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sys/vm/vnode_pager.c
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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, vm_ooffset_t); 87 88 struct pagerops vnodepagerops = { 89 .pgo_alloc = vnode_pager_alloc, 90 .pgo_dealloc = vnode_pager_dealloc, 91 .pgo_getpages = vnode_pager_getpages, 92 .pgo_putpages = vnode_pager_putpages, 93 .pgo_haspage = vnode_pager_haspage, 94 }; 95 96 int vnode_pbuf_freecnt; 97 98 /* Create the VM system backing object for this vnode */ 99 int 100 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 101 { 102 vm_object_t object; 103 vm_ooffset_t size = isize; 104 struct vattr va; 105 106 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 107 return (0); 108 109 while ((object = vp->v_object) != NULL) { 110 VM_OBJECT_LOCK(object); 111 if (!(object->flags & OBJ_DEAD)) { 112 VM_OBJECT_UNLOCK(object); 113 return (0); 114 } 115 VOP_UNLOCK(vp, 0, td); 116 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 117 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0); 118 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 119 } 120 121 if (size == 0) { 122 if (vn_isdisk(vp, NULL)) { 123 size = IDX_TO_OFF(INT_MAX); 124 } else { 125 if (VOP_GETATTR(vp, &va, td->td_ucred, td) != 0) 126 return (0); 127 size = va.va_size; 128 } 129 } 130 131 object = vnode_pager_alloc(vp, size, 0, 0); 132 /* 133 * Dereference the reference we just created. This assumes 134 * that the object is associated with the vp. 135 */ 136 VM_OBJECT_LOCK(object); 137 object->ref_count--; 138 VM_OBJECT_UNLOCK(object); 139 vrele(vp); 140 141 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 142 143 return (0); 144 } 145 146 void 147 vnode_destroy_vobject(struct vnode *vp) 148 { 149 struct vm_object *obj; 150 151 obj = vp->v_object; 152 if (obj == NULL) 153 return; 154 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 155 VM_OBJECT_LOCK(obj); 156 if (obj->ref_count == 0) { 157 /* 158 * vclean() may be called twice. The first time 159 * removes the primary reference to the object, 160 * the second time goes one further and is a 161 * special-case to terminate the object. 162 * 163 * don't double-terminate the object 164 */ 165 if ((obj->flags & OBJ_DEAD) == 0) 166 vm_object_terminate(obj); 167 else 168 VM_OBJECT_UNLOCK(obj); 169 } else { 170 /* 171 * Woe to the process that tries to page now :-). 172 */ 173 vm_pager_deallocate(obj); 174 VM_OBJECT_UNLOCK(obj); 175 } 176 vp->v_object = NULL; 177 } 178 179 180 /* 181 * Allocate (or lookup) pager for a vnode. 182 * Handle is a vnode pointer. 183 * 184 * MPSAFE 185 */ 186 vm_object_t 187 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 188 vm_ooffset_t offset) 189 { 190 vm_object_t object; 191 struct vnode *vp; 192 193 /* 194 * Pageout to vnode, no can do yet. 195 */ 196 if (handle == NULL) 197 return (NULL); 198 199 vp = (struct vnode *) handle; 200 201 /* 202 * If the object is being terminated, wait for it to 203 * go away. 204 */ 205 retry: 206 while ((object = vp->v_object) != NULL) { 207 VM_OBJECT_LOCK(object); 208 if ((object->flags & OBJ_DEAD) == 0) 209 break; 210 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 211 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0); 212 } 213 214 if (vp->v_usecount == 0) 215 panic("vnode_pager_alloc: no vnode reference"); 216 217 if (object == NULL) { 218 /* 219 * Add an object of the appropriate size 220 */ 221 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 222 223 object->un_pager.vnp.vnp_size = size; 224 225 object->handle = handle; 226 if (VFS_NEEDSGIANT(vp->v_mount)) 227 vm_object_set_flag(object, OBJ_NEEDGIANT); 228 VI_LOCK(vp); 229 if (vp->v_object != NULL) { 230 /* 231 * Object has been created while we were sleeping 232 */ 233 VI_UNLOCK(vp); 234 vm_object_destroy(object); 235 goto retry; 236 } 237 vp->v_object = object; 238 VI_UNLOCK(vp); 239 } else { 240 object->ref_count++; 241 VM_OBJECT_UNLOCK(object); 242 } 243 vref(vp); 244 return (object); 245 } 246 247 /* 248 * The object must be locked. 