FreeBSD/Linux Kernel Cross Reference
sys/vm/vnode_pager.c
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 */
42
43 /*
44 * Page to/from files (vnodes).
45 */
46
47 /*
48 * TODO:
49 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
50 * greatly re-simplify the vnode_pager.
51 */
52
53 #include <sys/cdefs.h>
54 __FBSDID("$FreeBSD$");
55
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/proc.h>
59 #include <sys/vnode.h>
60 #include <sys/mount.h>
61 #include <sys/bio.h>
62 #include <sys/buf.h>
63 #include <sys/vmmeter.h>
64 #include <sys/limits.h>
65 #include <sys/conf.h>
66 #include <sys/sf_buf.h>
67
68 #include <machine/atomic.h>
69
70 #include <vm/vm.h>
71 #include <vm/vm_object.h>
72 #include <vm/vm_page.h>
73 #include <vm/vm_pager.h>
74 #include <vm/vm_map.h>
75 #include <vm/vnode_pager.h>
76 #include <vm/vm_extern.h>
77
78 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
79 daddr_t *rtaddress, int *run);
80 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
81 static int vnode_pager_input_old(vm_object_t object, vm_page_t m);
82 static void vnode_pager_dealloc(vm_object_t);
83 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int);
84 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *);
85 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
86 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
87 vm_ooffset_t, struct ucred *cred);
88
89 struct pagerops vnodepagerops = {
90 .pgo_alloc = vnode_pager_alloc,
91 .pgo_dealloc = vnode_pager_dealloc,
92 .pgo_getpages = vnode_pager_getpages,
93 .pgo_putpages = vnode_pager_putpages,
94 .pgo_haspage = vnode_pager_haspage,
95 };
96
97 int vnode_pbuf_freecnt;
98
99 /* Create the VM system backing object for this vnode */
100 int
101 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
102 {
103 vm_object_t object;
104 vm_ooffset_t size = isize;
105 struct vattr va;
106
107 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
108 return (0);
109
110 while ((object = vp->v_object) != NULL) {
111 VM_OBJECT_LOCK(object);
112 if (!(object->flags & OBJ_DEAD)) {
113 VM_OBJECT_UNLOCK(object);
114 return (0);
115 }
116 VOP_UNLOCK(vp, 0);
117 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
118 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0);
119 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
120 }
121
122 if (size == 0) {
123 if (vn_isdisk(vp, NULL)) {
124 size = IDX_TO_OFF(INT_MAX);
125 } else {
126 if (VOP_GETATTR(vp, &va, td->td_ucred))
127 return (0);
128 size = va.va_size;
129 }
130 }
131
132 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
133 /*
134 * Dereference the reference we just created. This assumes
135 * that the object is associated with the vp.
136 */
137 VM_OBJECT_LOCK(object);
138 object->ref_count--;
139 VM_OBJECT_UNLOCK(object);
140 vrele(vp);
141
142 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
143
144 return (0);
145 }
146
147 void
148 vnode_destroy_vobject(struct vnode *vp)
149 {
150 struct vm_object *obj;
151
152 obj = vp->v_object;
153 if (obj == NULL)
154 return;
155 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
156 VM_OBJECT_LOCK(obj);
157 if (obj->ref_count == 0) {
158 /*
159 * vclean() may be called twice. The first time
160 * removes the primary reference to the object,
161 * the second time goes one further and is a
162 * special-case to terminate the object.
163 *
164 * don't double-terminate the object
165 */
166 if ((obj->flags & OBJ_DEAD) == 0)
167 vm_object_terminate(obj);
168 else
169 VM_OBJECT_UNLOCK(obj);
170 } else {
171 /*
172 * Woe to the process that tries to page now :-).
173 */
174 vm_pager_deallocate(obj);
175 VM_OBJECT_UNLOCK(obj);
176 }
177 vp->v_object = NULL;
178 }
179
180
181 /*
182 * Allocate (or lookup) pager for a vnode.
183 * Handle is a vnode pointer.
184 *
185 * MPSAFE
186 */
187 vm_object_t
188 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
189 vm_ooffset_t offset, struct ucred *cred)
190 {
191 vm_object_t object;
192 struct vnode *vp;
193
194 /*
195 * Pageout to vnode, no can do yet.
196 */
197 if (handle == NULL)
198 return (NULL);
199
200 vp = (struct vnode *) handle;
201
202 /*
203 * If the object is being terminated, wait for it to
204 * go away.
