1 /* $NetBSD: ntfs_ihash.c,v 1.10 2012/01/27 19:48:40 para 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 1.10 2012/01/27 19:48:40 para 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 #include <sys/mallocvar.h> 46 47 #include <fs/ntfs/ntfs.h> 48 #include <fs/ntfs/ntfs_inode.h> 49 #include <fs/ntfs/ntfs_ihash.h> 50 51 /* 52 * Structures associated with inode cacheing. 53 */ 54 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl; 55 static u_long ntfs_nthash; /* size of hash table - 1 */ 56 #define NTNOHASH(device, inum) ((minor(device) + (inum)) & ntfs_nthash) 57 static kmutex_t ntfs_nthash_lock; 58 kmutex_t ntfs_hashlock; 59 60 /* 61 * Initialize inode hash table. 62 */ 63 void 64 ntfs_nthashinit(void) 65 { 66 mutex_init(&ntfs_hashlock, MUTEX_DEFAULT, IPL_NONE); 67 mutex_init(&ntfs_nthash_lock, MUTEX_DEFAULT, IPL_NONE); 68 ntfs_nthashtbl = hashinit(desiredvnodes, HASH_LIST, true, &ntfs_nthash); 69 } 70 71 /* 72 * Reinitialize inode hash table. 73 */ 74 75 void 76 ntfs_nthashreinit(void) 77 { 78 struct ntnode *ip; 79 struct nthashhead *oldhash, *hash; 80 u_long oldmask, mask, val; 81 int i; 82 83 hash = hashinit(desiredvnodes, HASH_LIST, true, &mask); 84 85 mutex_enter(&ntfs_nthash_lock); 86 oldhash = ntfs_nthashtbl; 87 oldmask = ntfs_nthash; 88 ntfs_nthashtbl = hash; 89 ntfs_nthash = mask; 90 for (i = 0; i <= oldmask; i++) { 91 while ((ip = LIST_FIRST(&oldhash[i])) != NULL) { 92 LIST_REMOVE(ip, i_hash); 93 val = NTNOHASH(ip->i_dev, ip->i_number); 94 LIST_INSERT_HEAD(&hash[val], ip, i_hash); 95 } 96 } 97 mutex_exit(&ntfs_nthash_lock); 98 hashdone(oldhash, HASH_LIST, oldmask); 99 } 100 101 /* 102 * Free the inode hash table. Called from ntfs_done(), only needed 103 * on NetBSD. 104 */ 105 void 106 ntfs_nthashdone(void) 107 { 108 hashdone(ntfs_nthashtbl, HASH_LIST, ntfs_nthash); 109 mutex_destroy(&ntfs_hashlock); 110 mutex_destroy(&ntfs_nthash_lock); 111 } 112 113 /* 114 * Use the device/inum pair to find the incore inode, and return a pointer 115 * to it. If it is in core, return it, even if it is locked. 116 */ 117 struct ntnode * 118 ntfs_nthashlookup(dev_t dev, ino_t inum) 119 { 120 struct ntnode *ip; 121 struct nthashhead *ipp; 122 123 mutex_enter(&ntfs_nthash_lock); 124 ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)]; 125 LIST_FOREACH(ip, ipp, i_hash) { 126 if (inum == ip->i_number && dev == ip->i_dev) 127 break; 128 } 129 mutex_exit(&ntfs_nthash_lock); 130 131 return (ip); 132 } 133 134 /* 135 * Insert the ntnode into the hash table. 136 */ 137 void 138 ntfs_nthashins(struct ntnode *ip) 139 { 140 struct nthashhead *ipp; 141 142 mutex_enter(&ntfs_nthash_lock); 143 ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)]; 144 LIST_INSERT_HEAD(ipp, ip, i_hash); 145 ip->i_flag |= IN_HASHED; 146 mutex_exit(&ntfs_nthash_lock); 147 } 148 149 /* 150 * Remove the inode from the hash table. 151 */ 152 void 153 ntfs_nthashrem(struct ntnode *ip) 154 { 155 mutex_enter(&ntfs_nthash_lock); 156 if (ip->i_flag & IN_HASHED) { 157 ip->i_flag &= ~IN_HASHED; 158 LIST_REMOVE(ip, i_hash); 159 } 160 mutex_exit(&ntfs_nthash_lock); 161 } 162