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 1.19 2005/06/02 20:57:21 swildner 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>
57 #include <sys/kernel.h>
59 #include <sys/vnode.h>
60 #include <sys/mount.h>
62 #include <sys/vmmeter.h>
64 #include <sys/sfbuf.h>
65 #include <sys/thread2.h>
68 #include <vm/vm_object.h>
69 #include <vm/vm_page.h>
70 #include <vm/vm_pager.h>
71 #include <vm/vm_map.h>
72 #include <vm/vnode_pager.h>
73 #include <vm/vm_extern.h>
75 static vm_offset_t vnode_pager_addr (struct vnode *vp, vm_ooffset_t address,
77 static void vnode_pager_iodone (struct buf *bp);
78 static int vnode_pager_input_smlfs (vm_object_t object, vm_page_t m);
79 static int vnode_pager_input_old (vm_object_t object, vm_page_t m);
80 static void vnode_pager_dealloc (vm_object_t);
81 static int vnode_pager_getpages (vm_object_t, vm_page_t *, int, int);
82 static void vnode_pager_putpages (vm_object_t, vm_page_t *, int, boolean_t, int *);
83 static boolean_t vnode_pager_haspage (vm_object_t, vm_pindex_t, int *, int *);
85 struct pagerops vnodepagerops = {
95 int vnode_pbuf_freecnt = -1; /* start out unlimited */
98 * Allocate (or lookup) pager for a vnode.
99 * Handle is a vnode pointer.
102 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
109 * Pageout to vnode, no can do yet.
115 * XXX hack - This initialization should be put somewhere else.
117 if (vnode_pbuf_freecnt < 0) {
118 vnode_pbuf_freecnt = nswbuf / 2 + 1;
121 vp = (struct vnode *) handle;
124 * Prevent race condition when allocating the object. This
125 * can happen with NFS vnodes since the nfsnode isn't locked.
127 while (vp->v_flag & VOLOCK) {
128 vp->v_flag |= VOWANT;
129 tsleep(vp, 0, "vnpobj", 0);
131 vp->v_flag |= VOLOCK;
134 * If the object is being terminated, wait for it to
137 while (((object = vp->v_object) != NULL) &&
138 (object->flags & OBJ_DEAD)) {
139 tsleep(object, 0, "vadead", 0);
142 if (vp->v_usecount == 0)
143 panic("vnode_pager_alloc: no vnode reference");
145 if (object == NULL) {
147 * And an object of the appropriate size
149 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
152 object->un_pager.vnp.vnp_size = size;
154 object->handle = handle;
155 vp->v_object = object;
162 vp->v_flag &= ~VOLOCK;
163 if (vp->v_flag & VOWANT) {
164 vp->v_flag &= ~VOWANT;
171 vnode_pager_dealloc(vm_object_t object)
173 struct vnode *vp = object->handle;
176 panic("vnode_pager_dealloc: pager already dealloced");
178 vm_object_pip_wait(object, "vnpdea");
180 object->handle = NULL;
181 object->type = OBJT_DEAD;
183 vp->v_flag &= ~(VTEXT | VOBJBUF);
187 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
190 struct vnode *vp = object->handle;
196 int pagesperblock, blocksperpage;
199 * If no vp or vp is doomed or marked transparent to VM, we do not
202 if ((vp == NULL) || (vp->v_flag & VRECLAIMED))
206 * If filesystem no longer mounted or offset beyond end of file we do
209 if ((vp->v_mount == NULL) ||
210 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size))
213 bsize = vp->v_mount->mnt_stat.f_iosize;
214 pagesperblock = bsize / PAGE_SIZE;
216 if (pagesperblock > 0) {
217 reqblock = pindex / pagesperblock;
219 blocksperpage = (PAGE_SIZE / bsize);
220 reqblock = pindex * blocksperpage;
222 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn,
228 if (pagesperblock > 0) {
229 poff = pindex - (reqblock * pagesperblock);
231 *before *= pagesperblock;
236 *after *= pagesperblock;
237 numafter = pagesperblock - (poff + 1);
238 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) {
239 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex)));
245 *before /= blocksperpage;
249 *after /= blocksperpage;
256 * Lets the VM system know about a change in size for a file.
257 * We adjust our own internal size and flush any cached pages in
258 * the associated object that are affected by the size change.
260 * Note: this routine may be invoked as a result of a pager put
261 * operation (possibly at object termination time), so we must be careful.
