Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/vm/vnode_pager.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
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/buf.h> 60 #include <sys/vmmeter.h> 61 62 #include <vm/vm.h> 63 #include <vm/vm_prot.h> 64 #include <vm/vm_object.h> 65 #include <vm/vm_page.h> 66 #include <vm/vm_pager.h> 67 #include <vm/vm_map.h> 68 #include <vm/vnode_pager.h> 69 #include <vm/vm_extern.h> 70 71 static vm_offset_t vnode_pager_addr __P((struct vnode *vp, vm_ooffset_t address, 72 int *run)); 73 static void vnode_pager_iodone __P((struct buf *bp)); 74 static int vnode_pager_input_smlfs __P((vm_object_t object, vm_page_t m)); 75 static int vnode_pager_input_old __P((vm_object_t object, vm_page_t m)); 76 static void vnode_pager_dealloc __P((vm_object_t)); 77 static int vnode_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 78 static int vnode_pager_putpages __P((vm_object_t, vm_page_t *, int, boolean_t, int *)); 79 static boolean_t vnode_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *)); 80 81 struct pagerops vnodepagerops = { 82 NULL, 83 vnode_pager_alloc, 84 vnode_pager_dealloc, 85 vnode_pager_getpages, 86 vnode_pager_putpages, 87 vnode_pager_haspage, 88 NULL 89 }; 90 91 92 /* 93 * Allocate (or lookup) pager for a vnode. 94 * Handle is a vnode pointer. 95 */ 96 vm_object_t 97 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 98 vm_ooffset_t offset) 99 { 100 vm_object_t object; 101 struct vnode *vp; 102 103 /* 104 * Pageout to vnode, no can do yet. 105 */ 106 if (handle == NULL) 107 return (NULL); 108 109 vp = (struct vnode *) handle; 110 111 /* 112 * Prevent race condition when allocating the object. This 113 * can happen with NFS vnodes since the nfsnode isn't locked. 114 */ 115 while (vp->v_flag & VOLOCK) { 116 vp->v_flag |= VOWANT; 117 tsleep(vp, PVM, "vnpobj", 0); 118 } 119 vp->v_flag |= VOLOCK; 120 121 /* 122 * If the object is being terminated, wait for it to 123 * go away. 124 */ 125 while (((object = vp->v_object) != NULL) && 126 (object->flags & OBJ_DEAD)) { 127 tsleep(object, PVM, "vadead", 0); 128 } 129 130 if (vp->v_usecount == 0) 131 panic("vnode_pager_alloc: no vnode reference"); 132 133 if (object == NULL) { 134 /* 135 * And an object of the appropriate size 136 */ 137 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 138 object->flags = 0; 139 140 object->un_pager.vnp.vnp_size = size; 141 142 object->handle = handle; 143 vp->v_object = object; 144 vp->v_usecount++; 145 } else { 146 object->ref_count++; 147 vp->v_usecount++; 148 } 149 150 vp->v_flag &= ~VOLOCK; 151 if (vp->v_flag & VOWANT) { 152 vp->v_flag &= ~VOWANT; 153 wakeup(vp); 154 } 155 return (object); 156 } 157 158 static void 159 vnode_pager_dealloc(object) 160 vm_object_t object; 161 { 162 register struct vnode *vp = object->handle; 163 164 if (vp == NULL) 165 panic("vnode_pager_dealloc: pager already dealloced"); 166 167 vm_object_pip_wait(object, "vnpdea"); 168 169 object->handle = NULL; 170 object->type = OBJT_DEAD; 171 vp->v_object = NULL; 172 vp->v_flag &= ~(VTEXT | VOBJBUF); 173 } 174 175 static boolean_t 176 vnode_pager_haspage(object, pindex, before, after) 177 vm_object_t object; 178 vm_pindex_t pindex; 179 int *before; 180 int *after; 181 { 182 struct vnode *vp = object->handle; 183 daddr_t bn; 184 int err; 185 daddr_t reqblock; 186 int poff; 187 int bsize; 188 int pagesperblock, blocksperpage; 189 190 if ((vp == NULL) || (vp->v_flag & VDOOMED)) 191 return FALSE; 192 193 /* 194 * If filesystem no longer mounted or offset beyond end of file we do 195 * not have the page. 196 */ 197 if ((vp->v_mount == NULL) || 198 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 199 return FALSE; 200 201 bsize = vp->v_mount->mnt_stat.f_iosize; 202 pagesperblock = bsize / PAGE_SIZE; 203 blocksperpage = 0; 204 