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 43 /* 44 * Page to/from files (vnodes). 45 */ 46 47 /* 48 * TODO: 49 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 50 * greatly re-simplify the vnode_pager. 51 */ 52 53 #include <sys/cdefs.h> 54 #include "opt_vm.h" 55 56 #include <sys/param.h> 57 #include <sys/kernel.h> 58 #include <sys/systm.h> 59 #include <sys/sysctl.h> 60 #include <sys/proc.h> 61 #include <sys/vnode.h> 62 #include <sys/mount.h> 63 #include <sys/bio.h> 64 #include <sys/buf.h> 65 #include <sys/vmmeter.h> 66 #include <sys/ktr.h> 67 #include <sys/limits.h> 68 #include <sys/conf.h> 69 #include <sys/refcount.h> 70 #include <sys/rwlock.h> 71 #include <sys/sf_buf.h> 72 #include <sys/domainset.h> 73 #include <sys/user.h> 74 75 #include <machine/atomic.h> 76 77 #include <vm/vm.h> 78 #include <vm/vm_param.h> 79 #include <vm/vm_object.h> 80 #include <vm/vm_page.h> 81 #include <vm/vm_pager.h> 82 #include <vm/vm_map.h> 83 #include <vm/vnode_pager.h> 84 #include <vm/vm_extern.h> 85 #include <vm/uma.h> 86 87 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 88 daddr_t *rtaddress, int *run); 89 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 90 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 91 static void vnode_pager_dealloc(vm_object_t); 92 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 93 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, 94 int *, vop_getpages_iodone_t, void *); 95 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 96 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 97 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 98 vm_ooffset_t, struct ucred *cred); 99 static int vnode_pager_generic_getpages_done(struct buf *); 100 static void vnode_pager_generic_getpages_done_async(struct buf *); 101 static void vnode_pager_update_writecount(vm_object_t, vm_offset_t, 102 vm_offset_t); 103 static void vnode_pager_release_writecount(vm_object_t, vm_offset_t, 104 vm_offset_t); 105 static void vnode_pager_getvp(vm_object_t, struct vnode **, bool *); 106 107 const struct pagerops vnodepagerops = { 108 .pgo_kvme_type = KVME_TYPE_VNODE, 109 .pgo_alloc = vnode_pager_alloc, 110 .pgo_dealloc = vnode_pager_dealloc, 111 .pgo_getpages = vnode_pager_getpages, 112 .pgo_getpages_async = vnode_pager_getpages_async, 113 .pgo_putpages = vnode_pager_putpages, 114 .pgo_haspage = vnode_pager_haspage, 115 .pgo_update_writecount = vnode_pager_update_writecount, 116 .pgo_release_writecount = vnode_pager_release_writecount, 117 .pgo_set_writeable_dirty = vm_object_set_writeable_dirty_, 118 .pgo_mightbedirty = vm_object_mightbedirty_, 119 .pgo_getvp = vnode_pager_getvp, 120 }; 121 122 static struct domainset *vnode_domainset = NULL; 123 124 SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset, 125 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_RW, &vnode_domainset, 0, 126 sysctl_handle_domainset, "A", "Default vnode NUMA policy"); 127 128 static int nvnpbufs; 129 SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 130 &nvnpbufs, 0, "number of physical buffers allocated for vnode pager"); 131 132 static uma_zone_t vnode_pbuf_zone; 133 134 static void 135 vnode_pager_init(void *dummy) 136 { 137 138 #ifdef __LP64__ 139 nvnpbufs = nswbuf * 2; 140 #else 141 nvnpbufs = nswbuf / 2; 142 #endif 143 TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs); 144 vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs); 145 } 146 SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL); 147 148 /* Create the VM system backing object for this vnode */ 149 int 150 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 151 { 152 vm_object_t object; 153 vm_ooffset_t size = isize; 154 bool last; 155 156 if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE) 157 return (0); 158 159 object = vp->v_object; 160 if (object != NULL) 161 return (0); 162 163 if (size == 0) { 164 if (vn_isdisk(vp)) { 165 size = IDX_TO_OFF(INT_MAX); 166 } else { 167 if (vn_getsize_locked(vp, &size, td->td_ucred) != 0) 168 return (0); 169 } 170 } 171 172 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 173 /* 174 * Dereference the reference we just created. This assumes 175 * that the object is associated with the vp. We still have 176 * to serialize with vnode_pager_dealloc() for the last 177 * potential reference. 178 */ 179 VM_OBJECT_RLOCK(object); 180 last = refcount_release(&object->ref_count); 181 VM_OBJECT_RUNLOCK(object); 182 if (last) 183 vrele(vp); 184 185 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 186 187 return (0); 188 } 189 190 void 191 vnode_destroy_vobject(struct vnode *vp) 192 { 193 struct vm_object *obj; 194 195 obj = vp->v_object; 196 if (obj == NULL || obj->handle != vp) 197 return; 198 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 199 VM_OBJECT_WLOCK(obj); 200 MPASS(obj->type == OBJT_VNODE); 201 umtx_shm_object_terminated(obj); 202 if (obj->ref_count == 0) { 203 KASSERT((obj->flags & OBJ_DEAD) == 0, 204 ("vnode_destroy_vobject: Terminating dead object")); 205 vm_object_set_flag(obj, OBJ_DEAD); 206 207 /* 208 * Clean pages and flush buffers. 209 */ 210 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC); 211 VM_OBJECT_WUNLOCK(obj); 212 213 vinvalbuf(vp, V_SAVE, 0, 0); 214 215 BO_LOCK(&vp->v_bufobj); 216 vp->v_bufobj.bo_flag |= BO_DEAD; 217 BO_UNLOCK(&vp->v_bufobj); 218 219 VM_OBJECT_WLOCK(obj); 220 vm_object_terminate(obj); 221 } else { 222 /* 223 * Woe to the process that tries to page now :-). 224 */ 225 vm_pager_deallocate(obj); 226 VM_OBJECT_WUNLOCK(obj); 227 } 228 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object)); 229 } 230 231 /* 232 * Allocate (or lookup) pager for a vnode. 233 * Handle is a vnode pointer. 