Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / vm / vnode_pager.c
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1/*
2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
4 * All rights reserved.
5 * Copyright (c) 1993, 1994 John S. Dyson
6 * Copyright (c) 1995, David Greenman
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
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.
27 *
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
38 * SUCH DAMAGE.
39 *
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 */
43
44/*
45 * Page to/from files (vnodes).
46 */
47
48/*
49 * TODO:
50 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
51 * greatly re-simplify the vnode_pager.
52 */
53
54#include <sys/param.h>
55#include <sys/systm.h>
56#include <sys/proc.h>
57#include <sys/vnode.h>
58#include <sys/mount.h>
59#include <sys/buf.h>
60#include <sys/vmmeter.h>
61#include <sys/conf.h>
62
63#include <vm/vm.h>
64#include <vm/vm_object.h>
65#include <vm/vm_page.h>
66#include <vm/vm_pager.h>
67#include <vm/vm_map.h>
68#include <vm/vnode_pager.h>
69#include <vm/vm_extern.h>
70
71static vm_offset_t vnode_pager_addr __P((struct vnode *vp, vm_ooffset_t address,
72 int *run));
73static void vnode_pager_iodone __P((struct buf *bp));
74static int vnode_pager_input_smlfs __P((vm_object_t object, vm_page_t m));
75static int vnode_pager_input_old __P((vm_object_t object, vm_page_t m));
76static void vnode_pager_dealloc __P((vm_object_t));
77static int vnode_pager_getpages __P((vm_object_t, vm_page_t *, int, int));
78static void vnode_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *));
79static boolean_t vnode_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *));
80
81struct pagerops vnodepagerops = {
82 NULL,
83 vnode_pager_alloc,
84 vnode_pager_dealloc,
85 vnode_pager_getpages,
86 vnode_pager_putpages,
87 vnode_pager_haspage,
88 NULL
89};
90
91int vnode_pbuf_freecnt = -1; /* start out unlimited */
92
93/*
94 * Allocate (or lookup) pager for a vnode.
95 * Handle is a vnode pointer.
96 */
97vm_object_t
98vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
99 vm_ooffset_t offset)
100{
101 vm_object_t object;
102 struct vnode *vp;
103
104 /*
105 * Pageout to vnode, no can do yet.
106 */
107 if (handle == NULL)
108 return (NULL);
109
110 /*
111 * XXX hack - This initialization should be put somewhere else.
112 */
113 if (vnode_pbuf_freecnt < 0) {
114 vnode_pbuf_freecnt = nswbuf / 2 + 1;
115 }
116
117 vp = (struct vnode *) handle;
118
119 /*
120 * Prevent race condition when allocating the object. This
121 * can happen with NFS vnodes since the nfsnode isn't locked.
122 */
123 while (vp->v_flag & VOLOCK) {
124 vp->v_flag |= VOWANT;
125 tsleep(vp, PVM, "vnpobj", 0);
126 }
127 vp->v_flag |= VOLOCK;
128
129 /*
130 * If the object is being terminated, wait for it to
131 * go away.
132 */
133 while (((object = vp->v_object) != NULL) &&
134 (object->flags & OBJ_DEAD)) {
135 tsleep(object, PVM, "vadead", 0);
136 }
137
138 if (vp->v_usecount == 0)
139 panic("vnode_pager_alloc: no vnode reference");
140
141 if (object == NULL) {
142 /*
143 * And an object of the appropriate size
144 */
145 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
146 object->flags = 0;
147
148 object->un_pager.vnp.vnp_size = size;
149
150 object->handle = handle;
151 vp->v_object = object;
152 vp->v_usecount++;
153 } else {
154 object->ref_count++;
155 vp->v_usecount++;
156 }
157
158 vp->v_flag &= ~VOLOCK;
159 if (vp->v_flag & VOWANT) {
160 vp->v_flag &= ~VOWANT;
161 wakeup(vp);
162 }
163 return (object);
164}
165
166static void
167vnode_pager_dealloc(object)
168 vm_object_t object;
169{
170 register struct vnode *vp = object->handle;
171
172 if (vp == NULL)
173 panic("vnode_pager_dealloc: pager already dealloced");
174
175 vm_object_pip_wait(object, "vnpdea");
176
177 object->handle = NULL;
178 object->type = OBJT_DEAD;
179 vp->v_object = NULL;
180 vp->v_flag &= ~(VTEXT | VOBJBUF);
181}
182
183static boolean_t
184vnode_pager_haspage(object, pindex, before, after)
185 vm_object_t object;
186 vm_pindex_t pindex;
187 int *before;
188 int *after;
189{
190 struct vnode *vp = object->handle;
191 daddr_t bn;
192 int err;
193 daddr_t reqblock;
194 int poff;
195 int bsize;
196 int pagesperblock, blocksperpage;
197
198 /*
199 * If no vp or vp is doomed or marked transparent to VM, we do not
200 * have the page.
