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sys/vm/vnode_pager.c
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1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1990 University of Utah. 5 * Copyright (c) 1991 The Regents of the University of California. 6 * All rights reserved. 7 * Copyright (c) 1993, 1994 John S. Dyson 8 * Copyright (c) 1995, David Greenman 9 * 10 * This code is derived from software contributed to Berkeley by 11 * the Systems Programming Group of the University of Utah Computer 12 * Science Department. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91 43 */ 44 45 /* 46 * Page to/from files (vnodes). 47 */ 48 49 /* 50 * TODO: 51 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will 52 * greatly re-simplify the vnode_pager. 53 */ 54 55 #include <sys/cdefs.h> 56 __FBSDID("$FreeBSD$"); 57 58 #include "opt_vm.h" 59 60 #include <sys/param.h> 61 #include <sys/kernel.h> 62 #include <sys/systm.h> 63 #include <sys/sysctl.h> 64 #include <sys/proc.h> 65 #include <sys/vnode.h> 66 #include <sys/mount.h> 67 #include <sys/bio.h> 68 #include <sys/buf.h> 69 #include <sys/vmmeter.h> 70 #include <sys/ktr.h> 71 #include <sys/limits.h> 72 #include <sys/conf.h> 73 #include <sys/refcount.h> 74 #include <sys/rwlock.h> 75 #include <sys/sf_buf.h> 76 #include <sys/domainset.h> 77 #include <sys/user.h> 78 79 #include <machine/atomic.h> 80 81 #include <vm/vm.h> 82 #include <vm/vm_param.h> 83 #include <vm/vm_object.h> 84 #include <vm/vm_page.h> 85 #include <vm/vm_pager.h> 86 #include <vm/vm_map.h> 87 #include <vm/vnode_pager.h> 88 #include <vm/vm_extern.h> 89 #include <vm/uma.h> 90 91 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, 92 daddr_t *rtaddress, int *run); 93 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); 94 static int vnode_pager_input_old(vm_object_t object, vm_page_t m); 95 static void vnode_pager_dealloc(vm_object_t); 96 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 97 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, 98 int *, vop_getpages_iodone_t, void *); 99 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 100 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 101 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 102 vm_ooffset_t, struct ucred *cred); 103 static int vnode_pager_generic_getpages_done(struct buf *); 104 static void vnode_pager_generic_getpages_done_async(struct buf *); 105 static void vnode_pager_update_writecount(vm_object_t, vm_offset_t, 106 vm_offset_t); 107 static void vnode_pager_release_writecount(vm_object_t, vm_offset_t, 108 vm_offset_t); 109 static void vnode_pager_getvp(vm_object_t, struct vnode **, bool *); 110 111 const struct pagerops vnodepagerops = { 112 .pgo_kvme_type = KVME_TYPE_VNODE, 113 .pgo_alloc = vnode_pager_alloc, 114 .pgo_dealloc = vnode_pager_dealloc, 115 .pgo_getpages = vnode_pager_getpages, 116 .pgo_getpages_async = vnode_pager_getpages_async, 117 .pgo_putpages = vnode_pager_putpages, 118 .pgo_haspage = vnode_pager_haspage, 119 .pgo_update_writecount = vnode_pager_update_writecount, 120 .pgo_release_writecount = vnode_pager_release_writecount, 121 .pgo_set_writeable_dirty = vm_object_set_writeable_dirty_, 122 .pgo_mightbedirty = vm_object_mightbedirty_, 123 .pgo_getvp = vnode_pager_getvp, 124 }; 125 126 static struct domainset *vnode_domainset = NULL; 127 128 SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset, 129 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_RW, &vnode_domainset, 0, 130 sysctl_handle_domainset, "A", "Default vnode NUMA policy"); 131 132 static int nvnpbufs; 133 SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 134 &nvnpbufs, 0, "number of physical buffers allocated for vnode pager"); 135 136 static uma_zone_t vnode_pbuf_zone; 137 138 static void 139 vnode_pager_init(void *dummy) 140 { 141 142 #ifdef __LP64__ 143 nvnpbufs = nswbuf * 2; 144 #else 145 nvnpbufs = nswbuf / 2; 146 #endif 147 TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs); 148 vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs); 149 } 150 SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL); 151 152 /* Create the VM system backing object for this vnode */ 153 int 154 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) 155 { 156 vm_object_t object; 157 vm_ooffset_t size = isize; 158 bool last; 159 160 if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE) 161 return (0); 162 163 object = vp->v_object; 164 if (object != NULL) 165 return (0); 166 167 if (size == 0) { 168 if (vn_isdisk(vp)) { 169 size = IDX_TO_OFF(INT_MAX); 170 } else { 171 if (vn_getsize_locked(vp, &size, td->td_ucred) != 0) 172 return (0); 173 } 174 } 175 176 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); 177 /* 178 * Dereference the reference we just created. This assumes 179 * that the object is associated with the vp. We still have 180 * to serialize with vnode_pager_dealloc() for the last 181 * potential reference. 182 */ 183 VM_OBJECT_RLOCK(object); 184 last = refcount_release(&object->ref_count); 185 VM_OBJECT_RUNLOCK(object); 186 if (last) 187 vrele(vp); 188 189 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); 190 191 return (0); 192 } 193 194 void 195 vnode_destroy_vobject(struct vnode *vp) 196 { 197 struct vm_object *obj; 198 199 obj = vp->v_object; 200 if (obj == NULL || obj->handle != vp) 201 return; 202 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); 203 VM_OBJECT_WLOCK(obj); 204 MPASS(obj->type == OBJT_VNODE); 205 umtx_shm_object_terminated(obj); 206 if (obj->ref_count == 0) { 207 KASSERT((obj->flags & OBJ_DEAD) == 0, 208 ("vnode_destroy_vobject: Terminating dead object")); 209 vm_object_set_flag(obj, OBJ_DEAD); 210 211 /* 212 * Clean pages and flush buffers. 213 */ 214 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC); 215 VM_OBJECT_WUNLOCK(obj); 216 217 vinvalbuf(vp, V_SAVE, 0, 0); 218 219 BO_LOCK(&vp->v_bufobj); 220 vp->v_bufobj.bo_flag |= BO_DEAD; 221 BO_UNLOCK(&vp->v_bufobj); 222 223 VM_OBJECT_WLOCK(obj); 224 vm_object_terminate(obj); 225 } else { 226 /* 227 * Woe to the process that tries to page now :-). 