249 */ 250 static void 251 vnode_pager_dealloc(object) 252 vm_object_t object; 253 { 254 struct vnode *vp = object->handle; 255 256 if (vp == NULL) 257 panic("vnode_pager_dealloc: pager already dealloced"); 258 259 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 260 vm_object_pip_wait(object, "vnpdea"); 261 262 object->handle = NULL; 263 object->type = OBJT_DEAD; 264 if (object->flags & OBJ_DISCONNECTWNT) { 265 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 266 wakeup(object); 267 } 268 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 269 vp->v_object = NULL; 270 vp->v_vflag &= ~VV_TEXT; 271 } 272 273 static boolean_t 274 vnode_pager_haspage(object, pindex, before, after) 275 vm_object_t object; 276 vm_pindex_t pindex; 277 int *before; 278 int *after; 279 { 280 struct vnode *vp = object->handle; 281 daddr_t bn; 282 int err; 283 daddr_t reqblock; 284 int poff; 285 int bsize; 286 int pagesperblock, blocksperpage; 287 int vfslocked; 288 289 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 290 /* 291 * If no vp or vp is doomed or marked transparent to VM, we do not 292 * have the page. 293 */ 294 if (vp == NULL || vp->v_iflag & VI_DOOMED) 295 return FALSE; 296 /* 297 * If the offset is beyond end of file we do 298 * not have the page. 299 */ 300 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 301 return FALSE; 302 303 bsize = vp->v_mount->mnt_stat.f_iosize; 304 pagesperblock = bsize / PAGE_SIZE; 305 blocksperpage = 0; 306 if (pagesperblock > 0) { 307 reqblock = pindex / pagesperblock; 308 } else { 309 blocksperpage = (PAGE_SIZE / bsize); 310 reqblock = pindex * blocksperpage; 311 } 312 VM_OBJECT_UNLOCK(object); 313 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 314 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 315 VFS_UNLOCK_GIANT(vfslocked); 316 VM_OBJECT_LOCK(object); 317 if (err) 318 return TRUE; 319 if (bn == -1) 320 return FALSE; 321 if (pagesperblock > 0) { 322 poff = pindex - (reqblock * pagesperblock); 323 if (before) { 324 *before *= pagesperblock; 325 *before += poff; 326 } 327 if (after) { 328 int numafter; 329 *after *= pagesperblock; 330 numafter = pagesperblock - (poff + 1); 331 if (IDX_TO_OFF(pindex + numafter) > 332 object->un_pager.vnp.vnp_size) { 333 numafter = 334 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 335 pindex; 336 } 337 *after += numafter; 338 } 339 } else { 340 if (before) { 341 *before /= blocksperpage; 342 } 343 344 if (after) { 345 *after /= blocksperpage; 346 } 347 } 348 return TRUE; 349 } 350 351 /* 352 * Lets the VM system know about a change in size for a file. 353 * We adjust our own internal size and flush any cached pages in 354 * the associated object that are affected by the size change. 355 * 356 * Note: this routine may be invoked as a result of a pager put 357 * operation (possibly at object termination time), so we must be careful. 358 */ 359 void 360 vnode_pager_setsize(vp, nsize) 361 struct vnode *vp; 362 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 VM_OBJECT_LOCK(object); 371 if (nsize == object->un_pager.vnp.vnp_size) { 372 /* 373 * Hasn't changed size 374 */ 375 VM_OBJECT_UNLOCK(object); 376 return; 377 } 378 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 379 if (nsize < object->un_pager.vnp.vnp_size) { 380 /* 381 * File has shrunk. Toss any cached pages beyond the new EOF. 382 */ 383 if (nobjsize < object->size) 384 vm_object_page_remove(object, nobjsize, object->size, 385 FALSE); 386 /* 387 * this gets rid of garbage at the end of a page that is now 388 * only partially backed by the vnode. 