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: releng/9.0/sys/vm/vnode_pager.c 225418 2011-09-06 10:30:11Z kib $");
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 0);
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_clear_dirty(m, base, PAGE_SIZE - base);
433 } else if ((nsize & PAGE_MASK) &&
434 __predict_false(object->cache != NULL)) {
435 vm_page_cache_free(object, OFF_TO_IDX(nsize),
436 nobjsize);
437 }
438 }
439 object->un_pager.vnp.vnp_size = nsize;
440 object->size = nobjsize;
441 VM_OBJECT_UNLOCK(object);
442 }
443
444 /*
445 * calculate the linear (byte) disk address of specified virtual
446 * file address
447 */
448 static int
449 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
450 int *run)
451 {
452 int bsize;
453 int err;
454 daddr_t vblock;
455 daddr_t voffset;
456
457 if (address < 0)
458 return -1;
459
460 if (vp->v_iflag & VI_DOOMED)
461 return -1;
462
463 bsize = vp->v_mount->mnt_stat.f_iosize;
464 vblock = address / bsize;
465 voffset = address % bsize;
466
467 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
468 if (err == 0) {
469 if (*rtaddress != -1)
470 *rtaddress += voffset / DEV_BSIZE;
471 if (run) {
472 *run += 1;
473 *run *= bsize/PAGE_SIZE;
474 *run -= voffset/PAGE_SIZE;
475 }
476 }
477
478 return (err);
479 }
480
481 /*
482 * small block filesystem vnode pager input
483 */
484 static int
485 vnode_pager_input_smlfs(object, m)
486 vm_object_t object;
487 vm_page_t m;
488 {
489 int bits, i;
490 struct vnode *vp;
491 struct bufobj *bo;
492 struct buf *bp;
493 struct sf_buf *sf;
494 daddr_t fileaddr;
495 vm_offset_t bsize;
496 int error = 0;
497
498 vp = object->handle;
499 if (vp->v_iflag & VI_DOOMED)
500 return VM_PAGER_BAD;
501
502 bsize = vp->v_mount->mnt_stat.f_iosize;
503
504 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
505
506 sf = sf_buf_alloc(m, 0);
507
508 for (i = 0; i < PAGE_SIZE / bsize; i++) {
509 vm_ooffset_t address;
510
511 bits = vm_page_bits(i * bsize, bsize);
512 if (m->valid & bits)
513 continue;
514
515 address = IDX_TO_OFF(m->pindex) + i * bsize;
516 if (address >= object->un_pager.vnp.vnp_size) {
517 fileaddr = -1;
518 } else {
519 error = vnode_pager_addr(vp, address, &fileaddr, NULL);
520 if (error)
521 break;
522 }
523 if (fileaddr != -1) {
524 bp = getpbuf(&vnode_pbuf_freecnt);
525
526 /* build a minimal buffer header */
527 bp->b_iocmd = BIO_READ;
528 bp->b_iodone = bdone;
529 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
530 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
531 bp->b_rcred = crhold(curthread->td_ucred);
532 bp->b_wcred = crhold(curthread->td_ucred);
533 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
534 bp->b_blkno = fileaddr;
535 pbgetbo(bo, bp);
536 bp->b_bcount = bsize;
537 bp->b_bufsize = bsize;
538 bp->b_runningbufspace = bp->b_bufsize;
539 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
540
541 /* do the input */
542 bp->b_iooffset = dbtob(bp->b_blkno);
543 bstrategy(bp);
544
545 bwait(bp, PVM, "vnsrd");
546
547 if ((bp->b_ioflags & BIO_ERROR) != 0)
548 error = EIO;
549
550 /*
551 * free the buffer header back to the swap buffer pool
552 */
553 pbrelbo(bp);
554 relpbuf(bp, &vnode_pbuf_freecnt);
555 if (error)
556 break;
557 } else
558 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
559 KASSERT((m->dirty & bits) == 0,
560 ("vnode_pager_input_smlfs: page %p is dirty", m));
561 VM_OBJECT_LOCK(object);
562 m->valid |= bits;
563 VM_OBJECT_UNLOCK(object);
564 }
565 sf_buf_free(sf);
566 if (error) {
567 return VM_PAGER_ERROR;
568 }
569 return VM_PAGER_OK;
570 }
571
572 /*
573 * old style vnode pager input routine
574 */
575 static int
576 vnode_pager_input_old(object, m)
577 vm_object_t object;
578 vm_page_t m;
579 {
580 struct uio auio;
581 struct iovec aiov;
582 int error;
583 int size;
584 struct sf_buf *sf;
585 struct vnode *vp;
586
587 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
588 error = 0;
589
590 /*
591 * Return failure if beyond current EOF
592 */
593 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
594 return VM_PAGER_BAD;
595 } else {
596 size = PAGE_SIZE;
597 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
598 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
599 vp = object->handle;
600 VM_OBJECT_UNLOCK(object);
601
602 /*
603 * Allocate a kernel virtual address and initialize so that
604 * we can use VOP_READ/WRITE routines.
