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 static 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 * MPSAFE 107 */ 108 vm_object_t 109 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 110 vm_ooffset_t offset) 111 { 112 vm_object_t object; 113 struct vnode *vp; 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 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc"); 124 125 mtx_lock(&Giant); 126 /* 127 * Prevent race condition when allocating the object. This 128 * can happen with NFS vnodes since the nfsnode isn't locked. 129 */ 130 VI_LOCK(vp); 131 while (vp->v_iflag & VI_OLOCK) { 132 vp->v_iflag |= VI_OWANT; 133 msleep(vp, VI_MTX(vp), PVM, "vnpobj", 0); 134 } 135 vp->v_iflag |= VI_OLOCK; 136 VI_UNLOCK(vp); 137 138 /* 139 * If the object is being terminated, wait for it to 140 * go away. 141 */ 142 while (((object = vp->v_object) != NULL) && 143 (object->flags & OBJ_DEAD)) { 144 tsleep(object, PVM, "vadead", 0); 145 } 146 147 if (vp->v_usecount == 0) 148 panic("vnode_pager_alloc: no vnode reference"); 149 150 if (object == NULL) { 151 /* 152 * And an object of the appropriate size 153 */ 154 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 155 156 object->un_pager.vnp.vnp_size = size; 157 158 object->handle = handle; 159 vp->v_object = object; 160 } else { 161 object->ref_count++; 162 } 163 VI_LOCK(vp); 164 vp->v_usecount++; 165 vp->v_iflag &= ~VI_OLOCK; 166 if (vp->v_iflag & VI_OWANT) { 167 vp->v_iflag &= ~VI_OWANT; 168 wakeup(vp); 169 } 170 VI_UNLOCK(vp); 171 mtx_unlock(&Giant); 172 return (object); 173 } 174 175 static void 176 vnode_pager_dealloc(object) 177 vm_object_t object; 178 { 179 struct vnode *vp = object->handle; 180 181 GIANT_REQUIRED; 182 if (vp == NULL) 183 panic("vnode_pager_dealloc: pager already dealloced"); 184 185 vm_object_pip_wait(object, "vnpdea"); 186 187 object->handle = NULL; 188 object->type = OBJT_DEAD; 189 ASSERT_VOP_LOCKED(vp, "vnode_pager_dealloc"); 190 vp->v_object = NULL; 191 vp->v_vflag &= ~(VV_TEXT | VV_OBJBUF); 192 } 193 194 static boolean_t 195 vnode_pager_haspage(object, pindex, before, after) 196 vm_object_t object; 197 vm_pindex_t pindex; 198 int *before; 199 int *after; 200 { 201 struct vnode *vp = object->handle; 202 daddr_t bn; 203 int err; 204 daddr_t reqblock; 205 int poff; 206 int bsize; 207 int pagesperblock, blocksperpage; 208 209 GIANT_REQUIRED; 210 /* 211 * If no vp or vp is doomed or marked transparent to VM, we do not 212 * have the page. 213 */ 214 if (vp == NULL) 215 return FALSE; 216 217 VI_LOCK(vp); 218 if (vp->v_iflag & VI_DOOMED) { 219 VI_UNLOCK(vp); 220 return FALSE; 221 } 222 VI_UNLOCK(vp); 223 /* 224 * If filesystem no longer mounted or offset beyond end of file we do 225 * not have the page. 226 */ 227 if ((vp->v_mount == NULL) || 228 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 229 return FALSE; 230 231 bsize = vp->v_mount->mnt_stat.f_iosize; 232 pagesperblock = bsize / PAGE_SIZE; 233 blocksperpage = 0; 234 if (pagesperblock > 0) { 235 reqblock = pindex / pagesperblock; 236 } else { 237 blocksperpage = (PAGE_SIZE / bsize); 238 reqblock = pindex * blocksperpage; 239 } 240 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 241 after, before); 242 if (err) 243 return TRUE; 244 if (bn == -1) 245 return FALSE; 246 if (pagesperblock > 0) { 247 poff = pindex - (reqblock * pagesperblock); 248 if (before) { 249 *before *= pagesperblock; 250 *before += poff; 251 } 252 if (after) { 253 int numafter; 254 *after *= pagesperblock; 255 numafter = pagesperblock - (poff + 1); 256 if (IDX_TO_OFF(pindex + numafter) > 257 object->un_pager.vnp.vnp_size) { 258 numafter = 259 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 260 pindex; 261 } 262 *after += numafter; 263 } 264 } else { 265 if (before) { 266 *before /= blocksperpage; 267 } 268 269 if (after) { 270 *after /= blocksperpage; 271 } 272 } 273 return TRUE; 274 } 275 276 /* 277 * Lets the VM system know about a change in size for a file. 278 * We adjust our own internal size and flush any cached pages in 279 * the associated object that are affected by the size change. 