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/7.3/sys/vm/vnode_pager.c 192154 2009-05-15 19:54:19Z jhb $");
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, vm_ooffset_t);
87
88 struct pagerops vnodepagerops = {
89 .pgo_alloc = vnode_pager_alloc,
90 .pgo_dealloc = vnode_pager_dealloc,
91 .pgo_getpages = vnode_pager_getpages,
92 .pgo_putpages = vnode_pager_putpages,
93 .pgo_haspage = vnode_pager_haspage,
94 };
95
96 int vnode_pbuf_freecnt;
97
98 /* Create the VM system backing object for this vnode */
99 int
100 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
101 {
102 vm_object_t object;
103 vm_ooffset_t size = isize;
104 struct vattr va;
105
106 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
107 return (0);
108
109 while ((object = vp->v_object) != NULL) {
110 VM_OBJECT_LOCK(object);
111 if (!(object->flags & OBJ_DEAD)) {
112 VM_OBJECT_UNLOCK(object);
113 return (0);
114 }
115 VOP_UNLOCK(vp, 0, td);
116 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
117 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0);
118 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
119 }
120
121 if (size == 0) {
122 if (vn_isdisk(vp, NULL)) {
123 size = IDX_TO_OFF(INT_MAX);
124 } else {
125 if (VOP_GETATTR(vp, &va, td->td_ucred, td) != 0)
126 return (0);
127 size = va.va_size;
128 }
129 }
130
131 object = vnode_pager_alloc(vp, size, 0, 0);
132 /*
133 * Dereference the reference we just created. This assumes
134 * that the object is associated with the vp.
135 */
136 VM_OBJECT_LOCK(object);
137 object->ref_count--;
138 VM_OBJECT_UNLOCK(object);
139 vrele(vp);
140
141 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
142
143 return (0);
144 }
145
146 void
147 vnode_destroy_vobject(struct vnode *vp)
148 {
149 struct vm_object *obj;
150
151 obj = vp->v_object;
152 if (obj == NULL)
153 return;
154 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
155 VM_OBJECT_LOCK(obj);
156 if (obj->ref_count == 0) {
157 /*
158 * vclean() may be called twice. The first time
159 * removes the primary reference to the object,
160 * the second time goes one further and is a
161 * special-case to terminate the object.
162 *
163 * don't double-terminate the object
164 */
165 if ((obj->flags & OBJ_DEAD) == 0)
166 vm_object_terminate(obj);
167 else
168 VM_OBJECT_UNLOCK(obj);
169 } else {
170 /*
171 * Woe to the process that tries to page now :-).
172 */
173 vm_pager_deallocate(obj);
174 VM_OBJECT_UNLOCK(obj);
175 }
176 vp->v_object = NULL;
177 }
178
179
180 /*
181 * Allocate (or lookup) pager for a vnode.
182 * Handle is a vnode pointer.
183 *
184 * MPSAFE
185 */
186 vm_object_t
187 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
188 vm_ooffset_t offset)
189 {
190 vm_object_t object;
191 struct vnode *vp;
192
193 /*
194 * Pageout to vnode, no can do yet.
195 */
196 if (handle == NULL)
197 return (NULL);
198
199 vp = (struct vnode *) handle;
200
201 /*
202 * If the object is being terminated, wait for it to
203 * go away.
204 */
205 retry:
206 while ((object = vp->v_object) != NULL) {
207 VM_OBJECT_LOCK(object);
208 if ((object->flags & OBJ_DEAD) == 0)
209 break;
210 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
211 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0);
212 }
213
214 if (vp->v_usecount == 0)
215 panic("vnode_pager_alloc: no vnode reference");
216
217 if (object == NULL) {
218 /*
219 * Add an object of the appropriate size
220 */
221 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
222
223 object->un_pager.vnp.vnp_size = size;
224
225 object->handle = handle;
226 if (VFS_NEEDSGIANT(vp->v_mount))
227 vm_object_set_flag(object, OBJ_NEEDGIANT);
228 VI_LOCK(vp);
229 if (vp->v_object != NULL) {
230 /*
231 * Object has been created while we were sleeping
232 */
233 VI_UNLOCK(vp);
234 vm_object_destroy(object);
235 goto retry;
236 }
237 vp->v_object = object;
238 VI_UNLOCK(vp);
239 } else {
240 object->ref_count++;
241 VM_OBJECT_UNLOCK(object);
242 }
243 vref(vp);
244 return (object);
245 }
246
247 /*
248 * The object must be locked.