264 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize)
266 vm_pindex_t nobjsize;
267 vm_object_t object = vp->v_object;
273 * Hasn't changed size
275 if (nsize == object->un_pager.vnp.vnp_size)
278 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
281 * File has shrunk. Toss any cached pages beyond the new EOF.
283 if (nsize < object->un_pager.vnp.vnp_size) {
284 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size);
285 if (nobjsize < object->size) {
286 vm_object_page_remove(object, nobjsize, object->size,
290 * This gets rid of garbage at the end of a page that is now
291 * only partially backed by the vnode. Since we are setting
292 * the entire page valid & clean after we are done we have
293 * to be sure that the portion of the page within the file
294 * bounds is already valid. If it isn't then making it
295 * valid would create a corrupt block.
297 if (nsize & PAGE_MASK) {
301 m = vm_page_lookup(object, OFF_TO_IDX(nsize));
303 int base = (int)nsize & PAGE_MASK;
304 int size = PAGE_SIZE - base;
308 * Clear out partial-page garbage in case
309 * the page has been mapped.
311 sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
312 kva = sf_buf_kva(sf);
313 bzero((caddr_t)kva + base, size);
317 * XXX work around SMP data integrity race
318 * by unmapping the page from user processes.
319 * The garbage we just cleared may be mapped
320 * to a user process running on another cpu
321 * and this code is not running through normal
322 * I/O channels which handle SMP issues for
323 * us, so unmap page to synchronize all cpus.
325 * XXX should vm_pager_unmap_page() have
328 vm_page_protect(m, VM_PROT_NONE);
331 * Clear out partial-page dirty bits. This
332 * has the side effect of setting the valid
333 * bits, but that is ok. There are a bunch
334 * of places in the VM system where we expected
335 * m->dirty == VM_PAGE_BITS_ALL. The file EOF
336 * case is one of them. If the page is still
337 * partially dirty, make it fully dirty.
339 * note that we do not clear out the valid
340 * bits. This would prevent bogus_page
341 * replacement from working properly.
343 vm_page_set_validclean(m, base, size);
345 m->dirty = VM_PAGE_BITS_ALL;
349 object->un_pager.vnp.vnp_size = nsize;
350 object->size = nobjsize;
354 vnode_pager_freepage(vm_page_t m)
360 * calculate the linear (byte) disk address of specified virtual
364 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, int *run)
377 if (vp->v_mount == NULL)
380 bsize = vp->v_mount->mnt_stat.f_iosize;
381 vblock = address / bsize;
382 voffset = address % bsize;
384 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL);
386 if (err || (block == -1))
389 rtaddress = block + voffset / DEV_BSIZE;
392 *run *= bsize/PAGE_SIZE;
393 *run -= voffset/PAGE_SIZE;
401 * interrupt routine for I/O completion
404 vnode_pager_iodone(struct buf *bp)
406 bp->b_flags |= B_DONE;
411 * small block file system vnode pager input
414 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m)
417 struct vnode *dp, *vp;
426 if (vp->v_mount == NULL)
429 bsize = vp->v_mount->mnt_stat.f_iosize;
432 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL);
434 sf = sf_buf_alloc(m, 0);
435 kva = sf_buf_kva(sf);
437 for (i = 0; i < PAGE_SIZE / bsize; i++) {
438 vm_ooffset_t address;
440 if (vm_page_bits(i * bsize, bsize) & m->valid)
443 address = IDX_TO_OFF(m->pindex) + i * bsize;
444 if (address >= object->un_pager.vnp.vnp_size) {
447 fileaddr = vnode_pager_addr(vp, address, NULL);
449 if (fileaddr != -1) {
450 bp = getpbuf(&vnode_pbuf_freecnt);
452 /* build a minimal buffer header */
453 bp->b_flags = B_READ | B_CALL;
454 bp->b_iodone = vnode_pager_iodone;
455 bp->b_data = (caddr_t) kva + i * bsize;
456 bp->b_blkno = fileaddr;
458 bp->b_bcount = bsize;
459 bp->b_bufsize = bsize;
460 bp->b_runningbufspace = bp->b_bufsize;
461 runningbufspace += bp->b_runningbufspace;
464 VOP_STRATEGY(bp->b_vp, bp);
466 /* we definitely need to be at splvm here */
469 while ((bp->b_flags & B_DONE) == 0) {
470 tsleep(bp, 0, "vnsrd", 0);
473 if ((bp->b_flags & B_ERROR) != 0)
477 * free the buffer header back to the swap buffer pool
479 relpbuf(bp, &vnode_pbuf_freecnt);
483 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
485 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
486 bzero((caddr_t) kva + i * bsize, bsize);
490 pmap_clear_modify(m);
491 vm_page_flag_clear(m, PG_ZERO);
493 return VM_PAGER_ERROR;
501 * old style vnode pager output routine
504 vnode_pager_input_old(vm_object_t object, vm_page_t m)
516 * Return failure if beyond current EOF
518 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
522 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
523 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
526 * Allocate a kernel virtual address and initialize so that
527 * we can use VOP_READ/WRITE routines.
