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 1.73 1997/08/25 22:15:31 bde Exp $ 42 */ 43 44 /* 45 * Page to/from files (vnodes). 46 */ 47 48 /* 49 * TODO: 50 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 51 * greatly re-simplify the vnode_pager. 52 */ 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/proc.h> 57 #include <sys/vnode.h> 58 #include <sys/mount.h> 59 #include <sys/buf.h> 60 #include <sys/vmmeter.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_prot.h> 64 #include <vm/vm_object.h> 65 #include <vm/vm_page.h> 66 #include <vm/vm_pager.h> 67 #include <vm/vnode_pager.h> 68 #include <vm/vm_extern.h> 69 70 static vm_offset_t vnode_pager_addr __P((struct vnode *vp, vm_ooffset_t address, 71 int *run)); 72 static void vnode_pager_iodone __P((struct buf *bp)); 73 static int vnode_pager_input_smlfs __P((vm_object_t object, vm_page_t m)); 74 static int vnode_pager_input_old __P((vm_object_t object, vm_page_t m)); 75 static void vnode_pager_dealloc __P((vm_object_t)); 76 static int vnode_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 77 static int vnode_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *)); 78 static boolean_t vnode_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *)); 79 80 struct pagerops vnodepagerops = { 81 NULL, 82 vnode_pager_alloc, 83 vnode_pager_dealloc, 84 vnode_pager_getpages, 85 vnode_pager_putpages, 86 vnode_pager_haspage, 87 NULL 88 }; 89 90 static int vnode_pager_leaf_getpages __P((vm_object_t object, vm_page_t *m, 91 int count, int reqpage)); 92 static int vnode_pager_leaf_putpages __P((vm_object_t object, vm_page_t *m, 93 int count, boolean_t sync, 94 int *rtvals)); 95 96 /* 97 * Allocate (or lookup) pager for a vnode. 98 * Handle is a vnode pointer. 99 */ 100 vm_object_t 101 vnode_pager_alloc(void *handle, vm_size_t size, vm_prot_t prot, 102 vm_ooffset_t offset) 103 { 104 vm_object_t object; 105 struct vnode *vp; 106 107 /* 108 * Pageout to vnode, no can do yet. 109 */ 110 if (handle == NULL) 111 return (NULL); 112 113 vp = (struct vnode *) handle; 114 115 /* 116 * Prevent race condition when allocating the object. This 117 * can happen with NFS vnodes since the nfsnode isn't locked. 118 */ 119 while (vp->v_flag & VOLOCK) { 120 vp->v_flag |= VOWANT; 121 tsleep(vp, PVM, "vnpobj", 0); 122 } 123 vp->v_flag |= VOLOCK; 124 125 /* 126 * If the object is being terminated, wait for it to 127 * go away. 128 */ 129 while (((object = vp->v_object) != NULL) && 130 (object->flags & OBJ_DEAD)) { 131 tsleep(object, PVM, "vadead", 0); 132 } 133 134 if (object == NULL) { 135 /* 136 * And an object of the appropriate size 137 */ 138 object = vm_object_allocate(OBJT_VNODE, size); 139 if (vp->v_type == VREG) 140 object->flags = OBJ_CANPERSIST; 141 else 142 object->flags = 0; 143 144 if (vp->v_usecount == 0) 145 panic("vnode_pager_alloc: no vnode reference"); 146 /* 147 * Hold a reference to the vnode and initialize object data. 148 */ 149 vp->v_usecount++; 150 object->un_pager.vnp.vnp_size = (vm_ooffset_t) size * PAGE_SIZE; 151 152 object->handle = handle; 153 vp->v_object = object; 154 } else { 155 /* 156 * vm_object_reference() will remove the object from the cache if 157 * found and gain a reference to the object. 