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 * $FreeBSD$ 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/bio.h> 60 #include <sys/buf.h> 61 #include <sys/vmmeter.h> 62 #include <sys/conf.h> 63 64 #include <vm/vm.h> 65 #include <vm/vm_object.h> 66 #include <vm/vm_page.h> 67 #include <vm/vm_pager.h> 68 #include <vm/vm_map.h> 69 #include <vm/vnode_pager.h> 70 #include <vm/vm_extern.h> 71 72 static void vnode_pager_init(void); 73 static vm_offset_t vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 74 int *run); 75 static void vnode_pager_iodone(struct buf *bp); 76 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 77 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 78 static void vnode_pager_dealloc(vm_object_t); 79 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int); 80 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); 81 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 82 83 struct pagerops vnodepagerops = { 84 vnode_pager_init, 85 vnode_pager_alloc, 86 vnode_pager_dealloc, 87 vnode_pager_getpages, 88 vnode_pager_putpages, 89 vnode_pager_haspage, 90 NULL 91 }; 92 93 int vnode_pbuf_freecnt; 94 95 void 96 vnode_pager_init(void) 97 { 98 99 vnode_pbuf_freecnt = nswbuf / 2 + 1; 100 } 101 102 /* 103 * Allocate (or lookup) pager for a vnode. 104 * Handle is a vnode pointer. 105 */ 106 vm_object_t 107 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 108 vm_ooffset_t offset) 109 { 110 vm_object_t object; 111 struct vnode *vp; 112 113 GIANT_REQUIRED; 114 115 /* 116 * Pageout to vnode, no can do yet. 117 */ 118 if (handle == NULL) 119 return (NULL); 120 121 vp = (struct vnode *) handle; 122 123 /* 124 * Prevent race condition when allocating the object. This 125 * can happen with NFS vnodes since the nfsnode isn't locked. 126 */ 127 while (vp->v_flag & VOLOCK) { 128 vp->v_flag |= VOWANT; 129 tsleep(vp, PVM, "vnpobj", 0); 130 } 131 vp->v_flag |= VOLOCK; 132 133 /* 134 * If the object is being terminated, wait for it to 135 * go away. 136 */ 137 while (((object = vp->v_object) != NULL) && 138 (object->flags & OBJ_DEAD)) { 139 tsleep(object, PVM, "vadead", 0); 140 } 141 142 if (vp->v_usecount == 0) 143 panic("vnode_pager_alloc: no vnode reference"); 144 145 if (object == NULL) { 146 /* 147 * And an object of the appropriate size 148 */ 149 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 150 object->flags = 0; 151 152 object->un_pager.vnp.vnp_size = size; 153 154 object->handle = handle; 155 vp->v_object = object; 156 vp->v_usecount++; 157 } else { 158 object->ref_count++; 159 vp->v_usecount++; 160 } 161 162 vp->v_flag &= ~VOLOCK; 163 if (vp->v_flag & VOWANT) { 164 vp->v_flag &= ~VOWANT; 165 wakeup(vp); 166 } 167 return (object); 168 } 169 170 static void 171 vnode_pager_dealloc(object) 172 vm_object_t object; 173 { 174 struct vnode *vp = object->handle; 175 176 GIANT_REQUIRED; 177 if (vp == NULL) 178 panic("vnode_pager_dealloc: pager already dealloced"); 179 180 vm_object_pip_wait(object, "vnpdea"); 181 182 object->handle = NULL; 183 object->type = OBJT_DEAD; 184 vp->v_object = NULL; 185 vp->v_flag &= ~(VTEXT | VOBJBUF); 186 } 187 188 static boolean_t 189 vnode_pager_haspage(object, pindex, before, after) 190 vm_object_t object; 191 vm_pindex_t pindex; 192 int *before; 193 int *after; 194 { 195 struct vnode *vp = object->handle; 196 daddr64_t bn; 197 int err; 198 daddr_t reqblock; 199 int poff; 200 int bsize; 201 int pagesperblock, blocksperpage; 202 203 GIANT_REQUIRED; 204 /* 205 * If no vp or vp is doomed or marked transparent to VM, we do not 206 * have the page. 207 */ 208 if ((vp == NULL) || (vp->v_flag & VDOOMED)) 209 return FALSE; 210 211 /* 212 * If filesystem no longer mounted or