201 */
202 if ((vp == NULL) || (vp->v_flag & VDOOMED))
203 return FALSE;
204
205 /*
206 * If filesystem no longer mounted or offset beyond end of file we do
207 * not have the page.
208 */
209 if ((vp->v_mount == NULL) ||
210 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size))
211 return FALSE;
212
213 bsize = vp->v_mount->mnt_stat.f_iosize;
214 pagesperblock = bsize / PAGE_SIZE;
215 blocksperpage = 0;
216 if (pagesperblock > 0) {
217 reqblock = pindex / pagesperblock;
218 } else {
219 blocksperpage = (PAGE_SIZE / bsize);
220 reqblock = pindex * blocksperpage;
221 }
222 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn,
223 after, before);
224 if (err)
225 return TRUE;
226 if ( bn == -1)
227 return FALSE;
228 if (pagesperblock > 0) {
229 poff = pindex - (reqblock * pagesperblock);
230 if (before) {
231 *before *= pagesperblock;
232 *before += poff;
233 }
234 if (after) {
235 int numafter;
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)));
240 }
241 *after += numafter;
242 }
243 } else {
244 if (before) {
245 *before /= blocksperpage;
246 }
247
248 if (after) {
249 *after /= blocksperpage;
250 }
251 }
252 return TRUE;
253}
254
255/*
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.
259 *
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.
262 */
263void
264vnode_pager_setsize(vp, nsize)
265 struct vnode *vp;
266 vm_ooffset_t nsize;
267{
268 vm_pindex_t nobjsize;
269 vm_object_t object = vp->v_object;
270
271 if (object == NULL)
272 return;
273
274 /*
275 * Hasn't changed size
276 */
277 if (nsize == object->un_pager.vnp.vnp_size)
278 return;
279
280 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
281
282 /*
283 * File has shrunk. Toss any cached pages beyond the new EOF.
284 */
285 if (nsize < object->un_pager.vnp.vnp_size) {
286 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size);
287 if (nobjsize < object->size) {
288 vm_object_page_remove(object, nobjsize, object->size,
289 FALSE);
290 }
291 /*
292 * this gets rid of garbage at the end of a page that is now
293 * only partially backed by the vnode.
294 *
295 * XXX for some reason (I don't know yet), if we take a
296 * completely invalid page and mark it partially valid
297 * it can screw up NFS reads, so we don't allow the case.
298 */
299 if (nsize & PAGE_MASK) {
300 vm_offset_t kva;
301 vm_page_t m;
302
303 m = vm_page_lookup(object, OFF_TO_IDX(nsize));
304 if (m && m->valid) {
305 int base = (int)nsize & PAGE_MASK;
306 int size = PAGE_SIZE - base;
307
308 /*
309 * Clear out partial-page garbage in case
310 * the page has been mapped.
311 */
312 kva = vm_pager_map_page(m);
313 bzero((caddr_t)kva + base, size);
314 vm_pager_unmap_page(kva);
315
316 /*
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.
324 *
325 * XXX should vm_pager_unmap_page() have
326 * dealt with this?
327 */
328 vm_page_protect(m, VM_PROT_NONE);
329
330 /*
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.
338 *
339 * note that we do not clear out the valid
340 * bits. This would prevent bogus_page
341 * replacement from working properly.
