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/rwlock.h> 67 #include <sys/sf_buf.h> 68 69 #include <machine/atomic.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_param.h> 73 #include <vm/vm_object.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_pager.h> 76 #include <vm/vm_map.h> 77 #include <vm/vnode_pager.h> 78 #include <vm/vm_extern.h> 79 80 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 81 daddr_t *rtaddress, int *run); 82 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 83 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 84 static void vnode_pager_dealloc(vm_object_t); 85 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int); 86 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); 87 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 88 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 89 vm_ooffset_t, struct ucred *cred); 90 91 struct pagerops vnodepagerops = { 92 .pgo_alloc = vnode_pager_alloc, 93 .pgo_dealloc = vnode_pager_dealloc, 94 .pgo_getpages = vnode_pager_getpages, 95 .pgo_putpages = vnode_pager_putpages, 96 .pgo_haspage = vnode_pager_haspage, 97 }; 98 99 int vnode_pbuf_freecnt; 100 101 /* Create the VM system backing object for this vnode */ 102 int 103 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 104 { 105 vm_object_t object; 106 vm_ooffset_t size = isize; 107 struct vattr va; 108 109 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 110 return (0); 111 112 while ((object = vp->v_object) != NULL) { 113 VM_OBJECT_WLOCK(object); 114 if (!(object->flags & OBJ_DEAD)) { 115 VM_OBJECT_WUNLOCK(object); 116 return (0); 117 } 118 VOP_UNLOCK(vp, 0); 119 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 120 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vodead", 0); 121 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 122 } 123 124 if (size == 0) { 125 if (vn_isdisk(vp, NULL)) { 126 size = IDX_TO_OFF(INT_MAX); 127 } else { 128 if (VOP_GETATTR(vp, &va, td->td_ucred)) 129 return (0); 130 size = va.va_size; 131 } 132 } 133 134 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 135 /* 136 * Dereference the reference we just created. This assumes 137 * that the object is associated with the vp. 138 */ 139 VM_OBJECT_WLOCK(object); 140 object->ref_count--; 141 VM_OBJECT_WUNLOCK(object); 142 vrele(vp); 143 144 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 145 146 return (0); 147 } 148 149 void 150 vnode_destroy_vobject(struct vnode *vp) 151 { 152 struct vm_object *obj; 153 154 obj = vp->v_object; 155 if (obj == NULL) 156 return; 157 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 158 VM_OBJECT_WLOCK(obj); 159 if (obj->ref_count == 0) { 160 /* 161 * don't double-terminate the object 162 */ 163 if ((obj->flags & OBJ_DEAD) == 0) 164 vm_object_terminate(obj); 165 else 166 VM_OBJECT_WUNLOCK(obj); 167 } else { 168 /* 169 * Woe to the process that tries to page now :-). 170 */ 171 vm_pager_deallocate(obj); 172 VM_OBJECT_WUNLOCK(obj); 173 } 174 vp->v_object = NULL; 175 } 176 177 178 /* 179 * Allocate (or lookup) pager for a vnode. 180 * Handle is a vnode pointer. 181 * 182 * MPSAFE 183 */ 184 vm_object_t 185 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 186 vm_ooffset_t offset, struct ucred *cred) 187 { 188 vm_object_t object; 189 struct vnode *vp; 190 191 /* 192 * Pageout to vnode, no can do yet. 193 */ 194 if (handle == NULL) 195 return (NULL); 196 197 vp = (struct vnode *) handle; 198 199 /* 200 * If the object is being terminated, wait for it to 201 * go away. 202 */ 203 retry: 204 while ((object = vp->v_object) != NULL) { 205 VM_OBJECT_WLOCK(object); 206 if ((object->flags & OBJ_DEAD) == 0) 207 break; 208 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 209 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vadead", 0); 210 } 211 212 KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference")); 