offset beyond end of file we do 213 * not have the page. 214 */ 215 if ((vp->v_mount == NULL) || 216 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 217 return FALSE; 218 219 bsize = vp->v_mount->mnt_stat.f_iosize; 220 pagesperblock = bsize / PAGE_SIZE; 221 blocksperpage = 0; 222 if (pagesperblock > 0) { 223 reqblock = pindex / pagesperblock; 224 } else { 225 blocksperpage = (PAGE_SIZE / bsize); 226 reqblock = pindex * blocksperpage; 227 } 228 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 229 after, before); 230 if (err) 231 return TRUE; 232 if (bn == -1) 233 return FALSE; 234 if (pagesperblock > 0) { 235 poff = pindex - (reqblock * pagesperblock); 236 if (before) { 237 *before *= pagesperblock; 238 *before += poff; 239 } 240 if (after) { 241 int numafter; 242 *after *= pagesperblock; 243 numafter = pagesperblock - (poff + 1); 244 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { 245 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex))); 246 } 247 *after += numafter; 248 } 249 } else { 250 if (before) { 251 *before /= blocksperpage; 252 } 253 254 if (after) { 255 *after /= blocksperpage; 256 } 257 } 258 return TRUE; 259 } 260 261 /* 262 * Lets the VM system know about a change in size for a file. 263 * We adjust our own internal size and flush any cached pages in 264 * the associated object that are affected by the size change. 265 * 266 * Note: this routine may be invoked as a result of a pager put 267 * operation (possibly at object termination time), so we must be careful. 268 */ 269 void 270 vnode_pager_setsize(vp, nsize) 271 struct vnode *vp; 272 vm_ooffset_t nsize; 273 { 274 vm_pindex_t nobjsize; 275 vm_object_t object = vp->v_object; 276 277 GIANT_REQUIRED; 278 279 if (object == NULL) 280 return; 281 282 /* 283 * Hasn't changed size 284 */ 285 if (nsize == object->un_pager.vnp.vnp_size) 286 return; 287 288 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 289 290 /* 291 * File has shrunk. Toss any cached pages beyond the new EOF. 292 */ 293 if (nsize < object->un_pager.vnp.vnp_size) { 294 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size); 295 if (nobjsize < object->size) { 296 vm_object_page_remove(object, nobjsize, object->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 * XXX for some reason (I don't know yet), if we take a 304 * completely invalid page and mark it partially valid 305 * it can screw up NFS reads, so we don't allow the case. 306 */ 307 if (nsize & PAGE_MASK) { 308 vm_offset_t kva; 309 vm_page_t m; 310 311 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 312 if (m && m->valid) { 313 int base = (int)nsize & PAGE_MASK; 314 int size = PAGE_SIZE - base; 315 316 /* 317 * Clear out partial-page garbage in case 318 * the page has been mapped. 319 */ 320 kva = vm_pager_map_page(m); 321 bzero((caddr_t)kva + base, size); 322 vm_pager_unmap_page(kva); 323 324 /* 325 * XXX work around SMP data integrity race 326 * by unmapping the page from user processes. 327 * The garbage we just cleared may be mapped 328 * to a user process running on another cpu 329 * and this code is not running through normal 330 * I/O channels which handle SMP issues for 331 * us, so unmap page to synchronize all cpus. 332 * 333 * XXX should vm_pager_unmap_page() have 334 * dealt with this? 335 */ 336 vm_page_protect(m, VM_PROT_NONE); 337 338 /* 339 * Clear out partial-page dirty bits. This 340 * has the side effect of setting the valid 341 * bits, but that is ok. There are a bunch 342 * of places in the VM system where we expected 343 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 344 * case is one of them. If the page is still 345 * partially dirty, make it fully dirty. 