if (pagesperblock > 0) { 205 reqblock = pindex / pagesperblock; 206 } else { 207 blocksperpage = (PAGE_SIZE / bsize); 208 reqblock = pindex * blocksperpage; 209 } 210 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 211 after, before); 212 if (err) 213 return TRUE; 214 if ( bn == -1) 215 return FALSE; 216 if (pagesperblock > 0) { 217 poff = pindex - (reqblock * pagesperblock); 218 if (before) { 219 *before *= pagesperblock; 220 *before += poff; 221 } 222 if (after) { 223 int numafter; 224 *after *= pagesperblock; 225 numafter = pagesperblock - (poff + 1); 226 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { 227 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex))); 228 } 229 *after += numafter; 230 } 231 } else { 232 if (before) { 233 *before /= blocksperpage; 234 } 235 236 if (after) { 237 *after /= blocksperpage; 238 } 239 } 240 return TRUE; 241 } 242 243 /* 244 * Lets the VM system know about a change in size for a file. 245 * We adjust our own internal size and flush any cached pages in 246 * the associated object that are affected by the size change. 247 * 248 * Note: this routine may be invoked as a result of a pager put 249 * operation (possibly at object termination time), so we must be careful. 250 */ 251 void 252 vnode_pager_setsize(vp, nsize) 253 struct vnode *vp; 254 vm_ooffset_t nsize; 255 { 256 vm_pindex_t nobjsize; 257 vm_object_t object = vp->v_object; 258 259 if (object == NULL) 260 return; 261 262 /* 263 * Hasn't changed size 264 */ 265 if (nsize == object->un_pager.vnp.vnp_size) 266 return; 267 268 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 269 270 /* 271 * File has shrunk. Toss any cached pages beyond the new EOF. 272 */ 273 if (nsize < object->un_pager.vnp.vnp_size) { 274 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size); 275 if (nobjsize < object->size) { 276 vm_object_page_remove(object, nobjsize, object->size, 277 FALSE); 278 } 279 /* 280 * this gets rid of garbage at the end of a page that is now 281 * only partially backed by the vnode... 282 */ 283 if (nsize & PAGE_MASK) { 284 vm_offset_t kva; 285 vm_page_t m; 286 287 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 288 if (m) { 289 kva = vm_pager_map_page(m); 290 bzero((caddr_t) kva + (nsize & PAGE_MASK), 291 (int) (round_page(nsize) - nsize)); 292 vm_pager_unmap_page(kva); 293 } 294 } 295 } 296 object->un_pager.vnp.vnp_size = nsize; 297 object->size = nobjsize; 298 } 299 300 void 301 vnode_pager_freepage(m) 302 vm_page_t m; 303 { 304 vm_page_free(m); 305 } 306 307 /* 308 * calculate the linear (byte) disk address of specified virtual 309 * file address 310 */ 311 static vm_offset_t 312 vnode_pager_addr(vp, address, run) 313 struct vnode *vp; 314 vm_ooffset_t address; 315 int *run; 316 { 317 int rtaddress; 318 int bsize; 319 daddr_t block; 320 struct vnode *rtvp; 321 int err; 322 daddr_t vblock; 323 int voffset; 324 325 if ((int) address < 0) 326 return -1; 327 328 if (vp->v_mount == NULL) 329 return -1; 330 331 bsize = vp->v_mount->mnt_stat.f_iosize; 332 vblock = address / bsize; 333 voffset = address % bsize; 334 335 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 336 337 if (err || (block == -1)) 338 rtaddress = -1; 339 else { 340 rtaddress = block + voffset / DEV_BSIZE; 341 if( run) { 342 *run += 1; 343 *run *= bsize/PAGE_SIZE; 344 *run -= voffset/PAGE_SIZE; 345 } 346 } 347 348 return rtaddress; 349 } 350 351 /* 352 * interrupt routine for I/O completion 353 */ 354 static void 355 vnode_pager_iodone(bp) 356 struct buf *bp; 357 { 358 bp->b_flags |= B_DONE; 359 wakeup(bp); 360 } 361 362 /* 363 * small block file system vnode pager input 364 */ 365 static int 366 vnode_pager_input_smlfs(object, m) 367 vm_object_t object; 368 vm_page_t m; 369 { 370 int i; 371 int s; 372 struct vnode *dp, *vp; 373 struct buf *bp; 374 