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 */ 42 43 /* 44 * Page to/from files (vnodes). 45 */ 46 47 /* 48 * TODO: 49 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 50 * greatly re-simplify the vnode_pager. 51 */ 52 53 #include <sys/cdefs.h> 54 __FBSDID("$FreeBSD$"); 55 56 #include <sys/param.h> 57 #include <sys/systm.h> 58 #include <sys/proc.h> 59 #include <sys/vnode.h> 60 #include <sys/mount.h> 61 #include <sys/bio.h> 62 #include <sys/buf.h> 63 #include <sys/vmmeter.h> 64 #include <sys/conf.h> 65 66 #include <vm/vm.h> 67 #include <vm/vm_object.h> 68 #include <vm/vm_page.h> 69 #include <vm/vm_pager.h> 70 #include <vm/vm_map.h> 71 #include <vm/vnode_pager.h> 72 #include <vm/vm_extern.h> 73 74 static void vnode_pager_init(void); 75 static vm_offset_t vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 76 int *run); 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 .pgo_init = vnode_pager_init, 86 .pgo_alloc = vnode_pager_alloc, 87 .pgo_dealloc = vnode_pager_dealloc, 88 .pgo_getpages = vnode_pager_getpages, 89 .pgo_putpages = vnode_pager_putpages, 90 .pgo_haspage = vnode_pager_haspage, 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 VM_OBJECT_LOCK(object); 144 if ((object->flags & OBJ_DEAD) == 0) 145 break; 146 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0); 147 } 148 149 if (vp->v_usecount == 0) 150 panic("vnode_pager_alloc: no vnode reference"); 151 152 if (object == NULL) { 153 /* 154 * And an object of the appropriate size 155 */ 156 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 157 158 object->un_pager.vnp.vnp_size = size; 159 160 object->handle = handle; 161 vp->v_object = object; 162 } else { 163 object->ref_count++; 164 VM_OBJECT_UNLOCK(object); 165 } 166 VI_LOCK(vp); 167 vp->v_usecount++; 168 vp->v_iflag &= ~VI_OLOCK; 169 if (vp->v_iflag & VI_OWANT) { 170 vp->v_iflag &= ~VI_OWANT; 171 wakeup(vp); 172 } 173 VI_UNLOCK(vp); 174 mtx_unlock(&Giant); 175 return (object); 176 } 177 178 /* 179 * The object must be locked. 180 */ 181 static void 182 vnode_pager_dealloc(object) 183 vm_object_t object; 184 { 185 struct vnode *vp = object->handle; 186 187 if (vp == NULL) 188 panic("vnode_pager_dealloc: pager already dealloced"); 189 190 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 191 vm_object_pip_wait(object, "vnpdea"); 192 193 object->handle = NULL; 194 object->type = OBJT_DEAD; 195 ASSERT_VOP_LOCKED(vp, "vnode_pager_dealloc"); 196 vp->v_object = NULL; 197 vp->v_vflag &= ~(VV_TEXT | VV_OBJBUF); 198 } 199 200 static boolean_t 201 vnode_pager_haspage(object, pindex, before, after) 202 vm_object_t object; 203 vm_pindex_t pindex; 204 int *before; 205 int *after; 206 { 207 struct vnode *vp = object->handle; 208 daddr_t bn; 209 int err; 210 daddr_t reqblock; 211 int poff; 212 int bsize; 213 int pagesperblock, blocksperpage; 214 215 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 216 /* 217 * If no vp or vp is doomed or marked transparent to VM, we do not 218 * have the page. 219 */ 220 if (vp == NULL) 221 return FALSE; 222 223 VI_LOCK(vp); 224 if (vp->v_iflag & VI_DOOMED) { 225 VI_UNLOCK(vp); 226 return FALSE; 227 } 228 VI_UNLOCK(vp); 229 /* 230 * If filesystem no longer mounted or offset beyond end of file we do 231 * not have the page. 232 */ 233 if ((vp->v_mount == NULL) || 234 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 