228 */ 229 vm_pager_deallocate(obj); 230 VM_OBJECT_WUNLOCK(obj); 231 } 232 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object)); 233 } 234 235 /* 236 * Allocate (or lookup) pager for a vnode. 237 * Handle is a vnode pointer. 238 */ 239 vm_object_t 240 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 241 vm_ooffset_t offset, struct ucred *cred) 242 { 243 vm_object_t object; 244 struct vnode *vp; 245 246 /* 247 * Pageout to vnode, no can do yet. 248 */ 249 if (handle == NULL) 250 return (NULL); 251 252 vp = (struct vnode *)handle; 253 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc"); 254 VNPASS(vp->v_usecount > 0, vp); 255 retry: 256 object = vp->v_object; 257 258 if (object == NULL) { 259 /* 260 * Add an object of the appropriate size 261 */ 262 object = vm_object_allocate(OBJT_VNODE, 263 OFF_TO_IDX(round_page(size))); 264 265 object->un_pager.vnp.vnp_size = size; 266 object->un_pager.vnp.writemappings = 0; 267 object->domain.dr_policy = vnode_domainset; 268 object->handle = handle; 269 if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) { 270 VM_OBJECT_WLOCK(object); 271 vm_object_set_flag(object, OBJ_SIZEVNLOCK); 272 VM_OBJECT_WUNLOCK(object); 273 } 274 VI_LOCK(vp); 275 if (vp->v_object != NULL) { 276 /* 277 * Object has been created while we were allocating. 278 */ 279 VI_UNLOCK(vp); 280 VM_OBJECT_WLOCK(object); 281 KASSERT(object->ref_count == 1, 282 ("leaked ref %p %d", object, object->ref_count)); 283 object->type = OBJT_DEAD; 284 refcount_init(&object->ref_count, 0); 285 VM_OBJECT_WUNLOCK(object); 286 vm_object_destroy(object); 287 goto retry; 288 } 289 vp->v_object = object; 290 VI_UNLOCK(vp); 291 vrefact(vp); 292 } else { 293 vm_object_reference(object); 294 #if VM_NRESERVLEVEL > 0 295 if ((object->flags & OBJ_COLORED) == 0) { 296 VM_OBJECT_WLOCK(object); 297 vm_object_color(object, 0); 298 VM_OBJECT_WUNLOCK(object); 299 } 300 #endif 301 } 302 return (object); 303 } 304 305 /* 306 * The object must be locked. 307 */ 308 static void 309 vnode_pager_dealloc(vm_object_t object) 310 { 311 struct vnode *vp; 312 int refs; 313 314 vp = object->handle; 315 if (vp == NULL) 316 panic("vnode_pager_dealloc: pager already dealloced"); 317 318 VM_OBJECT_ASSERT_WLOCKED(object); 319 vm_object_pip_wait(object, "vnpdea"); 320 refs = object->ref_count; 321 322 object->handle = NULL; 323 object->type = OBJT_DEAD; 324 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); 325 if (object->un_pager.vnp.writemappings > 0) { 326 object->un_pager.vnp.writemappings = 0; 327 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 328 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 329 __func__, vp, vp->v_writecount); 330 } 331 vp->v_object = NULL; 332 VI_LOCK(vp); 333 334 /* 335 * vm_map_entry_set_vnode_text() cannot reach this vnode by 336 * following object->handle. Clear all text references now. 337 * This also clears the transient references from 338 * kern_execve(), which is fine because dead_vnodeops uses nop 339 * for VOP_UNSET_TEXT(). 340 */ 341 if (vp->v_writecount < 0) 342 vp->v_writecount = 0; 343 VI_UNLOCK(vp); 344 VM_OBJECT_WUNLOCK(object); 345 if (refs > 0) 346 vunref(vp); 347 VM_OBJECT_WLOCK(object); 348 } 349 350 static boolean_t 351 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 352 int *after) 353 { 354 struct vnode *vp = object->handle; 355 daddr_t bn; 356 uintptr_t lockstate; 357 int err; 358 daddr_t reqblock; 359 int poff; 360 int bsize; 361 int pagesperblock, blocksperpage; 362 363 VM_OBJECT_ASSERT_LOCKED(object); 364 /* 365 * If no vp or vp is doomed or marked transparent to VM, we do not 366 * have the page. 367 */ 368 if (vp == NULL || VN_IS_DOOMED(vp)) 369 return FALSE; 370 /* 371 * If the offset is beyond end of file we do 372 * not have the page. 373 */ 374 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) 375 return FALSE; 376 377 bsize = vp->v_mount->mnt_stat.f_iosize; 378 pagesperblock = bsize / PAGE_SIZE; 379 blocksperpage = 0; 380 if (pagesperblock > 0) { 381 reqblock = pindex / pagesperblock; 382 } else { 383 blocksperpage = (PAGE_SIZE / bsize); 384 reqblock = pindex * blocksperpage; 385 } 386 lockstate = VM_OBJECT_DROP(object); 387 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); 388 VM_OBJECT_PICKUP(object, lockstate); 389 if (err) 390 return TRUE; 391 if (bn == -1) 392 return FALSE; 393 if (pagesperblock > 0) { 394 poff = pindex - (reqblock * pagesperblock); 395 if (before) { 396 *before *= pagesperblock; 397 *before += poff; 398 } 399 if (after) { 400 /* 401 * The BMAP vop can report a partial block in the 402 * 'after', but must not report blocks after EOF. 403 * Assert the latter, and truncate 'after' in case 404 * of the former. 405 */ 406 KASSERT((reqblock + *after) * pagesperblock < 407 roundup2(object->size, pagesperblock), 408 ("%s: reqblock %jd after %d size %ju", __func__, 409 (intmax_t )reqblock, *after, 410 (uintmax_t )object->size)); 411 *after *= pagesperblock; 412 *after += pagesperblock - (poff + 1); 413 if (pindex + *after >= object->size) 414 *after = object->size - 1 - pindex; 415 } 416 } else { 417 if (before) { 418 *before /= blocksperpage; 419 } 420 421 if (after) { 422 *after /= blocksperpage; 423 } 424 } 425 return TRUE; 426 } 427 428 /* 429 * Internal routine clearing partial-page content 430 */ 431 static void 432 vnode_pager_subpage_purge(struct vm_page *m, int base, int end) 433 { 434 int size; 435 436 KASSERT(end > base && end <= PAGE_SIZE, 437 ("%s: start %d end %d", __func__, base, end)); 438 size = end - base; 439 440 /* 441 * Clear out partial-page garbage in case 442 * the page has been mapped. 443 */ 444 pmap_zero_page_area(m, base, size); 445 446 /* 447 * Update the valid bits to reflect the blocks 448 * that have been zeroed. Some of these valid 449 * bits may have already been set. 450 */ 451 vm_page_set_valid_range(m, base, size); 452 453 /* 454 * Round up "base" to the next block boundary so 455 * that the dirty bit for a partially zeroed 456 * block is not cleared. 457 */ 458 base = roundup2(base, DEV_BSIZE); 459 end = rounddown2(end, DEV_BSIZE); 460 461 if (end > base) { 462 /* 463 * Clear out partial-page dirty bits. 464 * 465 * note that we do not clear out the 466 * valid bits. This would prevent 467 * bogus_page replacement from working 468 * properly. 