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 1.12 2004/10/12 19:20:56 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, 0, "hpfs_hphashlock", 0, 0); 70 hpfs_hphashtbl = HASHINIT(desiredvnodes, M_HPFSHASH, M_WAITOK, 71 &hpfs_hphash); 72 lwkt_token_init(&hpfs_hphash_token); 73 } 74 75 /* 76 * Free the inode hash. 77 */ 78 int 79 hpfs_hphash_uninit(struct vfsconf *vfc) 80 { 81 lwkt_tokref ilock; 82 83 lwkt_gettoken(&ilock, &hpfs_hphash_token); 84 if (hpfs_hphashtbl) 85 free(hpfs_hphashtbl, M_HPFSHASH); 86 lwkt_reltoken(&ilock); 87 88 return 0; 89 } 90 91 /* 92 * Use the device/inum pair to find the incore inode, and return a pointer 93 * to it. If it is in core, return it, even if it is locked. 94 */ 95 struct hpfsnode * 96 hpfs_hphashlookup(dev_t dev, lsn_t ino) 97 { 98 struct hpfsnode *hp; 99 lwkt_tokref ilock; 100 101 lwkt_gettoken(&ilock, &hpfs_hphash_token); 102 for (hp = HPNOHASH(dev, ino)->lh_first; hp; hp = hp->h_hash.le_next) { 103 if (ino == hp->h_no && dev == hp->h_dev) 104 break; 105 } 106 lwkt_reltoken(&ilock); 107 108 return (hp); 109 } 110 111 struct vnode * 112 hpfs_hphashvget(dev_t dev, lsn_t ino, struct thread *td) 113 { 114 struct hpfsnode *hp; 115 lwkt_tokref ilock; 116 struct vnode *vp; 117 118 lwkt_gettoken(&ilock, &hpfs_hphash_token); 119 loop: 120 for (hp = HPNOHASH(dev, ino)->lh_first; hp; hp = hp->h_hash.le_next) { 121 if (ino != hp->h_no || dev != hp->h_dev) 122 continue; 123 vp = HPTOV(hp); 124 125 if (vget(vp, LK_EXCLUSIVE, td)) 126 goto loop; 127 /* 128 * We must check to see if the inode has been ripped 129 * out from under us after blocking. 130 */ 131 for (hp = HPNOHASH(dev, ino)->lh_first; hp; hp = hp->h_hash.le_next) { 132 if (ino == hp->h_no && dev == hp->h_dev) 133 break; 134 } 135 if (hp == NULL || vp != HPTOV(hp)) { 136 vput(vp); 137 goto loop; 138 } 139 140 /* 141 * Or if the vget fails (due to a race) 142 */ 143 lwkt_reltoken(&ilock); 144 return (vp); 145 } 146 lwkt_reltoken(&ilock); 147 return (NULLVP); 148 } 149 150 /* 151 * Insert the hpfsnode into the hash table. 152 */ 153 void 154 hpfs_hphashins(struct hpfsnode *hp) 155 { 156 struct hphashhead *hpp; 157 lwkt_tokref ilock; 158 159 lwkt_gettoken(&ilock, &hpfs_hphash_token); 160 hpp = HPNOHASH(hp->h_dev, hp->h_no); 161 hp->h_flag |= H_HASHED; 162 LIST_INSERT_HEAD(hpp, hp, h_hash); 163 lwkt_reltoken(&ilock); 164 } 165 166 /* 167 * Remove the inode from the hash table. 168 */ 169 void 170 hpfs_hphashrem(struct hpfsnode *hp) 171 { 172 lwkt_tokref ilock; 173 174 lwkt_gettoken(&ilock, &hpfs_hphash_token); 175 if (hp->h_flag & H_HASHED) { 176 hp->h_flag &= ~H_HASHED; 177 LIST_REMOVE(hp, h_hash); 178 #ifdef DIAGNOSTIC 179 hp->h_hash.le_next = NULL; 180 hp->h_hash.le_prev = NULL; 181 #endif 182 } 183 lwkt_reltoken(&ilock); 184 } 185