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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/gnu/ext2fs/ext2_ihash.c,v 1.5 2006/10/14 16:26:38 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>
49 #include "ext2_extern.h"
51 static MALLOC_DEFINE(M_EXT2IHASH, "EXT2 ihash", "EXT2 Inode hash tables");
53 * Structures associated with inode cacheing.
55 static struct inode **ext2_ihashtbl;
56 static u_long ext2_ihash; /* size of hash table - 1 */
57 static struct lwkt_token ext2_ihash_token;
59 #define INOHASH(device, inum) (&ext2_ihashtbl[(minor(device) + (inum)) & ext2_ihash])
62 * Initialize inode hash table.
68 while (ext2_ihash < desiredvnodes)
70 ext2_ihashtbl = kmalloc(sizeof(void *) * ext2_ihash, M_EXT2IHASH, M_WAITOK|M_ZERO);
72 lwkt_token_init(&ext2_ihash_token);
76 ext2_uninit(struct vfsconf *vfc)
80 lwkt_gettoken(&ilock, &ext2_ihash_token);
82 kfree(ext2_ihashtbl, M_EXT2IHASH);
83 lwkt_reltoken(&ilock);
88 * Use the device/inum pair to find the incore inode, and return a pointer
89 * to it. If it is in core, return it, even if it is locked.
92 ext2_ihashlookup(cdev_t dev, ino_t inum)
97 lwkt_gettoken(&ilock, &ext2_ihash_token);
98 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
99 if (inum == ip->i_number && dev == ip->i_dev)
102 lwkt_reltoken(&ilock);
109 * Use the device/inum pair to find the incore inode, and return a pointer
110 * to it. If it is in core, but locked, wait for it.
112 * Note that the serializing tokens do not prevent other processes from
113 * playing with the data structure being protected while we are blocked.
114 * They do protect us from preemptive interrupts which might try to
115 * play with the protected data structure.
118 ext2_ihashget(cdev_t dev, ino_t inum)
124 lwkt_gettoken(&ilock, &ext2_ihash_token);
126 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
127 if (inum != ip->i_number || dev != ip->i_dev)
130 if (vget(vp, LK_EXCLUSIVE))
133 * We must check to see if the inode has been ripped
134 * out from under us after blocking.
136 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
137 if (inum == ip->i_number && dev == ip->i_dev)
140 if (ip == NULL || ITOV(ip) != vp) {
144 lwkt_reltoken(&ilock);
147 lwkt_reltoken(&ilock);
152 * Check to see if an inode is in the hash table. This is used to interlock
153 * file free operations to ensure that the vnode is not reused due to a
154 * reallocate of its inode number before we have had a chance to recycle it.
157 ext2_ihashcheck(cdev_t dev, ino_t inum)
162 lwkt_gettoken(&ilock, &ext2_ihash_token);
163 for (ip = *INOHASH(dev, inum); ip; ip = ip->i_next) {
164 if (inum == ip->i_number && dev == ip->i_dev)
167 lwkt_reltoken(&ilock);
172 * Insert the inode into the hash table, and return it locked.
175 ext2_ihashins(struct inode *ip)
181 KKASSERT((ip->i_flag & IN_HASHED) == 0);
182 lwkt_gettoken(&ilock, &ext2_ihash_token);
183 ipp = INOHASH(ip->i_dev, ip->i_number);
184 while ((iq = *ipp) != NULL) {
185 if (ip->i_dev == iq->i_dev && ip->i_number == iq->i_number) {
186 lwkt_reltoken(&ilock);
193 ip->i_flag |= IN_HASHED;
194 lwkt_reltoken(&ilock);
199 * Remove the inode from the hash table.
202 ext2_ihashrem(struct inode *ip)
208 lwkt_gettoken(&ilock, &ext2_ihash_token);
209 if (ip->i_flag & IN_HASHED) {
210 ipp = INOHASH(ip->i_dev, ip->i_number);
211 while ((iq = *ipp) != NULL) {
219 ip->i_flag &= ~IN_HASHED;
221 lwkt_reltoken(&ilock);