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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 ASSERT_VOP_ELOCKED(vp, "vnode_pager_alloc"); 202 203 /* 204 * If the object is being terminated, wait for it to 205 * go away. 206 */ 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 * And 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 if (VFS_NEEDSGIANT(vp->v_mount)) 228 vm_object_set_flag(object, OBJ_NEEDGIANT); 229 vp->v_object = object; 230 } else { 231 object->ref_count++; 232 VM_OBJECT_UNLOCK(object); 233 } 234 vref(vp); 235 return (object); 236 } 237 238 /* 239 * The object must be locked. 240 */ 241 static void 242 vnode_pager_dealloc(object) 243 vm_object_t object; 244 { 245 struct vnode *vp = object->handle; 246 247 if (vp == NULL) 248 panic("vnode_pager_dealloc: pager already dealloced"); 249 250 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 251 vm_object_pip_wait(object, "vnpdea"); 252 253 object->handle = NULL; 254 object->type = OBJT_DEAD; 255 if (object->flags & OBJ_DISCONNECTWNT) { 256 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 257 wakeup(object); 258 } 259 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 260 vp->v_object = NULL; 261 vp->v_vflag &= ~VV_TEXT; 262 } 263 264 static boolean_t 265 vnode_pager_haspage(object, pindex, before, after) 266 vm_object_t object; 267 vm_pindex_t pindex; 268 int *before; 269 int *after; 270 { 271 struct vnode *vp = object->handle; 272 daddr_t bn; 273 int err; 274 daddr_t reqblock; 275 int poff; 276 int bsize; 277 int pagesperblock, blocksperpage; 278 int vfslocked; 279 280 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 281 /* 282 * If no vp or vp is doomed or marked transparent to VM, we do not 283 * have the page. 284 */ 285 if (vp == NULL || vp->v_iflag & VI_DOOMED) 286 return FALSE; 287 /* 288 * If the offset is beyond end of file we do 289 * not have the page. 290 */ 291 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 292 return FALSE; 293 294 bsize = vp->v_mount->mnt_stat.f_iosize; 295 pagesperblock = bsize / PAGE_SIZE; 296 blocksperpage = 0; 297 if (pagesperblock > 0) { 298 reqblock = pindex / pagesperblock; 299 } else { 300 blocksperpage = (PAGE_SIZE / bsize); 301 reqblock = pindex * blocksperpage; 302 } 303 VM_OBJECT_UNLOCK(object); 304 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 305 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 306 VFS_UNLOCK_GIANT(vfslocked); 307 VM_OBJECT_LOCK(object); 308 if (err) 309 return TRUE; 310 if (bn == -1) 311 return FALSE; 312 if (pagesperblock > 0) { 313 poff = pindex - (reqblock * pagesperblock); 314 if (before) { 315 *before *= pagesperblock; 316 *before += poff; 317 } 318 if (after) { 319 int numafter; 320 *after *= pagesperblock; 321 numafter = pagesperblock - (poff + 1); 322 if (IDX_TO_OFF(pindex + numafter) > 323 object->un_pager.vnp.vnp_size) { 324 numafter = 325 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 326 pindex; 327 } 328 *after += numafter; 329 } 330 } else { 331 if (before) { 332 *before /= blocksperpage; 333 } 334 335 if (after) { 336 *after /= blocksperpage; 337 } 338 } 339 return TRUE; 340 } 341 342 /* 343 * Lets the VM system know about a change in size for a file. 344 * We adjust our own internal size and flush any cached pages in 345 * the associated object that are affected by the size change. 346 * 347 * Note: this routine may be invoked as a result of a pager put 348 * operation (possibly at object termination time), so we must be careful. 