1 /* $NetBSD: genfs_io.c,v 1.21 2009/10/21 21:12:06 rmind 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 1.21 2009/10/21 21:12:06 rmind 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/namei.h> 42 #include <sys/vnode.h> 43 #include <sys/fcntl.h> 44 #include <sys/kmem.h> 45 #include <sys/poll.h> 46 #include <sys/mman.h> 47 #include <sys/file.h> 48 #include <sys/kauth.h> 49 #include <sys/fstrans.h> 50 #include <sys/buf.h> 51 52 #include <miscfs/genfs/genfs.h> 53 #include <miscfs/genfs/genfs_node.h> 54 #include <miscfs/specfs/specdev.h> 55 56 #include <uvm/uvm.h> 57 #include <uvm/uvm_pager.h> 58 59 static int genfs_do_directio(struct vmspace *, vaddr_t, size_t, struct vnode *, 60 off_t, enum uio_rw); 61 static void genfs_dio_iodone(struct buf *); 62 63 static int genfs_do_io(struct vnode *, off_t, vaddr_t, size_t, int, enum uio_rw, 64 void (*)(struct buf *)); 65 static inline void genfs_rel_pages(struct vm_page **, int); 66 67 int genfs_maxdio = MAXPHYS; 68 69 static inline void 70 genfs_rel_pages(struct vm_page **pgs, int npages) 71 { 72 int i; 73 74 for (i = 0; i < npages; i++) { 75 struct vm_page *pg = pgs[i]; 76 77 if (pg == NULL || pg == PGO_DONTCARE) 78 continue; 79 if (pg->flags & PG_FAKE) { 80 pg->flags |= PG_RELEASED; 81 } 82 } 83 mutex_enter(&uvm_pageqlock); 84 uvm_page_unbusy(pgs, npages); 85 mutex_exit(&uvm_pageqlock); 86 } 87 88 /* 89 * generic VM getpages routine. 90 * Return PG_BUSY pages for the given range, 91 * reading from backing store if necessary. 92 */ 93 94 int 95 genfs_getpages(void *v) 96 { 97 struct vop_getpages_args /* { 98 struct vnode *a_vp; 99 voff_t a_offset; 100 struct vm_page **a_m; 101 int *a_count; 102 int a_centeridx; 103 vm_prot_t a_access_type; 104 int a_advice; 105 int a_flags; 106 } */ *ap = v; 107 108 off_t newsize, diskeof, memeof; 109 off_t offset, origoffset, startoffset, endoffset; 110 daddr_t lbn, blkno; 111 int i, error, npages, orignpages, npgs, run, ridx, pidx, pcount; 112 int fs_bshift, fs_bsize, dev_bshift; 113 const int flags = ap->a_flags; 114 size_t bytes, iobytes, tailstart, tailbytes, totalbytes, skipbytes; 115 vaddr_t kva; 116 struct buf *bp, *mbp; 117 struct vnode *vp = ap->a_vp; 118 struct vnode *devvp; 119 struct genfs_node *gp = VTOG(vp); 120 struct uvm_object *uobj = &vp->v_uobj; 121 struct vm_page *pg, **pgs, *pgs_onstack[UBC_MAX_PAGES]; 122 int pgs_size; 123 kauth_cred_t cred = curlwp->l_cred; /* XXXUBC curlwp */ 124 const bool async = (flags & PGO_SYNCIO) == 0; 125 const bool write = (ap->a_access_type & VM_PROT_WRITE) != 0; 126 bool sawhole = false; 127 bool has_trans = false; 128 const bool overwrite = (flags & PGO_OVERWRITE) != 0; 129 const bool blockalloc = write && (flags & PGO_NOBLOCKALLOC) == 0; 130 voff_t origvsize; 131 UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); 132 133 UVMHIST_LOG(ubchist, "vp %p off 0x%x/%x count %d", 134 vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); 135 136 KASSERT(vp->v_type == VREG || vp->v_type == VDIR || 137 vp->v_type == VLNK || vp->v_type == VBLK); 138 139 pgs = NULL; 140 pgs_size = 0; 141 142 startover: 143 error = 0; 144 origvsize = vp->v_size; 145 origoffset = ap->a_offset; 146 orignpages = *ap->a_count; 147 GOP_SIZE(vp, origvsize, &diskeof, 0); 148 if (flags & PGO_PASTEOF) { 149 #if defined(DIAGNOSTIC) 150 off_t writeeof; 151 #endif /* defined(DIAGNOSTIC) */ 152 153 newsize = MAX(origvsize, 154 origoffset + (orignpages << PAGE_SHIFT)); 155 GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_MEM); 156 #if defined(DIAGNOSTIC) 157 GOP_SIZE(vp, vp->v_writesize, &writeeof, GOP_SIZE_MEM); 158 if (newsize > round_page(writeeof)) { 159 panic("%s: past eof", __func__); 160 } 161 #endif /* defined(DIAGNOSTIC) */ 162 } else { 163 GOP_SIZE(vp, origvsize, &memeof, GOP_SIZE_MEM); 164 } 165 KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); 166 KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); 167 KASSERT(orignpages > 0); 168 169 /* 170 * Bounds-check the request. 171 */ 172 173 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { 174 if ((flags & PGO_LOCKED) == 0) { 175 mutex_exit(&uobj->vmobjlock); 176 } 177 UVMHIST_LOG(ubchist, "off 0x%x count %d goes past EOF 0x%x", 178 origoffset, *ap->a_count, memeof,0); 179 error = EINVAL; 180 goto out_err; 181 } 182 183 /* uobj is locked */ 184 185 if ((flags & PGO_NOTIMESTAMP) == 0 && 186 (vp->v_type != VBLK || 187 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 188 int updflags = 0; 189 190 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) { 191 updflags = GOP_UPDATE_ACCESSED; 192 } 193 if (write) { 194 updflags |= GOP_UPDATE_MODIFIED; 195 } 196 if (updflags != 0) { 197 GOP_MARKUPDATE(vp, updflags); 198 } 199 } 200 201 if (write) { 202 gp->g_dirtygen++; 203 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 204 vn_syncer_add_to_worklist(vp, filedelay); 205 } 206 if ((vp->v_iflag & (VI_WRMAP|VI_WRMAPDIRTY)) == VI_WRMAP) { 207 vp->v_iflag |= VI_WRMAPDIRTY; 208 } 209 } 210 211 /* 212 * For PGO_LOCKED requests, just return whatever's in memory. 213 */ 214 215 if (flags & PGO_LOCKED) { 216 int nfound; 217 218 npages = *ap->a_count; 219 #if defined(DEBUG) 220 for (i = 0; i < npages; i++) { 221 pg = ap->a_m[i]; 222 KASSERT(pg == NULL || pg == PGO_DONTCARE); 223 } 224 #endif /* defined(DEBUG) */ 225 nfound = uvn_findpages(uobj, origoffset, &npages, 226 ap->a_m, UFP_NOWAIT|UFP_NOALLOC|(write ? UFP_NORDONLY : 0)); 227 KASSERT(npages == *ap->a_count); 228 if (nfound == 0) { 229 error = EBUSY; 230 goto out_err; 231 } 232 if (!rw_tryenter(&gp->g_glock, RW_READER)) { 233 genfs_rel_pages(ap->a_m, npages); 234 235 /* 236 * restore the array. 237 */ 238 239 for (i = 0; i < npages; i++) { 240 pg = ap->a_m[i]; 241 242 if (pg != NULL || pg != PGO_DONTCARE) { 243 ap->a_m[i] = NULL; 244 } 245 } 246 } else { 247 rw_exit(&gp->g_glock); 248 } 249 error = (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 250 goto out_err; 251 } 252 mutex_exit(&uobj->vmobjlock); 253 254 /* 255 * find the requested pages and make some simple checks. 