487 lines
12 KiB
C
487 lines
12 KiB
C
/*-
|
|
* SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
|
|
*
|
|
* 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. 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.
|
|
*/
|
|
|
|
/*
|
|
* Paging space routine stubs. Emulates a matchmaker-like interface
|
|
* for builtin pagers.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "opt_param.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/bio.h>
|
|
#include <sys/buf.h>
|
|
#include <sys/ucred.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/rwlock.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm_kern.h>
|
|
#include <vm/vm_object.h>
|
|
#include <vm/vm_page.h>
|
|
#include <vm/vm_pager.h>
|
|
#include <vm/vm_extern.h>
|
|
#include <vm/uma.h>
|
|
|
|
uma_zone_t pbuf_zone;
|
|
static int pbuf_init(void *, int, int);
|
|
static int pbuf_ctor(void *, int, void *, int);
|
|
static void pbuf_dtor(void *, int, void *);
|
|
|
|
static int dead_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
|
|
static vm_object_t dead_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
|
|
vm_ooffset_t, struct ucred *);
|
|
static void dead_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
|
|
static boolean_t dead_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
|
|
static void dead_pager_dealloc(vm_object_t);
|
|
|
|
static int
|
|
dead_pager_getpages(vm_object_t obj, vm_page_t *ma, int count, int *rbehind,
|
|
int *rahead)
|
|
{
|
|
|
|
return (VM_PAGER_FAIL);
|
|
}
|
|
|
|
static vm_object_t
|
|
dead_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
|
|
vm_ooffset_t off, struct ucred *cred)
|
|
{
|
|
|
|
return (NULL);
|
|
}
|
|
|
|
static void
|
|
dead_pager_putpages(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(vm_object_t object, vm_pindex_t pindex, int *prev, int *next)
|
|
{
|
|
|
|
if (prev != NULL)
|
|
*prev = 0;
|
|
if (next != NULL)
|
|
*next = 0;
|
|
return (FALSE);
|
|
}
|
|
|
|
static void
|
|
dead_pager_dealloc(vm_object_t object)
|
|
{
|
|
|
|
}
|
|
|
|
static struct pagerops deadpagerops = {
|
|
.pgo_alloc = dead_pager_alloc,
|
|
.pgo_dealloc = dead_pager_dealloc,
|
|
.pgo_getpages = dead_pager_getpages,
|
|
.pgo_putpages = dead_pager_putpages,
|
|
.pgo_haspage = dead_pager_haspage,
|
|
};
|
|
|
|
struct pagerops *pagertab[] = {
|
|
&defaultpagerops, /* OBJT_DEFAULT */
|
|
&swappagerops, /* OBJT_SWAP */
|
|
&vnodepagerops, /* OBJT_VNODE */
|
|
&devicepagerops, /* OBJT_DEVICE */
|
|
&physpagerops, /* OBJT_PHYS */
|
|
&deadpagerops, /* OBJT_DEAD */
|
|
&sgpagerops, /* OBJT_SG */
|
|
&mgtdevicepagerops, /* OBJT_MGTDEVICE */
|
|
};
|
|
|
|
void
|
|
vm_pager_init(void)
|
|
{
|
|
struct pagerops **pgops;
|
|
|
|
/*
|
|
* Initialize known pagers
|
|
*/
|
|
for (pgops = pagertab; pgops < &pagertab[nitems(pagertab)]; pgops++)
|
|
if ((*pgops)->pgo_init != NULL)
|
|
(*(*pgops)->pgo_init)();
|
|
}
|
|
|
|
static int nswbuf_max;
|
|
|
|
void
|
|
vm_pager_bufferinit(void)
|
|
{
|
|
|
|
/* Main zone for paging bufs. */
|
|
pbuf_zone = uma_zcreate("pbuf", sizeof(struct buf),
|
|
pbuf_ctor, pbuf_dtor, pbuf_init, NULL, UMA_ALIGN_CACHE,
|
|
UMA_ZONE_VM | UMA_ZONE_NOFREE);
|
|
/* Few systems may still use this zone directly, so it needs a limit. */
|
|
nswbuf_max += uma_zone_set_max(pbuf_zone, NSWBUF_MIN);
|
|
}
|
|
|
|
uma_zone_t
|
|
pbuf_zsecond_create(char *name, int max)
|
|
{
|
|
uma_zone_t zone;
|
|
|
|
zone = uma_zsecond_create(name, pbuf_ctor, pbuf_dtor, NULL, NULL,
|
|
pbuf_zone);
|
|
/*
|
|
* uma_prealloc() rounds up to items per slab. If we would prealloc
|
|
* immediately on every pbuf_zsecond_create(), we may accumulate too
|
|
* much of difference between hard limit and prealloced items, which
|
|
* means wasted memory.
