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 * Internal routine clearing partial-page content 432 */ 433 static void 434 vnode_pager_subpage_purge(struct vm_page *m, int base, int end) 435 { 436 int size; 437 438 KASSERT(end > base && end <= PAGE_SIZE, 439 ("%s: start %d end %d", __func__, base, end)); 440 size = end - base; 441 442 /* 443 * Clear out partial-page garbage in case 444 * the page has been mapped. 445 */ 446 pmap_zero_page_area(m, base, size); 447 448 /* 449 * Update the valid bits to reflect the blocks 450 * that have been zeroed. Some of these valid 451 * bits may have already been set. 452 */ 453 vm_page_set_valid_range(m, base, size); 454 455 /* 456 * Round up "base" to the next block boundary so 457 * that the dirty bit for a partially zeroed 458 * block is not cleared. 459 */ 460 base = roundup2(base, DEV_BSIZE); 461 end = rounddown2(end, DEV_BSIZE); 462 463 if (end > base) { 464 /* 465 * Clear out partial-page dirty bits. 466 * 467 * note that we do not clear out the 468 * valid bits. This would prevent 469 * bogus_page replacement from working 470 * properly. 471 */ 472 vm_page_clear_dirty(m, base, end - base); 473 } 474 475 } 476 477 /* 478 * Lets the VM system know about a change in size for a file. 479 * We adjust our own internal size and flush any cached pages in 480 * the associated object that are affected by the size change. 481 * 482 * Note: this routine may be invoked as a result of a pager put 483 * operation (possibly at object termination time), so we must be careful. 484 */ 485 void 486 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 487 { 488 vm_object_t object; 489 vm_page_t m; 490 vm_pindex_t nobjsize; 491 492 if ((object = vp->v_object) == NULL) 493 return; 494 #ifdef DEBUG_VFS_LOCKS 495 { 496 struct mount *mp; 497 498 mp = vp->v_mount; 499 if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0) 500 assert_vop_elocked(vp, 501 "vnode_pager_setsize and not locked vnode"); 502 } 503 #endif 504 VM_OBJECT_WLOCK(object); 505 if (object->type == OBJT_DEAD) { 506 VM_OBJECT_WUNLOCK(object); 507 return; 508 } 509 KASSERT(object->type == OBJT_VNODE, 510 ("not vnode-backed object %p", object)); 511 if (nsize == object->un_pager.vnp.vnp_size) { 512 /* 513 * Hasn't changed size 514 */ 515 VM_OBJECT_WUNLOCK(object); 516 return; 517 } 518 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 519 if (nsize < object->un_pager.vnp.vnp_size) { 520 /* 521 * File has shrunk. Toss any cached pages beyond the new EOF. 522 */ 523 if (nobjsize < object->size) 524 vm_object_page_remove(object, nobjsize, object->size, 525 0); 526 /* 527 * this gets rid of garbage at the end of a page that is now 528 * only partially backed by the vnode. 529 * 530 * XXX for some reason (I don't know yet), if we take a 531 * completely invalid page and mark it partially valid 532 * it can screw up NFS reads, so we don't allow the case. 533 */ 534 if (!(nsize & PAGE_MASK)) 535 goto out; 536 m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT); 537 if (m == NULL) 538 goto out; 539 if (!vm_page_none_valid(m)) 540 vnode_pager_subpage_purge(m, (int)nsize & PAGE_MASK, 541 PAGE_SIZE); 542 vm_page_xunbusy(m); 543 } 544 out: 545 #if defined(__powerpc__) && !defined(__powerpc64__) 546 object->un_pager.vnp.vnp_size = nsize; 547 #else 548 atomic_store_64(&object->un_pager.vnp.vnp_size, nsize); 549 #endif 550 object->size = nobjsize; 551 VM_OBJECT_WUNLOCK(object); 552 } 553 554 /* 555 * Lets the VM system know about the purged range for a file. We toss away any 556 * cached pages in the associated object that are affected by the purge 557 * operation. Partial-page area not aligned to page boundaries will be zeroed 558 * and the dirty blocks in DEV_BSIZE unit within a page will not be flushed. 559 */ 560 void 561 vnode_pager_purge_range(struct vnode *vp, vm_ooffset_t start, vm_ooffset_t end) 562 { 563 struct vm_page *m; 564 struct vm_object *object; 565 vm_pindex_t pi, pistart, piend; 566 bool same_page; 567 int base, pend; 568 569 ASSERT_VOP_LOCKED(vp, "vnode_pager_purge_range"); 570 571 object = vp->v_object; 572 pi = start + PAGE_MASK < start ? OBJ_MAX_SIZE : 573 OFF_TO_IDX(start + PAGE_MASK); 574 pistart = OFF_TO_IDX(start); 575 piend = end == 0 ? OBJ_MAX_SIZE : OFF_TO_IDX(end); 576 same_page = pistart == piend; 577 if ((end != 0 && end <= start) || object == NULL) 578 return; 579 580 VM_OBJECT_WLOCK(object); 581 582 if (pi < piend) 583 vm_object_page_remove(object, pi, piend, 0); 584 585 if ((start & PAGE_MASK) != 0) { 586 base = (int)start & PAGE_MASK; 587 pend = same_page ? (int)end & PAGE_MASK : PAGE_SIZE; 588 m = vm_page_grab(object, pistart, VM_ALLOC_NOCREAT); 589 if (m != NULL) { 590 if (!vm_page_none_valid(m)) 591 vnode_pager_subpage_purge(m, base, pend); 592 vm_page_xunbusy(m); 593 } 594 if (same_page) 595 goto out; 596 } 597 if ((end & PAGE_MASK) != 0) { 598 base = same_page ? (int)start & PAGE_MASK : 0 ; 599 pend = (int)end & PAGE_MASK; 600 m = vm_page_grab(object, piend, VM_ALLOC_NOCREAT); 601 if (m != NULL) { 602 if (!vm_page_none_valid(m)) 603 vnode_pager_subpage_purge(m, base, pend); 604 vm_page_xunbusy(m); 605 } 606 } 607 out: 608 VM_OBJECT_WUNLOCK(object); 609 } 610 611 /* 612 * calculate the linear (byte) disk address of specified virtual 613 * file address 614 */ 615 static int 616 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 617 int *run) 618 { 619 int bsize; 620 int err; 621 daddr_t vblock; 622 daddr_t voffset; 623 624 if (VN_IS_DOOMED(vp)) 625 return -1; 626 627 bsize = vp->v_mount->mnt_stat.f_iosize; 628 vblock = address / bsize; 629 voffset = address % bsize; 630 631 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 632 if (err == 0) { 633 if (*rtaddress != -1) 634 *rtaddress += voffset / DEV_BSIZE; 635 if (run) { 636 *run += 1; 637 *run *= bsize / PAGE_SIZE; 638 *run -= voffset / PAGE_SIZE; 639 } 640 } 641 642 return (err); 643 } 644 645 /* 646 * small block filesystem vnode pager input 647 */ 648 static int 649 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 650 { 651 struct vnode *vp; 652 struct bufobj *bo; 653 struct buf *bp; 654 struct sf_buf *sf; 655 daddr_t fileaddr; 656 vm_offset_t bsize; 657 vm_page_bits_t bits; 658 int error, i; 659 660 error = 0; 661 vp = object->handle; 662 if (VN_IS_DOOMED(vp)) 663 return VM_PAGER_BAD; 664 665 bsize = vp->v_mount->mnt_stat.f_iosize; 666 667 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 668 669 sf = sf_buf_alloc(m, 0); 670 671 for (i = 0; i < PAGE_SIZE / bsize; i++) { 672 vm_ooffset_t address; 673 674 bits = vm_page_bits(i * bsize, bsize); 675 if (m->valid & bits) 676 continue; 677 678 address = IDX_TO_OFF(m->pindex) + i * bsize; 679 if (address >= object->un_pager.vnp.vnp_size) { 680 fileaddr = -1; 681 } else { 682 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 683 if (error) 684 break; 685 } 686 if (fileaddr != -1) { 687 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 688 689 /* build a minimal buffer header */ 690 bp->b_iocmd = BIO_READ; 691 bp->b_iodone = bdone; 692 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 693 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 694 bp->b_rcred = crhold(curthread->td_ucred); 695 bp->b_wcred = crhold(curthread->td_ucred); 696 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 697 bp->b_blkno = fileaddr; 698 pbgetbo(bo, bp); 699 bp->b_vp = vp; 700 bp->b_bcount = bsize; 701 bp->b_bufsize = bsize; 702 bp->b_runningbufspace = bp->b_bufsize; 703 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 704 705 /* do the input */ 706 bp->b_iooffset = dbtob(bp->b_blkno); 707 bstrategy(bp); 708 709 bwait(bp, PVM, "vnsrd"); 710 711 if ((bp->b_ioflags & BIO_ERROR) != 0) { 712 KASSERT(bp->b_error != 0, 713 ("%s: buf error but b_error == 0\n", __func__)); 714 error = bp->b_error; 715 } 716 717 /* 718 * free the buffer header back to the swap buffer pool 719 */ 720 bp->b_vp = NULL; 721 pbrelbo(bp); 722 uma_zfree(vnode_pbuf_zone, bp); 723 if (error) 724 break; 725 } else 726 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 727 KASSERT((m->dirty & bits) == 0, 728 ("vnode_pager_input_smlfs: page %p is dirty", m)); 729 vm_page_bits_set(m, &m->valid, bits); 730 } 731 sf_buf_free(sf); 732 if (error) { 733 return VM_PAGER_ERROR; 734 } 735 return VM_PAGER_OK; 736 } 737 738 /* 739 * old style vnode pager input routine 740 */ 741 static int 742 vnode_pager_input_old(vm_object_t object, vm_page_t m) 743 { 744 struct uio auio; 745 struct iovec aiov; 746 int error; 747 int size; 748 struct sf_buf *sf; 749 struct vnode *vp; 750 751 VM_OBJECT_ASSERT_WLOCKED(object); 752 error = 0; 753 754 /* 755 * Return failure if beyond current EOF 756 */ 757 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 758 return VM_PAGER_BAD; 759 } else { 760 size = PAGE_SIZE; 761 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 762 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 763 vp = object->handle; 764 VM_OBJECT_WUNLOCK(object); 765 766 /* 767 * Allocate a kernel virtual address and initialize so that 768 * we can use VOP_READ/WRITE routines. 