1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1990 University of Utah. 5 * Copyright (c) 1991 The Regents of the University of California. 6 * All rights reserved. 7 * Copyright (c) 1993, 1994 John S. Dyson 8 * Copyright (c) 1995, David Greenman 9 * 10 * This code is derived from software contributed to Berkeley by 11 * the Systems Programming Group of the University of Utah Computer 12 * Science Department. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91 43 */ 44 45 /* 46 * Page to/from files (vnodes). 47 */ 48 49 /* 50 * TODO: 51 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 52 * greatly re-simplify the vnode_pager. 53 */ 54 55 #include <sys/cdefs.h> 56 __FBSDID("$FreeBSD$"); 57 58 #include "opt_vm.h" 59 60 #include <sys/param.h> 61 #include <sys/kernel.h> 62 #include <sys/systm.h> 63 #include <sys/sysctl.h> 64 #include <sys/proc.h> 65 #include <sys/vnode.h> 66 #include <sys/mount.h> 67 #include <sys/bio.h> 68 #include <sys/buf.h> 69 #include <sys/vmmeter.h> 70 #include <sys/ktr.h> 71 #include <sys/limits.h> 72 #include <sys/conf.h> 73 #include <sys/refcount.h> 74 #include <sys/rwlock.h> 75 #include <sys/sf_buf.h> 76 #include <sys/domainset.h> 77 78 #include <machine/atomic.h> 79 80 #include <vm/vm.h> 81 #include <vm/vm_param.h> 82 #include <vm/vm_object.h> 83 #include <vm/vm_page.h> 84 #include <vm/vm_pager.h> 85 #include <vm/vm_map.h> 86 #include <vm/vnode_pager.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 91 daddr_t *rtaddress, int *run); 92 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 93 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 94 static void vnode_pager_dealloc(vm_object_t); 95 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 96 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, 97 int *, vop_getpages_iodone_t, void *); 98 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 99 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 100 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 101 vm_ooffset_t, struct ucred *cred); 102 static int vnode_pager_generic_getpages_done(struct buf *); 103 static void vnode_pager_generic_getpages_done_async(struct buf *); 104 static void vnode_pager_update_writecount(vm_object_t, vm_offset_t, 105 vm_offset_t); 106 static void vnode_pager_release_writecount(vm_object_t, vm_offset_t, 107 vm_offset_t); 108 109 struct pagerops vnodepagerops = { 110 .pgo_alloc = vnode_pager_alloc, 111 .pgo_dealloc = vnode_pager_dealloc, 112 .pgo_getpages = vnode_pager_getpages, 113 .pgo_getpages_async = vnode_pager_getpages_async, 114 .pgo_putpages = vnode_pager_putpages, 115 .pgo_haspage = vnode_pager_haspage, 116 .pgo_update_writecount = vnode_pager_update_writecount, 117 .pgo_release_writecount = vnode_pager_release_writecount, 118 }; 119 120 static struct domainset *vnode_domainset = NULL; 121 122 SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset, CTLTYPE_STRING | CTLFLAG_RW, 123 &vnode_domainset, 0, sysctl_handle_domainset, "A", 124 "Default vnode NUMA policy"); 125 126 static int nvnpbufs; 127 SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 128 &nvnpbufs, 0, "number of physical buffers allocated for vnode pager"); 129 130 static uma_zone_t vnode_pbuf_zone; 131 132 static void 133 vnode_pager_init(void *dummy) 134 { 135 136 #ifdef __LP64__ 137 nvnpbufs = nswbuf * 2; 138 #else 139 nvnpbufs = nswbuf / 2; 140 #endif 141 TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs); 142 vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs); 143 } 144 SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL); 145 146 /* Create the VM system backing object for this vnode */ 147 int 148 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 149 { 150 vm_object_t object; 151 vm_ooffset_t size = isize; 152 struct vattr va; 153 bool last; 154 155 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 156 return (0); 157 158 object = vp->v_object; 159 if (object != NULL) 160 return (0); 161 162 if (size == 0) { 163 if (vn_isdisk(vp, NULL)) { 164 size = IDX_TO_OFF(INT_MAX); 165 } else { 166 if (VOP_GETATTR(vp, &va, td->td_ucred)) 167 return (0); 168 size = va.va_size; 169 } 170 } 171 172 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 173 /* 174 * Dereference the reference we just created. This assumes 175 * that the object is associated with the vp. We still have 176 * to serialize with vnode_pager_dealloc() for the last 177 * potential reference. 178 */ 179 VM_OBJECT_RLOCK(object); 180 last = refcount_release(&object->ref_count); 181 VM_OBJECT_RUNLOCK(object); 182 if (last) 183 vrele(vp); 184 185 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 186 187 return (0); 188 } 189 190 void 191 vnode_destroy_vobject(struct vnode *vp) 192 { 193 struct vm_object *obj; 194 195 obj = vp->v_object; 196 if (obj == NULL || obj->handle != vp) 197 return; 198 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 199 VM_OBJECT_WLOCK(obj); 200 MPASS(obj->type == OBJT_VNODE); 201 umtx_shm_object_terminated(obj); 202 if (obj->ref_count == 0) { 203 /* 204 * don't double-terminate the object 205 */ 206 if ((obj->flags & OBJ_DEAD) == 0) { 207 vm_object_set_flag(obj, OBJ_DEAD); 208 209 /* 210 * Clean pages and flush buffers. 211 */ 212 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC); 213 VM_OBJECT_WUNLOCK(obj); 214 215 vinvalbuf(vp, V_SAVE, 0, 0); 216 217 BO_LOCK(&vp->v_bufobj); 218 vp->v_bufobj.bo_flag |= BO_DEAD; 219 BO_UNLOCK(&vp->v_bufobj); 220 221 VM_OBJECT_WLOCK(obj); 222 vm_object_terminate(obj); 223 } else { 224 /* 225 * Waiters were already handled during object 226 * termination. The exclusive vnode lock hopefully 227 * prevented new waiters from referencing the dying 228 * object. 