256 * leave space in the page array for a whole block. 257 */ 258 259 if (vp->v_type != VBLK) { 260 fs_bshift = vp->v_mount->mnt_fs_bshift; 261 dev_bshift = vp->v_mount->mnt_dev_bshift; 262 } else { 263 fs_bshift = DEV_BSHIFT; 264 dev_bshift = DEV_BSHIFT; 265 } 266 fs_bsize = 1 << fs_bshift; 267 268 orignpages = MIN(orignpages, 269 round_page(memeof - origoffset) >> PAGE_SHIFT); 270 npages = orignpages; 271 startoffset = origoffset & ~(fs_bsize - 1); 272 endoffset = round_page((origoffset + (npages << PAGE_SHIFT) + 273 fs_bsize - 1) & ~(fs_bsize - 1)); 274 endoffset = MIN(endoffset, round_page(memeof)); 275 ridx = (origoffset - startoffset) >> PAGE_SHIFT; 276 277 pgs_size = sizeof(struct vm_page *) * 278 ((endoffset - startoffset) >> PAGE_SHIFT); 279 if (pgs_size > sizeof(pgs_onstack)) { 280 pgs = kmem_zalloc(pgs_size, async ? KM_NOSLEEP : KM_SLEEP); 281 if (pgs == NULL) { 282 pgs = pgs_onstack; 283 error = ENOMEM; 284 goto out_err; 285 } 286 } else { 287 pgs = pgs_onstack; 288 (void)memset(pgs, 0, pgs_size); 289 } 290 291 292 UVMHIST_LOG(ubchist, "ridx %d npages %d startoff %ld endoff %ld", 293 ridx, npages, startoffset, endoffset); 294 295 if (!has_trans) { 296 fstrans_start(vp->v_mount, FSTRANS_SHARED); 297 has_trans = true; 298 } 299 300 /* 301 * hold g_glock to prevent a race with truncate. 302 * 303 * check if our idea of v_size is still valid. 304 */ 305 306 if (blockalloc) { 307 rw_enter(&gp->g_glock, RW_WRITER); 308 } else { 309 rw_enter(&gp->g_glock, RW_READER); 310 } 311 mutex_enter(&uobj->vmobjlock); 312 if (vp->v_size < origvsize) { 313 rw_exit(&gp->g_glock); 314 if (pgs != pgs_onstack) 315 kmem_free(pgs, pgs_size); 316 goto startover; 317 } 318 319 if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], 320 async ? UFP_NOWAIT : UFP_ALL) != orignpages) { 321 rw_exit(&gp->g_glock); 322 KASSERT(async != 0); 323 genfs_rel_pages(&pgs[ridx], orignpages); 324 mutex_exit(&uobj->vmobjlock); 325 error = EBUSY; 326 goto out_err; 327 } 328 329 /* 330 * if the pages are already resident, just return them. 331 */ 332 333 for (i = 0; i < npages; i++) { 334 struct vm_page *pg1 = pgs[ridx + i]; 335 336 if ((pg1->flags & PG_FAKE) || 337 (blockalloc && (pg1->flags & PG_RDONLY))) { 338 break; 339 } 340 } 341 if (i == npages) { 342 rw_exit(&gp->g_glock); 343 UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); 344 npages += ridx; 345 goto out; 346 } 347 348 /* 349 * if PGO_OVERWRITE is set, don't bother reading the pages. 350 */ 351 352 if (overwrite) { 353 rw_exit(&gp->g_glock); 354 UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); 355 356 for (i = 0; i < npages; i++) { 357 struct vm_page *pg1 = pgs[ridx + i]; 358 359 pg1->flags &= ~(PG_RDONLY|PG_CLEAN); 360 } 361 npages += ridx; 362 goto out; 363 } 364 365 /* 366 * the page wasn't resident and we're not overwriting, 367 * so we're going to have to do some i/o. 368 * find any additional pages needed to cover the expanded range. 369 */ 370 371 npages = (endoffset - startoffset) >> PAGE_SHIFT; 372 if (startoffset != origoffset || npages != orignpages) { 373 374 /* 375 * we need to avoid deadlocks caused by locking 376 * additional pages at lower offsets than pages we 377 * already have locked. unlock them all and start over. 378 */ 379 380 genfs_rel_pages(&pgs[ridx], orignpages); 381 memset(pgs, 0, pgs_size); 382 383 UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x", 384 startoffset, endoffset, 0,0); 385 npgs = npages; 386 if (uvn_findpages(uobj, startoffset, &npgs, pgs, 387 async ? UFP_NOWAIT : UFP_ALL) != npages) { 388 rw_exit(&gp->g_glock); 389 KASSERT(async != 0); 390 genfs_rel_pages(pgs, npages); 391 mutex_exit(&uobj->vmobjlock); 392 error = EBUSY; 393 goto out_err; 394 } 395 } 396 mutex_exit(&uobj->vmobjlock); 397 398 /* 399 * read the desired page(s). 400 */ 401 402 totalbytes = npages << PAGE_SHIFT; 403 bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); 404 tailbytes = totalbytes - bytes; 405 skipbytes = 0; 406 407 kva = uvm_pagermapin(pgs, npages, 408 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 409 410 mbp = getiobuf(vp, true); 411 mbp->b_bufsize = totalbytes; 412 mbp->b_data = (void *)kva; 413 mbp->b_resid = mbp->b_bcount = bytes; 414 mbp->b_cflags = BC_BUSY; 415 if (async) { 416 mbp->b_flags = B_READ | B_ASYNC; 417 mbp->b_iodone = uvm_aio_biodone; 418 } else { 419 mbp->b_flags = B_READ; 420 mbp->b_iodone = NULL; 421 } 422 if (async) 423 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 424 else 425 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 426 427 /* 428 * if EOF is in the middle of the range, zero the part past EOF. 429 * skip over pages which are not PG_FAKE since in that case they have 430 * valid data that we need to preserve. 431 */ 432 433 tailstart = bytes; 434 while (tailbytes > 0) { 435 const int len = PAGE_SIZE - (tailstart & PAGE_MASK); 436 437 KASSERT(len <= tailbytes); 438 if ((pgs[tailstart >> PAGE_SHIFT]->flags & PG_FAKE) != 0) { 439 memset((void *)(kva + tailstart), 0, len); 440 UVMHIST_LOG(ubchist, "tailbytes %p 0x%x 0x%x", 441 kva, tailstart, len, 0); 442 } 443 tailstart += len; 444 tailbytes -= len; 445 } 446 447 /* 448 * now loop over the pages, reading as needed. 