vnode_pager.c revision 28558
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 * $Id: vnode_pager.c,v 1.71 1997/05/19 14:36:56 dfr Exp $ 42 */ 43 44/* 45 * Page to/from files (vnodes). 46 */ 47 48/* 49 * TODO: 50 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 51 * greatly re-simplify the vnode_pager. 52 */ 53 54#include <sys/param.h> 55#include <sys/systm.h> 56#include <sys/kernel.h> 57#include <sys/proc.h> 58#include <sys/malloc.h> 59#include <sys/vnode.h> 60#include <sys/uio.h> 61#include <sys/mount.h> 62#include <sys/buf.h> 63#include <sys/vmmeter.h> 64 65#include <vm/vm.h> 66#include <vm/vm_param.h> 67#include <vm/vm_prot.h> 68#include <vm/vm_object.h> 69#include <vm/vm_page.h> 70#include <vm/vm_pager.h> 71#include <vm/vnode_pager.h> 72#include <vm/vm_extern.h> 73 74static vm_offset_t vnode_pager_addr __P((struct vnode *vp, vm_ooffset_t address, 75 int *run)); 76static void vnode_pager_iodone __P((struct buf *bp)); 77static int vnode_pager_input_smlfs __P((vm_object_t object, vm_page_t m)); 78static int vnode_pager_input_old __P((vm_object_t object, vm_page_t m)); 79static void vnode_pager_dealloc __P((vm_object_t)); 80static int vnode_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 81static int vnode_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *)); 82static boolean_t vnode_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *)); 83 84struct pagerops vnodepagerops = { 85 NULL, 86 vnode_pager_alloc, 87 vnode_pager_dealloc, 88 vnode_pager_getpages, 89 vnode_pager_putpages, 90 vnode_pager_haspage, 91 NULL 92}; 93 94static int vnode_pager_leaf_getpages __P((vm_object_t object, vm_page_t *m, 95 int count, int reqpage)); 96static int vnode_pager_leaf_putpages __P((vm_object_t object, vm_page_t *m, 97 int count, boolean_t sync, 98 int *rtvals)); 99 100/* 101 * Allocate (or lookup) pager for a vnode. 102 * Handle is a vnode pointer. 103 */ 104vm_object_t 105vnode_pager_alloc(handle, size, prot, offset) 106 void *handle; 107 vm_size_t size; 108 vm_prot_t prot; 109 vm_ooffset_t offset; 110{ 111 vm_object_t object; 112 struct vnode *vp; 113 114 /* 115 * Pageout to vnode, no can do yet. 116 */ 117 if (handle == NULL) 118 return (NULL); 119 120 vp = (struct vnode *) handle; 121 122 /* 123 * Prevent race condition when allocating the object. This 124 * can happen with NFS vnodes since the nfsnode isn't locked. 125 */ 126 while (vp->v_flag & VOLOCK) { 127 vp->v_flag |= VOWANT; 128 tsleep(vp, PVM, "vnpobj", 0); 129 } 130 vp->v_flag |= VOLOCK; 131 132 /* 133 * If the object is being terminated, wait for it to 134 * go away. 135 */ 136 while (((object = vp->v_object) != NULL) && 137 (object->flags & OBJ_DEAD)) { 138 tsleep(object, PVM, "vadead", 0); 139 } 140 141 if (object == NULL) { 142 /* 143 * And an object of the appropriate size 144 */ 145 object = vm_object_allocate(OBJT_VNODE, size); 146 if (vp->v_type == VREG) 147 object->flags = OBJ_CANPERSIST; 148 else 149 object->flags = 0; 150 151 if (vp->v_usecount == 0) 152 panic("vnode_pager_alloc: no vnode reference"); 153 /* 154 * Hold a reference to the vnode and initialize object data. 155 */ 156 vp->v_usecount++; 157 object->un_pager.vnp.vnp_size = (vm_ooffset_t) size * PAGE_SIZE; 158 159 object->handle = handle; 160 vp->v_object = object; 161 } else { 162 /* 163 * vm_object_reference() will remove the object from the cache if 164 * found and gain a reference to the object. 