229 */ 230 vp->v_object = NULL; 231 VM_OBJECT_WUNLOCK(obj); 232 } 233 } else { 234 /* 235 * Woe to the process that tries to page now :-). 236 */ 237 vm_pager_deallocate(obj); 238 VM_OBJECT_WUNLOCK(obj); 239 } 240 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object)); 241 } 242 243 244 /* 245 * Allocate (or lookup) pager for a vnode. 246 * Handle is a vnode pointer. 247 */ 248 vm_object_t 249 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 250 vm_ooffset_t offset, struct ucred *cred) 251 { 252 vm_object_t object; 253 struct vnode *vp; 254 255 /* 256 * Pageout to vnode, no can do yet. 257 */ 258 if (handle == NULL) 259 return (NULL); 260 261 vp = (struct vnode *)handle; 262 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc"); 263 KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference")); 264 retry: 265 object = vp->v_object; 266 267 if (object == NULL) { 268 /* 269 * Add an object of the appropriate size 270 */ 271 object = vm_object_allocate(OBJT_VNODE, 272 OFF_TO_IDX(round_page(size))); 273 274 object->un_pager.vnp.vnp_size = size; 275 object->un_pager.vnp.writemappings = 0; 276 object->domain.dr_policy = vnode_domainset; 277 object->handle = handle; 278 if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) { 279 VM_OBJECT_WLOCK(object); 280 vm_object_set_flag(object, OBJ_SIZEVNLOCK); 281 VM_OBJECT_WUNLOCK(object); 282 } 283 VI_LOCK(vp); 284 if (vp->v_object != NULL) { 285 /* 286 * Object has been created while we were allocating. 287 */ 288 VI_UNLOCK(vp); 289 VM_OBJECT_WLOCK(object); 290 KASSERT(object->ref_count == 1, 291 ("leaked ref %p %d", object, object->ref_count)); 292 object->type = OBJT_DEAD; 293 refcount_init(&object->ref_count, 0); 294 VM_OBJECT_WUNLOCK(object); 295 vm_object_destroy(object); 296 goto retry; 297 } 298 vp->v_object = object; 299 VI_UNLOCK(vp); 300 vrefact(vp); 301 } else { 302 vm_object_reference(object); 303 #if VM_NRESERVLEVEL > 0 304 if ((object->flags & OBJ_COLORED) == 0) { 305 VM_OBJECT_WLOCK(object); 306 vm_object_color(object, 0); 307 VM_OBJECT_WUNLOCK(object); 308 } 309 #endif 310 } 311 return (object); 312 } 313 314 /* 315 * The object must be locked. 316 */ 317 static void 318 vnode_pager_dealloc(vm_object_t object) 319 { 320 struct vnode *vp; 321 int refs; 322 323 vp = object->handle; 324 if (vp == NULL) 325 panic("vnode_pager_dealloc: pager already dealloced"); 326 327 VM_OBJECT_ASSERT_WLOCKED(object); 328 vm_object_pip_wait(object, "vnpdea"); 329 refs = object->ref_count; 330 331 object->handle = NULL; 332 object->type = OBJT_DEAD; 333 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 334 if (object->un_pager.vnp.writemappings > 0) { 335 object->un_pager.vnp.writemappings = 0; 336 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 337 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 338 __func__, vp, vp->v_writecount); 339 } 340 vp->v_object = NULL; 341 VI_LOCK(vp); 342 343 /* 344 * vm_map_entry_set_vnode_text() cannot reach this vnode by 345 * following object->handle. Clear all text references now. 346 * This also clears the transient references from 347 * kern_execve(), which is fine because dead_vnodeops uses nop 348 * for VOP_UNSET_TEXT(). 349 */ 350 if (vp->v_writecount < 0) 351 vp->v_writecount = 0; 352 VI_UNLOCK(vp); 353 VM_OBJECT_WUNLOCK(object); 354 if (refs > 0) 355 vunref(vp); 356 VM_OBJECT_WLOCK(object); 357 } 358 359 static boolean_t 360 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 361 int *after) 362 { 363 struct vnode *vp = object->handle; 364 daddr_t bn; 365 uintptr_t lockstate; 366 int err; 367 daddr_t reqblock; 368 int poff; 369 int bsize; 370 int pagesperblock, blocksperpage; 371 372 VM_OBJECT_ASSERT_LOCKED(object); 373 /* 374 * If no vp or vp is doomed or marked transparent to VM, we do not 375 * have the page. 376 */ 377 if (vp == NULL || VN_IS_DOOMED(vp)) 378 return FALSE; 379 /* 380 * If the offset is beyond end of file we do 381 * not have the page. 382 */ 383 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 384 return FALSE; 385 386 bsize = vp->v_mount->mnt_stat.f_iosize; 387 pagesperblock = bsize / PAGE_SIZE; 388 blocksperpage = 0; 389 if (pagesperblock > 0) { 390 reqblock = pindex / pagesperblock; 391 } else { 392 blocksperpage = (PAGE_SIZE / bsize); 393 reqblock = pindex * blocksperpage; 394 } 395 lockstate = VM_OBJECT_DROP(object); 396 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 397 VM_OBJECT_PICKUP(object, lockstate); 398 if (err) 399 return TRUE; 400 if (bn == -1) 401 return FALSE; 402 if (pagesperblock > 0) { 403 poff = pindex - (reqblock * pagesperblock); 404 if (before) { 405 *before *= pagesperblock; 406 *before += poff; 407 } 408 if (after) { 409 /* 410 * The BMAP vop can report a partial block in the 411 * 'after', but must not report blocks after EOF. 412 * Assert the latter, and truncate 'after' in case 413 * of the former. 414 */ 415 KASSERT((reqblock + *after) * pagesperblock < 416 roundup2(object->size, pagesperblock), 417 ("%s: reqblock %jd after %d size %ju", __func__, 418 (intmax_t )reqblock, *after, 419 (uintmax_t )object->size)); 420 *after *= pagesperblock; 421 *after += pagesperblock - (poff + 1); 422 if (pindex + *after >= object->size) 423 *after = object->size - 1 - pindex; 424 } 425 } else { 426 if (before) { 427 *before /= blocksperpage; 428 } 429 430 if (after) { 431 *after /= blocksperpage; 432 } 433 } 434 return TRUE; 435 } 436 437 /* 438 * Lets the VM system know about a change in size for a file. 439 * We adjust our own internal size and flush any cached pages in 440 * the associated object that are affected by the size change. 