1 /* $NetBSD: genfs_io.c,v 1.101 2020/08/19 07:29:00 simonb Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.101 2020/08/19 07:29:00 simonb Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/proc.h> 39 #include <sys/kernel.h> 40 #include <sys/mount.h> 41 #include <sys/vnode.h> 42 #include <sys/kmem.h> 43 #include <sys/kauth.h> 44 #include <sys/fstrans.h> 45 #include <sys/buf.h> 46 #include <sys/atomic.h> 47 48 #include <miscfs/genfs/genfs.h> 49 #include <miscfs/genfs/genfs_node.h> 50 #include <miscfs/specfs/specdev.h> 51 52 #include <uvm/uvm.h> 53 #include <uvm/uvm_pager.h> 54 #include <uvm/uvm_page_array.h> 55 56 static int genfs_do_directio(struct vmspace *, vaddr_t, size_t, struct vnode *, 57 off_t, enum uio_rw); 58 static void genfs_dio_iodone(struct buf *); 59 60 static int genfs_getpages_read(struct vnode *, struct vm_page **, int, off_t, 61 off_t, bool, bool, bool, bool); 62 static int genfs_do_io(struct vnode *, off_t, vaddr_t, size_t, int, enum uio_rw, 63 void (*)(struct buf *)); 64 static void genfs_rel_pages(struct vm_page **, unsigned int); 65 66 int genfs_maxdio = MAXPHYS; 67 68 static void 69 genfs_rel_pages(struct vm_page **pgs, unsigned int npages) 70 { 71 unsigned int i; 72 73 for (i = 0; i < npages; i++) { 74 struct vm_page *pg = pgs[i]; 75 76 if (pg == NULL || pg == PGO_DONTCARE) 77 continue; 78 KASSERT(uvm_page_owner_locked_p(pg, true)); 79 if (pg->flags & PG_FAKE) { 80 pg->flags |= PG_RELEASED; 81 } 82 } 83 uvm_page_unbusy(pgs, npages); 84 } 85 86 /* 87 * generic VM getpages routine. 88 * Return PG_BUSY pages for the given range, 89 * reading from backing store if necessary. 90 */ 91 92 int 93 genfs_getpages(void *v) 94 { 95 struct vop_getpages_args /* { 96 struct vnode *a_vp; 97 voff_t a_offset; 98 struct vm_page **a_m; 99 int *a_count; 100 int a_centeridx; 101 vm_prot_t a_access_type; 102 int a_advice; 103 int a_flags; 104 } */ * const ap = v; 105 106 off_t diskeof, memeof; 107 int i, error, npages, iflag; 108 const int flags = ap->a_flags; 109 struct vnode * const vp = ap->a_vp; 110 struct uvm_object * const uobj = &vp->v_uobj; 111 const bool async = (flags & PGO_SYNCIO) == 0; 112 const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; 113 const bool overwrite = (flags & PGO_OVERWRITE) != 0; 114 const bool blockalloc = memwrite && (flags & PGO_NOBLOCKALLOC) == 0; 115 const bool need_wapbl = (vp->v_mount->mnt_wapbl && 116 (flags & PGO_JOURNALLOCKED) == 0); 117 const bool glocked = (flags & PGO_GLOCKHELD) != 0; 118 bool holds_wapbl = false; 119 struct mount *trans_mount = NULL; 120 UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); 121 122 UVMHIST_LOG(ubchist, "vp %#jx off 0x%jx/%jx count %jd", 123 (uintptr_t)vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); 124 125 KASSERT(memwrite >= overwrite); 126 KASSERT(vp->v_type == VREG || vp->v_type == VDIR || 127 vp->v_type == VLNK || vp->v_type == VBLK); 128 129 /* 130 * the object must be locked. it can only be a read lock when 131 * processing a read fault with PGO_LOCKED. 132 */ 133 134 KASSERT(rw_lock_held(uobj->vmobjlock)); 135 KASSERT(rw_write_held(uobj->vmobjlock) || 136 ((flags & PGO_LOCKED) != 0 && !memwrite)); 137 138 #ifdef DIAGNOSTIC 139 if ((flags & PGO_JOURNALLOCKED) && vp->v_mount->mnt_wapbl) 140 WAPBL_JLOCK_ASSERT(vp->v_mount); 141 #endif 142 143 /* 144 * check for reclaimed vnode. v_interlock is not held here, but 145 * VI_DEADCHECK is set with vmobjlock held. 146 */ 147 148 iflag = atomic_load_relaxed(&vp->v_iflag); 149 if (__predict_false((iflag & VI_DEADCHECK) != 0)) { 150 mutex_enter(vp->v_interlock); 151 error = vdead_check(vp, VDEAD_NOWAIT); 152 mutex_exit(vp->v_interlock); 153 if (error) { 154 if ((flags & PGO_LOCKED) == 0) 155 rw_exit(uobj->vmobjlock); 156 return error; 157 } 158 } 159 160 startover: 161 error = 0; 162 const voff_t origvsize = vp->v_size; 163 const off_t origoffset = ap->a_offset; 164 const int orignpages = *ap->a_count; 165 166 GOP_SIZE(vp, origvsize, &diskeof, 0); 167 if (flags & PGO_PASTEOF) { 168 off_t newsize; 169 #if defined(DIAGNOSTIC) 170 off_t writeeof; 171 #endif /* defined(DIAGNOSTIC) */ 172 173 newsize = MAX(origvsize, 174 origoffset + (orignpages << PAGE_SHIFT)); 175 GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_MEM); 176 #if defined(DIAGNOSTIC) 177 GOP_SIZE(vp, vp->v_writesize, &writeeof, GOP_SIZE_MEM); 178 if (newsize > round_page(writeeof)) { 179 panic("%s: past eof: %" PRId64 " vs. %" PRId64, 180 __func__, newsize, round_page(writeeof)); 181 } 182 #endif /* defined(DIAGNOSTIC) */ 183 } else { 184 GOP_SIZE(vp, origvsize, &memeof, GOP_SIZE_MEM); 185 } 186 KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); 187 KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); 188 KASSERT(orignpages > 0); 189 190 /* 191 * Bounds-check the request. 192 */ 193 194 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { 195 if ((flags & PGO_LOCKED) == 0) { 196 rw_exit(uobj->vmobjlock); 197 } 198 UVMHIST_LOG(ubchist, "off 0x%jx count %jd goes past EOF 0x%jx", 199 origoffset, *ap->a_count, memeof,0); 200 error = EINVAL; 201 goto out_err; 202 } 203 204 /* uobj is locked */ 205 206 if ((flags & PGO_NOTIMESTAMP) == 0 && 207 (vp->v_type != VBLK || 208 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 209 int updflags = 0; 210 211 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) { 212 updflags = GOP_UPDATE_ACCESSED; 213 } 214 if (memwrite) { 215 updflags |= GOP_UPDATE_MODIFIED; 216 } 217 if (updflags != 0) { 218 GOP_MARKUPDATE(vp, updflags); 219 } 220 } 221 222 /* 223 * For PGO_LOCKED requests, just return whatever's in memory. 224 */ 225 226 if (flags & PGO_LOCKED) { 227 int nfound; 228 struct vm_page *pg; 229 230 KASSERT(!glocked); 231 npages = *ap->a_count; 232 #if defined(DEBUG) 233 for (i = 0; i < npages; i++) { 234 pg = ap->a_m[i]; 235 KASSERT(pg == NULL || pg == PGO_DONTCARE); 236 } 237 #endif /* defined(DEBUG) */ 238 nfound = uvn_findpages(uobj, origoffset, &npages, 239 ap->a_m, NULL, 240 UFP_NOWAIT | UFP_NOALLOC | UFP_NOBUSY | 241 (memwrite ? UFP_NORDONLY : 0)); 242 KASSERT(npages == *ap->a_count); 243 if (nfound == 0) { 244 error = EBUSY; 245 goto out_err; 246 } 247 /* 248 * lock and unlock g_glock to ensure that no one is truncating 249 * the file behind us. 250 */ 251 if (!genfs_node_rdtrylock(vp)) { 252 /* 253 * restore the array. 