389 * 390 * XXX for some reason (I don't know yet), if we take a 391 * completely invalid page and mark it partially valid 392 * it can screw up NFS reads, so we don't allow the case. 393 */ 394 if ((nsize & PAGE_MASK) && 395 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 396 m->valid != 0) { 397 int base = (int)nsize & PAGE_MASK; 398 int size = PAGE_SIZE - base; 399 400 /* 401 * Clear out partial-page garbage in case 402 * the page has been mapped. 403 */ 404 pmap_zero_page_area(m, base, size); 405 406 /* 407 * XXX work around SMP data integrity race 408 * by unmapping the page from user processes. 409 * The garbage we just cleared may be mapped 410 * to a user process running on another cpu 411 * and this code is not running through normal 412 * I/O channels which handle SMP issues for 413 * us, so unmap page to synchronize all cpus. 414 * 415 * XXX should vm_pager_unmap_page() have 416 * dealt with this? 417 */ 418 vm_page_lock_queues(); 419 pmap_remove_all(m); 420 421 /* 422 * Clear out partial-page dirty bits. This 423 * has the side effect of setting the valid 424 * bits, but that is ok. There are a bunch 425 * of places in the VM system where we expected 426 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 427 * case is one of them. If the page is still 428 * partially dirty, make it fully dirty. 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_set_validclean(m, base, size); 435 if (m->dirty != 0) 436 m->dirty = VM_PAGE_BITS_ALL; 437 vm_page_unlock_queues(); 438 } else if ((nsize & PAGE_MASK) && 439 __predict_false(object->cache != NULL)) { 440 vm_page_cache_free(object, OFF_TO_IDX(nsize), 441 nobjsize); 442 } 443 } 444 object->un_pager.vnp.vnp_size = nsize; 445 object->size = nobjsize; 446 VM_OBJECT_UNLOCK(object); 447 } 448 449 /* 450 * calculate the linear (byte) disk address of specified virtual 451 * file address 452 */ 453 static int 454 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 455 int *run) 456 { 457 int bsize; 458 int err; 459 daddr_t vblock; 460 daddr_t voffset; 461 462 if (address < 0) 463 return -1; 464 465 if (vp->v_iflag & VI_DOOMED) 466 return -1; 467 468 bsize = vp->v_mount->mnt_stat.f_iosize; 469 vblock = address / bsize; 470 voffset = address % bsize; 471 472 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 473 if (err == 0) { 474 if (*rtaddress != -1) 475 *rtaddress += voffset / DEV_BSIZE; 476 if (run) { 477 *run += 1; 478 *run *= bsize/PAGE_SIZE; 479 *run -= voffset/PAGE_SIZE; 480 } 481 } 482 483 return (err); 484 } 485 486 /* 487 * small block filesystem vnode pager input 488 */ 489 static int 490 vnode_pager_input_smlfs(object, m) 491 vm_object_t object; 492 vm_page_t m; 493 { 494 int i; 495 struct vnode *vp; 496 struct bufobj *bo; 497 struct buf *bp; 498 struct sf_buf *sf; 499 daddr_t fileaddr; 500 vm_offset_t bsize; 501 int error = 0; 502 503 vp = object->handle; 504 if (vp->v_iflag & VI_DOOMED) 505 return VM_PAGER_BAD; 506 507 bsize = vp->v_mount->mnt_stat.f_iosize; 508 509 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 510 511 sf = sf_buf_alloc(m, 0); 512 513 for (i = 0; i < PAGE_SIZE / bsize; i++) { 514 vm_ooffset_t address; 515 516 if (vm_page_bits(i * bsize, bsize) & m->valid) 517 continue; 518 519 address = IDX_TO_OFF(m->pindex) + i * bsize; 520 if (address >= object->un_pager.vnp.vnp_size) { 521 fileaddr = -1; 522 } else { 523 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 524 if (error) 525 break; 526 } 527 if (fileaddr != -1) { 528 bp = getpbuf(&vnode_pbuf_freecnt); 529 530 /* build a minimal buffer header */ 531 bp->b_iocmd = BIO_READ; 532 bp->b_iodone = bdone; 533 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 534 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 535 bp->b_rcred = crhold(curthread->td_ucred); 536 bp->b_wcred = crhold(curthread->td_ucred); 537 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 538 bp->b_blkno = fileaddr; 539 pbgetbo(bo, bp); 540 bp->b_bcount = bsize; 541 bp->b_bufsize = bsize; 542 