346 * 347 * note that we do not clear out the valid 348 * bits. This would prevent bogus_page 349 * replacement from working properly. 350 */ 351 vm_page_set_validclean(m, base, size); 352 if (m->dirty != 0) 353 m->dirty = VM_PAGE_BITS_ALL; 354 } 355 } 356 } 357 object->un_pager.vnp.vnp_size = nsize; 358 object->size = nobjsize; 359 } 360 361 /* 362 * calculate the linear (byte) disk address of specified virtual 363 * file address 364 */ 365 static vm_offset_t 366 vnode_pager_addr(vp, address, run) 367 struct vnode *vp; 368 vm_ooffset_t address; 369 int *run; 370 { 371 int rtaddress; 372 int bsize; 373 daddr64_t block; 374 struct vnode *rtvp; 375 int err; 376 daddr_t vblock; 377 int voffset; 378 379 GIANT_REQUIRED; 380 if ((int) address < 0) 381 return -1; 382 383 if (vp->v_mount == NULL) 384 return -1; 385 386 bsize = vp->v_mount->mnt_stat.f_iosize; 387 vblock = address / bsize; 388 voffset = address % bsize; 389 390 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 391 392 if (err || (block == -1)) 393 rtaddress = -1; 394 else { 395 rtaddress = block + voffset / DEV_BSIZE; 396 if (run) { 397 *run += 1; 398 *run *= bsize/PAGE_SIZE; 399 *run -= voffset/PAGE_SIZE; 400 } 401 } 402 403 return rtaddress; 404 } 405 406 /* 407 * interrupt routine for I/O completion 408 */ 409 static void 410 vnode_pager_iodone(bp) 411 struct buf *bp; 412 { 413 bp->b_flags |= B_DONE; 414 wakeup(bp); 415 } 416 417 /* 418 * small block file system vnode pager input 419 */ 420 static int 421 vnode_pager_input_smlfs(object, m) 422 vm_object_t object; 423 vm_page_t m; 424 { 425 int i; 426 int s; 427 struct vnode *dp, *vp; 428 struct buf *bp; 429 vm_offset_t kva; 430 int fileaddr; 431 vm_offset_t bsize; 432 int error = 0; 433 434 GIANT_REQUIRED; 435 436 vp = object->handle; 437 if (vp->v_mount == NULL) 438 return VM_PAGER_BAD; 439 440 bsize = vp->v_mount->mnt_stat.f_iosize; 441 442 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 443 444 kva = vm_pager_map_page(m); 445 446 for (i = 0; i < PAGE_SIZE / bsize; i++) { 447 vm_ooffset_t address; 448 449 if (vm_page_bits(i * bsize, bsize) & m->valid) 450 continue; 451 452 address = IDX_TO_OFF(m->pindex) + i * bsize; 453 if (address >= object->un_pager.vnp.vnp_size) { 454 fileaddr = -1; 455 } else { 456 fileaddr = vnode_pager_addr(vp, address, NULL); 457 } 458 if (fileaddr != -1) { 459 bp = getpbuf(&vnode_pbuf_freecnt); 460 461 /* build a minimal buffer header */ 462 bp->b_iocmd = BIO_READ; 463 bp->b_iodone = vnode_pager_iodone; 464 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 465 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 466 bp->b_rcred = crhold(curthread->td_ucred); 467 bp->b_wcred = crhold(curthread->td_ucred); 468 bp->b_data = (caddr_t) kva + i * bsize; 469 bp->b_blkno = fileaddr; 470 pbgetvp(dp, bp); 471 bp->b_bcount = bsize; 472 bp->b_bufsize = bsize; 473 bp->b_runningbufspace = bp->b_bufsize; 474 runningbufspace += bp->b_runningbufspace; 475 476 /* do the input */ 477 BUF_STRATEGY(bp); 478 479 /* we definitely need to be at splvm here */ 480 481 s = splvm(); 482 while ((bp->b_flags & B_DONE) == 0) { 483 tsleep(bp, PVM, "vnsrd", 0); 484 } 485 splx(s); 486 if ((bp->b_ioflags & BIO_ERROR) != 0) 487 error = EIO; 488 489 /* 490 * free the buffer header back to the swap buffer pool 491 */ 492 relpbuf(bp, &vnode_pbuf_freecnt); 493 if (error) 494 break; 495 496 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 497 } else { 498 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 499 bzero((caddr_t) kva + i * bsize, bsize); 500 } 501 } 502 vm_pager_unmap_page(kva); 503 pmap_clear_modify(m); 504 vm_page_flag_clear(m, PG_ZERO); 505 if (error) { 506 return VM_PAGER_ERROR; 507 } 508 return VM_PAGER_OK; 509 