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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: releng/5.0/sys/vm/vnode_pager.c 107347 2002-11-27 19:51:48Z alc $ 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 #include <sys/stdint.h> 64 65 #include <vm/vm.h> 66 #include <vm/vm_object.h> 67 #include <vm/vm_page.h> 68 #include <vm/vm_pager.h> 69 #include <vm/vm_map.h> 70 #include <vm/vnode_pager.h> 71 #include <vm/vm_extern.h> 72 73 static void vnode_pager_init(void); 74 static vm_offset_t vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 75 int *run); 76 static void vnode_pager_iodone(struct buf *bp); 77 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 78 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 79 static void vnode_pager_dealloc(vm_object_t); 80 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int); 81 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); 82 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 83 84 struct pagerops vnodepagerops = { 85 vnode_pager_init, 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 int vnode_pbuf_freecnt; 95 96 static void 97 vnode_pager_init(void) 98 { 99 100 vnode_pbuf_freecnt = nswbuf / 2 + 1; 101 } 102 103 /* 104 * Allocate (or lookup) pager for a vnode. 105 * Handle is a vnode pointer. 106 * 107 * MPSAFE 108 */ 109 vm_object_t 110 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 111 vm_ooffset_t offset) 112 { 113 vm_object_t object; 114 struct vnode *vp; 115 116 /* 117 * Pageout to vnode, no can do yet. 118 */ 119 if (handle == NULL) 120 return (NULL); 121 122 vp = (struct vnode *) handle; 123 124 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc"); 125 126 mtx_lock(&Giant); 127 /* 128 * Prevent race condition when allocating the object. This 129 * can happen with NFS vnodes since the nfsnode isn't locked. 130 */ 131 VI_LOCK(vp); 132 while (vp->v_iflag & VI_OLOCK) { 133 vp->v_iflag |= VI_OWANT; 134 msleep(vp, VI_MTX(vp), PVM, "vnpobj", 0); 135 } 136 vp->v_iflag |= VI_OLOCK; 137 VI_UNLOCK(vp); 138 139 /* 140 * If the object is being terminated, wait for it to 141 * go away. 142 */ 143 while (((object = vp->v_object) != NULL) && 144 (object->flags & OBJ_DEAD)) { 145 tsleep(object, PVM, "vadead", 0); 146 } 147 148 if (vp->v_usecount == 0) 149 panic("vnode_pager_alloc: no vnode reference"); 150 151 if (object == NULL) { 152 /* 153 * And an object of the appropriate size 154 */ 155 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 156 157 object->un_pager.vnp.vnp_size = size; 158 159 object->handle = handle; 160 vp->v_object = object; 161 } else { 162 object->ref_count++; 163 } 164 VI_LOCK(vp); 165 vp->v_usecount++; 166 vp->v_iflag &= ~VI_OLOCK; 167 if (vp->v_iflag & VI_OWANT) { 168 vp->v_iflag &= ~VI_OWANT; 169 wakeup(vp); 170 } 171 VI_UNLOCK(vp); 172 mtx_unlock(&Giant); 173 return (object); 174 } 175 176 static void 177 vnode_pager_dealloc(object) 178 vm_object_t object; 179 { 180 struct vnode *vp = object->handle; 181 182 GIANT_REQUIRED; 183 if (vp == NULL) 184 panic("vnode_pager_dealloc: pager already dealloced"); 185 186 vm_object_pip_wait(object, "vnpdea"); 187 188 object->handle = NULL; 189 object->type = OBJT_DEAD; 190 ASSERT_VOP_LOCKED(vp, "vnode_pager_dealloc"); 191 vp->v_object = NULL; 192 vp->v_vflag &= ~(VV_TEXT | VV_OBJBUF); 193 } 194 195 static boolean_t 196 vnode_pager_haspage(object, pindex, before, after) 197 