449 */ 450 451 bp = NULL; 452 for (offset = startoffset; 453 bytes > 0; 454 offset += iobytes, bytes -= iobytes) { 455 456 /* 457 * skip pages which don't need to be read. 458 */ 459 460 pidx = (offset - startoffset) >> PAGE_SHIFT; 461 while ((pgs[pidx]->flags & PG_FAKE) == 0) { 462 size_t b; 463 464 KASSERT((offset & (PAGE_SIZE - 1)) == 0); 465 if ((pgs[pidx]->flags & PG_RDONLY)) { 466 sawhole = true; 467 } 468 b = MIN(PAGE_SIZE, bytes); 469 offset += b; 470 bytes -= b; 471 skipbytes += b; 472 pidx++; 473 UVMHIST_LOG(ubchist, "skipping, new offset 0x%x", 474 offset, 0,0,0); 475 if (bytes == 0) { 476 goto loopdone; 477 } 478 } 479 480 /* 481 * bmap the file to find out the blkno to read from and 482 * how much we can read in one i/o. if bmap returns an error, 483 * skip the rest of the top-level i/o. 484 */ 485 486 lbn = offset >> fs_bshift; 487 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 488 if (error) { 489 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n", 490 lbn, error,0,0); 491 skipbytes += bytes; 492 goto loopdone; 493 } 494 495 /* 496 * see how many pages can be read with this i/o. 497 * reduce the i/o size if necessary to avoid 498 * overwriting pages with valid data. 499 */ 500 501 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 502 bytes); 503 if (offset + iobytes > round_page(offset)) { 504 pcount = 1; 505 while (pidx + pcount < npages && 506 pgs[pidx + pcount]->flags & PG_FAKE) { 507 pcount++; 508 } 509 iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - 510 (offset - trunc_page(offset))); 511 } 512 513 /* 514 * if this block isn't allocated, zero it instead of 515 * reading it. unless we are going to allocate blocks, 516 * mark the pages we zeroed PG_RDONLY. 517 */ 518 519 if (blkno < 0) { 520 int holepages = (round_page(offset + iobytes) - 521 trunc_page(offset)) >> PAGE_SHIFT; 522 UVMHIST_LOG(ubchist, "lbn 0x%x -> HOLE", lbn,0,0,0); 523 524 sawhole = true; 525 memset((char *)kva + (offset - startoffset), 0, 526 iobytes); 527 skipbytes += iobytes; 528 529 for (i = 0; i < holepages; i++) { 530 if (write) { 531 pgs[pidx + i]->flags &= ~PG_CLEAN; 532 } 533 if (!blockalloc) { 534 pgs[pidx + i]->flags |= PG_RDONLY; 535 } 536 } 537 continue; 538 } 539 540 /* 541 * allocate a sub-buf for this piece of the i/o 542 * (or just use mbp if there's only 1 piece), 543 * and start it going. 544 */ 545 546 if (offset == startoffset && iobytes == bytes) { 547 bp = mbp; 548 } else { 549 bp = getiobuf(vp, true); 550 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 551 } 552 bp->b_lblkno = 0; 553 554 /* adjust physical blkno for partial blocks */ 555 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 556 dev_bshift); 557 558 UVMHIST_LOG(ubchist, 559 "bp %p offset 0x%x bcount 0x%x blkno 0x%x", 560 bp, offset, iobytes, bp->b_blkno); 561 562 VOP_STRATEGY(devvp, bp); 563 } 564 565 loopdone: 566 nestiobuf_done(mbp, skipbytes, error); 567 if (async) { 568 UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); 569 rw_exit(&gp->g_glock); 570 error = 0; 571 goto out_err; 572 } 573 if (bp != NULL) { 574 error = biowait(mbp); 575 } 576 577 /* Remove the mapping (make KVA available as soon as possible) */ 578 uvm_pagermapout(kva, npages); 579 580 /* 581 * if this we encountered a hole then we have to do a little more work. 582 * for read faults, we marked the page PG_RDONLY so that future 583 * write accesses to the page will fault again. 584 * for write faults, we must make sure that the backing store for 585 * the page is completely allocated while the pages are locked. 586 */ 587 588 if (!error && sawhole && blockalloc) { 589 /* 590 * XXX: This assumes that we come here only via 591 * the mmio path 592 */ 593 if (vp->v_mount->mnt_wapbl) { 594 error = WAPBL_BEGIN(vp->v_mount); 595 } 596 597 if (!error) { 598 error = GOP_ALLOC(vp, startoffset, 599 npages << PAGE_SHIFT, 0, cred); 600 if (vp->v_mount->mnt_wapbl) { 601 WAPBL_END(vp->v_mount); 602 } 603 } 604 605 UVMHIST_LOG(ubchist, "gop_alloc off 0x%x/0x%x -> %d", 606 startoffset, npages << PAGE_SHIFT, error,0); 607 if (!error) { 608 for (i = 0; i < npages; i++) { 609 if (pgs[i] == NULL) { 610 continue; 611 } 612 pgs[i]->flags &= ~(PG_CLEAN|PG_RDONLY); 613 UVMHIST_LOG(ubchist, "mark dirty pg %p", 614 pgs[i],0,0,0); 615 } 616 } 617 } 618 rw_exit(&gp->g_glock); 619 620 putiobuf(mbp); 621 622 mutex_enter(&uobj->vmobjlock); 623 624 /* 625 * we're almost done! release the pages... 626 * for errors, we free the pages. 627 * otherwise we activate them and mark them as valid and clean. 628 * also, unbusy pages that were not actually requested. 629 */ 630 631 if (error) { 632 for (i = 0; i < npages; i++) { 633 if (pgs[i] == NULL) { 634 continue; 635 } 636 UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", 637 pgs[i], pgs[i]->flags, 0,0); 638 if (pgs[i]->flags & PG_FAKE) { 639 pgs[i]->flags |= PG_RELEASED; 640 } 641 } 642 mutex_enter(&uvm_pageqlock); 643 uvm_page_unbusy(pgs, npages); 644 mutex_exit(&uvm_pageqlock); 645 mutex_exit(&uobj->vmobjlock); 646 UVMHIST_LOG(ubchist, "returning error %d", error,0,0,0); 647 goto out_err; 648 } 649 650 out: 651 UVMHIST_LOG(ubchist, "succeeding, npages %d", npages,0,0,0); 652 error = 0; 653 mutex_enter(&uvm_pageqlock); 654 for (i = 0; i < npages; i++) { 655 pg = pgs[i]; 656 if (pg == NULL) { 657 continue; 658 } 659 UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", 660 pg, pg->flags, 0,0); 661 if (pg->flags & PG_FAKE && !overwrite) { 662 pg->flags &= ~(PG_FAKE); 663 pmap_clear_modify(pgs[i]); 664 } 665 KASSERT(!write || !blockalloc || (pg->flags & PG_RDONLY) == 0); 666 if (i < ridx || i >= ridx + orignpages || async) { 667 UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x", 668 pg, pg->offset,0,0); 669 if (pg->flags & PG_WANTED) { 670 wakeup(pg); 671 } 672 if (pg->flags & PG_FAKE) { 673 KASSERT(overwrite); 674 uvm_pagezero(pg); 675 } 676 if (pg->flags & PG_RELEASED) { 677 uvm_pagefree(pg); 678 continue; 679 } 680 uvm_pageenqueue(pg); 681 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE); 682 UVM_PAGE_OWN(pg, NULL); 683 } 684 } 685 mutex_exit(&uvm_pageqlock); 686 mutex_exit(&uobj->vmobjlock); 687 if (ap->a_m != NULL) { 688 memcpy(ap->a_m, &pgs[ridx], 689 orignpages * sizeof(struct vm_page *)); 690 } 691 692 out_err: 693 if (pgs != NULL && pgs != pgs_onstack) 694 kmem_free(pgs, pgs_size); 695 if (has_trans) 696 fstrans_done(vp->v_mount); 697 return (error); 698 } 699 700 /* 701 * generic VM putpages routine. 702 * Write the given range of pages to backing store. 703 * 704 * => "offhi == 0" means flush all pages at or after "offlo". 