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freebsd-dev/sys/vm/vnode_pager.c
David Greenman 976e77fc9c 1) Some of the counters in the vmmeter struct don't fit well into the Mach VM 
scheme of things, so I've changed them to be more appropriate. page in/ous
   are now associated with the pager that did them. Nuked v_fault as the
   only fault of interest that wouldn't be already counted in v_trap is a VM
   fault, and this is counted seperately.
2) Implemented most of the remaining counters and corrected the counting of
   some that were done wrong. They are all almost correct now...just a few
   minor ones left to fix.
1994-10-15 13:33:09 +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
*
* 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 1.13 1994/10/14 12:26:18 davidg Exp $
*/
/*
* Page to/from files (vnodes).
*
* TODO:
* pageouts
* fix credential use (uses current process credentials now)
*/
/*
* MODIFICATIONS:
* John S. Dyson 08 Dec 93
*
* This file in conjunction with some vm_fault mods, eliminate the performance
* advantage for using the buffer cache and minimize memory copies.
*
* 1) Supports multiple - block reads
* 2) Bypasses buffer cache for reads
*
* TODO:
*
* 1) Totally bypass buffer cache for reads
* (Currently will still sometimes use buffer cache for reads)
* 2) Bypass buffer cache for writes
* (Code does not support it, but mods are simple)
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/uio.h>
#include <sys/mount.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vnode_pager.h>
#include <sys/buf.h>
#include <miscfs/specfs/specdev.h>
int vnode_pager_putmulti();
void vnode_pager_init();
vm_pager_t vnode_pager_alloc(caddr_t, vm_offset_t, vm_prot_t, vm_offset_t);
void vnode_pager_dealloc();
int vnode_pager_getpage();
int vnode_pager_getmulti();
int vnode_pager_putpage();
boolean_t vnode_pager_haspage();
struct pagerops vnodepagerops = {
vnode_pager_init,
vnode_pager_alloc,
vnode_pager_dealloc,
vnode_pager_getpage,
vnode_pager_getmulti,
vnode_pager_putpage,
vnode_pager_putmulti,
vnode_pager_haspage
};
static int vnode_pager_input(vn_pager_t vnp, vm_page_t * m, int count, int reqpage);
static int vnode_pager_output(vn_pager_t vnp, vm_page_t * m, int count, int *rtvals);
extern vm_map_t pager_map;
struct pagerlst vnode_pager_list; /* list of managed vnodes */
#define MAXBP (PAGE_SIZE/DEV_BSIZE);
void
vnode_pager_init()
{
TAILQ_INIT(&vnode_pager_list);
}
/*
* Allocate (or lookup) pager for a vnode.
* Handle is a vnode pointer.
*/
vm_pager_t
vnode_pager_alloc(handle, size, prot, offset)
caddr_t handle;
vm_size_t size;
vm_prot_t prot;
vm_offset_t offset;
{
register vm_pager_t pager;
register vn_pager_t vnp;
vm_object_t object;
struct vattr vattr;
struct vnode *vp;
struct proc *p = curproc; /* XXX */
/*
* Pageout to vnode, no can do yet.
*/
if (handle == NULL)
return (NULL);
/*
* Vnodes keep a pointer to any associated pager so no need to lookup
* with vm_pager_lookup.
*/
vp = (struct vnode *) handle;
object = (vm_object_t) vp->v_vmdata;
pager = NULL;
if( object != NULL)
pager = object->pager;
if (pager == NULL) {
/*
* Allocate pager structures
*/
pager = (vm_pager_t) malloc(sizeof *pager, M_VMPAGER, M_WAITOK);
if (pager == NULL)
return (NULL);
vnp = (vn_pager_t) malloc(sizeof *vnp, M_VMPGDATA, M_WAITOK);
if (vnp == NULL) {
free((caddr_t) pager, M_VMPAGER);
return (NULL);
}
/*
* And an object of the appropriate size
*/
if (VOP_GETATTR(vp, &vattr, p->p_ucred, p) == 0) {
object = vm_object_allocate(round_page(vattr.va_size));
vm_object_enter(object, pager);
vm_object_setpager(object, pager, 0, TRUE);
} else {
free((caddr_t) vnp, M_VMPGDATA);
free((caddr_t) pager, M_VMPAGER);
return (NULL);
}
/*
* Hold a reference to the vnode and initialize pager data.