234 */ 235 vm_object_t 236 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 237 vm_ooffset_t offset, struct ucred *cred) 238 { 239 vm_object_t object; 240 struct vnode *vp; 241 242 /* 243 * Pageout to vnode, no can do yet. 244 */ 245 if (handle == NULL) 246 return (NULL); 247 248 vp = (struct vnode *)handle; 249 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc"); 250 VNPASS(vp->v_usecount > 0, vp); 251 retry: 252 object = vp->v_object; 253 254 if (object == NULL) { 255 /* 256 * Add an object of the appropriate size 257 */ 258 object = vm_object_allocate(OBJT_VNODE, 259 OFF_TO_IDX(round_page(size))); 260 261 object->un_pager.vnp.vnp_size = size; 262 object->un_pager.vnp.writemappings = 0; 263 object->domain.dr_policy = vnode_domainset; 264 object->handle = handle; 265 if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) { 266 VM_OBJECT_WLOCK(object); 267 vm_object_set_flag(object, OBJ_SIZEVNLOCK); 268 VM_OBJECT_WUNLOCK(object); 269 } 270 VI_LOCK(vp); 271 if (vp->v_object != NULL) { 272 /* 273 * Object has been created while we were allocating. 274 */ 275 VI_UNLOCK(vp); 276 VM_OBJECT_WLOCK(object); 277 KASSERT(object->ref_count == 1, 278 ("leaked ref %p %d", object, object->ref_count)); 279 object->type = OBJT_DEAD; 280 refcount_init(&object->ref_count, 0); 281 VM_OBJECT_WUNLOCK(object); 282 vm_object_destroy(object); 283 goto retry; 284 } 285 vp->v_object = object; 286 VI_UNLOCK(vp); 287 vrefact(vp); 288 } else { 289 vm_object_reference(object); 290 #if VM_NRESERVLEVEL > 0 291 if ((object->flags & OBJ_COLORED) == 0) { 292 VM_OBJECT_WLOCK(object); 293 vm_object_color(object, 0); 294 VM_OBJECT_WUNLOCK(object); 295 } 296 #endif 297 } 298 return (object); 299 } 300 301 /* 302 * The object must be locked. 303 */ 304 static void 305 vnode_pager_dealloc(vm_object_t object) 306 { 307 struct vnode *vp; 308 int refs; 309 310 vp = object->handle; 311 if (vp == NULL) 312 panic("vnode_pager_dealloc: pager already dealloced"); 313 314 VM_OBJECT_ASSERT_WLOCKED(object); 315 vm_object_pip_wait(object, "vnpdea"); 316 refs = object->ref_count; 317 318 object->handle = NULL; 319 object->type = OBJT_DEAD; 320 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 321 if (object->un_pager.vnp.writemappings > 0) { 322 object->un_pager.vnp.writemappings = 0; 323 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 324 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 325 __func__, vp, vp->v_writecount); 326 } 327 vp->v_object = NULL; 328 VI_LOCK(vp); 329 330 /* 331 * vm_map_entry_set_vnode_text() cannot reach this vnode by 332 * following object->handle. Clear all text references now. 333 * This also clears the transient references from 334 * kern_execve(), which is fine because dead_vnodeops uses nop 335 * for VOP_UNSET_TEXT(). 336 */ 337 if (vp->v_writecount < 0) 338 vp->v_writecount = 0; 339 VI_UNLOCK(vp); 340 VM_OBJECT_WUNLOCK(object); 341 if (refs > 0) 342 vunref(vp); 343 VM_OBJECT_WLOCK(object); 344 } 345 346 static boolean_t 347 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 348 int *after) 349 { 350 struct vnode *vp = object->handle; 351 daddr_t bn; 352 uintptr_t lockstate; 353 int err; 354 daddr_t reqblock; 355 int poff; 356 int bsize; 357 int pagesperblock, blocksperpage; 358 359 VM_OBJECT_ASSERT_LOCKED(object); 360 /* 361 * If no vp or vp is doomed or marked transparent to VM, we do not 362 * have the page. 363 */ 364 if (vp == NULL || VN_IS_DOOMED(vp)) 365 return FALSE; 366 /* 367 * If the offset is beyond end of file we do 368 * not have the page. 369 */ 370 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 371 return FALSE; 372 373 bsize = vp->v_mount->mnt_stat.f_iosize; 374 pagesperblock = bsize / PAGE_SIZE; 375 blocksperpage = 0; 376 if (pagesperblock > 0) { 377 reqblock = pindex / pagesperblock; 378 } else { 379 blocksperpage = (PAGE_SIZE / bsize); 380 reqblock = pindex * blocksperpage; 381 } 382 lockstate = VM_OBJECT_DROP(object); 383 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 384 VM_OBJECT_PICKUP(object, lockstate); 385 if (err) 386 return TRUE; 387 if (bn == -1) 388 return FALSE; 389 if (pagesperblock > 0) { 390 poff = pindex - (reqblock * pagesperblock); 391 if (before) { 392 *before *= pagesperblock; 393 *before += poff; 394 } 395 if (after) { 396 /* 397 * The BMAP vop can report a partial block in the 398 * 'after', but must not report blocks after EOF. 399 * Assert the latter, and truncate 'after' in case 400 * of the former. 401 */ 402 KASSERT((reqblock + *after) * pagesperblock < 403 roundup2(object->size, pagesperblock), 404 ("%s: reqblock %jd after %d size %ju", __func__, 405 (intmax_t )reqblock, *after, 406 (uintmax_t )object->size)); 407 *after *= pagesperblock; 408 *after += pagesperblock - (poff + 1); 409 if (pindex + *after >= object->size) 410 *after = object->size - 1 - pindex; 411 } 412 } else { 413 if (before) { 414 *before /= blocksperpage; 415 } 416 417 if (after) { 418 *after /= blocksperpage; 419 } 420 } 421 return TRUE; 422 } 423 424 /* 425 * Internal routine clearing partial-page content 426 */ 427 static void 428 vnode_pager_subpage_purge(struct vm_page *m, int base, int end) 429 { 430 int size; 431 432 KASSERT(end > base && end <= PAGE_SIZE, 433 ("%s: start %d end %d", __func__, base, end)); 434 size = end - base; 435 436 /* 437 * Clear out partial-page garbage in case 438 * the page has been mapped. 439 */ 440 pmap_zero_page_area(m, base, size); 441 442 /* 443 * Update the valid bits to reflect the blocks 444 * that have been zeroed. Some of these valid 445 * bits may have already been set. 446 */ 447 vm_page_set_valid_range(m, base, size); 448 449 /* 450 * Round up "base" to the next block boundary so 451 * that the dirty bit for a partially zeroed 452 * block is not cleared. 453 */ 454 base = roundup2(base, DEV_BSIZE); 455 end = rounddown2(end, DEV_BSIZE); 456 457 if (end > base) { 458 /* 459 * Clear out partial-page dirty bits. 460 * 461 * note that we do not clear out the 462 * valid bits. This would prevent 463 * bogus_page replacement from working 464 * properly. 465 */ 466 vm_page_clear_dirty(m, base, end - base); 467 } 468 469 } 470 471 /* 472 * Lets the VM system know about a change in size for a file. 473 * We adjust our own internal size and flush any cached pages in 474 * the associated object that are affected by the size change. 475 * 476 * Note: this routine may be invoked as a result of a pager put 477 * operation (possibly at object termination time), so we must be careful. 