254 */ 255 256 for (i = 0; i < npages; i++) { 257 pg = ap->a_m[i]; 258 259 if (pg != NULL && pg != PGO_DONTCARE) { 260 ap->a_m[i] = NULL; 261 } 262 KASSERT(ap->a_m[i] == NULL || 263 ap->a_m[i] == PGO_DONTCARE); 264 } 265 } else { 266 genfs_node_unlock(vp); 267 } 268 error = (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 269 if (error == 0 && memwrite) { 270 for (i = 0; i < npages; i++) { 271 pg = ap->a_m[i]; 272 if (pg == NULL || pg == PGO_DONTCARE) { 273 continue; 274 } 275 if (uvm_pagegetdirty(pg) == 276 UVM_PAGE_STATUS_CLEAN) { 277 uvm_pagemarkdirty(pg, 278 UVM_PAGE_STATUS_UNKNOWN); 279 } 280 } 281 } 282 goto out_err; 283 } 284 rw_exit(uobj->vmobjlock); 285 286 /* 287 * find the requested pages and make some simple checks. 288 * leave space in the page array for a whole block. 289 */ 290 291 const int fs_bshift = (vp->v_type != VBLK) ? 292 vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; 293 const int fs_bsize = 1 << fs_bshift; 294 #define blk_mask (fs_bsize - 1) 295 #define trunc_blk(x) ((x) & ~blk_mask) 296 #define round_blk(x) (((x) + blk_mask) & ~blk_mask) 297 298 const int orignmempages = MIN(orignpages, 299 round_page(memeof - origoffset) >> PAGE_SHIFT); 300 npages = orignmempages; 301 const off_t startoffset = trunc_blk(origoffset); 302 const off_t endoffset = MIN( 303 round_page(round_blk(origoffset + (npages << PAGE_SHIFT))), 304 round_page(memeof)); 305 const int ridx = (origoffset - startoffset) >> PAGE_SHIFT; 306 307 const int pgs_size = sizeof(struct vm_page *) * 308 ((endoffset - startoffset) >> PAGE_SHIFT); 309 struct vm_page **pgs, *pgs_onstack[UBC_MAX_PAGES]; 310 311 if (pgs_size > sizeof(pgs_onstack)) { 312 pgs = kmem_zalloc(pgs_size, async ? KM_NOSLEEP : KM_SLEEP); 313 if (pgs == NULL) { 314 pgs = pgs_onstack; 315 error = ENOMEM; 316 goto out_err; 317 } 318 } else { 319 pgs = pgs_onstack; 320 (void)memset(pgs, 0, pgs_size); 321 } 322 323 UVMHIST_LOG(ubchist, "ridx %jd npages %jd startoff %#jx endoff %#jx", 324 ridx, npages, startoffset, endoffset); 325 326 if (trans_mount == NULL) { 327 trans_mount = vp->v_mount; 328 fstrans_start(trans_mount); 329 /* 330 * check if this vnode is still valid. 331 */ 332 mutex_enter(vp->v_interlock); 333 error = vdead_check(vp, 0); 334 mutex_exit(vp->v_interlock); 335 if (error) 336 goto out_err_free; 337 /* 338 * XXX: This assumes that we come here only via 339 * the mmio path 340 */ 341 if (blockalloc && need_wapbl) { 342 error = WAPBL_BEGIN(trans_mount); 343 if (error) 344 goto out_err_free; 345 holds_wapbl = true; 346 } 347 } 348 349 /* 350 * hold g_glock to prevent a race with truncate. 351 * 352 * check if our idea of v_size is still valid. 353 */ 354 355 KASSERT(!glocked || genfs_node_wrlocked(vp)); 356 if (!glocked) { 357 if (blockalloc) { 358 genfs_node_wrlock(vp); 359 } else { 360 genfs_node_rdlock(vp); 361 } 362 } 363 rw_enter(uobj->vmobjlock, RW_WRITER); 364 if (vp->v_size < origvsize) { 365 if (!glocked) { 366 genfs_node_unlock(vp); 367 } 368 if (pgs != pgs_onstack) 369 kmem_free(pgs, pgs_size); 370 goto startover; 371 } 372 373 if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], NULL, 374 async ? UFP_NOWAIT : UFP_ALL) != orignmempages) { 375 if (!glocked) { 376 genfs_node_unlock(vp); 377 } 378 KASSERT(async != 0); 379 genfs_rel_pages(&pgs[ridx], orignmempages); 380 rw_exit(uobj->vmobjlock); 381 error = EBUSY; 382 goto out_err_free; 383 } 384 385 /* 386 * if PGO_OVERWRITE is set, don't bother reading the pages. 387 */ 388 389 if (overwrite) { 390 if (!glocked) { 391 genfs_node_unlock(vp); 392 } 393 UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); 394 395 for (i = 0; i < npages; i++) { 396 struct vm_page *pg = pgs[ridx + i]; 397 398 /* 399 * it's caller's responsibility to allocate blocks 400 * beforehand for the overwrite case. 401 */ 402 403 KASSERT((pg->flags & PG_RDONLY) == 0 || !blockalloc); 404 pg->flags &= ~PG_RDONLY; 405 406 /* 407 * mark the page DIRTY. 408 * otherwise another thread can do putpages and pull 409 * our vnode from syncer's queue before our caller does 410 * ubc_release. note that putpages won't see CLEAN 411 * pages even if they are BUSY. 412 */ 413 414 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 415 } 416 npages += ridx; 417 goto out; 418 } 419 420 /* 421 * if the pages are already resident, just return them. 422 */ 423 424 for (i = 0; i < npages; i++) { 425 struct vm_page *pg = pgs[ridx + i]; 426 427 if ((pg->flags & PG_FAKE) || 428 (blockalloc && (pg->flags & PG_RDONLY) != 0)) { 429 break; 430 } 431 } 432 if (i == npages) { 433 if (!glocked) { 434 genfs_node_unlock(vp); 435 } 436 UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); 437 npages += ridx; 438 goto out; 439 } 440 441 /* 442 * the page wasn't resident and we're not overwriting, 443 * so we're going to have to do some i/o. 444 * find any additional pages needed to cover the expanded range. 445 */ 446 447 npages = (endoffset - startoffset) >> PAGE_SHIFT; 448 if (startoffset != origoffset || npages != orignmempages) { 449 int npgs; 450 451 /* 452 * we need to avoid deadlocks caused by locking 453 * additional pages at lower offsets than pages we 454 * already have locked. unlock them all and start over. 455 */ 456 457 genfs_rel_pages(&pgs[ridx], orignmempages); 458 memset(pgs, 0, pgs_size); 459 460 UVMHIST_LOG(ubchist, "reset npages start 0x%jx end 0x%jx", 461 startoffset, endoffset, 0,0); 462 npgs = npages; 463 if (uvn_findpages(uobj, startoffset, &npgs, pgs, NULL, 464 async ? UFP_NOWAIT : UFP_ALL) != npages) { 465 if (!glocked) { 466 genfs_node_unlock(vp); 467 } 468 KASSERT(async != 0); 469 genfs_rel_pages(pgs, npages); 470 rw_exit(uobj->vmobjlock); 471 error = EBUSY; 472 goto out_err_free; 473 } 474 } 475 476 rw_exit(uobj->vmobjlock); 477 error = genfs_getpages_read(vp, pgs, npages, startoffset, diskeof, 478 async, memwrite, blockalloc, glocked); 479 if (!glocked) { 480 genfs_node_unlock(vp); 481 } 482 if (error == 0 && async) 483 goto out_err_free; 484 rw_enter(uobj->vmobjlock, RW_WRITER); 485 486 /* 487 * we're almost done! release the pages... 488 * for errors, we free the pages. 489 * otherwise we activate them and mark them as valid and clean. 490 * also, unbusy pages that were not actually requested. 491 */ 492 493 if (error) { 494 genfs_rel_pages(pgs, npages); 495 rw_exit(uobj->vmobjlock); 496 UVMHIST_LOG(ubchist, "returning error %jd", error,0,0,0); 497 goto out_err_free; 498 } 499 500 out: 501 UVMHIST_LOG(ubchist, "succeeding, npages %jd", npages,0,0,0); 502 error = 0; 503 for (i = 0; i < npages; i++) { 504 struct vm_page *pg = pgs[i]; 505 if (pg == NULL) { 506 continue; 507 } 508 UVMHIST_LOG(ubchist, "examining pg %#jx flags 0x%jx", 509 (uintptr_t)pg, pg->flags, 0,0); 510 if (pg->flags & PG_FAKE && !overwrite) { 511 /* 512 * we've read page's contents from the backing storage. 513 * 514 * for a read fault, we keep them CLEAN; if we 515 * encountered a hole while reading, the pages can 516 * already been dirtied with zeros. 