441 * 442 * Note: this routine may be invoked as a result of a pager put 443 * operation (possibly at object termination time), so we must be careful. 444 */ 445 void 446 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 447 { 448 vm_object_t object; 449 vm_page_t m; 450 vm_pindex_t nobjsize; 451 452 if ((object = vp->v_object) == NULL) 453 return; 454 #ifdef DEBUG_VFS_LOCKS 455 { 456 struct mount *mp; 457 458 mp = vp->v_mount; 459 if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0) 460 assert_vop_elocked(vp, 461 "vnode_pager_setsize and not locked vnode"); 462 } 463 #endif 464 VM_OBJECT_WLOCK(object); 465 if (object->type == OBJT_DEAD) { 466 VM_OBJECT_WUNLOCK(object); 467 return; 468 } 469 KASSERT(object->type == OBJT_VNODE, 470 ("not vnode-backed object %p", object)); 471 if (nsize == object->un_pager.vnp.vnp_size) { 472 /* 473 * Hasn't changed size 474 */ 475 VM_OBJECT_WUNLOCK(object); 476 return; 477 } 478 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 479 if (nsize < object->un_pager.vnp.vnp_size) { 480 /* 481 * File has shrunk. Toss any cached pages beyond the new EOF. 482 */ 483 if (nobjsize < object->size) 484 vm_object_page_remove(object, nobjsize, object->size, 485 0); 486 /* 487 * this gets rid of garbage at the end of a page that is now 488 * only partially backed by the vnode. 489 * 490 * XXX for some reason (I don't know yet), if we take a 491 * completely invalid page and mark it partially valid 492 * it can screw up NFS reads, so we don't allow the case. 493 */ 494 if (!(nsize & PAGE_MASK)) 495 goto out; 496 m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT); 497 if (m == NULL) 498 goto out; 499 if (!vm_page_none_valid(m)) { 500 int base = (int)nsize & PAGE_MASK; 501 int size = PAGE_SIZE - base; 502 503 /* 504 * Clear out partial-page garbage in case 505 * the page has been mapped. 506 */ 507 pmap_zero_page_area(m, base, size); 508 509 /* 510 * Update the valid bits to reflect the blocks that 511 * have been zeroed. Some of these valid bits may 512 * have already been set. 513 */ 514 vm_page_set_valid_range(m, base, size); 515 516 /* 517 * Round "base" to the next block boundary so that the 518 * dirty bit for a partially zeroed block is not 519 * cleared. 520 */ 521 base = roundup2(base, DEV_BSIZE); 522 523 /* 524 * Clear out partial-page dirty bits. 525 * 526 * note that we do not clear out the valid 527 * bits. This would prevent bogus_page 528 * replacement from working properly. 529 */ 530 vm_page_clear_dirty(m, base, PAGE_SIZE - base); 531 } 532 vm_page_xunbusy(m); 533 } 534 out: 535 object->un_pager.vnp.vnp_size = nsize; 536 object->size = nobjsize; 537 VM_OBJECT_WUNLOCK(object); 538 } 539 540 /* 541 * calculate the linear (byte) disk address of specified virtual 542 * file address 543 */ 544 static int 545 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 546 int *run) 547 { 548 int bsize; 549 int err; 550 daddr_t vblock; 551 daddr_t voffset; 552 553 if (address < 0) 554 return -1; 555 556 if (VN_IS_DOOMED(vp)) 557 return -1; 558 559 bsize = vp->v_mount->mnt_stat.f_iosize; 560 vblock = address / bsize; 561 voffset = address % bsize; 562 563 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 564 if (err == 0) { 565 if (*rtaddress != -1) 566 *rtaddress += voffset / DEV_BSIZE; 567 if (run) { 568 *run += 1; 569 *run *= bsize / PAGE_SIZE; 570 *run -= voffset / PAGE_SIZE; 571 } 572 } 573 574 return (err); 575 } 576 577 /* 578 * small block filesystem vnode pager input 579 */ 580 static int 581 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 582 { 583 struct vnode *vp; 584 struct bufobj *bo; 585 struct buf *bp; 586 struct sf_buf *sf; 587 daddr_t fileaddr; 588 vm_offset_t bsize; 589 vm_page_bits_t bits; 590 int error, i; 591 592 error = 0; 593 vp = object->handle; 594 if (VN_IS_DOOMED(vp)) 595 return VM_PAGER_BAD; 596 597 bsize = vp->v_mount->mnt_stat.f_iosize; 598 599 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 600 601 sf = sf_buf_alloc(m, 0); 602 603 for (i = 0; i < PAGE_SIZE / bsize; i++) { 604 vm_ooffset_t address; 605 606 bits = vm_page_bits(i * bsize, bsize); 607 if (m->valid & bits) 608 continue; 609 610 address = IDX_TO_OFF(m->pindex) + i * bsize; 611 if (address >= object->un_pager.vnp.vnp_size) { 612 fileaddr = -1; 613 } else { 614 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 615 if (error) 616 break; 617 } 618 if (fileaddr != -1) { 619 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 620 621 /* build a minimal buffer header */ 622 bp->b_iocmd = BIO_READ; 623 bp->b_iodone = bdone; 624 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 625 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 626 bp->b_rcred = crhold(curthread->td_ucred); 627 bp->b_wcred = crhold(curthread->td_ucred); 628 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 629 bp->b_blkno = fileaddr; 630 pbgetbo(bo, bp); 631 bp->b_vp = vp; 632 bp->b_bcount = bsize; 633 bp->b_bufsize = bsize; 634 bp->b_runningbufspace = bp->b_bufsize; 635 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 636 637 /* do the input */ 638 bp->b_iooffset = dbtob(bp->b_blkno); 639 bstrategy(bp); 640 641 bwait(bp, PVM, "vnsrd"); 642 643 if ((bp->b_ioflags & BIO_ERROR) != 0) 644 error = EIO; 645 646 /* 647 * free the buffer header back to the swap buffer pool 648 */ 649 bp->b_vp = NULL; 650 pbrelbo(bp); 651 uma_zfree(vnode_pbuf_zone, bp); 652 if (error) 653 break; 654 } else 655 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 656 KASSERT((m->dirty & bits) == 0, 657 ("vnode_pager_input_smlfs: page %p is dirty", m)); 658 vm_page_bits_set(m, &m->valid, bits); 659 } 660 sf_buf_free(sf); 661 if (error) { 662 return VM_PAGER_ERROR; 663 } 664 return VM_PAGER_OK; 665 } 666 667 /* 668 * old style vnode pager input routine 669 */ 670 static int 671 vnode_pager_input_old(vm_object_t object, vm_page_t m) 672 { 673 struct uio auio; 674 struct iovec aiov; 675 int error; 676 int size; 677 struct sf_buf *sf; 678 struct vnode *vp; 679 680 VM_OBJECT_ASSERT_WLOCKED(object); 681 error = 0; 682 683 /* 684 * Return failure if beyond current EOF 685 */ 686 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 687 return VM_PAGER_BAD; 688 } else { 689 size = PAGE_SIZE; 690 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 691 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 692 vp = object->handle; 693 VM_OBJECT_WUNLOCK(object); 694 695 /* 696 * Allocate a kernel virtual address and initialize so that 697 * we can use VOP_READ/WRITE routines. 