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: src/sys/vm/vnode_pager.c,v 1.116.2.7 2002/12/31 09:34:51 dillon Exp $ 42 * $DragonFly: src/sys/vm/vnode_pager.c,v 1.17 2004/12/10 19:50:32 dillon Exp $ 43 */ 44 45 /* 46 * Page to/from files (vnodes). 47 */ 48 49 /* 50 * TODO: 51 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 52 * greatly re-simplify the vnode_pager. 53 */ 54 55 #include <sys/param.h> 56 #include <sys/systm.h> 57 #include <sys/kernel.h> 58 #include <sys/proc.h> 59 #include <sys/vnode.h> 60 #include <sys/mount.h> 61 #include <sys/buf.h> 62 #include <sys/vmmeter.h> 63 #include <sys/conf.h> 64 #include <sys/sfbuf.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 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 NULL, 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 = -1; /* start out unlimited */ 95 96 /* 97 * Allocate (or lookup) pager for a vnode. 98 * Handle is a vnode pointer. 99 */ 100 vm_object_t 101 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 102 vm_ooffset_t offset) 103 { 104 vm_object_t object; 105 struct vnode *vp; 106 107 /* 108 * Pageout to vnode, no can do yet. 109 */ 110 if (handle == NULL) 111 return (NULL); 112 113 /* 114 * XXX hack - This initialization should be put somewhere else. 115 */ 116 if (vnode_pbuf_freecnt < 0) { 117 vnode_pbuf_freecnt = nswbuf / 2 + 1; 118 } 119 120 vp = (struct vnode *) handle; 121 122 /* 123 * Prevent race condition when allocating the object. This 124 * can happen with NFS vnodes since the nfsnode isn't locked. 125 */ 126 while (vp->v_flag & VOLOCK) { 127 vp->v_flag |= VOWANT; 128 tsleep(vp, 0, "vnpobj", 0); 129 } 130 vp->v_flag |= VOLOCK; 131 132 /* 133 * If the object is being terminated, wait for it to 134 * go away. 135 */ 136 while (((object = vp->v_object) != NULL) && 137 (object->flags & OBJ_DEAD)) { 138 tsleep(object, 0, "vadead", 0); 139 } 140 141 if (vp->v_usecount == 0) 142 panic("vnode_pager_alloc: no vnode reference"); 143 144 if (object == NULL) { 145 /* 146 * And an object of the appropriate size 147 */ 148 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 149 object->flags = 0; 150 151 object->un_pager.vnp.vnp_size = size; 152 153 object->handle = handle; 154 vp->v_object = object; 155 vp->v_usecount++; 156 } else { 157 object->ref_count++; 158 vp->v_usecount++; 159 } 160 161 vp->v_flag &= ~VOLOCK; 162 if (vp->v_flag & VOWANT) { 163 vp->v_flag &= ~VOWANT; 164 wakeup(vp); 165 } 166 return (object); 167 } 168 169 static void 170 vnode_pager_dealloc(vm_object_t object) 171 { 172 struct vnode *vp = object->handle; 173 174 if (vp == NULL) 175 panic("vnode_pager_dealloc: pager already dealloced"); 176 177 vm_object_pip_wait(object, "vnpdea"); 178 179 object->handle = NULL; 180 object->type = OBJT_DEAD; 181 vp->v_object = NULL; 182 vp->v_flag &= ~(VTEXT | VOBJBUF); 183 } 184 185 static boolean_t 186 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 187 int *after) 188 { 189 struct vnode *vp = object->handle; 190 daddr_t bn; 191 int err; 192 daddr_t reqblock; 193 int poff; 194 int bsize; 195 int pagesperblock, blocksperpage; 196 197 /* 198 * If no vp or vp is doomed or marked transparent to VM, we do not 199 * have the page. 200 */ 201 if ((vp == NULL) || (vp->v_flag & VRECLAIMED)) 202 return FALSE; 203 204 /* 205 * If filesystem no longer mounted or offset beyond end of file we do 206 * not have the page. 207 */ 208 if ((vp->v_mount == NULL) || 209 (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)) 210 return FALSE; 211 212 bsize = vp->v_mount->mnt_stat.f_iosize; 213 pagesperblock = bsize / PAGE_SIZE; 214 blocksperpage = 0; 215 if (pagesperblock > 0) { 216 reqblock = pindex / pagesperblock; 217 } else { 218 blocksperpage = (PAGE_SIZE / bsize); 219 reqblock = pindex * blocksperpage; 220 } 221 