517 */ 518 KASSERTMSG(blockalloc || uvm_pagegetdirty(pg) == 519 UVM_PAGE_STATUS_CLEAN, "page %p not clean", pg); 520 pg->flags &= ~PG_FAKE; 521 } 522 KASSERT(!memwrite || !blockalloc || (pg->flags & PG_RDONLY) == 0); 523 if (i < ridx || i >= ridx + orignmempages || async) { 524 UVMHIST_LOG(ubchist, "unbusy pg %#jx offset 0x%jx", 525 (uintptr_t)pg, pg->offset,0,0); 526 if (pg->flags & PG_FAKE) { 527 KASSERT(overwrite); 528 uvm_pagezero(pg); 529 } 530 if (pg->flags & PG_RELEASED) { 531 uvm_pagefree(pg); 532 continue; 533 } 534 uvm_pagelock(pg); 535 uvm_pageenqueue(pg); 536 uvm_pagewakeup(pg); 537 uvm_pageunlock(pg); 538 pg->flags &= ~(PG_BUSY|PG_FAKE); 539 UVM_PAGE_OWN(pg, NULL); 540 } else if (memwrite && !overwrite && 541 uvm_pagegetdirty(pg) == UVM_PAGE_STATUS_CLEAN) { 542 /* 543 * for a write fault, start dirtiness tracking of 544 * requested pages. 545 */ 546 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_UNKNOWN); 547 } 548 } 549 rw_exit(uobj->vmobjlock); 550 if (ap->a_m != NULL) { 551 memcpy(ap->a_m, &pgs[ridx], 552 orignmempages * sizeof(struct vm_page *)); 553 } 554 555 out_err_free: 556 if (pgs != NULL && pgs != pgs_onstack) 557 kmem_free(pgs, pgs_size); 558 out_err: 559 if (trans_mount != NULL) { 560 if (holds_wapbl) 561 WAPBL_END(trans_mount); 562 fstrans_done(trans_mount); 563 } 564 return error; 565 } 566 567 /* 568 * genfs_getpages_read: Read the pages in with VOP_BMAP/VOP_STRATEGY. 569 * 570 * "glocked" (which is currently not actually used) tells us not whether 571 * the genfs_node is locked on entry (it always is) but whether it was 572 * locked on entry to genfs_getpages. 573 */ 574 static int 575 genfs_getpages_read(struct vnode *vp, struct vm_page **pgs, int npages, 576 off_t startoffset, off_t diskeof, 577 bool async, bool memwrite, bool blockalloc, bool glocked) 578 { 579 struct uvm_object * const uobj = &vp->v_uobj; 580 const int fs_bshift = (vp->v_type != VBLK) ? 581 vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; 582 const int dev_bshift = (vp->v_type != VBLK) ? 583 vp->v_mount->mnt_dev_bshift : DEV_BSHIFT; 584 kauth_cred_t const cred = curlwp->l_cred; /* XXXUBC curlwp */ 585 size_t bytes, iobytes, tailstart, tailbytes, totalbytes, skipbytes; 586 vaddr_t kva; 587 struct buf *bp, *mbp; 588 bool sawhole = false; 589 int i; 590 int error = 0; 591 592 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 593 594 /* 595 * read the desired page(s). 596 */ 597 598 totalbytes = npages << PAGE_SHIFT; 599 bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); 600 tailbytes = totalbytes - bytes; 601 skipbytes = 0; 602 603 kva = uvm_pagermapin(pgs, npages, 604 UVMPAGER_MAPIN_READ | (async ? 0 : UVMPAGER_MAPIN_WAITOK)); 605 if (kva == 0) 606 return EBUSY; 607 608 mbp = getiobuf(vp, true); 609 mbp->b_bufsize = totalbytes; 610 mbp->b_data = (void *)kva; 611 mbp->b_resid = mbp->b_bcount = bytes; 612 mbp->b_cflags |= BC_BUSY; 613 if (async) { 614 mbp->b_flags = B_READ | B_ASYNC; 615 mbp->b_iodone = uvm_aio_aiodone; 616 } else { 617 mbp->b_flags = B_READ; 618 mbp->b_iodone = NULL; 619 } 620 if (async) 621 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 622 else 623 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 624 625 /* 626 * if EOF is in the middle of the range, zero the part past EOF. 627 * skip over pages which are not PG_FAKE since in that case they have 628 * valid data that we need to preserve. 629 */ 630 631 tailstart = bytes; 632 while (tailbytes > 0) { 633 const int len = PAGE_SIZE - (tailstart & PAGE_MASK); 634 635 KASSERT(len <= tailbytes); 636 if ((pgs[tailstart >> PAGE_SHIFT]->flags & PG_FAKE) != 0) { 637 memset((void *)(kva + tailstart), 0, len); 638 UVMHIST_LOG(ubchist, "tailbytes %#jx 0x%jx 0x%jx", 639 (uintptr_t)kva, tailstart, len, 0); 640 } 641 tailstart += len; 642 tailbytes -= len; 643 } 644 645 /* 646 * now loop over the pages, reading as needed. 647 */ 648 649 bp = NULL; 650 off_t offset; 651 for (offset = startoffset; 652 bytes > 0; 653 offset += iobytes, bytes -= iobytes) { 654 int run; 655 daddr_t lbn, blkno; 656 int pidx; 657 struct vnode *devvp; 658 659 /* 660 * skip pages which don't need to be read. 661 */ 662 663 pidx = (offset - startoffset) >> PAGE_SHIFT; 664 while ((pgs[pidx]->flags & PG_FAKE) == 0) { 665 size_t b; 666 667 KASSERT((offset & (PAGE_SIZE - 1)) == 0); 668 if ((pgs[pidx]->flags & PG_RDONLY)) { 669 sawhole = true; 670 } 671 b = MIN(PAGE_SIZE, bytes); 672 offset += b; 673 bytes -= b; 674 skipbytes += b; 675 pidx++; 676 UVMHIST_LOG(ubchist, "skipping, new offset 0x%jx", 677 offset, 0,0,0); 678 if (bytes == 0) { 679 goto loopdone; 680 } 681 } 682 683 /* 684 * bmap the file to find out the blkno to read from and 685 * how much we can read in one i/o. if bmap returns an error, 686 * skip the rest of the top-level i/o. 687 */ 688 689 lbn = offset >> fs_bshift; 690 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 691 if (error) { 692 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%jx -> %jd", 693 lbn,error,0,0); 694 skipbytes += bytes; 695 bytes = 0; 696 goto loopdone; 697 } 698 699 /* 700 * see how many pages can be read with this i/o. 701 * reduce the i/o size if necessary to avoid 702 * overwriting pages with valid data. 703 */ 704 705 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 706 bytes); 707 if (offset + iobytes > round_page(offset)) { 708 int pcount; 709 710 pcount = 1; 711 while (pidx + pcount < npages && 712 pgs[pidx + pcount]->flags & PG_FAKE) { 713 pcount++; 714 } 715 iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - 716 (offset - trunc_page(offset))); 717 } 718 719 /* 720 * if this block isn't allocated, zero it instead of 721 * reading it. unless we are going to allocate blocks, 722 * mark the pages we zeroed PG_RDONLY. 723 */ 724 725 if (blkno == (daddr_t)-1) { 726 int holepages = (round_page(offset + iobytes) - 727 trunc_page(offset)) >> PAGE_SHIFT; 728 UVMHIST_LOG(ubchist, "lbn 0x%jx -> HOLE", lbn,0,0,0); 729 730 sawhole = true; 731 memset((char *)kva + (offset - startoffset), 0, 732 iobytes); 733 skipbytes += iobytes; 734 735 if (!blockalloc) { 736 rw_enter(uobj->vmobjlock, RW_WRITER); 737 for (i = 0; i < holepages; i++) { 738 pgs[pidx + i]->flags |= PG_RDONLY; 739 } 740 rw_exit(uobj->vmobjlock); 741 } 742 continue; 743 } 744 745 /* 746 * allocate a sub-buf for this piece of the i/o 747 * (or just use mbp if there's only 1 piece), 748 * and start it going. 