349 */ 350 void 351 vnode_pager_setsize(vp, nsize) 352 struct vnode *vp; 353 vm_ooffset_t nsize; 354 { 355 vm_object_t object; 356 vm_page_t m; 357 vm_pindex_t nobjsize; 358 359 if ((object = vp->v_object) == NULL) 360 return; 361 VM_OBJECT_LOCK(object); 362 if (nsize == object->un_pager.vnp.vnp_size) { 363 /* 364 * Hasn't changed size 365 */ 366 VM_OBJECT_UNLOCK(object); 367 return; 368 } 369 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 370 if (nsize < object->un_pager.vnp.vnp_size) { 371 /* 372 * File has shrunk. Toss any cached pages beyond the new EOF. 373 */ 374 if (nobjsize < object->size) 375 vm_object_page_remove(object, nobjsize, object->size, 376 FALSE); 377 /* 378 * this gets rid of garbage at the end of a page that is now 379 * only partially backed by the vnode. 380 * 381 * XXX for some reason (I don't know yet), if we take a 382 * completely invalid page and mark it partially valid 383 * it can screw up NFS reads, so we don't allow the case. 384 */ 385 if ((nsize & PAGE_MASK) && 386 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 387 m->valid != 0) { 388 int base = (int)nsize & PAGE_MASK; 389 int size = PAGE_SIZE - base; 390 391 /* 392 * Clear out partial-page garbage in case 393 * the page has been mapped. 394 */ 395 pmap_zero_page_area(m, base, size); 396 397 /* 398 * XXX work around SMP data integrity race 399 * by unmapping the page from user processes. 400 * The garbage we just cleared may be mapped 401 * to a user process running on another cpu 402 * and this code is not running through normal 403 * I/O channels which handle SMP issues for 404 * us, so unmap page to synchronize all cpus. 405 * 406 * XXX should vm_pager_unmap_page() have 407 * dealt with this? 408 */ 409 vm_page_lock_queues(); 410 pmap_remove_all(m); 411 412 /* 413 * Clear out partial-page dirty bits. This 414 * has the side effect of setting the valid 415 * bits, but that is ok. There are a bunch 416 * of places in the VM system where we expected 417 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 418 * case is one of them. If the page is still 419 * partially dirty, make it fully dirty. 420 * 421 * note that we do not clear out the valid 422 * bits. This would prevent bogus_page 423 * replacement from working properly. 424 */ 425 vm_page_set_validclean(m, base, size); 426 if (m->dirty != 0) 427 m->dirty = VM_PAGE_BITS_ALL; 428 vm_page_unlock_queues(); 429 } else if ((nsize & PAGE_MASK) && 430 __predict_false(object->cache != NULL)) { 431 vm_page_cache_free(object, OFF_TO_IDX(nsize), 432 nobjsize); 433 } 434 } 435 object->un_pager.vnp.vnp_size = nsize; 436 object->size = nobjsize; 437 VM_OBJECT_UNLOCK(object); 438 } 439 440 /* 441 * calculate the linear (byte) disk address of specified virtual 442 * file address 443 */ 444 static int 445 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 446 int *run) 447 { 448 int bsize; 449 int err; 450 daddr_t vblock; 451 daddr_t voffset; 452 453 if (address < 0) 454 return -1; 455 456 if (vp->v_iflag & VI_DOOMED) 457 return -1; 458 459 bsize = vp->v_mount->mnt_stat.f_iosize; 460 vblock = address / bsize; 461 voffset = address % bsize; 462 463 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 464 if (err == 0) { 465 if (*rtaddress != -1) 466 *rtaddress += voffset / DEV_BSIZE; 467 if (run) { 468 *run += 1; 469 *run *= bsize/PAGE_SIZE; 470 *run -= voffset/PAGE_SIZE; 471 } 472 } 473 474 return (err); 475 } 476 477 /* 478 * small