00a3fe968b
Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D30168
1615 lines
44 KiB
C
1615 lines
44 KiB
C
/*-
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* SPDX-License-Identifier: BSD-4-Clause
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*
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* Copyright (c) 1990 University of Utah.
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* Copyright (c) 1991 The Regents of the University of California.
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* All rights reserved.
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* Copyright (c) 1993, 1994 John S. Dyson
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* Copyright (c) 1995, David Greenman
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*
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* This code is derived from software contributed to Berkeley by
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* the Systems Programming Group of the University of Utah Computer
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* Science Department.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91
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*/
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/*
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* Page to/from files (vnodes).
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*/
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/*
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* TODO:
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* Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
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* greatly re-simplify the vnode_pager.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_vm.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/sysctl.h>
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#include <sys/proc.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/bio.h>
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#include <sys/buf.h>
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#include <sys/vmmeter.h>
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#include <sys/ktr.h>
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#include <sys/limits.h>
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#include <sys/conf.h>
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#include <sys/refcount.h>
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#include <sys/rwlock.h>
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#include <sys/sf_buf.h>
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#include <sys/domainset.h>
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#include <sys/user.h>
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#include <machine/atomic.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_object.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pager.h>
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#include <vm/vm_map.h>
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#include <vm/vnode_pager.h>
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#include <vm/vm_extern.h>
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#include <vm/uma.h>
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static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
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daddr_t *rtaddress, int *run);
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static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
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static int vnode_pager_input_old(vm_object_t object, vm_page_t m);
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static void vnode_pager_dealloc(vm_object_t);
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static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
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static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *,
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int *, vop_getpages_iodone_t, void *);
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static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
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static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
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static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
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vm_ooffset_t, struct ucred *cred);
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static int vnode_pager_generic_getpages_done(struct buf *);
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static void vnode_pager_generic_getpages_done_async(struct buf *);
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static void vnode_pager_update_writecount(vm_object_t, vm_offset_t,
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vm_offset_t);
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static void vnode_pager_release_writecount(vm_object_t, vm_offset_t,
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vm_offset_t);
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static void vnode_pager_getvp(vm_object_t, struct vnode **, bool *);
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const struct pagerops vnodepagerops = {
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.pgo_kvme_type = KVME_TYPE_VNODE,
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.pgo_alloc = vnode_pager_alloc,
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.pgo_dealloc = vnode_pager_dealloc,
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.pgo_getpages = vnode_pager_getpages,
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.pgo_getpages_async = vnode_pager_getpages_async,
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.pgo_putpages = vnode_pager_putpages,
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.pgo_haspage = vnode_pager_haspage,
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.pgo_update_writecount = vnode_pager_update_writecount,
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.pgo_release_writecount = vnode_pager_release_writecount,
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.pgo_set_writeable_dirty = vm_object_set_writeable_dirty_,
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.pgo_mightbedirty = vm_object_mightbedirty_,
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.pgo_getvp = vnode_pager_getvp,
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};
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static struct domainset *vnode_domainset = NULL;
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SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset,
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CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_RW, &vnode_domainset, 0,
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sysctl_handle_domainset, "A", "Default vnode NUMA policy");
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static int nvnpbufs;
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SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
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&nvnpbufs, 0, "number of physical buffers allocated for vnode pager");
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static uma_zone_t vnode_pbuf_zone;
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static void
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vnode_pager_init(void *dummy)
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{
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#ifdef __LP64__
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nvnpbufs = nswbuf * 2;
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#else
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nvnpbufs = nswbuf / 2;
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#endif
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TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs);
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vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs);
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}
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SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL);
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/* Create the VM system backing object for this vnode */
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int
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vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
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{
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vm_object_t object;
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vm_ooffset_t size = isize;
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struct vattr va;
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bool last;
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if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE)
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return (0);
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object = vp->v_object;
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if (object != NULL)
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return (0);
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if (size == 0) {
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if (vn_isdisk(vp)) {
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size = IDX_TO_OFF(INT_MAX);
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} else {
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if (VOP_GETATTR(vp, &va, td->td_ucred))
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return (0);
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size = va.va_size;
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}
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}
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object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
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/*
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* Dereference the reference we just created. This assumes
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* that the object is associated with the vp. We still have
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* to serialize with vnode_pager_dealloc() for the last
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* potential reference.
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*/
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VM_OBJECT_RLOCK(object);
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last = refcount_release(&object->ref_count);
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VM_OBJECT_RUNLOCK(object);
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if (last)
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vrele(vp);
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KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
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return (0);
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}
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void
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vnode_destroy_vobject(struct vnode *vp)
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{
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struct vm_object *obj;
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obj = vp->v_object;
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if (obj == NULL || obj->handle != vp)
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return;
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ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
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VM_OBJECT_WLOCK(obj);
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MPASS(obj->type == OBJT_VNODE);
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umtx_shm_object_terminated(obj);
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if (obj->ref_count == 0) {
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KASSERT((obj->flags & OBJ_DEAD) == 0,
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("vnode_destroy_vobject: Terminating dead object"));
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vm_object_set_flag(obj, OBJ_DEAD);
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/*
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* Clean pages and flush buffers.
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*/
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vm_object_page_clean(obj, 0, 0, OBJPC_SYNC);
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VM_OBJECT_WUNLOCK(obj);
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vinvalbuf(vp, V_SAVE, 0, 0);
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BO_LOCK(&vp->v_bufobj);
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vp->v_bufobj.bo_flag |= BO_DEAD;
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BO_UNLOCK(&vp->v_bufobj);
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VM_OBJECT_WLOCK(obj);
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vm_object_terminate(obj);
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} else {
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/*
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* Woe to the process that tries to page now :-).
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*/
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vm_pager_deallocate(obj);
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VM_OBJECT_WUNLOCK(obj);
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}
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KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object));
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}
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/*
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* Allocate (or lookup) pager for a vnode.
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* Handle is a vnode pointer.
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*/
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vm_object_t
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vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
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vm_ooffset_t offset, struct ucred *cred)
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{
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vm_object_t object;
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struct vnode *vp;
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/*
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* Pageout to vnode, no can do yet.
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*/
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if (handle == NULL)
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return (NULL);
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vp = (struct vnode *)handle;
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ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc");
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VNPASS(vp->v_usecount > 0, vp);
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retry:
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object = vp->v_object;
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if (object == NULL) {
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/*
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* Add an object of the appropriate size
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*/
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object = vm_object_allocate(OBJT_VNODE,
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OFF_TO_IDX(round_page(size)));
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object->un_pager.vnp.vnp_size = size;
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object->un_pager.vnp.writemappings = 0;
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object->domain.dr_policy = vnode_domainset;
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object->handle = handle;
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if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) {
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VM_OBJECT_WLOCK(object);
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vm_object_set_flag(object, OBJ_SIZEVNLOCK);
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VM_OBJECT_WUNLOCK(object);
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}
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VI_LOCK(vp);
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if (vp->v_object != NULL) {
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/*
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* Object has been created while we were allocating.
