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freebsd-dev/sys/vm/vnode_pager.c
John Dyson bef608bd7e Some VM improvements, including elimination of alot of Sig-11 
problems.  Tor Egge and others have helped with various VM bugs
lately, but don't blame him -- blame me!!!

pmap.c:
1)	Create an object for kernel page table allocations.  This
	fixes a bogus allocation method previously used for such, by
	grabbing pages from the kernel object, using bogus pindexes.
	(This was a code cleanup, and perhaps a minor system stability
	 issue.)

pmap.c:
2)	Pre-set the modify and accessed bits when prudent.  This will
	decrease bus traffic under certain circumstances.

vfs_bio.c, vfs_cluster.c:
3)	Rather than calculating the beginning virtual byte offset
	multiple times, stick the offset into the buffer header, so
	that the calculated offset can be reused.  (Long long multiplies
	are often expensive, and this is a probably unmeasurable performance
	improvement, and code cleanup.)

vfs_bio.c:
4)	Handle write recursion more intelligently (but not perfectly) so
	that it is less likely to cause a system panic, and is also
	much more robust.

vfs_bio.c:
5)	getblk incorrectly wrote out blocks that are incorrectly sized.
	The problem is fixed, and writes blocks out ONLY when B_DELWRI
	is true.

vfs_bio.c:
6)	Check that already constituted buffers have fully valid pages.  If
	not, then make sure that the B_CACHE bit is not set. (This was
	a major source of Sig-11 type problems.)

vfs_bio.c:
7)	Fix a potential system deadlock due to an incorrectly specified
	sleep priority while waiting for a buffer write operation.  The
	change that I made opens the system up to serious problems, and
	we need to examine the issue of process sleep priorities.

vfs_cluster.c, vfs_bio.c:
8)	Make clustered reads work more correctly (and more completely)
	when buffers are already constituted, but not fully valid.
	(This was another system reliability issue.)

vfs_subr.c, ffs_inode.c:
9)	Create a vtruncbuf function, which is used by filesystems that
	can truncate files.  The vinvalbuf forced a file sync type operation,
	while vtruncbuf only invalidates the buffers past the new end of file,
	and also invalidates the appropriate pages.  (This was a system reliabiliy
	and performance issue.)

10)	Modify FFS to use vtruncbuf.

vm_object.c:
11)	Make the object rundown mechanism for OBJT_VNODE type objects work
	more correctly.  Included in that fix, create pager entries for
	the OBJT_DEAD pager type, so that paging requests that might slip
	in during race conditions are properly handled.  (This was a system
	reliability issue.)

vm_page.c:
12)	Make some of the page validation routines be a little less picky
	about arguments passed to them.  Also, support page invalidation
	change the object generation count so that we handle generation
	counts a little more robustly.

vm_pageout.c:
13)	Further reduce pageout daemon activity when the system doesn't
	need help from it.  There should be no additional performance
	decrease even when the pageout daemon is running.  (This was
	a significant performance issue.)

vnode_pager.c:
14)	Teach the vnode pager to handle race conditions during vnode
	deallocations.
1998-03-16 01:56:03 +00:00