165 */ 166 vm_object_reference(object); 167 } 168 169 if (vp->v_type == VREG) 170 vp->v_flag |= VVMIO; 171 172 vp->v_flag &= ~VOLOCK; 173 if (vp->v_flag & VOWANT) { 174 vp->v_flag &= ~VOWANT; 175 wakeup(vp); 176 } 177 return (object); 178} 179 180static void 181vnode_pager_dealloc(object) 182 vm_object_t object; 183{ 184 register struct vnode *vp = object->handle; 185 186 if (vp == NULL) 187 panic("vnode_pager_dealloc: pager already dealloced"); 188 189 if (object->paging_in_progress) { 190 int s = splbio(); 191 while (object->paging_in_progress) { 192 object->flags |= OBJ_PIPWNT; 193 tsleep(object, PVM, "vnpdea", 0); 194 } 195 splx(s); 196 } 197 198 object->handle = NULL; 199 200 vp->v_object = NULL; 201 vp->v_flag &= ~(VTEXT | VVMIO); 202 vrele(vp); 203} 204 205static boolean_t 206vnode_pager_haspage(object, pindex, before, after) 207 vm_object_t object; 208 vm_pindex_t pindex; 209 int *before; 210 int *after; 211{ 212 struct vnode *vp = object->handle; 213 daddr_t bn; 214 int err; 215 daddr_t reqblock; 216 int poff; 217 int bsize; 218 int pagesperblock, blocksperpage; 219 220 /* 221 * If filesystem no longer mounted or offset beyond end of file we do 222 * not have the page. 223 */ 224 if ((vp->v_mount == NULL) || 225 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 226 return FALSE; 227 228 bsize = vp->v_mount->mnt_stat.f_iosize; 229 pagesperblock = bsize / PAGE_SIZE; 230 blocksperpage = 0; 231 if (pagesperblock > 0) { 232 reqblock = pindex / pagesperblock; 233 } else { 234 blocksperpage = (PAGE_SIZE / bsize); 235 reqblock = pindex * blocksperpage; 236 } 237 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 238 after, before); 239 if (err) 240 return TRUE; 241 if ( bn == -1) 242 return FALSE; 243 if (pagesperblock > 0) { 244 poff = pindex - (reqblock * pagesperblock); 245 if (before) { 246 *before *= pagesperblock; 247 *before += poff; 248 } 249 if (after) { 250 int numafter; 251 *after *= pagesperblock; 252 numafter = pagesperblock - (poff + 1); 253 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { 254 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex))); 255 } 256 *after += numafter; 257 } 258 } else { 259 if (before) { 260 *before /= blocksperpage; 261 } 262 263 if (after) { 264 *after /= blocksperpage; 265 } 266 } 267 return TRUE; 268} 269 270/* 271 * Lets the VM system know about a change in size for a file. 272 * We adjust our own internal size and flush any cached pages in 273 * the associated object that are affected by the size change. 274 * 275 * Note: this routine may be invoked as a result of a pager put 276 * operation (possibly at object termination time), so we must be careful. 277 */ 278void 279vnode_pager_setsize(vp, nsize) 280 struct vnode *vp; 281 vm_ooffset_t nsize; 282{ 283 vm_object_t object = vp->v_object; 284 285 if (object == NULL) 286 return; 287 288 /* 289 * Hasn't changed size 290 */ 291 if (nsize == object->un_pager.vnp.vnp_size) 292 return; 293 294 /* 295 * File has shrunk. Toss any cached pages beyond the new EOF. 296 */ 297 if (nsize < object->un_pager.vnp.vnp_size) { 298 vm_ooffset_t nsizerounded; 299 nsizerounded = IDX_TO_OFF(OFF_TO_IDX(nsize + PAGE_MASK)); 300 if (nsizerounded < object->un_pager.vnp.vnp_size) { 301 vm_object_page_remove(object, 302 OFF_TO_IDX(nsize + PAGE_MASK), 303 OFF_TO_IDX(object->un_pager.vnp.vnp_size), 304 FALSE); 305 } 306 /* 307 * this gets rid of garbage at the end of a page that is now 308 * only partially backed by the vnode... 