vm_object_t object; 198 vm_pindex_t pindex; 199 int *before; 200 int *after; 201 { 202 struct vnode *vp = object->handle; 203 daddr_t bn; 204 int err; 205 daddr_t reqblock; 206 int poff; 207 int bsize; 208 int pagesperblock, blocksperpage; 209 210 GIANT_REQUIRED; 211 /* 212 * If no vp or vp is doomed or marked transparent to VM, we do not 213 * have the page. 214 */ 215 if (vp == NULL) 216 return FALSE; 217 218 VI_LOCK(vp); 219 if (vp->v_iflag & VI_DOOMED) { 220 VI_UNLOCK(vp); 221 return FALSE; 222 } 223 VI_UNLOCK(vp); 224 /* 225 * If filesystem no longer mounted or offset beyond end of file we do 226 * not have the page. 227 */ 228 if ((vp->v_mount == NULL) || 229 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 230 return FALSE; 231 232 bsize = vp->v_mount->mnt_stat.f_iosize; 233 pagesperblock = bsize / PAGE_SIZE; 234 blocksperpage = 0; 235 if (pagesperblock > 0) { 236 reqblock = pindex / pagesperblock; 237 } else { 238 blocksperpage = (PAGE_SIZE / bsize); 239 reqblock = pindex * blocksperpage; 240 } 241 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 242 after, before); 243 if (err) 244 return TRUE; 245 if (bn == -1) 246 return FALSE; 247 if (pagesperblock > 0) { 248 poff = pindex - (reqblock * pagesperblock); 249 if (before) { 250 *before *= pagesperblock; 251 *before += poff; 252 } 253 if (after) { 254 int numafter; 255 *after *= pagesperblock; 256 numafter = pagesperblock - (poff + 1); 257 if (IDX_TO_OFF(pindex + numafter) > 258 object->un_pager.vnp.vnp_size) { 259 numafter = 260 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 261 pindex; 262 } 263 *after += numafter; 264 } 265 } else { 266 if (before) { 267 *before /= blocksperpage; 268 } 269 270 if (after) { 271 *after /= blocksperpage; 272 } 273 } 274 return TRUE; 275 } 276 277 /* 278 * Lets the VM system know about a change in size for a file. 279 * We adjust our own internal size and flush any cached pages in 280 * the associated object that are affected by the size change. 281 * 282 * Note: this routine may be invoked as a result of a pager put 283 * operation (possibly at object termination time), so we must be careful. 284 */ 285 void 286 vnode_pager_setsize(vp, nsize) 287 struct vnode *vp; 288 vm_ooffset_t nsize; 289 { 290 vm_pindex_t nobjsize; 291 vm_object_t object = vp->v_object; 292 293 GIANT_REQUIRED; 294 295 if (object == NULL) 296 return; 297 298 /* 299 * Hasn't changed size 300 */ 301 if (nsize == object->un_pager.vnp.vnp_size) 302 return; 303 304 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 305 306 /* 307 * File has shrunk. Toss any cached pages beyond the new EOF. 308 */ 309 if (nsize < object->un_pager.vnp.vnp_size) { 310 #ifdef ENABLE_VFS_IOOPT 311 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size); 312 #endif 313 if (nobjsize < object->size) { 314 vm_object_page_remove(object, nobjsize, object->size, 315 FALSE); 316 } 317 /* 318 * this gets rid of garbage at the end of a page that is now 319 * only partially backed by the vnode. 320 * 321 * XXX for some reason (I don't know yet), if we take a 322 * completely invalid page and mark it partially valid 323 * it can screw up NFS reads, so we don't allow the case. 324 */ 325 if (nsize & PAGE_MASK) { 326 vm_page_t m; 327 328 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 329 if (m && m->valid) { 330 int base = (int)nsize & PAGE_MASK; 331 int size = PAGE_SIZE - base; 332 333 /* 334 * Clear out partial-page garbage in case 335 * the page has been mapped. 