205 */
206 retry:
207 while ((object = vp->v_object) != NULL) {
208 VM_OBJECT_LOCK(object);
209 if ((object->flags & OBJ_DEAD) == 0)
210 break;
211 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
212 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0);
213 }
214
215 if (vp->v_usecount == 0)
216 panic("vnode_pager_alloc: no vnode reference");
217
218 if (object == NULL) {
219 /*
220 * Add an object of the appropriate size
221 */
222 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
223
224 object->un_pager.vnp.vnp_size = size;
225
226 object->handle = handle;
227 VI_LOCK(vp);
228 if (vp->v_object != NULL) {
229 /*
230 * Object has been created while we were sleeping
231 */
232 VI_UNLOCK(vp);
233 vm_object_destroy(object);
234 goto retry;
235 }
236 vp->v_object = object;
237 VI_UNLOCK(vp);
238 } else {
239 object->ref_count++;
240 VM_OBJECT_UNLOCK(object);
241 }
242 vref(vp);
243 return (object);
244 }
245
246 /*
247 * The object must be locked.
248 */
249 static void
250 vnode_pager_dealloc(object)
251 vm_object_t object;
252 {
253 struct vnode *vp;
254 int refs;
255
256 vp = object->handle;
257 if (vp == NULL)
258 panic("vnode_pager_dealloc: pager already dealloced");
259
260 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
261 vm_object_pip_wait(object, "vnpdea");
262 refs = object->ref_count;
263
264 object->handle = NULL;
265 object->type = OBJT_DEAD;
266 if (object->flags & OBJ_DISCONNECTWNT) {
267 vm_object_clear_flag(object, OBJ_DISCONNECTWNT);
268 wakeup(object);
269 }
270 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
271 vp->v_object = NULL;
272 vp->v_vflag &= ~VV_TEXT;
273 while (refs-- > 0)
274 vunref(vp);
275 }
276
277 static boolean_t
278 vnode_pager_haspage(object, pindex, before, after)
279 vm_object_t object;
280 vm_pindex_t pindex;
281 int *before;
282 int *after;
283 {
284 struct vnode *vp = object->handle;
285 daddr_t bn;
286 int err;
287 daddr_t reqblock;
288 int poff;
289 int bsize;
290 int pagesperblock, blocksperpage;
291 int vfslocked;
292
293 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
294 /*
295 * If no vp or vp is doomed or marked transparent to VM, we do not
296 * have the page.
297 */
298 if (vp == NULL || vp->v_iflag & VI_DOOMED)
299 return FALSE;
300 /*
301 * If the offset is beyond end of file we do
302 * not have the page.
303 */
304 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
305 return FALSE;
306
307 bsize = vp->v_mount->mnt_stat.f_iosize;
308 pagesperblock = bsize / PAGE_SIZE;
309 blocksperpage = 0;
310 if (pagesperblock > 0) {
311 reqblock = pindex / pagesperblock;
312 } else {
313 blocksperpage = (PAGE_SIZE / bsize);
314 reqblock = pindex * blocksperpage;
315 }
316 VM_OBJECT_UNLOCK(object);
317 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
318 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
319 VFS_UNLOCK_GIANT(vfslocked);
320 VM_OBJECT_LOCK(object);
321 if (err)
322 return TRUE;
323 if (bn == -1)
324 return FALSE;
325 if (pagesperblock > 0) {
326 poff = pindex - (reqblock * pagesperblock);
327 if (before) {
328 *before *= pagesperblock;
329 *before += poff;
330 }
331 if (after) {
332 int numafter;
333 *after *= pagesperblock;
334 numafter = pagesperblock - (poff + 1);
335 if (IDX_TO_OFF(pindex + numafter) >
336 object->un_pager.vnp.vnp_size) {
337 numafter =
338 OFF_TO_IDX(object->un_pager.vnp.vnp_size) -
339 pindex;
340 }
341 *after += numafter;
342 }
343 } else {
344 if (before) {
345 *before /= blocksperpage;
346 }
347
348 if (after) {
349 *after /= blocksperpage;
350 }
351 }
352 return TRUE;
353 }
354
355 /*
356 * Lets the VM system know about a change in size for a file.
357 * We adjust our own internal size and flush any cached pages in
358 * the associated object that are affected by the size change.
359 *
360 * Note: this routine may be invoked as a result of a pager put
361 * operation (possibly at object termination time), so we must be careful.
