2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
5 * Copyright (c) 1993, 1994 John S. Dyson
6 * Copyright (c) 1995, David Greenman
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91
41 * $FreeBSD: src/sys/vm/vnode_pager.c,v 1.116.2.7 2002/12/31 09:34:51 dillon Exp $
42 * $DragonFly: src/sys/vm/vnode_pager.c,v 1.12 2004/03/23 22:54:32 dillon Exp $
46 * Page to/from files (vnodes).
51 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
52 * greatly re-simplify the vnode_pager.
55 #include <sys/param.h>
56 #include <sys/systm.h>
58 #include <sys/vnode.h>
59 #include <sys/mount.h>
61 #include <sys/vmmeter.h>
65 #include <vm/vm_object.h>
66 #include <vm/vm_page.h>
67 #include <vm/vm_pager.h>
68 #include <vm/vm_map.h>
69 #include <vm/vnode_pager.h>
70 #include <vm/vm_extern.h>
72 static vm_offset_t vnode_pager_addr (struct vnode *vp, vm_ooffset_t address,
74 static void vnode_pager_iodone (struct buf *bp);
75 static int vnode_pager_input_smlfs (vm_object_t object, vm_page_t m);
76 static int vnode_pager_input_old (vm_object_t object, vm_page_t m);
77 static void vnode_pager_dealloc (vm_object_t);
78 static int vnode_pager_getpages (vm_object_t, vm_page_t *, int, int);
79 static void vnode_pager_putpages (vm_object_t, vm_page_t *, int, boolean_t, int *);
80 static boolean_t vnode_pager_haspage (vm_object_t, vm_pindex_t, int *, int *);
82 struct pagerops vnodepagerops = {
92 int vnode_pbuf_freecnt = -1; /* start out unlimited */
95 * Allocate (or lookup) pager for a vnode.
96 * Handle is a vnode pointer.
99 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
106 * Pageout to vnode, no can do yet.
112 * XXX hack - This initialization should be put somewhere else.
114 if (vnode_pbuf_freecnt < 0) {
115 vnode_pbuf_freecnt = nswbuf / 2 + 1;
118 vp = (struct vnode *) handle;
121 * Prevent race condition when allocating the object. This
122 * can happen with NFS vnodes since the nfsnode isn't locked.
124 while (vp->v_flag & VOLOCK) {
125 vp->v_flag |= VOWANT;
126 tsleep(vp, 0, "vnpobj", 0);
128 vp->v_flag |= VOLOCK;
131 * If the object is being terminated, wait for it to
134 while (((object = vp->v_object) != NULL) &&
135 (object->flags & OBJ_DEAD)) {
136 tsleep(object, 0, "vadead", 0);
139 if (vp->v_usecount == 0)
140 panic("vnode_pager_alloc: no vnode reference");
142 if (object == NULL) {
144 * And an object of the appropriate size
146 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
149 object->un_pager.vnp.vnp_size = size;
151 object->handle = handle;
152 vp->v_object = object;
159 vp->v_flag &= ~VOLOCK;
160 if (vp->v_flag & VOWANT) {
161 vp->v_flag &= ~VOWANT;
168 vnode_pager_dealloc(vm_object_t object)
170 struct vnode *vp = object->handle;
173 panic("vnode_pager_dealloc: pager already dealloced");
175 vm_object_pip_wait(object, "vnpdea");
177 object->handle = NULL;
178 object->type = OBJT_DEAD;
180 vp->v_flag &= ~(VTEXT | VOBJBUF);
184 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
187 struct vnode *vp = object->handle;
193 int pagesperblock, blocksperpage;
196 * If no vp or vp is doomed or marked transparent to VM, we do not
199 if ((vp == NULL) || (vp->v_flag & VDOOMED))
203 * If filesystem no longer mounted or offset beyond end of file we do
206 if ((vp->v_mount == NULL) ||
207 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size))
210 bsize = vp->v_mount->mnt_stat.f_iosize;
211 pagesperblock = bsize / PAGE_SIZE;
213 if (pagesperblock > 0) {
214 reqblock = pindex / pagesperblock;
216 blocksperpage = (PAGE_SIZE / bsize);
217 reqblock = pindex * blocksperpage;
219 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn,
225 if (pagesperblock > 0) {
226 poff = pindex - (reqblock * pagesperblock);
228 *before *= pagesperblock;
233 *after *= pagesperblock;
234 numafter = pagesperblock - (poff + 1);
235 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) {
236 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex)));
242 *before /= blocksperpage;
246 *after /= blocksperpage;
253 * Lets the VM system know about a change in size for a file.