478 */ 479 void 480 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 481 { 482 vm_object_t object; 483 vm_page_t m; 484 vm_pindex_t nobjsize; 485 486 if ((object = vp->v_object) == NULL) 487 return; 488 #ifdef DEBUG_VFS_LOCKS 489 { 490 struct mount *mp; 491 492 mp = vp->v_mount; 493 if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0) 494 assert_vop_elocked(vp, 495 "vnode_pager_setsize and not locked vnode"); 496 } 497 #endif 498 VM_OBJECT_WLOCK(object); 499 if (object->type == OBJT_DEAD) { 500 VM_OBJECT_WUNLOCK(object); 501 return; 502 } 503 KASSERT(object->type == OBJT_VNODE, 504 ("not vnode-backed object %p", object)); 505 if (nsize == object->un_pager.vnp.vnp_size) { 506 /* 507 * Hasn't changed size 508 */ 509 VM_OBJECT_WUNLOCK(object); 510 return; 511 } 512 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 513 if (nsize < object->un_pager.vnp.vnp_size) { 514 /* 515 * File has shrunk. Toss any cached pages beyond the new EOF. 516 */ 517 if (nobjsize < object->size) 518 vm_object_page_remove(object, nobjsize, object->size, 519 0); 520 /* 521 * this gets rid of garbage at the end of a page that is now 522 * only partially backed by the vnode. 523 * 524 * XXX for some reason (I don't know yet), if we take a 525 * completely invalid page and mark it partially valid 526 * it can screw up NFS reads, so we don't allow the case. 527 */ 528 if (!(nsize & PAGE_MASK)) 529 goto out; 530 m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT); 531 if (m == NULL) 532 goto out; 533 if (!vm_page_none_valid(m)) 534 vnode_pager_subpage_purge(m, (int)nsize & PAGE_MASK, 535 PAGE_SIZE); 536 vm_page_xunbusy(m); 537 } 538 out: 539 #if defined(__powerpc__) && !defined(__powerpc64__) 540 object->un_pager.vnp.vnp_size = nsize; 541 #else 542 atomic_store_64(&object->un_pager.vnp.vnp_size, nsize); 543 #endif 544 object->size = nobjsize; 545 VM_OBJECT_WUNLOCK(object); 546 } 547 548 /* 549 * Lets the VM system know about the purged range for a file. We toss away any 550 * cached pages in the associated object that are affected by the purge 551 * operation. Partial-page area not aligned to page boundaries will be zeroed 552 * and the dirty blocks in DEV_BSIZE unit within a page will not be flushed. 553 */ 554 void 555 vnode_pager_purge_range(struct vnode *vp, vm_ooffset_t start, vm_ooffset_t end) 556 { 557 struct vm_page *m; 558 struct vm_object *object; 559 vm_pindex_t pi, pistart, piend; 560 bool same_page; 561 int base, pend; 562 563 ASSERT_VOP_LOCKED(vp, "vnode_pager_purge_range"); 564 565 object = vp->v_object; 566 pi = start + PAGE_MASK < start ? OBJ_MAX_SIZE : 567 OFF_TO_IDX(start + PAGE_MASK); 568 pistart = OFF_TO_IDX(start); 569 piend = end == 0 ? OBJ_MAX_SIZE : OFF_TO_IDX(end); 570 same_page = pistart == piend; 571 if ((end != 0 && end <= start) || object == NULL) 572 return; 573 574 VM_OBJECT_WLOCK(object); 575 576 if (pi < piend) 577 vm_object_page_remove(object, pi, piend, 0); 578 579 if ((start & PAGE_MASK) != 0) { 580 base = (int)start & PAGE_MASK; 581 pend = same_page ? (int)end & PAGE_MASK : PAGE_SIZE; 582 m = vm_page_grab(object, pistart, VM_ALLOC_NOCREAT); 583 if (m != NULL) { 584 if (!vm_page_none_valid(m)) 585 vnode_pager_subpage_purge(m, base, pend); 586 vm_page_xunbusy(m); 587 } 588 if (same_page) 589 goto out; 590 } 591 if ((end & PAGE_MASK) != 0) { 592 base = same_page ? (int)start & PAGE_MASK : 0 ; 593 pend = (int)end & PAGE_MASK; 594 m = vm_page_grab(object, piend, VM_ALLOC_NOCREAT); 595 if (m != NULL) { 596 if (!vm_page_none_valid(m)) 597 vnode_pager_subpage_purge(m, base, pend); 598 vm_page_xunbusy(m); 599 } 600 } 601 out: 602 VM_OBJECT_WUNLOCK(object); 603 } 604 605 /* 606 * calculate the linear (byte) disk address of specified virtual 607 * file address 608 */ 609 static int 610 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 611 int *run) 612 { 613 int bsize; 614 int err; 615 daddr_t vblock; 616 daddr_t voffset; 617 618 if (VN_IS_DOOMED(vp)) 619 return -1; 620 621 bsize = vp->v_mount->mnt_stat.f_iosize; 622 vblock = address / bsize; 623 voffset = address % bsize; 624 625 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 626 if (err == 0) { 627 if (*rtaddress != -1) 628 *rtaddress += voffset / DEV_BSIZE; 629 if (run) { 630 *run += 1; 631 *run *= bsize / PAGE_SIZE; 632 *run -= voffset / PAGE_SIZE; 633 } 634 } 635 636 return (err); 637 } 638 639 static void 640 vnode_pager_input_bdone(struct buf *bp) 641 { 642 runningbufwakeup(bp); 643 bdone(bp); 644 } 645 646 /* 647 * small block filesystem vnode pager input 648 */ 649 static int 650 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 651 { 652 struct vnode *vp; 653 struct bufobj *bo; 654 struct buf *bp; 655 struct sf_buf *sf; 656 daddr_t fileaddr; 657 vm_offset_t bsize; 658 vm_page_bits_t bits; 659 int error, i; 660 661 error = 0; 662 vp = object->handle; 663 if (VN_IS_DOOMED(vp)) 664 return VM_PAGER_BAD; 665 666 bsize = vp->v_mount->mnt_stat.f_iosize; 667 668 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 669 670 sf = sf_buf_alloc(m, 0); 671 672 for (i = 0; i < PAGE_SIZE / bsize; i++) { 673 vm_ooffset_t address; 674 675 bits = vm_page_bits(i * bsize, bsize); 676 if (m->valid & bits) 677 continue; 678 679 address = IDX_TO_OFF(m->pindex) + i * bsize; 680 if (address >= object->un_pager.vnp.vnp_size) { 681 fileaddr = -1; 682 } else { 683 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 684 if (error) 685 break; 686 } 687 if (fileaddr != -1) { 688 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 689 690 /* build a minimal buffer header */ 691 bp->b_iocmd = BIO_READ; 692 bp->b_iodone = vnode_pager_input_bdone; 693 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 694 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 695 bp->b_rcred = crhold(curthread->td_ucred); 696 bp->b_wcred = crhold(curthread->td_ucred); 697 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 698 bp->b_blkno = fileaddr; 699 pbgetbo(bo, bp); 700 bp->b_vp = vp; 701 bp->b_bcount = bsize; 702 bp->b_bufsize = bsize; 703 bp->b_runningbufspace = bp->b_bufsize; 704 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 705 706 /* do the input */ 707 bp->b_iooffset = dbtob(bp->b_blkno); 708 bstrategy(bp); 709 710 