| 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 | |