1 /* $NetBSD: genfs_io.c,v 1.74 2018/12/10 21:10:52 jdolecek 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 1.74 2018/12/10 21:10:52 jdolecek 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 47 #include <miscfs/genfs/genfs.h> 48 #include <miscfs/genfs/genfs_node.h> 49 #include <miscfs/specfs/specdev.h> 50 51 #include <uvm/uvm.h> 52 #include <uvm/uvm_pager.h> 53 54 static int genfs_do_directio(struct vmspace *, vaddr_t, size_t, struct vnode *, 55 off_t, enum uio_rw); 56 static void genfs_dio_iodone(struct buf *); 57 58 static int genfs_getpages_read(struct vnode *, struct vm_page **, int, off_t, 59 off_t, bool, bool, bool, bool); 60 static int genfs_do_io(struct vnode *, off_t, vaddr_t, size_t, int, enum uio_rw, 61 void (*)(struct buf *)); 62 static void genfs_rel_pages(struct vm_page **, unsigned int); 63 static void genfs_markdirty(struct vnode *); 64 65 int genfs_maxdio = MAXPHYS; 66 67 static void 68 genfs_rel_pages(struct vm_page **pgs, unsigned int npages) 69 { 70 unsigned int i; 71 72 for (i = 0; i < npages; i++) { 73 struct vm_page *pg = pgs[i]; 74 75 if (pg == NULL || pg == PGO_DONTCARE) 76 continue; 77 KASSERT(uvm_page_locked_p(pg)); 78 if (pg->flags & PG_FAKE) { 79 pg->flags |= PG_RELEASED; 80 } 81 } 82 mutex_enter(&uvm_pageqlock); 83 uvm_page_unbusy(pgs, npages); 84 mutex_exit(&uvm_pageqlock); 85 } 86 87 static void 88 genfs_markdirty(struct vnode *vp) 89 { 90 struct genfs_node * const gp = VTOG(vp); 91 92 KASSERT(mutex_owned(vp->v_interlock)); 93 gp->g_dirtygen++; 94 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 95 vn_syncer_add_to_worklist(vp, filedelay); 96 } 97 if ((vp->v_iflag & (VI_WRMAP|VI_WRMAPDIRTY)) == VI_WRMAP) { 98 vp->v_iflag |= VI_WRMAPDIRTY; 99 } 100 } 101 102 /* 103 * generic VM getpages routine. 104 * Return PG_BUSY pages for the given range, 105 * reading from backing store if necessary. 106 */ 107 108 int 109 genfs_getpages(void *v) 110 { 111 struct vop_getpages_args /* { 112 struct vnode *a_vp; 113 voff_t a_offset; 114 struct vm_page **a_m; 115 int *a_count; 116 int a_centeridx; 117 vm_prot_t a_access_type; 118 int a_advice; 119 int a_flags; 120 } */ * const ap = v; 121 122 off_t diskeof, memeof; 123 int i, error, npages; 124 const int flags = ap->a_flags; 125 struct vnode * const vp = ap->a_vp; 126 struct uvm_object * const uobj = &vp->v_uobj; 127 const bool async = (flags & PGO_SYNCIO) == 0; 128 const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; 129 const bool overwrite = (flags & PGO_OVERWRITE) != 0; 130 const bool blockalloc = memwrite && (flags & PGO_NOBLOCKALLOC) == 0; 131 const bool need_wapbl = (vp->v_mount->mnt_wapbl && 132 (flags & PGO_JOURNALLOCKED) == 0); 133 const bool glocked = (flags & PGO_GLOCKHELD) != 0; 134 bool holds_wapbl = false; 135 struct mount *trans_mount = NULL; 136 UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); 137 138 UVMHIST_LOG(ubchist, "vp %#jx off 0x%jx/%jx count %jd", 139 (uintptr_t)vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); 140 141 KASSERT(vp->v_type == VREG || vp->v_type == VDIR || 142 vp->v_type == VLNK || vp->v_type == VBLK); 143 144 #ifdef DIAGNOSTIC 145 if ((flags & PGO_JOURNALLOCKED) && vp->v_mount->mnt_wapbl) 146 WAPBL_JLOCK_ASSERT(vp->v_mount); 147 #endif 148 149 error = vdead_check(vp, VDEAD_NOWAIT); 150 if (error) { 151 if ((flags & PGO_LOCKED) == 0) 152 mutex_exit(uobj->vmobjlock); 153 return error; 154 } 155 156 startover: 157 error = 0; 158 const voff_t origvsize = vp->v_size; 159 const off_t origoffset = ap->a_offset; 160 const int orignpages = *ap->a_count; 161 162 GOP_SIZE(vp, origvsize, &diskeof, 0); 163 if (flags & PGO_PASTEOF) { 164 off_t newsize; 165 #if defined(DIAGNOSTIC) 166 off_t writeeof; 167 #endif /* defined(DIAGNOSTIC) */ 168 169 newsize = MAX(origvsize, 170 origoffset + (orignpages << PAGE_SHIFT)); 171 GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_MEM); 172 #if defined(DIAGNOSTIC) 173 GOP_SIZE(vp, vp->v_writesize, &writeeof, GOP_SIZE_MEM); 174 if (newsize > round_page(writeeof)) { 175 panic("%s: past eof: %" PRId64 " vs. %" PRId64, 176 __func__, newsize, round_page(writeeof)); 177 } 178 #endif /* defined(DIAGNOSTIC) */ 179 } else { 180 GOP_SIZE(vp, origvsize, &memeof, GOP_SIZE_MEM); 181 } 182 KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); 183 KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); 184 KASSERT(orignpages > 0); 185 186 /* 187 * Bounds-check the request. 188 */ 189 190 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { 191 if ((flags & PGO_LOCKED) == 0) { 192 mutex_exit(uobj->vmobjlock); 193 } 194 UVMHIST_LOG(ubchist, "off 0x%jx count %jd goes past EOF 0x%jx", 195 origoffset, *ap->a_count, memeof,0); 196 error = EINVAL; 197 goto out_err; 198 } 199 200 /* uobj is locked */ 201 202 if ((flags & PGO_NOTIMESTAMP) == 0 && 203 (vp->v_type != VBLK || 204 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 205 int updflags = 0; 206 207 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) { 208 updflags = GOP_UPDATE_ACCESSED; 209 } 210 if (memwrite) { 211 updflags |= GOP_UPDATE_MODIFIED; 212 } 213 if (updflags != 0) { 214 GOP_MARKUPDATE(vp, updflags); 215 } 216 } 217 218 /* 219 * For PGO_LOCKED requests, just return whatever's in memory. 220 */ 221 222 if (flags & PGO_LOCKED) { 223 int nfound; 224 struct vm_page *pg; 225 226 KASSERT(!glocked); 227 npages = *ap->a_count; 228 #if defined(DEBUG) 229 for (i = 0; i < npages; i++) { 230 pg = ap->a_m[i]; 231 KASSERT(pg == NULL || pg == PGO_DONTCARE); 232 } 233 #endif /* defined(DEBUG) */ 234 nfound = uvn_findpages(uobj, origoffset, &npages, 235 ap->a_m, UFP_NOWAIT|UFP_NOALLOC|(memwrite ? UFP_NORDONLY : 0)); 236 KASSERT(npages == *ap->a_count); 237 if (nfound == 0) { 238 error = EBUSY; 239 goto out_err; 240 } 241 if (!genfs_node_rdtrylock(vp)) { 242 genfs_rel_pages(ap->a_m, npages); 243 244 /* 245 * restore the array. 246 */ 247 248 for (i = 0; i < npages; i++) { 249 pg = ap->a_m[i]; 250 251 if (pg != NULL && pg != PGO_DONTCARE) { 252 ap->a_m[i] = NULL; 253 } 254 KASSERT(ap->a_m[i] == NULL || 255 ap->a_m[i] == PGO_DONTCARE); 256 } 257 } else { 258 genfs_node_unlock(vp); 259 } 260 error = (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 261 if (error == 0 && memwrite) { 262 genfs_markdirty(vp); 263 } 264 goto out_err; 265 } 266 mutex_exit(uobj->vmobjlock); 267 268 /* 269 * find the requested pages and make some simple checks. 270 * leave space in the page array for a whole block. 271 */ 272 273 const int fs_bshift = (vp->v_type != VBLK) ? 