280 * 281 * Note: this routine may be invoked as a result of a pager put 282 * operation (possibly at object termination time), so we must be careful. 283 */ 284 void 285 vnode_pager_setsize(vp, nsize) 286 struct vnode *vp; 287 vm_ooffset_t nsize; 288 { 289 vm_pindex_t nobjsize; 290 vm_object_t object = vp->v_object; 291 292 GIANT_REQUIRED; 293 294 if (object == NULL) 295 return; 296 297 /* 298 * Hasn't changed size 299 */ 300 if (nsize == object->un_pager.vnp.vnp_size) 301 return; 302 303 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 304 305 /* 306 * File has shrunk. Toss any cached pages beyond the new EOF. 307 */ 308 if (nsize < object->un_pager.vnp.vnp_size) { 309 if (nobjsize < object->size) { 310 vm_object_lock(object); 311 vm_object_page_remove(object, nobjsize, object->size, 312 FALSE); 313 vm_object_unlock(object); 314 } 315 /* 316 * this gets rid of garbage at the end of a page that is now 317 * only partially backed by the vnode. 318 * 319 * XXX for some reason (I don't know yet), if we take a 320 * completely invalid page and mark it partially valid 321 * it can screw up NFS reads, so we don't allow the case. 322 */ 323 if (nsize & PAGE_MASK) { 324 vm_page_t m; 325 326 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 327 if (m && m->valid) { 328 int base = (int)nsize & PAGE_MASK; 329 int size = PAGE_SIZE - base; 330 331 /* 332 * Clear out partial-page garbage in case 333 * the page has been mapped. 334 */ 335 pmap_zero_page_area(m, base, size); 336 337 vm_page_lock_queues(); 338 /* 339 * XXX work around SMP data integrity race 340 * by unmapping the page from user processes. 341 * The garbage we just cleared may be mapped 342 * to a user process running on another cpu 343 * and this code is not running through normal 344 * I/O channels which handle SMP issues for 345 * us, so unmap page to synchronize all cpus. 346 * 347 * XXX should vm_pager_unmap_page() have 348 * dealt with this? 349 */ 350 pmap_remove_all(m); 351 352 /* 353 * Clear out partial-page dirty bits. This 354 * has the side effect of setting the valid 355 * bits, but that is ok. There are a bunch 356 * of places in the VM system where we expected 357 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 358 * case is one of them. If the page is still 359 * partially dirty, make it fully dirty. 360 * 361 * note that we do not clear out the valid 362 * bits. This would prevent bogus_page 363 * replacement from working properly. 364 */ 365 vm_page_set_validclean(m, base, size); 366 if (m->dirty != 0) 367 m->dirty = VM_PAGE_BITS_ALL; 368 vm_page_unlock_queues(); 369 } 370 } 371 } 372 object->un_pager.vnp.vnp_size = nsize; 373 object->size = nobjsize; 374 } 375 376 /* 377 * calculate the linear (byte) disk address of specified virtual 378 * file address 379 */ 380 static vm_offset_t 381 vnode_pager_addr(vp, address, run) 382 struct vnode *vp; 383 vm_ooffset_t address; 384 int *run; 385 { 386 int rtaddress; 387 int bsize; 388 daddr_t block; 389 struct vnode *rtvp; 390 int err; 391 daddr_t vblock; 392 int voffset; 393 394 GIANT_REQUIRED; 395 if ((int) address < 0) 396 return -1; 397 398 if (vp->v_mount == NULL) 399 return -1; 400 401 bsize = vp->v_mount->mnt_stat.f_iosize; 402 vblock = address / bsize; 403 voffset = address % bsize; 404 405 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 406 407 if (err || (block == -1)) 408 rtaddress = -1; 409 else { 410 rtaddress = block + voffset / DEV_BSIZE; 411 if (run) { 412 *run += 1; 413 *run *= bsize/PAGE_SIZE; 414 *run -= voffset/PAGE_SIZE; 415 } 416 } 417 418 return rtaddress; 419 } 420 421 /* 422 * interrupt routine for I/O completion 423 */ 424 static void 425 vnode_pager_iodone(bp) 426 struct buf *bp; 427 { 428 bp->b_flags |= B_DONE; 429 wakeup(bp); 430 } 431 432 /* 433 * small block filesystem vnode pager input 434 */ 435 static int 436 vnode_pager_input_smlfs(object, m) 437 vm_object_t object; 438 vm_page_t m; 439 { 440 int i; 441 int s; 442 struct vnode *dp, *vp; 443 struct buf *bp; 444 vm_offset_t kva; 445 int fileaddr; 446 vm_offset_t bsize; 447 int error = 0; 448 449 GIANT_REQUIRED; 450 451 vp = object->handle; 452 if (vp->v_mount == NULL) 453 return VM_PAGER_BAD; 454 455 bsize = vp->v_mount->mnt_stat.f_iosize; 456 457 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 458 459 kva = vm_pager_map_page(m); 460 461 for (i = 0; i < PAGE_SIZE / bsize; i++) { 462 vm_ooffset_t address; 463 464 if (vm_page_bits(i * bsize, bsize) & m->valid) 465 continue; 466 467 address = IDX_TO_OFF(m->pindex) + i * bsize; 468 if (address >= object->un_pager.vnp.vnp_size) { 469 fileaddr = -1; 470 } else { 471 fileaddr = vnode_pager_addr(vp, address, NULL); 472 } 473 if (fileaddr != -1) { 474 bp = getpbuf(&vnode_pbuf_freecnt); 475 476 /* build a minimal buffer header */ 477 bp->b_iocmd = BIO_READ; 478 bp->b_iodone = vnode_pager_iodone; 479 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 480 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 481 bp->b_rcred = crhold(curthread->td_ucred); 482 bp->b_wcred = crhold(curthread->td_ucred); 483 bp->b_data = (caddr_t) kva + i * bsize; 484 bp->b_blkno = fileaddr; 485 pbgetvp(dp, bp); 486 bp->b_bcount = bsize; 487 bp->b_bufsize = bsize; 488 bp->b_runningbufspace = bp->b_bufsize; 489 runningbufspace += bp->b_runningbufspace; 490 491 /* do the input */ 492 VOP_SPECSTRATEGY(bp->b_vp, bp); 493 494 /* we definitely need to be at splvm here */ 495 496 s = splvm(); 497 while ((bp->b_flags & B_DONE) == 0) { 498 tsleep(bp, PVM, "vnsrd", 0); 499 } 500 splx(s); 501 if ((bp->b_ioflags & BIO_ERROR) != 0) 502 error = EIO; 503 504 /* 505 * free the buffer header back to the swap buffer pool 506 */ 507 relpbuf(bp, &vnode_pbuf_freecnt); 508 if (error) 509 break; 510 511 vm_page_lock_queues(); 512 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 513 vm_page_unlock_queues(); 514 } else { 515 vm_page_lock_queues(); 516 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 517 vm_page_unlock_queues(); 518 bzero((caddr_t) kva + i * bsize, bsize); 519 } 520 } 521 vm_pager_unmap_page(kva); 522 vm_page_lock_queues(); 523 pmap_clear_modify(m); 524 vm_page_flag_clear(m, PG_ZERO); 525 vm_page_unlock_queues(); 526 if (error) { 527 return VM_PAGER_ERROR; 528 } 529 return VM_PAGER_OK; 530 531 } 532 533 534 /* 535 * old style vnode pager output routine 536 */ 537 static int 538 vnode_pager_input_old(object, m) 539 vm_object_t object; 540 vm_page_t m; 541 { 542 struct uio auio; 543 struct iovec aiov; 544 int error; 545 int size; 546 vm_offset_t kva; 547 struct vnode *vp; 548 549 GIANT_REQUIRED; 550 error = 0; 551 552 /* 553 * Return failure if beyond current EOF 554 */ 555 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 556 return VM_PAGER_BAD; 557 } else { 558 size = PAGE_SIZE; 559 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 560 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 561 562 /* 563 * Allocate a kernel virtual address and initialize so that 564 * we can use VOP_READ/WRITE routines. 