block filesystem vnode pager input 479 */ 480 static int 481 vnode_pager_input_smlfs(object, m) 482 vm_object_t object; 483 vm_page_t m; 484 { 485 int i; 486 struct vnode *vp; 487 struct bufobj *bo; 488 struct buf *bp; 489 struct sf_buf *sf; 490 daddr_t fileaddr; 491 vm_offset_t bsize; 492 int error = 0; 493 494 vp = object->handle; 495 if (vp->v_iflag & VI_DOOMED) 496 return VM_PAGER_BAD; 497 498 bsize = vp->v_mount->mnt_stat.f_iosize; 499 500 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 501 502 sf = sf_buf_alloc(m, 0); 503 504 for (i = 0; i < PAGE_SIZE / bsize; i++) { 505 vm_ooffset_t address; 506 507 if (vm_page_bits(i * bsize, bsize) & m->valid) 508 continue; 509 510 address = IDX_TO_OFF(m->pindex) + i * bsize; 511 if (address >= object->un_pager.vnp.vnp_size) { 512 fileaddr = -1; 513 } else { 514 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 515 if (error) 516 break; 517 } 518 if (fileaddr != -1) { 519 bp = getpbuf(&vnode_pbuf_freecnt); 520 521 /* build a minimal buffer header */ 522 bp->b_iocmd = BIO_READ; 523 bp->b_iodone = bdone; 524 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 525 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 526 bp->b_rcred = crhold(curthread->td_ucred); 527 bp->b_wcred = crhold(curthread->td_ucred); 528 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 529 bp->b_blkno = fileaddr; 530 pbgetbo(bo, bp); 531 bp->b_bcount = bsize; 532 bp->b_bufsize = bsize; 533 bp->b_runningbufspace = bp->b_bufsize; 534 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 535 536 /* do the input */ 537 bp->b_iooffset = dbtob(bp->b_blkno); 538 bstrategy(bp); 539 540 bwait(bp, PVM, "vnsrd"); 541 542 if ((bp->b_ioflags & BIO_ERROR) != 0) 543 error = EIO; 544 545 /* 546 * free the buffer header back to the swap buffer pool 547 */ 548 pbrelbo(bp); 549 relpbuf(bp, &vnode_pbuf_freecnt); 550 if (error) 551 break; 552 553 VM_OBJECT_LOCK(object); 554 vm_page_lock_queues(); 555 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 556 vm_page_unlock_queues(); 557 VM_OBJECT_UNLOCK(object); 558 } else { 559 VM_OBJECT_LOCK(object); 560 vm_page_lock_queues(); 561 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 562 vm_page_unlock_queues(); 563 VM_OBJECT_UNLOCK(object); 564 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 565 } 566 } 567 sf_buf_free(sf); 568 vm_page_lock_queues(); 569 pmap_clear_modify(m); 570 vm_page_unlock_queues(); 571 if (error) { 572 return VM_PAGER_ERROR; 573 } 574 return VM_PAGER_OK; 575 576 } 577 578 579 /* 580 * old style vnode pager input routine 581 */ 582 static int 583 vnode_pager_input_old(object, m) 584 vm_object_t object; 585 vm_page_t m; 586 { 587 struct uio auio; 588 struct iovec aiov; 589 int error; 590 int size; 591 struct sf_buf *sf; 592 struct vnode *vp; 593 594 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 595 error = 0; 596 597 /* 598 * Return failure if beyond current EOF 599 */ 600 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 601 return VM_PAGER_BAD; 602 } else { 603 size = PAGE_SIZE; 604 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 605 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 606 vp = object->handle; 607 VM_OBJECT_UNLOCK(object); 608 609 /* 610 * Allocate a kernel virtual address and initialize so that 611 * we can use VOP_READ/WRITE routines. 