342 */
343 vm_page_set_validclean(m, base, size);
344 if (m->dirty != 0)
345 m->dirty = VM_PAGE_BITS_ALL;
346 }
347 }
348 }
349 object->un_pager.vnp.vnp_size = nsize;
350 object->size = nobjsize;
351}
352
353void
354vnode_pager_freepage(m)
355 vm_page_t m;
356{
357 vm_page_free(m);
358}
359
360/*
361 * calculate the linear (byte) disk address of specified virtual
362 * file address
363 */
364static vm_offset_t
365vnode_pager_addr(vp, address, run)
366 struct vnode *vp;
367 vm_ooffset_t address;
368 int *run;
369{
370 int rtaddress;
371 int bsize;
372 daddr_t block;
373 struct vnode *rtvp;
374 int err;
375 daddr_t vblock;
376 int voffset;
377
378 if ((int) address < 0)
379 return -1;
380
381 if (vp->v_mount == NULL)
382 return -1;
383
384 bsize = vp->v_mount->mnt_stat.f_iosize;
385 vblock = address / bsize;
386 voffset = address % bsize;
387
388 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL);
389
390 if (err || (block == -1))
391 rtaddress = -1;
392 else {
393 rtaddress = block + voffset / DEV_BSIZE;
394 if( run) {
395 *run += 1;
396 *run *= bsize/PAGE_SIZE;
397 *run -= voffset/PAGE_SIZE;
398 }
399 }
400
401 return rtaddress;
402}
403
404/*
405 * interrupt routine for I/O completion
406 */
407static void
408vnode_pager_iodone(bp)
409 struct buf *bp;
410{
411 bp->b_flags |= B_DONE;
412 wakeup(bp);
413}
414
415/*
416 * small block file system vnode pager input
417 */
418static int
419vnode_pager_input_smlfs(object, m)
420 vm_object_t object;
421 vm_page_t m;
422{
423 int i;
424 int s;
425 struct vnode *dp, *vp;
426 struct buf *bp;
427 vm_offset_t kva;
428 int fileaddr;
429 vm_offset_t bsize;
430 int error = 0;
431
432 vp = object->handle;
433 if (vp->v_mount == NULL)
434 return VM_PAGER_BAD;
435
436 bsize = vp->v_mount->mnt_stat.f_iosize;
437
438
439 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL);
440
441 kva = vm_pager_map_page(m);
442
443 for (i = 0; i < PAGE_SIZE / bsize; i++) {
444 vm_ooffset_t address;
445
446 if (vm_page_bits(i * bsize, bsize) & m->valid)
447 continue;
448
449 address = IDX_TO_OFF(m->pindex) + i * bsize;
450 if (address >= object->un_pager.vnp.vnp_size) {
451 fileaddr = -1;
452 } else {
453 fileaddr = vnode_pager_addr(vp, address, NULL);
454 }
455 if (fileaddr != -1) {
456 bp = getpbuf(&vnode_pbuf_freecnt);
457
458 /* build a minimal buffer header */
459 bp->b_flags = B_READ | B_CALL;
460 bp->b_iodone = vnode_pager_iodone;
461 bp->b_rcred = bp->b_wcred = curproc->p_ucred;
462 if (bp->b_rcred != NOCRED)
463 crhold(bp->b_rcred);
464 if (bp->b_wcred != NOCRED)
465 crhold(bp->b_wcred);
466 bp->b_data = (caddr_t) kva + i * bsize;
467 bp->b_blkno = fileaddr;
468 pbgetvp(dp, bp);
469 bp->b_bcount = bsize;
470 bp->b_bufsize = bsize;
471 bp->b_runningbufspace = bp->b_bufsize;
472 runningbufspace += bp->b_runningbufspace;
473
474 /* do the input */
475 VOP_STRATEGY(bp->b_vp, bp);
476
477 /* we definitely need to be at splvm here */
478
479 s = splvm();
480 while ((bp->b_flags & B_DONE) == 0) {
481 tsleep(bp, PVM, "vnsrd", 0);
482 }
483 splx(s);
484 if ((bp->b_flags & B_ERROR) != 0)
485 error = EIO;
486
487 /*
488 * free the buffer header back to the swap buffer pool
489 */
490 relpbuf(bp, &vnode_pbuf_freecnt);
491 if (error)
492 break;
493
494 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
495 } else {
496 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
497 bzero((caddr_t) kva + i * bsize, bsize);
498 }
499 }
500 vm_pager_unmap_page(kva);
501 pmap_clear_modify(m);
502 vm_page_flag_clear(m, PG_ZERO);
503 if (error) {
504 return VM_PAGER_ERROR;
505 }
506 return VM_PAGER_OK;
507
508}
509
510
511/*
512 * old style vnode pager output routine
513 */
514static int
515vnode_pager_input_old(object, m)
516 vm_object_t object;
517 vm_page_t m;
518{
519 struct uio auio;
520 struct iovec aiov;
521 int error;
522 int size;
523 vm_offset_t kva;
524
525 error = 0;
526
527 /*
528 * Return failure if beyond current EOF
529 */
530 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
531 return VM_PAGER_BAD;
532 } else {
533 size = PAGE_SIZE;
534 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
535 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
536
537 /*
538 * Allocate a kernel virtual address and initialize so that
539 * we can use VOP_READ/WRITE routines.