529 sf = sf_buf_alloc(m, 0);
530 kva = sf_buf_kva(sf);
532 aiov.iov_base = (caddr_t) kva;
534 auio.uio_iov = &aiov;
536 auio.uio_offset = IDX_TO_OFF(m->pindex);
537 auio.uio_segflg = UIO_SYSSPACE;
538 auio.uio_rw = UIO_READ;
539 auio.uio_resid = size;
540 auio.uio_td = curthread;
542 error = VOP_READ(((struct vnode *)object->handle),
543 &auio, 0, proc0.p_ucred);
545 int count = size - auio.uio_resid;
549 else if (count != PAGE_SIZE)
550 bzero((caddr_t) kva + count, PAGE_SIZE - count);
554 pmap_clear_modify(m);
556 vm_page_flag_clear(m, PG_ZERO);
558 m->valid = VM_PAGE_BITS_ALL;
559 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
563 * generic vnode pager input routine
567 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
568 * implement their own VOP_GETPAGES, their VOP_GETPAGES should call to
569 * vnode_pager_generic_getpages() to implement the previous behaviour.
571 * All other FS's should use the bypass to get to the local media
572 * backing vp's VOP_GETPAGES.
575 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
579 int bytes = count * PAGE_SIZE;
583 * XXX temporary diagnostic message to help track stale FS code,
584 * Returning EOPNOTSUPP from here may make things unhappy.
586 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
587 if (rtval == EOPNOTSUPP) {
588 printf("vnode_pager: *** WARNING *** stale FS getpages\n");
589 rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage);
596 * This is now called from local media FS's to operate against their
597 * own vnodes if they fail to implement VOP_GETPAGES.
600 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
605 off_t foff, tfoff, nextoff;
606 int i, size, bsize, first, firstaddr;
614 object = vp->v_object;
615 count = bytecount / PAGE_SIZE;
617 if (vp->v_mount == NULL)
620 bsize = vp->v_mount->mnt_stat.f_iosize;
622 /* get the UNDERLYING device for the file with VOP_BMAP() */
625 * originally, we did not check for an error return value -- assuming
626 * an fs always has a bmap entry point -- that assumption is wrong!!!
628 foff = IDX_TO_OFF(m[reqpage]->pindex);
631 * if we can't bmap, use old VOP code
633 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) {
634 for (i = 0; i < count; i++) {
636 vnode_pager_freepage(m[i]);
639 mycpu->gd_cnt.v_vnodein++;
640 mycpu->gd_cnt.v_vnodepgsin++;
641 return vnode_pager_input_old(object, m[reqpage]);
644 * if the blocksize is smaller than a page size, then use
645 * special small filesystem code. NFS sometimes has a small
646 * blocksize, but it can handle large reads itself.
648 } else if ((PAGE_SIZE / bsize) > 1 &&
649 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
650 for (i = 0; i < count; i++) {
652 vnode_pager_freepage(m[i]);
655 mycpu->gd_cnt.v_vnodein++;
656 mycpu->gd_cnt.v_vnodepgsin++;
657 return vnode_pager_input_smlfs(object, m[reqpage]);
661 * If we have a completely valid page available to us, we can
662 * clean up and return. Otherwise we have to re-read the
665 * Note that this does not work with NFS, so NFS has its own
666 * getpages routine. The problem is that NFS can have partially
667 * valid pages associated with the buffer cache due to the piecemeal
668 * write support. If we were to fall through and re-read the media
669 * as we do here, dirty data could be lost.