213 214 if (object == NULL) { 215 /* 216 * Add an object of the appropriate size 217 */ 218 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 219 220 object->un_pager.vnp.vnp_size = size; 221 object->un_pager.vnp.writemappings = 0; 222 223 object->handle = handle; 224 VI_LOCK(vp); 225 if (vp->v_object != NULL) { 226 /* 227 * Object has been created while we were sleeping 228 */ 229 VI_UNLOCK(vp); 230 vm_object_destroy(object); 231 goto retry; 232 } 233 vp->v_object = object; 234 VI_UNLOCK(vp); 235 } else { 236 object->ref_count++; 237 VM_OBJECT_WUNLOCK(object); 238 } 239 vref(vp); 240 return (object); 241 } 242 243 /* 244 * The object must be locked. 245 */ 246 static void 247 vnode_pager_dealloc(vm_object_t object) 248 { 249 struct vnode *vp; 250 int refs; 251 252 vp = object->handle; 253 if (vp == NULL) 254 panic("vnode_pager_dealloc: pager already dealloced"); 255 256 VM_OBJECT_ASSERT_WLOCKED(object); 257 vm_object_pip_wait(object, "vnpdea"); 258 refs = object->ref_count; 259 260 object->handle = NULL; 261 object->type = OBJT_DEAD; 262 if (object->flags & OBJ_DISCONNECTWNT) { 263 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 264 wakeup(object); 265 } 266 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 267 if (object->un_pager.vnp.writemappings > 0) { 268 object->un_pager.vnp.writemappings = 0; 269 VOP_ADD_WRITECOUNT(vp, -1); 270 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 271 __func__, vp, vp->v_writecount); 272 } 273 vp->v_object = NULL; 274 VOP_UNSET_TEXT(vp); 275 VM_OBJECT_WUNLOCK(object); 276 while (refs-- > 0) 277 vunref(vp); 278 VM_OBJECT_WLOCK(object); 279 } 280 281 static boolean_t 282 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 283 int *after) 284 { 285 struct vnode *vp = object->handle; 286 daddr_t bn; 287 int err; 288 daddr_t reqblock; 289 int poff; 290 int bsize; 291 int pagesperblock, blocksperpage; 292 293 VM_OBJECT_ASSERT_WLOCKED(object); 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_WUNLOCK(object); 317 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 318 VM_OBJECT_WLOCK(object); 319 if (err) 320 return TRUE; 321 if (bn == -1) 322 return FALSE; 323 if (pagesperblock > 0) { 324 poff = pindex - (reqblock * pagesperblock); 325 if (before) { 326 *before *= pagesperblock; 327 *before += poff; 328 } 329 if (after) { 330 int numafter; 331 *after *= pagesperblock; 332 numafter = pagesperblock - (poff + 1); 333 if (IDX_TO_OFF(pindex + numafter) > 334 object->un_pager.vnp.vnp_size) { 335 numafter = 336 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 337 pindex; 338 } 339 *after += numafter; 340 } 341 } else { 342 if (before) { 343 *before /= blocksperpage; 344 } 345 346 if (after) { 347 *after /= blocksperpage; 348 } 349 } 350 return TRUE; 351 } 352 353 /* 354 * Lets the VM system know about a change in size for a file. 355 * We adjust our own internal size and flush any cached pages in 356 * the associated object that are affected by the size change. 357 * 358 * Note: this routine may be invoked as a result of a pager put 359 * operation (possibly at object termination time), so we must be careful. 360 */ 361 void 362 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 363 { 364 vm_object_t object; 365 vm_page_t m; 366 vm_pindex_t nobjsize; 367 368 if ((object = vp->v_object) == NULL) 369 return; 370 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */ 371 VM_OBJECT_WLOCK(object); 372 if (object->type == OBJT_DEAD) { 373 VM_OBJECT_WUNLOCK(object); 374 return; 375 } 376 KASSERT(object->type == OBJT_VNODE, 377 ("not vnode-backed object %p", object)); 378 if (nsize == object->un_pager.vnp.vnp_size) { 379 /* 380 * Hasn't changed size 381 */ 382 VM_OBJECT_WUNLOCK(object); 383 return; 384 } 385 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 386 if (nsize < object->un_pager.vnp.vnp_size) { 387 /* 388 * File has shrunk. Toss any cached pages beyond the new EOF. 389 */ 390 if (nobjsize < object->size) 391 vm_object_page_remove(object, nobjsize, object->size, 392 0); 393 /* 394 * this gets rid of garbage at the end of a page that is now 395 * only partially backed by the vnode. 