749 */ 750 751 if (offset == startoffset && iobytes == bytes) { 752 bp = mbp; 753 } else { 754 UVMHIST_LOG(ubchist, "vp %#jx bp %#jx num now %jd", 755 (uintptr_t)vp, (uintptr_t)bp, vp->v_numoutput, 0); 756 bp = getiobuf(vp, true); 757 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 758 } 759 bp->b_lblkno = 0; 760 761 /* adjust physical blkno for partial blocks */ 762 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 763 dev_bshift); 764 765 UVMHIST_LOG(ubchist, 766 "bp %#jx offset 0x%x bcount 0x%x blkno 0x%x", 767 (uintptr_t)bp, offset, bp->b_bcount, bp->b_blkno); 768 769 VOP_STRATEGY(devvp, bp); 770 } 771 772 loopdone: 773 nestiobuf_done(mbp, skipbytes, error); 774 if (async) { 775 UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); 776 return 0; 777 } 778 if (bp != NULL) { 779 error = biowait(mbp); 780 } 781 782 /* Remove the mapping (make KVA available as soon as possible) */ 783 uvm_pagermapout(kva, npages); 784 785 /* 786 * if this we encountered a hole then we have to do a little more work. 787 * for read faults, we marked the page PG_RDONLY so that future 788 * write accesses to the page will fault again. 789 * for write faults, we must make sure that the backing store for 790 * the page is completely allocated while the pages are locked. 791 */ 792 793 if (!error && sawhole && blockalloc) { 794 error = GOP_ALLOC(vp, startoffset, 795 npages << PAGE_SHIFT, 0, cred); 796 UVMHIST_LOG(ubchist, "gop_alloc off 0x%jx/0x%jx -> %jd", 797 startoffset, npages << PAGE_SHIFT, error,0); 798 if (!error) { 799 rw_enter(uobj->vmobjlock, RW_WRITER); 800 for (i = 0; i < npages; i++) { 801 struct vm_page *pg = pgs[i]; 802 803 if (pg == NULL) { 804 continue; 805 } 806 pg->flags &= ~PG_RDONLY; 807 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY); 808 UVMHIST_LOG(ubchist, "mark dirty pg %#jx", 809 (uintptr_t)pg, 0, 0, 0); 810 } 811 rw_exit(uobj->vmobjlock); 812 } 813 } 814 815 putiobuf(mbp); 816 return error; 817 } 818 819 /* 820 * generic VM putpages routine. 821 * Write the given range of pages to backing store. 822 * 823 * => "offhi == 0" means flush all pages at or after "offlo". 824 * => object should be locked by caller. we return with the 825 * object unlocked. 826 * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). 827 * thus, a caller might want to unlock higher level resources 828 * (e.g. vm_map) before calling flush. 829 * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, we will not block 830 * => if PGO_ALLPAGES is set, then all pages in the object will be processed. 831 * 832 * note on "cleaning" object and PG_BUSY pages: 833 * this routine is holding the lock on the object. the only time 834 * that it can run into a PG_BUSY page that it does not own is if 835 * some other process has started I/O on the page (e.g. either 836 * a pagein, or a pageout). if the PG_BUSY page is being paged 837 * in, then it can not be dirty (!UVM_PAGE_STATUS_CLEAN) because no 838 * one has had a chance to modify it yet. if the PG_BUSY page is 839 * being paged out then it means that someone else has already started 840 * cleaning the page for us (how nice!). in this case, if we 841 * have syncio specified, then after we make our pass through the 842 * object we need to wait for the other PG_BUSY pages to clear 843 * off (i.e. we need to do an iosync). also note that once a 844 * page is PG_BUSY it must stay in its object until it is un-busyed. 845 */ 846 847 int 848 genfs_putpages(void *v) 849 { 850 struct vop_putpages_args /* { 851 struct vnode *a_vp; 852 voff_t a_offlo; 853 voff_t a_offhi; 854 int a_flags; 855 } */ * const ap = v; 856 857 return genfs_do_putpages(ap->a_vp, ap->a_offlo, ap->a_offhi, 858 ap->a_flags, NULL); 859 } 860 861 int 862 genfs_do_putpages(struct vnode *vp, off_t startoff, off_t endoff, 863 int origflags, struct vm_page **busypg) 864 { 865 struct uvm_object * const uobj = &vp->v_uobj; 866 krwlock_t * const slock = uobj->vmobjlock; 867 off_t nextoff; 868 int i, error, npages, nback; 869 int freeflag; 870 /* 871 * This array is larger than it should so that it's size is constant. 872 * The right size is MAXPAGES. 873 */ 874 struct vm_page *pgs[MAXPHYS / MIN_PAGE_SIZE]; 875 #define MAXPAGES (MAXPHYS / PAGE_SIZE) 876 struct vm_page *pg, *tpg; 877 struct uvm_page_array a; 878 bool wasclean, needs_clean; 879 bool async = (origflags & PGO_SYNCIO) == 0; 880 bool pagedaemon = curlwp == uvm.pagedaemon_lwp; 881 struct mount *trans_mp; 882 int flags; 883 bool modified; /* if we write out any pages */ 884 bool holds_wapbl; 885 bool cleanall; /* try to pull off from the syncer's list */ 886 bool onworklst; 887 bool nodirty; 888 const bool dirtyonly = (origflags & (PGO_DEACTIVATE|PGO_FREE)) == 0; 889 890 UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); 891 892 KASSERT(origflags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); 893 KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); 894 KASSERT(startoff < endoff || endoff == 0); 895 KASSERT(rw_write_held(slock)); 896 897 UVMHIST_LOG(ubchist, "vp %#jx pages %jd off 0x%jx len 0x%jx", 898 (uintptr_t)vp, uobj->uo_npages, startoff, endoff - startoff); 899 900 #ifdef DIAGNOSTIC 901 if ((origflags & PGO_JOURNALLOCKED) && vp->v_mount->mnt_wapbl) 902 WAPBL_JLOCK_ASSERT(vp->v_mount); 903 #endif 904 905 trans_mp = NULL; 906 holds_wapbl = false; 907 908 retry: 909 modified = false; 910 flags = origflags; 911 912 /* 913 * shortcut if we have no pages to process. 914 */ 915 916 nodirty = uvm_obj_clean_p(uobj); 917 #ifdef DIAGNOSTIC 918 mutex_enter(vp->v_interlock); 919 KASSERT((vp->v_iflag & VI_ONWORKLST) != 0 || nodirty); 920 mutex_exit(vp->v_interlock); 921 #endif 922 if (uobj->uo_npages == 0 || (dirtyonly && nodirty)) { 923 mutex_enter(vp->v_interlock); 924 if (vp->v_iflag & VI_ONWORKLST && LIST_EMPTY(&vp->v_dirtyblkhd)) { 925 vn_syncer_remove_from_worklist(vp); 926 } 927 mutex_exit(vp->v_interlock); 928 if (trans_mp) { 929 if (holds_wapbl) 930 WAPBL_END(trans_mp); 931 fstrans_done(trans_mp); 932 } 933 rw_exit(slock); 934 return (0); 935 } 936 937 /* 938 * the vnode has pages, set up to process the request. 939 */ 940 941 if (trans_mp == NULL && (flags & PGO_CLEANIT) != 0) { 942 if (pagedaemon) { 943 /* Pagedaemon must not sleep here. */ 944 trans_mp = vp->v_mount; 945 error = fstrans_start_nowait(trans_mp); 946 if (error) { 947 rw_exit(slock); 948 return error; 949 } 950 } else { 951 /* 952 * Cannot use vdeadcheck() here as this operation 953 * usually gets used from VOP_RECLAIM(). Test for 954 * change of v_mount instead and retry on change. 