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 1.14 2004/05/13 17:40:19 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>
63 #include <sys/sfbuf.h>
66 #include <vm/vm_object.h>
67 #include <vm/vm_page.h>
68 #include <vm/vm_pager.h>
69 #include <vm/vm_map.h>
70 #include <vm/vnode_pager.h>
71 #include <vm/vm_extern.h>
73 static vm_offset_t vnode_pager_addr (struct vnode *vp, vm_ooffset_t address,
75 static void vnode_pager_iodone (struct buf *bp);
76 static int vnode_pager_input_smlfs (vm_object_t object, vm_page_t m);
77 static int vnode_pager_input_old (vm_object_t object, vm_page_t m);
78 static void vnode_pager_dealloc (vm_object_t);
79 static int vnode_pager_getpages (vm_object_t, vm_page_t *, int, int);
80 static void vnode_pager_putpages (vm_object_t, vm_page_t *, int, boolean_t, int *);
81 static boolean_t vnode_pager_haspage (vm_object_t, vm_pindex_t, int *, int *);
83 struct pagerops vnodepagerops = {
93 int vnode_pbuf_freecnt = -1; /* start out unlimited */
96 * Allocate (or lookup) pager for a vnode.
97 * Handle is a vnode pointer.
100 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
107 * Pageout to vnode, no can do yet.
113 * XXX hack - This initialization should be put somewhere else.
115 if (vnode_pbuf_freecnt < 0) {
116 vnode_pbuf_freecnt = nswbuf / 2 + 1;
119 vp = (struct vnode *) handle;
122 * Prevent race condition when allocating the object. This
123 * can happen with NFS vnodes since the nfsnode isn't locked.
125 while (vp->v_flag & VOLOCK) {
126 vp->v_flag |= VOWANT;
127 tsleep(vp, 0, "vnpobj", 0);
129 vp->v_flag |= VOLOCK;
132 * If the object is being terminated, wait for it to
135 while (((object = vp->v_object) != NULL) &&
136 (object->flags & OBJ_DEAD)) {
137 tsleep(object, 0, "vadead", 0);
140 if (vp->v_usecount == 0)
141 panic("vnode_pager_alloc: no vnode reference");
143 if (object == NULL) {
145 * And an object of the appropriate size
147 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
150 object->un_pager.vnp.vnp_size = size;
152 object->handle = handle;
153 vp->v_object = object;
160 vp->v_flag &= ~VOLOCK;
161 if (vp->v_flag & VOWANT) {
162 vp->v_flag &= ~VOWANT;
169 vnode_pager_dealloc(vm_object_t object)
171 struct vnode *vp = object->handle;
174 panic("vnode_pager_dealloc: pager already dealloced");
176 vm_object_pip_wait(object, "vnpdea");
178 object->handle = NULL;
179 object->type = OBJT_DEAD;
181 vp->v_flag &= ~(VTEXT | VOBJBUF);
185 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
188 struct vnode *vp = object->handle;
194 int pagesperblock, blocksperpage;
197 * If no vp or vp is doomed or marked transparent to VM, we do not
200 if ((vp == NULL) || (vp->v_flag & VDOOMED))
204 * If filesystem no longer mounted or offset beyond end of file we do
207 if ((vp->v_mount == NULL) ||
208 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size))
211 bsize = vp->v_mount->mnt_stat.f_iosize;
212 pagesperblock = bsize / PAGE_SIZE;
214 if (pagesperblock > 0) {
215 reqblock = pindex / pagesperblock;
217 blocksperpage = (PAGE_SIZE / bsize);
218 reqblock = pindex * blocksperpage;
220 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn,
226 if (pagesperblock > 0) {
227 poff = pindex - (reqblock * pagesperblock);
229 *before *= pagesperblock;
234 *after *= pagesperblock;
235 numafter = pagesperblock - (poff + 1);
236 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) {
237 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex)));
243 *before /= blocksperpage;
247 *after /= blocksperpage;
254 * Lets the VM system know about a change in size for a file.
255 * We adjust our own internal size and flush any cached pages in
256 * the associated object that are affected by the size change.
258 * Note: this routine may be invoked as a result of a pager put
259 * operation (possibly at object termination time), so we must be careful.
262 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize)
264 vm_pindex_t nobjsize;
265 vm_object_t object = vp->v_object;
271 * Hasn't changed size
273 if (nsize == object->un_pager.vnp.vnp_size)
276 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
279 * File has shrunk. Toss any cached pages beyond the new EOF.
