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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: releng/6.4/sys/vm/vnode_pager.c 181128 2008-08-01 19:50:07Z jhb $"); 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 /* 99 * Compatibility function for RELENG_6, in which vnode_create_vobject() 100 * takes file size as size_t due to an oversight. The type may not just 101 * change to off_t because the ABI to 3rd party modules must be preserved 102 * for RELENG_6 lifetime. 103 */ 104 int 105 vnode_create_vobject(struct vnode *vp, size_t isize __unused, struct thread *td) 106 { 107 108 /* 109 * Size of 0 will indicate to vnode_create_vobject_off() 110 * VOP_GETATTR() is to be called to get the actual size. 111 */ 112 return (vnode_create_vobject_off(vp, 0, td)); 113 } 114 115 /* 116 * Create the VM system backing object for this vnode -- for RELENG_6 only. 117 * In HEAD, vnode_create_vobject() has been fixed to take file size as off_t 118 * and so it can be used as is. 119 */ 120 int 121 vnode_create_vobject_off(struct vnode *vp, off_t isize, struct thread *td) 122 { 123 vm_object_t object; 124 vm_ooffset_t size = isize; 125 struct vattr va; 126 127 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 128 return (0); 129 130 while ((object = vp->v_object) != NULL) { 131 VM_OBJECT_LOCK(object); 132 if (!(object->flags & OBJ_DEAD)) { 133 VM_OBJECT_UNLOCK(object); 134 return (0); 135 } 136 VOP_UNLOCK(vp, 0, td); 137 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 138 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0); 139 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 140 } 141 142 if (size == 0) { 143 if (vn_isdisk(vp, NULL)) { 144 size = IDX_TO_OFF(INT_MAX); 145 } else { 146 if (VOP_GETATTR(vp, &va, td->td_ucred, td) != 0) 147 return (0); 148 size = va.va_size; 149 } 150 } 151 152 object = vnode_pager_alloc(vp, size, 0, 0); 153 /* 154 * Dereference the reference we just created. This assumes 155 * that the object is associated with the vp. 156 */ 157 VM_OBJECT_LOCK(object); 158 object->ref_count--; 159 VM_OBJECT_UNLOCK(object); 160 vrele(vp); 161 162 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 163 164 return (0); 165 } 166 167 void 168 vnode_destroy_vobject(struct vnode *vp) 169 { 170 struct vm_object *obj; 171 172 obj = vp->v_object; 173 if (obj == NULL) 174 return; 175 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 176 VM_OBJECT_LOCK(obj); 177 if (obj->ref_count == 0) { 178 /* 179 * vclean() may be called twice. The first time 180 * removes the primary reference to the object, 181 * the second time goes one further and is a 182 * special-case to terminate the object. 183 * 184 * don't double-terminate the object 185 */ 186 if ((obj->flags & OBJ_DEAD) == 0) 187 vm_object_terminate(obj); 188 else 189 VM_OBJECT_UNLOCK(obj); 190 } else { 191 /* 192 * Woe to the process that tries to page now :-). 193 */ 194 vm_pager_deallocate(obj); 195 VM_OBJECT_UNLOCK(obj); 196 } 197 vp->v_object = NULL; 198 } 199 200 201 /* 202 * Allocate (or lookup) pager for a vnode. 203 * Handle is a vnode pointer. 204 * 205 * MPSAFE 206 */ 207 vm_object_t 208 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 209 vm_ooffset_t offset) 210 { 211 vm_object_t object; 212 struct vnode *vp; 213 214 /* 215 * Pageout to vnode, no can do yet. 216 */ 217 if (handle == NULL) 218 return (NULL); 219 220 vp = (struct vnode *) handle; 221 222 /* 223 * If the object is being terminated, wait for it to 224 * go away. 225 */ 226 retry: 227 while ((object = vp->v_object) != NULL) { 228 VM_OBJECT_LOCK(object); 229 if ((object->flags & OBJ_DEAD) == 0) 230 break; 231 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 232 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0); 233 } 234 235 if (vp->v_usecount == 0) 236 panic("vnode_pager_alloc: no vnode reference"); 237 238 if (object == NULL) { 239 /* 240 * Add an object of the appropriate size 241 */ 242 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 243 244 object->un_pager.vnp.vnp_size = size; 245 246 object->handle = handle; 247 if (VFS_NEEDSGIANT(vp->v_mount)) 248 vm_object_set_flag(object, OBJ_NEEDGIANT); 249 VI_LOCK(vp); 250 if (vp->v_object != NULL) { 251 /* 252 * Object has been created while we were sleeping 253 */ 254 VI_UNLOCK(vp); 255 vm_object_destroy(object); 256 goto retry; 257 } 258 vp->v_object = object; 259 VI_UNLOCK(vp); 260 } else { 261 object->ref_count++; 262 VM_OBJECT_UNLOCK(object); 263 } 264 vref(vp); 265 return (object); 266 } 267 268 /* 269 * The object must be locked. 270 */ 271 static void 272 vnode_pager_dealloc(object) 273 vm_object_t object; 274 { 275 struct vnode *vp = object->handle; 276 277 if (vp == NULL) 278 panic("vnode_pager_dealloc: pager already dealloced"); 279 280 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 281 vm_object_pip_wait(object, "vnpdea"); 282 283 object->handle = NULL; 284 object->type = OBJT_DEAD; 285 if (object->flags & OBJ_DISCONNECTWNT) { 286 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 287 wakeup(object); 288 } 289 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 290 vp->v_object = NULL; 291 vp->v_vflag &= ~VV_TEXT; 292 } 293 294 static boolean_t 295 vnode_pager_haspage(object, pindex, before, after) 296 vm_object_t object; 297 vm_pindex_t pindex; 298 int *before; 299 int *after; 300 { 301 struct vnode *vp = object->handle; 302 daddr_t bn; 303 int err; 304 daddr_t reqblock; 305 int poff; 306 int bsize; 307 int pagesperblock, blocksperpage; 308 int vfslocked; 309 310 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 311 /* 312 * If no vp or vp is doomed or marked transparent to VM, we do not 313 * have the page. 314 */ 315 if (vp == NULL || vp->v_iflag & VI_DOOMED) 316 return FALSE; 317 /* 318 * If the offset is beyond end of file we do 319 * not have the page. 320 */ 321 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 322 return FALSE; 323 324 bsize = vp->v_mount->mnt_stat.f_iosize; 325 pagesperblock = bsize / PAGE_SIZE; 326 blocksperpage = 0; 327 if (pagesperblock > 0) { 328 reqblock = pindex / pagesperblock; 329 } else { 330 blocksperpage = (PAGE_SIZE / bsize); 331 reqblock = pindex * blocksperpage; 332 } 333 VM_OBJECT_UNLOCK(object); 334 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 335 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 336 VFS_UNLOCK_GIANT(vfslocked); 337 VM_OBJECT_LOCK(object); 338 if (err) 339 return TRUE; 340 if (bn == -1) 341 return FALSE; 342 if (pagesperblock > 0) { 343 poff = pindex - (reqblock * pagesperblock); 344 if (before) { 345 *before *= pagesperblock; 346 *before += poff; 347 } 348 if (after) { 349 int numafter; 350 *after *= pagesperblock; 351 numafter = pagesperblock - (poff + 1); 352 if (IDX_TO_OFF(pindex + numafter) > 353 object->un_pager.vnp.vnp_size) { 354 numafter = 355 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 356 pindex; 357 } 358 *after += numafter; 359 } 360 } else { 361 if (before) { 362 *before /= blocksperpage; 363 } 364 365 if (after) { 366 *after /= blocksperpage; 367 } 368 } 369 return TRUE; 370 } 371 372 /* 373 * Lets the VM system know about a change in size for a file. 374 * We adjust our own internal size and flush any cached pages in 375 * the associated object that are affected by the size change. 376 * 377 * Note: this routine may be invoked as a result of a pager put 378 * operation (possibly at object termination time), so we must be careful. 