540 */
541 kva = vm_pager_map_page(m);
542
543 aiov.iov_base = (caddr_t) kva;
544 aiov.iov_len = size;
545 auio.uio_iov = &aiov;
546 auio.uio_iovcnt = 1;
547 auio.uio_offset = IDX_TO_OFF(m->pindex);
548 auio.uio_segflg = UIO_SYSSPACE;
549 auio.uio_rw = UIO_READ;
550 auio.uio_resid = size;
551 auio.uio_procp = curproc;
552
553 error = VOP_READ(object->handle, &auio, 0, curproc->p_ucred);
554 if (!error) {
555 register int count = size - auio.uio_resid;
556
557 if (count == 0)
558 error = EINVAL;
559 else if (count != PAGE_SIZE)
560 bzero((caddr_t) kva + count, PAGE_SIZE - count);
561 }
562 vm_pager_unmap_page(kva);
563 }
564 pmap_clear_modify(m);
565 vm_page_undirty(m);
566 vm_page_flag_clear(m, PG_ZERO);
567 if (!error)
568 m->valid = VM_PAGE_BITS_ALL;
569 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
570}
571
572/*
573 * generic vnode pager input routine
574 */
575
576/*
577 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
578 * implement their own VOP_GETPAGES, their VOP_GETPAGES should call to
579 * vnode_pager_generic_getpages() to implement the previous behaviour.
580 *
581 * All other FS's should use the bypass to get to the local media
582 * backing vp's VOP_GETPAGES.
583 */
584static int
585vnode_pager_getpages(object, m, count, reqpage)
586 vm_object_t object;
587 vm_page_t *m;
588 int count;
589 int reqpage;
590{
591 int rtval;
592 struct vnode *vp;
593 int bytes = count * PAGE_SIZE;
594
595 vp = object->handle;
596 /*
597 * XXX temporary diagnostic message to help track stale FS code,
598 * Returning EOPNOTSUPP from here may make things unhappy.
599 */
600 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
601 if (rtval == EOPNOTSUPP) {
602 printf("vnode_pager: *** WARNING *** stale FS getpages\n");
603 rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage);
604 }
605 return rtval;
606}
607
608
609/*
610 * This is now called from local media FS's to operate against their
611 * own vnodes if they fail to implement VOP_GETPAGES.
612 */
613int
614vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
615 struct vnode *vp;
616 vm_page_t *m;
617 int bytecount;
618 int reqpage;
619{
620 vm_object_t object;
621 vm_offset_t kva;
622 off_t foff, tfoff, nextoff;
623 int i, size, bsize, first, firstaddr;
624 struct vnode *dp;
625 int runpg;
626 int runend;
627 struct buf *bp;
628 int s;
629 int count;
630 int error = 0;
631
632 object = vp->v_object;
633 count = bytecount / PAGE_SIZE;
634
635 if (vp->v_mount == NULL)
636 return VM_PAGER_BAD;
637
638 bsize = vp->v_mount->mnt_stat.f_iosize;
639
640 /* get the UNDERLYING device for the file with VOP_BMAP() */
641
642 /*
643 * originally, we did not check for an error return value -- assuming
644 * an fs always has a bmap entry point -- that assumption is wrong!!!
645 */
646 foff = IDX_TO_OFF(m[reqpage]->pindex);
647
648 /*
649 * if we can't bmap, use old VOP code
650 */
651 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) {
652 for (i = 0; i < count; i++) {
653 if (i != reqpage) {
654 vnode_pager_freepage(m[i]);
655 }
656 }
657 cnt.v_vnodein++;
658 cnt.v_vnodepgsin++;
659 return vnode_pager_input_old(object, m[reqpage]);
660
661 /*
662 * if the blocksize is smaller than a page size, then use
663 * special small filesystem code. NFS sometimes has a small
664 * blocksize, but it can handle large reads itself.