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/*
* Copyright (c) 1990 University of Utah.
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 1993, 1994 John S. Dyson
* Copyright (c) 1995, David Greenman
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91
* $Id: vnode_pager.c,v 1.90 1998/03/09 08:58:53 msmith Exp $
*/
/*
* Page to/from files (vnodes).
*/
/*
* TODO:
* Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
* greatly re-simplify the vnode_pager.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_prot.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_map.h>
#include <vm/vnode_pager.h>
#include <vm/vm_extern.h>
static vm_offset_t vnode_pager_addr __P((struct vnode *vp, vm_ooffset_t address,
int *run));
static void vnode_pager_iodone __P((struct buf *bp));
static int vnode_pager_input_smlfs __P((vm_object_t object, vm_page_t m));
static int vnode_pager_input_old __P((vm_object_t object, vm_page_t m));
static void vnode_pager_dealloc __P((vm_object_t));
static int vnode_pager_getpages __P((vm_object_t, vm_page_t *, int, int));
static int vnode_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *));
static boolean_t vnode_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *));
struct pagerops vnodepagerops = {
NULL,
vnode_pager_alloc,
vnode_pager_dealloc,
vnode_pager_getpages,
vnode_pager_putpages,
vnode_pager_haspage,
NULL
};
/*
* Allocate (or lookup) pager for a vnode.
* Handle is a vnode pointer.
*/
vm_object_t
vnode_pager_alloc(void *handle, vm_size_t size, vm_prot_t prot,
vm_ooffset_t offset)
{
vm_object_t object;
struct vnode *vp;
/*
* Pageout to vnode, no can do yet.
*/
if (handle == NULL)
return (NULL);
vp = (struct vnode *) handle;
/*
* Prevent race condition when allocating the object. This
* can happen with NFS vnodes since the nfsnode isn't locked.
*/
while (vp->v_flag & VOLOCK) {
vp->v_flag |= VOWANT;
tsleep(vp, PVM, "vnpobj", 0);
}
vp->v_flag |= VOLOCK;
/*
* If the object is being terminated, wait for it to
* go away.
*/
while (((object = vp->v_object) != NULL) &&
(object->flags & OBJ_DEAD)) {
tsleep(object, PVM, "vadead", 0);
}
if (vp->v_usecount == 0)
panic("vnode_pager_alloc: no vnode reference");
if (object == NULL) {
/*
* And an object of the appropriate size
*/
object = vm_object_allocate(OBJT_VNODE, size);
object->flags = 0;
object->un_pager.vnp.vnp_size = (vm_ooffset_t) size * PAGE_SIZE;
object->handle = handle;
vp->v_object = object;
vp->v_usecount++;
} else {
object->ref_count++;
vp->v_usecount++;
}
vp->v_flag &= ~VOLOCK;
if (vp->v_flag & VOWANT) {
vp->v_flag &= ~VOWANT;
wakeup(vp);
}
return (object);
}
static void
vnode_pager_dealloc(object)
vm_object_t object;
{
register struct vnode *vp = object->handle;
if (vp == NULL)
panic("vnode_pager_dealloc: pager already dealloced");
vm_object_pip_wait(object, "vnpdea");
object->handle = NULL;
object->type = OBJT_DEAD;
vp->v_object = NULL;
vp->v_flag &= ~(VTEXT | VOBJBUF);
}
static boolean_t
vnode_pager_haspage(object, pindex, before, after)
vm_object_t object;
vm_pindex_t pindex;
int *before;
int *after;
{
struct vnode *vp = object->handle;
daddr_t bn;
int err;
daddr_t reqblock;
int poff;
int bsize;
int pagesperblock, blocksperpage;
if ((vp == NULL) || (vp->v_flag & VDOOMED))
return FALSE;
/*
* If filesystem no longer mounted or offset beyond end of file we do
* not have the page.
*/
if ((vp->v_mount == NULL) ||
(IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size))
return FALSE;
bsize = vp->v_mount->mnt_stat.f_iosize;
pagesperblock = bsize / PAGE_SIZE;
blocksperpage = 0;
