freebsd-dev/sys/gnu/ext2fs/ext2_ihash.c
1997-02-22 09:48:43 +00:00

151 lines
4.3 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
* $Id$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
/*
* Structures associated with inode cacheing.
*/
LIST_HEAD(ihashhead, inode) *ihashtbl;
u_long ihash; /* size of hash table - 1 */
#define INOHASH(device, inum) (&ihashtbl[((device) + (inum)) & ihash])
struct simplelock ufs_ihash_slock;
/*
* Initialize inode hash table.
*/
void
ufs_ihashinit()
{
ihashtbl = hashinit(desiredvnodes, M_UFSMNT, &ihash);
simple_lock_init(&ufs_ihash_slock);
}
/*
* 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 vnode *
ufs_ihashlookup(dev, inum)
dev_t dev;
ino_t inum;
{
struct inode *ip;
simple_lock(&ufs_ihash_slock);
for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next)
if (inum == ip->i_number && dev == ip->i_dev)
break;
simple_unlock(&ufs_ihash_slock);
if (ip)
return (ITOV(ip));
return (NULLVP);
}
/*
* 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 *
ufs_ihashget(dev, inum)
dev_t dev;
ino_t inum;
{
struct proc *p = curproc; /* XXX */
struct inode *ip;
struct vnode *vp;
loop:
simple_lock(&ufs_ihash_slock);
for (ip = INOHASH(dev, inum)->lh_first; ip; ip = ip->i_hash.le_next) {
if (inum == ip->i_number && dev == ip->i_dev) {
vp = ITOV(ip);
simple_lock(&vp->v_interlock);
simple_unlock(&ufs_ihash_slock);
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))
goto loop;
return (vp);
}
}
simple_unlock(&ufs_ihash_slock);
return (NULL);
}
/*
* Insert the inode into the hash table, and return it locked.
*/
void
ufs_ihashins(ip)
struct inode *ip;
{
struct proc *p = curproc; /* XXX */
struct ihashhead *ipp;
/* lock the inode, then put it on the appropriate hash list */
lockmgr(&ip->i_lock, LK_EXCLUSIVE, (struct simplelock *)0, p);
simple_lock(&ufs_ihash_slock);
ipp = INOHASH(ip->i_dev, ip->i_number);
LIST_INSERT_HEAD(ipp, ip, i_hash);
simple_unlock(&ufs_ihash_slock);
}
/*
* Remove the inode from the hash table.
*/
void
ufs_ihashrem(ip)
struct inode *ip;
{
simple_lock(&ufs_ihash_slock);
LIST_REMOVE(ip, i_hash);
#ifdef DIAGNOSTIC
ip->i_hash.le_next = NULL;
ip->i_hash.le_prev = NULL;
#endif
simple_unlock(&ufs_ihash_slock);
}