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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/6.3/sys/vm/vnode_pager.c 172428 2007-10-03 21:06:05Z 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 ASSERT_VOP_ELOCKED(vp, "vnode_pager_alloc"); 223 224 /* 225 * If the object is being terminated, wait for it to 226 * go away. 227 */ 228 while ((object = vp->v_object) != NULL) { 229 VM_OBJECT_LOCK(object); 230 if ((object->flags & OBJ_DEAD) == 0) 231 break; 232 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 233 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0); 234 } 235 236 if (vp->v_usecount == 0) 237 panic("vnode_pager_alloc: no vnode reference"); 238 239 if (object == NULL) { 240 /* 241 * And an object of the appropriate size 242 */ 243 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 244 245 object->un_pager.vnp.vnp_size = size; 246 247 object->handle = handle; 248 if (VFS_NEEDSGIANT(vp->v_mount)) 249 vm_object_set_flag(object, OBJ_NEEDGIANT); 250 vp->v_object = object; 251 } else { 252 object->ref_count++; 253 VM_OBJECT_UNLOCK(object); 254 } 255 vref(vp); 256 return (object); 257 } 258 259 /* 260 * The object must be locked. 261 */ 262 static void 263 vnode_pager_dealloc(object) 264 vm_object_t object; 265 { 266 struct vnode *vp = object->handle; 267 268 if (vp == NULL) 269 panic("vnode_pager_dealloc: pager already dealloced"); 270 271 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 272 vm_object_pip_wait(object, "vnpdea"); 273 274 object->handle = NULL; 275 object->type = OBJT_DEAD; 276 if (object->flags & OBJ_DISCONNECTWNT) { 277 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 278 wakeup(object); 279 } 280 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 281 vp->v_object = NULL; 282 vp->v_vflag &= ~VV_TEXT; 283 } 284 285 static boolean_t 286 vnode_pager_haspage(object, pindex, before, after) 287 vm_object_t object; 288 vm_pindex_t pindex; 289 int *before; 290 int *after; 291 { 292 struct vnode *vp = object->handle; 293 daddr_t bn; 294 int err; 295 daddr_t reqblock; 296 int poff; 297 int bsize; 298 int pagesperblock, blocksperpage; 299 int vfslocked; 300 301 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 302 /* 303 * If no vp or vp is doomed or marked transparent to VM, we do not 304 * have the page. 305 */ 306 if (vp == NULL || vp->v_iflag & VI_DOOMED) 307 return FALSE; 308 /* 309 * If the offset is beyond end of file we do 310 * not have the page. 311 */ 312 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 313 return FALSE; 314 315 bsize = vp->v_mount->mnt_stat.f_iosize; 316 pagesperblock = bsize / PAGE_SIZE; 317 blocksperpage = 0; 318 if (pagesperblock > 0) { 319 reqblock = pindex / pagesperblock; 320 } else { 321 blocksperpage = (PAGE_SIZE / bsize); 322 reqblock = pindex * blocksperpage; 323 } 324 VM_OBJECT_UNLOCK(object); 325 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 326 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 327 VFS_UNLOCK_GIANT(vfslocked); 328 VM_OBJECT_LOCK(object); 329 if (err) 330 return TRUE; 331 if (bn == -1) 332 return FALSE; 333 if (pagesperblock > 0) { 334 poff = pindex - (reqblock * pagesperblock); 335 if (before) { 336 *before *= pagesperblock; 337 *before += poff; 338 } 339 if (after) { 340 int numafter; 341 *after *= pagesperblock; 342 numafter = pagesperblock - (poff + 1); 343 if (IDX_TO_OFF(pindex + numafter) > 344 object->un_pager.vnp.vnp_size) { 345 numafter = 346 OFF_TO_IDX(object->un_pager.vnp.vnp_size) - 347 pindex; 348 } 349 *after += numafter; 350 } 351 } else { 352 if (before) { 353 *before /= blocksperpage; 354 } 355 356 if (after) { 357 *after /= blocksperpage; 358 } 359 } 360 return TRUE; 361 } 362 363 /* 364 * Lets the VM system know about a change in size for a file. 365 * We adjust our own internal size and flush any cached pages in 366 * the associated object that are affected by the size change. 