vm_offset_t kva; 375 int fileaddr; 376 vm_offset_t bsize; 377 int error = 0; 378 379 vp = object->handle; 380 if (vp->v_mount == NULL) 381 return VM_PAGER_BAD; 382 383 bsize = vp->v_mount->mnt_stat.f_iosize; 384 385 386 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 387 388 kva = vm_pager_map_page(m); 389 390 for (i = 0; i < PAGE_SIZE / bsize; i++) { 391 392 if ((vm_page_bits(IDX_TO_OFF(m->pindex) + i * bsize, bsize) & m->valid)) 393 continue; 394 395 fileaddr = vnode_pager_addr(vp, 396 IDX_TO_OFF(m->pindex) + i * bsize, (int *)0); 397 if (fileaddr != -1) { 398 bp = getpbuf(); 399 400 /* build a minimal buffer header */ 401 bp->b_flags = B_BUSY | B_READ | B_CALL; 402 bp->b_iodone = vnode_pager_iodone; 403 bp->b_proc = curproc; 404 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 405 if (bp->b_rcred != NOCRED) 406 crhold(bp->b_rcred); 407 if (bp->b_wcred != NOCRED) 408 crhold(bp->b_wcred); 409 bp->b_data = (caddr_t) kva + i * bsize; 410 bp->b_blkno = fileaddr; 411 pbgetvp(dp, bp); 412 bp->b_bcount = bsize; 413 bp->b_bufsize = bsize; 414 415 /* do the input */ 416 VOP_STRATEGY(bp->b_vp, bp); 417 418 /* we definitely need to be at splvm here */ 419 420 s = splvm(); 421 while ((bp->b_flags & B_DONE) == 0) { 422 tsleep(bp, PVM, "vnsrd", 0); 423 } 424 splx(s); 425 if ((bp->b_flags & B_ERROR) != 0) 426 error = EIO; 427 428 /* 429 * free the buffer header back to the swap buffer pool 430 */ 431 relpbuf(bp); 432 if (error) 433 break; 434 435 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 436 } else { 437 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 438 bzero((caddr_t) kva + i * bsize, bsize); 439 } 440 } 441 vm_pager_unmap_page(kva); 442 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 443 vm_page_flag_clear(m, PG_ZERO); 444 if (error) { 445 return VM_PAGER_ERROR; 446 } 447 return VM_PAGER_OK; 448 449 } 450 451 452 /* 453 * old style vnode pager output routine 454 */ 455 static int 456 vnode_pager_input_old(object, m) 457 vm_object_t object; 458 vm_page_t m; 459 { 460 struct uio auio; 461 struct iovec aiov; 462 int error; 463 int size; 464 vm_offset_t kva; 465 466 error = 0; 467 468 /* 469 * Return failure if beyond current EOF 470 */ 471 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 472 return VM_PAGER_BAD; 473 } else { 474 size = PAGE_SIZE; 475 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 476 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 477 478 /* 479 * Allocate a kernel virtual address and initialize so that 480 * we can use VOP_READ/WRITE routines. 481 */ 482 kva = vm_pager_map_page(m); 483 484 aiov.iov_base = (caddr_t) kva; 485 aiov.iov_len = size; 486 auio.uio_iov = &aiov; 487 auio.uio_iovcnt = 1; 488 auio.uio_offset = IDX_TO_OFF(m->pindex); 489 auio.uio_segflg = UIO_SYSSPACE; 490 auio.uio_rw = UIO_READ; 491 auio.uio_resid = size; 492 auio.uio_procp = curproc; 493 494 error = VOP_READ(object->handle, &auio, 0, curproc->p_ucred); 495 if (!error) { 496 register int count = size - auio.uio_resid; 497 498 if (count == 0) 499 error = EINVAL; 500 else if (count != PAGE_SIZE) 501 bzero((caddr_t) kva + count, PAGE_SIZE - count); 502 } 503 vm_pager_unmap_page(kva); 504 } 505 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 506 m->dirty = 0; 507 vm_page_flag_clear(m, PG_ZERO); 508 if (!error) 509 m->valid = VM_PAGE_BITS_ALL; 510 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 511 } 512 513 /* 514 * generic vnode pager input routine 515 */ 516 517 /* 518 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 519 * implement their own VOP_GETPAGES, their VOP_GETPAGES should call to 520 * vnode_pager_generic_getpages() to implement the previous behaviour. 521 * 522 * All other FS's should use the bypass to get to the local media 523 * backing vp's VOP_GETPAGES. 