1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1990 University of Utah. 5 * Copyright (c) 1991 The Regents of the University of California. 6 * All rights reserved. 7 * Copyright (c) 1993, 1994 John S. Dyson 8 * Copyright (c) 1995, David Greenman 9 * 10 * This code is derived from software contributed to Berkeley by 11 * the Systems Programming Group of the University of Utah Computer 12 * Science Department. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91 43 */ 44 45 /* 46 * Page to/from files (vnodes). 47 */ 48 49 /* 50 * TODO: 51 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 52 * greatly re-simplify the vnode_pager. 53 */ 54 55 #include <sys/cdefs.h> 56 __FBSDID("$FreeBSD$"); 57 58 #include "opt_vm.h" 59 60 #include <sys/param.h> 61 #include <sys/kernel.h> 62 #include <sys/systm.h> 63 #include <sys/sysctl.h> 64 #include <sys/proc.h> 65 #include <sys/vnode.h> 66 #include <sys/mount.h> 67 #include <sys/bio.h> 68 #include <sys/buf.h> 69 #include <sys/vmmeter.h> 70 #include <sys/ktr.h> 71 #include <sys/limits.h> 72 #include <sys/conf.h> 73 #include <sys/rwlock.h> 74 #include <sys/sf_buf.h> 75 #include <sys/domainset.h> 76 77 #include <machine/atomic.h> 78 79 #include <vm/vm.h> 80 #include <vm/vm_param.h> 81 #include <vm/vm_object.h> 82 #include <vm/vm_page.h> 83 #include <vm/vm_pager.h> 84 #include <vm/vm_map.h> 85 #include <vm/vnode_pager.h> 86 #include <vm/vm_extern.h> 87 #include <vm/uma.h> 88 89 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 90 daddr_t *rtaddress, int *run); 91 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 92 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 93 static void vnode_pager_dealloc(vm_object_t); 94 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 95 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, 96 int *, vop_getpages_iodone_t, void *); 97 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 98 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 99 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 100 vm_ooffset_t, struct ucred *cred); 101 static int vnode_pager_generic_getpages_done(struct buf *); 102 static void vnode_pager_generic_getpages_done_async(struct buf *); 103 104 struct pagerops vnodepagerops = { 105 .pgo_alloc = vnode_pager_alloc, 106 .pgo_dealloc = vnode_pager_dealloc, 107 .pgo_getpages = vnode_pager_getpages, 108 .pgo_getpages_async = vnode_pager_getpages_async, 109 .pgo_putpages = vnode_pager_putpages, 110 .pgo_haspage = vnode_pager_haspage, 111 }; 112 113 static struct domainset *vnode_domainset = NULL; 114 115 SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset, CTLTYPE_STRING | CTLFLAG_RW, 116 &vnode_domainset, 0, sysctl_handle_domainset, "A", 117 "Default vnode NUMA policy"); 118 119 static int nvnpbufs; 120 SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 121 &nvnpbufs, 0, "number of physical buffers allocated for vnode pager"); 122 123 static uma_zone_t vnode_pbuf_zone; 124 125 static void 126 vnode_pager_init(void *dummy) 127 { 128 129 #ifdef __LP64__ 130 nvnpbufs = nswbuf * 2; 131 #else 132 nvnpbufs = nswbuf / 2; 133 #endif 134 TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs); 135 vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs); 136 } 137 SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL); 138 139 /* Create the VM system backing object for this vnode */ 140 int 141 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 142 { 143 vm_object_t object; 144 vm_ooffset_t size = isize; 145 struct vattr va; 146 147 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 148 return (0); 149 150 while ((object = vp->v_object) != NULL) { 151 VM_OBJECT_WLOCK(object); 152 if (!(object->flags & OBJ_DEAD)) { 153 VM_OBJECT_WUNLOCK(object); 154 return (0); 155 } 156 VOP_UNLOCK(vp, 0); 157 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 158 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vodead", 0); 159 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 160 } 161 162 if (size == 0) { 163 if (vn_isdisk(vp, NULL)) { 164 size = IDX_TO_OFF(INT_MAX); 165 } else { 166 if (VOP_GETATTR(vp, &va, td->td_ucred)) 167 return (0); 168 size = va.va_size; 169 } 170 } 171 172 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 173 /* 174 * Dereference the reference we just created. This assumes 175 * that the object is associated with the vp. 176 */ 177 VM_OBJECT_WLOCK(object); 178 object->ref_count--; 179 VM_OBJECT_WUNLOCK(object); 180 vrele(vp); 181 182 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 183 184 return (0); 185 } 186 187 void 188 vnode_destroy_vobject(struct vnode *vp) 189 { 190 struct vm_object *obj; 191 192 obj = vp->v_object; 193 if (obj == NULL) 194 return; 195 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 196 VM_OBJECT_WLOCK(obj); 197 umtx_shm_object_terminated(obj); 198 if (obj->ref_count == 0) { 199 /* 200 * don't double-terminate the object 201 */ 202 if ((obj->flags & OBJ_DEAD) == 0) { 203 vm_object_terminate(obj); 204 } else { 205 /* 206 * Waiters were already handled during object 207 * termination. The exclusive vnode lock hopefully 208 * prevented new waiters from referencing the dying 209 * object. 210 */ 211 KASSERT((obj->flags & OBJ_DISCONNECTWNT) == 0, 212 ("OBJ_DISCONNECTWNT set obj %p flags %x", 213 obj, obj->flags)); 214 vp->v_object = NULL; 215 VM_OBJECT_WUNLOCK(obj); 216 } 217 } else { 218 /* 219 * Woe to the process that tries to page now :-). 220 */ 221 vm_pager_deallocate(obj); 222 VM_OBJECT_WUNLOCK(obj); 223 } 224 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object)); 225 } 226 227 228 /* 229 * Allocate (or lookup) pager for a vnode. 230 * Handle is a vnode pointer. 