565 */ 566 kva = vm_pager_map_page(m); 567 568 vp = object->handle; 569 aiov.iov_base = (caddr_t) kva; 570 aiov.iov_len = size; 571 auio.uio_iov = &aiov; 572 auio.uio_iovcnt = 1; 573 auio.uio_offset = IDX_TO_OFF(m->pindex); 574 auio.uio_segflg = UIO_SYSSPACE; 575 auio.uio_rw = UIO_READ; 576 auio.uio_resid = size; 577 auio.uio_td = curthread; 578 579 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 580 if (!error) { 581 int count = size - auio.uio_resid; 582 583 if (count == 0) 584 error = EINVAL; 585 else if (count != PAGE_SIZE) 586 bzero((caddr_t) kva + count, PAGE_SIZE - count); 587 } 588 vm_pager_unmap_page(kva); 589 } 590 vm_page_lock_queues(); 591 pmap_clear_modify(m); 592 vm_page_undirty(m); 593 vm_page_flag_clear(m, PG_ZERO); 594 if (!error) 595 m->valid = VM_PAGE_BITS_ALL; 596 vm_page_unlock_queues(); 597 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 598 } 599 600 /* 601 * generic vnode pager input routine 602 */ 603 604 /* 605 * Local media VFS's that do not implement their own VOP_GETPAGES 606 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 607 * to implement the previous behaviour. 608 * 609 * All other FS's should use the bypass to get to the local media 610 * backing vp's VOP_GETPAGES. 611 */ 612 static int 613 vnode_pager_getpages(object, m, count, reqpage) 614 vm_object_t object; 615 vm_page_t *m; 616 int count; 617 int reqpage; 618 { 619 int rtval; 620 struct vnode *vp; 621 int bytes = count * PAGE_SIZE; 622 623 GIANT_REQUIRED; 624 vp = object->handle; 625 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 626 KASSERT(rtval != EOPNOTSUPP, 627 ("vnode_pager: FS getpages not implemented\n")); 628 return rtval; 629 } 630 631 /* 632 * This is now called from local media FS's to operate against their 633 * own vnodes if they fail to implement VOP_GETPAGES. 634 */ 635 int 636 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 637 struct vnode *vp; 638 vm_page_t *m; 639 int bytecount; 640 int reqpage; 641 { 642 vm_object_t object; 643 vm_offset_t kva; 644 off_t foff, tfoff, nextoff; 645 int i, j, size, bsize, first, firstaddr; 646 struct vnode *dp; 647 int runpg; 648 int runend; 649 struct buf *bp; 650 int s; 651 int count; 652 int error = 0; 653 654 GIANT_REQUIRED; 655 object = vp->v_object; 656 count = bytecount / PAGE_SIZE; 657 658 if (vp->v_mount == NULL) 659 return VM_PAGER_BAD; 660 661 bsize = vp->v_mount->mnt_stat.f_iosize; 662 663 /* get the UNDERLYING device for the file with VOP_BMAP() */ 664 665 /* 666 * originally, we did not check for an error return value -- assuming 667 * an fs always has a bmap entry point -- that assumption is wrong!!! 668 */ 669 foff = IDX_TO_OFF(m[reqpage]->pindex); 670 671 /* 672 * if we can't bmap, use old VOP code 673 */ 674 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 675 vm_page_lock_queues(); 676 for (i = 0; i < count; i++) 677 if (i != reqpage) 678 vm_page_free(m[i]); 679 vm_page_unlock_queues(); 680 cnt.v_vnodein++; 681 cnt.v_vnodepgsin++; 682 return vnode_pager_input_old(object, m[reqpage]); 683 684 /* 685 * if the blocksize is smaller than a page size, then use 686 * special small filesystem code. NFS sometimes has a small 687 * blocksize, but it can handle large reads itself. 688 */ 689 } else if ((PAGE_SIZE / bsize) > 1 && 690 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 691 vm_page_lock_queues(); 692 for (i = 0; i < count; i++) 693 if (i != reqpage) 694 vm_page_free(m[i]); 695 vm_page_unlock_queues(); 696 cnt.v_vnodein++; 697 cnt.v_vnodepgsin++; 698 return vnode_pager_input_smlfs(object, m[reqpage]); 699 } 700 701 /* 702 * If we have a completely valid page available to us, we can 703 * clean up and return. Otherwise we have to re-read the 704 * media. 