235 return FALSE; 236 237 bsize = vp->v_mount->mnt_stat.f_iosize; 238 pagesperblock = bsize / PAGE_SIZE; 239 blocksperpage = 0; 240 if (pagesperblock > 0) { 241 reqblock = pindex / pagesperblock; 242 } else { 243 blocksperpage = (PAGE_SIZE / bsize); 244 reqblock = pindex * blocksperpage; 245 } 246 VM_OBJECT_UNLOCK(object); 247 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 248 VM_OBJECT_LOCK(object); 249 if (err) 250 return TRUE; 251 if (bn == -1) 252 return FALSE; 253 if (pagesperblock > 0) { 254 poff = pindex - (reqblock * pagesperblock); 255 if (before) { 256 *before *= pagesperblock; 257 *before += poff; 258 } 259 if (after) { 260 int numafter; 261 *after *= pagesperblock; 262 numafter = pagesperblock - (poff + 1); 263 if (IDX_TO_OFF(pindex + numafter) > 264 object->un_pager.vnp.vnp_size) { 265 numafter = 266 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 267 pindex; 268 } 269 *after += numafter; 270 } 271 } else { 272 if (before) { 273 *before /= blocksperpage; 274 } 275 276 if (after) { 277 *after /= blocksperpage; 278 } 279 } 280 return TRUE; 281 } 282 283 /* 284 * Lets the VM system know about a change in size for a file. 285 * We adjust our own internal size and flush any cached pages in 286 * the associated object that are affected by the size change. 287 * 288 * Note: this routine may be invoked as a result of a pager put 289 * operation (possibly at object termination time), so we must be careful. 290 */ 291 void 292 vnode_pager_setsize(vp, nsize) 293 struct vnode *vp; 294 vm_ooffset_t nsize; 295 { 296 vm_object_t object; 297 vm_page_t m; 298 vm_pindex_t nobjsize; 299 300 if ((object = vp->v_object) == NULL) 301 return; 302 VM_OBJECT_LOCK(object); 303 if (nsize == object->un_pager.vnp.vnp_size) { 304 /* 305 * Hasn't changed size 306 */ 307 VM_OBJECT_UNLOCK(object); 308 return; 309 } 310 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 311 if (nsize < object->un_pager.vnp.vnp_size) { 312 /* 313 * File has shrunk. Toss any cached pages beyond the new EOF. 314 */ 315 if (nobjsize < object->size) 316 vm_object_page_remove(object, nobjsize, object->size, 317 FALSE); 318 /* 319 * this gets rid of garbage at the end of a page that is now 320 * only partially backed by the vnode. 321 * 322 * XXX for some reason (I don't know yet), if we take a 323 * completely invalid page and mark it partially valid 324 * it can screw up NFS reads, so we don't allow the case. 325 */ 326 if ((nsize & PAGE_MASK) && 327 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL) { 328 vm_page_lock_queues(); 329 if (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 /* 340 * XXX work around SMP data integrity race 341 * by unmapping the page from user processes. 342 * The garbage we just cleared may be mapped 343 * to a user process running on another cpu 344 * and this code is not running through normal 345 * I/O channels which handle SMP issues for 346 * us, so unmap page to synchronize all cpus. 347 * 348 * XXX should vm_pager_unmap_page() have 349 * dealt with this? 350 */ 351 pmap_remove_all(m); 352 353 /* 354 * Clear out partial-page dirty bits. This 355 * has the side effect of setting the valid 356 * bits, but that is ok. There are a bunch 357 * of places in the VM system where we expected 358 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 359 * case is one of them. If the page is still 360 * partially dirty, make it fully dirty. 