*/
VREF(vp);
vnp->vnp_flags = 0;
vnp->vnp_vp = vp;
vnp->vnp_size = vattr.va_size;
TAILQ_INSERT_TAIL(&vnode_pager_list, pager, pg_list);
pager->pg_handle = handle;
pager->pg_type = PG_VNODE;
pager->pg_ops = &vnodepagerops;
pager->pg_data = (caddr_t) vnp;
vp->v_vmdata = (caddr_t) object;
} else {
/*
* vm_object_lookup() will remove the object from the cache if
* found and also gain a reference to the object.
*/
(void) vm_object_lookup(pager);
}
return (pager);
}
void
vnode_pager_dealloc(pager)
vm_pager_t pager;
{
register vn_pager_t vnp = (vn_pager_t) pager->pg_data;
register struct vnode *vp;
vp = vnp->vnp_vp;
if (vp) {
vp->v_vmdata = NULL;
vp->v_flag &= ~(VTEXT|VVMIO);
vrele(vp);
}
TAILQ_REMOVE(&vnode_pager_list, pager, pg_list);
free((caddr_t) vnp, M_VMPGDATA);
free((caddr_t) pager, M_VMPAGER);
}
int
vnode_pager_getmulti(pager, m, count, reqpage, sync)
vm_pager_t pager;
vm_page_t *m;
int count;
int reqpage;
boolean_t sync;
{
return vnode_pager_input((vn_pager_t) pager->pg_data, m, count, reqpage);
}
int
vnode_pager_getpage(pager, m, sync)
vm_pager_t pager;
vm_page_t m;
boolean_t sync;
{
vm_page_t marray[1];
if (pager == NULL)
return FALSE;
marray[0] = m;
return vnode_pager_input((vn_pager_t) pager->pg_data, marray, 1, 0);
}
boolean_t
vnode_pager_putpage(pager, m, sync)
vm_pager_t pager;
vm_page_t m;
boolean_t sync;
{
vm_page_t marray[1];
int rtvals[1];
if (pager == NULL)
return FALSE;
marray[0] = m;
vnode_pager_output((vn_pager_t) pager->pg_data, marray, 1, rtvals);
return rtvals[0];
}
int
vnode_pager_putmulti(pager, m, c, sync, rtvals)
vm_pager_t pager;
vm_page_t *m;
int c;
boolean_t sync;
int *rtvals;
{
return vnode_pager_output((vn_pager_t) pager->pg_data, m, c, rtvals);
}
boolean_t
vnode_pager_haspage(pager, offset)
vm_pager_t pager;
vm_offset_t offset;
{
register vn_pager_t vnp = (vn_pager_t) pager->pg_data;
daddr_t bn;
int err;
/*
* Offset beyond end of file, do not have the page
*/
if (offset >= vnp->vnp_size) {
return (FALSE);
}
/*
* Read the index to find the disk block to read from. If there is no
* block, report that we don't have this data.
*
* Assumes that the vnode has whole page or nothing.
*/
err = VOP_BMAP(vnp->vnp_vp,
offset / vnp->vnp_vp->v_mount->mnt_stat.f_iosize,
(struct vnode **) 0, &bn, 0);
/*
printf("vnode_pager_haspage: (%d)0x%x: err: %d, bn: %d\n",
offset, offset, err, bn);
*/
if (err) {
return (TRUE);
}
return ((long) bn < 0 ? FALSE : TRUE);
}
/*
* Lets the VM system know about a change in size for a file.
* If this vnode is mapped into some address space (i.e. we have a pager
* for it) 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;
u_long nsize;
{
register vn_pager_t vnp;
register vm_object_t object;
vm_pager_t pager;
/*
* Not a mapped vnode
*/
if (vp == NULL || vp->v_type != VREG || vp->v_vmdata == NULL)
return;
/*
* Hasn't changed size
*/
object = (vm_object_t) vp->v_vmdata;
if( object == NULL)
return;
if( (pager = object->pager) == NULL)
return;
vnp = (vn_pager_t) pager->pg_data;
if (nsize == vnp->vnp_size)
return;
/*
* No object. This can happen during object termination since
* vm_object_page_clean is called after the object has been removed
* from the hash table, and clean may cause vnode write operations
* which can wind up back here.