err = VOP_BMAP(vp, reqblock, (struct vnode **) 0, &bn, 222 after, before); 223 if (err) 224 return TRUE; 225 if ( bn == -1) 226 return FALSE; 227 if (pagesperblock > 0) { 228 poff = pindex - (reqblock * pagesperblock); 229 if (before) { 230 *before *= pagesperblock; 231 *before += poff; 232 } 233 if (after) { 234 int numafter; 235 *after *= pagesperblock; 236 numafter = pagesperblock - (poff + 1); 237 if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { 238 numafter = OFF_TO_IDX((object->un_pager.vnp.vnp_size - IDX_TO_OFF(pindex))); 239 } 240 *after += numafter; 241 } 242 } else { 243 if (before) { 244 *before /= blocksperpage; 245 } 246 247 if (after) { 248 *after /= blocksperpage; 249 } 250 } 251 return TRUE; 252 } 253 254 /* 255 * Lets the VM system know about a change in size for a file. 256 * We adjust our own internal size and flush any cached pages in 257 * the associated object that are affected by the size change. 258 * 259 * Note: this routine may be invoked as a result of a pager put 260 * operation (possibly at object termination time), so we must be careful. 261 */ 262 void 263 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 264 { 265 vm_pindex_t nobjsize; 266 vm_object_t object = vp->v_object; 267 268 if (object == NULL) 269 return; 270 271 /* 272 * Hasn't changed size 273 */ 274 if (nsize == object->un_pager.vnp.vnp_size) 275 return; 276 277 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 278 279 /* 280 * File has shrunk. Toss any cached pages beyond the new EOF. 281 */ 282 if (nsize < object->un_pager.vnp.vnp_size) { 283 vm_freeze_copyopts(object, OFF_TO_IDX(nsize), object->size); 284 if (nobjsize < object->size) { 285 vm_object_page_remove(object, nobjsize, object->size, 286 FALSE); 287 } 288 /* 289 * This gets rid of garbage at the end of a page that is now 290 * only partially backed by the vnode. Since we are setting 291 * the entire page valid & clean after we are done we have 292 * to be sure that the portion of the page within the file 293 * bounds is already valid. If it isn't then making it 294 * valid would create a corrupt block. 295 */ 296 if (nsize & PAGE_MASK) { 297 vm_offset_t kva; 298 vm_page_t m; 299 300 m = vm_page_lookup(object, OFF_TO_IDX(nsize)); 301 if (m && m->valid) { 302 int base = (int)nsize & PAGE_MASK; 303 int size = PAGE_SIZE - base; 304 struct sf_buf *sf; 305 306 /* 307 * Clear out partial-page garbage in case 308 * the page has been mapped. 309 */ 310 sf = sf_buf_alloc(m, SFBA_QUICK); 311 kva = sf_buf_kva(sf); 312 bzero((caddr_t)kva + base, size); 313 sf_buf_free(sf); 314 315 /* 316 * XXX work around SMP data integrity race 317 * by unmapping the page from user processes. 318 * The garbage we just cleared may be mapped 319 * to a user process running on another cpu 320 * and this code is not running through normal 321 * I/O channels which handle SMP issues for 322 * us, so unmap page to synchronize all cpus. 323 * 324 * XXX should vm_pager_unmap_page() have 325 * dealt with this? 326 */ 327 vm_page_protect(m, VM_PROT_NONE); 328 329 /* 330 * Clear out partial-page dirty bits. This 331 * has the side effect of setting the valid 332 * bits, but that is ok. There are a bunch 333 * of places in the VM system where we expected 334 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 335 * case is one of them. If the page is still 336 * partially dirty, make it fully dirty. 337 * 338 * note that we do not clear out the valid 339 * bits. This would prevent bogus_page 340 * replacement from working properly. 