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