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 #include <sys/user.h> 78 79 #include <machine/atomic.h> 80 81 #include <vm/vm.h> 82 #include <vm/vm_param.h> 83 #include <vm/vm_object.h> 84 #include <vm/vm_page.h> 85 #include <vm/vm_pager.h> 86 #include <vm/vm_map.h> 87 #include <vm/vnode_pager.h> 88 #include <vm/vm_extern.h> 89 #include <vm/uma.h> 90 91 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 92 daddr_t *rtaddress, int *run); 93 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 94 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 95 static void vnode_pager_dealloc(vm_object_t); 96 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 97 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, 98 int *, vop_getpages_iodone_t, void *); 99 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 100 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 101 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 102 vm_ooffset_t, struct ucred *cred); 103 static int vnode_pager_generic_getpages_done(struct buf *); 104 static void vnode_pager_generic_getpages_done_async(struct buf *); 105 static void vnode_pager_update_writecount(vm_object_t, vm_offset_t, 106 vm_offset_t); 107 static void vnode_pager_release_writecount(vm_object_t, vm_offset_t, 108 vm_offset_t); 109 static void vnode_pager_getvp(vm_object_t, struct vnode **, bool *); 110 111 const struct pagerops vnodepagerops = { 112 .pgo_kvme_type = KVME_TYPE_VNODE, 113 .pgo_alloc = vnode_pager_alloc, 114 .pgo_dealloc = vnode_pager_dealloc, 115 .pgo_getpages = vnode_pager_getpages, 116 .pgo_getpages_async = vnode_pager_getpages_async, 117 .pgo_putpages = vnode_pager_putpages, 118 .pgo_haspage = vnode_pager_haspage, 119 .pgo_update_writecount = vnode_pager_update_writecount, 120 .pgo_release_writecount = vnode_pager_release_writecount, 121 .pgo_set_writeable_dirty = vm_object_set_writeable_dirty_, 122 .pgo_mightbedirty = vm_object_mightbedirty_, 123 .pgo_getvp = vnode_pager_getvp, 124 }; 125 126 static struct domainset *vnode_domainset = NULL; 127 128 SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset, 129 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_RW, &vnode_domainset, 0, 130 sysctl_handle_domainset, "A", "Default vnode NUMA policy"); 131 132 static int nvnpbufs; 133 SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 134 &nvnpbufs, 0, "number of physical buffers allocated for vnode pager"); 135 136 static uma_zone_t vnode_pbuf_zone; 137 138 static void 139 vnode_pager_init(void *dummy) 140 { 141 142 #ifdef __LP64__ 143 nvnpbufs = nswbuf * 2; 144 #else 145 nvnpbufs = nswbuf / 2; 146 #endif 147 TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs); 148 vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs); 149 } 150 SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL); 151 152 /* Create the VM system backing object for this vnode */ 153 int 154 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 155 { 156 vm_object_t object; 157 vm_ooffset_t size = isize; 158 struct vattr va; 159 bool last; 160 161 if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE) 162 return (0); 163 164 object = vp->v_object; 165 if (object != NULL) 166 return (0); 167 168 if (size == 0) { 169 if (vn_isdisk(vp)) { 170 size = IDX_TO_OFF(INT_MAX); 171 } else { 172 if (VOP_GETATTR(vp, &va, td->td_ucred)) 173 return (0); 174 size = va.va_size; 175 } 176 } 177 178 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 179 /* 180 * Dereference the reference we just created. This assumes 181 * that the object is associated with the vp. We still have 182 * to serialize with vnode_pager_dealloc() for the last 183 * potential reference. 184 */ 185 VM_OBJECT_RLOCK(object); 186 last = refcount_release(&object->ref_count); 187 VM_OBJECT_RUNLOCK(object); 188 if (last) 189 vrele(vp); 190 191 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 192 193 return (0); 194 } 195 196 void 197 vnode_destroy_vobject(struct vnode *vp) 198 { 199 struct vm_object *obj; 200 201 obj = vp->v_object; 202 if (obj == NULL || obj->handle != vp) 203 return; 204 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 205 VM_OBJECT_WLOCK(obj); 206 MPASS(obj->type == OBJT_VNODE); 207 umtx_shm_object_terminated(obj); 208 if (obj->ref_count == 0) { 209 KASSERT((obj->flags & OBJ_DEAD) == 0, 210 ("vnode_destroy_vobject: Terminating dead object")); 211 vm_object_set_flag(obj, OBJ_DEAD); 212 213 /* 214 * Clean pages and flush buffers. 215 */ 216 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC); 217 VM_OBJECT_WUNLOCK(obj); 218 219 vinvalbuf(vp, V_SAVE, 0, 0); 220 221 BO_LOCK(&vp->v_bufobj); 222 vp->v_bufobj.bo_flag |= BO_DEAD; 223 BO_UNLOCK(&vp->v_bufobj); 224 225 VM_OBJECT_WLOCK(obj); 226 vm_object_terminate(obj); 227 } else { 228 /* 229 * Woe to the process that tries to page now :-). 230 */ 231 vm_pager_deallocate(obj); 232 VM_OBJECT_WUNLOCK(obj); 233 } 234 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object)); 235 } 236 237 /* 238 * Allocate (or lookup) pager for a vnode. 239 * Handle is a vnode pointer. 240 */ 241 vm_object_t 242 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 243 vm_ooffset_t offset, struct ucred *cred) 244 { 245 vm_object_t object; 246 struct vnode *vp; 247 248 /* 249 * Pageout to vnode, no can do yet. 250 */ 251 if (handle == NULL) 252 return (NULL); 253 254 vp = (struct vnode *)handle; 255 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc"); 256 VNPASS(vp->v_usecount > 0, vp); 257 retry: 258 object = vp->v_object; 259 260 if (object == NULL) { 261 /* 262 * Add an object of the appropriate size 263 */ 264 object = vm_object_allocate(OBJT_VNODE, 265 OFF_TO_IDX(round_page(size))); 266 267 object->un_pager.vnp.vnp_size = size; 268 object->un_pager.vnp.writemappings = 0; 269 object->domain.dr_policy = vnode_domainset; 270 object->handle = handle; 271 if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) { 272 VM_OBJECT_WLOCK(object); 273 vm_object_set_flag(object, OBJ_SIZEVNLOCK); 274 VM_OBJECT_WUNLOCK(object); 275 } 276 VI_LOCK(vp); 277 if (vp->v_object != NULL) { 278 /* 279 * Object has been created while we were allocating. 