1 /* $NetBSD: genfs_io.c,v 1.1 2007/10/17 16:45:00 pooka 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 1.1 2007/10/17 16:45:00 pooka 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 51 #include <miscfs/genfs/genfs.h> 52 #include <miscfs/genfs/genfs_node.h> 53 #include <miscfs/specfs/specdev.h> 54 55 #include <uvm/uvm.h> 56 #include <uvm/uvm_pager.h> 57 58 static int genfs_do_directio(struct vmspace *, vaddr_t, size_t, struct vnode *, 59 off_t, enum uio_rw); 60 static void genfs_dio_iodone(struct buf *); 61 62 static int genfs_do_io(struct vnode *, off_t, vaddr_t, size_t, int, enum uio_rw, 63 void (*)(struct buf *)); 64 static inline void genfs_rel_pages(struct vm_page **, int); 65 66 #define MAX_READ_PAGES 16 /* XXXUBC 16 */ 67 68 int genfs_maxdio = MAXPHYS; 69 70 static inline void 71 genfs_rel_pages(struct vm_page **pgs, int npages) 72 { 73 int i; 74 75 for (i = 0; i < npages; i++) { 76 struct vm_page *pg = pgs[i]; 77 78 if (pg == NULL || pg == PGO_DONTCARE) 79 continue; 80 if (pg->flags & PG_FAKE) { 81 pg->flags |= PG_RELEASED; 82 } 83 } 84 uvm_lock_pageq(); 85 uvm_page_unbusy(pgs, npages); 86 uvm_unlock_pageq(); 87 } 88 89 /* 90 * generic VM getpages routine. 91 * Return PG_BUSY pages for the given range, 92 * reading from backing store if necessary. 93 */ 94 95 int 96 genfs_getpages(void *v) 97 { 98 struct vop_getpages_args /* { 99 struct vnode *a_vp; 100 voff_t a_offset; 101 struct vm_page **a_m; 102 int *a_count; 103 int a_centeridx; 104 vm_prot_t a_access_type; 105 int a_advice; 106 int a_flags; 107 } */ *ap = v; 108 109 off_t newsize, diskeof, memeof; 110 off_t offset, origoffset, startoffset, endoffset; 111 daddr_t lbn, blkno; 112 int i, error, npages, orignpages, npgs, run, ridx, pidx, pcount; 113 int fs_bshift, fs_bsize, dev_bshift; 114 int flags = ap->a_flags; 115 size_t bytes, iobytes, tailstart, tailbytes, totalbytes, skipbytes; 116 vaddr_t kva; 117 struct buf *bp, *mbp; 118 struct vnode *vp = ap->a_vp; 119 struct vnode *devvp; 120 struct genfs_node *gp = VTOG(vp); 121 struct uvm_object *uobj = &vp->v_uobj; 122 struct vm_page *pg, **pgs, *pgs_onstack[MAX_READ_PAGES]; 123 int pgs_size; 124 kauth_cred_t cred = curlwp->l_cred; /* XXXUBC curlwp */ 125 bool async = (flags & PGO_SYNCIO) == 0; 126 bool write = (ap->a_access_type & VM_PROT_WRITE) != 0; 127 bool sawhole = false; 128 bool has_trans = false; 129 bool overwrite = (flags & PGO_OVERWRITE) != 0; 130 bool blockalloc = write && (flags & PGO_NOBLOCKALLOC) == 0; 131 voff_t origvsize; 132 UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); 133 134 UVMHIST_LOG(ubchist, "vp %p off 0x%x/%x count %d", 135 vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); 136 137 KASSERT(vp->v_type == VREG || vp->v_type == VDIR || 138 vp->v_type == VLNK || vp->v_type == VBLK); 139 140 /* XXXUBC temp limit */ 141 if (*ap->a_count > MAX_READ_PAGES) { 142 panic("genfs_getpages: too many pages"); 143 } 144 145 pgs = pgs_onstack; 146 pgs_size = sizeof(pgs_onstack); 147 148 startover: 149 error = 0; 150 origvsize = vp->v_size; 151 origoffset = ap->a_offset; 152 orignpages = *ap->a_count; 153 GOP_SIZE(vp, origvsize, &diskeof, 0); 154 if (flags & PGO_PASTEOF) { 155 #if defined(DIAGNOSTIC) 156 off_t writeeof; 157 #endif /* defined(DIAGNOSTIC) */ 158 159 newsize = MAX(origvsize, 160 origoffset + (orignpages << PAGE_SHIFT)); 161 GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_MEM); 162 #if defined(DIAGNOSTIC) 163 GOP_SIZE(vp, vp->v_writesize, &writeeof, GOP_SIZE_MEM); 164 if (newsize > round_page(writeeof)) { 165 panic("%s: past eof", __func__); 166 } 167 #endif /* defined(DIAGNOSTIC) */ 168 } else { 169 GOP_SIZE(vp, origvsize, &memeof, GOP_SIZE_MEM); 170 } 171 KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); 172 KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); 173 KASSERT(orignpages > 0); 174 175 /* 176 * Bounds-check the request. 