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*/
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VI_UNLOCK(vp);
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VM_OBJECT_WLOCK(object);
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KASSERT(object->ref_count == 1,
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("leaked ref %p %d", object, object->ref_count));
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object->type = OBJT_DEAD;
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refcount_init(&object->ref_count, 0);
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VM_OBJECT_WUNLOCK(object);
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vm_object_destroy(object);
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goto retry;
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}
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vp->v_object = object;
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VI_UNLOCK(vp);
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vrefact(vp);
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} else {
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vm_object_reference(object);
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#if VM_NRESERVLEVEL > 0
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if ((object->flags & OBJ_COLORED) == 0) {
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VM_OBJECT_WLOCK(object);
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vm_object_color(object, 0);
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VM_OBJECT_WUNLOCK(object);
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}
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#endif
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}
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return (object);
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}
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/*
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* The object must be locked.
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*/
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static void
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vnode_pager_dealloc(vm_object_t object)
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{
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struct vnode *vp;
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int refs;
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vp = object->handle;
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if (vp == NULL)
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panic("vnode_pager_dealloc: pager already dealloced");
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VM_OBJECT_ASSERT_WLOCKED(object);
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vm_object_pip_wait(object, "vnpdea");
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refs = object->ref_count;
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object->handle = NULL;
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object->type = OBJT_DEAD;
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ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
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if (object->un_pager.vnp.writemappings > 0) {
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object->un_pager.vnp.writemappings = 0;
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VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
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CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
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__func__, vp, vp->v_writecount);
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}
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vp->v_object = NULL;
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VI_LOCK(vp);
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/*
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* vm_map_entry_set_vnode_text() cannot reach this vnode by
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* following object->handle. Clear all text references now.
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* This also clears the transient references from
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* kern_execve(), which is fine because dead_vnodeops uses nop
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* for VOP_UNSET_TEXT().
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*/
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if (vp->v_writecount < 0)
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vp->v_writecount = 0;
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VI_UNLOCK(vp);
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VM_OBJECT_WUNLOCK(object);
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if (refs > 0)
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vunref(vp);
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VM_OBJECT_WLOCK(object);
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}
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static boolean_t
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vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
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int *after)
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{
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struct vnode *vp = object->handle;
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daddr_t bn;
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uintptr_t lockstate;
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int err;
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daddr_t reqblock;
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int poff;
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int bsize;
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int pagesperblock, blocksperpage;
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VM_OBJECT_ASSERT_LOCKED(object);
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/*
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* If no vp or vp is doomed or marked transparent to VM, we do not
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* have the page.
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*/
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if (vp == NULL || VN_IS_DOOMED(vp))
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return FALSE;
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/*
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* If the offset is beyond end of file we do
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* not have the page.
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*/
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if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
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return FALSE;
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bsize = vp->v_mount->mnt_stat.f_iosize;
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pagesperblock = bsize / PAGE_SIZE;
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blocksperpage = 0;
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if (pagesperblock > 0) {
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reqblock = pindex / pagesperblock;
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} else {
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blocksperpage = (PAGE_SIZE / bsize);
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reqblock = pindex * blocksperpage;
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}
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lockstate = VM_OBJECT_DROP(object);
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err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
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VM_OBJECT_PICKUP(object, lockstate);
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if (err)
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return TRUE;
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if (bn == -1)
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return FALSE;
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if (pagesperblock > 0) {
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poff = pindex - (reqblock * pagesperblock);
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if (before) {
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*before *= pagesperblock;
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*before += poff;
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}
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if (after) {
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/*
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* The BMAP vop can report a partial block in the
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* 'after', but must not report blocks after EOF.
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* Assert the latter, and truncate 'after' in case
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* of the former.
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*/
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KASSERT((reqblock + *after) * pagesperblock <
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roundup2(object->size, pagesperblock),
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("%s: reqblock %jd after %d size %ju", __func__,
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(intmax_t )reqblock, *after,
|
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(uintmax_t )object->size));
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*after *= pagesperblock;
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*after += pagesperblock - (poff + 1);
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if (pindex + *after >= object->size)
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*after = object->size - 1 - pindex;
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}
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} else {
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if (before) {
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*before /= blocksperpage;
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}
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|
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if (after) {
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*after /= blocksperpage;
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}
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}
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return TRUE;
|
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}
|
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|
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/*
|
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* Lets the VM system know about a change in size for a file.
|
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* We adjust our own internal size and flush any cached pages in
|
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* the associated object that are affected by the size change.
|
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*
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* Note: this routine may be invoked as a result of a pager put
|
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* operation (possibly at object termination time), so we must be careful.
|
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*/
|
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void
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vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize)
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{
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vm_object_t object;
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vm_page_t m;
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vm_pindex_t nobjsize;
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|
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if ((object = vp->v_object) == NULL)
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return;
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#ifdef DEBUG_VFS_LOCKS
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{
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struct mount *mp;
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mp = vp->v_mount;
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if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0)
|
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assert_vop_elocked(vp,
|
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"vnode_pager_setsize and not locked vnode");
|
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}
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#endif
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VM_OBJECT_WLOCK(object);
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if (object->type == OBJT_DEAD) {
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VM_OBJECT_WUNLOCK(object);
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return;
|
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}
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KASSERT(object->type == OBJT_VNODE,
|
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("not vnode-backed object %p", object));
|
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if (nsize == object->un_pager.vnp.vnp_size) {
|
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/*
|
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* Hasn't changed size
|
|
*/
|
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VM_OBJECT_WUNLOCK(object);
|
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return;
|
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}
|
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nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
|
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if (nsize < object->un_pager.vnp.vnp_size) {
|
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/*
|
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* File has shrunk. Toss any cached pages beyond the new EOF.
|
|
*/
|
|
if (nobjsize < object->size)
|
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vm_object_page_remove(object, nobjsize, object->size,
|
|
0);
|
|
/*
|
|
* this gets rid of garbage at the end of a page that is now
|
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* only partially backed by the vnode.
|
|
*
|
|
* XXX for some reason (I don't know yet), if we take a
|
|
* completely invalid page and mark it partially valid
|
|
* it can screw up NFS reads, so we don't allow the case.
|
|
*/
|
|
if (!(nsize & PAGE_MASK))
|
|
goto out;
|
|
m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT);
|
|
if (m == NULL)
|
|
goto out;
|
|
if (!vm_page_none_valid(m)) {
|
|
int base = (int)nsize & PAGE_MASK;
|
|
int size = PAGE_SIZE - base;
|
|
|
|
/*
|
|
* Clear out partial-page garbage in case
|
|
* the page has been mapped.
