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 8.2 (Berkeley) 09/05/93 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(device, inum) (((device) + (inum)) & 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 device/inum pair to find the incore inode, and return a pointer 39 * to it. If it is in core, return it, even if it is locked. 40 */ 41 struct vnode * 42 ufs_ihashlookup(device, inum) 43 dev_t device; 44 ino_t inum; 45 { 46 register struct inode **ipp, *ip; 47 48 ipp = &ihashtbl[INOHASH(device, inum)]; 49 for (ip = *ipp; ip; ip = ip->i_next) 50 if (inum == ip->i_number && device == ip->i_dev) 51 return (ITOV(ip)); 52 return (NULL); 53 } 54 55 /* 56 * Use the device/inum pair to find the incore inode, and return a pointer 57 * to it. If it is in core, but locked, wait for it. 58 */ 59 struct vnode * 60 ufs_ihashget(device, inum) 61 dev_t device; 62 ino_t inum; 63 { 64 register struct inode **ipp, *ip; 65 struct vnode *vp; 66 67 ipp = &ihashtbl[INOHASH(device, inum)]; 68 retry: for (ip = *ipp; ip != NULL; ip = ip->i_next) 69 if (inum == ip->i_number && device == ip->i_dev) { 70 if (ip->i_flag & ILOCKED) { 71 ip->i_flag |= IWANT; 72 sleep(ip, PINOD); 73 goto retry; 74 } 75 vp = ITOV(ip); 76 if (vget(vp)) 77 goto retry; 78 return (vp); 79 } 80 return (NULL); 81 } 82 83 /* 84 * Insert the inode into the hash table, and return it locked. 85 */ 86 void 87 ufs_ihashins(ip) 88 struct inode *ip; 89 { 90 struct inode **ipp, *iq; 91 92 ipp = &ihashtbl[INOHASH(ip->i_dev, ip->i_number)]; 93 if (iq = *ipp) 94 iq->i_prev = &ip->i_next; 95 ip->i_next = iq; 96 ip->i_prev = ipp; 97 *ipp = ip; 98 if ((ip->i_flag & ILOCKED) != 0) 99 panic("ufs_ihashins: already locked"); 100 if (curproc) 101 ip->i_lockholder = curproc->p_pid; 102 else 103 ip->i_lockholder = -1; 104 ip->i_flag |= ILOCKED; 105 } 106 107 /* 108 * Remove the inode from the hash table. 109 */ 110 void 111 ufs_ihashrem(ip) 112 register struct inode *ip; 113 { 114 register struct inode *iq; 115 116 if (iq = ip->i_next) 117 iq->i_prev = ip->i_prev; 118 *ip->i_prev = iq; 119 #ifdef DIAGNOSTIC 120 ip->i_next = NULL; 121 ip->i_prev = NULL; 122 #endif 123 } 124