177 */ 178 179 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { 180 if ((flags & PGO_LOCKED) == 0) { 181 simple_unlock(&uobj->vmobjlock); 182 } 183 UVMHIST_LOG(ubchist, "off 0x%x count %d goes past EOF 0x%x", 184 origoffset, *ap->a_count, memeof,0); 185 error = EINVAL; 186 goto out_err; 187 } 188 189 /* uobj is locked */ 190 191 if ((flags & PGO_NOTIMESTAMP) == 0 && 192 (vp->v_type != VBLK || 193 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 194 int updflags = 0; 195 196 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) { 197 updflags = GOP_UPDATE_ACCESSED; 198 } 199 if (write) { 200 updflags |= GOP_UPDATE_MODIFIED; 201 } 202 if (updflags != 0) { 203 GOP_MARKUPDATE(vp, updflags); 204 } 205 } 206 207 if (write) { 208 gp->g_dirtygen++; 209 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 210 vn_syncer_add_to_worklist(vp, filedelay); 211 } 212 if ((vp->v_iflag & (VI_WRMAP|VI_WRMAPDIRTY)) == VI_WRMAP) { 213 vp->v_iflag |= VI_WRMAPDIRTY; 214 } 215 } 216 217 /* 218 * For PGO_LOCKED requests, just return whatever's in memory. 219 */ 220 221 if (flags & PGO_LOCKED) { 222 int nfound; 223 224 npages = *ap->a_count; 225 #if defined(DEBUG) 226 for (i = 0; i < npages; i++) { 227 pg = ap->a_m[i]; 228 KASSERT(pg == NULL || pg == PGO_DONTCARE); 229 } 230 #endif /* defined(DEBUG) */ 231 nfound = uvn_findpages(uobj, origoffset, &npages, 232 ap->a_m, UFP_NOWAIT|UFP_NOALLOC|(write ? UFP_NORDONLY : 0)); 233 KASSERT(npages == *ap->a_count); 234 if (nfound == 0) { 235 error = EBUSY; 236 goto out_err; 237 } 238 if (!rw_tryenter(&gp->g_glock, RW_READER)) { 239 genfs_rel_pages(ap->a_m, npages); 240 241 /* 242 * restore the array. 243 */ 244 245 for (i = 0; i < npages; i++) { 246 pg = ap->a_m[i]; 247 248 if (pg != NULL || pg != PGO_DONTCARE) { 249 ap->a_m[i] = NULL; 250 } 251 } 252 } else { 253 rw_exit(&gp->g_glock); 254 } 255 error = (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 256 goto out_err; 257 } 258 simple_unlock(&uobj->vmobjlock); 259 260 /* 261 * find the requested pages and make some simple checks. 262 * leave space in the page array for a whole block. 263 */ 264 265 if (vp->v_type != VBLK) { 266 fs_bshift = vp->v_mount->mnt_fs_bshift; 267 dev_bshift = vp->v_mount->mnt_dev_bshift; 268 } else { 269 fs_bshift = DEV_BSHIFT; 270 dev_bshift = DEV_BSHIFT; 271 } 272 fs_bsize = 1 << fs_bshift; 273 274 orignpages = MIN(orignpages, 275 round_page(memeof - origoffset) >> PAGE_SHIFT); 276 npages = orignpages; 277 startoffset = origoffset & ~(fs_bsize - 1); 278 endoffset = round_page((origoffset + (npages << PAGE_SHIFT) + 279 fs_bsize - 1) & ~(fs_bsize - 1)); 280 endoffset = MIN(endoffset, round_page(memeof)); 281 ridx = (origoffset - startoffset) >> PAGE_SHIFT; 282 283 pgs_size = sizeof(struct vm_page *) * 284 ((endoffset - startoffset) >> PAGE_SHIFT); 285 if (pgs_size > sizeof(pgs_onstack)) { 286 pgs = kmem_zalloc(pgs_size, async ? KM_NOSLEEP : KM_SLEEP); 287 if (pgs == NULL) { 288 pgs = pgs_onstack; 289 error = ENOMEM; 290 goto out_err; 291 } 292 } else { 293 /* pgs == pgs_onstack */ 294 memset(pgs, 0, pgs_size); 295 } 296 UVMHIST_LOG(ubchist, "ridx %d npages %d startoff %ld endoff %ld", 297 ridx, npages, startoffset, endoffset); 298 299 if (!has_trans) { 300 fstrans_start(vp->v_mount, FSTRANS_SHARED); 301 has_trans = true; 302 } 303 304 /* 305 * hold g_glock to prevent a race with truncate. 