367 * 368 * Note: this routine may be invoked as a result of a pager put 369 * operation (possibly at object termination time), so we must be careful. 370 */ 371 void 372 vnode_pager_setsize(vp, nsize) 373 struct vnode *vp; 374 vm_ooffset_t nsize; 375 { 376 vm_object_t object; 377 vm_page_t m; 378 vm_pindex_t nobjsize; 379 380 if ((object = vp->v_object) == NULL) 381 return; 382 VM_OBJECT_LOCK(object); 383 if (nsize == object->un_pager.vnp.vnp_size) { 384 /* 385 * Hasn't changed size 386 */ 387 VM_OBJECT_UNLOCK(object); 388 return; 389 } 390 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 391 if (nsize < object->un_pager.vnp.vnp_size) { 392 /* 393 * File has shrunk. Toss any cached pages beyond the new EOF. 394 */ 395 if (nobjsize < object->size) 396 vm_object_page_remove(object, nobjsize, object->size, 397 FALSE); 398 /* 399 * this gets rid of garbage at the end of a page that is now 400 * only partially backed by the vnode. 401 * 402 * XXX for some reason (I don't know yet), if we take a 403 * completely invalid page and mark it partially valid 404 * it can screw up NFS reads, so we don't allow the case. 405 */ 406 if ((nsize & PAGE_MASK) && 407 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 408 m->valid != 0) { 409 int base = (int)nsize & PAGE_MASK; 410 int size = PAGE_SIZE - base; 411 412 /* 413 * Clear out partial-page garbage in case 414 * the page has been mapped. 415 */ 416 pmap_zero_page_area(m, base, size); 417 418 /* 419 * XXX work around SMP data integrity race 420 * by unmapping the page from user processes. 421 * The garbage we just cleared may be mapped 422 * to a user process running on another cpu 423 * and this code is not running through normal 424 * I/O channels which handle SMP issues for 425 * us, so unmap page to synchronize all cpus. 426 * 427 * XXX should vm_pager_unmap_page() have 428 * dealt with this? 429 */ 430 vm_page_lock_queues(); 431 pmap_remove_all(m); 432 433 /* 434 * Clear out partial-page dirty bits. This 435 * has the side effect of setting the valid 436 * bits, but that is ok. There are a bunch 437 * of places in the VM system where we expected 438 * m->dirty == VM_PAGE_BITS_ALL. The file EOF 439 * case is one of them. If the page is still 440 * partially dirty, make it fully dirty. 441 * 442 * note that we do not clear out the valid 443 * bits. This would prevent bogus_page 444 * replacement from working properly. 445 */ 446 vm_page_set_validclean(m, base, size); 447 if (m->dirty != 0) 448 m->dirty = VM_PAGE_BITS_ALL; 449 vm_page_unlock_queues(); 450 } 451 } 452 object->un_pager.vnp.vnp_size = nsize; 453 object->size = nobjsize; 454 VM_OBJECT_UNLOCK(object); 455 } 456 457 /* 458 * calculate the linear (byte) disk address of specified virtual 459 * file address 460 */ 461 static int 462 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 463 int *run) 464 { 465 int bsize; 466 int err; 467 daddr_t vblock; 468 daddr_t voffset; 469 470 if (address < 0) 471 return -1; 472 473 if (vp->v_iflag & VI_DOOMED) 474 return -1; 475 476 bsize = vp->v_mount->mnt_stat.f_iosize; 