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/limits.h> 65 #include <sys/conf.h> 66 #include <sys/sf_buf.h> 67 68 #include <machine/atomic.h> 69 70 #include <vm/vm.h> 71 #include <vm/vm_object.h> 72 #include <vm/vm_page.h> 73 #include <vm/vm_pager.h> 74 #include <vm/vm_map.h> 75 #include <vm/vnode_pager.h> 76 #include <vm/vm_extern.h> 77 78 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 79 daddr_t *rtaddress, int *run); 80 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 81 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 82 static void vnode_pager_dealloc(vm_object_t); 83 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int); 84 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); 85 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 86 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 87 vm_ooffset_t, struct ucred *cred); 88 89 struct pagerops vnodepagerops = { 90 .pgo_alloc = vnode_pager_alloc, 91 .pgo_dealloc = vnode_pager_dealloc, 92 .pgo_getpages = vnode_pager_getpages, 93 .pgo_putpages = vnode_pager_putpages, 94 .pgo_haspage = vnode_pager_haspage, 95 }; 96 97 int vnode_pbuf_freecnt; 98 99 /* Create the VM system backing object for this vnode */ 100 int 101 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 102 { 103 vm_object_t object; 104 vm_ooffset_t size = isize; 105 struct vattr va; 106 107 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 108 return (0); 109 110 while ((object = vp->v_object) != NULL) { 111 VM_OBJECT_LOCK(object); 112 if (!(object->flags & OBJ_DEAD)) { 113 VM_OBJECT_UNLOCK(object); 114 return (0); 115 } 116 VOP_UNLOCK(vp, 0); 117 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 118 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0); 119 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 120 } 121 122 if (size == 0) { 123 if (vn_isdisk(vp, NULL)) { 124 size = IDX_TO_OFF(INT_MAX); 125 } else { 126 if (VOP_GETATTR(vp, &va, td->td_ucred)) 127 return (0); 128 size = va.va_size; 129 } 130 } 131 132 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 133 /* 134 * Dereference the reference we just created. This assumes 135 * that the object is associated with the vp. 136 */ 137 VM_OBJECT_LOCK(object); 138 object->ref_count--; 139 VM_OBJECT_UNLOCK(object); 140 vrele(vp); 141 142 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 143 144 return (0); 145 } 146 147 void 148 vnode_destroy_vobject(struct vnode *vp) 149 { 150 struct vm_object *obj; 151 152 obj = vp->v_object; 153 if (obj == NULL) 154 return; 155 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 156 VM_OBJECT_LOCK(obj); 157 if (obj->ref_count == 0) { 158 /* 159 * vclean() may be called twice. The first time 160 * removes the primary reference to the object, 161 * the second time goes one further and is a 162 * special-case to terminate the object. 163 * 164 * don't double-terminate the object 165 */ 166 if ((obj->flags & OBJ_DEAD) == 0) 167 vm_object_terminate(obj); 168 else 169 VM_OBJECT_UNLOCK(obj); 170 } else { 171 /* 172 * Woe to the process that tries to page now :-). 173 */ 174 vm_pager_deallocate(obj); 175 VM_OBJECT_UNLOCK(obj); 176 } 177 vp->v_object = NULL; 178 } 179 180 181 /* 182 * Allocate (or lookup) pager for a vnode. 183 * Handle is a vnode pointer. 