769 */ 770 sf = sf_buf_alloc(m, 0); 771 772 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 773 aiov.iov_len = size; 774 auio.uio_iov = &aiov; 775 auio.uio_iovcnt = 1; 776 auio.uio_offset = IDX_TO_OFF(m->pindex); 777 auio.uio_segflg = UIO_SYSSPACE; 778 auio.uio_rw = UIO_READ; 779 auio.uio_resid = size; 780 auio.uio_td = curthread; 781 782 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 783 if (!error) { 784 int count = size - auio.uio_resid; 785 786 if (count == 0) 787 error = EINVAL; 788 else if (count != PAGE_SIZE) 789 bzero((caddr_t)sf_buf_kva(sf) + count, 790 PAGE_SIZE - count); 791 } 792 sf_buf_free(sf); 793 794 VM_OBJECT_WLOCK(object); 795 } 796 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 797 if (!error) 798 vm_page_valid(m); 799 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 800 } 801 802 /* 803 * generic vnode pager input routine 804 */ 805 806 /* 807 * Local media VFS's that do not implement their own VOP_GETPAGES 808 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 809 * to implement the previous behaviour. 810 * 811 * All other FS's should use the bypass to get to the local media 812 * backing vp's VOP_GETPAGES. 813 */ 814 static int 815 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 816 int *rahead) 817 { 818 struct vnode *vp; 819 int rtval; 820 821 /* Handle is stable with paging in progress. */ 822 vp = object->handle; 823 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 824 KASSERT(rtval != EOPNOTSUPP, 825 ("vnode_pager: FS getpages not implemented\n")); 826 return rtval; 827 } 828 829 static int 830 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 831 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 832 { 833 struct vnode *vp; 834 int rtval; 835 836 vp = object->handle; 837 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 838 KASSERT(rtval != EOPNOTSUPP, 839 ("vnode_pager: FS getpages_async not implemented\n")); 840 return (rtval); 841 } 842 843 /* 844 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 845 * local filesystems, where partially valid pages can only occur at 846 * the end of file. 847 */ 848 int 849 vnode_pager_local_getpages(struct vop_getpages_args *ap) 850 { 851 852 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 853 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 854 } 855 856 int 857 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 858 { 859 int error; 860 861 error = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 862 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg); 863 if (error != 0 && ap->a_iodone != NULL) 864 ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error); 865 return (error); 866 } 867 868 /* 869 * This is now called from local media FS's to operate against their 870 * own vnodes if they fail to implement VOP_GETPAGES. 871 */ 872 int 873 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 874 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 875 { 876 vm_object_t object; 877 struct bufobj *bo; 878 struct buf *bp; 879 off_t foff; 880 #ifdef INVARIANTS 881 off_t blkno0; 882 #endif 883 int bsize, pagesperblock; 884 int error, before, after, rbehind, rahead, poff, i; 885 int bytecount, secmask; 886 887 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 888 ("%s does not support devices", __func__)); 889 890 if (VN_IS_DOOMED(vp)) 891 return (VM_PAGER_BAD); 892 893 object = vp->v_object; 894 foff = IDX_TO_OFF(m[0]->pindex); 895 bsize = vp->v_mount->mnt_stat.f_iosize; 896 pagesperblock = bsize / PAGE_SIZE; 897 898 KASSERT(foff < object->un_pager.vnp.vnp_size, 899 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 900 KASSERT(count <= atop(maxphys), 901 ("%s: requested %d pages", __func__, count)); 902 903 /* 904 * The last page has valid blocks. Invalid part can only 905 * exist at the end of file, and the page is made fully valid 906 * by zeroing in vm_pager_get_pages(). 907 */ 908 if (!vm_page_none_valid(m[count - 1]) && --count == 0) { 909 if (iodone != NULL) 910 iodone(arg, m, 1, 0); 911 return (VM_PAGER_OK); 912 } 913 914 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 915 MPASS((bp->b_flags & B_MAXPHYS) != 0); 916 917 /* 918 * Get the underlying device blocks for the file with VOP_BMAP(). 919 * If the file system doesn't support VOP_BMAP, use old way of 920 * getting pages via VOP_READ. 921 */ 922 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 923 if (error == EOPNOTSUPP) { 924 uma_zfree(vnode_pbuf_zone, bp); 925 VM_OBJECT_WLOCK(object); 926 for (i = 0; i < count; i++) { 927 VM_CNT_INC(v_vnodein); 928 VM_CNT_INC(v_vnodepgsin); 929 error = vnode_pager_input_old(object, m[i]); 930 if (error) 931 break; 932 } 933 VM_OBJECT_WUNLOCK(object); 934 return (error); 935 } else if (error != 0) { 936 uma_zfree(vnode_pbuf_zone, bp); 937 return (VM_PAGER_ERROR); 938 } 939 940 /* 941 * If the file system supports BMAP, but blocksize is smaller 942 * than a page size, then use special small filesystem code. 943 */ 944 if (pagesperblock == 0) { 945 uma_zfree(vnode_pbuf_zone, bp); 946 for (i = 0; i < count; i++) { 947 VM_CNT_INC(v_vnodein); 948 VM_CNT_INC(v_vnodepgsin); 949 error = vnode_pager_input_smlfs(object, m[i]); 950 if (error) 951 break; 952 } 953 return (error); 954 } 955 956 /* 957 * A sparse file can be encountered only for a single page request, 958 * which may not be preceded by call to vm_pager_haspage(). 