bwait(bp, PVM, "vnsrd"); 711 712 if ((bp->b_ioflags & BIO_ERROR) != 0) { 713 KASSERT(bp->b_error != 0, 714 ("%s: buf error but b_error == 0\n", __func__)); 715 error = bp->b_error; 716 } 717 718 /* 719 * free the buffer header back to the swap buffer pool 720 */ 721 bp->b_vp = NULL; 722 pbrelbo(bp); 723 uma_zfree(vnode_pbuf_zone, bp); 724 if (error) 725 break; 726 } else 727 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 728 KASSERT((m->dirty & bits) == 0, 729 ("vnode_pager_input_smlfs: page %p is dirty", m)); 730 vm_page_bits_set(m, &m->valid, bits); 731 } 732 sf_buf_free(sf); 733 if (error) { 734 return VM_PAGER_ERROR; 735 } 736 return VM_PAGER_OK; 737 } 738 739 /* 740 * old style vnode pager input routine 741 */ 742 static int 743 vnode_pager_input_old(vm_object_t object, vm_page_t m) 744 { 745 struct uio auio; 746 struct iovec aiov; 747 int error; 748 int size; 749 struct sf_buf *sf; 750 struct vnode *vp; 751 752 VM_OBJECT_ASSERT_WLOCKED(object); 753 error = 0; 754 755 /* 756 * Return failure if beyond current EOF 757 */ 758 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 759 return VM_PAGER_BAD; 760 } else { 761 size = PAGE_SIZE; 762 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 763 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 764 vp = object->handle; 765 VM_OBJECT_WUNLOCK(object); 766 767 /* 768 * Allocate a kernel virtual address and initialize so that 769 * we can use VOP_READ/WRITE routines. 770 */ 771 sf = sf_buf_alloc(m, 0); 772 773 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 774 aiov.iov_len = size; 775 auio.uio_iov = &aiov; 776 auio.uio_iovcnt = 1; 777 auio.uio_offset = IDX_TO_OFF(m->pindex); 778 auio.uio_segflg = UIO_SYSSPACE; 779 auio.uio_rw = UIO_READ; 780 auio.uio_resid = size; 781 auio.uio_td = curthread; 782 783 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 784 if (!error) { 785 int count = size - auio.uio_resid; 786 787 if (count == 0) 788 error = EINVAL; 789 else if (count != PAGE_SIZE) 790 bzero((caddr_t)sf_buf_kva(sf) + count, 791 PAGE_SIZE - count); 792 } 793 sf_buf_free(sf); 794 795 VM_OBJECT_WLOCK(object); 796 } 797 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 798 if (!error) 799 vm_page_valid(m); 800 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 801 } 802 803 /* 804 * generic vnode pager input routine 805 */ 806 807 /* 808 * Local media VFS's that do not implement their own VOP_GETPAGES 809 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 810 * to implement the previous behaviour. 811 * 812 * All other FS's should use the bypass to get to the local media 813 * backing vp's VOP_GETPAGES. 814 */ 815 static int 816 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 817 int *rahead) 818 { 819 struct vnode *vp; 820 int rtval; 821 822 /* Handle is stable with paging in progress. */ 823 vp = object->handle; 824 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 825 KASSERT(rtval != EOPNOTSUPP, 826 ("vnode_pager: FS getpages not implemented\n")); 827 return rtval; 828 } 829 830 static int 831 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 832 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 833 { 834 struct vnode *vp; 835 int rtval; 836 837 vp = object->handle; 838 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 839 KASSERT(rtval != EOPNOTSUPP, 840 ("vnode_pager: FS getpages_async not implemented\n")); 841 return (rtval); 842 } 843 844 /* 845 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 846 * local filesystems, where partially valid pages can only occur at 847 * the end of file. 848 */ 849 int 850 vnode_pager_local_getpages(struct vop_getpages_args *ap) 851 { 852 853 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 854 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 855 } 856 857 int 858 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 859 { 860 int error; 861 862 error = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 863 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg); 864 if (error != 0 && ap->a_iodone != NULL) 865 ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error); 866 return (error); 867 } 868 869 /* 870 * This is now called from local media FS's to operate against their 871 * own vnodes if they fail to implement VOP_GETPAGES. 872 */ 873 int 874 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 875 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 876 { 877 vm_object_t object; 878 struct bufobj *bo; 879 struct buf *bp; 880 off_t foff; 881 #ifdef INVARIANTS 882 off_t blkno0; 883 #endif 884 int bsize, pagesperblock; 885 int error, before, after, rbehind, rahead, poff, i; 886 int bytecount, secmask; 887 888 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 889 ("%s does not support devices", __func__)); 890 891 if (VN_IS_DOOMED(vp)) 892 return (VM_PAGER_BAD); 893 894 object = vp->v_object; 895 foff = IDX_TO_OFF(m[0]->pindex); 896 bsize = vp->v_mount->mnt_stat.f_iosize; 897 pagesperblock = bsize / PAGE_SIZE; 898 899 KASSERT(foff < object->un_pager.vnp.vnp_size, 900 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 901 KASSERT(count <= atop(maxphys), 902 ("%s: requested %d pages", __func__, count)); 903 904 /* 905 * The last page has valid blocks. Invalid part can only 906 * exist at the end of file, and the page is made fully valid 907 * by zeroing in vm_pager_get_pages(). 908 */ 909 if (!vm_page_none_valid(m[count - 1]) && --count == 0) { 910 if (iodone != NULL) 911 iodone(arg, m, 1, 0); 912 return (VM_PAGER_OK); 913 } 914 915 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 916 MPASS((bp->b_flags & B_MAXPHYS) != 0); 917 918 /* 919 * Get the underlying device blocks for the file with VOP_BMAP(). 