sys/fs/ntfs/ntfs_ihash.c

   1 /*      $NetBSD: ntfs_ihash.c,v 1.8 2009/03/14 15:36:22 dsl Exp $       */
   2
   3 /*
   4  * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
  32  * Id: ntfs_ihash.c,v 1.5 1999/05/12 09:42:58 semenu Exp
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __KERNEL_RCSID(0, "$NetBSD: ntfs_ihash.c,v 1.8 2009/03/14 15:36:22 dsl Exp $");
  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/proc.h>
  44 #include <sys/mount.h>
  45
  46 #include <fs/ntfs/ntfs.h>
  47 #include <fs/ntfs/ntfs_inode.h>
  48 #include <fs/ntfs/ntfs_ihash.h>
  49
  50 /*
  51  * Structures associated with inode cacheing.
  52  */
  53 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
  54 static u_long   ntfs_nthash;            /* size of hash table - 1 */
  55 #define NTNOHASH(device, inum)  ((minor(device) + (inum)) & ntfs_nthash)
  56 static kmutex_t ntfs_nthash_lock;
  57 kmutex_t ntfs_hashlock;
  58
  59 /*
  60  * Initialize inode hash table.
  61  */
  62 void
  63 ntfs_nthashinit(void)
  64 {
  65         mutex_init(&ntfs_hashlock, MUTEX_DEFAULT, IPL_NONE);
  66         mutex_init(&ntfs_nthash_lock, MUTEX_DEFAULT, IPL_NONE);
  67         ntfs_nthashtbl = hashinit(desiredvnodes, HASH_LIST, true, &ntfs_nthash);
  68 }
  69
  70 /*
  71  * Reinitialize inode hash table.
  72  */
  73
  74 void
  75 ntfs_nthashreinit(void)
  76 {
  77         struct ntnode *ip;
  78         struct nthashhead *oldhash, *hash;
  79         u_long oldmask, mask, val;
  80         int i;
  81
  82         hash = hashinit(desiredvnodes, HASH_LIST, true, &mask);
  83
  84         mutex_enter(&ntfs_nthash_lock);
  85         oldhash = ntfs_nthashtbl;
  86         oldmask = ntfs_nthash;
  87         ntfs_nthashtbl = hash;
  88         ntfs_nthash = mask;
  89         for (i = 0; i <= oldmask; i++) {
  90                 while ((ip = LIST_FIRST(&oldhash[i])) != NULL) {
  91                         LIST_REMOVE(ip, i_hash);
  92                         val = NTNOHASH(ip->i_dev, ip->i_number);
  93                         LIST_INSERT_HEAD(&hash[val], ip, i_hash);
  94                 }
  95         }
  96         mutex_exit(&ntfs_nthash_lock);
  97         hashdone(oldhash, HASH_LIST, oldmask);
  98 }
  99
 100 /*
 101  * Free the inode hash table. Called from ntfs_done(), only needed
 102  * on NetBSD.
 103  */
 104 void
 105 ntfs_nthashdone(void)
 106 {
 107         hashdone(ntfs_nthashtbl, HASH_LIST, ntfs_nthash);
 108         mutex_destroy(&ntfs_hashlock);
 109         mutex_destroy(&ntfs_nthash_lock);
 110 }
 111
 112 /*
 113  * Use the device/inum pair to find the incore inode, and return a pointer
 114  * to it. If it is in core, return it, even if it is locked.
 115  */
 116 struct ntnode *
 117 ntfs_nthashlookup(dev_t dev, ino_t inum)
 118 {
 119         struct ntnode *ip;
 120         struct nthashhead *ipp;
 121
 122         mutex_enter(&ntfs_nthash_lock);
 123         ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)];
 124         LIST_FOREACH(ip, ipp, i_hash) {
 125                 if (inum == ip->i_number && dev == ip->i_dev)
 126                         break;
 127         }
 128         mutex_exit(&ntfs_nthash_lock);
 129
 130         return (ip);
 131 }
 132
 133 /*
 134  * Insert the ntnode into the hash table.
 135  */
 136 void
 137 ntfs_nthashins(struct ntnode *ip)
 138 {
 139         struct nthashhead *ipp;
 140
 141         mutex_enter(&ntfs_nthash_lock);
 142         ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)];
 143         LIST_INSERT_HEAD(ipp, ip, i_hash);
 144         ip->i_flag |= IN_HASHED;
 145         mutex_exit(&ntfs_nthash_lock);
 146 }
 147
 148 /*
 149  * Remove the inode from the hash table.
 150  */
 151 void
 152 ntfs_nthashrem(struct ntnode *ip)
 153 {
 154         mutex_enter(&ntfs_nthash_lock);
 155         if (ip->i_flag & IN_HASHED) {
 156                 ip->i_flag &= ~IN_HASHED;
 157                 LIST_REMOVE(ip, i_hash);
 158         }
 159         mutex_exit(&ntfs_nthash_lock);
 160 }