158 */ 159 vm_object_reference(object); 160 } 161 162 if (vp->v_type == VREG) 163 vp->v_flag |= VVMIO; 164 165 vp->v_flag &= ~VOLOCK; 166 if (vp->v_flag & VOWANT) { 167 vp->v_flag &= ~VOWANT; 168 wakeup(vp); 169 } 170 return (object); 171 } 172 173 static void 174 vnode_pager_dealloc(object) 175 vm_object_t object; 176 { 177 register struct vnode *vp = object->handle; 178 179 if (vp == NULL) 180 panic("vnode_pager_dealloc: pager already dealloced"); 181 182 if (object->paging_in_progress) { 183 int s = splbio(); 184 while (object->paging_in_progress) { 185 object->flags |= OBJ_PIPWNT; 186 tsleep(object, PVM, "vnpdea", 0); 187 } 188 splx(s); 189 } 190 191 object->handle = NULL; 192 193 vp->v_object = NULL; 194 vp->v_flag &= ~(VTEXT | VVMIO); 195 vrele(vp); 196 } 197 198 static boolean_t 199 vnode_pager_haspage(object, pindex, before, after) 200 vm_object_t object; 201 vm_pindex_t pindex; 202 int *before; 203 int *after; 204 { 205 struct vnode *vp = object->handle; 206 daddr_t bn; 207 int err; 208 daddr_t reqblock; 209 int poff; 210 int bsize; 211 int pagesperblock, blocksperpage; 212 213 /* 214 * If filesystem no longer mounted or offset beyond end of file we do 215 * not have the page. 216 */ 217 if ((vp->v_mount == NULL) || 218 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 219 return FALSE; 220 221 bsize = vp->v_mount->mnt_stat.f_iosize; 222 pagesperblock = bsize / PAGE_SIZE; 223 blocksperpage = 0; 224 if (pagesperblock > 0) { 225 reqblock = pindex / pagesperblock; 226 } else { 227 blocksperpage = (PAGE_SIZE / bsize); 228 reqblock = pindex * blocksperpage; 229 } 230 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 231 after, before); 232 if (err) 233 return TRUE; 234 if ( bn == -1) 235 return FALSE; 236 if (pagesperblock > 0) { 237 poff = pindex - (reqblock * pagesperblock); 238 if (before) { 239 *before *= pagesperblock; 240 *before += poff; 241 } 242 if (after) { 243 int numafter; 244 *after *= pagesperblock; 245 numafter = pagesperblock - (poff + 1); 246 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { 247 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex))); 248 } 249 *after += numafter; 250 } 251 } else { 252 if (before) { 253 *before /= blocksperpage; 254 } 255 256 if (after) { 257 *after /= blocksperpage; 258 } 259 } 260 return TRUE; 261 } 262 263 /* 264 * Lets the VM system know about a change in size for a file. 265 * We adjust our own internal size and flush any cached pages in 266 * the associated object that are affected by the size change. 267 * 268 * Note: this routine may be invoked as a result of a pager put 269 * operation (possibly at object termination time), so we must be careful. 270 */ 271 void 272 vnode_pager_setsize(vp, nsize) 273 struct vnode *vp; 274 vm_ooffset_t nsize; 275 { 276 vm_object_t object = vp->v_object; 277 278 if (object == NULL) 279 return; 280 281 /* 282 * Hasn't changed size 283 */ 284 if (nsize == object->un_pager.vnp.vnp_size) 285 return; 286 287 /* 288 * File has shrunk. Toss any cached pages beyond the new EOF. 289 */ 290 if (nsize < object->un_pager.vnp.vnp_size) { 291 vm_ooffset_t nsizerounded; 292 nsizerounded = IDX_TO_OFF(OFF_TO_IDX(nsize + PAGE_MASK)); 293 if (nsizerounded < object->un_pager.vnp.vnp_size) { 294 vm_object_page_remove(object, 295 OFF_TO_IDX(nsize + PAGE_MASK), 296 OFF_TO_IDX(object->un_pager.vnp.vnp_size), 297 FALSE); 298 } 299 /* 300 * this gets rid of garbage at the end of a page that is now 301 * only partially backed by the vnode... 