612 */ 613 sf = sf_buf_alloc(m, 0); 614 615 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 616 aiov.iov_len = size; 617 auio.uio_iov = &aiov; 618 auio.uio_iovcnt = 1; 619 auio.uio_offset = IDX_TO_OFF(m->pindex); 620 auio.uio_segflg = UIO_SYSSPACE; 621 auio.uio_rw = UIO_READ; 622 auio.uio_resid = size; 623 auio.uio_td = curthread; 624 625 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 626 if (!error) { 627 int count = size - auio.uio_resid; 628 629 if (count == 0) 630 error = EINVAL; 631 else if (count != PAGE_SIZE) 632 bzero((caddr_t)sf_buf_kva(sf) + count, 633 PAGE_SIZE - count); 634 } 635 sf_buf_free(sf); 636 637 VM_OBJECT_LOCK(object); 638 } 639 vm_page_lock_queues(); 640 pmap_clear_modify(m); 641 vm_page_undirty(m); 642 vm_page_unlock_queues(); 643 if (!error) 644 m->valid = VM_PAGE_BITS_ALL; 645 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 646 } 647 648 /* 649 * generic vnode pager input routine 650 */ 651 652 /* 653 * Local media VFS's that do not implement their own VOP_GETPAGES 654 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 655 * to implement the previous behaviour. 656 * 657 * All other FS's should use the bypass to get to the local media 658 * backing vp's VOP_GETPAGES. 659 */ 660 static int 661 vnode_pager_getpages(object, m, count, reqpage) 662 vm_object_t object; 663 vm_page_t *m; 664 int count; 665 int reqpage; 666 { 667 int rtval; 668 struct vnode *vp; 669 int bytes = count * PAGE_SIZE; 670 int vfslocked; 671 672 vp = object->handle; 673 VM_OBJECT_UNLOCK(object); 674 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 675 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 676 KASSERT(rtval != EOPNOTSUPP, 677 ("vnode_pager: FS getpages not implemented\n")); 678 VFS_UNLOCK_GIANT(vfslocked); 679 VM_OBJECT_LOCK(object); 680 return rtval; 681 } 682 683 /* 684 * This is now called from local media FS's to operate against their 685 * own vnodes if they fail to implement VOP_GETPAGES. 686 */ 687 int 688 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 689 struct vnode *vp; 690 vm_page_t *m; 691 int bytecount; 692 int reqpage; 693 { 694 vm_object_t object; 695 vm_offset_t kva; 696 off_t foff, tfoff, nextoff; 697 int i, j, size, bsize, first; 698 daddr_t firstaddr, reqblock; 699 struct bufobj *bo; 700 int runpg; 701 int runend; 702 struct buf *bp; 703 int count; 704 int error; 705 706 object = vp->v_object; 707 count = bytecount / PAGE_SIZE; 708 709 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 710 ("vnode_pager_generic_getpages does not support devices")); 711 if (vp->v_iflag & VI_DOOMED) 712 return VM_PAGER_BAD; 713 714 bsize = vp->v_mount->mnt_stat.f_iosize; 715 716 /* get the UNDERLYING device for the file with VOP_BMAP() */ 717 718 /* 719 * originally, we did not check for an error return value -- assuming 720 * an fs always has a bmap entry point -- that assumption is wrong!!! 721 */ 722 foff = IDX_TO_OFF(m[reqpage]->pindex); 723 724 /* 725 * if we can't bmap, use old VOP code 726 */ 727 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL); 728 if (error == EOPNOTSUPP) { 729 VM_OBJECT_LOCK(object); 730 vm_page_lock_queues(); 731 for (i = 0; i < count; i++) 732 if (i != reqpage) 733 vm_page_free(m[i]); 734 vm_page_unlock_queues(); 735 PCPU_INC(cnt.v_vnodein); 736 PCPU_INC(cnt.v_vnodepgsin); 737 error = vnode_pager_input_old(object, m[reqpage]); 738 VM_OBJECT_UNLOCK(object); 739 return (error); 740 } else if (error != 0) { 741 VM_OBJECT_LOCK(object); 742 vm_page_lock_queues(); 743 for (i = 0; i < count; i++) 744 if (i != reqpage) 745 vm_page_free(m[i]); 746 vm_page_unlock_queues(); 747 VM_OBJECT_UNLOCK(object); 748 return (VM_PAGER_ERROR); 749 750 /* 751 * if the blocksize is smaller than a page size, then use 752 * special small filesystem code. NFS sometimes has a small 753 * blocksize, but it can handle large reads itself. 