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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 1.19 2006/09/10 01:26:41 dillon 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 struct inode **ihashtbl;
55 static u_long ihash; /* size of hash table - 1 */
56 static struct lwkt_token ufs_ihash_token;
58 #define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash])
61 * Initialize inode hash table.
67 while (ihash < desiredvnodes)
69 ihashtbl = kmalloc(sizeof(void *) * ihash, M_UFSIHASH, M_WAITOK|M_ZERO);
71 lwkt_token_init(&ufs_ihash_token);
75 ufs_uninit(struct vfsconf *vfc)
79 lwkt_gettoken(&ilock, &ufs_ihash_token);
81 kfree(ihashtbl, M_UFSIHASH);
82 lwkt_reltoken(&ilock);
87 * Use the device/inum pair to find the incore inode, and return a pointer
88 * to it. If it is in core, return it, even if it is locked.
91 ufs_ihashlookup(cdev_t dev, ino_t inum)
96 lwkt_gettoken(&ilock, &ufs_ihash_token);
97 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
98 if (inum == ip->i_number && dev == ip->i_dev)
101 lwkt_reltoken(&ilock);
108 * Use the device/inum pair to find the incore inode, and return a pointer
109 * to it. If it is in core, but locked, wait for it.
111 * Note that the serializing tokens do not prevent other processes from
112 * playing with the data structure being protected while we are blocked.
113 * They do protect us from preemptive interrupts which might try to
114 * play with the protected data structure.
117 ufs_ihashget(cdev_t dev, ino_t inum)
123 lwkt_gettoken(&ilock, &ufs_ihash_token);
125 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
126 if (inum != ip->i_number || dev != ip->i_dev)
129 if (vget(vp, LK_EXCLUSIVE))
132 * We must check to see if the inode has been ripped
133 * out from under us after blocking.
135 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
136 if (inum == ip->i_number && dev == ip->i_dev)
139 if (ip == NULL || ITOV(ip) != vp) {
143 lwkt_reltoken(&ilock);
146 lwkt_reltoken(&ilock);
151 * Check to see if an inode is in the hash table. This is used to interlock
152 * file free operations to ensure that the vnode is not reused due to a
153 * reallocate of its inode number before we have had a chance to recycle it.
156 ufs_ihashcheck(cdev_t dev, ino_t inum)
161 lwkt_gettoken(&ilock, &ufs_ihash_token);
162 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
163 if (inum == ip->i_number && dev == ip->i_dev) {
165 printf("conflict with vnode %p", ip->i_vnode);
166 if (TAILQ_FIRST(&ip->i_vnode->v_namecache))
167 printf(" ncp %s", TAILQ_FIRST(&ip->i_vnode->v_namecache)->nc_name);
173 lwkt_reltoken(&ilock);
178 * Insert the inode into the hash table, and return it locked.
181 ufs_ihashins(struct inode *ip)
187 KKASSERT((ip->i_flag & IN_HASHED) == 0);
188 lwkt_gettoken(&ilock, &ufs_ihash_token);
189 ipp = INOHASH(ip->i_dev, ip->i_number);
190 while ((iq = *ipp) != NULL) {
191 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
192 lwkt_reltoken(&ilock);
199 ip->i_flag |= IN_HASHED;
200 lwkt_reltoken(&ilock);
205 * Remove the inode from the hash table.
208 ufs_ihashrem(struct inode *ip)
214 lwkt_gettoken(&ilock, &ufs_ihash_token);
215 if (ip->i_flag & IN_HASHED) {
216 ipp = INOHASH(ip->i_dev, ip->i_number);
217 while ((iq = *ipp) != NULL) {
225 ip->i_flag &= ~IN_HASHED;
227 lwkt_reltoken(&ilock);