|
|
*/
|
|
pmap_zero_page_area(m, base, size);
|
|
|
|
/*
|
|
* Update the valid bits to reflect the blocks that
|
|
* have been zeroed. Some of these valid bits may
|
|
* have already been set.
|
|
*/
|
|
vm_page_set_valid_range(m, base, size);
|
|
|
|
/*
|
|
* Round "base" to the next block boundary so that the
|
|
* dirty bit for a partially zeroed block is not
|
|
* cleared.
|
|
*/
|
|
base = roundup2(base, DEV_BSIZE);
|
|
|
|
/*
|
|
* Clear out partial-page dirty bits.
|
|
*
|
|
* note that we do not clear out the valid
|
|
* bits. This would prevent bogus_page
|
|
* replacement from working properly.
|
|
*/
|
|
vm_page_clear_dirty(m, base, PAGE_SIZE - base);
|
|
}
|
|
vm_page_xunbusy(m);
|
|
}
|
|
out:
|
|
#if defined(__powerpc__) && !defined(__powerpc64__)
|
|
object->un_pager.vnp.vnp_size = nsize;
|
|
#else
|
|
atomic_store_64(&object->un_pager.vnp.vnp_size, nsize);
|
|
#endif
|
|
object->size = nobjsize;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
}
|
|
|
|
/*
|
|
* calculate the linear (byte) disk address of specified virtual
|
|
* file address
|
|
*/
|
|
static int
|
|
vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
|
|
int *run)
|
|
{
|
|
int bsize;
|
|
int err;
|
|
daddr_t vblock;
|
|
daddr_t voffset;
|
|
|
|
if (VN_IS_DOOMED(vp))
|
|
return -1;
|
|
|
|
bsize = vp->v_mount->mnt_stat.f_iosize;
|
|
vblock = address / bsize;
|
|
voffset = address % bsize;
|
|
|
|
err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
|
|
if (err == 0) {
|
|
if (*rtaddress != -1)
|
|
*rtaddress += voffset / DEV_BSIZE;
|
|
if (run) {
|
|
*run += 1;
|
|
*run *= bsize / PAGE_SIZE;
|
|
*run -= voffset / PAGE_SIZE;
|
|
}
|
|
}
|
|
|
|
return (err);
|
|
}
|
|
|
|
/*
|
|
* small block filesystem vnode pager input
|
|
*/
|
|
static int
|
|
vnode_pager_input_smlfs(vm_object_t object, vm_page_t m)
|
|
{
|
|
struct vnode *vp;
|
|
struct bufobj *bo;
|
|
struct buf *bp;
|
|
struct sf_buf *sf;
|
|
daddr_t fileaddr;
|
|
vm_offset_t bsize;
|
|
vm_page_bits_t bits;
|
|
int error, i;
|
|
|
|
error = 0;
|
|
vp = object->handle;
|
|
if (VN_IS_DOOMED(vp))
|
|
return VM_PAGER_BAD;
|
|
|
|
bsize = vp->v_mount->mnt_stat.f_iosize;
|
|
|
|
VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
|
|
|
|
sf = sf_buf_alloc(m, 0);
|
|
|
|
for (i = 0; i < PAGE_SIZE / bsize; i++) {
|
|
vm_ooffset_t address;
|
|
|
|
bits = vm_page_bits(i * bsize, bsize);
|
|
if (m->valid & bits)
|
|
continue;
|
|
|
|
address = IDX_TO_OFF(m->pindex) + i * bsize;
|
|
if (address >= object->un_pager.vnp.vnp_size) {
|
|
fileaddr = -1;
|
|
} else {
|
|
error = vnode_pager_addr(vp, address, &fileaddr, NULL);
|
|
if (error)
|
|
break;
|
|
}
|
|
if (fileaddr != -1) {
|
|
bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK);
|
|
|
|
/* build a minimal buffer header */
|
|
bp->b_iocmd = BIO_READ;
|
|
bp->b_iodone = bdone;
|
|
KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
|
|
KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
|
|
bp->b_rcred = crhold(curthread->td_ucred);
|
|
bp->b_wcred = crhold(curthread->td_ucred);
|
|
bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
|
|
bp->b_blkno = fileaddr;
|
|
pbgetbo(bo, bp);
|
|
bp->b_vp = vp;
|
|
bp->b_bcount = bsize;
|
|
bp->b_bufsize = bsize;
|
|
bp->b_runningbufspace = bp->b_bufsize;
|
|
atomic_add_long(&runningbufspace, bp->b_runningbufspace);
|
|
|
|
/* do the input */
|
|
bp->b_iooffset = dbtob(bp->b_blkno);
|
|
bstrategy(bp);
|
|
|
|
bwait(bp, PVM, "vnsrd");
|
|
|
|
if ((bp->b_ioflags & BIO_ERROR) != 0) {
|
|
KASSERT(bp->b_error != 0,
|
|
("%s: buf error but b_error == 0\n", __func__));
|
|
error = bp->b_error;
|
|
}
|
|
|
|
/*
|
|
* free the buffer header back to the swap buffer pool
|
|
*/
|
|
bp->b_vp = NULL;
|
|
pbrelbo(bp);
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
if (error)
|
|
break;
|
|
} else
|
|
bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
|
|
KASSERT((m->dirty & bits) == 0,
|
|
("vnode_pager_input_smlfs: page %p is dirty", m));
|
|
vm_page_bits_set(m, &m->valid, bits);
|
|
}
|
|
sf_buf_free(sf);
|
|
if (error) {
|
|
return VM_PAGER_ERROR;
|
|
}
|
|
return VM_PAGER_OK;
|
|
}
|
|
|
|
/*
|
|
* old style vnode pager input routine
|
|
*/
|
|
static int
|
|
vnode_pager_input_old(vm_object_t object, vm_page_t m)
|
|
{
|
|
struct uio auio;
|
|
struct iovec aiov;
|
|
int error;
|
|
int size;
|
|
struct sf_buf *sf;
|
|
struct vnode *vp;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
error = 0;
|
|
|
|
/*
|
|
* Return failure if beyond current EOF
|
|
*/
|
|
if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
|
|
return VM_PAGER_BAD;
|
|
} else {
|
|
size = PAGE_SIZE;
|
|
if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
|
|
size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
|
|
vp = object->handle;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
|
|
/*
|
|
* Allocate a kernel virtual address and initialize so that
|
|
* we can use VOP_READ/WRITE routines.