281 if (nsize < object->un_pager.vnp.vnp_size) {
282 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size);
283 if (nobjsize < object->size) {
284 vm_object_page_remove(object, nobjsize, object->size,
288 * This gets rid of garbage at the end of a page that is now
289 * only partially backed by the vnode. Since we are setting
290 * the entire page valid & clean after we are done we have
291 * to be sure that the portion of the page within the file
292 * bounds is already valid. If it isn't then making it
293 * valid would create a corrupt block.
295 if (nsize & PAGE_MASK) {
299 m = vm_page_lookup(object, OFF_TO_IDX(nsize));
301 int base = (int)nsize & PAGE_MASK;
302 int size = PAGE_SIZE - base;
306 * Clear out partial-page garbage in case
307 * the page has been mapped.
309 sf = sf_buf_alloc(m, SFBA_QUICK);
310 kva = sf_buf_kva(sf);
311 bzero((caddr_t)kva + base, size);
315 * XXX work around SMP data integrity race
316 * by unmapping the page from user processes.
317 * The garbage we just cleared may be mapped
318 * to a user process running on another cpu
319 * and this code is not running through normal
320 * I/O channels which handle SMP issues for
321 * us, so unmap page to synchronize all cpus.
323 * XXX should vm_pager_unmap_page() have
326 vm_page_protect(m, VM_PROT_NONE);
329 * Clear out partial-page dirty bits. This
330 * has the side effect of setting the valid
331 * bits, but that is ok. There are a bunch
332 * of places in the VM system where we expected
333 * m->dirty == VM_PAGE_BITS_ALL. The file EOF
334 * case is one of them. If the page is still
335 * partially dirty, make it fully dirty.
337 * note that we do not clear out the valid
338 * bits. This would prevent bogus_page
339 * replacement from working properly.
341 vm_page_set_validclean(m, base, size);
343 m->dirty = VM_PAGE_BITS_ALL;
347 object->un_pager.vnp.vnp_size = nsize;
348 object->size = nobjsize;
352 vnode_pager_freepage(vm_page_t m)
358 * calculate the linear (byte) disk address of specified virtual
362 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, int *run)
372 if ((int) address < 0)
375 if (vp->v_mount == NULL)
378 bsize = vp->v_mount->mnt_stat.f_iosize;
379 vblock = address / bsize;
380 voffset = address % bsize;
382 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL);
384 if (err || (block == -1))
387 rtaddress = block + voffset / DEV_BSIZE;
390 *run *= bsize/PAGE_SIZE;
391 *run -= voffset/PAGE_SIZE;
399 * interrupt routine for I/O completion
402 vnode_pager_iodone(struct buf *bp)
404 bp->b_flags |= B_DONE;
409 * small block file system vnode pager input
412 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m)
416 struct vnode *dp, *vp;
425 if (vp->v_mount == NULL)
428 bsize = vp->v_mount->mnt_stat.f_iosize;
431 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL);
433 sf = sf_buf_alloc(m, 0);
434 kva = sf_buf_kva(sf);
436 for (i = 0; i < PAGE_SIZE / bsize; i++) {
437 vm_ooffset_t address;
439 if (vm_page_bits(i * bsize, bsize) & m->valid)
442 address = IDX_TO_OFF(m->pindex) + i * bsize;
443 if (address >= object->un_pager.vnp.vnp_size) {
446 fileaddr = vnode_pager_addr(vp, address, NULL);
448 if (fileaddr != -1) {
449 bp = getpbuf(&vnode_pbuf_freecnt);
451 /* build a minimal buffer header */
452 bp->b_flags = B_READ | B_CALL;
453 bp->b_iodone = vnode_pager_iodone;
454 bp->b_data = (caddr_t) kva + i * bsize;
455 bp->b_blkno = fileaddr;
457 bp->b_bcount = bsize;
458 bp->b_bufsize = bsize;
459 bp->b_runningbufspace = bp->b_bufsize;
460 runningbufspace += bp->b_runningbufspace;
463 VOP_STRATEGY(bp->b_vp, bp);
465 /* we definitely need to be at splvm here */
468 while ((bp->b_flags & B_DONE) == 0) {
469 tsleep(bp, 0, "vnsrd", 0);
472 if ((bp->b_flags & B_ERROR) != 0)
476 * free the buffer header back to the swap buffer pool
478 relpbuf(bp, &vnode_pbuf_freecnt);
482 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
484 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
485 bzero((caddr_t) kva + i * bsize, bsize);
489 pmap_clear_modify(m);
490 vm_page_flag_clear(m, PG_ZERO);
492 return VM_PAGER_ERROR;
500 * old style vnode pager output routine
503 vnode_pager_input_old(vm_object_t object, vm_page_t m)
515 * Return failure if beyond current EOF
517 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
521 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
522 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
525 * Allocate a kernel virtual address and initialize so that
526 * we can use VOP_READ/WRITE routines.