184 * 185 * MPSAFE 186 */ 187 vm_object_t 188 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 189 vm_ooffset_t offset, struct ucred *cred) 190 { 191 vm_object_t object; 192 struct vnode *vp; 193 194 /* 195 * Pageout to vnode, no can do yet. 196 */ 197 if (handle == NULL) 198 return (NULL); 199 200 vp = (struct vnode *) handle; 201 202 /* 203 * If the object is being terminated, wait for it to 204 * go away. 205 */ 206 retry: 207 while ((object = vp->v_object) != NULL) { 208 VM_OBJECT_LOCK(object); 209 if ((object->flags & OBJ_DEAD) == 0) 210 break; 211 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 212 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0); 213 } 214 215 if (vp->v_usecount == 0) 216 panic("vnode_pager_alloc: no vnode reference"); 217 218 if (object == NULL) { 219 /* 220 * Add an object of the appropriate size 221 */ 222 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 223 224 object->un_pager.vnp.vnp_size = size; 225 226 object->handle = handle; 227 VI_LOCK(vp); 228 if (vp->v_object != NULL) { 229 /* 230 * Object has been created while we were sleeping 231 */ 232 VI_UNLOCK(vp); 233 vm_object_destroy(object); 234 goto retry; 235 } 236 vp->v_object = object; 237 VI_UNLOCK(vp); 238 } else { 239 object->ref_count++; 240 VM_OBJECT_UNLOCK(object); 241 } 242 vref(vp); 243 return (object); 244 } 245 246 /* 247 * The object must be locked. 248 */ 249 static void 250 vnode_pager_dealloc(object) 251 vm_object_t object; 252 { 253 struct vnode *vp; 254 int refs; 255 256 vp = object->handle; 257 if (vp == NULL) 258 panic("vnode_pager_dealloc: pager already dealloced"); 259 260 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 261 vm_object_pip_wait(object, "vnpdea"); 262 refs = object->ref_count; 263 264 object->handle = NULL; 265 object->type = OBJT_DEAD; 266 if (object->flags & OBJ_DISCONNECTWNT) { 267 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 268 wakeup(object); 269 } 270 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 271 vp->v_object = NULL; 272 vp->v_vflag &= ~VV_TEXT; 273 while (refs-- > 0) 274 vunref(vp); 275 } 276 277 static boolean_t 278 vnode_pager_haspage(object, pindex, before, after) 279 vm_object_t object; 280 vm_pindex_t pindex; 281 int *before; 282 int *after; 283 { 284 struct vnode *vp = object->handle; 285 daddr_t bn; 286 int err; 287 daddr_t reqblock; 288 int poff; 289 int bsize; 290 int pagesperblock, blocksperpage; 291 int vfslocked; 292 293 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 294 /* 295 * If no vp or vp is doomed or marked transparent to VM, we do not 296 * have the page. 297 */ 298 if (vp == NULL || vp->v_iflag & VI_DOOMED) 299 return FALSE; 300 /* 301 * If the offset is beyond end of file we do 302 * not have the page. 303 */ 304 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 305 return FALSE; 306 307 bsize = vp->v_mount->mnt_stat.f_iosize; 308 pagesperblock = bsize / PAGE_SIZE; 309 blocksperpage = 0; 310 if (pagesperblock > 0) { 311 reqblock = pindex / pagesperblock; 312 } else { 313 blocksperpage = (PAGE_SIZE / bsize); 314 reqblock = pindex * blocksperpage; 315 } 316 VM_OBJECT_UNLOCK(object); 317 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 318 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 319 VFS_UNLOCK_GIANT(vfslocked); 320 VM_OBJECT_LOCK(object); 321 if (err) 322 return TRUE; 323 if (bn == -1) 324 return FALSE; 325 if (pagesperblock > 0) { 326 poff = pindex - (reqblock * pagesperblock); 327 if (before) { 328 *before *= pagesperblock; 329 *before += poff; 330 } 331 if (after) { 332 int numafter; 333 *after *= pagesperblock; 334 numafter = pagesperblock - (poff + 1); 335 if (IDX_TO_OFF(pindex + numafter) > 336 object->un_pager.vnp.vnp_size) { 337 numafter = 338 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 339 pindex; 340 } 341 *after += numafter; 342 } 343 } else { 344 if (before) { 345 *before /= blocksperpage; 346 } 347 348 if (after) { 349 *after /= blocksperpage; 350 } 351 } 352 return TRUE; 353 } 354 355 /* 356 * Lets the VM system know about a change in size for a file. 357 * We adjust our own internal size and flush any cached pages in 358 * the associated object that are affected by the size change. 