309 */ 310 if (nsize & PAGE_MASK) { 311 vm_offset_t kva; 312 vm_page_t m; 313 314 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 315 if (m) { 316 kva = vm_pager_map_page(m); 317 bzero((caddr_t) kva + (nsize & PAGE_MASK), 318 (int) (round_page(nsize) - nsize)); 319 vm_pager_unmap_page(kva); 320 } 321 } 322 } 323 object->un_pager.vnp.vnp_size = nsize; 324 object->size = OFF_TO_IDX(nsize + PAGE_MASK); 325} 326 327void 328vnode_pager_umount(mp) 329 register struct mount *mp; 330{ 331 struct proc *p = curproc; /* XXX */ 332 struct vnode *vp, *nvp; 333 334loop: 335 for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) { 336 /* 337 * Vnode can be reclaimed by getnewvnode() while we 338 * traverse the list. 339 */ 340 if (vp->v_mount != mp) 341 goto loop; 342 343 /* 344 * Save the next pointer now since uncaching may terminate the 345 * object and render vnode invalid 346 */ 347 nvp = vp->v_mntvnodes.le_next; 348 349 if (vp->v_object != NULL) { 350 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 351 vnode_pager_uncache(vp, p); 352 VOP_UNLOCK(vp, 0, p); 353 } 354 } 355} 356 357/* 358 * Remove vnode associated object from the object cache. 359 * This routine must be called with the vnode locked. 360 * 361 * XXX unlock the vnode. 362 * We must do this since uncaching the object may result in its 363 * destruction which may initiate paging activity which may necessitate 364 * re-locking the vnode. 365 */ 366void 367vnode_pager_uncache(vp, p) 368 struct vnode *vp; 369 struct proc *p; 370{ 371 vm_object_t object; 372 373 /* 374 * Not a mapped vnode 375 */ 376 object = vp->v_object; 377 if (object == NULL) 378 return; 379 380 vm_object_reference(object); 381 382 /* 383 * XXX We really should handle locking on 384 * VBLK devices... 385 */ 386 if (vp->v_type != VBLK) 387 VOP_UNLOCK(vp, 0, p); 388 pager_cache(object, FALSE); 389 if (vp->v_type != VBLK) 390 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 391 return; 392} 393 394 395void 396vnode_pager_freepage(m) 397 vm_page_t m; 398{ 399 PAGE_WAKEUP(m); 400 vm_page_free(m); 401} 402 403/* 404 * calculate the linear (byte) disk address of specified virtual 405 * file address 406 */ 407static vm_offset_t 408vnode_pager_addr(vp, address, run) 409 struct vnode *vp; 410 vm_ooffset_t address; 411 int *run; 412{ 413 int rtaddress; 414 int bsize; 415 daddr_t block; 416 struct vnode *rtvp; 417 int err; 418 daddr_t vblock; 419 int voffset; 420 421 if ((int) address < 0) 422 return -1; 423 424 if (vp->v_mount == NULL) 425 return -1; 426 427 bsize = vp->v_mount->mnt_stat.f_iosize; 428 vblock = address / bsize; 429 voffset = address % bsize; 430 431 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 432 433 if (err || (block == -1)) 434 rtaddress = -1; 435 else { 436 rtaddress = block + voffset / DEV_BSIZE; 437 if( run) { 438 *run += 1; 439 *run *= bsize/PAGE_SIZE; 440 *run -= voffset/PAGE_SIZE; 441 } 442 } 443 444 return rtaddress; 445} 446 447/* 448 * interrupt routine