469 */ 470 vm_page_clear_dirty(m, base, end - base); 471 } 472 473 } 474 475 /* 476 * Lets the VM system know about a change in size for a file. 477 * We adjust our own internal size and flush any cached pages in 478 * the associated object that are affected by the size change. 479 * 480 * Note: this routine may be invoked as a result of a pager put 481 * operation (possibly at object termination time), so we must be careful. 482 */ 483 void 484 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize) 485 { 486 vm_object_t object; 487 vm_page_t m; 488 vm_pindex_t nobjsize; 489 490 if ((object = vp->v_object) == NULL) 491 return; 492 #ifdef DEBUG_VFS_LOCKS 493 { 494 struct mount *mp; 495 496 mp = vp->v_mount; 497 if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0) 498 assert_vop_elocked(vp, 499 "vnode_pager_setsize and not locked vnode"); 500 } 501 #endif 502 VM_OBJECT_WLOCK(object); 503 if (object->type == OBJT_DEAD) { 504 VM_OBJECT_WUNLOCK(object); 505 return; 506 } 507 KASSERT(object->type == OBJT_VNODE, 508 ("not vnode-backed object %p", object)); 509 if (nsize == object->un_pager.vnp.vnp_size) { 510 /* 511 * Hasn't changed size 512 */ 513 VM_OBJECT_WUNLOCK(object); 514 return; 515 } 516 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); 517 if (nsize < object->un_pager.vnp.vnp_size) { 518 /* 519 * File has shrunk. Toss any cached pages beyond the new EOF. 520 */ 521 if (nobjsize < object->size) 522 vm_object_page_remove(object, nobjsize, object->size, 523 0); 524 /* 525 * this gets rid of garbage at the end of a page that is now 526 * only partially backed by the vnode. 527 * 528 * XXX for some reason (I don't know yet), if we take a 529 * completely invalid page and mark it partially valid 530 * it can screw up NFS reads, so we don't allow the case. 531 */ 532 if (!(nsize & PAGE_MASK)) 533 goto out; 534 m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT); 535 if (m == NULL) 536 goto out; 537 if (!vm_page_none_valid(m)) 538 vnode_pager_subpage_purge(m, (int)nsize & PAGE_MASK, 539 PAGE_SIZE); 540 vm_page_xunbusy(m); 541 } 542 out: 543 #if defined(__powerpc__) && !defined(__powerpc64__) 544 object->un_pager.vnp.vnp_size = nsize; 545 #else 546 atomic_store_64(&object->un_pager.vnp.vnp_size, nsize); 547 #endif 548 object->size = nobjsize; 549 VM_OBJECT_WUNLOCK(object); 550 } 551 552 /* 553 * Lets the VM system know about the purged range for a file. We toss away any 554 * cached pages in the associated object that are affected by the purge 555 * operation. Partial-page area not aligned to page boundaries will be zeroed 556 * and the dirty blocks in DEV_BSIZE unit within a page will not be flushed. 557 */ 558 void 559 vnode_pager_purge_range(struct vnode *vp, vm_ooffset_t start, vm_ooffset_t end) 560 { 561 struct vm_page *m; 562 struct vm_object *object; 563 vm_pindex_t pi, pistart, piend; 564 bool same_page; 565 int base, pend; 566 567 ASSERT_VOP_LOCKED(vp, "vnode_pager_purge_range"); 568 569 object = vp->v_object; 570 pi = start + PAGE_MASK < start ? OBJ_MAX_SIZE : 571 OFF_TO_IDX(start + PAGE_MASK); 572 pistart = OFF_TO_IDX(start); 573 piend = end == 0 ? OBJ_MAX_SIZE : OFF_TO_IDX(end); 574 same_page = pistart == piend; 575 if ((end != 0 && end <= start) || object == NULL) 576 return; 577 578 VM_OBJECT_WLOCK(object); 579 580 if (pi < piend) 581 vm_object_page_remove(object, pi, piend, 0); 582 583 if ((start & PAGE_MASK) != 0) { 584 base = (int)start & PAGE_MASK; 585 pend = same_page ? (int)end & PAGE_MASK : PAGE_SIZE; 586 m = vm_page_grab(object, pistart, VM_ALLOC_NOCREAT); 587 if (m != NULL) { 588 if (!vm_page_none_valid(m)) 589 vnode_pager_subpage_purge(m, base, pend); 590 vm_page_xunbusy(m); 591 } 592 if (same_page) 593 goto out; 594 } 595 if ((end & PAGE_MASK) != 0) { 596 base = same_page ? (int)start & PAGE_MASK : 0 ; 597 pend = (int)end & PAGE_MASK; 598 m = vm_page_grab(object, piend, VM_ALLOC_NOCREAT); 599 if (m != NULL) { 600 if (!vm_page_none_valid(m)) 601 vnode_pager_subpage_purge(m, base, pend); 602 vm_page_xunbusy(m); 603 } 604 } 605 out: 606 VM_OBJECT_WUNLOCK(object); 607 } 608 609 /* 610 * calculate the linear (byte) disk address of specified virtual 611 * file address 612 */ 613 static int 614 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, 615 int *run) 616 { 617 int bsize; 618 int err; 619 daddr_t vblock; 620 daddr_t voffset; 621 622 if (VN_IS_DOOMED(vp)) 623 return -1; 624 625 bsize = vp->v_mount->mnt_stat.f_iosize; 626 vblock = address / bsize; 627 voffset = address % bsize; 628 629 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); 630 if (err == 0) { 631 if (*rtaddress != -1) 632 *rtaddress += voffset / DEV_BSIZE; 633 if (run) { 634 *run += 1; 635 *run *= bsize / PAGE_SIZE; 636 *run -= voffset / PAGE_SIZE; 637 } 638 } 639 640 return (err); 641 } 642 643 /* 644 * small block filesystem vnode pager input 645 */ 646 static int 647 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m) 648 { 649 struct vnode *vp; 650 struct bufobj *bo; 651 struct buf *bp; 652 struct sf_buf *sf; 653 daddr_t fileaddr; 654 vm_offset_t bsize; 655 vm_page_bits_t bits; 656 int error, i; 657 658 error = 0; 659 vp = object->handle; 660 if (VN_IS_DOOMED(vp)) 661 return VM_PAGER_BAD; 662 663 bsize = vp->v_mount->mnt_stat.f_iosize; 664 665 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); 666 667 sf = sf_buf_alloc(m, 0); 668 669 for (i = 0; i < PAGE_SIZE / bsize; i++) { 670 vm_ooffset_t address; 671 672 bits = vm_page_bits(i * bsize, bsize); 673 if (m->valid & bits) 674 continue; 675 676 address = IDX_TO_OFF(m->pindex) + i * bsize; 677 if (address >= object->un_pager.vnp.vnp_size) { 678 fileaddr = -1; 679 } else { 680 error = vnode_pager_addr(vp, address, &fileaddr, NULL); 681 if (error) 682 break; 683 } 684 if (fileaddr != -1) { 685 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 686 687 /* build a minimal buffer header */ 688 bp->b_iocmd = BIO_READ; 689 bp->b_iodone = bdone; 690 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 691 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 