306 * 307 * check if our idea of v_size is still valid. 308 */ 309 310 if (blockalloc) { 311 rw_enter(&gp->g_glock, RW_WRITER); 312 } else { 313 rw_enter(&gp->g_glock, RW_READER); 314 } 315 simple_lock(&uobj->vmobjlock); 316 if (vp->v_size < origvsize) { 317 rw_exit(&gp->g_glock); 318 if (pgs != pgs_onstack) 319 kmem_free(pgs, pgs_size); 320 goto startover; 321 } 322 323 if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], 324 async ? UFP_NOWAIT : UFP_ALL) != orignpages) { 325 rw_exit(&gp->g_glock); 326 KASSERT(async != 0); 327 genfs_rel_pages(&pgs[ridx], orignpages); 328 simple_unlock(&uobj->vmobjlock); 329 error = EBUSY; 330 goto out_err; 331 } 332 333 /* 334 * if the pages are already resident, just return them. 335 */ 336 337 for (i = 0; i < npages; i++) { 338 struct vm_page *pg1 = pgs[ridx + i]; 339 340 if ((pg1->flags & PG_FAKE) || 341 (blockalloc && (pg1->flags & PG_RDONLY))) { 342 break; 343 } 344 } 345 if (i == npages) { 346 rw_exit(&gp->g_glock); 347 UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); 348 npages += ridx; 349 goto out; 350 } 351 352 /* 353 * if PGO_OVERWRITE is set, don't bother reading the pages. 354 */ 355 356 if (overwrite) { 357 rw_exit(&gp->g_glock); 358 UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); 359 360 for (i = 0; i < npages; i++) { 361 struct vm_page *pg1 = pgs[ridx + i]; 362 363 pg1->flags &= ~(PG_RDONLY|PG_CLEAN); 364 } 365 npages += ridx; 366 goto out; 367 } 368 369 /* 370 * the page wasn't resident and we're not overwriting, 371 * so we're going to have to do some i/o. 372 * find any additional pages needed to cover the expanded range. 373 */ 374 375 npages = (endoffset - startoffset) >> PAGE_SHIFT; 376 if (startoffset != origoffset || npages != orignpages) { 377 378 /* 379 * we need to avoid deadlocks caused by locking 380 * additional pages at lower offsets than pages we 381 * already have locked. unlock them all and start over. 382 */ 383 384 genfs_rel_pages(&pgs[ridx], orignpages); 385 memset(pgs, 0, pgs_size); 386 387 UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x", 388 startoffset, endoffset, 0,0); 389 npgs = npages; 390 if (uvn_findpages(uobj, startoffset, &npgs, pgs, 391 async ? UFP_NOWAIT : UFP_ALL) != npages) { 392 rw_exit(&gp->g_glock); 393 KASSERT(async != 0); 394 genfs_rel_pages(pgs, npages); 395 simple_unlock(&uobj->vmobjlock); 396 error = EBUSY; 397 goto out_err; 398 } 399 } 400 simple_unlock(&uobj->vmobjlock); 401 402 /* 403 * read the desired page(s). 404 */ 405 406 totalbytes = npages << PAGE_SHIFT; 407 bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); 408 tailbytes = totalbytes - bytes; 409 skipbytes = 0; 410 411 kva = uvm_pagermapin(pgs, npages, 412 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 413 414 mbp = getiobuf(); 415 mbp->b_bufsize = totalbytes; 416 mbp->b_data = (void *)kva; 417 mbp->b_resid = mbp->b_bcount = bytes; 418 mbp->b_flags = B_BUSY|B_READ| (async ? B_CALL|B_ASYNC : 0); 419 mbp->b_iodone = (async ? uvm_aio_biodone : 0); 420 mbp->b_vp = vp; 421 if (async) 422 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 423 else 424 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 425 426 /* 427 * if EOF is in the middle of the range, zero the part past EOF. 428 * skip over pages which are not PG_FAKE since in that case they have 429 * valid data that we need to preserve. 