274 vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; 275 const int fs_bsize = 1 << fs_bshift; 276 #define blk_mask (fs_bsize - 1) 277 #define trunc_blk(x) ((x) & ~blk_mask) 278 #define round_blk(x) (((x) + blk_mask) & ~blk_mask) 279 280 const int orignmempages = MIN(orignpages, 281 round_page(memeof - origoffset) >> PAGE_SHIFT); 282 npages = orignmempages; 283 const off_t startoffset = trunc_blk(origoffset); 284 const off_t endoffset = MIN( 285 round_page(round_blk(origoffset + (npages << PAGE_SHIFT))), 286 round_page(memeof)); 287 const int ridx = (origoffset - startoffset) >> PAGE_SHIFT; 288 289 const int pgs_size = sizeof(struct vm_page *) * 290 ((endoffset - startoffset) >> PAGE_SHIFT); 291 struct vm_page **pgs, *pgs_onstack[UBC_MAX_PAGES]; 292 293 if (pgs_size > sizeof(pgs_onstack)) { 294 pgs = kmem_zalloc(pgs_size, async ? KM_NOSLEEP : KM_SLEEP); 295 if (pgs == NULL) { 296 pgs = pgs_onstack; 297 error = ENOMEM; 298 goto out_err; 299 } 300 } else { 301 pgs = pgs_onstack; 302 (void)memset(pgs, 0, pgs_size); 303 } 304 305 UVMHIST_LOG(ubchist, "ridx %jd npages %jd startoff %jd endoff %jd", 306 ridx, npages, startoffset, endoffset); 307 308 if (trans_mount == NULL) { 309 trans_mount = vp->v_mount; 310 fstrans_start(trans_mount); 311 /* 312 * check if this vnode is still valid. 313 */ 314 mutex_enter(vp->v_interlock); 315 error = vdead_check(vp, 0); 316 mutex_exit(vp->v_interlock); 317 if (error) 318 goto out_err_free; 319 /* 320 * XXX: This assumes that we come here only via 321 * the mmio path 322 */ 323 if (blockalloc && need_wapbl) { 324 error = WAPBL_BEGIN(trans_mount); 325 if (error) 326 goto out_err_free; 327 holds_wapbl = true; 328 } 329 } 330 331 /* 332 * hold g_glock to prevent a race with truncate. 333 * 334 * check if our idea of v_size is still valid. 335 */ 336 337 KASSERT(!glocked || genfs_node_wrlocked(vp)); 338 if (!glocked) { 339 if (blockalloc) { 340 genfs_node_wrlock(vp); 341 } else { 342 genfs_node_rdlock(vp); 343 } 344 } 345 mutex_enter(uobj->vmobjlock); 346 if (vp->v_size < origvsize) { 347 if (!glocked) { 348 genfs_node_unlock(vp); 349 } 350 if (pgs != pgs_onstack) 351 kmem_free(pgs, pgs_size); 352 goto startover; 353 } 354 355 if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], 356 async ? UFP_NOWAIT : UFP_ALL) != orignmempages) { 357 if (!glocked) { 358 genfs_node_unlock(vp); 359 } 360 KASSERT(async != 0); 361 genfs_rel_pages(&pgs[ridx], orignmempages); 362 mutex_exit(uobj->vmobjlock); 363 error = EBUSY; 364 goto out_err_free; 365 } 366 367 /* 368 * if the pages are already resident, just return them. 369 */ 370 371 for (i = 0; i < npages; i++) { 372 struct vm_page *pg = pgs[ridx + i]; 373 374 if ((pg->flags & PG_FAKE) || 375 (blockalloc && (pg->flags & PG_RDONLY))) { 376 break; 377 } 378 } 379 if (i == npages) { 380 if (!glocked) { 381 genfs_node_unlock(vp); 382 } 383 UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); 384 npages += ridx; 385 goto out; 386 } 387 388 /* 389 * if PGO_OVERWRITE is set, don't bother reading the pages. 390 */ 391 392 if (overwrite) { 393 if (!glocked) { 394 genfs_node_unlock(vp); 395 } 396 UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); 397 398 for (i = 0; i < npages; i++) { 399 struct vm_page *pg = pgs[ridx + i]; 400 401 pg->flags &= ~(PG_RDONLY|PG_CLEAN); 402 } 403 npages += ridx; 404 goto out; 405 } 406 407 /* 408 * the page wasn't resident and we're not overwriting, 409 * so we're going to have to do some i/o. 410 * find any additional pages needed to cover the expanded range. 411 */ 412 413 npages = (endoffset - startoffset) >> PAGE_SHIFT; 414 if (startoffset != origoffset || npages != orignmempages) { 415 int npgs; 416 417 /* 418 * we need to avoid deadlocks caused by locking 419 * additional pages at lower offsets than pages we 420 * already have locked. unlock them all and start over. 421 */ 422 423 genfs_rel_pages(&pgs[ridx], orignmempages); 424 memset(pgs, 0, pgs_size); 425 426 UVMHIST_LOG(ubchist, "reset npages start 0x%jx end 0x%jx", 427 startoffset, endoffset, 0,0); 428 npgs = npages; 429 if (uvn_findpages(uobj, startoffset, &npgs, pgs, 430 async ? UFP_NOWAIT : UFP_ALL) != npages) { 431 if (!glocked) { 432 genfs_node_unlock(vp); 433 } 434 KASSERT(async != 0); 435 genfs_rel_pages(pgs, npages); 436 mutex_exit(uobj->vmobjlock); 437 error = EBUSY; 438 goto out_err_free; 439 } 440 } 441 442 mutex_exit(uobj->vmobjlock); 443 error = genfs_getpages_read(vp, pgs, npages, startoffset, diskeof, 444 async, memwrite, blockalloc, glocked); 445 if (!glocked) { 446 genfs_node_unlock(vp); 447 } 448 if (error == 0 && async) 449 goto out_err_free; 450 mutex_enter(uobj->vmobjlock); 451 452 /* 453 * we're almost done! release the pages... 454 * for errors, we free the pages. 455 * otherwise we activate them and mark them as valid and clean. 456 * also, unbusy pages that were not actually requested. 457 */ 458 459 if (error) { 460 genfs_rel_pages(pgs, npages); 461 mutex_exit(uobj->vmobjlock); 462 UVMHIST_LOG(ubchist, "returning error %jd", error,0,0,0); 463 goto out_err_free; 464 } 465 466 out: 467 UVMHIST_LOG(ubchist, "succeeding, npages %jd", npages,0,0,0); 468 error = 0; 469 mutex_enter(&uvm_pageqlock); 470 for (i = 0; i < npages; i++) { 471 struct vm_page *pg = pgs[i]; 472 if (pg == NULL) { 473 continue; 474 } 475 UVMHIST_LOG(ubchist, "examining pg %#jx flags 0x%jx", 476 (uintptr_t)pg, pg->flags, 0,0); 477 if (pg->flags & PG_FAKE && !overwrite) { 478 pg->flags &= ~(PG_FAKE); 479 pmap_clear_modify(pgs[i]); 480 } 481 KASSERT(!memwrite || !blockalloc || (pg->flags & PG_RDONLY) == 0); 482 if (i < ridx || i >= ridx + orignmempages || async) { 483 UVMHIST_LOG(ubchist, "unbusy pg %#jx offset 0x%jx", 484 (uintptr_t)pg, pg->offset,0,0); 485 if (pg->flags & PG_WANTED) { 486 wakeup(pg); 487 } 488 if (pg->flags & PG_FAKE) { 489 KASSERT(overwrite); 490 uvm_pagezero(pg); 491 } 492 if (pg->flags & PG_RELEASED) { 493 uvm_pagefree(pg); 494 continue; 495 } 496 uvm_pageenqueue(pg); 497 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE); 498 UVM_PAGE_OWN(pg, NULL); 499 } 500 } 501 mutex_exit(&uvm_pageqlock); 502 if (memwrite) { 503 genfs_markdirty(vp); 504 } 505 mutex_exit(uobj->vmobjlock); 506 if (ap->a_m != NULL) { 507 memcpy(ap->a_m, &pgs[ridx], 508 orignmempages * sizeof(struct vm_page *)); 509 } 510 511 out_err_free: 512 if (pgs != NULL && pgs != pgs_onstack) 513 kmem_free(pgs, pgs_size); 514 out_err: 515 if (trans_mount != NULL) { 516 if (holds_wapbl) 517 WAPBL_END(trans_mount); 518 fstrans_done(trans_mount); 519 } 520 return error; 521 } 522 523 /* 524 * genfs_getpages_read: Read the pages in with VOP_BMAP/VOP_STRATEGY. 