608 lines
14 KiB
C
608 lines
14 KiB
C
/*
|
|
* Copyright (c) 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* The Mach Operating System project at Carnegie-Mellon University.
|
|
*
|
|
* 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.
|
|
*
|
|
* from: @(#)vm_pager.c 8.6 (Berkeley) 1/12/94
|
|
*
|
|
*
|
|
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
|
|
* All rights reserved.
|
|
*
|
|
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
|
|
*
|
|
* Permission to use, copy, modify and distribute this software and
|
|
* its documentation is hereby granted, provided that both the copyright
|
|
* notice and this permission notice appear in all copies of the
|
|
* software, derivative works or modified versions, and any portions
|
|
* thereof, and that both notices appear in supporting documentation.
|
|
*
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
|
|
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
|
*
|
|
* Carnegie Mellon requests users of this software to return to
|
|
*
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
|
* School of Computer Science
|
|
* Carnegie Mellon University
|
|
* Pittsburgh PA 15213-3890
|
|
*
|
|
* any improvements or extensions that they make and grant Carnegie the
|
|
* rights to redistribute these changes.
|
|
*
|
|
* $Id: vm_pager.c,v 1.50 1999/07/04 00:25:38 mckusick Exp $
|
|
*/
|
|
|
|
/*
|
|
* Paging space routine stubs. Emulates a matchmaker-like interface
|
|
* for builtin pagers.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/buf.h>
|
|
#include <sys/ucred.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/proc.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm_prot.h>
|
|
#include <vm/vm_object.h>
|
|
#include <vm/vm_page.h>
|
|
#include <vm/vm_pager.h>
|
|
#include <vm/vm_extern.h>
|
|
|
|
MALLOC_DEFINE(M_VMPGDATA, "VM pgdata", "XXX: VM pager private data");
|
|
|
|
extern struct pagerops defaultpagerops;
|
|
extern struct pagerops swappagerops;
|
|
extern struct pagerops vnodepagerops;
|
|
extern struct pagerops devicepagerops;
|
|
|
|
int cluster_pbuf_freecnt = -1; /* unlimited to begin with */
|
|
|
|
static int dead_pager_getpages __P((vm_object_t, vm_page_t *, int, int));
|
|
static vm_object_t dead_pager_alloc __P((void *, vm_ooffset_t, vm_prot_t,
|
|
vm_ooffset_t));
|
|
static void dead_pager_putpages __P((vm_object_t, vm_page_t *, int, int, int *));
|
|
static boolean_t dead_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *));
|
|
static void dead_pager_dealloc __P((vm_object_t));
|
|
|
|
static int
|
|
dead_pager_getpages(obj, ma, count, req)
|
|
vm_object_t obj;
|
|
vm_page_t *ma;
|
|
int count;
|
|
int req;
|
|
{
|
|
return VM_PAGER_FAIL;
|
|
}
|
|
|
|
static vm_object_t
|
|
dead_pager_alloc(handle, size, prot, off)
|
|
void *handle;
|
|
vm_ooffset_t size;
|
|
vm_prot_t prot;
|
|
vm_ooffset_t off;
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
dead_pager_putpages(object, m, count, flags, rtvals)
|
|
vm_object_t object;
|
|
vm_page_t *m;
|
|
int count;
|
|
int flags;
|
|
int *rtvals;
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
rtvals[i] = VM_PAGER_AGAIN;
|
|
}
|
|
}
|
|
|
|
static int
|
|
dead_pager_haspage(object, pindex, prev, next)
|
|
vm_object_t object;
|
|
vm_pindex_t pindex;
|
|
int *prev;
|
|
int *next;
|
|
{
|
|
if (prev)
|
|
*prev = 0;
|
|
if (next)
|
|
*next = 0;
|
|
return FALSE;
|
|
}
|
|
|
|
static void
|
|
dead_pager_dealloc(object)
|
|
vm_object_t object;
|
|
{
|
|
return;
|
|
}
|
|
|
|
static struct pagerops deadpagerops = {
|
|
NULL,
|
|
dead_pager_alloc,
|
|
dead_pager_dealloc,
|
|
dead_pager_getpages,
|
|
dead_pager_putpages,
|
|
dead_pager_haspage,
|
|
NULL
|
|
};
|
|
|
|
struct pagerops *pagertab[] = {
|
|
&defaultpagerops, /* OBJT_DEFAULT */
|
|
&swappagerops, /* OBJT_SWAP */
|
|
&vnodepagerops, /* OBJT_VNODE */
|
|
&devicepagerops, /* OBJT_DEVICE */
|
|
&deadpagerops /* OBJT_DEAD */
|
|
};
|
|
|
|
int npagers = sizeof(pagertab) / sizeof(pagertab[0]);
|
|
|
|
/*
|
|
* Kernel address space for mapping pages.