692 bp->b_rcred = crhold(curthread->td_ucred); 693 bp->b_wcred = crhold(curthread->td_ucred); 694 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; 695 bp->b_blkno = fileaddr; 696 pbgetbo(bo, bp); 697 bp->b_vp = vp; 698 bp->b_bcount = bsize; 699 bp->b_bufsize = bsize; 700 bp->b_runningbufspace = bp->b_bufsize; 701 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 702 703 /* do the input */ 704 bp->b_iooffset = dbtob(bp->b_blkno); 705 bstrategy(bp); 706 707 bwait(bp, PVM, "vnsrd"); 708 709 if ((bp->b_ioflags & BIO_ERROR) != 0) { 710 KASSERT(bp->b_error != 0, 711 ("%s: buf error but b_error == 0\n", __func__)); 712 error = bp->b_error; 713 } 714 715 /* 716 * free the buffer header back to the swap buffer pool 717 */ 718 bp->b_vp = NULL; 719 pbrelbo(bp); 720 uma_zfree(vnode_pbuf_zone, bp); 721 if (error) 722 break; 723 } else 724 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); 725 KASSERT((m->dirty & bits) == 0, 726 ("vnode_pager_input_smlfs: page %p is dirty", m)); 727 vm_page_bits_set(m, &m->valid, bits); 728 } 729 sf_buf_free(sf); 730 if (error) { 731 return VM_PAGER_ERROR; 732 } 733 return VM_PAGER_OK; 734 } 735 736 /* 737 * old style vnode pager input routine 738 */ 739 static int 740 vnode_pager_input_old(vm_object_t object, vm_page_t m) 741 { 742 struct uio auio; 743 struct iovec aiov; 744 int error; 745 int size; 746 struct sf_buf *sf; 747 struct vnode *vp; 748 749 VM_OBJECT_ASSERT_WLOCKED(object); 750 error = 0; 751 752 /* 753 * Return failure if beyond current EOF 754 */ 755 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { 756 return VM_PAGER_BAD; 757 } else { 758 size = PAGE_SIZE; 759 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) 760 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); 761 vp = object->handle; 762 VM_OBJECT_WUNLOCK(object); 763 764 /* 765 * Allocate a kernel virtual address and initialize so that 766 * we can use VOP_READ/WRITE routines. 767 */ 768 sf = sf_buf_alloc(m, 0); 769 770 aiov.iov_base = (caddr_t)sf_buf_kva(sf); 771 aiov.iov_len = size; 772 auio.uio_iov = &aiov; 773 auio.uio_iovcnt = 1; 774 auio.uio_offset = IDX_TO_OFF(m->pindex); 775 auio.uio_segflg = UIO_SYSSPACE; 776 auio.uio_rw = UIO_READ; 777 auio.uio_resid = size; 778 auio.uio_td = curthread; 779 780 error = VOP_READ(vp, &auio, 0, curthread->td_ucred); 781 if (!error) { 782 int count = size - auio.uio_resid; 783 784 if (count == 0) 785 error = EINVAL; 786 else if (count != PAGE_SIZE) 787 bzero((caddr_t)sf_buf_kva(sf) + count, 788 PAGE_SIZE - count); 789 } 790 sf_buf_free(sf); 791 792 VM_OBJECT_WLOCK(object); 793 } 794 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); 795 if (!error) 796 vm_page_valid(m); 797 return error ? VM_PAGER_ERROR : VM_PAGER_OK; 798 } 799 800 /* 801 * generic vnode pager input routine 802 */ 803 804 /* 805 * Local media VFS's that do not implement their own VOP_GETPAGES 806 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() 807 * to implement the previous behaviour. 808 * 809 * All other FS's should use the bypass to get to the local media 810 * backing vp's VOP_GETPAGES. 811 */ 812 static int 813 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind, 814 int *rahead) 815 { 816 struct vnode *vp; 817 int rtval; 818 819 /* Handle is stable with paging in progress. */ 820 vp = object->handle; 821 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead); 822 KASSERT(rtval != EOPNOTSUPP, 823 ("vnode_pager: FS getpages not implemented\n")); 824 return rtval; 825 } 826 827 static int 828 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count, 829 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg) 830 { 831 struct vnode *vp; 832 int rtval; 833 834 vp = object->handle; 835 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg); 836 KASSERT(rtval != EOPNOTSUPP, 837 ("vnode_pager: FS getpages_async not implemented\n")); 838 return (rtval); 839 } 840 841 /* 842 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for 843 * local filesystems, where partially valid pages can only occur at 844 * the end of file. 845 */ 846 int 847 vnode_pager_local_getpages(struct vop_getpages_args *ap) 848 { 849 850 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 851 ap->a_rbehind, ap->a_rahead, NULL, NULL)); 852 } 853 854 int 855 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap) 856 { 857 int error; 858 859 error = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, 860 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg); 861 if (error != 0 && ap->a_iodone != NULL) 862 ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error); 863 return (error); 864 } 865 866 /* 867 * This is now called from local media FS's to operate against their 868 * own vnodes if they fail to implement VOP_GETPAGES. 869 */ 870 int 871 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count, 872 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg) 873 { 874 vm_object_t object; 875 struct bufobj *bo; 876 struct buf *bp; 877 off_t foff; 878 #ifdef INVARIANTS 879 off_t blkno0; 880 #endif 881 int bsize, pagesperblock; 882 int error, before, after, rbehind, rahead, poff, i; 883 int bytecount, secmask; 884 885 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, 886 ("%s does not support devices", __func__)); 887 888 if (VN_IS_DOOMED(vp)) 889 return (VM_PAGER_BAD); 890 891 object = vp->v_object; 892 foff = IDX_TO_OFF(m[0]->pindex); 893 bsize = vp->v_mount->mnt_stat.f_iosize; 894 pagesperblock = bsize / PAGE_SIZE; 895 896 KASSERT(foff < object->un_pager.vnp.vnp_size, 897 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp)); 898 KASSERT(count <= atop(maxphys), 899 ("%s: requested %d pages", __func__, count)); 900 901 /* 902 * The last page has valid blocks. Invalid part can only 903 * exist at the end of file, and the page is made fully valid 904 * by zeroing in vm_pager_get_pages(). 905 */ 906 if (!vm_page_none_valid(m[count - 1]) && --count == 0) { 907 if (iodone != NULL) 908 iodone(arg, m, 1, 0); 909 return (VM_PAGER_OK); 910 } 911 912 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK); 913 MPASS((bp->b_flags & B_MAXPHYS) != 0); 914 915 /* 916 * Get the underlying device blocks for the file with VOP_BMAP(). 