362 */
363 void
364 vnode_pager_setsize(vp, nsize)
365 struct vnode *vp;
366 vm_ooffset_t nsize;
367 {
368 vm_object_t object;
369 vm_page_t m;
370 vm_pindex_t nobjsize;
371
372 if ((object = vp->v_object) == NULL)
373 return;
374 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */
375 VM_OBJECT_LOCK(object);
376 if (nsize == object->un_pager.vnp.vnp_size) {
377 /*
378 * Hasn't changed size
379 */
380 VM_OBJECT_UNLOCK(object);
381 return;
382 }
383 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
384 if (nsize < object->un_pager.vnp.vnp_size) {
385 /*
386 * File has shrunk. Toss any cached pages beyond the new EOF.
387 */
388 if (nobjsize < object->size)
389 vm_object_page_remove(object, nobjsize, object->size,
390 FALSE);
391 /*
392 * this gets rid of garbage at the end of a page that is now
393 * only partially backed by the vnode.
394 *
395 * XXX for some reason (I don't know yet), if we take a
396 * completely invalid page and mark it partially valid
397 * it can screw up NFS reads, so we don't allow the case.
398 */
399 if ((nsize & PAGE_MASK) &&
400 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL &&
401 m->valid != 0) {
402 int base = (int)nsize & PAGE_MASK;
403 int size = PAGE_SIZE - base;
404
405 /*
406 * Clear out partial-page garbage in case
407 * the page has been mapped.
408 */
409 pmap_zero_page_area(m, base, size);
410
411 /*
412 * Update the valid bits to reflect the blocks that
413 * have been zeroed. Some of these valid bits may
414 * have already been set.
415 */
416 vm_page_set_valid(m, base, size);
417
418 /*
419 * Round "base" to the next block boundary so that the
420 * dirty bit for a partially zeroed block is not
421 * cleared.
422 */
423 base = roundup2(base, DEV_BSIZE);
424
425 /*
426 * Clear out partial-page dirty bits.
427 *
428 * note that we do not clear out the valid
429 * bits. This would prevent bogus_page
430 * replacement from working properly.
431 */
432 vm_page_lock_queues();
433 vm_page_clear_dirty(m, base, PAGE_SIZE - base);
434 vm_page_unlock_queues();
435 } else if ((nsize & PAGE_MASK) &&
436 __predict_false(object->cache != NULL)) {
437 vm_page_cache_free(object, OFF_TO_IDX(nsize),
438 nobjsize);
439 }
440 }
441 object->un_pager.vnp.vnp_size = nsize;
442 object->size = nobjsize;
443 VM_OBJECT_UNLOCK(object);
444 }
445
446 /*
447 * calculate the linear (byte) disk address of specified virtual
448 * file address
449 */
450 static int
451 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
452 int *run)
453 {
454 int bsize;
455 int err;
456 daddr_t vblock;
457 daddr_t voffset;
458
459 if (address < 0)
460 return -1;
461
462 if (vp->v_iflag & VI_DOOMED)
463 return -1;
464
465 bsize = vp->v_mount->mnt_stat.f_iosize;
466 vblock = address / bsize;
467 voffset = address % bsize;
468
469 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
470 if (err == 0) {
471 if (*rtaddress != -1)
472 *rtaddress += voffset / DEV_BSIZE;
473 if (run) {
474 *run += 1;
475 *run *= bsize/PAGE_SIZE;
476 *run -= voffset/PAGE_SIZE;
477 }
478 }
479
480 return (err);
481 }
482
483 /*
484 * small block filesystem vnode pager input
485 */
486 static int
487 vnode_pager_input_smlfs(object, m)
488 vm_object_t object;
489 vm_page_t m;
490 {
491 int bits, i;
492 struct vnode *vp;
493 struct bufobj *bo;
494 struct buf *bp;
495 struct sf_buf *sf;
496 daddr_t fileaddr;
497 vm_offset_t bsize;
498 int error = 0;
499
500 vp = object->handle;
501 if (vp->v_iflag & VI_DOOMED)
502 return VM_PAGER_BAD;
503
504 bsize = vp->v_mount->mnt_stat.f_iosize;
505
506 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
507
508 sf = sf_buf_alloc(m, 0);
509
510 for (i = 0; i < PAGE_SIZE / bsize; i++) {
