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sys/vm/vnode_pager.c
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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 * $FreeBSD: src/sys/vm/vnode_pager.c,v 1.65.2.4 1999/09/05 08:24:43 peter 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 74 static vm_offset_t vnode_pager_addr __P((struct vnode *vp, vm_ooffset_t address, 75 int *run)); 76 static void vnode_pager_iodone __P((struct buf *bp)); 77 static int vnode_pager_input_smlfs __P((vm_object_t object, vm_page_t m)); 78 static int vnode_pager_input_old __P((vm_object_t object, vm_page_t m)); 79 static void vnode_pager_dealloc __P((vm_object_t)); 80 static int vnode_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 81 static int vnode_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *)); 82 static boolean_t vnode_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *)); 83 84 struct 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 94 static int vnode_pager_leaf_getpages __P((vm_object_t object, vm_page_t *m, 95 int count, int reqpage)); 96 static 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 */ 104 vm_object_t 105 vnode_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 } 179 180 static void 181 vnode_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 vp->v_flag |= VAGE; 203 vrele(vp); 204 } 205 206 static boolean_t 207 vnode_pager_haspage(object, pindex, before, after) 208 vm_object_t object; 209 vm_pindex_t pindex; 210 int *before; 211 int *after; 212 { 213 struct vnode *vp = object->handle; 214 daddr_t bn; 215 int err; 216 daddr_t reqblock; 217 int poff; 218 int bsize; 219 int pagesperblock, blocksperpage; 220 221 /* 222 * If filesystem no longer mounted or offset beyond end of file we do 223 * not have the page. 224 */ 225 if ((vp->v_mount == NULL) || 226 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 227 return FALSE; 228 229 bsize = vp->v_mount->mnt_stat.f_iosize; 230 pagesperblock = bsize / PAGE_SIZE; 231 blocksperpage = 0; 232 if (pagesperblock > 0) { 233 reqblock = pindex / pagesperblock; 234 } else { 235 blocksperpage = (PAGE_SIZE / bsize); 236 reqblock = pindex * blocksperpage; 237 } 238 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 239 after, before); 240 if (err) 241 return TRUE; 242 if ( bn == -1) 243 return FALSE; 244 if (pagesperblock > 0) { 245 poff = pindex - (reqblock * pagesperblock); 246 if (before) { 247 *before *= pagesperblock; 248 *before += poff; 249 } 250 if (after) { 251 int numafter; 252 *after *= pagesperblock; 253 numafter = pagesperblock - (poff + 1); 254 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { 255 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex))); 256 } 257 *after += numafter; 258 } 259 } else { 260 if (before) { 261 *before /= blocksperpage; 262 } 263 264 if (after) { 265 *after /= blocksperpage; 266 } 267 } 268 return TRUE; 269 } 270 271 /* 272 * Lets the VM system know about a change in size for a file. 273 * We adjust our own internal size and flush any cached pages in 274 * the associated object that are affected by the size change. 275 * 276 * Note: this routine may be invoked as a result of a pager put 277 * operation (possibly at object termination time), so we must be careful. 