|
|
* Used by pagers where KVAs are needed for IO.
|
|
*
|
|
* XXX needs to be large enough to support the number of pending async
|
|
* cleaning requests (NPENDINGIO == 64) * the maximum swap cluster size
|
|
* (MAXPHYS == 64k) if you want to get the most efficiency.
|
|
*/
|
|
#define PAGER_MAP_SIZE (8 * 1024 * 1024)
|
|
|
|
int pager_map_size = PAGER_MAP_SIZE;
|
|
vm_map_t pager_map;
|
|
static int bswneeded;
|
|
static vm_offset_t swapbkva; /* swap buffers kva */
|
|
|
|
void
|
|
vm_pager_init()
|
|
{
|
|
struct pagerops **pgops;
|
|
|
|
/*
|
|
* Initialize known pagers
|
|
*/
|
|
for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
|
|
if (pgops && ((*pgops)->pgo_init != NULL))
|
|
(*(*pgops)->pgo_init) ();
|
|
}
|
|
|
|
void
|
|
vm_pager_bufferinit()
|
|
{
|
|
struct buf *bp;
|
|
int i;
|
|
|
|
bp = swbuf;
|
|
/*
|
|
* Now set up swap and physical I/O buffer headers.
|
|
*/
|
|
for (i = 0; i < nswbuf; i++, bp++) {
|
|
TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
|
|
BUF_LOCKINIT(bp);
|
|
LIST_INIT(&bp->b_dep);
|
|
bp->b_rcred = bp->b_wcred = NOCRED;
|
|
bp->b_xflags = 0;
|
|
}
|
|
|
|
cluster_pbuf_freecnt = nswbuf / 2;
|
|
|
|
swapbkva = kmem_alloc_pageable(pager_map, nswbuf * MAXPHYS);
|
|
if (!swapbkva)
|
|
panic("Not enough pager_map VM space for physical buffers");
|
|
}
|
|
|
|
/*
|
|
* Allocate an instance of a pager of the given type.
|
|
* Size, protection and offset parameters are passed in for pagers that
|
|
* need to perform page-level validation (e.g. the device pager).
|
|
*/
|
|
vm_object_t
|
|
vm_pager_allocate(objtype_t type, void *handle, vm_ooffset_t size, vm_prot_t prot,
|
|
vm_ooffset_t off)
|
|
{
|
|
struct pagerops *ops;
|
|
|
|
ops = pagertab[type];
|
|
if (ops)
|
|
return ((*ops->pgo_alloc) (handle, size, prot, off));
|
|
return (NULL);
|
|
}
|
|
|
|
void
|
|
vm_pager_deallocate(object)
|
|
vm_object_t object;
|
|
{
|
|
(*pagertab[object->type]->pgo_dealloc) (object);
|
|
}
|
|
|
|
/*
|
|
* vm_pager_strategy:
|
|
*
|
|
* called with no specific spl
|
|
* Execute strategy routine directly to pager.