396 * 397 * XXX for some reason (I don't know yet), if we take a 398 * completely invalid page and mark it partially valid 399 * it can screw up NFS reads, so we don't allow the case. 400 */ 401 if ((nsize & PAGE_MASK) && 402 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 403 m->valid != 0) { 404 int base = (int)nsize & PAGE_MASK; 405 int size = PAGE_SIZE - base; 406 407 /* 408 * Clear out partial-page garbage in case 409 * the page has been mapped. 410 */ 411 pmap_zero_page_area(m, base, size); 412 413 /* 414 * Update the valid bits to reflect the blocks that 415 * have been zeroed. Some of these valid bits may 416 * have already been set. 417 */ 418 vm_page_set_valid_range(m, base, size); 419 420 /* 421 * Round "base" to the next block boundary so that the 422 * dirty bit for a partially zeroed block is not 423 * cleared. 424 */ 425 base = roundup2(base, DEV_BSIZE); 426 427 /* 428 * Clear out partial-page dirty bits. 429 * 430 * note that we do not clear out the valid 431 * bits. This would prevent bogus_page 432 * replacement from working properly. 433 */ 434 vm_page_clear_dirty(m, base, PAGE_SIZE - base); 435 } else if ((nsize & PAGE_MASK) && 436 vm_page_is_cached(object, OFF_TO_IDX(nsize))) { 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_WUNLOCK(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(vm_object_t object, vm_page_t m) 488 { 489 struct vnode *vp; 490 struct bufobj *bo; 491 struct buf *bp; 492 struct sf_buf *sf; 493 daddr_t fileaddr; 494 vm_offset_t bsize; 495 vm_page_bits_t bits; 496 int error, i; 497 498 error = 0; 499 vp = object->handle; 500 if (vp->v_iflag & VI_DOOMED) 501 return VM_PAGER_BAD; 502 503 bsize = vp->v_mount->mnt_stat.f_iosize; 504 505 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 506 507 sf = sf_buf_alloc(m, 0); 508 509 for (i = 0; i < PAGE_SIZE / bsize; i++) { 510 vm_ooffset_t address; 511 512 bits = vm_page_bits(i * bsize, bsize); 513 if (m->valid & bits) 514 continue; 515 516 address = IDX_TO_OFF(m->pindex) + i * bsize; 517 if (address >= object->un_pager.vnp.vnp_size) { 518 fileaddr = -1; 519 } else { 520 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 521 if (error) 522 break; 523 } 524 if (fileaddr != -1) { 525 bp = getpbuf(&vnode_pbuf_freecnt); 526 527 /* build a minimal buffer header */ 528 bp->b_iocmd = BIO_READ; 529 bp->b_iodone = bdone; 530 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 531 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 532 bp->b_rcred = crhold(curthread->td_ucred); 533 bp->b_wcred = crhold(curthread->td_ucred); 534 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 535 bp->b_blkno = fileaddr; 536 pbgetbo(bo, bp); 537 bp->b_vp = vp; 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 bp->b_vp = NULL; 556 pbrelbo(bp); 557 relpbuf(bp, &vnode_pbuf_freecnt); 558 if (error) 559 break; 560 } else 561 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 562 KASSERT((m->dirty & bits) == 0, 563 ("vnode_pager_input_smlfs: page %p is dirty", m)); 564 VM_OBJECT_WLOCK(object); 565 m->valid |= bits; 566 VM_OBJECT_WUNLOCK(object); 567 } 568 sf_buf_free(sf); 569 if (error) { 570 return VM_PAGER_ERROR; 571 } 572 return VM_PAGER_OK; 573 } 574 575 /* 576 * old style vnode pager input routine 577 */ 578 static int 579 vnode_pager_input_old(vm_object_t object, vm_page_t m) 580 { 581 struct uio auio; 582 struct iovec aiov; 583 int error; 584 int size; 585 struct sf_buf *sf; 586 struct vnode *vp; 587 588 VM_OBJECT_ASSERT_WLOCKED(object); 589 error = 0; 590 591 /* 592 * Return failure if beyond current EOF 593 */ 594 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 595 return VM_PAGER_BAD; 596 } else { 597 size = PAGE_SIZE; 598 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 599 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 600 vp = object->handle; 601 VM_OBJECT_WUNLOCK(object); 602 603 /* 604 * Allocate a kernel virtual address and initialize so that 605 * we can use VOP_READ/WRITE routines. 