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 "opt_vm.h" 57 58 #include <sys/param.h> 59 #include <sys/systm.h> 60 #include <sys/proc.h> 61 #include <sys/vnode.h> 62 #include <sys/mount.h> 63 #include <sys/bio.h> 64 #include <sys/buf.h> 65 #include <sys/vmmeter.h> 66 #include <sys/limits.h> 67 #include <sys/conf.h> 68 #include <sys/rwlock.h> 69 #include <sys/sf_buf.h> 70 71 #include <machine/atomic.h> 72 73 #include <vm/vm.h> 74 #include <vm/vm_param.h> 75 #include <vm/vm_object.h> 76 #include <vm/vm_page.h> 77 #include <vm/vm_pager.h> 78 #include <vm/vm_map.h> 79 #include <vm/vnode_pager.h> 80 #include <vm/vm_extern.h> 81 82 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 83 daddr_t *rtaddress, int *run); 84 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 85 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 86 static void vnode_pager_dealloc(vm_object_t); 87 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 88 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, 89 int *, vop_getpages_iodone_t, void *); 90 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 91 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 92 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 93 vm_ooffset_t, struct ucred *cred); 94 static int vnode_pager_generic_getpages_done(struct buf *); 95 static void vnode_pager_generic_getpages_done_async(struct buf *); 96 97 struct pagerops vnodepagerops = { 98 .pgo_alloc = vnode_pager_alloc, 99 .pgo_dealloc = vnode_pager_dealloc, 100 .pgo_getpages = vnode_pager_getpages, 101 .pgo_getpages_async = vnode_pager_getpages_async, 102 .pgo_putpages = vnode_pager_putpages, 103 .pgo_haspage = vnode_pager_haspage, 104 }; 105 106 int vnode_pbuf_freecnt; 107 int vnode_async_pbuf_freecnt; 108 109 /* Create the VM system backing object for this vnode */ 110 int 111 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 112 { 113 vm_object_t object; 114 vm_ooffset_t size = isize; 115 struct vattr va; 116 117 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 118 return (0); 119 120 while ((object = vp->v_object) != NULL) { 121 VM_OBJECT_WLOCK(object); 122 if (!(object->flags & OBJ_DEAD)) { 123 VM_OBJECT_WUNLOCK(object); 124 return (0); 125 } 126 VOP_UNLOCK(vp, 0); 127 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 128 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vodead", 0); 129 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 130 } 131 132 if (size == 0) { 133 if (vn_isdisk(vp, NULL)) { 134 size = IDX_TO_OFF(INT_MAX); 135 } else { 136 if (VOP_GETATTR(vp, &va, td->td_ucred)) 137 return (0); 138 size = va.va_size; 139 } 140 } 141 142 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 143 /* 144 * Dereference the reference we just created. This assumes 145 * that the object is associated with the vp. 146 */ 147 VM_OBJECT_WLOCK(object); 148 object->ref_count--; 149 VM_OBJECT_WUNLOCK(object); 150 vrele(vp); 151 152 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 153 154 return (0); 155 } 156 157 void 158 vnode_destroy_vobject(struct vnode *vp) 159 { 160 struct vm_object *obj; 161 162 obj = vp->v_object; 163 if (obj == NULL) 164 return; 165 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 166 VM_OBJECT_WLOCK(obj); 167 umtx_shm_object_terminated(obj); 168 if (obj->ref_count == 0) { 169 /* 170 * don't double-terminate the object 171 */ 172 if ((obj->flags & OBJ_DEAD) == 0) { 173 vm_object_terminate(obj); 174 } else { 175 /* 176 * Waiters were already handled during object 177 * termination. The exclusive vnode lock hopefully 178 * prevented new waiters from referencing the dying 179 * object. 180 */ 181 KASSERT((obj->flags & OBJ_DISCONNECTWNT) == 0, 182 ("OBJ_DISCONNECTWNT set obj %p flags %x", 183 obj, obj->flags)); 184 vp->v_object = NULL; 185 VM_OBJECT_WUNLOCK(obj); 186 } 187 } else { 188 /* 189 * Woe to the process that tries to page now :-). 190 */ 191 vm_pager_deallocate(obj); 192 VM_OBJECT_WUNLOCK(obj); 193 } 194 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object)); 195 } 196 197 198 /* 199 * Allocate (or lookup) pager for a vnode. 200 * Handle is a vnode pointer. 201 * 202 * MPSAFE 203 */ 204 vm_object_t 205 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 206 vm_ooffset_t offset, struct ucred *cred) 207 { 208 vm_object_t object; 209 struct vnode *vp; 210 211 /* 212 * Pageout to vnode, no can do yet. 213 */ 214 if (handle == NULL) 215 return (NULL); 216 217 vp = (struct vnode *) handle; 218 219 /* 220 * If the object is being terminated, wait for it to 221 * go away. 222 */ 223 retry: 224 while ((object = vp->v_object) != NULL) { 225 VM_OBJECT_WLOCK(object); 226 if ((object->flags & OBJ_DEAD) == 0) 227 break; 228 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 229 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vadead", 0); 230 } 231 232 KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference")); 