249 */
250 static void
251 vnode_pager_dealloc(object)
252 vm_object_t object;
253 {
254 struct vnode *vp = object->handle;
255
256 if (vp == NULL)
257 panic("vnode_pager_dealloc: pager already dealloced");
258
259 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
260 vm_object_pip_wait(object, "vnpdea");
261
262 object->handle = NULL;
263 object->type = OBJT_DEAD;
264 if (object->flags & OBJ_DISCONNECTWNT) {
265 vm_object_clear_flag(object, OBJ_DISCONNECTWNT);
266 wakeup(object);
267 }
268 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
269 vp->v_object = NULL;
270 vp->v_vflag &= ~VV_TEXT;
271 }
272
273 static boolean_t
274 vnode_pager_haspage(object, pindex, before, after)
275 vm_object_t object;
276 vm_pindex_t pindex;
277 int *before;
278 int *after;
279 {
280 struct vnode *vp = object->handle;
281 daddr_t bn;
282 int err;
283 daddr_t reqblock;
284 int poff;
285 int bsize;
286 int pagesperblock, blocksperpage;
287 int vfslocked;
288
289 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
290 /*
291 * If no vp or vp is doomed or marked transparent to VM, we do not
292 * have the page.
293 */
294 if (vp == NULL || vp->v_iflag & VI_DOOMED)
295 return FALSE;
296 /*
297 * If the offset is beyond end of file we do
298 * not have the page.
299 */
300 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
301 return FALSE;
302
303 bsize = vp->v_mount->mnt_stat.f_iosize;
304 pagesperblock = bsize / PAGE_SIZE;
305 blocksperpage = 0;
306 if (pagesperblock > 0) {
307 reqblock = pindex / pagesperblock;
308 } else {
309 blocksperpage = (PAGE_SIZE / bsize);
310 reqblock = pindex * blocksperpage;
311 }
312 VM_OBJECT_UNLOCK(object);
313 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
314 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
315 VFS_UNLOCK_GIANT(vfslocked);
316 VM_OBJECT_LOCK(object);
317 if (err)
318 return TRUE;
319 if (bn == -1)
320 return FALSE;
321 if (pagesperblock > 0) {
322 poff = pindex - (reqblock * pagesperblock);
323 if (before) {
324 *before *= pagesperblock;
325 *before += poff;
326 }
327 if (after) {
328 int numafter;
329 *after *= pagesperblock;
330 numafter = pagesperblock - (poff + 1);
331 if (IDX_TO_OFF(pindex + numafter) >
332 object->un_pager.vnp.vnp_size) {
333 numafter =
334 OFF_TO_IDX(object->un_pager.vnp.vnp_size) -
335 pindex;
336 }
337 *after += numafter;
338 }
339 } else {
340 if (before) {
341 *before /= blocksperpage;
342 }
343
344 if (after) {
345 *after /= blocksperpage;
346 }
347 }
348 return TRUE;
349 }
350
351 /*
352 * Lets the VM system know about a change in size for a file.
353 * We adjust our own internal size and flush any cached pages in
354 * the associated object that are affected by the size change.
355 *
356 * Note: this routine may be invoked as a result of a pager put
357 * operation (possibly at object termination time), so we must be careful.
358 */
359 void
360 vnode_pager_setsize(vp, nsize)
361 struct vnode *vp;
362 vm_ooffset_t nsize;
363 {
364 vm_object_t object;
365 vm_page_t m;
366 vm_pindex_t nobjsize;
367
368 if ((object = vp->v_object) == NULL)
369 return;
370 VM_OBJECT_LOCK(object);
371 if (nsize == object->un_pager.vnp.vnp_size) {
372 /*
373 * Hasn't changed size
374 */
375 VM_OBJECT_UNLOCK(object);
376 return;
377 }
378 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
379 if (nsize < object->un_pager.vnp.vnp_size) {
380 /*
381 * File has shrunk. Toss any cached pages beyond the new EOF.