|
|
*/
|
|
sf = sf_buf_alloc(m, 0);
|
|
|
|
aiov.iov_base = (caddr_t)sf_buf_kva(sf);
|
|
aiov.iov_len = size;
|
|
auio.uio_iov = &aiov;
|
|
auio.uio_iovcnt = 1;
|
|
auio.uio_offset = IDX_TO_OFF(m->pindex);
|
|
auio.uio_segflg = UIO_SYSSPACE;
|
|
auio.uio_rw = UIO_READ;
|
|
auio.uio_resid = size;
|
|
auio.uio_td = curthread;
|
|
|
|
error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
|
|
if (!error) {
|
|
int count = size - auio.uio_resid;
|
|
|
|
if (count == 0)
|
|
error = EINVAL;
|
|
else if (count != PAGE_SIZE)
|
|
bzero((caddr_t)sf_buf_kva(sf) + count,
|
|
PAGE_SIZE - count);
|
|
}
|
|
sf_buf_free(sf);
|
|
|
|
VM_OBJECT_WLOCK(object);
|
|
}
|
|
KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
|
|
if (!error)
|
|
vm_page_valid(m);
|
|
return error ? VM_PAGER_ERROR : VM_PAGER_OK;
|
|
}
|
|
|
|
/*
|
|
* generic vnode pager input routine
|
|
*/
|
|
|
|
/*
|
|
* Local media VFS's that do not implement their own VOP_GETPAGES
|
|
* should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
|
|
* to implement the previous behaviour.
|
|
*
|
|
* All other FS's should use the bypass to get to the local media
|
|
* backing vp's VOP_GETPAGES.
|
|
*/
|
|
static int
|
|
vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
|
|
int *rahead)
|
|
{
|
|
struct vnode *vp;
|
|
int rtval;
|
|
|
|
/* Handle is stable with paging in progress. */
|
|
vp = object->handle;
|
|
rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead);
|
|
KASSERT(rtval != EOPNOTSUPP,
|
|
("vnode_pager: FS getpages not implemented\n"));
|
|
return rtval;
|
|
}
|
|
|
|
static int
|
|
vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count,
|
|
int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg)
|
|
{
|
|
struct vnode *vp;
|
|
int rtval;
|
|
|
|
vp = object->handle;
|
|
rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg);
|
|
KASSERT(rtval != EOPNOTSUPP,
|
|
("vnode_pager: FS getpages_async not implemented\n"));
|
|
return (rtval);
|
|
}
|
|
|
|
/*
|
|
* The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for
|
|
* local filesystems, where partially valid pages can only occur at
|
|
* the end of file.
|
|
*/
|
|
int
|
|
vnode_pager_local_getpages(struct vop_getpages_args *ap)
|
|
{
|
|
|
|
return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
|
|
ap->a_rbehind, ap->a_rahead, NULL, NULL));
|
|
}
|
|
|
|
int
|
|
vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap)
|
|
{
|
|
int error;
|
|
|
|
error = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
|
|
ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg);
|
|
if (error != 0 && ap->a_iodone != NULL)
|
|
ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* This is now called from local media FS's to operate against their
|
|
* own vnodes if they fail to implement VOP_GETPAGES.
|
|
*/
|
|
int
|
|
vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count,
|
|
int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg)
|
|
{
|
|
vm_object_t object;
|
|
struct bufobj *bo;
|
|
struct buf *bp;
|
|
off_t foff;
|
|
#ifdef INVARIANTS
|
|
off_t blkno0;
|
|
#endif
|
|
int bsize, pagesperblock;
|
|
int error, before, after, rbehind, rahead, poff, i;
|
|
int bytecount, secmask;
|
|
|
|
KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
|
|
("%s does not support devices", __func__));
|
|
|
|
if (VN_IS_DOOMED(vp))
|
|
return (VM_PAGER_BAD);
|
|
|
|
object = vp->v_object;
|
|
foff = IDX_TO_OFF(m[0]->pindex);
|
|
bsize = vp->v_mount->mnt_stat.f_iosize;
|
|
pagesperblock = bsize / PAGE_SIZE;
|
|
|
|
KASSERT(foff < object->un_pager.vnp.vnp_size,
|
|
("%s: page %p offset beyond vp %p size", __func__, m[0], vp));
|
|
KASSERT(count <= atop(maxphys),
|
|
("%s: requested %d pages", __func__, count));
|
|
|
|
/*
|
|
* The last page has valid blocks. Invalid part can only
|
|
* exist at the end of file, and the page is made fully valid
|
|
* by zeroing in vm_pager_get_pages().
|
|
*/
|
|
if (!vm_page_none_valid(m[count - 1]) && --count == 0) {
|
|
if (iodone != NULL)
|
|
iodone(arg, m, 1, 0);
|
|
return (VM_PAGER_OK);
|
|
}
|
|
|
|
bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK);
|
|
MPASS((bp->b_flags & B_MAXPHYS) != 0);
|
|
|
|
/*
|
|
* Get the underlying device blocks for the file with VOP_BMAP().
|
|
* If the file system doesn't support VOP_BMAP, use old way of
|
|
* getting pages via VOP_READ.
|
|
*/
|
|
error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before);
|
|
if (error == EOPNOTSUPP) {
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
VM_OBJECT_WLOCK(object);
|
|
for (i = 0; i < count; i++) {
|
|
VM_CNT_INC(v_vnodein);
|
|
VM_CNT_INC(v_vnodepgsin);
|
|
error = vnode_pager_input_old(object, m[i]);
|
|
if (error)
|
|
break;
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return (error);
|
|
} else if (error != 0) {
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
return (VM_PAGER_ERROR);
|
|
}
|
|
|
|
/*
|
|
* If the file system supports BMAP, but blocksize is smaller
|
|
* than a page size, then use special small filesystem code.
|
|
*/
|
|
if (pagesperblock == 0) {
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
for (i = 0; i < count; i++) {
|
|
VM_CNT_INC(v_vnodein);
|
|
VM_CNT_INC(v_vnodepgsin);
|
|
error = vnode_pager_input_smlfs(object, m[i]);
|
|
if (error)
|
|
break;
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* A sparse file can be encountered only for a single page request,
|
|
* which may not be preceded by call to vm_pager_haspage().
|
|
*/
|
|
if (bp->b_blkno == -1) {
|
|
KASSERT(count == 1,
|
|
("%s: array[%d] request to a sparse file %p", __func__,
|
|
count, vp));
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
pmap_zero_page(m[0]);
|
|
KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty",
|
|
__func__, m[0]));
|
|
vm_page_valid(m[0]);
|
|
return (VM_PAGER_OK);
|
|
}
|
|
|
|
#ifdef INVARIANTS
|
|
blkno0 = bp->b_blkno;
|
|
#endif
|
|
bp->b_blkno += (foff % bsize) / DEV_BSIZE;
|
|
|
|
/* Recalculate blocks available after/before to pages. */
|
|
poff = (foff % bsize) / PAGE_SIZE;
|
|
before *= pagesperblock;
|
|
before += poff;
|
|
after *= pagesperblock;
|
|
after += pagesperblock - (poff + 1);
|
|
if (m[0]->pindex + after >= object->size)
|
|
after = object->size - 1 - m[0]->pindex;
|
|
KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d",
|
|
__func__, count, after + 1));
|
|
after -= count - 1;
|
|
|
|
/* Trim requested rbehind/rahead to possible values. */
|
|
rbehind = a_rbehind ? *a_rbehind : 0;
|
|
rahead = a_rahead ? *a_rahead : 0;
|
|
rbehind = min(rbehind, before);
|
|
rbehind = min(rbehind, m[0]->pindex);
|
|
rahead = min(rahead, after);
|
|
rahead = min(rahead, object->size - m[count - 1]->pindex);
|
|
/*
|
|
* Check that total amount of pages fit into buf. Trim rbehind and
|
|
* rahead evenly if not.