302 */ 303 if (nsize & PAGE_MASK) { 304 vm_offset_t kva; 305 vm_page_t m; 306 307 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 308 if (m) { 309 kva = vm_pager_map_page(m); 310 bzero((caddr_t) kva + (nsize & PAGE_MASK), 311 (int) (round_page(nsize) - nsize)); 312 vm_pager_unmap_page(kva); 313 } 314 } 315 } 316 object->un_pager.vnp.vnp_size = nsize; 317 object->size = OFF_TO_IDX(nsize + PAGE_MASK); 318 } 319 320 void 321 vnode_pager_umount(mp) 322 register struct mount *mp; 323 { 324 struct proc *p = curproc; /* XXX */ 325 struct vnode *vp, *nvp; 326 327 loop: 328 for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) { 329 /* 330 * Vnode can be reclaimed by getnewvnode() while we 331 * traverse the list. 332 */ 333 if (vp->v_mount != mp) 334 goto loop; 335 336 /* 337 * Save the next pointer now since uncaching may terminate the 338 * object and render vnode invalid 339 */ 340 nvp = vp->v_mntvnodes.le_next; 341 342 if (vp->v_object != NULL) { 343 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 344 vnode_pager_uncache(vp, p); 345 VOP_UNLOCK(vp, 0, p); 346 } 347 } 348 } 349 350 /* 351 * Remove vnode associated object from the object cache. 352 * This routine must be called with the vnode locked. 353 * 354 * XXX unlock the vnode. 355 * We must do this since uncaching the object may result in its 356 * destruction which may initiate paging activity which may necessitate 357 * re-locking the vnode. 358 */ 359 void 360 vnode_pager_uncache(vp, p) 361 struct vnode *vp; 362 struct proc *p; 363 { 364 vm_object_t object; 365 366 /* 367 * Not a mapped vnode 368 */ 369 object = vp->v_object; 370 if (object == NULL) 371 return; 372 373 vm_object_reference(object); 374 375 /* 376 * XXX We really should handle locking on 377 * VBLK devices... 378 */ 379 if (vp->v_type != VBLK) 380 VOP_UNLOCK(vp, 0, p); 381 pager_cache(object, FALSE); 382 if (vp->v_type != VBLK) 383 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 384 return; 385 } 386 387 388 void 389 vnode_pager_freepage(m) 390 vm_page_t m; 391 { 392 PAGE_WAKEUP(m); 393 vm_page_free(m); 394 } 395 396 /* 397 * calculate the linear (byte) disk address of specified virtual 398 * file address 399 */ 400 static vm_offset_t 401 vnode_pager_addr(vp, address, run) 402 struct vnode *vp; 403 vm_ooffset_t address; 404 int *run; 405 { 406 int rtaddress; 407 int bsize; 408 daddr_t block; 409 struct vnode *rtvp; 410 int err; 411 daddr_t vblock; 412 int voffset; 413 414 if ((int) address < 0) 415 return -1; 416 417 if (vp->v_mount == NULL) 418 return -1; 419 420 bsize = vp->v_mount->mnt_stat.f_iosize; 421 vblock = address / bsize; 422 voffset = address % bsize; 423 424 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 425 426 if (err || (block == -1)) 427 rtaddress = -1; 428 else { 429 rtaddress = block + voffset / DEV_BSIZE; 430 if( run) { 431 *run += 1; 432 *run *= bsize/PAGE_SIZE; 433 *run -= voffset/PAGE_SIZE; 434 } 435 } 436 437 return rtaddress; 438 } 439 440 /* 441 * interrupt routine for I/O completion 442 */ 443 static void 444 vnode_pager_iodone(bp) 445 struct buf *bp; 446 { 