*/
object = vm_object_lookup(pager);
if (object == NULL)
return;
/*
* File has shrunk. Toss any cached pages beyond the new EOF.
*/
if (nsize < vnp->vnp_size) {
vm_object_lock(object);
vm_object_page_remove(object,
round_page((vm_offset_t) nsize), vnp->vnp_size);
vm_object_unlock(object);
/*
* 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, trunc_page((vm_offset_t) nsize));
if (m) {
kva = vm_pager_map_page(m);
bzero((caddr_t) kva + (nsize & PAGE_MASK),
round_page(nsize) - nsize);
vm_pager_unmap_page(kva);
}
}
} else {
/*
* this allows the filesystem and VM cache to stay in sync if
* the VM page hasn't been modified... After the page is
* removed -- it will be faulted back in from the filesystem
* cache.
*/
if (vnp->vnp_size & PAGE_MASK) {
vm_page_t m;
m = vm_page_lookup(object, trunc_page(vnp->vnp_size));
if (m && (m->flags & PG_CLEAN)) {
vm_object_lock(object);
vm_object_page_remove(object,
vnp->vnp_size, vnp->vnp_size);
vm_object_unlock(object);
}
}
}
vnp->vnp_size = (vm_offset_t) nsize;
object->size = round_page(nsize);
vm_object_deallocate(object);
}
void
vnode_pager_umount(mp)
register struct mount *mp;
{
register vm_pager_t pager, npager;
struct vnode *vp;
pager = vnode_pager_list.tqh_first;
while (pager) {
/*
* Save the next pointer now since uncaching may terminate the
* object and render pager invalid
*/
vp = ((vn_pager_t) pager->pg_data)->vnp_vp;
npager = pager->pg_list.tqe_next;
if (mp == (struct mount *) 0 || vp->v_mount == mp)
(void) vnode_pager_uncache(vp);
pager = npager;
}
}
/*
* Remove vnode associated object from the object cache.
*
* Note: this routine may be invoked as a result of a pager put
* operation (possibly at object termination time), so we must be careful.
*/
boolean_t
vnode_pager_uncache(vp)
register struct vnode *vp;
{
register vm_object_t object;
boolean_t uncached, locked;
vm_pager_t pager;
/*
* Not a mapped vnode
*/
object = (vm_object_t) vp->v_vmdata;
if( object == NULL)
return(TRUE);
pager = object->pager;
if (pager == NULL)
return (TRUE);
/*
* Unlock the vnode if it is currently locked. We do this since
* uncaching the object may result in its destruction which may
* initiate paging activity which may necessitate locking the vnode.
*/
locked = VOP_ISLOCKED(vp);
if (locked)
VOP_UNLOCK(vp);
/*
* Must use vm_object_lookup() as it actually removes the object from
* the cache list.
*/
object = vm_object_lookup(pager);
if (object) {
uncached = (object->ref_count <= 1);
pager_cache(object, FALSE);
} else
uncached = TRUE;
if (locked)
VOP_LOCK(vp);
return (uncached);
}
void
vnode_pager_freepage(m)
vm_page_t m;
{
PAGE_WAKEUP(m);
vm_page_free(m);
}
/*
* calculate the linear (byte) disk address of specified virtual
* file address
*/
vm_offset_t
vnode_pager_addr(vp, address)
struct vnode *vp;
vm_offset_t address;
{
int rtaddress;
int bsize;
vm_offset_t block;
struct vnode *rtvp;
int err;
int vblock, voffset;
bsize = vp->v_mount->mnt_stat.f_iosize;
vblock = address / bsize;
voffset = address % bsize;
err = VOP_BMAP(vp, vblock, &rtvp, &block, 0);
if (err)
rtaddress = -1;
else
rtaddress = block * DEV_BSIZE + voffset;
return rtaddress;
}
/*
* interrupt routine for I/O completion
*/
void
vnode_pager_iodone(bp)
struct buf *bp;
{
bp->b_flags |= B_DONE;
wakeup((caddr_t) bp);
if( bp->b_flags & B_ASYNC) {
vm_offset_t paddr;
vm_page_t m;