231 * 232 * MPSAFE 233 */ 234 vm_object_t 235 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 236 vm_ooffset_t offset, struct ucred *cred) 237 { 238 vm_object_t object; 239 struct vnode *vp; 240 241 /* 242 * Pageout to vnode, no can do yet. 243 */ 244 if (handle == NULL) 245 return (NULL); 246 247 vp = (struct vnode *) handle; 248 249 /* 250 * If the object is being terminated, wait for it to 251 * go away. 252 */ 253 retry: 254 while ((object = vp->v_object) != NULL) { 255 VM_OBJECT_WLOCK(object); 256 if ((object->flags & OBJ_DEAD) == 0) 257 break; 258 vm_object_set_flag(object, OBJ_DISCONNECTWNT); 259 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vadead", 0); 260 } 261 262 KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference")); 263 264 if (object == NULL) { 265 /* 266 * Add an object of the appropriate size 267 */ 268 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); 269 270 object->un_pager.vnp.vnp_size = size; 271 object->un_pager.vnp.writemappings = 0; 272 object->domain.dr_policy = vnode_domainset; 273 274 object->handle = handle; 275 VI_LOCK(vp); 276 if (vp->v_object != NULL) { 277 /* 278 * Object has been created while we were sleeping 279 */ 280 VI_UNLOCK(vp); 281 VM_OBJECT_WLOCK(object); 282 KASSERT(object->ref_count == 1, 283 ("leaked ref %p %d", object, object->ref_count)); 284 object->type = OBJT_DEAD; 285 object->ref_count = 0; 286 VM_OBJECT_WUNLOCK(object); 287 vm_object_destroy(object); 288 goto retry; 289 } 290 vp->v_object = object; 291 VI_UNLOCK(vp); 292 } else { 293 object->ref_count++; 294 #if VM_NRESERVLEVEL > 0 295 vm_object_color(object, 0); 296 #endif 297 VM_OBJECT_WUNLOCK(object); 298 } 299 vrefact(vp); 300 return (object); 301 } 302 303 /* 304 * The object must be locked. 305 */ 306 static void 307 vnode_pager_dealloc(vm_object_t object) 308 { 309 struct vnode *vp; 310 int refs; 311 312 vp = object->handle; 313 if (vp == NULL) 314 panic("vnode_pager_dealloc: pager already dealloced"); 315 316 VM_OBJECT_ASSERT_WLOCKED(object); 317 vm_object_pip_wait(object, "vnpdea"); 318 refs = object->ref_count; 319 320 object->handle = NULL; 321 object->type = OBJT_DEAD; 322 if (object->flags & OBJ_DISCONNECTWNT) { 323 vm_object_clear_flag(object, OBJ_DISCONNECTWNT); 324 wakeup(object); 325 } 326 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 327 if (object->un_pager.vnp.writemappings > 0) { 328 object->un_pager.vnp.writemappings = 0; 329 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 330 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 331 __func__, vp, vp->v_writecount); 332 } 333 vp->v_object = NULL; 334 VI_LOCK(vp); 335 336 /* 337 * vm_map_entry_set_vnode_text() cannot reach this vnode by 338 * following object->handle. Clear all text references now. 339 * This also clears the transient references from 340 * kern_execve(), which is fine because dead_vnodeops uses nop 341 * for VOP_UNSET_TEXT(). 342 */ 343 if (vp->v_writecount < 0) 344 vp->v_writecount = 0; 345 VI_UNLOCK(vp); 346 VM_OBJECT_WUNLOCK(object); 347 while (refs-- > 0) 348 vunref(vp); 349 VM_OBJECT_WLOCK(object); 350 } 351 352 static boolean_t 353 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 354 int *after) 355 { 356 struct vnode *vp = object->handle; 357 daddr_t bn; 358 int err; 359 daddr_t reqblock; 360 int poff; 361 int bsize; 362 int pagesperblock, blocksperpage; 363 364 VM_OBJECT_ASSERT_WLOCKED(object); 365 /* 366 * If no vp or vp is doomed or marked transparent to VM, we do not 367 * have the page. 368 */ 369 if (vp == NULL || vp->v_iflag & VI_DOOMED) 370 return FALSE; 371 /* 372 * If the offset is beyond end of file we do 373 * not have the page. 374 */ 375 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 376 return FALSE; 377 378 bsize = vp->v_mount->mnt_stat.f_iosize; 379 pagesperblock = bsize / PAGE_SIZE; 380 blocksperpage = 0; 381 if (pagesperblock > 0) { 382 reqblock = pindex / pagesperblock; 383 } else { 384 blocksperpage = (PAGE_SIZE / bsize); 385 reqblock = pindex * blocksperpage; 386 } 387 VM_OBJECT_WUNLOCK(object); 388 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 389 VM_OBJECT_WLOCK(object); 390 if (err) 391 return TRUE; 392 if (bn == -1) 393 return FALSE; 394 if (pagesperblock > 0) { 395 poff = pindex - (reqblock * pagesperblock); 396 if (before) { 397 *before *= pagesperblock; 398 *before += poff; 399 } 400 if (after) { 401 /* 402 * The BMAP vop can report a partial block in the 403 * 'after', but must not report blocks after EOF. 404 * Assert the latter, and truncate 'after' in case 405 * of the former. 406 */ 407 KASSERT((reqblock + *after) * pagesperblock < 408 roundup2(object->size, pagesperblock), 409 ("%s: reqblock %jd after %d size %ju", __func__, 410 (intmax_t )reqblock, *after, 411 (uintmax_t )object->size)); 412 *after *= pagesperblock; 413 *after += pagesperblock - (poff + 1); 414 if (pindex + *after >= object->size) 415 *after = object->size - 1 - pindex; 416 } 417 } else { 418 if (before) { 419 *before /= blocksperpage; 420 } 421 422 if (after) { 423 *after /= blocksperpage; 424 } 425 } 426 return TRUE; 427 } 428 429 /* 430 * Lets the VM system know about a change in size for a file. 431 * We adjust our own internal size and flush any cached pages in 432 * the associated object that are affected by the size change. 433 * 434 * Note: this routine may be invoked as a result of a pager put 435 * operation (possibly at object termination time), so we must be careful. 