510 } 511 512 513 /* 514 * old style vnode pager output routine 515 */ 516 static int 517 vnode_pager_input_old(object, m) 518 vm_object_t object; 519 vm_page_t m; 520 { 521 struct uio auio; 522 struct iovec aiov; 523 int error; 524 int size; 525 vm_offset_t kva; 526 struct vnode *vp; 527 528 GIANT_REQUIRED; 529 error = 0; 530 531 /* 532 * Return failure if beyond current EOF 533 */ 534 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 535 return VM_PAGER_BAD; 536 } else { 537 size = PAGE_SIZE; 538 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 539 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 540 541 /* 542 * Allocate a kernel virtual address and initialize so that 543 * we can use VOP_READ/WRITE routines. 544 */ 545 kva = vm_pager_map_page(m); 546 547 vp = object->handle; 548 aiov.iov_base = (caddr_t) kva; 549 aiov.iov_len = size; 550 auio.uio_iov = &aiov; 551 auio.uio_iovcnt = 1; 552 auio.uio_offset = IDX_TO_OFF(m->pindex); 553 auio.uio_segflg = UIO_SYSSPACE; 554 auio.uio_rw = UIO_READ; 555 auio.uio_resid = size; 556 auio.uio_td = curthread; 557 558 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 559 if (!error) { 560 int count = size - auio.uio_resid; 561 562 if (count == 0) 563 error = EINVAL; 564 else if (count != PAGE_SIZE) 565 bzero((caddr_t) kva + count, PAGE_SIZE - count); 566 } 567 vm_pager_unmap_page(kva); 568 } 569 pmap_clear_modify(m); 570 vm_page_undirty(m); 571 vm_page_flag_clear(m, PG_ZERO); 572 if (!error) 573 m->valid = VM_PAGE_BITS_ALL; 574 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 575 } 576 577 /* 578 * generic vnode pager input routine 579 */ 580 581 /* 582 * Local media VFS's that do not implement their own VOP_GETPAGES 583 * should have their VOP_GETPAGES should call to 584 * vnode_pager_generic_getpages() to implement the previous behaviour. 585 * 586 * All other FS's should use the bypass to get to the local media 587 * backing vp's VOP_GETPAGES. 588 */ 589 static int 590 vnode_pager_getpages(object, m, count, reqpage) 591 vm_object_t object; 592 vm_page_t *m; 593 int count; 594 int reqpage; 595 { 596 int rtval; 597 struct vnode *vp; 598 int bytes = count * PAGE_SIZE; 599 600 GIANT_REQUIRED; 601 vp = object->handle; 602 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 603 KASSERT(rtval != EOPNOTSUPP, 604 ("vnode_pager: FS getpages not implemented\n")); 605 return rtval; 606 } 607 608 609 /* 610 * This is now called from local media FS's to operate against their 611 * own vnodes if they fail to implement VOP_GETPAGES. 612 */ 613 int 614 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 615 struct vnode *vp; 616 vm_page_t *m; 617 int bytecount; 618 int reqpage; 619 { 620 vm_object_t object; 621 vm_offset_t kva; 622 off_t foff, tfoff, nextoff; 623 int i, size, bsize, first, firstaddr; 624 struct vnode *dp; 625 int runpg; 626 int runend; 627 struct buf *bp; 628 int s; 629 int count; 630 int error = 0; 631 632 GIANT_REQUIRED; 633 object = vp->v_object; 634 count = bytecount / PAGE_SIZE; 635 636 if (vp->v_mount == NULL) 637 return VM_PAGER_BAD; 638 639 bsize = vp->v_mount->mnt_stat.f_iosize; 640 641 /* get the UNDERLYING device for the file with VOP_BMAP() */ 642 643 /* 644 * originally, we did not check for an error return value -- assuming 645 * an fs always has a bmap entry point -- that assumption is wrong!!! 646 */ 647 foff = IDX_TO_OFF(m[reqpage]->pindex); 648 649 /* 650 * if we can't bmap, use old VOP code 651 */ 652 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 653 for (i = 0; i < count; i++) { 654 if (i != reqpage) { 655 vm_page_free(m[i]); 656 } 657 } 658 cnt.v_vnodein++; 659 cnt.v_vnodepgsin++; 660 return vnode_pager_input_old(object, m[reqpage]); 661 662 /* 663 * if the blocksize is smaller than a page size, then use 664 * special small filesystem code. NFS sometimes has a small 665 * blocksize, but it can handle large reads itself. 