|
|
*/
|
|
if (rbehind + rahead + count > atop(maxphys)) {
|
|
int trim, sum;
|
|
|
|
trim = rbehind + rahead + count - atop(maxphys) + 1;
|
|
sum = rbehind + rahead;
|
|
if (rbehind == before) {
|
|
/* Roundup rbehind trim to block size. */
|
|
rbehind -= roundup(trim * rbehind / sum, pagesperblock);
|
|
if (rbehind < 0)
|
|
rbehind = 0;
|
|
} else
|
|
rbehind -= trim * rbehind / sum;
|
|
rahead -= trim * rahead / sum;
|
|
}
|
|
KASSERT(rbehind + rahead + count <= atop(maxphys),
|
|
("%s: behind %d ahead %d count %d maxphys %lu", __func__,
|
|
rbehind, rahead, count, maxphys));
|
|
|
|
/*
|
|
* Fill in the bp->b_pages[] array with requested and optional
|
|
* read behind or read ahead pages. Read behind pages are looked
|
|
* up in a backward direction, down to a first cached page. Same
|
|
* for read ahead pages, but there is no need to shift the array
|
|
* in case of encountering a cached page.
|
|
*/
|
|
i = bp->b_npages = 0;
|
|
if (rbehind) {
|
|
vm_pindex_t startpindex, tpindex;
|
|
vm_page_t p;
|
|
|
|
VM_OBJECT_WLOCK(object);
|
|
startpindex = m[0]->pindex - rbehind;
|
|
if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL &&
|
|
p->pindex >= startpindex)
|
|
startpindex = p->pindex + 1;
|
|
|
|
/* tpindex is unsigned; beware of numeric underflow. */
|
|
for (tpindex = m[0]->pindex - 1;
|
|
tpindex >= startpindex && tpindex < m[0]->pindex;
|
|
tpindex--, i++) {
|
|
p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL);
|
|
if (p == NULL) {
|
|
/* Shift the array. */
|
|
for (int j = 0; j < i; j++)
|
|
bp->b_pages[j] = bp->b_pages[j +
|
|
tpindex + 1 - startpindex];
|
|
break;
|
|
}
|
|
bp->b_pages[tpindex - startpindex] = p;
|
|
}
|
|
|
|
bp->b_pgbefore = i;
|
|
bp->b_npages += i;
|
|
bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE;
|
|
} else
|
|
bp->b_pgbefore = 0;
|
|
|
|
/* Requested pages. */
|
|
for (int j = 0; j < count; j++, i++)
|
|
bp->b_pages[i] = m[j];
|
|
bp->b_npages += count;
|
|
|
|
if (rahead) {
|
|
vm_pindex_t endpindex, tpindex;
|
|
vm_page_t p;
|
|
|
|
if (!VM_OBJECT_WOWNED(object))
|
|
VM_OBJECT_WLOCK(object);
|
|
endpindex = m[count - 1]->pindex + rahead + 1;
|
|
if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL &&
|
|
p->pindex < endpindex)
|
|
endpindex = p->pindex;
|
|
if (endpindex > object->size)
|
|
endpindex = object->size;
|
|
|
|
for (tpindex = m[count - 1]->pindex + 1;
|
|
tpindex < endpindex; i++, tpindex++) {
|
|
p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL);
|
|
if (p == NULL)
|
|
break;
|
|
bp->b_pages[i] = p;
|
|
}
|
|
|
|
bp->b_pgafter = i - bp->b_npages;
|
|
bp->b_npages = i;
|
|
} else
|
|
bp->b_pgafter = 0;
|
|
|
|
if (VM_OBJECT_WOWNED(object))
|
|
VM_OBJECT_WUNLOCK(object);
|
|
|
|
/* Report back actual behind/ahead read. */
|
|
if (a_rbehind)
|
|
*a_rbehind = bp->b_pgbefore;
|
|
if (a_rahead)
|
|
*a_rahead = bp->b_pgafter;
|
|
|
|
#ifdef INVARIANTS
|
|
KASSERT(bp->b_npages <= atop(maxphys),
|
|
("%s: buf %p overflowed", __func__, bp));
|
|
for (int j = 1, prev = 0; j < bp->b_npages; j++) {
|
|
if (bp->b_pages[j] == bogus_page)
|
|
continue;
|
|
KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex ==
|
|
j - prev, ("%s: pages array not consecutive, bp %p",
|
|
__func__, bp));
|
|
prev = j;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Recalculate first offset and bytecount with regards to read behind.
|
|
* Truncate bytecount to vnode real size and round up physical size
|
|
* for real devices.
|
|
*/
|
|
foff = IDX_TO_OFF(bp->b_pages[0]->pindex);
|
|
bytecount = bp->b_npages << PAGE_SHIFT;
|
|
if ((foff + bytecount) > object->un_pager.vnp.vnp_size)
|
|
bytecount = object->un_pager.vnp.vnp_size - foff;
|
|
secmask = bo->bo_bsize - 1;
|
|
KASSERT(secmask < PAGE_SIZE && secmask > 0,
|
|
("%s: sector size %d too large", __func__, secmask + 1));
|
|
bytecount = (bytecount + secmask) & ~secmask;
|
|
|
|
/*
|
|
* And map the pages to be read into the kva, if the filesystem
|
|
* requires mapped buffers.