436 */ 437 void 438 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 439 { 440 vm_object_t object; 441 vm_page_t m; 442 vm_pindex_t nobjsize; 443 444 if ((object = vp->v_object) == NULL) 445 return; 446 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */ 447 VM_OBJECT_WLOCK(object); 448 if (object->type == OBJT_DEAD) { 449 VM_OBJECT_WUNLOCK(object); 450 return; 451 } 452 KASSERT(object->type == OBJT_VNODE, 453 ("not vnode-backed object %p", object)); 454 if (nsize == object->un_pager.vnp.vnp_size) { 455 /* 456 * Hasn't changed size 457 */ 458 VM_OBJECT_WUNLOCK(object); 459 return; 460 } 461 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 462 if (nsize < object->un_pager.vnp.vnp_size) { 463 /* 464 * File has shrunk. Toss any cached pages beyond the new EOF. 465 */ 466 if (nobjsize < object->size) 467 vm_object_page_remove(object, nobjsize, object->size, 468 0); 469 /* 470 * this gets rid of garbage at the end of a page that is now 471 * only partially backed by the vnode. 472 * 473 * XXX for some reason (I don't know yet), if we take a 474 * completely invalid page and mark it partially valid 475 * it can screw up NFS reads, so we don't allow the case. 476 */ 477 if ((nsize & PAGE_MASK) && 478 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && 479 m->valid != 0) { 480 int base = (int)nsize & PAGE_MASK; 481 int size = PAGE_SIZE - base; 482 483 /* 484 * Clear out partial-page garbage in case 485 * the page has been mapped. 486 */ 487 pmap_zero_page_area(m, base, size); 488 489 /* 490 * Update the valid bits to reflect the blocks that 491 * have been zeroed. Some of these valid bits may 492 * have already been set. 493 */ 494 vm_page_set_valid_range(m, base, size); 495 496 /* 497 * Round "base" to the next block boundary so that the 498 * dirty bit for a partially zeroed block is not 499 * cleared. 500 */ 501 base = roundup2(base, DEV_BSIZE); 502 503 /* 504 * Clear out partial-page dirty bits. 505 * 506 * note that we do not clear out the valid 507 * bits. This would prevent bogus_page 508 * replacement from working properly. 509 */ 510 vm_page_clear_dirty(m, base, PAGE_SIZE - base); 511 } 512 } 513 object->un_pager.vnp.vnp_size = nsize; 514 object->size = nobjsize; 515 VM_OBJECT_WUNLOCK(object); 516 } 517 518 /* 519 * calculate the linear (byte) disk address of specified virtual 520 * file address 521 */ 522 static int 523 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 524 int *run) 525 { 526 int bsize; 527 int err; 528 daddr_t vblock; 529 daddr_t voffset; 530 531 if (address < 0) 532 return -1; 533 534 if (vp->v_iflag & VI_DOOMED) 535 return -1; 536 537 bsize = vp->v_mount->mnt_stat.f_iosize; 538 vblock = address / bsize; 539 voffset = address % bsize; 540 541 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 542 if (err == 0) { 543 if (*rtaddress != -1) 544 *rtaddress += voffset / DEV_BSIZE; 545 if (run) { 546 *run += 1; 547 *run *= bsize/PAGE_SIZE; 548 *run -= voffset/PAGE_SIZE; 549 } 550 } 551 552 return (err); 553 } 554 555 /* 556 * small block filesystem vnode pager input 557 */ 558 static int 559 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 560 { 561 struct vnode *vp; 562 struct bufobj *bo; 563 struct buf *bp; 564 struct sf_buf *sf; 565 daddr_t fileaddr; 566 vm_offset_t bsize; 567 vm_page_bits_t bits; 568 int error, i; 569 570 error = 0; 571 vp = object->handle; 572 if (vp->v_iflag & VI_DOOMED) 573 return VM_PAGER_BAD; 574 575 bsize = vp->v_mount->mnt_stat.f_iosize; 576 577 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 578 579 sf = sf_buf_alloc(m, 0); 580 581 for (i = 0; i < PAGE_SIZE / bsize; i++) { 582 vm_ooffset_t address; 583 584 bits = vm_page_bits(i * bsize, bsize); 585 if (m->valid & bits) 586 continue; 587 588 address = IDX_TO_OFF(m->pindex) + i * bsize; 589 if (address >= object->un_pager.vnp.vnp_size) { 590 fileaddr = -1; 591 } else { 592 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 593 if (error) 594 break; 595 } 596 if (fileaddr != -1) { 597 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 598 599 /* build a minimal buffer header */ 600 bp->b_iocmd = BIO_READ; 601 bp->b_iodone = bdone; 602 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 603 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 604 bp->b_rcred = crhold(curthread->td_ucred); 605 bp->b_wcred = crhold(curthread->td_ucred); 606 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 607 bp->b_blkno = fileaddr; 608 pbgetbo(bo, bp); 609 bp->b_vp = vp; 610 bp->b_bcount = bsize; 611 bp->b_bufsize = bsize; 612 bp->b_runningbufspace = bp->b_bufsize; 613 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 614 615 /* do the input */ 616 bp->b_iooffset = dbtob(bp->b_blkno); 617 bstrategy(bp); 618 619 bwait(bp, PVM, "vnsrd"); 620 621 if ((bp->b_ioflags & BIO_ERROR) != 0) 622 error = EIO; 623 624 /* 625 * free the buffer header back to the swap buffer pool 626 */ 627 bp->b_vp = NULL; 628 pbrelbo(bp); 629 uma_zfree(vnode_pbuf_zone, bp); 630 if (error) 631 break; 632 } else 633 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 634 KASSERT((m->dirty & bits) == 0, 635 ("vnode_pager_input_smlfs: page %p is dirty", m)); 636 VM_OBJECT_WLOCK(object); 637 m->valid |= bits; 638 VM_OBJECT_WUNLOCK(object); 639 } 640 sf_buf_free(sf); 641 if (error) { 642 return VM_PAGER_ERROR; 643 } 644 return VM_PAGER_OK; 645 } 646 647 /* 648 * old style vnode pager input routine 649 */ 650 static int 651 vnode_pager_input_old(vm_object_t object, vm_page_t m) 652 { 653 struct uio auio; 654 struct iovec aiov; 655 int error; 656 int size; 657 struct sf_buf *sf; 658 struct vnode *vp; 659 660 VM_OBJECT_ASSERT_WLOCKED(object); 661 error = 0; 662 663 /* 664 * Return failure if beyond current EOF 665 */ 666 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 667 return VM_PAGER_BAD; 668 } else { 669 size = PAGE_SIZE; 670 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 671 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 672 vp = object->handle; 673 VM_OBJECT_WUNLOCK(object); 674 675 /* 676 * Allocate a kernel virtual address and initialize so that 677 * we can use VOP_READ/WRITE routines. 