524 */ 525 static int 526 vnode_pager_getpages(object, m, count, reqpage) 527 vm_object_t object; 528 vm_page_t *m; 529 int count; 530 int reqpage; 531 { 532 int rtval; 533 struct vnode *vp; 534 int bytes = count * PAGE_SIZE; 535 536 vp = object->handle; 537 /* 538 * XXX temporary diagnostic message to help track stale FS code, 539 * Returning EOPNOTSUPP from here may make things unhappy. 540 */ 541 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 542 if (rtval == EOPNOTSUPP) { 543 printf("vnode_pager: *** WARNING *** stale FS getpages\n"); 544 rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage); 545 } 546 return rtval; 547 } 548 549 550 /* 551 * This is now called from local media FS's to operate against their 552 * own vnodes if they fail to implement VOP_GETPAGES. 553 */ 554 int 555 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 556 struct vnode *vp; 557 vm_page_t *m; 558 int bytecount; 559 int reqpage; 560 { 561 vm_object_t object; 562 vm_offset_t kva; 563 off_t foff, tfoff, nextoff; 564 int i, size, bsize, first, firstaddr; 565 struct vnode *dp; 566 int runpg; 567 int runend; 568 struct buf *bp; 569 int s; 570 int count; 571 int error = 0; 572 573 object = vp->v_object; 574 count = bytecount / PAGE_SIZE; 575 576 if (vp->v_mount == NULL) 577 return VM_PAGER_BAD; 578 579 bsize = vp->v_mount->mnt_stat.f_iosize; 580 581 /* get the UNDERLYING device for the file with VOP_BMAP() */ 582 583 /* 584 * originally, we did not check for an error return value -- assuming 585 * an fs always has a bmap entry point -- that assumption is wrong!!! 586 */ 587 foff = IDX_TO_OFF(m[reqpage]->pindex); 588 589 /* 590 * if we can't bmap, use old VOP code 591 */ 592 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 593 for (i = 0; i < count; i++) { 594 if (i != reqpage) { 595 vnode_pager_freepage(m[i]); 596 } 597 } 598 cnt.v_vnodein++; 599 cnt.v_vnodepgsin++; 600 return vnode_pager_input_old(object, m[reqpage]); 601 602 /* 603 * if the blocksize is smaller than a page size, then use 604 * special small filesystem code. NFS sometimes has a small 605 * blocksize, but it can handle large reads itself. 606 */ 607 } else if ((PAGE_SIZE / bsize) > 1 && 608 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 609 for (i = 0; i < count; i++) { 610 if (i != reqpage) { 611 vnode_pager_freepage(m[i]); 612 } 613 } 614 cnt.v_vnodein++; 615 cnt.v_vnodepgsin++; 616 return vnode_pager_input_smlfs(object, m[reqpage]); 617 } 618 /* 619 * if ANY DEV_BSIZE blocks are valid on a large filesystem block 620 * then, the entire page is valid -- 621 * XXX no it isn't 622 */ 623 624 if (m[reqpage]->valid != VM_PAGE_BITS_ALL) 625 m[reqpage]->valid = 0; 626 627 if (m[reqpage]->valid) { 628 m[reqpage]->valid = VM_PAGE_BITS_ALL; 629 for (i = 0; i < count; i++) { 630 if (i != reqpage) 631 vnode_pager_freepage(m[i]); 632 } 633 return VM_PAGER_OK; 634 } 635 636 /* 637 * here on direct device I/O 638 */ 639 640 firstaddr = -1; 641 /* 642 * calculate the run that includes the required page 643 */ 644 for(first = 0, i = 0; i < count; i = runend) { 645 firstaddr = vnode_pager_addr(vp, 646 IDX_TO_OFF(m[i]->pindex), &runpg); 647 if (firstaddr == -1) { 648 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 649 /* XXX no %qd in kernel. */ 650 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx", 651 firstaddr, (u_long)(foff >> 32), 652 (u_long)(u_int32_t)foff, 653 (u_long)(u_int32_t) 654 (object->un_pager.vnp.vnp_size >> 32), 655 (u_long)(u_int32_t) 656 object->un_pager.vnp.vnp_size); 657 } 658 vnode_pager_freepage(m[i]); 659 runend = i + 1; 660 first = runend; 661 continue; 662 } 663 runend = i + runpg; 664 if (runend <= reqpage) { 665 int j; 666 for (j = i; j < runend; j++) { 667 vnode_pager_freepage(m[j]); 668 } 669 } else { 670 if (runpg < (count - first)) { 671 for (i = first + runpg; i < count; i++) 672 vnode_pager_freepage(m[i]); 673 count = first + runpg; 674 } 675 break; 676 } 677 first = runend; 678 } 679 680 /* 681 * the first and last page have been calculated now, move input pages 682 * to be zero based... 