955 */ 956 rw_exit(slock); 957 trans_mp = vp->v_mount; 958 fstrans_start(trans_mp); 959 if (vp->v_mount != trans_mp) { 960 fstrans_done(trans_mp); 961 trans_mp = NULL; 962 } else { 963 holds_wapbl = (trans_mp->mnt_wapbl && 964 (origflags & PGO_JOURNALLOCKED) == 0); 965 if (holds_wapbl) { 966 error = WAPBL_BEGIN(trans_mp); 967 if (error) { 968 fstrans_done(trans_mp); 969 return error; 970 } 971 } 972 } 973 rw_enter(slock, RW_WRITER); 974 goto retry; 975 } 976 } 977 978 error = 0; 979 wasclean = uvm_obj_nowriteback_p(uobj); 980 nextoff = startoff; 981 if (endoff == 0 || flags & PGO_ALLPAGES) { 982 endoff = trunc_page(LLONG_MAX); 983 } 984 985 /* 986 * if this vnode is known not to have dirty pages, 987 * don't bother to clean it out. 988 */ 989 990 if (nodirty) { 991 #if !defined(DEBUG) 992 if (dirtyonly) { 993 goto skip_scan; 994 } 995 #endif /* !defined(DEBUG) */ 996 flags &= ~PGO_CLEANIT; 997 } 998 999 /* 1000 * start the loop to scan pages. 1001 */ 1002 1003 cleanall = true; 1004 freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED; 1005 uvm_page_array_init(&a, uobj, dirtyonly ? (UVM_PAGE_ARRAY_FILL_DIRTY | 1006 (!async ? UVM_PAGE_ARRAY_FILL_WRITEBACK : 0)) : 0); 1007 for (;;) { 1008 bool pgprotected; 1009 1010 /* 1011 * if !dirtyonly, iterate over all resident pages in the range. 1012 * 1013 * if dirtyonly, only possibly dirty pages are interesting. 1014 * however, if we are asked to sync for integrity, we should 1015 * wait on pages being written back by other threads as well. 1016 */ 1017 1018 pg = uvm_page_array_fill_and_peek(&a, nextoff, 0); 1019 if (pg == NULL) { 1020 break; 1021 } 1022 1023 KASSERT(pg->uobject == uobj); 1024 KASSERT((pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 1025 (pg->flags & (PG_BUSY)) != 0); 1026 KASSERT(pg->offset >= startoff); 1027 KASSERT(pg->offset >= nextoff); 1028 KASSERT(!dirtyonly || 1029 uvm_pagegetdirty(pg) != UVM_PAGE_STATUS_CLEAN || 1030 uvm_obj_page_writeback_p(pg)); 1031 1032 if (pg->offset >= endoff) { 1033 break; 1034 } 1035 1036 /* 1037 * a preempt point. 1038 */ 1039 1040 if (preempt_needed()) { 1041 nextoff = pg->offset; /* visit this page again */ 1042 rw_exit(slock); 1043 preempt(); 1044 /* 1045 * as we dropped the object lock, our cached pages can 1046 * be stale. 1047 */ 1048 uvm_page_array_clear(&a); 1049 rw_enter(slock, RW_WRITER); 1050 continue; 1051 } 1052 1053 /* 1054 * if the current page is busy, wait for it to become unbusy. 1055 */ 1056 1057 if ((pg->flags & PG_BUSY) != 0) { 1058 UVMHIST_LOG(ubchist, "busy %#jx", (uintptr_t)pg, 1059 0, 0, 0); 1060 if ((pg->flags & (PG_RELEASED|PG_PAGEOUT)) != 0 1061 && (flags & PGO_BUSYFAIL) != 0) { 1062 UVMHIST_LOG(ubchist, "busyfail %#jx", 1063 (uintptr_t)pg, 0, 0, 0); 1064 error = EDEADLK; 1065 if (busypg != NULL) 1066 *busypg = pg; 1067 break; 1068 } 1069 if (pagedaemon) { 1070 /* 1071 * someone has taken the page while we 1072 * dropped the lock for fstrans_start. 1073 */ 1074 break; 1075 } 1076 /* 1077 * don't bother to wait on other's activities 1078 * unless we are asked to sync for integrity. 1079 */ 1080 if (!async && (flags & PGO_RECLAIM) == 0) { 1081 wasclean = false; 1082 nextoff = pg->offset + PAGE_SIZE; 1083 uvm_page_array_advance(&a); 1084 continue; 1085 } 1086 nextoff = pg->offset; /* visit this page again */ 1087 uvm_pagewait(pg, slock, "genput"); 1088 /* 1089 * as we dropped the object lock, our cached pages can 1090 * be stale. 1091 */ 1092 uvm_page_array_clear(&a); 1093 rw_enter(slock, RW_WRITER); 1094 continue; 1095 } 1096 1097 nextoff = pg->offset + PAGE_SIZE; 1098 uvm_page_array_advance(&a); 1099 1100 /* 1101 * if we're freeing, remove all mappings of the page now. 1102 * if we're cleaning, check if the page is needs to be cleaned. 1103 */ 1104 1105 pgprotected = false; 1106 if (flags & PGO_FREE) { 1107 pmap_page_protect(pg, VM_PROT_NONE); 1108 pgprotected = true; 1109 } else if (flags & PGO_CLEANIT) { 1110 1111 /* 1112 * if we still have some hope to pull this vnode off 1113 * from the syncer queue, write-protect the page. 1114 */ 1115 1116 if (cleanall && wasclean) { 1117 1118 /* 1119 * uobj pages get wired only by uvm_fault 1120 * where uobj is locked. 1121 */ 1122 1123 if (pg->wire_count == 0) { 1124 pmap_page_protect(pg, 1125 VM_PROT_READ|VM_PROT_EXECUTE); 1126 pgprotected = true; 1127 } else { 1128 cleanall = false; 1129 } 1130 } 1131 } 1132 1133 if (flags & PGO_CLEANIT) { 1134 needs_clean = uvm_pagecheckdirty(pg, pgprotected); 1135 } else { 1136 needs_clean = false; 1137 } 1138 1139 /* 1140 * if we're cleaning, build a cluster. 1141 * the cluster will consist of pages which are currently dirty. 1142 * if not cleaning, just operate on the one page. 1143 */ 1144 1145 if (needs_clean) { 1146 wasclean = false; 1147 memset(pgs, 0, sizeof(pgs)); 1148 pg->flags |= PG_BUSY; 1149 UVM_PAGE_OWN(pg, "genfs_putpages"); 1150 1151 /* 1152 * let the fs constrain the offset range of the cluster. 1153 * we additionally constrain the range here such that 1154 * it fits in the "pgs" pages array. 1155 */ 1156 1157 off_t fslo, fshi, genlo, lo, off = pg->offset; 1158 GOP_PUTRANGE(vp, off, &fslo, &fshi); 1159 KASSERT(fslo == trunc_page(fslo)); 1160 KASSERT(fslo <= off); 1161 KASSERT(fshi == trunc_page(fshi)); 1162 KASSERT(fshi == 0 || off < fshi); 1163 1164 if (off > MAXPHYS / 2) 1165 genlo = trunc_page(off - (MAXPHYS / 2)); 1166 else 1167 genlo = 0; 1168 lo = MAX(fslo, genlo); 1169 1170 /* 1171 * first look backward. 1172 */ 1173 1174 npages = (off - lo) >> PAGE_SHIFT; 1175 nback = npages; 1176 uvn_findpages(uobj, off - PAGE_SIZE, &nback, 1177 &pgs[0], NULL, 1178 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); 1179 if (nback) { 1180 memmove(&pgs[0], &pgs[npages - nback], 1181 nback * sizeof(pgs[0])); 1182 if (npages - nback < nback) 1183 memset(&pgs[nback], 0, 1184 (npages - nback) * sizeof(pgs[0])); 1185 else 1186 memset(&pgs[npages - nback], 0, 1187 nback * sizeof(pgs[0])); 1188 } 1189 1190 /* 1191 * then plug in our page of interest. 1192 */ 1193 1194 pgs[nback] = pg; 1195 1196 /* 1197 * then look forward to fill in the remaining space in 1198 * the array of pages. 1199 * 1200 * pass our cached array of pages so that hopefully 1201 * uvn_findpages can find some good pages in it. 1202 * the array a was filled above with the one of 1203 * following sets of flags: 1204 * 0 1205 * UVM_PAGE_ARRAY_FILL_DIRTY 1206 * UVM_PAGE_ARRAY_FILL_DIRTY|WRITEBACK 1207 * 1208 * XXX this is fragile but it'll work: the array 1209 * was earlier filled sparsely, but UFP_DIRTYONLY 1210 * implies dense. see corresponding comment in 1211 * uvn_findpages(). 1212 */ 1213 1214 npages = MAXPAGES - nback - 1; 1215 if (fshi) 1216 npages = MIN(npages, 1217 (fshi - off - 1) >> PAGE_SHIFT); 1218 uvn_findpages(uobj, off + PAGE_SIZE, &npages, 1219 &pgs[nback + 1], &a, 1220 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); 1221 npages += nback + 1; 1222 } else { 1223 pgs[0] = pg; 1224 npages = 1; 1225 nback = 0; 1226 } 1227 1228 /* 1229 * apply FREE or DEACTIVATE options if requested. 