382 */
383 if (nobjsize < object->size)
384 vm_object_page_remove(object, nobjsize, object->size,
385 FALSE);
386 /*
387 * this gets rid of garbage at the end of a page that is now
388 * only partially backed by the vnode.
389 *
390 * XXX for some reason (I don't know yet), if we take a
391 * completely invalid page and mark it partially valid
392 * it can screw up NFS reads, so we don't allow the case.
393 */
394 if ((nsize & PAGE_MASK) &&
395 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL &&
396 m->valid != 0) {
397 int base = (int)nsize & PAGE_MASK;
398 int size = PAGE_SIZE - base;
399
400 /*
401 * Clear out partial-page garbage in case
402 * the page has been mapped.
403 */
404 pmap_zero_page_area(m, base, size);
405
406 /*
407 * Clear out partial-page dirty bits. This
408 * has the side effect of setting the valid
409 * bits, but that is ok. There are a bunch
410 * of places in the VM system where we expected
411 * m->dirty == VM_PAGE_BITS_ALL. The file EOF
412 * case is one of them. If the page is still
413 * partially dirty, make it fully dirty.
414 *
415 * note that we do not clear out the valid
416 * bits. This would prevent bogus_page
417 * replacement from working properly.
418 */
419 vm_page_lock_queues();
420 vm_page_set_validclean(m, base, size);
421 if (m->dirty != 0)
422 m->dirty = VM_PAGE_BITS_ALL;
423 vm_page_unlock_queues();
424 } else if ((nsize & PAGE_MASK) &&
425 __predict_false(object->cache != NULL)) {
426 vm_page_cache_free(object, OFF_TO_IDX(nsize),
427 nobjsize);
428 }
429 }
430 object->un_pager.vnp.vnp_size = nsize;
431 object->size = nobjsize;
432 VM_OBJECT_UNLOCK(object);
433 }
434
435 /*
436 * calculate the linear (byte) disk address of specified virtual
437 * file address
438 */
439 static int
440 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
441 int *run)
442 {
443 int bsize;
444 int err;
445 daddr_t vblock;
446 daddr_t voffset;
447
448 if (address < 0)
449 return -1;
450
451 if (vp->v_iflag & VI_DOOMED)
452 return -1;
453
454 bsize = vp->v_mount->mnt_stat.f_iosize;
455 vblock = address / bsize;
456 voffset = address % bsize;
457
458 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
459 if (err == 0) {
460 if (*rtaddress != -1)
461 *rtaddress += voffset / DEV_BSIZE;
462 if (run) {
463 *run += 1;
464 *run *= bsize/PAGE_SIZE;
465 *run -= voffset/PAGE_SIZE;
466 }
467 }
468
469 return (err);
470 }
471
472 /*
473 * small block filesystem vnode pager input
474 */
475 static int
476 vnode_pager_input_smlfs(object, m)
477 vm_object_t object;
478 vm_page_t m;
479 {
480 int i;
481 struct vnode *vp;
482 struct bufobj *bo;
483 struct buf *bp;
484 struct sf_buf *sf;
485 daddr_t fileaddr;
486 vm_offset_t bsize;
487 int error = 0;
488
489 vp = object->handle;
490 if (vp->v_iflag & VI_DOOMED)
491 return VM_PAGER_BAD;
492
493 bsize = vp->v_mount->mnt_stat.f_iosize;
494
495 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
496
497 sf = sf_buf_alloc(m, 0);
498
499 for (i = 0; i < PAGE_SIZE / bsize; i++) {
500 vm_ooffset_t address;
501
502 if (vm_page_bits(i * bsize, bsize) & m->valid)
503 continue;
504
505 address = IDX_TO_OFF(m->pindex) + i * bsize;
506 if (address >= object->un_pager.vnp.vnp_size) {
507 fileaddr = -1;
508 } else {
509 error = vnode_pager_addr(vp, address, &fileaddr, NULL);
510 if (error)
511 break;
512 }
513 if (fileaddr != -1) {
514 bp = getpbuf(&vnode_pbuf_freecnt);
515
516 /* build a minimal buffer header */
517 bp->b_iocmd = BIO_READ;
518 bp->b_iodone = bdone;
519 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
520 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
