freebsd-dev/sys/fs/ntfs/ntfs_ihash.c
Ed Schouten 29d4cb241b Don't enforce unique device minor number policy anymore.
Except for the case where we use the cloner library (clone_create() and
friends), there is no reason to enforce a unique device minor number
policy. There are various drivers in the source tree that allocate unr
pools and such to provide minor numbers, without using them themselves.

Because we still need to support unique device minor numbers for the
cloner library, introduce a new flag called D_NEEDMINOR. All cdevsw's
that are used in combination with the cloner library should be marked
with this flag to make the cloning work.

This means drivers can now freely use si_drv0 to store their own flags
and state, making it effectively the same as si_drv1 and si_drv2. We
still keep the minor() and dev2unit() routines around to make drivers
happy.

The NTFS code also used the minor number in its hash table. We should
not do this anymore. If the si_drv0 field would be changed, it would no
longer end up in the same list.

Approved by:	philip (mentor)
2008-06-11 18:55:19 +00:00

131 lines
3.7 KiB
C

/* $NetBSD: ntfs_ihash.c,v 1.5 1999/09/30 16:56:40 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.
* 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/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <fs/ntfs/ntfs.h>
#include <fs/ntfs/ntfs_inode.h>
#include <fs/ntfs/ntfs_ihash.h>
MALLOC_DEFINE(M_NTFSNTHASH, "ntfs_nthash", "NTFS ntnode hash tables");
/*
* Structures associated with inode cacheing.
*/
static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
static u_long ntfs_nthash; /* size of hash table - 1 */
#define NTNOHASH(inum) (&ntfs_nthashtbl[(inum) & ntfs_nthash])
static struct mtx ntfs_nthash_mtx;
struct lock ntfs_hashlock;
/*
* Initialize inode hash table.
*/
void
ntfs_nthashinit()
{
lockinit(&ntfs_hashlock, PINOD, "ntfs_nthashlock", 0, 0);
ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash);
mtx_init(&ntfs_nthash_mtx, "ntfs nthash", NULL, MTX_DEF);
}
/*
* Destroy inode hash table.
*/
void
ntfs_nthashdestroy(void)
{
hashdestroy(ntfs_nthashtbl, M_NTFSNTHASH, ntfs_nthash);
lockdestroy(&ntfs_hashlock);
mtx_destroy(&ntfs_nthash_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 ntnode *
ntfs_nthashlookup(dev, inum)
struct cdev *dev;
ino_t inum;
{
struct ntnode *ip;
mtx_lock(&ntfs_nthash_mtx);
LIST_FOREACH(ip, NTNOHASH(inum), i_hash)
if (inum == ip->i_number && dev == ip->i_dev)
break;
mtx_unlock(&ntfs_nthash_mtx);
return (ip);
}
/*
* Insert the ntnode into the hash table.
*/
void
ntfs_nthashins(ip)
struct ntnode *ip;
{
struct nthashhead *ipp;
mtx_lock(&ntfs_nthash_mtx);
ipp = NTNOHASH(ip->i_number);
LIST_INSERT_HEAD(ipp, ip, i_hash);
ip->i_flag |= IN_HASHED;
mtx_unlock(&ntfs_nthash_mtx);
}
/*
* Remove the inode from the hash table.
*/
void
ntfs_nthashrem(ip)
struct ntnode *ip;
{
mtx_lock(&ntfs_nthash_mtx);
if (ip->i_flag & IN_HASHED) {
ip->i_flag &= ~IN_HASHED;
LIST_REMOVE(ip, i_hash);
}
mtx_unlock(&ntfs_nthash_mtx);
}