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