521 bp->b_rcred = crhold(curthread->td_ucred);
522 bp->b_wcred = crhold(curthread->td_ucred);
523 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
524 bp->b_blkno = fileaddr;
525 pbgetbo(bo, bp);
526 bp->b_bcount = bsize;
527 bp->b_bufsize = bsize;
528 bp->b_runningbufspace = bp->b_bufsize;
529 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
530
531 /* do the input */
532 bp->b_iooffset = dbtob(bp->b_blkno);
533 bstrategy(bp);
534
535 bwait(bp, PVM, "vnsrd");
536
537 if ((bp->b_ioflags & BIO_ERROR) != 0)
538 error = EIO;
539
540 /*
541 * free the buffer header back to the swap buffer pool
542 */
543 pbrelbo(bp);
544 relpbuf(bp, &vnode_pbuf_freecnt);
545 if (error)
546 break;
547
548 VM_OBJECT_LOCK(object);
549 vm_page_lock_queues();
550 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
551 vm_page_unlock_queues();
552 VM_OBJECT_UNLOCK(object);
553 } else {
554 VM_OBJECT_LOCK(object);
555 vm_page_lock_queues();
556 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize);
557 vm_page_unlock_queues();
558 VM_OBJECT_UNLOCK(object);
559 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
560 }
561 }
562 sf_buf_free(sf);
563 vm_page_lock_queues();
564 pmap_clear_modify(m);
565 vm_page_unlock_queues();
566 if (error) {
567 return VM_PAGER_ERROR;
568 }
569 return VM_PAGER_OK;
570
571 }
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 vm_page_lock_queues();
635 pmap_clear_modify(m);
636 vm_page_undirty(m);
637 vm_page_unlock_queues();
638 if (!error)
639 m->valid = VM_PAGE_BITS_ALL;
640 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
641 }
642
643 /*
644 * generic vnode pager input routine
645 */
646
647 /*
648 * Local media VFS's that do not implement their own VOP_GETPAGES
649 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
650 * to implement the previous behaviour.
651 *
652 * All other FS's should use the bypass to get to the local media
653 * backing vp's VOP_GETPAGES.
654 */
655 static int
656 vnode_pager_getpages(object, m, count, reqpage)
657 vm_object_t object;
658 vm_page_t *m;
659 int count;
660 int reqpage;
661 {
662 int rtval;
663 struct vnode *vp;
664 int bytes = count * PAGE_SIZE;
665 int vfslocked;
666
667 vp = object->handle;
668 VM_OBJECT_UNLOCK(object);
669 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
670 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
671 KASSERT(rtval != EOPNOTSUPP,
672 ("vnode_pager: FS getpages not implemented\n"));
673 VFS_UNLOCK_GIANT(vfslocked);
674 VM_OBJECT_LOCK(object);
675 return rtval;
676 }
677
678 /*
679 * This is now called from local media FS's to operate against their
680 * own vnodes if they fail to implement VOP_GETPAGES.
681 */
682 int
683 vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
684 struct vnode *vp;
685 vm_page_t *m;
686 int bytecount;
687 int reqpage;
688 {
689 vm_object_t object;
690 vm_offset_t kva;
691 off_t foff, tfoff, nextoff;
692 int i, j, size, bsize, first;
693 daddr_t firstaddr, reqblock;
694 struct bufobj *bo;
695 int runpg;
696 int runend;
697 struct buf *bp;
698 int count;
699 int error;
700
701 object = vp->v_object;
702 count = bytecount / PAGE_SIZE;
703
704 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
705 ("vnode_pager_generic_getpages does not support devices"));
706 if (vp->v_iflag & VI_DOOMED)
707 return VM_PAGER_BAD;
708
709 bsize = vp->v_mount->mnt_stat.f_iosize;
710
711 /* get the UNDERLYING device for the file with VOP_BMAP() */
712
713 /*
714 * originally, we did not check for an error return value -- assuming
715 * an fs always has a bmap entry point -- that assumption is wrong!!!