678 */ 679 sf = sf_buf_alloc(m, 0); 680 681 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 682 aiov.iov_len = size; 683 auio.uio_iov = &aiov; 684 auio.uio_iovcnt = 1; 685 auio.uio_offset = IDX_TO_OFF(m->pindex); 686 auio.uio_segflg = UIO_SYSSPACE; 687 auio.uio_rw = UIO_READ; 688 auio.uio_resid = size; 689 auio.uio_td = curthread; 690 691 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 692 if (!error) { 693 int count = size - auio.uio_resid; 694 695 if (count == 0) 696 error = EINVAL; 697 else if (count != PAGE_SIZE) 698 bzero((caddr_t)sf_buf_kva(sf) + count, 699 PAGE_SIZE - count); 700 } 701 sf_buf_free(sf); 702 703 VM_OBJECT_WLOCK(object); 704 } 705 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 706 if (!error) 707 m->valid = VM_PAGE_BITS_ALL; 708 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 709 } 710 711 /* 712 * generic vnode pager input routine 713 */ 714 715 /* 716 * Local media VFS's that do not implement their own VOP_GETPAGES 717 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 718 * to implement the previous behaviour. 719 * 720 * All other FS's should use the bypass to get to the local media 721 * backing vp's VOP_GETPAGES. 722 */ 723 static int 724 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 725 int *rahead) 726 { 727 struct vnode *vp; 728 int rtval; 729 730 vp = object->handle; 731 VM_OBJECT_WUNLOCK(object); 732 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 733 KASSERT(rtval != EOPNOTSUPP, 734 ("vnode_pager: FS getpages not implemented\n")); 735 VM_OBJECT_WLOCK(object); 736 return rtval; 737 } 738 739 static int 740 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 741 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 742 { 743 struct vnode *vp; 744 int rtval; 745 746 vp = object->handle; 747 VM_OBJECT_WUNLOCK(object); 748 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 749 KASSERT(rtval != EOPNOTSUPP, 750 ("vnode_pager: FS getpages_async not implemented\n")); 751 VM_OBJECT_WLOCK(object); 752 return (rtval); 753 } 754 755 /* 756 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 757 * local filesystems, where partially valid pages can only occur at 758 * the end of file. 759 */ 760 int 761 vnode_pager_local_getpages(struct vop_getpages_args *ap) 762 { 763 764 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 765 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 766 } 767 768 int 769 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 770 { 771 772 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 773 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg)); 774 } 775 776 /* 777 * This is now called from local media FS's to operate against their 778 * own vnodes if they fail to implement VOP_GETPAGES. 779 */ 780 int 781 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 782 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 783 { 784 vm_object_t object; 785 struct bufobj *bo; 786 struct buf *bp; 787 off_t foff; 788 #ifdef INVARIANTS 789 off_t blkno0; 790 #endif 791 int bsize, pagesperblock; 792 int error, before, after, rbehind, rahead, poff, i; 793 int bytecount, secmask; 794 795 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 796 ("%s does not support devices", __func__)); 797 798 if (vp->v_iflag & VI_DOOMED) 799 return (VM_PAGER_BAD); 800 801 object = vp->v_object; 802 foff = IDX_TO_OFF(m[0]->pindex); 803 bsize = vp->v_mount->mnt_stat.f_iosize; 804 pagesperblock = bsize / PAGE_SIZE; 805 806 KASSERT(foff < object->un_pager.vnp.vnp_size, 807 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 808 KASSERT(count <= nitems(bp->b_pages), 809 ("%s: requested %d pages", __func__, count)); 810 811 /* 812 * The last page has valid blocks. Invalid part can only 813 * exist at the end of file, and the page is made fully valid 814 * by zeroing in vm_pager_get_pages(). 815 */ 816 if (m[count - 1]->valid != 0 && --count == 0) { 817 if (iodone != NULL) 818 iodone(arg, m, 1, 0); 819 return (VM_PAGER_OK); 820 } 821 822 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 823 824 /* 825 * Get the underlying device blocks for the file with VOP_BMAP(). 826 * If the file system doesn't support VOP_BMAP, use old way of 827 * getting pages via VOP_READ. 828 */ 829 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 830 if (error == EOPNOTSUPP) { 831 uma_zfree(vnode_pbuf_zone, bp); 832 VM_OBJECT_WLOCK(object); 833 for (i = 0; i < count; i++) { 834 VM_CNT_INC(v_vnodein); 835 VM_CNT_INC(v_vnodepgsin); 836 error = vnode_pager_input_old(object, m[i]); 837 if (error) 838 break; 839 } 840 VM_OBJECT_WUNLOCK(object); 841 return (error); 842 } else if (error != 0) { 843 uma_zfree(vnode_pbuf_zone, bp); 844 return (VM_PAGER_ERROR); 845 } 846 847 /* 848 * If the file system supports BMAP, but blocksize is smaller 849 * than a page size, then use special small filesystem code. 850 */ 851 if (pagesperblock == 0) { 852 uma_zfree(vnode_pbuf_zone, bp); 853 for (i = 0; i < count; i++) { 854 VM_CNT_INC(v_vnodein); 855 VM_CNT_INC(v_vnodepgsin); 856 error = vnode_pager_input_smlfs(object, m[i]); 857 if (error) 858 break; 859 } 860 return (error); 861 } 862 863 /* 864 * A sparse file can be encountered only for a single page request, 865 * which may not be preceded by call to vm_pager_haspage(). 