freebsd-dev/sys/gnu/ext2fs/ext2_ihash.c
Poul-Henning Kamp bfbb9ce670 Divorce "dev_t" from the "major|minor" bitmap, which is now called
udev_t in the kernel but still called dev_t in userland.

Provide functions to manipulate both types:
        major()         umajor()
        minor()         uminor()
        makedev()       umakedev()
        dev2udev()      udev2dev()

For now they're functions, they will become in-line functions
after one of the next two steps in this process.

Return major/minor/makedev to macro-hood for userland.

Register a name in cdevsw[] for the "filedescriptor" driver.

In the kernel the udev_t appears in places where we have the
major/minor number combination, (ie: a potential device: we
may not have the driver nor the device), like in inodes, vattr,
cdevsw registration and so on, whereas the dev_t appears where
we carry around a reference to a actual device.

In the future the cdevsw and the aliased-from vnode will be hung
directly from the dev_t, along with up to two softc pointers for
the device driver and a few houskeeping bits.  This will essentially
replace the current "alias" check code (same buck, bigger bang).

A little stunt has been provided to try to catch places where the
wrong type is being used (dev_t vs udev_t), if you see something
not working, #undef DEVT_FASCIST in kern/kern_conf.c and see if
it makes a difference.  If it does, please try to track it down
(many hands make light work) or at least try to reproduce it
as simply as possible, and describe how to do that.

Without DEVT_FASCIST I belive this patch is a no-op.

Stylistic/posixoid comments about the userland view of the <sys/*.h>
files welcome now, from userland they now contain the end result.

Next planned step: make all dev_t's refer to the same devsw[] which
means convert BLK's to CHR's at the perimeter of the vnodes and
other places where they enter the game (bootdev, mknod, sysctl).
1999-05-11 19:55:07 +00:00

160 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
* $Id: ufs_ihash.c,v 1.18 1999/01/02 11:34:56 bde Exp $
*/
#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/proc.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
static MALLOC_DEFINE(M_UFSIHASH, "UFS ihash", "UFS Inode hash tables");
/*
* Structures associated with inode cacheing.
*/
static LIST_HEAD(ihashhead, inode) *ihashtbl;
static u_long ihash; /* size of hash table - 1 */
#define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash])
#ifndef NULL_SIMPLELOCKS
static struct simplelock ufs_ihash_slock;
#endif
/*
* Initialize inode hash table.
*/
void
ufs_ihashinit()
{
ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &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);
ip->i_flag |= IN_HASHED;
simple_unlock(&ufs_ihash_slock);
}
/*
* Remove the inode from the hash table.
*/
void
ufs_ihashrem(ip)
struct inode *ip;
{
simple_lock(&ufs_ihash_slock);
if (ip->i_flag & IN_HASHED) {
ip->i_flag &= ~IN_HASHED;
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);
}