280 */ 281 VI_UNLOCK(vp); 282 VM_OBJECT_WLOCK(object); 283 KASSERT(object->ref_count == 1, 284 ("leaked ref %p %d", object, object->ref_count)); 285 object->type = OBJT_DEAD; 286 refcount_init(&object->ref_count, 0); 287 VM_OBJECT_WUNLOCK(object); 288 vm_object_destroy(object); 289 goto retry; 290 } 291 vp->v_object = object; 292 VI_UNLOCK(vp); 293 vrefact(vp); 294 } else { 295 vm_object_reference(object); 296 #if VM_NRESERVLEVEL > 0 297 if ((object->flags & OBJ_COLORED) == 0) { 298 VM_OBJECT_WLOCK(object); 299 vm_object_color(object, 0); 300 VM_OBJECT_WUNLOCK(object); 301 } 302 #endif 303 } 304 return (object); 305 } 306 307 /* 308 * The object must be locked. 309 */ 310 static void 311 vnode_pager_dealloc(vm_object_t object) 312 { 313 struct vnode *vp; 314 int refs; 315 316 vp = object->handle; 317 if (vp == NULL) 318 panic("vnode_pager_dealloc: pager already dealloced"); 319 320 VM_OBJECT_ASSERT_WLOCKED(object); 321 vm_object_pip_wait(object, "vnpdea"); 322 refs = object->ref_count; 323 324 object->handle = NULL; 325 object->type = OBJT_DEAD; 326 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 327 if (object->un_pager.vnp.writemappings > 0) { 328 object->un_pager.vnp.writemappings = 0; 329 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 330 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 331 __func__, vp, vp->v_writecount); 332 } 333 vp->v_object = NULL; 334 VI_LOCK(vp); 335 336 /* 337 * vm_map_entry_set_vnode_text() cannot reach this vnode by 338 * following object->handle. Clear all text references now. 339 * This also clears the transient references from 340 * kern_execve(), which is fine because dead_vnodeops uses nop 341 * for VOP_UNSET_TEXT(). 342 */ 343 if (vp->v_writecount < 0) 344 vp->v_writecount = 0; 345 VI_UNLOCK(vp); 346 VM_OBJECT_WUNLOCK(object); 347 if (refs > 0) 348 vunref(vp); 349 VM_OBJECT_WLOCK(object); 350 } 351 352 static boolean_t 353 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 354 int *after) 355 { 356 struct vnode *vp = object->handle; 357 daddr_t bn; 358 uintptr_t lockstate; 359 int err; 360 daddr_t reqblock; 361 int poff; 362 int bsize; 363 int pagesperblock, blocksperpage; 364 365 VM_OBJECT_ASSERT_LOCKED(object); 366 /* 367 * If no vp or vp is doomed or marked transparent to VM, we do not 368 * have the page. 369 */ 370 if (vp == NULL || VN_IS_DOOMED(vp)) 371 return FALSE; 372 /* 373 * If the offset is beyond end of file we do 374 * not have the page. 375 */ 376 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 377 return FALSE; 378 379 bsize = vp->v_mount->mnt_stat.f_iosize; 380 pagesperblock = bsize / PAGE_SIZE; 381 blocksperpage = 0; 382 if (pagesperblock > 0) { 383 reqblock = pindex / pagesperblock; 384 } else { 385 blocksperpage = (PAGE_SIZE / bsize); 386 reqblock = pindex * blocksperpage; 387 } 388 lockstate = VM_OBJECT_DROP(object); 389 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 390 VM_OBJECT_PICKUP(object, lockstate); 391 if (err) 392 return TRUE; 393 if (bn == -1) 394 return FALSE; 395 if (pagesperblock > 0) { 396 poff = pindex - (reqblock * pagesperblock); 397 if (before) { 398 *before *= pagesperblock; 399 *before += poff; 400 } 401 if (after) { 402 /* 403 * The BMAP vop can report a partial block in the 404 * 'after', but must not report blocks after EOF. 405 * Assert the latter, and truncate 'after' in case 406 * of the former. 407 */ 408 KASSERT((reqblock + *after) * pagesperblock < 409 roundup2(object->size, pagesperblock), 410 ("%s: reqblock %jd after %d size %ju", __func__, 411 (intmax_t )reqblock, *after, 412 (uintmax_t )object->size)); 413 *after *= pagesperblock; 414 *after += pagesperblock - (poff + 1); 415 if (pindex + *after >= object->size) 416 *after = object->size - 1 - pindex; 417 } 418 } else { 419 if (before) { 420 *before /= blocksperpage; 421 } 422 423 if (after) { 424 *after /= blocksperpage; 425 } 426 } 427 return TRUE; 428 } 429 430 /* 431 * Lets the VM system know about a change in size for a file. 432 * We adjust our own internal size and flush any cached pages in 433 * the associated object that are affected by the size change. 434 * 435 * Note: this routine may be invoked as a result of a pager put 436 * operation (possibly at object termination time), so we must be careful. 437 */ 438 void 439 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 440 { 441 vm_object_t object; 442 vm_page_t m; 443 vm_pindex_t nobjsize; 444 445 if ((object = vp->v_object) == NULL) 446 return; 447 #ifdef DEBUG_VFS_LOCKS 448 { 449 struct mount *mp; 450 451 mp = vp->v_mount; 452 if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0) 453 assert_vop_elocked(vp, 454 "vnode_pager_setsize and not locked vnode"); 455 } 456 #endif 457 VM_OBJECT_WLOCK(object); 458 if (object->type == OBJT_DEAD) { 459 VM_OBJECT_WUNLOCK(object); 460 return; 461 } 462 KASSERT(object->type == OBJT_VNODE, 463 ("not vnode-backed object %p", object)); 464 if (nsize == object->un_pager.vnp.vnp_size) { 465 /* 466 * Hasn't changed size 467 */ 468 VM_OBJECT_WUNLOCK(object); 469 return; 470 } 471 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 472 if (nsize < object->un_pager.vnp.vnp_size) { 473 /* 474 * File has shrunk. Toss any cached pages beyond the new EOF. 475 */ 476 if (nobjsize < object->size) 477 vm_object_page_remove(object, nobjsize, object->size, 478 0); 479 /* 480 * this gets rid of garbage at the end of a page that is now 481 * only partially backed by the vnode. 