866 */ 867 if (bp->b_blkno == -1) { 868 KASSERT(count == 1, 869 ("%s: array[%d] request to a sparse file %p", __func__, 870 count, vp)); 871 uma_zfree(vnode_pbuf_zone, bp); 872 pmap_zero_page(m[0]); 873 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 874 __func__, m[0])); 875 VM_OBJECT_WLOCK(object); 876 m[0]->valid = VM_PAGE_BITS_ALL; 877 VM_OBJECT_WUNLOCK(object); 878 return (VM_PAGER_OK); 879 } 880 881 #ifdef INVARIANTS 882 blkno0 = bp->b_blkno; 883 #endif 884 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 885 886 /* Recalculate blocks available after/before to pages. */ 887 poff = (foff % bsize) / PAGE_SIZE; 888 before *= pagesperblock; 889 before += poff; 890 after *= pagesperblock; 891 after += pagesperblock - (poff + 1); 892 if (m[0]->pindex + after >= object->size) 893 after = object->size - 1 - m[0]->pindex; 894 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 895 __func__, count, after + 1)); 896 after -= count - 1; 897 898 /* Trim requested rbehind/rahead to possible values. */ 899 rbehind = a_rbehind ? *a_rbehind : 0; 900 rahead = a_rahead ? *a_rahead : 0; 901 rbehind = min(rbehind, before); 902 rbehind = min(rbehind, m[0]->pindex); 903 rahead = min(rahead, after); 904 rahead = min(rahead, object->size - m[count - 1]->pindex); 905 /* 906 * Check that total amount of pages fit into buf. Trim rbehind and 907 * rahead evenly if not. 908 */ 909 if (rbehind + rahead + count > nitems(bp->b_pages)) { 910 int trim, sum; 911 912 trim = rbehind + rahead + count - nitems(bp->b_pages) + 1; 913 sum = rbehind + rahead; 914 if (rbehind == before) { 915 /* Roundup rbehind trim to block size. */ 916 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 917 if (rbehind < 0) 918 rbehind = 0; 919 } else 920 rbehind -= trim * rbehind / sum; 921 rahead -= trim * rahead / sum; 922 } 923 KASSERT(rbehind + rahead + count <= nitems(bp->b_pages), 924 ("%s: behind %d ahead %d count %d", __func__, 925 rbehind, rahead, count)); 926 927 /* 928 * Fill in the bp->b_pages[] array with requested and optional 929 * read behind or read ahead pages. Read behind pages are looked 930 * up in a backward direction, down to a first cached page. Same 931 * for read ahead pages, but there is no need to shift the array 932 * in case of encountering a cached page. 933 */ 934 i = bp->b_npages = 0; 935 if (rbehind) { 936 vm_pindex_t startpindex, tpindex; 937 vm_page_t p; 938 939 VM_OBJECT_WLOCK(object); 940 startpindex = m[0]->pindex - rbehind; 941 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 942 p->pindex >= startpindex) 943 startpindex = p->pindex + 1; 944 945 /* tpindex is unsigned; beware of numeric underflow. */ 946 for (tpindex = m[0]->pindex - 1; 947 tpindex >= startpindex && tpindex < m[0]->pindex; 948 tpindex--, i++) { 949 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 950 if (p == NULL) { 951 /* Shift the array. */ 952 for (int j = 0; j < i; j++) 953 bp->b_pages[j] = bp->b_pages[j + 954 tpindex + 1 - startpindex]; 955 break; 956 } 957 bp->b_pages[tpindex - startpindex] = p; 958 } 959 960 bp->b_pgbefore = i; 961 bp->b_npages += i; 962 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 963 } else 964 bp->b_pgbefore = 0; 965 966 /* Requested pages. */ 967 for (int j = 0; j < count; j++, i++) 968 bp->b_pages[i] = m[j]; 969 bp->b_npages += count; 970 971 if (rahead) { 972 vm_pindex_t endpindex, tpindex; 973 vm_page_t p; 974 975 if (!VM_OBJECT_WOWNED(object)) 976 VM_OBJECT_WLOCK(object); 977 endpindex = m[count - 1]->pindex + rahead + 1; 978 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 979 p->pindex < endpindex) 980 endpindex = p->pindex; 981 if (endpindex > object->size) 982 endpindex = object->size; 983 984 for (tpindex = m[count - 1]->pindex + 1; 985 tpindex < endpindex; i++, tpindex++) { 986 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 987 if (p == NULL) 988 break; 989 bp->b_pages[i] = p; 990 } 991 992 bp->b_pgafter = i - bp->b_npages; 993 bp->b_npages = i; 994 } else 995 bp->b_pgafter = 0; 996 997 if (VM_OBJECT_WOWNED(object)) 998 VM_OBJECT_WUNLOCK(object); 999 1000 /* Report back actual behind/ahead read. */ 1001 if (a_rbehind) 1002 *a_rbehind = bp->b_pgbefore; 1003 if (a_rahead) 1004 *a_rahead = bp->b_pgafter; 1005 1006 #ifdef INVARIANTS 1007 KASSERT(bp->b_npages <= nitems(bp->b_pages), 1008 ("%s: buf %p overflowed", __func__, bp)); 1009 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 1010 if (bp->b_pages[j] == bogus_page) 1011 continue; 1012 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 1013 j - prev, ("%s: pages array not consecutive, bp %p", 1014 __func__, bp)); 1015 prev = j; 1016 } 1017 #endif 1018 1019 /* 1020 * Recalculate first offset and bytecount with regards to read behind. 1021 * Truncate bytecount to vnode real size and round up physical size 1022 * for real devices. 1023 */ 1024 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1025 bytecount = bp->b_npages << PAGE_SHIFT; 1026 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 1027 bytecount = object->un_pager.vnp.vnp_size - foff; 1028 secmask = bo->bo_bsize - 1; 1029 KASSERT(secmask < PAGE_SIZE && secmask > 0, 1030 ("%s: sector size %d too large", __func__, secmask + 1)); 1031 bytecount = (bytecount + secmask) & ~secmask; 1032 1033 /* 1034 * And map the pages to be read into the kva, if the filesystem 1035 * requires mapped buffers. 