716 */
717 foff = IDX_TO_OFF(m[reqpage]->pindex);
718
719 /*
720 * if we can't bmap, use old VOP code
721 */
722 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL);
723 if (error == EOPNOTSUPP) {
724 VM_OBJECT_LOCK(object);
725 vm_page_lock_queues();
726 for (i = 0; i < count; i++)
727 if (i != reqpage)
728 vm_page_free(m[i]);
729 vm_page_unlock_queues();
730 PCPU_INC(cnt.v_vnodein);
731 PCPU_INC(cnt.v_vnodepgsin);
732 error = vnode_pager_input_old(object, m[reqpage]);
733 VM_OBJECT_UNLOCK(object);
734 return (error);
735 } else if (error != 0) {
736 VM_OBJECT_LOCK(object);
737 vm_page_lock_queues();
738 for (i = 0; i < count; i++)
739 if (i != reqpage)
740 vm_page_free(m[i]);
741 vm_page_unlock_queues();
742 VM_OBJECT_UNLOCK(object);
743 return (VM_PAGER_ERROR);
744
745 /*
746 * if the blocksize is smaller than a page size, then use
747 * special small filesystem code. NFS sometimes has a small
748 * blocksize, but it can handle large reads itself.
749 */
750 } else if ((PAGE_SIZE / bsize) > 1 &&
751 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
752 VM_OBJECT_LOCK(object);
753 vm_page_lock_queues();
754 for (i = 0; i < count; i++)
755 if (i != reqpage)
756 vm_page_free(m[i]);
757 vm_page_unlock_queues();
758 VM_OBJECT_UNLOCK(object);
759 PCPU_INC(cnt.v_vnodein);
760 PCPU_INC(cnt.v_vnodepgsin);
761 return vnode_pager_input_smlfs(object, m[reqpage]);
762 }
763
764 /*
765 * If we have a completely valid page available to us, we can
766 * clean up and return. Otherwise we have to re-read the
767 * media.
768 */
769 VM_OBJECT_LOCK(object);
770 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
771 vm_page_lock_queues();
772 for (i = 0; i < count; i++)
773 if (i != reqpage)
774 vm_page_free(m[i]);
775 vm_page_unlock_queues();
776 VM_OBJECT_UNLOCK(object);
777 return VM_PAGER_OK;
778 } else if (reqblock == -1) {
779 pmap_zero_page(m[reqpage]);
780 vm_page_undirty(m[reqpage]);
781 m[reqpage]->valid = VM_PAGE_BITS_ALL;
782 vm_page_lock_queues();
783 for (i = 0; i < count; i++)
784 if (i != reqpage)
785 vm_page_free(m[i]);
786 vm_page_unlock_queues();
787 VM_OBJECT_UNLOCK(object);
788 return (VM_PAGER_OK);
789 }
790 m[reqpage]->valid = 0;
791 VM_OBJECT_UNLOCK(object);
792
793 /*
794 * here on direct device I/O
795 */
796 firstaddr = -1;
797
798 /*
799 * calculate the run that includes the required page
800 */
801 for (first = 0, i = 0; i < count; i = runend) {
802 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr,
803 &runpg) != 0) {
804 VM_OBJECT_LOCK(object);
805 vm_page_lock_queues();
806 for (; i < count; i++)
807 if (i != reqpage)
808 vm_page_free(m[i]);
809 vm_page_unlock_queues();
810 VM_OBJECT_UNLOCK(object);
811 return (VM_PAGER_ERROR);
812 }
813 if (firstaddr == -1) {
814 VM_OBJECT_LOCK(object);
815 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
816 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx",
817 (intmax_t)firstaddr, (uintmax_t)(foff >> 32),
818 (uintmax_t)foff,
819 (uintmax_t)
820 (object->un_pager.vnp.vnp_size >> 32),
821 (uintmax_t)object->un_pager.vnp.vnp_size);
822 }
823 vm_page_lock_queues();
824 vm_page_free(m[i]);
825 vm_page_unlock_queues();
826 VM_OBJECT_UNLOCK(object);
827 runend = i + 1;
828 first = runend;
829 continue;
830 }
831 runend = i + runpg;
832 if (runend <= reqpage) {
833 VM_OBJECT_LOCK(object);
834 vm_page_lock_queues();
835 for (j = i; j < runend; j++)
836 vm_page_free(m[j]);
837 vm_page_unlock_queues();
838 VM_OBJECT_UNLOCK(object);
839 } else {
840 if (runpg < (count - first)) {
841 VM_OBJECT_LOCK(object);
842 vm_page_lock_queues();
843 for (i = first + runpg; i < count; i++)
844 vm_page_free(m[i]);
845 vm_page_unlock_queues();
846 VM_OBJECT_UNLOCK(object);
847 count = first + runpg;
848 }
849 break;
850 }
851 first = runend;
852 }
853
854 /*
855 * the first and last page have been calculated now, move input pages
856 * to be zero based...