254 * We adjust our own internal size and flush any cached pages in
255 * the associated object that are affected by the size change.
257 * Note: this routine may be invoked as a result of a pager put
258 * operation (possibly at object termination time), so we must be careful.
261 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize)
263 vm_pindex_t nobjsize;
264 vm_object_t object = vp->v_object;
270 * Hasn't changed size
272 if (nsize == object->un_pager.vnp.vnp_size)
275 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
278 * File has shrunk. Toss any cached pages beyond the new EOF.
280 if (nsize < object->un_pager.vnp.vnp_size) {
281 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size);
282 if (nobjsize < object->size) {
283 vm_object_page_remove(object, nobjsize, object->size,
287 * this gets rid of garbage at the end of a page that is now
288 * only partially backed by the vnode.
290 * XXX for some reason (I don't know yet), if we take a
291 * completely invalid page and mark it partially valid
292 * it can screw up NFS reads, so we don't allow the case.
294 if (nsize & PAGE_MASK) {
298 m = vm_page_lookup(object, OFF_TO_IDX(nsize));
300 int base = (int)nsize & PAGE_MASK;
301 int size = PAGE_SIZE - base;
304 * Clear out partial-page garbage in case
305 * the page has been mapped.
307 kva = vm_pager_map_page(m);
308 bzero((caddr_t)kva + base, size);
309 vm_pager_unmap_page(kva);
312 * XXX work around SMP data integrity race
313 * by unmapping the page from user processes.
314 * The garbage we just cleared may be mapped
315 * to a user process running on another cpu
316 * and this code is not running through normal
317 * I/O channels which handle SMP issues for
318 * us, so unmap page to synchronize all cpus.
320 * XXX should vm_pager_unmap_page() have
323 vm_page_protect(m, VM_PROT_NONE);
326 * Clear out partial-page dirty bits. This
327 * has the side effect of setting the valid
328 * bits, but that is ok. There are a bunch
329 * of places in the VM system where we expected
330 * m->dirty == VM_PAGE_BITS_ALL. The file EOF
331 * case is one of them. If the page is still
332 * partially dirty, make it fully dirty.
334 * note that we do not clear out the valid
335 * bits. This would prevent bogus_page
336 * replacement from working properly.
338 vm_page_set_validclean(m, base, size);
340 m->dirty = VM_PAGE_BITS_ALL;
344 object->un_pager.vnp.vnp_size = nsize;
345 object->size = nobjsize;
349 vnode_pager_freepage(vm_page_t m)
355 * calculate the linear (byte) disk address of specified virtual
359 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, int *run)
369 if ((int) address < 0)
372 if (vp->v_mount == NULL)
375 bsize = vp->v_mount->mnt_stat.f_iosize;
376 vblock = address / bsize;
377 voffset = address % bsize;
379 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL);
381 if (err || (block == -1))
384 rtaddress = block + voffset / DEV_BSIZE;
387 *run *= bsize/PAGE_SIZE;
388 *run -= voffset/PAGE_SIZE;
396 * interrupt routine for I/O completion
399 vnode_pager_iodone(struct buf *bp)
401 bp->b_flags |= B_DONE;
406 * small block file system vnode pager input
409 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m)
413 struct vnode *dp, *vp;
421 if (vp->v_mount == NULL)
424 bsize = vp->v_mount->mnt_stat.f_iosize;
427 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL);
429 kva = vm_pager_map_page(m);
431 for (i = 0; i < PAGE_SIZE / bsize; i++) {
432 vm_ooffset_t address;
434 if (vm_page_bits(i * bsize, bsize) & m->valid)
437 address = IDX_TO_OFF(m->pindex) + i * bsize;
438 if (address >= object->un_pager.vnp.vnp_size) {
441 fileaddr = vnode_pager_addr(vp, address, NULL);
443 if (fileaddr != -1) {
444 bp = getpbuf(&vnode_pbuf_freecnt);
446 /* build a minimal buffer header */
447 bp->b_flags = B_READ | B_CALL;
448 bp->b_iodone = vnode_pager_iodone;
449 bp->b_data = (caddr_t) kva + i * bsize;
450 bp->b_blkno = fileaddr;
452 bp->b_bcount = bsize;
453 bp->b_bufsize = bsize;
454 bp->b_runningbufspace = bp->b_bufsize;
455 runningbufspace += bp->b_runningbufspace;
458 VOP_STRATEGY(bp->b_vp, bp);
460 /* we definitely need to be at splvm here */
463 while ((bp->b_flags & B_DONE) == 0) {
464 tsleep(bp, 0, "vnsrd", 0);
467 if ((bp->b_flags & B_ERROR) != 0)
471 * free the buffer header back to the swap buffer pool
473 relpbuf(bp, &vnode_pbuf_freecnt);
477 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
479 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
480 bzero((caddr_t) kva + i * bsize, bsize);
483 vm_pager_unmap_page(kva);
484 pmap_clear_modify(m);
485 vm_page_flag_clear(m, PG_ZERO);
487 return VM_PAGER_ERROR;
495 * old style vnode pager output routine
498 vnode_pager_input_old(vm_object_t object, vm_page_t m)
509 * Return failure if beyond current EOF
511 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
515 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
516 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
519 * Allocate a kernel virtual address and initialize so that
520 * we can use VOP_READ/WRITE routines.