1036 */ 1037 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1038 unmapped_buf_allowed) { 1039 bp->b_data = unmapped_buf; 1040 bp->b_offset = 0; 1041 } else { 1042 bp->b_data = bp->b_kvabase; 1043 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1044 } 1045 1046 /* Build a minimal buffer header. */ 1047 bp->b_iocmd = BIO_READ; 1048 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1049 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1050 bp->b_rcred = crhold(curthread->td_ucred); 1051 bp->b_wcred = crhold(curthread->td_ucred); 1052 pbgetbo(bo, bp); 1053 bp->b_vp = vp; 1054 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1055 bp->b_iooffset = dbtob(bp->b_blkno); 1056 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1057 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1058 IDX_TO_OFF(m[0]->pindex) % bsize, 1059 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1060 "blkno0 %ju b_blkno %ju", bsize, 1061 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1062 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1063 1064 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1065 VM_CNT_INC(v_vnodein); 1066 VM_CNT_ADD(v_vnodepgsin, bp->b_npages); 1067 1068 if (iodone != NULL) { /* async */ 1069 bp->b_pgiodone = iodone; 1070 bp->b_caller1 = arg; 1071 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1072 bp->b_flags |= B_ASYNC; 1073 BUF_KERNPROC(bp); 1074 bstrategy(bp); 1075 return (VM_PAGER_OK); 1076 } else { 1077 bp->b_iodone = bdone; 1078 bstrategy(bp); 1079 bwait(bp, PVM, "vnread"); 1080 error = vnode_pager_generic_getpages_done(bp); 1081 for (i = 0; i < bp->b_npages; i++) 1082 bp->b_pages[i] = NULL; 1083 bp->b_vp = NULL; 1084 pbrelbo(bp); 1085 uma_zfree(vnode_pbuf_zone, bp); 1086 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1087 } 1088 } 1089 1090 static void 1091 vnode_pager_generic_getpages_done_async(struct buf *bp) 1092 { 1093 int error; 1094 1095 error = vnode_pager_generic_getpages_done(bp); 1096 /* Run the iodone upon the requested range. */ 1097 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1098 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1099 for (int i = 0; i < bp->b_npages; i++) 1100 bp->b_pages[i] = NULL; 1101 bp->b_vp = NULL; 1102 pbrelbo(bp); 1103 uma_zfree(vnode_pbuf_zone, bp); 1104 } 1105 1106 static int 1107 vnode_pager_generic_getpages_done(struct buf *bp) 1108 { 1109 vm_object_t object; 1110 off_t tfoff, nextoff; 1111 int i, error; 1112 1113 error = (bp->b_ioflags & BIO_ERROR) != 0 ? EIO : 0; 1114 object = bp->b_vp->v_object; 1115 1116 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1117 if (!buf_mapped(bp)) { 1118 bp->b_data = bp->b_kvabase; 1119 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1120 bp->b_npages); 1121 } 1122 bzero(bp->b_data + bp->b_bcount, 1123 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1124 } 1125 if (buf_mapped(bp)) { 1126 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1127 bp->b_data = unmapped_buf; 1128 } 1129 1130 VM_OBJECT_WLOCK(object); 1131 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1132 i < bp->b_npages; i++, tfoff = nextoff) { 1133 vm_page_t mt; 1134 1135 nextoff = tfoff + PAGE_SIZE; 1136 mt = bp->b_pages[i]; 1137 1138 if (nextoff <= object->un_pager.vnp.vnp_size) { 1139 /* 1140 * Read filled up entire page. 1141 */ 1142 mt->valid = VM_PAGE_BITS_ALL; 1143 KASSERT(mt->dirty == 0, 1144 ("%s: page %p is dirty", __func__, mt)); 1145 KASSERT(!pmap_page_is_mapped(mt), 1146 ("%s: page %p is mapped", __func__, mt)); 1147 } else { 1148 /* 1149 * Read did not fill up entire page. 1150 * 1151 * Currently we do not set the entire page valid, 1152 * we just try to clear the piece that we couldn't 1153 * read. 1154 */ 1155 vm_page_set_valid_range(mt, 0, 1156 object->un_pager.vnp.vnp_size - tfoff); 1157 KASSERT((mt->dirty & vm_page_bits(0, 1158 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1159 ("%s: page %p is dirty", __func__, mt)); 1160 } 1161 1162 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1163 vm_page_readahead_finish(mt); 1164 } 1165 VM_OBJECT_WUNLOCK(object); 1166 if (error != 0) 1167 printf("%s: I/O read error %d\n", __func__, error); 1168 1169 return (error); 1170 } 1171 1172 /* 1173 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1174 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1175 * vnode_pager_generic_putpages() to implement the previous behaviour. 1176 * 1177 * All other FS's should use the bypass to get to the local media 1178 * backing vp's VOP_PUTPAGES. 1179 */ 1180 static void 1181 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1182 int flags, int *rtvals) 1183 { 1184 int rtval; 1185 struct vnode *vp; 1186 int bytes = count * PAGE_SIZE; 1187 1188 /* 1189 * Force synchronous operation if we are extremely low on memory 1190 * to prevent a low-memory deadlock. VOP operations often need to 1191 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1192 * operation ). The swapper handles the case by limiting the amount 1193 * of asynchronous I/O, but that sort of solution doesn't scale well 1194 * for the vnode pager without a lot of work. 1195 * 1196 * Also, the backing vnode's iodone routine may not wake the pageout 1197 * daemon up. This should be probably be addressed XXX. 1198 */ 1199 1200 if (vm_page_count_min()) 1201 flags |= VM_PAGER_PUT_SYNC; 1202 1203 /* 1204 * Call device-specific putpages function 1205 */ 1206 vp = object->handle; 1207 VM_OBJECT_WUNLOCK(object); 1208 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1209 KASSERT(rtval != EOPNOTSUPP, 1210 ("vnode_pager: stale FS putpages\n")); 1211 VM_OBJECT_WLOCK(object); 1212 } 1213 1214 static int 1215 vn_off2bidx(vm_ooffset_t offset) 1216 { 1217 1218 return ((offset & PAGE_MASK) / DEV_BSIZE); 1219 } 1220 1221 static bool 1222 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset) 1223 { 1224 1225 KASSERT(IDX_TO_OFF(m->pindex) <= offset && 1226 offset < IDX_TO_OFF(m->pindex + 1), 1227 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex, 1228 (uintmax_t)offset)); 1229 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0); 1230 } 1231 1232 /* 1233 * This is now called from local media FS's to operate against their 1234 * own vnodes if they fail to implement VOP_PUTPAGES. 