917 * If the file system doesn't support VOP_BMAP, use old way of 918 * getting pages via VOP_READ. 919 */ 920 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before); 921 if (error == EOPNOTSUPP) { 922 uma_zfree(vnode_pbuf_zone, bp); 923 VM_OBJECT_WLOCK(object); 924 for (i = 0; i < count; i++) { 925 VM_CNT_INC(v_vnodein); 926 VM_CNT_INC(v_vnodepgsin); 927 error = vnode_pager_input_old(object, m[i]); 928 if (error) 929 break; 930 } 931 VM_OBJECT_WUNLOCK(object); 932 return (error); 933 } else if (error != 0) { 934 uma_zfree(vnode_pbuf_zone, bp); 935 return (VM_PAGER_ERROR); 936 } 937 938 /* 939 * If the file system supports BMAP, but blocksize is smaller 940 * than a page size, then use special small filesystem code. 941 */ 942 if (pagesperblock == 0) { 943 uma_zfree(vnode_pbuf_zone, bp); 944 for (i = 0; i < count; i++) { 945 VM_CNT_INC(v_vnodein); 946 VM_CNT_INC(v_vnodepgsin); 947 error = vnode_pager_input_smlfs(object, m[i]); 948 if (error) 949 break; 950 } 951 return (error); 952 } 953 954 /* 955 * A sparse file can be encountered only for a single page request, 956 * which may not be preceded by call to vm_pager_haspage(). 957 */ 958 if (bp->b_blkno == -1) { 959 KASSERT(count == 1, 960 ("%s: array[%d] request to a sparse file %p", __func__, 961 count, vp)); 962 uma_zfree(vnode_pbuf_zone, bp); 963 pmap_zero_page(m[0]); 964 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty", 965 __func__, m[0])); 966 vm_page_valid(m[0]); 967 return (VM_PAGER_OK); 968 } 969 970 #ifdef INVARIANTS 971 blkno0 = bp->b_blkno; 972 #endif 973 bp->b_blkno += (foff % bsize) / DEV_BSIZE; 974 975 /* Recalculate blocks available after/before to pages. */ 976 poff = (foff % bsize) / PAGE_SIZE; 977 before *= pagesperblock; 978 before += poff; 979 after *= pagesperblock; 980 after += pagesperblock - (poff + 1); 981 if (m[0]->pindex + after >= object->size) 982 after = object->size - 1 - m[0]->pindex; 983 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d", 984 __func__, count, after + 1)); 985 after -= count - 1; 986 987 /* Trim requested rbehind/rahead to possible values. */ 988 rbehind = a_rbehind ? *a_rbehind : 0; 989 rahead = a_rahead ? *a_rahead : 0; 990 rbehind = min(rbehind, before); 991 rbehind = min(rbehind, m[0]->pindex); 992 rahead = min(rahead, after); 993 rahead = min(rahead, object->size - m[count - 1]->pindex); 994 /* 995 * Check that total amount of pages fit into buf. Trim rbehind and 996 * rahead evenly if not. 997 */ 998 if (rbehind + rahead + count > atop(maxphys)) { 999 int trim, sum; 1000 1001 trim = rbehind + rahead + count - atop(maxphys) + 1; 1002 sum = rbehind + rahead; 1003 if (rbehind == before) { 1004 /* Roundup rbehind trim to block size. */ 1005 rbehind -= roundup(trim * rbehind / sum, pagesperblock); 1006 if (rbehind < 0) 1007 rbehind = 0; 1008 } else 1009 rbehind -= trim * rbehind / sum; 1010 rahead -= trim * rahead / sum; 1011 } 1012 KASSERT(rbehind + rahead + count <= atop(maxphys), 1013 ("%s: behind %d ahead %d count %d maxphys %lu", __func__, 1014 rbehind, rahead, count, maxphys)); 1015 1016 /* 1017 * Fill in the bp->b_pages[] array with requested and optional 1018 * read behind or read ahead pages. Read behind pages are looked 1019 * up in a backward direction, down to a first cached page. Same 1020 * for read ahead pages, but there is no need to shift the array 1021 * in case of encountering a cached page. 1022 */ 1023 i = bp->b_npages = 0; 1024 if (rbehind) { 1025 vm_pindex_t startpindex, tpindex; 1026 vm_page_t p; 1027 1028 VM_OBJECT_WLOCK(object); 1029 startpindex = m[0]->pindex - rbehind; 1030 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL && 1031 p->pindex >= startpindex) 1032 startpindex = p->pindex + 1; 1033 1034 /* tpindex is unsigned; beware of numeric underflow. */ 1035 for (tpindex = m[0]->pindex - 1; 1036 tpindex >= startpindex && tpindex < m[0]->pindex; 1037 tpindex--, i++) { 1038 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1039 if (p == NULL) { 1040 /* Shift the array. */ 1041 for (int j = 0; j < i; j++) 1042 bp->b_pages[j] = bp->b_pages[j + 1043 tpindex + 1 - startpindex]; 1044 break; 1045 } 1046 bp->b_pages[tpindex - startpindex] = p; 1047 } 1048 1049 bp->b_pgbefore = i; 1050 bp->b_npages += i; 1051 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE; 1052 } else 1053 bp->b_pgbefore = 0; 1054 1055 /* Requested pages. */ 1056 for (int j = 0; j < count; j++, i++) 1057 bp->b_pages[i] = m[j]; 1058 bp->b_npages += count; 1059 1060 if (rahead) { 1061 vm_pindex_t endpindex, tpindex; 1062 vm_page_t p; 1063 1064 if (!VM_OBJECT_WOWNED(object)) 1065 VM_OBJECT_WLOCK(object); 1066 endpindex = m[count - 1]->pindex + rahead + 1; 1067 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL && 1068 p->pindex < endpindex) 1069 endpindex = p->pindex; 1070 if (endpindex > object->size) 1071 endpindex = object->size; 1072 1073 for (tpindex = m[count - 1]->pindex + 1; 1074 tpindex < endpindex; i++, tpindex++) { 1075 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL); 1076 if (p == NULL) 1077 break; 1078 bp->b_pages[i] = p; 1079 } 1080 1081 bp->b_pgafter = i - bp->b_npages; 1082 bp->b_npages = i; 1083 } else 1084 bp->b_pgafter = 0; 1085 1086 if (VM_OBJECT_WOWNED(object)) 1087 VM_OBJECT_WUNLOCK(object); 1088 1089 /* Report back actual behind/ahead read. */ 1090 if (a_rbehind) 1091 *a_rbehind = bp->b_pgbefore; 1092 if (a_rahead) 1093 *a_rahead = bp->b_pgafter; 1094 1095 #ifdef INVARIANTS 1096 KASSERT(bp->b_npages <= atop(maxphys), 1097 ("%s: buf %p overflowed", __func__, bp)); 1098 for (int j = 1, prev = 0; j < bp->b_npages; j++) { 1099 if (bp->b_pages[j] == bogus_page) 1100 continue; 1101 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex == 1102 j - prev, ("%s: pages array not consecutive, bp %p", 1103 __func__, bp)); 1104 prev = j; 1105 } 1106 #endif 1107 1108 /* 1109 * Recalculate first offset and bytecount with regards to read behind. 1110 * Truncate bytecount to vnode real size and round up physical size 1111 * for real devices. 