359 * 360 * Note: this routine may be invoked as a result of a pager put 361 * operation (possibly at object termination time), so we must be careful. 362 */ 363 void 364 vnode_pager_setsize(vp, nsize) 365 struct vnode *vp; 366 vm_ooffset_t nsize; 367 { 368 vm_object_t object; 369 vm_page_t m; 370 vm_pindex_t nobjsize; 371 372 if ((object = vp->v_object) == NULL) 373 return; 374 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */ 375 VM_OBJECT_LOCK(object); 376 if (nsize == object->un_pager.vnp.vnp_size) { 377 /* 378 * Hasn't changed size 379 */ 380 VM_OBJECT_UNLOCK(object); 381 return; 382 } 383 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 384 if (nsize < object->un_pager.vnp.vnp_size) { 385 /* 386 * File has shrunk. Toss any cached pages beyond the new EOF. 387 */ 388 if (nobjsize < object->size) 389 vm_object_page_remove(object, nobjsize, object->size, 390 FALSE); 391 /* 392 * this gets rid of garbage at the end of a page that is now 393 * only partially backed by the vnode. 394 * 395 * XXX for some reason (I don't know yet), if we take a 396 * completely invalid page and mark it partially valid 397 * it can screw up NFS reads, so we don't allow the case. 398 */ 399 if ((nsize & PAGE_MASK) && 400 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 401 m->valid != 0) { 402 int base = (int)nsize & PAGE_MASK; 403 int size = PAGE_SIZE - base; 404 405 /* 406 * Clear out partial-page garbage in case 407 * the page has been mapped. 408 */ 409 pmap_zero_page_area(m, base, size); 410 411 /* 412 * Update the valid bits to reflect the blocks that 413 * have been zeroed. Some of these valid bits may 414 * have already been set. 415 */ 416 vm_page_set_valid(m, base, size); 417 418 /* 419 * Round "base" to the next block boundary so that the 420 * dirty bit for a partially zeroed block is not 421 * cleared. 422 */ 423 base = roundup2(base, DEV_BSIZE); 424 425 /* 426 * Clear out partial-page dirty bits. 427 * 428 * note that we do not clear out the valid 429 * bits. This would prevent bogus_page 430 * replacement from working properly. 431 */ 432 vm_page_lock_queues(); 433 vm_page_clear_dirty(m, base, PAGE_SIZE - base); 434 vm_page_unlock_queues(); 435 } else if ((nsize & PAGE_MASK) && 436 __predict_false(object->cache != NULL)) { 437 vm_page_cache_free(object, OFF_TO_IDX(nsize), 438 nobjsize); 439 } 440 } 441 object->un_pager.vnp.vnp_size = nsize; 442 object->size = nobjsize; 443 VM_OBJECT_UNLOCK(object); 444 } 445 446 /* 447 * calculate the linear (byte) disk address of specified virtual 448 * file address 449 */ 450 static int 451 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 452 int *run) 453 { 454 int bsize; 455 int err; 456 daddr_t vblock; 457 daddr_t voffset; 458 459 if (address < 0) 460 return -1; 461 462 if (vp->v_iflag & VI_DOOMED) 463 return -1; 464 465 bsize = vp->v_mount->mnt_stat.f_iosize; 466 vblock = address / bsize; 467 voffset = address % bsize; 468 469 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 470 if (err == 0) { 471 if (*rtaddress != -1) 472 *rtaddress += voffset / DEV_BSIZE; 473 if (run) { 474 *run += 1; 475 *run *= bsize/PAGE_SIZE; 476 *run -= voffset/PAGE_SIZE; 477 } 478 } 479 480 return (err); 481 } 482 483 /* 484 * small block filesystem vnode pager input 485 */ 486 static int 487 vnode_pager_input_smlfs(object, m) 488 vm_object_t object; 489 vm_page_t m; 490 { 491 int bits, i; 492 struct vnode *vp; 493 struct bufobj *bo; 494 struct buf *bp; 495 struct sf_buf *sf; 496 daddr_t fileaddr; 497 vm_offset_t bsize; 498 int error = 0; 499 500 vp = object->handle; 501 if (vp->v_iflag & VI_DOOMED) 502 return VM_PAGER_BAD; 503 504 bsize = vp->v_mount->mnt_stat.f_iosize; 505 506 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 