665 */
666 } else if ((PAGE_SIZE / bsize) > 1 &&
667 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
668 for (i = 0; i < count; i++) {
669 if (i != reqpage) {
670 vnode_pager_freepage(m[i]);
671 }
672 }
673 cnt.v_vnodein++;
674 cnt.v_vnodepgsin++;
675 return vnode_pager_input_smlfs(object, m[reqpage]);
676 }
677
678 /*
679 * If we have a completely valid page available to us, we can
680 * clean up and return. Otherwise we have to re-read the
681 * media.
682 */
683
684 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
685 for (i = 0; i < count; i++) {
686 if (i != reqpage)
687 vnode_pager_freepage(m[i]);
688 }
689 return VM_PAGER_OK;
690 }
691 m[reqpage]->valid = 0;
692
693 /*
694 * here on direct device I/O
695 */
696
697 firstaddr = -1;
698 /*
699 * calculate the run that includes the required page
700 */
701 for(first = 0, i = 0; i < count; i = runend) {
702 firstaddr = vnode_pager_addr(vp,
703 IDX_TO_OFF(m[i]->pindex), &runpg);
704 if (firstaddr == -1) {
705 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
706 /* XXX no %qd in kernel. */
707 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx",
708 firstaddr, (u_long)(foff >> 32),
709 (u_long)(u_int32_t)foff,
710 (u_long)(u_int32_t)
711 (object->un_pager.vnp.vnp_size >> 32),
712 (u_long)(u_int32_t)
713 object->un_pager.vnp.vnp_size);
714 }
715 vnode_pager_freepage(m[i]);
716 runend = i + 1;
717 first = runend;
718 continue;
719 }
720 runend = i + runpg;
721 if (runend <= reqpage) {
722 int j;
723 for (j = i; j < runend; j++) {
724 vnode_pager_freepage(m[j]);
725 }
726 } else {
727 if (runpg < (count - first)) {
728 for (i = first + runpg; i < count; i++)
729 vnode_pager_freepage(m[i]);
730 count = first + runpg;
731 }
732 break;
733 }
734 first = runend;
735 }
736
737 /*
738 * the first and last page have been calculated now, move input pages
739 * to be zero based...
740 */
741 if (first != 0) {
742 for (i = first; i < count; i++) {
743 m[i - first] = m[i];
744 }
745 count -= first;
746 reqpage -= first;
747 }
748
749 /*
750 * calculate the file virtual address for the transfer
751 */
752 foff = IDX_TO_OFF(m[0]->pindex);
753
754 /*
755 * calculate the size of the transfer
756 */
757 size = count * PAGE_SIZE;
758 if ((foff + size) > object->un_pager.vnp.vnp_size)
759 size = object->un_pager.vnp.vnp_size - foff;
760
761 /*
762 * round up physical size for real devices.
763 */
764 if (dp->v_type == VBLK || dp->v_type == VCHR) {
765 int secmask = dp->v_rdev->si_bsize_phys - 1;
766 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1));
767 size = (size + secmask) & ~secmask;
768 }
769
770 bp = getpbuf(&vnode_pbuf_freecnt);
771 kva = (vm_offset_t) bp->b_data;
772
773 /*
774 * and map the pages to be read into the kva
775 */
776 pmap_qenter(kva, m, count);
777
778 /* build a minimal buffer header */
779 bp->b_flags = B_READ | B_CALL;
780 bp->b_iodone = vnode_pager_iodone;
781 /* B_PHYS is not set, but it is nice to fill this in */
782 bp->b_rcred = bp->b_wcred = curproc->p_ucred;
783 if (bp->b_rcred != NOCRED)
784 crhold(bp->b_rcred);
785 if (bp->b_wcred != NOCRED)
786 crhold(bp->b_wcred);
787 bp->b_blkno = firstaddr;
788 pbgetvp(dp, bp);
789 bp->b_bcount = size;
790 bp->b_bufsize = size;
791 bp->b_runningbufspace = bp->b_bufsize;
792 runningbufspace += bp->b_runningbufspace;
793
794 cnt.v_vnodein++;
795 cnt.v_vnodepgsin += count;
796
797 /* do the input */
798 VOP_STRATEGY(bp->b_vp, bp);
799
800 s = splvm();
801 /* we definitely need to be at splvm here */
802
803 while ((bp->b_flags & B_DONE) == 0) {
804 tsleep(bp, PVM, "vnread", 0);
805 }
806 splx(s);
807 if ((bp->b_flags & B_ERROR) != 0)
808 error = EIO;
809
810 if (!error) {
811 if (size != count * PAGE_SIZE)
812 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
813 }
814 pmap_qremove(kva, count);
815
816 /*
817 * free the buffer header back to the swap buffer pool
818 */
819 relpbuf(bp, &vnode_pbuf_freecnt);
820
821 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
822 vm_page_t mt;
823
824 nextoff = tfoff + PAGE_SIZE;
825 mt = m[i];
826
827 if (nextoff <= object->un_pager.vnp.vnp_size) {
828 /*
829 * Read filled up entire page.
