151