507 508 sf = sf_buf_alloc(m, 0); 509 510 for (i = 0; i < PAGE_SIZE / bsize; i++) { 511 vm_ooffset_t address; 512 513 bits = vm_page_bits(i * bsize, bsize); 514 if (m->valid & bits) 515 continue; 516 517 address = IDX_TO_OFF(m->pindex) + i * bsize; 518 if (address >= object->un_pager.vnp.vnp_size) { 519 fileaddr = -1; 520 } else { 521 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 522 if (error) 523 break; 524 } 525 if (fileaddr != -1) { 526 bp = getpbuf(&vnode_pbuf_freecnt); 527 528 /* build a minimal buffer header */ 529 bp->b_iocmd = BIO_READ; 530 bp->b_iodone = bdone; 531 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 532 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 533 bp->b_rcred = crhold(curthread->td_ucred); 534 bp->b_wcred = crhold(curthread->td_ucred); 535 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 536 bp->b_blkno = fileaddr; 537 pbgetbo(bo, bp); 538 bp->b_bcount = bsize; 539 bp->b_bufsize = bsize; 540 bp->b_runningbufspace = bp->b_bufsize; 541 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 542 543 /* do the input */ 544 bp->b_iooffset = dbtob(bp->b_blkno); 545 bstrategy(bp); 546 547 bwait(bp, PVM, "vnsrd"); 548 549 if ((bp->b_ioflags & BIO_ERROR) != 0) 550 error = EIO; 551 552 /* 553 * free the buffer header back to the swap buffer pool 554 */ 555 pbrelbo(bp); 556 relpbuf(bp, &vnode_pbuf_freecnt); 557 if (error) 558 break; 559 } else 560 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 561 KASSERT((m->dirty & bits) == 0, 562 ("vnode_pager_input_smlfs: page %p is dirty", m)); 563 VM_OBJECT_LOCK(object); 564 m->valid |= bits; 565 VM_OBJECT_UNLOCK(object); 566 } 567 sf_buf_free(sf); 568 if (error) { 569 return VM_PAGER_ERROR; 570 } 571 return VM_PAGER_OK; 572 } 573 574 /* 575 * old style vnode pager input routine 576 */ 577 static int 578 vnode_pager_input_old(object, m) 579 vm_object_t object; 580 vm_page_t m; 581 { 582 struct uio auio; 583 struct iovec aiov; 584 int error; 585 int size; 586 struct sf_buf *sf; 587 struct vnode *vp; 588 589 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 590 error = 0; 591 592 /* 593 * Return failure if beyond current EOF 594 */ 595 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 596 return VM_PAGER_BAD; 597 } else { 598 size = PAGE_SIZE; 599 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 600 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 601 vp = object->handle; 602 VM_OBJECT_UNLOCK(object); 603 604 /* 605 * Allocate a kernel virtual address and initialize so that 606 * we can use VOP_READ/WRITE routines. 607 */ 608 sf = sf_buf_alloc(m, 0); 609 610 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 611 aiov.iov_len = size; 612 auio.uio_iov = &aiov; 613 auio.uio_iovcnt = 1; 614 auio.uio_offset = IDX_TO_OFF(m->pindex); 615 auio.uio_segflg = UIO_SYSSPACE; 616 auio.uio_rw = UIO_READ; 617 auio.uio_resid = size; 618 auio.uio_td = curthread; 619 620 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 621 if (!error) { 622 int count = size - auio.uio_resid; 623 624 if (count == 0) 625 error = EINVAL; 626 else if (count != PAGE_SIZE) 627 bzero((caddr_t)sf_buf_kva(sf) + count, 628 PAGE_SIZE - count); 629 } 630 sf_buf_free(sf); 631 632 VM_OBJECT_LOCK(object); 633 } 634 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 635 if (!error) 636 m->valid = VM_PAGE_BITS_ALL; 637 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 638 } 639 640 /* 641 * generic vnode pager input routine 642 */ 643 644 /* 645 * Local media VFS's that do not implement their own VOP_GETPAGES 646 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 647 * to implement the previous behaviour. 648 * 649 * All other FS's should use the bypass to get to the local media 650 * backing vp's VOP_GETPAGES. 