379 */ 380 void 381 vnode_pager_setsize(vp, nsize) 382 struct vnode *vp; 383 vm_ooffset_t nsize; 384 { 385 vm_object_t object; 386 vm_page_t m; 387 vm_pindex_t nobjsize; 388 389 if ((object = vp->v_object) == NULL) 390 return; 391 VM_OBJECT_LOCK(object); 392 if (nsize == object->un_pager.vnp.vnp_size) { 393 /* 394 * Hasn't changed size 395 */ 396 VM_OBJECT_UNLOCK(object); 397 return; 398 } 399 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 400 if (nsize < object->un_pager.vnp.vnp_size) { 401 /* 402 * File has shrunk. Toss any cached pages beyond the new EOF. 403 */ 404 if (nobjsize < object->size) 405 vm_object_page_remove(object, nobjsize, object->size, 406 FALSE); 407 /* 408 * this gets rid of garbage at the end of a page that is now 409 * only partially backed by the vnode. 410 * 411 * XXX for some reason (I don't know yet), if we take a 412 * completely invalid page and mark it partially valid 413 * it can screw up NFS reads, so we don't allow the case. 414 */ 415 if ((nsize & PAGE_MASK) && 416 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 417 m->valid != 0) { 418 int base = (int)nsize & PAGE_MASK; 419 int size = PAGE_SIZE - base; 420 421 /* 422 * Clear out partial-page garbage in case 423 * the page has been mapped. 424 */ 425 pmap_zero_page_area(m, base, size); 426 427 /* 428 * XXX work around SMP data integrity race 429 * by unmapping the page from user processes. 430 * The garbage we just cleared may be mapped 431 * to a user process running on another cpu 432 * and this code is not running through normal 433 * I/O channels which handle SMP issues for 434 * us, so unmap page to synchronize all cpus. 435 * 436 * XXX should vm_pager_unmap_page() have 437 * dealt with this? 438 */ 439 vm_page_lock_queues(); 440 pmap_remove_all(m); 441 442 /* 443 * Clear out partial-page dirty bits. This 444 * has the side effect of setting the valid 445 * bits, but that is ok. There are a bunch 446 * of places in the VM system where we expected 447 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 448 * case is one of them. If the page is still 449 * partially dirty, make it fully dirty. 450 * 451 * note that we do not clear out the valid 452 * bits. This would prevent bogus_page 453 * replacement from working properly. 454 */ 455 vm_page_set_validclean(m, base, size); 456 if (m->dirty != 0) 457 m->dirty = VM_PAGE_BITS_ALL; 458 vm_page_unlock_queues(); 459 } 460 } 461 object->un_pager.vnp.vnp_size = nsize; 462 object->size = nobjsize; 463 VM_OBJECT_UNLOCK(object); 464 } 465 466 /* 467 * calculate the linear (byte) disk address of specified virtual 468 * file address 469 */ 470 static int 471 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 472 int *run) 473 { 474 int bsize; 475 int err; 476 daddr_t vblock; 477 daddr_t voffset; 478 479 if (address < 0) 480 return -1; 481 482 if (vp->v_iflag & VI_DOOMED) 483 return -1; 484 485 bsize = vp->v_mount->mnt_stat.f_iosize; 486 vblock = address / bsize; 487 voffset = address % bsize; 488 489 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 490 if (err == 0) { 491 if (*rtaddress != -1) 492 *rtaddress += voffset / DEV_BSIZE; 493 if (run) { 494 *run += 1; 495 *run *= bsize/PAGE_SIZE; 496 *run -= voffset/PAGE_SIZE; 497 } 498 } 499 500 return (err); 501 } 502 503 /* 504 * small block filesystem vnode pager input 505 */ 506 static int 507 vnode_pager_input_smlfs(object, m) 508 vm_object_t object; 509 vm_page_t m; 510 { 511 int i; 512 struct vnode *vp; 513 struct bufobj *bo; 514 struct buf *bp; 515 struct sf_buf *sf; 516 daddr_t fileaddr; 517 vm_offset_t bsize; 518 int error = 0; 519 520 vp = object->handle; 521 if (vp->v_iflag & VI_DOOMED) 522 return VM_PAGER_BAD; 523 524 bsize = vp->v_mount->mnt_stat.f_iosize; 525 526 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 527 528 sf = sf_buf_alloc(m, 0); 529 530 for (i = 0; i < PAGE_SIZE / bsize; i++) { 531 vm_ooffset_t address; 532 533 if (vm_page_bits(i * bsize, bsize) & m->valid) 534 continue; 535 536 address = IDX_TO_OFF(m->pindex) + i * bsize; 537 if (address >= object->un_pager.vnp.vnp_size) { 538 fileaddr = -1; 539 } else { 540 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 541 if (error) 542 break; 543 } 544 