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 1.2 2003/06/17 04:28:59 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 <ufs/ufs/quota.h> 47 #include <ufs/ufs/inode.h> 48 #include <ufs/ufs/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 #ifndef NULL_SIMPLELOCKS 58 static struct simplelock ufs_ihash_slock; 59 #endif 60 61 /* 62 * Initialize inode hash table. 63 */ 64 void 65 ufs_ihashinit() 66 { 67 68 ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &ihash); 69 simple_lock_init(&ufs_ihash_slock); 70 } 71 72 /* 73 * Use the device/inum pair to find the incore inode, and return a pointer 74 * to it. If it is in core, return it, even if it is locked. 75 */ 76 struct vnode * 77 ufs_ihashlookup(dev, inum) 78 dev_t dev; 79 ino_t inum; 80 { 81 struct inode *ip; 82 83 simple_lock(&ufs_ihash_slock); 84 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) 85 if (inum == ip->i_number && dev == ip->i_dev) 86 break; 87 simple_unlock(&ufs_ihash_slock); 88 89 if (ip) 90 return (ITOV(ip)); 91 return (NULLVP); 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, but locked, wait for it. 97 */ 98 struct vnode * 99 ufs_ihashget(dev, inum) 100 dev_t dev; 101 ino_t inum; 102 { 103 struct proc *p = curproc; /* XXX */ 104 struct inode *ip; 105 struct vnode *vp; 106 107 loop: 108 simple_lock(&ufs_ihash_slock); 109 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) { 110 if (inum == ip->i_number && dev == ip->i_dev) { 111 vp = ITOV(ip); 112 simple_lock(&vp->v_interlock); 113 simple_unlock(&ufs_ihash_slock); 114 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) 115 goto loop; 116 return (vp); 117 } 118 } 119 simple_unlock(&ufs_ihash_slock); 120 return (NULL); 121 } 122 123 /* 124 * Insert the inode into the hash table, and return it locked. 125 */ 126 void 127 ufs_ihashins(ip) 128 struct inode *ip; 129 { 130 struct proc *p = curproc; /* XXX */ 131 struct ihashhead *ipp; 132 133 /* lock the inode, then put it on the appropriate hash list */ 134 lockmgr(&ip->i_lock, LK_EXCLUSIVE, (struct simplelock *)0, p); 135 136 simple_lock(&ufs_ihash_slock); 137 ipp = INOHASH(ip->i_dev, ip->i_number); 138 LIST_INSERT_HEAD(ipp, ip, i_hash); 139 ip->i_flag |= IN_HASHED; 140 simple_unlock(&ufs_ihash_slock); 141 } 142 143 /* 144 * Remove the inode from the hash table. 145 */ 146 void 147 ufs_ihashrem(ip) 148 struct inode *ip; 149 { 150 simple_lock(&ufs_ihash_slock); 151 if (ip->i_flag & IN_HASHED) { 152 ip->i_flag &= ~IN_HASHED; 153 LIST_REMOVE(ip, i_hash); 154 #ifdef DIAGNOSTIC 155 ip->i_hash.le_next = NULL; 156 ip->i_hash.le_prev = NULL; 157 #endif 158 } 159 simple_unlock(&ufs_ihash_slock); 160 } 161