430 */ 431 432 tailstart = bytes; 433 while (tailbytes > 0) { 434 const int len = PAGE_SIZE - (tailstart & PAGE_MASK); 435 436 KASSERT(len <= tailbytes); 437 if ((pgs[tailstart >> PAGE_SHIFT]->flags & PG_FAKE) != 0) { 438 memset((void *)(kva + tailstart), 0, len); 439 UVMHIST_LOG(ubchist, "tailbytes %p 0x%x 0x%x", 440 kva, tailstart, len, 0); 441 } 442 tailstart += len; 443 tailbytes -= len; 444 } 445 446 /* 447 * now loop over the pages, reading as needed. 448 */ 449 450 bp = NULL; 451 for (offset = startoffset; 452 bytes > 0; 453 offset += iobytes, bytes -= iobytes) { 454 455 /* 456 * skip pages which don't need to be read. 457 */ 458 459 pidx = (offset - startoffset) >> PAGE_SHIFT; 460 while ((pgs[pidx]->flags & PG_FAKE) == 0) { 461 size_t b; 462 463 KASSERT((offset & (PAGE_SIZE - 1)) == 0); 464 if ((pgs[pidx]->flags & PG_RDONLY)) { 465 sawhole = true; 466 } 467 b = MIN(PAGE_SIZE, bytes); 468 offset += b; 469 bytes -= b; 470 skipbytes += b; 471 pidx++; 472 UVMHIST_LOG(ubchist, "skipping, new offset 0x%x", 473 offset, 0,0,0); 474 if (bytes == 0) { 475 goto loopdone; 476 } 477 } 478 479 /* 480 * bmap the file to find out the blkno to read from and 481 * how much we can read in one i/o. if bmap returns an error, 482 * skip the rest of the top-level i/o. 483 */ 484 485 lbn = offset >> fs_bshift; 486 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 487 if (error) { 488 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n", 489 lbn, error,0,0); 490 skipbytes += bytes; 491 goto loopdone; 492 } 493 494 /* 495 * see how many pages can be read with this i/o. 496 * reduce the i/o size if necessary to avoid 497 * overwriting pages with valid data. 498 */ 499 500 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 501 bytes); 502 if (offset + iobytes > round_page(offset)) { 503 pcount = 1; 504 while (pidx + pcount < npages && 505 pgs[pidx + pcount]->flags & PG_FAKE) { 506 pcount++; 507 } 508 iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - 509 (offset - trunc_page(offset))); 510 } 511 512 /* 513 * if this block isn't allocated, zero it instead of 514 * reading it. unless we are going to allocate blocks, 515 * mark the pages we zeroed PG_RDONLY. 516 */ 517 518 if (blkno < 0) { 519 int holepages = (round_page(offset + iobytes) - 520 trunc_page(offset)) >> PAGE_SHIFT; 521 UVMHIST_LOG(ubchist, "lbn 0x%x -> HOLE", lbn,0,0,0); 522 523 sawhole = true; 524 memset((char *)kva + (offset - startoffset), 0, 525 iobytes); 526 skipbytes += iobytes; 527 528 for (i = 0; i < holepages; i++) { 529 if (write) { 530 pgs[pidx + i]->flags &= ~PG_CLEAN; 531 } 532 if (!blockalloc) { 533 pgs[pidx + i]->flags |= PG_RDONLY; 534 } 535 } 536 continue; 537 } 538 539 /* 540 * allocate a sub-buf for this piece of the i/o 541 * (or just use mbp if there's only 1 piece), 542 * and start it going. 