bp->b_runningbufspace = bp->b_bufsize; 543 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 544 545 /* do the input */ 546 bp->b_iooffset = dbtob(bp->b_blkno); 547 bstrategy(bp); 548 549 bwait(bp, PVM, "vnsrd"); 550 551 if ((bp->b_ioflags & BIO_ERROR) != 0) 552 error = EIO; 553 554 /* 555 * free the buffer header back to the swap buffer pool 556 */ 557 pbrelbo(bp); 558 relpbuf(bp, &vnode_pbuf_freecnt); 559 if (error) 560 break; 561 562 VM_OBJECT_LOCK(object); 563 vm_page_lock_queues(); 564 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 565 vm_page_unlock_queues(); 566 VM_OBJECT_UNLOCK(object); 567 } else { 568 VM_OBJECT_LOCK(object); 569 vm_page_lock_queues(); 570 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 571 vm_page_unlock_queues(); 572 VM_OBJECT_UNLOCK(object); 573 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 574 } 575 } 576 sf_buf_free(sf); 577 vm_page_lock_queues(); 578 pmap_clear_modify(m); 579 vm_page_unlock_queues(); 580 if (error) { 581 return VM_PAGER_ERROR; 582 } 583 return VM_PAGER_OK; 584 585 } 586 587 588 /* 589 * old style vnode pager input routine 590 */ 591 static int 592 vnode_pager_input_old(object, m) 593 vm_object_t object; 594 vm_page_t m; 595 { 596 struct uio auio; 597 struct iovec aiov; 598 int error; 599 int size; 600 struct sf_buf *sf; 601 struct vnode *vp; 602 603 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 604 error = 0; 605 606 /* 607 * Return failure if beyond current EOF 608 */ 609 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 610 return VM_PAGER_BAD; 611 } else { 612 size = PAGE_SIZE; 613 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 614 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 615 vp = object->handle; 616 VM_OBJECT_UNLOCK(object); 617 618 /* 619 * Allocate a kernel virtual address and initialize so that 620 * we can use VOP_READ/WRITE routines. 621 */ 622 sf = sf_buf_alloc(m, 0); 623 624 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 625 aiov.iov_len = size; 626 auio.uio_iov = &aiov; 627 auio.uio_iovcnt = 1; 628 auio.uio_offset = IDX_TO_OFF(m->pindex); 629 auio.uio_segflg = UIO_SYSSPACE; 630 auio.uio_rw = UIO_READ; 631 auio.uio_resid = size; 632 auio.uio_td = curthread; 633 634 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 635 if (!error) { 636 int count = size - auio.uio_resid; 637 638 if (count == 0) 639 error = EINVAL; 640 else if (count != PAGE_SIZE) 641 bzero((caddr_t)sf_buf_kva(sf) + count, 642 PAGE_SIZE - count); 643 } 644 sf_buf_free(sf); 645 646 VM_OBJECT_LOCK(object); 647 } 648 vm_page_lock_queues(); 649 pmap_clear_modify(m); 650 vm_page_undirty(m); 651 vm_page_unlock_queues(); 652 if (!error) 653 m->valid = VM_PAGE_BITS_ALL; 654 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 655 } 656 657 /* 658 * generic vnode pager input routine 659 */ 660 661 /* 662 * Local media VFS's that do not implement their own VOP_GETPAGES 663 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 664 * to implement the previous behaviour. 665 * 666 * All other FS's should use the bypass to get to the local media 667 * backing vp's VOP_GETPAGES. 668 */ 669 static int 670 vnode_pager_getpages(object, m, count, reqpage) 671 vm_object_t object; 672 vm_page_t *m; 673 int count; 674 int reqpage; 675 { 676 int rtval; 677 struct vnode *vp; 678 int bytes = count * PAGE_SIZE; 679 int vfslocked; 680 681 vp = object->handle; 682 VM_OBJECT_UNLOCK(object); 683 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 684 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 685 KASSERT(rtval != EOPNOTSUPP, 686 ("vnode_pager: FS getpages not implemented\n")); 687 VFS_UNLOCK_GIANT(vfslocked); 688 VM_OBJECT_LOCK(object); 689 return rtval; 690 } 691 692 /* 693 * This is now called from local media FS's to operate against their 694 * own vnodes if they fail to implement VOP_GETPAGES. 