522 kva = vm_pager_map_page(m);
524 aiov.iov_base = (caddr_t) kva;
526 auio.uio_iov = &aiov;
528 auio.uio_offset = IDX_TO_OFF(m->pindex);
529 auio.uio_segflg = UIO_SYSSPACE;
530 auio.uio_rw = UIO_READ;
531 auio.uio_resid = size;
532 auio.uio_td = curthread;
534 error = VOP_READ(object->handle, &auio, 0, proc0.p_ucred);
536 int count = size - auio.uio_resid;
540 else if (count != PAGE_SIZE)
541 bzero((caddr_t) kva + count, PAGE_SIZE - count);
543 vm_pager_unmap_page(kva);
545 pmap_clear_modify(m);
547 vm_page_flag_clear(m, PG_ZERO);
549 m->valid = VM_PAGE_BITS_ALL;
550 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
554 * generic vnode pager input routine
558 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
559 * implement their own VOP_GETPAGES, their VOP_GETPAGES should call to
560 * vnode_pager_generic_getpages() to implement the previous behaviour.
562 * All other FS's should use the bypass to get to the local media
563 * backing vp's VOP_GETPAGES.
566 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
570 int bytes = count * PAGE_SIZE;
574 * XXX temporary diagnostic message to help track stale FS code,
575 * Returning EOPNOTSUPP from here may make things unhappy.
577 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
578 if (rtval == EOPNOTSUPP) {
579 printf("vnode_pager: *** WARNING *** stale FS getpages\n");
580 rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage);
587 * This is now called from local media FS's to operate against their
588 * own vnodes if they fail to implement VOP_GETPAGES.
591 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
596 off_t foff, tfoff, nextoff;
597 int i, size, bsize, first, firstaddr;
606 object = vp->v_object;
607 count = bytecount / PAGE_SIZE;
609 if (vp->v_mount == NULL)
612 bsize = vp->v_mount->mnt_stat.f_iosize;
614 /* get the UNDERLYING device for the file with VOP_BMAP() */
617 * originally, we did not check for an error return value -- assuming
618 * an fs always has a bmap entry point -- that assumption is wrong!!!
620 foff = IDX_TO_OFF(m[reqpage]->pindex);
623 * if we can't bmap, use old VOP code
625 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) {
626 for (i = 0; i < count; i++) {
628 vnode_pager_freepage(m[i]);
631 mycpu->gd_cnt.v_vnodein++;
632 mycpu->gd_cnt.v_vnodepgsin++;
633 return vnode_pager_input_old(object, m[reqpage]);
636 * if the blocksize is smaller than a page size, then use
637 * special small filesystem code. NFS sometimes has a small
638 * blocksize, but it can handle large reads itself.