1230 */ 1231 1232 for (i = 0; i < npages; i++) { 1233 tpg = pgs[i]; 1234 KASSERT(tpg->uobject == uobj); 1235 KASSERT(i == 0 || 1236 pgs[i-1]->offset + PAGE_SIZE == tpg->offset); 1237 KASSERT(!needs_clean || uvm_pagegetdirty(pgs[i]) != 1238 UVM_PAGE_STATUS_DIRTY); 1239 if (needs_clean) { 1240 /* 1241 * mark pages as WRITEBACK so that concurrent 1242 * fsync can find and wait for our activities. 1243 */ 1244 uvm_obj_page_set_writeback(pgs[i]); 1245 } 1246 if (tpg->offset < startoff || tpg->offset >= endoff) 1247 continue; 1248 if (flags & PGO_DEACTIVATE && tpg->wire_count == 0) { 1249 uvm_pagelock(tpg); 1250 uvm_pagedeactivate(tpg); 1251 uvm_pageunlock(tpg); 1252 } else if (flags & PGO_FREE) { 1253 pmap_page_protect(tpg, VM_PROT_NONE); 1254 if (tpg->flags & PG_BUSY) { 1255 tpg->flags |= freeflag; 1256 if (pagedaemon) { 1257 uvm_pageout_start(1); 1258 uvm_pagelock(tpg); 1259 uvm_pagedequeue(tpg); 1260 uvm_pageunlock(tpg); 1261 } 1262 } else { 1263 1264 /* 1265 * ``page is not busy'' 1266 * implies that npages is 1 1267 * and needs_clean is false. 1268 */ 1269 1270 KASSERT(npages == 1); 1271 KASSERT(!needs_clean); 1272 KASSERT(pg == tpg); 1273 KASSERT(nextoff == 1274 tpg->offset + PAGE_SIZE); 1275 uvm_pagefree(tpg); 1276 if (pagedaemon) 1277 uvmexp.pdfreed++; 1278 } 1279 } 1280 } 1281 if (needs_clean) { 1282 modified = true; 1283 KASSERT(nextoff == pg->offset + PAGE_SIZE); 1284 KASSERT(nback < npages); 1285 nextoff = pg->offset + ((npages - nback) << PAGE_SHIFT); 1286 KASSERT(pgs[nback] == pg); 1287 KASSERT(nextoff == pgs[npages - 1]->offset + PAGE_SIZE); 1288 1289 /* 1290 * start the i/o. 1291 */ 1292 rw_exit(slock); 1293 error = GOP_WRITE(vp, pgs, npages, flags); 1294 /* 1295 * as we dropped the object lock, our cached pages can 1296 * be stale. 1297 */ 1298 uvm_page_array_clear(&a); 1299 rw_enter(slock, RW_WRITER); 1300 if (error) { 1301 break; 1302 } 1303 } 1304 } 1305 uvm_page_array_fini(&a); 1306 1307 /* 1308 * update ctime/mtime if the modification we started writing out might 1309 * be from mmap'ed write. 1310 * 1311 * this is necessary when an application keeps a file mmaped and 1312 * repeatedly modifies it via the window. note that, because we 1313 * don't always write-protect pages when cleaning, such modifications 1314 * might not involve any page faults. 1315 */ 1316 1317 mutex_enter(vp->v_interlock); 1318 if (modified && (vp->v_iflag & VI_WRMAP) != 0 && 1319 (vp->v_type != VBLK || 1320 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 1321 GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED); 1322 } 1323 1324 /* 1325 * if we no longer have any possibly dirty pages, take us off the 1326 * syncer list. 1327 */ 1328 1329 if ((vp->v_iflag & VI_ONWORKLST) != 0 && uvm_obj_clean_p(uobj) && 1330 LIST_EMPTY(&vp->v_dirtyblkhd)) { 1331 vn_syncer_remove_from_worklist(vp); 1332 } 1333 1334 #if !defined(DEBUG) 1335 skip_scan: 1336 #endif /* !defined(DEBUG) */ 1337 1338 /* Wait for output to complete. */ 1339 rw_exit(slock); 1340 if (!wasclean && !async && vp->v_numoutput != 0) { 1341 while (vp->v_numoutput != 0) 1342 cv_wait(&vp->v_cv, vp->v_interlock); 1343 } 1344 onworklst = (vp->v_iflag & VI_ONWORKLST) != 0; 1345 mutex_exit(vp->v_interlock); 1346 1347 if ((flags & PGO_RECLAIM) != 0 && onworklst) { 1348 /* 1349 * in the case of PGO_RECLAIM, ensure to make the vnode clean. 1350 * retrying is not a big deal because, in many cases, 1351 * uobj->uo_npages is already 0 here. 1352 */ 1353 rw_enter(slock, RW_WRITER); 1354 goto retry; 1355 } 1356 1357 if (trans_mp) { 1358 if (holds_wapbl) 1359 WAPBL_END(trans_mp); 1360 fstrans_done(trans_mp); 1361 } 1362 1363 return (error); 1364 } 1365 1366 /* 1367 * Default putrange method for file systems that do not care 1368 * how many pages are given to one GOP_WRITE() call. 1369 */ 1370 void 1371 genfs_gop_putrange(struct vnode *vp, off_t off, off_t *lop, off_t *hip) 1372 { 1373 1374 *lop = 0; 1375 *hip = 0; 1376 } 1377 1378 int 1379 genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1380 { 1381 off_t off; 1382 vaddr_t kva; 1383 size_t len; 1384 int error; 1385 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1386 1387 UVMHIST_LOG(ubchist, "vp %#jx pgs %#jx npages %jd flags 0x%jx", 1388 (uintptr_t)vp, (uintptr_t)pgs, npages, flags); 1389 1390 off = pgs[0]->offset; 1391 kva = uvm_pagermapin(pgs, npages, 1392 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1393 len = npages << PAGE_SHIFT; 1394 1395 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1396 uvm_aio_aiodone); 1397 1398 return error; 1399 } 1400 1401 /* 1402 * genfs_gop_write_rwmap: 1403 * 1404 * a variant of genfs_gop_write. it's used by UDF for its directory buffers. 1405 * this maps pages with PROT_WRITE so that VOP_STRATEGY can modifies 1406 * the contents before writing it out to the underlying storage. 1407 */ 1408 1409 int 1410 genfs_gop_write_rwmap(struct vnode *vp, struct vm_page **pgs, int npages, 1411 int flags) 1412 { 1413 off_t off; 1414 vaddr_t kva; 1415 size_t len; 1416 int error; 1417 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1418 1419 UVMHIST_LOG(ubchist, "vp %#jx pgs %#jx npages %jd flags 0x%jx", 1420 (uintptr_t)vp, (uintptr_t)pgs, npages, flags); 1421 1422 off = pgs[0]->offset; 1423 kva = uvm_pagermapin(pgs, npages, 1424 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1425 len = npages << PAGE_SHIFT; 1426 1427 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1428 uvm_aio_aiodone); 1429 1430 return error; 1431 } 1432 1433 /* 1434 * Backend routine for doing I/O to vnode pages. Pages are already locked 1435 * and mapped into kernel memory. Here we just look up the underlying 1436 * device block addresses and call the strategy routine. 1437 */ 1438 1439 static int 1440 genfs_do_io(struct vnode *vp, off_t off, vaddr_t kva, size_t len, int flags, 1441 enum uio_rw rw, void (*iodone)(struct buf *)) 1442 { 1443 int s, error; 1444 int fs_bshift, dev_bshift; 1445 off_t eof, offset, startoffset; 1446 size_t bytes, iobytes, skipbytes; 1447 struct buf *mbp, *bp; 1448 const bool async = (flags & PGO_SYNCIO) == 0; 1449 const bool lazy = (flags & PGO_LAZY) == 0; 1450 const bool iowrite = rw == UIO_WRITE; 1451 const int brw = iowrite ? B_WRITE : B_READ; 1452 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1453 1454 UVMHIST_LOG(ubchist, "vp %#jx kva %#jx len 0x%jx flags 0x%jx", 1455 (uintptr_t)vp, (uintptr_t)kva, len, flags); 1456 1457 KASSERT(vp->v_size <= vp->v_writesize); 1458 GOP_SIZE(vp, vp->v_writesize, &eof, 0); 1459 if (vp->v_type != VBLK) { 1460 fs_bshift = vp->v_mount->mnt_fs_bshift; 1461 dev_bshift = vp->v_mount->mnt_dev_bshift; 1462 } else { 1463 fs_bshift = DEV_BSHIFT; 1464 dev_bshift = DEV_BSHIFT; 1465 } 1466 error = 0; 1467 startoffset = off; 1468 bytes = MIN(len, eof - startoffset); 1469 skipbytes = 0; 1470 KASSERT(bytes != 0); 1471 1472 if (iowrite) { 1473 /* 1474 * why += 2? 