HardenedBSD/sys/vm/vm_swap.c
David Greenman 55e8e4749f Fixed problem with no swap on boot device, but there is some on an
alternate device (as specified via kernel config file)...that casues
the machine to panic.
1994-09-11 03:55:39 +00:00

435 lines
11 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 1.4 1994/08/06 09:15:41 davidg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/dmap.h> /* XXX */
#include <sys/vnode.h>
#include <sys/map.h>
#include <sys/file.h>
#include <miscfs/specfs/specdev.h>
/*
* Indirect driver for multi-controller paging.
*/
int nswap, nswdev;
int vm_swap_size;
#ifdef SEQSWAP
int niswdev; /* number of interleaved swap devices */
int niswap; /* size of interleaved swap area */
#endif
int bswneeded;
vm_offset_t swapbkva; /* swap buffers kva */
/*
* Set up swap devices.
* Initialize linked list of free swap
* headers. These do not actually point
* to buffers, but rather to pages that
* are being swapped in and out.
*/
void
swapinit()
{
register int i;
register struct buf *sp = swbuf;
register struct proc *p = &proc0; /* XXX */
struct swdevt *swp;
int error;
/*
* Count swap devices, and adjust total swap space available.
* Some of the space will not be countable until later (dynamically
* configurable devices) and some of the counted space will not be
* available until a swapon() system call is issued, both usually
* happen when the system goes multi-user.
*
* If using NFS for swap, swdevt[0] will already be bdevvp'd. XXX
*/
#ifdef SEQSWAP
nswdev = niswdev = 0;
nswap = niswap = 0;
/*
* All interleaved devices must come first
*/
for (swp = swdevt; swp->sw_dev != NODEV || swp->sw_vp != NULL; swp++) {
if (swp->sw_flags & SW_SEQUENTIAL)
break;
niswdev++;
if (swp->sw_nblks > niswap)
niswap = swp->sw_nblks;
}
niswap = roundup(niswap, dmmax);
niswap *= niswdev;
if (swdevt[0].sw_vp == NULL &&
bdevvp(swdevt[0].sw_dev, &swdevt[0].sw_vp))
panic("swapvp");
/*
* The remainder must be sequential
*/
for ( ; swp->sw_dev != NODEV; swp++) {
if ((swp->sw_flags & SW_SEQUENTIAL) == 0)
panic("binit: mis-ordered swap devices");
nswdev++;
if (swp->sw_nblks > 0) {
if (swp->sw_nblks % dmmax)
swp->sw_nblks -= (swp->sw_nblks % dmmax);
nswap += swp->sw_nblks;
}
}
nswdev += niswdev;
if (nswdev == 0)
panic("swapinit");
nswap += niswap;
#else
nswdev = 0;
nswap = 0;
for (swp = swdevt; swp->sw_dev != NODEV || swp->sw_vp != NULL; swp++) {
nswdev++;
if (swp->sw_nblks > nswap)
nswap = swp->sw_nblks;
}
if (nswdev == 0)
panic("swapinit");
if (nswdev > 1)
nswap = ((nswap + dmmax - 1) / dmmax) * dmmax;
nswap *= nswdev;
if (swdevt[0].sw_vp == NULL &&
bdevvp(swdevt[0].sw_dev, &swdevt[0].sw_vp))
panic("swapvp");
#endif
/*
* If there is no swap configured, tell the user. If there is,
* try to make swap on boot device available now. If this fails,
* no swap space is available there or it isn't configured.
*/
if (nswap == 0)
printf("WARNING: no swap space found\n");
else if (error = swfree(p, 0)) {
printf("WARNING: no swap on boot device - use swapon\n");
}
}
void
swstrategy(bp)
register struct buf *bp;
{
int sz, off, seg, index;
register struct swdevt *sp;
struct vnode *vp;
#ifdef GENERIC
/*
* A mini-root gets copied into the front of the swap
* and we run over top of the swap area just long
* enough for us to do a mkfs and restor of the real
* root (sure beats rewriting standalone restor).
*/
#define MINIROOTSIZE 4096
if (rootdev == dumpdev)
bp->b_blkno += MINIROOTSIZE;
#endif
sz = howmany(bp->b_bcount, DEV_BSIZE);
if (bp->b_blkno + sz > nswap) {
bp->b_error = EINVAL;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
if (nswdev > 1) {
#ifdef SEQSWAP
if (bp->b_blkno < niswap) {
if (niswdev > 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 % niswdev;
seg /= niswdev;
bp->b_blkno = seg*dmmax + off;
} else
index = 0;
} else {
register struct swdevt *swp;
bp->b_blkno -= niswap;
for (index = niswdev, swp = &swdevt[niswdev];
swp->sw_dev != NODEV;
swp++, index++) {
if (bp->b_blkno < swp->sw_nblks)
break;
bp->b_blkno -= swp->sw_nblks;
}
if (swp->sw_dev == NODEV ||
bp->b_blkno+sz > swp->sw_nblks) {
bp->b_error = swp->sw_dev == NODEV ?