959 */ 960 if (bp->b_blkno == -1) { 961 KASSERT(count == 1, 962 ("%s: array[%d] request to a sparse file %p", __func__, 963 count, vp)); 964 uma_zfree(vnode_pbuf_zone, bp); 965 pmap_zero_page(m[0]); 966 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 967 __func__, m[0])); 968 vm_page_valid(m[0]); 969 return (VM_PAGER_OK); 970 } 971 972 #ifdef INVARIANTS 973 blkno0 = bp->b_blkno; 974 #endif 975 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 976 977 /* Recalculate blocks available after/before to pages. */ 978 poff = (foff % bsize) / PAGE_SIZE; 979 before *= pagesperblock; 980 before += poff; 981 after *= pagesperblock; 982 after += pagesperblock - (poff + 1); 983 if (m[0]->pindex + after >= object->size) 984 after = object->size - 1 - m[0]->pindex; 985 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 986 __func__, count, after + 1)); 987 after -= count - 1; 988 989 /* Trim requested rbehind/rahead to possible values. */ 990 rbehind = a_rbehind ? *a_rbehind : 0; 991 rahead = a_rahead ? *a_rahead : 0; 992 rbehind = min(rbehind, before); 993 rbehind = min(rbehind, m[0]->pindex); 994 rahead = min(rahead, after); 995 rahead = min(rahead, object->size - m[count - 1]->pindex); 996 /* 997 * Check that total amount of pages fit into buf. Trim rbehind and 998 * rahead evenly if not. 999 */ 1000 if (rbehind + rahead + count > atop(maxphys)) { 1001 int trim, sum; 1002 1003 trim = rbehind + rahead + count - atop(maxphys) + 1; 1004 sum = rbehind + rahead; 1005 if (rbehind == before) { 1006 /* Roundup rbehind trim to block size. */ 1007 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 1008 if (rbehind < 0) 1009 rbehind = 0; 1010 } else 1011 rbehind -= trim * rbehind / sum; 1012 rahead -= trim * rahead / sum; 1013 } 1014 KASSERT(rbehind + rahead + count <= atop(maxphys), 1015 ("%s: behind %d ahead %d count %d maxphys %lu", __func__, 1016 rbehind, rahead, count, maxphys)); 1017 1018 /* 1019 * Fill in the bp->b_pages[] array with requested and optional 1020 * read behind or read ahead pages. Read behind pages are looked 1021 * up in a backward direction, down to a first cached page. Same 1022 * for read ahead pages, but there is no need to shift the array 1023 * in case of encountering a cached page. 1024 */ 1025 i = bp->b_npages = 0; 1026 if (rbehind) { 1027 vm_pindex_t startpindex, tpindex; 1028 vm_page_t p; 1029 1030 VM_OBJECT_WLOCK(object); 1031 startpindex = m[0]->pindex - rbehind; 1032 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 1033 p->pindex >= startpindex) 1034 startpindex = p->pindex + 1; 1035 1036 /* tpindex is unsigned; beware of numeric underflow. */ 1037 for (tpindex = m[0]->pindex - 1; 1038 tpindex >= startpindex && tpindex < m[0]->pindex; 1039 tpindex--, i++) { 1040 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1041 if (p == NULL) { 1042 /* Shift the array. */ 1043 for (int j = 0; j < i; j++) 1044 bp->b_pages[j] = bp->b_pages[j + 1045 tpindex + 1 - startpindex]; 1046 break; 1047 } 1048 bp->b_pages[tpindex - startpindex] = p; 1049 } 1050 1051 bp->b_pgbefore = i; 1052 bp->b_npages += i; 1053 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 1054 } else 1055 bp->b_pgbefore = 0; 1056 1057 /* Requested pages. */ 1058 for (int j = 0; j < count; j++, i++) 1059 bp->b_pages[i] = m[j]; 1060 bp->b_npages += count; 1061 1062 if (rahead) { 1063 vm_pindex_t endpindex, tpindex; 1064 vm_page_t p; 1065 1066 if (!VM_OBJECT_WOWNED(object)) 1067 VM_OBJECT_WLOCK(object); 1068 endpindex = m[count - 1]->pindex + rahead + 1; 1069 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 1070 p->pindex < endpindex) 1071 endpindex = p->pindex; 1072 if (endpindex > object->size) 1073 endpindex = object->size; 1074 1075 for (tpindex = m[count - 1]->pindex + 1; 1076 tpindex < endpindex; i++, tpindex++) { 1077 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1078 if (p == NULL) 1079 break; 1080 bp->b_pages[i] = p; 1081 } 1082 1083 bp->b_pgafter = i - bp->b_npages; 1084 bp->b_npages = i; 1085 } else 1086 bp->b_pgafter = 0; 1087 1088 if (VM_OBJECT_WOWNED(object)) 1089 VM_OBJECT_WUNLOCK(object); 1090 1091 /* Report back actual behind/ahead read. */ 1092 if (a_rbehind) 1093 *a_rbehind = bp->b_pgbefore; 1094 if (a_rahead) 1095 *a_rahead = bp->b_pgafter; 1096 1097 #ifdef INVARIANTS 1098 KASSERT(bp->b_npages <= atop(maxphys), 1099 ("%s: buf %p overflowed", __func__, bp)); 1100 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 1101 if (bp->b_pages[j] == bogus_page) 1102 continue; 1103 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 1104 j - prev, ("%s: pages array not consecutive, bp %p", 1105 __func__, bp)); 1106 prev = j; 1107 } 1108 #endif 1109 1110 /* 1111 * Recalculate first offset and bytecount with regards to read behind. 