1 /* $OpenBSD: ufs_ihash.c,v 1.25 2021/03/11 13:31:36 jsg Exp $ */ 2 /* $NetBSD: ufs_ihash.c,v 1.3 1996/02/09 22:36:04 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 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 8.4 (Berkeley) 12/30/93 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/vnode.h> 38 #include <sys/malloc.h> 39 40 #include <ufs/ufs/quota.h> 41 #include <ufs/ufs/inode.h> 42 #include <ufs/ufs/ufs_extern.h> 43 44 #include <crypto/siphash.h> 45 46 /* 47 * Structures associated with inode caching. 48 */ 49 LIST_HEAD(ihashhead, inode) *ihashtbl; 50 u_long ihash; /* size of hash table - 1 */ 51 SIPHASH_KEY ihashkey; 52 53 struct ihashhead *ufs_ihash(dev_t, ufsino_t); 54 #define INOHASH(device, inum) ufs_ihash((device), (inum)) 55 56 struct ihashhead * 57 ufs_ihash(dev_t dev, ufsino_t inum) 58 { 59 SIPHASH_CTX ctx; 60 61 SipHash24_Init(&ctx, &ihashkey); 62 SipHash24_Update(&ctx, &dev, sizeof(dev)); 63 SipHash24_Update(&ctx, &inum, sizeof(inum)); 64 65 return (&ihashtbl[SipHash24_End(&ctx) & ihash]); 66 } 67 68 /* 69 * Initialize inode hash table. 70 */ 71 void 72 ufs_ihashinit(void) 73 { 74 ihashtbl = hashinit(initialvnodes, M_UFSMNT, M_WAITOK, &ihash); 75 arc4random_buf(&ihashkey, sizeof(ihashkey)); 76 } 77 78 /* 79 * Use the device/inum pair to find the incore inode, and return a pointer 80 * to it. If it is in core, return it, even if it is locked. 81 */ 82 struct vnode * 83 ufs_ihashlookup(dev_t dev, ufsino_t inum) 84 { 85 struct inode *ip; 86 struct ihashhead *ipp; 87 88 /* XXXLOCKING lock hash list */ 89 ipp = INOHASH(dev, inum); 90 LIST_FOREACH(ip, ipp, i_hash) { 91 if (inum == ip->i_number && dev == ip->i_dev) 92 break; 93 } 94 /* XXXLOCKING unlock hash list? */ 95 96 if (ip) 97 return (ITOV(ip)); 98 99 return (NULLVP); 100 } 101 102 /* 103 * Use the device/inum pair to find the incore inode, and return a pointer 104 * to it. If it is in core, but locked, wait for it. 105 */ 106 struct vnode * 107 ufs_ihashget(dev_t dev, ufsino_t inum) 108 { 109 struct ihashhead *ipp; 110 struct inode *ip; 111 struct vnode *vp; 112 loop: 113 /* XXXLOCKING lock hash list */ 114 ipp = INOHASH(dev, inum); 115 LIST_FOREACH(ip, ipp, i_hash) { 116 if (inum == ip->i_number && dev == ip->i_dev) { 117 vp = ITOV(ip); 118 /* XXXLOCKING unlock hash list? */ 119 if (vget(vp, LK_EXCLUSIVE)) 120 goto loop; 121 return (vp); 122 } 123 } 124 /* XXXLOCKING unlock hash list? */ 125 return (NULL); 126 } 127 128 /* 129 * Insert the inode into the hash table, and return it locked. 130 */ 131 int 132 ufs_ihashins(struct inode *ip) 133 { 134 struct inode *curip; 135 struct ihashhead *ipp; 136 dev_t dev = ip->i_dev; 137 ufsino_t inum = ip->i_number; 138 139 /* lock the inode, then put it on the appropriate hash list */ 140 rrw_enter(&ip->i_lock, RW_WRITE); 141 142 /* XXXLOCKING lock hash list */ 143 144 ipp = INOHASH(dev, inum); 145 LIST_FOREACH(curip, ipp, i_hash) { 146 if (inum == curip->i_number && dev == curip->i_dev) { 147 /* XXXLOCKING unlock hash list? */ 148 rrw_exit(&ip->i_lock); 149 return (EEXIST); 150 } 151 } 152 153 SET(ip->i_flag, IN_HASHED); 154 LIST_INSERT_HEAD(ipp, ip, i_hash); 155 /* XXXLOCKING unlock hash list? */ 156 157 return (0); 158 } 159 160 /* 161 * Remove the inode from the hash table. 162 */ 163 void 164 ufs_ihashrem(struct inode *ip) 165 { 166 /* XXXLOCKING lock hash list */ 167 168 if (ip->i_hash.le_prev == NULL) 169 return; 170 if (ISSET(ip->i_flag, IN_HASHED)) { 171 LIST_REMOVE(ip, i_hash); 172 CLR(ip->i_flag, IN_HASHED); 173 } 174 #ifdef DIAGNOSTIC 175 ip->i_hash.le_next = NULL; 176 ip->i_hash.le_prev = NULL; 177 #endif 178 /* XXXLOCKING unlock hash list? */ 179 } 180