vm_object_t obj = 0;
int i;
int npages;
paddr = (vm_offset_t) bp->b_data;
if( bp->b_bufsize != bp->b_bcount)
bzero( bp->b_data + bp->b_bcount,
bp->b_bufsize - bp->b_bcount);
npages = (bp->b_bufsize + PAGE_SIZE - 1) / PAGE_SIZE;
/*
printf("bcount: %d, bufsize: %d, npages: %d\n",
bp->b_bcount, bp->b_bufsize, npages);
*/
for( i = 0; i < npages; i++) {
m = PHYS_TO_VM_PAGE(pmap_kextract(paddr + i * PAGE_SIZE));
obj = m->object;
if( m) {
m->flags |= PG_CLEAN;
m->flags &= ~(PG_LAUNDRY|PG_FAKE);
PAGE_WAKEUP(m);
} else {
panic("vnode_pager_iodone: page is gone!!!");
}
}
pmap_qremove( paddr, npages);
if( obj) {
--obj->paging_in_progress;
if( obj->paging_in_progress == 0)
wakeup((caddr_t) obj);
} else {
panic("vnode_pager_iodone: object is gone???");
}
HOLDRELE(bp->b_vp);
relpbuf(bp);
}
}
/*
* small block file system vnode pager input
*/
int
vnode_pager_input_smlfs(vnp, m)
vn_pager_t vnp;
vm_page_t m;
{
int i;
int s;
vm_offset_t paging_offset;
struct vnode *dp, *vp;
struct buf *bp;
vm_offset_t foff;
vm_offset_t kva;
int fileaddr;
int block;
vm_offset_t bsize;
int error = 0;
paging_offset = m->object->paging_offset;
vp = vnp->vnp_vp;
bsize = vp->v_mount->mnt_stat.f_iosize;
foff = m->offset + paging_offset;
VOP_BMAP(vp, foff, &dp, 0, 0);
kva = vm_pager_map_page(m);
for (i = 0; i < PAGE_SIZE / bsize; i++) {
/*
* calculate logical block and offset
*/
block = foff / bsize + i;
s = splbio();
while ((bp = incore(vp, block)) != 0) {
int amount;
/*
* wait until the buffer is avail or gone
*/
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
tsleep((caddr_t) bp, PVM, "vnwblk", 0);
continue;
}
amount = bsize;
if ((foff + bsize) > vnp->vnp_size)
amount = vnp->vnp_size - foff;
/*
* make sure that this page is in the buffer
*/
if ((amount > 0) && amount <= bp->b_bcount) {
bp->b_flags |= B_BUSY;
splx(s);
/*
* copy the data from the buffer
*/
bcopy(bp->b_un.b_addr, (caddr_t) kva + i * bsize, amount);
if (amount < bsize) {
bzero((caddr_t) kva + amount, bsize - amount);
}
bp->b_flags &= ~B_BUSY;
wakeup((caddr_t) bp);
goto nextblock;
}
break;
}
splx(s);
fileaddr = vnode_pager_addr(vp, foff + i * bsize);
if (fileaddr != -1) {
bp = getpbuf();
VHOLD(vp);
/* 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_un.b_addr = (caddr_t) kva + i * bsize;
bp->b_blkno = fileaddr / DEV_BSIZE;
bgetvp(dp, bp);
bp->b_bcount = bsize;
bp->b_bufsize = bsize;
/* do the input */
VOP_STRATEGY(bp);
/* we definitely need to be at splbio here */
s = splbio();
while ((bp->b_flags & B_DONE) == 0) {
tsleep((caddr_t) 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);
HOLDRELE(vp);
if (error)
break;
} else {
bzero((caddr_t) kva + i * bsize, bsize);
}
nextblock:
}
vm_pager_unmap_page(kva);
if (error) {
return VM_PAGER_FAIL;
}
pmap_clear_modify(VM_PAGE_TO_PHYS(m));
m->flags |= PG_CLEAN;
m->flags &= ~PG_LAUNDRY;
return VM_PAGER_OK;
}
/*
* old style vnode pager output routine
*/
int
vnode_pager_input_old(vnp, m)
vn_pager_t vnp;
vm_page_t m;
{
struct uio auio;
struct iovec aiov;
int error;
int size;
vm_offset_t foff;
vm_offset_t kva;
error = 0;
foff = m->offset + m->object->paging_offset;
/*
* Return failure if beyond current EOF
*/
if (foff >= vnp->vnp_size) {
return VM_PAGER_BAD;
} else {
size = PAGE_SIZE;
if (foff + size > vnp->vnp_size)
size = vnp->vnp_size - foff;
/*
