1 /* $OpenBSD: ntfs_ihash.c,v 1.15 2014/07/12 18:43:52 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/kernel.h> 39 #include <sys/rwlock.h> 40 #include <sys/vnode.h> 41 #include <sys/malloc.h> 42 #include <sys/proc.h> 43 #include <sys/mount.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 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl; 53 static u_long ntfs_nthash; /* size of hash table - 1 */ 54 #define NTNOHASH(device, inum) ((minor(device) + (inum)) & ntfs_nthash) 55 struct rwlock ntfs_hashlock = RWLOCK_INITIALIZER("ntfs_nthashlock"); 56 57 /* 58 * Initialize inode hash table. 59 */ 60 void 61 ntfs_nthashinit(void) 62 { 63 u_long nthash; 64 void *nthashtbl; 65 66 if (ntfs_nthashtbl) 67 return; 68 69 nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, M_WAITOK, &nthash); 70 if (ntfs_nthashtbl) { 71 free(nthashtbl, M_NTFSNTHASH, 0); 72 return; 73 } 74 ntfs_nthashtbl = nthashtbl; 75 ntfs_nthash = nthash; 76 } 77 78 /* 79 * Use the device/inum pair to find the incore inode, and return a pointer 80 * to it. If it is in core, return it, even if it is locked. 81 */ 82 struct ntnode * 83 ntfs_nthashlookup(dev_t dev, ntfsino_t inum) 84 { 85 struct ntnode *ip; 86 struct nthashhead *ipp; 87 88 /* XXXLOCKING lock hash list? */ 89 ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)]; 90 LIST_FOREACH(ip, ipp, i_hash) { 91 if (inum == ip->i_number && dev == ip->i_dev) 92 break; 93 } 94 /* XXXLOCKING unlock hash list? */ 95 96 return (ip); 97 } 98 99 /* 100 * Insert the ntnode into the hash table. 101 */ 102 void 103 ntfs_nthashins(struct ntnode *ip) 104 { 105 struct nthashhead *ipp; 106 107 /* XXXLOCKING lock hash list? */ 108 ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)]; 109 LIST_INSERT_HEAD(ipp, ip, i_hash); 110 ip->i_flag |= IN_HASHED; 111 /* XXXLOCKING unlock hash list? */ 112 } 113 114 /* 115 * Remove the inode from the hash table. 116 */ 117 void 118 ntfs_nthashrem(struct ntnode *ip) 119 { 120 /* XXXLOCKING lock hash list? */ 121 if (ip->i_flag & IN_HASHED) { 122 ip->i_flag &= ~IN_HASHED; 123 LIST_REMOVE(ip, i_hash); 124 } 125 /* XXXLOCKING unlock hash list? */ 126 } 127