543 */ 544 545 if (offset == startoffset && iobytes == bytes) { 546 bp = mbp; 547 } else { 548 bp = getiobuf(); 549 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 550 } 551 bp->b_lblkno = 0; 552 553 /* adjust physical blkno for partial blocks */ 554 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 555 dev_bshift); 556 557 UVMHIST_LOG(ubchist, 558 "bp %p offset 0x%x bcount 0x%x blkno 0x%x", 559 bp, offset, iobytes, bp->b_blkno); 560 561 VOP_STRATEGY(devvp, bp); 562 } 563 564 loopdone: 565 nestiobuf_done(mbp, skipbytes, error); 566 if (async) { 567 UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); 568 rw_exit(&gp->g_glock); 569 error = 0; 570 goto out_err; 571 } 572 if (bp != NULL) { 573 error = biowait(mbp); 574 } 575 putiobuf(mbp); 576 uvm_pagermapout(kva, npages); 577 578 /* 579 * if this we encountered a hole then we have to do a little more work. 580 * for read faults, we marked the page PG_RDONLY so that future 581 * write accesses to the page will fault again. 582 * for write faults, we must make sure that the backing store for 583 * the page is completely allocated while the pages are locked. 584 */ 585 586 if (!error && sawhole && blockalloc) { 587 error = GOP_ALLOC(vp, startoffset, npages << PAGE_SHIFT, 0, 588 cred); 589 UVMHIST_LOG(ubchist, "gop_alloc off 0x%x/0x%x -> %d", 590 startoffset, npages << PAGE_SHIFT, error,0); 591 if (!error) { 592 for (i = 0; i < npages; i++) { 593 if (pgs[i] == NULL) { 594 continue; 595 } 596 pgs[i]->flags &= ~(PG_CLEAN|PG_RDONLY); 597 UVMHIST_LOG(ubchist, "mark dirty pg %p", 598 pgs[i],0,0,0); 599 } 600 } 601 } 602 rw_exit(&gp->g_glock); 603 simple_lock(&uobj->vmobjlock); 604 605 /* 606 * we're almost done! release the pages... 607 * for errors, we free the pages. 608 * otherwise we activate them and mark them as valid and clean. 609 * also, unbusy pages that were not actually requested. 610 */ 611 612 if (error) { 613 for (i = 0; i < npages; i++) { 614 if (pgs[i] == NULL) { 615 continue; 616 } 617 UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", 618 pgs[i], pgs[i]->flags, 0,0); 619 if (pgs[i]->flags & PG_FAKE) { 620 pgs[i]->flags |= PG_RELEASED; 621 } 622 } 623 uvm_lock_pageq(); 624 uvm_page_unbusy(pgs, npages); 625 uvm_unlock_pageq(); 626 simple_unlock(&uobj->vmobjlock); 627 UVMHIST_LOG(ubchist, "returning error %d", error,0,0,0); 628 goto out_err; 629 } 630 631 out: 632 UVMHIST_LOG(ubchist, "succeeding, npages %d", npages,0,0,0); 633 error = 0; 634 uvm_lock_pageq(); 635 for (i = 0; i < npages; i++) { 636 pg = pgs[i]; 637 if (pg == NULL) { 638 continue; 639 } 640 UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", 641 pg, pg->flags, 0,0); 642 if (pg->flags & PG_FAKE && !overwrite) { 643 pg->flags &= ~(PG_FAKE); 644 pmap_clear_modify(pgs[i]); 645 } 646 KASSERT(!write || !blockalloc || (pg->flags & PG_RDONLY) == 0); 647 if (i < ridx || i >= ridx + orignpages || async) { 648 UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x", 649 pg, pg->offset,0,0); 650 if (pg->flags & PG_WANTED) { 651 wakeup(pg); 652 } 653 if (pg->flags & PG_FAKE) { 654 KASSERT(overwrite); 655 uvm_pagezero(pg); 656 } 657 if (pg->flags & PG_RELEASED) { 658 uvm_pagefree(pg); 659 continue; 660 } 661 uvm_pageenqueue(pg); 662 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE); 663 UVM_PAGE_OWN(pg, NULL); 664 } 665 } 666 uvm_unlock_pageq(); 667 simple_unlock(&uobj->vmobjlock); 668 if (ap->a_m != NULL) { 669 memcpy(ap->a_m, &pgs[ridx], 670 orignpages * sizeof(struct vm_page *)); 671 } 672 673 out_err: 674 if (pgs != pgs_onstack) 675 kmem_free(pgs, pgs_size); 676 if (has_trans) 677 fstrans_done(vp->v_mount); 678 return (error); 679 } 680 681 /* 682 * generic VM putpages routine. 683 * Write the given range of pages to backing store. 684 * 685 * => "offhi == 0" means flush all pages at or after "offlo". 