* 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 = foff;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_READ;
auio.uio_resid = size;
auio.uio_procp = (struct proc *) 0;
error = VOP_READ(vnp->vnp_vp, &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->flags |= PG_CLEAN;
m->flags &= ~PG_LAUNDRY;
return error ? VM_PAGER_FAIL : VM_PAGER_OK;
}
/*
* generic vnode pager input routine
*/
int
vnode_pager_input(vnp, m, count, reqpage)
register vn_pager_t vnp;
vm_page_t *m;
int count, reqpage;
{
int i;
vm_offset_t kva, foff;
int size, sizea;
vm_object_t object;
vm_offset_t paging_offset;
struct vnode *dp, *vp;
int bsize;
int first, last;
int reqaddr, firstaddr;
int block, offset;
struct buf *bp, *bpa;
int counta;
int s;
int failflag;
int error = 0;
object = m[reqpage]->object; /* all vm_page_t items are in same
* object */
paging_offset = object->paging_offset;
vp = vnp->vnp_vp;
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 = m[reqpage]->offset + paging_offset;
/*
* if we can't bmap, use old VOP code
*/
if (VOP_BMAP(vp, foff, &dp, 0, 0)) {
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(vnp, 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(vnp, m[reqpage]);
}
/*
* here on direct device I/O
*/
#ifdef NOTYET
if( (vp->v_flag & VVMIO) == 0) {
#endif
/*
* This pathetic hack gets data from the buffer cache, if it's there.
* I believe that this is not really necessary, and the ends can be
* gotten by defaulting to the normal vfs read behavior, but this
* might be more efficient, because the will NOT invoke read-aheads
* and one of the purposes of this code is to bypass the buffer cache
* and keep from flushing it by reading in a program.
*/
/*
* calculate logical block and offset
*/
block = foff / bsize;
offset = foff % bsize;
s = splbio();
/*
* if we have a buffer in core, then try to use it
*/
while ((bp = incore(vp, block)) != 0) {
int amount;
/*
* wait until the buffer is avail or gone
*/
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
tsleep((caddr_t) bp, PVM, "vnwblk", 0);
continue;
}
amount = PAGE_SIZE;
if ((foff + amount) > vnp->vnp_size)
amount = vnp->vnp_size - foff;
/*
* make sure that this page is in the buffer
*/
if ((amount > 0) && (offset + amount) <= bp->b_bcount) {
bp->b_flags |= B_BUSY;
splx(s);
kva = kmem_alloc_wait( pager_map, PAGE_SIZE);
/*
* map the requested page
*/
pmap_qenter(kva, &m[reqpage], 1);
/*
* copy the data from the buffer
*/
bcopy(bp->b_un.b_addr + offset, (caddr_t) kva, amount);
if (amount < PAGE_SIZE) {
bzero((caddr_t) kva + amount, PAGE_SIZE - amount);
}
/*
* unmap the page and free the kva
*/
pmap_qremove( kva, 1);
kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
/*
* release the buffer back to the block subsystem
*/
bp->b_flags &= ~B_BUSY;
wakeup((caddr_t) bp);
/*
* we did not have to do any work to get the requested
* page, the read behind/ahead does not justify a read
*/
for (i = 0; i < count; i++) {
if (i != reqpage) {
vnode_pager_freepage(m[i]);
}
}
count = 1;
reqpage = 0;
m[0] = m[reqpage];
/*
* sorry for the goto
*/
goto finishup;
}
/*
* buffer is nowhere to be found, read from the disk
*/
break;
}
splx(s);
#ifdef NOTYET
}
#endif
reqaddr = vnode_pager_addr(vp, foff);
s = splbio();
/*
* Make sure that our I/O request is contiguous. Scan backward and
* stop for the first discontiguous entry or stop for a page being in
* buffer cache.