920 * If the file system doesn't support VOP_BMAP, use old way of 921 * getting pages via VOP_READ. 922 */ 923 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 924 if (error == EOPNOTSUPP) { 925 uma_zfree(vnode_pbuf_zone, bp); 926 VM_OBJECT_WLOCK(object); 927 for (i = 0; i < count; i++) { 928 VM_CNT_INC(v_vnodein); 929 VM_CNT_INC(v_vnodepgsin); 930 error = vnode_pager_input_old(object, m[i]); 931 if (error) 932 break; 933 } 934 VM_OBJECT_WUNLOCK(object); 935 return (error); 936 } else if (error != 0) { 937 uma_zfree(vnode_pbuf_zone, bp); 938 return (VM_PAGER_ERROR); 939 } 940 941 /* 942 * If the file system supports BMAP, but blocksize is smaller 943 * than a page size, then use special small filesystem code. 944 */ 945 if (pagesperblock == 0) { 946 uma_zfree(vnode_pbuf_zone, bp); 947 for (i = 0; i < count; i++) { 948 VM_CNT_INC(v_vnodein); 949 VM_CNT_INC(v_vnodepgsin); 950 error = vnode_pager_input_smlfs(object, m[i]); 951 if (error) 952 break; 953 } 954 return (error); 955 } 956 957 /* 958 * A sparse file can be encountered only for a single page request, 959 * which may not be preceded by call to vm_pager_haspage(). 960 */ 961 if (bp->b_blkno == -1) { 962 KASSERT(count == 1, 963 ("%s: array[%d] request to a sparse file %p", __func__, 964 count, vp)); 965 uma_zfree(vnode_pbuf_zone, bp); 966 pmap_zero_page(m[0]); 967 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 968 __func__, m[0])); 969 vm_page_valid(m[0]); 970 return (VM_PAGER_OK); 971 } 972 973 #ifdef INVARIANTS 974 blkno0 = bp->b_blkno; 975 #endif 976 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 977 978 /* Recalculate blocks available after/before to pages. */ 979 poff = (foff % bsize) / PAGE_SIZE; 980 before *= pagesperblock; 981 before += poff; 982 after *= pagesperblock; 983 after += pagesperblock - (poff + 1); 984 if (m[0]->pindex + after >= object->size) 985 after = object->size - 1 - m[0]->pindex; 986 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 987 __func__, count, after + 1)); 988 after -= count - 1; 989 990 /* Trim requested rbehind/rahead to possible values. */ 991 rbehind = a_rbehind ? *a_rbehind : 0; 992 rahead = a_rahead ? *a_rahead : 0; 993 rbehind = min(rbehind, before); 994 rbehind = min(rbehind, m[0]->pindex); 995 rahead = min(rahead, after); 996 rahead = min(rahead, object->size - m[count - 1]->pindex); 997 /* 998 * Check that total amount of pages fit into buf. Trim rbehind and 999 * rahead evenly if not. 1000 */ 1001 if (rbehind + rahead + count > atop(maxphys)) { 1002 int trim, sum; 1003 1004 trim = rbehind + rahead + count - atop(maxphys) + 1; 1005 sum = rbehind + rahead; 1006 if (rbehind == before) { 1007 /* Roundup rbehind trim to block size. */ 1008 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 1009 if (rbehind < 0) 1010 rbehind = 0; 1011 } else 1012 rbehind -= trim * rbehind / sum; 1013 rahead -= trim * rahead / sum; 1014 } 1015 KASSERT(rbehind + rahead + count <= atop(maxphys), 1016 ("%s: behind %d ahead %d count %d maxphys %lu", __func__, 1017 rbehind, rahead, count, maxphys)); 1018 1019 /* 1020 * Fill in the bp->b_pages[] array with requested and optional 1021 * read behind or read ahead pages. Read behind pages are looked 1022 * up in a backward direction, down to a first cached page. Same 1023 * for read ahead pages, but there is no need to shift the array 1024 * in case of encountering a cached page. 1025 */ 1026 i = bp->b_npages = 0; 1027 if (rbehind) { 1028 vm_pindex_t startpindex, tpindex; 1029 vm_page_t p; 1030 1031 VM_OBJECT_WLOCK(object); 1032 startpindex = m[0]->pindex - rbehind; 1033 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 1034 p->pindex >= startpindex) 1035 startpindex = p->pindex + 1; 1036 1037 /* tpindex is unsigned; beware of numeric underflow. */ 1038 for (tpindex = m[0]->pindex - 1; 1039 tpindex >= startpindex && tpindex < m[0]->pindex; 1040 tpindex--, i++) { 1041 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1042 if (p == NULL) { 1043 /* Shift the array. */ 1044 for (int j = 0; j < i; j++) 1045 bp->b_pages[j] = bp->b_pages[j + 1046 tpindex + 1 - startpindex]; 1047 break; 1048 } 1049 bp->b_pages[tpindex - startpindex] = p; 1050 } 1051 1052 bp->b_pgbefore = i; 1053 bp->b_npages += i; 1054 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 1055 } else 1056 bp->b_pgbefore = 0; 1057 1058 /* Requested pages. */ 1059 for (int j = 0; j < count; j++, i++) 1060 bp->b_pages[i] = m[j]; 1061 bp->b_npages += count; 1062 1063 if (rahead) { 1064 vm_pindex_t endpindex, tpindex; 1065 vm_page_t p; 1066 1067 if (!VM_OBJECT_WOWNED(object)) 1068 VM_OBJECT_WLOCK(object); 1069 endpindex = m[count - 1]->pindex + rahead + 1; 1070 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 1071 p->pindex < endpindex) 1072 endpindex = p->pindex; 1073 if (endpindex > object->size) 1074 endpindex = object->size; 1075 1076 for (tpindex = m[count - 1]->pindex + 1; 1077 tpindex < endpindex; i++, tpindex++) { 1078 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1079 if (p == NULL) 1080 break; 1081 bp->b_pages[i] = p; 1082 } 1083 1084 bp->b_pgafter = i - bp->b_npages; 1085 bp->b_npages = i; 1086 } else 1087 bp->b_pgafter = 0; 1088 1089 if (VM_OBJECT_WOWNED(object)) 1090 VM_OBJECT_WUNLOCK(object); 1091 1092 /* Report back actual behind/ahead read. */ 1093 if (a_rbehind) 1094 *a_rbehind = bp->b_pgbefore; 1095 if (a_rahead) 1096 *a_rahead = bp->b_pgafter; 1097 1098 #ifdef INVARIANTS 1099 KASSERT(bp->b_npages <= atop(maxphys), 1100 ("%s: buf %p overflowed", __func__, bp)); 1101 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 1102 if (bp->b_pages[j] == bogus_page) 1103 continue; 1104 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 1105 j - prev, ("%s: pages array not consecutive, bp %p", 1106 __func__, bp)); 1107 prev = j; 1108 } 1109 #endif 1110 1111 /* 1112 * Recalculate first offset and bytecount with regards to read behind. 1113 * Truncate bytecount to vnode real size and round up physical size 1114 * for real devices. 1115 */ 1116 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1117 bytecount = bp->b_npages << PAGE_SHIFT; 1118 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 1119 bytecount = object->un_pager.vnp.vnp_size - foff; 1120 secmask = bo->bo_bsize - 1; 1121 KASSERT(secmask < PAGE_SIZE && secmask > 0, 1122 ("%s: sector size %d too large", __func__, secmask + 1)); 1123 bytecount = (bytecount + secmask) & ~secmask; 1124 1125 /* 1126 * And map the pages to be read into the kva, if the filesystem 1127 * requires mapped buffers. 