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 8.3 (Berkeley) 09/23/93 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 *ip; 47 48 for (ip = ihashtbl[INOHASH(device, inum)];; ip = ip->i_next) { 49 if (ip == NULL) 50 return (NULL); 51 if (inum == ip->i_number && device == ip->i_dev) 52 return (ITOV(ip)); 53 } 54 /* NOTREACHED */ 55 } 56 57 /* 58 * Use the device/inum pair to find the incore inode, and return a pointer 59 * to it. If it is in core, but locked, wait for it. 60 */ 61 struct vnode * 62 ufs_ihashget(device, inum) 63 dev_t device; 64 ino_t inum; 65 { 66 register struct inode *ip; 67 struct vnode *vp; 68 69 for (;;) 70 for (ip = ihashtbl[INOHASH(device, inum)];; ip = ip->i_next) { 71 if (ip == NULL) 72 return (NULL); 73 if (inum == ip->i_number && device == ip->i_dev) { 74 if (ip->i_flag & IN_LOCKED) { 75 ip->i_flag |= IN_WANTED; 76 sleep(ip, PINOD); 77 break; 78 } 79 vp = ITOV(ip); 80 if (!vget(vp)) 81 return (vp); 82 break; 83 } 84 } 85 /* NOTREACHED */ 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 & IN_LOCKED) 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 |= IN_LOCKED; 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