705 * => object should be locked by caller. we return with the 706 * object unlocked. 707 * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). 708 * thus, a caller might want to unlock higher level resources 709 * (e.g. vm_map) before calling flush. 710 * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, we will not block 711 * => if PGO_ALLPAGES is set, then all pages in the object will be processed. 712 * => NOTE: we rely on the fact that the object's memq is a TAILQ and 713 * that new pages are inserted on the tail end of the list. thus, 714 * we can make a complete pass through the object in one go by starting 715 * at the head and working towards the tail (new pages are put in 716 * front of us). 717 * => NOTE: we are allowed to lock the page queues, so the caller 718 * must not be holding the page queue lock. 719 * 720 * note on "cleaning" object and PG_BUSY pages: 721 * this routine is holding the lock on the object. the only time 722 * that it can run into a PG_BUSY page that it does not own is if 723 * some other process has started I/O on the page (e.g. either 724 * a pagein, or a pageout). if the PG_BUSY page is being paged 725 * in, then it can not be dirty (!PG_CLEAN) because no one has 726 * had a chance to modify it yet. if the PG_BUSY page is being 727 * paged out then it means that someone else has already started 728 * cleaning the page for us (how nice!). in this case, if we 729 * have syncio specified, then after we make our pass through the 730 * object we need to wait for the other PG_BUSY pages to clear 731 * off (i.e. we need to do an iosync). also note that once a 732 * page is PG_BUSY it must stay in its object until it is un-busyed. 733 * 734 * note on page traversal: 735 * we can traverse the pages in an object either by going down the 736 * linked list in "uobj->memq", or we can go over the address range 737 * by page doing hash table lookups for each address. depending 738 * on how many pages are in the object it may be cheaper to do one 739 * or the other. we set "by_list" to true if we are using memq. 740 * if the cost of a hash lookup was equal to the cost of the list 741 * traversal we could compare the number of pages in the start->stop 742 * range to the total number of pages in the object. however, it 743 * seems that a hash table lookup is more expensive than the linked 744 * list traversal, so we multiply the number of pages in the 745 * range by an estimate of the relatively higher cost of the hash lookup. 746 */ 747 748 int 749 genfs_putpages(void *v) 750 { 751 struct vop_putpages_args /* { 752 struct vnode *a_vp; 753 voff_t a_offlo; 754 voff_t a_offhi; 755 int a_flags; 756 } */ *ap = v; 757 758 return genfs_do_putpages(ap->a_vp, ap->a_offlo, ap->a_offhi, 759 ap->a_flags, NULL); 760 } 761 762 int 763 genfs_do_putpages(struct vnode *vp, off_t startoff, off_t endoff, 764 int origflags, struct vm_page **busypg) 765 { 766 struct uvm_object *uobj = &vp->v_uobj; 767 kmutex_t *slock = &uobj->vmobjlock; 768 off_t off; 769 /* Even for strange MAXPHYS, the shift rounds down to a page */ 770 #define maxpages (MAXPHYS >> PAGE_SHIFT) 771 int i, error, npages, nback; 772 int freeflag; 773 struct vm_page *pgs[maxpages], *pg, *nextpg, *tpg, curmp, endmp; 774 bool wasclean, by_list, needs_clean, yld; 775 bool async = (origflags & PGO_SYNCIO) == 0; 776 bool pagedaemon = curlwp == uvm.pagedaemon_lwp; 777 struct lwp *l = curlwp ? curlwp : &lwp0; 778 struct genfs_node *gp = VTOG(vp); 779 int flags; 780 int dirtygen; 781 bool modified; 782 bool need_wapbl; 783 bool has_trans; 784 bool cleanall; 785 bool onworklst; 786 787 UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); 788 789 KASSERT(origflags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); 790 KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); 791 KASSERT(startoff < endoff || endoff == 0); 792 793 UVMHIST_LOG(ubchist, "vp %p pages %d off 0x%x len 0x%x", 794 vp, uobj->uo_npages, startoff, endoff - startoff); 795 796 has_trans = false; 797 need_wapbl = (!pagedaemon && vp->v_mount && vp->v_mount->mnt_wapbl && 798 (origflags & PGO_JOURNALLOCKED) == 0); 799 800 retry: 801 modified = false; 802 flags = origflags; 803 KASSERT((vp->v_iflag & VI_ONWORKLST) != 0 || 804 (vp->v_iflag & VI_WRMAPDIRTY) == 0); 805 if (uobj->uo_npages == 0) { 806 if (vp->v_iflag & VI_ONWORKLST) { 807 vp->v_iflag &= ~VI_WRMAPDIRTY; 808 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 809 vn_syncer_remove_from_worklist(vp); 810 } 811 if (has_trans) { 812 if (need_wapbl) 813 WAPBL_END(vp->v_mount); 814 fstrans_done(vp->v_mount); 815 } 816 mutex_exit(slock); 817 return (0); 818 } 819 820 /* 821 * the vnode has pages, set up to process the request. 822 */ 823 824 if (!has_trans && (flags & PGO_CLEANIT) != 0) { 825 mutex_exit(slock); 826 if (pagedaemon) { 827 error = fstrans_start_nowait(vp->v_mount, FSTRANS_LAZY); 828 if (error) 829 return error; 830 } else 831 fstrans_start(vp->v_mount, FSTRANS_LAZY); 832 if (need_wapbl) { 833 error = WAPBL_BEGIN(vp->v_mount); 834 if (error) { 835 fstrans_done(vp->v_mount); 836 return error; 837 } 838 } 839 has_trans = true; 840 mutex_enter(slock); 841 goto retry; 842 } 843 844 error = 0; 845 wasclean = (vp->v_numoutput == 0); 846 off = startoff; 847 if (endoff == 0 || flags & PGO_ALLPAGES) { 848 endoff = trunc_page(LLONG_MAX); 849 } 850 by_list = (uobj->uo_npages <= 851 ((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_TREE_PENALTY); 852 853 #if !defined(DEBUG) 854 /* 855 * if this vnode is known not to have dirty pages, 856 * don't bother to clean it out. 857 */ 858 859 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 860 if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == 0) { 861 goto skip_scan; 862 } 863 flags &= ~PGO_CLEANIT; 864 } 865 #endif /* !defined(DEBUG) */ 866 867 /* 868 * start the loop. when scanning by list, hold the last page 869 * in the