698 */ 699 sf = sf_buf_alloc(m, 0); 700 701 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 702 aiov.iov_len = size; 703 auio.uio_iov = &aiov; 704 auio.uio_iovcnt = 1; 705 auio.uio_offset = IDX_TO_OFF(m->pindex); 706 auio.uio_segflg = UIO_SYSSPACE; 707 auio.uio_rw = UIO_READ; 708 auio.uio_resid = size; 709 auio.uio_td = curthread; 710 711 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 712 if (!error) { 713 int count = size - auio.uio_resid; 714 715 if (count == 0) 716 error = EINVAL; 717 else if (count != PAGE_SIZE) 718 bzero((caddr_t)sf_buf_kva(sf) + count, 719 PAGE_SIZE - count); 720 } 721 sf_buf_free(sf); 722 723 VM_OBJECT_WLOCK(object); 724 } 725 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 726 if (!error) 727 vm_page_valid(m); 728 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 729 } 730 731 /* 732 * generic vnode pager input routine 733 */ 734 735 /* 736 * Local media VFS's that do not implement their own VOP_GETPAGES 737 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 738 * to implement the previous behaviour. 739 * 740 * All other FS's should use the bypass to get to the local media 741 * backing vp's VOP_GETPAGES. 742 */ 743 static int 744 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 745 int *rahead) 746 { 747 struct vnode *vp; 748 int rtval; 749 750 vp = object->handle; 751 VM_OBJECT_WUNLOCK(object); 752 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 753 KASSERT(rtval != EOPNOTSUPP, 754 ("vnode_pager: FS getpages not implemented\n")); 755 VM_OBJECT_WLOCK(object); 756 return rtval; 757 } 758 759 static int 760 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 761 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 762 { 763 struct vnode *vp; 764 int rtval; 765 766 vp = object->handle; 767 VM_OBJECT_WUNLOCK(object); 768 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 769 KASSERT(rtval != EOPNOTSUPP, 770 ("vnode_pager: FS getpages_async not implemented\n")); 771 VM_OBJECT_WLOCK(object); 772 return (rtval); 773 } 774 775 /* 776 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 777 * local filesystems, where partially valid pages can only occur at 778 * the end of file. 779 */ 780 int 781 vnode_pager_local_getpages(struct vop_getpages_args *ap) 782 { 783 784 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 785 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 786 } 787 788 int 789 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 790 { 791 792 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 793 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg)); 794 } 795 796 /* 797 * This is now called from local media FS's to operate against their 798 * own vnodes if they fail to implement VOP_GETPAGES. 799 */ 800 int 801 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 802 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 803 { 804 vm_object_t object; 805 struct bufobj *bo; 806 struct buf *bp; 807 off_t foff; 808 #ifdef INVARIANTS 809 off_t blkno0; 810 #endif 811 int bsize, pagesperblock; 812 int error, before, after, rbehind, rahead, poff, i; 813 int bytecount, secmask; 814 815 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 816 ("%s does not support devices", __func__)); 817 818 if (VN_IS_DOOMED(vp)) 819 return (VM_PAGER_BAD); 820 821 object = vp->v_object; 822 foff = IDX_TO_OFF(m[0]->pindex); 823 bsize = vp->v_mount->mnt_stat.f_iosize; 824 pagesperblock = bsize / PAGE_SIZE; 825 826 KASSERT(foff < object->un_pager.vnp.vnp_size, 827 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 828 KASSERT(count <= nitems(bp->b_pages), 829 ("%s: requested %d pages", __func__, count)); 830 831 /* 832 * The last page has valid blocks. Invalid part can only 833 * exist at the end of file, and the page is made fully valid 834 * by zeroing in vm_pager_get_pages(). 835 */ 836 if (!vm_page_none_valid(m[count - 1]) && --count == 0) { 837 if (iodone != NULL) 838 iodone(arg, m, 1, 0); 839 return (VM_PAGER_OK); 840 } 841 842 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 843 844 /* 845 * Get the underlying device blocks for the file with VOP_BMAP(). 846 * If the file system doesn't support VOP_BMAP, use old way of 847 * getting pages via VOP_READ. 848 */ 849 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 850 if (error == EOPNOTSUPP) { 851 uma_zfree(vnode_pbuf_zone, bp); 852 VM_OBJECT_WLOCK(object); 853 for (i = 0; i < count; i++) { 854 VM_CNT_INC(v_vnodein); 855 VM_CNT_INC(v_vnodepgsin); 856 error = vnode_pager_input_old(object, m[i]); 857 if (error) 858 break; 859 } 860 VM_OBJECT_WUNLOCK(object); 861 return (error); 862 } else if (error != 0) { 863 uma_zfree(vnode_pbuf_zone, bp); 864 return (VM_PAGER_ERROR); 865 } 866 867 /* 868 * If the file system supports BMAP, but blocksize is smaller 869 * than a page size, then use special small filesystem code. 870 */ 871 if (pagesperblock == 0) { 872 uma_zfree(vnode_pbuf_zone, bp); 873 for (i = 0; i < count; i++) { 874 VM_CNT_INC(v_vnodein); 875 VM_CNT_INC(v_vnodepgsin); 876 error = vnode_pager_input_smlfs(object, m[i]); 877 if (error) 878 break; 879 } 880 return (error); 881 } 882 883 /* 884 * A sparse file can be encountered only for a single page request, 885 * which may not be preceded by call to vm_pager_haspage(). 