|
|
*/
|
|
if (nswbuf_max > 0)
|
|
nswbuf_max += uma_zone_set_max(zone, max);
|
|
else
|
|
uma_prealloc(pbuf_zone, uma_zone_set_max(zone, max));
|
|
|
|
return (zone);
|
|
}
|
|
|
|
static void
|
|
pbuf_prealloc(void *arg __unused)
|
|
{
|
|
|
|
uma_prealloc(pbuf_zone, nswbuf_max);
|
|
nswbuf_max = -1;
|
|
}
|
|
|
|
SYSINIT(pbuf, SI_SUB_KTHREAD_BUF, SI_ORDER_ANY, pbuf_prealloc, NULL);
|
|
|
|
/*
|
|
* 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 ucred *cred)
|
|
{
|
|
vm_object_t ret;
|
|
struct pagerops *ops;
|
|
|
|
ops = pagertab[type];
|
|
if (ops)
|
|
ret = (*ops->pgo_alloc)(handle, size, prot, off, cred);
|
|
else
|
|
ret = NULL;
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* The object must be locked.
|
|
*/
|
|
void
|
|
vm_pager_deallocate(vm_object_t object)
|
|
{
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
(*pagertab[object->type]->pgo_dealloc) (object);
|
|
}
|
|
|
|
static void
|
|
vm_pager_assert_in(vm_object_t object, vm_page_t *m, int count)
|
|
{
|
|
#ifdef INVARIANTS
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
KASSERT(count > 0, ("%s: 0 count", __func__));
|
|
/*
|
|
* All pages must be busied, not mapped, not fully valid,
|
|
* not dirty and belong to the proper object.
|
|
*/
|
|
for (int i = 0 ; i < count; i++) {
|
|
if (m[i] == bogus_page)
|
|
continue;
|
|
vm_page_assert_xbusied(m[i]);
|
|
KASSERT(!pmap_page_is_mapped(m[i]),
|
|
("%s: page %p is mapped", __func__, m[i]));
|
|
KASSERT(m[i]->valid != VM_PAGE_BITS_ALL,
|
|
("%s: request for a valid page %p", __func__, m[i]));
|
|
KASSERT(m[i]->dirty == 0,
|
|
("%s: page %p is dirty", __func__, m[i]));
|
|
KASSERT(m[i]->object == object,
|
|
("%s: wrong object %p/%p", __func__, object, m[i]->object));
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Page in the pages for the object using its associated pager.
|
|
* The requested page must be fully valid on successful return.
|
|
*/
|
|
int
|
|
vm_pager_get_pages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
|
|
int *rahead)
|
|
{
|
|
#ifdef INVARIANTS
|
|
vm_pindex_t pindex = m[0]->pindex;
|
|
#endif
|
|
int r;
|
|
|
|
vm_pager_assert_in(object, m, count);
|
|
|
|
r = (*pagertab[object->type]->pgo_getpages)(object, m, count, rbehind,
|
|
rahead);
|
|
if (r != VM_PAGER_OK)
|
|
return (r);
|
|
|
|
for (int i = 0; i < count; i++) {
|
|
/*
|
|
* If pager has replaced a page, assert that it had
|
|
* updated the array.
|
|
*/
|
|
KASSERT(m[i] == vm_page_lookup(object, pindex++),
|
|
("%s: mismatch page %p pindex %ju", __func__,
|
|
m[i], (uintmax_t )pindex - 1));
|
|
/*
|
|
* Zero out partially filled data.
|
|
*/
|
|
if (m[i]->valid != VM_PAGE_BITS_ALL)
|
|
vm_page_zero_invalid(m[i], TRUE);
|
|
}
|
|
return (VM_PAGER_OK);
|
|
}
|
|
|
|
int
|
|
vm_pager_get_pages_async(vm_object_t object, vm_page_t *m, int count,
|
|
int *rbehind, int *rahead, pgo_getpages_iodone_t iodone, void *arg)
|
|
{
|
|
|
|
vm_pager_assert_in(object, m, count);
|
|
|
|
return ((*pagertab[object->type]->pgo_getpages_async)(object, m,
|
|
count, rbehind, rahead, iodone, arg));
|
|
}
|
|
|
|
/*
|
|
* vm_pager_put_pages() - inline, see vm/vm_pager.h
|
|
* vm_pager_has_page() - inline, see vm/vm_pager.h
|
|
*/
|
|
|
|
/*
|
|
* Search the specified pager object list for an object with the
|
|
* specified handle. If an object with the specified handle is found,
|
|
* increase its reference count and return it. Otherwise, return NULL.
|
|
*
|
|
* The pager object list must be locked.