477 vblock = address / bsize; 478 voffset = address % bsize; 479 480 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 481 if (err == 0) { 482 if (*rtaddress != -1) 483 *rtaddress += voffset / DEV_BSIZE; 484 if (run) { 485 *run += 1; 486 *run *= bsize/PAGE_SIZE; 487 *run -= voffset/PAGE_SIZE; 488 } 489 } 490 491 return (err); 492 } 493 494 /* 495 * small block filesystem vnode pager input 496 */ 497 static int 498 vnode_pager_input_smlfs(object, m) 499 vm_object_t object; 500 vm_page_t m; 501 { 502 int i; 503 struct vnode *vp; 504 struct bufobj *bo; 505 struct buf *bp; 506 struct sf_buf *sf; 507 daddr_t fileaddr; 508 vm_offset_t bsize; 509 int error = 0; 510 511 vp = object->handle; 512 if (vp->v_iflag & VI_DOOMED) 513 return VM_PAGER_BAD; 514 515 bsize = vp->v_mount->mnt_stat.f_iosize; 516 517 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 518 519 sf = sf_buf_alloc(m, 0); 520 521 for (i = 0; i < PAGE_SIZE / bsize; i++) { 522 vm_ooffset_t address; 523 524 if (vm_page_bits(i * bsize, bsize) & m->valid) 525 continue; 526 527 address = IDX_TO_OFF(m->pindex) + i * bsize; 528 if (address >= object->un_pager.vnp.vnp_size) { 529 fileaddr = -1; 530 } else { 531 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 532 if (error) 533 break; 534 } 535 if (fileaddr != -1) { 536 bp = getpbuf(&vnode_pbuf_freecnt); 537 538 /* build a minimal buffer header */ 539 bp->b_iocmd = BIO_READ; 540 bp->b_iodone = bdone; 541 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 542 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 543 bp->b_rcred = crhold(curthread->td_ucred); 544 bp->b_wcred = crhold(curthread->td_ucred); 545 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 546 bp->b_blkno = fileaddr; 547 pbgetbo(bo, bp); 548 bp->b_bcount = bsize; 549 bp->b_bufsize = bsize; 550 bp->b_runningbufspace = bp->b_bufsize; 551 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 552 553 /* do the input */ 554 bp->b_iooffset = dbtob(bp->b_blkno); 555 bstrategy(bp); 556 557 bwait(bp, PVM, "vnsrd"); 558 559 if ((bp->b_ioflags & BIO_ERROR) != 0) 560 error = EIO; 561 562 /* 563 * free the buffer header back to the swap buffer pool 564 */ 565 pbrelbo(bp); 566 relpbuf(bp, &vnode_pbuf_freecnt); 567 if (error) 568 break; 569 570 VM_OBJECT_LOCK(object); 571 vm_page_lock_queues(); 572 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 573 vm_page_unlock_queues(); 574 VM_OBJECT_UNLOCK(object); 575 } else { 576 VM_OBJECT_LOCK(object); 577 vm_page_lock_queues(); 578 vm_page_set_validclean(m, (i * bsize) & PAGE_MASK, bsize); 579 vm_page_unlock_queues(); 580 VM_OBJECT_UNLOCK(object); 581 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 582 } 583 } 584 sf_buf_free(sf); 585 vm_page_lock_queues(); 586 pmap_clear_modify(m); 587 vm_page_unlock_queues(); 588 if (error) { 589 return VM_PAGER_ERROR; 590 } 591 return VM_PAGER_OK; 592 593 } 594 595 596 /* 597 * old style vnode pager input routine 598 */ 599 static int 600 vnode_pager_input_old(object, m) 601 vm_object_t object; 602 vm_page_t m; 603 { 604 struct uio auio; 605 struct iovec aiov; 606 int error; 607 int size; 608 struct sf_buf *sf; 609 struct vnode *vp; 610 611 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 612 error = 0; 613 614 /* 615 * Return failure if beyond current EOF 616 */ 617 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 618 return VM_PAGER_BAD; 619 } else { 620 size = PAGE_SIZE; 621 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 622 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 623 vp = object->handle; 624 VM_OBJECT_UNLOCK(object); 625 626 /* 627 * Allocate a kernel virtual address and initialize so that 628 * we can use VOP_READ/WRITE routines. 