1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95 34 * $FreeBSD: src/sys/fs/hpfs/hpfs_hash.c,v 1.1 1999/12/09 19:09:58 semenu Exp $ 35 * $DragonFly: src/sys/vfs/hpfs/hpfs_hash.c,v 1.16 2006/09/10 01:26:40 dillon Exp $ 36 */ 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/mount.h> 44 #include <sys/malloc.h> 45 #include <sys/proc.h> 46 47 #include "hpfs.h" 48 49 MALLOC_DEFINE(M_HPFSHASH, "HPFS hash", "HPFS node hash tables"); 50 51 /* 52 * Structures associated with hpfsnode cacheing. 53 */ 54 static LIST_HEAD(hphashhead, hpfsnode) *hpfs_hphashtbl; 55 static u_long hpfs_hphash; /* size of hash table - 1 */ 56 #define HPNOHASH(dev, lsn) (&hpfs_hphashtbl[(minor(dev) + (lsn)) & hpfs_hphash]) 57 #ifndef NULL_SIMPLELOCKS 58 static struct lwkt_token hpfs_hphash_token; 59 #endif 60 struct lock hpfs_hphash_lock; 61 62 /* 63 * Initialize inode hash table. 64 */ 65 void 66 hpfs_hphashinit(void) 67 { 68 69 lockinit (&hpfs_hphash_lock, "hpfs_hphashlock", 0, 0); 70 hpfs_hphashtbl = HASHINIT(desiredvnodes, M_HPFSHASH, M_WAITOK, 71 &hpfs_hphash); 72 lwkt_token_init(&hpfs_hphash_token, "hpfsihash"); 73 } 74 75 /* 76 * Free the inode hash. 77 */ 78 int 79 hpfs_hphash_uninit(struct vfsconf *vfc) 80 { 81 lwkt_gettoken(&hpfs_hphash_token); 82 if (hpfs_hphashtbl) 83 kfree(hpfs_hphashtbl, M_HPFSHASH); 84 lwkt_reltoken(&hpfs_hphash_token); 85 86 return 0; 87 } 88 89 /* 90 * Use the device/inum pair to find the incore inode, and return a pointer 91 * to it. If it is in core, return it, even if it is locked. 92 */ 93 struct hpfsnode * 94 hpfs_hphashlookup(cdev_t dev, lsn_t ino) 95 { 96 struct hpfsnode *hp; 97 98 lwkt_gettoken(&hpfs_hphash_token); 99 for (hp = HPNOHASH(dev, ino)->lh_first; hp; hp = hp->h_hash.le_next) { 100 if (ino == hp->h_no && dev == hp->h_dev) 101 break; 102 } 103 lwkt_reltoken(&hpfs_hphash_token); 104 105 return (hp); 106 } 107 108 struct vnode * 109 hpfs_hphashvget(cdev_t dev, lsn_t ino) 110 { 111 struct hpfsnode *hp; 112 struct vnode *vp; 113 114 lwkt_gettoken(&hpfs_hphash_token); 115 loop: 116 for (hp = HPNOHASH(dev, ino)->lh_first; hp; hp = hp->h_hash.le_next) { 117 if (ino != hp->h_no || dev != hp->h_dev) 118 continue; 119 vp = HPTOV(hp); 120 121 if (vget(vp, LK_EXCLUSIVE)) 122 goto loop; 123 /* 124 * We must check to see if the inode has been ripped 125 * out from under us after blocking. 126 */ 127 for (hp = HPNOHASH(dev, ino)->lh_first; hp; hp = hp->h_hash.le_next) { 128 if (ino == hp->h_no && dev == hp->h_dev) 129 break; 130 } 131 if (hp == NULL || vp != HPTOV(hp)) { 132 vput(vp); 133 goto loop; 134 } 135 136 /* 137 * Or if the vget fails (due to a race) 138 */ 139 lwkt_reltoken(&hpfs_hphash_token); 140 return (vp); 141 } 142 lwkt_reltoken(&hpfs_hphash_token); 143 return (NULLVP); 144 } 145 146 /* 147 * Insert the hpfsnode into the hash table. 148 */ 149 void 150 hpfs_hphashins(struct hpfsnode *hp) 151 { 152 struct hphashhead *hpp; 153 154 lwkt_gettoken(&hpfs_hphash_token); 155 hpp = HPNOHASH(hp->h_dev, hp->h_no); 156 hp->h_flag |= H_HASHED; 157 LIST_INSERT_HEAD(hpp, hp, h_hash); 158 lwkt_reltoken(&hpfs_hphash_token); 159 } 160 161 /* 162 * Remove the inode from the hash table. 163 */ 164 void 165 hpfs_hphashrem(struct hpfsnode *hp) 166 { 167 lwkt_gettoken(&hpfs_hphash_token); 168 if (hp->h_flag & H_HASHED) { 169 hp->h_flag &= ~H_HASHED; 170 LIST_REMOVE(hp, h_hash); 171 #ifdef DIAGNOSTIC 172 hp->h_hash.le_next = NULL; 173 hp->h_hash.le_prev = NULL; 174 #endif 175 } 176 lwkt_reltoken(&hpfs_hphash_token); 177 } 178