if (fileaddr != -1) { 545 bp = getpbuf(&vnode_pbuf_freecnt); 546 547 /* build a minimal buffer header */ 548 bp->b_iocmd = BIO_READ; 549 bp->b_iodone = bdone; 550 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 551 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 552 bp->b_rcred = crhold(curthread->td_ucred); 553 bp->b_wcred = crhold(curthread->td_ucred); 554 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 555 bp->b_blkno = fileaddr; 556 pbgetbo(bo, bp); 557 bp->b_bcount = bsize; 558 bp->b_bufsize = bsize; 559 bp->b_runningbufspace = bp->b_bufsize; 560 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 561 562 /* do the input */ 563 bp->b_iooffset = dbtob(bp->b_blkno); 564 bstrategy(bp); 565 566 bwait(bp, PVM, "vnsrd"); 567 568 if ((bp->b_ioflags & BIO_ERROR) != 0) 569 error = EIO; 570 571 /* 572 * free the buffer header back to the swap buffer pool 573 */ 574 pbrelbo(bp); 575 relpbuf(bp, &vnode_pbuf_freecnt); 576 if (error) 577 break; 578 579 VM_OBJECT_LOCK(object); 580 vm_page_lock_queues(); 581 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 582 vm_page_unlock_queues(); 583 VM_OBJECT_UNLOCK(object); 584 } else { 585 VM_OBJECT_LOCK(object); 586 vm_page_lock_queues(); 587 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 588 vm_page_unlock_queues(); 589 VM_OBJECT_UNLOCK(object); 590 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 591 } 592 } 593 sf_buf_free(sf); 594 vm_page_lock_queues(); 595 pmap_clear_modify(m); 596 vm_page_unlock_queues(); 597 if (error) { 598 return VM_PAGER_ERROR; 599 } 600 return VM_PAGER_OK; 601 602 } 603 604 605 /* 606 * old style vnode pager input routine 607 */ 608 static int 609 vnode_pager_input_old(object, m) 610 vm_object_t object; 611 vm_page_t m; 612 { 613 struct uio auio; 614 struct iovec aiov; 615 int error; 616 int size; 617 struct sf_buf *sf; 618 struct vnode *vp; 619 620 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 621 error = 0; 622 623 /* 624 * Return failure if beyond current EOF 625 */ 626 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 627 return VM_PAGER_BAD; 628 } else { 629 size = PAGE_SIZE; 630 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 631 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 632 vp = object->handle; 633 VM_OBJECT_UNLOCK(object); 634 635 /* 636 * Allocate a kernel virtual address and initialize so that 637 * we can use VOP_READ/WRITE routines. 638 */ 639 sf = sf_buf_alloc(m, 0); 640 641 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 642 aiov.iov_len = size; 643 auio.uio_iov = &aiov; 644 auio.uio_iovcnt = 1; 645 auio.uio_offset = IDX_TO_OFF(m->pindex); 646 auio.uio_segflg = UIO_SYSSPACE; 647 auio.uio_rw = UIO_READ; 648 auio.uio_resid = size; 649 auio.uio_td = curthread; 650 651 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 652 if (!error) { 653 int count = size - auio.uio_resid; 654 655 if (count == 0) 656 error = EINVAL; 657 else if (count != PAGE_SIZE) 658 bzero((caddr_t)sf_buf_kva(sf) + count, 659 PAGE_SIZE - count); 660 } 661 sf_buf_free(sf); 662 663 VM_OBJECT_LOCK(object); 664 } 665 vm_page_lock_queues(); 666 pmap_clear_modify(m); 667 vm_page_undirty(m); 668 vm_page_unlock_queues(); 669 if (!error) 670 m->valid = VM_PAGE_BITS_ALL; 671 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 672 } 673 674 /* 675 * generic vnode pager input routine 676 */ 677 678 /* 679 * Local media VFS's that do not implement their own VOP_GETPAGES 680 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 681 * to implement the previous behaviour. 682 * 683 * All other FS's should use the bypass to get to the local media 684 * backing vp's VOP_GETPAGES. 