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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 1.12 2004/05/18 00:16:46 cpressey Exp $
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
42 #include <sys/vnode.h>
43 #include <sys/malloc.h>
48 #include "ufs_extern.h"
50 static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables");
52 * Structures associated with inode cacheing.
54 static LIST_HEAD(ihashhead, inode) *ihashtbl;
55 static u_long ihash; /* size of hash table - 1 */
56 #define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash])
57 static struct lwkt_token ufs_ihash_token;
60 * Initialize inode hash table.
65 ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &ihash);
66 lwkt_token_init(&ufs_ihash_token);
70 * Use the device/inum pair to find the incore inode, and return a pointer
71 * to it. If it is in core, return it, even if it is locked.
74 ufs_ihashlookup(dev_t dev, ino_t inum)
79 lwkt_gettoken(&ilock, &ufs_ihash_token);
80 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
81 if (inum == ip->i_number && dev == ip->i_dev)
84 lwkt_reltoken(&ilock);
92 * Use the device/inum pair to find the incore inode, and return a pointer
93 * to it. If it is in core, but locked, wait for it.
95 * Note that the serializing tokens do not prevent other processes from
96 * playing with the data structure being protected while we are blocked.
97 * They do protect us from preemptive interrupts which might try to
98 * play with the protected data structure.
101 ufs_ihashget(dev_t dev, ino_t inum)
103 struct thread *td = curthread; /* XXX */
109 lwkt_gettoken(&ilock, &ufs_ihash_token);
111 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
112 if (inum != ip->i_number || dev != ip->i_dev)
115 lwkt_gettoken(&vlock, vp->v_interlock);
117 * We must check to see if the inode has been ripped
118 * out from under us after blocking.
120 for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
121 if (inum == ip->i_number && dev == ip->i_dev)
124 if (ip == NULL || ITOV(ip) != vp) {
125 lwkt_reltoken(&vlock);
128 if (vget(vp, &vlock, LK_EXCLUSIVE | LK_INTERLOCK, td))
130 lwkt_reltoken(&ilock);
133 lwkt_reltoken(&ilock);
138 * Insert the inode into the hash table, and return it locked.
141 ufs_ihashins(struct inode *ip)
143 struct thread *td = curthread; /* XXX */
144 struct ihashhead *ipp;
147 /* lock the inode, then put it on the appropriate hash list */
148 lockmgr(&ip->i_lock, LK_EXCLUSIVE, NULL, td);
150 lwkt_gettoken(&ilock, &ufs_ihash_token);
151 ipp = INOHASH(ip->i_dev, ip->i_number);
152 LIST_INSERT_HEAD(ipp, ip, i_hash);
153 ip->i_flag |= IN_HASHED;
154 lwkt_reltoken(&ilock);
158 * Remove the inode from the hash table.
161 ufs_ihashrem(struct inode *ip)
165 lwkt_gettoken(&ilock, &ufs_ihash_token);
166 if (ip->i_flag & IN_HASHED) {
167 ip->i_flag &= ~IN_HASHED;
168 LIST_REMOVE(ip, i_hash);
170 ip->i_hash.le_next = NULL;
171 ip->i_hash.le_prev = NULL;
174 lwkt_reltoken(&ilock);