*/
failflag = 0;
first = reqpage;
for (i = reqpage - 1; i >= 0; --i) {
if (failflag ||
#ifdef NOTYET
((vp->v_flag & VVMIO) == 0 && incore(vp, (foff + (i - reqpage) * PAGE_SIZE) / bsize)) ||
#else
(incore(vp, (foff + (i - reqpage) * PAGE_SIZE) / bsize)) ||
#endif
(vnode_pager_addr(vp, m[i]->offset + paging_offset))
!= reqaddr + (i - reqpage) * PAGE_SIZE) {
vnode_pager_freepage(m[i]);
failflag = 1;
} else {
first = i;
}
}
/*
* Scan forward and stop for the first non-contiguous entry or stop
* for a page being in buffer cache.
*/
failflag = 0;
last = reqpage + 1;
for (i = reqpage + 1; i < count; i++) {
if (failflag ||
#ifdef NOTYET
((vp->v_flag & VVMIO) == 0 && incore(vp, (foff + (i - reqpage) * PAGE_SIZE) / bsize)) ||
#else
(incore(vp, (foff + (i - reqpage) * PAGE_SIZE) / bsize)) ||
#endif
(vnode_pager_addr(vp, m[i]->offset + paging_offset))
!= reqaddr + (i - reqpage) * PAGE_SIZE) {
vnode_pager_freepage(m[i]);
failflag = 1;
} else {
last = i + 1;
}
}
splx(s);
/*
* the first and last page have been calculated now, move input pages
* to be zero based...
*/
count = last;
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 = m[0]->offset + paging_offset;
/*
* and get the disk physical address (in bytes)
*/
firstaddr = vnode_pager_addr(vp, foff);
/*
* calculate the size of the transfer
*/
size = count * PAGE_SIZE;
if ((foff + size) > vnp->vnp_size)
size = 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);
counta = 0;
if( count*PAGE_SIZE > bsize)
counta = (count - reqpage) - 1;
bpa = 0;
sizea = 0;
if( counta) {
bpa = getpbuf();
count -= counta;
sizea = size - count*PAGE_SIZE;
size = count * PAGE_SIZE;
}
bp = getpbuf();
kva = (vm_offset_t)bp->b_data;
/*
* and map the pages to be read into the kva
*/
pmap_qenter(kva, m, count);
VHOLD(vp);
/* 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 / DEV_BSIZE;
bgetvp(dp, bp);
bp->b_bcount = size;
bp->b_bufsize = size;
cnt.v_vnodein++;
cnt.v_vnodepgsin += count;
/* do the input */
VOP_STRATEGY(bp);
if( counta) {
for(i=0;i<counta;i++) {
vm_page_deactivate(m[count+i]);
}
pmap_qenter((vm_offset_t)bpa->b_data, &m[count], counta);
++m[count]->object->paging_in_progress;
VHOLD(vp);
bpa->b_flags = B_BUSY | B_READ | B_CALL | B_ASYNC;
bpa->b_iodone = vnode_pager_iodone;
/* B_PHYS is not set, but it is nice to fill this in */
bpa->b_proc = curproc;
bpa->b_rcred = bpa->b_wcred = bpa->b_proc->p_ucred;
if (bpa->b_rcred != NOCRED)
crhold(bpa->b_rcred);
if (bpa->b_wcred != NOCRED)
crhold(bpa->b_wcred);
bpa->b_blkno = (firstaddr + count * PAGE_SIZE) / DEV_BSIZE;
bgetvp(dp, bpa);
bpa->b_bcount = sizea;
bpa->b_bufsize = counta*PAGE_SIZE;
cnt.v_vnodepgsin += counta;
VOP_STRATEGY(bpa);
}
s = splbio();
/* we definitely need to be at splbio here */
while ((bp->b_flags & B_DONE) == 0) {
tsleep((caddr_t) 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);
HOLDRELE(vp);
finishup:
for (i = 0; i < count; i++) {
pmap_clear_modify(VM_PAGE_TO_PHYS(m[i]));
m[i]->flags |= PG_CLEAN;
m[i]->flags &= ~PG_LAUNDRY;
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) {
vm_page_deactivate(m[i]);
PAGE_WAKEUP(m[i]);
m[i]->flags &= ~PG_FAKE;
} else {
vnode_pager_freepage(m[i]);
}
}
}
if (error) {
printf("vnode_pager_input: read error\n");