695 */ 696 int 697 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 698 struct vnode *vp; 699 vm_page_t *m; 700 int bytecount; 701 int reqpage; 702 { 703 vm_object_t object; 704 vm_offset_t kva; 705 off_t foff, tfoff, nextoff; 706 int i, j, size, bsize, first; 707 daddr_t firstaddr, reqblock; 708 struct bufobj *bo; 709 int runpg; 710 int runend; 711 struct buf *bp; 712 int count; 713 int error; 714 715 object = vp->v_object; 716 count = bytecount / PAGE_SIZE; 717 718 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 719 ("vnode_pager_generic_getpages does not support devices")); 720 if (vp->v_iflag & VI_DOOMED) 721 return VM_PAGER_BAD; 722 723 bsize = vp->v_mount->mnt_stat.f_iosize; 724 725 /* get the UNDERLYING device for the file with VOP_BMAP() */ 726 727 /* 728 * originally, we did not check for an error return value -- assuming 729 * an fs always has a bmap entry point -- that assumption is wrong!!! 730 */ 731 foff = IDX_TO_OFF(m[reqpage]->pindex); 732 733 /* 734 * if we can't bmap, use old VOP code 735 */ 736 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL); 737 if (error == EOPNOTSUPP) { 738 VM_OBJECT_LOCK(object); 739 vm_page_lock_queues(); 740 for (i = 0; i < count; i++) 741 if (i != reqpage) 742 vm_page_free(m[i]); 743 vm_page_unlock_queues(); 744 PCPU_INC(cnt.v_vnodein); 745 PCPU_INC(cnt.v_vnodepgsin); 746 error = vnode_pager_input_old(object, m[reqpage]); 747 VM_OBJECT_UNLOCK(object); 748 return (error); 749 } else if (error != 0) { 750 VM_OBJECT_LOCK(object); 751 vm_page_lock_queues(); 752 for (i = 0; i < count; i++) 753 if (i != reqpage) 754 vm_page_free(m[i]); 755 vm_page_unlock_queues(); 756 VM_OBJECT_UNLOCK(object); 757 return (VM_PAGER_ERROR); 758 759 /* 760 * if the blocksize is smaller than a page size, then use 761 * special small filesystem code. NFS sometimes has a small 762 * blocksize, but it can handle large reads itself. 763 */ 764 } else if ((PAGE_SIZE / bsize) > 1 && 765 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 766 VM_OBJECT_LOCK(object); 767 vm_page_lock_queues(); 768 for (i = 0; i < count; i++) 769 if (i != reqpage) 770 vm_page_free(m[i]); 771 vm_page_unlock_queues(); 772 VM_OBJECT_UNLOCK(object); 773 PCPU_INC(cnt.v_vnodein); 774 PCPU_INC(cnt.v_vnodepgsin); 775 return vnode_pager_input_smlfs(object, m[reqpage]); 776 } 777 778 /* 779 * If we have a completely valid page available to us, we can 780 * clean up and return. Otherwise we have to re-read the 781 * media. 782 */ 783 VM_OBJECT_LOCK(object); 784 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 785 vm_page_lock_queues(); 786 for (i = 0; i < count; i++) 787 if (i != reqpage) 788 vm_page_free(m[i]); 789 vm_page_unlock_queues(); 790 VM_OBJECT_UNLOCK(object); 791 return VM_PAGER_OK; 792 } else if (reqblock == -1) { 793 pmap_zero_page(m[reqpage]); 794 vm_page_undirty(m[reqpage]); 795 m[reqpage]->valid = VM_PAGE_BITS_ALL; 796 vm_page_lock_queues(); 797 for (i = 0; i < count; i++) 798 if (i != reqpage) 799 vm_page_free(m[i]); 800 vm_page_unlock_queues(); 801 VM_OBJECT_UNLOCK(object); 802 return (VM_PAGER_OK); 803 } 804 m[reqpage]->valid = 0; 805 VM_OBJECT_UNLOCK(object); 806 807 /* 808 * here on direct device I/O 809 */ 810 firstaddr = -1; 811 812 /* 813 * calculate the run that includes the required page 814 */ 815 for (first = 0, i = 0; i < count; i = runend) { 816 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, 817 &runpg) != 0) { 818 VM_OBJECT_LOCK(object); 819 vm_page_lock_queues(); 820 for (; i < count; i++) 821 if (i != reqpage) 822 vm_page_free(m[i]); 823 vm_page_unlock_queues(); 824 VM_OBJECT_UNLOCK(object); 825 return (VM_PAGER_ERROR); 826 } 827 if (firstaddr == -1) { 828 VM_OBJECT_LOCK(object); 829 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 830 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 831 (intmax_t)firstaddr, (uintmax_t)(foff >> 32), 832 (uintmax_t)foff, 833 (uintmax_t) 834 (object->un_pager.vnp.vnp_size >> 32), 835 (uintmax_t)object->un_pager.vnp.vnp_size); 836 } 837 vm_page_lock_queues(); 838 vm_page_free(m[i]); 839 vm_page_unlock_queues(); 840 VM_OBJECT_UNLOCK(object); 841 runend = i + 1; 842 first = runend; 843 continue; 844 } 845 runend = i + runpg; 846 if (runend <= reqpage) { 847 VM_OBJECT_LOCK(object); 848 vm_page_lock_queues(); 849 for (j = i; j < runend; j++) 850 vm_page_free(m[j]); 851 vm_page_unlock_queues(); 852 VM_OBJECT_UNLOCK(object); 853 } else { 854 if (runpg < (count - first)) { 855 VM_OBJECT_LOCK(object); 856 vm_page_lock_queues(); 857 for (i = first + runpg; i < count; i++) 858 vm_page_free(m[i]); 859 vm_page_unlock_queues(); 860 VM_OBJECT_UNLOCK(object); 861 count = first + runpg; 862 } 863 break; 864 } 865 first = runend; 866 } 867 868 /* 869 * the first and last page have been calculated now, move input pages 870 * to be zero based... 871 */ 872 if (first != 0) { 873 m += first; 874 count -= first; 875 reqpage -= first; 876 } 877 878 /* 879 * calculate the file virtual address for the transfer 880 */ 881 foff = IDX_TO_OFF(m[0]->pindex); 882 883 /* 884 * calculate the size of the transfer 885 */ 886 size = count * PAGE_SIZE; 887 KASSERT(count > 0, ("zero count")); 888 if ((foff + size) > object->un_pager.vnp.vnp_size) 889 size = object->un_pager.vnp.vnp_size - foff; 890 KASSERT(size > 0, ("zero size")); 891 892 /* 893 * round up physical size for real devices. 894 */ 895 if (1) { 896 int secmask = bo->bo_bsize - 1; 897 KASSERT(secmask < PAGE_SIZE && secmask > 0, 898 ("vnode_pager_generic_getpages: sector size %d too large", 899 secmask + 1)); 900 size = (size + secmask) & ~secmask; 901 } 902 903 bp = getpbuf(&vnode_pbuf_freecnt); 904 kva = (vm_offset_t) bp->b_data; 905 906 /* 907 * and map the pages to be read into the kva 908 */ 909 pmap_qenter(kva, m, count); 910 911 /* build a minimal buffer header */ 912 bp->b_iocmd = BIO_READ; 913 bp->b_iodone = bdone; 914 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 915 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 916 bp->b_rcred = crhold(curthread->td_ucred); 917 bp->b_wcred = crhold(curthread->td_ucred); 918 bp->b_blkno = firstaddr; 919 pbgetbo(bo, bp); 920 bp->b_bcount = size; 921 bp->b_bufsize = size; 922 bp->b_runningbufspace = bp->b_bufsize; 923 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 924 925 PCPU_INC(cnt.v_vnodein); 926 PCPU_ADD(cnt.v_vnodepgsin, count); 927 928 /* do the input */ 929 bp->b_iooffset = dbtob(bp->b_blkno); 930 bstrategy(bp); 931 932 bwait(bp, PVM, "vnread"); 933 934 if ((bp->b_ioflags & BIO_ERROR) != 0) 935 error = EIO; 936 937 if (!error) { 938 if (size != count * PAGE_SIZE) 939 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 940 } 941 pmap_qremove(kva, count); 942 943 /* 944 * free the buffer header back to the swap buffer pool 945 */ 946 pbrelbo(bp); 947 relpbuf(bp, &vnode_pbuf_freecnt); 948 949 VM_OBJECT_LOCK(object); 950 vm_page_lock_queues(); 951 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 952 vm_page_t mt; 953 954 nextoff = tfoff + PAGE_SIZE; 955 mt = m[i]; 956 957 if (nextoff <= object->un_pager.vnp.vnp_size) { 958 /* 959 * Read filled up entire page. 960 */ 961 mt->valid = VM_PAGE_BITS_ALL; 962 vm_page_undirty(mt); /* should be an assert? XXX */ 963 pmap_clear_modify(mt); 964 } else { 965 /* 966 * Read did not fill up entire page. Since this 967 * is getpages, the page may be mapped, so we have 968 * to zero the invalid portions of the page even 969 * though we aren't setting them valid. 