686 * => object should be locked by caller. we return with the 687 * object unlocked. 688 * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). 689 * thus, a caller might want to unlock higher level resources 690 * (e.g. vm_map) before calling flush. 691 * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, we will not block 692 * => if PGO_ALLPAGES is set, then all pages in the object will be processed. 693 * => NOTE: we rely on the fact that the object's memq is a TAILQ and 694 * that new pages are inserted on the tail end of the list. thus, 695 * we can make a complete pass through the object in one go by starting 696 * at the head and working towards the tail (new pages are put in 697 * front of us). 698 * => NOTE: we are allowed to lock the page queues, so the caller 699 * must not be holding the page queue lock. 700 * 701 * note on "cleaning" object and PG_BUSY pages: 702 * this routine is holding the lock on the object. the only time 703 * that it can run into a PG_BUSY page that it does not own is if 704 * some other process has started I/O on the page (e.g. either 705 * a pagein, or a pageout). if the PG_BUSY page is being paged 706 * in, then it can not be dirty (!PG_CLEAN) because no one has 707 * had a chance to modify it yet. if the PG_BUSY page is being 708 * paged out then it means that someone else has already started 709 * cleaning the page for us (how nice!). in this case, if we 710 * have syncio specified, then after we make our pass through the 711 * object we need to wait for the other PG_BUSY pages to clear 712 * off (i.e. we need to do an iosync). also note that once a 713 * page is PG_BUSY it must stay in its object until it is un-busyed. 714 * 715 * note on page traversal: 716 * we can traverse the pages in an object either by going down the 717 * linked list in "uobj->memq", or we can go over the address range 718 * by page doing hash table lookups for each address. depending 719 * on how many pages are in the object it may be cheaper to do one 720 * or the other. we set "by_list" to true if we are using memq. 721 * if the cost of a hash lookup was equal to the cost of the list 722 * traversal we could compare the number of pages in the start->stop 723 * range to the total number of pages in the object. however, it 724 * seems that a hash table lookup is more expensive than the linked 725 * list traversal, so we multiply the number of pages in the 726 * range by an estimate of the relatively higher cost of the hash lookup. 727 */ 728 729 int 730 genfs_putpages(void *v) 731 { 732 struct vop_putpages_args /* { 733 struct vnode *a_vp; 734 voff_t a_offlo; 735 voff_t a_offhi; 736 int a_flags; 737 } */ *ap = v; 738 739 return genfs_do_putpages(ap->a_vp, ap->a_offlo, ap->a_offhi, 740 ap->a_flags, NULL); 741 } 742 743 int 744 genfs_do_putpages(struct vnode *vp, off_t startoff, off_t endoff, int flags, 745 struct vm_page **busypg) 746 { 747 struct uvm_object *uobj = &vp->v_uobj; 748 struct simplelock *slock = &uobj->vmobjlock; 749 off_t off; 750 /* Even for strange MAXPHYS, the shift rounds down to a page */ 751 #define maxpages (MAXPHYS >> PAGE_SHIFT) 752 int i, s, error, npages, nback; 753 int freeflag; 754 struct vm_page *pgs[maxpages], *pg, *nextpg, *tpg, curmp, endmp; 755 bool wasclean, by_list, needs_clean, yld; 756 bool async = (flags & PGO_SYNCIO) == 0; 757 bool pagedaemon = curlwp == uvm.pagedaemon_lwp; 758 struct lwp *l = curlwp ? curlwp : &lwp0; 