336 */ 337 pmap_zero_page_area(m, base, size); 338 339 vm_page_lock_queues(); 340 /* 341 * XXX work around SMP data integrity race 342 * by unmapping the page from user processes. 343 * The garbage we just cleared may be mapped 344 * to a user process running on another cpu 345 * and this code is not running through normal 346 * I/O channels which handle SMP issues for 347 * us, so unmap page to synchronize all cpus. 348 * 349 * XXX should vm_pager_unmap_page() have 350 * dealt with this? 351 */ 352 pmap_remove_all(m); 353 354 /* 355 * Clear out partial-page dirty bits. This 356 * has the side effect of setting the valid 357 * bits, but that is ok. There are a bunch 358 * of places in the VM system where we expected 359 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 360 * case is one of them. If the page is still 361 * partially dirty, make it fully dirty. 362 * 363 * note that we do not clear out the valid 364 * bits. This would prevent bogus_page 365 * replacement from working properly. 366 */ 367 vm_page_set_validclean(m, base, size); 368 if (m->dirty != 0) 369 m->dirty = VM_PAGE_BITS_ALL; 370 vm_page_unlock_queues(); 371 } 372 } 373 } 374 object->un_pager.vnp.vnp_size = nsize; 375 object->size = nobjsize; 376 } 377 378 /* 379 * calculate the linear (byte) disk address of specified virtual 380 * file address 381 */ 382 static vm_offset_t 383 vnode_pager_addr(vp, address, run) 384 struct vnode *vp; 385 vm_ooffset_t address; 386 int *run; 387 { 388 int rtaddress; 389 int bsize; 390 daddr_t block; 391 struct vnode *rtvp; 392 int err; 393 daddr_t vblock; 394 int voffset; 395 396 GIANT_REQUIRED; 397 if ((int) address < 0) 398 return -1; 399 400 if (vp->v_mount == NULL) 401 return -1; 402 403 bsize = vp->v_mount->mnt_stat.f_iosize; 404 vblock = address / bsize; 405 voffset = address % bsize; 406 407 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 408 409 if (err || (block == -1)) 410 rtaddress = -1; 411 else { 412 rtaddress = block + voffset / DEV_BSIZE; 413 if (run) { 414 *run += 1; 415 *run *= bsize/PAGE_SIZE; 416 *run -= voffset/PAGE_SIZE; 417 } 418 } 419 420 return rtaddress; 421 } 422 423 /* 424 * interrupt routine for I/O completion 425 */ 426 static void 427 vnode_pager_iodone(bp) 428 struct buf *bp; 429 { 430 bp->b_flags |= B_DONE; 431 wakeup(bp); 432 } 433 434 /* 435 * small block filesystem vnode pager input 436 */ 437 static int 438 vnode_pager_input_smlfs(object, m) 439 vm_object_t object; 440 vm_page_t m; 441 { 442 int i; 443 int s; 444 struct vnode *dp, *vp; 445 struct buf *bp; 446 vm_offset_t kva; 447 int fileaddr; 448 vm_offset_t bsize; 449 int error = 0; 450 451 GIANT_REQUIRED; 452 453 vp = object->handle; 454 if (vp->v_mount == NULL) 455 return VM_PAGER_BAD; 456 457 bsize = vp->v_mount->mnt_stat.f_iosize; 458 459 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 460 461 kva = vm_pager_map_page(m); 462 463 for (i = 0; i < PAGE_SIZE / bsize; i++) { 464 vm_ooffset_t address; 465 466 if (vm_page_bits(i * bsize, bsize) & m->valid) 467 continue; 468 469 address = IDX_TO_OFF(m->pindex) + i * bsize; 470 if (address >= object->un_pager.vnp.vnp_size) { 471 fileaddr = -1; 472 } else { 473 fileaddr = vnode_pager_addr(vp, address, NULL); 474 } 475 if (fileaddr != -1) { 476 bp = getpbuf(&vnode_pbuf_freecnt); 477 478 /* build a minimal buffer