970 * 971 * Currently we do not set the entire page valid, 972 * we just try to clear the piece that we couldn't 973 * read. 974 */ 975 vm_page_set_validclean(mt, 0, 976 object->un_pager.vnp.vnp_size - tfoff); 977 /* handled by vm_fault now */ 978 /* vm_page_zero_invalid(mt, FALSE); */ 979 } 980 981 if (i != reqpage) { 982 983 /* 984 * whether or not to leave the page activated is up in 985 * the air, but we should put the page on a page queue 986 * somewhere. (it already is in the object). Result: 987 * It appears that empirical results show that 988 * deactivating pages is best. 989 */ 990 991 /* 992 * just in case someone was asking for this page we 993 * now tell them that it is ok to use 994 */ 995 if (!error) { 996 if (mt->oflags & VPO_WANTED) 997 vm_page_activate(mt); 998 else 999 vm_page_deactivate(mt); 1000 vm_page_wakeup(mt); 1001 } else { 1002 vm_page_free(mt); 1003 } 1004 } 1005 } 1006 vm_page_unlock_queues(); 1007 VM_OBJECT_UNLOCK(object); 1008 if (error) { 1009 printf("vnode_pager_getpages: I/O read error\n"); 1010 } 1011 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 1012 } 1013 1014 /* 1015 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1016 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1017 * vnode_pager_generic_putpages() to implement the previous behaviour. 1018 * 1019 * All other FS's should use the bypass to get to the local media 1020 * backing vp's VOP_PUTPAGES. 1021 */ 1022 static void 1023 vnode_pager_putpages(object, m, count, sync, rtvals) 1024 vm_object_t object; 1025 vm_page_t *m; 1026 int count; 1027 boolean_t sync; 1028 int *rtvals; 1029 { 1030 int rtval; 1031 struct vnode *vp; 1032 struct mount *mp; 1033 int bytes = count * PAGE_SIZE; 1034 1035 /* 1036 * Force synchronous operation if we are extremely low on memory 1037 * to prevent a low-memory deadlock. VOP operations often need to 1038 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1039 * operation ). The swapper handles the case by limiting the amount 1040 * of asynchronous I/O, but that sort of solution doesn't scale well 1041 * for the vnode pager without a lot of work. 1042 * 1043 * Also, the backing vnode's iodone routine may not wake the pageout 1044 * daemon up. This should be probably be addressed XXX. 1045 */ 1046 1047 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 1048 sync |= OBJPC_SYNC; 1049 1050 /* 1051 * Call device-specific putpages function 1052 */ 1053 vp = object->handle; 1054 VM_OBJECT_UNLOCK(object); 1055 if (vp->v_type != VREG) 1056 mp = NULL; 1057 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 1058 KASSERT(rtval != EOPNOTSUPP, 1059 ("vnode_pager: stale FS putpages\n")); 1060 VM_OBJECT_LOCK(object); 1061 } 1062 1063 1064 /* 1065 * This is now called from local media FS's to operate against their 1066 * own vnodes if they fail to implement VOP_PUTPAGES. 1067 * 1068 * This is typically called indirectly via the pageout daemon and 1069 * clustering has already typically occured, so in general we ask the 1070 * underlying filesystem to write the data out asynchronously rather 1071 * then delayed. 1072 */ 1073 int 1074 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 1075 struct vnode *vp; 1076 vm_page_t *m; 1077 int bytecount; 1078 int flags; 1079 int *rtvals; 1080 { 1081 int i; 1082 vm_object_t object; 1083 int count; 1084 1085 int maxsize, ncount; 1086 vm_ooffset_t poffset; 1087 struct uio auio; 1088 struct iovec aiov; 1089 int error; 1090 int ioflags; 1091 int ppscheck = 0; 1092 static struct timeval lastfail; 1093 static int curfail; 1094 1095 object = vp->v_object; 1096 count = bytecount / PAGE_SIZE; 1097 1098 for (i = 0; i < count; i++) 1099 rtvals[i] = VM_PAGER_AGAIN; 1100 1101 if ((int64_t)m[0]->pindex < 0) { 1102 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1103 (long)m[0]->pindex, (u_long)m[0]->dirty); 1104 rtvals[0] = VM_PAGER_BAD; 1105 return VM_PAGER_BAD; 1106 } 1107 1108 maxsize = count * PAGE_SIZE; 1109 ncount = count; 1110 1111 poffset = IDX_TO_OFF(m[0]->pindex); 1112 1113 /* 1114 * If the page-aligned write is larger then the actual file we 1115 * have to invalidate pages occuring beyond the file EOF. However, 1116 * there is an edge case where a file may not be page-aligned where 1117 * the last page is partially invalid. In this case the filesystem 1118 * may not properly clear the dirty bits for the entire page (which 1119 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1120 * With the page locked we are free to fix-up the dirty bits here. 1121 * 1122 * We do not under any circumstances truncate the valid bits, as 1123 * this will screw up bogus page replacement. 