528 sf = sf_buf_alloc(m, 0);
529 kva = sf_buf_kva(sf);
531 aiov.iov_base = (caddr_t) kva;
533 auio.uio_iov = &aiov;
535 auio.uio_offset = IDX_TO_OFF(m->pindex);
536 auio.uio_segflg = UIO_SYSSPACE;
537 auio.uio_rw = UIO_READ;
538 auio.uio_resid = size;
539 auio.uio_td = curthread;
541 error = VOP_READ(object->handle, &auio, 0, proc0.p_ucred);
543 int count = size - auio.uio_resid;
547 else if (count != PAGE_SIZE)
548 bzero((caddr_t) kva + count, PAGE_SIZE - count);
552 pmap_clear_modify(m);
554 vm_page_flag_clear(m, PG_ZERO);
556 m->valid = VM_PAGE_BITS_ALL;
557 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
561 * generic vnode pager input routine
565 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
566 * implement their own VOP_GETPAGES, their VOP_GETPAGES should call to
567 * vnode_pager_generic_getpages() to implement the previous behaviour.
569 * All other FS's should use the bypass to get to the local media
570 * backing vp's VOP_GETPAGES.
573 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
577 int bytes = count * PAGE_SIZE;
581 * XXX temporary diagnostic message to help track stale FS code,
582 * Returning EOPNOTSUPP from here may make things unhappy.
584 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
585 if (rtval == EOPNOTSUPP) {
586 printf("vnode_pager: *** WARNING *** stale FS getpages\n");
587 rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage);
594 * This is now called from local media FS's to operate against their
595 * own vnodes if they fail to implement VOP_GETPAGES.
598 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
603 off_t foff, tfoff, nextoff;
604 int i, size, bsize, first, firstaddr;
613 object = vp->v_object;
614 count = bytecount / PAGE_SIZE;
616 if (vp->v_mount == NULL)
619 bsize = vp->v_mount->mnt_stat.f_iosize;
621 /* get the UNDERLYING device for the file with VOP_BMAP() */
624 * originally, we did not check for an error return value -- assuming
625 * an fs always has a bmap entry point -- that assumption is wrong!!!
627 foff = IDX_TO_OFF(m[reqpage]->pindex);
630 * if we can't bmap, use old VOP code
632 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) {
633 for (i = 0; i < count; i++) {
635 vnode_pager_freepage(m[i]);
638 mycpu->gd_cnt.v_vnodein++;
639 mycpu->gd_cnt.v_vnodepgsin++;
640 return vnode_pager_input_old(object, m[reqpage]);
643 * if the blocksize is smaller than a page size, then use
644 * special small filesystem code. NFS sometimes has a small
645 * blocksize, but it can handle large reads itself.
647 } else if ((PAGE_SIZE / bsize) > 1 &&
648 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
649 for (i = 0; i < count; i++) {
651 vnode_pager_freepage(m[i]);
654 mycpu->gd_cnt.v_vnodein++;
655 mycpu->gd_cnt.v_vnodepgsin++;
656 return vnode_pager_input_smlfs(object, m[reqpage]);
660 * If we have a completely valid page available to us, we can
661 * clean up and return. Otherwise we have to re-read the
664 * Note that this does not work with NFS, so NFS has its own
665 * getpages routine. The problem is that NFS can have partially
666 * valid pages associated with the buffer cache due to the piecemeal
667 * write support. If we were to fall through and re-read the media
668 * as we do here, dirty data could be lost.