651 */ 652 static int 653 vnode_pager_getpages(object, m, count, reqpage) 654 vm_object_t object; 655 vm_page_t *m; 656 int count; 657 int reqpage; 658 { 659 int rtval; 660 struct vnode *vp; 661 int bytes = count * PAGE_SIZE; 662 int vfslocked; 663 664 vp = object->handle; 665 VM_OBJECT_UNLOCK(object); 666 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 667 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 668 KASSERT(rtval != EOPNOTSUPP, 669 ("vnode_pager: FS getpages not implemented\n")); 670 VFS_UNLOCK_GIANT(vfslocked); 671 VM_OBJECT_LOCK(object); 672 return rtval; 673 } 674 675 /* 676 * This is now called from local media FS's to operate against their 677 * own vnodes if they fail to implement VOP_GETPAGES. 678 */ 679 int 680 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 681 struct vnode *vp; 682 vm_page_t *m; 683 int bytecount; 684 int reqpage; 685 { 686 vm_object_t object; 687 vm_offset_t kva; 688 off_t foff, tfoff, nextoff; 689 int i, j, size, bsize, first; 690 daddr_t firstaddr, reqblock; 691 struct bufobj *bo; 692 int runpg; 693 int runend; 694 struct buf *bp; 695 int count; 696 int error; 697 698 object = vp->v_object; 699 count = bytecount / PAGE_SIZE; 700 701 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 702 ("vnode_pager_generic_getpages does not support devices")); 703 if (vp->v_iflag & VI_DOOMED) 704 return VM_PAGER_BAD; 705 706 bsize = vp->v_mount->mnt_stat.f_iosize; 707 708 /* get the UNDERLYING device for the file with VOP_BMAP() */ 709 710 /* 711 * originally, we did not check for an error return value -- assuming 712 * an fs always has a bmap entry point -- that assumption is wrong!!! 713 */ 714 foff = IDX_TO_OFF(m[reqpage]->pindex); 715 716 /* 717 * if we can't bmap, use old VOP code 718 */ 719 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL); 720 if (error == EOPNOTSUPP) { 721 VM_OBJECT_LOCK(object); 722 vm_page_lock_queues(); 723 for (i = 0; i < count; i++) 724 if (i != reqpage) 725 vm_page_free(m[i]); 726 vm_page_unlock_queues(); 727 PCPU_INC(cnt.v_vnodein); 728 PCPU_INC(cnt.v_vnodepgsin); 729 error = vnode_pager_input_old(object, m[reqpage]); 730 VM_OBJECT_UNLOCK(object); 731 return (error); 732 } else if (error != 0) { 733 VM_OBJECT_LOCK(object); 734 vm_page_lock_queues(); 735 for (i = 0; i < count; i++) 736 if (i != reqpage) 737 vm_page_free(m[i]); 738 vm_page_unlock_queues(); 739 VM_OBJECT_UNLOCK(object); 740 return (VM_PAGER_ERROR); 741 742 /* 743 * if the blocksize is smaller than a page size, then use 744 * special small filesystem code. NFS sometimes has a small 745 * blocksize, but it can handle large reads itself. 746 */ 747 } else if ((PAGE_SIZE / bsize) > 1 && 748 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 749 VM_OBJECT_LOCK(object); 750 vm_page_lock_queues(); 751 for (i = 0; i < count; i++) 752 if (i != reqpage) 753 vm_page_free(m[i]); 754 vm_page_unlock_queues(); 755 VM_OBJECT_UNLOCK(object); 756 PCPU_INC(cnt.v_vnodein); 757 PCPU_INC(cnt.v_vnodepgsin); 758 return vnode_pager_input_smlfs(object, m[reqpage]); 759 } 760 761 /* 762 * If we have a completely valid page available to us, we can 763 * clean up and return. Otherwise we have to re-read the 764 * media. 