if (pagesperblock > 0) {
reqblock = pindex / pagesperblock;
} else {
blocksperpage = (PAGE_SIZE / bsize);
reqblock = pindex * blocksperpage;
}
err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn,
after, before);
if (err)
return TRUE;
if ( bn == -1)
return FALSE;
if (pagesperblock > 0) {
poff = pindex - (reqblock * pagesperblock);
if (before) {
*before *= pagesperblock;
*before += poff;
}
if (after) {
int numafter;
*after *= pagesperblock;
numafter = pagesperblock - (poff + 1);
if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) {
numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex)));
}
*after += numafter;
}
} else {
if (before) {
*before /= blocksperpage;
}
if (after) {
*after /= blocksperpage;
}
}
return TRUE;
}
/*
* Lets the VM system know about a change in size for a file.
* We adjust our own internal size and flush any cached pages in
* the associated object that are affected by the size change.
*
* Note: this routine may be invoked as a result of a pager put
* operation (possibly at object termination time), so we must be careful.
*/
void
vnode_pager_setsize(vp, nsize)
struct vnode *vp;
vm_ooffset_t nsize;
{
vm_object_t object = vp->v_object;
if (object == NULL)
return;
/*
* Hasn't changed size
*/
if (nsize == object->un_pager.vnp.vnp_size)
return;
/*
* File has shrunk. Toss any cached pages beyond the new EOF.
*/
if (nsize < object->un_pager.vnp.vnp_size) {
vm_ooffset_t nsizerounded;
nsizerounded = IDX_TO_OFF(OFF_TO_IDX(nsize + PAGE_MASK));
if (nsizerounded < object->un_pager.vnp.vnp_size) {
vm_pindex_t st, end;
st = OFF_TO_IDX(nsize + PAGE_MASK);
end = OFF_TO_IDX(object->un_pager.vnp.vnp_size);
vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size);
vm_object_page_remove(object, st, end, FALSE);
}
/*
* this gets rid of garbage at the end of a page that is now
* only partially backed by the vnode...
*/
if (nsize & PAGE_MASK) {
vm_offset_t kva;
vm_page_t m;
m = vm_page_lookup(object, OFF_TO_IDX(nsize));
if (m) {
kva = vm_pager_map_page(m);
bzero((caddr_t) kva + (nsize & PAGE_MASK),
(int) (round_page(nsize) - nsize));
vm_pager_unmap_page(kva);
}
}
}
object->un_pager.vnp.vnp_size = nsize;
object->size = OFF_TO_IDX(nsize + PAGE_MASK);
}
void
vnode_pager_freepage(m)
vm_page_t m;
{
vm_page_free(m);
}
/*
* calculate the linear (byte) disk address of specified virtual
* file address
*/
static vm_offset_t
vnode_pager_addr(vp, address, run)
struct vnode *vp;
vm_ooffset_t address;
int *run;
{
int rtaddress;
int bsize;
daddr_t block;
struct vnode *rtvp;
int err;
daddr_t vblock;
int voffset;
if ((int) address < 0)
return -1;
if (vp->v_mount == NULL)
return -1;
bsize = vp->v_mount->mnt_stat.f_iosize;
vblock = address / bsize;
voffset = address % bsize;
err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL);
if (err || (block == -1))
rtaddress = -1;
else {
rtaddress = block + voffset / DEV_BSIZE;
if( run) {
*run += 1;
*run *= bsize/PAGE_SIZE;
*run -= voffset/PAGE_SIZE;
}
}
return rtaddress;
}
/*
* interrupt routine for I/O completion
*/
static void
vnode_pager_iodone(bp)
struct buf *bp;
{
bp->b_flags |= B_DONE;
wakeup(bp);
}
/*
* small block file system vnode pager input
*/
static int
vnode_pager_input_smlfs(object, m)
vm_object_t object;
vm_page_t m;
{
int i;
int s;
struct vnode *dp, *vp;
struct buf *bp;
vm_offset_t kva;
int fileaddr;
vm_offset_t bsize;
int error = 0;
vp = object->handle;
if (vp->v_mount == NULL)
return VM_PAGER_BAD;
bsize = vp->v_mount->mnt_stat.f_iosize;
VOP_BMAP(vp, 0, &dp, 0, NULL, NULL);
kva = vm_pager_map_page(m);
for (i = 0; i < PAGE_SIZE / bsize; i++) {
