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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95 34 * $FreeBSD: src/sys/ufs/ufs/ufs_ihash.c,v 1.20 1999/08/28 00:52:29 peter Exp $ 35 * $DragonFly: src/sys/vfs/ufs/ufs_ihash.c,v 1.6 2003/08/07 21:17:44 dillon Exp $ 36 */ 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/malloc.h> 44 #include <sys/proc.h> 45 46 #include "quota.h" 47 #include "inode.h" 48 #include "ufs_extern.h" 49 50 static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables"); 51 /* 52 * Structures associated with inode cacheing. 53 */ 54 static LIST_HEAD(ihashhead, inode) *ihashtbl; 55 static u_long ihash; /* size of hash table - 1 */ 56 #define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash]) 57 static struct lwkt_token ufs_ihash_token; 58 59 /* 60 * Initialize inode hash table. 61 */ 62 void 63 ufs_ihashinit() 64 { 65 ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &ihash); 66 lwkt_inittoken(&ufs_ihash_token); 67 } 68 69 /* 70 * Use the device/inum pair to find the incore inode, and return a pointer 71 * to it. If it is in core, return it, even if it is locked. 72 */ 73 struct vnode * 74 ufs_ihashlookup(dev, inum) 75 dev_t dev; 76 ino_t inum; 77 { 78 struct inode *ip; 79 80 lwkt_gettoken(&ufs_ihash_token); 81 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) 82 if (inum == ip->i_number && dev == ip->i_dev) 83 break; 84 lwkt_reltoken(&ufs_ihash_token); 85 86 if (ip) 87 return (ITOV(ip)); 88 return (NULLVP); 89 } 90 91 /* 92 * Use the device/inum pair to find the incore inode, and return a pointer 93 * to it. If it is in core, but locked, wait for it. 94 */ 95 struct vnode * 96 ufs_ihashget(dev_t dev, ino_t inum) 97 { 98 struct thread *td = curthread; /* XXX */ 99 struct inode *ip; 100 struct vnode *vp; 101 int gen; 102 int vgen; 103 104 gen = lwkt_gettoken(&ufs_ihash_token); 105 loop: 106 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) { 107 if (inum == ip->i_number && dev == ip->i_dev) { 108 vp = ITOV(ip); 109 vgen = lwkt_gettoken(&vp->v_interlock); 110 if (lwkt_gentoken(&ufs_ihash_token, &gen) != 0) { 111 lwkt_reltoken(&vp->v_interlock); 112 goto loop; 113 } 114 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) { 115 lwkt_gentoken(&ufs_ihash_token, &gen); 116 goto loop; 117 } 118 lwkt_reltoken(&ufs_ihash_token); 119 return (vp); 120 } 121 } 122 lwkt_reltoken(&ufs_ihash_token); 123 return (NULL); 124 } 125 126 /* 127 * Insert the inode into the hash table, and return it locked. 128 */ 129 void 130 ufs_ihashins(struct inode *ip) 131 { 132 struct thread *td = curthread; /* XXX */ 133 struct ihashhead *ipp; 134 135 /* lock the inode, then put it on the appropriate hash list */ 136 lockmgr(&ip->i_lock, LK_EXCLUSIVE, NULL, td); 137 138 lwkt_gettoken(&ufs_ihash_token); 139 ipp = INOHASH(ip->i_dev, ip->i_number); 140 LIST_INSERT_HEAD(ipp, ip, i_hash); 141 ip->i_flag |= IN_HASHED; 142 lwkt_reltoken(&ufs_ihash_token); 143 } 144 145 /* 146 * Remove the inode from the hash table. 147 */ 148 void 149 ufs_ihashrem(ip) 150 struct inode *ip; 151 { 152 lwkt_gettoken(&ufs_ihash_token); 153 if (ip->i_flag & IN_HASHED) { 154 ip->i_flag &= ~IN_HASHED; 155 LIST_REMOVE(ip, i_hash); 156 #ifdef DIAGNOSTIC 157 ip->i_hash.le_next = NULL; 158 ip->i_hash.le_prev = NULL; 159 #endif 160 } 161 lwkt_reltoken(&ufs_ihash_token); 162 } 163