|
|
*/
|
|
|
|
void
|
|
vm_pager_strategy(vm_object_t object, struct buf *bp)
|
|
{
|
|
if (pagertab[object->type]->pgo_strategy) {
|
|
(*pagertab[object->type]->pgo_strategy)(object, bp);
|
|
} else {
|
|
bp->b_flags |= B_ERROR;
|
|
bp->b_error = ENXIO;
|
|
biodone(bp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_pager_get_pages() - inline, see vm/vm_pager.h
|
|
* vm_pager_put_pages() - inline, see vm/vm_pager.h
|
|
* vm_pager_has_page() - inline, see vm/vm_pager.h
|
|
* vm_pager_page_inserted() - inline, see vm/vm_pager.h
|
|
* vm_pager_page_removed() - inline, see vm/vm_pager.h
|
|
*/
|
|
|
|
#if 0
|
|
/*
|
|
* vm_pager_sync:
|
|
*
|
|
* Called by pageout daemon before going back to sleep.
|
|
* Gives pagers a chance to clean up any completed async pageing
|
|
* operations.
|
|
*/
|
|
void
|
|
vm_pager_sync()
|
|
{
|
|
struct pagerops **pgops;
|
|
|
|
for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
|
|
if (pgops && ((*pgops)->pgo_sync != NULL))
|
|
(*(*pgops)->pgo_sync) ();
|
|
}
|
|
|
|
#endif
|
|
|
|
vm_offset_t
|
|
vm_pager_map_page(m)
|
|
vm_page_t m;
|
|
{
|
|
vm_offset_t kva;
|
|
|
|
kva = kmem_alloc_wait(pager_map, PAGE_SIZE);
|
|
pmap_kenter(kva, VM_PAGE_TO_PHYS(m));
|
|
return (kva);
|
|
}
|
|
|
|
void
|
|
vm_pager_unmap_page(kva)
|
|
vm_offset_t kva;
|
|
{
|
|
pmap_kremove(kva);
|
|
kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
|
|
}
|
|
|
|
vm_object_t
|
|
vm_pager_object_lookup(pg_list, handle)
|
|
register struct pagerlst *pg_list;
|
|
void *handle;
|
|
{
|
|
register vm_object_t object;
|
|
|
|
for (object = TAILQ_FIRST(pg_list); object != NULL; object = TAILQ_NEXT(object,pager_object_list))
|
|
if (object->handle == handle)
|
|
return (object);
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* initialize a physical buffer
|
|
*/
|
|
|
|
static void
|
|
initpbuf(struct buf *bp)
|
|
{
|
|
bp->b_rcred = NOCRED;
|
|
bp->b_wcred = NOCRED;
|
|
bp->b_qindex = QUEUE_NONE;
|
|
bp->b_data = (caddr_t) (MAXPHYS * (bp - swbuf)) + swapbkva;
|
|
bp->b_kvabase = bp->b_data;
|
|
bp->b_kvasize = MAXPHYS;
|
|
bp->b_xflags = 0;
|
|
bp->b_flags = 0;
|
|
bp->b_error = 0;
|
|
BUF_LOCK(bp, LK_EXCLUSIVE);
|
|
}
|
|
|
|
/*
|
|
* allocate a physical buffer
|
|
*
|
|
* There are a limited number (nswbuf) of physical buffers. We need
|
|
* to make sure that no single subsystem is able to hog all of them,
|
|
* so each subsystem implements a counter which is typically initialized
|
|
* to 1/2 nswbuf. getpbuf() decrements this counter in allocation and
|
|
* increments it on release, and blocks if the counter hits zero. A
|
|
* subsystem may initialize the counter to -1 to disable the feature,
|
|
* but it must still be sure to match up all uses of getpbuf() with
|
|
* relpbuf() using the same variable.