361 * 362 * note that we do not clear out the valid 363 * bits. This would prevent bogus_page 364 * replacement from working properly. 365 */ 366 vm_page_set_validclean(m, base, size); 367 if (m->dirty != 0) 368 m->dirty = VM_PAGE_BITS_ALL; 369 } 370 vm_page_unlock_queues(); 371 } 372 } 373 object->un_pager.vnp.vnp_size = nsize; 374 object->size = nobjsize; 375 VM_OBJECT_UNLOCK(object); 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 int err; 392 daddr_t vblock; 393 int voffset; 394 395 GIANT_REQUIRED; 396 if ((int) address < 0) 397 return -1; 398 399 if (vp->v_mount == NULL) 400 return -1; 401 402 bsize = vp->v_mount->mnt_stat.f_iosize; 403 vblock = address / bsize; 404 voffset = address % bsize; 405 406 err = VOP_BMAP(vp, vblock, NULL, &block, run, NULL); 407 408 if (err || (block == -1)) 409 rtaddress = -1; 410 else { 411 rtaddress = block + voffset / DEV_BSIZE; 412 if (run) { 413 *run += 1; 414 *run *= bsize/PAGE_SIZE; 415 *run -= voffset/PAGE_SIZE; 416 } 417 } 418 419 return rtaddress; 420 } 421 422 /* 423 * small block filesystem vnode pager input 424 */ 425 static int 426 vnode_pager_input_smlfs(object, m) 427 vm_object_t object; 428 vm_page_t m; 429 { 430 int i; 431 struct vnode *dp, *vp; 432 struct buf *bp; 433 vm_offset_t kva; 434 int fileaddr; 435 vm_offset_t bsize; 436 int error = 0; 437 438 GIANT_REQUIRED; 439 440 vp = object->handle; 441 if (vp->v_mount == NULL) 442 return VM_PAGER_BAD; 443 444 bsize = vp->v_mount->mnt_stat.f_iosize; 445 446 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 447 448 kva = vm_pager_map_page(m); 449 450 for (i = 0; i < PAGE_SIZE / bsize; i++) { 451 vm_ooffset_t address; 452 453 if (vm_page_bits(i * bsize, bsize) & m->valid) 454 continue; 455 456 address = IDX_TO_OFF(m->pindex) + i * bsize; 457 if (address >= object->un_pager.vnp.vnp_size) { 458 fileaddr = -1; 459 } else { 460 fileaddr = vnode_pager_addr(vp, address, NULL); 461 } 462 if (fileaddr != -1) { 463 bp = getpbuf(&vnode_pbuf_freecnt); 464 465 /* build a minimal buffer header */ 466 bp->b_iocmd = BIO_READ; 467 bp->b_iodone = bdone; 468 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 469 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 470 bp->b_rcred = crhold(curthread->td_ucred); 471 bp->b_wcred = crhold(curthread->td_ucred); 472 bp->b_data = (caddr_t) kva + i * bsize; 473 bp->b_blkno = fileaddr; 474 pbgetvp(dp, bp); 475 bp->b_bcount = bsize; 476 bp->b_bufsize = bsize; 477 bp->b_runningbufspace = bp->b_bufsize; 478 runningbufspace += bp->b_runningbufspace; 479 480 /* do the input */ 481 VOP_SPECSTRATEGY(bp->b_vp, bp); 482 483 /* we definitely need to be at splvm here */ 484 485 bwait(bp, PVM, "vnsrd"); 486 487 if ((bp->b_ioflags & BIO_ERROR) != 0) 488 error = EIO; 489 490 /* 491 * free the buffer header back to the swap buffer pool 492 */ 493 relpbuf(bp, &vnode_pbuf_freecnt); 494 if (error) 495 break; 496 497 vm_page_lock_queues(); 498 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 499 vm_page_unlock_queues(); 500 } else { 501 vm_page_lock_queues(); 502 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 503 vm_page_unlock_queues(); 504 bzero((caddr_t) kva + i * bsize, bsize); 505 } 506 } 507 vm_pager_unmap_page(kva); 508 vm_page_lock_queues(); 509 pmap_clear_modify(m); 510 