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