672 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
673 for (i = 0; i < count; i++) {
675 vnode_pager_freepage(m[i]);
679 m[reqpage]->valid = 0;
682 * here on direct device I/O
687 * calculate the run that includes the required page
689 for(first = 0, i = 0; i < count; i = runend) {
690 firstaddr = vnode_pager_addr(vp,
691 IDX_TO_OFF(m[i]->pindex), &runpg);
692 if (firstaddr == -1) {
693 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
694 /* XXX no %qd in kernel. */
695 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx",
696 firstaddr, (u_long)(foff >> 32),
697 (u_long)(u_int32_t)foff,
699 (object->un_pager.vnp.vnp_size >> 32),
701 object->un_pager.vnp.vnp_size);
703 vnode_pager_freepage(m[i]);
709 if (runend <= reqpage) {
711 for (j = i; j < runend; j++) {
712 vnode_pager_freepage(m[j]);
715 if (runpg < (count - first)) {
716 for (i = first + runpg; i < count; i++)
717 vnode_pager_freepage(m[i]);
718 count = first + runpg;
726 * the first and last page have been calculated now, move input pages
727 * to be zero based...
730 for (i = first; i < count; i++) {
738 * calculate the file virtual address for the transfer
740 foff = IDX_TO_OFF(m[0]->pindex);
743 * calculate the size of the transfer
745 size = count * PAGE_SIZE;
746 if ((foff + size) > object->un_pager.vnp.vnp_size)
747 size = object->un_pager.vnp.vnp_size - foff;
750 * round up physical size for real devices.
752 if (dp->v_type == VBLK || dp->v_type == VCHR) {
753 int secmask = dp->v_rdev->si_bsize_phys - 1;
754 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1));
755 size = (size + secmask) & ~secmask;
758 bp = getpbuf(&vnode_pbuf_freecnt);
759 kva = (vm_offset_t) bp->b_data;
762 * and map the pages to be read into the kva
764 pmap_qenter(kva, m, count);
766 /* build a minimal buffer header */
767 bp->b_flags = B_READ | B_CALL;
768 bp->b_iodone = vnode_pager_iodone;
769 /* B_PHYS is not set, but it is nice to fill this in */
770 bp->b_blkno = firstaddr;
773 bp->b_bufsize = size;
774 bp->b_runningbufspace = bp->b_bufsize;
775 runningbufspace += bp->b_runningbufspace;
777 mycpu->gd_cnt.v_vnodein++;
778 mycpu->gd_cnt.v_vnodepgsin += count;
781 VOP_STRATEGY(bp->b_vp, bp);
784 /* we definitely need to be at splvm here */
786 while ((bp->b_flags & B_DONE) == 0) {
787 tsleep(bp, 0, "vnread", 0);
790 if ((bp->b_flags & B_ERROR) != 0)
794 if (size != count * PAGE_SIZE)
795 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
797 pmap_qremove(kva, count);
800 * free the buffer header back to the swap buffer pool
802 relpbuf(bp, &vnode_pbuf_freecnt);
804 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
807 nextoff = tfoff + PAGE_SIZE;
810 if (nextoff <= object->un_pager.vnp.vnp_size) {
812 * Read filled up entire page.
814 mt->valid = VM_PAGE_BITS_ALL;
815 vm_page_undirty(mt); /* should be an assert? XXX */
816 pmap_clear_modify(mt);
819 * Read did not fill up entire page. Since this
820 * is getpages, the page may be mapped, so we have
821 * to zero the invalid portions of the page even
822 * though we aren't setting them valid.
824 * Currently we do not set the entire page valid,
825 * we just try to clear the piece that we couldn't
828 vm_page_set_validclean(mt, 0,
829 object->un_pager.vnp.vnp_size - tfoff);
830 /* handled by vm_fault now */
831 /* vm_page_zero_invalid(mt, FALSE); */
834 vm_page_flag_clear(mt, PG_ZERO);
838 * whether or not to leave the page activated is up in
839 * the air, but we should put the page on a page queue
840 * somewhere. (it already is in the object). Result:
841 * It appears that empirical results show that
842 * deactivating pages is best.
846 * just in case someone was asking for this page we
847 * now tell them that it is ok to use
850 if (mt->flags & PG_WANTED)
851 vm_page_activate(mt);
853 vm_page_deactivate(mt);
856 vnode_pager_freepage(mt);
861 printf("vnode_pager_getpages: I/O read error\n");
863 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
867 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
868 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
869 * vnode_pager_generic_putpages() to implement the previous behaviour.
871 * All other FS's should use the bypass to get to the local media
872 * backing vp's VOP_PUTPAGES.
875 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
876 boolean_t sync, int *rtvals)
880 int bytes = count * PAGE_SIZE;
883 * Force synchronous operation if we are extremely low on memory
884 * to prevent a low-memory deadlock. VOP operations often need to
885 * allocate more memory to initiate the I/O ( i.e. do a BMAP
886 * operation ). The swapper handles the case by limiting the amount
887 * of asynchronous I/O, but that sort of solution doesn't scale well
888 * for the vnode pager without a lot of work.