vm_page_flag_clear(m, PG_ZERO); 511 vm_page_unlock_queues(); 512 if (error) { 513 return VM_PAGER_ERROR; 514 } 515 return VM_PAGER_OK; 516 517 } 518 519 520 /* 521 * old style vnode pager output routine 522 */ 523 static int 524 vnode_pager_input_old(object, m) 525 vm_object_t object; 526 vm_page_t m; 527 { 528 struct uio auio; 529 struct iovec aiov; 530 int error; 531 int size; 532 vm_offset_t kva; 533 struct vnode *vp; 534 535 GIANT_REQUIRED; 536 error = 0; 537 538 /* 539 * Return failure if beyond current EOF 540 */ 541 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 542 return VM_PAGER_BAD; 543 } else { 544 size = PAGE_SIZE; 545 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 546 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 547 548 /* 549 * Allocate a kernel virtual address and initialize so that 550 * we can use VOP_READ/WRITE routines. 551 */ 552 kva = vm_pager_map_page(m); 553 554 vp = object->handle; 555 aiov.iov_base = (caddr_t) kva; 556 aiov.iov_len = size; 557 auio.uio_iov = &aiov; 558 auio.uio_iovcnt = 1; 559 auio.uio_offset = IDX_TO_OFF(m->pindex); 560 auio.uio_segflg = UIO_SYSSPACE; 561 auio.uio_rw = UIO_READ; 562 auio.uio_resid = size; 563 auio.uio_td = curthread; 564 565 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 566 if (!error) { 567 int count = size - auio.uio_resid; 568 569 if (count == 0) 570 error = EINVAL; 571 else if (count != PAGE_SIZE) 572 bzero((caddr_t) kva + count, PAGE_SIZE - count); 573 } 574 vm_pager_unmap_page(kva); 575 } 576 vm_page_lock_queues(); 577 pmap_clear_modify(m); 578 vm_page_undirty(m); 579 vm_page_flag_clear(m, PG_ZERO); 580 if (!error) 581 m->valid = VM_PAGE_BITS_ALL; 582 vm_page_unlock_queues(); 583 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 584 } 585 586 /* 587 * generic vnode pager input routine 588 */ 589 590 /* 591 * Local media VFS's that do not implement their own VOP_GETPAGES 592 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 593 * to implement the previous behaviour. 594 * 595 * All other FS's should use the bypass to get to the local media 596 * backing vp's VOP_GETPAGES. 597 */ 598 static int 599 vnode_pager_getpages(object, m, count, reqpage) 600 vm_object_t object; 601 vm_page_t *m; 602 int count; 603 int reqpage; 604 { 605 int rtval; 606 struct vnode *vp; 607 int bytes = count * PAGE_SIZE; 608 609 vp = object->handle; 610 VM_OBJECT_UNLOCK(object); 611 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 612 KASSERT(rtval != EOPNOTSUPP, 613 ("vnode_pager: FS getpages not implemented\n")); 614 VM_OBJECT_LOCK(object); 615 return rtval; 616 } 617 618 /* 619 * This is now called from local media FS's to operate against their 620 * own vnodes if they fail to implement VOP_GETPAGES. 621 */ 622 int 623 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 624 struct vnode *vp; 625 vm_page_t *m; 626 int bytecount; 627 int reqpage; 628 { 629 vm_object_t object; 630 vm_offset_t kva; 631 off_t foff, tfoff, nextoff; 632 int i, j, size, bsize, first, firstaddr; 633 struct vnode *dp; 634 int runpg; 635 int runend; 636 struct buf *bp; 637 int count; 638 int error = 0; 639 640 GIANT_REQUIRED; 641 object = vp->v_object; 642 count = bytecount / PAGE_SIZE; 643 644 if (vp->v_mount == NULL) 645 return VM_PAGER_BAD; 646 647 bsize = vp->v_mount->mnt_stat.f_iosize; 648 649 /* get the UNDERLYING device for the file with VOP_BMAP() */ 650 651 /* 652 * originally, we did not check for an error return value -- assuming 653 * an fs always has a bmap entry point -- that assumption is wrong!!! 