685 */ 686 static int 687 vnode_pager_getpages(object, m, count, reqpage) 688 vm_object_t object; 689 vm_page_t *m; 690 int count; 691 int reqpage; 692 { 693 int rtval; 694 struct vnode *vp; 695 int bytes = count * PAGE_SIZE; 696 int vfslocked; 697 698 vp = object->handle; 699 VM_OBJECT_UNLOCK(object); 700 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 701 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 702 KASSERT(rtval != EOPNOTSUPP, 703 ("vnode_pager: FS getpages not implemented\n")); 704 VFS_UNLOCK_GIANT(vfslocked); 705 VM_OBJECT_LOCK(object); 706 return rtval; 707 } 708 709 /* 710 * This is now called from local media FS's to operate against their 711 * own vnodes if they fail to implement VOP_GETPAGES. 712 */ 713 int 714 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 715 struct vnode *vp; 716 vm_page_t *m; 717 int bytecount; 718 int reqpage; 719 { 720 vm_object_t object; 721 vm_offset_t kva; 722 off_t foff, tfoff, nextoff; 723 int i, j, size, bsize, first; 724 daddr_t firstaddr, reqblock; 725 struct bufobj *bo; 726 int runpg; 727 int runend; 728 struct buf *bp; 729 int count; 730 int error = 0; 731 732 object = vp->v_object; 733 count = bytecount / PAGE_SIZE; 734 735 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 736 ("vnode_pager_generic_getpages does not support devices")); 737 if (vp->v_iflag & VI_DOOMED) 738 return VM_PAGER_BAD; 739 740 bsize = vp->v_mount->mnt_stat.f_iosize; 741 742 /* get the UNDERLYING device for the file with VOP_BMAP() */ 743 744 /* 745 * originally, we did not check for an error return value -- assuming 746 * an fs always has a bmap entry point -- that assumption is wrong!!! 747 */ 748 foff = IDX_TO_OFF(m[reqpage]->pindex); 749 750 /* 751 * if we can't bmap, use old VOP code 752 */ 753 if (VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL)) { 754 VM_OBJECT_LOCK(object); 755 vm_page_lock_queues(); 756 for (i = 0; i < count; i++) 757 if (i != reqpage) 758 vm_page_free(m[i]); 759 vm_page_unlock_queues(); 760 cnt.v_vnodein++; 761 cnt.v_vnodepgsin++; 762 error = vnode_pager_input_old(object, m[reqpage]); 763 VM_OBJECT_UNLOCK(object); 764 return (error); 765 766 /* 767 * if the blocksize is smaller than a page size, then use 768 * special small filesystem code. NFS sometimes has a small 769 * blocksize, but it can handle large reads itself. 770 */ 771 } else if ((PAGE_SIZE / bsize) > 1 && 772 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 773 VM_OBJECT_LOCK(object); 774 vm_page_lock_queues(); 775 for (i = 0; i < count; i++) 776 if (i != reqpage) 777 vm_page_free(m[i]); 778 vm_page_unlock_queues(); 779 VM_OBJECT_UNLOCK(object); 780 cnt.v_vnodein++; 781 cnt.v_vnodepgsin++; 782 return vnode_pager_input_smlfs(object, m[reqpage]); 783 } 784 785 /* 786 * If we have a completely valid page available to us, we can 787 * clean up and return. Otherwise we have to re-read the 788 * media. 789 */ 790 VM_OBJECT_LOCK(object); 791 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 792 vm_page_lock_queues(); 793 for (i = 0; i < count; i++) 794 if (i != reqpage) 795 vm_page_free(m[i]); 796 vm_page_unlock_queues(); 797 VM_OBJECT_UNLOCK(object); 798 return VM_PAGER_OK; 799 } else if (reqblock == -1) { 800 pmap_zero_page(m[reqpage]); 801 vm_page_undirty(m[reqpage]); 802 m[reqpage]->valid = VM_PAGE_BITS_ALL; 803 vm_page_lock_queues(); 804 for (i = 0; i < count; i++) 805 if (i != reqpage) 806 vm_page_free(m[i]); 807 vm_page_unlock_queues(); 808 VM_OBJECT_UNLOCK(object); 809 return (VM_PAGER_OK); 810 } 811 m[reqpage]->valid = 0; 812 VM_OBJECT_UNLOCK(object); 813 814 /* 815 * here on direct device I/O 816 */ 817 firstaddr = -1; 818 819 /* 820 * calculate the run that includes the required page 821 */ 822 for (first = 0, i = 0; i < count; i = runend) { 823 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, 824 &runpg) != 0) { 825 VM_OBJECT_LOCK(object); 826 vm_page_lock_queues(); 827 for (; i < count; i++) 828 if (i != reqpage) 829 vm_page_free(m[i]); 830 vm_page_unlock_queues(); 831 VM_OBJECT_UNLOCK(object); 832 return (VM_PAGER_ERROR); 833 } 834 if (firstaddr == -1) { 835 