|
|
*
|
|
* NOTE: pfreecnt can be NULL, but this 'feature' will be removed
|
|
* relatively soon when the rest of the subsystems get smart about it. XXX
|
|
*/
|
|
struct buf *
|
|
getpbuf(pfreecnt)
|
|
int *pfreecnt;
|
|
{
|
|
int s;
|
|
struct buf *bp;
|
|
|
|
s = splvm();
|
|
|
|
for (;;) {
|
|
if (pfreecnt) {
|
|
while (*pfreecnt == 0) {
|
|
tsleep(pfreecnt, PVM, "wswbuf0", 0);
|
|
}
|
|
}
|
|
|
|
/* get a bp from the swap buffer header pool */
|
|
if ((bp = TAILQ_FIRST(&bswlist)) != NULL)
|
|
break;
|
|
|
|
bswneeded = 1;
|
|
tsleep(&bswneeded, PVM, "wswbuf1", 0);
|
|
/* loop in case someone else grabbed one */
|
|
}
|
|
TAILQ_REMOVE(&bswlist, bp, b_freelist);
|
|
if (pfreecnt)
|
|
--*pfreecnt;
|
|
splx(s);
|
|
|
|
initpbuf(bp);
|
|
return bp;
|
|
}
|
|
|
|
/*
|
|
* allocate a physical buffer, if one is available.
|
|
*
|
|
* Note that there is no NULL hack here - all subsystems using this
|
|
* call understand how to use pfreecnt.
|
|
*/
|
|
struct buf *
|
|
trypbuf(pfreecnt)
|
|
int *pfreecnt;
|
|
{
|
|
int s;
|
|
struct buf *bp;
|
|
|
|
s = splvm();
|
|
if (*pfreecnt == 0 || (bp = TAILQ_FIRST(&bswlist)) == NULL) {
|
|
splx(s);
|
|
return NULL;
|
|
}
|
|
TAILQ_REMOVE(&bswlist, bp, b_freelist);
|
|
|
|
--*pfreecnt;
|
|
|
|
splx(s);
|
|
|
|
initpbuf(bp);
|
|
|
|
return bp;
|
|
}
|
|
|
|
/*
|
|
* release a physical buffer
|
|
*
|
|
* NOTE: pfreecnt can be NULL, but this 'feature' will be removed
|
|
* relatively soon when the rest of the subsystems get smart about it. XXX
|
|
*/
|
|
void
|
|
relpbuf(bp, pfreecnt)
|
|
struct buf *bp;
|
|
int *pfreecnt;
|
|
{
|
|
int s;
|
|
|
|
s = splvm();
|
|
|
|
if (bp->b_rcred != NOCRED) {
|
|
crfree(bp->b_rcred);
|
|
bp->b_rcred = NOCRED;
|
|
}
|
|
if (bp->b_wcred != NOCRED) {
|
|
crfree(bp->b_wcred);
|
|
bp->b_wcred = NOCRED;
|
|
}
|
|
|
|
if (bp->b_vp)
|
|
pbrelvp(bp);
|
|
|
|
BUF_UNLOCK(bp);
|
|
|
|
TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
|
|
|
|
if (bswneeded) {
|
|
bswneeded = 0;
|
|
wakeup(&bswneeded);
|
|
}
|
|
if (pfreecnt) {
|
|
if (++*pfreecnt == 1)
|
|
wakeup(pfreecnt);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
/********************************************************
|
|
* CHAINING FUNCTIONS *
|
|
********************************************************
|
|
*
|
|
* These functions support recursion of I/O operations
|
|
* on bp's, typically by chaining one or more 'child' bp's
|
|
* to the parent. Synchronous, asynchronous, and semi-synchronous
|
|
* chaining is possible.
|
|
*/
|
|
|
|
/*
|
|
* vm_pager_chain_iodone:
|
|
*
|
|
* io completion routine for child bp. Currently we fudge a bit
|
|
* on dealing with b_resid. Since users of these routines may issue
|
|
* multiple children simultaniously, sequencing of the error can be lost.