886 */ 887 if (bp->b_blkno == -1) { 888 KASSERT(count == 1, 889 ("%s: array[%d] request to a sparse file %p", __func__, 890 count, vp)); 891 uma_zfree(vnode_pbuf_zone, bp); 892 pmap_zero_page(m[0]); 893 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 894 __func__, m[0])); 895 vm_page_valid(m[0]); 896 return (VM_PAGER_OK); 897 } 898 899 #ifdef INVARIANTS 900 blkno0 = bp->b_blkno; 901 #endif 902 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 903 904 /* Recalculate blocks available after/before to pages. */ 905 poff = (foff % bsize) / PAGE_SIZE; 906 before *= pagesperblock; 907 before += poff; 908 after *= pagesperblock; 909 after += pagesperblock - (poff + 1); 910 if (m[0]->pindex + after >= object->size) 911 after = object->size - 1 - m[0]->pindex; 912 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 913 __func__, count, after + 1)); 914 after -= count - 1; 915 916 /* Trim requested rbehind/rahead to possible values. */ 917 rbehind = a_rbehind ? *a_rbehind : 0; 918 rahead = a_rahead ? *a_rahead : 0; 919 rbehind = min(rbehind, before); 920 rbehind = min(rbehind, m[0]->pindex); 921 rahead = min(rahead, after); 922 rahead = min(rahead, object->size - m[count - 1]->pindex); 923 /* 924 * Check that total amount of pages fit into buf. Trim rbehind and 925 * rahead evenly if not. 926 */ 927 if (rbehind + rahead + count > nitems(bp->b_pages)) { 928 int trim, sum; 929 930 trim = rbehind + rahead + count - nitems(bp->b_pages) + 1; 931 sum = rbehind + rahead; 932 if (rbehind == before) { 933 /* Roundup rbehind trim to block size. */ 934 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 935 if (rbehind < 0) 936 rbehind = 0; 937 } else 938 rbehind -= trim * rbehind / sum; 939 rahead -= trim * rahead / sum; 940 } 941 KASSERT(rbehind + rahead + count <= nitems(bp->b_pages), 942 ("%s: behind %d ahead %d count %d", __func__, 943 rbehind, rahead, count)); 944 945 /* 946 * Fill in the bp->b_pages[] array with requested and optional 947 * read behind or read ahead pages. Read behind pages are looked 948 * up in a backward direction, down to a first cached page. Same 949 * for read ahead pages, but there is no need to shift the array 950 * in case of encountering a cached page. 951 */ 952 i = bp->b_npages = 0; 953 if (rbehind) { 954 vm_pindex_t startpindex, tpindex; 955 vm_page_t p; 956 957 VM_OBJECT_WLOCK(object); 958 startpindex = m[0]->pindex - rbehind; 959 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 960 p->pindex >= startpindex) 961 startpindex = p->pindex + 1; 962 963 /* tpindex is unsigned; beware of numeric underflow. */ 964 for (tpindex = m[0]->pindex - 1; 965 tpindex >= startpindex && tpindex < m[0]->pindex; 966 tpindex--, i++) { 967 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 968 if (p == NULL) { 969 /* Shift the array. */ 970 for (int j = 0; j < i; j++) 971 bp->b_pages[j] = bp->b_pages[j + 972 tpindex + 1 - startpindex]; 973 break; 974 } 975 bp->b_pages[tpindex - startpindex] = p; 976 } 977 978 bp->b_pgbefore = i; 979 bp->b_npages += i; 980 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 981 } else 982 bp->b_pgbefore = 0; 983 984 /* Requested pages. */ 985 for (int j = 0; j < count; j++, i++) 986 bp->b_pages[i] = m[j]; 987 bp->b_npages += count; 988 989 if (rahead) { 990 vm_pindex_t endpindex, tpindex; 991 vm_page_t p; 992 993 if (!VM_OBJECT_WOWNED(object)) 994 VM_OBJECT_WLOCK(object); 995 endpindex = m[count - 1]->pindex + rahead + 1; 996 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 997 p->pindex < endpindex) 998 endpindex = p->pindex; 999 if (endpindex > object->size) 1000 endpindex = object->size; 1001 1002 for (tpindex = m[count - 1]->pindex + 1; 1003 tpindex < endpindex; i++, tpindex++) { 1004 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1005 if (p == NULL) 1006 break; 1007 bp->b_pages[i] = p; 1008 } 1009 1010 bp->b_pgafter = i - bp->b_npages; 1011 bp->b_npages = i; 1012 } else 1013 bp->b_pgafter = 0; 1014 1015 if (VM_OBJECT_WOWNED(object)) 1016 VM_OBJECT_WUNLOCK(object); 1017 1018 /* Report back actual behind/ahead read. */ 1019 if (a_rbehind) 1020 *a_rbehind = bp->b_pgbefore; 1021 if (a_rahead) 1022 *a_rahead = bp->b_pgafter; 1023 1024 #ifdef INVARIANTS 1025 KASSERT(bp->b_npages <= nitems(bp->b_pages), 1026 ("%s: buf %p overflowed", __func__, bp)); 1027 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 1028 if (bp->b_pages[j] == bogus_page) 1029 continue; 1030 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 1031 j - prev, ("%s: pages array not consecutive, bp %p", 1032 __func__, bp)); 1033 prev = j; 1034 } 1035 #endif 1036 1037 /* 1038 * Recalculate first offset and bytecount with regards to read behind. 1039 * Truncate bytecount to vnode real size and round up physical size 1040 * for real devices. 1041 */ 1042 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1043 bytecount = bp->b_npages << PAGE_SHIFT; 1044 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 1045 bytecount = object->un_pager.vnp.vnp_size - foff; 1046 secmask = bo->bo_bsize - 1; 1047 KASSERT(secmask < PAGE_SIZE && secmask > 0, 1048 ("%s: sector size %d too large", __func__, secmask + 1)); 1049 bytecount = (bytecount + secmask) & ~secmask; 1050 1051 /* 1052 * And map the pages to be read into the kva, if the filesystem 1053 * requires mapped buffers. 