705 */ 706 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 707 vm_page_lock_queues(); 708 for (i = 0; i < count; i++) 709 if (i != reqpage) 710 vm_page_free(m[i]); 711 vm_page_unlock_queues(); 712 return VM_PAGER_OK; 713 } 714 m[reqpage]->valid = 0; 715 716 /* 717 * here on direct device I/O 718 */ 719 firstaddr = -1; 720 721 /* 722 * calculate the run that includes the required page 723 */ 724 for (first = 0, i = 0; i < count; i = runend) { 725 firstaddr = vnode_pager_addr(vp, 726 IDX_TO_OFF(m[i]->pindex), &runpg); 727 if (firstaddr == -1) { 728 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 729 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 730 firstaddr, (uintmax_t)(foff >> 32), 731 (uintmax_t)foff, 732 (uintmax_t) 733 (object->un_pager.vnp.vnp_size >> 32), 734 (uintmax_t)object->un_pager.vnp.vnp_size); 735 } 736 vm_page_lock_queues(); 737 vm_page_free(m[i]); 738 vm_page_unlock_queues(); 739 runend = i + 1; 740 first = runend; 741 continue; 742 } 743 runend = i + runpg; 744 if (runend <= reqpage) { 745 vm_page_lock_queues(); 746 for (j = i; j < runend; j++) 747 vm_page_free(m[j]); 748 vm_page_unlock_queues(); 749 } else { 750 if (runpg < (count - first)) { 751 vm_page_lock_queues(); 752 for (i = first + runpg; i < count; i++) 753 vm_page_free(m[i]); 754 vm_page_unlock_queues(); 755 count = first + runpg; 756 } 757 break; 758 } 759 first = runend; 760 } 761 762 /* 763 * the first and last page have been calculated now, move input pages 764 * to be zero based... 765 */ 766 if (first != 0) { 767 for (i = first; i < count; i++) { 768 m[i - first] = m[i]; 769 } 770 count -= first; 771 reqpage -= first; 772 } 773 774 /* 775 * calculate the file virtual address for the transfer 776 */ 777 foff = IDX_TO_OFF(m[0]->pindex); 778 779 /* 780 * calculate the size of the transfer 781 */ 782 size = count * PAGE_SIZE; 783 if ((foff + size) > object->un_pager.vnp.vnp_size) 784 size = object->un_pager.vnp.vnp_size - foff; 785 786 /* 787 * round up physical size for real devices. 788 */ 789 if (dp->v_type == VBLK || dp->v_type == VCHR) { 790 int secmask = dp->v_rdev->si_bsize_phys - 1; 791 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1)); 792 size = (size + secmask) & ~secmask; 793 } 794 795 bp = getpbuf(&vnode_pbuf_freecnt); 796 kva = (vm_offset_t) bp->b_data; 797 798 /* 799 * and map the pages to be read into the kva 800 */ 801 pmap_qenter(kva, m, count); 802 803 /* build a minimal buffer header */ 804 bp->b_iocmd = BIO_READ; 805 bp->b_iodone = vnode_pager_iodone; 806 /* B_PHYS is not set, but it is nice to fill this in */ 807 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 808 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 809 bp->b_rcred = crhold(curthread->td_ucred); 810 bp->b_wcred = crhold(curthread->td_ucred); 811 bp->b_blkno = firstaddr; 812 pbgetvp(dp, bp); 813 bp->b_bcount = size; 814 bp->b_bufsize = size; 815 bp->b_runningbufspace = bp->b_bufsize; 816 runningbufspace += bp->b_runningbufspace; 817 818 cnt.v_vnodein++; 819 cnt.v_vnodepgsin += count; 820 821 /* do the input */ 822 if (dp->v_type == VCHR) 823 VOP_SPECSTRATEGY(bp->b_vp, bp); 824 else 825 VOP_STRATEGY(bp->b_vp, bp); 826 827 s = splvm(); 828 /* we definitely need to be at splvm here */ 829 830 while ((bp->b_flags & B_DONE) == 0) { 831 tsleep(bp, PVM, "vnread", 0); 832 } 833 splx(s); 834 if ((bp->b_ioflags & BIO_ERROR) != 0) 835 error = EIO; 836 837 if (!error) { 838 if (size != count * PAGE_SIZE) 839 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 840 } 841 pmap_qremove(kva, count); 842 843 /* 844 * free the buffer header back to the swap buffer pool 845 */ 846 relpbuf(bp, &vnode_pbuf_freecnt); 847 848 vm_page_lock_queues(); 849 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 850 vm_page_t mt; 851 852 nextoff = tfoff + PAGE_SIZE; 853 mt = m[i]; 854 855 if (nextoff <= object->un_pager.vnp.vnp_size) { 856 /* 857 * Read filled up entire page. 858 */ 859 mt->valid = VM_PAGE_BITS_ALL; 860 vm_page_undirty(mt); /* should be an assert? XXX */ 861 pmap_clear_modify(mt); 862 } else { 863 /* 864 * Read did not fill up entire page. Since this 865 * is getpages, the page may be mapped, so we have 866 * to zero the invalid portions of the page even 867 * though we aren't setting them valid. 