525 * 526 * "glocked" (which is currently not actually used) tells us not whether 527 * the genfs_node is locked on entry (it always is) but whether it was 528 * locked on entry to genfs_getpages. 529 */ 530 static int 531 genfs_getpages_read(struct vnode *vp, struct vm_page **pgs, int npages, 532 off_t startoffset, off_t diskeof, 533 bool async, bool memwrite, bool blockalloc, bool glocked) 534 { 535 struct uvm_object * const uobj = &vp->v_uobj; 536 const int fs_bshift = (vp->v_type != VBLK) ? 537 vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; 538 const int dev_bshift = (vp->v_type != VBLK) ? 539 vp->v_mount->mnt_dev_bshift : DEV_BSHIFT; 540 kauth_cred_t const cred = curlwp->l_cred; /* XXXUBC curlwp */ 541 size_t bytes, iobytes, tailstart, tailbytes, totalbytes, skipbytes; 542 vaddr_t kva; 543 struct buf *bp, *mbp; 544 bool sawhole = false; 545 int i; 546 int error = 0; 547 548 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 549 550 /* 551 * read the desired page(s). 552 */ 553 554 totalbytes = npages << PAGE_SHIFT; 555 bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); 556 tailbytes = totalbytes - bytes; 557 skipbytes = 0; 558 559 kva = uvm_pagermapin(pgs, npages, 560 UVMPAGER_MAPIN_READ | (async ? 0 : UVMPAGER_MAPIN_WAITOK)); 561 if (kva == 0) 562 return EBUSY; 563 564 mbp = getiobuf(vp, true); 565 mbp->b_bufsize = totalbytes; 566 mbp->b_data = (void *)kva; 567 mbp->b_resid = mbp->b_bcount = bytes; 568 mbp->b_cflags = BC_BUSY; 569 if (async) { 570 mbp->b_flags = B_READ | B_ASYNC; 571 mbp->b_iodone = uvm_aio_biodone; 572 } else { 573 mbp->b_flags = B_READ; 574 mbp->b_iodone = NULL; 575 } 576 if (async) 577 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 578 else 579 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 580 581 /* 582 * if EOF is in the middle of the range, zero the part past EOF. 583 * skip over pages which are not PG_FAKE since in that case they have 584 * valid data that we need to preserve. 585 */ 586 587 tailstart = bytes; 588 while (tailbytes > 0) { 589 const int len = PAGE_SIZE - (tailstart & PAGE_MASK); 590 591 KASSERT(len <= tailbytes); 592 if ((pgs[tailstart >> PAGE_SHIFT]->flags & PG_FAKE) != 0) { 593 memset((void *)(kva + tailstart), 0, len); 594 UVMHIST_LOG(ubchist, "tailbytes %#jx 0x%jx 0x%jx", 595 (uintptr_t)kva, tailstart, len, 0); 596 } 597 tailstart += len; 598 tailbytes -= len; 599 } 600 601 /* 602 * now loop over the pages, reading as needed. 603 */ 604 605 bp = NULL; 606 off_t offset; 607 for (offset = startoffset; 608 bytes > 0; 609 offset += iobytes, bytes -= iobytes) { 610 int run; 611 daddr_t lbn, blkno; 612 int pidx; 613 struct vnode *devvp; 614 615 /* 616 * skip pages which don't need to be read. 617 */ 618 619 pidx = (offset - startoffset) >> PAGE_SHIFT; 620 while ((pgs[pidx]->flags & PG_FAKE) == 0) { 621 size_t b; 622 623 KASSERT((offset & (PAGE_SIZE - 1)) == 0); 624 if ((pgs[pidx]->flags & PG_RDONLY)) { 625 sawhole = true; 626 } 627 b = MIN(PAGE_SIZE, bytes); 628 offset += b; 629 bytes -= b; 630 skipbytes += b; 631 pidx++; 632 UVMHIST_LOG(ubchist, "skipping, new offset 0x%jx", 633 offset, 0,0,0); 634 if (bytes == 0) { 635 goto loopdone; 636 } 637 } 638 639 /* 640 * bmap the file to find out the blkno to read from and 641 * how much we can read in one i/o. if bmap returns an error, 642 * skip the rest of the top-level i/o. 643 */ 644 645 lbn = offset >> fs_bshift; 646 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 647 if (error) { 648 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%jx -> %jd\n", 649 lbn,error,0,0); 650 skipbytes += bytes; 651 bytes = 0; 652 goto loopdone; 653 } 654 655 /* 656 * see how many pages can be read with this i/o. 657 * reduce the i/o size if necessary to avoid 658 * overwriting pages with valid data. 659 */ 660 661 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 662 bytes); 663 if (offset + iobytes > round_page(offset)) { 664 int pcount; 665 666 pcount = 1; 667 while (pidx + pcount < npages && 668 pgs[pidx + pcount]->flags & PG_FAKE) { 669 pcount++; 670 } 671 iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - 672 (offset - trunc_page(offset))); 673 } 674 675 /* 676 * if this block isn't allocated, zero it instead of 677 * reading it. unless we are going to allocate blocks, 678 * mark the pages we zeroed PG_RDONLY. 679 */ 680 681 if (blkno == (daddr_t)-1) { 682 int holepages = (round_page(offset + iobytes) - 683 trunc_page(offset)) >> PAGE_SHIFT; 684 UVMHIST_LOG(ubchist, "lbn 0x%jx -> HOLE", lbn,0,0,0); 685 686 sawhole = true; 687 memset((char *)kva + (offset - startoffset), 0, 688 iobytes); 689 skipbytes += iobytes; 690 691 mutex_enter(uobj->vmobjlock); 692 for (i = 0; i < holepages; i++) { 693 if (memwrite) { 694 pgs[pidx + i]->flags &= ~PG_CLEAN; 695 } 696 if (!blockalloc) { 697 pgs[pidx + i]->flags |= PG_RDONLY; 698 } 699 } 700 mutex_exit(uobj->vmobjlock); 701 continue; 702 } 703 704 /* 705 * allocate a sub-buf for this piece of the i/o 706 * (or just use mbp if there's only 1 piece), 707 * and start it going. 708 */ 709 710 if (offset == startoffset && iobytes == bytes) { 711 bp = mbp; 712 } else { 713 UVMHIST_LOG(ubchist, "vp %#jx bp %#jx num now %jd", 714 (uintptr_t)vp, (uintptr_t)bp, vp->v_numoutput, 0); 715 bp = getiobuf(vp, true); 716 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 717 } 718 bp->b_lblkno = 0; 719 720 /* adjust physical blkno for partial blocks */ 721 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 722 dev_bshift); 723 724 UVMHIST_LOG(ubchist, 725 "bp %#jx offset 0x%x bcount 0x%x blkno 0x%x", 726 (uintptr_t)bp, offset, bp->b_bcount, bp->b_blkno); 727 728 VOP_STRATEGY(devvp, bp); 729 } 730 731 loopdone: 732 nestiobuf_done(mbp, skipbytes, error); 733 if (async) { 734 UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); 735 return 0; 736 } 737 if (bp != NULL) { 738 error = biowait(mbp); 739 } 740 741 /* Remove the mapping (make KVA available as soon as possible) */ 742 uvm_pagermapout(kva, npages); 743 744 /* 745 * if this we encountered a hole then we have to do a little more work. 746 * for read faults, we marked the page PG_RDONLY so that future 747 * write accesses to the page will fault again. 748 * for write faults, we must make sure that the backing store for 749 * the page is completely allocated while the pages are locked. 750 */ 751 752 if (!error && sawhole && blockalloc) { 753 error = GOP_ALLOC(vp, startoffset, 754 npages << PAGE_SHIFT, 0, cred); 755 UVMHIST_LOG(ubchist, "gop_alloc off 0x%jx/0x%jx -> %jd", 756 startoffset, npages << PAGE_SHIFT, error,0); 757 if (!error) { 758 mutex_enter(uobj->vmobjlock); 759 for (i = 0; i < npages; i++) { 760 struct vm_page *pg = pgs[i]; 761 762 if (pg == NULL) { 763 continue; 764 } 765 pg->flags &= ~(PG_CLEAN|PG_RDONLY); 766 UVMHIST_LOG(ubchist, "mark dirty pg %#jx", 767 (uintptr_t)pg, 0, 0, 0); 768 } 769 mutex_exit(uobj->vmobjlock); 770 } 771 } 772 773 putiobuf(mbp); 774 return error; 775 } 776 777 /* 778 * generic VM putpages routine. 