list before we start. pages allocated after we start 870 * will be added to the end of the list, so we can stop at the 871 * current last page. 872 */ 873 874 cleanall = (flags & PGO_CLEANIT) != 0 && wasclean && 875 startoff == 0 && endoff == trunc_page(LLONG_MAX) && 876 (vp->v_iflag & VI_ONWORKLST) != 0; 877 dirtygen = gp->g_dirtygen; 878 freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED; 879 if (by_list) { 880 curmp.uobject = uobj; 881 curmp.offset = (voff_t)-1; 882 curmp.flags = PG_BUSY; 883 endmp.uobject = uobj; 884 endmp.offset = (voff_t)-1; 885 endmp.flags = PG_BUSY; 886 pg = TAILQ_FIRST(&uobj->memq); 887 TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq.queue); 888 } else { 889 pg = uvm_pagelookup(uobj, off); 890 } 891 nextpg = NULL; 892 while (by_list || off < endoff) { 893 894 /* 895 * if the current page is not interesting, move on to the next. 896 */ 897 898 KASSERT(pg == NULL || pg->uobject == uobj); 899 KASSERT(pg == NULL || 900 (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 901 (pg->flags & PG_BUSY) != 0); 902 if (by_list) { 903 if (pg == &endmp) { 904 break; 905 } 906 if (pg->offset < startoff || pg->offset >= endoff || 907 pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 908 if (pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 909 wasclean = false; 910 } 911 pg = TAILQ_NEXT(pg, listq.queue); 912 continue; 913 } 914 off = pg->offset; 915 } else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 916 if (pg != NULL) { 917 wasclean = false; 918 } 919 off += PAGE_SIZE; 920 if (off < endoff) { 921 pg = uvm_pagelookup(uobj, off); 922 } 923 continue; 924 } 925 926 /* 927 * if the current page needs to be cleaned and it's busy, 928 * wait for it to become unbusy. 929 */ 930 931 yld = (l->l_cpu->ci_schedstate.spc_flags & 932 SPCF_SHOULDYIELD) && !pagedaemon; 933 if (pg->flags & PG_BUSY || yld) { 934 UVMHIST_LOG(ubchist, "busy %p", pg,0,0,0); 935 if (flags & PGO_BUSYFAIL && pg->flags & PG_BUSY) { 936 UVMHIST_LOG(ubchist, "busyfail %p", pg, 0,0,0); 937 error = EDEADLK; 938 if (busypg != NULL) 939 *busypg = pg; 940 break; 941 } 942 if (pagedaemon) { 943 /* 944 * someone has taken the page while we 945 * dropped the lock for fstrans_start. 946 */ 947 break; 948 } 949 if (by_list) { 950 TAILQ_INSERT_BEFORE(pg, &curmp, listq.queue); 951 UVMHIST_LOG(ubchist, "curmp next %p", 952 TAILQ_NEXT(&curmp, listq.queue), 0,0,0); 953 } 954 if (yld) { 955 mutex_exit(slock); 956 preempt(); 957 mutex_enter(slock); 958 } else { 959 pg->flags |= PG_WANTED; 960 UVM_UNLOCK_AND_WAIT(pg, slock, 0, "genput", 0); 961 mutex_enter(slock); 962 } 963 if (by_list) { 964 UVMHIST_LOG(ubchist, "after next %p", 965 TAILQ_NEXT(&curmp, listq.queue), 0,0,0); 966 pg = TAILQ_NEXT(&curmp, listq.queue); 967 TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); 968 } else { 969 pg = uvm_pagelookup(uobj, off); 970 } 971 continue; 972 } 973 974 /* 975 * if we're freeing, remove all mappings of the page now. 976 * if we're cleaning, check if the page is needs to be cleaned. 977 */ 978 979 if (flags & PGO_FREE) { 980 pmap_page_protect(pg, VM_PROT_NONE); 981 } else if (flags & PGO_CLEANIT) { 982 983 /* 984 * if we still have some hope to pull this vnode off 985 * from the syncer queue, write-protect the page. 986 */ 987 988 if (cleanall && wasclean && 989 gp->g_dirtygen == dirtygen) { 990 991 /* 992 * uobj pages get wired only by uvm_fault 993 * where uobj is locked. 994 */ 995 996 if (pg->wire_count == 0) { 997 pmap_page_protect(pg, 998 VM_PROT_READ|VM_PROT_EXECUTE); 999 } else { 1000 cleanall = false; 1001 } 1002 } 1003 } 1004 1005 if (flags & PGO_CLEANIT) { 1006 needs_clean = pmap_clear_modify(pg) || 1007 (pg->flags & PG_CLEAN) == 0; 1008 pg->flags |= PG_CLEAN; 1009 } else { 1010 needs_clean = false; 1011 } 1012 1013 /* 1014 * if we're cleaning, build a cluster. 1015 * the cluster will consist of pages which are currently dirty, 1016 * but they will be returned to us marked clean. 1017 * if not cleaning, just operate on the one page. 1018 */ 1019 1020 if (needs_clean) { 1021 KDASSERT((vp->v_iflag & VI_ONWORKLST)); 1022 wasclean = false; 1023 memset(pgs, 0, sizeof(pgs)); 1024 pg->flags |= PG_BUSY; 1025 UVM_PAGE_OWN(pg, "genfs_putpages"); 1026 1027 /* 1028 * first look backward. 1029 */ 1030 1031 npages = MIN(maxpages >> 1, off >> PAGE_SHIFT); 1032 nback = npages; 1033 uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0], 1034 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); 1035 if (nback) { 1036 memmove(&pgs[0], &pgs[npages - nback], 1037 nback * sizeof(pgs[0])); 1038 if (npages - nback < nback) 1039 memset(&pgs[nback], 0, 1040 (npages - nback) * sizeof(pgs[0])); 1041 else 1042 memset(&pgs[npages - nback], 0, 1043 nback * sizeof(pgs[0])); 1044 } 1045 1046 /* 1047 * then plug in our page of interest. 1048 */ 1049 1050 pgs[nback] = pg; 1051 1052 /* 1053 * then look forward to fill in the remaining space in 1054 * the array of pages. 1055 */ 1056 1057 npages = maxpages - nback - 1; 1058 uvn_findpages(uobj, off + PAGE_SIZE, &npages, 1059 &pgs[nback + 1], 1060 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); 1061 npages += nback + 1; 1062 } else { 1063 pgs[0] = pg; 1064 npages = 1; 1065 nback = 0; 1066 } 1067 1068 /* 1069 * apply FREE or DEACTIVATE options if requested. 1070 */ 1071 1072 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1073 mutex_enter(&uvm_pageqlock); 1074 } 1075 for (i = 0; i < npages; i++) { 1076 tpg = pgs[i]; 1077 KASSERT(tpg->uobject == uobj); 1078 if (by_list && tpg == TAILQ_NEXT(pg, listq.queue)) 1079 pg = tpg; 1080 if (tpg->offset < startoff || tpg->offset >= endoff) 1081 continue; 1082 if (flags & PGO_DEACTIVATE && tpg->wire_count == 0) { 1083 uvm_pagedeactivate(tpg); 1084 } else if (flags & PGO_FREE) { 1085 pmap_page_protect(tpg, VM_PROT_NONE); 1086 if (tpg->flags & PG_BUSY) { 1087 tpg->flags |= freeflag; 1088 if (pagedaemon) { 1089 uvm_pageout_start(1); 1090 uvm_pagedequeue(tpg); 1091 } 1092 } else { 1093 1094 /* 1095 * ``page is not busy'' 1096 * implies that npages is 1 1097 * and needs_clean is false. 