629 */ 630 sf = sf_buf_alloc(m, 0); 631 632 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 633 aiov.iov_len = size; 634 auio.uio_iov = &aiov; 635 auio.uio_iovcnt = 1; 636 auio.uio_offset = IDX_TO_OFF(m->pindex); 637 auio.uio_segflg = UIO_SYSSPACE; 638 auio.uio_rw = UIO_READ; 639 auio.uio_resid = size; 640 auio.uio_td = curthread; 641 642 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 643 if (!error) { 644 int count = size - auio.uio_resid; 645 646 if (count == 0) 647 error = EINVAL; 648 else if (count != PAGE_SIZE) 649 bzero((caddr_t)sf_buf_kva(sf) + count, 650 PAGE_SIZE - count); 651 } 652 sf_buf_free(sf); 653 654 VM_OBJECT_LOCK(object); 655 } 656 vm_page_lock_queues(); 657 pmap_clear_modify(m); 658 vm_page_undirty(m); 659 vm_page_unlock_queues(); 660 if (!error) 661 m->valid = VM_PAGE_BITS_ALL; 662 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 663 } 664 665 /* 666 * generic vnode pager input routine 667 */ 668 669 /* 670 * Local media VFS's that do not implement their own VOP_GETPAGES 671 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 672 * to implement the previous behaviour. 673 * 674 * All other FS's should use the bypass to get to the local media 675 * backing vp's VOP_GETPAGES. 676 */ 677 static int 678 vnode_pager_getpages(object, m, count, reqpage) 679 vm_object_t object; 680 vm_page_t *m; 681 int count; 682 int reqpage; 683 { 684 int rtval; 685 struct vnode *vp; 686 int bytes = count * PAGE_SIZE; 687 int vfslocked; 688 689 vp = object->handle; 690 VM_OBJECT_UNLOCK(object); 691 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 692 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); 693 KASSERT(rtval != EOPNOTSUPP, 694 ("vnode_pager: FS getpages not implemented\n")); 695 VFS_UNLOCK_GIANT(vfslocked); 696 VM_OBJECT_LOCK(object); 697 return rtval; 698 } 699 700 /* 701 * This is now called from local media FS's to operate against their 702 * own vnodes if they fail to implement VOP_GETPAGES. 703 */ 704 int 705 vnode_pager_generic_getpages(vp, m, bytecount, reqpage) 706 struct vnode *vp; 707 vm_page_t *m; 708 int bytecount; 709 int reqpage; 710 { 711 vm_object_t object; 712 vm_offset_t kva; 713 off_t foff, tfoff, nextoff; 714 int i, j, size, bsize, first; 715 daddr_t firstaddr, reqblock; 716 struct bufobj *bo; 717 int runpg; 718 int runend; 719 struct buf *bp; 720 int count; 721 int error = 0; 722 723 object = vp->v_object; 724 count = bytecount / PAGE_SIZE; 725 726 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 727 ("vnode_pager_generic_getpages does not support devices")); 728 if (vp->v_iflag & VI_DOOMED) 729 return VM_PAGER_BAD; 730 731 bsize = vp->v_mount->mnt_stat.f_iosize; 732 733 /* get the UNDERLYING device for the file with VOP_BMAP() */ 734 735 /* 736 * originally, we did not check for an error return value -- assuming 737 * an fs always has a bmap entry point -- that assumption is wrong!!! 738 */ 739 foff = IDX_TO_OFF(m[reqpage]->pindex); 740 741 /* 742 * if we can't bmap, use old VOP code 743 */ 744 if (VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL)) { 745 VM_OBJECT_LOCK(object); 746 vm_page_lock_queues(); 747 for (i = 0; i < count; i++) 748 if (i != reqpage) 749 vm_page_free(m[i]); 750 vm_page_unlock_queues(); 751 cnt.v_vnodein++; 752 cnt.v_vnodepgsin++; 753 error = vnode_pager_input_old(object, m[reqpage]); 754 VM_OBJECT_UNLOCK(object); 755 return (error); 756 757 /* 758 * if the blocksize is smaller than a page size, then use 759 * special small filesystem code. NFS sometimes has a small 760 * blocksize, but it can handle large reads itself. 