if ((vm_page_bits(IDX_TO_OFF(m->pindex) + i * bsize, bsize) & m->valid))
continue;
fileaddr = vnode_pager_addr(vp,
IDX_TO_OFF(m->pindex) + i * bsize, (int *)0);
if (fileaddr != -1) {
bp = getpbuf();
/* build a minimal buffer header */
bp->b_flags = B_BUSY | B_READ | B_CALL;
bp->b_iodone = vnode_pager_iodone;
bp->b_proc = curproc;
bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred;
if (bp->b_rcred != NOCRED)
crhold(bp->b_rcred);
if (bp->b_wcred != NOCRED)
crhold(bp->b_wcred);
bp->b_data = (caddr_t) kva + i * bsize;
bp->b_blkno = fileaddr;
pbgetvp(dp, bp);
bp->b_bcount = bsize;
bp->b_bufsize = bsize;
/* do the input */
VOP_STRATEGY(bp);
/* we definitely need to be at splvm here */
s = splvm();
while ((bp->b_flags & B_DONE) == 0) {
tsleep(bp, PVM, "vnsrd", 0);
}
splx(s);
if ((bp->b_flags & B_ERROR) != 0)
error = EIO;
/*
* free the buffer header back to the swap buffer pool
*/
relpbuf(bp);
if (error)
break;
vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
} else {
vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
bzero((caddr_t) kva + i * bsize, bsize);
}
}
vm_pager_unmap_page(kva);
pmap_clear_modify(VM_PAGE_TO_PHYS(m));
m->flags &= ~PG_ZERO;
if (error) {
return VM_PAGER_ERROR;
}
return VM_PAGER_OK;
}
/*
* old style vnode pager output routine
*/
static int
vnode_pager_input_old(object, m)
vm_object_t object;
vm_page_t m;
{
struct uio auio;
struct iovec aiov;
int error;
int size;
vm_offset_t kva;
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);
/*
* Allocate a kernel virtual address and initialize so that
* we can use VOP_READ/WRITE routines.
*/
kva = vm_pager_map_page(m);
aiov.iov_base = (caddr_t) kva;
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_procp = (struct proc *) 0;
error = VOP_READ(object->handle, &auio, 0, curproc->p_ucred);
if (!error) {
register int count = size - auio.uio_resid;
if (count == 0)
error = EINVAL;
else if (count != PAGE_SIZE)
bzero((caddr_t) kva + count, PAGE_SIZE - count);
}
vm_pager_unmap_page(kva);
}
pmap_clear_modify(VM_PAGE_TO_PHYS(m));
m->dirty = 0;
m->flags &= ~PG_ZERO;
return error ? VM_PAGER_ERROR : VM_PAGER_OK;
}
/*
* generic vnode pager input routine
*/
/*
* EOPNOTSUPP is no longer legal. For local media VFS's that do not
* implement their own VOP_GETPAGES, their VOP_GETPAGES should 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(object, m, count, reqpage)
vm_object_t object;
vm_page_t *m;
int count;
int reqpage;
{
int rtval;
struct vnode *vp;
int bytes = count * PAGE_SIZE;
vp = object->handle;
/*
* XXX temporary diagnostic message to help track stale FS code,
* Returning EOPNOTSUPP from here may make things unhappy.
*/
rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
if (rtval == EOPNOTSUPP) {
printf("vnode_pager: *** WARNING *** stale FS getpages\n");
rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage);
}
return rtval;
}
/*
* 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(vp, m, bytecount, reqpage)
struct vnode *vp;
vm_page_t *m;
int bytecount;
int reqpage;
{
vm_object_t object;
vm_offset_t kva;
off_t foff, tfoff, nextoff;
int i, size, bsize, first, firstaddr;
struct vnode *dp;
int runpg;
int runend;
struct buf *bp;
int s;
int count;
int error = 0;
object = vp->v_object;
count = bytecount / PAGE_SIZE;
if (vp->v_mount == NULL)
return VM_PAGER_BAD;
bsize = vp->v_mount->mnt_stat.f_iosize;
/* get the UNDERLYING device for the file with VOP_BMAP() */
/*
* originally, we did not check for an error return value -- assuming
* an fs always has a bmap entry point -- that assumption is wrong!!!
*/