830 */
831 mt->valid = VM_PAGE_BITS_ALL;
832 vm_page_undirty(mt); /* should be an assert? XXX */
833 pmap_clear_modify(mt);
834 } else {
835 /*
836 * Read did not fill up entire page. Since this
837 * is getpages, the page may be mapped, so we have
838 * to zero the invalid portions of the page even
839 * though we aren't setting them valid.
840 *
841 * Currently we do not set the entire page valid,
842 * we just try to clear the piece that we couldn't
843 * read.
844 */
845 vm_page_set_validclean(mt, 0,
846 object->un_pager.vnp.vnp_size - tfoff);
847 /* handled by vm_fault now */
848 /* vm_page_zero_invalid(mt, FALSE); */
849 }
850
851 vm_page_flag_clear(mt, PG_ZERO);
852 if (i != reqpage) {
853
854 /*
855 * whether or not to leave the page activated is up in
856 * the air, but we should put the page on a page queue
857 * somewhere. (it already is in the object). Result:
858 * It appears that empirical results show that
859 * deactivating pages is best.
860 */
861
862 /*
863 * just in case someone was asking for this page we
864 * now tell them that it is ok to use
865 */
866 if (!error) {
867 if (mt->flags & PG_WANTED)
868 vm_page_activate(mt);
869 else
870 vm_page_deactivate(mt);
871 vm_page_wakeup(mt);
872 } else {
873 vnode_pager_freepage(mt);
874 }
875 }
876 }
877 if (error) {
878 printf("vnode_pager_getpages: I/O read error\n");
879 }
880 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
881}
882
883/*
884 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
885 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
886 * vnode_pager_generic_putpages() to implement the previous behaviour.
887 *
888 * All other FS's should use the bypass to get to the local media
889 * backing vp's VOP_PUTPAGES.
890 */
891static void
892vnode_pager_putpages(object, m, count, sync, rtvals)
893 vm_object_t object;
894 vm_page_t *m;
895 int count;
896 boolean_t sync;
897 int *rtvals;
898{
899 int rtval;
900 struct vnode *vp;
901 int bytes = count * PAGE_SIZE;
902
903 /*
904 * Force synchronous operation if we are extremely low on memory
905 * to prevent a low-memory deadlock. VOP operations often need to
906 * allocate more memory to initiate the I/O ( i.e. do a BMAP
907 * operation ). The swapper handles the case by limiting the amount
908 * of asynchronous I/O, but that sort of solution doesn't scale well
909 * for the vnode pager without a lot of work.
910 *
911 * Also, the backing vnode's iodone routine may not wake the pageout
912 * daemon up. This should be probably be addressed XXX.
913 */
914
915 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min)
916 sync |= OBJPC_SYNC;
917
918 /*
919 * Call device-specific putpages function
920 */
921
922 vp = object->handle;
923 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
924 if (rtval == EOPNOTSUPP) {
925 printf("vnode_pager: *** WARNING *** stale FS putpages\n");
926 rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals);
927 }
928}
929
930
931/*
932 * This is now called from local media FS's to operate against their
933 * own vnodes if they fail to implement VOP_PUTPAGES.
934 *
935 * This is typically called indirectly via the pageout daemon and
936 * clustering has already typically occured, so in general we ask the
937 * underlying filesystem to write the data out asynchronously rather
938 * then delayed.
