1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)ufs_ihash.c 8.1 (Berkeley) 06/11/93 8 */ 9 10 #include <sys/param.h> 11 #include <sys/systm.h> 12 #include <sys/vnode.h> 13 #include <sys/malloc.h> 14 #include <sys/proc.h> 15 16 #include <ufs/ufs/quota.h> 17 #include <ufs/ufs/inode.h> 18 #include <ufs/ufs/ufs_extern.h> 19 20 /* 21 * Structures associated with inode cacheing. 22 */ 23 struct inode **ihashtbl; 24 u_long ihash; /* size of hash table - 1 */ 25 #define INOHASH(dev, ino) (((dev) + (ino)) & ihash) 26 27 /* 28 * Initialize inode hash table. 29 */ 30 void 31 ufs_ihashinit() 32 { 33 34 ihashtbl = hashinit(desiredvnodes, M_UFSMNT, &ihash); 35 } 36 37 /* 38 * Use the dev/ino pair to find the incore inode, and return a pointer to it. 39 * If it is in core, return it, even if it is locked. 40 */ 41 struct vnode * 42 ufs_ihashlookup(dev, ino) 43 dev_t dev; 44 ino_t ino; 45 { 46 register struct inode **ipp, *ip; 47 48 ipp = &ihashtbl[INOHASH(dev, ino)]; 49 loop: 50 for (ip = *ipp; ip; ip = ip->i_next) { 51 if (ino != ip->i_number || dev != ip->i_dev) 52 continue; 53 return (ITOV(ip)); 54 } 55 return (NULL); 56 } 57 58 /* 59 * Use the dev/ino pair to find the incore inode, and return a pointer to it. 60 * If it is in core, but locked, wait for it. 61 */ 62 struct vnode * 63 ufs_ihashget(dev, ino) 64 dev_t dev; 65 ino_t ino; 66 { 67 register struct inode **ipp, *ip; 68 struct vnode *vp; 69 70 ipp = &ihashtbl[INOHASH(dev, ino)]; 71 loop: 72 for (ip = *ipp; ip; ip = ip->i_next) { 73 if (ino != ip->i_number || dev != ip->i_dev) 74 continue; 75 if ((ip->i_flag & ILOCKED) != 0) { 76 ip->i_flag |= IWANT; 77 sleep((caddr_t)ip, PINOD); 78 goto loop; 79 } 80 vp = ITOV(ip); 81 if (vget(vp)) 82 goto loop; 83 return (vp); 84 } 85 return (NULL); 86 } 87 88 /* 89 * Insert the inode into the hash table, and return it locked. 90 */ 91 void 92 ufs_ihashins(ip) 93 struct inode *ip; 94 { 95 struct inode **ipp, *iq; 96 97 ipp = &ihashtbl[INOHASH(ip->i_dev, ip->i_number)]; 98 if (iq = *ipp) 99 iq->i_prev = &ip->i_next; 100 ip->i_next = iq; 101 ip->i_prev = ipp; 102 *ipp = ip; 103 if ((ip->i_flag & ILOCKED) != 0) 104 panic("ufs_ihashins: already locked"); 105 if (curproc) 106 ip->i_lockholder = curproc->p_pid; 107 else 108 ip->i_lockholder = -1; 109 ip->i_flag |= ILOCKED; 110 } 111 112 /* 113 * Remove the inode from the hash table. 114 */ 115 void 116 ufs_ihashrem(ip) 117 register struct inode *ip; 118 { 119 register struct inode *iq; 120 121 if (iq = ip->i_next) 122 iq->i_prev = ip->i_prev; 123 *ip->i_prev = iq; 124 #ifdef DIAGNOSTIC 125 ip->i_next = NULL; 126 ip->i_prev = NULL; 127 #endif 128 } 129