761 */ 762 } else if ((PAGE_SIZE / bsize) > 1 && 763 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { 764 VM_OBJECT_LOCK(object); 765 vm_page_lock_queues(); 766 for (i = 0; i < count; i++) 767 if (i != reqpage) 768 vm_page_free(m[i]); 769 vm_page_unlock_queues(); 770 VM_OBJECT_UNLOCK(object); 771 cnt.v_vnodein++; 772 cnt.v_vnodepgsin++; 773 return vnode_pager_input_smlfs(object, m[reqpage]); 774 } 775 776 /* 777 * If we have a completely valid page available to us, we can 778 * clean up and return. Otherwise we have to re-read the 779 * media. 780 */ 781 VM_OBJECT_LOCK(object); 782 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { 783 vm_page_lock_queues(); 784 for (i = 0; i < count; i++) 785 if (i != reqpage) 786 vm_page_free(m[i]); 787 vm_page_unlock_queues(); 788 VM_OBJECT_UNLOCK(object); 789 return VM_PAGER_OK; 790 } else if (reqblock == -1) { 791 pmap_zero_page(m[reqpage]); 792 vm_page_undirty(m[reqpage]); 793 m[reqpage]->valid = VM_PAGE_BITS_ALL; 794 vm_page_lock_queues(); 795 for (i = 0; i < count; i++) 796 if (i != reqpage) 797 vm_page_free(m[i]); 798 vm_page_unlock_queues(); 799 VM_OBJECT_UNLOCK(object); 800 return (VM_PAGER_OK); 801 } 802 m[reqpage]->valid = 0; 803 VM_OBJECT_UNLOCK(object); 804 805 /* 806 * here on direct device I/O 807 */ 808 firstaddr = -1; 809 810 /* 811 * calculate the run that includes the required page 812 */ 813 for (first = 0, i = 0; i < count; i = runend) { 814 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, 815 &runpg) != 0) { 816 VM_OBJECT_LOCK(object); 817 vm_page_lock_queues(); 818 for (; i < count; i++) 819 if (i != reqpage) 820 vm_page_free(m[i]); 821 vm_page_unlock_queues(); 822 VM_OBJECT_UNLOCK(object); 823 return (VM_PAGER_ERROR); 824 } 825 if (firstaddr == -1) { 826 VM_OBJECT_LOCK(object); 827 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { 828 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", 829 (intmax_t)firstaddr, (uintmax_t)(foff >> 32), 830 (uintmax_t)foff, 831 (uintmax_t) 832 (object->un_pager.vnp.vnp_size >> 32), 833 (uintmax_t)object->un_pager.vnp.vnp_size); 834 } 835 vm_page_lock_queues(); 836 vm_page_free(m[i]); 837 vm_page_unlock_queues(); 838 VM_OBJECT_UNLOCK(object); 839 runend = i + 1; 840 first = runend; 841 continue; 842 } 843 runend = i + runpg; 844 if (runend <= reqpage) { 845 VM_OBJECT_LOCK(object); 846 vm_page_lock_queues(); 847 for (j = i; j < runend; j++) 848 vm_page_free(m[j]); 849 vm_page_unlock_queues(); 850 VM_OBJECT_UNLOCK(object); 851 } else { 852 if (runpg < (count - first)) { 853 VM_OBJECT_LOCK(object); 854 vm_page_lock_queues(); 855 for (i = first + runpg; i < count; i++) 856 vm_page_free(m[i]); 857 vm_page_unlock_queues(); 858 VM_OBJECT_UNLOCK(object); 859 count = first + runpg; 860 } 861 break; 862 } 863 first = runend; 864 } 865 866 /* 867 * the first and last page have been calculated now, move input pages 868 * to be zero based... 869 */ 870 if (first != 0) { 871 m += first; 872 count -= first; 873 reqpage -= first; 874 } 875 876 /* 877 * calculate the file virtual address for the transfer 878 */ 879 foff = IDX_TO_OFF(m[0]->pindex); 880 881 /* 882 * calculate the size of the transfer 883 */ 884 size = count * PAGE_SIZE; 885 KASSERT(count > 0, ("zero count")); 886 if ((foff + size) > object->un_pager.vnp.vnp_size) 887 size = object->un_pager.vnp.vnp_size - foff; 888 KASSERT(size > 0, ("zero size")); 889 890 /* 891 * round up physical size for real devices. 