654 */ 655 foff = IDX_TO_OFF(m[reqpage]->pindex); 656 657 /* 658 * if we can't bmap, use old VOP code 659 */ 660 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 661 VM_OBJECT_LOCK(object); 662 vm_page_lock_queues(); 663 for (i = 0; i < count; i++) 664 if (i != reqpage) 665 vm_page_free(m[i]); 666 vm_page_unlock_queues(); 667 VM_OBJECT_UNLOCK(object); 668 cnt.v_vnodein++; 669 cnt.v_vnodepgsin++; 670 return vnode_pager_input_old(object, m[reqpage]); 671 672 /* 673 * if the blocksize is smaller than a page size, then use 674 * special small filesystem code. NFS sometimes has a small 675 * blocksize, but it can handle large reads itself. 676 */ 677 } else if ((PAGE_SIZE / bsize) > 1 && 678 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 679 VM_OBJECT_LOCK(object); 680 vm_page_lock_queues(); 681 for (i = 0; i < count; i++) 682 if (i != reqpage) 683 vm_page_free(m[i]); 684 vm_page_unlock_queues(); 685 VM_OBJECT_UNLOCK(object); 686 cnt.v_vnodein++; 687 cnt.v_vnodepgsin++; 688 return vnode_pager_input_smlfs(object, m[reqpage]); 689 } 690 691 /* 692 * If we have a completely valid page available to us, we can 693 * clean up and return. Otherwise we have to re-read the 694 * media. 695 */ 696 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 697 VM_OBJECT_LOCK(object); 698 vm_page_lock_queues(); 699 for (i = 0; i < count; i++) 700 if (i != reqpage) 701 vm_page_free(m[i]); 702 vm_page_unlock_queues(); 703 VM_OBJECT_UNLOCK(object); 704 return VM_PAGER_OK; 705 } 706 m[reqpage]->valid = 0; 707 708 /* 709 * here on direct device I/O 710 */ 711 firstaddr = -1; 712 713 /* 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 VM_OBJECT_LOCK(object); 721 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 722 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 723 firstaddr, (uintmax_t)(foff >> 32), 724 (uintmax_t)foff, 725 (uintmax_t) 726 (object->un_pager.vnp.vnp_size >> 32), 727 (uintmax_t)object->un_pager.vnp.vnp_size); 728 } 729 vm_page_lock_queues(); 730 vm_page_free(m[i]); 731 vm_page_unlock_queues(); 732 VM_OBJECT_UNLOCK(object); 733 runend = i + 1; 734 first = runend; 735 continue; 736 } 737 runend = i + runpg; 738 if (runend <= reqpage) { 739 VM_OBJECT_LOCK(object); 740 vm_page_lock_queues(); 741 for (j = i; j < runend; j++) 742 vm_page_free(m[j]); 743 vm_page_unlock_queues(); 744 VM_OBJECT_UNLOCK(object); 745 } else { 746 if (runpg < (count - first)) { 747 VM_OBJECT_LOCK(object); 748 vm_page_lock_queues(); 749 for (i = first + runpg; i < count; i++) 750 vm_page_free(m[i]); 751 vm_page_unlock_queues(); 752 VM_OBJECT_UNLOCK(object); 753 count = first + runpg; 754 } 755 break; 756 } 757 first = runend; 758 } 759 760 /* 761 * the first and last page have been calculated now, move input pages 762 * to be zero based... 763 */ 764 if (first != 0) { 765 for (i = first; i < count; i++) { 766 m[i - first] = m[i]; 767 } 768 count -= first; 769 reqpage -= first; 770 } 771 772 /* 773 * calculate the file virtual address for the transfer 774 */ 775 foff = IDX_TO_OFF(m[0]->pindex); 776 777 /* 778 * calculate the size of the transfer 779 */ 780 size = count * PAGE_SIZE; 781 if ((foff + size) > object->un_pager.vnp.vnp_size) 782 size = object->un_pager.vnp.vnp_size - foff; 783 784 /* 785 * round up physical size for real devices. 