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