233 234 if (object == NULL) { 235 /* 236 * Add an object of the appropriate size 237 */ 238 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 239 240 object->un_pager.vnp.vnp_size = size; 241 object->un_pager.vnp.writemappings = 0; 242 243 object->handle = handle; 244 VI_LOCK(vp); 245 if (vp->v_object != NULL) { 246 /* 247 * Object has been created while we were sleeping 248 */ 249 VI_UNLOCK(vp); 250 VM_OBJECT_WLOCK(object); 251 KASSERT(object->ref_count == 1, 252 ("leaked ref %p %d", object, object->ref_count)); 253 object->type = OBJT_DEAD; 254 object->ref_count = 0; 255 VM_OBJECT_WUNLOCK(object); 256 vm_object_destroy(object); 257 goto retry; 258 } 259 vp->v_object = object; 260 VI_UNLOCK(vp); 261 } else { 262 object->ref_count++; 263 #if VM_NRESERVLEVEL > 0 264 vm_object_color(object, 0); 265 #endif 266 VM_OBJECT_WUNLOCK(object); 267 } 268 vrefact(vp); 269 return (object); 270 } 271 272 /* 273 * The object must be locked. 274 */ 275 static void 276 vnode_pager_dealloc(vm_object_t object) 277 { 278 struct vnode *vp; 279 int refs; 280 281 vp = object->handle; 282 if (vp == NULL) 283 panic("vnode_pager_dealloc: pager already dealloced"); 284 285 VM_OBJECT_ASSERT_WLOCKED(object); 286 vm_object_pip_wait(object, "vnpdea"); 287 refs = object->ref_count; 288 289 object->handle = NULL; 290 object->type = OBJT_DEAD; 291 if (object->flags & OBJ_DISCONNECTWNT) { 292 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 293 wakeup(object); 294 } 295 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 296 if (object->un_pager.vnp.writemappings > 0) { 297 object->un_pager.vnp.writemappings = 0; 298 VOP_ADD_WRITECOUNT(vp, -1); 299 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 300 __func__, vp, vp->v_writecount); 301 } 302 vp->v_object = NULL; 303 VOP_UNSET_TEXT(vp); 304 VM_OBJECT_WUNLOCK(object); 305 while (refs-- > 0) 306 vunref(vp); 307 VM_OBJECT_WLOCK(object); 308 } 309 310 static boolean_t 311 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 312 int *after) 313 { 314 struct vnode *vp = object->handle; 315 daddr_t bn; 316 int err; 317 daddr_t reqblock; 318 int poff; 319 int bsize; 320 int pagesperblock, blocksperpage; 321 322 VM_OBJECT_ASSERT_WLOCKED(object); 323 /* 324 * If no vp or vp is doomed or marked transparent to VM, we do not 325 * have the page. 326 */ 327 if (vp == NULL || vp->v_iflag & VI_DOOMED) 328 return FALSE; 329 /* 330 * If the offset is beyond end of file we do 331 * not have the page. 332 */ 333 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 334 return FALSE; 335 336 bsize = vp->v_mount->mnt_stat.f_iosize; 337 pagesperblock = bsize / PAGE_SIZE; 338 blocksperpage = 0; 339 if (pagesperblock > 0) { 340 reqblock = pindex / pagesperblock; 341 } else { 342 blocksperpage = (PAGE_SIZE / bsize); 343 reqblock = pindex * blocksperpage; 344 } 345 VM_OBJECT_WUNLOCK(object); 346 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 347 VM_OBJECT_WLOCK(object); 348 if (err) 349 return TRUE; 350 if (bn == -1) 351 return FALSE; 352 if (pagesperblock > 0) { 353 poff = pindex - (reqblock * pagesperblock); 354 if (before) { 355 *before *= pagesperblock; 356 *before += poff; 357 } 358 if (after) { 359 /* 360 * The BMAP vop can report a partial block in the 361 * 'after', but must not report blocks after EOF. 362 * Assert the latter, and truncate 'after' in case 363 * of the former. 364 */ 365 KASSERT((reqblock + *after) * pagesperblock < 366 roundup2(object->size, pagesperblock), 367 ("%s: reqblock %jd after %d size %ju", __func__, 368 (intmax_t )reqblock, *after, 369 (uintmax_t )object->size)); 370 *after *= pagesperblock; 371 *after += pagesperblock - (poff + 1); 372 if (pindex + *after >= object->size) 373 *after = object->size - 1 - pindex; 374 } 375 } else { 376 if (before) { 377 *before /= blocksperpage; 378 } 379 380 if (after) { 381 *after /= blocksperpage; 382 } 383 } 384 return TRUE; 385 } 386 387 /* 388 * Lets the VM system know about a change in size for a file. 389 * We adjust our own internal size and flush any cached pages in 390 * the associated object that are affected by the size change. 391 * 392 * Note: this routine may be invoked as a result of a pager put 393 * operation (possibly at object termination time), so we must be careful. 394 */ 395 void 396 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 397 { 398 vm_object_t object; 399 vm_page_t m; 400 vm_pindex_t nobjsize; 401 402 if ((object = vp->v_object) == NULL) 403 return; 404 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */ 405 VM_OBJECT_WLOCK(object); 406 if (object->type == OBJT_DEAD) { 407 VM_OBJECT_WUNLOCK(object); 408 return; 409 } 410 KASSERT(object->type == OBJT_VNODE, 411 ("not vnode-backed object %p", object)); 412 if (nsize == object->un_pager.vnp.vnp_size) { 413 /* 414 * Hasn't changed size 415 */ 416 VM_OBJECT_WUNLOCK(object); 417 return; 418 } 419 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 420 if (nsize < object->un_pager.vnp.vnp_size) { 421 /* 422 * File has shrunk. Toss any cached pages beyond the new EOF. 423 */ 424 if (nobjsize < object->size) 425 vm_object_page_remove(object, nobjsize, object->size, 426 0); 427 /* 428 * this gets rid of garbage at the end of a page that is now 429 * only partially backed by the vnode. 