bsd/ufs/ufs/ufs_ihash.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
  56  */
  57
  58 #include <sys/param.h>
  59 #include <sys/systm.h>
  60 #include <sys/vnode.h>
  61 #include <sys/malloc.h>
  62 #include <sys/proc.h>
  63
  64 #include <ufs/ufs/quota.h>
  65 #include <ufs/ufs/inode.h>
  66 #include <ufs/ufs/ufs_extern.h>
  67
  68 /*
  69  * Structures associated with inode cacheing.
  70  */
  71 LIST_HEAD(ihashhead, inode) *ihashtbl;
  72 u_long  ihash;          /* size of hash table - 1 */
  73 #define INOHASH(device, inum)   (&ihashtbl[((device) + (inum)) & ihash])
  74 struct slock ufs_ihash_slock;
  75
  76 /*
  77  * Initialize inode hash table.
  78  */
  79 void
  80 ufs_ihashinit()
  81 {
  82
  83         ihashtbl = hashinit(desiredvnodes, M_UFSMNT, &ihash);
  84         simple_lock_init(&ufs_ihash_slock);
  85 }
  86
  87 /*
  88  * Use the device/inum pair to find the incore inode, and return a pointer
  89  * to it. If it is in core, return it, even if it is locked.
  90  */
  91 struct vnode *
  92 ufs_ihashlookup(dev, inum)
  93         dev_t dev;
  94         ino_t inum;
  95 {
  96         struct inode *ip;
  97
  98         simple_lock(&ufs_ihash_slock);
  99         for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next)
 100                 if (inum == ip->i_number && dev == ip->i_dev)
 101                         break;
 102         simple_unlock(&ufs_ihash_slock);
 103
 104         if (ip)
 105                 return (ITOV(ip));
 106         return (NULLVP);
 107 }
 108
 109 /*
 110  * Use the device/inum pair to find the incore inode, and return a pointer
 111  * to it. If it is in core, but locked, wait for it.
 112  */
 113 struct vnode *
 114 ufs_ihashget(dev, inum)
 115         dev_t dev;
 116         ino_t inum;
 117 {
 118         struct proc *p = current_proc();        /* XXX */
 119         struct inode *ip;
 120         struct vnode *vp;
 121
 122 loop:
 123         simple_lock(&ufs_ihash_slock);
 124         for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
 125                 if (inum == ip->i_number && dev == ip->i_dev) {
 126                         vp = ITOV(ip);
 127                         simple_lock(&vp->v_interlock);
 128                         simple_unlock(&ufs_ihash_slock);
 129                         if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))
 130                                 goto loop;
 131                         return (vp);
 132                 }
 133         }
 134         simple_unlock(&ufs_ihash_slock);
 135         return (NULL);
 136 }
 137
 138 /*
 139 * Insert the inode into the hash table, and return it locked.
 140  */
 141 void
 142 ufs_ihashins(ip)
 143         struct inode *ip;
 144 {
 145         struct proc *p = current_proc();                /* XXX */
 146         struct ihashhead *ipp;
 147
 148         /* lock the inode, then put it on the appropriate hash list */
 149         lockmgr(&ip->i_lock, LK_EXCLUSIVE, (struct slock *)0, p);
 150
 151         simple_lock(&ufs_ihash_slock);
 152         ipp = INOHASH(ip->i_dev, ip->i_number);
 153         LIST_INSERT_HEAD(ipp, ip, i_hash);
 154         simple_unlock(&ufs_ihash_slock);
 155 }
 156
 157 /*
 158  * Remove the inode from the hash table.
 159  */
 160 void
 161 ufs_ihashrem(ip)
 162         struct inode *ip;
 163 {
 164         struct inode *iq;
 165
 166         simple_lock(&ufs_ihash_slock);
 167         LIST_REMOVE(ip, i_hash);
 168 #if DIAGNOSTIC
 169         ip->i_hash.le_next = NULL;
 170         ip->i_hash.le_prev = NULL;
 171 #endif
 172         simple_unlock(&ufs_ihash_slock);
 173 }