765 */ 766 VM_OBJECT_LOCK(object); 767 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 768 vm_page_lock_queues(); 769 for (i = 0; i < count; i++) 770 if (i != reqpage) 771 vm_page_free(m[i]); 772 vm_page_unlock_queues(); 773 VM_OBJECT_UNLOCK(object); 774 return VM_PAGER_OK; 775 } else if (reqblock == -1) { 776 pmap_zero_page(m[reqpage]); 777 KASSERT(m[reqpage]->dirty == 0, 778 ("vnode_pager_generic_getpages: page %p is dirty", m)); 779 m[reqpage]->valid = VM_PAGE_BITS_ALL; 780 vm_page_lock_queues(); 781 for (i = 0; i < count; i++) 782 if (i != reqpage) 783 vm_page_free(m[i]); 784 vm_page_unlock_queues(); 785 VM_OBJECT_UNLOCK(object); 786 return (VM_PAGER_OK); 787 } 788 m[reqpage]->valid = 0; 789 VM_OBJECT_UNLOCK(object); 790 791 /* 792 * here on direct device I/O 793 */ 794 firstaddr = -1; 795 796 /* 797 * calculate the run that includes the required page 798 */ 799 for (first = 0, i = 0; i < count; i = runend) { 800 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, 801 &runpg) != 0) { 802 VM_OBJECT_LOCK(object); 803 vm_page_lock_queues(); 804 for (; i < count; i++) 805 if (i != reqpage) 806 vm_page_free(m[i]); 807 vm_page_unlock_queues(); 808 VM_OBJECT_UNLOCK(object); 809 return (VM_PAGER_ERROR); 810 } 811 if (firstaddr == -1) { 812 VM_OBJECT_LOCK(object); 813 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 814 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 815 (intmax_t)firstaddr, (uintmax_t)(foff >> 32), 816 (uintmax_t)foff, 817 (uintmax_t) 818 (object->un_pager.vnp.vnp_size >> 32), 819 (uintmax_t)object->un_pager.vnp.vnp_size); 820 } 821 vm_page_lock_queues(); 822 vm_page_free(m[i]); 823 vm_page_unlock_queues(); 824 VM_OBJECT_UNLOCK(object); 825 runend = i + 1; 826 first = runend; 827 continue; 828 } 829 runend = i + runpg; 830 if (runend <= reqpage) { 831 VM_OBJECT_LOCK(object); 832 vm_page_lock_queues(); 833 for (j = i; j < runend; j++) 834 vm_page_free(m[j]); 835 vm_page_unlock_queues(); 836 VM_OBJECT_UNLOCK(object); 837 } else { 838 if (runpg < (count - first)) { 839 VM_OBJECT_LOCK(object); 840 vm_page_lock_queues(); 841 for (i = first + runpg; i < count; i++) 842 vm_page_free(m[i]); 843 vm_page_unlock_queues(); 844 VM_OBJECT_UNLOCK(object); 845 count = first + runpg; 846 } 847 break; 848 } 849 first = runend; 850 } 851 852 /* 853 * the first and last page have been calculated now, move input pages 854 * to be zero based... 855 */ 856 if (first != 0) { 857 m += first; 858 count -= first; 859 reqpage -= first; 860 } 861 862 /* 863 * calculate the file virtual address for the transfer 864 */ 865 foff = IDX_TO_OFF(m[0]->pindex); 866 867 /* 868 * calculate the size of the transfer 869 */ 870 size = count * PAGE_SIZE; 871 KASSERT(count > 0, ("zero count")); 872 if ((foff + size) > object->un_pager.vnp.vnp_size) 873 size = object->un_pager.vnp.vnp_size - foff; 874 KASSERT(size > 0, ("zero size")); 875 876 /* 877 * round up physical size for real devices. 878 */ 879 if (1) { 880 int secmask = bo->bo_bsize - 1; 881 KASSERT(secmask < PAGE_SIZE && secmask > 0, 882 ("vnode_pager_generic_getpages: sector size %d too large", 883 secmask + 1)); 884 size = (size + secmask) & ~secmask; 885 } 886 887 bp = getpbuf(&vnode_pbuf_freecnt); 888 kva = (vm_offset_t) bp->b_data; 889 890 /* 891 * and map the pages to be read into the kva 892 */ 893 pmap_qenter(kva, m, count); 894 895 /* build a minimal buffer header */ 896 bp->b_iocmd = BIO_READ; 897 bp->b_iodone = bdone; 898 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 899 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 900 bp->b_rcred = crhold(curthread->td_ucred); 901 bp->b_wcred = crhold(curthread->td_ucred); 902 bp->b_blkno = firstaddr; 903 pbgetbo(bo, bp); 904 bp->b_bcount = size; 905 bp->b_bufsize = size; 906 bp->b_runningbufspace = bp->b_bufsize; 907 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 908 909 PCPU_INC(cnt.v_vnodein); 910 PCPU_ADD(cnt.v_vnodepgsin, count); 911 912 /* do the input */ 913 bp->b_iooffset = dbtob(bp->b_blkno); 914 bstrategy(bp); 915 916 bwait(bp, PVM, "vnread"); 917 918 if ((bp->b_ioflags & BIO_ERROR) != 0) 919 error = EIO; 920 921 if (!error) { 922 if (size != count * PAGE_SIZE) 923 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 