430 * 431 * XXX for some reason (I don't know yet), if we take a 432 * completely invalid page and mark it partially valid 433 * it can screw up NFS reads, so we don't allow the case. 434 */ 435 if ((nsize & PAGE_MASK) && 436 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 437 m->valid != 0) { 438 int base = (int)nsize & PAGE_MASK; 439 int size = PAGE_SIZE - base; 440 441 /* 442 * Clear out partial-page garbage in case 443 * the page has been mapped. 444 */ 445 pmap_zero_page_area(m, base, size); 446 447 /* 448 * Update the valid bits to reflect the blocks that 449 * have been zeroed. Some of these valid bits may 450 * have already been set. 451 */ 452 vm_page_set_valid_range(m, base, size); 453 454 /* 455 * Round "base" to the next block boundary so that the 456 * dirty bit for a partially zeroed block is not 457 * cleared. 458 */ 459 base = roundup2(base, DEV_BSIZE); 460 461 /* 462 * Clear out partial-page dirty bits. 463 * 464 * note that we do not clear out the valid 465 * bits. This would prevent bogus_page 466 * replacement from working properly. 467 */ 468 vm_page_clear_dirty(m, base, PAGE_SIZE - base); 469 } 470 } 471 object->un_pager.vnp.vnp_size = nsize; 472 object->size = nobjsize; 473 VM_OBJECT_WUNLOCK(object); 474 } 475 476 /* 477 * calculate the linear (byte) disk address of specified virtual 478 * file address 479 */ 480 static int 481 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 482 int *run) 483 { 484 int bsize; 485 int err; 486 daddr_t vblock; 487 daddr_t voffset; 488 489 if (address < 0) 490 return -1; 491 492 if (vp->v_iflag & VI_DOOMED) 493 return -1; 494 495 bsize = vp->v_mount->mnt_stat.f_iosize; 496 vblock = address / bsize; 497 voffset = address % bsize; 498 499 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 500 if (err == 0) { 501 if (*rtaddress != -1) 502 *rtaddress += voffset / DEV_BSIZE; 503 if (run) { 504 *run += 1; 505 *run *= bsize/PAGE_SIZE; 506 *run -= voffset/PAGE_SIZE; 507 } 508 } 509 510 return (err); 511 } 512 513 /* 514 * small block filesystem vnode pager input 515 */ 516 static int 517 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 518 { 519 struct vnode *vp; 520 struct bufobj *bo; 521 struct buf *bp; 522 struct sf_buf *sf; 523 daddr_t fileaddr; 524 vm_offset_t bsize; 525 vm_page_bits_t bits; 526 int error, i; 527 528 error = 0; 529 vp = object->handle; 530 if (vp->v_iflag & VI_DOOMED) 531 return VM_PAGER_BAD; 532 533 bsize = vp->v_mount->mnt_stat.f_iosize; 534 535 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 536 537 sf = sf_buf_alloc(m, 0); 538 539 for (i = 0; i < PAGE_SIZE / bsize; i++) { 540 vm_ooffset_t address; 541 542 bits = vm_page_bits(i * bsize, bsize); 543 if (m->valid & bits) 544 continue; 545 546 address = IDX_TO_OFF(m->pindex) + i * bsize; 547 if (address >= object->un_pager.vnp.vnp_size) { 548 fileaddr = -1; 549 } else { 550 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 551 if (error) 552 break; 553 } 554 if (fileaddr != -1) { 555 bp = getpbuf(&vnode_pbuf_freecnt); 556 557 /* build a minimal buffer header */ 558 bp->b_iocmd = BIO_READ; 559 bp->b_iodone = bdone; 560 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 561 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 562 bp->b_rcred = crhold(curthread->td_ucred); 563 bp->b_wcred = crhold(curthread->td_ucred); 564 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 565 bp->b_blkno = fileaddr; 566 pbgetbo(bo, bp); 567 bp->b_vp = vp; 568 bp->b_bcount = bsize; 569 bp->b_bufsize = bsize; 570 bp->b_runningbufspace = bp->b_bufsize; 571 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 572 573 /* do the input */ 574 bp->b_iooffset = dbtob(bp->b_blkno); 575 bstrategy(bp); 576 577 bwait(bp, PVM, "vnsrd"); 578 579 if ((bp->b_ioflags & BIO_ERROR) != 0) 580 error = EIO; 581 582 /* 583 * free the buffer header back to the swap buffer pool 584 */ 585 bp->b_vp = NULL; 586 pbrelbo(bp); 587 relpbuf(bp, &vnode_pbuf_freecnt); 588 if (error) 589 break; 590 } else 591 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 592 KASSERT((m->dirty & bits) == 0, 593 ("vnode_pager_input_smlfs: page %p is dirty", m)); 594 VM_OBJECT_WLOCK(object); 595 m->valid |= bits; 596 VM_OBJECT_WUNLOCK(object); 597 } 598 sf_buf_free(sf); 599 if (error) { 600 return VM_PAGER_ERROR; 601 } 602 return VM_PAGER_OK; 603 } 604 605 /* 606 * old style vnode pager input routine 607 */ 608 static int 609 vnode_pager_input_old(vm_object_t object, vm_page_t m) 610 { 611 struct uio auio; 612 struct iovec aiov; 613 int error; 614 int size; 615 struct sf_buf *sf; 616 struct vnode *vp; 617 618 VM_OBJECT_ASSERT_WLOCKED(object); 619 error = 0; 620 621 /* 622 * Return failure if beyond current EOF 623 */ 624 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 625 return VM_PAGER_BAD; 626 } else { 627 size = PAGE_SIZE; 628 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 629 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 630 vp = object->handle; 631 VM_OBJECT_WUNLOCK(object); 632 633 /* 634 * Allocate a kernel virtual address and initialize so that 635 * we can use VOP_READ/WRITE routines. 