384 lines
9.2 KiB
C
384 lines
9.2 KiB
C
/*
|
|
* Copyright (c) 1982, 1986, 1989, 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. 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.
|
|
*
|
|
* @(#)vm_swap.c 8.5 (Berkeley) 2/17/94
|
|
* $Id: vm_swap.c,v 1.59 1999/01/21 10:17:12 dillon Exp $
|
|
*/
|
|
|
|
#include "opt_devfs.h"
|
|
#include "opt_swap.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/buf.h>
|
|
#include <sys/conf.h>
|
|
#ifdef DEVFS
|
|
#include <sys/devfsext.h>
|
|
#endif
|
|
#include <sys/proc.h>
|
|
#include <sys/namei.h>
|
|
#include <sys/dmap.h> /* XXX */
|
|
#include <sys/vnode.h>
|
|
#include <sys/fcntl.h>
|
|
#include <sys/blist.h>
|
|
#include <sys/kernel.h>
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_extern.h>
|
|
#include <vm/swap_pager.h>
|
|
|
|
#include <miscfs/specfs/specdev.h>
|
|
|
|
/*
|
|
* "sw" is a fake device implemented
|
|
* in vm_swap.c and used only internally to get to swstrategy.
|
|
* It cannot be provided to the users, because the
|
|
* swstrategy routine munches the b_dev and b_blkno entries
|
|
* before calling the appropriate driver. This would horribly
|
|
* confuse, e.g. the hashing routines. Instead, /dev/drum is
|
|
* provided as a character (raw) device.
|
|
*/
|
|
|
|
static d_strategy_t swstrategy;
|
|
static d_read_t swread;
|
|
static d_write_t swwrite;
|
|
|
|
#define CDEV_MAJOR 4
|
|
#define BDEV_MAJOR 26
|
|
|
|
static struct cdevsw sw_cdevsw =
|
|
{ nullopen, nullclose, swread, swwrite, /*4*/
|
|
noioc, nostop, noreset, nodevtotty,/* swap */
|
|
seltrue, nommap, swstrategy, "sw",
|
|
NULL, -1, nodump, nopsize,
|
|
0, 0, -1};
|
|
|
|
static dev_t swapdev = makedev(BDEV_MAJOR, 0);
|
|
|
|
/*
|
|
* Indirect driver for multi-controller paging.
|
|
*/
|
|
|
|
#ifndef NSWAPDEV
|
|
#define NSWAPDEV 4
|
|
#endif
|
|
static struct swdevt should_be_malloced[NSWAPDEV];
|
|
static struct swdevt *swdevt = should_be_malloced;
|
|
struct vnode *swapdev_vp;
|
|
static int nswap; /* first block after the interleaved devs */
|
|
static int nswdev = NSWAPDEV;
|
|
int vm_swap_size;
|
|
|
|
static int
|
|
swread(dev_t dev, struct uio *uio, int ioflag)
|
|
{
|
|
return (physio(swstrategy, NULL, dev, 1, minphys, uio));
|
|
}
|
|
|
|
static int
|
|
swwrite(dev_t dev, struct uio *uio, int ioflag)
|
|
{
|
|
return (physio(swstrategy, NULL, dev, 0, minphys, uio));
|
|
}
|
|
|
|
/*
|
|
* swstrategy:
|
|
*
|
|
* Perform swap strategy interleave device selection
|
|
*
|
|
* The bp is expected to be B_BUSY and *not* B_DONE on call.
|
|
*/
|
|
|
|
static void
|
|
swstrategy(bp)
|
|
register struct buf *bp;
|
|
{
|
|
int s, sz, off, seg, index;
|
|
register struct swdevt *sp;
|
|
struct vnode *vp;
|
|
|
|
sz = howmany(bp->b_bcount, PAGE_SIZE);
|
|
/*
|
|
* Convert interleaved swap into per-device swap. Note that
|
|
* the block size is left in PAGE_SIZE'd chunks (for the newswap)
|
|
* here.