868 * 869 * Currently we do not set the entire page valid, 870 * we just try to clear the piece that we couldn't 871 * read. 872 */ 873 vm_page_set_validclean(mt, 0, 874 object->un_pager.vnp.vnp_size - tfoff); 875 /* handled by vm_fault now */ 876 /* vm_page_zero_invalid(mt, FALSE); */ 877 } 878 879 vm_page_flag_clear(mt, PG_ZERO); 880 if (i != reqpage) { 881 882 /* 883 * whether or not to leave the page activated is up in 884 * the air, but we should put the page on a page queue 885 * somewhere. (it already is in the object). Result: 886 * It appears that empirical results show that 887 * deactivating pages is best. 888 */ 889 890 /* 891 * just in case someone was asking for this page we 892 * now tell them that it is ok to use 893 */ 894 if (!error) { 895 if (mt->flags & PG_WANTED) 896 vm_page_activate(mt); 897 else 898 vm_page_deactivate(mt); 899 vm_page_wakeup(mt); 900 } else { 901 vm_page_free(mt); 902 } 903 } 904 } 905 vm_page_unlock_queues(); 906 if (error) { 907 printf("vnode_pager_getpages: I/O read error\n"); 908 } 909 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 910 } 911 912 /* 913 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 914 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 915 * vnode_pager_generic_putpages() to implement the previous behaviour. 916 * 917 * All other FS's should use the bypass to get to the local media 918 * backing vp's VOP_PUTPAGES. 919 */ 920 static void 921 vnode_pager_putpages(object, m, count, sync, rtvals) 922 vm_object_t object; 923 vm_page_t *m; 924 int count; 925 boolean_t sync; 926 int *rtvals; 927 { 928 int rtval; 929 struct vnode *vp; 930 struct mount *mp; 931 int bytes = count * PAGE_SIZE; 932 933 GIANT_REQUIRED; 934 /* 935 * Force synchronous operation if we are extremely low on memory 936 * to prevent a low-memory deadlock. VOP operations often need to 937 * allocate more memory to initiate the I/O ( i.e. do a BMAP 938 * operation ). The swapper handles the case by limiting the amount 939 * of asynchronous I/O, but that sort of solution doesn't scale well 940 * for the vnode pager without a lot of work. 941 * 942 * Also, the backing vnode's iodone routine may not wake the pageout 943 * daemon up. This should be probably be addressed XXX. 944 */ 945 946 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 947 sync |= OBJPC_SYNC; 948 949 /* 950 * Call device-specific putpages function 951 */ 952 vp = object->handle; 953 if (vp->v_type != VREG) 954 mp = NULL; 955 (void)vn_start_write(vp, &mp, V_WAIT); 956 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 957 KASSERT(rtval != EOPNOTSUPP, 958 ("vnode_pager: stale FS putpages\n")); 959 vn_finished_write(mp); 960 } 961 962 963 /* 964 * This is now called from local media FS's to operate against their 965 * own vnodes if they fail to implement VOP_PUTPAGES. 966 * 967 * This is typically called indirectly via the pageout daemon and 968 * clustering has already typically occured, so in general we ask the 969 * underlying filesystem to write the data out asynchronously rather 970 * then delayed. 