1112 */ 1113 foff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1114 bytecount = bp->b_npages << PAGE_SHIFT; 1115 if ((foff + bytecount) > object->un_pager.vnp.vnp_size) 1116 bytecount = object->un_pager.vnp.vnp_size - foff; 1117 secmask = bo->bo_bsize - 1; 1118 KASSERT(secmask < PAGE_SIZE && secmask > 0, 1119 ("%s: sector size %d too large", __func__, secmask + 1)); 1120 bytecount = (bytecount + secmask) & ~secmask; 1121 1122 /* 1123 * And map the pages to be read into the kva, if the filesystem 1124 * requires mapped buffers. 1125 */ 1126 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 && 1127 unmapped_buf_allowed) { 1128 bp->b_data = unmapped_buf; 1129 bp->b_offset = 0; 1130 } else { 1131 bp->b_data = bp->b_kvabase; 1132 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages); 1133 } 1134 1135 /* Build a minimal buffer header. */ 1136 bp->b_iocmd = BIO_READ; 1137 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); 1138 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); 1139 bp->b_rcred = crhold(curthread->td_ucred); 1140 bp->b_wcred = crhold(curthread->td_ucred); 1141 pbgetbo(bo, bp); 1142 bp->b_vp = vp; 1143 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount; 1144 bp->b_iooffset = dbtob(bp->b_blkno); 1145 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) == 1146 (blkno0 - bp->b_blkno) * DEV_BSIZE + 1147 IDX_TO_OFF(m[0]->pindex) % bsize, 1148 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju " 1149 "blkno0 %ju b_blkno %ju", bsize, 1150 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex, 1151 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno)); 1152 1153 atomic_add_long(&runningbufspace, bp->b_runningbufspace); 1154 VM_CNT_INC(v_vnodein); 1155 VM_CNT_ADD(v_vnodepgsin, bp->b_npages); 1156 1157 if (iodone != NULL) { /* async */ 1158 bp->b_pgiodone = iodone; 1159 bp->b_caller1 = arg; 1160 bp->b_iodone = vnode_pager_generic_getpages_done_async; 1161 bp->b_flags |= B_ASYNC; 1162 BUF_KERNPROC(bp); 1163 bstrategy(bp); 1164 return (VM_PAGER_OK); 1165 } else { 1166 bp->b_iodone = bdone; 1167 bstrategy(bp); 1168 bwait(bp, PVM, "vnread"); 1169 error = vnode_pager_generic_getpages_done(bp); 1170 for (i = 0; i < bp->b_npages; i++) 1171 bp->b_pages[i] = NULL; 1172 bp->b_vp = NULL; 1173 pbrelbo(bp); 1174 uma_zfree(vnode_pbuf_zone, bp); 1175 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK); 1176 } 1177 } 1178 1179 static void 1180 vnode_pager_generic_getpages_done_async(struct buf *bp) 1181 { 1182 int error; 1183 1184 error = vnode_pager_generic_getpages_done(bp); 1185 /* Run the iodone upon the requested range. */ 1186 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore, 1187 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error); 1188 for (int i = 0; i < bp->b_npages; i++) 1189 bp->b_pages[i] = NULL; 1190 bp->b_vp = NULL; 1191 pbrelbo(bp); 1192 uma_zfree(vnode_pbuf_zone, bp); 1193 } 1194 1195 static int 1196 vnode_pager_generic_getpages_done(struct buf *bp) 1197 { 1198 vm_object_t object; 1199 off_t tfoff, nextoff; 1200 int i, error; 1201 1202 KASSERT((bp->b_ioflags & BIO_ERROR) == 0 || bp->b_error != 0, 1203 ("%s: buf error but b_error == 0\n", __func__)); 1204 error = (bp->b_ioflags & BIO_ERROR) != 0 ? bp->b_error : 0; 1205 object = bp->b_vp->v_object; 1206 1207 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) { 1208 if (!buf_mapped(bp)) { 1209 bp->b_data = bp->b_kvabase; 1210 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, 1211 bp->b_npages); 1212 } 1213 bzero(bp->b_data + bp->b_bcount, 1214 PAGE_SIZE * bp->b_npages - bp->b_bcount); 1215 } 1216 if (buf_mapped(bp)) { 1217 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); 1218 bp->b_data = unmapped_buf; 1219 } 1220 1221 /* 1222 * If the read failed, we must free any read ahead/behind pages here. 1223 * The requested pages are freed by the caller (for sync requests) 1224 * or by the bp->b_pgiodone callback (for async requests). 1225 */ 1226 if (error != 0) { 1227 VM_OBJECT_WLOCK(object); 1228 for (i = 0; i < bp->b_pgbefore; i++) 1229 vm_page_free_invalid(bp->b_pages[i]); 1230 for (i = bp->b_npages - bp->b_pgafter; i < bp->b_npages; i++) 1231 vm_page_free_invalid(bp->b_pages[i]); 1232 VM_OBJECT_WUNLOCK(object); 1233 return (error); 1234 } 1235 1236 /* Read lock to protect size. */ 1237 VM_OBJECT_RLOCK(object); 1238 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex); 1239 i < bp->b_npages; i++, tfoff = nextoff) { 1240 vm_page_t mt; 1241 1242 nextoff = tfoff + PAGE_SIZE; 1243 mt = bp->b_pages[i]; 1244 if (mt == bogus_page) 1245 continue; 1246 1247 if (nextoff <= object->un_pager.vnp.vnp_size) { 1248 /* 1249 * Read filled up entire page. 1250 */ 1251 vm_page_valid(mt); 1252 KASSERT(mt->dirty == 0, 1253 ("%s: page %p is dirty", __func__, mt)); 1254 KASSERT(!pmap_page_is_mapped(mt), 1255 ("%s: page %p is mapped", __func__, mt)); 1256 } else { 1257 /* 1258 * Read did not fill up entire page. 1259 * 1260 * Currently we do not set the entire page valid, 1261 * we just try to clear the piece that we couldn't 1262 * read. 1263 */ 1264 vm_page_set_valid_range(mt, 0, 1265 object->un_pager.vnp.vnp_size - tfoff); 1266 KASSERT((mt->dirty & vm_page_bits(0, 1267 object->un_pager.vnp.vnp_size - tfoff)) == 0, 1268 ("%s: page %p is dirty", __func__, mt)); 1269 } 1270 1271 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) 1272 vm_page_readahead_finish(mt); 1273 } 1274 VM_OBJECT_RUNLOCK(object); 1275 1276 return (error); 1277 } 1278 1279 /* 1280 * EOPNOTSUPP is no longer legal. For local media VFS's that do not 1281 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to 1282 * vnode_pager_generic_putpages() to implement the previous behaviour. 1283 * 1284 * All other FS's should use the bypass to get to the local media 1285 * backing vp's VOP_PUTPAGES. 