}
return (error ? VM_PAGER_FAIL : VM_PAGER_OK);
}
/*
* old-style vnode pager output routine
*/
int
vnode_pager_output_old(vnp, m)
register vn_pager_t vnp;
vm_page_t m;
{
vm_offset_t foff;
vm_offset_t kva;
vm_offset_t size;
struct iovec aiov;
struct uio auio;
struct vnode *vp;
int error;
vp = vnp->vnp_vp;
foff = m->offset + m->object->paging_offset;
/*
* Return failure if beyond current EOF
*/
if (foff >= vnp->vnp_size) {
return VM_PAGER_BAD;
} else {
size = PAGE_SIZE;
if (foff + size > vnp->vnp_size)
size = vnp->vnp_size - foff;
/*
* Allocate a kernel virtual address and initialize so that
* we can use VOP_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 = foff;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_WRITE;
auio.uio_resid = size;
auio.uio_procp = (struct proc *) 0;
error = VOP_WRITE(vp, &auio, 0, curproc->p_ucred);
if (!error) {
if ((size - auio.uio_resid) == 0) {
error = EINVAL;
}
}
vm_pager_unmap_page(kva);
return error ? VM_PAGER_FAIL : VM_PAGER_OK;
}
}
/*
* vnode pager output on a small-block file system
*/
int
vnode_pager_output_smlfs(vnp, m)
vn_pager_t vnp;
vm_page_t m;
{
int i;
int s;
vm_offset_t paging_offset;
struct vnode *dp, *vp;
struct buf *bp;
vm_offset_t foff;
vm_offset_t kva;
int fileaddr;
vm_offset_t bsize;
int error = 0;
paging_offset = m->object->paging_offset;
vp = vnp->vnp_vp;
bsize = vp->v_mount->mnt_stat.f_iosize;
foff = m->offset + paging_offset;
VOP_BMAP(vp, foff, &dp, 0, 0);
kva = vm_pager_map_page(m);
for (i = 0; !error && i < (PAGE_SIZE / bsize); i++) {
/*
* calculate logical block and offset
*/
fileaddr = vnode_pager_addr(vp, foff + i * bsize);
if (fileaddr != -1) {
s = splbio();
bp = incore(vp, (foff / bsize) + i);
if (bp) {
bp = getblk(vp, (foff / bsize) + i, bp->b_bufsize, 0, 0);
bp->b_flags |= B_INVAL;
brelse(bp);
}
splx(s);
bp = getpbuf();
VHOLD(vp);
/* build a minimal buffer header */
bp->b_flags = B_BUSY | B_CALL | B_WRITE;
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_un.b_addr = (caddr_t) kva + i * bsize;
bp->b_blkno = fileaddr / DEV_BSIZE;
bgetvp(dp, bp);
++dp->v_numoutput;
/* for NFS */
bp->b_dirtyoff = 0;
bp->b_dirtyend = bsize;
bp->b_bcount = bsize;
bp->b_bufsize = bsize;
/* do the input */
VOP_STRATEGY(bp);
/* we definitely need to be at splbio here */
s = splbio();
while ((bp->b_flags & B_DONE) == 0) {
tsleep((caddr_t) bp, PVM, "vnswrt", 0);
}
splx(s);
if ((bp->b_flags & B_ERROR) != 0)
error = EIO;
/*
* free the buffer header back to the swap buffer pool
*/
relpbuf(bp);
HOLDRELE(vp);
}
}
vm_pager_unmap_page(kva);
if (error)
return VM_PAGER_FAIL;
else
return VM_PAGER_OK;
}
/*
* generic vnode pager output routine
*/
int
vnode_pager_output(vnp, m, count, rtvals)
vn_pager_t vnp;
vm_page_t *m;
int count;
int *rtvals;
{
int i, j;
vm_offset_t kva, foff;
int size;
vm_object_t object;
vm_offset_t paging_offset;
struct vnode *dp, *vp;
struct buf *bp;
vm_offset_t reqaddr;
int bsize;
int s;
int error = 0;
retryoutput:
object = m[0]->object; /* all vm_page_t items are in same object */
paging_offset = object->paging_offset;
vp = vnp->vnp_vp;
bsize = vp->v_mount->mnt_stat.f_iosize;
for (i = 0; i < count; i++)
rtvals[i] = VM_PAGER_AGAIN;
/*