1054 */ 1055 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1056 unmapped_buf_allowed) { 1057 bp->b_data = unmapped_buf; 1058 bp->b_offset = 0; 1059 } else { 1060 bp->b_data = bp->b_kvabase; 1061 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1062 } 1063 1064 /* Build a minimal buffer header. */ 1065 bp->b_iocmd = BIO_READ; 1066 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1067 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1068 bp->b_rcred = crhold(curthread->td_ucred); 1069 bp->b_wcred = crhold(curthread->td_ucred); 1070 pbgetbo(bo, bp); 1071 bp->b_vp = vp; 1072 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1073 bp->b_iooffset = dbtob(bp->b_blkno); 1074 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1075 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1076 IDX_TO_OFF(m[0]->pindex) % bsize, 1077 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1078 "blkno0 %ju b_blkno %ju", bsize, 1079 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1080 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1081 1082 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1083 VM_CNT_INC(v_vnodein); 1084 VM_CNT_ADD(v_vnodepgsin, bp->b_npages); 1085 1086 if (iodone != NULL) { /* async */ 1087 bp->b_pgiodone = iodone; 1088 bp->b_caller1 = arg; 1089 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1090 bp->b_flags |= B_ASYNC; 1091 BUF_KERNPROC(bp); 1092 bstrategy(bp); 1093 return (VM_PAGER_OK); 1094 } else { 1095 bp->b_iodone = bdone; 1096 bstrategy(bp); 1097 bwait(bp, PVM, "vnread"); 1098 error = vnode_pager_generic_getpages_done(bp); 1099 for (i = 0; i < bp->b_npages; i++) 1100 bp->b_pages[i] = NULL; 1101 bp->b_vp = NULL; 1102 pbrelbo(bp); 1103 uma_zfree(vnode_pbuf_zone, bp); 1104 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1105 } 1106 } 1107 1108 static void 1109 vnode_pager_generic_getpages_done_async(struct buf *bp) 1110 { 1111 int error; 1112 1113 error = vnode_pager_generic_getpages_done(bp); 1114 /* Run the iodone upon the requested range. */ 1115 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1116 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1117 for (int i = 0; i < bp->b_npages; i++) 1118 bp->b_pages[i] = NULL; 1119 bp->b_vp = NULL; 1120 pbrelbo(bp); 1121 uma_zfree(vnode_pbuf_zone, bp); 1122 } 1123 1124 static int 1125 vnode_pager_generic_getpages_done(struct buf *bp) 1126 { 1127 vm_object_t object; 1128 off_t tfoff, nextoff; 1129 int i, error; 1130 1131 error = (bp->b_ioflags & BIO_ERROR) != 0 ? EIO : 0; 1132 object = bp->b_vp->v_object; 1133 1134 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1135 if (!buf_mapped(bp)) { 1136 bp->b_data = bp->b_kvabase; 1137 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1138 bp->b_npages); 1139 } 1140 bzero(bp->b_data + bp->b_bcount, 1141 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1142 } 1143 if (buf_mapped(bp)) { 1144 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1145 bp->b_data = unmapped_buf; 1146 } 1147 1148 /* Read lock to protect size. */ 1149 VM_OBJECT_RLOCK(object); 1150 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1151 i < bp->b_npages; i++, tfoff = nextoff) { 1152 vm_page_t mt; 1153 1154 nextoff = tfoff + PAGE_SIZE; 1155 mt = bp->b_pages[i]; 1156 if (mt == bogus_page) 1157 continue; 1158 1159 if (nextoff <= object->un_pager.vnp.vnp_size) { 1160 /* 1161 * Read filled up entire page. 1162 */ 1163 vm_page_valid(mt); 1164 KASSERT(mt->dirty == 0, 1165 ("%s: page %p is dirty", __func__, mt)); 1166 KASSERT(!pmap_page_is_mapped(mt), 1167 ("%s: page %p is mapped", __func__, mt)); 1168 } else { 1169 /* 1170 * Read did not fill up entire page. 1171 * 1172 * Currently we do not set the entire page valid, 1173 * we just try to clear the piece that we couldn't 1174 * read. 1175 */ 1176 vm_page_set_valid_range(mt, 0, 1177 object->un_pager.vnp.vnp_size - tfoff); 1178 KASSERT((mt->dirty & vm_page_bits(0, 1179 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1180 ("%s: page %p is dirty", __func__, mt)); 1181 } 1182 1183 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1184 vm_page_readahead_finish(mt); 1185 } 1186 VM_OBJECT_RUNLOCK(object); 1187 if (error != 0) 1188 printf("%s: I/O read error %d\n", __func__, error); 1189 1190 return (error); 1191 } 1192 1193 /* 1194 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1195 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1196 * vnode_pager_generic_putpages() to implement the previous behaviour. 1197 * 1198 * All other FS's should use the bypass to get to the local media 1199 * backing vp's VOP_PUTPAGES. 1200 */ 1201 static void 1202 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1203 int flags, int *rtvals) 1204 { 1205 int rtval; 1206 struct vnode *vp; 1207 int bytes = count * PAGE_SIZE; 1208 1209 /* 1210 * Force synchronous operation if we are extremely low on memory 1211 * to prevent a low-memory deadlock. VOP operations often need to 1212 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1213 * operation ). The swapper handles the case by limiting the amount 1214 * of asynchronous I/O, but that sort of solution doesn't scale well 1215 * for the vnode pager without a lot of work. 1216 * 1217 * Also, the backing vnode's iodone routine may not wake the pageout 1218 * daemon up. This should be probably be addressed XXX. 1219 */ 1220 1221 if (vm_page_count_min()) 1222 flags |= VM_PAGER_PUT_SYNC; 1223 1224 /* 1225 * Call device-specific putpages function 1226 */ 1227 vp = object->handle; 1228 VM_OBJECT_WUNLOCK(object); 1229 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1230 KASSERT(rtval != EOPNOTSUPP, 1231 ("vnode_pager: stale FS putpages\n")); 1232 VM_OBJECT_WLOCK(object); 1233 } 1234 1235 static int 1236 vn_off2bidx(vm_ooffset_t offset) 1237 { 1238 1239 return ((offset & PAGE_MASK) / DEV_BSIZE); 1240 } 1241 1242 static bool 1243 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset) 1244 { 1245 1246 KASSERT(IDX_TO_OFF(m->pindex) <= offset && 1247 offset < IDX_TO_OFF(m->pindex + 1), 1248 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex, 1249 (uintmax_t)offset)); 1250 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0); 1251 } 1252 1253 /* 1254 * This is now called from local media FS's to operate against their 1255 * own vnodes if they fail to implement VOP_PUTPAGES. 