278 */ 279 void 280 vnode_pager_setsize(vp, nsize) 281 struct vnode *vp; 282 vm_ooffset_t nsize; 283 { 284 vm_object_t object = vp->v_object; 285 286 if (object == NULL) 287 return; 288 289 /* 290 * Hasn't changed size 291 */ 292 if (nsize == object->un_pager.vnp.vnp_size) 293 return; 294 295 /* 296 * File has shrunk. Toss any cached pages beyond the new EOF. 297 */ 298 if (nsize < object->un_pager.vnp.vnp_size) { 299 vm_ooffset_t nsizerounded; 300 nsizerounded = IDX_TO_OFF(OFF_TO_IDX(nsize + PAGE_MASK)); 301 if (nsizerounded < object->un_pager.vnp.vnp_size) { 302 vm_object_page_remove(object, 303 OFF_TO_IDX(nsize + PAGE_MASK), 304 OFF_TO_IDX(object->un_pager.vnp.vnp_size), 305 FALSE); 306 } 307 /* 308 * this gets rid of garbage at the end of a page that is now 309 * only partially backed by the vnode... 310 */ 311 if (nsize & PAGE_MASK) { 312 vm_offset_t kva; 313 vm_page_t m; 314 315 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 316 if (m) { 317 kva = vm_pager_map_page(m); 318 bzero((caddr_t) kva + (nsize & PAGE_MASK), 319 (int) (round_page(nsize) - nsize)); 320 vm_pager_unmap_page(kva); 321 } 322 } 323 } 324 object->un_pager.vnp.vnp_size = nsize; 325 object->size = OFF_TO_IDX(nsize + PAGE_MASK); 326 } 327 328 void 329 vnode_pager_umount(mp) 330 register struct mount *mp; 331 { 332 struct vnode *vp, *nvp; 333 334 loop: 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 VOP_LOCK(vp); 351 vnode_pager_uncache(vp); 352 VOP_UNLOCK(vp); 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 */ 366 void 367 vnode_pager_uncache(vp) 368 struct vnode *vp; 369 { 370 vm_object_t object; 371 372 /* 373 * Not a mapped vnode 374 */ 375 object = vp->v_object; 376 if (object == NULL) 377 return; 378 379 vm_object_reference(object); 380 381 /* 382 * XXX We really should handle locking on 383 * VBLK devices... 384 */ 385 if (vp->v_type != VBLK) 386 VOP_UNLOCK(vp); 387 pager_cache(object, FALSE); 388 if (vp->v_type != VBLK) 389 VOP_LOCK(vp); 390 return; 391 } 392 393 394 void 395 vnode_pager_freepage(m) 396 vm_page_t m; 397 { 398 PAGE_WAKEUP(m); 399 vm_page_free(m); 400 } 401 402 /* 403 * calculate the linear (byte) disk address of specified virtual 404 * file address 405 */ 406 static vm_offset_t 407 vnode_pager_addr(vp, address, run) 408 struct vnode *vp; 409 vm_ooffset_t address; 410 int *run; 411 { 412 int rtaddress; 413 int bsize; 414 daddr_t block; 415 struct vnode *rtvp; 416 int err; 417 daddr_t vblock; 418 int voffset; 419 420 if ((int) address < 0) 421 return -1; 422 423 if (vp->v_mount == NULL) 424 return -1; 425 426 bsize = vp->v_mount->mnt_stat.f_iosize; 427 vblock = address / bsize; 428 voffset = address % bsize; 429 430 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 431 432 if (err || (block == -1)) 433 rtaddress = -1; 434 else { 435 rtaddress = block + voffset / DEV_BSIZE; 436 if( run) { 437 *run += 1; 438 *run *= bsize/PAGE_SIZE; 439 *run -= voffset/PAGE_SIZE; 440 } 441 } 442 443 return rtaddress; 444 } 445 446 /* 447 * interrupt routine for I/O completion 448 */ 449 static void 450 vnode_pager_iodone(bp) 451 struct buf *bp; 452 { 453 bp->b_flags |= B_DONE; 454 wakeup(bp); 455 } 456 457 /* 458 * small block file system vnode pager input 459 */ 460 static