VM_OBJECT_LOCK(object); 836 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 837 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 838 (intmax_t)firstaddr, (uintmax_t)(foff >> 32), 839 (uintmax_t)foff, 840 (uintmax_t) 841 (object->un_pager.vnp.vnp_size >> 32), 842 (uintmax_t)object->un_pager.vnp.vnp_size); 843 } 844 vm_page_lock_queues(); 845 vm_page_free(m[i]); 846 vm_page_unlock_queues(); 847 VM_OBJECT_UNLOCK(object); 848 runend = i + 1; 849 first = runend; 850 continue; 851 } 852 runend = i + runpg; 853 if (runend <= reqpage) { 854 VM_OBJECT_LOCK(object); 855 vm_page_lock_queues(); 856 for (j = i; j < runend; j++) 857 vm_page_free(m[j]); 858 vm_page_unlock_queues(); 859 VM_OBJECT_UNLOCK(object); 860 } else { 861 if (runpg < (count - first)) { 862 VM_OBJECT_LOCK(object); 863 vm_page_lock_queues(); 864 for (i = first + runpg; i < count; i++) 865 vm_page_free(m[i]); 866 vm_page_unlock_queues(); 867 VM_OBJECT_UNLOCK(object); 868 count = first + runpg; 869 } 870 break; 871 } 872 first = runend; 873 } 874 875 /* 876 * the first and last page have been calculated now, move input pages 877 * to be zero based... 878 */ 879 if (first != 0) { 880 m += first; 881 count -= first; 882 reqpage -= first; 883 } 884 885 /* 886 * calculate the file virtual address for the transfer 887 */ 888 foff = IDX_TO_OFF(m[0]->pindex); 889 890 /* 891 * calculate the size of the transfer 892 */ 893 size = count * PAGE_SIZE; 894 KASSERT(count > 0, ("zero count")); 895 if ((foff + size) > object->un_pager.vnp.vnp_size) 896 size = object->un_pager.vnp.vnp_size - foff; 897 KASSERT(size > 0, ("zero size")); 898 899 /* 900 * round up physical size for real devices. 901 */ 902 if (1) { 903 int secmask = bo->bo_bsize - 1; 904 KASSERT(secmask < PAGE_SIZE && secmask > 0, 905 ("vnode_pager_generic_getpages: sector size %d too large", 906 secmask + 1)); 907 size = (size + secmask) & ~secmask; 908 } 909 910 bp = getpbuf(&vnode_pbuf_freecnt); 911 kva = (vm_offset_t) bp->b_data; 912 913 /* 914 * and map the pages to be read into the kva 915 */ 916 pmap_qenter(kva, m, count); 917 918 /* build a minimal buffer header */ 919 bp->b_iocmd = BIO_READ; 920 bp->b_iodone = bdone; 921 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 922 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 923 bp->b_rcred = crhold(curthread->td_ucred); 924 bp->b_wcred = crhold(curthread->td_ucred); 925 bp->b_blkno = firstaddr; 926 pbgetbo(bo, bp); 927 bp->b_bcount = size; 928 bp->b_bufsize = size; 929 bp->b_runningbufspace = bp->b_bufsize; 930 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 931 932 cnt.v_vnodein++; 933 cnt.v_vnodepgsin += count; 934 935 /* do the input */ 936 bp->b_iooffset = dbtob(bp->b_blkno); 937 bstrategy(bp); 938 939 bwait(bp, PVM, "vnread"); 940 941 if ((bp->b_ioflags & BIO_ERROR) != 0) 942 error = EIO; 943 944 if (!error) { 945 if (size != count * PAGE_SIZE) 946 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 947 } 948 pmap_qremove(kva, count); 949 950 /* 951 * free the buffer header back to the swap buffer pool 952 */ 953 pbrelbo(bp); 954 relpbuf(bp, &vnode_pbuf_freecnt); 955 956 VM_OBJECT_LOCK(object); 957 vm_page_lock_queues(); 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 vm_page_undirty(mt); /* should be an assert? XXX */ 970 pmap_clear_modify(mt); 971 } else { 972 /* 973 * Read did not fill up entire page. Since this 974 * is getpages, the page may be mapped, so we have 975 * to zero the invalid portions of the page even 976 * though we aren't setting them valid. 