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 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/vnode.h> 42 #include <sys/malloc.h> 43 #include <sys/proc.h> 44 #include <sys/mount.h> 45 46 #include "quota.h" 47 #include "inode.h" 48 #include "ufs_extern.h" 49 #include "ufsmount.h" 50 51 static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables"); 52 53 #define INOHASH(ump, inum) \ 54 (&ump->um_ihashtbl[inum & ump->um_ihash]) 55 56 /* 57 * Initialize inode hash table. 58 */ 59 void 60 ufs_ihashinit(struct ufsmount *ump) 61 { 62 u_long target = desiredvnodes / 4 + 1; 63 64 ump->um_ihash = 16; 65 while (ump->um_ihash < target) 66 ump->um_ihash <<= 1; 67 ump->um_ihashtbl = kmalloc(sizeof(void *) * ump->um_ihash, M_UFSIHASH, 68 M_WAITOK|M_ZERO); 69 --ump->um_ihash; 70 } 71 72 void 73 ufs_ihashuninit(struct ufsmount *ump) 74 { 75 if (ump->um_ihashtbl) { 76 kfree(ump->um_ihashtbl, M_UFSIHASH); 77 ump->um_ihashtbl = NULL; 78 } 79 } 80 81 /* 82 * Use the device/inum pair to find the incore inode, and return a pointer 83 * to it. If it is in core, return it, even if it is locked. 84 */ 85 struct vnode * 86 ufs_ihashlookup(struct ufsmount *ump, cdev_t dev, ino_t inum) 87 { 88 struct inode *ip = NULL; 89 90 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) { 91 if (inum == ip->i_number && dev == ip->i_dev) 92 break; 93 } 94 if (ip) 95 return (ITOV(ip)); 96 return (NULLVP); 97 } 98 99 /* 100 * Use the device/inum pair to find the incore inode, and return a pointer 101 * to it. If it is in core, but locked, wait for it. 102 * 103 * This subroutine may block. 104 */ 105 struct vnode * 106 ufs_ihashget(struct ufsmount *ump, cdev_t dev, ino_t inum) 107 { 108 struct inode *ip; 109 struct vnode *vp; 110 111 loop: 112 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) { 113 if (inum != ip->i_number || dev != ip->i_dev) 114 continue; 115 vp = ITOV(ip); 116 if (vget(vp, LK_EXCLUSIVE)) 117 goto loop; 118 /* 119 * We must check to see if the inode has been ripped 120 * out from under us after blocking. 121 */ 122 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) { 123 if (inum == ip->i_number && dev == ip->i_dev) 124 break; 125 } 126 if (ip == NULL || ITOV(ip) != vp) { 127 vput(vp); 128 goto loop; 129 } 130 return (vp); 131 } 132 return (NULL); 133 } 134 135 /* 136 * Check to see if an inode is in the hash table. This is used to interlock 137 * file free operations to ensure that the vnode is not reused due to a 138 * reallocate of its inode number before we have had a chance to recycle it. 139 */ 140 int 141 ufs_ihashcheck(struct ufsmount *ump, cdev_t dev, ino_t inum) 142 { 143 struct inode *ip; 144 145 for (ip = *INOHASH(ump, inum); ip; ip = ip->i_next) { 146 if (inum == ip->i_number && dev == ip->i_dev) 147 break; 148 } 149 return(ip ? 1 : 0); 150 } 151 152 /* 153 * Insert the inode into the hash table, and return it locked. 154 */ 155 int 156 ufs_ihashins(struct ufsmount *ump, struct inode *ip) 157 { 158 struct inode **ipp; 159 struct inode *iq; 160 161 KKASSERT((ip->i_flag & IN_HASHED) == 0); 162 ipp = INOHASH(ump, ip->i_number); 163 while ((iq = *ipp) != NULL) { 164 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) { 165 return(EBUSY); 166 } 167 ipp = &iq->i_next; 168 } 169 ip->i_next = NULL; 170 *ipp = ip; 171 ip->i_flag |= IN_HASHED; 172 return(0); 173 } 174 175 /* 176 * Remove the inode from the hash table. 177 */ 178 void 179 ufs_ihashrem(struct ufsmount *ump, struct inode *ip) 180 { 181 struct inode **ipp; 182 struct inode *iq; 183 184 if (ip->i_flag & IN_HASHED) { 185 ipp = INOHASH(ump, ip->i_number); 186 while ((iq = *ipp) != NULL) { 187 if (ip == iq) 188 break; 189 ipp = &iq->i_next; 190 } 191 KKASSERT(ip == iq); 192 *ipp = ip->i_next; 193 ip->i_next = NULL; 194 ip->i_flag &= ~IN_HASHED; 195 } 196 } 197 198