683 */ 684 if (first != 0) { 685 for (i = first; i < count; i++) { 686 m[i - first] = m[i]; 687 } 688 count -= first; 689 reqpage -= first; 690 } 691 692 /* 693 * calculate the file virtual address for the transfer 694 */ 695 foff = IDX_TO_OFF(m[0]->pindex); 696 697 /* 698 * calculate the size of the transfer 699 */ 700 size = count * PAGE_SIZE; 701 if ((foff + size) > object->un_pager.vnp.vnp_size) 702 size = object->un_pager.vnp.vnp_size - foff; 703 704 /* 705 * round up physical size for real devices 706 */ 707 if (dp->v_type == VBLK || dp->v_type == VCHR) 708 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 709 710 bp = getpbuf(); 711 kva = (vm_offset_t) bp->b_data; 712 713 /* 714 * and map the pages to be read into the kva 715 */ 716 pmap_qenter(kva, m, count); 717 718 /* build a minimal buffer header */ 719 bp->b_flags = B_BUSY | B_READ | B_CALL; 720 bp->b_iodone = vnode_pager_iodone; 721 /* B_PHYS is not set, but it is nice to fill this in */ 722 bp->b_proc = curproc; 723 bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; 724 if (bp->b_rcred != NOCRED) 725 crhold(bp->b_rcred); 726 if (bp->b_wcred != NOCRED) 727 crhold(bp->b_wcred); 728 bp->b_blkno = firstaddr; 729 pbgetvp(dp, bp); 730 bp->b_bcount = size; 731 bp->b_bufsize = size; 732 733 cnt.v_vnodein++; 734 cnt.v_vnodepgsin += count; 735 736 /* do the input */ 737 VOP_STRATEGY(bp->b_vp, bp); 738 739 s = splvm(); 740 /* we definitely need to be at splvm here */ 741 742 while ((bp->b_flags & B_DONE) == 0) { 743 tsleep(bp, PVM, "vnread", 0); 744 } 745 splx(s); 746 if ((bp->b_flags & B_ERROR) != 0) 747 error = EIO; 748 749 if (!error) { 750 if (size != count * PAGE_SIZE) 751 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 752 } 753 pmap_qremove(kva, count); 754 755 /* 756 * free the buffer header back to the swap buffer pool 757 */ 758 relpbuf(bp); 759 760 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 761 vm_page_t mt; 762 763 nextoff = tfoff + PAGE_SIZE; 764 mt = m[i]; 765 766 if (nextoff <= size) { 767 mt->valid = VM_PAGE_BITS_ALL; 768 mt->dirty = 0; 769 pmap_clear_modify(VM_PAGE_TO_PHYS(mt)); 770 } else { 771 int nvalid = ((size + DEV_BSIZE - 1) - tfoff) & ~(DEV_BSIZE - 1); 772 vm_page_set_validclean(mt, 0, nvalid); 773 } 774 775 vm_page_flag_clear(mt, PG_ZERO); 776 if (i != reqpage) { 777 778 /* 779 * whether or not to leave the page activated is up in 780 * the air, but we should put the page on a page queue 781 * somewhere. (it already is in the object). Result: 782 * It appears that emperical results show that 783 * deactivating pages is best. 784 */ 785 786 /* 787 * just in case someone was asking for this page we 788 * now tell them that it is ok to use 789 */ 790 if (!error) { 791 if (mt->flags & PG_WANTED) 792 vm_page_activate(mt); 793 else 794 vm_page_deactivate(mt); 795 vm_page_wakeup(mt); 796 } else { 797 vnode_pager_freepage(mt); 798 } 799 } 800 } 801 if (error) { 802 printf("vnode_pager_getpages: I/O read error\n"); 803 } 804 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 805 } 806 807 /* 808 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 809 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 810 * vnode_pager_generic_putpages() to implement the previous behaviour. 811 * 812 * All other FS's should use the bypass to get to the local media 813 * backing vp's VOP_PUTPAGES. 