1124 */ 1125 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1126 if (object->un_pager.vnp.vnp_size > poffset) { 1127 int pgoff; 1128 1129 maxsize = object->un_pager.vnp.vnp_size - poffset; 1130 ncount = btoc(maxsize); 1131 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1132 vm_page_lock_queues(); 1133 vm_page_clear_dirty(m[ncount - 1], pgoff, 1134 PAGE_SIZE - pgoff); 1135 vm_page_unlock_queues(); 1136 } 1137 } else { 1138 maxsize = 0; 1139 ncount = 0; 1140 } 1141 if (ncount < count) { 1142 for (i = ncount; i < count; i++) { 1143 rtvals[i] = VM_PAGER_BAD; 1144 } 1145 } 1146 } 1147 1148 /* 1149 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1150 * rather then a bdwrite() to prevent paging I/O from saturating 1151 * the buffer cache. Dummy-up the sequential heuristic to cause 1152 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1153 * the system decides how to cluster. 1154 */ 1155 ioflags = IO_VMIO; 1156 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1157 ioflags |= IO_SYNC; 1158 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1159 ioflags |= IO_ASYNC; 1160 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1161 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1162 1163 aiov.iov_base = (caddr_t) 0; 1164 aiov.iov_len = maxsize; 1165 auio.uio_iov = &aiov; 1166 auio.uio_iovcnt = 1; 1167 auio.uio_offset = poffset; 1168 auio.uio_segflg = UIO_NOCOPY; 1169 auio.uio_rw = UIO_WRITE; 1170 auio.uio_resid = maxsize; 1171 auio.uio_td = (struct thread *) 0; 1172 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1173 PCPU_INC(cnt.v_vnodeout); 1174 PCPU_ADD(cnt.v_vnodepgsout, ncount); 1175 1176 if (error) { 1177 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1178 printf("vnode_pager_putpages: I/O error %d\n", error); 1179 } 1180 if (auio.uio_resid) { 1181 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1182 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1183 auio.uio_resid, (u_long)m[0]->pindex); 1184 } 1185 for (i = 0; i < ncount; i++) { 1186 rtvals[i] = VM_PAGER_OK; 1187 } 1188 return rtvals[0]; 1189 } 1190 1191 struct vnode * 1192 vnode_pager_lock(vm_object_t first_object) 1193 { 1194 struct vnode *vp; 1195 vm_object_t backing_object, object; 1196 1197 VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED); 1198 for (object = first_object; object != NULL; object = backing_object) { 1199 if (object->type != OBJT_VNODE) { 1200 if ((backing_object = object->backing_object) != NULL) 1201 VM_OBJECT_LOCK(backing_object); 1202 if (object != first_object) 1203 VM_OBJECT_UNLOCK(object); 1204 continue; 1205 } 1206 retry: 1207 if (object->flags & OBJ_DEAD) { 1208 if (object != first_object) 1209 VM_OBJECT_UNLOCK(object); 1210 return NULL; 1211 } 1212 vp = object->handle; 1213 VI_LOCK(vp); 1214 VM_OBJECT_UNLOCK(object); 1215 if (first_object != object) 1216 VM_OBJECT_UNLOCK(first_object); 1217 VFS_ASSERT_GIANT(vp->v_mount); 1218 if (vget(vp, LK_CANRECURSE | LK_INTERLOCK | 1219 LK_RETRY | LK_SHARED, curthread)) { 1220 VM_OBJECT_LOCK(first_object); 1221 if (object != first_object) 1222 VM_OBJECT_LOCK(object); 1223 if (object->type != OBJT_VNODE) { 1224 if (object != first_object) 1225 VM_OBJECT_UNLOCK(object); 1226 return NULL; 1227 } 1228 printf("vnode_pager_lock: retrying\n"); 1229 goto retry; 1230 } 1231 VM_OBJECT_LOCK(first_object); 1232 return (vp); 1233 } 1234 return NULL; 1235 }
Cache object: 140539d8a0cc3f123993934fbd7f74f9
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