header */ 479 bp->b_iocmd = BIO_READ; 480 bp->b_iodone = vnode_pager_iodone; 481 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 482 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 483 bp->b_rcred = crhold(curthread->td_ucred); 484 bp->b_wcred = crhold(curthread->td_ucred); 485 bp->b_data = (caddr_t) kva + i * bsize; 486 bp->b_blkno = fileaddr; 487 pbgetvp(dp, bp); 488 bp->b_bcount = bsize; 489 bp->b_bufsize = bsize; 490 bp->b_runningbufspace = bp->b_bufsize; 491 runningbufspace += bp->b_runningbufspace; 492 493 /* do the input */ 494 BUF_STRATEGY(bp); 495 496 /* we definitely need to be at splvm here */ 497 498 s = splvm(); 499 while ((bp->b_flags & B_DONE) == 0) { 500 tsleep(bp, PVM, "vnsrd", 0); 501 } 502 splx(s); 503 if ((bp->b_ioflags & BIO_ERROR) != 0) 504 error = EIO; 505 506 /* 507 * free the buffer header back to the swap buffer pool 508 */ 509 relpbuf(bp, &vnode_pbuf_freecnt); 510 if (error) 511 break; 512 513 vm_page_lock_queues(); 514 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 515 vm_page_unlock_queues(); 516 } else { 517 vm_page_lock_queues(); 518 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 519 vm_page_unlock_queues(); 520 bzero((caddr_t) kva + i * bsize, bsize); 521 } 522 } 523 vm_pager_unmap_page(kva); 524 vm_page_lock_queues(); 525 pmap_clear_modify(m); 526 vm_page_flag_clear(m, PG_ZERO); 527 vm_page_unlock_queues(); 528 if (error) { 529 return VM_PAGER_ERROR; 530 } 531 return VM_PAGER_OK; 532 533 } 534 535 536 /* 537 * old style vnode pager output routine 538 */ 539 static int 540 vnode_pager_input_old(object, m) 541 vm_object_t object; 542 vm_page_t m; 543 { 544 struct uio auio; 545 struct iovec aiov; 546 int error; 547 int size; 548 vm_offset_t kva; 549 struct vnode *vp; 550 551 GIANT_REQUIRED; 552 error = 0; 553 554 /* 555 * Return failure if beyond current EOF 556 */ 557 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 558 return VM_PAGER_BAD; 559 } else { 560 size = PAGE_SIZE; 561 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 562 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 563 564 /* 565 * Allocate a kernel virtual address and initialize so that 566 * we can use VOP_READ/WRITE routines. 567 */ 568 kva = vm_pager_map_page(m); 569 570 vp = object->handle; 571 aiov.iov_base = (caddr_t) kva; 572 aiov.iov_len = size; 573 auio.uio_iov = &aiov; 574 auio.uio_iovcnt = 1; 575 auio.uio_offset = IDX_TO_OFF(m->pindex); 576 auio.uio_segflg = UIO_SYSSPACE; 577 auio.uio_rw = UIO_READ; 578 auio.uio_resid = size; 579 auio.uio_td = curthread; 580 581 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 582 if (!error) { 583 int count = size - auio.uio_resid; 584 585 if (count == 0) 586 error = EINVAL; 587 else if (count != PAGE_SIZE) 588 bzero((caddr_t) kva + count, PAGE_SIZE - count); 589 } 590 vm_pager_unmap_page(kva); 591 } 592 vm_page_lock_queues(); 593 pmap_clear_modify(m); 594 vm_page_undirty(m); 595 vm_page_flag_clear(m, PG_ZERO); 596 if (!error) 597 m->valid = VM_PAGE_BITS_ALL; 598 vm_page_unlock_queues(); 599 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 600 } 601 602 /* 603 * generic vnode pager input routine 604 */ 605 606 /* 607 * Local media VFS's that do not implement their own VOP_GETPAGES 608 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 609 * to implement the previous behaviour. 610 * 611 * All other FS's should use the bypass to get to the local media 612 * backing vp's VOP_GETPAGES. 