foff = IDX_TO_OFF(m[reqpage]->pindex);
/*
* if we can't bmap, use old VOP code
*/
if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) {
for (i = 0; i < count; i++) {
if (i != reqpage) {
vnode_pager_freepage(m[i]);
}
}
cnt.v_vnodein++;
cnt.v_vnodepgsin++;
return vnode_pager_input_old(object, m[reqpage]);
/*
* if the blocksize is smaller than a page size, then use
* special small filesystem code. NFS sometimes has a small
* blocksize, but it can handle large reads itself.
*/
} else if ((PAGE_SIZE / bsize) > 1 &&
(vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) {
for (i = 0; i < count; i++) {
if (i != reqpage) {
vnode_pager_freepage(m[i]);
}
}
cnt.v_vnodein++;
cnt.v_vnodepgsin++;
return vnode_pager_input_smlfs(object, m[reqpage]);
}
/*
* if ANY DEV_BSIZE blocks are valid on a large filesystem block
* then, the entire page is valid --
* XXX no it isn't
*/
if (m[reqpage]->valid != VM_PAGE_BITS_ALL)
m[reqpage]->valid = 0;
if (m[reqpage]->valid) {
m[reqpage]->valid = VM_PAGE_BITS_ALL;
for (i = 0; i < count; i++) {
if (i != reqpage)
vnode_pager_freepage(m[i]);
}
return VM_PAGER_OK;
}
/*
* here on direct device I/O
*/
firstaddr = -1;
/*
* calculate the run that includes the required page
*/
for(first = 0, i = 0; i < count; i = runend) {
firstaddr = vnode_pager_addr(vp,
IDX_TO_OFF(m[i]->pindex), &runpg);
if (firstaddr == -1) {
if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: %ld, vnp_size: %d",
firstaddr, foff, object->un_pager.vnp.vnp_size);
}
vnode_pager_freepage(m[i]);
runend = i + 1;
first = runend;
continue;
}
runend = i + runpg;
if (runend <= reqpage) {
int j;
for (j = i; j < runend; j++) {
vnode_pager_freepage(m[j]);
}
} else {
if (runpg < (count - first)) {
for (i = first + runpg; i < count; i++)
vnode_pager_freepage(m[i]);
count = first + runpg;
}
break;
}
first = runend;
}
/*
* the first and last page have been calculated now, move input pages
* to be zero based...
*/
if (first != 0) {
for (i = first; i < count; i++) {
m[i - first] = m[i];
}
count -= first;
reqpage -= first;
}
/*
* calculate the file virtual address for the transfer
*/
foff = IDX_TO_OFF(m[0]->pindex);
/*
* calculate the size of the transfer
*/
size = count * PAGE_SIZE;
if ((foff + size) > object->un_pager.vnp.vnp_size)
size = object->un_pager.vnp.vnp_size - foff;
/*
* round up physical size for real devices
*/
if (dp->v_type == VBLK || dp->v_type == VCHR)
size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
bp = getpbuf();
kva = (vm_offset_t) bp->b_data;
/*
* and map the pages to be read into the kva
*/
pmap_qenter(kva, m, count);
/* build a minimal buffer header */
bp->b_flags = B_BUSY | B_READ | B_CALL;
bp->b_iodone = vnode_pager_iodone;
/* B_PHYS is not set, but it is nice to fill this in */
bp->b_proc = curproc;
bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred;
if (bp->b_rcred != NOCRED)
crhold(bp->b_rcred);
if (bp->b_wcred != NOCRED)
crhold(bp->b_wcred);
bp->b_blkno = firstaddr;
pbgetvp(dp, bp);
bp->b_bcount = size;
bp->b_bufsize = size;
cnt.v_vnodein++;
cnt.v_vnodepgsin += count;
/* do the input */
VOP_STRATEGY(bp);
s = splvm();
/* we definitely need to be at splvm here */
while ((bp->b_flags & B_DONE) == 0) {
tsleep(bp, PVM, "vnread", 0);
}
splx(s);
if ((bp->b_flags & B_ERROR) != 0)
error = EIO;
if (!error) {
if (size != count * PAGE_SIZE)
bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
}
pmap_qremove(kva, count);
/*
* free the buffer header back to the swap buffer pool
*/
relpbuf(bp);
for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
vm_page_t mt;
nextoff = tfoff + PAGE_SIZE;