606 */ 607 sf = sf_buf_alloc(m, 0); 608 609 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 610 aiov.iov_len = size; 611 auio.uio_iov = &aiov; 612 auio.uio_iovcnt = 1; 613 auio.uio_offset = IDX_TO_OFF(m->pindex); 614 auio.uio_segflg = UIO_SYSSPACE; 615 auio.uio_rw = UIO_READ; 616 auio.uio_resid = size; 617 auio.uio_td = curthread; 618 619 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 620 if (!error) { 621 int count = size - auio.uio_resid; 622 623 if (count == 0) 624 error = EINVAL; 625 else if (count != PAGE_SIZE) 626 bzero((caddr_t)sf_buf_kva(sf) + count, 627 PAGE_SIZE - count); 628 } 629 sf_buf_free(sf); 630 631 VM_OBJECT_WLOCK(object); 632 } 633 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 634 if (!error) 635 m->valid = VM_PAGE_BITS_ALL; 636 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 637 } 638 639 /* 640 * generic vnode pager input routine 641 */ 642 643 /* 644 * Local media VFS's that do not implement their own VOP_GETPAGES 645 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 646 * to implement the previous behaviour. 647 * 648 * All other FS's should use the bypass to get to the local media 649 * backing vp's VOP_GETPAGES. 650 */ 651 static int 652 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage) 653 { 654 int rtval; 655 struct vnode *vp; 656 int bytes = count * PAGE_SIZE; 657 658 vp = object->handle; 659 VM_OBJECT_WUNLOCK(object); 660 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 661 KASSERT(rtval != EOPNOTSUPP, 662 ("vnode_pager: FS getpages not implemented\n")); 663 VM_OBJECT_WLOCK(object); 664 return rtval; 665 } 666 667 /* 668 * This is now called from local media FS's to operate against their 669 * own vnodes if they fail to implement VOP_GETPAGES. 670 */ 671 int 672 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount, 673 int reqpage) 674 { 675 vm_object_t object; 676 vm_offset_t kva; 677 off_t foff, tfoff, nextoff; 678 int i, j, size, bsize, first; 679 daddr_t firstaddr, reqblock; 680 struct bufobj *bo; 681 int runpg; 682 int runend; 683 struct buf *bp; 684 struct mount *mp; 685 int count; 686 int error; 687 688 object = vp->v_object; 689 count = bytecount / PAGE_SIZE; 690 691 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 692 ("vnode_pager_generic_getpages does not support devices")); 693 if (vp->v_iflag & VI_DOOMED) 694 return VM_PAGER_BAD; 695 696 bsize = vp->v_mount->mnt_stat.f_iosize; 697 698 /* get the UNDERLYING device for the file with VOP_BMAP() */ 699 700 /* 701 * originally, we did not check for an error return value -- assuming 702 * an fs always has a bmap entry point -- that assumption is wrong!!! 703 */ 704 foff = IDX_TO_OFF(m[reqpage]->pindex); 705 706 /* 707 * if we can't bmap, use old VOP code 708 */ 709 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL); 710 if (error == EOPNOTSUPP) { 711 VM_OBJECT_WLOCK(object); 712 713 for (i = 0; i < count; i++) 714 if (i != reqpage) { 715 vm_page_lock(m[i]); 716 vm_page_free(m[i]); 717 vm_page_unlock(m[i]); 718 } 719 PCPU_INC(cnt.v_vnodein); 720 PCPU_INC(cnt.v_vnodepgsin); 721 error = vnode_pager_input_old(object, m[reqpage]); 722 VM_OBJECT_WUNLOCK(object); 723 return (error); 724 } else if (error != 0) { 725 VM_OBJECT_WLOCK(object); 726 for (i = 0; i < count; i++) 727 if (i != reqpage) { 728 vm_page_lock(m[i]); 729 vm_page_free(m[i]); 730 vm_page_unlock(m[i]); 731 } 732 VM_OBJECT_WUNLOCK(object); 733 return (VM_PAGER_ERROR); 734 735 /* 736 * if the blocksize is smaller than a page size, then use 737 * special small filesystem code. NFS sometimes has a small 738 * blocksize, but it can handle large reads itself. 