636 */ 637 sf = sf_buf_alloc(m, 0); 638 639 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 640 aiov.iov_len = size; 641 auio.uio_iov = &aiov; 642 auio.uio_iovcnt = 1; 643 auio.uio_offset = IDX_TO_OFF(m->pindex); 644 auio.uio_segflg = UIO_SYSSPACE; 645 auio.uio_rw = UIO_READ; 646 auio.uio_resid = size; 647 auio.uio_td = curthread; 648 649 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 650 if (!error) { 651 int count = size - auio.uio_resid; 652 653 if (count == 0) 654 error = EINVAL; 655 else if (count != PAGE_SIZE) 656 bzero((caddr_t)sf_buf_kva(sf) + count, 657 PAGE_SIZE - count); 658 } 659 sf_buf_free(sf); 660 661 VM_OBJECT_WLOCK(object); 662 } 663 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 664 if (!error) 665 m->valid = VM_PAGE_BITS_ALL; 666 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 667 } 668 669 /* 670 * generic vnode pager input routine 671 */ 672 673 /* 674 * Local media VFS's that do not implement their own VOP_GETPAGES 675 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 676 * to implement the previous behaviour. 677 * 678 * All other FS's should use the bypass to get to the local media 679 * backing vp's VOP_GETPAGES. 680 */ 681 static int 682 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 683 int *rahead) 684 { 685 struct vnode *vp; 686 int rtval; 687 688 vp = object->handle; 689 VM_OBJECT_WUNLOCK(object); 690 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 691 KASSERT(rtval != EOPNOTSUPP, 692 ("vnode_pager: FS getpages not implemented\n")); 693 VM_OBJECT_WLOCK(object); 694 return rtval; 695 } 696 697 static int 698 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 699 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 700 { 701 struct vnode *vp; 702 int rtval; 703 704 vp = object->handle; 705 VM_OBJECT_WUNLOCK(object); 706 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 707 KASSERT(rtval != EOPNOTSUPP, 708 ("vnode_pager: FS getpages_async not implemented\n")); 709 VM_OBJECT_WLOCK(object); 710 return (rtval); 711 } 712 713 /* 714 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 715 * local filesystems, where partially valid pages can only occur at 716 * the end of file. 717 */ 718 int 719 vnode_pager_local_getpages(struct vop_getpages_args *ap) 720 { 721 722 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 723 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 724 } 725 726 int 727 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 728 { 729 730 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 731 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg)); 732 } 733 734 /* 735 * This is now called from local media FS's to operate against their 736 * own vnodes if they fail to implement VOP_GETPAGES. 737 */ 738 int 739 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 740 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 741 { 742 vm_object_t object; 743 struct bufobj *bo; 744 struct buf *bp; 745 off_t foff; 746 #ifdef INVARIANTS 747 off_t blkno0; 748 #endif 749 int bsize, pagesperblock, *freecnt; 750 int error, before, after, rbehind, rahead, poff, i; 751 int bytecount, secmask; 752 753 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 754 ("%s does not support devices", __func__)); 755 756 if (vp->v_iflag & VI_DOOMED) 757 return (VM_PAGER_BAD); 758 759 object = vp->v_object; 760 foff = IDX_TO_OFF(m[0]->pindex); 761 bsize = vp->v_mount->mnt_stat.f_iosize; 762 pagesperblock = bsize / PAGE_SIZE; 763 764 KASSERT(foff < object->un_pager.vnp.vnp_size, 765 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 766 KASSERT(count <= sizeof(bp->b_pages), 767 ("%s: requested %d pages", __func__, count)); 768 769 /* 770 * The last page has valid blocks. Invalid part can only 771 * exist at the end of file, and the page is made fully valid 772 * by zeroing in vm_pager_get_pages(). 773 */ 774 if (m[count - 1]->valid != 0 && --count == 0) { 775 if (iodone != NULL) 776 iodone(arg, m, 1, 0); 777 return (VM_PAGER_OK); 778 } 779 780 /* 781 * Synchronous and asynchronous paging operations use different 782 * free pbuf counters. This is done to avoid asynchronous requests 783 * to consume all pbufs. 784 * Allocate the pbuf at the very beginning of the function, so that 785 * if we are low on certain kind of pbufs don't even proceed to BMAP, 786 * but sleep. 