613 */ 614 static int 615 vnode_pager_getpages(object, m, count, reqpage) 616 vm_object_t object; 617 vm_page_t *m; 618 int count; 619 int reqpage; 620 { 621 int rtval; 622 struct vnode *vp; 623 int bytes = count * PAGE_SIZE; 624 625 GIANT_REQUIRED; 626 vp = object->handle; 627 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 628 KASSERT(rtval != EOPNOTSUPP, 629 ("vnode_pager: FS getpages not implemented\n")); 630 return rtval; 631 } 632 633 /* 634 * This is now called from local media FS's to operate against their 635 * own vnodes if they fail to implement VOP_GETPAGES. 636 */ 637 int 638 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 639 struct vnode *vp; 640 vm_page_t *m; 641 int bytecount; 642 int reqpage; 643 { 644 vm_object_t object; 645 vm_offset_t kva; 646 off_t foff, tfoff, nextoff; 647 int i, j, size, bsize, first, firstaddr; 648 struct vnode *dp; 649 int runpg; 650 int runend; 651 struct buf *bp; 652 int s; 653 int count; 654 int error = 0; 655 656 GIANT_REQUIRED; 657 object = vp->v_object; 658 count = bytecount / PAGE_SIZE; 659 660 if (vp->v_mount == NULL) 661 return VM_PAGER_BAD; 662 663 bsize = vp->v_mount->mnt_stat.f_iosize; 664 665 /* get the UNDERLYING device for the file with VOP_BMAP() */ 666 667 /* 668 * originally, we did not check for an error return value -- assuming 669 * an fs always has a bmap entry point -- that assumption is wrong!!! 670 */ 671 foff = IDX_TO_OFF(m[reqpage]->pindex); 672 673 /* 674 * if we can't bmap, use old VOP code 675 */ 676 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 677 vm_page_lock_queues(); 678 for (i = 0; i < count; i++) 679 if (i != reqpage) 680 vm_page_free(m[i]); 681 vm_page_unlock_queues(); 682 cnt.v_vnodein++; 683 cnt.v_vnodepgsin++; 684 return vnode_pager_input_old(object, m[reqpage]); 685 686 /* 687 * if the blocksize is smaller than a page size, then use 688 * special small filesystem code. NFS sometimes has a small 689 * blocksize, but it can handle large reads itself. 690 */ 691 } else if ((PAGE_SIZE / bsize) > 1 && 692 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 693 vm_page_lock_queues(); 694 for (i = 0; i < count; i++) 695 if (i != reqpage) 696 vm_page_free(m[i]); 697 vm_page_unlock_queues(); 698 cnt.v_vnodein++; 699 cnt.v_vnodepgsin++; 700 return vnode_pager_input_smlfs(object, m[reqpage]); 701 } 702 703 /* 704 * If we have a completely valid page available to us, we can 705 * clean up and return. Otherwise we have to re-read the 706 * media. 707 */ 708 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 709 vm_page_lock_queues(); 710 for (i = 0; i < count; i++) 711 if (i != reqpage) 712 vm_page_free(m[i]); 713 vm_page_unlock_queues(); 714 return VM_PAGER_OK; 715 } 716 m[reqpage]->valid = 0; 717 718 /* 719 * here on direct device I/O 720 */ 721 firstaddr = -1; 722 723 /* 724 * calculate the run that includes the required page 725 */ 726 for (first = 0, i = 0; i < count; i = runend) { 727 firstaddr = vnode_pager_addr(vp, 728 IDX_TO_OFF(m[i]->pindex), &runpg); 729 if (firstaddr == -1) { 730 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 731 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 732 firstaddr, (uintmax_t)(foff >> 32), 733 (uintmax_t)foff, 734 (uintmax_t) 735 (object->un_pager.vnp.vnp_size >> 32), 736 (uintmax_t)object->un_pager.vnp.vnp_size); 737 } 738 vm_page_lock_queues(); 