|
|
*/
|
|
|
|
if (nswdev > 1) {
|
|
off = bp->b_blkno % dmmax;
|
|
if (off + sz > dmmax) {
|
|
bp->b_error = EINVAL;
|
|
bp->b_flags |= B_ERROR;
|
|
biodone(bp);
|
|
return;
|
|
}
|
|
seg = bp->b_blkno / dmmax;
|
|
index = seg % nswdev;
|
|
seg /= nswdev;
|
|
bp->b_blkno = seg * dmmax + off;
|
|
} else {
|
|
index = 0;
|
|
}
|
|
sp = &swdevt[index];
|
|
if (bp->b_blkno + sz > sp->sw_nblks) {
|
|
bp->b_error = EINVAL;
|
|
bp->b_flags |= B_ERROR;
|
|
biodone(bp);
|
|
return;
|
|
}
|
|
bp->b_dev = sp->sw_dev;
|
|
if (sp->sw_vp == NULL) {
|
|
bp->b_error = ENODEV;
|
|
bp->b_flags |= B_ERROR;
|
|
biodone(bp);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Convert from PAGE_SIZE'd to DEV_BSIZE'd chunks for the actual I/O
|
|
*/
|
|
bp->b_blkno = ctodb(bp->b_blkno);
|
|
|
|
vhold(sp->sw_vp);
|
|
s = splvm();
|
|
if ((bp->b_flags & B_READ) == 0) {
|
|
vp = bp->b_vp;
|
|
if (vp) {
|
|
vp->v_numoutput--;
|
|
if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
|
|
vp->v_flag &= ~VBWAIT;
|
|
wakeup(&vp->v_numoutput);
|
|
}
|
|
}
|
|
sp->sw_vp->v_numoutput++;
|
|
}
|
|
pbreassignbuf(bp, sp->sw_vp);
|
|
splx(s);
|
|
VOP_STRATEGY(bp->b_vp, bp);
|
|
}
|
|
|
|
/*
|
|
* System call swapon(name) enables swapping on device name,
|
|
* which must be in the swdevsw. Return EBUSY
|
|
* if already swapping on this device.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct swapon_args {
|
|
char *name;
|
|
};
|
|
#endif
|
|
|
|
/* ARGSUSED */
|
|
int
|
|
swapon(p, uap)
|
|
struct proc *p;
|
|
struct swapon_args *uap;
|
|
{
|
|
register struct vnode *vp;
|
|
dev_t dev;
|
|
struct nameidata nd;
|
|
int error;
|
|
|
|
error = suser(p->p_ucred, &p->p_acflag);
|
|
if (error)
|
|
return (error);
|
|
|
|
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->name, p);
|
|
error = namei(&nd);
|
|
if (error)
|
|
return (error);
|
|
|
|
vp = nd.ni_vp;
|
|
|
|
switch (vp->v_type) {
|
|
case VBLK:
|
|
dev = vp->v_rdev;
|
|
if (major(dev) >= nblkdev || bdevsw[major(dev)] == NULL) {
|
|
error = ENXIO;
|
|
break;
|
|
}
|
|
error = swaponvp(p, vp, dev, 0);
|
|
break;
|
|
case VCHR:
|
|
/*
|
|
* For now, we disallow swapping to regular files.
|
|
* It requires logical->physcal block translation
|
|
* support in the swap pager before it will work.
|
|
*/
|
|
error = ENOTBLK;
|
|
break;
|
|
#if 0
|
|
error = VOP_GETATTR(vp, &attr, p->p_ucred, p);
|
|
if (!error)
|
|
error = swaponvp(p, vp, NODEV, attr.va_size / DEV_BSIZE);
|
|
break;
|
|
#endif
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
|
|
if (error)
|
|
vrele(vp);
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Swfree(index) frees the index'th portion of the swap map.
|
|
* Each of the nswdev devices provides 1/nswdev'th of the swap
|
|
* space, which is laid out with blocks of dmmax pages circularly
|
|
* among the devices.
|
|
*
|
|
* The new swap code uses page-sized blocks. The old swap code used
|
|
* DEV_BSIZE'd chunks.