1098 */ 1099 1100 nextpg = TAILQ_NEXT(tpg, listq.queue); 1101 uvm_pagefree(tpg); 1102 if (pagedaemon) 1103 uvmexp.pdfreed++; 1104 } 1105 } 1106 } 1107 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1108 mutex_exit(&uvm_pageqlock); 1109 } 1110 if (needs_clean) { 1111 modified = true; 1112 1113 /* 1114 * start the i/o. if we're traversing by list, 1115 * keep our place in the list with a marker page. 1116 */ 1117 1118 if (by_list) { 1119 TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp, 1120 listq.queue); 1121 } 1122 mutex_exit(slock); 1123 error = GOP_WRITE(vp, pgs, npages, flags); 1124 mutex_enter(slock); 1125 if (by_list) { 1126 pg = TAILQ_NEXT(&curmp, listq.queue); 1127 TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); 1128 } 1129 if (error) { 1130 break; 1131 } 1132 if (by_list) { 1133 continue; 1134 } 1135 } 1136 1137 /* 1138 * find the next page and continue if there was no error. 1139 */ 1140 1141 if (by_list) { 1142 if (nextpg) { 1143 pg = nextpg; 1144 nextpg = NULL; 1145 } else { 1146 pg = TAILQ_NEXT(pg, listq.queue); 1147 } 1148 } else { 1149 off += (npages - nback) << PAGE_SHIFT; 1150 if (off < endoff) { 1151 pg = uvm_pagelookup(uobj, off); 1152 } 1153 } 1154 } 1155 if (by_list) { 1156 TAILQ_REMOVE(&uobj->memq, &endmp, listq.queue); 1157 } 1158 1159 if (modified && (vp->v_iflag & VI_WRMAPDIRTY) != 0 && 1160 (vp->v_type != VBLK || 1161 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 1162 GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED); 1163 } 1164 1165 /* 1166 * if we're cleaning and there was nothing to clean, 1167 * take us off the syncer list. if we started any i/o 1168 * and we're doing sync i/o, wait for all writes to finish. 1169 */ 1170 1171 if (cleanall && wasclean && gp->g_dirtygen == dirtygen && 1172 (vp->v_iflag & VI_ONWORKLST) != 0) { 1173 #if defined(DEBUG) 1174 TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { 1175 if ((pg->flags & PG_CLEAN) == 0) { 1176 printf("%s: %p: !CLEAN\n", __func__, pg); 1177 } 1178 if (pmap_is_modified(pg)) { 1179 printf("%s: %p: modified\n", __func__, pg); 1180 } 1181 } 1182 #endif /* defined(DEBUG) */ 1183 vp->v_iflag &= ~VI_WRMAPDIRTY; 1184 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 1185 vn_syncer_remove_from_worklist(vp); 1186 } 1187 1188 #if !defined(DEBUG) 1189 skip_scan: 1190 #endif /* !defined(DEBUG) */ 1191 1192 /* Wait for output to complete. */ 1193 if (!wasclean && !async && vp->v_numoutput != 0) { 1194 while (vp->v_numoutput != 0) 1195 cv_wait(&vp->v_cv, slock); 1196 } 1197 onworklst = (vp->v_iflag & VI_ONWORKLST) != 0; 1198 mutex_exit(slock); 1199 1200 if ((flags & PGO_RECLAIM) != 0 && onworklst) { 1201 /* 1202 * in the case of PGO_RECLAIM, ensure to make the vnode clean. 1203 * retrying is not a big deal because, in many cases, 1204 * uobj->uo_npages is already 0 here. 1205 */ 1206 mutex_enter(slock); 1207 goto retry; 1208 } 1209 1210 if (has_trans) { 1211 if (need_wapbl) 1212 WAPBL_END(vp->v_mount); 1213 fstrans_done(vp->v_mount); 1214 } 1215 1216 return (error); 1217 } 1218 1219 int 1220 genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1221 { 1222 off_t off; 1223 vaddr_t kva; 1224 size_t len; 1225 int error; 1226 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1227 1228 UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x", 1229 vp, pgs, npages, flags); 1230 1231 off = pgs[0]->offset; 1232 kva = uvm_pagermapin(pgs, npages, 1233 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1234 len = npages << PAGE_SHIFT; 1235 1236 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1237 uvm_aio_biodone); 1238 1239 return error; 1240 } 1241 1242 int 1243 genfs_gop_write_rwmap(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1244 { 1245 off_t off; 1246 vaddr_t kva; 1247 size_t len; 1248 int error; 1249 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1250 1251 UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x", 1252 vp, pgs, npages, flags); 1253 1254 off = pgs[0]->offset; 1255 kva = uvm_pagermapin(pgs, npages, 1256 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1257 len = npages << PAGE_SHIFT; 1258 1259 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1260 uvm_aio_biodone); 1261 1262 return error; 1263 } 1264 1265 /* 1266 * Backend routine for doing I/O to vnode pages. Pages are already locked 1267 * and mapped into kernel memory. Here we just look up the underlying 1268 * device block addresses and call the strategy routine. 1269 */ 1270 1271 static int 1272 genfs_do_io(struct vnode *vp, off_t off, vaddr_t kva, size_t len, int flags, 1273 enum uio_rw rw, void (*iodone)(struct buf *)) 1274 { 1275 int s, error, run; 1276 int fs_bshift, dev_bshift; 1277 off_t eof, offset, startoffset; 1278 size_t bytes, iobytes, skipbytes; 1279 daddr_t lbn, blkno; 1280 struct buf *mbp, *bp; 1281 struct vnode *devvp; 1282 bool async = (flags & PGO_SYNCIO) == 0; 1283 bool write = rw == UIO_WRITE; 1284 int brw = write ? B_WRITE : B_READ; 1285 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1286 1287 UVMHIST_LOG(ubchist, "vp %p kva %p len 0x%x flags 0x%x", 1288 vp, kva, len, flags); 1289 1290 KASSERT(vp->v_size <= vp->v_writesize); 1291 GOP_SIZE(vp, vp->v_writesize, &eof, 0); 1292 if (vp->v_type != VBLK) { 1293 fs_bshift = vp->v_mount->mnt_fs_bshift; 1294 dev_bshift = vp->v_mount->mnt_dev_bshift; 1295 } else { 1296 fs_bshift = DEV_BSHIFT; 1297 dev_bshift = DEV_BSHIFT; 1298 } 1299 error = 0; 1300 startoffset = off; 1301 bytes = MIN(len, eof - startoffset); 1302 skipbytes = 0; 1303 KASSERT(bytes != 0); 1304 1305 if (write) { 1306 mutex_enter(&vp->v_interlock); 1307 vp->v_numoutput += 2; 1308 mutex_exit(&vp->v_interlock); 1309 } 1310 mbp = getiobuf(vp, true); 1311 UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x", 1312 