482 * 483 * XXX for some reason (I don't know yet), if we take a 484 * completely invalid page and mark it partially valid 485 * it can screw up NFS reads, so we don't allow the case. 486 */ 487 if (!(nsize & PAGE_MASK)) 488 goto out; 489 m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT); 490 if (m == NULL) 491 goto out; 492 if (!vm_page_none_valid(m)) { 493 int base = (int)nsize & PAGE_MASK; 494 int size = PAGE_SIZE - base; 495 496 /* 497 * Clear out partial-page garbage in case 498 * the page has been mapped. 499 */ 500 pmap_zero_page_area(m, base, size); 501 502 /* 503 * Update the valid bits to reflect the blocks that 504 * have been zeroed. Some of these valid bits may 505 * have already been set. 506 */ 507 vm_page_set_valid_range(m, base, size); 508 509 /* 510 * Round "base" to the next block boundary so that the 511 * dirty bit for a partially zeroed block is not 512 * cleared. 513 */ 514 base = roundup2(base, DEV_BSIZE); 515 516 /* 517 * Clear out partial-page dirty bits. 518 * 519 * note that we do not clear out the valid 520 * bits. This would prevent bogus_page 521 * replacement from working properly. 522 */ 523 vm_page_clear_dirty(m, base, PAGE_SIZE - base); 524 } 525 vm_page_xunbusy(m); 526 } 527 out: 528 #if defined(__powerpc__) && !defined(__powerpc64__) 529 object->un_pager.vnp.vnp_size = nsize; 530 #else 531 atomic_store_64(&object->un_pager.vnp.vnp_size, nsize); 532 #endif 533 object->size = nobjsize; 534 VM_OBJECT_WUNLOCK(object); 535 } 536 537 /* 538 * calculate the linear (byte) disk address of specified virtual 539 * file address 540 */ 541 static int 542 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 543 int *run) 544 { 545 int bsize; 546 int err; 547 daddr_t vblock; 548 daddr_t voffset; 549 550 if (VN_IS_DOOMED(vp)) 551 return -1; 552 553 bsize = vp->v_mount->mnt_stat.f_iosize; 554 vblock = address / bsize; 555 voffset = address % bsize; 556 557 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 558 if (err == 0) { 559 if (*rtaddress != -1) 560 *rtaddress += voffset / DEV_BSIZE; 561 if (run) { 562 *run += 1; 563 *run *= bsize / PAGE_SIZE; 564 *run -= voffset / PAGE_SIZE; 565 } 566 } 567 568 return (err); 569 } 570 571 /* 572 * small block filesystem vnode pager input 573 */ 574 static int 575 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 576 { 577 struct vnode *vp; 578 struct bufobj *bo; 579 struct buf *bp; 580 struct sf_buf *sf; 581 daddr_t fileaddr; 582 vm_offset_t bsize; 583 vm_page_bits_t bits; 584 int error, i; 585 586 error = 0; 587 vp = object->handle; 588 if (VN_IS_DOOMED(vp)) 589 return VM_PAGER_BAD; 590 591 bsize = vp->v_mount->mnt_stat.f_iosize; 592 593 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 594 595 sf = sf_buf_alloc(m, 0); 596 597 for (i = 0; i < PAGE_SIZE / bsize; i++) { 598 vm_ooffset_t address; 599 600 bits = vm_page_bits(i * bsize, bsize); 601 if (m->valid & bits) 602 continue; 603 604 address = IDX_TO_OFF(m->pindex) + i * bsize; 605 if (address >= object->un_pager.vnp.vnp_size) { 606 fileaddr = -1; 607 } else { 608 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 609 if (error) 610 break; 611 } 612 if (fileaddr != -1) { 613 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 614 615 /* build a minimal buffer header */ 616 bp->b_iocmd = BIO_READ; 617 bp->b_iodone = bdone; 618 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 619 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 620 bp->b_rcred = crhold(curthread->td_ucred); 621 bp->b_wcred = crhold(curthread->td_ucred); 622 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 623 bp->b_blkno = fileaddr; 624 pbgetbo(bo, bp); 625 bp->b_vp = vp; 626 bp->b_bcount = bsize; 627 bp->b_bufsize = bsize; 628 bp->b_runningbufspace = bp->b_bufsize; 629 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 630 631 /* do the input */ 632 bp->b_iooffset = dbtob(bp->b_blkno); 633 bstrategy(bp); 634 635 bwait(bp, PVM, "vnsrd"); 636 637 if ((bp->b_ioflags & BIO_ERROR) != 0) { 638 KASSERT(bp->b_error != 0, 639 ("%s: buf error but b_error == 0\n", __func__)); 640 error = bp->b_error; 641 } 642 643 /* 644 * free the buffer header back to the swap buffer pool 645 */ 646 bp->b_vp = NULL; 647 pbrelbo(bp); 648 uma_zfree(vnode_pbuf_zone, bp); 649 if (error) 650 break; 651 } else 652 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 653 KASSERT((m->dirty & bits) == 0, 654 ("vnode_pager_input_smlfs: page %p is dirty", m)); 655 vm_page_bits_set(m, &m->valid, bits); 656 } 657 sf_buf_free(sf); 658 if (error) { 659 return VM_PAGER_ERROR; 660 } 661 return VM_PAGER_OK; 662 } 663 664 /* 665 * old style vnode pager input routine 666 */ 667 static int 668 vnode_pager_input_old(vm_object_t object, vm_page_t m) 669 { 670 struct uio auio; 671 struct iovec aiov; 672 int error; 673 int size; 674 struct sf_buf *sf; 675 struct vnode *vp; 676 677 VM_OBJECT_ASSERT_WLOCKED(object); 678 error = 0; 679 680 /* 681 * Return failure if beyond current EOF 682 */ 683 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 684 return VM_PAGER_BAD; 685 } else { 686 size = PAGE_SIZE; 687 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 688 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 689 vp = object->handle; 690 VM_OBJECT_WUNLOCK(object); 691 692 /* 693 * Allocate a kernel virtual address and initialize so that 694 * we can use VOP_READ/WRITE routines. 