1286 */ 1287 static void 1288 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count, 1289 int flags, int *rtvals) 1290 { 1291 int rtval __diagused; 1292 struct vnode *vp; 1293 int bytes = count * PAGE_SIZE; 1294 1295 /* 1296 * Force synchronous operation if we are extremely low on memory 1297 * to prevent a low-memory deadlock. VOP operations often need to 1298 * allocate more memory to initiate the I/O ( i.e. do a BMAP 1299 * operation ). The swapper handles the case by limiting the amount 1300 * of asynchronous I/O, but that sort of solution doesn't scale well 1301 * for the vnode pager without a lot of work. 1302 * 1303 * Also, the backing vnode's iodone routine may not wake the pageout 1304 * daemon up. This should be probably be addressed XXX. 1305 */ 1306 1307 if (vm_page_count_min()) 1308 flags |= VM_PAGER_PUT_SYNC; 1309 1310 /* 1311 * Call device-specific putpages function 1312 */ 1313 vp = object->handle; 1314 VM_OBJECT_WUNLOCK(object); 1315 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals); 1316 KASSERT(rtval != EOPNOTSUPP, 1317 ("vnode_pager: stale FS putpages\n")); 1318 VM_OBJECT_WLOCK(object); 1319 } 1320 1321 static int 1322 vn_off2bidx(vm_ooffset_t offset) 1323 { 1324 1325 return ((offset & PAGE_MASK) / DEV_BSIZE); 1326 } 1327 1328 static bool 1329 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset) 1330 { 1331 1332 KASSERT(IDX_TO_OFF(m->pindex) <= offset && 1333 offset < IDX_TO_OFF(m->pindex + 1), 1334 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex, 1335 (uintmax_t)offset)); 1336 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0); 1337 } 1338 1339 /* 1340 * This is now called from local media FS's to operate against their 1341 * own vnodes if they fail to implement VOP_PUTPAGES. 1342 * 1343 * This is typically called indirectly via the pageout daemon and 1344 * clustering has already typically occurred, so in general we ask the 1345 * underlying filesystem to write the data out asynchronously rather 1346 * then delayed. 1347 */ 1348 int 1349 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, 1350 int flags, int *rtvals) 1351 { 1352 vm_object_t object; 1353 vm_page_t m; 1354 vm_ooffset_t maxblksz, next_offset, poffset, prev_offset; 1355 struct uio auio; 1356 struct iovec aiov; 1357 off_t prev_resid, wrsz; 1358 int count, error, i, maxsize, ncount, pgoff, ppscheck; 1359 bool in_hole; 1360 static struct timeval lastfail; 1361 static int curfail; 1362 1363 object = vp->v_object; 1364 count = bytecount / PAGE_SIZE; 1365 1366 for (i = 0; i < count; i++) 1367 rtvals[i] = VM_PAGER_ERROR; 1368 1369 if ((int64_t)ma[0]->pindex < 0) { 1370 printf("vnode_pager_generic_putpages: " 1371 "attempt to write meta-data 0x%jx(%lx)\n", 1372 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty); 1373 rtvals[0] = VM_PAGER_BAD; 1374 return (VM_PAGER_BAD); 1375 } 1376 1377 maxsize = count * PAGE_SIZE; 1378 ncount = count; 1379 1380 poffset = IDX_TO_OFF(ma[0]->pindex); 1381 1382 /* 1383 * If the page-aligned write is larger then the actual file we 1384 * have to invalidate pages occurring beyond the file EOF. However, 1385 * there is an edge case where a file may not be page-aligned where 1386 * the last page is partially invalid. In this case the filesystem 1387 * may not properly clear the dirty bits for the entire page (which 1388 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). 1389 * With the page busied we are free to fix up the dirty bits here. 1390 * 1391 * We do not under any circumstances truncate the valid bits, as 1392 * this will screw up bogus page replacement. 1393 */ 1394 VM_OBJECT_RLOCK(object); 1395 if (maxsize + poffset > object->un_pager.vnp.vnp_size) { 1396 if (object->un_pager.vnp.vnp_size > poffset) { 1397 maxsize = object->un_pager.vnp.vnp_size - poffset; 1398 ncount = btoc(maxsize); 1399 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { 1400 pgoff = roundup2(pgoff, DEV_BSIZE); 1401 1402 /* 1403 * If the page is busy and the following 1404 * conditions hold, then the page's dirty 1405 * field cannot be concurrently changed by a 1406 * pmap operation. 1407 */ 1408 m = ma[ncount - 1]; 1409 vm_page_assert_sbusied(m); 1410 KASSERT(!pmap_page_is_write_mapped(m), 1411 ("vnode_pager_generic_putpages: page %p is not read-only", m)); 1412 MPASS(m->dirty != 0); 1413 vm_page_clear_dirty(m, pgoff, PAGE_SIZE - 1414 pgoff); 1415 } 1416 } else { 1417 maxsize = 0; 1418 ncount = 0; 1419 } 1420 for (i = ncount; i < count; i++) 1421 rtvals[i] = VM_PAGER_BAD; 1422 } 1423 VM_OBJECT_RUNLOCK(object); 1424 1425 auio.uio_iov = &aiov; 1426 auio.uio_segflg = UIO_NOCOPY; 1427 auio.uio_rw = UIO_WRITE; 1428 auio.uio_td = NULL; 1429 maxblksz = roundup2(poffset + maxsize, DEV_BSIZE); 1430 1431 for (prev_offset = poffset; prev_offset < maxblksz;) { 1432 /* Skip clean blocks. */ 1433 for (in_hole = true; in_hole && prev_offset < maxblksz;) { 1434 m = ma[OFF_TO_IDX(prev_offset - poffset)]; 1435 for (i = vn_off2bidx(prev_offset); 1436 i < sizeof(vm_page_bits_t) * NBBY && 1437 prev_offset < maxblksz; i++) { 1438 if (vn_dirty_blk(m, prev_offset)) { 1439 in_hole = false; 1440 break; 1441 } 1442 prev_offset += DEV_BSIZE; 1443 } 1444 } 1445 if (in_hole) 1446 goto write_done; 1447 1448 /* Find longest run of dirty blocks. */ 1449 for (next_offset = prev_offset; next_offset < maxblksz;) { 1450 m = ma[OFF_TO_IDX(next_offset - poffset)]; 1451 for (i = vn_off2bidx(next_offset); 1452 i < sizeof(vm_page_bits_t) * NBBY && 1453 next_offset < maxblksz; i++) { 1454 if (!vn_dirty_blk(m, next_offset)) 1455 goto start_write; 1456 next_offset += DEV_BSIZE; 1457 } 1458 } 1459 start_write: 1460 if (next_offset > poffset + maxsize) 1461 next_offset = poffset + maxsize; 1462 1463 /* 1464 * Getting here requires finding a dirty block in the 1465 * 'skip clean blocks' loop. 1466 */ 1467 MPASS(prev_offset < next_offset); 1468 1469 aiov.iov_base = NULL; 1470 auio.uio_iovcnt = 1; 1471 auio.uio_offset = prev_offset; 1472 prev_resid = auio.uio_resid = aiov.iov_len = next_offset - 1473 prev_offset; 1474 error = VOP_WRITE(vp, &auio, 1475 vnode_pager_putpages_ioflags(flags), curthread->td_ucred); 1476 1477 wrsz = prev_resid - auio.uio_resid; 1478 if (wrsz == 0) { 1479 if (ppsratecheck(&lastfail, &curfail, 1) != 0) { 1480 vn_printf(vp, "vnode_pager_putpages: " 1481 "zero-length write at %ju resid %zd\n", 1482 auio.uio_offset, auio.uio_resid); 1483 } 1484 break; 1485 } 1486 1487 /* Adjust the starting offset for next iteration. */ 1488 prev_offset += wrsz; 1489 MPASS(auio.uio_offset == prev_offset); 1490 1491 ppscheck = 0; 1492 if (error != 0 && (ppscheck = ppsratecheck(&lastfail, 1493 &curfail, 1)) != 0) 1494 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n", 1495 error); 1496 if (auio.uio_resid != 0 && (ppscheck != 0 || 1497 ppsratecheck(&lastfail, &curfail, 1) != 0)) 1498 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd " 1499 "at %ju\n", auio.uio_resid, 1500 (uintmax_t)ma[0]->pindex); 1501 if (error != 0 || auio.uio_resid != 0) 1502 break; 1503 } 1504 write_done: 1505 /* Mark completely processed pages. */ 1506 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++) 1507 rtvals[i] = VM_PAGER_OK; 1508 /* Mark partial EOF page. */ 1509 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0) 1510 rtvals[i++] = VM_PAGER_OK; 1511 /* Unwritten pages in range, free bonus if the page is clean. */ 1512 for (; i < ncount; i++) 1513 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR; 1514 VM_CNT_ADD(v_vnodepgsout, i); 1515 VM_CNT_INC(v_vnodeout); 1516 return (rtvals[0]); 1517 } 1518 1519 int 1520 vnode_pager_putpages_ioflags(int pager_flags) 1521 { 1522 int ioflags; 1523 1524 /* 1525 * Pageouts are already clustered, use IO_ASYNC to force a 1526 * bawrite() rather then a bdwrite() to prevent paging I/O 1527 * from saturating the buffer cache. Dummy-up the sequential 1528 * heuristic to cause large ranges to cluster. If neither 1529 * IO_SYNC or IO_ASYNC is set, the system decides how to 1530 * cluster. 1531 */ 1532 ioflags = IO_VMIO; 1533 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0) 1534 ioflags |= IO_SYNC; 1535 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0) 1536 ioflags |= IO_ASYNC; 1537 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0; 1538 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0; 1539 ioflags |= IO_SEQMAX << IO_SEQSHIFT; 1540 return (ioflags); 1541 } 1542 1543 /* 1544 * vnode_pager_undirty_pages(). 1545 * 1546 * A helper to mark pages as clean after pageout that was possibly 1547 * done with a short write. The lpos argument specifies the page run 1548 * length in bytes, and the written argument specifies how many bytes 1549 * were actually written. eof is the offset past the last valid byte 1550 * in the vnode using the absolute file position of the first byte in 1551 * the run as the base from which it is computed. 1552 */ 1553 void 1554 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof, 1555 int lpos) 1556 { 1557 int i, pos, pos_devb; 1558 1559 if (written == 0 && eof >= lpos) 1560 return; 1561 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { 1562 if (pos < trunc_page(written)) { 1563 rtvals[i] = VM_PAGER_OK; 1564 vm_page_undirty(ma[i]); 1565 } else { 1566 /* Partially written page. */ 1567 rtvals[i] = VM_PAGER_AGAIN; 1568 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); 1569 } 1570 } 1571 if (eof >= lpos) /* avoid truncation */ 1572 return; 1573 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) { 1574 if (pos != trunc_page(pos)) { 1575 /* 1576 * The page contains the last valid byte in 1577 * the vnode, mark the rest of the page as 1578 * clean, potentially making the whole page 1579 * clean. 1580 */ 1581 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE); 1582 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE - 1583 pos_devb); 1584 1585 /* 1586 * If the page was cleaned, report the pageout 1587 * on it as successful. msync() no longer 1588 * needs to write out the page, endlessly 1589 * creating write requests and dirty buffers. 1590 */ 1591 if (ma[i]->dirty == 0) 1592 rtvals[i] = VM_PAGER_OK; 1593 1594 pos = round_page(pos); 1595 } else { 1596 /* vm_pageout_flush() clears dirty */ 1597 rtvals[i] = VM_PAGER_BAD; 1598 pos += PAGE_SIZE; 1599 } 1600 } 1601 } 1602 1603 static void 1604 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, 1605 vm_offset_t end) 1606 { 1607 struct vnode *vp; 1608 vm_ooffset_t old_wm; 1609 1610 VM_OBJECT_WLOCK(object); 1611 if (object->type != OBJT_VNODE) { 1612 VM_OBJECT_WUNLOCK(object); 1613 return; 1614 } 1615 old_wm = object->un_pager.vnp.writemappings; 1616 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; 1617 vp = object->handle; 1618 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { 1619 ASSERT_VOP_LOCKED(vp, "v_writecount inc"); 1620 VOP_ADD_WRITECOUNT_CHECKED(vp, 1); 1621 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1622 __func__, vp, vp->v_writecount); 1623 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { 1624 ASSERT_VOP_LOCKED(vp, "v_writecount dec"); 1625 VOP_ADD_WRITECOUNT_CHECKED(vp, -1); 1626 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1627 __func__, vp, vp->v_writecount); 1628 } 1629 VM_OBJECT_WUNLOCK(object); 1630 } 1631 1632 static void 1633 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, 1634 vm_offset_t end) 1635 { 1636 struct vnode *vp; 1637 struct mount *mp; 1638 vm_offset_t inc; 1639 1640 VM_OBJECT_WLOCK(object); 1641 1642 /* 1643 * First, recheck the object type to account for the race when 1644 * the vnode is reclaimed. 1645 */ 1646 if (object->type != OBJT_VNODE) { 1647 VM_OBJECT_WUNLOCK(object); 1648 return; 1649 } 1650 1651 /* 1652 * Optimize for the case when writemappings is not going to 1653 * zero. 1654 */ 1655 inc = end - start; 1656 if (object->un_pager.vnp.writemappings != inc) { 1657 object->un_pager.vnp.writemappings -= inc; 1658 VM_OBJECT_WUNLOCK(object); 1659 return; 1660 } 1661 1662 vp = object->handle; 1663 vhold(vp); 1664 VM_OBJECT_WUNLOCK(object); 1665 mp = NULL; 1666 vn_start_write(vp, &mp, V_WAIT); 1667 vn_lock(vp, LK_SHARED | LK_RETRY); 1668 1669 /* 1670 * Decrement the object's writemappings, by swapping the start 1671 * and end arguments for vnode_pager_update_writecount(). If 1672 * there was not a race with vnode reclaimation, then the 1673 * vnode's v_writecount is decremented. 1674 */ 1675 vnode_pager_update_writecount(object, end, start); 1676 VOP_UNLOCK(vp); 1677 vdrop(vp); 1678 if (mp != NULL) 1679 vn_finished_write(mp); 1680 } 1681 1682 static void 1683 vnode_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) 1684 { 1685 *vpp = object->handle; 1686 }
Cache object: a532f2654cbba58e4101aee38dad32e6
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