|
|
*/
|
|
|
|
static void
|
|
vm_pager_chain_iodone(struct buf *nbp)
|
|
{
|
|
struct buf *bp;
|
|
|
|
if ((bp = nbp->b_chain.parent) != NULL) {
|
|
if (nbp->b_flags & B_ERROR) {
|
|
bp->b_flags |= B_ERROR;
|
|
bp->b_error = nbp->b_error;
|
|
} else if (nbp->b_resid != 0) {
|
|
bp->b_flags |= B_ERROR;
|
|
bp->b_error = EINVAL;
|
|
} else {
|
|
bp->b_resid -= nbp->b_bcount;
|
|
}
|
|
nbp->b_chain.parent = NULL;
|
|
--bp->b_chain.count;
|
|
if (bp->b_flags & B_WANT) {
|
|
bp->b_flags &= ~B_WANT;
|
|
wakeup(bp);
|
|
}
|
|
if (!bp->b_chain.count && (bp->b_flags & B_AUTOCHAINDONE)) {
|
|
bp->b_flags &= ~B_AUTOCHAINDONE;
|
|
if (bp->b_resid != 0 && !(bp->b_flags & B_ERROR)) {
|
|
bp->b_flags |= B_ERROR;
|
|
bp->b_error = EINVAL;
|
|
}
|
|
biodone(bp);
|
|
}
|
|
}
|
|
nbp->b_flags |= B_DONE;
|
|
nbp->b_flags &= ~B_ASYNC;
|
|
relpbuf(nbp, NULL);
|
|
}
|
|
|
|
/*
|
|
* getchainbuf:
|
|
*
|
|
* Obtain a physical buffer and chain it to its parent buffer. When
|
|
* I/O completes, the parent buffer will be B_SIGNAL'd. Errors are
|
|
* automatically propogated to the parent
|
|
*
|
|
* Since these are brand new buffers, we do not have to clear B_INVAL
|
|
* and B_ERROR because they are already clear.
|
|
*/
|
|
|
|
struct buf *
|
|
getchainbuf(struct buf *bp, struct vnode *vp, int flags)
|
|
{
|
|
struct buf *nbp = getpbuf(NULL);
|
|
|
|
nbp->b_chain.parent = bp;
|
|
++bp->b_chain.count;
|
|
|
|
if (bp->b_chain.count > 4)
|
|
waitchainbuf(bp, 4, 0);
|
|
|
|
nbp->b_flags = B_CALL | (bp->b_flags & B_ORDERED) | flags;
|
|
nbp->b_rcred = nbp->b_wcred = proc0.p_ucred;
|
|
nbp->b_iodone = vm_pager_chain_iodone;
|
|
|
|
crhold(nbp->b_rcred);
|
|
crhold(nbp->b_wcred);
|
|
|
|
if (vp)
|
|
pbgetvp(vp, nbp);
|
|
return(nbp);
|
|
}
|
|
|
|
void
|
|
flushchainbuf(struct buf *nbp)
|
|
{
|
|
if (nbp->b_bcount) {
|
|
nbp->b_bufsize = nbp->b_bcount;
|
|
if ((nbp->b_flags & B_READ) == 0)
|
|
nbp->b_dirtyend = nbp->b_bcount;
|
|
VOP_STRATEGY(nbp->b_vp, nbp);
|
|
} else {
|
|
biodone(nbp);
|
|
}
|
|
}
|
|
|
|
void
|
|
waitchainbuf(struct buf *bp, int count, int done)
|
|
{
|
|
int s;
|
|
|
|
s = splbio();
|
|
while (bp->b_chain.count > count) {
|
|
bp->b_flags |= B_WANT;
|
|
tsleep(bp, PRIBIO + 4, "bpchain", 0);
|
|
}
|
|
if (done) {
|
|
if (bp->b_resid != 0 && !(bp->b_flags & B_ERROR)) {
|
|
bp->b_flags |= B_ERROR;
|
|
bp->b_error = EINVAL;
|
|
}
|
|
biodone(bp);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
void
|
|
autochaindone(struct buf *bp)
|
|
{
|
|
int s;
|
|
|
|
s = splbio();
|
|
if (bp->b_chain.count == 0)
|
|
biodone(bp);
|
|
else
|
|
bp->b_flags |= B_AUTOCHAINDONE;
|
|
splx(s);
|
|
}
|
|
|