640 } else if ((PAGE_SIZE / bsize) > 1 &&
641 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
642 for (i = 0; i < count; i++) {
644 vnode_pager_freepage(m[i]);
647 mycpu->gd_cnt.v_vnodein++;
648 mycpu->gd_cnt.v_vnodepgsin++;
649 return vnode_pager_input_smlfs(object, m[reqpage]);
653 * If we have a completely valid page available to us, we can
654 * clean up and return. Otherwise we have to re-read the
658 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
659 for (i = 0; i < count; i++) {
661 vnode_pager_freepage(m[i]);
665 m[reqpage]->valid = 0;
668 * here on direct device I/O
673 * calculate the run that includes the required page
675 for(first = 0, i = 0; i < count; i = runend) {
676 firstaddr = vnode_pager_addr(vp,
677 IDX_TO_OFF(m[i]->pindex), &runpg);
678 if (firstaddr == -1) {
679 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
680 /* XXX no %qd in kernel. */
681 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx",
682 firstaddr, (u_long)(foff >> 32),
683 (u_long)(u_int32_t)foff,
685 (object->un_pager.vnp.vnp_size >> 32),
687 object->un_pager.vnp.vnp_size);
689 vnode_pager_freepage(m[i]);
695 if (runend <= reqpage) {
697 for (j = i; j < runend; j++) {
698 vnode_pager_freepage(m[j]);
701 if (runpg < (count - first)) {
702 for (i = first + runpg; i < count; i++)
703 vnode_pager_freepage(m[i]);
704 count = first + runpg;
712 * the first and last page have been calculated now, move input pages
713 * to be zero based...
716 for (i = first; i < count; i++) {
724 * calculate the file virtual address for the transfer
726 foff = IDX_TO_OFF(m[0]->pindex);
729 * calculate the size of the transfer
731 size = count * PAGE_SIZE;
732 if ((foff + size) > object->un_pager.vnp.vnp_size)
733 size = object->un_pager.vnp.vnp_size - foff;
736 * round up physical size for real devices.
738 if (dp->v_type == VBLK || dp->v_type == VCHR) {
739 int secmask = dp->v_rdev->si_bsize_phys - 1;
740 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1));
741 size = (size + secmask) & ~secmask;
744 bp = getpbuf(&vnode_pbuf_freecnt);
745 kva = (vm_offset_t) bp->b_data;
748 * and map the pages to be read into the kva
750 pmap_qenter(kva, m, count);
752 /* build a minimal buffer header */
753 bp->b_flags = B_READ | B_CALL;
754 bp->b_iodone = vnode_pager_iodone;
755 /* B_PHYS is not set, but it is nice to fill this in */
756 bp->b_blkno = firstaddr;
759 bp->b_bufsize = size;
760 bp->b_runningbufspace = bp->b_bufsize;
761 runningbufspace += bp->b_runningbufspace;
763 mycpu->gd_cnt.v_vnodein++;
764 mycpu->gd_cnt.v_vnodepgsin += count;
767 VOP_STRATEGY(bp->b_vp, bp);
770 /* we definitely need to be at splvm here */
772 while ((bp->b_flags & B_DONE) == 0) {
773 tsleep(bp, 0, "vnread", 0);
776 if ((bp->b_flags & B_ERROR) != 0)
780 if (size != count * PAGE_SIZE)
781 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
783 pmap_qremove(kva, count);
786 * free the buffer header back to the swap buffer pool
788 relpbuf(bp, &vnode_pbuf_freecnt);
790 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
793 nextoff = tfoff + PAGE_SIZE;
796 if (nextoff <= object->un_pager.vnp.vnp_size) {
798 * Read filled up entire page.
800 mt->valid = VM_PAGE_BITS_ALL;
801 vm_page_undirty(mt); /* should be an assert? XXX */
802 pmap_clear_modify(mt);
805 * Read did not fill up entire page. Since this
806 * is getpages, the page may be mapped, so we have
807 * to zero the invalid portions of the page even
808 * though we aren't setting them valid.
810 * Currently we do not set the entire page valid,
811 * we just try to clear the piece that we couldn't
814 vm_page_set_validclean(mt, 0,
815 object->un_pager.vnp.vnp_size - tfoff);
816 /* handled by vm_fault now */
817 /* vm_page_zero_invalid(mt, FALSE); */
820 vm_page_flag_clear(mt, PG_ZERO);
824 * whether or not to leave the page activated is up in
825 * the air, but we should put the page on a page queue
826 * somewhere. (it already is in the object). Result:
827 * It appears that empirical results show that
828 * deactivating pages is best.
832 * just in case someone was asking for this page we
833 * now tell them that it is ok to use
836 if (mt->flags & PG_WANTED)
837 vm_page_activate(mt);
839 vm_page_deactivate(mt);
842 vnode_pager_freepage(mt);
847 printf("vnode_pager_getpages: I/O read error\n");
849 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
853 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
854 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
855 * vnode_pager_generic_putpages() to implement the previous behaviour.
857 * All other FS's should use the bypass to get to the local media
858 * backing vp's VOP_PUTPAGES.