977 * 978 * Currently we do not set the entire page valid, 979 * we just try to clear the piece that we couldn't 980 * read. 981 */ 982 vm_page_set_validclean(mt, 0, 983 object->un_pager.vnp.vnp_size - tfoff); 984 /* handled by vm_fault now */ 985 /* vm_page_zero_invalid(mt, FALSE); */ 986 } 987 988 if (i != reqpage) { 989 990 /* 991 * whether or not to leave the page activated is up in 992 * the air, but we should put the page on a page queue 993 * somewhere. (it already is in the object). Result: 994 * It appears that empirical results show that 995 * deactivating pages is best. 996 */ 997 998 /* 999 * just in case someone was asking for this page we 1000 * now tell them that it is ok to use 1001 */ 1002 if (!error) { 1003 if (mt->flags & PG_WANTED) 1004 vm_page_activate(mt); 1005 else 1006 vm_page_deactivate(mt); 1007 vm_page_wakeup(mt); 1008 } else { 1009 vm_page_free(mt); 1010 } 1011 } 1012 } 1013 vm_page_unlock_queues(); 1014 VM_OBJECT_UNLOCK(object); 1015 if (error) { 1016 printf("vnode_pager_getpages: I/O read error\n"); 1017 } 1018 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 1019 } 1020 1021 /* 1022 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1023 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1024 * vnode_pager_generic_putpages() to implement the previous behaviour. 1025 * 1026 * All other FS's should use the bypass to get to the local media 1027 * backing vp's VOP_PUTPAGES. 1028 */ 1029 static void 1030 vnode_pager_putpages(object, m, count, sync, rtvals) 1031 vm_object_t object; 1032 vm_page_t *m; 1033 int count; 1034 boolean_t sync; 1035 int *rtvals; 1036 { 1037 int rtval; 1038 struct vnode *vp; 1039 struct mount *mp; 1040 int bytes = count * PAGE_SIZE; 1041 1042 /* 1043 * Force synchronous operation if we are extremely low on memory 1044 * to prevent a low-memory deadlock. VOP operations often need to 1045 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1046 * operation ). The swapper handles the case by limiting the amount 1047 * of asynchronous I/O, but that sort of solution doesn't scale well 1048 * for the vnode pager without a lot of work. 1049 * 1050 * Also, the backing vnode's iodone routine may not wake the pageout 1051 * daemon up. This should be probably be addressed XXX. 1052 */ 1053 1054 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 1055 sync |= OBJPC_SYNC; 1056 1057 /* 1058 * Call device-specific putpages function 1059 */ 1060 vp = object->handle; 1061 VM_OBJECT_UNLOCK(object); 1062 if (vp->v_type != VREG) 1063 mp = NULL; 1064 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 1065 KASSERT(rtval != EOPNOTSUPP, 1066 ("vnode_pager: stale FS putpages\n")); 1067 VM_OBJECT_LOCK(object); 1068 } 1069 1070 1071 /* 1072 * This is now called from local media FS's to operate against their 1073 * own vnodes if they fail to implement VOP_PUTPAGES. 1074 * 1075 * This is typically called indirectly via the pageout daemon and 1076 * clustering has already typically occured, so in general we ask the 1077 * underlying filesystem to write the data out asynchronously rather 1078 * then delayed. 1079 */ 1080 int 1081 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 1082 struct vnode *vp; 1083 vm_page_t *m; 1084 int bytecount; 1085 int flags; 1086 int *rtvals; 1087 { 1088 int i; 1089 vm_object_t object; 1090 int count; 1091 1092 int maxsize, ncount; 1093 vm_ooffset_t poffset; 1094 struct uio auio; 1095 struct iovec aiov; 1096 int error; 1097 int ioflags; 1098 int ppscheck = 0; 1099 static struct timeval lastfail; 1100 static int curfail; 1101 1102 object = vp->v_object; 1103 count = bytecount / PAGE_SIZE; 1104 1105 for (i = 0; i < count; i++) 1106 rtvals[i] = VM_PAGER_AGAIN; 1107 1108 if ((int64_t)m[0]->pindex < 0) { 1109 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1110 (long)m[0]->pindex, (u_long)m[0]->dirty); 1111 rtvals[0] = VM_PAGER_BAD; 1112 return VM_PAGER_BAD; 1113 } 1114 1115 maxsize = count * PAGE_SIZE; 1116 ncount = count; 1117 1118 poffset = IDX_TO_OFF(m[0]->pindex); 1119 1120 /* 1121 * If the page-aligned write is larger then the actual file we 1122 * have to invalidate pages occuring beyond the file EOF. However, 1123 * there is an edge case where a file may not be page-aligned where 1124 * the last page is partially invalid. In this case the filesystem 1125 * may not properly clear the dirty bits for the entire page (which 1126 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1127 * With the page locked we are free to fix-up the dirty bits here. 1128 * 1129 * We do not under any circumstances truncate the valid bits, as 1130 * this will screw up bogus page replacement. 