for I/O completion 449 */ 450static void 451vnode_pager_iodone(bp) 452 struct buf *bp; 453{ 454 bp->b_flags |= B_DONE; 455 wakeup(bp); 456} 457 458/* 459 * small block file system vnode pager input 460 */ 461static int 462vnode_pager_input_smlfs(object, m) 463 vm_object_t object; 464 vm_page_t m; 465{ 466 int i; 467 int s; 468 struct vnode *dp, *vp; 469 struct buf *bp; 470 vm_offset_t kva; 471 int fileaddr; 472 vm_offset_t bsize; 473 int error = 0; 474 475 vp = object->handle; 476 if (vp->v_mount == NULL) 477 return VM_PAGER_BAD; 478 479 bsize = vp->v_mount->mnt_stat.f_iosize; 480 481 482 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 483 484 kva = vm_pager_map_page(m); 485 486 for (i = 0; i < PAGE_SIZE / bsize; i++) { 487 488 if ((vm_page_bits(IDX_TO_OFF(m->pindex) + i * bsize, bsize) & m->valid)) 489 continue; 490 491 fileaddr = vnode_pager_addr(vp, 492 IDX_TO_OFF(m->pindex) + i * bsize, (int *)0); 493 if (fileaddr != -1) { 494 bp = getpbuf(); 495 496 /* build a minimal buffer header */ 497 bp->b_flags = B_BUSY | B_READ | B_CALL; 498 bp->b_iodone = vnode_pager_iodone; 499 bp->b_proc = curproc; 500 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 501 if (bp->b_rcred != NOCRED) 502 crhold(bp->b_rcred); 503 if (bp->b_wcred != NOCRED) 504 crhold(bp->b_wcred); 505 bp->b_un.b_addr = (caddr_t) kva + i * bsize; 506 bp->b_blkno = fileaddr; 507 pbgetvp(dp, bp); 508 bp->b_bcount = bsize; 509 bp->b_bufsize = bsize; 510 511 /* do the input */ 512 VOP_STRATEGY(bp); 513 514 /* we definitely need to be at splbio here */ 515 516 s = splbio(); 517 while ((bp->b_flags & B_DONE) == 0) { 518 tsleep(bp, PVM, "vnsrd", 0); 519 } 520 splx(s); 521 if ((bp->b_flags & B_ERROR) != 0) 522 error = EIO; 523 524 /* 525 * free the buffer header back to the swap buffer pool 526 */ 527 relpbuf(bp); 528 if (error) 529 break; 530 531 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 532 } else { 533 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 534 bzero((caddr_t) kva + i * bsize, bsize); 535 } 536 } 537 vm_pager_unmap_page(kva); 538 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 539 m->flags &= ~PG_ZERO; 540 if (error) { 541 return VM_PAGER_ERROR; 542 } 543 return VM_PAGER_OK; 544 545} 546 547 548/* 549 * old style vnode pager output routine 550 */ 551static int 552vnode_pager_input_old(object, m) 553 vm_object_t object; 554 vm_page_t m; 555{ 556 struct uio auio; 557 struct iovec aiov; 558 int error; 559 int size; 560 vm_offset_t kva; 561 562 error = 0; 563 564 /* 565 * Return failure if beyond current EOF 566 */ 567 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 568 return VM_PAGER_BAD; 569 } else { 570 size = PAGE_SIZE; 571 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 572 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 573 574 /* 575 * Allocate a kernel virtual address and initialize so that 576 * we can use VOP_READ/WRITE routines. 