447 bp->b_flags |= B_DONE; 448 wakeup(bp); 449 } 450 451 /* 452 * small block file system vnode pager input 453 */ 454 static int 455 vnode_pager_input_smlfs(object, m) 456 vm_object_t object; 457 vm_page_t m; 458 { 459 int i; 460 int s; 461 struct vnode *dp, *vp; 462 struct buf *bp; 463 vm_offset_t kva; 464 int fileaddr; 465 vm_offset_t bsize; 466 int error = 0; 467 468 vp = object->handle; 469 if (vp->v_mount == NULL) 470 return VM_PAGER_BAD; 471 472 bsize = vp->v_mount->mnt_stat.f_iosize; 473 474 475 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 476 477 kva = vm_pager_map_page(m); 478 479 for (i = 0; i < PAGE_SIZE / bsize; i++) { 480 481 if ((vm_page_bits(IDX_TO_OFF(m->pindex) + i * bsize, bsize) & m->valid)) 482 continue; 483 484 fileaddr = vnode_pager_addr(vp, 485 IDX_TO_OFF(m->pindex) + i * bsize, (int *)0); 486 if (fileaddr != -1) { 487 bp = getpbuf(); 488 489 /* build a minimal buffer header */ 490 bp->b_flags = B_BUSY | B_READ | B_CALL; 491 bp->b_iodone = vnode_pager_iodone; 492 bp->b_proc = curproc; 493 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 494 if (bp->b_rcred != NOCRED) 495 crhold(bp->b_rcred); 496 if (bp->b_wcred != NOCRED) 497 crhold(bp->b_wcred); 498 bp->b_un.b_addr = (caddr_t) kva + i * bsize; 499 bp->b_blkno = fileaddr; 500 pbgetvp(dp, bp); 501 bp->b_bcount = bsize; 502 bp->b_bufsize = bsize; 503 504 /* do the input */ 505 VOP_STRATEGY(bp); 506 507 /* we definitely need to be at splbio here */ 508 509 s = splbio(); 510 while ((bp->b_flags & B_DONE) == 0) { 511 tsleep(bp, PVM, "vnsrd", 0); 512 } 513 splx(s); 514 if ((bp->b_flags & B_ERROR) != 0) 515 error = EIO; 516 517 /* 518 * free the buffer header back to the swap buffer pool 519 */ 520 relpbuf(bp); 521 if (error) 522 break; 523 524 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 525 } else { 526 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 527 bzero((caddr_t) kva + i * bsize, bsize); 528 } 529 } 530 vm_pager_unmap_page(kva); 531 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 532 m->flags &= ~PG_ZERO; 533 if (error) { 534 return VM_PAGER_ERROR; 535 } 536 return VM_PAGER_OK; 537 538 } 539 540 541 /* 542 * old style vnode pager output routine 543 */ 544 static int 545 vnode_pager_input_old(object, m) 546 vm_object_t object; 547 vm_page_t m; 548 { 549 struct uio auio; 550 struct iovec aiov; 551 int error; 552 int size; 553 vm_offset_t kva; 554 555 error = 0; 556 557 /* 558 * Return failure if beyond current EOF 559 */ 560 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 561 return VM_PAGER_BAD; 562 } else { 563 size = PAGE_SIZE; 564 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 565 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 566 567 /* 568 * Allocate a kernel virtual address and initialize so that 569 * we can use VOP_READ/WRITE routines. 