786 */ 787 if (dp->v_type == VBLK || dp->v_type == VCHR) { 788 int secmask = dp->v_rdev->si_bsize_phys - 1; 789 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1)); 790 size = (size + secmask) & ~secmask; 791 } 792 793 bp = getpbuf(&vnode_pbuf_freecnt); 794 kva = (vm_offset_t) bp->b_data; 795 796 /* 797 * and map the pages to be read into the kva 798 */ 799 pmap_qenter(kva, m, count); 800 801 /* build a minimal buffer header */ 802 bp->b_iocmd = BIO_READ; 803 bp->b_iodone = bdone; 804 /* B_PHYS is not set, but it is nice to fill this in */ 805 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 806 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 807 bp->b_rcred = crhold(curthread->td_ucred); 808 bp->b_wcred = crhold(curthread->td_ucred); 809 bp->b_blkno = firstaddr; 810 pbgetvp(dp, bp); 811 bp->b_bcount = size; 812 bp->b_bufsize = size; 813 bp->b_runningbufspace = bp->b_bufsize; 814 runningbufspace += bp->b_runningbufspace; 815 816 cnt.v_vnodein++; 817 cnt.v_vnodepgsin += count; 818 819 /* do the input */ 820 if (dp->v_type == VCHR) 821 VOP_SPECSTRATEGY(bp->b_vp, bp); 822 else 823 VOP_STRATEGY(bp->b_vp, bp); 824 825 bwait(bp, PVM, "vnread"); 826 827 if ((bp->b_ioflags & BIO_ERROR) != 0) 828 error = EIO; 829 830 if (!error) { 831 if (size != count * PAGE_SIZE) 832 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 833 } 834 pmap_qremove(kva, count); 835 836 /* 837 * free the buffer header back to the swap buffer pool 838 */ 839 relpbuf(bp, &vnode_pbuf_freecnt); 840 841 VM_OBJECT_LOCK(object); 842 vm_page_lock_queues(); 843 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 844 vm_page_t mt; 845 846 nextoff = tfoff + PAGE_SIZE; 847 mt = m[i]; 848 849 if (nextoff <= object->un_pager.vnp.vnp_size) { 850 /* 851 * Read filled up entire page. 852 */ 853 mt->valid = VM_PAGE_BITS_ALL; 854 vm_page_undirty(mt); /* should be an assert? XXX */ 855 pmap_clear_modify(mt); 856 } else { 857 /* 858 * Read did not fill up entire page. Since this 859 * is getpages, the page may be mapped, so we have 860 * to zero the invalid portions of the page even 861 * though we aren't setting them valid. 862 * 863 * Currently we do not set the entire page valid, 864 * we just try to clear the piece that we couldn't 865 * read. 866 */ 867 vm_page_set_validclean(mt, 0, 868 object->un_pager.vnp.vnp_size - tfoff); 869 /* handled by vm_fault now */ 870 /* vm_page_zero_invalid(mt, FALSE); */ 871 } 872 873 vm_page_flag_clear(mt, PG_ZERO); 874 if (i != reqpage) { 875 876 /* 877 * whether or not to leave the page activated is up in 878 * the air, but we should put the page on a page queue 879 * somewhere. (it already is in the object). Result: 880 * It appears that empirical results show that 881 * deactivating pages is best. 882 */ 883 884 /* 885 * just in case someone was asking for this page we 886 * now tell them that it is ok to use 887 */ 888 if (!error) { 889 if (mt->flags & PG_WANTED) 890 vm_page_activate(mt); 891 else 892 vm_page_deactivate(mt); 893 vm_page_wakeup(mt); 894 } else { 895 vm_page_free(mt); 896 } 897 } 898 } 899 vm_page_unlock_queues(); 900 VM_OBJECT_UNLOCK(object); 901 if (error) { 902 printf("vnode_pager_getpages: I/O read error\n"); 903 } 904 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 905 } 906 907 /* 908 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 909 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 910 * vnode_pager_generic_putpages() to implement the previous behaviour. 