754 */ 755 } else if ((PAGE_SIZE / bsize) > 1 && 756 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 757 VM_OBJECT_LOCK(object); 758 vm_page_lock_queues(); 759 for (i = 0; i < count; i++) 760 if (i != reqpage) 761 vm_page_free(m[i]); 762 vm_page_unlock_queues(); 763 VM_OBJECT_UNLOCK(object); 764 PCPU_INC(cnt.v_vnodein); 765 PCPU_INC(cnt.v_vnodepgsin); 766 return vnode_pager_input_smlfs(object, m[reqpage]); 767 } 768 769 /* 770 * If we have a completely valid page available to us, we can 771 * clean up and return. Otherwise we have to re-read the 772 * media. 773 */ 774 VM_OBJECT_LOCK(object); 775 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 776 vm_page_lock_queues(); 777 for (i = 0; i < count; i++) 778 if (i != reqpage) 779 vm_page_free(m[i]); 780 vm_page_unlock_queues(); 781 VM_OBJECT_UNLOCK(object); 782 return VM_PAGER_OK; 783 } else if (reqblock == -1) { 784 pmap_zero_page(m[reqpage]); 785 vm_page_undirty(m[reqpage]); 786 m[reqpage]->valid = VM_PAGE_BITS_ALL; 787 vm_page_lock_queues(); 788 for (i = 0; i < count; i++) 789 if (i != reqpage) 790 vm_page_free(m[i]); 791 vm_page_unlock_queues(); 792 VM_OBJECT_UNLOCK(object); 793 return (VM_PAGER_OK); 794 } 795 m[reqpage]->valid = 0; 796 VM_OBJECT_UNLOCK(object); 797 798 /* 799 * here on direct device I/O 800 */ 801 firstaddr = -1; 802 803 /* 804 * calculate the run that includes the required page 805 */ 806 for (first = 0, i = 0; i < count; i = runend) { 807 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, 808 &runpg) != 0) { 809 VM_OBJECT_LOCK(object); 810 vm_page_lock_queues(); 811 for (; i < count; i++) 812 if (i != reqpage) 813 vm_page_free(m[i]); 814 vm_page_unlock_queues(); 815 VM_OBJECT_UNLOCK(object); 816 return (VM_PAGER_ERROR); 817 } 818 if (firstaddr == -1) { 819 VM_OBJECT_LOCK(object); 820 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 821 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 822 (intmax_t)firstaddr, (uintmax_t)(foff >> 32), 823 (uintmax_t)foff, 824 (uintmax_t) 825 (object->un_pager.vnp.vnp_size >> 32), 826 (uintmax_t)object->un_pager.vnp.vnp_size); 827 } 828 vm_page_lock_queues(); 829 vm_page_free(m[i]); 830 vm_page_unlock_queues(); 831 VM_OBJECT_UNLOCK(object); 832 runend = i + 1; 833 first = runend; 834 continue; 835 } 836 runend = i + runpg; 837 if (runend <= reqpage) { 838 VM_OBJECT_LOCK(object); 839 vm_page_lock_queues(); 840 for (j = i; j < runend; j++) 841 vm_page_free(m[j]); 842 vm_page_unlock_queues(); 843 VM_OBJECT_UNLOCK(object); 844 } else { 845 if (runpg < (count - first)) { 846 VM_OBJECT_LOCK(object); 847 vm_page_lock_queues(); 848 for (i = first + runpg; i < count; i++) 849 vm_page_free(m[i]); 850 vm_page_unlock_queues(); 851 VM_OBJECT_UNLOCK(object); 852 count = first + runpg; 853 } 854 break; 855 } 856 first = runend; 857 } 858 859 /* 860 * the first and last page have been calculated now, move input pages 861 * to be zero based... 862 */ 863 if (first != 0) { 864 m += first; 865 count -= first; 866 reqpage -= first; 867 } 868 869 /* 870 * calculate the file virtual address for the transfer 871 */ 872 foff = IDX_TO_OFF(m[0]->pindex); 873 874 /* 875 * calculate the size of the transfer 876 */ 877 size = count * PAGE_SIZE; 878 KASSERT(count > 0, ("zero count")); 879 if ((foff + size) > object->un_pager.vnp.vnp_size) 880 size = object->un_pager.vnp.vnp_size - foff; 881 KASSERT(size > 0, ("zero size")); 882 883 /* 884 * round up physical size for real devices. 