1235 * 1236 * This is typically called indirectly via the pageout daemon and 1237 * clustering has already typically occurred, so in general we ask the 1238 * underlying filesystem to write the data out asynchronously rather 1239 * then delayed. 1240 */ 1241 int 1242 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1243 int flags, int *rtvals) 1244 { 1245 vm_object_t object; 1246 vm_page_t m; 1247 vm_ooffset_t maxblksz, next_offset, poffset, prev_offset; 1248 struct uio auio; 1249 struct iovec aiov; 1250 off_t prev_resid, wrsz; 1251 int count, error, i, maxsize, ncount, pgoff, ppscheck; 1252 bool in_hole; 1253 static struct timeval lastfail; 1254 static int curfail; 1255 1256 object = vp->v_object; 1257 count = bytecount / PAGE_SIZE; 1258 1259 for (i = 0; i < count; i++) 1260 rtvals[i] = VM_PAGER_ERROR; 1261 1262 if ((int64_t)ma[0]->pindex < 0) { 1263 printf("vnode_pager_generic_putpages: " 1264 "attempt to write meta-data 0x%jx(%lx)\n", 1265 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty); 1266 rtvals[0] = VM_PAGER_BAD; 1267 return (VM_PAGER_BAD); 1268 } 1269 1270 maxsize = count * PAGE_SIZE; 1271 ncount = count; 1272 1273 poffset = IDX_TO_OFF(ma[0]->pindex); 1274 1275 /* 1276 * If the page-aligned write is larger then the actual file we 1277 * have to invalidate pages occurring beyond the file EOF. However, 1278 * there is an edge case where a file may not be page-aligned where 1279 * the last page is partially invalid. In this case the filesystem 1280 * may not properly clear the dirty bits for the entire page (which 1281 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1282 * With the page locked we are free to fix-up the dirty bits here. 1283 * 1284 * We do not under any circumstances truncate the valid bits, as 1285 * this will screw up bogus page replacement. 1286 */ 1287 VM_OBJECT_RLOCK(object); 1288 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1289 if (!VM_OBJECT_TRYUPGRADE(object)) { 1290 VM_OBJECT_RUNLOCK(object); 1291 VM_OBJECT_WLOCK(object); 1292 if (maxsize + poffset <= object->un_pager.vnp.vnp_size) 1293 goto downgrade; 1294 } 1295 if (object->un_pager.vnp.vnp_size > poffset) { 1296 maxsize = object->un_pager.vnp.vnp_size - poffset; 1297 ncount = btoc(maxsize); 1298 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1299 pgoff = roundup2(pgoff, DEV_BSIZE); 1300 1301 /* 1302 * If the object is locked and the following 1303 * conditions hold, then the page's dirty 1304 * field cannot be concurrently changed by a 1305 * pmap operation. 1306 */ 1307 m = ma[ncount - 1]; 1308 vm_page_assert_sbusied(m); 1309 KASSERT(!pmap_page_is_write_mapped(m), 1310 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1311 MPASS(m->dirty != 0); 1312 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1313 pgoff); 1314 } 1315 } else { 1316 maxsize = 0; 1317 ncount = 0; 1318 } 1319 for (i = ncount; i < count; i++) 1320 rtvals[i] = VM_PAGER_BAD; 1321 downgrade: 1322 VM_OBJECT_LOCK_DOWNGRADE(object); 1323 } 1324 1325 auio.uio_iov = &aiov; 1326 auio.uio_segflg = UIO_NOCOPY; 1327 auio.uio_rw = UIO_WRITE; 1328 auio.uio_td = NULL; 1329 maxblksz = roundup2(poffset + maxsize, DEV_BSIZE); 1330 1331 for (prev_offset = poffset; prev_offset < maxblksz;) { 1332 /* Skip clean blocks. */ 1333 for (in_hole = true; in_hole && prev_offset < maxblksz;) { 1334 m = ma[OFF_TO_IDX(prev_offset - poffset)]; 1335 for (i = vn_off2bidx(prev_offset); 1336 i < sizeof(vm_page_bits_t) * NBBY && 1337 prev_offset < maxblksz; i++) { 1338 if (vn_dirty_blk(m, prev_offset)) { 1339 in_hole = false; 1340 break; 1341 } 1342 prev_offset += DEV_BSIZE; 1343 } 1344 } 1345 if (in_hole) 1346 goto write_done; 1347 1348 /* Find longest run of dirty blocks. */ 1349 for (next_offset = prev_offset; next_offset < maxblksz;) { 1350 m = ma[OFF_TO_IDX(next_offset - poffset)]; 1351 for (i = vn_off2bidx(next_offset); 1352 i < sizeof(vm_page_bits_t) * NBBY && 1353 next_offset < maxblksz; i++) { 1354 if (!vn_dirty_blk(m, next_offset)) 1355 goto start_write; 1356 next_offset += DEV_BSIZE; 1357 } 1358 } 1359 start_write: 1360 if (next_offset > poffset + maxsize) 1361 next_offset = poffset + maxsize; 1362 1363 /* 1364 * Getting here requires finding a dirty block in the 1365 * 'skip clean blocks' loop. 1366 */ 1367 MPASS(prev_offset < next_offset); 1368 1369 VM_OBJECT_RUNLOCK(object); 1370 aiov.iov_base = NULL; 1371 auio.uio_iovcnt = 1; 1372 auio.uio_offset = prev_offset; 1373 prev_resid = auio.uio_resid = aiov.iov_len = next_offset - 1374 prev_offset; 1375 error = VOP_WRITE(vp, &auio, 1376 vnode_pager_putpages_ioflags(flags), curthread->td_ucred); 1377 1378 wrsz = prev_resid - auio.uio_resid; 1379 if (wrsz == 0) { 1380 if (ppsratecheck(&lastfail, &curfail, 1) != 0) { 1381 vn_printf(vp, "vnode_pager_putpages: " 1382 "zero-length write at %ju resid %zd\n", 1383 auio.uio_offset, auio.uio_resid); 1384 } 1385 VM_OBJECT_RLOCK(object); 1386 break; 1387 } 1388 1389 /* Adjust the starting offset for next iteration. */ 1390 prev_offset += wrsz; 1391 MPASS(auio.uio_offset == prev_offset); 1392 1393 ppscheck = 0; 1394 if (error != 0 && (ppscheck = ppsratecheck(&lastfail, 1395 &curfail, 1)) != 0) 1396 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n", 1397 error); 1398 if (auio.uio_resid != 0 && (ppscheck != 0 || 1399 ppsratecheck(&lastfail, &curfail, 1) != 0)) 1400 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd " 1401 "at %ju\n", auio.uio_resid, 1402 (uintmax_t)ma[0]->pindex); 1403 VM_OBJECT_RLOCK(object); 1404 if (error != 0 || auio.uio_resid != 0) 1405 break; 