695 */ 696 sf = sf_buf_alloc(m, 0); 697 698 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 699 aiov.iov_len = size; 700 auio.uio_iov = &aiov; 701 auio.uio_iovcnt = 1; 702 auio.uio_offset = IDX_TO_OFF(m->pindex); 703 auio.uio_segflg = UIO_SYSSPACE; 704 auio.uio_rw = UIO_READ; 705 auio.uio_resid = size; 706 auio.uio_td = curthread; 707 708 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 709 if (!error) { 710 int count = size - auio.uio_resid; 711 712 if (count == 0) 713 error = EINVAL; 714 else if (count != PAGE_SIZE) 715 bzero((caddr_t)sf_buf_kva(sf) + count, 716 PAGE_SIZE - count); 717 } 718 sf_buf_free(sf); 719 720 VM_OBJECT_WLOCK(object); 721 } 722 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 723 if (!error) 724 vm_page_valid(m); 725 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 726 } 727 728 /* 729 * generic vnode pager input routine 730 */ 731 732 /* 733 * Local media VFS's that do not implement their own VOP_GETPAGES 734 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 735 * to implement the previous behaviour. 736 * 737 * All other FS's should use the bypass to get to the local media 738 * backing vp's VOP_GETPAGES. 739 */ 740 static int 741 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 742 int *rahead) 743 { 744 struct vnode *vp; 745 int rtval; 746 747 /* Handle is stable with paging in progress. */ 748 vp = object->handle; 749 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 750 KASSERT(rtval != EOPNOTSUPP, 751 ("vnode_pager: FS getpages not implemented\n")); 752 return rtval; 753 } 754 755 static int 756 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 757 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 758 { 759 struct vnode *vp; 760 int rtval; 761 762 vp = object->handle; 763 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 764 KASSERT(rtval != EOPNOTSUPP, 765 ("vnode_pager: FS getpages_async not implemented\n")); 766 return (rtval); 767 } 768 769 /* 770 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 771 * local filesystems, where partially valid pages can only occur at 772 * the end of file. 773 */ 774 int 775 vnode_pager_local_getpages(struct vop_getpages_args *ap) 776 { 777 778 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 779 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 780 } 781 782 int 783 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 784 { 785 int error; 786 787 error = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 788 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg); 789 if (error != 0 && ap->a_iodone != NULL) 790 ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error); 791 return (error); 792 } 793 794 /* 795 * This is now called from local media FS's to operate against their 796 * own vnodes if they fail to implement VOP_GETPAGES. 797 */ 798 int 799 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 800 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 801 { 802 vm_object_t object; 803 struct bufobj *bo; 804 struct buf *bp; 805 off_t foff; 806 #ifdef INVARIANTS 807 off_t blkno0; 808 #endif 809 int bsize, pagesperblock; 810 int error, before, after, rbehind, rahead, poff, i; 811 int bytecount, secmask; 812 813 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 814 ("%s does not support devices", __func__)); 815 816 if (VN_IS_DOOMED(vp)) 817 return (VM_PAGER_BAD); 818 819 object = vp->v_object; 820 foff = IDX_TO_OFF(m[0]->pindex); 821 bsize = vp->v_mount->mnt_stat.f_iosize; 822 pagesperblock = bsize / PAGE_SIZE; 823 824 KASSERT(foff < object->un_pager.vnp.vnp_size, 825 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 826 KASSERT(count <= atop(maxphys), 827 ("%s: requested %d pages", __func__, count)); 828 829 /* 830 * The last page has valid blocks. Invalid part can only 831 * exist at the end of file, and the page is made fully valid 832 * by zeroing in vm_pager_get_pages(). 833 */ 834 if (!vm_page_none_valid(m[count - 1]) && --count == 0) { 835 if (iodone != NULL) 836 iodone(arg, m, 1, 0); 837 return (VM_PAGER_OK); 838 } 839 840 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 841 MPASS((bp->b_flags & B_MAXPHYS) != 0); 842 843 /* 844 * Get the underlying device blocks for the file with VOP_BMAP(). 845 * If the file system doesn't support VOP_BMAP, use old way of 846 * getting pages via VOP_READ. 847 */ 848 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 849 if (error == EOPNOTSUPP) { 850 uma_zfree(vnode_pbuf_zone, bp); 851 VM_OBJECT_WLOCK(object); 852 for (i = 0; i < count; i++) { 853 VM_CNT_INC(v_vnodein); 854 VM_CNT_INC(v_vnodepgsin); 855 error = vnode_pager_input_old(object, m[i]); 856 if (error) 857 break; 858 } 859 VM_OBJECT_WUNLOCK(object); 860 return (error); 861 } else if (error != 0) { 862 uma_zfree(vnode_pbuf_zone, bp); 863 return (VM_PAGER_ERROR); 864 } 865 866 /* 867 * If the file system supports BMAP, but blocksize is smaller 868 * than a page size, then use special small filesystem code. 869 */ 870 if (pagesperblock == 0) { 871 uma_zfree(vnode_pbuf_zone, bp); 872 for (i = 0; i < count; i++) { 873 VM_CNT_INC(v_vnodein); 874 VM_CNT_INC(v_vnodepgsin); 875 error = vnode_pager_input_smlfs(object, m[i]); 876 if (error) 877 break; 878 } 879 return (error); 880 } 881 882 /* 883 * A sparse file can be encountered only for a single page request, 884 * which may not be preceded by call to vm_pager_haspage(). 