1128 */ 1129 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1130 unmapped_buf_allowed) { 1131 bp->b_data = unmapped_buf; 1132 bp->b_offset = 0; 1133 } else { 1134 bp->b_data = bp->b_kvabase; 1135 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1136 } 1137 1138 /* Build a minimal buffer header. */ 1139 bp->b_iocmd = BIO_READ; 1140 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1141 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1142 bp->b_rcred = crhold(curthread->td_ucred); 1143 bp->b_wcred = crhold(curthread->td_ucred); 1144 pbgetbo(bo, bp); 1145 bp->b_vp = vp; 1146 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1147 bp->b_iooffset = dbtob(bp->b_blkno); 1148 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1149 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1150 IDX_TO_OFF(m[0]->pindex) % bsize, 1151 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1152 "blkno0 %ju b_blkno %ju", bsize, 1153 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1154 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1155 1156 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1157 VM_CNT_INC(v_vnodein); 1158 VM_CNT_ADD(v_vnodepgsin, bp->b_npages); 1159 1160 if (iodone != NULL) { /* async */ 1161 bp->b_pgiodone = iodone; 1162 bp->b_caller1 = arg; 1163 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1164 bp->b_flags |= B_ASYNC; 1165 BUF_KERNPROC(bp); 1166 bstrategy(bp); 1167 return (VM_PAGER_OK); 1168 } else { 1169 bp->b_iodone = bdone; 1170 bstrategy(bp); 1171 bwait(bp, PVM, "vnread"); 1172 error = vnode_pager_generic_getpages_done(bp); 1173 for (i = 0; i < bp->b_npages; i++) 1174 bp->b_pages[i] = NULL; 1175 bp->b_vp = NULL; 1176 pbrelbo(bp); 1177 uma_zfree(vnode_pbuf_zone, bp); 1178 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1179 } 1180 } 1181 1182 static void 1183 vnode_pager_generic_getpages_done_async(struct buf *bp) 1184 { 1185 int error; 1186 1187 error = vnode_pager_generic_getpages_done(bp); 1188 /* Run the iodone upon the requested range. */ 1189 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1190 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1191 for (int i = 0; i < bp->b_npages; i++) 1192 bp->b_pages[i] = NULL; 1193 bp->b_vp = NULL; 1194 pbrelbo(bp); 1195 uma_zfree(vnode_pbuf_zone, bp); 1196 } 1197 1198 static int 1199 vnode_pager_generic_getpages_done(struct buf *bp) 1200 { 1201 vm_object_t object; 1202 off_t tfoff, nextoff; 1203 int i, error; 1204 1205 KASSERT((bp->b_ioflags & BIO_ERROR) == 0 || bp->b_error != 0, 1206 ("%s: buf error but b_error == 0\n", __func__)); 1207 error = (bp->b_ioflags & BIO_ERROR) != 0 ? bp->b_error : 0; 1208 object = bp->b_vp->v_object; 1209 1210 runningbufwakeup(bp); 1211 1212 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1213 if (!buf_mapped(bp)) { 1214 bp->b_data = bp->b_kvabase; 1215 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1216 bp->b_npages); 1217 } 1218 bzero(bp->b_data + bp->b_bcount, 1219 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1220 } 1221 if (buf_mapped(bp)) { 1222 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1223 bp->b_data = unmapped_buf; 1224 } 1225 1226 /* 1227 * If the read failed, we must free any read ahead/behind pages here. 1228 * The requested pages are freed by the caller (for sync requests) 1229 * or by the bp->b_pgiodone callback (for async requests). 1230 */ 1231 if (error != 0) { 1232 VM_OBJECT_WLOCK(object); 1233 for (i = 0; i < bp->b_pgbefore; i++) 1234 vm_page_free_invalid(bp->b_pages[i]); 1235 for (i = bp->b_npages - bp->b_pgafter; i < bp->b_npages; i++) 1236 vm_page_free_invalid(bp->b_pages[i]); 1237 VM_OBJECT_WUNLOCK(object); 1238 return (error); 1239 } 1240 1241 /* Read lock to protect size. */ 1242 VM_OBJECT_RLOCK(object); 1243 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1244 i < bp->b_npages; i++, tfoff = nextoff) { 1245 vm_page_t mt; 1246 1247 nextoff = tfoff + PAGE_SIZE; 1248 mt = bp->b_pages[i]; 1249 if (mt == bogus_page) 1250 continue; 1251 1252 if (nextoff <= object->un_pager.vnp.vnp_size) { 1253 /* 1254 * Read filled up entire page. 1255 */ 1256 vm_page_valid(mt); 1257 KASSERT(mt->dirty == 0, 1258 ("%s: page %p is dirty", __func__, mt)); 1259 KASSERT(!pmap_page_is_mapped(mt), 1260 ("%s: page %p is mapped", __func__, mt)); 1261 } else { 1262 /* 1263 * Read did not fill up entire page. 1264 * 1265 * Currently we do not set the entire page valid, 1266 * we just try to clear the piece that we couldn't 1267 * read. 1268 */ 1269 vm_page_set_valid_range(mt, 0, 1270 object->un_pager.vnp.vnp_size - tfoff); 1271 KASSERT((mt->dirty & vm_page_bits(0, 1272 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1273 ("%s: page %p is dirty", __func__, mt)); 1274 } 1275 1276 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1277 vm_page_readahead_finish(mt); 1278 } 1279 VM_OBJECT_RUNLOCK(object); 1280 1281 return (error); 1282 } 1283 1284 /* 1285 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1286 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1287 * vnode_pager_generic_putpages() to implement the previous behaviour. 1288 * 1289 * All other FS's should use the bypass to get to the local media 1290 * backing vp's VOP_PUTPAGES. 1291 */ 1292 static void 1293 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1294 int flags, int *rtvals) 1295 { 1296 int rtval __diagused; 1297 struct vnode *vp; 1298 int bytes = count * PAGE_SIZE; 1299 1300 /* 1301 * Force synchronous operation if we are extremely low on memory 1302 * to prevent a low-memory deadlock. VOP operations often need to 1303 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1304 * operation ). The swapper handles the case by limiting the amount 1305 * of asynchronous I/O, but that sort of solution doesn't scale well 1306 * for the vnode pager without a lot of work. 1307 * 1308 * Also, the backing vnode's iodone routine may not wake the pageout 1309 * daemon up. This should be probably be addressed XXX. 1310 */ 1311 1312 if (vm_page_count_min()) 1313 flags |= VM_PAGER_PUT_SYNC; 1314 1315 /* 1316 * Call device-specific putpages function 1317 */ 1318 vp = object->handle; 1319 VM_OBJECT_WUNLOCK(object); 1320 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1321 KASSERT(rtval != EOPNOTSUPP, 1322 ("vnode_pager: stale FS putpages\n")); 1323 VM_OBJECT_WLOCK(object); 1324 } 1325 1326 static int 1327 vn_off2bidx(vm_ooffset_t offset) 1328 { 1329 1330 return ((offset & PAGE_MASK) / DEV_BSIZE); 1331 } 1332 1333 static bool 1334 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset) 1335 { 1336 1337 KASSERT(IDX_TO_OFF(m->pindex) <= offset && 1338 offset < IDX_TO_OFF(m->pindex + 1), 1339 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex, 1340 (uintmax_t)offset)); 1341 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0); 1342 } 1343 1344 /* 1345 * This is now called from local media FS's to operate against their 1346 * own vnodes if they fail to implement VOP_PUTPAGES. 