1112 * Truncate bytecount to vnode real size and round up physical size 1113 * for real devices. 1114 */ 1115 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1116 bytecount = bp->b_npages << PAGE_SHIFT; 1117 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 1118 bytecount = object->un_pager.vnp.vnp_size - foff; 1119 secmask = bo->bo_bsize - 1; 1120 KASSERT(secmask < PAGE_SIZE && secmask > 0, 1121 ("%s: sector size %d too large", __func__, secmask + 1)); 1122 bytecount = (bytecount + secmask) & ~secmask; 1123 1124 /* 1125 * And map the pages to be read into the kva, if the filesystem 1126 * requires mapped buffers. 1127 */ 1128 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1129 unmapped_buf_allowed) { 1130 bp->b_data = unmapped_buf; 1131 bp->b_offset = 0; 1132 } else { 1133 bp->b_data = bp->b_kvabase; 1134 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1135 } 1136 1137 /* Build a minimal buffer header. */ 1138 bp->b_iocmd = BIO_READ; 1139 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1140 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1141 bp->b_rcred = crhold(curthread->td_ucred); 1142 bp->b_wcred = crhold(curthread->td_ucred); 1143 pbgetbo(bo, bp); 1144 bp->b_vp = vp; 1145 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1146 bp->b_iooffset = dbtob(bp->b_blkno); 1147 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1148 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1149 IDX_TO_OFF(m[0]->pindex) % bsize, 1150 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1151 "blkno0 %ju b_blkno %ju", bsize, 1152 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1153 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1154 1155 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1156 VM_CNT_INC(v_vnodein); 1157 VM_CNT_ADD(v_vnodepgsin, bp->b_npages); 1158 1159 if (iodone != NULL) { /* async */ 1160 bp->b_pgiodone = iodone; 1161 bp->b_caller1 = arg; 1162 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1163 bp->b_flags |= B_ASYNC; 1164 BUF_KERNPROC(bp); 1165 bstrategy(bp); 1166 return (VM_PAGER_OK); 1167 } else { 1168 bp->b_iodone = bdone; 1169 bstrategy(bp); 1170 bwait(bp, PVM, "vnread"); 1171 error = vnode_pager_generic_getpages_done(bp); 1172 for (i = 0; i < bp->b_npages; i++) 1173 bp->b_pages[i] = NULL; 1174 bp->b_vp = NULL; 1175 pbrelbo(bp); 1176 uma_zfree(vnode_pbuf_zone, bp); 1177 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1178 } 1179 } 1180 1181 static void 1182 vnode_pager_generic_getpages_done_async(struct buf *bp) 1183 { 1184 int error; 1185 1186 error = vnode_pager_generic_getpages_done(bp); 1187 /* Run the iodone upon the requested range. */ 1188 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1189 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1190 for (int i = 0; i < bp->b_npages; i++) 1191 bp->b_pages[i] = NULL; 1192 bp->b_vp = NULL; 1193 pbrelbo(bp); 1194 uma_zfree(vnode_pbuf_zone, bp); 1195 } 1196 1197 static int 1198 vnode_pager_generic_getpages_done(struct buf *bp) 1199 { 1200 vm_object_t object; 1201 off_t tfoff, nextoff; 1202 int i, error; 1203 1204 KASSERT((bp->b_ioflags & BIO_ERROR) == 0 || bp->b_error != 0, 1205 ("%s: buf error but b_error == 0\n", __func__)); 1206 error = (bp->b_ioflags & BIO_ERROR) != 0 ? bp->b_error : 0; 1207 object = bp->b_vp->v_object; 1208 1209 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1210 if (!buf_mapped(bp)) { 1211 bp->b_data = bp->b_kvabase; 1212 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1213 bp->b_npages); 1214 } 1215 bzero(bp->b_data + bp->b_bcount, 1216 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1217 } 1218 if (buf_mapped(bp)) { 1219 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1220 bp->b_data = unmapped_buf; 1221 } 1222 1223 /* 1224 * If the read failed, we must free any read ahead/behind pages here. 1225 * The requested pages are freed by the caller (for sync requests) 1226 * or by the bp->b_pgiodone callback (for async requests). 