|
|
*/
|
|
if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 &&
|
|
unmapped_buf_allowed) {
|
|
bp->b_data = unmapped_buf;
|
|
bp->b_offset = 0;
|
|
} else {
|
|
bp->b_data = bp->b_kvabase;
|
|
pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages);
|
|
}
|
|
|
|
/* Build a minimal buffer header. */
|
|
bp->b_iocmd = BIO_READ;
|
|
KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
|
|
KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
|
|
bp->b_rcred = crhold(curthread->td_ucred);
|
|
bp->b_wcred = crhold(curthread->td_ucred);
|
|
pbgetbo(bo, bp);
|
|
bp->b_vp = vp;
|
|
bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount;
|
|
bp->b_iooffset = dbtob(bp->b_blkno);
|
|
KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) ==
|
|
(blkno0 - bp->b_blkno) * DEV_BSIZE +
|
|
IDX_TO_OFF(m[0]->pindex) % bsize,
|
|
("wrong offsets bsize %d m[0] %ju b_pages[0] %ju "
|
|
"blkno0 %ju b_blkno %ju", bsize,
|
|
(uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex,
|
|
(uintmax_t)blkno0, (uintmax_t)bp->b_blkno));
|
|
|
|
atomic_add_long(&runningbufspace, bp->b_runningbufspace);
|
|
VM_CNT_INC(v_vnodein);
|
|
VM_CNT_ADD(v_vnodepgsin, bp->b_npages);
|
|
|
|
if (iodone != NULL) { /* async */
|
|
bp->b_pgiodone = iodone;
|
|
bp->b_caller1 = arg;
|
|
bp->b_iodone = vnode_pager_generic_getpages_done_async;
|
|
bp->b_flags |= B_ASYNC;
|
|
BUF_KERNPROC(bp);
|
|
bstrategy(bp);
|
|
return (VM_PAGER_OK);
|
|
} else {
|
|
bp->b_iodone = bdone;
|
|
bstrategy(bp);
|
|
bwait(bp, PVM, "vnread");
|
|
error = vnode_pager_generic_getpages_done(bp);
|
|
for (i = 0; i < bp->b_npages; i++)
|
|
bp->b_pages[i] = NULL;
|
|
bp->b_vp = NULL;
|
|
pbrelbo(bp);
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK);
|
|
}
|
|
}
|
|
|
|
static void
|
|
vnode_pager_generic_getpages_done_async(struct buf *bp)
|
|
{
|
|
int error;
|
|
|
|
error = vnode_pager_generic_getpages_done(bp);
|
|
/* Run the iodone upon the requested range. */
|
|
bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore,
|
|
bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error);
|
|
for (int i = 0; i < bp->b_npages; i++)
|
|
bp->b_pages[i] = NULL;
|
|
bp->b_vp = NULL;
|
|
pbrelbo(bp);
|
|
uma_zfree(vnode_pbuf_zone, bp);
|
|
}
|
|
|
|
static int
|
|
vnode_pager_generic_getpages_done(struct buf *bp)
|
|
{
|
|
vm_object_t object;
|
|
off_t tfoff, nextoff;
|
|
int i, error;
|
|
|
|
KASSERT((bp->b_ioflags & BIO_ERROR) == 0 || bp->b_error != 0,
|
|
("%s: buf error but b_error == 0\n", __func__));
|
|
error = (bp->b_ioflags & BIO_ERROR) != 0 ? bp->b_error : 0;
|
|
object = bp->b_vp->v_object;
|
|
|
|
if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) {
|
|
if (!buf_mapped(bp)) {
|
|
bp->b_data = bp->b_kvabase;
|
|
pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages,
|
|
bp->b_npages);
|
|
}
|
|
bzero(bp->b_data + bp->b_bcount,
|
|
PAGE_SIZE * bp->b_npages - bp->b_bcount);
|
|
}
|
|
if (buf_mapped(bp)) {
|
|
pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages);
|
|
bp->b_data = unmapped_buf;
|
|
}
|
|
|
|
/*
|
|
* If the read failed, we must free any read ahead/behind pages here.
|
|
* The requested pages are freed by the caller (for sync requests)
|
|
* or by the bp->b_pgiodone callback (for async requests).
|
|
*/
|
|
if (error != 0) {
|
|
VM_OBJECT_WLOCK(object);
|
|
for (i = 0; i < bp->b_pgbefore; i++)
|
|
vm_page_free_invalid(bp->b_pages[i]);
|
|
for (i = bp->b_npages - bp->b_pgafter; i < bp->b_npages; i++)
|
|
vm_page_free_invalid(bp->b_pages[i]);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return (error);
|
|
}
|
|
|
|
/* Read lock to protect size. */
|
|
VM_OBJECT_RLOCK(object);
|
|
for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex);
|
|
i < bp->b_npages; i++, tfoff = nextoff) {
|
|
vm_page_t mt;
|
|
|
|
nextoff = tfoff + PAGE_SIZE;
|
|
mt = bp->b_pages[i];
|
|
if (mt == bogus_page)
|
|
continue;
|
|
|
|
if (nextoff <= object->un_pager.vnp.vnp_size) {
|
|
/*
|
|
* Read filled up entire page.
|
|
*/
|
|
vm_page_valid(mt);
|
|
KASSERT(mt->dirty == 0,
|
|
("%s: page %p is dirty", __func__, mt));
|
|
KASSERT(!pmap_page_is_mapped(mt),
|
|
("%s: page %p is mapped", __func__, mt));
|
|
} else {
|
|
/*
|
|
* Read did not fill up entire page.
|
|
*
|
|
* Currently we do not set the entire page valid,
|
|
* we just try to clear the piece that we couldn't
|
|
* read.
|
|
*/
|
|
vm_page_set_valid_range(mt, 0,
|
|
object->un_pager.vnp.vnp_size - tfoff);
|
|
KASSERT((mt->dirty & vm_page_bits(0,
|
|
object->un_pager.vnp.vnp_size - tfoff)) == 0,
|
|
("%s: page %p is dirty", __func__, mt));
|
|
}
|
|
|
|
if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter)
|
|
vm_page_readahead_finish(mt);
|
|
}
|
|
VM_OBJECT_RUNLOCK(object);
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* EOPNOTSUPP is no longer legal. For local media VFS's that do not
|
|
* implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
|
|
* vnode_pager_generic_putpages() to implement the previous behaviour.
|
|
*
|
|
* All other FS's should use the bypass to get to the local media
|
|
* backing vp's VOP_PUTPAGES.
|
|
*/
|
|
static void
|
|
vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
|
|
int flags, int *rtvals)
|
|
{
|
|
int rtval;
|
|
struct vnode *vp;
|
|
int bytes = count * PAGE_SIZE;
|
|
|
|
/*
|
|
* Force synchronous operation if we are extremely low on memory
|
|
* to prevent a low-memory deadlock. VOP operations often need to
|
|
* allocate more memory to initiate the I/O ( i.e. do a BMAP
|
|
* operation ). The swapper handles the case by limiting the amount
|
|
* of asynchronous I/O, but that sort of solution doesn't scale well
|
|
* for the vnode pager without a lot of work.
|
|
*
|
|
* Also, the backing vnode's iodone routine may not wake the pageout
|
|
* daemon up. This should be probably be addressed XXX.