570 */ 571 kva = vm_pager_map_page(m); 572 573 aiov.iov_base = (caddr_t) kva; 574 aiov.iov_len = size; 575 auio.uio_iov = &aiov; 576 auio.uio_iovcnt = 1; 577 auio.uio_offset = IDX_TO_OFF(m->pindex); 578 auio.uio_segflg = UIO_SYSSPACE; 579 auio.uio_rw = UIO_READ; 580 auio.uio_resid = size; 581 auio.uio_procp = (struct proc *) 0; 582 583 error = VOP_READ(object->handle, &auio, 0, curproc->p_ucred); 584 if (!error) { 585 register int count = size - auio.uio_resid; 586 587 if (count == 0) 588 error = EINVAL; 589 else if (count != PAGE_SIZE) 590 bzero((caddr_t) kva + count, PAGE_SIZE - count); 591 } 592 vm_pager_unmap_page(kva); 593 } 594 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 595 m->dirty = 0; 596 m->flags &= ~PG_ZERO; 597 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 598 } 599 600 /* 601 * generic vnode pager input routine 602 */ 603 604 static int 605 vnode_pager_getpages(object, m, count, reqpage) 606 vm_object_t object; 607 vm_page_t *m; 608 int count; 609 int reqpage; 610 { 611 int rtval; 612 struct vnode *vp; 613 if (object->flags & OBJ_VNODE_GONE) 614 return VM_PAGER_ERROR; 615 vp = object->handle; 616 rtval = VOP_GETPAGES(vp, m, count*PAGE_SIZE, reqpage, 0); 617 if (rtval == EOPNOTSUPP) 618 return vnode_pager_leaf_getpages(object, m, count, reqpage); 619 else 620 return rtval; 621 } 622 623 static int 624 vnode_pager_leaf_getpages(object, m, count, reqpage) 625 vm_object_t object; 626 vm_page_t *m; 627 int count; 628 int reqpage; 629 { 630 vm_offset_t kva; 631 off_t foff; 632 int i, size, bsize, first, firstaddr; 633 struct vnode *dp, *vp; 634 int runpg; 635 int runend; 636 struct buf *bp; 637 int s; 638 int error = 0; 639 640 vp = object->handle; 641 if (vp->v_mount == NULL) 642 return VM_PAGER_BAD; 643 644 bsize = vp->v_mount->mnt_stat.f_iosize; 645 646 /* get the UNDERLYING device for the file with VOP_BMAP() */ 647 648 /* 649 * originally, we did not check for an error return value -- assuming 650 * an fs always has a bmap entry point -- that assumption is wrong!!! 651 */ 652 foff = IDX_TO_OFF(m[reqpage]->pindex); 653 654 /* 655 * if we can't bmap, use old VOP code 656 */ 657 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 658 for (i = 0; i < count; i++) { 659 if (i != reqpage) { 660 vnode_pager_freepage(m[i]); 661 } 662 } 663 cnt.v_vnodein++; 664 cnt.v_vnodepgsin++; 665 return vnode_pager_input_old(object, m[reqpage]); 666 667 /* 668 * if the blocksize is smaller than a page size, then use 669 * special small filesystem code. NFS sometimes has a small 670 * blocksize, but it can handle large reads itself. 671 */ 672 } else if ((PAGE_SIZE / bsize) > 1 && 673 (vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) { 674 675 for (i = 0; i < count; i++) { 676 if (i != reqpage) { 677 vnode_pager_freepage(m[i]); 678 } 679 } 680 cnt.v_vnodein++; 681 cnt.v_vnodepgsin++; 682 return vnode_pager_input_smlfs(object, m[reqpage]); 683 } 684 /* 685 * if ANY DEV_BSIZE blocks are valid on a large filesystem block 686 * then, the entire page is valid -- 687 * XXX no it isn't 688 */ 689 690 if (m[reqpage]->valid != VM_PAGE_BITS_ALL) 691 m[reqpage]->valid = 0; 692 693 if (m[reqpage]->valid) { 694 m[reqpage]->valid = VM_PAGE_BITS_ALL; 695 for (i = 0; i < count; i++) { 696 if (i != reqpage) 697 vnode_pager_freepage(m[i]); 698 } 699 return VM_PAGER_OK; 700 } 701 702 /* 703 * here on direct device I/O 704 */ 705 706 firstaddr = -1; 707 /* 708 * calculate the run that includes the required page 709 */ 710 for(first = 0, i = 0; i < count; i = runend) { 711 firstaddr = vnode_pager_addr(vp, 712 IDX_TO_OFF(m[i]->pindex), &runpg); 713 if (firstaddr == -1) { 714 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 715 panic("vnode_pager_putpages: unexpected missing page: firstaddr: %d, foff: %ld, vnp_size: %d", 716 firstaddr, foff, object->un_pager.vnp.vnp_size); 717 } 718 vnode_pager_freepage(m[i]); 719 runend = i + 1; 720 first = runend; 721 continue; 722 } 723 runend = i + runpg; 724 if (runend <= reqpage) { 725 int j; 726 for (j = i; j < runend; j++) { 727 vnode_pager_freepage(m[j]); 728 } 729 } else { 730 if (runpg < (count - first)) { 731 for (i = first + runpg; i < count; i++) 732 vnode_pager_freepage(m[i]); 733 count = first + runpg; 734 } 735 break; 736 } 737 first = runend; 738 } 739 740 /* 741 * the first and last page have been calculated now, move input pages 742 * to be zero based... 743 */ 744 if (first != 0) { 745 for (i = first; i < count; i++) { 746 m[i - first] = m[i]; 747 } 748 count -= first; 749 reqpage -= first; 750 } 751 752 /* 753 * calculate the file virtual address for the transfer 754 */ 755 foff = IDX_TO_OFF(m[0]->pindex); 756 757 /* 758 * calculate the size of the transfer 759 */ 760 size = count * PAGE_SIZE; 761 if ((foff + size) > object->un_pager.vnp.vnp_size) 762 size = object->un_pager.vnp.vnp_size - foff; 763 764 /* 765 * round up physical size for real devices 766 */ 767 if (dp->v_type == VBLK || dp->v_type == VCHR) 768 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 769 770 bp = getpbuf(); 771 kva = (vm_offset_t) bp->b_data; 772 773 /* 774 * and map the pages to be read into the kva 775 */ 776 pmap_qenter(kva, m, count); 777 778 /* build a minimal buffer header */ 779 bp->b_flags = B_BUSY | B_READ | B_CALL; 780 bp->b_iodone = vnode_pager_iodone; 781 /* B_PHYS is not set, but it is nice to fill this in */ 782 bp->b_proc = curproc; 783 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 784 if (bp->b_rcred != NOCRED) 785 crhold(bp->b_rcred); 786 if (bp->b_wcred != NOCRED) 787 crhold(bp->b_wcred); 788 bp->b_blkno = firstaddr; 789 pbgetvp(dp, bp); 790 bp->b_bcount = size; 791 bp->b_bufsize = size; 792 793 cnt.v_vnodein++; 794 cnt.v_vnodepgsin += count; 795 796 /* do the input */ 797 VOP_STRATEGY(bp); 798 799 s = splbio(); 800 /* we definitely need to be at splbio here */ 801 802 while ((bp->b_flags & B_DONE) == 0) { 803 tsleep(bp, PVM, "vnread", 0); 804 } 805 splx(s); 806 if ((bp->b_flags & B_ERROR) != 0) 807 error = EIO; 808 809 if (!error) { 810 if (size != count * PAGE_SIZE) 811 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 812 } 813 pmap_qremove(kva, count); 814 815 /* 816 * free the buffer header back to the swap buffer pool 817 */ 818 relpbuf(bp); 819 820 for (i = 0; i < count; i++) { 821 pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); 822 m[i]->dirty = 0; 823 m[i]->valid = VM_PAGE_BITS_ALL; 824 m[i]->flags &= ~PG_ZERO; 825 if (i != reqpage) { 826 827 /* 828 * whether or not to leave the page activated is up in 829 * the air, but we should put the page on a page queue 830 * somewhere. (it already is in the object). Result: 831 * It appears that emperical results show that 832 * deactivating pages is best. 833 */ 834 835 /* 836 * just in case someone was asking for this page we 837 * now tell them that it is ok to use 838 */ 839 if (!error) { 840 vm_page_deactivate(m[i]); 841 PAGE_WAKEUP(m[i]); 842 } else { 843 vnode_pager_freepage(m[i]); 844 } 845 } 846 } 847 if (error) { 