861 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
862 boolean_t sync, int *rtvals)
866 int bytes = count * PAGE_SIZE;
869 * Force synchronous operation if we are extremely low on memory
870 * to prevent a low-memory deadlock. VOP operations often need to
871 * allocate more memory to initiate the I/O ( i.e. do a BMAP
872 * operation ). The swapper handles the case by limiting the amount
873 * of asynchronous I/O, but that sort of solution doesn't scale well
874 * for the vnode pager without a lot of work.
876 * Also, the backing vnode's iodone routine may not wake the pageout
877 * daemon up. This should be probably be addressed XXX.
880 if ((vmstats.v_free_count + vmstats.v_cache_count) < vmstats.v_pageout_free_min)
884 * Call device-specific putpages function
888 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
889 if (rtval == EOPNOTSUPP) {
890 printf("vnode_pager: *** WARNING *** stale FS putpages\n");
891 rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals);
897 * This is now called from local media FS's to operate against their
898 * own vnodes if they fail to implement VOP_PUTPAGES.
900 * This is typically called indirectly via the pageout daemon and
901 * clustering has already typically occured, so in general we ask the
902 * underlying filesystem to write the data out asynchronously rather
906 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *m, int bytecount,
907 int flags, int *rtvals)
914 vm_ooffset_t poffset;
920 object = vp->v_object;
921 count = bytecount / PAGE_SIZE;
923 for (i = 0; i < count; i++)
924 rtvals[i] = VM_PAGER_AGAIN;
926 if ((int) m[0]->pindex < 0) {
927 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n",
928 (long)m[0]->pindex, m[0]->dirty);
929 rtvals[0] = VM_PAGER_BAD;
933 maxsize = count * PAGE_SIZE;
936 poffset = IDX_TO_OFF(m[0]->pindex);
939 * If the page-aligned write is larger then the actual file we
940 * have to invalidate pages occuring beyond the file EOF. However,
941 * there is an edge case where a file may not be page-aligned where
942 * the last page is partially invalid. In this case the filesystem
943 * may not properly clear the dirty bits for the entire page (which
944 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
945 * With the page locked we are free to fix-up the dirty bits here.
947 * We do not under any circumstances truncate the valid bits, as
948 * this will screw up bogus page replacement.
950 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
951 if (object->un_pager.vnp.vnp_size > poffset) {
954 maxsize = object->un_pager.vnp.vnp_size - poffset;
955 ncount = btoc(maxsize);
956 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
957 vm_page_clear_dirty(m[ncount - 1], pgoff,
964 if (ncount < count) {
965 for (i = ncount; i < count; i++) {
966 rtvals[i] = VM_PAGER_BAD;
972 * pageouts are already clustered, use IO_ASYNC to force a bawrite()
973 * rather then a bdwrite() to prevent paging I/O from saturating
974 * the buffer cache. Dummy-up the sequential heuristic to cause
975 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
976 * the system decides how to cluster.
979 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
981 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
983 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
984 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
986 aiov.iov_base = (caddr_t) 0;
987 aiov.iov_len = maxsize;
988 auio.uio_iov = &aiov;
990 auio.uio_offset = poffset;
991 auio.uio_segflg = UIO_NOCOPY;
992 auio.uio_rw = UIO_WRITE;
993 auio.uio_resid = maxsize;
995 error = VOP_WRITE(vp, &auio, ioflags, proc0.p_ucred);
996 mycpu->gd_cnt.v_vnodeout++;
997 mycpu->gd_cnt.v_vnodepgsout += ncount;
1000 printf("vnode_pager_putpages: I/O error %d\n", error);
1002 if (auio.uio_resid) {
1003 printf("vnode_pager_putpages: residual I/O %d at %lu\n",
1004 auio.uio_resid, (u_long)m[0]->pindex);
1006 for (i = 0; i < ncount; i++) {
1007 rtvals[i] = VM_PAGER_OK;
1013 vnode_pager_lock(vm_object_t object)
1015 struct thread *td = curthread; /* XXX */
1017 for (; object != NULL; object = object->backing_object) {
1018 if (object->type != OBJT_VNODE)
1020 if (object->flags & OBJ_DEAD)
1023 while (vget(object->handle, NULL,
1024 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, td)) {
1025 if ((object->flags & OBJ_DEAD) ||
1026 (object->type != OBJT_VNODE)) {
1029 printf("vnode_pager_lock: retrying\n");
1031 return object->handle;