939 */
940int
941vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals)
942 struct vnode *vp;
943 vm_page_t *m;
944 int bytecount;
945 int flags;
946 int *rtvals;
947{
948 int i;
949 vm_object_t object;
950 int count;
951
952 int maxsize, ncount;
953 vm_ooffset_t poffset;
954 struct uio auio;
955 struct iovec aiov;
956 int error;
957 int ioflags;
958
959 object = vp->v_object;
960 count = bytecount / PAGE_SIZE;
961
962 for (i = 0; i < count; i++)
963 rtvals[i] = VM_PAGER_AGAIN;
964
965 if ((int) m[0]->pindex < 0) {
966 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n",
967 (long)m[0]->pindex, m[0]->dirty);
968 rtvals[0] = VM_PAGER_BAD;
969 return VM_PAGER_BAD;
970 }
971
972 maxsize = count * PAGE_SIZE;
973 ncount = count;
974
975 poffset = IDX_TO_OFF(m[0]->pindex);
976
977 /*
978 * If the page-aligned write is larger then the actual file we
979 * have to invalidate pages occuring beyond the file EOF. However,
980 * there is an edge case where a file may not be page-aligned where
981 * the last page is partially invalid. In this case the filesystem
982 * may not properly clear the dirty bits for the entire page (which
983 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
984 * With the page locked we are free to fix-up the dirty bits here.
985 *
986 * We do not under any circumstances truncate the valid bits, as
987 * this will screw up bogus page replacement.
988 */
989 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
990 if (object->un_pager.vnp.vnp_size > poffset) {
991 int pgoff;
992
993 maxsize = object->un_pager.vnp.vnp_size - poffset;
994 ncount = btoc(maxsize);
995 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
996 vm_page_clear_dirty(m[ncount - 1], pgoff,
997 PAGE_SIZE - pgoff);
998 }
999 } else {
1000 maxsize = 0;
1001 ncount = 0;
1002 }
1003 if (ncount < count) {
1004 for (i = ncount; i < count; i++) {
1005 rtvals[i] = VM_PAGER_BAD;
1006 }
1007 }
1008 }
1009
1010 /*
1011 * pageouts are already clustered, use IO_ASYNC to force a bawrite()
1012 * rather then a bdwrite() to prevent paging I/O from saturating
1013 * the buffer cache. Dummy-up the sequential heuristic to cause
1014 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
1015 * the system decides how to cluster.
1016 */
1017 ioflags = IO_VMIO;
1018 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1019 ioflags |= IO_SYNC;
1020 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1021 ioflags |= IO_ASYNC;
1022 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1023 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1024
1025 aiov.iov_base = (caddr_t) 0;
1026 aiov.iov_len = maxsize;
1027 auio.uio_iov = &aiov;
1028 auio.uio_iovcnt = 1;
1029 auio.uio_offset = poffset;
1030 auio.uio_segflg = UIO_NOCOPY;
1031 auio.uio_rw = UIO_WRITE;
1032 auio.uio_resid = maxsize;
1033 auio.uio_procp = (struct proc *) 0;
1034 error = VOP_WRITE(vp, &auio, ioflags, curproc->p_ucred);
1035 cnt.v_vnodeout++;
1036 cnt.v_vnodepgsout += ncount;
1037
1038 if (error) {
1039 printf("vnode_pager_putpages: I/O error %d\n", error);
1040 }
1041 if (auio.uio_resid) {
1042 printf("vnode_pager_putpages: residual I/O %d at %lu\n",
1043 auio.uio_resid, (u_long)m[0]->pindex);
1044 }
1045 for (i = 0; i < ncount; i++) {
1046 rtvals[i] = VM_PAGER_OK;
1047 }
1048 return rtvals[0];
1049}
1050
1051struct vnode *
1052vnode_pager_lock(object)
1053 vm_object_t object;
1054{
1055 struct proc *p = curproc; /* XXX */
1056
1057 for (; object != NULL; object = object->backing_object) {
1058 if (object->type != OBJT_VNODE)
1059 continue;
1060 if (object->flags & OBJ_DEAD)
1061 return NULL;
1062
1063 while (vget(object->handle,
1064 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, p)) {
1065 if ((object->flags & OBJ_DEAD) || (object->type != OBJT_VNODE))
1066 return NULL;
1067 printf("vnode_pager_lock: retrying\n");
1068 }
1069 return object->handle;
1070 }
1071 return NULL;
1072}