sys/vfs/ntfs/ntfs_ihash.c

   1 /*      $NetBSD: ntfs_ihash.c,v 1.5 1999/09/30 16:56:40 jdolecek 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  * $FreeBSD: src/sys/ntfs/ntfs_ihash.c,v 1.7 1999/12/03 20:37:39 semenu Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/kernel.h>
  38 #include <sys/lock.h>
  39 #include <sys/vnode.h>
  40 #include <sys/malloc.h>
  41 #include <sys/proc.h>
  42 #include <sys/mount.h>
  43
  44 #include "ntfs.h"
  45 #include "ntfs_inode.h"
  46 #include "ntfs_ihash.h"
  47
  48 MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
  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)  (&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
  56 static struct lwkt_token ntfs_nthash_slock;
  57 struct lock ntfs_hashlock;
  58
  59 /*
  60  * Initialize inode hash table.
  61  */
  62 void
  63 ntfs_nthashinit(void)
  64 {
  65         int hsize = vfs_inodehashsize();
  66
  67         lockinit(&ntfs_hashlock, "ntfs_nthashlock", 0, 0);
  68         ntfs_nthashtbl = hashinit(hsize, M_NTFSNTHASH, &ntfs_nthash);
  69         lwkt_token_init(&ntfs_nthash_slock, "ntfsihash");
  70 }
  71
  72 /*
  73  * Free the inode hash table.
  74  */
  75 int
  76 ntfs_nthash_uninit(struct vfsconf *vfc)
  77 {
  78         lwkt_gettoken(&ntfs_nthash_slock);
  79         if (ntfs_nthashtbl)
  80                 hashdestroy(ntfs_nthashtbl, M_NTFSNTHASH, ntfs_nthash);
  81         lwkt_reltoken(&ntfs_nthash_slock);
  82
  83         return 0;
  84 }
  85
  86 /*
  87  * Use the device/inum pair to find the incore inode, and return a pointer
  88  * to it. If it is in core, return it, even if it is locked.
  89  */
  90 struct ntnode *
  91 ntfs_nthashlookup(cdev_t dev, ino_t inum)
  92 {
  93         struct ntnode *ip;
  94
  95         lwkt_gettoken(&ntfs_nthash_slock);
  96         for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
  97                 if (inum == ip->i_number && dev == ip->i_dev)
  98                         break;
  99         }
 100         lwkt_reltoken(&ntfs_nthash_slock);
 101
 102         return (ip);
 103 }
 104
 105 /*
 106  * Insert the ntnode into the hash table.
 107  */
 108 void
 109 ntfs_nthashins(struct ntnode *ip)
 110 {
 111         struct nthashhead *ipp;
 112
 113         lwkt_gettoken(&ntfs_nthash_slock);
 114         ipp = NTNOHASH(ip->i_dev, ip->i_number);
 115         LIST_INSERT_HEAD(ipp, ip, i_hash);
 116         ip->i_flag |= IN_HASHED;
 117         lwkt_reltoken(&ntfs_nthash_slock);
 118 }
 119
 120 /*
 121  * Remove the inode from the hash table.
 122  */
 123 void
 124 ntfs_nthashrem(struct ntnode *ip)
 125 {
 126         lwkt_gettoken(&ntfs_nthash_slock);
 127         if (ip->i_flag & IN_HASHED) {
 128                 ip->i_flag &= ~IN_HASHED;
 129                 LIST_REMOVE(ip, i_hash);
 130 #ifdef DIAGNOSTIC
 131                 ip->i_hash.le_next = NULL;
 132                 ip->i_hash.le_prev = NULL;
 133 #endif
 134         }
 135         lwkt_reltoken(&ntfs_nthash_slock);
 136 }