ntfs_ihash.c revision 151897
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 * 4. 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: head/sys/fs/ntfs/ntfs_ihash.c 151897 2005-10-31 15:41:29Z rwatson $ 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/mount.h> 42#include <sys/mutex.h> 43 44#include <fs/ntfs/ntfs.h> 45#include <fs/ntfs/ntfs_inode.h> 46#include <fs/ntfs/ntfs_ihash.h> 47 48MALLOC_DEFINE(M_NTFSNTHASH, "ntfs_nthash", "NTFS ntnode hash tables"); 49 50/* 51 * Structures associated with inode cacheing. 52 */ 53static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl; 54static u_long ntfs_nthash; /* size of hash table - 1 */ 55#define NTNOHASH(device, inum) (&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash]) 56static struct mtx ntfs_nthash_mtx; 57struct lock ntfs_hashlock; 58 59/* 60 * Initialize inode hash table. 61 */ 62void 63ntfs_nthashinit() 64{ 65 lockinit(&ntfs_hashlock, PINOD, "ntfs_nthashlock", 0, 0); 66 ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash); 67 mtx_init(&ntfs_nthash_mtx, "ntfs nthash", NULL, MTX_DEF); 68} 69 70/* 71 * Destroy inode hash table. 72 */ 73void 74ntfs_nthashdestroy(void) 75{ 76 lockdestroy(&ntfs_hashlock); 77 mtx_destroy(&ntfs_nthash_mtx); 78} 79 80/* 81 * Use the device/inum pair to find the incore inode, and return a pointer 82 * to it. If it is in core, return it, even if it is locked. 83 */ 84struct ntnode * 85ntfs_nthashlookup(dev, inum) 86 struct cdev *dev; 87 ino_t inum; 88{ 89 struct ntnode *ip; 90 91 mtx_lock(&ntfs_nthash_mtx); 92 LIST_FOREACH(ip, NTNOHASH(dev, inum), i_hash) 93 if (inum == ip->i_number && dev == ip->i_dev) 94 break; 95 mtx_unlock(&ntfs_nthash_mtx); 96 97 return (ip); 98} 99 100/* 101 * Insert the ntnode into the hash table. 102 */ 103void 104ntfs_nthashins(ip) 105 struct ntnode *ip; 106{ 107 struct nthashhead *ipp; 108 109 mtx_lock(&ntfs_nthash_mtx); 110 ipp = NTNOHASH(ip->i_dev, ip->i_number); 111 LIST_INSERT_HEAD(ipp, ip, i_hash); 112 ip->i_flag |= IN_HASHED; 113 mtx_unlock(&ntfs_nthash_mtx); 114} 115 116/* 117 * Remove the inode from the hash table. 118 */ 119void 120ntfs_nthashrem(ip) 121 struct ntnode *ip; 122{ 123 mtx_lock(&ntfs_nthash_mtx); 124 if (ip->i_flag & IN_HASHED) { 125 ip->i_flag &= ~IN_HASHED; 126 LIST_REMOVE(ip, i_hash); 127 } 128 mtx_unlock(&ntfs_nthash_mtx); 129} 130