605 */
606 sf = sf_buf_alloc(m, 0);
607
608 aiov.iov_base = (caddr_t)sf_buf_kva(sf);
609 aiov.iov_len = size;
610 auio.uio_iov = &aiov;
611 auio.uio_iovcnt = 1;
612 auio.uio_offset = IDX_TO_OFF(m->pindex);
613 auio.uio_segflg = UIO_SYSSPACE;
614 auio.uio_rw = UIO_READ;
615 auio.uio_resid = size;
616 auio.uio_td = curthread;
617
618 error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
619 if (!error) {
620 int count = size - auio.uio_resid;
621
622 if (count == 0)
623 error = EINVAL;
624 else if (count != PAGE_SIZE)
625 bzero((caddr_t)sf_buf_kva(sf) + count,
626 PAGE_SIZE - count);
627 }
628 sf_buf_free(sf);
629
630 VM_OBJECT_LOCK(object);
631 }
632 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
633 if (!error)
634 m->valid = VM_PAGE_BITS_ALL;
635 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
636 }
637
638 /*
639 * generic vnode pager input routine
640 */
641
642 /*
643 * Local media VFS's that do not implement their own VOP_GETPAGES
644 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
645 * to implement the previous behaviour.
646 *
647 * All other FS's should use the bypass to get to the local media
648 * backing vp's VOP_GETPAGES.
649 */
650 static int
651 vnode_pager_getpages(object, m, count, reqpage)
652 vm_object_t object;
653 vm_page_t *m;
654 int count;
655 int reqpage;
656 {
657 int rtval;
658 struct vnode *vp;
659 int bytes = count * PAGE_SIZE;
660 int vfslocked;
661
662 vp = object->handle;
663 VM_OBJECT_UNLOCK(object);
664 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
665 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
666 KASSERT(rtval != EOPNOTSUPP,
667 ("vnode_pager: FS getpages not implemented\n"));
668 VFS_UNLOCK_GIANT(vfslocked);
669 VM_OBJECT_LOCK(object);
670 return rtval;
671 }
672
673 /*
674 * This is now called from local media FS's to operate against their
675 * own vnodes if they fail to implement VOP_GETPAGES.
676 */
677 int
678 vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
679 struct vnode *vp;
680 vm_page_t *m;
681 int bytecount;
682 int reqpage;
683 {
684 vm_object_t object;
685 vm_offset_t kva;
686 off_t foff, tfoff, nextoff;
687 int i, j, size, bsize, first;
688 daddr_t firstaddr, reqblock;
689 struct bufobj *bo;
690 int runpg;
691 int runend;
692 struct buf *bp;
693 int count;
694 int error;
695
696 object = vp->v_object;
697 count = bytecount / PAGE_SIZE;
698
699 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
700 ("vnode_pager_generic_getpages does not support devices"));
701 if (vp->v_iflag & VI_DOOMED)
702 return VM_PAGER_BAD;
703
704 bsize = vp->v_mount->mnt_stat.f_iosize;
705
706 /* get the UNDERLYING device for the file with VOP_BMAP() */
707
708 /*
709 * originally, we did not check for an error return value -- assuming
710 * an fs always has a bmap entry point -- that assumption is wrong!!!
