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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  *      @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
  36  * $FreeBSD: src/sys/ntfs/ntfs_ihash.c,v 1.7 1999/12/03 20:37:39 semenu Exp $
  37  * $DragonFly: src/sys/vfs/ntfs/ntfs_ihash.c,v 1.12 2006/09/10 01:26:41 dillon Exp $
  38  */
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/kernel.h>
  43 #include <sys/lock.h>
  44 #include <sys/vnode.h>
  45 #include <sys/malloc.h>
  46 #include <sys/proc.h>
  47 #include <sys/mount.h>
  48
  49 #include "ntfs.h"
  50 #include "ntfs_inode.h"
  51 #include "ntfs_ihash.h"
  52
  53 MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
  54
  55 /*
  56  * Structures associated with inode cacheing.
  57  */
  58 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
  59 static u_long   ntfs_nthash;            /* size of hash table - 1 */
  60 #define NTNOHASH(device, inum)  (&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
  61 static struct lwkt_token ntfs_nthash_slock;
  62 struct lock ntfs_hashlock;
  63
  64 /*
  65  * Initialize inode hash table.
  66  */
  67 void
  68 ntfs_nthashinit(void)
  69 {
  70         lockinit(&ntfs_hashlock, "ntfs_nthashlock", 0, 0);
  71         ntfs_nthashtbl = HASHINIT(desiredvnodes, M_NTFSNTHASH, M_WAITOK,
  72             &ntfs_nthash);
  73         lwkt_token_init(&ntfs_nthash_slock);
  74 }
  75
  76 /*
  77  * Free the inode hash table.
  78  */
  79 int
  80 ntfs_nthash_uninit(struct vfsconf *vfc)
  81 {
  82         lwkt_tokref ilock;
  83
  84         lwkt_gettoken(&ilock, &ntfs_nthash_slock);
  85         if (ntfs_nthashtbl)
  86                 kfree(ntfs_nthashtbl, M_NTFSNTHASH);
  87         lwkt_reltoken(&ilock);
  88
  89         return 0;
  90 }
  91
  92 /*
  93  * Use the device/inum pair to find the incore inode, and return a pointer
  94  * to it. If it is in core, return it, even if it is locked.
  95  */
  96 struct ntnode *
  97 ntfs_nthashlookup(cdev_t dev, ino_t inum)
  98 {
  99         struct ntnode *ip;
 100         lwkt_tokref ilock;
 101
 102         lwkt_gettoken(&ilock, &ntfs_nthash_slock);
 103         for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
 104                 if (inum == ip->i_number && dev == ip->i_dev)
 105                         break;
 106         }
 107         lwkt_reltoken(&ilock);
 108
 109         return (ip);
 110 }
 111
 112 /*
 113  * Insert the ntnode into the hash table.
 114  */
 115 void
 116 ntfs_nthashins(struct ntnode *ip)
 117 {
 118         struct nthashhead *ipp;
 119         lwkt_tokref ilock;
 120
 121         lwkt_gettoken(&ilock, &ntfs_nthash_slock);
 122         ipp = NTNOHASH(ip->i_dev, ip->i_number);
 123         LIST_INSERT_HEAD(ipp, ip, i_hash);
 124         ip->i_flag |= IN_HASHED;
 125         lwkt_reltoken(&ilock);
 126 }
 127
 128 /*
 129  * Remove the inode from the hash table.
 130  */
 131 void
 132 ntfs_nthashrem(struct ntnode *ip)
 133 {
 134         lwkt_tokref ilock;
 135
 136         lwkt_gettoken(&ilock, &ntfs_nthash_slock);
 137         if (ip->i_flag & IN_HASHED) {
 138                 ip->i_flag &= ~IN_HASHED;
 139                 LIST_REMOVE(ip, i_hash);
 140 #ifdef DIAGNOSTIC
 141                 ip->i_hash.le_next = NULL;
 142                 ip->i_hash.le_prev = NULL;
 143 #endif
 144         }
 145         lwkt_reltoken(&ilock);
 146 }