924 } 925 pmap_qremove(kva, count); 926 927 /* 928 * free the buffer header back to the swap buffer pool 929 */ 930 pbrelbo(bp); 931 relpbuf(bp, &vnode_pbuf_freecnt); 932 933 VM_OBJECT_LOCK(object); 934 vm_page_lock_queues(); 935 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 936 vm_page_t mt; 937 938 nextoff = tfoff + PAGE_SIZE; 939 mt = m[i]; 940 941 if (nextoff <= object->un_pager.vnp.vnp_size) { 942 /* 943 * Read filled up entire page. 944 */ 945 mt->valid = VM_PAGE_BITS_ALL; 946 KASSERT(mt->dirty == 0, 947 ("vnode_pager_generic_getpages: page %p is dirty", 948 mt)); 949 KASSERT(!pmap_page_is_mapped(mt), 950 ("vnode_pager_generic_getpages: page %p is mapped", 951 mt)); 952 } else { 953 /* 954 * Read did not fill up entire page. 955 * 956 * Currently we do not set the entire page valid, 957 * we just try to clear the piece that we couldn't 958 * read. 959 */ 960 vm_page_set_valid(mt, 0, 961 object->un_pager.vnp.vnp_size - tfoff); 962 KASSERT((mt->dirty & vm_page_bits(0, 963 object->un_pager.vnp.vnp_size - tfoff)) == 0, 964 ("vnode_pager_generic_getpages: page %p is dirty", 965 mt)); 966 } 967 968 if (i != reqpage) { 969 970 /* 971 * whether or not to leave the page activated is up in 972 * the air, but we should put the page on a page queue 973 * somewhere. (it already is in the object). Result: 974 * It appears that empirical results show that 975 * deactivating pages is best. 976 */ 977 978 /* 979 * just in case someone was asking for this page we 980 * now tell them that it is ok to use 981 */ 982 if (!error) { 983 if (mt->oflags & VPO_WANTED) 984 vm_page_activate(mt); 985 else 986 vm_page_deactivate(mt); 987 vm_page_wakeup(mt); 988 } else { 989 vm_page_free(mt); 990 } 991 } 992 } 993 vm_page_unlock_queues(); 994 VM_OBJECT_UNLOCK(object); 995 if (error) { 996 printf("vnode_pager_getpages: I/O read error\n"); 997 } 998 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 999 } 1000 1001 /* 1002 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1003 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1004 * vnode_pager_generic_putpages() to implement the previous behaviour. 1005 * 1006 * All other FS's should use the bypass to get to the local media 1007 * backing vp's VOP_PUTPAGES. 1008 */ 1009 static void 1010 vnode_pager_putpages(object, m, count, sync, rtvals) 1011 vm_object_t object; 1012 vm_page_t *m; 1013 int count; 1014 boolean_t sync; 1015 int *rtvals; 1016 { 1017 int rtval; 1018 struct vnode *vp; 1019 int bytes = count * PAGE_SIZE; 1020 1021 /* 1022 * Force synchronous operation if we are extremely low on memory 1023 * to prevent a low-memory deadlock. VOP operations often need to 1024 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1025 * operation ). The swapper handles the case by limiting the amount 1026 * of asynchronous I/O, but that sort of solution doesn't scale well 1027 * for the vnode pager without a lot of work. 1028 * 1029 * Also, the backing vnode's iodone routine may not wake the pageout 1030 * daemon up. This should be probably be addressed XXX. 1031 */ 1032 1033 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 1034 sync |= OBJPC_SYNC; 1035 1036 /* 1037 * Call device-specific putpages function 1038 */ 1039 vp = object->handle; 1040 VM_OBJECT_UNLOCK(object); 1041 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 1042 KASSERT(rtval != EOPNOTSUPP, 1043 ("vnode_pager: stale FS putpages\n")); 1044 VM_OBJECT_LOCK(object); 1045 } 1046 1047 1048 /* 1049 * This is now called from local media FS's to operate against their 1050 * own vnodes if they fail to implement VOP_PUTPAGES. 1051 * 1052 * This is typically called indirectly via the pageout daemon and 1053 * clustering has already typically occured, so in general we ask the 1054 * underlying filesystem to write the data out asynchronously rather 1055 * then delayed. 