711 */
712 foff = IDX_TO_OFF(m[reqpage]->pindex);
713
714 /*
715 * if we can't bmap, use old VOP code
716 */
717 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL);
718 if (error == EOPNOTSUPP) {
719 VM_OBJECT_LOCK(object);
720
721 for (i = 0; i < count; i++)
722 if (i != reqpage) {
723 vm_page_lock(m[i]);
724 vm_page_free(m[i]);
725 vm_page_unlock(m[i]);
726 }
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 for (i = 0; i < count; i++)
735 if (i != reqpage) {
736 vm_page_lock(m[i]);
737 vm_page_free(m[i]);
738 vm_page_unlock(m[i]);
739 }
740 VM_OBJECT_UNLOCK(object);
741 return (VM_PAGER_ERROR);
742
743 /*
744 * if the blocksize is smaller than a page size, then use
745 * special small filesystem code. NFS sometimes has a small
746 * blocksize, but it can handle large reads itself.
747 */
748 } else if ((PAGE_SIZE / bsize) > 1 &&
749 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
750 VM_OBJECT_LOCK(object);
751 for (i = 0; i < count; i++)
752 if (i != reqpage) {
753 vm_page_lock(m[i]);
754 vm_page_free(m[i]);
755 vm_page_unlock(m[i]);
756 }
757 VM_OBJECT_UNLOCK(object);
758 PCPU_INC(cnt.v_vnodein);
759 PCPU_INC(cnt.v_vnodepgsin);
760 return vnode_pager_input_smlfs(object, m[reqpage]);
761 }
762
763 /*
764 * If we have a completely valid page available to us, we can
765 * clean up and return. Otherwise we have to re-read the
766 * media.
767 */
768 VM_OBJECT_LOCK(object);
769 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
770 for (i = 0; i < count; i++)
771 if (i != reqpage) {
772 vm_page_lock(m[i]);
773 vm_page_free(m[i]);
774 vm_page_unlock(m[i]);
775 }
776 VM_OBJECT_UNLOCK(object);
777 return VM_PAGER_OK;
778 } else if (reqblock == -1) {
779 pmap_zero_page(m[reqpage]);
780 KASSERT(m[reqpage]->dirty == 0,
781 ("vnode_pager_generic_getpages: page %p is dirty", m));
782 m[reqpage]->valid = VM_PAGE_BITS_ALL;
783 for (i = 0; i < count; i++)
784 if (i != reqpage) {
785 vm_page_lock(m[i]);
786 vm_page_free(m[i]);
787 vm_page_unlock(m[i]);
788 }
789 VM_OBJECT_UNLOCK(object);
790 return (VM_PAGER_OK);
791 }
792 m[reqpage]->valid = 0;
793 VM_OBJECT_UNLOCK(object);
794
795 /*
796 * here on direct device I/O
797 */
798 firstaddr = -1;
799
800 /*
801 * calculate the run that includes the required page
802 */
803 for (first = 0, i = 0; i < count; i = runend) {
804 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr,
805 &runpg) != 0) {
806 VM_OBJECT_LOCK(object);
807 for (; i < count; i++)
808 if (i != reqpage) {
809 vm_page_lock(m[i]);
810 vm_page_free(m[i]);
811 vm_page_unlock(m[i]);
812 }
813 VM_OBJECT_UNLOCK(object);
814 return (VM_PAGER_ERROR);
815 }
816 if (firstaddr == -1) {
817 VM_OBJECT_LOCK(object);
818 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
819 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx",
820 (intmax_t)firstaddr, (uintmax_t)(foff >> 32),
821 (uintmax_t)foff,
822 (uintmax_t)
823 (object->un_pager.vnp.vnp_size >> 32),
824 (uintmax_t)object->un_pager.vnp.vnp_size);
825 }
826 vm_page_lock(m[i]);
827 vm_page_free(m[i]);
828 vm_page_unlock(m[i]);
829 VM_OBJECT_UNLOCK(object);
830 runend = i + 1;
831 first = runend;
832 continue;
833 }
834 runend = i + runpg;
835 if (runend <= reqpage) {
836 VM_OBJECT_LOCK(object);
837 for (j = i; j < runend; j++) {
838 vm_page_lock(m[j]);
839 vm_page_free(m[j]);
840 vm_page_unlock(m[j]);
841 }
842 VM_OBJECT_UNLOCK(object);
843 } else {
844 if (runpg < (count - first)) {
845 VM_OBJECT_LOCK(object);
846 for (i = first + runpg; i < count; i++) {
847 vm_page_lock(m[i]);
848 vm_page_free(m[i]);
849 vm_page_unlock(m[i]);
850 }
851 VM_OBJECT_UNLOCK(object);
852 count = first + runpg;
853 }
854 break;
855 }
856 first = runend;
857 }
858
859 /*
860 * the first and last page have been calculated now, move input pages
861 * to be zero based...