857 */
858 if (first != 0) {
859 m += first;
860 count -= first;
861 reqpage -= first;
862 }
863
864 /*
865 * calculate the file virtual address for the transfer
866 */
867 foff = IDX_TO_OFF(m[0]->pindex);
868
869 /*
870 * calculate the size of the transfer
871 */
872 size = count * PAGE_SIZE;
873 KASSERT(count > 0, ("zero count"));
874 if ((foff + size) > object->un_pager.vnp.vnp_size)
875 size = object->un_pager.vnp.vnp_size - foff;
876 KASSERT(size > 0, ("zero size"));
877
878 /*
879 * round up physical size for real devices.
880 */
881 if (1) {
882 int secmask = bo->bo_bsize - 1;
883 KASSERT(secmask < PAGE_SIZE && secmask > 0,
884 ("vnode_pager_generic_getpages: sector size %d too large",
885 secmask + 1));
886 size = (size + secmask) & ~secmask;
887 }
888
889 bp = getpbuf(&vnode_pbuf_freecnt);
890 kva = (vm_offset_t) bp->b_data;
891
892 /*
893 * and map the pages to be read into the kva
894 */
895 pmap_qenter(kva, m, count);
896
897 /* build a minimal buffer header */
898 bp->b_iocmd = BIO_READ;
899 bp->b_iodone = bdone;
900 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
901 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
902 bp->b_rcred = crhold(curthread->td_ucred);
903 bp->b_wcred = crhold(curthread->td_ucred);
904 bp->b_blkno = firstaddr;
905 pbgetbo(bo, bp);
906 bp->b_bcount = size;
907 bp->b_bufsize = size;
908 bp->b_runningbufspace = bp->b_bufsize;
909 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
910
911 PCPU_INC(cnt.v_vnodein);
912 PCPU_ADD(cnt.v_vnodepgsin, count);
913
914 /* do the input */
915 bp->b_iooffset = dbtob(bp->b_blkno);
916 bstrategy(bp);
917
918 bwait(bp, PVM, "vnread");
919
920 if ((bp->b_ioflags & BIO_ERROR) != 0)
921 error = EIO;
922
923 if (!error) {
924 if (size != count * PAGE_SIZE)
925 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
926 }
927 pmap_qremove(kva, count);
928
929 /*
930 * free the buffer header back to the swap buffer pool
931 */
932 pbrelbo(bp);
933 relpbuf(bp, &vnode_pbuf_freecnt);
934
935 VM_OBJECT_LOCK(object);
936 vm_page_lock_queues();
937 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
938 vm_page_t mt;
939
940 nextoff = tfoff + PAGE_SIZE;
941 mt = m[i];
942
943 if (nextoff <= object->un_pager.vnp.vnp_size) {
944 /*
945 * Read filled up entire page.
946 */
947 mt->valid = VM_PAGE_BITS_ALL;
948 vm_page_undirty(mt); /* should be an assert? XXX */
949 pmap_clear_modify(mt);
950 } else {
951 /*
952 * Read did not fill up entire page. Since this
953 * is getpages, the page may be mapped, so we have
954 * to zero the invalid portions of the page even
955 * though we aren't setting them valid.
