xref: /dragonfly/sys/vfs/ntfs/ntfs_ihash.c (revision 6a3cbbc2)
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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ufs_ihash.c	8.7 (Berkeley) 5/17/95
32  * $FreeBSD: src/sys/ntfs/ntfs_ihash.c,v 1.7 1999/12/03 20:37:39 semenu Exp $
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/vnode.h>
40 #include <sys/malloc.h>
41 #include <sys/proc.h>
42 #include <sys/mount.h>
43 
44 #include "ntfs.h"
45 #include "ntfs_inode.h"
46 #include "ntfs_ihash.h"
47 
48 MALLOC_DEFINE(M_NTFSNTHASH, "NTFS nthash", "NTFS ntnode hash tables");
49 
50 /*
51  * Structures associated with inode cacheing.
52  */
53 static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
54 static u_long	ntfs_nthash;		/* size of hash table - 1 */
55 #define	NTNOHASH(device, inum)	(&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
56 static struct lwkt_token ntfs_nthash_slock;
57 struct lock ntfs_hashlock;
58 
59 /*
60  * Initialize inode hash table.
61  */
62 void
63 ntfs_nthashinit(void)
64 {
65 	int hsize = vfs_inodehashsize();
66 
67 	lockinit(&ntfs_hashlock, "ntfs_nthashlock", 0, 0);
68 	ntfs_nthashtbl = hashinit(hsize, M_NTFSNTHASH, &ntfs_nthash);
69 	lwkt_token_init(&ntfs_nthash_slock, "ntfsihash");
70 }
71 
72 /*
73  * Free the inode hash table.
74  */
75 int
76 ntfs_nthash_uninit(struct vfsconf *vfc)
77 {
78 	lwkt_gettoken(&ntfs_nthash_slock);
79 	if (ntfs_nthashtbl)
80 		hashdestroy(ntfs_nthashtbl, M_NTFSNTHASH, ntfs_nthash);
81 	lwkt_reltoken(&ntfs_nthash_slock);
82 
83 	return 0;
84 }
85 
86 /*
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.
89  */
90 struct ntnode *
91 ntfs_nthashlookup(cdev_t dev, ino_t inum)
92 {
93 	struct ntnode *ip;
94 
95 	lwkt_gettoken(&ntfs_nthash_slock);
96 	for (ip = NTNOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
97 		if (inum == ip->i_number && dev == ip->i_dev)
98 			break;
99 	}
100 	lwkt_reltoken(&ntfs_nthash_slock);
101 
102 	return (ip);
103 }
104 
105 /*
106  * Insert the ntnode into the hash table.
107  */
108 void
109 ntfs_nthashins(struct ntnode *ip)
110 {
111 	struct nthashhead *ipp;
112 
113 	lwkt_gettoken(&ntfs_nthash_slock);
114 	ipp = NTNOHASH(ip->i_dev, ip->i_number);
115 	LIST_INSERT_HEAD(ipp, ip, i_hash);
116 	ip->i_flag |= IN_HASHED;
117 	lwkt_reltoken(&ntfs_nthash_slock);
118 }
119 
120 /*
121  * Remove the inode from the hash table.
122  */
123 void
124 ntfs_nthashrem(struct ntnode *ip)
125 {
126 	lwkt_gettoken(&ntfs_nthash_slock);
127 	if (ip->i_flag & IN_HASHED) {
128 		ip->i_flag &= ~IN_HASHED;
129 		LIST_REMOVE(ip, i_hash);
130 #ifdef DIAGNOSTIC
131 		ip->i_hash.le_next = NULL;
132 		ip->i_hash.le_prev = NULL;
133 #endif
134 	}
135 	lwkt_reltoken(&ntfs_nthash_slock);
136 }
137