862 */
863 if (first != 0) {
864 m += first;
865 count -= first;
866 reqpage -= first;
867 }
868
869 /*
870 * calculate the file virtual address for the transfer
871 */
872 foff = IDX_TO_OFF(m[0]->pindex);
873
874 /*
875 * calculate the size of the transfer
876 */
877 size = count * PAGE_SIZE;
878 KASSERT(count > 0, ("zero count"));
879 if ((foff + size) > object->un_pager.vnp.vnp_size)
880 size = object->un_pager.vnp.vnp_size - foff;
881 KASSERT(size > 0, ("zero size"));
882
883 /*
884 * round up physical size for real devices.
885 */
886 if (1) {
887 int secmask = bo->bo_bsize - 1;
888 KASSERT(secmask < PAGE_SIZE && secmask > 0,
889 ("vnode_pager_generic_getpages: sector size %d too large",
890 secmask + 1));
891 size = (size + secmask) & ~secmask;
892 }
893
894 bp = getpbuf(&vnode_pbuf_freecnt);
895 kva = (vm_offset_t) bp->b_data;
896
897 /*
898 * and map the pages to be read into the kva
899 */
900 pmap_qenter(kva, m, count);
901
902 /* build a minimal buffer header */
903 bp->b_iocmd = BIO_READ;
904 bp->b_iodone = bdone;
905 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
906 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
907 bp->b_rcred = crhold(curthread->td_ucred);
908 bp->b_wcred = crhold(curthread->td_ucred);
909 bp->b_blkno = firstaddr;
910 pbgetbo(bo, bp);
911 bp->b_bcount = size;
912 bp->b_bufsize = size;
913 bp->b_runningbufspace = bp->b_bufsize;
914 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
915
916 PCPU_INC(cnt.v_vnodein);
917 PCPU_ADD(cnt.v_vnodepgsin, count);
918
919 /* do the input */
920 bp->b_iooffset = dbtob(bp->b_blkno);
921 bstrategy(bp);
922
923 bwait(bp, PVM, "vnread");
924
925 if ((bp->b_ioflags & BIO_ERROR) != 0)
926 error = EIO;
927
928 if (!error) {
929 if (size != count * PAGE_SIZE)
930 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
931 }
932 pmap_qremove(kva, count);
933
934 /*
935 * free the buffer header back to the swap buffer pool
936 */
937 pbrelbo(bp);
938 relpbuf(bp, &vnode_pbuf_freecnt);
939
940 VM_OBJECT_LOCK(object);
941 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
942 vm_page_t mt;
943
944 nextoff = tfoff + PAGE_SIZE;
945 mt = m[i];
946
947 if (nextoff <= object->un_pager.vnp.vnp_size) {
948 /*
949 * Read filled up entire page.
950 */
951 mt->valid = VM_PAGE_BITS_ALL;
952 KASSERT(mt->dirty == 0,
953 ("vnode_pager_generic_getpages: page %p is dirty",
954 mt));
955 KASSERT(!pmap_page_is_mapped(mt),
956 ("vnode_pager_generic_getpages: page %p is mapped",
957 mt));
958 } else {
959 /*
960 * Read did not fill up entire page.
961 *
962 * Currently we do not set the entire page valid,
963 * we just try to clear the piece that we couldn't
964 * read.