511 vm_ooffset_t address;
512
513 bits = vm_page_bits(i * bsize, bsize);
514 if (m->valid & bits)
515 continue;
516
517 address = IDX_TO_OFF(m->pindex) + i * bsize;
518 if (address >= object->un_pager.vnp.vnp_size) {
519 fileaddr = -1;
520 } else {
521 error = vnode_pager_addr(vp, address, &fileaddr, NULL);
522 if (error)
523 break;
524 }
525 if (fileaddr != -1) {
526 bp = getpbuf(&vnode_pbuf_freecnt);
527
528 /* build a minimal buffer header */
529 bp->b_iocmd = BIO_READ;
530 bp->b_iodone = bdone;
531 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
532 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
533 bp->b_rcred = crhold(curthread->td_ucred);
534 bp->b_wcred = crhold(curthread->td_ucred);
535 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
536 bp->b_blkno = fileaddr;
537 pbgetbo(bo, bp);
538 bp->b_bcount = bsize;
539 bp->b_bufsize = bsize;
540 bp->b_runningbufspace = bp->b_bufsize;
541 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
542
543 /* do the input */
544 bp->b_iooffset = dbtob(bp->b_blkno);
545 bstrategy(bp);
546
547 bwait(bp, PVM, "vnsrd");
548
549 if ((bp->b_ioflags & BIO_ERROR) != 0)
550 error = EIO;
551
552 /*
553 * free the buffer header back to the swap buffer pool
554 */
555 pbrelbo(bp);
556 relpbuf(bp, &vnode_pbuf_freecnt);
557 if (error)
558 break;
559 } else
560 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
561 KASSERT((m->dirty & bits) == 0,
562 ("vnode_pager_input_smlfs: page %p is dirty", m));
563 VM_OBJECT_LOCK(object);
564 m->valid |= bits;
565 VM_OBJECT_UNLOCK(object);
566 }
567 sf_buf_free(sf);
568 if (error) {
569 return VM_PAGER_ERROR;
570 }
571 return VM_PAGER_OK;
572 }
573
574 /*
575 * old style vnode pager input routine
576 */
577 static int
578 vnode_pager_input_old(object, m)
579 vm_object_t object;
580 vm_page_t m;
581 {
582 struct uio auio;
583 struct iovec aiov;
584 int error;
585 int size;
586 struct sf_buf *sf;
587 struct vnode *vp;
588
589 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
590 error = 0;
591
592 /*
593 * Return failure if beyond current EOF
594 */
595 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
596 return VM_PAGER_BAD;
597 } else {
598 size = PAGE_SIZE;
599 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
600 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
601 vp = object->handle;
602 VM_OBJECT_UNLOCK(object);
603
604 /*
605 * Allocate a kernel virtual address and initialize so that
606 * we can use VOP_READ/WRITE routines.
607 */
608 sf = sf_buf_alloc(m, 0);
609
610 aiov.iov_base = (caddr_t)sf_buf_kva(sf);
611 aiov.iov_len = size;
612 auio.uio_iov = &aiov;
613 auio.uio_iovcnt = 1;
614 auio.uio_offset = IDX_TO_OFF(m->pindex);
615 auio.uio_segflg = UIO_SYSSPACE;
616 auio.uio_rw = UIO_READ;
617 auio.uio_resid = size;
618 auio.uio_td = curthread;
619
620 error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
621 if (!error) {
622 int count = size - auio.uio_resid;
623
624 if (count == 0)
625 error = EINVAL;
626 else if (count != PAGE_SIZE)
627 bzero((caddr_t)sf_buf_kva(sf) + count,
628 PAGE_SIZE - count);
629 }
630 sf_buf_free(sf);
631
632 VM_OBJECT_LOCK(object);
633 }
634 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
635 if (!error)
636 m->valid = VM_PAGE_BITS_ALL;
637 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
638 }
639
640 /*
641 * generic vnode pager input routine
642 */
643
644 /*
645 * Local media VFS's that do not implement their own VOP_GETPAGES
646 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
647 * to implement the previous behaviour.
648 *
649 * All other FS's should use the bypass to get to the local media
650 * backing vp's VOP_GETPAGES.