956 *
957 * Currently we do not set the entire page valid,
958 * we just try to clear the piece that we couldn't
959 * read.
960 */
961 vm_page_set_validclean(mt, 0,
962 object->un_pager.vnp.vnp_size - tfoff);
963 /* handled by vm_fault now */
964 /* vm_page_zero_invalid(mt, FALSE); */
965 }
966
967 if (i != reqpage) {
968
969 /*
970 * whether or not to leave the page activated is up in
971 * the air, but we should put the page on a page queue
972 * somewhere. (it already is in the object). Result:
973 * It appears that empirical results show that
974 * deactivating pages is best.
975 */
976
977 /*
978 * just in case someone was asking for this page we
979 * now tell them that it is ok to use
980 */
981 if (!error) {
982 if (mt->oflags & VPO_WANTED)
983 vm_page_activate(mt);
984 else
985 vm_page_deactivate(mt);
986 vm_page_wakeup(mt);
987 } else {
988 vm_page_free(mt);
989 }
990 }
991 }
992 vm_page_unlock_queues();
993 VM_OBJECT_UNLOCK(object);
994 if (error) {
995 printf("vnode_pager_getpages: I/O read error\n");
996 }
997 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
998 }
999
1000 /*
1001 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
1002 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
1003 * vnode_pager_generic_putpages() to implement the previous behaviour.
1004 *
1005 * All other FS's should use the bypass to get to the local media
1006 * backing vp's VOP_PUTPAGES.
1007 */
1008 static void
1009 vnode_pager_putpages(object, m, count, sync, rtvals)
1010 vm_object_t object;
1011 vm_page_t *m;
1012 int count;
1013 boolean_t sync;
1014 int *rtvals;
1015 {
1016 int rtval;
1017 struct vnode *vp;
1018 struct mount *mp;
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 if (vp->v_type != VREG)
1042 mp = NULL;
1043 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
1044 KASSERT(rtval != EOPNOTSUPP,
1045 ("vnode_pager: stale FS putpages\n"));
1046 VM_OBJECT_LOCK(object);
1047 }
1048
1049
1050 /*
1051 * This is now called from local media FS's to operate against their
1052 * own vnodes if they fail to implement VOP_PUTPAGES.
1053 *
1054 * This is typically called indirectly via the pageout daemon and
1055 * clustering has already typically occured, so in general we ask the
1056 * underlying filesystem to write the data out asynchronously rather
1057 * then delayed.
1058 */
1059 int
1060 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals)
1061 struct vnode *vp;
1062 vm_page_t *m;
1063 int bytecount;
1064 int flags;
1065 int *rtvals;
1066 {
1067 int i;
1068 vm_object_t object;
1069 int count;
1070
1071 int maxsize, ncount;
1072 vm_ooffset_t poffset;
1073 struct uio auio;
1074 struct iovec aiov;
1075 int error;
1076 int ioflags;
1077 int ppscheck = 0;
1078 static struct timeval lastfail;
1079 static int curfail;
1080
1081 object = vp->v_object;
1082 count = bytecount / PAGE_SIZE;
1083
1084 for (i = 0; i < count; i++)
1085 rtvals[i] = VM_PAGER_AGAIN;
1086
1087 if ((int64_t)m[0]->pindex < 0) {
1088 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n",
1089 (long)m[0]->pindex, (u_long)m[0]->dirty);
1090 rtvals[0] = VM_PAGER_BAD;
1091 return VM_PAGER_BAD;
1092 }
1093
1094 maxsize = count * PAGE_SIZE;
1095 ncount = count;
1096
1097 poffset = IDX_TO_OFF(m[0]->pindex);
1098
1099 /*
1100 * If the page-aligned write is larger then the actual file we
1101 * have to invalidate pages occuring beyond the file EOF. However,
1102 * there is an edge case where a file may not be page-aligned where
1103 * the last page is partially invalid. In this case the filesystem
1104 * may not properly clear the dirty bits for the entire page (which
1105 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1106 * With the page locked we are free to fix-up the dirty bits here.
1107 *
1108 * We do not under any circumstances truncate the valid bits, as
1109 * this will screw up bogus page replacement.