779 * Write the given range of pages to backing store. 780 * 781 * => "offhi == 0" means flush all pages at or after "offlo". 782 * => object should be locked by caller. we return with the 783 * object unlocked. 784 * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). 785 * thus, a caller might want to unlock higher level resources 786 * (e.g. vm_map) before calling flush. 787 * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, we will not block 788 * => if PGO_ALLPAGES is set, then all pages in the object will be processed. 789 * => NOTE: we rely on the fact that the object's memq is a TAILQ and 790 * that new pages are inserted on the tail end of the list. thus, 791 * we can make a complete pass through the object in one go by starting 792 * at the head and working towards the tail (new pages are put in 793 * front of us). 794 * => NOTE: we are allowed to lock the page queues, so the caller 795 * must not be holding the page queue lock. 796 * 797 * note on "cleaning" object and PG_BUSY pages: 798 * this routine is holding the lock on the object. the only time 799 * that it can run into a PG_BUSY page that it does not own is if 800 * some other process has started I/O on the page (e.g. either 801 * a pagein, or a pageout). if the PG_BUSY page is being paged 802 * in, then it can not be dirty (!PG_CLEAN) because no one has 803 * had a chance to modify it yet. if the PG_BUSY page is being 804 * paged out then it means that someone else has already started 805 * cleaning the page for us (how nice!). in this case, if we 806 * have syncio specified, then after we make our pass through the 807 * object we need to wait for the other PG_BUSY pages to clear 808 * off (i.e. we need to do an iosync). also note that once a 809 * page is PG_BUSY it must stay in its object until it is un-busyed. 810 * 811 * note on page traversal: 812 * we can traverse the pages in an object either by going down the 813 * linked list in "uobj->memq", or we can go over the address range 814 * by page doing hash table lookups for each address. depending 815 * on how many pages are in the object it may be cheaper to do one 816 * or the other. we set "by_list" to true if we are using memq. 817 * if the cost of a hash lookup was equal to the cost of the list 818 * traversal we could compare the number of pages in the start->stop 819 * range to the total number of pages in the object. however, it 820 * seems that a hash table lookup is more expensive than the linked 821 * list traversal, so we multiply the number of pages in the 822 * range by an estimate of the relatively higher cost of the hash lookup. 823 */ 824 825 int 826 genfs_putpages(void *v) 827 { 828 struct vop_putpages_args /* { 829 struct vnode *a_vp; 830 voff_t a_offlo; 831 voff_t a_offhi; 832 int a_flags; 833 } */ * const ap = v; 834 835 return genfs_do_putpages(ap->a_vp, ap->a_offlo, ap->a_offhi, 836 ap->a_flags, NULL); 837 } 838 839 int 840 genfs_do_putpages(struct vnode *vp, off_t startoff, off_t endoff, 841 int origflags, struct vm_page **busypg) 842 { 843 struct uvm_object * const uobj = &vp->v_uobj; 844 kmutex_t * const slock = uobj->vmobjlock; 845 off_t off; 846 int i, error, npages, nback; 847 int freeflag; 848 /* 849 * This array is larger than it should so that it's size is constant. 850 * The right size is MAXPAGES. 851 */ 852 struct vm_page *pgs[MAXPHYS / MIN_PAGE_SIZE]; 853 #define MAXPAGES (MAXPHYS / PAGE_SIZE) 854 struct vm_page *pg, *nextpg, *tpg, curmp, endmp; 855 bool wasclean, by_list, needs_clean, yld; 856 bool async = (origflags & PGO_SYNCIO) == 0; 857 bool pagedaemon = curlwp == uvm.pagedaemon_lwp; 858 struct lwp * const l = curlwp ? curlwp : &lwp0; 859 struct genfs_node * const gp = VTOG(vp); 860 struct mount *trans_mp; 861 int flags; 862 int dirtygen; 863 bool modified; 864 bool holds_wapbl; 865 bool cleanall; 866 bool onworklst; 867 868 UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); 869 870 KASSERT(origflags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); 871 KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); 872 KASSERT(startoff < endoff || endoff == 0); 873 874 UVMHIST_LOG(ubchist, "vp %#jx pages %jd off 0x%jx len 0x%jx", 875 (uintptr_t)vp, uobj->uo_npages, startoff, endoff - startoff); 876 877 #ifdef DIAGNOSTIC 878 if ((origflags & PGO_JOURNALLOCKED) && vp->v_mount->mnt_wapbl) 879 WAPBL_JLOCK_ASSERT(vp->v_mount); 880 #endif 881 882 trans_mp = NULL; 883 holds_wapbl = false; 884 885 retry: 886 modified = false; 887 flags = origflags; 888 KASSERT((vp->v_iflag & VI_ONWORKLST) != 0 || 889 (vp->v_iflag & VI_WRMAPDIRTY) == 0); 890 if (uobj->uo_npages == 0) { 891 if (vp->v_iflag & VI_ONWORKLST) { 892 vp->v_iflag &= ~VI_WRMAPDIRTY; 893 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 894 vn_syncer_remove_from_worklist(vp); 895 } 896 if (trans_mp) { 897 if (holds_wapbl) 898 WAPBL_END(trans_mp); 899 fstrans_done(trans_mp); 900 } 901 mutex_exit(slock); 902 return (0); 903 } 904 905 /* 906 * the vnode has pages, set up to process the request. 907 */ 908 909 if (trans_mp == NULL && (flags & PGO_CLEANIT) != 0) { 910 if (pagedaemon) { 911 /* Pagedaemon must not sleep here. */ 912 trans_mp = vp->v_mount; 913 error = fstrans_start_nowait(trans_mp); 914 if (error) { 915 mutex_exit(slock); 916 return error; 917 } 918 } else { 919 /* 920 * Cannot use vdeadcheck() here as this operation 921 * usually gets used from VOP_RECLAIM(). Test for 922 * change of v_mount instead and retry on change. 