739 vm_page_free(m[i]); 740 vm_page_unlock_queues(); 741 runend = i + 1; 742 first = runend; 743 continue; 744 } 745 runend = i + runpg; 746 if (runend <= reqpage) { 747 vm_page_lock_queues(); 748 for (j = i; j < runend; j++) 749 vm_page_free(m[j]); 750 vm_page_unlock_queues(); 751 } else { 752 if (runpg < (count - first)) { 753 vm_page_lock_queues(); 754 for (i = first + runpg; i < count; i++) 755 vm_page_free(m[i]); 756 vm_page_unlock_queues(); 757 count = first + runpg; 758 } 759 break; 760 } 761 first = runend; 762 } 763 764 /* 765 * the first and last page have been calculated now, move input pages 766 * to be zero based... 767 */ 768 if (first != 0) { 769 for (i = first; i < count; i++) { 770 m[i - first] = m[i]; 771 } 772 count -= first; 773 reqpage -= first; 774 } 775 776 /* 777 * calculate the file virtual address for the transfer 778 */ 779 foff = IDX_TO_OFF(m[0]->pindex); 780 781 /* 782 * calculate the size of the transfer 783 */ 784 size = count * PAGE_SIZE; 785 if ((foff + size) > object->un_pager.vnp.vnp_size) 786 size = object->un_pager.vnp.vnp_size - foff; 787 788 /* 789 * round up physical size for real devices. 790 */ 791 if (dp->v_type == VBLK || dp->v_type == VCHR) { 792 int secmask = dp->v_rdev->si_bsize_phys - 1; 793 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1)); 794 size = (size + secmask) & ~secmask; 795 } 796 797 bp = getpbuf(&vnode_pbuf_freecnt); 798 kva = (vm_offset_t) bp->b_data; 799 800 /* 801 * and map the pages to be read into the kva 802 */ 803 pmap_qenter(kva, m, count); 804 805 /* build a minimal buffer header */ 806 bp->b_iocmd = BIO_READ; 807 bp->b_iodone = vnode_pager_iodone; 808 /* B_PHYS is not set, but it is nice to fill this in */ 809 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 810 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 811 bp->b_rcred = crhold(curthread->td_ucred); 812 bp->b_wcred = crhold(curthread->td_ucred); 813 bp->b_blkno = firstaddr; 814 pbgetvp(dp, bp); 815 bp->b_bcount = size; 816 bp->b_bufsize = size; 817 bp->b_runningbufspace = bp->b_bufsize; 818 runningbufspace += bp->b_runningbufspace; 819 820 cnt.v_vnodein++; 821 cnt.v_vnodepgsin += count; 822 823 /* do the input */ 824 BUF_STRATEGY(bp); 825 826 s = splvm(); 827 /* we definitely need to be at splvm here */ 828 829 while ((bp->b_flags & B_DONE) == 0) { 830 tsleep(bp, PVM, "vnread", 0); 831 } 832 splx(s); 833 if ((bp->b_ioflags & BIO_ERROR) != 0) 834 error = EIO; 835 836 if (!error) { 837 if (size != count * PAGE_SIZE) 838 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 839 } 840 pmap_qremove(kva, count); 841 842 /* 843 * free the buffer header back to the swap buffer pool 844 */ 845 relpbuf(bp, &vnode_pbuf_freecnt); 846 847 vm_page_lock_queues(); 848 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 849 vm_page_t mt; 850 851 nextoff = tfoff + PAGE_SIZE; 852 mt = m[i]; 853 854 if (nextoff <= object->un_pager.vnp.vnp_size) { 855 /* 856 * Read filled up entire page. 857 */ 858 mt->valid = VM_PAGE_BITS_ALL; 859 vm_page_undirty(mt); /* should be an assert? XXX */ 860 pmap_clear_modify(mt); 861 } else { 862 /* 863 * Read did not fill up entire page. Since this 864 * is getpages, the page may be mapped, so we have 865 * to zero the invalid portions of the page even 866 * though we aren't setting them valid. 