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/ufs/ufs/ufs_ihash.c,v 1.20 1999/08/28 00:52:29 peter Exp $ 35 * $DragonFly: src/sys/vfs/ufs/ufs_ihash.c,v 1.17 2006/05/06 02:43:14 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/malloc.h> 44 #include <sys/proc.h> 45 46 #include "quota.h" 47 #include "inode.h" 48 #include "ufs_extern.h" 49 50 static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables"); 51 /* 52 * Structures associated with inode cacheing. 53 */ 54 static struct inode **ihashtbl; 55 static u_long ihash; /* size of hash table - 1 */ 56 static struct lwkt_token ufs_ihash_token; 57 58 #define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash]) 59 60 /* 61 * Initialize inode hash table. 62 */ 63 void 64 ufs_ihashinit(void) 65 { 66 ihash = 16; 67 while (ihash < desiredvnodes) 68 ihash <<= 1; 69 ihashtbl = malloc(sizeof(void *) * ihash, M_UFSIHASH, M_WAITOK|M_ZERO); 70 --ihash; 71 lwkt_token_init(&ufs_ihash_token); 72 } 73 74 int 75 ufs_uninit(struct vfsconf *vfc) 76 { 77 lwkt_tokref ilock; 78 79 lwkt_gettoken(&ilock, &ufs_ihash_token); 80 if (ihashtbl) 81 free(ihashtbl, M_UFSIHASH); 82 lwkt_reltoken(&ilock); 83 84 return (0); 85 } 86 /* 87 * Use the device/inum pair to find the incore inode, and return a pointer 88 * to it. If it is in core, return it, even if it is locked. 89 */ 90 struct vnode * 91 ufs_ihashlookup(dev_t dev, ino_t inum) 92 { 93 struct inode *ip; 94 lwkt_tokref ilock; 95 96 lwkt_gettoken(&ilock, &ufs_ihash_token); 97 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) { 98 if (inum == ip->i_number && dev == ip->i_dev) 99 break; 100 } 101 lwkt_reltoken(&ilock); 102 if (ip) 103 return (ITOV(ip)); 104 return (NULLVP); 105 } 106 107 /* 108 * Use the device/inum pair to find the incore inode, and return a pointer 109 * to it. If it is in core, but locked, wait for it. 110 * 111 * Note that the serializing tokens do not prevent other processes from 112 * playing with the data structure being protected while we are blocked. 113 * They do protect us from preemptive interrupts which might try to 114 * play with the protected data structure. 115 */ 116 struct vnode * 117 ufs_ihashget(dev_t dev, ino_t inum) 118 { 119 lwkt_tokref ilock; 120 struct inode *ip; 121 struct vnode *vp; 122 123 lwkt_gettoken(&ilock, &ufs_ihash_token); 124 loop: 125 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) { 126 if (inum != ip->i_number || dev != ip->i_dev) 127 continue; 128 vp = ITOV(ip); 129 if (vget(vp, LK_EXCLUSIVE)) 130 goto loop; 131 /* 132 * We must check to see if the inode has been ripped 133 * out from under us after blocking. 134 */ 135 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) { 136 if (inum == ip->i_number && dev == ip->i_dev) 137 break; 138 } 139 if (ip == NULL || ITOV(ip) != vp) { 140 vput(vp); 141 goto loop; 142 } 143 lwkt_reltoken(&ilock); 144 return (vp); 145 } 146 lwkt_reltoken(&ilock); 147 return (NULL); 148 } 149 150 /* 151 * Check to see if an inode is in the hash table. This is used to interlock 152 * file free operations to ensure that the vnode is not reused due to a 153 * reallocate of its inode number before we have had a chance to recycle it. 154 */ 155 int 156 ufs_ihashcheck(dev_t dev, ino_t inum) 157 { 158 lwkt_tokref ilock; 159 struct inode *ip; 160 161 lwkt_gettoken(&ilock, &ufs_ihash_token); 162 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) { 163 if (inum == ip->i_number && dev == ip->i_dev) { 164 if (ip->i_vnode) { 165 printf("conflict with vnode %p", ip->i_vnode); 166 if (TAILQ_FIRST(&ip->i_vnode->v_namecache)) 167 printf(" ncp %s", TAILQ_FIRST(&ip->i_vnode->v_namecache)->nc_name); 168 printf("\n"); 169 } 170 break; 171 } 172 } 173 lwkt_reltoken(&ilock); 174 return(ip ? 1 : 0); 175 } 176 177 /* 178 * Insert the inode into the hash table, and return it locked. 179 */ 180 int 181 ufs_ihashins(struct inode *ip) 182 { 183 struct inode **ipp; 184 struct inode *iq; 185 lwkt_tokref ilock; 186 187 KKASSERT((ip->i_flag & IN_HASHED) == 0); 188 lwkt_gettoken(&ilock, &ufs_ihash_token); 189 ipp = INOHASH(ip->i_dev, ip->i_number); 190 while ((iq = *ipp) != NULL) { 191 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) { 192 lwkt_reltoken(&ilock); 193 return(EBUSY); 194 } 195 ipp = &iq->i_next; 196 } 197 ip->i_next = NULL; 198 *ipp = ip; 199 ip->i_flag |= IN_HASHED; 200 lwkt_reltoken(&ilock); 201 return(0); 202 } 203 204 /* 205 * Remove the inode from the hash table. 206 */ 207 void 208 ufs_ihashrem(struct inode *ip) 209 { 210 lwkt_tokref ilock; 211 struct inode **ipp; 212 struct inode *iq; 213 214 lwkt_gettoken(&ilock, &ufs_ihash_token); 215 if (ip->i_flag & IN_HASHED) { 216 ipp = INOHASH(ip->i_dev, ip->i_number); 217 while ((iq = *ipp) != NULL) { 218 if (ip == iq) 219 break; 220 ipp = &iq->i_next; 221 } 222 KKASSERT(ip == iq); 223 *ipp = ip->i_next; 224 ip->i_next = NULL; 225 ip->i_flag &= ~IN_HASHED; 226 } 227 lwkt_reltoken(&ilock); 228 } 229 230