341 */ 342 vm_page_set_validclean(m, base, size); 343 if (m->dirty != 0) 344 m->dirty = VM_PAGE_BITS_ALL; 345 } 346 } 347 } 348 object->un_pager.vnp.vnp_size = nsize; 349 object->size = nobjsize; 350 } 351 352 void 353 vnode_pager_freepage(vm_page_t m) 354 { 355 vm_page_free(m); 356 } 357 358 /* 359 * calculate the linear (byte) disk address of specified virtual 360 * file address 361 */ 362 static vm_offset_t 363 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, int *run) 364 { 365 int rtaddress; 366 int bsize; 367 daddr_t block; 368 struct vnode *rtvp; 369 int err; 370 daddr_t vblock; 371 int voffset; 372 373 if (address < 0) 374 return -1; 375 376 if (vp->v_mount == NULL) 377 return -1; 378 379 bsize = vp->v_mount->mnt_stat.f_iosize; 380 vblock = address / bsize; 381 voffset = address % bsize; 382 383 err = VOP_BMAP(vp, vblock, &rtvp, &block, run, NULL); 384 385 if (err || (block == -1)) 386 rtaddress = -1; 387 else { 388 rtaddress = block + voffset / DEV_BSIZE; 389 if( run) { 390 *run += 1; 391 *run *= bsize/PAGE_SIZE; 392 *run -= voffset/PAGE_SIZE; 393 } 394 } 395 396 return rtaddress; 397 } 398 399 /* 400 * interrupt routine for I/O completion 401 */ 402 static void 403 vnode_pager_iodone(struct buf *bp) 404 { 405 bp->b_flags |= B_DONE; 406 wakeup(bp); 407 } 408 409 /* 410 * small block file system vnode pager input 411 */ 412 static int 413 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 414 { 415 int i; 416 int s; 417 struct vnode *dp, *vp; 418 struct buf *bp; 419 vm_offset_t kva; 420 struct sf_buf *sf; 421 int fileaddr; 422 vm_offset_t bsize; 423 int error = 0; 424 425 vp = object->handle; 426 if (vp->v_mount == NULL) 427 return VM_PAGER_BAD; 428 429 bsize = vp->v_mount->mnt_stat.f_iosize; 430 431 432 VOP_BMAP(vp, 0, &dp, 0, NULL, NULL); 433 434 sf = sf_buf_alloc(m, 0); 435 kva = sf_buf_kva(sf); 436 437 for (i = 0; i < PAGE_SIZE / bsize; i++) { 438 vm_ooffset_t address; 439 440 if (vm_page_bits(i * bsize, bsize) & m->valid) 441 continue; 442 443 address = IDX_TO_OFF(m->pindex) + i * bsize; 444 if (address >= object->un_pager.vnp.vnp_size) { 445 fileaddr = -1; 446 } else { 447 fileaddr = vnode_pager_addr(vp, address, NULL); 448 } 449 if (fileaddr != -1) { 450 bp = getpbuf(&vnode_pbuf_freecnt); 451 452 /* build a minimal buffer header */ 453 bp->b_flags = B_READ | B_CALL; 454 bp->b_iodone = vnode_pager_iodone; 455 bp->b_data = (caddr_t) kva + i * bsize; 456 bp->b_blkno = fileaddr; 457 pbgetvp(dp, bp); 458 bp->b_bcount = bsize; 459 bp->b_bufsize = bsize; 460 bp->b_runningbufspace = bp->b_bufsize; 461 runningbufspace += bp->b_runningbufspace; 462 463 /* do the input */ 464 VOP_STRATEGY(bp->b_vp, bp); 465 466 /* we definitely need to be at splvm here */ 467 468 s = splvm(); 469 while ((bp->b_flags & B_DONE) == 0) { 470 tsleep(bp, 0, "vnsrd", 0); 471 } 472 splx(s); 473 if ((bp->b_flags & B_ERROR) != 0) 474 error = EIO; 475 476 /* 477 * free the buffer header back to the swap buffer pool 478 */ 479 relpbuf(bp, &vnode_pbuf_freecnt); 480 if (error) 481 break; 482 483 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 484 } else { 485 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 486 bzero((caddr_t) kva + i * bsize, bsize); 487 } 488 } 489 sf_buf_free(sf); 490 pmap_clear_modify(m); 491 vm_page_flag_clear(m, PG_ZERO); 492 if (error) { 493 return VM_PAGER_ERROR; 494 } 495 return VM_PAGER_OK; 496 497 } 498 499 500 /* 501 * old style vnode pager output routine 502 */ 503 static int 504 vnode_pager_input_old(vm_object_t object, vm_page_t m) 505 { 506 struct uio auio; 507 struct iovec aiov; 508 int error; 509 int size; 510 vm_offset_t kva; 511 struct sf_buf *sf; 512 513 error = 0; 514 515 /* 516 * Return failure if beyond current EOF 517 */ 518 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 519 return VM_PAGER_BAD; 520 } else { 521 size = PAGE_SIZE; 522 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 523 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 524 525 /* 526 * Allocate a kernel virtual address and initialize so that 527 * we can use VOP_READ/WRITE routines. 