int 461 vnode_pager_input_smlfs(object, m) 462 vm_object_t object; 463 vm_page_t m; 464 { 465 int i; 466 int s; 467 struct vnode *dp, *vp; 468 struct buf *bp; 469 vm_offset_t kva; 470 int fileaddr; 471 vm_offset_t bsize; 472 int error = 0; 473 474 vp = object->handle; 475 if (vp->v_mount == NULL) 476 return VM_PAGER_BAD; 477 478 bsize = vp->v_mount->mnt_stat.f_iosize; 479 480 481 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 482 483 kva = vm_pager_map_page(m); 484 485 for (i = 0; i < PAGE_SIZE / bsize; i++) { 486 487 if ((vm_page_bits(IDX_TO_OFF(m->pindex) + i * bsize, bsize) & m->valid)) 488 continue; 489 490 fileaddr = vnode_pager_addr(vp, 491 IDX_TO_OFF(m->pindex) + i * bsize, (int *)0); 492 if (fileaddr != -1) { 493 bp = getpbuf(); 494 495 /* build a minimal buffer header */ 496 bp->b_flags = B_BUSY | B_READ | B_CALL; 497 bp->b_iodone = vnode_pager_iodone; 498 bp->b_proc = curproc; 499 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 500 if (bp->b_rcred != NOCRED) 501 crhold(bp->b_rcred); 502 if (bp->b_wcred != NOCRED) 503 crhold(bp->b_wcred); 504 bp->b_un.b_addr = (caddr_t) kva + i * bsize; 505 bp->b_blkno = fileaddr; 506 pbgetvp(dp, bp); 507 bp->b_bcount = bsize; 508 bp->b_bufsize = bsize; 509 510 /* do the input */ 511 VOP_STRATEGY(bp); 512 513 /* we definitely need to be at splbio here */ 514 515 s = splbio(); 516 while ((bp->b_flags & B_DONE) == 0) { 517 tsleep(bp, PVM, "vnsrd", 0); 518 } 519 splx(s); 520 if ((bp->b_flags & B_ERROR) != 0) 521 error = EIO; 522 523 /* 524 * free the buffer header back to the swap buffer pool 525 */ 526 relpbuf(bp); 527 if (error) 528 break; 529 530 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 531 } else { 532 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 533 bzero((caddr_t) kva + i * bsize, bsize); 534 } 535 } 536 vm_pager_unmap_page(kva); 537 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 538 m->flags &= ~PG_ZERO; 539 if (error) { 540 return VM_PAGER_ERROR; 541 } 542 return VM_PAGER_OK; 543 544 } 545 546 547 /* 548 * old style vnode pager output routine 549 */ 550 static int 551 vnode_pager_input_old(object, m) 552 vm_object_t object; 553 vm_page_t m; 554 { 555 struct uio auio; 556 struct iovec aiov; 557 int error; 558 int size; 559 vm_offset_t kva; 560 561 error = 0; 562 563 /* 564 * Return failure if beyond current EOF 565 */ 566 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 567 return VM_PAGER_BAD; 568 } else { 569 size = PAGE_SIZE; 570 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 571 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 572 573 /* 574 * Allocate a kernel virtual address and initialize so that 575 * we can use VOP_READ/WRITE routines. 576 */ 577 kva = vm_pager_map_page(m); 578 579 aiov.iov_base = (caddr_t) kva; 580 aiov.iov_len = size; 581 auio.uio_iov = &aiov; 582 auio.uio_iovcnt = 1; 583 auio.uio_offset = IDX_TO_OFF(m->pindex); 584 auio.uio_segflg = UIO_SYSSPACE; 585 auio.uio_rw = UIO_READ; 586 auio.uio_resid = size; 587 auio.uio_procp = (struct proc *) 0; 588 589 error = VOP_READ(object->handle, &auio, 0, curproc->p_ucred); 590 if (!error) { 591 register int count = size - auio.uio_resid; 592 593 if (count == 0) 594 error = EINVAL; 595 else if (count != PAGE_SIZE) 