vp, mbp, vp->v_numoutput, bytes); 1313 mbp->b_bufsize = len; 1314 mbp->b_data = (void *)kva; 1315 mbp->b_resid = mbp->b_bcount = bytes; 1316 mbp->b_cflags = BC_BUSY | BC_AGE; 1317 if (async) { 1318 mbp->b_flags = brw | B_ASYNC; 1319 mbp->b_iodone = iodone; 1320 } else { 1321 mbp->b_flags = brw; 1322 mbp->b_iodone = NULL; 1323 } 1324 if (curlwp == uvm.pagedaemon_lwp) 1325 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 1326 else if (async) 1327 BIO_SETPRIO(mbp, BPRIO_TIMENONCRITICAL); 1328 else 1329 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 1330 1331 bp = NULL; 1332 for (offset = startoffset; 1333 bytes > 0; 1334 offset += iobytes, bytes -= iobytes) { 1335 lbn = offset >> fs_bshift; 1336 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 1337 if (error) { 1338 UVMHIST_LOG(ubchist, "VOP_BMAP() -> %d", error,0,0,0); 1339 skipbytes += bytes; 1340 bytes = 0; 1341 break; 1342 } 1343 1344 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 1345 bytes); 1346 if (blkno == (daddr_t)-1) { 1347 if (!write) { 1348 memset((char *)kva + (offset - startoffset), 0, 1349 iobytes); 1350 } 1351 skipbytes += iobytes; 1352 continue; 1353 } 1354 1355 /* if it's really one i/o, don't make a second buf */ 1356 if (offset == startoffset && iobytes == bytes) { 1357 bp = mbp; 1358 } else { 1359 UVMHIST_LOG(ubchist, "vp %p bp %p num now %d", 1360 vp, bp, vp->v_numoutput, 0); 1361 bp = getiobuf(vp, true); 1362 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 1363 } 1364 bp->b_lblkno = 0; 1365 1366 /* adjust physical blkno for partial blocks */ 1367 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 1368 dev_bshift); 1369 UVMHIST_LOG(ubchist, 1370 "vp %p offset 0x%x bcount 0x%x blkno 0x%x", 1371 vp, offset, bp->b_bcount, bp->b_blkno); 1372 1373 VOP_STRATEGY(devvp, bp); 1374 } 1375 if (skipbytes) { 1376 UVMHIST_LOG(ubchist, "skipbytes %d", skipbytes, 0,0,0); 1377 } 1378 nestiobuf_done(mbp, skipbytes, error); 1379 if (async) { 1380 UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); 1381 return (0); 1382 } 1383 UVMHIST_LOG(ubchist, "waiting for mbp %p", mbp,0,0,0); 1384 error = biowait(mbp); 1385 s = splbio(); 1386 (*iodone)(mbp); 1387 splx(s); 1388 UVMHIST_LOG(ubchist, "returning, error %d", error,0,0,0); 1389 return (error); 1390 } 1391 1392 int 1393 genfs_compat_getpages(void *v) 1394 { 1395 struct vop_getpages_args /* { 1396 struct vnode *a_vp; 1397 voff_t a_offset; 1398 struct vm_page **a_m; 1399 int *a_count; 1400 int a_centeridx; 1401 vm_prot_t a_access_type; 1402 int a_advice; 1403 int a_flags; 1404 } */ *ap = v; 1405 1406 off_t origoffset; 1407 struct vnode *vp = ap->a_vp; 1408 struct uvm_object *uobj = &vp->v_uobj; 1409 struct vm_page *pg, **pgs; 1410 vaddr_t kva; 1411 int i, error, orignpages, npages; 1412 struct iovec iov; 1413 struct uio uio; 1414 kauth_cred_t cred = curlwp->l_cred; 1415 bool write = (ap->a_access_type & VM_PROT_WRITE) != 0; 1416 1417 error = 0; 1418 origoffset = ap->a_offset; 1419 orignpages = *ap->a_count; 1420 pgs = ap->a_m; 1421 1422 if (write && (vp->v_iflag & VI_ONWORKLST) == 0) { 1423 vn_syncer_add_to_worklist(vp, filedelay); 1424 } 1425 if (ap->a_flags & PGO_LOCKED) { 1426 uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, 1427 UFP_NOWAIT|UFP_NOALLOC| (write ? UFP_NORDONLY : 0)); 1428 1429 return (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 1430 } 1431 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) { 1432 mutex_exit(&uobj->vmobjlock); 1433 return (EINVAL); 1434 } 1435 if ((ap->a_flags & PGO_SYNCIO) == 0) { 1436 mutex_exit(&uobj->vmobjlock); 1437 return 0; 1438 } 1439 npages = orignpages; 1440 uvn_findpages(uobj, origoffset, &npages, pgs, UFP_ALL); 1441 mutex_exit(&uobj->vmobjlock); 1442 kva = uvm_pagermapin(pgs, npages, 1443 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1444 for (i = 0; i < npages; i++) { 1445 pg = pgs[i]; 1446 if ((pg->flags & PG_FAKE) == 0) { 1447 continue; 1448 } 1449 iov.iov_base = (char *)kva + (i << PAGE_SHIFT); 1450 iov.iov_len = PAGE_SIZE; 1451 uio.uio_iov = &iov; 1452 uio.uio_iovcnt = 1; 1453 uio.uio_offset = origoffset + (i << PAGE_SHIFT); 1454 uio.uio_rw = UIO_READ; 1455 uio.uio_resid = PAGE_SIZE; 1456 UIO_SETUP_SYSSPACE(&uio); 1457 /* XXX vn_lock */ 1458 error = VOP_READ(vp, &uio, 0, cred); 1459 if (error) { 1460 break; 1461 } 1462 if (uio.uio_resid) { 1463 memset(iov.iov_base, 0, uio.uio_resid); 1464 } 1465 } 1466 uvm_pagermapout(kva, npages); 1467 mutex_enter(&uobj->vmobjlock); 1468 mutex_enter(&uvm_pageqlock); 1469 for (i = 0; i < npages; i++) { 1470 pg = pgs[i]; 1471 if (error && (pg->flags & PG_FAKE) != 0) { 1472 pg->flags |= PG_RELEASED; 1473 } else { 1474 pmap_clear_modify(pg); 1475 uvm_pageactivate(pg); 1476 } 1477 } 1478 if (error) { 1479 uvm_page_unbusy(pgs, npages); 1480 } 1481 mutex_exit(&uvm_pageqlock); 1482 mutex_exit(&uobj->vmobjlock); 1483 return (error); 1484 } 1485 1486 int 1487 genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, 1488 int flags) 1489 { 1490 off_t offset; 1491 struct iovec iov; 1492 struct uio uio; 1493 kauth_cred_t cred = curlwp->l_cred; 1494 struct buf *bp; 1495 vaddr_t kva; 1496 int error; 1497 1498 offset = pgs[0]->offset; 1499 kva = uvm_pagermapin(pgs, npages, 1500 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1501 1502 iov.iov_base = (void *)kva; 1503 iov.iov_len = npages << PAGE_SHIFT; 1504 uio.uio_iov = &iov; 1505 uio.uio_iovcnt = 1; 1506 uio.uio_offset = offset; 1507 uio.uio_rw = UIO_WRITE; 1508 uio.uio_resid = npages << PAGE_SHIFT; 1509 UIO_SETUP_SYSSPACE(&uio); 1510 /* XXX vn_lock */ 1511 error = VOP_WRITE(vp, &uio, 0, cred); 1512 1513 mutex_enter(&vp->v_interlock); 1514 vp->v_numoutput++; 1515 mutex_exit(&vp->v_interlock); 1516 1517 bp = getiobuf(vp, true); 1518 bp->b_cflags = BC_BUSY | BC_AGE; 1519 bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift; 1520 bp->b_data = (char *)kva; 1521 bp->b_bcount = npages << PAGE_SHIFT; 1522 bp->b_bufsize = npages << PAGE_SHIFT; 1523 bp->b_resid = 0; 1524 bp->b_error = error; 1525 uvm_aio_aiodone(bp); 1526 return (error); 1527 } 1528 1529 /* 1530 * Process a uio using direct I/O. If we reach a part of the request 1531 * which cannot be processed in this fashion for some reason, just return. 