739 */ 740 } else if ((PAGE_SIZE / bsize) > 1 && 741 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 742 VM_OBJECT_WLOCK(object); 743 for (i = 0; i < count; i++) 744 if (i != reqpage) { 745 vm_page_lock(m[i]); 746 vm_page_free(m[i]); 747 vm_page_unlock(m[i]); 748 } 749 VM_OBJECT_WUNLOCK(object); 750 PCPU_INC(cnt.v_vnodein); 751 PCPU_INC(cnt.v_vnodepgsin); 752 return vnode_pager_input_smlfs(object, m[reqpage]); 753 } 754 755 /* 756 * If we have a completely valid page available to us, we can 757 * clean up and return. Otherwise we have to re-read the 758 * media. 759 */ 760 VM_OBJECT_WLOCK(object); 761 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 762 for (i = 0; i < count; i++) 763 if (i != reqpage) { 764 vm_page_lock(m[i]); 765 vm_page_free(m[i]); 766 vm_page_unlock(m[i]); 767 } 768 VM_OBJECT_WUNLOCK(object); 769 return VM_PAGER_OK; 770 } else if (reqblock == -1) { 771 pmap_zero_page(m[reqpage]); 772 KASSERT(m[reqpage]->dirty == 0, 773 ("vnode_pager_generic_getpages: page %p is dirty", m)); 774 m[reqpage]->valid = VM_PAGE_BITS_ALL; 775 for (i = 0; i < count; i++) 776 if (i != reqpage) { 777 vm_page_lock(m[i]); 778 vm_page_free(m[i]); 779 vm_page_unlock(m[i]); 780 } 781 VM_OBJECT_WUNLOCK(object); 782 return (VM_PAGER_OK); 783 } 784 m[reqpage]->valid = 0; 785 VM_OBJECT_WUNLOCK(object); 786 787 /* 788 * here on direct device I/O 789 */ 790 firstaddr = -1; 791 792 /* 793 * calculate the run that includes the required page 794 */ 795 for (first = 0, i = 0; i < count; i = runend) { 796 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, 797 &runpg) != 0) { 798 VM_OBJECT_WLOCK(object); 799 for (; i < count; i++) 800 if (i != reqpage) { 801 vm_page_lock(m[i]); 802 vm_page_free(m[i]); 803 vm_page_unlock(m[i]); 804 } 805 VM_OBJECT_WUNLOCK(object); 806 return (VM_PAGER_ERROR); 807 } 808 if (firstaddr == -1) { 809 VM_OBJECT_WLOCK(object); 810 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 811 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 812 (intmax_t)firstaddr, (uintmax_t)(foff >> 32), 813 (uintmax_t)foff, 814 (uintmax_t) 815 (object->un_pager.vnp.vnp_size >> 32), 816 (uintmax_t)object->un_pager.vnp.vnp_size); 817 } 818 vm_page_lock(m[i]); 819 vm_page_free(m[i]); 820 vm_page_unlock(m[i]); 821 VM_OBJECT_WUNLOCK(object); 822 runend = i + 1; 823 first = runend; 824 continue; 825 } 826 runend = i + runpg; 827 if (runend <= reqpage) { 828 VM_OBJECT_WLOCK(object); 829 for (j = i; j < runend; j++) { 830 vm_page_lock(m[j]); 831 vm_page_free(m[j]); 832 vm_page_unlock(m[j]); 833 } 834 VM_OBJECT_WUNLOCK(object); 835 } else { 836 if (runpg < (count - first)) { 837 VM_OBJECT_WLOCK(object); 838 for (i = first + runpg; i < count; i++) { 839 vm_page_lock(m[i]); 840 vm_page_free(m[i]); 841 vm_page_unlock(m[i]); 842 } 843 VM_OBJECT_WUNLOCK(object); 844 count = first + runpg; 845 } 846 break; 847 } 848 first = runend; 849 } 850 851 /* 852 * the first and last page have been calculated now, move input pages 853 * to be zero based... 854 */ 855 if (first != 0) { 856 m += first; 857 count -= first; 858 reqpage -= first; 859 } 860 861 /* 862 * calculate the file virtual address for the transfer 863 */ 864 foff = IDX_TO_OFF(m[0]->pindex); 865 866 /* 867 * calculate the size of the transfer 868 */ 869 size = count * PAGE_SIZE; 870 KASSERT(count > 0, ("zero count")); 871 if ((foff + size) > object->un_pager.vnp.vnp_size) 872 size = object->un_pager.vnp.vnp_size - foff; 873 KASSERT(size > 0, ("zero size")); 874 875 /* 876 * round up physical size for real devices. 