1131 */ 1132 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1133 if (object->un_pager.vnp.vnp_size > poffset) { 1134 int pgoff; 1135 1136 maxsize = object->un_pager.vnp.vnp_size - poffset; 1137 ncount = btoc(maxsize); 1138 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1139 vm_page_lock_queues(); 1140 vm_page_clear_dirty(m[ncount - 1], pgoff, 1141 PAGE_SIZE - pgoff); 1142 vm_page_unlock_queues(); 1143 } 1144 } else { 1145 maxsize = 0; 1146 ncount = 0; 1147 } 1148 if (ncount < count) { 1149 for (i = ncount; i < count; i++) { 1150 rtvals[i] = VM_PAGER_BAD; 1151 } 1152 } 1153 } 1154 1155 /* 1156 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1157 * rather then a bdwrite() to prevent paging I/O from saturating 1158 * the buffer cache. Dummy-up the sequential heuristic to cause 1159 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1160 * the system decides how to cluster. 1161 */ 1162 ioflags = IO_VMIO; 1163 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1164 ioflags |= IO_SYNC; 1165 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1166 ioflags |= IO_ASYNC; 1167 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1168 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1169 1170 aiov.iov_base = (caddr_t) 0; 1171 aiov.iov_len = maxsize; 1172 auio.uio_iov = &aiov; 1173 auio.uio_iovcnt = 1; 1174 auio.uio_offset = poffset; 1175 auio.uio_segflg = UIO_NOCOPY; 1176 auio.uio_rw = UIO_WRITE; 1177 auio.uio_resid = maxsize; 1178 auio.uio_td = (struct thread *) 0; 1179 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1180 cnt.v_vnodeout++; 1181 cnt.v_vnodepgsout += ncount; 1182 1183 if (error) { 1184 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1185 printf("vnode_pager_putpages: I/O error %d\n", error); 1186 } 1187 if (auio.uio_resid) { 1188 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1189 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1190 auio.uio_resid, (u_long)m[0]->pindex); 1191 } 1192 for (i = 0; i < ncount; i++) { 1193 rtvals[i] = VM_PAGER_OK; 1194 } 1195 return rtvals[0]; 1196 } 1197 1198 struct vnode * 1199 vnode_pager_lock(vm_object_t first_object) 1200 { 1201 struct vnode *vp; 1202 vm_object_t backing_object, object; 1203 1204 VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED); 1205 for (object = first_object; object != NULL; object = backing_object) { 1206 if (object->type != OBJT_VNODE) { 1207 if ((backing_object = object->backing_object) != NULL) 1208 VM_OBJECT_LOCK(backing_object); 1209 if (object != first_object) 1210 VM_OBJECT_UNLOCK(object); 1211 continue; 1212 } 1213 retry: 1214 if (object->flags & OBJ_DEAD) { 1215 if (object != first_object) 1216 VM_OBJECT_UNLOCK(object); 1217 return NULL; 1218 } 1219 vp = object->handle; 1220 VI_LOCK(vp); 1221 VM_OBJECT_UNLOCK(object); 1222 if (first_object != object) 1223 VM_OBJECT_UNLOCK(first_object); 1224 VFS_ASSERT_GIANT(vp->v_mount); 1225 if (vget(vp, LK_CANRECURSE | LK_INTERLOCK | 1226 LK_RETRY | LK_SHARED, curthread)) { 1227 VM_OBJECT_LOCK(first_object); 1228 if (object != first_object) 1229 VM_OBJECT_LOCK(object); 1230 if (object->type != OBJT_VNODE) { 1231 if (object != first_object) 1232 VM_OBJECT_UNLOCK(object); 1233 return NULL; 1234 } 1235 printf("vnode_pager_lock: retrying\n"); 1236 goto retry; 1237 } 1238 VM_OBJECT_LOCK(first_object); 1239 return (vp); 1240 } 1241 return NULL; 1242 }
Cache object: 733ed65e17eb230fbf31992d7c5e3010
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