NetBSD/sys/fs/hfs/hfs_nhash.c

172 lines
5.5 KiB
C

/* $NetBSD: hfs_nhash.c,v 1.12 2011/06/12 03:35:53 rmind Exp $ */
/*-
* Copyright (c) 2005, 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Yevgeny Binder.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: hfs_nhash.c,v 1.12 2011/06/12 03:35:53 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/vmmeter.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/buf.h>
#include <sys/dirent.h>
#include <sys/msgbuf.h>
#include <fs/hfs/hfs.h>
LIST_HEAD(nhashhead, hfsnode) *nhashtbl;
u_long nhash; /* size of hash table - 1 */
#define HNOHASH(device, cnid, fork) (((device) + (cnid) + (fork)) & nhash)
kmutex_t hfs_hashlock;
kmutex_t hfs_nhash_lock;
/*
* Initialize hfsnode hash table.
*/
void
hfs_nhashinit(void)
{
nhashtbl = hashinit(desiredvnodes, HASH_LIST, true, &nhash);
mutex_init(&hfs_nhash_lock, MUTEX_DEFAULT, IPL_NONE);
mutex_init(&hfs_hashlock, MUTEX_DEFAULT, IPL_NONE);
}
/*
* Free hfsnode hash table.
*/
void
hfs_nhashdone(void)
{
hashdone(nhashtbl, HASH_LIST, nhash);
mutex_destroy(&hfs_nhash_lock);
mutex_destroy(&hfs_hashlock);
}
/*
* Use the device/inum pair to find the incore inode, and return a pointer
* to it. If it is in core, but locked, wait for it.
*/
struct vnode *
hfs_nhashget(dev_t dev, hfs_cnid_t cnid, uint8_t fork, int flags)
{
struct hfsnode *hp;
struct nhashhead *hpp;
struct vnode *vp;
loop:
mutex_enter(&hfs_nhash_lock);
hpp = &nhashtbl[HNOHASH(dev, cnid, fork)];
LIST_FOREACH(hp, hpp, h_hash) {
if (cnid == hp->h_rec.u.cnid && dev == hp->h_dev) {
vp = HTOV(hp);
if (flags == 0) {
mutex_exit(&hfs_nhash_lock);
} else {
mutex_enter(vp->v_interlock);
mutex_exit(&hfs_nhash_lock);
if (vget(vp, flags))
goto loop;
}
return vp;
}
}
mutex_exit(&hfs_nhash_lock);
return NULL;
}
/*
* Insert the hfsnode into the hash table, and return it locked.
*/
void
hfs_nhashinsert(struct hfsnode *hp)
{
struct nhashhead *hpp;
/* lock the inode, then put it on the appropriate hash list */
VOP_LOCK(HTOV(hp), LK_EXCLUSIVE);
mutex_enter(&hfs_nhash_lock);
hpp = &nhashtbl[HNOHASH(hp->h_dev, hp->h_rec.u.cnid, hp->h_fork)];
LIST_INSERT_HEAD(hpp, hp, h_hash);
mutex_exit(&hfs_nhash_lock);
}
/*
* Remove the inode from the hash table.
*/
void
hfs_nhashremove(struct hfsnode *hp)
{
mutex_enter(&hfs_nhash_lock);
LIST_REMOVE(hp, h_hash);
mutex_exit(&hfs_nhash_lock);
}