971 */ 972 int 973 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 974 struct vnode *vp; 975 vm_page_t *m; 976 int bytecount; 977 int flags; 978 int *rtvals; 979 { 980 int i; 981 vm_object_t object; 982 int count; 983 984 int maxsize, ncount; 985 vm_ooffset_t poffset; 986 struct uio auio; 987 struct iovec aiov; 988 int error; 989 int ioflags; 990 991 GIANT_REQUIRED; 992 object = vp->v_object; 993 count = bytecount / PAGE_SIZE; 994 995 for (i = 0; i < count; i++) 996 rtvals[i] = VM_PAGER_AGAIN; 997 998 if ((int) m[0]->pindex < 0) { 999 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n", 1000 (long)m[0]->pindex, m[0]->dirty); 1001 rtvals[0] = VM_PAGER_BAD; 1002 return VM_PAGER_BAD; 1003 } 1004 1005 maxsize = count * PAGE_SIZE; 1006 ncount = count; 1007 1008 poffset = IDX_TO_OFF(m[0]->pindex); 1009 1010 /* 1011 * If the page-aligned write is larger then the actual file we 1012 * have to invalidate pages occuring beyond the file EOF. However, 1013 * there is an edge case where a file may not be page-aligned where 1014 * the last page is partially invalid. In this case the filesystem 1015 * may not properly clear the dirty bits for the entire page (which 1016 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1017 * With the page locked we are free to fix-up the dirty bits here. 1018 * 1019 * We do not under any circumstances truncate the valid bits, as 1020 * this will screw up bogus page replacement. 1021 */ 1022 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1023 if (object->un_pager.vnp.vnp_size > poffset) { 1024 int pgoff; 1025 1026 maxsize = object->un_pager.vnp.vnp_size - poffset; 1027 ncount = btoc(maxsize); 1028 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1029 vm_page_clear_dirty(m[ncount - 1], pgoff, 1030 PAGE_SIZE - pgoff); 1031 } 1032 } else { 1033 maxsize = 0; 1034 ncount = 0; 1035 } 1036 if (ncount < count) { 1037 for (i = ncount; i < count; i++) { 1038 rtvals[i] = VM_PAGER_BAD; 1039 } 1040 } 1041 } 1042 1043 /* 1044 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1045 * rather then a bdwrite() to prevent paging I/O from saturating 1046 * the buffer cache. Dummy-up the sequential heuristic to cause 1047 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1048 * the system decides how to cluster. 1049 */ 1050 ioflags = IO_VMIO; 1051 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1052 ioflags |= IO_SYNC; 1053 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1054 ioflags |= IO_ASYNC; 1055 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1056 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1057 1058 aiov.iov_base = (caddr_t) 0; 1059 aiov.iov_len = maxsize; 1060 auio.uio_iov = &aiov; 1061 auio.uio_iovcnt = 1; 1062 auio.uio_offset = poffset; 1063 auio.uio_segflg = UIO_NOCOPY; 1064 auio.uio_rw = UIO_WRITE; 1065 auio.uio_resid = maxsize; 1066 auio.uio_td = (struct thread *) 0; 1067 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1068 cnt.v_vnodeout++; 1069 cnt.v_vnodepgsout += ncount; 1070 1071 if (error) { 1072 printf("vnode_pager_putpages: I/O error %d\n", error); 1073 } 1074 if (auio.uio_resid) { 1075 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1076 auio.uio_resid, (u_long)m[0]->pindex); 1077 } 1078 for (i = 0; i < ncount; i++) { 1079 rtvals[i] = VM_PAGER_OK; 1080 } 1081 return rtvals[0]; 1082 } 1083 1084 struct vnode * 1085 vnode_pager_lock(object) 1086 vm_object_t object; 1087 { 1088 struct thread *td = curthread; /* XXX */ 1089 1090 GIANT_REQUIRED; 1091 1092 for (; object != NULL; object = object->backing_object) { 1093 if (object->type != OBJT_VNODE) 1094 continue; 1095 if (object->flags & OBJ_DEAD) { 1096 return NULL; 1097 } 1098 1099 /* XXX; If object->handle can change, we need to cache it. */ 1100 while (vget(object->handle, 1101 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, td)){ 1102 if ((object->flags & OBJ_DEAD) || (object->type != OBJT_VNODE)) 1103 return NULL; 1104 printf("vnode_pager_lock: retrying\n"); 1105 } 1106 return object->handle; 1107 } 1108 return NULL; 1109 } 1110