|
|
*/
|
|
|
|
if (vm_page_count_min())
|
|
flags |= VM_PAGER_PUT_SYNC;
|
|
|
|
/*
|
|
* Call device-specific putpages function
|
|
*/
|
|
vp = object->handle;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals);
|
|
KASSERT(rtval != EOPNOTSUPP,
|
|
("vnode_pager: stale FS putpages\n"));
|
|
VM_OBJECT_WLOCK(object);
|
|
}
|
|
|
|
static int
|
|
vn_off2bidx(vm_ooffset_t offset)
|
|
{
|
|
|
|
return ((offset & PAGE_MASK) / DEV_BSIZE);
|
|
}
|
|
|
|
static bool
|
|
vn_dirty_blk(vm_page_t m, vm_ooffset_t offset)
|
|
{
|
|
|
|
KASSERT(IDX_TO_OFF(m->pindex) <= offset &&
|
|
offset < IDX_TO_OFF(m->pindex + 1),
|
|
("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex,
|
|
(uintmax_t)offset));
|
|
return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0);
|
|
}
|
|
|
|
/*
|
|
* This is now called from local media FS's to operate against their
|
|
* own vnodes if they fail to implement VOP_PUTPAGES.
|
|
*
|
|
* This is typically called indirectly via the pageout daemon and
|
|
* clustering has already typically occurred, so in general we ask the
|
|
* underlying filesystem to write the data out asynchronously rather
|
|
* then delayed.
|
|
*/
|
|
int
|
|
vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount,
|
|
int flags, int *rtvals)
|
|
{
|
|
vm_object_t object;
|
|
vm_page_t m;
|
|
vm_ooffset_t maxblksz, next_offset, poffset, prev_offset;
|
|
struct uio auio;
|
|
struct iovec aiov;
|
|
off_t prev_resid, wrsz;
|
|
int count, error, i, maxsize, ncount, pgoff, ppscheck;
|
|
bool in_hole;
|
|
static struct timeval lastfail;
|
|
static int curfail;
|
|
|
|
object = vp->v_object;
|
|
count = bytecount / PAGE_SIZE;
|
|
|
|
for (i = 0; i < count; i++)
|
|
rtvals[i] = VM_PAGER_ERROR;
|
|
|
|
if ((int64_t)ma[0]->pindex < 0) {
|
|
printf("vnode_pager_generic_putpages: "
|
|
"attempt to write meta-data 0x%jx(%lx)\n",
|
|
(uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty);
|
|
rtvals[0] = VM_PAGER_BAD;
|
|
return (VM_PAGER_BAD);
|
|
}
|
|
|
|
maxsize = count * PAGE_SIZE;
|
|
ncount = count;
|
|
|
|
poffset = IDX_TO_OFF(ma[0]->pindex);
|
|
|
|
/*
|
|
* If the page-aligned write is larger then the actual file we
|
|
* have to invalidate pages occurring beyond the file EOF. However,
|
|
* there is an edge case where a file may not be page-aligned where
|
|
* the last page is partially invalid. In this case the filesystem
|
|
* may not properly clear the dirty bits for the entire page (which
|
|
* could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
|
|
* With the page busied we are free to fix up the dirty bits here.
|
|
*
|
|
* We do not under any circumstances truncate the valid bits, as
|
|
* this will screw up bogus page replacement.
|
|
*/
|
|
VM_OBJECT_RLOCK(object);
|
|
if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
|
|
if (object->un_pager.vnp.vnp_size > poffset) {
|
|
maxsize = object->un_pager.vnp.vnp_size - poffset;
|
|
ncount = btoc(maxsize);
|
|
if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
|
|
pgoff = roundup2(pgoff, DEV_BSIZE);
|
|
|
|
/*
|
|
* If the page is busy and the following
|
|
* conditions hold, then the page's dirty
|
|
* field cannot be concurrently changed by a
|
|
* pmap operation.
|
|
*/
|
|
m = ma[ncount - 1];
|
|
vm_page_assert_sbusied(m);
|
|
KASSERT(!pmap_page_is_write_mapped(m),
|
|
("vnode_pager_generic_putpages: page %p is not read-only", m));
|
|
MPASS(m->dirty != 0);
|
|
vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
|
|
pgoff);
|
|
}
|
|
} else {
|
|
maxsize = 0;
|
|
ncount = 0;
|
|
}
|
|
for (i = ncount; i < count; i++)
|
|
rtvals[i] = VM_PAGER_BAD;
|
|
}
|
|
VM_OBJECT_RUNLOCK(object);
|
|
|
|
auio.uio_iov = &aiov;
|
|
auio.uio_segflg = UIO_NOCOPY;
|
|
auio.uio_rw = UIO_WRITE;
|
|
auio.uio_td = NULL;
|
|
maxblksz = roundup2(poffset + maxsize, DEV_BSIZE);
|
|
|
|
for (prev_offset = poffset; prev_offset < maxblksz;) {
|
|
/* Skip clean blocks. */
|
|
for (in_hole = true; in_hole && prev_offset < maxblksz;) {
|
|
m = ma[OFF_TO_IDX(prev_offset - poffset)];
|
|
for (i = vn_off2bidx(prev_offset);
|
|
i < sizeof(vm_page_bits_t) * NBBY &&
|
|
prev_offset < maxblksz; i++) {
|
|
if (vn_dirty_blk(m, prev_offset)) {
|
|
in_hole = false;
|
|
break;
|
|
}
|
|
prev_offset += DEV_BSIZE;
|
|
}
|
|
}
|
|
if (in_hole)
|
|
goto write_done;
|
|
|
|
/* Find longest run of dirty blocks. */
|
|
for (next_offset = prev_offset; next_offset < maxblksz;) {
|
|
m = ma[OFF_TO_IDX(next_offset - poffset)];
|
|
for (i = vn_off2bidx(next_offset);
|
|
i < sizeof(vm_page_bits_t) * NBBY &&
|
|
next_offset < maxblksz; i++) {
|
|
if (!vn_dirty_blk(m, next_offset))
|
|
goto start_write;
|
|
next_offset += DEV_BSIZE;
|
|
}
|
|
}
|
|
start_write:
|
|
if (next_offset > poffset + maxsize)
|
|
next_offset = poffset + maxsize;
|
|
|
|
/*
|
|
* Getting here requires finding a dirty block in the
|
|
* 'skip clean blocks' loop.