1227 */ 1228 if (error != 0) { 1229 VM_OBJECT_WLOCK(object); 1230 for (i = 0; i < bp->b_pgbefore; i++) 1231 vm_page_free_invalid(bp->b_pages[i]); 1232 for (i = bp->b_npages - bp->b_pgafter; i < bp->b_npages; i++) 1233 vm_page_free_invalid(bp->b_pages[i]); 1234 VM_OBJECT_WUNLOCK(object); 1235 return (error); 1236 } 1237 1238 /* Read lock to protect size. */ 1239 VM_OBJECT_RLOCK(object); 1240 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1241 i < bp->b_npages; i++, tfoff = nextoff) { 1242 vm_page_t mt; 1243 1244 nextoff = tfoff + PAGE_SIZE; 1245 mt = bp->b_pages[i]; 1246 if (mt == bogus_page) 1247 continue; 1248 1249 if (nextoff <= object->un_pager.vnp.vnp_size) { 1250 /* 1251 * Read filled up entire page. 1252 */ 1253 vm_page_valid(mt); 1254 KASSERT(mt->dirty == 0, 1255 ("%s: page %p is dirty", __func__, mt)); 1256 KASSERT(!pmap_page_is_mapped(mt), 1257 ("%s: page %p is mapped", __func__, mt)); 1258 } else { 1259 /* 1260 * Read did not fill up entire page. 1261 * 1262 * Currently we do not set the entire page valid, 1263 * we just try to clear the piece that we couldn't 1264 * read. 1265 */ 1266 vm_page_set_valid_range(mt, 0, 1267 object->un_pager.vnp.vnp_size - tfoff); 1268 KASSERT((mt->dirty & vm_page_bits(0, 1269 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1270 ("%s: page %p is dirty", __func__, mt)); 1271 } 1272 1273 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1274 vm_page_readahead_finish(mt); 1275 } 1276 VM_OBJECT_RUNLOCK(object); 1277 1278 return (error); 1279 } 1280 1281 /* 1282 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1283 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1284 * vnode_pager_generic_putpages() to implement the previous behaviour. 1285 * 1286 * All other FS's should use the bypass to get to the local media 1287 * backing vp's VOP_PUTPAGES. 1288 */ 1289 static void 1290 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1291 int flags, int *rtvals) 1292 { 1293 int rtval; 1294 struct vnode *vp; 1295 int bytes = count * PAGE_SIZE; 1296 1297 /* 1298 * Force synchronous operation if we are extremely low on memory 1299 * to prevent a low-memory deadlock. VOP operations often need to 1300 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1301 * operation ). The swapper handles the case by limiting the amount 1302 * of asynchronous I/O, but that sort of solution doesn't scale well 1303 * for the vnode pager without a lot of work. 1304 * 1305 * Also, the backing vnode's iodone routine may not wake the pageout 1306 * daemon up. This should be probably be addressed XXX. 1307 */ 1308 1309 if (vm_page_count_min()) 1310 flags |= VM_PAGER_PUT_SYNC; 1311 1312 /* 1313 * Call device-specific putpages function 1314 */ 1315 vp = object->handle; 1316 VM_OBJECT_WUNLOCK(object); 1317 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1318 KASSERT(rtval != EOPNOTSUPP, 1319 ("vnode_pager: stale FS putpages\n")); 1320 VM_OBJECT_WLOCK(object); 1321 } 1322 1323 static int 1324 vn_off2bidx(vm_ooffset_t offset) 1325 { 1326 1327 return ((offset & PAGE_MASK) / DEV_BSIZE); 1328 } 1329 1330 static bool 1331 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset) 1332 { 1333 1334 KASSERT(IDX_TO_OFF(m->pindex) <= offset && 1335 offset < IDX_TO_OFF(m->pindex + 1), 1336 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex, 1337 (uintmax_t)offset)); 1338 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0); 1339 } 1340 1341 /* 1342 * This is now called from local media FS's to operate against their 1343 * own vnodes if they fail to implement VOP_PUTPAGES. 1344 * 1345 * This is typically called indirectly via the pageout daemon and 1346 * clustering has already typically occurred, so in general we ask the 1347 * underlying filesystem to write the data out asynchronously rather 1348 * then delayed. 1349 */ 1350 int 1351 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1352 int flags, int *rtvals) 1353 { 1354 vm_object_t object; 1355 vm_page_t m; 1356 vm_ooffset_t maxblksz, next_offset, poffset, prev_offset; 1357 struct uio auio; 1358 struct iovec aiov; 1359 off_t prev_resid, wrsz; 1360 int count, error, i, maxsize, ncount, pgoff, ppscheck; 1361 bool in_hole; 1362 static struct timeval lastfail; 1363 static int curfail; 1364 1365 object = vp->v_object; 1366 count = bytecount / PAGE_SIZE; 1367 1368 for (i = 0; i < count; i++) 1369 rtvals[i] = VM_PAGER_ERROR; 1370 1371 if ((int64_t)ma[0]->pindex < 0) { 1372 printf("vnode_pager_generic_putpages: " 1373 "attempt to write meta-data 0x%jx(%lx)\n", 1374 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty); 1375 rtvals[0] = VM_PAGER_BAD; 1376 return (VM_PAGER_BAD); 1377 } 1378 1379 maxsize = count * PAGE_SIZE; 1380 ncount = count; 1381 1382 poffset = IDX_TO_OFF(ma[0]->pindex); 1383 1384 /* 1385 * If the page-aligned write is larger then the actual file we 1386 * have to invalidate pages occurring beyond the file EOF. However, 1387 * there is an edge case where a file may not be page-aligned where 1388 * the last page is partially invalid. In this case the filesystem 1389 * may not properly clear the dirty bits for the entire page (which 1390 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1391 * With the page busied we are free to fix up the dirty bits here. 1392 * 1393 * We do not under any circumstances truncate the valid bits, as 1394 * this will screw up bogus page replacement. 