911 * 912 * All other FS's should use the bypass to get to the local media 913 * backing vp's VOP_PUTPAGES. 914 */ 915 static void 916 vnode_pager_putpages(object, m, count, sync, rtvals) 917 vm_object_t object; 918 vm_page_t *m; 919 int count; 920 boolean_t sync; 921 int *rtvals; 922 { 923 int rtval; 924 struct vnode *vp; 925 struct mount *mp; 926 int bytes = count * PAGE_SIZE; 927 928 GIANT_REQUIRED; 929 /* 930 * Force synchronous operation if we are extremely low on memory 931 * to prevent a low-memory deadlock. VOP operations often need to 932 * allocate more memory to initiate the I/O ( i.e. do a BMAP 933 * operation ). The swapper handles the case by limiting the amount 934 * of asynchronous I/O, but that sort of solution doesn't scale well 935 * for the vnode pager without a lot of work. 936 * 937 * Also, the backing vnode's iodone routine may not wake the pageout 938 * daemon up. This should be probably be addressed XXX. 939 */ 940 941 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 942 sync |= OBJPC_SYNC; 943 944 /* 945 * Call device-specific putpages function 946 */ 947 vp = object->handle; 948 if (vp->v_type != VREG) 949 mp = NULL; 950 (void)vn_start_write(vp, &mp, V_WAIT); 951 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 952 KASSERT(rtval != EOPNOTSUPP, 953 ("vnode_pager: stale FS putpages\n")); 954 vn_finished_write(mp); 955 } 956 957 958 /* 959 * This is now called from local media FS's to operate against their 960 * own vnodes if they fail to implement VOP_PUTPAGES. 961 * 962 * This is typically called indirectly via the pageout daemon and 963 * clustering has already typically occured, so in general we ask the 964 * underlying filesystem to write the data out asynchronously rather 965 * then delayed. 966 */ 967 int 968 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 969 struct vnode *vp; 970 vm_page_t *m; 971 int bytecount; 972 int flags; 973 int *rtvals; 974 { 975 int i; 976 vm_object_t object; 977 int count; 978 979 int maxsize, ncount; 980 vm_ooffset_t poffset; 981 struct uio auio; 982 struct iovec aiov; 983 int error; 984 int ioflags; 985 986 GIANT_REQUIRED; 987 object = vp->v_object; 988 count = bytecount / PAGE_SIZE; 989 990 for (i = 0; i < count; i++) 991 rtvals[i] = VM_PAGER_AGAIN; 992 993 if ((int) m[0]->pindex < 0) { 994 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 995 (long)m[0]->pindex, (u_long)m[0]->dirty); 996 rtvals[0] = VM_PAGER_BAD; 997 return VM_PAGER_BAD; 998 } 999 1000 maxsize = count * PAGE_SIZE; 1001 ncount = count; 1002 1003 poffset = IDX_TO_OFF(m[0]->pindex); 1004 1005 /* 1006 * If the page-aligned write is larger then the actual file we 1007 * have to invalidate pages occuring beyond the file EOF. However, 1008 * there is an edge case where a file may not be page-aligned where 1009 * the last page is partially invalid. In this case the filesystem 1010 * may not properly clear the dirty bits for the entire page (which 1011 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1012 * With the page locked we are free to fix-up the dirty bits here. 1013 * 1014 * We do not under any circumstances truncate the valid bits, as 1015 * this will screw up bogus page replacement. 