|
|
*/
|
|
MPASS(prev_offset < next_offset);
|
|
|
|
aiov.iov_base = NULL;
|
|
auio.uio_iovcnt = 1;
|
|
auio.uio_offset = prev_offset;
|
|
prev_resid = auio.uio_resid = aiov.iov_len = next_offset -
|
|
prev_offset;
|
|
error = VOP_WRITE(vp, &auio,
|
|
vnode_pager_putpages_ioflags(flags), curthread->td_ucred);
|
|
|
|
wrsz = prev_resid - auio.uio_resid;
|
|
if (wrsz == 0) {
|
|
if (ppsratecheck(&lastfail, &curfail, 1) != 0) {
|
|
vn_printf(vp, "vnode_pager_putpages: "
|
|
"zero-length write at %ju resid %zd\n",
|
|
auio.uio_offset, auio.uio_resid);
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* Adjust the starting offset for next iteration. */
|
|
prev_offset += wrsz;
|
|
MPASS(auio.uio_offset == prev_offset);
|
|
|
|
ppscheck = 0;
|
|
if (error != 0 && (ppscheck = ppsratecheck(&lastfail,
|
|
&curfail, 1)) != 0)
|
|
vn_printf(vp, "vnode_pager_putpages: I/O error %d\n",
|
|
error);
|
|
if (auio.uio_resid != 0 && (ppscheck != 0 ||
|
|
ppsratecheck(&lastfail, &curfail, 1) != 0))
|
|
vn_printf(vp, "vnode_pager_putpages: residual I/O %zd "
|
|
"at %ju\n", auio.uio_resid,
|
|
(uintmax_t)ma[0]->pindex);
|
|
if (error != 0 || auio.uio_resid != 0)
|
|
break;
|
|
}
|
|
write_done:
|
|
/* Mark completely processed pages. */
|
|
for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++)
|
|
rtvals[i] = VM_PAGER_OK;
|
|
/* Mark partial EOF page. */
|
|
if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0)
|
|
rtvals[i++] = VM_PAGER_OK;
|
|
/* Unwritten pages in range, free bonus if the page is clean. */
|
|
for (; i < ncount; i++)
|
|
rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR;
|
|
VM_CNT_ADD(v_vnodepgsout, i);
|
|
VM_CNT_INC(v_vnodeout);
|
|
return (rtvals[0]);
|
|
}
|
|
|
|
int
|
|
vnode_pager_putpages_ioflags(int pager_flags)
|
|
{
|
|
int ioflags;
|
|
|
|
/*
|
|
* Pageouts are already clustered, use IO_ASYNC to force a
|
|
* bawrite() rather then a bdwrite() to prevent paging I/O
|
|
* from saturating the buffer cache. Dummy-up the sequential
|
|
* heuristic to cause large ranges to cluster. If neither
|
|
* IO_SYNC or IO_ASYNC is set, the system decides how to
|
|
* cluster.
|
|
*/
|
|
ioflags = IO_VMIO;
|
|
if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0)
|
|
ioflags |= IO_SYNC;
|
|
else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0)
|
|
ioflags |= IO_ASYNC;
|
|
ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0;
|
|
ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0;
|
|
ioflags |= IO_SEQMAX << IO_SEQSHIFT;
|
|
return (ioflags);
|
|
}
|
|
|
|
/*
|
|
* vnode_pager_undirty_pages().
|
|
*
|
|
* A helper to mark pages as clean after pageout that was possibly
|
|
* done with a short write. The lpos argument specifies the page run
|
|
* length in bytes, and the written argument specifies how many bytes
|
|
* were actually written. eof is the offset past the last valid byte
|
|
* in the vnode using the absolute file position of the first byte in
|
|
* the run as the base from which it is computed.
|
|
*/
|
|
void
|
|
vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof,
|
|
int lpos)
|
|
{
|
|
int i, pos, pos_devb;
|
|
|
|
if (written == 0 && eof >= lpos)
|
|
return;
|
|
for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
|
|
if (pos < trunc_page(written)) {
|
|
rtvals[i] = VM_PAGER_OK;
|
|
vm_page_undirty(ma[i]);
|
|
} else {
|
|
/* Partially written page. */
|
|
rtvals[i] = VM_PAGER_AGAIN;
|
|
vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
|
|
}
|
|
}
|
|
if (eof >= lpos) /* avoid truncation */
|
|
return;
|
|
for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) {
|
|
if (pos != trunc_page(pos)) {
|
|
/*
|
|
* The page contains the last valid byte in
|
|
* the vnode, mark the rest of the page as
|
|
* clean, potentially making the whole page
|
|
* clean.
|
|
*/
|
|
pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE);
|
|
vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE -
|
|
pos_devb);
|
|
|
|
/*
|
|
* If the page was cleaned, report the pageout
|
|
* on it as successful. msync() no longer
|
|
* needs to write out the page, endlessly
|
|
* creating write requests and dirty buffers.
|
|
*/
|
|
if (ma[i]->dirty == 0)
|
|
rtvals[i] = VM_PAGER_OK;
|
|
|
|
pos = round_page(pos);
|
|
} else {
|
|
/* vm_pageout_flush() clears dirty */
|
|
rtvals[i] = VM_PAGER_BAD;
|
|
pos += PAGE_SIZE;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
|
|
vm_offset_t end)
|
|
{
|
|
struct vnode *vp;
|
|
vm_ooffset_t old_wm;
|
|
|
|
VM_OBJECT_WLOCK(object);
|
|
if (object->type != OBJT_VNODE) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return;
|
|
}
|
|
old_wm = object->un_pager.vnp.writemappings;
|
|
object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start;
|
|
vp = object->handle;
|
|
if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
|
|
ASSERT_VOP_LOCKED(vp, "v_writecount inc");
|
|
VOP_ADD_WRITECOUNT_CHECKED(vp, 1);
|
|
CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
|
|
__func__, vp, vp->v_writecount);
|
|
} else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
|
|
ASSERT_VOP_LOCKED(vp, "v_writecount dec");
|
|
VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
|
|
CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
|
|
__func__, vp, vp->v_writecount);
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
}
|
|
|
|
static void
|
|
vnode_pager_release_writecount(vm_object_t object, vm_offset_t start,
|
|
vm_offset_t end)
|
|
{
|
|
struct vnode *vp;
|
|
struct mount *mp;
|
|
vm_offset_t inc;
|
|
|
|
VM_OBJECT_WLOCK(object);
|
|
|
|
/*
|
|
* First, recheck the object type to account for the race when
|
|
* the vnode is reclaimed.
|
|
*/
|
|
if (object->type != OBJT_VNODE) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Optimize for the case when writemappings is not going to
|
|
* zero.
|
|
*/
|
|
inc = end - start;
|
|
if (object->un_pager.vnp.writemappings != inc) {
|
|
object->un_pager.vnp.writemappings -= inc;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return;
|
|
}
|
|
|
|
vp = object->handle;
|
|
vhold(vp);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
mp = NULL;
|
|
vn_start_write(vp, &mp, V_WAIT);
|
|
vn_lock(vp, LK_SHARED | LK_RETRY);
|
|
|
|
/*
|
|
* Decrement the object's writemappings, by swapping the start
|
|
* and end arguments for vnode_pager_update_writecount(). If
|
|
* there was not a race with vnode reclaimation, then the
|
|
* vnode's v_writecount is decremented.
|
|
*/
|
|
vnode_pager_update_writecount(object, end, start);
|
|
VOP_UNLOCK(vp);
|
|
vdrop(vp);
|
|
if (mp != NULL)
|
|
vn_finished_write(mp);
|
|
}
|
|
|
|
static void
|
|
vnode_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
|
|
{
|
|
*vpp = object->handle;
|
|
}
|