965 */
966 vm_page_set_valid(mt, 0,
967 object->un_pager.vnp.vnp_size - tfoff);
968 KASSERT((mt->dirty & vm_page_bits(0,
969 object->un_pager.vnp.vnp_size - tfoff)) == 0,
970 ("vnode_pager_generic_getpages: page %p is dirty",
971 mt));
972 }
973
974 if (i != reqpage) {
975
976 /*
977 * whether or not to leave the page activated is up in
978 * the air, but we should put the page on a page queue
979 * somewhere. (it already is in the object). Result:
980 * It appears that empirical results show that
981 * deactivating pages is best.
982 */
983
984 /*
985 * just in case someone was asking for this page we
986 * now tell them that it is ok to use
987 */
988 if (!error) {
989 if (mt->oflags & VPO_WANTED) {
990 vm_page_lock(mt);
991 vm_page_activate(mt);
992 vm_page_unlock(mt);
993 } else {
994 vm_page_lock(mt);
995 vm_page_deactivate(mt);
996 vm_page_unlock(mt);
997 }
998 vm_page_wakeup(mt);
999 } else {
1000 vm_page_lock(mt);
1001 vm_page_free(mt);
1002 vm_page_unlock(mt);
1003 }
1004 }
1005 }
1006 VM_OBJECT_UNLOCK(object);
1007 if (error) {
1008 printf("vnode_pager_getpages: I/O read error\n");
1009 }
1010 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
1011 }
1012
1013 /*
1014 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
1015 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
1016 * vnode_pager_generic_putpages() to implement the previous behaviour.
1017 *
1018 * All other FS's should use the bypass to get to the local media
1019 * backing vp's VOP_PUTPAGES.
1020 */
1021 static void
1022 vnode_pager_putpages(object, m, count, sync, rtvals)
1023 vm_object_t object;
1024 vm_page_t *m;
1025 int count;
1026 boolean_t sync;
1027 int *rtvals;
1028 {
1029 int rtval;
1030 struct vnode *vp;
1031 int bytes = count * PAGE_SIZE;
1032
1033 /*
1034 * Force synchronous operation if we are extremely low on memory
1035 * to prevent a low-memory deadlock. VOP operations often need to
1036 * allocate more memory to initiate the I/O ( i.e. do a BMAP
1037 * operation ). The swapper handles the case by limiting the amount
1038 * of asynchronous I/O, but that sort of solution doesn't scale well
1039 * for the vnode pager without a lot of work.
1040 *
1041 * Also, the backing vnode's iodone routine may not wake the pageout
1042 * daemon up. This should be probably be addressed XXX.
1043 */
1044
1045 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min)
1046 sync |= OBJPC_SYNC;
1047
1048 /*
1049 * Call device-specific putpages function
1050 */
1051 vp = object->handle;
1052 VM_OBJECT_UNLOCK(object);
1053 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
1054 KASSERT(rtval != EOPNOTSUPP,
1055 ("vnode_pager: stale FS putpages\n"));
1056 VM_OBJECT_LOCK(object);
1057 }
1058
1059
1060 /*
1061 * This is now called from local media FS's to operate against their
1062 * own vnodes if they fail to implement VOP_PUTPAGES.
1063 *
1064 * This is typically called indirectly via the pageout daemon and
1065 * clustering has already typically occured, so in general we ask the
1066 * underlying filesystem to write the data out asynchronously rather
1067 * then delayed.
1068 */
1069 int
1070 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount,
1071 int flags, int *rtvals)
1072 {
1073 int i;
1074 vm_object_t object;
1075 vm_page_t m;
1076 int count;
1077
1078 int maxsize, ncount;
1079 vm_ooffset_t poffset;
1080 struct uio auio;
1081 struct iovec aiov;
1082 int error;
1083 int ioflags;
1084 int ppscheck = 0;
1085 static struct timeval lastfail;
1086 static int curfail;
1087
1088 object = vp->v_object;
1089 count = bytecount / PAGE_SIZE;
1090
1091 for (i = 0; i < count; i++)
1092 rtvals[i] = VM_PAGER_ERROR;
1093
1094 if ((int64_t)ma[0]->pindex < 0) {
1095 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n",
1096 (long)ma[0]->pindex, (u_long)ma[0]->dirty);
1097 rtvals[0] = VM_PAGER_BAD;
1098 return VM_PAGER_BAD;
1099 }
1100
1101 maxsize = count * PAGE_SIZE;
1102 ncount = count;
1103
1104 poffset = IDX_TO_OFF(ma[0]->pindex);
1105
1106 /*
1107 * If the page-aligned write is larger then the actual file we
1108 * have to invalidate pages occuring beyond the file EOF. However,
1109 * there is an edge case where a file may not be page-aligned where
1110 * the last page is partially invalid. In this case the filesystem
1111 * may not properly clear the dirty bits for the entire page (which
1112 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1113 * With the page locked we are free to fix-up the dirty bits here.
