Source to bsd/hfs/hfs_vhash.c
/*
* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
*
* @[email protected]
*
* "Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
* Reserved. This file contains Original Code and/or Modifications of
* Original Code as defined in and that are subject to the Apple Public
* Source License Version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. Please obtain a copy of the
* License at http://www.apple.com/publicsource and read it before using
* this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License."
*
* @[email protected]
*/
/* Copyright (c) 1998 Apple Computer, Inc. All Rights Reserved */
/*
* 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.
*
* @(#)hfs_vhash.c
* derived from @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
*/
#include <sys/param.h>
#include <mach/machine/vm_types.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include "hfs.h"
#include <libkern/libkern.h>
#include <mach/machine/simple_lock.h>
/*
* Structures associated with hfsnode cacheing.
*/
LIST_HEAD(vhashhead, hfsnode) *vhashtbl;
u_long vhash; /* size of hash table - 1 */
#define HFSNODEHASH(device, nodeID, forkType) (&vhashtbl[((device) + ((nodeID)<<2) + (forkType)) & vhash])
struct slock hfs_vhash_slock;
/*
* Initialize hfsnode hash table.
*/
void
hfs_vhashinit()
{
vhashtbl = hashinit(desiredvnodes, M_HFSMNT, &vhash);
simple_lock_init(&hfs_vhash_slock);
}
/*
* Use the device/dirID pair to find the incore hfsnode, and return a pointer
* to it. If it is in core, return it, even if it is locked.
*/
struct vnode *
hfs_vhashlookup(dev, nodeID, forkType)
dev_t dev;
UInt32 nodeID;
UInt8 forkType;
{
struct hfsnode *hp;
simple_lock(&hfs_vhash_slock);
for (hp = HFSNODEHASH(dev, nodeID, forkType)->lh_first; hp; hp = hp->h_hash.le_next)
if ((H_FILEID(hp) == nodeID) && (hp->h_dev == dev) && (H_FORKTYPE(hp) == forkType))
break;
simple_unlock(&hfs_vhash_slock);
if (hp)
return (HTOV(hp));
return (NULLVP);
}
/*
* Use the device/dirID pair to find the incore hfsnode, and return a pointer
* to it. If it is in core, but locked, wait for it.
*/
struct vnode *
hfs_vhashget(dev, nodeID, forkType)
dev_t dev;
UInt32 nodeID;
UInt8 forkType;
{
struct proc *p = CURRENT_PROC; /* XXX */
struct hfsnode *hp;
struct vnode *vp;
loop:
simple_lock(&hfs_vhash_slock);
for (hp = HFSNODEHASH(dev, nodeID, forkType)->lh_first; hp; hp = hp->h_hash.le_next) {
if ((H_FILEID(hp) == nodeID) && (hp->h_dev == dev) && (H_FORKTYPE(hp) == forkType)) {
vp = HTOV(hp);
simple_lock(&vp->v_interlock);
simple_unlock(&hfs_vhash_slock);
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))
goto loop;
return (vp);
}
}
simple_unlock(&hfs_vhash_slock);
return (NULL);
}
/*
* Lock the hfsnode and insert the hfsnode into the hash table, and return it locked.
*/
void
hfs_vhashins(hp)
struct hfsnode *hp;
{
struct vhashhead *ipp;
lockmgr(&hp->h_lock, LK_EXCLUSIVE, (struct slock *)0, CURRENT_PROC);
simple_lock(&hfs_vhash_slock);
ipp = HFSNODEHASH(hp->h_dev, H_FILEID(hp), H_FORKTYPE(hp));
LIST_INSERT_HEAD(ipp, hp, h_hash);
simple_unlock(&hfs_vhash_slock);
}
/*
* Insert a locked hfsnode into the hash table.
*/
void
hfs_vhashinslocked(hp)
struct hfsnode *hp;
{
struct vhashhead *ipp;
simple_lock(&hfs_vhash_slock);
ipp = HFSNODEHASH(hp->h_dev, H_FILEID(hp), H_FORKTYPE(hp));
LIST_INSERT_HEAD(ipp, hp, h_hash);
simple_unlock(&hfs_vhash_slock);
}
/*
* Remove the hfsnode from the hash table.
*/
void
hfs_vhashrem(hp)
struct hfsnode *hp;
{
simple_lock(&hfs_vhash_slock);
LIST_REMOVE(hp, h_hash);
#if DIAGNOSTIC
hp->h_hash.le_next = NULL;
hp->h_hash.le_prev = NULL;
#endif
simple_unlock(&hfs_vhash_slock);
}