814 */ 815 static int 816 vnode_pager_putpages(object, m, count, sync, rtvals) 817 vm_object_t object; 818 vm_page_t *m; 819 int count; 820 boolean_t sync; 821 int *rtvals; 822 { 823 int rtval; 824 struct vnode *vp; 825 int bytes = count * PAGE_SIZE; 826 827 /* 828 * Force synchronous operation if we are extremely low on memory 829 * to prevent a low-memory deadlock. VOP operations often need to 830 * allocate more memory to initiate the I/O ( i.e. do a BMAP 831 * operation ). The swapper handles the case by limiting the amount 832 * of asynchronous I/O, but that sort of solution doesn't scale well 833 * for the vnode pager without a lot of work. 834 * 835 * Also, the backing vnode's iodone routine may not wake the pageout 836 * daemon up. This should be probably be addressed XXX. 837 */ 838 839 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 840 sync |= OBJPC_SYNC; 841 842 /* 843 * Call device-specific putpages function 844 */ 845 846 vp = object->handle; 847 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 848 if (rtval == EOPNOTSUPP) { 849 printf("vnode_pager: *** WARNING *** stale FS putpages\n"); 850 rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals); 851 } 852 return rtval; 853 } 854 855 856 /* 857 * This is now called from local media FS's to operate against their 858 * own vnodes if they fail to implement VOP_GETPAGES. 859 */ 860 int 861 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 862 struct vnode *vp; 863 vm_page_t *m; 864 int bytecount; 865 int flags; 866 int *rtvals; 867 { 868 int i; 869 vm_object_t object; 870 int count; 871 872 int maxsize, ncount; 873 vm_ooffset_t poffset; 874 struct uio auio; 875 struct iovec aiov; 876 int error; 877 int ioflags; 878 879 object = vp->v_object; 880 count = bytecount / PAGE_SIZE; 881 882 for (i = 0; i < count; i++) 883 rtvals[i] = VM_PAGER_AGAIN; 884 885 if ((int) m[0]->pindex < 0) { 886 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%x(%x)\n", 887 m[0]->pindex, m[0]->dirty); 888 rtvals[0] = VM_PAGER_BAD; 889 return VM_PAGER_BAD; 890 } 891 892 maxsize = count * PAGE_SIZE; 893 ncount = count; 894 895 poffset = IDX_TO_OFF(m[0]->pindex); 896 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 897 if (object->un_pager.vnp.vnp_size > poffset) 898 maxsize = object->un_pager.vnp.vnp_size - poffset; 899 else 900 maxsize = 0; 901 ncount = btoc(maxsize); 902 if (ncount < count) { 903 for (i = ncount; i < count; i++) { 904 rtvals[i] = VM_PAGER_BAD; 905 } 906 } 907 } 908 909 ioflags = IO_VMIO; 910 ioflags |= (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) ? IO_SYNC: 0; 911 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 912 913 aiov.iov_base = (caddr_t) 0; 914 aiov.iov_len = maxsize; 915 auio.uio_iov = &aiov; 916 auio.uio_iovcnt = 1; 917 auio.uio_offset = poffset; 918 auio.uio_segflg = UIO_NOCOPY; 919 auio.uio_rw = UIO_WRITE; 920 auio.uio_resid = maxsize; 921 auio.uio_procp = (struct proc *) 0; 922 error = VOP_WRITE(vp, &auio, ioflags, curproc->p_ucred); 923 cnt.v_vnodeout++; 924 cnt.v_vnodepgsout += ncount; 925 926 if (error) { 927 printf("vnode_pager_putpages: I/O error %d\n", error); 928 } 929 if (auio.uio_resid) { 930 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 931 auio.uio_resid, (u_long)m[0]->pindex); 932 } 933 for (i = 0; i < ncount; i++) { 934 rtvals[i] = VM_PAGER_OK; 935 } 936 return rtvals[0]; 937 } 938 939 struct vnode * 940 vnode_pager_lock(object) 941 vm_object_t object; 942 { 943 struct proc *p = curproc; /* XXX */ 944 945 for (; object != NULL; object = object->backing_object) { 946 if (object->type != OBJT_VNODE) 947 continue; 948 if (object->flags & OBJ_DEAD) 949 return NULL; 950 951 while (vget(object->handle, 952 LK_NOPAUSE | LK_SHARED | LK_RETRY | LK_CANRECURSE, p)) { 953 if ((object->flags & OBJ_DEAD) || (object->type != OBJT_VNODE)) 954 return NULL; 955 printf("vnode_pager_lock: retrying\n"); 956 } 957 return object->handle; 958 } 959 return NULL; 960 }
Cache object: 3f54a5ec54ffe4f27d7f4077f4af6616
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]