923 */ 924 mutex_exit(slock); 925 trans_mp = vp->v_mount; 926 fstrans_start(trans_mp); 927 if (vp->v_mount != trans_mp) { 928 fstrans_done(trans_mp); 929 trans_mp = NULL; 930 } else { 931 holds_wapbl = (trans_mp->mnt_wapbl && 932 (origflags & PGO_JOURNALLOCKED) == 0); 933 if (holds_wapbl) { 934 error = WAPBL_BEGIN(trans_mp); 935 if (error) { 936 fstrans_done(trans_mp); 937 return error; 938 } 939 } 940 } 941 mutex_enter(slock); 942 goto retry; 943 } 944 } 945 946 error = 0; 947 wasclean = (vp->v_numoutput == 0); 948 off = startoff; 949 if (endoff == 0 || flags & PGO_ALLPAGES) { 950 endoff = trunc_page(LLONG_MAX); 951 } 952 by_list = (uobj->uo_npages <= 953 ((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_TREE_PENALTY); 954 955 /* 956 * if this vnode is known not to have dirty pages, 957 * don't bother to clean it out. 958 */ 959 960 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 961 #if !defined(DEBUG) 962 if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == 0) { 963 goto skip_scan; 964 } 965 #endif /* !defined(DEBUG) */ 966 flags &= ~PGO_CLEANIT; 967 } 968 969 /* 970 * start the loop. when scanning by list, hold the last page 971 * in the list before we start. pages allocated after we start 972 * will be added to the end of the list, so we can stop at the 973 * current last page. 974 */ 975 976 cleanall = (flags & PGO_CLEANIT) != 0 && wasclean && 977 startoff == 0 && endoff == trunc_page(LLONG_MAX) && 978 (vp->v_iflag & VI_ONWORKLST) != 0; 979 dirtygen = gp->g_dirtygen; 980 freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED; 981 if (by_list) { 982 curmp.flags = PG_MARKER; 983 endmp.flags = PG_MARKER; 984 pg = TAILQ_FIRST(&uobj->memq); 985 TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq.queue); 986 } else { 987 pg = uvm_pagelookup(uobj, off); 988 } 989 nextpg = NULL; 990 while (by_list || off < endoff) { 991 992 /* 993 * if the current page is not interesting, move on to the next. 994 */ 995 996 KASSERT(pg == NULL || pg->uobject == uobj || 997 (pg->flags & PG_MARKER) != 0); 998 KASSERT(pg == NULL || 999 (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 1000 (pg->flags & (PG_BUSY|PG_MARKER)) != 0); 1001 if (by_list) { 1002 if (pg == &endmp) { 1003 break; 1004 } 1005 if (pg->flags & PG_MARKER) { 1006 pg = TAILQ_NEXT(pg, listq.queue); 1007 continue; 1008 } 1009 if (pg->offset < startoff || pg->offset >= endoff || 1010 pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 1011 if (pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 1012 wasclean = false; 1013 } 1014 pg = TAILQ_NEXT(pg, listq.queue); 1015 continue; 1016 } 1017 off = pg->offset; 1018 } else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 1019 if (pg != NULL) { 1020 wasclean = false; 1021 } 1022 off += PAGE_SIZE; 1023 if (off < endoff) { 1024 pg = uvm_pagelookup(uobj, off); 1025 } 1026 continue; 1027 } 1028 1029 /* 1030 * if the current page needs to be cleaned and it's busy, 1031 * wait for it to become unbusy. 1032 */ 1033 1034 yld = (l->l_cpu->ci_schedstate.spc_flags & 1035 SPCF_SHOULDYIELD) && !pagedaemon; 1036 if (pg->flags & PG_BUSY || yld) { 1037 UVMHIST_LOG(ubchist, "busy %#jx", (uintptr_t)pg, 1038 0, 0, 0); 1039 if (flags & PGO_BUSYFAIL && pg->flags & PG_BUSY) { 1040 UVMHIST_LOG(ubchist, "busyfail %#jx", 1041 (uintptr_t)pg, 0, 0, 0); 1042 error = EDEADLK; 1043 if (busypg != NULL) 1044 *busypg = pg; 1045 break; 1046 } 1047 if (pagedaemon) { 1048 /* 1049 * someone has taken the page while we 1050 * dropped the lock for fstrans_start. 1051 */ 1052 break; 1053 } 1054 if (by_list) { 1055 TAILQ_INSERT_BEFORE(pg, &curmp, listq.queue); 1056 UVMHIST_LOG(ubchist, "curmp next %#jx", 1057 (uintptr_t)TAILQ_NEXT(&curmp, listq.queue), 1058 0, 0, 0); 1059 } 1060 if (yld) { 1061 mutex_exit(slock); 1062 preempt(); 1063 mutex_enter(slock); 1064 } else { 1065 pg->flags |= PG_WANTED; 1066 UVM_UNLOCK_AND_WAIT(pg, slock, 0, "genput", 0); 1067 mutex_enter(slock); 1068 } 1069 if (by_list) { 1070 UVMHIST_LOG(ubchist, "after next %#jx", 1071 (uintptr_t)TAILQ_NEXT(&curmp, listq.queue), 1072 0, 0, 0); 1073 pg = TAILQ_NEXT(&curmp, listq.queue); 1074 TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); 1075 } else { 1076 pg = uvm_pagelookup(uobj, off); 1077 } 1078 continue; 1079 } 1080 1081 /* 1082 * if we're freeing, remove all mappings of the page now. 1083 * if we're cleaning, check if the page is needs to be cleaned. 1084 */ 1085 1086 if (flags & PGO_FREE) { 1087 pmap_page_protect(pg, VM_PROT_NONE); 1088 } else if (flags & PGO_CLEANIT) { 1089 1090 /* 1091 * if we still have some hope to pull this vnode off 1092 * from the syncer queue, write-protect the page. 1093 */ 1094 1095 if (cleanall && wasclean && 1096 gp->g_dirtygen == dirtygen) { 1097 1098 /* 1099 * uobj pages get wired only by uvm_fault 1100 * where uobj is locked. 1101 */ 1102 1103 if (pg->wire_count == 0) { 1104 pmap_page_protect(pg, 1105 VM_PROT_READ|VM_PROT_EXECUTE); 1106 } else { 1107 cleanall = false; 1108 } 1109 } 1110 } 1111 1112 if (flags & PGO_CLEANIT) { 1113 needs_clean = pmap_clear_modify(pg) || 1114 (pg->flags & PG_CLEAN) == 0; 1115 pg->flags |= PG_CLEAN; 1116 } else { 1117 needs_clean = false; 1118 } 1119 1120 /* 1121 * if we're cleaning, build a cluster. 1122 * the cluster will consist of pages which are currently dirty, 1123 * but they will be returned to us marked clean. 1124 * if not cleaning, just operate on the one page. 1125 */ 1126 1127 if (needs_clean) { 1128 KDASSERT((vp->v_iflag & VI_ONWORKLST)); 1129 wasclean = false; 1130 memset(pgs, 0, sizeof(pgs)); 1131 pg->flags |= PG_BUSY; 1132 UVM_PAGE_OWN(pg, "genfs_putpages"); 1133 1134 /* 1135 * let the fs constrain the offset range of the cluster. 1136 * we additionally constrain the range here such that 1137 * it fits in the "pgs" pages array. 1138 */ 1139 1140 off_t fslo, fshi, genlo, lo; 1141 GOP_PUTRANGE(vp, off, &fslo, &fshi); 1142 KASSERT(fslo == trunc_page(fslo)); 1143 KASSERT(fslo <= off); 1144 KASSERT(fshi == trunc_page(fshi)); 1145 KASSERT(fshi == 0 || off < fshi); 1146 1147 if (off > MAXPHYS / 2) 1148 genlo = trunc_page(off - (MAXPHYS / 2)); 1149 else 1150 genlo = 0; 1151 lo = MAX(fslo, genlo); 1152 1153 /* 1154 * first look backward. 1155 */ 1156 1157 npages = (off - lo) >> PAGE_SHIFT; 1158 nback = npages; 1159 uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0], 1160 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); 1161 if (nback) { 1162 memmove(&pgs[0], &pgs[npages - nback], 1163 nback * sizeof(pgs[0])); 1164 if (npages - nback < nback) 1165 memset(&pgs[nback], 0, 1166 (npages - nback) * sizeof(pgs[0])); 1167 else 1168 memset(&pgs[npages - nback], 0, 1169 nback * sizeof(pgs[0])); 1170 } 1171 1172 /* 1173 * then plug in our page of interest. 1174 */ 1175 1176 pgs[nback] = pg; 1177 1178 /* 1179 * then look forward to fill in the remaining space in 1180 * the array of pages. 1181 */ 1182 1183 npages = MAXPAGES - nback - 1; 1184 if (fshi) 1185 npages = MIN(npages, 1186 (fshi - off - 1) >> PAGE_SHIFT); 1187 uvn_findpages(uobj, off + PAGE_SIZE, &npages, 1188 &pgs[nback + 1], 1189 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); 1190 npages += nback + 1; 1191 } else { 1192 pgs[0] = pg; 1193 npages = 1; 1194 nback = 0; 1195 } 1196 1197 /* 1198 * apply FREE or DEACTIVATE options if requested. 