596 bzero((caddr_t) kva + count, PAGE_SIZE - count); 597 } 598 vm_pager_unmap_page(kva); 599 } 600 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 601 m->dirty = 0; 602 m->flags &= ~PG_ZERO; 603 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 604 } 605 606 /* 607 * generic vnode pager input routine 608 */ 609 610 static int 611 vnode_pager_getpages(object, m, count, reqpage) 612 vm_object_t object; 613 vm_page_t *m; 614 int count; 615 int reqpage; 616 { 617 int rtval; 618 struct vnode *vp; 619 if (object->flags & OBJ_VNODE_GONE) 620 return VM_PAGER_ERROR; 621 vp = object->handle; 622 rtval = VOP_GETPAGES(vp, m, count*PAGE_SIZE, reqpage, 0); 623 if (rtval == EOPNOTSUPP) 624 return vnode_pager_leaf_getpages(object, m, count, reqpage); 625 else 626 return rtval; 627 } 628 629 static int 630 vnode_pager_leaf_getpages(object, m, count, reqpage) 631 vm_object_t object; 632 vm_page_t *m; 633 int count; 634 int reqpage; 635 { 636 vm_offset_t kva; 637 off_t foff; 638 int i, size, bsize, first, firstaddr; 639 struct vnode *dp, *vp; 640 int runpg; 641 int runend; 642 struct buf *bp; 643 int s; 644 int error = 0; 645 646 vp = object->handle; 647 if (vp->v_mount == NULL) 648 return VM_PAGER_BAD; 649 650 bsize = vp->v_mount->mnt_stat.f_iosize; 651 652 /* get the UNDERLYING device for the file with VOP_BMAP() */ 653 654 /* 655 * originally, we did not check for an error return value -- assuming 656 * an fs always has a bmap entry point -- that assumption is wrong!!! 657 */ 658 foff = IDX_TO_OFF(m[reqpage]->pindex); 659 660 /* 661 * if we can't bmap, use old VOP code 662 */ 663 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 664 for (i = 0; i < count; i++) { 665 if (i != reqpage) { 666 vnode_pager_freepage(m[i]); 667 } 668 } 669 cnt.v_vnodein++; 670 cnt.v_vnodepgsin++; 671 return vnode_pager_input_old(object, m[reqpage]); 672 673 /* 674 * if the blocksize is smaller than a page size, then use 675 * special small filesystem code. NFS sometimes has a small 676 * blocksize, but it can handle large reads itself. 677 */ 678 } else if ((PAGE_SIZE / bsize) > 1 && 679 (vp->v_mount->mnt_stat.f_type != MOUNT_NFS)) { 680 681 for (i = 0; i < count; i++) { 682 if (i != reqpage) { 683 vnode_pager_freepage(m[i]); 684 } 685 } 686 cnt.v_vnodein++; 687 cnt.v_vnodepgsin++; 688 return vnode_pager_input_smlfs(object, m[reqpage]); 689 } 690 /* 691 * if ANY DEV_BSIZE blocks are valid on a large filesystem block 692 * then, the entire page is valid -- 693 * XXX no it isn't 694 */ 695 if (m[reqpage]->valid != VM_PAGE_BITS_ALL) 696 m[reqpage]->valid = 0; 697 698 if (m[reqpage]->valid) { 699 m[reqpage]->valid = VM_PAGE_BITS_ALL; 700 701 for (i = 0; i < count; i++) { 702 if (i != reqpage) 703 vnode_pager_freepage(m[i]); 704 } 705 return VM_PAGER_OK; 706 } 707 708 /* 709 * here on direct device I/O 710 */ 711 712 firstaddr = -1; 713 /* 714 * calculate the run that includes the required page 715 */ 716 for(first = 0, i = 0; i < count; i = runend) { 717 firstaddr = vnode_pager_addr(vp, 718 IDX_TO_OFF(m[i]->pindex), &runpg); 719 if (firstaddr == -1) { 720 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 721 panic("vnode_pager_putpages: unexpected missing page: firstaddr: %d, foff: %ld, vnp_size: %d", 722 