freebsd-dev/sys/gnu/ext2fs/ext2_ihash.c
Bosko Milekic 9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00

154 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
* $FreeBSD$
*/
#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/mutex.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])
static struct mtx ufs_ihash_mtx;
/*
* Initialize inode hash table.
*/
void
ufs_ihashinit()
{
ihashtbl = hashinit(desiredvnodes, M_UFSIHASH, &ihash);
mtx_init(&ufs_ihash_mtx, "ufs ihash", MTX_DEF);
}
/*
* 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;
mtx_lock(&ufs_ihash_mtx);
LIST_FOREACH(ip, INOHASH(dev, inum), i_hash)
if (inum == ip->i_number && dev == ip->i_dev)
break;
mtx_unlock(&ufs_ihash_mtx);
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:
mtx_lock(&ufs_ihash_mtx);
LIST_FOREACH(ip, INOHASH(dev, inum), i_hash) {
if (inum == ip->i_number && dev == ip->i_dev) {
vp = ITOV(ip);
mtx_lock(&vp->v_interlock);
mtx_unlock(&ufs_ihash_mtx);
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))
goto loop;
return (vp);
}
}
mtx_unlock(&ufs_ihash_mtx);
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_vnode->v_lock, LK_EXCLUSIVE, (struct mtx *)0, p);
mtx_lock(&ufs_ihash_mtx);
ipp = INOHASH(ip->i_dev, ip->i_number);
LIST_INSERT_HEAD(ipp, ip, i_hash);
ip->i_flag |= IN_HASHED;
mtx_unlock(&ufs_ihash_mtx);
}
/*
* Remove the inode from the hash table.
*/
void
ufs_ihashrem(ip)
struct inode *ip;
{
mtx_lock(&ufs_ihash_mtx);
if (ip->i_flag & IN_HASHED) {
ip->i_flag &= ~IN_HASHED;
LIST_REMOVE(ip, i_hash);
}
mtx_unlock(&ufs_ihash_mtx);
}