1475 * 1 for biodone, 1 for uvm_aio_aiodone. 1476 */ 1477 mutex_enter(vp->v_interlock); 1478 vp->v_numoutput += 2; 1479 mutex_exit(vp->v_interlock); 1480 } 1481 mbp = getiobuf(vp, true); 1482 UVMHIST_LOG(ubchist, "vp %#jx mbp %#jx num now %jd bytes 0x%jx", 1483 (uintptr_t)vp, (uintptr_t)mbp, vp->v_numoutput, bytes); 1484 mbp->b_bufsize = len; 1485 mbp->b_data = (void *)kva; 1486 mbp->b_resid = mbp->b_bcount = bytes; 1487 mbp->b_cflags |= BC_BUSY | BC_AGE; 1488 if (async) { 1489 mbp->b_flags = brw | B_ASYNC; 1490 mbp->b_iodone = iodone; 1491 } else { 1492 mbp->b_flags = brw; 1493 mbp->b_iodone = NULL; 1494 } 1495 if (curlwp == uvm.pagedaemon_lwp) 1496 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 1497 else if (async || lazy) 1498 BIO_SETPRIO(mbp, BPRIO_TIMENONCRITICAL); 1499 else 1500 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 1501 1502 bp = NULL; 1503 for (offset = startoffset; 1504 bytes > 0; 1505 offset += iobytes, bytes -= iobytes) { 1506 int run; 1507 daddr_t lbn, blkno; 1508 struct vnode *devvp; 1509 1510 /* 1511 * bmap the file to find out the blkno to read from and 1512 * how much we can read in one i/o. if bmap returns an error, 1513 * skip the rest of the top-level i/o. 1514 */ 1515 1516 lbn = offset >> fs_bshift; 1517 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 1518 if (error) { 1519 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%jx -> %jd", 1520 lbn, error, 0, 0); 1521 skipbytes += bytes; 1522 bytes = 0; 1523 goto loopdone; 1524 } 1525 1526 /* 1527 * see how many pages can be read with this i/o. 1528 * reduce the i/o size if necessary to avoid 1529 * overwriting pages with valid data. 1530 */ 1531 1532 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 1533 bytes); 1534 1535 /* 1536 * if this block isn't allocated, zero it instead of 1537 * reading it. unless we are going to allocate blocks, 1538 * mark the pages we zeroed PG_RDONLY. 1539 */ 1540 1541 if (blkno == (daddr_t)-1) { 1542 if (!iowrite) { 1543 memset((char *)kva + (offset - startoffset), 0, 1544 iobytes); 1545 } 1546 skipbytes += iobytes; 1547 continue; 1548 } 1549 1550 /* 1551 * allocate a sub-buf for this piece of the i/o 1552 * (or just use mbp if there's only 1 piece), 1553 * and start it going. 1554 */ 1555 1556 if (offset == startoffset && iobytes == bytes) { 1557 bp = mbp; 1558 } else { 1559 UVMHIST_LOG(ubchist, "vp %#jx bp %#jx num now %jd", 1560 (uintptr_t)vp, (uintptr_t)bp, vp->v_numoutput, 0); 1561 bp = getiobuf(vp, true); 1562 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 1563 } 1564 bp->b_lblkno = 0; 1565 1566 /* adjust physical blkno for partial blocks */ 1567 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 1568 dev_bshift); 1569 1570 UVMHIST_LOG(ubchist, 1571 "bp %#jx offset 0x%jx bcount 0x%jx blkno 0x%jx", 1572 (uintptr_t)bp, offset, bp->b_bcount, bp->b_blkno); 1573 1574 VOP_STRATEGY(devvp, bp); 1575 } 1576 1577 loopdone: 1578 if (skipbytes) { 1579 UVMHIST_LOG(ubchist, "skipbytes %jd", skipbytes, 0,0,0); 1580 } 1581 nestiobuf_done(mbp, skipbytes, error); 1582 if (async) { 1583 UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); 1584 return (0); 1585 } 1586 UVMHIST_LOG(ubchist, "waiting for mbp %#jx", (uintptr_t)mbp, 0, 0, 0); 1587 error = biowait(mbp); 1588 s = splbio(); 1589 (*iodone)(mbp); 1590 splx(s); 1591 UVMHIST_LOG(ubchist, "returning, error %jd", error, 0, 0, 0); 1592 return (error); 1593 } 1594 1595 int 1596 genfs_compat_getpages(void *v) 1597 { 1598 struct vop_getpages_args /* { 1599 struct vnode *a_vp; 1600 voff_t a_offset; 1601 struct vm_page **a_m; 1602 int *a_count; 1603 int a_centeridx; 1604 vm_prot_t a_access_type; 1605 int a_advice; 1606 int a_flags; 1607 } */ *ap = v; 1608 1609 off_t origoffset; 1610 struct vnode *vp = ap->a_vp; 1611 struct uvm_object *uobj = &vp->v_uobj; 1612 struct vm_page *pg, **pgs; 1613 vaddr_t kva; 1614 int i, error, orignpages, npages; 1615 struct iovec iov; 1616 struct uio uio; 1617 kauth_cred_t cred = curlwp->l_cred; 1618 const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; 1619 1620 error = 0; 1621 origoffset = ap->a_offset; 1622 orignpages = *ap->a_count; 1623 pgs = ap->a_m; 1624 1625 if (ap->a_flags & PGO_LOCKED) { 1626 uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, NULL, 1627 UFP_NOWAIT|UFP_NOALLOC| (memwrite ? UFP_NORDONLY : 0)); 1628 1629 error = ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0; 1630 return error; 1631 } 1632 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) { 1633 rw_exit(uobj->vmobjlock); 1634 return EINVAL; 1635 } 1636 if ((ap->a_flags & PGO_SYNCIO) == 0) { 1637 rw_exit(uobj->vmobjlock); 1638 return 0; 1639 } 1640 npages = orignpages; 1641 uvn_findpages(uobj, origoffset, &npages, pgs, NULL, UFP_ALL); 1642 rw_exit(uobj->vmobjlock); 1643 kva = uvm_pagermapin(pgs, npages, 1644 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1645 for (i = 0; i < npages; i++) { 1646 pg = pgs[i]; 1647 if ((pg->flags & PG_FAKE) == 0) { 1648 continue; 1649 } 1650 iov.iov_base = (char *)kva + (i << PAGE_SHIFT); 1651 iov.iov_len = PAGE_SIZE; 1652 uio.uio_iov = &iov; 1653 uio.uio_iovcnt = 1; 1654 uio.uio_offset = origoffset + (i << PAGE_SHIFT); 1655 uio.uio_rw = UIO_READ; 1656 uio.uio_resid = PAGE_SIZE; 1657 UIO_SETUP_SYSSPACE(&uio); 1658 /* XXX vn_lock */ 1659 error = VOP_READ(vp, &uio, 0, cred); 1660 if (error) { 1661 break; 1662 } 1663 if (uio.uio_resid) { 1664 memset(iov.iov_base, 0, uio.uio_resid); 1665 } 1666 } 1667 uvm_pagermapout(kva, npages); 1668 rw_enter(uobj->vmobjlock, RW_WRITER); 1669 for (i = 0; i < npages; i++) { 1670 pg = pgs[i]; 1671 if (error && (pg->flags & PG_FAKE) != 0) { 1672 pg->flags |= PG_RELEASED; 1673 } else { 1674 uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_UNKNOWN); 1675 uvm_pagelock(pg); 1676 uvm_pageactivate(pg); 1677 uvm_pageunlock(pg); 1678 } 1679 } 1680 if (error) { 1681 uvm_page_unbusy(pgs, npages); 1682 } 1683 rw_exit(uobj->vmobjlock); 1684 return error; 1685 } 1686 1687 int 1688 genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, 1689 int flags) 1690 { 1691 off_t offset; 1692 struct iovec iov; 1693 struct uio uio; 1694 kauth_cred_t cred = curlwp->l_cred; 1695 struct buf *bp; 1696 vaddr_t kva; 1697 int error; 1698 1699 offset = pgs[0]->offset; 1700 kva = uvm_pagermapin(pgs, npages, 1701 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1702 1703 iov.iov_base = (void *)kva; 1704 iov.iov_len = npages << PAGE_SHIFT; 1705 uio.uio_iov = &iov; 1706 uio.uio_iovcnt = 1; 1707 uio.uio_offset = offset; 1708 uio.uio_rw = UIO_WRITE; 1709 uio.uio_resid = npages << PAGE_SHIFT; 1710 UIO_SETUP_SYSSPACE(&uio); 1711 /* XXX vn_lock */ 1712 error = VOP_WRITE(vp, &uio, 0, cred); 1713 1714 mutex_enter(vp->v_interlock); 1715 vp->v_numoutput++; 1716 mutex_exit(vp->v_interlock); 1717 1718 bp = getiobuf(vp, true); 1719 bp->b_cflags |= BC_BUSY | BC_AGE; 1720 bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift; 1721 bp->b_data = (char *)kva; 1722 bp->b_bcount = npages << PAGE_SHIFT; 1723 bp->b_bufsize = npages << PAGE_SHIFT; 1724 bp->b_resid = 0; 1725 bp->b_error = error; 1726 uvm_aio_aiodone(bp); 1727 return (error); 1728 } 1729 1730 /* 1731 * Process a uio using direct I/O. If we reach a part of the request 1732 * which cannot be processed in this fashion for some reason, just return. 