firstaddr, foff, object->un_pager.vnp.vnp_size); 723 } 724 vnode_pager_freepage(m[i]); 725 runend = i + 1; 726 first = runend; 727 continue; 728 } 729 runend = i + runpg; 730 if (runend <= reqpage) { 731 int j; 732 for (j = i; j < runend; j++) { 733 vnode_pager_freepage(m[j]); 734 } 735 } else { 736 if (runpg < (count - first)) { 737 for (i = first + runpg; i < count; i++) 738 vnode_pager_freepage(m[i]); 739 count = first + runpg; 740 } 741 break; 742 } 743 first = runend; 744 } 745 746 /* 747 * the first and last page have been calculated now, move input pages 748 * to be zero based... 749 */ 750 if (first != 0) { 751 for (i = first; i < count; i++) { 752 m[i - first] = m[i]; 753 } 754 count -= first; 755 reqpage -= first; 756 } 757 758 /* 759 * calculate the file virtual address for the transfer 760 */ 761 foff = IDX_TO_OFF(m[0]->pindex); 762 763 /* 764 * calculate the size of the transfer 765 */ 766 size = count * PAGE_SIZE; 767 if ((foff + size) > object->un_pager.vnp.vnp_size) 768 size = object->un_pager.vnp.vnp_size - foff; 769 770 /* 771 * round up physical size for real devices 772 */ 773 if (dp->v_type == VBLK || dp->v_type == VCHR) 774 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 775 776 bp = getpbuf(); 777 kva = (vm_offset_t) bp->b_data; 778 779 /* 780 * and map the pages to be read into the kva 781 */ 782 pmap_qenter(kva, m, count); 783 784 /* build a minimal buffer header */ 785 bp->b_flags = B_BUSY | B_READ | B_CALL; 786 bp->b_iodone = vnode_pager_iodone; 787 /* B_PHYS is not set, but it is nice to fill this in */ 788 bp->b_proc = curproc; 789 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 790 if (bp->b_rcred != NOCRED) 791 crhold(bp->b_rcred); 792 if (bp->b_wcred != NOCRED) 793 crhold(bp->b_wcred); 794 bp->b_blkno = firstaddr; 795 pbgetvp(dp, bp); 796 bp->b_bcount = size; 797 bp->b_bufsize = size; 798 799 cnt.v_vnodein++; 800 cnt.v_vnodepgsin += count; 801 802 /* do the input */ 803 VOP_STRATEGY(bp); 804 805 s = splbio(); 806 /* we definitely need to be at splbio here */ 807 808 while ((bp->b_flags & B_DONE) == 0) { 809 tsleep(bp, PVM, "vnread", 0); 810 } 811 splx(s); 812 if ((bp->b_flags & B_ERROR) != 0) 813 error = EIO; 814 815 if (!error) { 816 if (size != count * PAGE_SIZE) 817 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 818 } 819 pmap_qremove(kva, count); 820 821 /* 822 * free the buffer header back to the swap buffer pool 823 */ 824 relpbuf(bp); 825 826 for (i = 0; i < count; i++) { 827 pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); 828 m[i]->dirty = 0; 829 m[i]->valid = VM_PAGE_BITS_ALL; 830 m[i]->flags &= ~PG_ZERO; 831 if (i != reqpage) { 832 833 /* 834 * whether or not to leave the page activated is up in 835 * the air, but we should put the page on a page queue 836 * somewhere. (it already is in the object). Result: 837 * It appears that emperical results show that 838 * deactivating pages is best. 839 */ 840 841 /* 842 * just in case someone was asking for this page we 843 * now tell them that it is ok to use 844 */ 845 if (!error) { 846 vm_page_deactivate(m[i]); 847 PAGE_WAKEUP(m[i]); 848 } else { 849 vnode_pager_freepage(m[i]); 850 } 851 } 852 } 853 if (error) { 854 printf("vnode_pager_getpages: I/O read error\n"); 855 } 856 