671 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
672 for (i = 0; i < count; i++) {
674 vnode_pager_freepage(m[i]);
678 m[reqpage]->valid = 0;
681 * here on direct device I/O
686 * calculate the run that includes the required page
688 for(first = 0, i = 0; i < count; i = runend) {
689 firstaddr = vnode_pager_addr(vp,
690 IDX_TO_OFF(m[i]->pindex), &runpg);
691 if (firstaddr == -1) {
692 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
693 /* XXX no %qd in kernel. */
694 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx",
695 firstaddr, (u_long)(foff >> 32),
696 (u_long)(u_int32_t)foff,
698 (object->un_pager.vnp.vnp_size >> 32),
700 object->un_pager.vnp.vnp_size);
702 vnode_pager_freepage(m[i]);
708 if (runend <= reqpage) {
710 for (j = i; j < runend; j++) {
711 vnode_pager_freepage(m[j]);
714 if (runpg < (count - first)) {
715 for (i = first + runpg; i < count; i++)
716 vnode_pager_freepage(m[i]);
717 count = first + runpg;
725 * the first and last page have been calculated now, move input pages
726 * to be zero based...
729 for (i = first; i < count; i++) {
737 * calculate the file virtual address for the transfer
739 foff = IDX_TO_OFF(m[0]->pindex);
742 * calculate the size of the transfer
744 size = count * PAGE_SIZE;
745 if ((foff + size) > object->un_pager.vnp.vnp_size)
746 size = object->un_pager.vnp.vnp_size - foff;
749 * round up physical size for real devices.
751 if (dp->v_type == VBLK || dp->v_type == VCHR) {
752 int secmask = dp->v_rdev->si_bsize_phys - 1;
753 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1));
754 size = (size + secmask) & ~secmask;
757 bp = getpbuf(&vnode_pbuf_freecnt);
758 kva = (vm_offset_t) bp->b_data;
761 * and map the pages to be read into the kva
763 pmap_qenter(kva, m, count);
765 /* build a minimal buffer header */
766 bp->b_flags = B_READ | B_CALL;
767 bp->b_iodone = vnode_pager_iodone;
768 /* B_PHYS is not set, but it is nice to fill this in */
769 bp->b_blkno = firstaddr;
772 bp->b_bufsize = size;
773 bp->b_runningbufspace = bp->b_bufsize;
774 runningbufspace += bp->b_runningbufspace;
776 mycpu->gd_cnt.v_vnodein++;
777 mycpu->gd_cnt.v_vnodepgsin += count;
780 VOP_STRATEGY(bp->b_vp, bp);
783 /* we definitely need to be at splvm here */
785 while ((bp->b_flags & B_DONE) == 0) {
786 tsleep(bp, 0, "vnread", 0);
789 if ((bp->b_flags & B_ERROR) != 0)
793 if (size != count * PAGE_SIZE)
794 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
796 pmap_qremove(kva, count);
799 * free the buffer header back to the swap buffer pool
801 relpbuf(bp, &vnode_pbuf_freecnt);
803 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
806 nextoff = tfoff + PAGE_SIZE;
809 if (nextoff <= object->un_pager.vnp.vnp_size) {
811 * Read filled up entire page.
813 mt->valid = VM_PAGE_BITS_ALL;
814 vm_page_undirty(mt); /* should be an assert? XXX */
815 pmap_clear_modify(mt);
818 * Read did not fill up entire page. Since this
819 * is getpages, the page may be mapped, so we have
820 * to zero the invalid portions of the page even
821 * though we aren't setting them valid.
823 * Currently we do not set the entire page valid,
824 * we just try to clear the piece that we couldn't
827 vm_page_set_validclean(mt, 0,
828 object->un_pager.vnp.vnp_size - tfoff);
829 /* handled by vm_fault now */
830 /* vm_page_zero_invalid(mt, FALSE); */
833 vm_page_flag_clear(mt, PG_ZERO);
837 * whether or not to leave the page activated is up in
838 * the air, but we should put the page on a page queue
839 * somewhere. (it already is in the object). Result:
840 * It appears that empirical results show that
841 * deactivating pages is best.
845 * just in case someone was asking for this page we
846 * now tell them that it is ok to use
849 if (mt->flags & PG_WANTED)
850 vm_page_activate(mt);
852 vm_page_deactivate(mt);
855 vnode_pager_freepage(mt);
860 printf("vnode_pager_getpages: I/O read error\n");
862 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
866 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
867 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
868 * vnode_pager_generic_putpages() to implement the previous behaviour.
870 * All other FS's should use the bypass to get to the local media
871 * backing vp's VOP_PUTPAGES.