666 */ 667 } else if ((PAGE_SIZE / bsize) > 1 && 668 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 669 for (i = 0; i < count; i++) { 670 if (i != reqpage) { 671 vm_page_free(m[i]); 672 } 673 } 674 cnt.v_vnodein++; 675 cnt.v_vnodepgsin++; 676 return vnode_pager_input_smlfs(object, m[reqpage]); 677 } 678 679 /* 680 * If we have a completely valid page available to us, we can 681 * clean up and return. Otherwise we have to re-read the 682 * media. 683 */ 684 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 685 for (i = 0; i < count; i++) { 686 if (i != reqpage) 687 vm_page_free(m[i]); 688 } 689 return VM_PAGER_OK; 690 } 691 m[reqpage]->valid = 0; 692 693 /* 694 * here on direct device I/O 695 */ 696 firstaddr = -1; 697 698 /* 699 * calculate the run that includes the required page 700 */ 701 for (first = 0, i = 0; i < count; i = runend) { 702 firstaddr = vnode_pager_addr(vp, 703 IDX_TO_OFF(m[i]->pindex), &runpg); 704 if (firstaddr == -1) { 705 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 706 /* XXX no %qd in kernel. */ 707 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx", 708 firstaddr, (u_long)(foff >> 32), 709 (u_long)(u_int32_t)foff, 710 (u_long)(u_int32_t) 711 (object->un_pager.vnp.vnp_size >> 32), 712 (u_long)(u_int32_t) 713 object->un_pager.vnp.vnp_size); 714 } 715 vm_page_free(m[i]); 716 runend = i + 1; 717 first = runend; 718 continue; 719 } 720 runend = i + runpg; 721 if (runend <= reqpage) { 722 int j; 723 for (j = i; j < runend; j++) { 724 vm_page_free(m[j]); 725 } 726 } else { 727 if (runpg < (count - first)) { 728 for (i = first + runpg; i < count; i++) 729 vm_page_free(m[i]); 730 count = first + runpg; 731 } 732 break; 733 } 734 first = runend; 735 } 736 737 /* 738 * the first and last page have been calculated now, move input pages 739 * to be zero based... 740 */ 741 if (first != 0) { 742 for (i = first; i < count; i++) { 743 m[i - first] = m[i]; 744 } 745 count -= first; 746 reqpage -= first; 747 } 748 749 /* 750 * calculate the file virtual address for the transfer 751 */ 752 foff = IDX_TO_OFF(m[0]->pindex); 753 754 /* 755 * calculate the size of the transfer 756 */ 757 size = count * PAGE_SIZE; 758 if ((foff + size) > object->un_pager.vnp.vnp_size) 759 size = object->un_pager.vnp.vnp_size - foff; 760 761 /* 762 * round up physical size for real devices. 763 */ 764 if (dp->v_type == VBLK || dp->v_type == VCHR) { 765 int secmask = dp->v_rdev->si_bsize_phys - 1; 766 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1)); 767 size = (size + secmask) & ~secmask; 768 } 769 770 bp = getpbuf(&vnode_pbuf_freecnt); 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_iocmd = BIO_READ; 780 bp->b_iodone = vnode_pager_iodone; 781 /* B_PHYS is not set, but it is nice to fill this in */ 782 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 783 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 784 bp->b_rcred = crhold(curthread->td_ucred); 785 bp->b_wcred = crhold(curthread->td_ucred); 786 bp->b_blkno = firstaddr; 787 pbgetvp(dp, bp); 788 bp->b_bcount = size; 789 bp->b_bufsize = size; 790 bp->b_runningbufspace = bp->b_bufsize; 791 runningbufspace += bp->b_runningbufspace; 792 793 cnt.v_vnodein++; 794 cnt.v_vnodepgsin += count; 795 796 /* do the input */ 797 BUF_STRATEGY(bp); 798 799 s = splvm(); 800 /* we definitely need to be at splvm here */ 801 802 while ((bp->b_flags & B_DONE) == 0) { 803 tsleep(bp, PVM, "vnread", 0); 804 } 805 splx(s); 806 if ((bp->b_ioflags & BIO_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, &vnode_pbuf_freecnt); 819 820 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 821 vm_page_t mt; 822 823 nextoff = tfoff + PAGE_SIZE; 824 mt = m[i]; 825 826 if (nextoff <= object->un_pager.vnp.vnp_size) { 827 /* 828 * Read filled up entire page. 829 */ 830 mt->valid = VM_PAGE_BITS_ALL; 831 vm_page_undirty(mt); /* should be an assert? XXX */ 832 pmap_clear_modify(mt); 833 } else { 834 /* 835 * Read did not fill up entire page. Since this 836 * is getpages, the page may be mapped, so we have 837 * to zero the invalid portions of the page even 838 * though we aren't setting them valid. 839 * 840 * Currently we do not set the entire page valid, 841 * we just try to clear the piece that we couldn't 842 * read. 843 */ 844 vm_page_set_validclean(mt, 0, 845 object->un_pager.vnp.vnp_size - tfoff); 846 /* handled by vm_fault now */ 847 /* vm_page_zero_invalid(mt, FALSE); */ 848 } 849 850 vm_page_flag_clear(mt, PG_ZERO); 851 if (i != reqpage) { 852 853 /* 854 * whether or not to leave the page activated is up in 855 * the air, but we should put the page on a page queue 856 * somewhere. (it already is in the object). Result: 857 * It appears that empirical results show that 858 * deactivating pages is best. 859 */ 860 861 /* 862 * just in case someone was asking for this page we 863 * now tell them that it is ok to use 864 */ 865 if (!error) { 866 if (mt->flags & PG_WANTED) 867 vm_page_activate(mt); 868 else 869 vm_page_deactivate(mt); 870 vm_page_wakeup(mt); 871 } else { 872 vm_page_free(mt); 873 } 874 } 875 } 876 if (error) { 877 printf("vnode_pager_getpages: I/O read error\n"); 878 } 879 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 880 } 881 882 /* 883 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 884 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 885 * vnode_pager_generic_putpages() to implement the previous behaviour. 886 * 887 * All other FS's should use the bypass to get to the local media 888 * backing vp's VOP_PUTPAGES. 889 */ 890 static void 891 vnode_pager_putpages(object, m, count, sync, rtvals) 892 vm_object_t object; 893 vm_page_t *m; 894 int count; 895 boolean_t sync; 896 int *rtvals; 897 { 898 int rtval; 899 struct vnode *vp; 900 struct mount *mp; 901 int bytes = count * PAGE_SIZE; 902 903 GIANT_REQUIRED; 904 /* 905 * Force synchronous operation if we are extremely low on memory 906 * to prevent a low-memory deadlock. VOP operations often need to 907 * allocate more memory to initiate the I/O ( i.e. do a BMAP 908 * operation ). The swapper handles the case by limiting the amount 909 * of asynchronous I/O, but that sort of solution doesn't scale well 910 * for the vnode pager without a lot of work. 911 * 912 * Also, the backing vnode's iodone routine may not wake the pageout 913 * daemon up. This should be probably be addressed XXX. 914 */ 915 916 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 917 sync |= OBJPC_SYNC; 918 919 /* 920 * Call device-specific putpages function 921 */ 922 vp = object->handle; 923 if (vp->v_type != VREG) 924 mp = NULL; 925 (void)vn_start_write(vp, &mp, V_WAIT); 926 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 927 KASSERT(rtval != EOPNOTSUPP, 928 ("vnode_pager: stale FS putpages\n")); 929 vn_finished_write(mp); 930 } 931 932 933 /* 934 * This is now called from local media FS's to operate against their 935 * own vnodes if they fail to implement VOP_PUTPAGES. 936 * 937 * This is typically called indirectly via the pageout daemon and 938 * clustering has already typically occured, so in general we ask the 939 * underlying filesystem to write the data out asynchronously rather 940 * then delayed. 