1256 * 1257 * This is typically called indirectly via the pageout daemon and 1258 * clustering has already typically occurred, so in general we ask the 1259 * underlying filesystem to write the data out asynchronously rather 1260 * then delayed. 1261 */ 1262 int 1263 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1264 int flags, int *rtvals) 1265 { 1266 vm_object_t object; 1267 vm_page_t m; 1268 vm_ooffset_t maxblksz, next_offset, poffset, prev_offset; 1269 struct uio auio; 1270 struct iovec aiov; 1271 off_t prev_resid, wrsz; 1272 int count, error, i, maxsize, ncount, pgoff, ppscheck; 1273 bool in_hole; 1274 static struct timeval lastfail; 1275 static int curfail; 1276 1277 object = vp->v_object; 1278 count = bytecount / PAGE_SIZE; 1279 1280 for (i = 0; i < count; i++) 1281 rtvals[i] = VM_PAGER_ERROR; 1282 1283 if ((int64_t)ma[0]->pindex < 0) { 1284 printf("vnode_pager_generic_putpages: " 1285 "attempt to write meta-data 0x%jx(%lx)\n", 1286 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty); 1287 rtvals[0] = VM_PAGER_BAD; 1288 return (VM_PAGER_BAD); 1289 } 1290 1291 maxsize = count * PAGE_SIZE; 1292 ncount = count; 1293 1294 poffset = IDX_TO_OFF(ma[0]->pindex); 1295 1296 /* 1297 * If the page-aligned write is larger then the actual file we 1298 * have to invalidate pages occurring beyond the file EOF. However, 1299 * there is an edge case where a file may not be page-aligned where 1300 * the last page is partially invalid. In this case the filesystem 1301 * may not properly clear the dirty bits for the entire page (which 1302 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1303 * With the page locked we are free to fix-up the dirty bits here. 1304 * 1305 * We do not under any circumstances truncate the valid bits, as 1306 * this will screw up bogus page replacement. 1307 */ 1308 VM_OBJECT_RLOCK(object); 1309 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1310 if (object->un_pager.vnp.vnp_size > poffset) { 1311 maxsize = object->un_pager.vnp.vnp_size - poffset; 1312 ncount = btoc(maxsize); 1313 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1314 pgoff = roundup2(pgoff, DEV_BSIZE); 1315 1316 /* 1317 * If the page is busy and the following 1318 * conditions hold, then the page's dirty 1319 * field cannot be concurrently changed by a 1320 * pmap operation. 1321 */ 1322 m = ma[ncount - 1]; 1323 vm_page_assert_sbusied(m); 1324 KASSERT(!pmap_page_is_write_mapped(m), 1325 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1326 MPASS(m->dirty != 0); 1327 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1328 pgoff); 1329 } 1330 } else { 1331 maxsize = 0; 1332 ncount = 0; 1333 } 1334 for (i = ncount; i < count; i++) 1335 rtvals[i] = VM_PAGER_BAD; 1336 } 1337 VM_OBJECT_RUNLOCK(object); 1338 1339 auio.uio_iov = &aiov; 1340 auio.uio_segflg = UIO_NOCOPY; 1341 auio.uio_rw = UIO_WRITE; 1342 auio.uio_td = NULL; 1343 maxblksz = roundup2(poffset + maxsize, DEV_BSIZE); 1344 1345 for (prev_offset = poffset; prev_offset < maxblksz;) { 1346 /* Skip clean blocks. */ 1347 for (in_hole = true; in_hole && prev_offset < maxblksz;) { 1348 m = ma[OFF_TO_IDX(prev_offset - poffset)]; 1349 for (i = vn_off2bidx(prev_offset); 1350 i < sizeof(vm_page_bits_t) * NBBY && 1351 prev_offset < maxblksz; i++) { 1352 if (vn_dirty_blk(m, prev_offset)) { 1353 in_hole = false; 1354 break; 1355 } 1356 prev_offset += DEV_BSIZE; 1357 } 1358 } 1359 if (in_hole) 1360 goto write_done; 1361 1362 /* Find longest run of dirty blocks. */ 1363 for (next_offset = prev_offset; next_offset < maxblksz;) { 1364 m = ma[OFF_TO_IDX(next_offset - poffset)]; 1365 for (i = vn_off2bidx(next_offset); 1366 i < sizeof(vm_page_bits_t) * NBBY && 1367 next_offset < maxblksz; i++) { 1368 if (!vn_dirty_blk(m, next_offset)) 1369 goto start_write; 1370 next_offset += DEV_BSIZE; 1371 } 1372 } 1373 start_write: 1374 if (next_offset > poffset + maxsize) 1375 next_offset = poffset + maxsize; 1376 1377 /* 1378 * Getting here requires finding a dirty block in the 1379 * 'skip clean blocks' loop. 1380 */ 1381 MPASS(prev_offset < next_offset); 1382 1383 aiov.iov_base = NULL; 1384 auio.uio_iovcnt = 1; 1385 auio.uio_offset = prev_offset; 1386 prev_resid = auio.uio_resid = aiov.iov_len = next_offset - 1387 prev_offset; 1388 error = VOP_WRITE(vp, &auio, 1389 vnode_pager_putpages_ioflags(flags), curthread->td_ucred); 1390 1391 wrsz = prev_resid - auio.uio_resid; 1392 if (wrsz == 0) { 1393 if (ppsratecheck(&lastfail, &curfail, 1) != 0) { 1394 vn_printf(vp, "vnode_pager_putpages: " 1395 "zero-length write at %ju resid %zd\n", 1396 auio.uio_offset, auio.uio_resid); 1397 } 1398 break; 1399 } 1400 1401 /* Adjust the starting offset for next iteration. */ 1402 prev_offset += wrsz; 1403 MPASS(auio.uio_offset == prev_offset); 1404 1405 ppscheck = 0; 1406 if (error != 0 && (ppscheck = ppsratecheck(&lastfail, 1407 &curfail, 1)) != 0) 1408 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n", 1409 error); 1410 if (auio.uio_resid != 0 && (ppscheck != 0 || 1411 ppsratecheck(&lastfail, &curfail, 1) != 0)) 1412 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd " 1413 "at %ju\n", auio.uio_resid, 1414 (uintmax_t)ma[0]->pindex); 1415 if (error != 0 || auio.uio_resid != 0) 1416 break; 1417 } 1418 write_done: 1419 /* Mark completely processed pages. */ 1420 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++) 1421 rtvals[i] = VM_PAGER_OK; 1422 /* Mark partial EOF page. */ 1423 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0) 1424 rtvals[i++] = VM_PAGER_OK; 1425 /* Unwritten pages in range, free bonus if the page is clean. */ 1426 for (; i < ncount; i++) 1427 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR; 1428 VM_CNT_ADD(v_vnodepgsout, i); 1429 VM_CNT_INC(v_vnodeout); 1430 return (rtvals[0]); 1431 } 1432 1433 int 1434 vnode_pager_putpages_ioflags(int pager_flags) 1435 { 1436 int ioflags; 1437 1438 /* 1439 * Pageouts are already clustered, use IO_ASYNC to force a 1440 * bawrite() rather then a bdwrite() to prevent paging I/O 1441 * from saturating the buffer cache. Dummy-up the sequential 1442 * heuristic to cause large ranges to cluster. If neither 1443 * IO_SYNC or IO_ASYNC is set, the system decides how to 1444 * cluster. 1445 */ 1446 ioflags = IO_VMIO; 1447 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0) 1448 ioflags |= IO_SYNC; 1449 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0) 1450 ioflags |= IO_ASYNC; 1451 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0; 1452 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0; 1453 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1454 return (ioflags); 1455 } 1456 1457 /* 1458 * vnode_pager_undirty_pages(). 1459 * 1460 * A helper to mark pages as clean after pageout that was possibly 1461 * done with a short write. The lpos argument specifies the page run 1462 * length in bytes, and the written argument specifies how many bytes 1463 * were actually written. eof is the offset past the last valid byte 1464 * in the vnode using the absolute file position of the first byte in 1465 * the run as the base from which it is computed. 1466 */ 1467 void 1468 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof, 1469 int lpos) 1470 { 1471 vm_object_t obj; 1472 int i, pos, pos_devb; 1473 1474 if (written == 0 && eof >= lpos) 1475 return; 1476 obj = ma[0]->object; 1477 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1478 if (pos < trunc_page(written)) { 1479 rtvals[i] = VM_PAGER_OK; 1480 vm_page_undirty(ma[i]); 1481 } else { 1482 /* Partially written page. */ 1483 rtvals[i] = VM_PAGER_AGAIN; 1484 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1485 } 1486 } 1487 if (eof >= lpos) /* avoid truncation */ 1488 return; 1489 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) { 1490 if (pos != trunc_page(pos)) { 1491 /* 1492 * The page contains the last valid byte in 1493 * the vnode, mark the rest of the page as 1494 * clean, potentially making the whole page 1495 * clean. 1496 */ 1497 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE); 1498 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE - 1499 pos_devb); 1500 1501 /* 1502 * If the page was cleaned, report the pageout 1503 * on it as successful. msync() no longer 1504 * needs to write out the page, endlessly 1505 * creating write requests and dirty buffers. 1506 */ 1507 if (ma[i]->dirty == 0) 1508 rtvals[i] = VM_PAGER_OK; 1509 1510 pos = round_page(pos); 1511 } else { 1512 /* vm_pageout_flush() clears dirty */ 1513 rtvals[i] = VM_PAGER_BAD; 1514 pos += PAGE_SIZE; 1515 } 1516 } 1517 } 1518 1519 static void 1520 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1521 vm_offset_t end) 1522 { 1523 struct vnode *vp; 1524 vm_ooffset_t old_wm; 1525 1526 VM_OBJECT_WLOCK(object); 1527 if (object->type != OBJT_VNODE) { 1528 VM_OBJECT_WUNLOCK(object); 1529 return; 1530 } 1531 old_wm = object->un_pager.vnp.writemappings; 1532 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1533 vp = object->handle; 1534 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1535 ASSERT_VOP_LOCKED(vp, "v_writecount inc"); 1536 VOP_ADD_WRITECOUNT_CHECKED(vp, 1); 1537 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1538 __func__, vp, vp->v_writecount); 1539 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1540 ASSERT_VOP_LOCKED(vp, "v_writecount dec"); 1541 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1542 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1543 __func__, vp, vp->v_writecount); 1544 } 1545 VM_OBJECT_WUNLOCK(object); 1546 } 1547 1548 static void 1549 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1550 vm_offset_t end) 1551 { 1552 struct vnode *vp; 1553 struct mount *mp; 1554 vm_offset_t inc; 1555 1556 VM_OBJECT_WLOCK(object); 1557 1558 /* 1559 * First, recheck the object type to account for the race when 1560 * the vnode is reclaimed. 1561 */ 1562 if (object->type != OBJT_VNODE) { 1563 VM_OBJECT_WUNLOCK(object); 1564 return; 1565 } 1566 1567 /* 1568 * Optimize for the case when writemappings is not going to 1569 * zero. 1570 */ 1571 inc = end - start; 1572 if (object->un_pager.vnp.writemappings != inc) { 1573 object->un_pager.vnp.writemappings -= inc; 1574 VM_OBJECT_WUNLOCK(object); 1575 return; 1576 } 1577 1578 vp = object->handle; 1579 vhold(vp); 1580 VM_OBJECT_WUNLOCK(object); 1581 mp = NULL; 1582 vn_start_write(vp, &mp, V_WAIT); 1583 vn_lock(vp, LK_SHARED | LK_RETRY); 1584 1585 /* 1586 * Decrement the object's writemappings, by swapping the start 1587 * and end arguments for vnode_pager_update_writecount(). If 1588 * there was not a race with vnode reclaimation, then the 1589 * vnode's v_writecount is decremented. 1590 */ 1591 vnode_pager_update_writecount(object, end, start); 1592 VOP_UNLOCK(vp); 1593 vdrop(vp); 1594 if (mp != NULL) 1595 vn_finished_write(mp); 1596 } 1597