1395 */ 1396 VM_OBJECT_RLOCK(object); 1397 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1398 if (object->un_pager.vnp.vnp_size > poffset) { 1399 maxsize = object->un_pager.vnp.vnp_size - poffset; 1400 ncount = btoc(maxsize); 1401 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1402 pgoff = roundup2(pgoff, DEV_BSIZE); 1403 1404 /* 1405 * If the page is busy and the following 1406 * conditions hold, then the page's dirty 1407 * field cannot be concurrently changed by a 1408 * pmap operation. 1409 */ 1410 m = ma[ncount - 1]; 1411 vm_page_assert_sbusied(m); 1412 KASSERT(!pmap_page_is_write_mapped(m), 1413 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1414 MPASS(m->dirty != 0); 1415 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1416 pgoff); 1417 } 1418 } else { 1419 maxsize = 0; 1420 ncount = 0; 1421 } 1422 for (i = ncount; i < count; i++) 1423 rtvals[i] = VM_PAGER_BAD; 1424 } 1425 VM_OBJECT_RUNLOCK(object); 1426 1427 auio.uio_iov = &aiov; 1428 auio.uio_segflg = UIO_NOCOPY; 1429 auio.uio_rw = UIO_WRITE; 1430 auio.uio_td = NULL; 1431 maxblksz = roundup2(poffset + maxsize, DEV_BSIZE); 1432 1433 for (prev_offset = poffset; prev_offset < maxblksz;) { 1434 /* Skip clean blocks. */ 1435 for (in_hole = true; in_hole && prev_offset < maxblksz;) { 1436 m = ma[OFF_TO_IDX(prev_offset - poffset)]; 1437 for (i = vn_off2bidx(prev_offset); 1438 i < sizeof(vm_page_bits_t) * NBBY && 1439 prev_offset < maxblksz; i++) { 1440 if (vn_dirty_blk(m, prev_offset)) { 1441 in_hole = false; 1442 break; 1443 } 1444 prev_offset += DEV_BSIZE; 1445 } 1446 } 1447 if (in_hole) 1448 goto write_done; 1449 1450 /* Find longest run of dirty blocks. */ 1451 for (next_offset = prev_offset; next_offset < maxblksz;) { 1452 m = ma[OFF_TO_IDX(next_offset - poffset)]; 1453 for (i = vn_off2bidx(next_offset); 1454 i < sizeof(vm_page_bits_t) * NBBY && 1455 next_offset < maxblksz; i++) { 1456 if (!vn_dirty_blk(m, next_offset)) 1457 goto start_write; 1458 next_offset += DEV_BSIZE; 1459 } 1460 } 1461 start_write: 1462 if (next_offset > poffset + maxsize) 1463 next_offset = poffset + maxsize; 1464 1465 /* 1466 * Getting here requires finding a dirty block in the 1467 * 'skip clean blocks' loop. 1468 */ 1469 MPASS(prev_offset < next_offset); 1470 1471 aiov.iov_base = NULL; 1472 auio.uio_iovcnt = 1; 1473 auio.uio_offset = prev_offset; 1474 prev_resid = auio.uio_resid = aiov.iov_len = next_offset - 1475 prev_offset; 1476 error = VOP_WRITE(vp, &auio, 1477 vnode_pager_putpages_ioflags(flags), curthread->td_ucred); 1478 1479 wrsz = prev_resid - auio.uio_resid; 1480 if (wrsz == 0) { 1481 if (ppsratecheck(&lastfail, &curfail, 1) != 0) { 1482 vn_printf(vp, "vnode_pager_putpages: " 1483 "zero-length write at %ju resid %zd\n", 1484 auio.uio_offset, auio.uio_resid); 1485 } 1486 break; 1487 } 1488 1489 /* Adjust the starting offset for next iteration. */ 1490 prev_offset += wrsz; 1491 MPASS(auio.uio_offset == prev_offset); 1492 1493 ppscheck = 0; 1494 if (error != 0 && (ppscheck = ppsratecheck(&lastfail, 1495 &curfail, 1)) != 0) 1496 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n", 1497 error); 1498 if (auio.uio_resid != 0 && (ppscheck != 0 || 1499 ppsratecheck(&lastfail, &curfail, 1) != 0)) 1500 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd " 1501 "at %ju\n", auio.uio_resid, 1502 (uintmax_t)ma[0]->pindex); 1503 if (error != 0 || auio.uio_resid != 0) 1504 break; 1505 } 1506 write_done: 1507 /* Mark completely processed pages. */ 1508 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++) 1509 rtvals[i] = VM_PAGER_OK; 1510 /* Mark partial EOF page. */ 1511 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0) 1512 rtvals[i++] = VM_PAGER_OK; 1513 /* Unwritten pages in range, free bonus if the page is clean. */ 1514 for (; i < ncount; i++) 1515 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR; 1516 VM_CNT_ADD(v_vnodepgsout, i); 1517 VM_CNT_INC(v_vnodeout); 1518 return (rtvals[0]); 1519 } 1520 1521 int 1522 vnode_pager_putpages_ioflags(int pager_flags) 1523 { 1524 int ioflags; 1525 1526 /* 1527 * Pageouts are already clustered, use IO_ASYNC to force a 1528 * bawrite() rather then a bdwrite() to prevent paging I/O 1529 * from saturating the buffer cache. Dummy-up the sequential 1530 * heuristic to cause large ranges to cluster. If neither 1531 * IO_SYNC or IO_ASYNC is set, the system decides how to 1532 * cluster. 