877 */ 878 if (1) { 879 int secmask = bo->bo_bsize - 1; 880 KASSERT(secmask < PAGE_SIZE && secmask > 0, 881 ("vnode_pager_generic_getpages: sector size %d too large", 882 secmask + 1)); 883 size = (size + secmask) & ~secmask; 884 } 885 886 bp = getpbuf(&vnode_pbuf_freecnt); 887 kva = (vm_offset_t)bp->b_data; 888 889 /* 890 * and map the pages to be read into the kva, if the filesystem 891 * requires mapped buffers. 892 */ 893 mp = vp->v_mount; 894 if (mp != NULL && (mp->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 895 unmapped_buf_allowed) { 896 bp->b_data = unmapped_buf; 897 bp->b_kvabase = unmapped_buf; 898 bp->b_offset = 0; 899 bp->b_flags |= B_UNMAPPED; 900 bp->b_npages = count; 901 for (i = 0; i < count; i++) 902 bp->b_pages[i] = m[i]; 903 } else 904 pmap_qenter(kva, m, count); 905 906 /* build a minimal buffer header */ 907 bp->b_iocmd = BIO_READ; 908 bp->b_iodone = bdone; 909 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 910 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 911 bp->b_rcred = crhold(curthread->td_ucred); 912 bp->b_wcred = crhold(curthread->td_ucred); 913 bp->b_blkno = firstaddr; 914 pbgetbo(bo, bp); 915 bp->b_vp = vp; 916 bp->b_bcount = size; 917 bp->b_bufsize = size; 918 bp->b_runningbufspace = bp->b_bufsize; 919 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 920 921 PCPU_INC(cnt.v_vnodein); 922 PCPU_ADD(cnt.v_vnodepgsin, count); 923 924 /* do the input */ 925 bp->b_iooffset = dbtob(bp->b_blkno); 926 bstrategy(bp); 927 928 bwait(bp, PVM, "vnread"); 929 930 if ((bp->b_ioflags & BIO_ERROR) != 0) 931 error = EIO; 932 933 if (error == 0 && size != count * PAGE_SIZE) { 934 if ((bp->b_flags & B_UNMAPPED) != 0) { 935 bp->b_flags &= ~B_UNMAPPED; 936 pmap_qenter(kva, m, count); 937 } 938 bzero((caddr_t)kva + size, PAGE_SIZE * count - size); 939 } 940 if ((bp->b_flags & B_UNMAPPED) == 0) 941 pmap_qremove(kva, count); 942 if (mp != NULL && (mp->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0) { 943 bp->b_data = (caddr_t)kva; 944 bp->b_kvabase = (caddr_t)kva; 945 bp->b_flags &= ~B_UNMAPPED; 946 for (i = 0; i < count; i++) 947 bp->b_pages[i] = NULL; 948 } 949 950 /* 951 * free the buffer header back to the swap buffer pool 952 */ 953 bp->b_vp = NULL; 954 pbrelbo(bp); 955 relpbuf(bp, &vnode_pbuf_freecnt); 956 957 VM_OBJECT_WLOCK(object); 958 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 959 vm_page_t mt; 960 961 nextoff = tfoff + PAGE_SIZE; 962 mt = m[i]; 963 964 if (nextoff <= object->un_pager.vnp.vnp_size) { 965 /* 966 * Read filled up entire page. 967 */ 968 mt->valid = VM_PAGE_BITS_ALL; 969 KASSERT(mt->dirty == 0, 970 ("vnode_pager_generic_getpages: page %p is dirty", 971 mt)); 972 KASSERT(!pmap_page_is_mapped(mt), 973 ("vnode_pager_generic_getpages: page %p is mapped", 974 mt)); 975 } else { 976 /* 977 * Read did not fill up entire page. 978 * 979 * Currently we do not set the entire page valid, 980 * we just try to clear the piece that we couldn't 981 * read. 982 */ 983 vm_page_set_valid_range(mt, 0, 984 object->un_pager.vnp.vnp_size - tfoff); 985 KASSERT((mt->dirty & vm_page_bits(0, 986 object->un_pager.vnp.vnp_size - tfoff)) == 0, 987 ("vnode_pager_generic_getpages: page %p is dirty", 988 mt)); 989 } 990 991 if (i != reqpage) 992 vm_page_readahead_finish(mt); 993 } 994 VM_OBJECT_WUNLOCK(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(vm_object_t object, vm_page_t *m, int count, 1011 boolean_t sync, int *rtvals) 1012 { 1013 int rtval; 1014 struct vnode *vp; 1015 int bytes = count * PAGE_SIZE; 1016 1017 /* 1018 * Force synchronous operation if we are extremely low on memory 1019 * to prevent a low-memory deadlock. VOP operations often need to 1020 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1021 * operation ). The swapper handles the case by limiting the amount 1022 * of asynchronous I/O, but that sort of solution doesn't scale well 1023 * for the vnode pager without a lot of work. 1024 * 1025 * Also, the backing vnode's iodone routine may not wake the pageout 1026 * daemon up. This should be probably be addressed XXX. 1027 */ 1028 1029 if ((vm_cnt.v_free_count + vm_cnt.v_cache_count) < 1030 vm_cnt.v_pageout_free_min) 1031 sync |= OBJPC_SYNC; 1032 1033 /* 1034 * Call device-specific putpages function 1035 */ 1036 vp = object->handle; 1037 VM_OBJECT_WUNLOCK(object); 1038 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 1039 KASSERT(rtval != EOPNOTSUPP, 1040 ("vnode_pager: stale FS putpages\n")); 1041 VM_OBJECT_WLOCK(object); 1042 } 1043 1044 1045 /* 1046 * This is now called from local media FS's to operate against their 1047 * own vnodes if they fail to implement VOP_PUTPAGES. 1048 * 1049 * This is typically called indirectly via the pageout daemon and 1050 * clustering has already typically occured, so in general we ask the 1051 * underlying filesystem to write the data out asynchronously rather 1052 * then delayed. 1053 */ 1054 int 1055 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1056 int flags, int *rtvals) 1057 { 1058 int i; 1059 vm_object_t object; 1060 vm_page_t m; 1061 int count; 1062 1063 int maxsize, ncount; 1064 vm_ooffset_t poffset; 1065 struct uio auio; 1066 struct iovec aiov; 1067 int error; 1068 int ioflags; 1069 int ppscheck = 0; 1070 static struct timeval lastfail; 1071 static int curfail; 1072 1073 object = vp->v_object; 1074 count = bytecount / PAGE_SIZE; 1075 1076 for (i = 0; i < count; i++) 1077 rtvals[i] = VM_PAGER_ERROR; 1078 1079 if ((int64_t)ma[0]->pindex < 0) { 1080 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1081 (long)ma[0]->pindex, (u_long)ma[0]->dirty); 1082 rtvals[0] = VM_PAGER_BAD; 1083 return VM_PAGER_BAD; 1084 } 1085 1086 maxsize = count * PAGE_SIZE; 1087 ncount = count; 1088 1089 poffset = IDX_TO_OFF(ma[0]->pindex); 1090 1091 /* 1092 * If the page-aligned write is larger then the actual file we 1093 * have to invalidate pages occuring beyond the file EOF. However, 1094 * there is an edge case where a file may not be page-aligned where 1095 * the last page is partially invalid. In this case the filesystem 1096 * may not properly clear the dirty bits for the entire page (which 1097 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1098 * With the page locked we are free to fix-up the dirty bits here. 1099 * 1100 * We do not under any circumstances truncate the valid bits, as 1101 * this will screw up bogus page replacement. 1102 */ 1103 VM_OBJECT_WLOCK(object); 1104 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1105 if (object->un_pager.vnp.vnp_size > poffset) { 1106 int pgoff; 1107 1108 maxsize = object->un_pager.vnp.vnp_size - poffset; 1109 ncount = btoc(maxsize); 1110 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1111 /* 1112 * If the object is locked and the following 1113 * conditions hold, then the page's dirty 1114 * field cannot be concurrently changed by a 1115 * pmap operation. 1116 */ 1117 m = ma[ncount - 1]; 1118 vm_page_assert_sbusied(m); 1119 KASSERT(!pmap_page_is_write_mapped(m), 1120 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1121 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1122 pgoff); 1123 } 1124 } else { 1125 maxsize = 0; 1126 ncount = 0; 1127 } 1128 if (ncount < count) { 1129 for (i = ncount; i < count; i++) { 1130 rtvals[i] = VM_PAGER_BAD; 1131 } 1132 } 1133 } 1134 VM_OBJECT_WUNLOCK(object); 1135 1136 /* 1137 * pageouts are already clustered, use IO_ASYNC to force a bawrite() 1138 * rather then a bdwrite() to prevent paging I/O from saturating 1139 * the buffer cache. Dummy-up the sequential heuristic to cause 1140 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1141 * the system decides how to cluster. 