885 */ 886 if (1) { 887 int secmask = bo->bo_bsize - 1; 888 KASSERT(secmask < PAGE_SIZE && secmask > 0, 889 ("vnode_pager_generic_getpages: sector size %d too large", 890 secmask + 1)); 891 size = (size + secmask) & ~secmask; 892 } 893 894 bp = getpbuf(&vnode_pbuf_freecnt); 895 kva = (vm_offset_t) bp->b_data; 896 897 /* 898 * and map the pages to be read into the kva 899 */ 900 pmap_qenter(kva, m, count); 901 902 /* build a minimal buffer header */ 903 bp->b_iocmd = BIO_READ; 904 bp->b_iodone = bdone; 905 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 906 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 907 bp->b_rcred = crhold(curthread->td_ucred); 908 bp->b_wcred = crhold(curthread->td_ucred); 909 bp->b_blkno = firstaddr; 910 pbgetbo(bo, bp); 911 bp->b_bcount = size; 912 bp->b_bufsize = size; 913 bp->b_runningbufspace = bp->b_bufsize; 914 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 915 916 PCPU_INC(cnt.v_vnodein); 917 PCPU_ADD(cnt.v_vnodepgsin, count); 918 919 /* do the input */ 920 bp->b_iooffset = dbtob(bp->b_blkno); 921 bstrategy(bp); 922 923 bwait(bp, PVM, "vnread"); 924 925 if ((bp->b_ioflags & BIO_ERROR) != 0) 926 error = EIO; 927 928 if (!error) { 929 if (size != count * PAGE_SIZE) 930 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 931 } 932 pmap_qremove(kva, count); 933 934 /* 935 * free the buffer header back to the swap buffer pool 936 */ 937 pbrelbo(bp); 938 relpbuf(bp, &vnode_pbuf_freecnt); 939 940 VM_OBJECT_LOCK(object); 941 vm_page_lock_queues(); 942 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 943 vm_page_t mt; 944 945 nextoff = tfoff + PAGE_SIZE; 946 mt = m[i]; 947 948 if (nextoff <= object->un_pager.vnp.vnp_size) { 949 /* 950 * Read filled up entire page. 951 */ 952 mt->valid = VM_PAGE_BITS_ALL; 953 vm_page_undirty(mt); /* should be an assert? XXX */ 954 pmap_clear_modify(mt); 955 } else { 956 /* 957 * Read did not fill up entire page. Since this 958 * is getpages, the page may be mapped, so we have 959 * to zero the invalid portions of the page even 960 * though we aren't setting them valid. 961 * 962 * Currently we do not set the entire page valid, 963 * we just try to clear the piece that we couldn't 964 * read. 965 */ 966 vm_page_set_validclean(mt, 0, 967 object->un_pager.vnp.vnp_size - tfoff); 968 /* handled by vm_fault now */ 969 /* vm_page_zero_invalid(mt, FALSE); */ 970 } 971 972 if (i != reqpage) { 973 974 /* 975 * whether or not to leave the page activated is up in 976 * the air, but we should put the page on a page queue 977 * somewhere. (it already is in the object). Result: 978 * It appears that empirical results show that 979 * deactivating pages is best. 980 */ 981 982 /* 983 * just in case someone was asking for this page we 984 * now tell them that it is ok to use 985 */ 986 if (!error) { 987 if (mt->oflags & VPO_WANTED) 988 vm_page_activate(mt); 989 else 990 vm_page_deactivate(mt); 991 vm_page_wakeup(mt); 992 } else { 993 vm_page_free(mt); 994 } 995 } 996 } 997 vm_page_unlock_queues(); 998 VM_OBJECT_UNLOCK(object); 999 if (error) { 1000 printf("vnode_pager_getpages: I/O read error\n"); 1001 } 1002 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 1003 } 1004 1005 /* 1006 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1007 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1008 * vnode_pager_generic_putpages() to implement the previous behaviour. 