1406 } 1407 write_done: 1408 /* Mark completely processed pages. */ 1409 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++) 1410 rtvals[i] = VM_PAGER_OK; 1411 /* Mark partial EOF page. */ 1412 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0) 1413 rtvals[i++] = VM_PAGER_OK; 1414 /* Unwritten pages in range, free bonus if the page is clean. */ 1415 for (; i < ncount; i++) 1416 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR; 1417 VM_OBJECT_RUNLOCK(object); 1418 VM_CNT_ADD(v_vnodepgsout, i); 1419 VM_CNT_INC(v_vnodeout); 1420 return (rtvals[0]); 1421 } 1422 1423 int 1424 vnode_pager_putpages_ioflags(int pager_flags) 1425 { 1426 int ioflags; 1427 1428 /* 1429 * Pageouts are already clustered, use IO_ASYNC to force a 1430 * bawrite() rather then a bdwrite() to prevent paging I/O 1431 * from saturating the buffer cache. Dummy-up the sequential 1432 * heuristic to cause large ranges to cluster. If neither 1433 * IO_SYNC or IO_ASYNC is set, the system decides how to 1434 * cluster. 1435 */ 1436 ioflags = IO_VMIO; 1437 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0) 1438 ioflags |= IO_SYNC; 1439 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0) 1440 ioflags |= IO_ASYNC; 1441 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0; 1442 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0; 1443 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1444 return (ioflags); 1445 } 1446 1447 /* 1448 * vnode_pager_undirty_pages(). 1449 * 1450 * A helper to mark pages as clean after pageout that was possibly 1451 * done with a short write. The lpos argument specifies the page run 1452 * length in bytes, and the written argument specifies how many bytes 1453 * were actually written. eof is the offset past the last valid byte 1454 * in the vnode using the absolute file position of the first byte in 1455 * the run as the base from which it is computed. 1456 */ 1457 void 1458 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof, 1459 int lpos) 1460 { 1461 vm_object_t obj; 1462 int i, pos, pos_devb; 1463 1464 if (written == 0 && eof >= lpos) 1465 return; 1466 obj = ma[0]->object; 1467 VM_OBJECT_WLOCK(obj); 1468 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1469 if (pos < trunc_page(written)) { 1470 rtvals[i] = VM_PAGER_OK; 1471 vm_page_undirty(ma[i]); 1472 } else { 1473 /* Partially written page. */ 1474 rtvals[i] = VM_PAGER_AGAIN; 1475 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1476 } 1477 } 1478 if (eof >= lpos) /* avoid truncation */ 1479 goto done; 1480 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) { 1481 if (pos != trunc_page(pos)) { 1482 /* 1483 * The page contains the last valid byte in 1484 * the vnode, mark the rest of the page as 1485 * clean, potentially making the whole page 1486 * clean. 1487 */ 1488 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE); 1489 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE - 1490 pos_devb); 1491 1492 /* 1493 * If the page was cleaned, report the pageout 1494 * on it as successful. msync() no longer 1495 * needs to write out the page, endlessly 1496 * creating write requests and dirty buffers. 1497 */ 1498 if (ma[i]->dirty == 0) 1499 rtvals[i] = VM_PAGER_OK; 1500 1501 pos = round_page(pos); 1502 } else { 1503 /* vm_pageout_flush() clears dirty */ 1504 rtvals[i] = VM_PAGER_BAD; 1505 pos += PAGE_SIZE; 1506 } 1507 } 1508 done: 1509 VM_OBJECT_WUNLOCK(obj); 1510 } 1511 1512 void 1513 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1514 vm_offset_t end) 1515 { 1516 struct vnode *vp; 1517 vm_ooffset_t old_wm; 1518 1519 VM_OBJECT_WLOCK(object); 1520 if (object->type != OBJT_VNODE) { 1521 VM_OBJECT_WUNLOCK(object); 1522 return; 1523 } 1524 old_wm = object->un_pager.vnp.writemappings; 1525 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1526 vp = object->handle; 1527 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1528 ASSERT_VOP_LOCKED(vp, "v_writecount inc"); 1529 VOP_ADD_WRITECOUNT_CHECKED(vp, 1); 1530 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1531 __func__, vp, vp->v_writecount); 1532 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1533 ASSERT_VOP_LOCKED(vp, "v_writecount dec"); 1534 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1535 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1536 __func__, vp, vp->v_writecount); 1537 } 1538 VM_OBJECT_WUNLOCK(object); 1539 } 1540 1541 void 1542 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1543 vm_offset_t end) 1544 { 1545 struct vnode *vp; 1546 struct mount *mp; 1547 vm_offset_t inc; 1548 1549 VM_OBJECT_WLOCK(object); 1550 1551 /* 1552 * First, recheck the object type to account for the race when 1553 * the vnode is reclaimed. 1554 */ 1555 if (object->type != OBJT_VNODE) { 1556 VM_OBJECT_WUNLOCK(object); 1557 return; 1558 } 1559 1560 /* 1561 * Optimize for the case when writemappings is not going to 1562 * zero. 1563 */ 1564 inc = end - start; 1565 if (object->un_pager.vnp.writemappings != inc) { 1566 object->un_pager.vnp.writemappings -= inc; 1567 VM_OBJECT_WUNLOCK(object); 1568 return; 1569 } 1570 1571 vp = object->handle; 1572 vhold(vp); 1573 VM_OBJECT_WUNLOCK(object); 1574 mp = NULL; 1575 vn_start_write(vp, &mp, V_WAIT); 1576 vn_lock(vp, LK_SHARED | LK_RETRY); 1577 1578 /* 1579 * Decrement the object's writemappings, by swapping the start 1580 * and end arguments for vnode_pager_update_writecount(). If 1581 * there was not a race with vnode reclaimation, then the 1582 * vnode's v_writecount is decremented. 1583 */ 1584 vnode_pager_update_writecount(object, end, start); 1585 VOP_UNLOCK(vp, 0); 1586 vdrop(vp); 1587 if (mp != NULL) 1588 vn_finished_write(mp); 1589 } 1590