651 */
652 static int
653 vnode_pager_getpages(object, m, count, reqpage)
654 vm_object_t object;
655 vm_page_t *m;
656 int count;
657 int reqpage;
658 {
659 int rtval;
660 struct vnode *vp;
661 int bytes = count * PAGE_SIZE;
662 int vfslocked;
663
664 vp = object->handle;
665 VM_OBJECT_UNLOCK(object);
666 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
667 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
668 KASSERT(rtval != EOPNOTSUPP,
669 ("vnode_pager: FS getpages not implemented\n"));
670 VFS_UNLOCK_GIANT(vfslocked);
671 VM_OBJECT_LOCK(object);
672 return rtval;
673 }
674
675 /*
676 * This is now called from local media FS's to operate against their
677 * own vnodes if they fail to implement VOP_GETPAGES.
678 */
679 int
680 vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
681 struct vnode *vp;
682 vm_page_t *m;
683 int bytecount;
684 int reqpage;
685 {
686 vm_object_t object;
687 vm_offset_t kva;
688 off_t foff, tfoff, nextoff;
689 int i, j, size, bsize, first;
690 daddr_t firstaddr, reqblock;
691 struct bufobj *bo;
692 int runpg;
693 int runend;
694 struct buf *bp;
695 int count;
696 int error;
697
698 object = vp->v_object;
699 count = bytecount / PAGE_SIZE;
700
701 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
702 ("vnode_pager_generic_getpages does not support devices"));
703 if (vp->v_iflag & VI_DOOMED)
704 return VM_PAGER_BAD;
705
706 bsize = vp->v_mount->mnt_stat.f_iosize;
707
708 /* get the UNDERLYING device for the file with VOP_BMAP() */
709
710 /*
711 * originally, we did not check for an error return value -- assuming
712 * an fs always has a bmap entry point -- that assumption is wrong!!!
713 */
714 foff = IDX_TO_OFF(m[reqpage]->pindex);
715
716 /*
717 * if we can't bmap, use old VOP code
718 */
719 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL);
720 if (error == EOPNOTSUPP) {
721 VM_OBJECT_LOCK(object);
722 vm_page_lock_queues();
723 for (i = 0; i < count; i++)
724 if (i != reqpage)
725 vm_page_free(m[i]);
726 vm_page_unlock_queues();
727 PCPU_INC(cnt.v_vnodein);
728 PCPU_INC(cnt.v_vnodepgsin);
729 error = vnode_pager_input_old(object, m[reqpage]);
730 VM_OBJECT_UNLOCK(object);
731 return (error);
732 } else if (error != 0) {
733 VM_OBJECT_LOCK(object);
734 vm_page_lock_queues();
735 for (i = 0; i < count; i++)
736 if (i != reqpage)
737 vm_page_free(m[i]);
738 vm_page_unlock_queues();
739 VM_OBJECT_UNLOCK(object);
740 return (VM_PAGER_ERROR);
741
742 /*
743 * if the blocksize is smaller than a page size, then use
744 * special small filesystem code. NFS sometimes has a small
745 * blocksize, but it can handle large reads itself.
746 */
747 } else if ((PAGE_SIZE / bsize) > 1 &&
748 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
749 VM_OBJECT_LOCK(object);
750 vm_page_lock_queues();
751 for (i = 0; i < count; i++)
752 if (i != reqpage)
753 vm_page_free(m[i]);
754 vm_page_unlock_queues();
755 VM_OBJECT_UNLOCK(object);
756 PCPU_INC(cnt.v_vnodein);
757 PCPU_INC(cnt.v_vnodepgsin);
758 return vnode_pager_input_smlfs(object, m[reqpage]);
759 }
760
761 /*
762 * If we have a completely valid page available to us, we can
763 * clean up and return. Otherwise we have to re-read the
764 * media.