885 */ 886 if (bp->b_blkno == -1) { 887 KASSERT(count == 1, 888 ("%s: array[%d] request to a sparse file %p", __func__, 889 count, vp)); 890 uma_zfree(vnode_pbuf_zone, bp); 891 pmap_zero_page(m[0]); 892 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 893 __func__, m[0])); 894 vm_page_valid(m[0]); 895 return (VM_PAGER_OK); 896 } 897 898 #ifdef INVARIANTS 899 blkno0 = bp->b_blkno; 900 #endif 901 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 902 903 /* Recalculate blocks available after/before to pages. */ 904 poff = (foff % bsize) / PAGE_SIZE; 905 before *= pagesperblock; 906 before += poff; 907 after *= pagesperblock; 908 after += pagesperblock - (poff + 1); 909 if (m[0]->pindex + after >= object->size) 910 after = object->size - 1 - m[0]->pindex; 911 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 912 __func__, count, after + 1)); 913 after -= count - 1; 914 915 /* Trim requested rbehind/rahead to possible values. */ 916 rbehind = a_rbehind ? *a_rbehind : 0; 917 rahead = a_rahead ? *a_rahead : 0; 918 rbehind = min(rbehind, before); 919 rbehind = min(rbehind, m[0]->pindex); 920 rahead = min(rahead, after); 921 rahead = min(rahead, object->size - m[count - 1]->pindex); 922 /* 923 * Check that total amount of pages fit into buf. Trim rbehind and 924 * rahead evenly if not. 925 */ 926 if (rbehind + rahead + count > atop(maxphys)) { 927 int trim, sum; 928 929 trim = rbehind + rahead + count - atop(maxphys) + 1; 930 sum = rbehind + rahead; 931 if (rbehind == before) { 932 /* Roundup rbehind trim to block size. */ 933 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 934 if (rbehind < 0) 935 rbehind = 0; 936 } else 937 rbehind -= trim * rbehind / sum; 938 rahead -= trim * rahead / sum; 939 } 940 KASSERT(rbehind + rahead + count <= atop(maxphys), 941 ("%s: behind %d ahead %d count %d maxphys %lu", __func__, 942 rbehind, rahead, count, maxphys)); 943 944 /* 945 * Fill in the bp->b_pages[] array with requested and optional 946 * read behind or read ahead pages. Read behind pages are looked 947 * up in a backward direction, down to a first cached page. Same 948 * for read ahead pages, but there is no need to shift the array 949 * in case of encountering a cached page. 950 */ 951 i = bp->b_npages = 0; 952 if (rbehind) { 953 vm_pindex_t startpindex, tpindex; 954 vm_page_t p; 955 956 VM_OBJECT_WLOCK(object); 957 startpindex = m[0]->pindex - rbehind; 958 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 959 p->pindex >= startpindex) 960 startpindex = p->pindex + 1; 961 962 /* tpindex is unsigned; beware of numeric underflow. */ 963 for (tpindex = m[0]->pindex - 1; 964 tpindex >= startpindex && tpindex < m[0]->pindex; 965 tpindex--, i++) { 966 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 967 if (p == NULL) { 968 /* Shift the array. */ 969 for (int j = 0; j < i; j++) 970 bp->b_pages[j] = bp->b_pages[j + 971 tpindex + 1 - startpindex]; 972 break; 973 } 974 bp->b_pages[tpindex - startpindex] = p; 975 } 976 977 bp->b_pgbefore = i; 978 bp->b_npages += i; 979 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 980 } else 981 bp->b_pgbefore = 0; 982 983 /* Requested pages. */ 984 for (int j = 0; j < count; j++, i++) 985 bp->b_pages[i] = m[j]; 986 bp->b_npages += count; 987 988 if (rahead) { 989 vm_pindex_t endpindex, tpindex; 990 vm_page_t p; 991 992 if (!VM_OBJECT_WOWNED(object)) 993 VM_OBJECT_WLOCK(object); 994 endpindex = m[count - 1]->pindex + rahead + 1; 995 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 996 p->pindex < endpindex) 997 endpindex = p->pindex; 998 if (endpindex > object->size) 999 endpindex = object->size; 1000 1001 for (tpindex = m[count - 1]->pindex + 1; 1002 tpindex < endpindex; i++, tpindex++) { 1003 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1004 if (p == NULL) 1005 break; 1006 bp->b_pages[i] = p; 1007 } 1008 1009 bp->b_pgafter = i - bp->b_npages; 1010 bp->b_npages = i; 1011 } else 1012 bp->b_pgafter = 0; 1013 1014 if (VM_OBJECT_WOWNED(object)) 1015 VM_OBJECT_WUNLOCK(object); 1016 1017 /* Report back actual behind/ahead read. */ 1018 if (a_rbehind) 1019 *a_rbehind = bp->b_pgbefore; 1020 if (a_rahead) 1021 *a_rahead = bp->b_pgafter; 1022 1023 #ifdef INVARIANTS 1024 KASSERT(bp->b_npages <= atop(maxphys), 1025 ("%s: buf %p overflowed", __func__, bp)); 1026 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 1027 if (bp->b_pages[j] == bogus_page) 1028 continue; 1029 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 1030 j - prev, ("%s: pages array not consecutive, bp %p", 1031 __func__, bp)); 1032 prev = j; 1033 } 1034 #endif 1035 1036 /* 1037 * Recalculate first offset and bytecount with regards to read behind. 1038 * Truncate bytecount to vnode real size and round up physical size 1039 * for real devices. 1040 */ 1041 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1042 bytecount = bp->b_npages << PAGE_SHIFT; 1043 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 1044 bytecount = object->un_pager.vnp.vnp_size - foff; 1045 secmask = bo->bo_bsize - 1; 1046 KASSERT(secmask < PAGE_SIZE && secmask > 0, 1047 ("%s: sector size %d too large", __func__, secmask + 1)); 1048 bytecount = (bytecount + secmask) & ~secmask; 1049 1050 /* 1051 * And map the pages to be read into the kva, if the filesystem 1052 * requires mapped buffers. 