892 */ 893 if (1) { 894 int secmask = bo->bo_bsize - 1; 895 KASSERT(secmask < PAGE_SIZE && secmask > 0, 896 ("vnode_pager_generic_getpages: sector size %d too large", 897 secmask + 1)); 898 size = (size + secmask) & ~secmask; 899 } 900 901 bp = getpbuf(&vnode_pbuf_freecnt); 902 kva = (vm_offset_t) bp->b_data; 903 904 /* 905 * and map the pages to be read into the kva 906 */ 907 pmap_qenter(kva, m, count); 908 909 /* build a minimal buffer header */ 910 bp->b_iocmd = BIO_READ; 911 bp->b_iodone = bdone; 912 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 913 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 914 bp->b_rcred = crhold(curthread->td_ucred); 915 bp->b_wcred = crhold(curthread->td_ucred); 916 bp->b_blkno = firstaddr; 917 pbgetbo(bo, bp); 918 bp->b_bcount = size; 919 bp->b_bufsize = size; 920 bp->b_runningbufspace = bp->b_bufsize; 921 atomic_add_int(&runningbufspace, bp->b_runningbufspace); 922 923 cnt.v_vnodein++; 924 cnt.v_vnodepgsin += count; 925 926 /* do the input */ 927 bp->b_iooffset = dbtob(bp->b_blkno); 928 bstrategy(bp); 929 930 bwait(bp, PVM, "vnread"); 931 932 if ((bp->b_ioflags & BIO_ERROR) != 0) 933 error = EIO; 934 935 if (!error) { 936 if (size != count * PAGE_SIZE) 937 bzero((caddr_t) kva + size, PAGE_SIZE * count - size); 938 } 939 pmap_qremove(kva, count); 940 941 /* 942 * free the buffer header back to the swap buffer pool 943 */ 944 pbrelbo(bp); 945 relpbuf(bp, &vnode_pbuf_freecnt); 946 947 VM_OBJECT_LOCK(object); 948 vm_page_lock_queues(); 949 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { 950 vm_page_t mt; 951 952 nextoff = tfoff + PAGE_SIZE; 953 mt = m[i]; 954 955 if (nextoff <= object->un_pager.vnp.vnp_size) { 956 /* 957 * Read filled up entire page. 958 */ 959 mt->valid = VM_PAGE_BITS_ALL; 960 vm_page_undirty(mt); /* should be an assert? XXX */ 961 pmap_clear_modify(mt); 962 } else { 963 /* 964 * Read did not fill up entire page. Since this 965 * is getpages, the page may be mapped, so we have 966 * to zero the invalid portions of the page even 967 * though we aren't setting them valid. 968 * 969 * Currently we do not set the entire page valid, 970 * we just try to clear the piece that we couldn't 971 * read. 972 */ 973 vm_page_set_validclean(mt, 0, 974 object->un_pager.vnp.vnp_size - tfoff); 975 /* handled by vm_fault now */ 976 /* vm_page_zero_invalid(mt, FALSE); */ 977 } 978 979 if (i != reqpage) { 980 981 /* 982 * whether or not to leave the page activated is up in 983 * the air, but we should put the page on a page queue 984 * somewhere. (it already is in the object). Result: 985 * It appears that empirical results show that 986 * deactivating pages is best. 987 */ 988 989 /* 990 * just in case someone was asking for this page we 991 * now tell them that it is ok to use 992 */ 993 if (!error) { 994 if (mt->flags & PG_WANTED) 995 vm_page_activate(mt); 996 else 997 vm_page_deactivate(mt); 998 vm_page_wakeup(mt); 999 } else { 1000 vm_page_free(mt); 1001 } 1002 } 1003 } 1004 vm_page_unlock_queues(); 1005 VM_OBJECT_UNLOCK(object); 1006 if (error) { 1007 printf("vnode_pager_getpages: I/O read error\n"); 1008 } 1009 return (error ? VM_PAGER_ERROR : VM_PAGER_OK); 1010 } 1011 1012 /* 1013 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1014 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1015 * vnode_pager_generic_putpages() to implement the previous behaviour. 