1733 * The caller must handle some additional part of the request using 1734 * buffered I/O before trying direct I/O again. 1735 */ 1736 1737 void 1738 genfs_directio(struct vnode *vp, struct uio *uio, int ioflag) 1739 { 1740 struct vmspace *vs; 1741 struct iovec *iov; 1742 vaddr_t va; 1743 size_t len; 1744 const int mask = DEV_BSIZE - 1; 1745 int error; 1746 bool need_wapbl = (vp->v_mount && vp->v_mount->mnt_wapbl && 1747 (ioflag & IO_JOURNALLOCKED) == 0); 1748 1749 #ifdef DIAGNOSTIC 1750 if ((ioflag & IO_JOURNALLOCKED) && vp->v_mount->mnt_wapbl) 1751 WAPBL_JLOCK_ASSERT(vp->v_mount); 1752 #endif 1753 1754 /* 1755 * We only support direct I/O to user space for now. 1756 */ 1757 1758 if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) { 1759 return; 1760 } 1761 1762 /* 1763 * If the vnode is mapped, we would need to get the getpages lock 1764 * to stabilize the bmap, but then we would get into trouble while 1765 * locking the pages if the pages belong to this same vnode (or a 1766 * multi-vnode cascade to the same effect). Just fall back to 1767 * buffered I/O if the vnode is mapped to avoid this mess. 1768 */ 1769 1770 if (vp->v_vflag & VV_MAPPED) { 1771 return; 1772 } 1773 1774 if (need_wapbl) { 1775 error = WAPBL_BEGIN(vp->v_mount); 1776 if (error) 1777 return; 1778 } 1779 1780 /* 1781 * Do as much of the uio as possible with direct I/O. 1782 */ 1783 1784 vs = uio->uio_vmspace; 1785 while (uio->uio_resid) { 1786 iov = uio->uio_iov; 1787 if (iov->iov_len == 0) { 1788 uio->uio_iov++; 1789 uio->uio_iovcnt--; 1790 continue; 1791 } 1792 va = (vaddr_t)iov->iov_base; 1793 len = MIN(iov->iov_len, genfs_maxdio); 1794 len &= ~mask; 1795 1796 /* 1797 * If the next chunk is smaller than DEV_BSIZE or extends past 1798 * the current EOF, then fall back to buffered I/O. 1799 */ 1800 1801 if (len == 0 || uio->uio_offset + len > vp->v_size) { 1802 break; 1803 } 1804 1805 /* 1806 * Check alignment. The file offset must be at least 1807 * sector-aligned. The exact constraint on memory alignment 1808 * is very hardware-dependent, but requiring sector-aligned 1809 * addresses there too is safe. 1810 */ 1811 1812 if (uio->uio_offset & mask || va & mask) { 1813 break; 1814 } 1815 error = genfs_do_directio(vs, va, len, vp, uio->uio_offset, 1816 uio->uio_rw); 1817 if (error) { 1818 break; 1819 } 1820 iov->iov_base = (char *)iov->iov_base + len; 1821 iov->iov_len -= len; 1822 uio->uio_offset += len; 1823 uio->uio_resid -= len; 1824 } 1825 1826 if (need_wapbl) 1827 WAPBL_END(vp->v_mount); 1828 } 1829 1830 /* 1831 * Iodone routine for direct I/O. We don't do much here since the request is 1832 * always synchronous, so the caller will do most of the work after biowait(). 1833 */ 1834 1835 static void 1836 genfs_dio_iodone(struct buf *bp) 1837 { 1838 1839 KASSERT((bp->b_flags & B_ASYNC) == 0); 1840 if ((bp->b_flags & B_READ) == 0 && (bp->b_cflags & BC_AGE) != 0) { 1841 mutex_enter(bp->b_objlock); 1842 vwakeup(bp); 1843 mutex_exit(bp->b_objlock); 1844 } 1845 putiobuf(bp); 1846 } 1847 1848 /* 1849 * Process one chunk of a direct I/O request. 1850 */ 1851 1852 static int 1853 genfs_do_directio(struct vmspace *vs, vaddr_t uva, size_t len, struct vnode *vp, 1854 off_t off, enum uio_rw rw) 1855 { 1856 struct vm_map *map; 1857 struct pmap *upm, *kpm __unused; 1858 size_t klen = round_page(uva + len) - trunc_page(uva); 1859 off_t spoff, epoff; 1860 vaddr_t kva, puva; 1861 paddr_t pa; 1862 vm_prot_t prot; 1863 int error, rv __diagused, poff, koff; 1864 const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED | 1865 (rw == UIO_WRITE ? PGO_FREE : 0); 1866 1867 /* 1868 * For writes, verify that this range of the file already has fully 1869 * allocated backing store. If there are any holes, just punt and 1870 * make the caller take the buffered write path. 1871 */ 1872 1873 if (rw == UIO_WRITE) { 1874 daddr_t lbn, elbn, blkno; 1875 int bsize, bshift, run; 1876 1877 bshift = vp->v_mount->mnt_fs_bshift; 1878 bsize = 1 << bshift; 1879 lbn = off >> bshift; 1880 elbn = (off + len + bsize - 1) >> bshift; 1881 while (lbn < elbn) { 1882 error = VOP_BMAP(vp, lbn, NULL, &blkno, &run); 1883 if (error) { 1884 return error; 1885 } 1886 if (blkno == (daddr_t)-1) { 1887 return ENOSPC; 1888 } 1889 lbn += 1 + run; 1890 } 1891 } 1892 1893 /* 1894 * Flush any cached pages for parts of the file that we're about to 1895 * access. If we're writing, invalidate pages as well. 1896 */ 1897 1898 spoff = trunc_page(off); 1899 epoff = round_page(off + len); 1900 rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); 1901 error = VOP_PUTPAGES(vp, spoff, epoff, pgoflags); 1902 if (error) { 1903 return error; 1904 } 1905 1906 /* 1907 * Wire the user pages and remap them into kernel memory. 1908 */ 1909 1910 prot = rw == UIO_READ ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 1911 error = uvm_vslock(vs, (void *)uva, len, prot); 1912 if (error) { 1913 return error; 1914 } 1915 1916 map = &vs->vm_map; 1917 upm = vm_map_pmap(map); 1918 kpm = vm_map_pmap(kernel_map); 1919 puva = trunc_page(uva); 1920 kva = uvm_km_alloc(kernel_map, klen, atop(puva) & uvmexp.colormask, 1921 UVM_KMF_VAONLY | UVM_KMF_WAITVA | UVM_KMF_COLORMATCH); 1922 for (poff = 0; poff < klen; poff += PAGE_SIZE) { 1923 rv = pmap_extract(upm, puva + poff, &pa); 1924 KASSERT(rv); 1925 pmap_kenter_pa(kva + poff, pa, prot, PMAP_WIRED); 1926 } 1927 pmap_update(kpm); 1928 1929 /* 1930 * Do the I/O. 1931 */ 1932 1933 koff = uva - trunc_page(uva); 1934 error = genfs_do_io(vp, off, kva + koff, len, PGO_SYNCIO, rw, 1935 genfs_dio_iodone); 1936 1937 /* 1938 * Tear down the kernel mapping. 1939 */ 1940 1941 pmap_kremove(kva, klen); 1942 pmap_update(kpm); 1943 uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY); 1944 1945 /* 1946 * Unwire the user pages. 1947 */ 1948 1949 uvm_vsunlock(vs, (void *)uva, len); 1950 return error; 1951 } 1952