1053 */ 1054 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1055 unmapped_buf_allowed) { 1056 bp->b_data = unmapped_buf; 1057 bp->b_offset = 0; 1058 } else { 1059 bp->b_data = bp->b_kvabase; 1060 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1061 } 1062 1063 /* Build a minimal buffer header. */ 1064 bp->b_iocmd = BIO_READ; 1065 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1066 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1067 bp->b_rcred = crhold(curthread->td_ucred); 1068 bp->b_wcred = crhold(curthread->td_ucred); 1069 pbgetbo(bo, bp); 1070 bp->b_vp = vp; 1071 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1072 bp->b_iooffset = dbtob(bp->b_blkno); 1073 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1074 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1075 IDX_TO_OFF(m[0]->pindex) % bsize, 1076 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1077 "blkno0 %ju b_blkno %ju", bsize, 1078 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1079 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1080 1081 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1082 VM_CNT_INC(v_vnodein); 1083 VM_CNT_ADD(v_vnodepgsin, bp->b_npages); 1084 1085 if (iodone != NULL) { /* async */ 1086 bp->b_pgiodone = iodone; 1087 bp->b_caller1 = arg; 1088 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1089 bp->b_flags |= B_ASYNC; 1090 BUF_KERNPROC(bp); 1091 bstrategy(bp); 1092 return (VM_PAGER_OK); 1093 } else { 1094 bp->b_iodone = bdone; 1095 bstrategy(bp); 1096 bwait(bp, PVM, "vnread"); 1097 error = vnode_pager_generic_getpages_done(bp); 1098 for (i = 0; i < bp->b_npages; i++) 1099 bp->b_pages[i] = NULL; 1100 bp->b_vp = NULL; 1101 pbrelbo(bp); 1102 uma_zfree(vnode_pbuf_zone, bp); 1103 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1104 } 1105 } 1106 1107 static void 1108 vnode_pager_generic_getpages_done_async(struct buf *bp) 1109 { 1110 int error; 1111 1112 error = vnode_pager_generic_getpages_done(bp); 1113 /* Run the iodone upon the requested range. */ 1114 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1115 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1116 for (int i = 0; i < bp->b_npages; i++) 1117 bp->b_pages[i] = NULL; 1118 bp->b_vp = NULL; 1119 pbrelbo(bp); 1120 uma_zfree(vnode_pbuf_zone, bp); 1121 } 1122 1123 static int 1124 vnode_pager_generic_getpages_done(struct buf *bp) 1125 { 1126 vm_object_t object; 1127 off_t tfoff, nextoff; 1128 int i, error; 1129 1130 KASSERT((bp->b_ioflags & BIO_ERROR) == 0 || bp->b_error != 0, 1131 ("%s: buf error but b_error == 0\n", __func__)); 1132 error = (bp->b_ioflags & BIO_ERROR) != 0 ? bp->b_error : 0; 1133 object = bp->b_vp->v_object; 1134 1135 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1136 if (!buf_mapped(bp)) { 1137 bp->b_data = bp->b_kvabase; 1138 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1139 bp->b_npages); 1140 } 1141 bzero(bp->b_data + bp->b_bcount, 1142 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1143 } 1144 if (buf_mapped(bp)) { 1145 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1146 bp->b_data = unmapped_buf; 1147 } 1148 1149 /* 1150 * If the read failed, we must free any read ahead/behind pages here. 1151 * The requested pages are freed by the caller (for sync requests) 1152 * or by the bp->b_pgiodone callback (for async requests). 1153 */ 1154 if (error != 0) { 1155 VM_OBJECT_WLOCK(object); 1156 for (i = 0; i < bp->b_pgbefore; i++) 1157 vm_page_free_invalid(bp->b_pages[i]); 1158 for (i = bp->b_npages - bp->b_pgafter; i < bp->b_npages; i++) 1159 vm_page_free_invalid(bp->b_pages[i]); 1160 VM_OBJECT_WUNLOCK(object); 1161 return (error); 1162 } 1163 1164 /* Read lock to protect size. */ 1165 VM_OBJECT_RLOCK(object); 1166 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1167 i < bp->b_npages; i++, tfoff = nextoff) { 1168 vm_page_t mt; 1169 1170 nextoff = tfoff + PAGE_SIZE; 1171 mt = bp->b_pages[i]; 1172 if (mt == bogus_page) 1173 continue; 1174 1175 if (nextoff <= object->un_pager.vnp.vnp_size) { 1176 /* 1177 * Read filled up entire page. 1178 */ 1179 vm_page_valid(mt); 1180 KASSERT(mt->dirty == 0, 1181 ("%s: page %p is dirty", __func__, mt)); 1182 KASSERT(!pmap_page_is_mapped(mt), 1183 ("%s: page %p is mapped", __func__, mt)); 1184 } else { 1185 /* 1186 * Read did not fill up entire page. 1187 * 1188 * Currently we do not set the entire page valid, 1189 * we just try to clear the piece that we couldn't 1190 * read. 1191 */ 1192 vm_page_set_valid_range(mt, 0, 1193 object->un_pager.vnp.vnp_size - tfoff); 1194 KASSERT((mt->dirty & vm_page_bits(0, 1195 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1196 ("%s: page %p is dirty", __func__, mt)); 1197 } 1198 1199 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1200 vm_page_readahead_finish(mt); 1201 } 1202 VM_OBJECT_RUNLOCK(object); 1203 1204 return (error); 1205 } 1206 1207 /* 1208 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1209 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1210 * vnode_pager_generic_putpages() to implement the previous behaviour. 1211 * 1212 * All other FS's should use the bypass to get to the local media 1213 * backing vp's VOP_PUTPAGES. 1214 */ 1215 static void 1216 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1217 int flags, int *rtvals) 1218 { 1219 int rtval; 1220 struct vnode *vp; 1221 int bytes = count * PAGE_SIZE; 1222 1223 /* 1224 * Force synchronous operation if we are extremely low on memory 1225 * to prevent a low-memory deadlock. VOP operations often need to 1226 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1227 * operation ). The swapper handles the case by limiting the amount 1228 * of asynchronous I/O, but that sort of solution doesn't scale well 1229 * for the vnode pager without a lot of work. 1230 * 1231 * Also, the backing vnode's iodone routine may not wake the pageout 1232 * daemon up. This should be probably be addressed XXX. 1233 */ 1234 1235 if (vm_page_count_min()) 1236 flags |= VM_PAGER_PUT_SYNC; 1237 1238 /* 1239 * Call device-specific putpages function 1240 */ 1241 vp = object->handle; 1242 VM_OBJECT_WUNLOCK(object); 1243 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1244 KASSERT(rtval != EOPNOTSUPP, 1245 ("vnode_pager: stale FS putpages\n")); 1246 VM_OBJECT_WLOCK(object); 1247 } 1248 1249 static int 1250 vn_off2bidx(vm_ooffset_t offset) 1251 { 1252 1253 return ((offset & PAGE_MASK) / DEV_BSIZE); 1254 } 1255 1256 static bool 1257 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset) 1258 { 1259 1260 KASSERT(IDX_TO_OFF(m->pindex) <= offset && 1261 offset < IDX_TO_OFF(m->pindex + 1), 1262 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex, 1263 (uintmax_t)offset)); 1264 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0); 1265 } 1266 1267 /* 1268 * This is now called from local media FS's to operate against their 1269 * own vnodes if they fail to implement VOP_PUTPAGES. 