528 */ 529 sf = sf_buf_alloc(m, 0); 530 kva = sf_buf_kva(sf); 531 532 aiov.iov_base = (caddr_t) kva; 533 aiov.iov_len = size; 534 auio.uio_iov = &aiov; 535 auio.uio_iovcnt = 1; 536 auio.uio_offset = IDX_TO_OFF(m->pindex); 537 auio.uio_segflg = UIO_SYSSPACE; 538 auio.uio_rw = UIO_READ; 539 auio.uio_resid = size; 540 auio.uio_td = curthread; 541 542 error = VOP_READ(((struct vnode *)object->handle), 543 &auio, 0, proc0.p_ucred); 544 if (!error) { 545 int count = size - auio.uio_resid; 546 547 if (count == 0) 548 error = EINVAL; 549 else if (count != PAGE_SIZE) 550 bzero((caddr_t) kva + count, PAGE_SIZE - count); 551 } 552 sf_buf_free(sf); 553 } 554 pmap_clear_modify(m); 555 vm_page_undirty(m); 556 vm_page_flag_clear(m, PG_ZERO); 557 if (!error) 558 m->valid = VM_PAGE_BITS_ALL; 559 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 560 } 561 562 /* 563 * generic vnode pager input routine 564 */ 565 566 /* 567 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 568 * implement their own VOP_GETPAGES, their VOP_GETPAGES should call to 569 * vnode_pager_generic_getpages() to implement the previous behaviour. 570 * 571 * All other FS's should use the bypass to get to the local media 572 * backing vp's VOP_GETPAGES. 573 */ 574 static int 575 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage) 576 { 577 int rtval; 578 struct vnode *vp; 579 int bytes = count * PAGE_SIZE; 580 581 vp = object->handle; 582 /* 583 * XXX temporary diagnostic message to help track stale FS code, 584 * Returning EOPNOTSUPP from here may make things unhappy. 585 */ 586 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 587 if (rtval == EOPNOTSUPP) { 588 printf("vnode_pager: *** WARNING *** stale FS getpages\n"); 589 rtval = vnode_pager_generic_getpages( vp, m, bytes, reqpage); 590 } 591 return rtval; 592 } 593 594 595 /* 596 * This is now called from local media FS's to operate against their 597 * own vnodes if they fail to implement VOP_GETPAGES. 598 */ 599 int 600 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount, 601 int reqpage) 602 { 603 vm_object_t object; 604 vm_offset_t kva; 605 off_t foff, tfoff, nextoff; 606 int i, size, bsize, first, firstaddr; 607 struct vnode *dp; 608 int runpg; 609 int runend; 610 struct buf *bp; 611 int s; 612 int count; 613 int error = 0; 614 615 object = vp->v_object; 616 count = bytecount / PAGE_SIZE; 617 618 if (vp->v_mount == NULL) 619 return VM_PAGER_BAD; 620 621 bsize = vp->v_mount->mnt_stat.f_iosize; 622 623 /* get the UNDERLYING device for the file with VOP_BMAP() */ 624 625 /* 626 * originally, we did not check for an error return value -- assuming 627 * an fs always has a bmap entry point -- that assumption is wrong!!! 628 */ 629 foff = IDX_TO_OFF(m[reqpage]->pindex); 630 631 /* 632 * if we can't bmap, use old VOP code 633 */ 634 if (VOP_BMAP(vp, 0, &dp, 0, NULL, NULL)) { 635 for (i = 0; i < count; i++) { 636 if (i != reqpage) { 637 vnode_pager_freepage(m[i]); 638 } 639 } 640 mycpu->gd_cnt.v_vnodein++; 641 mycpu->gd_cnt.v_vnodepgsin++; 642 return vnode_pager_input_old(object, m[reqpage]); 643 644 /* 645 * if the blocksize is smaller than a page size, then use 646 * special small filesystem code. NFS sometimes has a small 647 * blocksize, but it can handle large reads itself. 648 */ 649 } else if ((PAGE_SIZE / bsize) > 1 && 650 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 651 for (i = 0; i < count; i++) { 652 if (i != reqpage) { 653 vnode_pager_freepage(m[i]); 654 } 655 } 656 mycpu->gd_cnt.v_vnodein++; 657 mycpu->gd_cnt.v_vnodepgsin++; 658 return vnode_pager_input_smlfs(object, m[reqpage]); 659 } 660 661 /* 662 * If we have a completely valid page available to us, we can 663 * clean up and return. Otherwise we have to re-read the 664 * media. 