1 /* $OpenBSD: fuse_ihash.c,v 1.1 2024/10/31 13:55:21 claudio Exp $ */ 2 /* $NetBSD: ufs_ihash.c,v 1.3 1996/02/09 22:36:04 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)ufs_ihash.c 8.4 (Berkeley) 12/30/93 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/vnode.h> 38 #include <sys/malloc.h> 39 #include <sys/mount.h> 40 #include <sys/lock.h> 41 42 #include "fusefs_node.h" 43 44 #include <crypto/siphash.h> 45 46 /* 47 * Structures associated with inode caching. 48 */ 49 LIST_HEAD(fuse_ihashhead, fusefs_node) *fuse_ihashtbl; 50 u_long fuse_ihashsz; /* size of hash table - 1 */ 51 SIPHASH_KEY fuse_ihashkey; 52 53 struct fuse_ihashhead *fuse_ihash(dev_t, ino_t); 54 55 struct fuse_ihashhead * 56 fuse_ihash(dev_t dev, ino_t inum) 57 { 58 SIPHASH_CTX ctx; 59 60 SipHash24_Init(&ctx, &fuse_ihashkey); 61 SipHash24_Update(&ctx, &dev, sizeof(dev)); 62 SipHash24_Update(&ctx, &inum, sizeof(inum)); 63 64 return (&fuse_ihashtbl[SipHash24_End(&ctx) & fuse_ihashsz]); 65 } 66 67 /* 68 * Initialize inode hash table. 69 */ 70 void 71 fuse_ihashinit(void) 72 { 73 fuse_ihashtbl = hashinit(initialvnodes, M_FUSEFS, M_WAITOK, 74 &fuse_ihashsz); 75 arc4random_buf(&fuse_ihashkey, sizeof(fuse_ihashkey)); 76 } 77 78 /* 79 * Use the device/inum pair to find the incore inode, and return a pointer 80 * to it. If it is in core, but locked, wait for it. 81 */ 82 struct vnode * 83 fuse_ihashget(dev_t dev, ino_t inum) 84 { 85 struct fuse_ihashhead *ipp; 86 struct fusefs_node *ip; 87 struct vnode *vp; 88 loop: 89 /* XXXLOCKING lock hash list */ 90 ipp = fuse_ihash(dev, inum); 91 LIST_FOREACH(ip, ipp, i_hash) { 92 if (inum == ip->i_number && dev == ip->i_dev) { 93 vp = ITOV(ip); 94 /* XXXLOCKING unlock hash list? */ 95 if (vget(vp, LK_EXCLUSIVE)) 96 goto loop; 97 98 return (vp); 99 } 100 } 101 /* XXXLOCKING unlock hash list? */ 102 return (NULL); 103 } 104 105 /* 106 * Insert the inode into the hash table, and return it locked. 107 */ 108 int 109 fuse_ihashins(struct fusefs_node *ip) 110 { 111 struct fusefs_node *curip; 112 struct fuse_ihashhead *ipp; 113 dev_t dev = ip->i_dev; 114 ino_t inum = ip->i_number; 115 116 /* lock the inode, then put it on the appropriate hash list */ 117 VOP_LOCK(ITOV(ip), LK_EXCLUSIVE); 118 119 /* XXXLOCKING lock hash list */ 120 121 ipp = fuse_ihash(dev, inum); 122 LIST_FOREACH(curip, ipp, i_hash) { 123 if (inum == curip->i_number && dev == curip->i_dev) { 124 /* XXXLOCKING unlock hash list? */ 125 VOP_UNLOCK(ITOV(ip)); 126 return (EEXIST); 127 } 128 } 129 130 LIST_INSERT_HEAD(ipp, ip, i_hash); 131 /* XXXLOCKING unlock hash list? */ 132 133 return (0); 134 } 135 136 /* 137 * Remove the inode from the hash table. 138 */ 139 void 140 fuse_ihashrem(struct fusefs_node *ip) 141 { 142 /* XXXLOCKING lock hash list */ 143 144 if (ip->i_hash.le_prev == NULL) 145 return; 146 LIST_REMOVE(ip, i_hash); 147 #ifdef DIAGNOSTIC 148 ip->i_hash.le_next = NULL; 149 ip->i_hash.le_prev = NULL; 150 #endif 151 /* XXXLOCKING unlock hash list? */ 152 } 153