765 */
766 VM_OBJECT_LOCK(object);
767 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
768 vm_page_lock_queues();
769 for (i = 0; i < count; i++)
770 if (i != reqpage)
771 vm_page_free(m[i]);
772 vm_page_unlock_queues();
773 VM_OBJECT_UNLOCK(object);
774 return VM_PAGER_OK;
775 } else if (reqblock == -1) {
776 pmap_zero_page(m[reqpage]);
777 KASSERT(m[reqpage]->dirty == 0,
778 ("vnode_pager_generic_getpages: page %p is dirty", m));
779 m[reqpage]->valid = VM_PAGE_BITS_ALL;
780 vm_page_lock_queues();
781 for (i = 0; i < count; i++)
782 if (i != reqpage)
783 vm_page_free(m[i]);
784 vm_page_unlock_queues();
785 VM_OBJECT_UNLOCK(object);
786 return (VM_PAGER_OK);
787 }
788 m[reqpage]->valid = 0;
789 VM_OBJECT_UNLOCK(object);
790
791 /*
792 * here on direct device I/O
793 */
794 firstaddr = -1;
795
796 /*
797 * calculate the run that includes the required page
798 */
799 for (first = 0, i = 0; i < count; i = runend) {
800 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr,
801 &runpg) != 0) {
802 VM_OBJECT_LOCK(object);
803 vm_page_lock_queues();
804 for (; i < count; i++)
805 if (i != reqpage)
806 vm_page_free(m[i]);
807 vm_page_unlock_queues();
808 VM_OBJECT_UNLOCK(object);
809 return (VM_PAGER_ERROR);
810 }
811 if (firstaddr == -1) {
812 VM_OBJECT_LOCK(object);
813 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
814 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx",
815 (intmax_t)firstaddr, (uintmax_t)(foff >> 32),
816 (uintmax_t)foff,
817 (uintmax_t)
818 (object->un_pager.vnp.vnp_size >> 32),
819 (uintmax_t)object->un_pager.vnp.vnp_size);
820 }
821 vm_page_lock_queues();
822 vm_page_free(m[i]);
823 vm_page_unlock_queues();
824 VM_OBJECT_UNLOCK(object);
825 runend = i + 1;
826 first = runend;
827 continue;
828 }
829 runend = i + runpg;
830 if (runend <= reqpage) {
831 VM_OBJECT_LOCK(object);
832 vm_page_lock_queues();
833 for (j = i; j < runend; j++)
834 vm_page_free(m[j]);
835 vm_page_unlock_queues();
836 VM_OBJECT_UNLOCK(object);
837 } else {
838 if (runpg < (count - first)) {
839 VM_OBJECT_LOCK(object);
840 vm_page_lock_queues();
841 for (i = first + runpg; i < count; i++)
842 vm_page_free(m[i]);
843 vm_page_unlock_queues();
844 VM_OBJECT_UNLOCK(object);
845 count = first + runpg;
846 }
847 break;
848 }
849 first = runend;
850 }
851
852 /*
853 * the first and last page have been calculated now, move input pages
854 * to be zero based...
855 */
856 if (first != 0) {
857 m += first;
858 count -= first;
859 reqpage -= first;
860 }
861
862 /*
863 * calculate the file virtual address for the transfer
864 */
865 foff = IDX_TO_OFF(m[0]->pindex);
866
867 /*
868 * calculate the size of the transfer
869 */
870 size = count * PAGE_SIZE;
871 KASSERT(count > 0, ("zero count"));
872 if ((foff + size) > object->un_pager.vnp.vnp_size)
873 size = object->un_pager.vnp.vnp_size - foff;
874 KASSERT(size > 0, ("zero size"));
875
876 /*
877 * round up physical size for real devices.
878 */
879 if (1) {
880 int secmask = bo->bo_bsize - 1;
881 KASSERT(secmask < PAGE_SIZE && secmask > 0,
882 ("vnode_pager_generic_getpages: sector size %d too large",
883 secmask + 1));
884 size = (size + secmask) & ~secmask;
885 }
886
887 bp = getpbuf(&vnode_pbuf_freecnt);
888 kva = (vm_offset_t) bp->b_data;
889
890 /*
891 * and map the pages to be read into the kva
892 */
893 pmap_qenter(kva, m, count);
894
895 /* build a minimal buffer header */
896 bp->b_iocmd = BIO_READ;
897 bp->b_iodone = bdone;
898 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
899 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
900 bp->b_rcred = crhold(curthread->td_ucred);
901 bp->b_wcred = crhold(curthread->td_ucred);
902 bp->b_blkno = firstaddr;
903 pbgetbo(bo, bp);
904 bp->b_bcount = size;
905 bp->b_bufsize = size;
906 bp->b_runningbufspace = bp->b_bufsize;
907 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
908
909 PCPU_INC(cnt.v_vnodein);
910 PCPU_ADD(cnt.v_vnodepgsin, count);
911
912 /* do the input */
913 bp->b_iooffset = dbtob(bp->b_blkno);
914 bstrategy(bp);
915
916 bwait(bp, PVM, "vnread");
917
918 if ((bp->b_ioflags & BIO_ERROR) != 0)
919 error = EIO;
920
921 if (!error) {
922 if (size != count * PAGE_SIZE)
923 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
924 }
925 pmap_qremove(kva, count);
926
927 /*
928 * free the buffer header back to the swap buffer pool
929 */
930 pbrelbo(bp);
931 relpbuf(bp, &vnode_pbuf_freecnt);
932
933 VM_OBJECT_LOCK(object);
934 vm_page_lock_queues();
935 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
936 vm_page_t mt;
937
938 nextoff = tfoff + PAGE_SIZE;
939 mt = m[i];
940
941 if (nextoff <= object->un_pager.vnp.vnp_size) {
942 /*
943 * Read filled up entire page.