ENODEV : EINVAL;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
}
#else
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;
#endif
} else
index = 0;
sp = &swdevt[index];
if ((bp->b_dev = sp->sw_dev) == NODEV)
panic("swstrategy");
if (sp->sw_vp == NULL) {
bp->b_error = ENODEV;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
VHOLD(sp->sw_vp);
if ((bp->b_flags & B_READ) == 0) {
if (vp = bp->b_vp) {
vp->v_numoutput--;
if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
vp->v_flag &= ~VBWAIT;
wakeup((caddr_t)&vp->v_numoutput);
}
}
sp->sw_vp->v_numoutput++;
}
if (bp->b_vp != NULL)
brelvp(bp);
bp->b_vp = sp->sw_vp;
VOP_STRATEGY(bp);
}
/*
* System call swapon(name) enables swapping on device name,
* which must be in the swdevsw. Return EBUSY
* if already swapping on this device.
*/
struct swapon_args {
char *name;
};
/* ARGSUSED */
int
swapon(p, uap, retval)
struct proc *p;
struct swapon_args *uap;
int *retval;
{
register struct vnode *vp;
register struct swdevt *sp;
dev_t dev;
int error;
struct nameidata nd;
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->name, p);
if (error = namei(&nd))
return (error);
vp = nd.ni_vp;
if (vp->v_type != VBLK) {
vrele(vp);
return (ENOTBLK);
}
dev = (dev_t)vp->v_rdev;
if (major(dev) >= nblkdev) {
vrele(vp);
return (ENXIO);
}
for (sp = &swdevt[0]; sp->sw_dev != NODEV; sp++) {
if (sp->sw_dev == dev) {
if (sp->sw_flags & SW_FREED) {
vrele(vp);
return (EBUSY);
}
sp->sw_vp = vp;
if (error = swfree(p, sp - swdevt)) {
vrele(vp);
return (error);
}
return (0);
}
#ifdef SEQSWAP
/*
* If we have reached a non-freed sequential device without
* finding what we are looking for, it is an error.
* That is because all interleaved devices must come first
* and sequential devices must be freed in order.
*/
if ((sp->sw_flags & (SW_SEQUENTIAL|SW_FREED)) == SW_SEQUENTIAL)
break;
#endif
}
vrele(vp);
return (EINVAL);
}
/*
* 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.
*/
int
swfree(p, index)
struct proc *p;
int index;
{
register struct swdevt *sp;
register swblk_t vsbase;
register long blk;
struct vnode *vp;
register swblk_t dvbase;
register int nblks;
int error;
sp = &swdevt[index];
vp = sp->sw_vp;
if (error = VOP_OPEN(vp, FREAD|FWRITE, p->p_ucred, p))
return (error);
sp->sw_flags |= SW_FREED;
nblks = sp->sw_nblks;
/*
* Some devices may not exist til after boot time.
* If so, their nblk count will be 0.
*/
if (nblks <= 0) {
int perdev;
dev_t dev = sp->sw_dev;
if (bdevsw[major(dev)].d_psize == 0 ||
(nblks = (*bdevsw[major(dev)].d_psize)(dev)) == -1) {
(void) VOP_CLOSE(vp, FREAD|FWRITE, p->p_ucred, p);
sp->sw_flags &= ~SW_FREED;
return (ENXIO);
}
#ifdef SEQSWAP
if (index < niswdev) {
perdev = niswap / niswdev;
if (nblks > perdev)
nblks = perdev;
} else {
if (nblks % dmmax)
nblks -= (nblks % dmmax);
nswap += nblks;
}
#else
perdev = nswap / nswdev;
if (nblks > perdev)
nblks = perdev;
#endif
sp->sw_nblks = nblks;
}
if (nblks == 0) {
(void) VOP_CLOSE(vp, FREAD|FWRITE, p->p_ucred, p);
sp->sw_flags &= ~SW_FREED;
return (0); /* XXX error? */
}
#ifdef SEQSWAP
if (sp->sw_flags & SW_SEQUENTIAL) {
register struct swdevt *swp;
blk = niswap;
for (swp = &swdevt[niswdev]; swp != sp; swp++)
blk += swp->sw_nblks;
#if 0
rmfree(swapmap, nblks, blk);
return (0);
#endif
rlist_free(&swapmap, blk, blk + nblks - 1);
vm_swap_size += nblks;
return (0);
}
#endif
for (dvbase = 0; dvbase < nblks; dvbase += dmmax) {
blk = nblks - dvbase;
#ifdef SEQSWAP
if ((vsbase = index*dmmax + dvbase*niswdev) >= niswap)
panic("swfree");
#else
if ((vsbase = index*dmmax + dvbase*nswdev) >= nswap)
panic("swfree");
#endif
if (blk > dmmax)
blk = dmmax;
#if 0
if (vsbase == 0) {
/*
* First of all chunks... initialize the swapmap.
* Don't use the first cluster of the device
* in case it starts with a label or boot block.
*/
rminit(swapmap, blk - ctod(CLSIZE),
vsbase + ctod(CLSIZE), "swap", nswapmap);
} else if (dvbase == 0) {
/*
* Don't use the first cluster of the device
* in case it starts with a label or boot block.
*/
rmfree(swapmap, blk - ctod(CLSIZE),
vsbase + ctod(CLSIZE));
} else
rmfree(swapmap, blk, vsbase);
#endif
/* XXX -- we need to exclude the first cluster as above */
/* but for now, this will work fine... */
rlist_free(&swapmap, vsbase, vsbase + blk - 1);
vm_swap_size += blk;
}
return (0);
}