874 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
875 boolean_t sync, int *rtvals)
879 int bytes = count * PAGE_SIZE;
882 * Force synchronous operation if we are extremely low on memory
883 * to prevent a low-memory deadlock. VOP operations often need to
884 * allocate more memory to initiate the I/O ( i.e. do a BMAP
885 * operation ). The swapper handles the case by limiting the amount
886 * of asynchronous I/O, but that sort of solution doesn't scale well
887 * for the vnode pager without a lot of work.
889 * Also, the backing vnode's iodone routine may not wake the pageout
890 * daemon up. This should be probably be addressed XXX.
893 if ((vmstats.v_free_count + vmstats.v_cache_count) < vmstats.v_pageout_free_min)
897 * Call device-specific putpages function
901 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
902 if (rtval == EOPNOTSUPP) {
903 printf("vnode_pager: *** WARNING *** stale FS putpages\n");
904 rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals);
910 * This is now called from local media FS's to operate against their
911 * own vnodes if they fail to implement VOP_PUTPAGES.
913 * This is typically called indirectly via the pageout daemon and
914 * clustering has already typically occured, so in general we ask the
915 * underlying filesystem to write the data out asynchronously rather
919 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *m, int bytecount,
920 int flags, int *rtvals)
927 vm_ooffset_t poffset;
933 object = vp->v_object;
934 count = bytecount / PAGE_SIZE;
936 for (i = 0; i < count; i++)
937 rtvals[i] = VM_PAGER_AGAIN;
939 if ((int) m[0]->pindex < 0) {
940 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n",
941 (long)m[0]->pindex, m[0]->dirty);
942 rtvals[0] = VM_PAGER_BAD;
946 maxsize = count * PAGE_SIZE;
949 poffset = IDX_TO_OFF(m[0]->pindex);
952 * If the page-aligned write is larger then the actual file we
953 * have to invalidate pages occuring beyond the file EOF. However,
954 * there is an edge case where a file may not be page-aligned where
955 * the last page is partially invalid. In this case the filesystem
956 * may not properly clear the dirty bits for the entire page (which
957 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
958 * With the page locked we are free to fix-up the dirty bits here.
960 * We do not under any circumstances truncate the valid bits, as
961 * this will screw up bogus page replacement.
963 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
964 if (object->un_pager.vnp.vnp_size > poffset) {
967 maxsize = object->un_pager.vnp.vnp_size - poffset;
968 ncount = btoc(maxsize);
969 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
970 vm_page_clear_dirty(m[ncount - 1], pgoff,
977 if (ncount < count) {
978 for (i = ncount; i < count; i++) {
979 rtvals[i] = VM_PAGER_BAD;
985 * pageouts are already clustered, use IO_ASYNC to force a bawrite()
986 * rather then a bdwrite() to prevent paging I/O from saturating
987 * the buffer cache. Dummy-up the sequential heuristic to cause
988 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
989 * the system decides how to cluster.
992 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
994 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
996 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
997 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
999 aiov.iov_base = (caddr_t) 0;
1000 aiov.iov_len = maxsize;
1001 auio.uio_iov = &aiov;
1002 auio.uio_iovcnt = 1;
1003 auio.uio_offset = poffset;
1004 auio.uio_segflg = UIO_NOCOPY;
1005 auio.uio_rw = UIO_WRITE;
1006 auio.uio_resid = maxsize;
1008 error = VOP_WRITE(vp, &auio, ioflags, proc0.p_ucred);
1009 mycpu->gd_cnt.v_vnodeout++;
1010 mycpu->gd_cnt.v_vnodepgsout += ncount;
1013 printf("vnode_pager_putpages: I/O error %d\n", error);
1015 if (auio.uio_resid) {
1016 printf("vnode_pager_putpages: residual I/O %d at %lu\n",
1017 auio.uio_resid, (u_long)m[0]->pindex);
1019 for (i = 0; i < ncount; i++) {
1020 rtvals[i] = VM_PAGER_OK;
1026 vnode_pager_lock(vm_object_t object)
1028 struct thread *td = curthread; /* XXX */
1030 for (; object != NULL; object = object->backing_object) {
1031 if (object->type != OBJT_VNODE)
1033 if (object->flags & OBJ_DEAD)
1036 while (vget(object->handle, NULL,
1037 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, td)) {
1038 if ((object->flags & OBJ_DEAD) ||
1039 (object->type != OBJT_VNODE)) {
1042 printf("vnode_pager_lock: retrying\n");
1044 return object->handle;