1016 * 1017 * All other FS's should use the bypass to get to the local media 1018 * backing vp's VOP_PUTPAGES. 1019 */ 1020 static void 1021 vnode_pager_putpages(object, m, count, sync, rtvals) 1022 vm_object_t object; 1023 vm_page_t *m; 1024 int count; 1025 boolean_t sync; 1026 int *rtvals; 1027 { 1028 int rtval; 1029 struct vnode *vp; 1030 struct mount *mp; 1031 int bytes = count * PAGE_SIZE; 1032 1033 /* 1034 * Force synchronous operation if we are extremely low on memory 1035 * to prevent a low-memory deadlock. VOP operations often need to 1036 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1037 * operation ). The swapper handles the case by limiting the amount 1038 * of asynchronous I/O, but that sort of solution doesn't scale well 1039 * for the vnode pager without a lot of work. 1040 * 1041 * Also, the backing vnode's iodone routine may not wake the pageout 1042 * daemon up. This should be probably be addressed XXX. 1043 */ 1044 1045 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) 1046 sync |= OBJPC_SYNC; 1047 1048 /* 1049 * Call device-specific putpages function 1050 */ 1051 vp = object->handle; 1052 VM_OBJECT_UNLOCK(object); 1053 if (vp->v_type != VREG) 1054 mp = NULL; 1055 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); 1056 KASSERT(rtval != EOPNOTSUPP, 1057 ("vnode_pager: stale FS putpages\n")); 1058 VM_OBJECT_LOCK(object); 1059 } 1060 1061 1062 /* 1063 * This is now called from local media FS's to operate against their 1064 * own vnodes if they fail to implement VOP_PUTPAGES. 1065 * 1066 * This is typically called indirectly via the pageout daemon and 1067 * clustering has already typically occured, so in general we ask the 1068 * underlying filesystem to write the data out asynchronously rather 1069 * then delayed. 1070 */ 1071 int 1072 vnode_pager_generic_putpages(vp, m, bytecount, flags, rtvals) 1073 struct vnode *vp; 1074 vm_page_t *m; 1075 int bytecount; 1076 int flags; 1077 int *rtvals; 1078 { 1079 int i; 1080 vm_object_t object; 1081 int count; 1082 1083 int maxsize, ncount; 1084 vm_ooffset_t poffset; 1085 struct uio auio; 1086 struct iovec aiov; 1087 int error; 1088 int ioflags; 1089 int ppscheck = 0; 1090 static struct timeval lastfail; 1091 static int curfail; 1092 1093 object = vp->v_object; 1094 count = bytecount / PAGE_SIZE; 1095 1096 for (i = 0; i < count; i++) 1097 rtvals[i] = VM_PAGER_AGAIN; 1098 1099 if ((int64_t)m[0]->pindex < 0) { 1100 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1101 (long)m[0]->pindex, (u_long)m[0]->dirty); 1102 rtvals[0] = VM_PAGER_BAD; 1103 return VM_PAGER_BAD; 1104 } 1105 1106 maxsize = count * PAGE_SIZE; 1107 ncount = count; 1108 1109 poffset = IDX_TO_OFF(m[0]->pindex); 1110 1111 /* 1112 * If the page-aligned write is larger then the actual file we 1113 * have to invalidate pages occuring beyond the file EOF. However, 1114 * there is an edge case where a file may not be page-aligned where 1115 * the last page is partially invalid. In this case the filesystem 1116 * may not properly clear the dirty bits for the entire page (which 1117 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1118 * With the page locked we are free to fix-up the dirty bits here. 1119 * 1120 * We do not under any circumstances truncate the valid bits, as 1121 * this will screw up bogus page replacement. 