xref: /dragonfly/sys/vfs/ntfs/ntfs_ihash.c (revision 25a2db75)
1 /*	$NetBSD: ntfs_ihash.c,v 1.5 1999/09/30 16:56:40 jdolecek Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)ufs_ihash.c	8.7 (Berkeley) 5/17/95
36  * $FreeBSD: src/sys/ntfs/ntfs_ihash.c,v 1.7 1999/12/03 20:37:39 semenu Exp $
37  */
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/lock.h>
43 #include <sys/vnode.h>
44 #include <sys/malloc.h>
45 #include <sys/proc.h>
46 #include <sys/mount.h>
47 
48 #include "ntfs.h"
49 #include "ntfs_inode.h"
50 #include "ntfs_ihash.h"
51 
52 MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
53 
54 /*
55  * Structures associated with inode cacheing.
56  */
57 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
58 static u_long	ntfs_nthash;		/* size of hash table - 1 */
59 #define	NTNOHASH(device, inum)	(&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
60 static struct lwkt_token ntfs_nthash_slock;
61 struct lock ntfs_hashlock;
62 
63 /*
64  * Initialize inode hash table.
65  */
66 void
67 ntfs_nthashinit(void)
68 {
69 	lockinit(&ntfs_hashlock, "ntfs_nthashlock", 0, 0);
70 	ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash);
71 	lwkt_token_init(&ntfs_nthash_slock, "ntfsihash");
72 }
73 
74 /*
75  * Free the inode hash table.
76  */
77 int
78 ntfs_nthash_uninit(struct vfsconf *vfc)
79 {
80 	lwkt_gettoken(&ntfs_nthash_slock);
81 	if (ntfs_nthashtbl)
82 		hashdestroy(ntfs_nthashtbl, M_NTFSNTHASH, ntfs_nthash);
83 	lwkt_reltoken(&ntfs_nthash_slock);
84 
85 	return 0;
86 }
87 
88 /*
89  * Use the device/inum pair to find the incore inode, and return a pointer
90  * to it. If it is in core, return it, even if it is locked.
91  */
92 struct ntnode *
93 ntfs_nthashlookup(cdev_t dev, ino_t inum)
94 {
95 	struct ntnode *ip;
96 
97 	lwkt_gettoken(&ntfs_nthash_slock);
98 	for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
99 		if (inum == ip->i_number && dev == ip->i_dev)
100 			break;
101 	}
102 	lwkt_reltoken(&ntfs_nthash_slock);
103 
104 	return (ip);
105 }
106 
107 /*
108  * Insert the ntnode into the hash table.
109  */
110 void
111 ntfs_nthashins(struct ntnode *ip)
112 {
113 	struct nthashhead *ipp;
114 
115 	lwkt_gettoken(&ntfs_nthash_slock);
116 	ipp = NTNOHASH(ip->i_dev, ip->i_number);
117 	LIST_INSERT_HEAD(ipp, ip, i_hash);
118 	ip->i_flag |= IN_HASHED;
119 	lwkt_reltoken(&ntfs_nthash_slock);
120 }
121 
122 /*
123  * Remove the inode from the hash table.
124  */
125 void
126 ntfs_nthashrem(struct ntnode *ip)
127 {
128 	lwkt_gettoken(&ntfs_nthash_slock);
129 	if (ip->i_flag & IN_HASHED) {
130 		ip->i_flag &= ~IN_HASHED;
131 		LIST_REMOVE(ip, i_hash);
132 #ifdef DIAGNOSTIC
133 		ip->i_hash.le_next = NULL;
134 		ip->i_hash.le_prev = NULL;
135 #endif
136 	}
137 	lwkt_reltoken(&ntfs_nthash_slock);
138 }
139