1533 */ 1534 ioflags = IO_VMIO; 1535 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0) 1536 ioflags |= IO_SYNC; 1537 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0) 1538 ioflags |= IO_ASYNC; 1539 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0; 1540 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0; 1541 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1542 return (ioflags); 1543 } 1544 1545 /* 1546 * vnode_pager_undirty_pages(). 1547 * 1548 * A helper to mark pages as clean after pageout that was possibly 1549 * done with a short write. The lpos argument specifies the page run 1550 * length in bytes, and the written argument specifies how many bytes 1551 * were actually written. eof is the offset past the last valid byte 1552 * in the vnode using the absolute file position of the first byte in 1553 * the run as the base from which it is computed. 1554 */ 1555 void 1556 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof, 1557 int lpos) 1558 { 1559 int i, pos, pos_devb; 1560 1561 if (written == 0 && eof >= lpos) 1562 return; 1563 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1564 if (pos < trunc_page(written)) { 1565 rtvals[i] = VM_PAGER_OK; 1566 vm_page_undirty(ma[i]); 1567 } else { 1568 /* Partially written page. */ 1569 rtvals[i] = VM_PAGER_AGAIN; 1570 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1571 } 1572 } 1573 if (eof >= lpos) /* avoid truncation */ 1574 return; 1575 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) { 1576 if (pos != trunc_page(pos)) { 1577 /* 1578 * The page contains the last valid byte in 1579 * the vnode, mark the rest of the page as 1580 * clean, potentially making the whole page 1581 * clean. 1582 */ 1583 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE); 1584 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE - 1585 pos_devb); 1586 1587 /* 1588 * If the page was cleaned, report the pageout 1589 * on it as successful. msync() no longer 1590 * needs to write out the page, endlessly 1591 * creating write requests and dirty buffers. 1592 */ 1593 if (ma[i]->dirty == 0) 1594 rtvals[i] = VM_PAGER_OK; 1595 1596 pos = round_page(pos); 1597 } else { 1598 /* vm_pageout_flush() clears dirty */ 1599 rtvals[i] = VM_PAGER_BAD; 1600 pos += PAGE_SIZE; 1601 } 1602 } 1603 } 1604 1605 static void 1606 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1607 vm_offset_t end) 1608 { 1609 struct vnode *vp; 1610 vm_ooffset_t old_wm; 1611 1612 VM_OBJECT_WLOCK(object); 1613 if (object->type != OBJT_VNODE) { 1614 VM_OBJECT_WUNLOCK(object); 1615 return; 1616 } 1617 old_wm = object->un_pager.vnp.writemappings; 1618 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1619 vp = object->handle; 1620 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1621 ASSERT_VOP_LOCKED(vp, "v_writecount inc"); 1622 VOP_ADD_WRITECOUNT_CHECKED(vp, 1); 1623 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1624 __func__, vp, vp->v_writecount); 1625 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1626 ASSERT_VOP_LOCKED(vp, "v_writecount dec"); 1627 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1628 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1629 __func__, vp, vp->v_writecount); 1630 } 1631 VM_OBJECT_WUNLOCK(object); 1632 } 1633 1634 static void 1635 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1636 vm_offset_t end) 1637 { 1638 struct vnode *vp; 1639 struct mount *mp; 1640 vm_offset_t inc; 1641 1642 VM_OBJECT_WLOCK(object); 1643 1644 /* 1645 * First, recheck the object type to account for the race when 1646 * the vnode is reclaimed. 1647 */ 1648 if (object->type != OBJT_VNODE) { 1649 VM_OBJECT_WUNLOCK(object); 1650 return; 1651 } 1652 1653 /* 1654 * Optimize for the case when writemappings is not going to 1655 * zero. 1656 */ 1657 inc = end - start; 1658 if (object->un_pager.vnp.writemappings != inc) { 1659 object->un_pager.vnp.writemappings -= inc; 1660 VM_OBJECT_WUNLOCK(object); 1661 return; 1662 } 1663 1664 vp = object->handle; 1665 vhold(vp); 1666 VM_OBJECT_WUNLOCK(object); 1667 mp = NULL; 1668 vn_start_write(vp, &mp, V_WAIT); 1669 vn_lock(vp, LK_SHARED | LK_RETRY); 1670 1671 /* 1672 * Decrement the object's writemappings, by swapping the start 1673 * and end arguments for vnode_pager_update_writecount(). If 1674 * there was not a race with vnode reclaimation, then the 1675 * vnode's v_writecount is decremented. 1676 */ 1677 vnode_pager_update_writecount(object, end, start); 1678 VOP_UNLOCK(vp); 1679 vdrop(vp); 1680 if (mp != NULL) 1681 vn_finished_write(mp); 1682 } 1683 1684 static void 1685 vnode_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) 1686 { 1687 *vpp = object->handle; 1688 } 1689