1009 * 1010 * All other FS's should use the bypass to get to the local media 1011 * backing vp's VOP_PUTPAGES. 1012 */ 1013 static void 1014 vnode_pager_putpages(object, m, count, sync, rtvals) 1015 vm_object_t object; 1016 vm_page_t *m; 1017 int count; 1018 boolean_t sync; 1019 int *rtvals; 1020 { 1021 int rtval; 1022 struct vnode *vp; 1023 struct mount *mp; 1024 int bytes = count * PAGE_SIZE; 1025 1026 /* 1027 * Force synchronous operation if we are extremely low on memory 1028 * to prevent a low-memory deadlock. VOP operations often need to 1029 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1030 * operation ). The swapper handles the case by limiting the amount 1031 * of asynchronous I/O, but that sort of solution doesn't scale well 1032 * for the vnode pager without a lot of work. 1033 * 1034 * Also, the backing vnode's iodone routine may not wake the pageout 1035 * daemon up. This should be probably be addressed XXX. 1036 */ 1037 1038 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 1039 sync |= OBJPC_SYNC; 1040 1041 /* 1042 * Call device-specific putpages function 1043 */ 1044 vp = object->handle; 1045 VM_OBJECT_UNLOCK(object); 1046 if (vp->v_type != VREG) 1047 mp = NULL; 1048 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 1049 KASSERT(rtval != EOPNOTSUPP, 1050 ("vnode_pager: stale FS putpages\n")); 1051 VM_OBJECT_LOCK(object); 1052 } 1053 1054 1055 /* 1056 * This is now called from local media FS's to operate against their 1057 * own vnodes if they fail to implement VOP_PUTPAGES. 1058 * 1059 * This is typically called indirectly via the pageout daemon and 1060 * clustering has already typically occured, so in general we ask the 1061 * underlying filesystem to write the data out asynchronously rather 1062 * then delayed. 1063 */ 1064 int 1065 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 1066 struct vnode *vp; 1067 vm_page_t *m; 1068 int bytecount; 1069 int flags; 1070 int *rtvals; 1071 { 1072 int i; 1073 vm_object_t object; 1074 int count; 1075 1076 int maxsize, ncount; 1077 vm_ooffset_t poffset; 1078 struct uio auio; 1079 struct iovec aiov; 1080 int error; 1081 int ioflags; 1082 int ppscheck = 0; 1083 static struct timeval lastfail; 1084 static int curfail; 1085 1086 object = vp->v_object; 1087 count = bytecount / PAGE_SIZE; 1088 1089 for (i = 0; i < count; i++) 1090 rtvals[i] = VM_PAGER_AGAIN; 1091 1092 if ((int64_t)m[0]->pindex < 0) { 1093 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1094 (long)m[0]->pindex, (u_long)m[0]->dirty); 1095 rtvals[0] = VM_PAGER_BAD; 1096 return VM_PAGER_BAD; 1097 } 1098 1099 maxsize = count * PAGE_SIZE; 1100 ncount = count; 1101 1102 poffset = IDX_TO_OFF(m[0]->pindex); 1103 1104 /* 1105 * If the page-aligned write is larger then the actual file we 1106 * have to invalidate pages occuring beyond the file EOF. However, 1107 * there is an edge case where a file may not be page-aligned where 1108 * the last page is partially invalid. In this case the filesystem 1109 * may not properly clear the dirty bits for the entire page (which 1110 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1111 * With the page locked we are free to fix-up the dirty bits here. 1112 * 1113 * We do not under any circumstances truncate the valid bits, as 1114 * this will screw up bogus page replacement. 