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 857 } 858 859 static int 860 vnode_pager_putpages(object, m, count, sync, rtvals) 861 vm_object_t object; 862 vm_page_t *m; 863 int count; 864 boolean_t sync; 865 int *rtvals; 866 { 867 int rtval; 868 struct vnode *vp; 869 870 if (object->flags & OBJ_VNODE_GONE) 871 return VM_PAGER_ERROR; 872 873 vp = object->handle; 874 rtval = VOP_PUTPAGES(vp, m, count*PAGE_SIZE, sync, rtvals, 0); 875 if (rtval == EOPNOTSUPP) 876 return vnode_pager_leaf_putpages(object, m, count, sync, rtvals); 877 else 878 return rtval; 879 } 880 881 /* 882 * generic vnode pager output routine 883 */ 884 static int 885 vnode_pager_leaf_putpages(object, m, count, sync, rtvals) 886 vm_object_t object; 887 vm_page_t *m; 888 int count; 889 boolean_t sync; 890 int *rtvals; 891 { 892 int i; 893 894 struct vnode *vp; 895 int maxsize, ncount; 896 vm_ooffset_t poffset; 897 struct uio auio; 898 struct iovec aiov; 899 int error; 900 901 vp = object->handle;; 902 for (i = 0; i < count; i++) 903 rtvals[i] = VM_PAGER_AGAIN; 904 905 if ((int) m[0]->pindex < 0) { 906 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%x(%x)\n", m[0]->pindex, m[0]->dirty); 907 rtvals[0] = VM_PAGER_BAD; 908 return VM_PAGER_BAD; 909 } 910 911 maxsize = count * PAGE_SIZE; 912 ncount = count; 913 914 poffset = IDX_TO_OFF(m[0]->pindex); 915 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 916 if (object->un_pager.vnp.vnp_size > poffset) 917 maxsize = object->un_pager.vnp.vnp_size - poffset; 918 else 919 maxsize = 0; 920 ncount = btoc(maxsize); 921 if (ncount < count) { 922 for (i = ncount; i < count; i++) { 923 rtvals[i] = VM_PAGER_BAD; 924 } 925 #ifdef BOGUS 926 if (ncount == 0) { 927 printf("vnode_pager_putpages: write past end of file: %d, %lu\n", 928 poffset, 929 (unsigned long) object->un_pager.vnp.vnp_size); 930 return rtvals[0]; 931 } 932 #endif 933 } 934 } 935 936 for (i = 0; i < count; i++) { 937 m[i]->busy++; 938 m[i]->flags &= ~PG_BUSY; 939 } 940 941 aiov.iov_base = (caddr_t) 0; 942 aiov.iov_len = maxsize; 943 auio.uio_iov = &aiov; 944 auio.uio_iovcnt = 1; 945 auio.uio_offset = poffset; 946 auio.uio_segflg = UIO_NOCOPY; 947 auio.uio_rw = UIO_WRITE; 948 auio.uio_resid = maxsize; 949 auio.uio_procp = (struct proc *) 0; 950 error = VOP_WRITE(vp, &auio, IO_VMIO|(sync?IO_SYNC:0), curproc->p_ucred); 951 cnt.v_vnodeout++; 952 cnt.v_vnodepgsout += ncount; 953 954 if (error) { 955 printf("vnode_pager_putpages: I/O error %d\n", error); 956 } 957 if (auio.uio_resid) { 958 printf("vnode_pager_putpages: residual I/O %d at %ld\n", 959 auio.uio_resid, m[0]->pindex); 960 } 961 for (i = 0; i < count; i++) { 962 m[i]->busy--; 963 if (i < ncount) { 964 rtvals[i] = VM_PAGER_OK; 965 } 966 if ((m[i]->busy == 0) && (m[i]->flags & PG_WANTED)) { 967 m[i]->flags &= ~PG_WANTED; 968 wakeup(m[i]); 969 } 970 } 971 return rtvals[0]; 972 } 973 974 struct vnode * 975 vnode_pager_lock(object) 976 vm_object_t object; 977 { 978 for (; object != NULL; object = object->backing_object) { 979 if (object->type != OBJT_VNODE) 980 continue; 981 982 VOP_LOCK(object->handle); 983 return object->handle; 984 } 985 return NULL; 986 }
Cache object: 51cd85c2b2808385f83e4cb2d08c060c
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