665 * 666 * Note that this does not work with NFS, so NFS has its own 667 * getpages routine. The problem is that NFS can have partially 668 * valid pages associated with the buffer cache due to the piecemeal 669 * write support. If we were to fall through and re-read the media 670 * as we do here, dirty data could be lost. 671 */ 672 673 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 674 for (i = 0; i < count; i++) { 675 if (i != reqpage) 676 vnode_pager_freepage(m[i]); 677 } 678 return VM_PAGER_OK; 679 } 680 m[reqpage]->valid = 0; 681 682 /* 683 * here on direct device I/O 684 */ 685 686 firstaddr = -1; 687 /* 688 * calculate the run that includes the required page 689 */ 690 for(first = 0, i = 0; i < count; i = runend) { 691 firstaddr = vnode_pager_addr(vp, 692 IDX_TO_OFF(m[i]->pindex), &runpg); 693 if (firstaddr == -1) { 694 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 695 /* XXX no %qd in kernel. */ 696 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %d, foff: 0x%lx%08lx, vnp_size: 0x%lx%08lx", 697 firstaddr, (u_long)(foff >> 32), 698 (u_long)(u_int32_t)foff, 699 (u_long)(u_int32_t) 700 (object->un_pager.vnp.vnp_size >> 32), 701 (u_long)(u_int32_t) 702 object->un_pager.vnp.vnp_size); 703 } 704 vnode_pager_freepage(m[i]); 705 runend = i + 1; 706 first = runend; 707 continue; 708 } 709 runend = i + runpg; 710 if (runend <= reqpage) { 711 int j; 712 for (j = i; j < runend; j++) { 713 vnode_pager_freepage(m[j]); 714 } 715 } else { 716 if (runpg < (count - first)) { 717 for (i = first + runpg; i < count; i++) 718 vnode_pager_freepage(m[i]); 719 count = first + runpg; 720 } 721 break; 722 } 723 first = runend; 724 } 725 726 /* 727 * the first and last page have been calculated now, move input pages 728 * to be zero based... 729 */ 730 if (first != 0) { 731 for (i = first; i < count; i++) { 732 m[i - first] = m[i]; 733 } 734 count -= first; 735 reqpage -= first; 736 } 737 738 /* 739 * calculate the file virtual address for the transfer 740 */ 741 foff = IDX_TO_OFF(m[0]->pindex); 742 743 /* 744 * calculate the size of the transfer 745 */ 746 size = count * PAGE_SIZE; 747 if ((foff + size) > object->un_pager.vnp.vnp_size) 748 size = object->un_pager.vnp.vnp_size - foff; 749 750 /* 751 * round up physical size for real devices. 752 */ 753 if (dp->v_type == VBLK || dp->v_type == VCHR) { 754 int secmask = dp->v_rdev->si_bsize_phys - 1; 755 KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large\n", secmask + 1)); 756 size = (size + secmask) & ~secmask; 757 } 758 759 bp = getpbuf(&vnode_pbuf_freecnt); 760 kva = (vm_offset_t) bp->b_data; 761 762 /* 763 * and map the pages to be read into the kva 764 */ 765 pmap_qenter(kva, m, count); 766 767 /* build a minimal buffer header */ 768 bp->b_flags = B_READ | B_CALL; 769 bp->b_iodone = vnode_pager_iodone; 770 /* B_PHYS is not set, but it is nice to fill this in */ 771 bp->b_blkno = firstaddr; 772 pbgetvp(dp, bp); 773 bp->b_bcount = size; 774 bp->b_bufsize = size; 775 bp->b_runningbufspace = bp->b_bufsize; 776 runningbufspace += bp->b_runningbufspace; 777 778 mycpu->gd_cnt.v_vnodein++; 779 mycpu->gd_cnt.v_vnodepgsin += count; 780 781 /* do the input */ 782 VOP_STRATEGY(bp->b_vp, bp); 783 784 s = splvm(); 785 /* we definitely need to be at splvm here */ 786 787 while ((bp->b_flags & B_DONE) == 0) { 788 tsleep(bp, 0, "vnread", 0); 789 } 790 splx(s); 791 if ((bp->b_flags & B_ERROR) != 0) 792 error = EIO; 793 794 if (!error) { 795 if (size != count * PAGE_SIZE) 796 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 797 } 798 pmap_qremove(kva, count); 799 800 /* 801 * free the buffer header back to the swap buffer pool 802 */ 803 relpbuf(bp, &vnode_pbuf_freecnt); 804 805 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 806 vm_page_t mt; 807 808 nextoff = tfoff + PAGE_SIZE; 809 mt = m[i]; 810 811 if (nextoff <= object->un_pager.vnp.vnp_size) { 812 /* 813 * Read filled up entire page. 814 */ 815 mt->valid = VM_PAGE_BITS_ALL; 816 vm_page_undirty(mt); /* should be an assert? XXX */ 817 pmap_clear_modify(mt); 818 } else { 819 /* 820 * Read did not fill up entire page. Since this 821 * is getpages, the page may be mapped, so we have 822 * to zero the invalid portions of the page even 823 * though we aren't setting them valid. 