1199 */ 1200 1201 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1202 mutex_enter(&uvm_pageqlock); 1203 } 1204 for (i = 0; i < npages; i++) { 1205 tpg = pgs[i]; 1206 KASSERT(tpg->uobject == uobj); 1207 if (by_list && tpg == TAILQ_NEXT(pg, listq.queue)) 1208 pg = tpg; 1209 if (tpg->offset < startoff || tpg->offset >= endoff) 1210 continue; 1211 if (flags & PGO_DEACTIVATE && tpg->wire_count == 0) { 1212 uvm_pagedeactivate(tpg); 1213 } else if (flags & PGO_FREE) { 1214 pmap_page_protect(tpg, VM_PROT_NONE); 1215 if (tpg->flags & PG_BUSY) { 1216 tpg->flags |= freeflag; 1217 if (pagedaemon) { 1218 uvm_pageout_start(1); 1219 uvm_pagedequeue(tpg); 1220 } 1221 } else { 1222 1223 /* 1224 * ``page is not busy'' 1225 * implies that npages is 1 1226 * and needs_clean is false. 1227 */ 1228 1229 nextpg = TAILQ_NEXT(tpg, listq.queue); 1230 uvm_pagefree(tpg); 1231 if (pagedaemon) 1232 uvmexp.pdfreed++; 1233 } 1234 } 1235 } 1236 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1237 mutex_exit(&uvm_pageqlock); 1238 } 1239 if (needs_clean) { 1240 modified = true; 1241 1242 /* 1243 * start the i/o. if we're traversing by list, 1244 * keep our place in the list with a marker page. 1245 */ 1246 1247 if (by_list) { 1248 TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp, 1249 listq.queue); 1250 } 1251 mutex_exit(slock); 1252 error = GOP_WRITE(vp, pgs, npages, flags); 1253 mutex_enter(slock); 1254 if (by_list) { 1255 pg = TAILQ_NEXT(&curmp, listq.queue); 1256 TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); 1257 } 1258 if (error) { 1259 break; 1260 } 1261 if (by_list) { 1262 continue; 1263 } 1264 } 1265 1266 /* 1267 * find the next page and continue if there was no error. 1268 */ 1269 1270 if (by_list) { 1271 if (nextpg) { 1272 pg = nextpg; 1273 nextpg = NULL; 1274 } else { 1275 pg = TAILQ_NEXT(pg, listq.queue); 1276 } 1277 } else { 1278 off += (npages - nback) << PAGE_SHIFT; 1279 if (off < endoff) { 1280 pg = uvm_pagelookup(uobj, off); 1281 } 1282 } 1283 } 1284 if (by_list) { 1285 TAILQ_REMOVE(&uobj->memq, &endmp, listq.queue); 1286 } 1287 1288 if (modified && (vp->v_iflag & VI_WRMAPDIRTY) != 0 && 1289 (vp->v_type != VBLK || 1290 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 1291 GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED); 1292 } 1293 1294 /* 1295 * if we're cleaning and there was nothing to clean, 1296 * take us off the syncer list. if we started any i/o 1297 * and we're doing sync i/o, wait for all writes to finish. 1298 */ 1299 1300 if (cleanall && wasclean && gp->g_dirtygen == dirtygen && 1301 (vp->v_iflag & VI_ONWORKLST) != 0) { 1302 #if defined(DEBUG) 1303 TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { 1304 if ((pg->flags & (PG_FAKE | PG_MARKER)) != 0) { 1305 continue; 1306 } 1307 if ((pg->flags & PG_CLEAN) == 0) { 1308 printf("%s: %p: !CLEAN\n", __func__, pg); 1309 } 1310 if (pmap_is_modified(pg)) { 1311 printf("%s: %p: modified\n", __func__, pg); 1312 } 1313 } 1314 #endif /* defined(DEBUG) */ 1315 vp->v_iflag &= ~VI_WRMAPDIRTY; 1316 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 1317 vn_syncer_remove_from_worklist(vp); 1318 } 1319 1320 #if !defined(DEBUG) 1321 skip_scan: 1322 #endif /* !defined(DEBUG) */ 1323 1324 /* Wait for output to complete. */ 1325 if (!wasclean && !async && vp->v_numoutput != 0) { 1326 while (vp->v_numoutput != 0) 1327 cv_wait(&vp->v_cv, slock); 1328 } 1329 onworklst = (vp->v_iflag & VI_ONWORKLST) != 0; 1330 mutex_exit(slock); 1331 1332 if ((flags & PGO_RECLAIM) != 0 && onworklst) { 1333 /* 1334 * in the case of PGO_RECLAIM, ensure to make the vnode clean. 1335 * retrying is not a big deal because, in many cases, 1336 * uobj->uo_npages is already 0 here. 1337 */ 1338 mutex_enter(slock); 1339 goto retry; 1340 } 1341 1342 if (trans_mp) { 1343 if (holds_wapbl) 1344 WAPBL_END(trans_mp); 1345 fstrans_done(trans_mp); 1346 } 1347 1348 return (error); 1349 } 1350 1351 /* 1352 * Default putrange method for file systems that do not care 1353 * how many pages are given to one GOP_WRITE() call. 1354 */ 1355 void 1356 genfs_gop_putrange(struct vnode *vp, off_t off, off_t *lop, off_t *hip) 1357 { 1358 1359 *lop = 0; 1360 *hip = 0; 1361 } 1362 1363 int 1364 genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1365 { 1366 off_t off; 1367 vaddr_t kva; 1368 size_t len; 1369 int error; 1370 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1371 1372 UVMHIST_LOG(ubchist, "vp %#jx pgs %#jx npages %jd flags 0x%jx", 1373 (uintptr_t)vp, (uintptr_t)pgs, npages, flags); 1374 1375 off = pgs[0]->offset; 1376 kva = uvm_pagermapin(pgs, npages, 1377 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1378 len = npages << PAGE_SHIFT; 1379 1380 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1381 uvm_aio_biodone); 1382 1383 return error; 1384 } 1385 1386 int 1387 genfs_gop_write_rwmap(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1388 { 1389 off_t off; 1390 vaddr_t kva; 1391 size_t len; 1392 int error; 1393 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1394 1395 UVMHIST_LOG(ubchist, "vp %#jx pgs %#jx npages %jd flags 0x%jx", 1396 (uintptr_t)vp, (uintptr_t)pgs, npages, flags); 1397 1398 off = pgs[0]->offset; 1399 kva = uvm_pagermapin(pgs, npages, 1400 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1401 len = npages << PAGE_SHIFT; 1402 1403 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1404 uvm_aio_biodone); 1405 1406 return error; 1407 } 1408 1409 /* 1410 * Backend routine for doing I/O to vnode pages. Pages are already locked 1411 * and mapped into kernel memory. Here we just look up the underlying 1412 * device block addresses and call the strategy routine. 1413 */ 1414 1415 static int 1416 genfs_do_io(struct vnode *vp, off_t off, vaddr_t kva, size_t len, int flags, 1417 enum uio_rw rw, void (*iodone)(struct buf *)) 1418 { 1419 int s, error; 1420 int fs_bshift, dev_bshift; 1421 off_t eof, offset, startoffset; 1422 size_t bytes, iobytes, skipbytes; 1423 struct buf *mbp, *bp; 1424 const bool async = (flags & PGO_SYNCIO) == 0; 1425 const bool lazy = (flags & PGO_LAZY) == 0; 1426 const bool iowrite = rw == UIO_WRITE; 1427 const int brw = iowrite ? B_WRITE : B_READ; 1428 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1429 1430 UVMHIST_LOG(ubchist, "vp %#jx kva %#jx len 0x%jx flags 0x%jx", 1431 (uintptr_t)vp, (uintptr_t)kva, len, flags); 1432 1433 KASSERT(vp->v_size <= vp->v_writesize); 1434 GOP_SIZE(vp, vp->v_writesize, &eof, 0); 1435 if (vp->v_type != VBLK) { 1436 fs_bshift = vp->v_mount->mnt_fs_bshift; 1437 dev_bshift = vp->v_mount->mnt_dev_bshift; 1438 } else { 1439 fs_bshift = DEV_BSHIFT; 1440 dev_bshift = DEV_BSHIFT; 1441 } 1442 error = 0; 1443 startoffset = off; 1444 bytes = MIN(len, eof - startoffset); 1445 skipbytes = 0; 1446 