1016 */ 1017 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1018 if (object->un_pager.vnp.vnp_size > poffset) { 1019 int pgoff; 1020 1021 maxsize = object->un_pager.vnp.vnp_size - poffset; 1022 ncount = btoc(maxsize); 1023 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1024 vm_page_lock_queues(); 1025 vm_page_clear_dirty(m[ncount - 1], pgoff, 1026 PAGE_SIZE - pgoff); 1027 vm_page_unlock_queues(); 1028 } 1029 } else { 1030 maxsize = 0; 1031 ncount = 0; 1032 } 1033 if (ncount < count) { 1034 for (i = ncount; i < count; i++) { 1035 rtvals[i] = VM_PAGER_BAD; 1036 } 1037 } 1038 } 1039 1040 /* 1041 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1042 * rather then a bdwrite() to prevent paging I/O from saturating 1043 * the buffer cache. Dummy-up the sequential heuristic to cause 1044 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1045 * the system decides how to cluster. 1046 */ 1047 ioflags = IO_VMIO; 1048 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1049 ioflags |= IO_SYNC; 1050 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1051 ioflags |= IO_ASYNC; 1052 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1053 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1054 1055 aiov.iov_base = (caddr_t) 0; 1056 aiov.iov_len = maxsize; 1057 auio.uio_iov = &aiov; 1058 auio.uio_iovcnt = 1; 1059 auio.uio_offset = poffset; 1060 auio.uio_segflg = UIO_NOCOPY; 1061 auio.uio_rw = UIO_WRITE; 1062 auio.uio_resid = maxsize; 1063 auio.uio_td = (struct thread *) 0; 1064 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1065 cnt.v_vnodeout++; 1066 cnt.v_vnodepgsout += ncount; 1067 1068 if (error) { 1069 printf("vnode_pager_putpages: I/O error %d\n", error); 1070 } 1071 if (auio.uio_resid) { 1072 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1073 auio.uio_resid, (u_long)m[0]->pindex); 1074 } 1075 for (i = 0; i < ncount; i++) { 1076 rtvals[i] = VM_PAGER_OK; 1077 } 1078 return rtvals[0]; 1079 } 1080 1081 struct vnode * 1082 vnode_pager_lock(vm_object_t first_object) 1083 { 1084 struct vnode *vp; 1085 vm_object_t backing_object, object; 1086 1087 VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED); 1088 for (object = first_object; object != NULL; object = backing_object) { 1089 if (object->type != OBJT_VNODE) { 1090 if ((backing_object = object->backing_object) != NULL) 1091 VM_OBJECT_LOCK(backing_object); 1092 if (object != first_object) 1093 VM_OBJECT_UNLOCK(object); 1094 continue; 1095 } 1096 retry: 1097 if (object->flags & OBJ_DEAD) { 1098 if (object != first_object) 1099 VM_OBJECT_UNLOCK(object); 1100 return NULL; 1101 } 1102 vp = object->handle; 1103 VI_LOCK(vp); 1104 VM_OBJECT_UNLOCK(object); 1105 if (first_object != object) 1106 VM_OBJECT_UNLOCK(first_object); 1107 if (vget(vp, LK_CANRECURSE | LK_INTERLOCK | LK_NOPAUSE | 1108 LK_RETRY | LK_SHARED, curthread)) { 1109 VM_OBJECT_LOCK(first_object); 1110 if (object != first_object) 1111 VM_OBJECT_LOCK(object); 1112 if (object->type != OBJT_VNODE) { 1113 if (object != first_object) 1114 VM_OBJECT_UNLOCK(object); 1115 return NULL; 1116 } 1117 printf("vnode_pager_lock: retrying\n"); 1118 goto retry; 1119 } 1120 VM_OBJECT_LOCK(first_object); 1121 return (vp); 1122 } 1123 return NULL; 1124 } 1125