|
|
*
|
|
* XXX locking when multiple swapon's run in parallel
|
|
*/
|
|
int
|
|
swaponvp(p, vp, dev, nblks)
|
|
struct proc *p;
|
|
struct vnode *vp;
|
|
dev_t dev;
|
|
u_long nblks;
|
|
{
|
|
int index;
|
|
register struct swdevt *sp;
|
|
register swblk_t vsbase;
|
|
register long blk;
|
|
swblk_t dvbase;
|
|
int error;
|
|
|
|
for (sp = swdevt, index = 0 ; index < nswdev; index++, sp++) {
|
|
if (sp->sw_vp == vp)
|
|
return EBUSY;
|
|
if (!sp->sw_vp)
|
|
goto found;
|
|
|
|
}
|
|
return EINVAL;
|
|
found:
|
|
error = VOP_OPEN(vp, FREAD | FWRITE, p->p_ucred, p);
|
|
if (error)
|
|
return (error);
|
|
|
|
if (nblks == 0 && dev != NODEV && (bdevsw[major(dev)]->d_psize == 0 ||
|
|
(nblks = (*bdevsw[major(dev)]->d_psize) (dev)) == -1)) {
|
|
(void) VOP_CLOSE(vp, FREAD | FWRITE, p->p_ucred, p);
|
|
return (ENXIO);
|
|
}
|
|
if (nblks == 0) {
|
|
(void) VOP_CLOSE(vp, FREAD | FWRITE, p->p_ucred, p);
|
|
return (ENXIO);
|
|
}
|
|
/*
|
|
* nblks is in DEV_BSIZE'd chunks, convert to PAGE_SIZE'd chunks.
|
|
* First chop nblks off to page-align it, then convert.
|
|
*
|
|
* sw->sw_nblks is in page-sized chunks now too.
|
|
*/
|
|
nblks &= ~(ctodb(1) - 1);
|
|
nblks = dbtoc(nblks);
|
|
|
|
sp->sw_vp = vp;
|
|
sp->sw_dev = dev;
|
|
sp->sw_flags |= SW_FREED;
|
|
sp->sw_nblks = nblks;
|
|
|
|
/*
|
|
* nblks, nswap, and dmmax are PAGE_SIZE'd parameters now, not
|
|
* DEV_BSIZE'd.
|
|
*/
|
|
|
|
if (nblks * nswdev > nswap)
|
|
nswap = (nblks+1) * nswdev;
|
|
|
|
if (swapblist == NULL)
|
|
swapblist = blist_create(nswap);
|
|
else
|
|
blist_resize(&swapblist, nswap, 0);
|
|
|
|
for (dvbase = dmmax; dvbase < nblks; dvbase += dmmax) {
|
|
blk = min(nblks - dvbase, dmmax);
|
|
vsbase = index * dmmax + dvbase * nswdev;
|
|
blist_free(swapblist, vsbase, blk);
|
|
vm_swap_size += blk;
|
|
}
|
|
|
|
if (!swapdev_vp) {
|
|
struct vnode *vp1;
|
|
struct vnode *nvp;
|
|
|
|
error = getnewvnode(VT_NON, (struct mount *) 0,
|
|
spec_vnodeop_p, &nvp);
|
|
if (error)
|
|
panic("Cannot get vnode for swapdev");
|
|
vp1 = nvp;
|
|
vp1->v_type = VBLK;
|
|
if ((nvp = checkalias(vp1, swapdev,
|
|
(struct mount *) 0))) {
|
|
vput(vp1);
|
|
vp1 = nvp;
|
|
}
|
|
swapdev_vp = vp1;
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
static sw_devsw_installed = 0;
|
|
#ifdef DEVFS
|
|
static void *drum_devfs_token;
|
|
#endif
|
|
|
|
static void sw_drvinit(void *unused)
|
|
{
|
|
|
|
if( ! sw_devsw_installed ) {
|
|
cdevsw_add_generic(BDEV_MAJOR, CDEV_MAJOR, &sw_cdevsw);
|
|
/*
|
|
* XXX: This is pretty gross, but it will disappear with
|
|
* the blockdevices RSN.
|
|
*/
|
|
sw_cdevsw.d_open = nullopen;
|
|
sw_cdevsw.d_close = nullclose;
|
|
sw_devsw_installed = 1;
|
|
#ifdef DEVFS
|
|
drum_devfs_token = devfs_add_devswf(&sw_cdevsw, 0, DV_CHR,
|
|
UID_ROOT, GID_KMEM, 0640,
|
|
"drum");
|
|
#endif
|
|
}
|
|
}
|
|
|
|
SYSINIT(swdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,sw_drvinit,NULL)
|
|
|