1347 * 1348 * This is typically called indirectly via the pageout daemon and 1349 * clustering has already typically occurred, so in general we ask the 1350 * underlying filesystem to write the data out asynchronously rather 1351 * then delayed. 1352 */ 1353 int 1354 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1355 int flags, int *rtvals) 1356 { 1357 vm_object_t object; 1358 vm_page_t m; 1359 vm_ooffset_t max_offset, next_offset, poffset, prev_offset; 1360 struct uio auio; 1361 struct iovec aiov; 1362 off_t prev_resid, wrsz; 1363 int count, error, i, maxsize, ncount, pgoff, ppscheck; 1364 bool in_hole; 1365 static struct timeval lastfail; 1366 static int curfail; 1367 1368 object = vp->v_object; 1369 count = bytecount / PAGE_SIZE; 1370 1371 for (i = 0; i < count; i++) 1372 rtvals[i] = VM_PAGER_ERROR; 1373 1374 if ((int64_t)ma[0]->pindex < 0) { 1375 printf("vnode_pager_generic_putpages: " 1376 "attempt to write meta-data 0x%jx(%lx)\n", 1377 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty); 1378 rtvals[0] = VM_PAGER_BAD; 1379 return (VM_PAGER_BAD); 1380 } 1381 1382 maxsize = count * PAGE_SIZE; 1383 ncount = count; 1384 1385 poffset = IDX_TO_OFF(ma[0]->pindex); 1386 1387 /* 1388 * If the page-aligned write is larger then the actual file we 1389 * have to invalidate pages occurring beyond the file EOF. However, 1390 * there is an edge case where a file may not be page-aligned where 1391 * the last page is partially invalid. In this case the filesystem 1392 * may not properly clear the dirty bits for the entire page (which 1393 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1394 * With the page busied we are free to fix up the dirty bits here. 1395 * 1396 * We do not under any circumstances truncate the valid bits, as 1397 * this will screw up bogus page replacement. 1398 */ 1399 VM_OBJECT_RLOCK(object); 1400 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1401 if (object->un_pager.vnp.vnp_size > poffset) { 1402 maxsize = object->un_pager.vnp.vnp_size - poffset; 1403 ncount = btoc(maxsize); 1404 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1405 pgoff = roundup2(pgoff, DEV_BSIZE); 1406 1407 /* 1408 * If the page is busy and the following 1409 * conditions hold, then the page's dirty 1410 * field cannot be concurrently changed by a 1411 * pmap operation. 1412 */ 1413 m = ma[ncount - 1]; 1414 vm_page_assert_sbusied(m); 1415 KASSERT(!pmap_page_is_write_mapped(m), 1416 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1417 MPASS(m->dirty != 0); 1418 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1419 pgoff); 1420 } 1421 } else { 1422 maxsize = 0; 1423 ncount = 0; 1424 } 1425 for (i = ncount; i < count; i++) 1426 rtvals[i] = VM_PAGER_BAD; 1427 } 1428 VM_OBJECT_RUNLOCK(object); 1429 1430 auio.uio_iov = &aiov; 1431 auio.uio_segflg = UIO_NOCOPY; 1432 auio.uio_rw = UIO_WRITE; 1433 auio.uio_td = NULL; 1434 max_offset = roundup2(poffset + maxsize, DEV_BSIZE); 1435 1436 for (prev_offset = poffset; prev_offset < max_offset;) { 1437 /* Skip clean blocks. */ 1438 for (in_hole = true; in_hole && prev_offset < max_offset;) { 1439 m = ma[OFF_TO_IDX(prev_offset - poffset)]; 1440 for (i = vn_off2bidx(prev_offset); 1441 i < sizeof(vm_page_bits_t) * NBBY && 1442 prev_offset < max_offset; i++) { 1443 if (vn_dirty_blk(m, prev_offset)) { 1444 in_hole = false; 1445 break; 1446 } 1447 prev_offset += DEV_BSIZE; 1448 } 1449 } 1450 if (in_hole) 1451 goto write_done; 1452 1453 /* Find longest run of dirty blocks. */ 1454 for (next_offset = prev_offset; next_offset < max_offset;) { 1455 m = ma[OFF_TO_IDX(next_offset - poffset)]; 1456 for (i = vn_off2bidx(next_offset); 1457 i < sizeof(vm_page_bits_t) * NBBY && 1458 next_offset < max_offset; i++) { 1459 if (!vn_dirty_blk(m, next_offset)) 1460 goto start_write; 1461 next_offset += DEV_BSIZE; 1462 } 1463 } 1464 start_write: 1465 if (next_offset > poffset + maxsize) 1466 next_offset = poffset + maxsize; 1467 if (prev_offset == next_offset) 1468 goto write_done; 1469 1470 /* 1471 * Getting here requires finding a dirty block in the 1472 * 'skip clean blocks' loop. 1473 */ 1474 1475 aiov.iov_base = NULL; 1476 auio.uio_iovcnt = 1; 1477 auio.uio_offset = prev_offset; 1478 prev_resid = auio.uio_resid = aiov.iov_len = next_offset - 1479 prev_offset; 1480 error = VOP_WRITE(vp, &auio, 1481 vnode_pager_putpages_ioflags(flags), curthread->td_ucred); 1482 1483 wrsz = prev_resid - auio.uio_resid; 1484 if (wrsz == 0) { 1485 if (ppsratecheck(&lastfail, &curfail, 1) != 0) { 1486 vn_printf(vp, "vnode_pager_putpages: " 1487 "zero-length write at %ju resid %zd\n", 1488 auio.uio_offset, auio.uio_resid); 1489 } 1490 break; 1491 } 1492 1493 /* Adjust the starting offset for next iteration. */ 1494 prev_offset += wrsz; 1495 MPASS(auio.uio_offset == prev_offset); 1496 1497 ppscheck = 0; 1498 if (error != 0 && (ppscheck = ppsratecheck(&lastfail, 1499 &curfail, 1)) != 0) 1500 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n", 1501 error); 1502 if (auio.uio_resid != 0 && (ppscheck != 0 || 1503 ppsratecheck(&lastfail, &curfail, 1) != 0)) 1504 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd " 1505 "at %ju\n", auio.uio_resid, 1506 (uintmax_t)ma[0]->pindex); 1507 if (error != 0 || auio.uio_resid != 0) 1508 break; 1509 } 1510 write_done: 1511 /* Mark completely processed pages. */ 1512 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++) 1513 rtvals[i] = VM_PAGER_OK; 1514 /* Mark partial EOF page. */ 1515 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0) 1516 rtvals[i++] = VM_PAGER_OK; 1517 /* Unwritten pages in range, free bonus if the page is clean. */ 1518 for (; i < ncount; i++) 1519 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR; 1520 VM_CNT_ADD(v_vnodepgsout, i); 1521 VM_CNT_INC(v_vnodeout); 1522 return (rtvals[0]); 1523 } 1524 1525 int 1526 vnode_pager_putpages_ioflags(int pager_flags) 1527 { 1528 int ioflags; 1529 1530 /* 1531 * Pageouts are already clustered, use IO_ASYNC to force a 1532 * bawrite() rather then a bdwrite() to prevent paging I/O 1533 * from saturating the buffer cache. Dummy-up the sequential 1534 * heuristic to cause large ranges to cluster. If neither 1535 * IO_SYNC or IO_ASYNC is set, the system decides how to 1536 * cluster. 