577 */ 578 kva = vm_pager_map_page(m); 579 580 aiov.iov_base = (caddr_t) kva; 581 aiov.iov_len = size; 582 auio.uio_iov = &aiov; 583 auio.uio_iovcnt = 1; 584 auio.uio_offset = IDX_TO_OFF(m->pindex); 585 auio.uio_segflg = UIO_SYSSPACE; 586 auio.uio_rw = UIO_READ; 587 auio.uio_resid = size; 588 auio.uio_procp = (struct proc *) 0; 589 590 error = VOP_READ(object->handle, &auio, 0, curproc->p_ucred); 591 if (!error) { 592 register int count = size - auio.uio_resid; 593 594 if (count == 0) 595 error = EINVAL; 596 else if (count != PAGE_SIZE) 597 bzero((caddr_t) kva + count, PAGE_SIZE - count); 598 } 599 vm_pager_unmap_page(kva); 600 } 601 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 602 m->dirty = 0; 603 m->flags &= ~PG_ZERO; 604 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 605} 606 607/* 608 * generic vnode pager input routine 609 */ 610 611static int 612vnode_pager_getpages(object, m, count, reqpage) 613 vm_object_t object; 614 vm_page_t *m; 615 int count; 616 int reqpage; 617{ 618 int rtval; 619 struct vnode *vp; 620 if (object->flags & OBJ_VNODE_GONE) 621 return VM_PAGER_ERROR; 622 vp = object->handle; 623 rtval = VOP_GETPAGES(vp, m, count*PAGE_SIZE, reqpage, 0); 624 if (rtval == EOPNOTSUPP) 625 return vnode_pager_leaf_getpages(object, m, count, reqpage); 626 else 627 return rtval; 628} 629 630static int 631vnode_pager_leaf_getpages(object, m, count, reqpage) 632 vm_object_t object; 633 vm_page_t *m; 634 int count; 635 int reqpage; 636{ 637 vm_offset_t kva; 638 off_t foff; 639 int i, size, bsize, first, firstaddr; 640 struct vnode *dp, *vp; 641 int runpg; 642 int runend; 643 struct buf *bp; 644 int s; 645 int error = 0; 646 647 vp = object->handle; 648 if (vp->v_mount == NULL) 649 return VM_PAGER_BAD; 650 651 bsize = vp->v_mount->mnt_stat.f_iosize; 652 653 /* get the UNDERLYING device for the file with VOP_BMAP() */ 654 655 /* 656 * originally, we did not check for an error return value -- assuming 657 * an fs always has a bmap entry point -- that assumption is wrong!!! 658 */ 659 foff = IDX_TO_OFF(m[reqpage]->pindex); 660 661 /* 662 * if we can't bmap, use old VOP code 663 */ 664 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 665 for (i = 0; i < count; i++) { 666 if (i != reqpage) { 667 vnode_pager_freepage(m[i]); 668 } 669 } 670 cnt.v_vnodein++; 671 cnt.v_vnodepgsin++; 672 return vnode_pager_input_old(object, m[reqpage]); 673 674 /* 675 * if the blocksize is smaller than a page size, then use 676 * special small filesystem code. NFS sometimes has a small 677 * blocksize, but it can handle large reads itself. 678 */ 679 } else if ((PAGE_SIZE / bsize) > 1 && 680 (vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) { 681 682 for (i = 0; i < count; i++) { 683 if (i != reqpage) { 684 vnode_pager_freepage(m[i]); 685 } 686 } 687 cnt.v_vnodein++; 688 cnt.v_vnodepgsin++; 689 return vnode_pager_input_smlfs(object, m[reqpage]); 690 } 691 /* 692 * if ANY DEV_BSIZE blocks are valid on a large filesystem block 693 * then, the entire page is valid -- 694 * XXX no it isn't 695 */ 696 697 if (m[reqpage]->valid != VM_PAGE_BITS_ALL) 698 m[reqpage]->valid = 0; 699 700 if (m[reqpage]->valid) { 701 m[reqpage]->valid = VM_PAGE_BITS_ALL; 702 for (i = 0; i < count; i++) { 703 if (i != reqpage) 704 vnode_pager_freepage(m[i]); 705 } 706 return VM_PAGER_OK; 707 } 708 709 /* 710 * here on direct device I/O 711 */ 712 713 firstaddr = -1; 714 /* 715 * calculate the run that includes the required page 716 */ 717 for(first = 0, i = 0; i < count; i = runend) { 718 firstaddr = vnode_pager_addr(vp, 719 IDX_TO_OFF(m[i]->pindex), &runpg); 720 if (firstaddr == -1) { 721 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 