KASSERT(bytes != 0); 1447 1448 if (iowrite) { 1449 mutex_enter(vp->v_interlock); 1450 vp->v_numoutput += 2; 1451 mutex_exit(vp->v_interlock); 1452 } 1453 mbp = getiobuf(vp, true); 1454 UVMHIST_LOG(ubchist, "vp %#jx mbp %#jx num now %jd bytes 0x%jx", 1455 (uintptr_t)vp, (uintptr_t)mbp, vp->v_numoutput, bytes); 1456 mbp->b_bufsize = len; 1457 mbp->b_data = (void *)kva; 1458 mbp->b_resid = mbp->b_bcount = bytes; 1459 mbp->b_cflags = BC_BUSY | BC_AGE; 1460 if (async) { 1461 mbp->b_flags = brw | B_ASYNC; 1462 mbp->b_iodone = iodone; 1463 } else { 1464 mbp->b_flags = brw; 1465 mbp->b_iodone = NULL; 1466 } 1467 if (curlwp == uvm.pagedaemon_lwp) 1468 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 1469 else if (async || lazy) 1470 BIO_SETPRIO(mbp, BPRIO_TIMENONCRITICAL); 1471 else 1472 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 1473 1474 bp = NULL; 1475 for (offset = startoffset; 1476 bytes > 0; 1477 offset += iobytes, bytes -= iobytes) { 1478 int run; 1479 daddr_t lbn, blkno; 1480 struct vnode *devvp; 1481 1482 /* 1483 * bmap the file to find out the blkno to read from and 1484 * how much we can read in one i/o. if bmap returns an error, 1485 * skip the rest of the top-level i/o. 1486 */ 1487 1488 lbn = offset >> fs_bshift; 1489 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 1490 if (error) { 1491 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%jx -> %jd\n", 1492 lbn, error, 0, 0); 1493 skipbytes += bytes; 1494 bytes = 0; 1495 goto loopdone; 1496 } 1497 1498 /* 1499 * see how many pages can be read with this i/o. 1500 * reduce the i/o size if necessary to avoid 1501 * overwriting pages with valid data. 1502 */ 1503 1504 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 1505 bytes); 1506 1507 /* 1508 * if this block isn't allocated, zero it instead of 1509 * reading it. unless we are going to allocate blocks, 1510 * mark the pages we zeroed PG_RDONLY. 1511 */ 1512 1513 if (blkno == (daddr_t)-1) { 1514 if (!iowrite) { 1515 memset((char *)kva + (offset - startoffset), 0, 1516 iobytes); 1517 } 1518 skipbytes += iobytes; 1519 continue; 1520 } 1521 1522 /* 1523 * allocate a sub-buf for this piece of the i/o 1524 * (or just use mbp if there's only 1 piece), 1525 * and start it going. 1526 */ 1527 1528 if (offset == startoffset && iobytes == bytes) { 1529 bp = mbp; 1530 } else { 1531 UVMHIST_LOG(ubchist, "vp %#jx bp %#jx num now %jd", 1532 (uintptr_t)vp, (uintptr_t)bp, vp->v_numoutput, 0); 1533 bp = getiobuf(vp, true); 1534 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 1535 } 1536 bp->b_lblkno = 0; 1537 1538 /* adjust physical blkno for partial blocks */ 1539 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 1540 dev_bshift); 1541 1542 UVMHIST_LOG(ubchist, 1543 "bp %#jx offset 0x%jx bcount 0x%jx blkno 0x%jx", 1544 (uintptr_t)bp, offset, bp->b_bcount, bp->b_blkno); 1545 1546 VOP_STRATEGY(devvp, bp); 1547 } 1548 1549 loopdone: 1550 if (skipbytes) { 1551 UVMHIST_LOG(ubchist, "skipbytes %jd", skipbytes, 0,0,0); 1552 } 1553 nestiobuf_done(mbp, skipbytes, error); 1554 if (async) { 1555 UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); 1556 return (0); 1557 } 1558 UVMHIST_LOG(ubchist, "waiting for mbp %#jx", (uintptr_t)mbp, 0, 0, 0); 1559 error = biowait(mbp); 1560 s = splbio(); 1561 (*iodone)(mbp); 1562 splx(s); 1563 UVMHIST_LOG(ubchist, "returning, error %jd", error, 0, 0, 0); 1564 return (error); 1565 } 1566 1567 int 1568 genfs_compat_getpages(void *v) 1569 { 1570 struct vop_getpages_args /* { 1571 struct vnode *a_vp; 1572 voff_t a_offset; 1573 struct vm_page **a_m; 1574 int *a_count; 1575 int a_centeridx; 1576 vm_prot_t a_access_type; 1577 int a_advice; 1578 int a_flags; 1579 } */ *ap = v; 1580 1581 off_t origoffset; 1582 struct vnode *vp = ap->a_vp; 1583 struct uvm_object *uobj = &vp->v_uobj; 1584 struct vm_page *pg, **pgs; 1585 vaddr_t kva; 1586 int i, error, orignpages, npages; 1587 struct iovec iov; 1588 struct uio uio; 1589 kauth_cred_t cred = curlwp->l_cred; 1590 const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; 1591 1592 error = 0; 1593 origoffset = ap->a_offset; 1594 orignpages = *ap->a_count; 1595 pgs = ap->a_m; 1596 1597 if (ap->a_flags & PGO_LOCKED) { 1598 uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, 1599 UFP_NOWAIT|UFP_NOALLOC| (memwrite ? UFP_NORDONLY : 0)); 1600 1601 error = ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0; 1602 if (error == 0 && memwrite) { 1603 genfs_markdirty(vp); 1604 } 1605 return error; 1606 } 1607 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) { 1608 mutex_exit(uobj->vmobjlock); 1609 return EINVAL; 1610 } 1611 if ((ap->a_flags & PGO_SYNCIO) == 0) { 1612 mutex_exit(uobj->vmobjlock); 1613 return 0; 1614 } 1615 npages = orignpages; 1616 uvn_findpages(uobj, origoffset, &npages, pgs, UFP_ALL); 1617 mutex_exit(uobj->vmobjlock); 1618 kva = uvm_pagermapin(pgs, npages, 1619 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1620 for (i = 0; i < npages; i++) { 1621 pg = pgs[i]; 1622 if ((pg->flags & PG_FAKE) == 0) { 1623 continue; 1624 } 1625 iov.iov_base = (char *)kva + (i << PAGE_SHIFT); 1626 iov.iov_len = PAGE_SIZE; 1627 uio.uio_iov = &iov; 1628 uio.uio_iovcnt = 1; 1629 uio.uio_offset = origoffset + (i << PAGE_SHIFT); 1630 uio.uio_rw = UIO_READ; 1631 uio.uio_resid = PAGE_SIZE; 1632 UIO_SETUP_SYSSPACE(&uio); 1633 /* XXX vn_lock */ 1634 error = VOP_READ(vp, &uio, 0, cred); 1635 if (error) { 1636 break; 1637 } 1638 if (uio.uio_resid) { 1639 memset(iov.iov_base, 0, uio.uio_resid); 1640 } 1641 } 1642 uvm_pagermapout(kva, npages); 1643 mutex_enter(uobj->vmobjlock); 1644 mutex_enter(&uvm_pageqlock); 1645 for (i = 0; i < npages; i++) { 1646 pg = pgs[i]; 1647 if (error && (pg->flags & PG_FAKE) != 0) { 1648 pg->flags |= PG_RELEASED; 1649 } else { 1650 pmap_clear_modify(pg); 1651 uvm_pageactivate(pg); 1652 } 1653 } 1654 if (error) { 1655 uvm_page_unbusy(pgs, npages); 1656 } 1657 mutex_exit(&uvm_pageqlock); 1658 if (error == 0 && memwrite) { 1659 genfs_markdirty(vp); 1660 } 1661 mutex_exit(uobj->vmobjlock); 1662 return error; 1663 } 1664 1665 int 1666 genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, 1667 int flags) 1668 { 1669 off_t offset; 1670 struct iovec iov; 1671 struct uio uio; 1672 kauth_cred_t cred = curlwp->l_cred; 1673 struct buf *bp; 1674 vaddr_t kva; 1675 int error; 1676 1677 offset = pgs[0]->offset; 1678 kva = uvm_pagermapin(pgs, npages, 1679 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1680 1681 iov.iov_base = (void *)kva; 1682 iov.iov_len = npages << PAGE_SHIFT; 1683 uio.uio_iov = &iov; 1684 uio.uio_iovcnt = 1; 1685 uio.uio_offset = offset; 1686 uio.uio_rw = UIO_WRITE; 1687 uio.uio_resid = npages << PAGE_SHIFT; 1688 UIO_SETUP_SYSSPACE(&uio); 1689 /* XXX vn_lock */ 1690 error = VOP_WRITE(vp, &uio, 0, cred); 1691 1692 mutex_enter(vp->v_interlock); 1693 vp->v_numoutput++; 1694 mutex_exit(vp->v_interlock); 1695 1696 bp = getiobuf(vp, true); 1697 bp->b_cflags = BC_BUSY | BC_AGE; 1698 bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift; 1699 bp->b_data = (char *)kva; 1700 bp->b_bcount = npages << PAGE_SHIFT; 1701 bp->b_bufsize = npages << PAGE_SHIFT; 1702 bp->b_resid = 0; 1703 bp->b_error = error; 1704 uvm_aio_aiodone(bp); 1705 return (error); 1706 } 1707 1708 /* 1709 * Process a uio using direct I/O. If we reach a part of the request 1710 * which cannot be processed in this fashion for some reason, just return. 