1537 */ 1538 ioflags = IO_VMIO; 1539 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0) 1540 ioflags |= IO_SYNC; 1541 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0) 1542 ioflags |= IO_ASYNC; 1543 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0; 1544 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0; 1545 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1546 return (ioflags); 1547 } 1548 1549 /* 1550 * vnode_pager_undirty_pages(). 1551 * 1552 * A helper to mark pages as clean after pageout that was possibly 1553 * done with a short write. The lpos argument specifies the page run 1554 * length in bytes, and the written argument specifies how many bytes 1555 * were actually written. eof is the offset past the last valid byte 1556 * in the vnode using the absolute file position of the first byte in 1557 * the run as the base from which it is computed. 1558 */ 1559 void 1560 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof, 1561 int lpos) 1562 { 1563 int i, pos, pos_devb; 1564 1565 if (written == 0 && eof >= lpos) 1566 return; 1567 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1568 if (pos < trunc_page(written)) { 1569 rtvals[i] = VM_PAGER_OK; 1570 vm_page_undirty(ma[i]); 1571 } else { 1572 /* Partially written page. */ 1573 rtvals[i] = VM_PAGER_AGAIN; 1574 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1575 } 1576 } 1577 if (eof >= lpos) /* avoid truncation */ 1578 return; 1579 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) { 1580 if (pos != trunc_page(pos)) { 1581 /* 1582 * The page contains the last valid byte in 1583 * the vnode, mark the rest of the page as 1584 * clean, potentially making the whole page 1585 * clean. 1586 */ 1587 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE); 1588 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE - 1589 pos_devb); 1590 1591 /* 1592 * If the page was cleaned, report the pageout 1593 * on it as successful. msync() no longer 1594 * needs to write out the page, endlessly 1595 * creating write requests and dirty buffers. 1596 */ 1597 if (ma[i]->dirty == 0) 1598 rtvals[i] = VM_PAGER_OK; 1599 1600 pos = round_page(pos); 1601 } else { 1602 /* vm_pageout_flush() clears dirty */ 1603 rtvals[i] = VM_PAGER_BAD; 1604 pos += PAGE_SIZE; 1605 } 1606 } 1607 } 1608 1609 static void 1610 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1611 vm_offset_t end) 1612 { 1613 struct vnode *vp; 1614 vm_ooffset_t old_wm; 1615 1616 VM_OBJECT_WLOCK(object); 1617 if (object->type != OBJT_VNODE) { 1618 VM_OBJECT_WUNLOCK(object); 1619 return; 1620 } 1621 old_wm = object->un_pager.vnp.writemappings; 1622 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1623 vp = object->handle; 1624 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1625 ASSERT_VOP_LOCKED(vp, "v_writecount inc"); 1626 VOP_ADD_WRITECOUNT_CHECKED(vp, 1); 1627 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1628 __func__, vp, vp->v_writecount); 1629 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1630 ASSERT_VOP_LOCKED(vp, "v_writecount dec"); 1631 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1632 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1633 __func__, vp, vp->v_writecount); 1634 } 1635 VM_OBJECT_WUNLOCK(object); 1636 } 1637 1638 static void 1639 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1640 vm_offset_t end) 1641 { 1642 struct vnode *vp; 1643 struct mount *mp; 1644 vm_offset_t inc; 1645 1646 VM_OBJECT_WLOCK(object); 1647 1648 /* 1649 * First, recheck the object type to account for the race when 1650 * the vnode is reclaimed. 1651 */ 1652 if (object->type != OBJT_VNODE) { 1653 VM_OBJECT_WUNLOCK(object); 1654 return; 1655 } 1656 1657 /* 1658 * Optimize for the case when writemappings is not going to 1659 * zero. 1660 */ 1661 inc = end - start; 1662 if (object->un_pager.vnp.writemappings != inc) { 1663 object->un_pager.vnp.writemappings -= inc; 1664 VM_OBJECT_WUNLOCK(object); 1665 return; 1666 } 1667 1668 vp = object->handle; 1669 vhold(vp); 1670 VM_OBJECT_WUNLOCK(object); 1671 mp = NULL; 1672 vn_start_write(vp, &mp, V_WAIT); 1673 vn_lock(vp, LK_SHARED | LK_RETRY); 1674 1675 /* 1676 * Decrement the object's writemappings, by swapping the start 1677 * and end arguments for vnode_pager_update_writecount(). If 1678 * there was not a race with vnode reclaimation, then the 1679 * vnode's v_writecount is decremented. 1680 */ 1681 vnode_pager_update_writecount(object, end, start); 1682 VOP_UNLOCK(vp); 1683 vdrop(vp); 1684 if (mp != NULL) 1685 vn_finished_write(mp); 1686 } 1687 1688 static void 1689 vnode_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) 1690 { 1691 *vpp = object->handle; 1692 } 1693 1694 static void 1695 vnode_pager_clean1(struct vnode *vp, int sync_flags) 1696 { 1697 struct vm_object *obj; 1698 1699 ASSERT_VOP_LOCKED(vp, "needs lock for writes"); 1700 obj = vp->v_object; 1701 if (obj == NULL) 1702 return; 1703 1704 VM_OBJECT_WLOCK(obj); 1705 vm_object_page_clean(obj, 0, 0, sync_flags); 1706 VM_OBJECT_WUNLOCK(obj); 1707 } 1708 1709 void 1710 vnode_pager_clean_sync(struct vnode *vp) 1711 { 1712 vnode_pager_clean1(vp, OBJPC_SYNC); 1713 } 1714 1715 void 1716 vnode_pager_clean_async(struct vnode *vp) 1717 { 1718 vnode_pager_clean1(vp, 0); 1719 } 1720