944 */
945 mt->valid = VM_PAGE_BITS_ALL;
946 KASSERT(mt->dirty == 0,
947 ("vnode_pager_generic_getpages: page %p is dirty",
948 mt));
949 KASSERT(!pmap_page_is_mapped(mt),
950 ("vnode_pager_generic_getpages: page %p is mapped",
951 mt));
952 } else {
953 /*
954 * Read did not fill up entire page.
955 *
956 * Currently we do not set the entire page valid,
957 * we just try to clear the piece that we couldn't
958 * read.
959 */
960 vm_page_set_valid(mt, 0,
961 object->un_pager.vnp.vnp_size - tfoff);
962 KASSERT((mt->dirty & vm_page_bits(0,
963 object->un_pager.vnp.vnp_size - tfoff)) == 0,
964 ("vnode_pager_generic_getpages: page %p is dirty",
965 mt));
966 }
967
968 if (i != reqpage) {
969
970 /*
971 * whether or not to leave the page activated is up in
972 * the air, but we should put the page on a page queue
973 * somewhere. (it already is in the object). Result:
974 * It appears that empirical results show that
975 * deactivating pages is best.
976 */
977
978 /*
979 * just in case someone was asking for this page we
980 * now tell them that it is ok to use
981 */
982 if (!error) {
983 if (mt->oflags & VPO_WANTED)
984 vm_page_activate(mt);
985 else
986 vm_page_deactivate(mt);
987 vm_page_wakeup(mt);
988 } else {
989 vm_page_free(mt);
990 }
991 }
992 }
993 vm_page_unlock_queues();
994 VM_OBJECT_UNLOCK(object);
995 if (error) {
996 printf("vnode_pager_getpages: I/O read error\n");
997 }
998 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
999 }
1000
1001 /*
1002 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
1003 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
1004 * vnode_pager_generic_putpages() to implement the previous behaviour.
1005 *
1006 * All other FS's should use the bypass to get to the local media
1007 * backing vp's VOP_PUTPAGES.
1008 */
1009 static void
1010 vnode_pager_putpages(object, m, count, sync, rtvals)
1011 vm_object_t object;
1012 vm_page_t *m;
1013 int count;
1014 boolean_t sync;
1015 int *rtvals;
1016 {
1017 int rtval;
1018 struct vnode *vp;
1019 int bytes = count * PAGE_SIZE;
1020
1021 /*
1022 * Force synchronous operation if we are extremely low on memory
1023 * to prevent a low-memory deadlock. VOP operations often need to
1024 * allocate more memory to initiate the I/O ( i.e. do a BMAP
1025 * operation ). The swapper handles the case by limiting the amount
1026 * of asynchronous I/O, but that sort of solution doesn't scale well
1027 * for the vnode pager without a lot of work.
1028 *
1029 * Also, the backing vnode's iodone routine may not wake the pageout
1030 * daemon up. This should be probably be addressed XXX.
1031 */
1032
1033 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min)
1034 sync |= OBJPC_SYNC;
1035
1036 /*
1037 * Call device-specific putpages function
1038 */
1039 vp = object->handle;
1040 VM_OBJECT_UNLOCK(object);
1041 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
1042 KASSERT(rtval != EOPNOTSUPP,
1043 ("vnode_pager: stale FS putpages\n"));
1044 VM_OBJECT_LOCK(object);
1045 }
1046
1047
1048 /*
1049 * This is now called from local media FS's to operate against their
1050 * own vnodes if they fail to implement VOP_PUTPAGES.
1051 *
1052 * This is typically called indirectly via the pageout daemon and
1053 * clustering has already typically occured, so in general we ask the
1054 * underlying filesystem to write the data out asynchronously rather
1055 * then delayed.