787 */ 788 freecnt = iodone != NULL ? 789 &vnode_async_pbuf_freecnt : &vnode_pbuf_freecnt; 790 bp = getpbuf(freecnt); 791 792 /* 793 * Get the underlying device blocks for the file with VOP_BMAP(). 794 * If the file system doesn't support VOP_BMAP, use old way of 795 * getting pages via VOP_READ. 796 */ 797 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 798 if (error == EOPNOTSUPP) { 799 relpbuf(bp, freecnt); 800 VM_OBJECT_WLOCK(object); 801 for (i = 0; i < count; i++) { 802 PCPU_INC(cnt.v_vnodein); 803 PCPU_INC(cnt.v_vnodepgsin); 804 error = vnode_pager_input_old(object, m[i]); 805 if (error) 806 break; 807 } 808 VM_OBJECT_WUNLOCK(object); 809 return (error); 810 } else if (error != 0) { 811 relpbuf(bp, freecnt); 812 return (VM_PAGER_ERROR); 813 } 814 815 /* 816 * If the file system supports BMAP, but blocksize is smaller 817 * than a page size, then use special small filesystem code. 818 */ 819 if (pagesperblock == 0) { 820 relpbuf(bp, freecnt); 821 for (i = 0; i < count; i++) { 822 PCPU_INC(cnt.v_vnodein); 823 PCPU_INC(cnt.v_vnodepgsin); 824 error = vnode_pager_input_smlfs(object, m[i]); 825 if (error) 826 break; 827 } 828 return (error); 829 } 830 831 /* 832 * A sparse file can be encountered only for a single page request, 833 * which may not be preceded by call to vm_pager_haspage(). 834 */ 835 if (bp->b_blkno == -1) { 836 KASSERT(count == 1, 837 ("%s: array[%d] request to a sparse file %p", __func__, 838 count, vp)); 839 relpbuf(bp, freecnt); 840 pmap_zero_page(m[0]); 841 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 842 __func__, m[0])); 843 VM_OBJECT_WLOCK(object); 844 m[0]->valid = VM_PAGE_BITS_ALL; 845 VM_OBJECT_WUNLOCK(object); 846 return (VM_PAGER_OK); 847 } 848 849 #ifdef INVARIANTS 850 blkno0 = bp->b_blkno; 851 #endif 852 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 853 854 /* Recalculate blocks available after/before to pages. */ 855 poff = (foff % bsize) / PAGE_SIZE; 856 before *= pagesperblock; 857 before += poff; 858 after *= pagesperblock; 859 after += pagesperblock - (poff + 1); 860 if (m[0]->pindex + after >= object->size) 861 after = object->size - 1 - m[0]->pindex; 862 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 863 __func__, count, after + 1)); 864 after -= count - 1; 865 866 /* Trim requested rbehind/rahead to possible values. */ 867 rbehind = a_rbehind ? *a_rbehind : 0; 868 rahead = a_rahead ? *a_rahead : 0; 869 rbehind = min(rbehind, before); 870 rbehind = min(rbehind, m[0]->pindex); 871 rahead = min(rahead, after); 872 rahead = min(rahead, object->size - m[count - 1]->pindex); 873 /* 874 * Check that total amount of pages fit into buf. Trim rbehind and 875 * rahead evenly if not. 876 */ 877 if (rbehind + rahead + count > nitems(bp->b_pages)) { 878 int trim, sum; 879 880 trim = rbehind + rahead + count - nitems(bp->b_pages) + 1; 881 sum = rbehind + rahead; 882 if (rbehind == before) { 883 /* Roundup rbehind trim to block size. */ 884 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 885 if (rbehind < 0) 886 rbehind = 0; 887 } else 888 rbehind -= trim * rbehind / sum; 889 rahead -= trim * rahead / sum; 890 } 891 KASSERT(rbehind + rahead + count <= nitems(bp->b_pages), 892 ("%s: behind %d ahead %d count %d", __func__, 893 rbehind, rahead, count)); 894 895 /* 896 * Fill in the bp->b_pages[] array with requested and optional 897 * read behind or read ahead pages. Read behind pages are looked 898 * up in a backward direction, down to a first cached page. Same 899 * for read ahead pages, but there is no need to shift the array 900 * in case of encountering a cached page. 901 */ 902 i = bp->b_npages = 0; 903 if (rbehind) { 904 vm_pindex_t startpindex, tpindex; 905 vm_page_t p; 906 907 VM_OBJECT_WLOCK(object); 908 startpindex = m[0]->pindex - rbehind; 909 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 910 p->pindex >= startpindex) 911 startpindex = p->pindex + 1; 912 913 /* tpindex is unsigned; beware of numeric underflow. */ 914 for (tpindex = m[0]->pindex - 1; 915 tpindex >= startpindex && tpindex < m[0]->pindex; 916 tpindex--, i++) { 917 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 918 if (p == NULL) { 919 /* Shift the array. */ 920 for (int j = 0; j < i; j++) 921 bp->b_pages[j] = bp->b_pages[j + 922 tpindex + 1 - startpindex]; 923 break; 924 } 925 bp->b_pages[tpindex - startpindex] = p; 926 } 927 928 bp->b_pgbefore = i; 929 bp->b_npages += i; 930 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 931 } else 932 bp->b_pgbefore = 0; 933 934 /* Requested pages. */ 935 for (int j = 0; j < count; j++, i++) 936 bp->b_pages[i] = m[j]; 937 bp->b_npages += count; 938 939 if (rahead) { 940 vm_pindex_t endpindex, tpindex; 941 vm_page_t p; 942 943 if (!VM_OBJECT_WOWNED(object)) 944 VM_OBJECT_WLOCK(object); 945 endpindex = m[count - 1]->pindex + rahead + 1; 946 