1114 *
1115 * We do not under any circumstances truncate the valid bits, as
1116 * this will screw up bogus page replacement.
1117 */
1118 VM_OBJECT_LOCK(object);
1119 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1120 if (object->un_pager.vnp.vnp_size > poffset) {
1121 int pgoff;
1122
1123 maxsize = object->un_pager.vnp.vnp_size - poffset;
1124 ncount = btoc(maxsize);
1125 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1126 /*
1127 * If the object is locked and the following
1128 * conditions hold, then the page's dirty
1129 * field cannot be concurrently changed by a
1130 * pmap operation.
1131 */
1132 m = ma[ncount - 1];
1133 KASSERT(m->busy > 0,
1134 ("vnode_pager_generic_putpages: page %p is not busy", m));
1135 KASSERT((m->aflags & PGA_WRITEABLE) == 0,
1136 ("vnode_pager_generic_putpages: page %p is not read-only", m));
1137 vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
1138 pgoff);
1139 }
1140 } else {
1141 maxsize = 0;
1142 ncount = 0;
1143 }
1144 if (ncount < count) {
1145 for (i = ncount; i < count; i++) {
1146 rtvals[i] = VM_PAGER_BAD;
1147 }
1148 }
1149 }
1150 VM_OBJECT_UNLOCK(object);
1151
1152 /*
1153 * pageouts are already clustered, use IO_ASYNC t o force a bawrite()
1154 * rather then a bdwrite() to prevent paging I/O from saturating
1155 * the buffer cache. Dummy-up the sequential heuristic to cause
1156 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
1157 * the system decides how to cluster.
1158 */
1159 ioflags = IO_VMIO;
1160 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1161 ioflags |= IO_SYNC;
1162 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1163 ioflags |= IO_ASYNC;
1164 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1165 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1166
1167 aiov.iov_base = (caddr_t) 0;
1168 aiov.iov_len = maxsize;
1169 auio.uio_iov = &aiov;
1170 auio.uio_iovcnt = 1;
1171 auio.uio_offset = poffset;
1172 auio.uio_segflg = UIO_NOCOPY;
1173 auio.uio_rw = UIO_WRITE;
1174 auio.uio_resid = maxsize;
1175 auio.uio_td = (struct thread *) 0;
1176 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred);
1177 PCPU_INC(cnt.v_vnodeout);
1178 PCPU_ADD(cnt.v_vnodepgsout, ncount);
1179
1180 if (error) {
1181 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1)))
1182 printf("vnode_pager_putpages: I/O error %d\n", error);
1183 }
1184 if (auio.uio_resid) {
1185 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1))
1186 printf("vnode_pager_putpages: residual I/O %zd at %lu\n",
1187 auio.uio_resid, (u_long)ma[0]->pindex);
1188 }
1189 for (i = 0; i < ncount; i++) {
1190 rtvals[i] = VM_PAGER_OK;
1191 }
1192 return rtvals[0];
1193 }
1194
1195 void
1196 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written)
1197 {
1198 vm_object_t obj;
1199 int i, pos;
1200
1201 if (written == 0)
1202 return;
1203 obj = ma[0]->object;
1204 VM_OBJECT_LOCK(obj);
1205 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
1206 if (pos < trunc_page(written)) {
1207 rtvals[i] = VM_PAGER_OK;
1208 vm_page_undirty(ma[i]);
1209 } else {
1210 /* Partially written page. */
1211 rtvals[i] = VM_PAGER_AGAIN;
1212 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
1213 }
1214 }
1215 VM_OBJECT_UNLOCK(obj);
1216 }
Cache object: 62c07cade89f198357b9aca18507fa89
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