824 * 825 * Currently we do not set the entire page valid, 826 * we just try to clear the piece that we couldn't 827 * read. 828 */ 829 vm_page_set_validclean(mt, 0, 830 object->un_pager.vnp.vnp_size - tfoff); 831 /* handled by vm_fault now */ 832 /* vm_page_zero_invalid(mt, FALSE); */ 833 } 834 835 vm_page_flag_clear(mt, PG_ZERO); 836 if (i != reqpage) { 837 838 /* 839 * whether or not to leave the page activated is up in 840 * the air, but we should put the page on a page queue 841 * somewhere. (it already is in the object). Result: 842 * It appears that empirical results show that 843 * deactivating pages is best. 844 */ 845 846 /* 847 * just in case someone was asking for this page we 848 * now tell them that it is ok to use 849 */ 850 if (!error) { 851 if (mt->flags & PG_WANTED) 852 vm_page_activate(mt); 853 else 854 vm_page_deactivate(mt); 855 vm_page_wakeup(mt); 856 } else { 857 vnode_pager_freepage(mt); 858 } 859 } 860 } 861 if (error) { 862 printf("vnode_pager_getpages: I/O read error\n"); 863 } 864 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 865 } 866 867 /* 868 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 869 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 870 * vnode_pager_generic_putpages() to implement the previous behaviour. 871 * 872 * All other FS's should use the bypass to get to the local media 873 * backing vp's VOP_PUTPAGES. 874 */ 875 static void 876 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 877 boolean_t sync, int *rtvals) 878 { 879 int rtval; 880 struct vnode *vp; 881 int bytes = count * PAGE_SIZE; 882 883 /* 884 * Force synchronous operation if we are extremely low on memory 885 * to prevent a low-memory deadlock. VOP operations often need to 886 * allocate more memory to initiate the I/O ( i.e. do a BMAP 887 * operation ). The swapper handles the case by limiting the amount 888 * of asynchronous I/O, but that sort of solution doesn't scale well 889 * for the vnode pager without a lot of work. 890 * 891 * Also, the backing vnode's iodone routine may not wake the pageout 892 * daemon up. This should be probably be addressed XXX. 893 */ 894 895 if ((vmstats.v_free_count + vmstats.v_cache_count) < vmstats.v_pageout_free_min) 896 sync |= OBJPC_SYNC; 897 898 /* 899 * Call device-specific putpages function 900 */ 901 902 vp = object->handle; 903 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 904 if (rtval == EOPNOTSUPP) { 905 printf("vnode_pager: *** WARNING *** stale FS putpages\n"); 906 rtval = vnode_pager_generic_putpages( vp, m, bytes, sync, rtvals); 907 } 908 } 909 910 911 /* 912 * This is now called from local media FS's to operate against their 913 * own vnodes if they fail to implement VOP_PUTPAGES. 914 * 915 * This is typically called indirectly via the pageout daemon and 916 * clustering has already typically occured, so in general we ask the 917 * underlying filesystem to write the data out asynchronously rather 918 * then delayed. 