867 * 868 * Currently we do not set the entire page valid, 869 * we just try to clear the piece that we couldn't 870 * read. 871 */ 872 vm_page_set_validclean(mt, 0, 873 object->un_pager.vnp.vnp_size - tfoff); 874 /* handled by vm_fault now */ 875 /* vm_page_zero_invalid(mt, FALSE); */ 876 } 877 878 vm_page_flag_clear(mt, PG_ZERO); 879 if (i != reqpage) { 880 881 /* 882 * whether or not to leave the page activated is up in 883 * the air, but we should put the page on a page queue 884 * somewhere. (it already is in the object). Result: 885 * It appears that empirical results show that 886 * deactivating pages is best. 887 */ 888 889 /* 890 * just in case someone was asking for this page we 891 * now tell them that it is ok to use 892 */ 893 if (!error) { 894 if (mt->flags & PG_WANTED) 895 vm_page_activate(mt); 896 else 897 vm_page_deactivate(mt); 898 vm_page_wakeup(mt); 899 } else { 900 vm_page_free(mt); 901 } 902 } 903 } 904 vm_page_unlock_queues(); 905 if (error) { 906 printf("vnode_pager_getpages: I/O read error\n"); 907 } 908 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 909 } 910 911 /* 912 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 913 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 914 * vnode_pager_generic_putpages() to implement the previous behaviour. 915 * 916 * All other FS's should use the bypass to get to the local media 917 * backing vp's VOP_PUTPAGES. 918 */ 919 static void 920 vnode_pager_putpages(object, m, count, sync, rtvals) 921 vm_object_t object; 922 vm_page_t *m; 923 int count; 924 boolean_t sync; 925 int *rtvals; 926 { 927 int rtval; 928 struct vnode *vp; 929 struct mount *mp; 930 int bytes = count * PAGE_SIZE; 931 932 GIANT_REQUIRED; 933 /* 934 * Force synchronous operation if we are extremely low on memory 935 * to prevent a low-memory deadlock. VOP operations often need to 936 * allocate more memory to initiate the I/O ( i.e. do a BMAP 937 * operation ). The swapper handles the case by limiting the amount 938 * of asynchronous I/O, but that sort of solution doesn't scale well 939 * for the vnode pager without a lot of work. 940 * 941 * Also, the backing vnode's iodone routine may not wake the pageout 942 * daemon up. This should be probably be addressed XXX. 943 */ 944 945 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 946 sync |= OBJPC_SYNC; 947 948 /* 949 * Call device-specific putpages function 950 */ 951 vp = object->handle; 952 if (vp->v_type != VREG) 953 mp = NULL; 954 (void)vn_start_write(vp, &mp, V_WAIT); 955 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 956 KASSERT(rtval != EOPNOTSUPP, 957 ("vnode_pager: stale FS putpages\n")); 958 vn_finished_write(mp); 959 } 960 961 962 /* 963 * This is now called from local media FS's to operate against their 964 * own vnodes if they fail to implement VOP_PUTPAGES. 965 * 966 * This is typically called indirectly via the pageout daemon and 967 * clustering has already typically occured, so in general we ask the 968 * underlying filesystem to write the data out asynchronously rather 969 * then delayed. 