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 947 p->pindex < endpindex) 948 endpindex = p->pindex; 949 if (endpindex > object->size) 950 endpindex = object->size; 951 952 for (tpindex = m[count - 1]->pindex + 1; 953 tpindex < endpindex; i++, tpindex++) { 954 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 955 if (p == NULL) 956 break; 957 bp->b_pages[i] = p; 958 } 959 960 bp->b_pgafter = i - bp->b_npages; 961 bp->b_npages = i; 962 } else 963 bp->b_pgafter = 0; 964 965 if (VM_OBJECT_WOWNED(object)) 966 VM_OBJECT_WUNLOCK(object); 967 968 /* Report back actual behind/ahead read. */ 969 if (a_rbehind) 970 *a_rbehind = bp->b_pgbefore; 971 if (a_rahead) 972 *a_rahead = bp->b_pgafter; 973 974 #ifdef INVARIANTS 975 KASSERT(bp->b_npages <= nitems(bp->b_pages), 976 ("%s: buf %p overflowed", __func__, bp)); 977 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 978 if (bp->b_pages[j] == bogus_page) 979 continue; 980 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 981 j - prev, ("%s: pages array not consecutive, bp %p", 982 __func__, bp)); 983 prev = j; 984 } 985 #endif 986 987 /* 988 * Recalculate first offset and bytecount with regards to read behind. 989 * Truncate bytecount to vnode real size and round up physical size 990 * for real devices. 991 */ 992 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 993 bytecount = bp->b_npages << PAGE_SHIFT; 994 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 995 bytecount = object->un_pager.vnp.vnp_size - foff; 996 secmask = bo->bo_bsize - 1; 997 KASSERT(secmask < PAGE_SIZE && secmask > 0, 998 ("%s: sector size %d too large", __func__, secmask + 1)); 999 bytecount = (bytecount + secmask) & ~secmask; 1000 1001 /* 1002 * And map the pages to be read into the kva, if the filesystem 1003 * requires mapped buffers. 1004 */ 1005 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1006 unmapped_buf_allowed) { 1007 bp->b_data = unmapped_buf; 1008 bp->b_offset = 0; 1009 } else { 1010 bp->b_data = bp->b_kvabase; 1011 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1012 } 1013 1014 /* Build a minimal buffer header. */ 1015 bp->b_iocmd = BIO_READ; 1016 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1017 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1018 bp->b_rcred = crhold(curthread->td_ucred); 1019 bp->b_wcred = crhold(curthread->td_ucred); 1020 pbgetbo(bo, bp); 1021 bp->b_vp = vp; 1022 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1023 bp->b_iooffset = dbtob(bp->b_blkno); 1024 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1025 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1026 IDX_TO_OFF(m[0]->pindex) % bsize, 1027 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1028 "blkno0 %ju b_blkno %ju", bsize, 1029 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1030 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1031 1032 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1033 PCPU_INC(cnt.v_vnodein); 1034 PCPU_ADD(cnt.v_vnodepgsin, bp->b_npages); 1035 1036 if (iodone != NULL) { /* async */ 1037 bp->b_pgiodone = iodone; 1038 bp->b_caller1 = arg; 1039 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1040 bp->b_flags |= B_ASYNC; 1041 BUF_KERNPROC(bp); 1042 bstrategy(bp); 1043 return (VM_PAGER_OK); 1044 } else { 1045 bp->b_iodone = bdone; 1046 bstrategy(bp); 1047 bwait(bp, PVM, "vnread"); 1048 error = vnode_pager_generic_getpages_done(bp); 1049 for (i = 0; i < bp->b_npages; i++) 1050 bp->b_pages[i] = NULL; 1051 bp->b_vp = NULL; 1052 pbrelbo(bp); 1053 relpbuf(bp, &vnode_pbuf_freecnt); 1054 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1055 } 1056 } 1057 1058 static void 1059 vnode_pager_generic_getpages_done_async(struct buf *bp) 1060 { 1061 int error; 1062 1063 error = vnode_pager_generic_getpages_done(bp); 1064 /* Run the iodone upon the requested range. */ 1065 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1066 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1067 for (int i = 0; i < bp->b_npages; i++) 1068 bp->b_pages[i] = NULL; 1069 bp->b_vp = NULL; 1070 pbrelbo(bp); 1071 relpbuf(bp, &vnode_async_pbuf_freecnt); 1072 } 1073 1074 static int 1075 vnode_pager_generic_getpages_done(struct buf *bp) 1076 { 1077 vm_object_t object; 1078 off_t tfoff, nextoff; 1079 int i, error; 1080 1081 error = (bp->b_ioflags & BIO_ERROR) != 0 ? EIO : 0; 1082 object = bp->b_vp->v_object; 1083 1084 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1085 if (!buf_mapped(bp)) { 1086 bp->b_data = bp->b_kvabase; 1087 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1088 bp->b_npages); 1089 } 1090 bzero(bp->b_data + bp->b_bcount, 1091 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1092 } 1093 if (buf_mapped(bp)) { 1094 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1095 bp->b_data = unmapped_buf; 1096 } 1097 1098 VM_OBJECT_WLOCK(object); 1099 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1100 i < bp->b_npages; i++, tfoff = nextoff) { 1101 vm_page_t mt; 1102 1103 nextoff = tfoff + PAGE_SIZE; 1104 mt = bp->b_pages[i]; 1105 1106 if (nextoff <= object->un_pager.vnp.vnp_size) { 1107 /* 1108 * Read filled up entire page. 1109 */ 1110 mt->valid = VM_PAGE_BITS_ALL; 1111 KASSERT(mt->dirty == 0, 1112 ("%s: page %p is dirty", __func__, mt)); 1113 KASSERT(!pmap_page_is_mapped(mt), 1114 ("%s: page %p is mapped", __func__, mt)); 1115 } else { 1116 /* 1117 * Read did not fill up entire page. 1118 * 1119 * Currently we do not set the entire page valid, 1120 * we just try to clear the piece that we couldn't 1121 * read. 1122 */ 1123 vm_page_set_valid_range(mt, 0, 1124 object->un_pager.vnp.vnp_size - tfoff); 1125 KASSERT((mt->dirty & vm_page_bits(0, 1126 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1127 ("%s: page %p is dirty", __func__, mt)); 1128 } 1129 1130 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1131 vm_page_readahead_finish(mt); 1132 } 1133 VM_OBJECT_WUNLOCK(object); 1134 if (error != 0) 1135 printf("%s: I/O read error %d\n", __func__, error); 1136 1137 return (error); 1138 } 1139 1140 /* 1141 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1142 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1143 * vnode_pager_generic_putpages() to implement the previous behaviour. 1144 * 1145 * All other FS's should use the bypass to get to the local media 1146 * backing vp's VOP_PUTPAGES. 1147 */ 1148 static void 1149 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1150 int flags, int *rtvals) 1151 { 1152 int rtval; 1153 struct vnode *vp; 1154 int bytes = count * PAGE_SIZE; 1155 1156 /* 1157 * Force synchronous operation if we are extremely low on memory 1158 * to prevent a low-memory deadlock. VOP operations often need to 1159 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1160 * operation ). The swapper handles the case by limiting the amount 1161 * of asynchronous I/O, but that sort of solution doesn't scale well 1162 * for the vnode pager without a lot of work. 1163 * 1164 * Also, the backing vnode's iodone routine may not wake the pageout 1165 * daemon up. This should be probably be addressed XXX. 1166 */ 1167 1168 if (vm_cnt.v_free_count < vm_cnt.v_pageout_free_min) 1169 flags |= VM_PAGER_PUT_SYNC; 1170 1171 /* 1172 * Call device-specific putpages function 1173 */ 1174 vp = object->handle; 1175 VM_OBJECT_WUNLOCK(object); 1176 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1177 KASSERT(rtval != EOPNOTSUPP, 1178 ("vnode_pager: stale FS putpages\n")); 1179 VM_OBJECT_WLOCK(object); 1180 } 1181 1182 1183 /* 1184 * This is now called from local media FS's to operate against their 1185 * own vnodes if they fail to implement VOP_PUTPAGES. 1186 * 1187 * This is typically called indirectly via the pageout daemon and 1188 * clustering has already typically occurred, so in general we ask the 1189 * underlying filesystem to write the data out asynchronously rather 1190 * then delayed. 1191 */ 1192 int 1193 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1194 int flags, int *rtvals) 1195 { 1196 int i; 1197 vm_object_t object; 1198 vm_page_t m; 1199 int count; 1200 1201 int maxsize, ncount; 1202 vm_ooffset_t poffset; 1203 struct uio auio; 1204 struct iovec aiov; 1205 int error; 1206 int ioflags; 1207 int ppscheck = 0; 1208 static struct timeval lastfail; 1209 static int curfail; 1210 1211 object = vp->v_object; 1212 count = bytecount / PAGE_SIZE; 1213 1214 for (i = 0; i < count; i++) 1215 rtvals[i] = VM_PAGER_ERROR; 1216 1217 if ((int64_t)ma[0]->pindex < 0) { 1218 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", 1219 (long)ma[0]->pindex, (u_long)ma[0]->dirty); 1220 rtvals[0] = VM_PAGER_BAD; 1221 return VM_PAGER_BAD; 1222 } 1223 1224 maxsize = count * PAGE_SIZE; 1225 ncount = count; 1226 1227 poffset = IDX_TO_OFF(ma[0]->pindex); 1228 1229 /* 1230 * If the page-aligned write is larger then the actual file we 1231 * have to invalidate pages occurring beyond the file EOF. However, 1232 * there is an edge case where a file may not be page-aligned where 1233 * the last page is partially invalid. In this case the filesystem 1234 * may not properly clear the dirty bits for the entire page (which 1235 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1236 * With the page locked we are free to fix-up the dirty bits here. 1237 * 1238 * We do not under any circumstances truncate the valid bits, as 1239 * this will screw up bogus page replacement. 1240 */ 1241 VM_OBJECT_WLOCK(object); 1242 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1243 if (object->un_pager.vnp.vnp_size > poffset) { 1244 int pgoff; 1245 1246 maxsize = object->un_pager.vnp.vnp_size - poffset; 1247 ncount = btoc(maxsize); 1248 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1249 /* 1250 * If the object is locked and the following 1251 * conditions hold, then the page's dirty 1252 * field cannot be concurrently changed by a 1253 * pmap operation. 