1110 */
1111 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1112 if (object->un_pager.vnp.vnp_size > poffset) {
1113 int pgoff;
1114
1115 maxsize = object->un_pager.vnp.vnp_size - poffset;
1116 ncount = btoc(maxsize);
1117 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1118 vm_page_lock_queues();
1119 vm_page_clear_dirty(m[ncount - 1], pgoff,
1120 PAGE_SIZE - pgoff);
1121 vm_page_unlock_queues();
1122 }
1123 } else {
1124 maxsize = 0;
1125 ncount = 0;
1126 }
1127 if (ncount < count) {
1128 for (i = ncount; i < count; i++) {
1129 rtvals[i] = VM_PAGER_BAD;
1130 }
1131 }
1132 }
1133
1134 /*
1135 * pageouts are already clustered, use IO_ASYNC t o force a bawrite()
1136 * rather then a bdwrite() to prevent paging I/O from saturating
1137 * the buffer cache. Dummy-up the sequential heuristic to cause
1138 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
1139 * the system decides how to cluster.
1140 */
1141 ioflags = IO_VMIO;
1142 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1143 ioflags |= IO_SYNC;
1144 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1145 ioflags |= IO_ASYNC;
1146 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1147 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1148
1149 aiov.iov_base = (caddr_t) 0;
1150 aiov.iov_len = maxsize;
1151 auio.uio_iov = &aiov;
1152 auio.uio_iovcnt = 1;
1153 auio.uio_offset = poffset;
1154 auio.uio_segflg = UIO_NOCOPY;
1155 auio.uio_rw = UIO_WRITE;
1156 auio.uio_resid = maxsize;
1157 auio.uio_td = (struct thread *) 0;
1158 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred);
1159 PCPU_INC(cnt.v_vnodeout);
1160 PCPU_ADD(cnt.v_vnodepgsout, ncount);
1161
1162 if (error) {
1163 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1)))
1164 printf("vnode_pager_putpages: I/O error %d\n", error);
1165 }
1166 if (auio.uio_resid) {
1167 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1))
1168 printf("vnode_pager_putpages: residual I/O %d at %lu\n",
1169 auio.uio_resid, (u_long)m[0]->pindex);
1170 }
1171 for (i = 0; i < ncount; i++) {
1172 rtvals[i] = VM_PAGER_OK;
1173 }
1174 return rtvals[0];
1175 }
1176
1177 struct vnode *
1178 vnode_pager_lock(vm_object_t first_object)
1179 {
1180 struct vnode *vp;
1181 vm_object_t backing_object, object;
1182
1183 VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED);
1184 for (object = first_object; object != NULL; object = backing_object) {
1185 if (object->type != OBJT_VNODE) {
1186 if ((backing_object = object->backing_object) != NULL)
1187 VM_OBJECT_LOCK(backing_object);
1188 if (object != first_object)
1189 VM_OBJECT_UNLOCK(object);
1190 continue;
1191 }
1192 retry:
1193 if (object->flags & OBJ_DEAD) {
1194 if (object != first_object)
1195 VM_OBJECT_UNLOCK(object);
1196 return NULL;
1197 }
1198 vp = object->handle;
1199 VI_LOCK(vp);
1200 VM_OBJECT_UNLOCK(object);
1201 if (first_object != object)
1202 VM_OBJECT_UNLOCK(first_object);
1203 VFS_ASSERT_GIANT(vp->v_mount);
1204 if (vget(vp, LK_CANRECURSE | LK_INTERLOCK |
1205 LK_RETRY | LK_SHARED, curthread)) {
1206 VM_OBJECT_LOCK(first_object);
1207 if (object != first_object)
1208 VM_OBJECT_LOCK(object);
1209 if (object->type != OBJT_VNODE) {
1210 if (object != first_object)
1211 VM_OBJECT_UNLOCK(object);
1212 return NULL;
1213 }
1214 printf("vnode_pager_lock: retrying\n");
1215 goto retry;
1216 }
1217 VM_OBJECT_LOCK(first_object);
1218 return (vp);
1219 }
1220 return NULL;
1221 }
Cache object: a594bdfc2a6e971c108bcd257afc1f2a
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