1115 */ 1116 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1117 if (object->un_pager.vnp.vnp_size > poffset) { 1118 int pgoff; 1119 1120 maxsize = object->un_pager.vnp.vnp_size - poffset; 1121 ncount = btoc(maxsize); 1122 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1123 vm_page_lock_queues(); 1124 vm_page_clear_dirty(m[ncount - 1], pgoff, 1125 PAGE_SIZE - pgoff); 1126 vm_page_unlock_queues(); 1127 } 1128 } else { 1129 maxsize = 0; 1130 ncount = 0; 1131 } 1132 if (ncount < count) { 1133 for (i = ncount; i < count; i++) { 1134 rtvals[i] = VM_PAGER_BAD; 1135 } 1136 } 1137 } 1138 1139 /* 1140 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1141 * rather then a bdwrite() to prevent paging I/O from saturating 1142 * the buffer cache. Dummy-up the sequential heuristic to cause 1143 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1144 * the system decides how to cluster. 1145 */ 1146 ioflags = IO_VMIO; 1147 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1148 ioflags |= IO_SYNC; 1149 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1150 ioflags |= IO_ASYNC; 1151 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1152 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1153 1154 aiov.iov_base = (caddr_t) 0; 1155 aiov.iov_len = maxsize; 1156 auio.uio_iov = &aiov; 1157 auio.uio_iovcnt = 1; 1158 auio.uio_offset = poffset; 1159 auio.uio_segflg = UIO_NOCOPY; 1160 auio.uio_rw = UIO_WRITE; 1161 auio.uio_resid = maxsize; 1162 auio.uio_td = (struct thread *) 0; 1163 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1164 PCPU_INC(cnt.v_vnodeout); 1165 PCPU_ADD(cnt.v_vnodepgsout, ncount); 1166 1167 if (error) { 1168 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1169 printf("vnode_pager_putpages: I/O error %d\n", error); 1170 } 1171 if (auio.uio_resid) { 1172 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1173 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1174 auio.uio_resid, (u_long)m[0]->pindex); 1175 } 1176 for (i = 0; i < ncount; i++) { 1177 rtvals[i] = VM_PAGER_OK; 1178 } 1179 return rtvals[0]; 1180 } 1181 1182 struct vnode * 1183 vnode_pager_lock(vm_object_t first_object) 1184 { 1185 struct vnode *vp; 1186 vm_object_t backing_object, object; 1187 1188 VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED); 1189 for (object = first_object; object != NULL; object = backing_object) { 1190 if (object->type != OBJT_VNODE) { 1191 if ((backing_object = object->backing_object) != NULL) 1192 VM_OBJECT_LOCK(backing_object); 1193 if (object != first_object) 1194 VM_OBJECT_UNLOCK(object); 1195 continue; 1196 } 1197 retry: 1198 if (object->flags & OBJ_DEAD) { 1199 if (object != first_object) 1200 VM_OBJECT_UNLOCK(object); 1201 return NULL; 1202 } 1203 vp = object->handle; 1204 VI_LOCK(vp); 1205 VM_OBJECT_UNLOCK(object); 1206 if (first_object != object) 1207 VM_OBJECT_UNLOCK(first_object); 1208 VFS_ASSERT_GIANT(vp->v_mount); 1209 if (vget(vp, LK_CANRECURSE | LK_INTERLOCK | 1210 LK_RETRY | LK_SHARED, curthread)) { 1211 VM_OBJECT_LOCK(first_object); 1212 if (object != first_object) 1213 VM_OBJECT_LOCK(object); 1214 if (object->type != OBJT_VNODE) { 1215 if (object != first_object) 1216 VM_OBJECT_UNLOCK(object); 1217 return NULL; 1218 } 1219 printf("vnode_pager_lock: retrying\n"); 1220 goto retry; 1221 } 1222 VM_OBJECT_LOCK(first_object); 1223 return (vp); 1224 } 1225 return NULL; 1226 }
Cache object: 46bf8658d677fd7bfe14468d791df67c
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