1254 */ 1255 m = ma[ncount - 1]; 1256 vm_page_assert_sbusied(m); 1257 KASSERT(!pmap_page_is_write_mapped(m), 1258 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1259 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1260 pgoff); 1261 } 1262 } else { 1263 maxsize = 0; 1264 ncount = 0; 1265 } 1266 if (ncount < count) { 1267 for (i = ncount; i < count; i++) { 1268 rtvals[i] = VM_PAGER_BAD; 1269 } 1270 } 1271 } 1272 VM_OBJECT_WUNLOCK(object); 1273 1274 /* 1275 * pageouts are already clustered, use IO_ASYNC to force a bawrite() 1276 * rather then a bdwrite() to prevent paging I/O from saturating 1277 * the buffer cache. Dummy-up the sequential heuristic to cause 1278 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, 1279 * the system decides how to cluster. 1280 */ 1281 ioflags = IO_VMIO; 1282 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) 1283 ioflags |= IO_SYNC; 1284 else if ((flags & VM_PAGER_CLUSTER_OK) == 0) 1285 ioflags |= IO_ASYNC; 1286 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; 1287 ioflags |= (flags & VM_PAGER_PUT_NOREUSE) ? IO_NOREUSE : 0; 1288 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1289 1290 aiov.iov_base = (caddr_t) 0; 1291 aiov.iov_len = maxsize; 1292 auio.uio_iov = &aiov; 1293 auio.uio_iovcnt = 1; 1294 auio.uio_offset = poffset; 1295 auio.uio_segflg = UIO_NOCOPY; 1296 auio.uio_rw = UIO_WRITE; 1297 auio.uio_resid = maxsize; 1298 auio.uio_td = (struct thread *) 0; 1299 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); 1300 PCPU_INC(cnt.v_vnodeout); 1301 PCPU_ADD(cnt.v_vnodepgsout, ncount); 1302 1303 if (error) { 1304 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) 1305 printf("vnode_pager_putpages: I/O error %d\n", error); 1306 } 1307 if (auio.uio_resid) { 1308 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) 1309 printf("vnode_pager_putpages: residual I/O %zd at %lu\n", 1310 auio.uio_resid, (u_long)ma[0]->pindex); 1311 } 1312 for (i = 0; i < ncount; i++) { 1313 rtvals[i] = VM_PAGER_OK; 1314 } 1315 return rtvals[0]; 1316 } 1317 1318 void 1319 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written) 1320 { 1321 vm_object_t obj; 1322 int i, pos; 1323 1324 if (written == 0) 1325 return; 1326 obj = ma[0]->object; 1327 VM_OBJECT_WLOCK(obj); 1328 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1329 if (pos < trunc_page(written)) { 1330 rtvals[i] = VM_PAGER_OK; 1331 vm_page_undirty(ma[i]); 1332 } else { 1333 /* Partially written page. */ 1334 rtvals[i] = VM_PAGER_AGAIN; 1335 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1336 } 1337 } 1338 VM_OBJECT_WUNLOCK(obj); 1339 } 1340 1341 void 1342 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1343 vm_offset_t end) 1344 { 1345 struct vnode *vp; 1346 vm_ooffset_t old_wm; 1347 1348 VM_OBJECT_WLOCK(object); 1349 if (object->type != OBJT_VNODE) { 1350 VM_OBJECT_WUNLOCK(object); 1351 return; 1352 } 1353 old_wm = object->un_pager.vnp.writemappings; 1354 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1355 vp = object->handle; 1356 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1357 ASSERT_VOP_ELOCKED(vp, "v_writecount inc"); 1358 VOP_ADD_WRITECOUNT(vp, 1); 1359 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1360 __func__, vp, vp->v_writecount); 1361 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1362 ASSERT_VOP_ELOCKED(vp, "v_writecount dec"); 1363 VOP_ADD_WRITECOUNT(vp, -1); 1364 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1365 __func__, vp, vp->v_writecount); 1366 } 1367 VM_OBJECT_WUNLOCK(object); 1368 } 1369 1370 void 1371 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1372 vm_offset_t end) 1373 { 1374 struct vnode *vp; 1375 struct mount *mp; 1376 vm_offset_t inc; 1377 1378 VM_OBJECT_WLOCK(object); 1379 1380 /* 1381 * First, recheck the object type to account for the race when 1382 * the vnode is reclaimed. 1383 */ 1384 if (object->type != OBJT_VNODE) { 1385 VM_OBJECT_WUNLOCK(object); 1386 return; 1387 } 1388 1389 /* 1390 * Optimize for the case when writemappings is not going to 1391 * zero. 1392 */ 1393 inc = end - start; 1394 if (object->un_pager.vnp.writemappings != inc) { 1395 object->un_pager.vnp.writemappings -= inc; 1396 VM_OBJECT_WUNLOCK(object); 1397 return; 1398 } 1399 1400 vp = object->handle; 1401 vhold(vp); 1402 VM_OBJECT_WUNLOCK(object); 1403 mp = NULL; 1404 vn_start_write(vp, &mp, V_WAIT); 1405 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1406 1407 /* 1408 * Decrement the object's writemappings, by swapping the start 1409 * and end arguments for vnode_pager_update_writecount(). If 1410 * there was not a race with vnode reclaimation, then the 1411 * vnode's v_writecount is decremented. 1412 */ 1413 vnode_pager_update_writecount(object, end, start); 1414 VOP_UNLOCK(vp, 0); 1415 vdrop(vp); 1416 if (mp != NULL) 1417 vn_finished_write(mp); 1418 } 1419