848 printf("vnode_pager_getpages: I/O read error\n"); 849 } 850 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 851 } 852 853 static int 854 vnode_pager_putpages(object, m, count, sync, rtvals) 855 vm_object_t object; 856 vm_page_t *m; 857 int count; 858 boolean_t sync; 859 int *rtvals; 860 { 861 int rtval; 862 struct vnode *vp; 863 864 if (object->flags & OBJ_VNODE_GONE) 865 return VM_PAGER_ERROR; 866 867 vp = object->handle; 868 rtval = VOP_PUTPAGES(vp, m, count*PAGE_SIZE, sync, rtvals, 0); 869 if (rtval == EOPNOTSUPP) 870 return vnode_pager_leaf_putpages(object, m, count, sync, rtvals); 871 else 872 return rtval; 873 } 874 875 /* 876 * generic vnode pager output routine 877 */ 878 static int 879 vnode_pager_leaf_putpages(object, m, count, sync, rtvals) 880 vm_object_t object; 881 vm_page_t *m; 882 int count; 883 boolean_t sync; 884 int *rtvals; 885 { 886 int i; 887 888 struct vnode *vp; 889 int maxsize, ncount; 890 vm_ooffset_t poffset; 891 struct uio auio; 892 struct iovec aiov; 893 int error; 894 895 vp = object->handle;; 896 for (i = 0; i < count; i++) 897 rtvals[i] = VM_PAGER_AGAIN; 898 899 if ((int) m[0]->pindex < 0) { 900 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%x(%x)\n", m[0]->pindex, m[0]->dirty); 901 rtvals[0] = VM_PAGER_BAD; 902 return VM_PAGER_BAD; 903 } 904 905 maxsize = count * PAGE_SIZE; 906 ncount = count; 907 908 poffset = IDX_TO_OFF(m[0]->pindex); 909 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 910 if (object->un_pager.vnp.vnp_size > poffset) 911 maxsize = object->un_pager.vnp.vnp_size - poffset; 912 else 913 maxsize = 0; 914 ncount = btoc(maxsize); 915 if (ncount < count) { 916 for (i = ncount; i < count; i++) { 917 rtvals[i] = VM_PAGER_BAD; 918 } 919 #ifdef BOGUS 920 if (ncount == 0) { 921 printf("vnode_pager_putpages: write past end of file: %d, %lu\n", 922 poffset, 923 (unsigned long) object->un_pager.vnp.vnp_size); 924 return rtvals[0]; 925 } 926 #endif 927 } 928 } 929 930 for (i = 0; i < count; i++) { 931 m[i]->busy++; 932 m[i]->flags &= ~PG_BUSY; 933 } 934 935 aiov.iov_base = (caddr_t) 0; 936 aiov.iov_len = maxsize; 937 auio.uio_iov = &aiov; 938 auio.uio_iovcnt = 1; 939 auio.uio_offset = poffset; 940 auio.uio_segflg = UIO_NOCOPY; 941 auio.uio_rw = UIO_WRITE; 942 auio.uio_resid = maxsize; 943 auio.uio_procp = (struct proc *) 0; 944 error = VOP_WRITE(vp, &auio, IO_VMIO|(sync?IO_SYNC:0), curproc->p_ucred); 945 cnt.v_vnodeout++; 946 cnt.v_vnodepgsout += ncount; 947 948 if (error) { 949 printf("vnode_pager_putpages: I/O error %d\n", error); 950 } 951 if (auio.uio_resid) { 952 printf("vnode_pager_putpages: residual I/O %d at %ld\n", 953 auio.uio_resid, m[0]->pindex); 954 } 955 for (i = 0; i < count; i++) { 956 m[i]->busy--; 957 if (i < ncount) { 958 rtvals[i] = VM_PAGER_OK; 959 } 960 if ((m[i]->busy == 0) && (m[i]->flags & PG_WANTED)) 961 wakeup(m[i]); 962 } 963 return rtvals[0]; 964 } 965 966 struct vnode * 967 vnode_pager_lock(object) 968 vm_object_t object; 969 { 970 struct proc *p = curproc; /* XXX */ 971 972 for (; object != NULL; object = object->backing_object) { 973 if (object->type != OBJT_VNODE) 974 continue; 975 976 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY | LK_CANRECURSE, p); 977 return object->handle; 978 } 979 return NULL; 980 } 981