Line data    Source code

       1             : /*      $OpenBSD: ntfs_ihash.c,v 1.20 2016/09/24 18:38:23 tedu Exp $    */
       2             : /*      $NetBSD: ntfs_ihash.c,v 1.1 2002/12/23 17:38:32 jdolecek Exp $  */
       3             : 
       4             : /*
       5             :  * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
       6             :  *      The Regents of the University of California.  All rights reserved.
       7             :  *
       8             :  * Redistribution and use in source and binary forms, with or without
       9             :  * modification, are permitted provided that the following conditions
      10             :  * are met:
      11             :  * 1. Redistributions of source code must retain the above copyright
      12             :  *    notice, this list of conditions and the following disclaimer.
      13             :  * 2. Redistributions in binary form must reproduce the above copyright
      14             :  *    notice, this list of conditions and the following disclaimer in the
      15             :  *    documentation and/or other materials provided with the distribution.
      16             :  * 3. Neither the name of the University nor the names of its contributors
      17             :  *    may be used to endorse or promote products derived from this software
      18             :  *    without specific prior written permission.
      19             :  *
      20             :  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      21             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      22             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      23             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      24             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      25             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      26             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      27             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      28             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      29             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      30             :  * SUCH DAMAGE.
      31             :  *
      32             :  *      @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
      33             :  * Id: ntfs_ihash.c,v 1.5 1999/05/12 09:42:58 semenu Exp
      34             :  */
      35             : 
      36             : #include <sys/param.h>
      37             : #include <sys/systm.h>
      38             : #include <sys/rwlock.h>
      39             : #include <sys/vnode.h>
      40             : #include <sys/malloc.h>
      41             : #include <sys/mount.h>
      42             : 
      43             : #include <crypto/siphash.h>
      44             : 
      45             : #include <ntfs/ntfs.h>
      46             : #include <ntfs/ntfs_inode.h>
      47             : #include <ntfs/ntfs_ihash.h>
      48             : 
      49             : /*
      50             :  * Structures associated with inode cacheing.
      51             :  */
      52             : u_int ntfs_hash(dev_t, ntfsino_t);
      53             : static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
      54             : static SIPHASH_KEY ntfs_nthashkey;
      55             : static u_long   ntfs_nthash;            /* size of hash table - 1 */
      56             : #define NTNOHASH(device, inum) ntfs_hash((device), (inum))
      57             : struct rwlock ntfs_hashlock = RWLOCK_INITIALIZER("ntfs_nthashlock");
      58             : 
      59             : /*
      60             :  * Initialize inode hash table.
      61             :  */
      62             : void
      63           0 : ntfs_nthashinit(void)
      64             : {
      65           0 :         u_long nthash;
      66             :         void *nthashtbl;
      67             : 
      68           0 :         if (ntfs_nthashtbl)
      69           0 :                 return;
      70             : 
      71           0 :         nthashtbl = hashinit(initialvnodes, M_NTFSNTHASH, M_WAITOK, &nthash);
      72           0 :         if (ntfs_nthashtbl) {
      73           0 :                 hashfree(nthashtbl, initialvnodes, M_NTFSNTHASH);
      74           0 :                 return;
      75             :         }
      76           0 :         ntfs_nthashtbl = nthashtbl;
      77           0 :         ntfs_nthash = nthash;
      78             : 
      79           0 :         arc4random_buf(&ntfs_nthashkey, sizeof(ntfs_nthashkey));
      80           0 : }
      81             : 
      82             : u_int
      83           0 : ntfs_hash(dev_t dev, ntfsino_t inum)
      84             : {
      85           0 :         SIPHASH_CTX ctx;
      86             : 
      87           0 :         SipHash24_Init(&ctx, &ntfs_nthashkey);
      88           0 :         SipHash24_Update(&ctx, &dev, sizeof(dev));
      89           0 :         SipHash24_Update(&ctx, &inum, sizeof(inum));
      90             : 
      91           0 :         return (SipHash24_End(&ctx) & ntfs_nthash);
      92           0 : }
      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, return it, even if it is locked.
      97             :  */
      98             : struct ntnode *
      99           0 : ntfs_nthashlookup(dev_t dev, ntfsino_t inum)
     100             : {
     101             :         struct ntnode *ip;
     102             :         struct nthashhead *ipp;
     103             : 
     104             :         /* XXXLOCKING lock hash list? */
     105           0 :         ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)];
     106           0 :         LIST_FOREACH(ip, ipp, i_hash) {
     107           0 :                 if (inum == ip->i_number && dev == ip->i_dev)
     108             :                         break;
     109             :         }
     110             :         /* XXXLOCKING unlock hash list? */
     111             : 
     112           0 :         return (ip);
     113             : }
     114             : 
     115             : /*
     116             :  * Insert the ntnode into the hash table.
     117             :  */
     118             : void
     119           0 : ntfs_nthashins(struct ntnode *ip)
     120             : {
     121             :         struct nthashhead *ipp;
     122             : 
     123             :         /* XXXLOCKING lock hash list? */
     124           0 :         ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)];
     125           0 :         LIST_INSERT_HEAD(ipp, ip, i_hash);
     126           0 :         ip->i_flag |= IN_HASHED;
     127             :         /* XXXLOCKING unlock hash list? */
     128           0 : }
     129             : 
     130             : /*
     131             :  * Remove the inode from the hash table.
     132             :  */
     133             : void
     134           0 : ntfs_nthashrem(struct ntnode *ip)
     135             : {
     136             :         /* XXXLOCKING lock hash list? */
     137           0 :         if (ip->i_flag & IN_HASHED) {
     138           0 :                 ip->i_flag &= ~IN_HASHED;
     139           0 :                 LIST_REMOVE(ip, i_hash);
     140           0 :         }
     141             :         /* XXXLOCKING unlock hash list? */
     142           0 : }