mt = m[i];
if (nextoff <= size) {
mt->valid = VM_PAGE_BITS_ALL;
mt->dirty = 0;
pmap_clear_modify(VM_PAGE_TO_PHYS(mt));
} else {
int nvalid = ((size + DEV_BSIZE - 1) - tfoff) & ~(DEV_BSIZE - 1);
vm_page_set_validclean(mt, 0, nvalid);
}
mt->flags &= ~PG_ZERO;
if (i != reqpage) {
/*
* whether or not to leave the page activated is up in
* the air, but we should put the page on a page queue
* somewhere. (it already is in the object). Result:
* It appears that emperical results show that
* deactivating pages is best.
*/
/*
* just in case someone was asking for this page we
* now tell them that it is ok to use
*/
if (!error) {
if (mt->flags & PG_WANTED)
vm_page_activate(mt);
else
vm_page_deactivate(mt);
PAGE_WAKEUP(mt);
} else {
vnode_pager_freepage(mt);
}
}
}
if (error) {
printf("vnode_pager_getpages: I/O read error\n");
}
return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
}
/*
* 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 int
vnode_pager_putpages(object, m, count, sync, rtvals)
vm_object_t object;
vm_page_t *m;
int count;
boolean_t sync;
int *rtvals;
{
int rtval;
struct vnode *vp;
int bytes = count * PAGE_SIZE;
vp = object->handle;
rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
if (rtval == EOPNOTSUPP) {
printf("vnode_pager: *** WARNING *** stale FS putpages\n");
rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals);
}
return rtval;
}
/*
* 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_putpages(vp, m, bytecount, flags, rtvals)
struct vnode *vp;
vm_page_t *m;
int bytecount;
int flags;
int *rtvals;
{
int i;
vm_object_t object;
int count;
int maxsize, ncount;
vm_ooffset_t poffset;
struct uio auio;
struct iovec aiov;
int error;
int ioflags;
object = vp->v_object;
count = bytecount / PAGE_SIZE;
for (i = 0; i < count; i++)
rtvals[i] = VM_PAGER_AGAIN;
if ((int) m[0]->pindex < 0) {
printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%x(%x)\n",
m[0]->pindex, m[0]->dirty);
rtvals[0] = VM_PAGER_BAD;
return VM_PAGER_BAD;
}
maxsize = count * PAGE_SIZE;
ncount = count;
poffset = IDX_TO_OFF(m[0]->pindex);
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;
else
maxsize = 0;
ncount = btoc(maxsize);
if (ncount < count) {
for (i = ncount; i < count; i++) {
rtvals[i] = VM_PAGER_BAD;
}
}
}
ioflags = IO_VMIO;
ioflags |= (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) ? IO_SYNC: 0;
ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
aiov.iov_base = (caddr_t) 0;
aiov.iov_len = maxsize;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = poffset;
auio.uio_segflg = UIO_NOCOPY;
auio.uio_rw = UIO_WRITE;
auio.uio_resid = maxsize;
auio.uio_procp = (struct proc *) 0;
error = VOP_WRITE(vp, &auio, ioflags, curproc->p_ucred);
cnt.v_vnodeout++;
cnt.v_vnodepgsout += ncount;
if (error) {
printf("vnode_pager_putpages: I/O error %d\n", error);
}
if (auio.uio_resid) {
printf("vnode_pager_putpages: residual I/O %d at %ld\n",
auio.uio_resid, m[0]->pindex);
}
for (i = 0; i < ncount; i++) {
rtvals[i] = VM_PAGER_OK;
}
return rtvals[0];
}
struct vnode *
vnode_pager_lock(object)
vm_object_t object;
{
struct proc *p = curproc; /* XXX */
for (; object != NULL; object = object->backing_object) {
if (object->type != OBJT_VNODE)
continue;
if (object->flags & OBJ_DEAD)
return NULL;
while (vget(object->handle,
LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, p)) {
if ((object->flags & OBJ_DEAD) || (object->type != OBJT_VNODE))
return NULL;
printf("vnode_pager_lock: retrying\n");
}
return object->handle;
}
return NULL;
}
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