1122 */ 1123 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1124 if (object->un_pager.vnp.vnp_size > poffset) { 1125 int pgoff; 1126 1127 maxsize = object->un_pager.vnp.vnp_size - poffset; 1128 ncount = btoc(maxsize); 1129 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1130 vm_page_lock_queues(); 1131 vm_page_clear_dirty(m[ncount - 1], pgoff, 1132 PAGE_SIZE - pgoff); 1133 vm_page_unlock_queues(); 1134 } 1135 } else { 1136 maxsize = 0; 1137 ncount = 0; 1138 } 1139 if (ncount < count) { 1140 for (i = ncount; i < count; i++) { 1141 rtvals[i] = VM_PAGER_BAD; 1142 } 1143 } 1144 } 1145 1146 /* 1147 * pageouts are already clustered, use IO_ASYNC t o force a bawrite() 1148 * rather then a bdwrite() to prevent paging I/O from saturating 1149 * the buffer cache. Dummy-up the sequential heuristic to cause 1150 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1151 * the system decides how to cluster. 1152 */ 1153 ioflags = IO_VMIO; 1154 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1155 ioflags |= IO_SYNC; 1156 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1157 ioflags |= IO_ASYNC; 1158 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1159 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1160 1161 aiov.iov_base = (caddr_t) 0; 1162 aiov.iov_len = maxsize; 1163 auio.uio_iov = &aiov; 1164 auio.uio_iovcnt = 1; 1165 auio.uio_offset = poffset; 1166 auio.uio_segflg = UIO_NOCOPY; 1167 auio.uio_rw = UIO_WRITE; 1168 auio.uio_resid = maxsize; 1169 auio.uio_td = (struct thread *) 0; 1170 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1171 cnt.v_vnodeout++; 1172 cnt.v_vnodepgsout += ncount; 1173 1174 if (error) { 1175 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1176 printf("vnode_pager_putpages: I/O error %d\n", error); 1177 } 1178 if (auio.uio_resid) { 1179 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1180 printf("vnode_pager_putpages: residual I/O %d at %lu\n", 1181 auio.uio_resid, (u_long)m[0]->pindex); 1182 } 1183 for (i = 0; i < ncount; i++) { 1184 rtvals[i] = VM_PAGER_OK; 1185 } 1186 return rtvals[0]; 1187 } 1188 1189 struct vnode * 1190 vnode_pager_lock(vm_object_t first_object) 1191 { 1192 struct vnode *vp; 1193 vm_object_t backing_object, object; 1194 1195 VM_OBJECT_LOCK_ASSERT(first_object, MA_OWNED); 1196 for (object = first_object; object != NULL; object = backing_object) { 1197 if (object->type != OBJT_VNODE) { 1198 if ((backing_object = object->backing_object) != NULL) 1199 VM_OBJECT_LOCK(backing_object); 1200 if (object != first_object) 1201 VM_OBJECT_UNLOCK(object); 1202 continue; 1203 } 1204 retry: 1205 if (object->flags & OBJ_DEAD) { 1206 if (object != first_object) 1207 VM_OBJECT_UNLOCK(object); 1208 return NULL; 1209 } 1210 vp = object->handle; 1211 VI_LOCK(vp); 1212 VM_OBJECT_UNLOCK(object); 1213 if (first_object != object) 1214 VM_OBJECT_UNLOCK(first_object); 1215 VFS_ASSERT_GIANT(vp->v_mount); 1216 if (vget(vp, LK_CANRECURSE | LK_INTERLOCK | 1217 LK_RETRY | LK_SHARED, curthread)) { 1218 VM_OBJECT_LOCK(first_object); 1219 if (object != first_object) 1220 VM_OBJECT_LOCK(object); 1221 if (object->type != OBJT_VNODE) { 1222 if (object != first_object) 1223 VM_OBJECT_UNLOCK(object); 1224 return NULL; 1225 } 1226 printf("vnode_pager_lock: retrying\n"); 1227 goto retry; 1228 } 1229 VM_OBJECT_LOCK(first_object); 1230 return (vp); 1231 } 1232 return NULL; 1233 }
Cache object: 8898bbf1f8975e70a9bee43d5dd1059e
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