1270 * 1271 * This is typically called indirectly via the pageout daemon and 1272 * clustering has already typically occurred, so in general we ask the 1273 * underlying filesystem to write the data out asynchronously rather 1274 * then delayed. 1275 */ 1276 int 1277 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1278 int flags, int *rtvals) 1279 { 1280 vm_object_t object; 1281 vm_page_t m; 1282 vm_ooffset_t maxblksz, next_offset, poffset, prev_offset; 1283 struct uio auio; 1284 struct iovec aiov; 1285 off_t prev_resid, wrsz; 1286 int count, error, i, maxsize, ncount, pgoff, ppscheck; 1287 bool in_hole; 1288 static struct timeval lastfail; 1289 static int curfail; 1290 1291 object = vp->v_object; 1292 count = bytecount / PAGE_SIZE; 1293 1294 for (i = 0; i < count; i++) 1295 rtvals[i] = VM_PAGER_ERROR; 1296 1297 if ((int64_t)ma[0]->pindex < 0) { 1298 printf("vnode_pager_generic_putpages: " 1299 "attempt to write meta-data 0x%jx(%lx)\n", 1300 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty); 1301 rtvals[0] = VM_PAGER_BAD; 1302 return (VM_PAGER_BAD); 1303 } 1304 1305 maxsize = count * PAGE_SIZE; 1306 ncount = count; 1307 1308 poffset = IDX_TO_OFF(ma[0]->pindex); 1309 1310 /* 1311 * If the page-aligned write is larger then the actual file we 1312 * have to invalidate pages occurring beyond the file EOF. However, 1313 * there is an edge case where a file may not be page-aligned where 1314 * the last page is partially invalid. In this case the filesystem 1315 * may not properly clear the dirty bits for the entire page (which 1316 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1317 * With the page busied we are free to fix up the dirty bits here. 1318 * 1319 * We do not under any circumstances truncate the valid bits, as 1320 * this will screw up bogus page replacement. 1321 */ 1322 VM_OBJECT_RLOCK(object); 1323 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1324 if (object->un_pager.vnp.vnp_size > poffset) { 1325 maxsize = object->un_pager.vnp.vnp_size - poffset; 1326 ncount = btoc(maxsize); 1327 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1328 pgoff = roundup2(pgoff, DEV_BSIZE); 1329 1330 /* 1331 * If the page is busy and the following 1332 * conditions hold, then the page's dirty 1333 * field cannot be concurrently changed by a 1334 * pmap operation. 1335 */ 1336 m = ma[ncount - 1]; 1337 vm_page_assert_sbusied(m); 1338 KASSERT(!pmap_page_is_write_mapped(m), 1339 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1340 MPASS(m->dirty != 0); 1341 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1342 pgoff); 1343 } 1344 } else { 1345 maxsize = 0; 1346 ncount = 0; 1347 } 1348 for (i = ncount; i < count; i++) 1349 rtvals[i] = VM_PAGER_BAD; 1350 } 1351 VM_OBJECT_RUNLOCK(object); 1352 1353 auio.uio_iov = &aiov; 1354 auio.uio_segflg = UIO_NOCOPY; 1355 auio.uio_rw = UIO_WRITE; 1356 auio.uio_td = NULL; 1357 maxblksz = roundup2(poffset + maxsize, DEV_BSIZE); 1358 1359 for (prev_offset = poffset; prev_offset < maxblksz;) { 1360 /* Skip clean blocks. */ 1361 for (in_hole = true; in_hole && prev_offset < maxblksz;) { 1362 m = ma[OFF_TO_IDX(prev_offset - poffset)]; 1363 for (i = vn_off2bidx(prev_offset); 1364 i < sizeof(vm_page_bits_t) * NBBY && 1365 prev_offset < maxblksz; i++) { 1366 if (vn_dirty_blk(m, prev_offset)) { 1367 in_hole = false; 1368 break; 1369 } 1370 prev_offset += DEV_BSIZE; 1371 } 1372 } 1373 if (in_hole) 1374 goto write_done; 1375 1376 /* Find longest run of dirty blocks. */ 1377 for (next_offset = prev_offset; next_offset < maxblksz;) { 1378 m = ma[OFF_TO_IDX(next_offset - poffset)]; 1379 for (i = vn_off2bidx(next_offset); 1380 i < sizeof(vm_page_bits_t) * NBBY && 1381 next_offset < maxblksz; i++) { 1382 if (!vn_dirty_blk(m, next_offset)) 1383 goto start_write; 1384 next_offset += DEV_BSIZE; 1385 } 1386 } 1387 start_write: 1388 if (next_offset > poffset + maxsize) 1389 next_offset = poffset + maxsize; 1390 1391 /* 1392 * Getting here requires finding a dirty block in the 1393 * 'skip clean blocks' loop. 1394 */ 1395 MPASS(prev_offset < next_offset); 1396 1397 aiov.iov_base = NULL; 1398 auio.uio_iovcnt = 1; 1399 auio.uio_offset = prev_offset; 1400 prev_resid = auio.uio_resid = aiov.iov_len = next_offset - 1401 prev_offset; 1402 error = VOP_WRITE(vp, &auio, 1403 vnode_pager_putpages_ioflags(flags), curthread->td_ucred); 1404 1405 wrsz = prev_resid - auio.uio_resid; 1406 if (wrsz == 0) { 1407 if (ppsratecheck(&lastfail, &curfail, 1) != 0) { 1408 vn_printf(vp, "vnode_pager_putpages: " 1409 "zero-length write at %ju resid %zd\n", 1410 auio.uio_offset, auio.uio_resid); 1411 } 1412 break; 1413 } 1414 1415 /* Adjust the starting offset for next iteration. */ 1416 prev_offset += wrsz; 1417 MPASS(auio.uio_offset == prev_offset); 1418 1419 ppscheck = 0; 1420 if (error != 0 && (ppscheck = ppsratecheck(&lastfail, 1421 &curfail, 1)) != 0) 1422 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n", 1423 error); 1424 if (auio.uio_resid != 0 && (ppscheck != 0 || 1425 ppsratecheck(&lastfail, &curfail, 1) != 0)) 1426 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd " 1427 "at %ju\n", auio.uio_resid, 1428 (uintmax_t)ma[0]->pindex); 1429 if (error != 0 || auio.uio_resid != 0) 1430 break; 1431 } 1432 write_done: 1433 /* Mark completely processed pages. */ 1434 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++) 1435 rtvals[i] = VM_PAGER_OK; 1436 /* Mark partial EOF page. */ 1437 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0) 1438 rtvals[i++] = VM_PAGER_OK; 1439 /* Unwritten pages in range, free bonus if the page is clean. */ 1440 for (; i < ncount; i++) 1441 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR; 1442 VM_CNT_ADD(v_vnodepgsout, i); 1443 VM_CNT_INC(v_vnodeout); 1444 return (rtvals[0]); 1445 } 1446 1447 int 1448 vnode_pager_putpages_ioflags(int pager_flags) 1449 { 1450 int ioflags; 1451 1452 /* 1453 * Pageouts are already clustered, use IO_ASYNC to force a 1454 * bawrite() rather then a bdwrite() to prevent paging I/O 1455 * from saturating the buffer cache. Dummy-up the sequential 1456 * heuristic to cause large ranges to cluster. If neither 1457 * IO_SYNC or IO_ASYNC is set, the system decides how to 1458 * cluster. 1459 */ 1460 ioflags = IO_VMIO; 1461 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0) 1462 ioflags |= IO_SYNC; 1463 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0) 1464 ioflags |= IO_ASYNC; 1465 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0; 1466 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0; 1467 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1468 return (ioflags); 1469 } 1470 1471 /* 1472 * vnode_pager_undirty_pages(). 1473 * 1474 * A helper to mark pages as clean after pageout that was possibly 1475 * done with a short write. The lpos argument specifies the page run 1476 * length in bytes, and the written argument specifies how many bytes 1477 * were actually written. eof is the offset past the last valid byte 1478 * in the vnode using the absolute file position of the first byte in 1479 * the run as the base from which it is computed. 1480 */ 1481 void 1482 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof, 1483 int lpos) 1484 { 1485 int i, pos, pos_devb; 1486 1487 if (written == 0 && eof >= lpos) 1488 return; 1489 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1490 if (pos < trunc_page(written)) { 1491 rtvals[i] = VM_PAGER_OK; 1492 vm_page_undirty(ma[i]); 1493 } else { 1494 /* Partially written page. */ 1495 rtvals[i] = VM_PAGER_AGAIN; 1496 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1497 } 1498 } 1499 if (eof >= lpos) /* avoid truncation */ 1500 return; 1501 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) { 1502 if (pos != trunc_page(pos)) { 1503 /* 1504 * The page contains the last valid byte in 1505 * the vnode, mark the rest of the page as 1506 * clean, potentially making the whole page 1507 * clean. 1508 */ 1509 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE); 1510 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE - 1511 pos_devb); 1512 1513 /* 1514 * If the page was cleaned, report the pageout 1515 * on it as successful. msync() no longer 1516 * needs to write out the page, endlessly 1517 * creating write requests and dirty buffers. 1518 */ 1519 if (ma[i]->dirty == 0) 1520 rtvals[i] = VM_PAGER_OK; 1521 1522 pos = round_page(pos); 1523 } else { 1524 /* vm_pageout_flush() clears dirty */ 1525 rtvals[i] = VM_PAGER_BAD; 1526 pos += PAGE_SIZE; 1527 } 1528 } 1529 } 1530 1531 static void 1532 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1533 vm_offset_t end) 1534 { 1535 struct vnode *vp; 1536 vm_ooffset_t old_wm; 1537 1538 VM_OBJECT_WLOCK(object); 1539 if (object->type != OBJT_VNODE) { 1540 VM_OBJECT_WUNLOCK(object); 1541 return; 1542 } 1543 old_wm = object->un_pager.vnp.writemappings; 1544 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1545 vp = object->handle; 1546 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1547 ASSERT_VOP_LOCKED(vp, "v_writecount inc"); 1548 VOP_ADD_WRITECOUNT_CHECKED(vp, 1); 1549 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1550 __func__, vp, vp->v_writecount); 1551 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1552 ASSERT_VOP_LOCKED(vp, "v_writecount dec"); 1553 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1554 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1555 __func__, vp, vp->v_writecount); 1556 } 1557 VM_OBJECT_WUNLOCK(object); 1558 } 1559 1560 static void 1561 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1562 vm_offset_t end) 1563 { 1564 struct vnode *vp; 1565 struct mount *mp; 1566 vm_offset_t inc; 1567 1568 VM_OBJECT_WLOCK(object); 1569 1570 /* 1571 * First, recheck the object type to account for the race when 1572 * the vnode is reclaimed. 1573 */ 1574 if (object->type != OBJT_VNODE) { 1575 VM_OBJECT_WUNLOCK(object); 1576 return; 1577 } 1578 1579 /* 1580 * Optimize for the case when writemappings is not going to 1581 * zero. 1582 */ 1583 inc = end - start; 1584 if (object->un_pager.vnp.writemappings != inc) { 1585 object->un_pager.vnp.writemappings -= inc; 1586 VM_OBJECT_WUNLOCK(object); 1587 return; 1588 } 1589 1590 vp = object->handle; 1591 vhold(vp); 1592 VM_OBJECT_WUNLOCK(object); 1593 mp = NULL; 1594 vn_start_write(vp, &mp, V_WAIT); 1595 vn_lock(vp, LK_SHARED | LK_RETRY); 1596 1597 /* 1598 * Decrement the object's writemappings, by swapping the start 1599 * and end arguments for vnode_pager_update_writecount(). If 1600 * there was not a race with vnode reclaimation, then the 1601 * vnode's v_writecount is decremented. 1602 */ 1603 vnode_pager_update_writecount(object, end, start); 1604 VOP_UNLOCK(vp); 1605 vdrop(vp); 1606 if (mp != NULL) 1607 vn_finished_write(mp); 1608 } 1609 1610 static void 1611 vnode_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) 1612 { 1613 *vpp = object->handle; 1614 } 1615