1142 */ 1143 ioflags = IO_VMIO; 1144 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1145 ioflags |= IO_SYNC; 1146 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1147 ioflags |= IO_ASYNC; 1148 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1149 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1150 1151 aiov.iov_base = (caddr_t) 0; 1152 aiov.iov_len = maxsize; 1153 auio.uio_iov = &aiov; 1154 auio.uio_iovcnt = 1; 1155 auio.uio_offset = poffset; 1156 auio.uio_segflg = UIO_NOCOPY; 1157 auio.uio_rw = UIO_WRITE; 1158 auio.uio_resid = maxsize; 1159 auio.uio_td = (struct thread *) 0; 1160 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1161 PCPU_INC(cnt.v_vnodeout); 1162 PCPU_ADD(cnt.v_vnodepgsout, ncount); 1163 1164 if (error) { 1165 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1166 printf("vnode_pager_putpages: I/O error %d\n", error); 1167 } 1168 if (auio.uio_resid) { 1169 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1170 printf("vnode_pager_putpages: residual I/O %zd at %lu\n", 1171 auio.uio_resid, (u_long)ma[0]->pindex); 1172 } 1173 for (i = 0; i < ncount; i++) { 1174 rtvals[i] = VM_PAGER_OK; 1175 } 1176 return rtvals[0]; 1177 } 1178 1179 void 1180 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written) 1181 { 1182 vm_object_t obj; 1183 int i, pos; 1184 1185 if (written == 0) 1186 return; 1187 obj = ma[0]->object; 1188 VM_OBJECT_WLOCK(obj); 1189 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1190 if (pos < trunc_page(written)) { 1191 rtvals[i] = VM_PAGER_OK; 1192 vm_page_undirty(ma[i]); 1193 } else { 1194 /* Partially written page. */ 1195 rtvals[i] = VM_PAGER_AGAIN; 1196 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1197 } 1198 } 1199 VM_OBJECT_WUNLOCK(obj); 1200 } 1201 1202 void 1203 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1204 vm_offset_t end) 1205 { 1206 struct vnode *vp; 1207 vm_ooffset_t old_wm; 1208 1209 VM_OBJECT_WLOCK(object); 1210 if (object->type != OBJT_VNODE) { 1211 VM_OBJECT_WUNLOCK(object); 1212 return; 1213 } 1214 old_wm = object->un_pager.vnp.writemappings; 1215 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1216 vp = object->handle; 1217 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1218 ASSERT_VOP_ELOCKED(vp, "v_writecount inc"); 1219 VOP_ADD_WRITECOUNT(vp, 1); 1220 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1221 __func__, vp, vp->v_writecount); 1222 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1223 ASSERT_VOP_ELOCKED(vp, "v_writecount dec"); 1224 VOP_ADD_WRITECOUNT(vp, -1); 1225 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1226 __func__, vp, vp->v_writecount); 1227 } 1228 VM_OBJECT_WUNLOCK(object); 1229 } 1230 1231 void 1232 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1233 vm_offset_t end) 1234 { 1235 struct vnode *vp; 1236 struct mount *mp; 1237 vm_offset_t inc; 1238 1239 VM_OBJECT_WLOCK(object); 1240 1241 /* 1242 * First, recheck the object type to account for the race when 1243 * the vnode is reclaimed. 1244 */ 1245 if (object->type != OBJT_VNODE) { 1246 VM_OBJECT_WUNLOCK(object); 1247 return; 1248 } 1249 1250 /* 1251 * Optimize for the case when writemappings is not going to 1252 * zero. 1253 */ 1254 inc = end - start; 1255 if (object->un_pager.vnp.writemappings != inc) { 1256 object->un_pager.vnp.writemappings -= inc; 1257 VM_OBJECT_WUNLOCK(object); 1258 return; 1259 } 1260 1261 vp = object->handle; 1262 vhold(vp); 1263 VM_OBJECT_WUNLOCK(object); 1264 mp = NULL; 1265 vn_start_write(vp, &mp, V_WAIT); 1266 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1267 1268 /* 1269 * Decrement the object's writemappings, by swapping the start 1270 * and end arguments for vnode_pager_update_writecount(). If 1271 * there was not a race with vnode reclaimation, then the 1272 * vnode's v_writecount is decremented. 1273 */ 1274 vnode_pager_update_writecount(object, end, start); 1275 VOP_UNLOCK(vp, 0); 1276 vdrop(vp); 1277 if (mp != NULL) 1278 vn_finished_write(mp); 1279 } 1280