|
|
*/
|
|
vm_object_t
|
|
vm_pager_object_lookup(struct pagerlst *pg_list, void *handle)
|
|
{
|
|
vm_object_t object;
|
|
|
|
TAILQ_FOREACH(object, pg_list, pager_object_list) {
|
|
if (object->handle == handle) {
|
|
VM_OBJECT_WLOCK(object);
|
|
if ((object->flags & OBJ_DEAD) == 0) {
|
|
vm_object_reference_locked(object);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
break;
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
}
|
|
}
|
|
return (object);
|
|
}
|
|
|
|
static int
|
|
pbuf_ctor(void *mem, int size, void *arg, int flags)
|
|
{
|
|
struct buf *bp = mem;
|
|
|
|
bp->b_vp = NULL;
|
|
bp->b_bufobj = NULL;
|
|
|
|
/* copied from initpbuf() */
|
|
bp->b_rcred = NOCRED;
|
|
bp->b_wcred = NOCRED;
|
|
bp->b_qindex = 0; /* On no queue (QUEUE_NONE) */
|
|
bp->b_data = bp->b_kvabase;
|
|
bp->b_xflags = 0;
|
|
bp->b_flags = 0;
|
|
bp->b_ioflags = 0;
|
|
bp->b_iodone = NULL;
|
|
bp->b_error = 0;
|
|
BUF_LOCK(bp, LK_EXCLUSIVE, NULL);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
pbuf_dtor(void *mem, int size, void *arg)
|
|
{
|
|
struct buf *bp = mem;
|
|
|
|
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;
|
|
}
|
|
|
|
BUF_UNLOCK(bp);
|
|
}
|
|
|
|
static int
|
|
pbuf_init(void *mem, int size, int flags)
|
|
{
|
|
struct buf *bp = mem;
|
|
|
|
bp->b_kvabase = (void *)kva_alloc(MAXPHYS);
|
|
if (bp->b_kvabase == NULL)
|
|
return (ENOMEM);
|
|
bp->b_kvasize = MAXPHYS;
|
|
BUF_LOCKINIT(bp);
|
|
LIST_INIT(&bp->b_dep);
|
|
bp->b_rcred = bp->b_wcred = NOCRED;
|
|
bp->b_xflags = 0;
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Associate a p-buffer with a vnode.
|
|
*
|
|
* Also sets B_PAGING flag to indicate that vnode is not fully associated
|
|
* with the buffer. i.e. the bp has not been linked into the vnode or
|
|
* ref-counted.
|
|
*/
|
|
void
|
|
pbgetvp(struct vnode *vp, struct buf *bp)
|
|
{
|
|
|
|
KASSERT(bp->b_vp == NULL, ("pbgetvp: not free"));
|
|
KASSERT(bp->b_bufobj == NULL, ("pbgetvp: not free (bufobj)"));
|
|
|
|
bp->b_vp = vp;
|
|
bp->b_flags |= B_PAGING;
|
|
bp->b_bufobj = &vp->v_bufobj;
|
|
}
|
|
|
|
/*
|
|
* Associate a p-buffer with a vnode.
|
|
*
|
|
* Also sets B_PAGING flag to indicate that vnode is not fully associated
|
|
* with the buffer. i.e. the bp has not been linked into the vnode or
|
|
* ref-counted.
|
|
*/
|
|
void
|
|
pbgetbo(struct bufobj *bo, struct buf *bp)
|
|
{
|
|
|
|
KASSERT(bp->b_vp == NULL, ("pbgetbo: not free (vnode)"));
|
|
KASSERT(bp->b_bufobj == NULL, ("pbgetbo: not free (bufobj)"));
|
|
|
|
bp->b_flags |= B_PAGING;
|
|
bp->b_bufobj = bo;
|
|
}
|
|
|
|
/*
|
|
* Disassociate a p-buffer from a vnode.
|
|
*/
|
|
void
|
|
pbrelvp(struct buf *bp)
|
|
{
|
|
|
|
KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
|
|
KASSERT(bp->b_bufobj != NULL, ("pbrelvp: NULL bufobj"));
|
|
KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
|
|
("pbrelvp: pager buf on vnode list."));
|
|
|
|
bp->b_vp = NULL;
|
|
bp->b_bufobj = NULL;
|
|
bp->b_flags &= ~B_PAGING;
|
|
}
|
|
|
|
/*
|
|
* Disassociate a p-buffer from a bufobj.
|
|
*/
|
|
void
|
|
pbrelbo(struct buf *bp)
|
|
{
|
|
|
|
KASSERT(bp->b_vp == NULL, ("pbrelbo: vnode"));
|
|
KASSERT(bp->b_bufobj != NULL, ("pbrelbo: NULL bufobj"));
|
|
KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
|
|
("pbrelbo: pager buf on vnode list."));
|
|
|
|
bp->b_bufobj = NULL;
|
|
bp->b_flags &= ~B_PAGING;
|
|
}
|