src/sys/ntfs/ntfs_ihash.c

143 lines
4.1 KiB
C

/* $OpenBSD: ntfs_ihash.c,v 1.21 2021/03/11 13:31:35 jsg Exp $ */
/* $NetBSD: ntfs_ihash.c,v 1.1 2002/12/23 17:38:32 jdolecek Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
* Id: ntfs_ihash.c,v 1.5 1999/05/12 09:42:58 semenu Exp
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/rwlock.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <crypto/siphash.h>
#include <ntfs/ntfs.h>
#include <ntfs/ntfs_inode.h>
#include <ntfs/ntfs_ihash.h>
/*
* Structures associated with inode caching.
*/
u_int ntfs_hash(dev_t, ntfsino_t);
static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
static SIPHASH_KEY ntfs_nthashkey;
static u_long ntfs_nthash; /* size of hash table - 1 */
#define NTNOHASH(device, inum) ntfs_hash((device), (inum))
struct rwlock ntfs_hashlock = RWLOCK_INITIALIZER("ntfs_nthashlock");
/*
* Initialize inode hash table.
*/
void
ntfs_nthashinit(void)
{
u_long nthash;
void *nthashtbl;
if (ntfs_nthashtbl)
return;
nthashtbl = hashinit(initialvnodes, M_NTFSNTHASH, M_WAITOK, &nthash);
if (ntfs_nthashtbl) {
hashfree(nthashtbl, initialvnodes, M_NTFSNTHASH);
return;
}
ntfs_nthashtbl = nthashtbl;
ntfs_nthash = nthash;
arc4random_buf(&ntfs_nthashkey, sizeof(ntfs_nthashkey));
}
u_int
ntfs_hash(dev_t dev, ntfsino_t inum)
{
SIPHASH_CTX ctx;
SipHash24_Init(&ctx, &ntfs_nthashkey);
SipHash24_Update(&ctx, &dev, sizeof(dev));
SipHash24_Update(&ctx, &inum, sizeof(inum));
return (SipHash24_End(&ctx) & ntfs_nthash);
}
/*
* Use the device/inum pair to find the incore inode, and return a pointer
* to it. If it is in core, return it, even if it is locked.
*/
struct ntnode *
ntfs_nthashlookup(dev_t dev, ntfsino_t inum)
{
struct ntnode *ip;
struct nthashhead *ipp;
/* XXXLOCKING lock hash list? */
ipp = &ntfs_nthashtbl[NTNOHASH(dev, inum)];
LIST_FOREACH(ip, ipp, i_hash) {
if (inum == ip->i_number && dev == ip->i_dev)
break;
}
/* XXXLOCKING unlock hash list? */
return (ip);
}
/*
* Insert the ntnode into the hash table.
*/
void
ntfs_nthashins(struct ntnode *ip)
{
struct nthashhead *ipp;
/* XXXLOCKING lock hash list? */
ipp = &ntfs_nthashtbl[NTNOHASH(ip->i_dev, ip->i_number)];
LIST_INSERT_HEAD(ipp, ip, i_hash);
ip->i_flag |= IN_HASHED;
/* XXXLOCKING unlock hash list? */
}
/*
* Remove the inode from the hash table.
*/
void
ntfs_nthashrem(struct ntnode *ip)
{
/* XXXLOCKING lock hash list? */
if (ip->i_flag & IN_HASHED) {
ip->i_flag &= ~IN_HASHED;
LIST_REMOVE(ip, i_hash);
}
/* XXXLOCKING unlock hash list? */
}