919 */ 920 int 921 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *m, int bytecount, 922 int flags, int *rtvals) 923 { 924 int i; 925 vm_object_t object; 926 int count; 927 928 int maxsize, ncount; 929 vm_ooffset_t poffset; 930 struct uio auio; 931 struct iovec aiov; 932 int error; 933 int ioflags; 934 935 object = vp->v_object; 936 count = bytecount / PAGE_SIZE; 937 938 for (i = 0; i < count; i++) 939 rtvals[i] = VM_PAGER_AGAIN; 940 941 if ((int) m[0]->pindex < 0) { 942 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%x)\n", 943 (long)m[0]->pindex, m[0]->dirty); 944 rtvals[0] = VM_PAGER_BAD; 945 return VM_PAGER_BAD; 946 } 947 948 maxsize = count * PAGE_SIZE; 949 ncount = count; 950 951 poffset = IDX_TO_OFF(m[0]->pindex); 952 953 /* 954 * If the page-aligned write is larger then the actual file we 955 * have to invalidate pages occuring beyond the file EOF. However, 956 * there is an edge case where a file may not be page-aligned where 957 * the last page is partially invalid. In this case the filesystem 958 * may not properly clear the dirty bits for the entire page (which 959 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 960 * With the page locked we are free to fix-up the dirty bits here. 961 * 962 * We do not under any circumstances truncate the valid bits, as 963 * this will screw up bogus page replacement. 964 */ 965 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 966 if (object->un_pager.vnp.vnp_size > poffset) { 967 int pgoff; 968 969 maxsize = object->un_pager.vnp.vnp_size - poffset; 970 ncount = btoc(maxsize); 971 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 972 vm_page_clear_dirty(m[ncount - 1], pgoff, 973 PAGE_SIZE - pgoff); 974 } 975 } else { 976 maxsize = 0; 977 ncount = 0; 978 } 979 if (ncount < count) { 980 for (i = ncount; i < count; i++) { 981 rtvals[i] = VM_PAGER_BAD; 982 } 983 } 984 } 985 986 /* 987 * pageouts are already clustered, use IO_ASYNC to force a bawrite() 988 * rather then a bdwrite() to prevent paging I/O from saturating 989 * the buffer cache. Dummy-up the sequential heuristic to cause 990 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 991 * the system decides how to cluster. 992 */ 993 ioflags = IO_VMIO; 994 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 995 ioflags |= IO_SYNC; 996 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 997 ioflags |= IO_ASYNC; 998 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 999 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1000 1001 aiov.iov_base = (caddr_t) 0; 1002 aiov.iov_len = maxsize; 1003 auio.uio_iov = &aiov; 1004 auio.uio_iovcnt = 1; 1005 auio.uio_offset = poffset; 1006 auio.uio_segflg = UIO_NOCOPY; 1007 auio.uio_rw = UIO_WRITE; 1008 auio.uio_resid = maxsize; 1009 auio.uio_td = NULL; 1010 error = VOP_WRITE(vp, &auio, ioflags, proc0.p_ucred); 1011 mycpu->gd_cnt.v_vnodeout++; 1012 mycpu->gd_cnt.v_vnodepgsout += ncount; 1013 1014 if (error) { 1015 printf("vnode_pager_putpages: I/O error %d\n", error); 1016 } 1017 if (auio.uio_resid) { 1018 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1019 auio.uio_resid, (u_long)m[0]->pindex); 1020 } 1021 for (i = 0; i < ncount; i++) { 1022 rtvals[i] = VM_PAGER_OK; 1023 } 1024 return rtvals[0]; 1025 } 1026 1027 struct vnode * 1028 vnode_pager_lock(vm_object_t object) 1029 { 1030 struct thread *td = curthread; /* XXX */ 1031 int error; 1032 1033 for (; object != NULL; object = object->backing_object) { 1034 if (object->type != OBJT_VNODE) 1035 continue; 1036 if (object->flags & OBJ_DEAD) 1037 return NULL; 1038 1039 for (;;) { 1040 struct vnode *vp = object->handle; 1041 error = vget(vp, LK_NOPAUSE | LK_SHARED | 1042 LK_RETRY | LK_CANRECURSE, td); 1043 if (error == 0) { 1044 if (object->handle != vp) { 1045 vput(vp); 1046 continue; 1047 } 1048 return (vp); 1049 } 1050 if ((object->flags & OBJ_DEAD) || 1051 (object->type != OBJT_VNODE)) { 1052 return NULL; 1053 } 1054 printf("vnode_pager_lock: vp %p error %d lockstatus %d, retrying\n", vp, error, lockstatus(&vp->v_lock, td)); 1055 tsleep(object->handle, 0, "vnpgrl", hz); 1056 } 1057 } 1058 return NULL; 1059 } 1060