1532 * The caller must handle some additional part of the request using 1533 * buffered I/O before trying direct I/O again. 1534 */ 1535 1536 void 1537 genfs_directio(struct vnode *vp, struct uio *uio, int ioflag) 1538 { 1539 struct vmspace *vs; 1540 struct iovec *iov; 1541 vaddr_t va; 1542 size_t len; 1543 const int mask = DEV_BSIZE - 1; 1544 int error; 1545 bool need_wapbl = (vp->v_mount && vp->v_mount->mnt_wapbl && 1546 (ioflag & IO_JOURNALLOCKED) == 0); 1547 1548 /* 1549 * We only support direct I/O to user space for now. 1550 */ 1551 1552 if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) { 1553 return; 1554 } 1555 1556 /* 1557 * If the vnode is mapped, we would need to get the getpages lock 1558 * to stabilize the bmap, but then we would get into trouble whil e 1559 * locking the pages if the pages belong to this same vnode (or a 1560 * multi-vnode cascade to the same effect). Just fall back to 1561 * buffered I/O if the vnode is mapped to avoid this mess. 1562 */ 1563 1564 if (vp->v_vflag & VV_MAPPED) { 1565 return; 1566 } 1567 1568 if (need_wapbl) { 1569 error = WAPBL_BEGIN(vp->v_mount); 1570 if (error) 1571 return; 1572 } 1573 1574 /* 1575 * Do as much of the uio as possible with direct I/O. 1576 */ 1577 1578 vs = uio->uio_vmspace; 1579 while (uio->uio_resid) { 1580 iov = uio->uio_iov; 1581 if (iov->iov_len == 0) { 1582 uio->uio_iov++; 1583 uio->uio_iovcnt--; 1584 continue; 1585 } 1586 va = (vaddr_t)iov->iov_base; 1587 len = MIN(iov->iov_len, genfs_maxdio); 1588 len &= ~mask; 1589 1590 /* 1591 * If the next chunk is smaller than DEV_BSIZE or extends past 1592 * the current EOF, then fall back to buffered I/O. 1593 */ 1594 1595 if (len == 0 || uio->uio_offset + len > vp->v_size) { 1596 break; 1597 } 1598 1599 /* 1600 * Check alignment. The file offset must be at least 1601 * sector-aligned. The exact constraint on memory alignment 1602 * is very hardware-dependent, but requiring sector-aligned 1603 * addresses there too is safe. 1604 */ 1605 1606 if (uio->uio_offset & mask || va & mask) { 1607 break; 1608 } 1609 error = genfs_do_directio(vs, va, len, vp, uio->uio_offset, 1610 uio->uio_rw); 1611 if (error) { 1612 break; 1613 } 1614 iov->iov_base = (char *)iov->iov_base + len; 1615 iov->iov_len -= len; 1616 uio->uio_offset += len; 1617 uio->uio_resid -= len; 1618 } 1619 1620 if (need_wapbl) 1621 WAPBL_END(vp->v_mount); 1622 } 1623 1624 /* 1625 * Iodone routine for direct I/O. We don't do much here since the request is 1626 * always synchronous, so the caller will do most of the work after biowait(). 1627 */ 1628 1629 static void 1630 genfs_dio_iodone(struct buf *bp) 1631 { 1632 1633 KASSERT((bp->b_flags & B_ASYNC) == 0); 1634 if ((bp->b_flags & B_READ) == 0 && (bp->b_cflags & BC_AGE) != 0) { 1635 mutex_enter(bp->b_objlock); 1636 vwakeup(bp); 1637 mutex_exit(bp->b_objlock); 1638 } 1639 putiobuf(bp); 1640 } 1641 1642 /* 1643 * Process one chunk of a direct I/O request. 1644 */ 1645 1646 static int 1647 genfs_do_directio(struct vmspace *vs, vaddr_t uva, size_t len, struct vnode *vp, 1648 off_t off, enum uio_rw rw) 1649 { 1650 struct vm_map *map; 1651 struct pmap *upm, *kpm; 1652 size_t klen = round_page(uva + len) - trunc_page(uva); 1653 off_t spoff, epoff; 1654 vaddr_t kva, puva; 1655 paddr_t pa; 1656 vm_prot_t prot; 1657 int error, rv, poff, koff; 1658 const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED | 1659 (rw == UIO_WRITE ? PGO_FREE : 0); 1660 1661 /* 1662 * For writes, verify that this range of the file already has fully 1663 * allocated backing store. If there are any holes, just punt and 1664 * make the caller take the buffered write path. 1665 */ 1666 1667 if (rw == UIO_WRITE) { 1668 daddr_t lbn, elbn, blkno; 1669 int bsize, bshift, run; 1670 1671 bshift = vp->v_mount->mnt_fs_bshift; 1672 bsize = 1 << bshift; 1673 lbn = off >> bshift; 1674 elbn = (off + len + bsize - 1) >> bshift; 1675 while (lbn < elbn) { 1676 error = VOP_BMAP(vp, lbn, NULL, &blkno, &run); 1677 if (error) { 1678 return error; 1679 } 1680 if (blkno == (daddr_t)-1) { 1681 return ENOSPC; 1682 } 1683 lbn += 1 + run; 1684 } 1685 } 1686 1687 /* 1688 * Flush any cached pages for parts of the file that we're about to 1689 * access. If we're writing, invalidate pages as well. 1690 */ 1691 1692 spoff = trunc_page(off); 1693 epoff = round_page(off + len); 1694 mutex_enter(&vp->v_interlock); 1695 error = VOP_PUTPAGES(vp, spoff, epoff, pgoflags); 1696 if (error) { 1697 return error; 1698 } 1699 1700 /* 1701 * Wire the user pages and remap them into kernel memory. 1702 */ 1703 1704 prot = rw == UIO_READ ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 1705 error = uvm_vslock(vs, (void *)uva, len, prot); 1706 if (error) { 1707 return error; 1708 } 1709 1710 map = &vs->vm_map; 1711 upm = vm_map_pmap(map); 1712 kpm = vm_map_pmap(kernel_map); 1713 kva = uvm_km_alloc(kernel_map, klen, 0, 1714 UVM_KMF_VAONLY | UVM_KMF_WAITVA); 1715 puva = trunc_page(uva); 1716 for (poff = 0; poff < klen; poff += PAGE_SIZE) { 1717 rv = pmap_extract(upm, puva + poff, &pa); 1718 KASSERT(rv); 1719 pmap_enter(kpm, kva + poff, pa, prot, prot | PMAP_WIRED); 1720 } 1721 pmap_update(kpm); 1722 1723 /* 1724 * Do the I/O. 1725 */ 1726 1727 koff = uva - trunc_page(uva); 1728 error = genfs_do_io(vp, off, kva + koff, len, PGO_SYNCIO, rw, 1729 genfs_dio_iodone); 1730 1731 /* 1732 * Tear down the kernel mapping. 1733 */ 1734 1735 pmap_remove(kpm, kva, kva + klen); 1736 pmap_update(kpm); 1737 uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY); 1738 1739 /* 1740 * Unwire the user pages. 1741 */ 1742 1743 uvm_vsunlock(vs, (void *)uva, len); 1744 return error; 1745 } 1746 1747