freebsd-dev/sys/fs/hpfs/hpfs_hash.c

180 lines
4.6 KiB
C

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/mutex.h>
#include <fs/hpfs/hpfs.h>
MALLOC_DEFINE(M_HPFSHASH, "HPFS hash", "HPFS node hash tables");
/*
* Structures associated with hpfsnode cacheing.
*/
static LIST_HEAD(hphashhead, hpfsnode) *hpfs_hphashtbl;
static u_long hpfs_hphash; /* size of hash table - 1 */
#define HPNOHASH(dev, lsn) (&hpfs_hphashtbl[(minor(dev) + (lsn)) & hpfs_hphash])
static struct mtx hpfs_hphash_mtx;
struct lock hpfs_hphash_lock;
/*
* Initialize inode hash table.
*/
void
hpfs_hphashinit()
{
lockinit (&hpfs_hphash_lock, PINOD, "hpfs_hphashlock", 0, 0);
hpfs_hphashtbl = hashinit(desiredvnodes, M_HPFSHASH, &hpfs_hphash);
mtx_init(&hpfs_hphash_mtx, "hpfs hphash", MTX_DEF);
}
/*
* Destroy inode hash table.
*/
void
hpfs_hphashdestroy(void)
{
lockdestroy(&hpfs_hphash_lock);
mtx_destroy(&hpfs_hphash_mtx);
}
/*
* 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 hpfsnode *
hpfs_hphashlookup(dev, ino)
dev_t dev;
lsn_t ino;
{
struct hpfsnode *hp;
mtx_lock(&hpfs_hphash_mtx);
LIST_FOREACH(hp, HPNOHASH(dev, ino), h_hash)
if (ino == hp->h_no && dev == hp->h_dev)
break;
mtx_unlock(&hpfs_hphash_mtx);
return (hp);
}
#if 0
struct hpfsnode *
hpfs_hphashget(dev, ino)
dev_t dev;
lsn_t ino;
{
struct hpfsnode *hp;
loop:
mtx_lock(&hpfs_hphash_mtx);
LIST_FOREACH(hp, HPNOHASH(dev, ino), h_hash) {
if (ino == hp->h_no && dev == hp->h_dev) {
lockmgr(&hp->h_intlock, LK_EXCLUSIVE | LK_INTERLOCK,
&hpfs_hphash_slock, NULL);
return (hp);
}
}
mtx_unlock(&hpfs_hphash_mtx);
return (hp);
}
#endif
struct vnode *
hpfs_hphashvget(dev, ino, td)
dev_t dev;
lsn_t ino;
struct thread *td;
{
struct hpfsnode *hp;
struct vnode *vp;
loop:
mtx_lock(&hpfs_hphash_mtx);
LIST_FOREACH(hp, HPNOHASH(dev, ino), h_hash) {
if (ino == hp->h_no && dev == hp->h_dev) {
vp = HPTOV(hp);
mtx_lock(&vp->v_interlock);
mtx_unlock(&hpfs_hphash_mtx);
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td))
goto loop;
return (vp);
}
}
mtx_unlock(&hpfs_hphash_mtx);
return (NULLVP);
}
/*
* Insert the hpfsnode into the hash table.
*/
void
hpfs_hphashins(hp)
struct hpfsnode *hp;
{
struct hphashhead *hpp;
mtx_lock(&hpfs_hphash_mtx);
hpp = HPNOHASH(hp->h_dev, hp->h_no);
hp->h_flag |= H_HASHED;
LIST_INSERT_HEAD(hpp, hp, h_hash);
mtx_unlock(&hpfs_hphash_mtx);
}
/*
* Remove the inode from the hash table.
*/
void
hpfs_hphashrem(hp)
struct hpfsnode *hp;
{
mtx_lock(&hpfs_hphash_mtx);
if (hp->h_flag & H_HASHED) {
hp->h_flag &= ~H_HASHED;
LIST_REMOVE(hp, h_hash);
}
mtx_unlock(&hpfs_hphash_mtx);
}