1056 */
1057 int
1058 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals)
1059 struct vnode *vp;
1060 vm_page_t *m;
1061 int bytecount;
1062 int flags;
1063 int *rtvals;
1064 {
1065 int i;
1066 vm_object_t object;
1067 int count;
1068
1069 int maxsize, ncount;
1070 vm_ooffset_t poffset;
1071 struct uio auio;
1072 struct iovec aiov;
1073 int error;
1074 int ioflags;
1075 int ppscheck = 0;
1076 static struct timeval lastfail;
1077 static int curfail;
1078
1079 object = vp->v_object;
1080 count = bytecount / PAGE_SIZE;
1081
1082 for (i = 0; i < count; i++)
1083 rtvals[i] = VM_PAGER_ERROR;
1084
1085 if ((int64_t)m[0]->pindex < 0) {
1086 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n",
1087 (long)m[0]->pindex, (u_long)m[0]->dirty);
1088 rtvals[0] = VM_PAGER_BAD;
1089 return VM_PAGER_BAD;
1090 }
1091
1092 maxsize = count * PAGE_SIZE;
1093 ncount = count;
1094
1095 poffset = IDX_TO_OFF(m[0]->pindex);
1096
1097 /*
1098 * If the page-aligned write is larger then the actual file we
1099 * have to invalidate pages occuring beyond the file EOF. However,
1100 * there is an edge case where a file may not be page-aligned where
1101 * the last page is partially invalid. In this case the filesystem
1102 * may not properly clear the dirty bits for the entire page (which
1103 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1104 * With the page locked we are free to fix-up the dirty bits here.
1105 *
1106 * We do not under any circumstances truncate the valid bits, as
1107 * this will screw up bogus page replacement.
1108 */
1109 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1110 if (object->un_pager.vnp.vnp_size > poffset) {
1111 int pgoff;
1112
1113 maxsize = object->un_pager.vnp.vnp_size - poffset;
1114 ncount = btoc(maxsize);
1115 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1116 vm_page_lock_queues();
1117 vm_page_clear_dirty(m[ncount - 1], pgoff,
1118 PAGE_SIZE - pgoff);
1119 vm_page_unlock_queues();
1120 }
1121 } else {
1122 maxsize = 0;
1123 ncount = 0;
1124 }
1125 if (ncount < count) {
1126 for (i = ncount; i < count; i++) {
1127 rtvals[i] = VM_PAGER_BAD;
1128 }
1129 }
1130 }
1131
1132 /*
1133 * pageouts are already clustered, use IO_ASYNC t o force a bawrite()
1134 * rather then a bdwrite() to prevent paging I/O from saturating
1135 * the buffer cache. Dummy-up the sequential heuristic to cause
1136 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
1137 * the system decides how to cluster.
1138 */
1139 ioflags = IO_VMIO;
1140 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1141 ioflags |= IO_SYNC;
1142 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1143 ioflags |= IO_ASYNC;
1144 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1145 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1146
1147 aiov.iov_base = (caddr_t) 0;
1148 aiov.iov_len = maxsize;
1149 auio.uio_iov = &aiov;
1150 auio.uio_iovcnt = 1;
1151 auio.uio_offset = poffset;
1152 auio.uio_segflg = UIO_NOCOPY;
1153 auio.uio_rw = UIO_WRITE;
1154 auio.uio_resid = maxsize;
1155 auio.uio_td = (struct thread *) 0;
1156 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred);
1157 PCPU_INC(cnt.v_vnodeout);
1158 PCPU_ADD(cnt.v_vnodepgsout, ncount);
1159
1160 if (error) {
1161 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1)))
1162 printf("vnode_pager_putpages: I/O error %d\n", error);
1163 }
1164 if (auio.uio_resid) {
1165 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1))
1166 printf("vnode_pager_putpages: residual I/O %zd at %lu\n",
1167 auio.uio_resid, (u_long)m[0]->pindex);
1168 }
1169 for (i = 0; i < ncount; i++) {
1170 rtvals[i] = VM_PAGER_OK;
1171 }
1172 return rtvals[0];
1173 }
1174
1175 void
1176 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written)
1177 {
1178 int i, pos;
1179
1180 vm_page_lock_queues();
1181 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
1182 if (pos < trunc_page(written)) {
1183 rtvals[i] = VM_PAGER_OK;
1184 vm_page_undirty(ma[i]);
1185 } else {
1186 /* Partially written page. */
1187 rtvals[i] = VM_PAGER_AGAIN;
1188 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
1189 }
1190 }
1191 vm_page_unlock_queues();
1192 }
Cache object: 0de00fdc43c7a2dca733505ce5e70ff4
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