941 */ 942 int 943 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 944 struct vnode *vp; 945 vm_page_t *m; 946 int bytecount; 947 int flags; 948 int *rtvals; 949 { 950 int i; 951 vm_object_t object; 952 int count; 953 954 int maxsize, ncount; 955 vm_ooffset_t poffset; 956 struct uio auio; 957 struct iovec aiov; 958 int error; 959 int ioflags; 960 961 GIANT_REQUIRED; 962 object = vp->v_object; 963 count = bytecount / PAGE_SIZE; 964 965 for (i = 0; i < count; i++) 966 rtvals[i] = VM_PAGER_AGAIN; 967 968 if ((int) m[0]->pindex < 0) { 969 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n", 970 (long)m[0]->pindex, m[0]->dirty); 971 rtvals[0] = VM_PAGER_BAD; 972 return VM_PAGER_BAD; 973 } 974 975 maxsize = count * PAGE_SIZE; 976 ncount = count; 977 978 poffset = IDX_TO_OFF(m[0]->pindex); 979 980 /* 981 * If the page-aligned write is larger then the actual file we 982 * have to invalidate pages occuring beyond the file EOF. However, 983 * there is an edge case where a file may not be page-aligned where 984 * the last page is partially invalid. In this case the filesystem 985 * may not properly clear the dirty bits for the entire page (which 986 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 987 * With the page locked we are free to fix-up the dirty bits here. 988 * 989 * We do not under any circumstances truncate the valid bits, as 990 * this will screw up bogus page replacement. 991 */ 992 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 993 if (object->un_pager.vnp.vnp_size > poffset) { 994 int pgoff; 995 996 maxsize = object->un_pager.vnp.vnp_size - poffset; 997 ncount = btoc(maxsize); 998 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 999 vm_page_clear_dirty(m[ncount - 1], pgoff, 1000 PAGE_SIZE - pgoff); 1001 } 1002 } else { 1003 maxsize = 0; 1004 ncount = 0; 1005 } 1006 if (ncount < count) { 1007 for (i = ncount; i < count; i++) { 1008 rtvals[i] = VM_PAGER_BAD; 1009 } 1010 } 1011 } 1012 1013 /* 1014 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1015 * rather then a bdwrite() to prevent paging I/O from saturating 1016 * the buffer cache. 1017 */ 1018 ioflags = IO_VMIO; 1019 ioflags |= (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) ? IO_SYNC: IO_ASYNC; 1020 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1021 1022 aiov.iov_base = (caddr_t) 0; 1023 aiov.iov_len = maxsize; 1024 auio.uio_iov = &aiov; 1025 auio.uio_iovcnt = 1; 1026 auio.uio_offset = poffset; 1027 auio.uio_segflg = UIO_NOCOPY; 1028 auio.uio_rw = UIO_WRITE; 1029 auio.uio_resid = maxsize; 1030 auio.uio_td = (struct thread *) 0; 1031 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1032 cnt.v_vnodeout++; 1033 cnt.v_vnodepgsout += ncount; 1034 1035 if (error) { 1036 printf("vnode_pager_putpages: I/O error %d\n", error); 1037 } 1038 if (auio.uio_resid) { 1039 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1040 auio.uio_resid, (u_long)m[0]->pindex); 1041 } 1042 for (i = 0; i < ncount; i++) { 1043 rtvals[i] = VM_PAGER_OK; 1044 } 1045 return rtvals[0]; 1046 } 1047 1048 struct vnode * 1049 vnode_pager_lock(object) 1050 vm_object_t object; 1051 { 1052 struct thread *td = curthread; /* XXX */ 1053 1054 GIANT_REQUIRED; 1055 1056 for (; object != NULL; object = object->backing_object) { 1057 if (object->type != OBJT_VNODE) 1058 continue; 1059 if (object->flags & OBJ_DEAD) { 1060 return NULL; 1061 } 1062 1063 /* XXX; If object->handle can change, we need to cache it. */ 1064 while (vget(object->handle, 1065 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, td)){ 1066 if ((object->flags & OBJ_DEAD) || (object->type != OBJT_VNODE)) 1067 return NULL; 1068 printf("vnode_pager_lock: retrying\n"); 1069 } 1070 return object->handle; 1071 } 1072 return NULL; 1073 } 1074