1056 */ 1057 int 1058 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 1059 struct vnode *vp; 1060 vm_page_t *m; 1061 int bytecount; 1062 int flags; 1063 int *rtvals; 1064 { 1065 int i; 1066 vm_object_t object; 1067 int count; 1068 1069 int maxsize, ncount; 1070 vm_ooffset_t poffset; 1071 struct uio auio; 1072 struct iovec aiov; 1073 int error; 1074 int ioflags; 1075 int ppscheck = 0; 1076 static struct timeval lastfail; 1077 static int curfail; 1078 1079 object = vp->v_object; 1080 count = bytecount / PAGE_SIZE; 1081 1082 for (i = 0; i < count; i++) 1083 rtvals[i] = VM_PAGER_AGAIN; 1084 1085 if ((int64_t)m[0]->pindex < 0) { 1086 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1087 (long)m[0]->pindex, (u_long)m[0]->dirty); 1088 rtvals[0] = VM_PAGER_BAD; 1089 return VM_PAGER_BAD; 1090 } 1091 1092 maxsize = count * PAGE_SIZE; 1093 ncount = count; 1094 1095 poffset = IDX_TO_OFF(m[0]->pindex); 1096 1097 /* 1098 * If the page-aligned write is larger then the actual file we 1099 * have to invalidate pages occuring beyond the file EOF. However, 1100 * there is an edge case where a file may not be page-aligned where 1101 * the last page is partially invalid. In this case the filesystem 1102 * may not properly clear the dirty bits for the entire page (which 1103 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1104 * With the page locked we are free to fix-up the dirty bits here. 1105 * 1106 * We do not under any circumstances truncate the valid bits, as 1107 * this will screw up bogus page replacement. 1108 */ 1109 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1110 if (object->un_pager.vnp.vnp_size > poffset) { 1111 int pgoff; 1112 1113 maxsize = object->un_pager.vnp.vnp_size - poffset; 1114 ncount = btoc(maxsize); 1115 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1116 vm_page_lock_queues(); 1117 vm_page_clear_dirty(m[ncount - 1], pgoff, 1118 PAGE_SIZE - pgoff); 1119 vm_page_unlock_queues(); 1120 } 1121 } else { 1122 maxsize = 0; 1123 ncount = 0; 1124 } 1125 if (ncount < count) { 1126 for (i = ncount; i < count; i++) { 1127 rtvals[i] = VM_PAGER_BAD; 1128 } 1129 } 1130 } 1131 1132 /* 1133 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1134 * rather then a bdwrite() to prevent paging I/O from saturating 1135 * the buffer cache. Dummy-up the sequential heuristic to cause 1136 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1137 * the system decides how to cluster. 1138 */ 1139 ioflags = IO_VMIO; 1140 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1141 ioflags |= IO_SYNC; 1142 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1143 ioflags |= IO_ASYNC; 1144 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1145 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1146 1147 aiov.iov_base = (caddr_t) 0; 1148 aiov.iov_len = maxsize; 1149 auio.uio_iov = &aiov; 1150 auio.uio_iovcnt = 1; 1151 auio.uio_offset = poffset; 1152 auio.uio_segflg = UIO_NOCOPY; 1153 auio.uio_rw = UIO_WRITE; 1154 auio.uio_resid = maxsize; 1155 auio.uio_td = (struct thread *) 0; 1156 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1157 PCPU_INC(cnt.v_vnodeout); 1158 PCPU_ADD(cnt.v_vnodepgsout, ncount); 1159 1160 if (error) { 1161 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1162 printf("vnode_pager_putpages: I/O error %d\n", error); 1163 } 1164 if (auio.uio_resid) { 1165 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1166 printf("vnode_pager_putpages: residual I/O %zd at %lu\n", 1167 auio.uio_resid, (u_long)m[0]->pindex); 1168 } 1169 for (i = 0; i < ncount; i++) { 1170 rtvals[i] = VM_PAGER_OK; 1171 } 1172 return rtvals[0]; 1173 } 1174