890 * Also, the backing vnode's iodone routine may not wake the pageout
891 * daemon up. This should be probably be addressed XXX.
894 if ((vmstats.v_free_count + vmstats.v_cache_count) < vmstats.v_pageout_free_min)
898 * Call device-specific putpages function
902 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
903 if (rtval == EOPNOTSUPP) {
904 printf("vnode_pager: *** WARNING *** stale FS putpages\n");
905 rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals);
911 * This is now called from local media FS's to operate against their
912 * own vnodes if they fail to implement VOP_PUTPAGES.
914 * This is typically called indirectly via the pageout daemon and
915 * clustering has already typically occured, so in general we ask the
916 * underlying filesystem to write the data out asynchronously rather
920 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *m, int bytecount,
921 int flags, int *rtvals)
928 vm_ooffset_t poffset;
934 object = vp->v_object;
935 count = bytecount / PAGE_SIZE;
937 for (i = 0; i < count; i++)
938 rtvals[i] = VM_PAGER_AGAIN;
940 if ((int) m[0]->pindex < 0) {
941 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n",
942 (long)m[0]->pindex, m[0]->dirty);
943 rtvals[0] = VM_PAGER_BAD;
947 maxsize = count * PAGE_SIZE;
950 poffset = IDX_TO_OFF(m[0]->pindex);
953 * If the page-aligned write is larger then the actual file we
954 * have to invalidate pages occuring beyond the file EOF. However,
955 * there is an edge case where a file may not be page-aligned where
956 * the last page is partially invalid. In this case the filesystem
957 * may not properly clear the dirty bits for the entire page (which
958 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
959 * With the page locked we are free to fix-up the dirty bits here.
961 * We do not under any circumstances truncate the valid bits, as
962 * this will screw up bogus page replacement.
964 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
965 if (object->un_pager.vnp.vnp_size > poffset) {
968 maxsize = object->un_pager.vnp.vnp_size - poffset;
969 ncount = btoc(maxsize);
970 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
971 vm_page_clear_dirty(m[ncount - 1], pgoff,
978 if (ncount < count) {
979 for (i = ncount; i < count; i++) {
980 rtvals[i] = VM_PAGER_BAD;
986 * pageouts are already clustered, use IO_ASYNC to force a bawrite()
987 * rather then a bdwrite() to prevent paging I/O from saturating
988 * the buffer cache. Dummy-up the sequential heuristic to cause
989 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
990 * the system decides how to cluster.
993 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
995 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
997 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
998 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1000 aiov.iov_base = (caddr_t) 0;
1001 aiov.iov_len = maxsize;
1002 auio.uio_iov = &aiov;
1003 auio.uio_iovcnt = 1;
1004 auio.uio_offset = poffset;
1005 auio.uio_segflg = UIO_NOCOPY;
1006 auio.uio_rw = UIO_WRITE;
1007 auio.uio_resid = maxsize;
1009 error = VOP_WRITE(vp, &auio, ioflags, proc0.p_ucred);
1010 mycpu->gd_cnt.v_vnodeout++;
1011 mycpu->gd_cnt.v_vnodepgsout += ncount;
1014 printf("vnode_pager_putpages: I/O error %d\n", error);
1016 if (auio.uio_resid) {
1017 printf("vnode_pager_putpages: residual I/O %d at %lu\n",
1018 auio.uio_resid, (u_long)m[0]->pindex);
1020 for (i = 0; i < ncount; i++) {
1021 rtvals[i] = VM_PAGER_OK;
1027 vnode_pager_lock(vm_object_t object)
1029 struct thread *td = curthread; /* XXX */
1032 for (; object != NULL; object = object->backing_object) {
1033 if (object->type != OBJT_VNODE)
1035 if (object->flags & OBJ_DEAD)
1039 struct vnode *vp = object->handle;
1040 error = vget(vp, LK_NOPAUSE | LK_SHARED |
1041 LK_RETRY | LK_CANRECURSE, td);
1043 if (object->handle != vp) {
1049 if ((object->flags & OBJ_DEAD) ||
1050 (object->type != OBJT_VNODE)) {
1053 printf("vnode_pager_lock: vp %p error %d lockstatus %d, retrying\n", vp, error, lockstatus(&vp->v_lock, td));
1054 tsleep(object->handle, 0, "vnpgrl", hz);