722 panic("vnode_pager_putpages: unexpected missing page: firstaddr: %d, foff: %ld, vnp_size: %d", 723 firstaddr, foff, object->un_pager.vnp.vnp_size); 724 } 725 vnode_pager_freepage(m[i]); 726 runend = i + 1; 727 first = runend; 728 continue; 729 } 730 runend = i + runpg; 731 if (runend <= reqpage) { 732 int j; 733 for (j = i; j < runend; j++) { 734 vnode_pager_freepage(m[j]); 735 } 736 } else { 737 if (runpg < (count - first)) { 738 for (i = first + runpg; i < count; i++) 739 vnode_pager_freepage(m[i]); 740 count = first + runpg; 741 } 742 break; 743 } 744 first = runend; 745 } 746 747 /* 748 * the first and last page have been calculated now, move input pages 749 * to be zero based... 750 */ 751 if (first != 0) { 752 for (i = first; i < count; i++) { 753 m[i - first] = m[i]; 754 } 755 count -= first; 756 reqpage -= first; 757 } 758 759 /* 760 * calculate the file virtual address for the transfer 761 */ 762 foff = IDX_TO_OFF(m[0]->pindex); 763 764 /* 765 * calculate the size of the transfer 766 */ 767 size = count * PAGE_SIZE; 768 if ((foff + size) > object->un_pager.vnp.vnp_size) 769 size = object->un_pager.vnp.vnp_size - foff; 770 771 /* 772 * round up physical size for real devices 773 */ 774 if (dp->v_type == VBLK || dp->v_type == VCHR) 775 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 776 777 bp = getpbuf(); 778 kva = (vm_offset_t) bp->b_data; 779 780 /* 781 * and map the pages to be read into the kva 782 */ 783 pmap_qenter(kva, m, count); 784 785 /* build a minimal buffer header */ 786 bp->b_flags = B_BUSY | B_READ | B_CALL; 787 bp->b_iodone = vnode_pager_iodone; 788 /* B_PHYS is not set, but it is nice to fill this in */ 789 bp->b_proc = curproc; 790 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 791 if (bp->b_rcred != NOCRED) 792 crhold(bp->b_rcred); 793 if (bp->b_wcred != NOCRED) 794 crhold(bp->b_wcred); 795 bp->b_blkno = firstaddr; 796 pbgetvp(dp, bp); 797 bp->b_bcount = size; 798 bp->b_bufsize = size; 799 800 cnt.v_vnodein++; 801 cnt.v_vnodepgsin += count; 802 803 /* do the input */ 804 VOP_STRATEGY(bp); 805 806 s = splbio(); 807 /* we definitely need to be at splbio here */ 808 809 while ((bp->b_flags & B_DONE) == 0) { 810 tsleep(bp, PVM, "vnread", 0); 811 } 812 splx(s); 813 if ((bp->b_flags & B_ERROR) != 0) 814 error = EIO; 815 816 if (!error) { 817 if (size != count * PAGE_SIZE) 818 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 819 } 820 pmap_qremove(kva, count); 821 822 /* 823 * free the buffer header back to the swap buffer pool 824 */ 825 relpbuf(bp); 826 827 for (i = 0; i < count; i++) { 828 pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); 829 m[i]->dirty = 0; 830 m[i]->valid = VM_PAGE_BITS_ALL; 831 m[i]->flags &= ~PG_ZERO; 832 if (i != reqpage) { 833 834 /* 835 * whether or not to leave the page activated is up in 836 * the air, but we should put the page on a page queue 837 * somewhere. (it already is in the object). Result: 838 * It appears that emperical results show that 839 * deactivating pages is best. 840 */ 841 842 /* 843 * just in case someone was asking for this page we 844 * now tell them that it is ok to use 845 */ 846 if (!error) { 847 vm_page_deactivate(m[i]); 848 PAGE_WAKEUP(m[i]); 849 } else { 850 vnode_pager_freepage(m[i]); 851 } 852 } 853 } 854 if (error) { 855 printf("vnode_pager_getpages: I/O read error\n"); 856 } 857 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 858} 859 860static int 861vnode_pager_putpages(object, m, count, sync, rtvals) 862 vm_object_t object; 863 vm_page_t *m; 864 int count; 865 boolean_t sync; 866 int *rtvals; 867{ 868 int rtval; 869 struct vnode *vp; 870 871 if (object->flags & OBJ_VNODE_GONE) 872 return VM_PAGER_ERROR; 873 874 vp = object->handle; 875 rtval = VOP_PUTPAGES(vp, m, count*PAGE_SIZE, sync, rtvals, 0); 876 if (rtval == EOPNOTSUPP) 877 return vnode_pager_leaf_putpages(object, m, count, sync, rtvals); 878 else 879 return rtval; 880} 881 882/* 883 * generic vnode pager output routine 884 */ 885static int 886vnode_pager_leaf_putpages(object, m, count, sync, rtvals) 887 vm_object_t object; 888 vm_page_t *m; 889 int count; 890 boolean_t sync; 891 int *rtvals; 892{ 893 int i; 894 895 struct vnode *vp; 896 int maxsize, ncount; 897 vm_ooffset_t poffset; 898 struct uio auio; 899 struct iovec aiov; 900 int error; 901 902 vp = object->handle;; 903 for (i = 0; i < count; i++) 904 rtvals[i] = VM_PAGER_AGAIN; 905 906 if ((int) m[0]->pindex < 0) { 907 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%x(%x)\n", m[0]->pindex, m[0]->dirty); 908 rtvals[0] = VM_PAGER_BAD; 909 return VM_PAGER_BAD; 910 } 911 912 maxsize = count * PAGE_SIZE; 913 ncount = count; 914 915 poffset = IDX_TO_OFF(m[0]->pindex); 916 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 917 if (object->un_pager.vnp.vnp_size > poffset) 918 maxsize = object->un_pager.vnp.vnp_size - poffset; 919 else 920 maxsize = 0; 921 ncount = btoc(maxsize); 922 if (ncount < count) { 923 for (i = ncount; i < count; i++) { 924 rtvals[i] = VM_PAGER_BAD; 925 } 926#ifdef BOGUS 927 if (ncount == 0) { 928 printf("vnode_pager_putpages: write past end of file: %d, %lu\n", 929 poffset, 930 (unsigned long) object->un_pager.vnp.vnp_size); 931 return rtvals[0]; 932 } 933#endif 934 } 935 } 936 937 for (i = 0; i < count; i++) { 938 m[i]->busy++; 939 m[i]->flags &= ~PG_BUSY; 940 } 941 942 aiov.iov_base = (caddr_t) 0; 943 aiov.iov_len = maxsize; 944 auio.uio_iov = &aiov; 945 auio.uio_iovcnt = 1; 946 auio.uio_offset = poffset; 947 auio.uio_segflg = UIO_NOCOPY; 948 auio.uio_rw = UIO_WRITE; 949 auio.uio_resid = maxsize; 950 auio.uio_procp = (struct proc *) 0; 951 error = VOP_WRITE(vp, &auio, IO_VMIO|(sync?IO_SYNC:0), curproc->p_ucred); 952 cnt.v_vnodeout++; 953 cnt.v_vnodepgsout += ncount; 954 955 if (error) { 956 printf("vnode_pager_putpages: I/O error %d\n", error); 957 } 958 if (auio.uio_resid) { 959 printf("vnode_pager_putpages: residual I/O %d at %ld\n", 960 auio.uio_resid, m[0]->pindex); 961 } 962 for (i = 0; i < count; i++) { 963 m[i]->busy--; 964 if (i < ncount) { 965 rtvals[i] = VM_PAGER_OK; 966 } 967 if ((m[i]->busy == 0) && (m[i]->flags & PG_WANTED)) 968 wakeup(m[i]); 969 } 970 return rtvals[0]; 971} 972 973struct vnode * 974vnode_pager_lock(object) 975 vm_object_t object; 976{ 977 struct proc *p = curproc; /* XXX */ 978 979 for (; object != NULL; object = object->backing_object) { 980 if (object->type != OBJT_VNODE) 981 continue; 982 983 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY | LK_CANRECURSE, p); 984 return object->handle; 985 } 986 return NULL; 987} 988