1711 * The caller must handle some additional part of the request using 1712 * buffered I/O before trying direct I/O again. 1713 */ 1714 1715 void 1716 genfs_directio(struct vnode *vp, struct uio *uio, int ioflag) 1717 { 1718 struct vmspace *vs; 1719 struct iovec *iov; 1720 vaddr_t va; 1721 size_t len; 1722 const int mask = DEV_BSIZE - 1; 1723 int error; 1724 bool need_wapbl = (vp->v_mount && vp->v_mount->mnt_wapbl && 1725 (ioflag & IO_JOURNALLOCKED) == 0); 1726 1727 #ifdef DIAGNOSTIC 1728 if ((ioflag & IO_JOURNALLOCKED) && vp->v_mount->mnt_wapbl) 1729 WAPBL_JLOCK_ASSERT(vp->v_mount); 1730 #endif 1731 1732 /* 1733 * We only support direct I/O to user space for now. 1734 */ 1735 1736 if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) { 1737 return; 1738 } 1739 1740 /* 1741 * If the vnode is mapped, we would need to get the getpages lock 1742 * to stabilize the bmap, but then we would get into trouble while 1743 * locking the pages if the pages belong to this same vnode (or a 1744 * multi-vnode cascade to the same effect). Just fall back to 1745 * buffered I/O if the vnode is mapped to avoid this mess. 1746 */ 1747 1748 if (vp->v_vflag & VV_MAPPED) { 1749 return; 1750 } 1751 1752 if (need_wapbl) { 1753 error = WAPBL_BEGIN(vp->v_mount); 1754 if (error) 1755 return; 1756 } 1757 1758 /* 1759 * Do as much of the uio as possible with direct I/O. 1760 */ 1761 1762 vs = uio->uio_vmspace; 1763 while (uio->uio_resid) { 1764 iov = uio->uio_iov; 1765 if (iov->iov_len == 0) { 1766 uio->uio_iov++; 1767 uio->uio_iovcnt--; 1768 continue; 1769 } 1770 va = (vaddr_t)iov->iov_base; 1771 len = MIN(iov->iov_len, genfs_maxdio); 1772 len &= ~mask; 1773 1774 /* 1775 * If the next chunk is smaller than DEV_BSIZE or extends past 1776 * the current EOF, then fall back to buffered I/O. 1777 */ 1778 1779 if (len == 0 || uio->uio_offset + len > vp->v_size) { 1780 break; 1781 } 1782 1783 /* 1784 * Check alignment. The file offset must be at least 1785 * sector-aligned. The exact constraint on memory alignment 1786 * is very hardware-dependent, but requiring sector-aligned 1787 * addresses there too is safe. 1788 */ 1789 1790 if (uio->uio_offset & mask || va & mask) { 1791 break; 1792 } 1793 error = genfs_do_directio(vs, va, len, vp, uio->uio_offset, 1794 uio->uio_rw); 1795 if (error) { 1796 break; 1797 } 1798 iov->iov_base = (char *)iov->iov_base + len; 1799 iov->iov_len -= len; 1800 uio->uio_offset += len; 1801 uio->uio_resid -= len; 1802 } 1803 1804 if (need_wapbl) 1805 WAPBL_END(vp->v_mount); 1806 } 1807 1808 /* 1809 * Iodone routine for direct I/O. We don't do much here since the request is 1810 * always synchronous, so the caller will do most of the work after biowait(). 1811 */ 1812 1813 static void 1814 genfs_dio_iodone(struct buf *bp) 1815 { 1816 1817 KASSERT((bp->b_flags & B_ASYNC) == 0); 1818 if ((bp->b_flags & B_READ) == 0 && (bp->b_cflags & BC_AGE) != 0) { 1819 mutex_enter(bp->b_objlock); 1820 vwakeup(bp); 1821 mutex_exit(bp->b_objlock); 1822 } 1823 putiobuf(bp); 1824 } 1825 1826 /* 1827 * Process one chunk of a direct I/O request. 1828 */ 1829 1830 static int 1831 genfs_do_directio(struct vmspace *vs, vaddr_t uva, size_t len, struct vnode *vp, 1832 off_t off, enum uio_rw rw) 1833 { 1834 struct vm_map *map; 1835 struct pmap *upm, *kpm __unused; 1836 size_t klen = round_page(uva + len) - trunc_page(uva); 1837 off_t spoff, epoff; 1838 vaddr_t kva, puva; 1839 paddr_t pa; 1840 vm_prot_t prot; 1841 int error, rv __diagused, poff, koff; 1842 const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED | 1843 (rw == UIO_WRITE ? PGO_FREE : 0); 1844 1845 /* 1846 * For writes, verify that this range of the file already has fully 1847 * allocated backing store. If there are any holes, just punt and 1848 * make the caller take the buffered write path. 1849 */ 1850 1851 if (rw == UIO_WRITE) { 1852 daddr_t lbn, elbn, blkno; 1853 int bsize, bshift, run; 1854 1855 bshift = vp->v_mount->mnt_fs_bshift; 1856 bsize = 1 << bshift; 1857 lbn = off >> bshift; 1858 elbn = (off + len + bsize - 1) >> bshift; 1859 while (lbn < elbn) { 1860 error = VOP_BMAP(vp, lbn, NULL, &blkno, &run); 1861 if (error) { 1862 return error; 1863 } 1864 if (blkno == (daddr_t)-1) { 1865 return ENOSPC; 1866 } 1867 lbn += 1 + run; 1868 } 1869 } 1870 1871 /* 1872 * Flush any cached pages for parts of the file that we're about to 1873 * access. If we're writing, invalidate pages as well. 1874 */ 1875 1876 spoff = trunc_page(off); 1877 epoff = round_page(off + len); 1878 mutex_enter(vp->v_interlock); 1879 error = VOP_PUTPAGES(vp, spoff, epoff, pgoflags); 1880 if (error) { 1881 return error; 1882 } 1883 1884 /* 1885 * Wire the user pages and remap them into kernel memory. 1886 */ 1887 1888 prot = rw == UIO_READ ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 1889 error = uvm_vslock(vs, (void *)uva, len, prot); 1890 if (error) { 1891 return error; 1892 } 1893 1894 map = &vs->vm_map; 1895 upm = vm_map_pmap(map); 1896 kpm = vm_map_pmap(kernel_map); 1897 puva = trunc_page(uva); 1898 kva = uvm_km_alloc(kernel_map, klen, atop(puva) & uvmexp.colormask, 1899 UVM_KMF_VAONLY | UVM_KMF_WAITVA | UVM_KMF_COLORMATCH); 1900 for (poff = 0; poff < klen; poff += PAGE_SIZE) { 1901 rv = pmap_extract(upm, puva + poff, &pa); 1902 KASSERT(rv); 1903 pmap_kenter_pa(kva + poff, pa, prot, PMAP_WIRED); 1904 } 1905 pmap_update(kpm); 1906 1907 /* 1908 * Do the I/O. 1909 */ 1910 1911 koff = uva - trunc_page(uva); 1912 error = genfs_do_io(vp, off, kva + koff, len, PGO_SYNCIO, rw, 1913 genfs_dio_iodone); 1914 1915 /* 1916 * Tear down the kernel mapping. 1917 */ 1918 1919 pmap_kremove(kva, klen); 1920 pmap_update(kpm); 1921 uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY); 1922 1923 /* 1924 * Unwire the user pages. 1925 */ 1926 1927 uvm_vsunlock(vs, (void *)uva, len); 1928 return error; 1929 } 1930