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 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/vnode.h> 42 #include <sys/malloc.h> 43 #include <sys/proc.h> 44 45 #include <ufs/ufs/quota.h> 46 #include <ufs/ufs/inode.h> 47 #include <ufs/ufs/ufs_extern.h> 48 49 static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables"); 50 /* 51 * Structures associated with inode cacheing. 52 */ 53 static LIST_HEAD(ihashhead, inode) *ihashtbl; 54 static u_long ihash; /* size of hash table - 1 */ 55 #define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash]) 56 #ifndef NULL_SIMPLELOCKS 57 static struct simplelock ufs_ihash_slock; 58 #endif 59 60 /* 61 * Initialize inode hash table. 62 */ 63 void 64 ufs_ihashinit() 65 { 66 67 ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &ihash); 68 simple_lock_init(&ufs_ihash_slock); 69 } 70 71 /* 72 * Use the device/inum pair to find the incore inode, and return a pointer 73 * to it. If it is in core, return it, even if it is locked. 74 */ 75 struct vnode * 76 ufs_ihashlookup(dev, inum) 77 dev_t dev; 78 ino_t inum; 79 { 80 struct inode *ip; 81 82 simple_lock(&ufs_ihash_slock); 83 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) 84 if (inum == ip->i_number && dev == ip->i_dev) 85 break; 86 simple_unlock(&ufs_ihash_slock); 87 88 if (ip) 89 return (ITOV(ip)); 90 return (NULLVP); 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, but locked, wait for it. 96 */ 97 struct vnode * 98 ufs_ihashget(dev, inum) 99 dev_t dev; 100 ino_t inum; 101 { 102 struct proc *p = curproc; /* XXX */ 103 struct inode *ip; 104 struct vnode *vp; 105 106 loop: 107 simple_lock(&ufs_ihash_slock); 108 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) { 109 if (inum == ip->i_number && dev == ip->i_dev) { 110 vp = ITOV(ip); 111 simple_lock(&vp->v_interlock); 112 simple_unlock(&ufs_ihash_slock); 113 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) 114 goto loop; 115 return (vp); 116 } 117 } 118 simple_unlock(&ufs_ihash_slock); 119 return (NULL); 120 } 121 122 /* 123 * Insert the inode into the hash table, and return it locked. 124 */ 125 void 126 ufs_ihashins(ip) 127 struct inode *ip; 128 { 129 struct proc *p = curproc; /* XXX */ 130 struct ihashhead *ipp; 131 132 /* lock the inode, then put it on the appropriate hash list */ 133 lockmgr(&ip->i_lock, LK_EXCLUSIVE, (struct simplelock *)0, p); 134 135 simple_lock(&ufs_ihash_slock); 136 ipp = INOHASH(ip->i_dev, ip->i_number); 137 LIST_INSERT_HEAD(ipp, ip, i_hash); 138 ip->i_flag |= IN_HASHED; 139 simple_unlock(&ufs_ihash_slock); 140 } 141 142 /* 143 * Remove the inode from the hash table. 144 */ 145 void 146 ufs_ihashrem(ip) 147 struct inode *ip; 148 { 149 simple_lock(&ufs_ihash_slock); 150 if (ip->i_flag & IN_HASHED) { 151 ip->i_flag &= ~IN_HASHED; 152 LIST_REMOVE(ip, i_hash); 153 #ifdef DIAGNOSTIC 154 ip->i_hash.le_next = NULL; 155 ip->i_hash.le_prev = NULL; 156 #endif 157 } 158 simple_unlock(&ufs_ihash_slock); 159 } 160