970 */ 971 int 972 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 973 struct vnode *vp; 974 vm_page_t *m; 975 int bytecount; 976 int flags; 977 int *rtvals; 978 { 979 int i; 980 vm_object_t object; 981 int count; 982 983 int maxsize, ncount; 984 vm_ooffset_t poffset; 985 struct uio auio; 986 struct iovec aiov; 987 int error; 988 int ioflags; 989 990 GIANT_REQUIRED; 991 object = vp->v_object; 992 count = bytecount / PAGE_SIZE; 993 994 for (i = 0; i < count; i++) 995 rtvals[i] = VM_PAGER_AGAIN; 996 997 if ((int) m[0]->pindex < 0) { 998 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n", 999 (long)m[0]->pindex, m[0]->dirty); 1000 rtvals[0] = VM_PAGER_BAD; 1001 return VM_PAGER_BAD; 1002 } 1003 1004 maxsize = count * PAGE_SIZE; 1005 ncount = count; 1006 1007 poffset = IDX_TO_OFF(m[0]->pindex); 1008 1009 /* 1010 * If the page-aligned write is larger then the actual file we 1011 * have to invalidate pages occuring beyond the file EOF. However, 1012 * there is an edge case where a file may not be page-aligned where 1013 * the last page is partially invalid. In this case the filesystem 1014 * may not properly clear the dirty bits for the entire page (which 1015 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1016 * With the page locked we are free to fix-up the dirty bits here. 1017 * 1018 * We do not under any circumstances truncate the valid bits, as 1019 * this will screw up bogus page replacement. 1020 */ 1021 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1022 if (object->un_pager.vnp.vnp_size > poffset) { 1023 int pgoff; 1024 1025 maxsize = object->un_pager.vnp.vnp_size - poffset; 1026 ncount = btoc(maxsize); 1027 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1028 vm_page_clear_dirty(m[ncount - 1], pgoff, 1029 PAGE_SIZE - pgoff); 1030 } 1031 } else { 1032 maxsize = 0; 1033 ncount = 0; 1034 } 1035 if (ncount < count) { 1036 for (i = ncount; i < count; i++) { 1037 rtvals[i] = VM_PAGER_BAD; 1038 } 1039 } 1040 } 1041 1042 /* 1043 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1044 * rather then a bdwrite() to prevent paging I/O from saturating 1045 * the buffer cache. 1046 */ 1047 ioflags = IO_VMIO; 1048 ioflags |= (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) ? IO_SYNC: IO_ASYNC; 1049 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1050 1051 aiov.iov_base = (caddr_t) 0; 1052 aiov.iov_len = maxsize; 1053 auio.uio_iov = &aiov; 1054 auio.uio_iovcnt = 1; 1055 auio.uio_offset = poffset; 1056 auio.uio_segflg = UIO_NOCOPY; 1057 auio.uio_rw = UIO_WRITE; 1058 auio.uio_resid = maxsize; 1059 auio.uio_td = (struct thread *) 0; 1060 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1061 cnt.v_vnodeout++; 1062 cnt.v_vnodepgsout += ncount; 1063 1064 if (error) { 1065 printf("vnode_pager_putpages: I/O error %d\n", error); 1066 } 1067 if (auio.uio_resid) { 1068 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1069 auio.uio_resid, (u_long)m[0]->pindex); 1070 } 1071 for (i = 0; i < ncount; i++) { 1072 rtvals[i] = VM_PAGER_OK; 1073 } 1074 return rtvals[0]; 1075 } 1076 1077 struct vnode * 1078 vnode_pager_lock(object) 1079 vm_object_t object; 1080 { 1081 struct thread *td = curthread; /* XXX */ 1082 1083 GIANT_REQUIRED; 1084 1085 for (; object != NULL; object = object->backing_object) { 1086 if (object->type != OBJT_VNODE) 1087 continue; 1088 if (object->flags & OBJ_DEAD) { 1089 return NULL; 1090 } 1091 1092 /* XXX; If object->handle can change, we need to cache it. */ 1093 while (vget(object->handle, 1094 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, td)){ 1095 if ((object->flags & OBJ_DEAD) || (object->type != OBJT_VNODE)) 1096 return NULL; 1097 printf("vnode_pager_lock: retrying\n"); 1098 } 1099 return object->handle; 1100 } 1101 return NULL; 1102 }
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