* if the filesystem does not have a bmap, then use the old code
*/
if (VOP_BMAP(vp, m[0]->offset + paging_offset, &dp, 0, 0)) {
rtvals[0] = vnode_pager_output_old(vnp, m[0]);
pmap_clear_modify(VM_PAGE_TO_PHYS(m[0]));
m[0]->flags |= PG_CLEAN;
m[0]->flags &= ~PG_LAUNDRY;
cnt.v_vnodeout++;
cnt.v_vnodepgsout++;
return rtvals[0];
}
/*
* if the filesystem has a small blocksize, then use the small block
* filesystem output code
*/
if ((bsize < PAGE_SIZE) &&
(vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) {
for (i = 0; i < count; i++) {
rtvals[i] = vnode_pager_output_smlfs(vnp, m[i]);
if (rtvals[i] == VM_PAGER_OK) {
pmap_clear_modify(VM_PAGE_TO_PHYS(m[i]));
m[i]->flags |= PG_CLEAN;
m[i]->flags &= ~PG_LAUNDRY;
}
}
cnt.v_vnodeout++;
cnt.v_vnodepgsout += count;
return rtvals[0];
}
for (i = 0; i < count; i++) {
foff = m[i]->offset + paging_offset;
if (foff >= vnp->vnp_size) {
for (j = i; j < count; j++)
rtvals[j] = VM_PAGER_BAD;
count = i;
break;
}
}
if (count == 0) {
return rtvals[0];
}
foff = m[0]->offset + paging_offset;
reqaddr = vnode_pager_addr(vp, foff);
/*
* Scan forward and stop for the first non-contiguous entry or stop
* for a page being in buffer cache.
*/
for (i = 1; i < count; i++) {
if (vnode_pager_addr(vp, m[i]->offset + paging_offset)
!= reqaddr + i * PAGE_SIZE) {
count = i;
break;
}
}
/*
* calculate the size of the transfer
*/
size = count * PAGE_SIZE;
if ((foff + size) > vnp->vnp_size)
size = 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);
#if 0
printf("vnode: writing foff: %d, devoff: %d, size: %d\n",
foff, reqaddr, size);
#endif
/*
* next invalidate the incore vfs_bio data
*/
#ifdef NOTYET
if( (vp->v_flag & VVMIO) == 0) {
#endif
for (i = 0; i < count; i++) {
int filblock = (foff + i * PAGE_SIZE) / bsize;
struct buf *fbp;
s = splbio();
fbp = incore(vp, filblock);
if (fbp) {
fbp = getblk(vp, filblock, fbp->b_bufsize, 0, 0);
if (fbp->b_flags & B_DELWRI) {
if (fbp->b_bufsize <= PAGE_SIZE)
fbp->b_flags &= ~B_DELWRI;
else {
bwrite(fbp);
fbp = getblk(vp, filblock,
fbp->b_bufsize, 0, 0);
}
}
fbp->b_flags |= B_INVAL;
brelse(fbp);
}
splx(s);
}
#ifdef NOTYET
}
#endif
VHOLD(vp);
/* build a minimal buffer header */
bp->b_flags = B_BUSY | B_WRITE | 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 = reqaddr / DEV_BSIZE;
bgetvp(dp, bp);
++dp->v_numoutput;
/* for NFS */
bp->b_dirtyoff = 0;
bp->b_dirtyend = size;
bp->b_bcount = size;
bp->b_bufsize = size;
cnt.v_vnodeout++;
cnt.v_vnodepgsout += count;
/* do the output */
VOP_STRATEGY(bp);
s = splbio();
/* we definitely need to be at splbio here */
while ((bp->b_flags & B_DONE) == 0) {
tsleep((caddr_t) bp, PVM, "vnwrite", 0);
}
splx(s);
if ((bp->b_flags & B_ERROR) != 0)
error = EIO;
pmap_qremove( kva, count);
/*
* free the buffer header back to the swap buffer pool
*/
relpbuf(bp);
HOLDRELE(vp);
if (!error) {
for (i = 0; i < count; i++) {
pmap_clear_modify(VM_PAGE_TO_PHYS(m[i]));
m[i]->flags |= PG_CLEAN;
m[i]->flags &= ~PG_LAUNDRY;
rtvals[i] = VM_PAGER_OK;
}
} else if (count != 1) {
error = 0;
count = 1;
goto retryoutput;
}
if (error) {
printf("vnode_pager_output: write error\n");
}
return (error ? VM_PAGER_FAIL : VM_PAGER_OK);
}
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