759 struct genfs_node *gp = VTOG(vp); 760 int dirtygen; 761 bool modified = false; 762 bool has_trans = false; 763 bool cleanall; 764 765 UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); 766 767 KASSERT(flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); 768 KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); 769 KASSERT(startoff < endoff || endoff == 0); 770 771 UVMHIST_LOG(ubchist, "vp %p pages %d off 0x%x len 0x%x", 772 vp, uobj->uo_npages, startoff, endoff - startoff); 773 774 KASSERT((vp->v_iflag & VI_ONWORKLST) != 0 || 775 (vp->v_iflag & VI_WRMAPDIRTY) == 0); 776 if (uobj->uo_npages == 0) { 777 s = splbio(); 778 if (vp->v_iflag & VI_ONWORKLST) { 779 vp->v_iflag &= ~VI_WRMAPDIRTY; 780 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 781 vn_syncer_remove_from_worklist(vp); 782 } 783 splx(s); 784 simple_unlock(slock); 785 return (0); 786 } 787 788 /* 789 * the vnode has pages, set up to process the request. 790 */ 791 792 if ((flags & PGO_CLEANIT) != 0) { 793 simple_unlock(slock); 794 if (pagedaemon) { 795 error = fstrans_start_nowait(vp->v_mount, FSTRANS_LAZY); 796 if (error) 797 return error; 798 } else 799 fstrans_start(vp->v_mount, FSTRANS_LAZY); 800 has_trans = true; 801 simple_lock(slock); 802 } 803 804 error = 0; 805 s = splbio(); 806 simple_lock(&global_v_numoutput_slock); 807 wasclean = (vp->v_numoutput == 0); 808 simple_unlock(&global_v_numoutput_slock); 809 splx(s); 810 off = startoff; 811 if (endoff == 0 || flags & PGO_ALLPAGES) { 812 endoff = trunc_page(LLONG_MAX); 813 } 814 by_list = (uobj->uo_npages <= 815 ((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_HASH_PENALTY); 816 817 #if !defined(DEBUG) 818 /* 819 * if this vnode is known not to have dirty pages, 820 * don't bother to clean it out. 821 */ 822 823 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 824 if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == 0) { 825 goto skip_scan; 826 } 827 flags &= ~PGO_CLEANIT; 828 } 829 #endif /* !defined(DEBUG) */ 830 831 /* 832 * start the loop. when scanning by list, hold the last page 833 * in the list before we start. pages allocated after we start 834 * will be added to the end of the list, so we can stop at the 835 * current last page. 836 */ 837 838 cleanall = (flags & PGO_CLEANIT) != 0 && wasclean && 839 startoff == 0 && endoff == trunc_page(LLONG_MAX) && 840 (vp->v_iflag & VI_ONWORKLST) != 0; 841 dirtygen = gp->g_dirtygen; 842 freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED; 843 if (by_list) { 844 curmp.uobject = uobj; 845 curmp.offset = (voff_t)-1; 846 curmp.flags = PG_BUSY; 847 endmp.uobject = uobj; 848 endmp.offset = (voff_t)-1; 849 endmp.flags = PG_BUSY; 850 pg = TAILQ_FIRST(&uobj->memq); 851 TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq); 852 uvm_lwp_hold(l); 853 } else { 854 pg = uvm_pagelookup(uobj, off); 855 } 856 nextpg = NULL; 857 while (by_list || off < endoff) { 858 859 /* 860 * if the current page is not interesting, move on to the next. 861 */ 862 863 KASSERT(pg == NULL || pg->uobject == uobj); 864 KASSERT(pg == NULL || 865 (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 866 (pg->flags & PG_BUSY) != 0); 867 if (by_list) { 868 if (pg == &endmp) { 869 break; 870 } 871 if (pg->offset < startoff || pg->offset >= endoff || 872 pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 873 if (pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 874 wasclean = false; 875 } 876 pg = TAILQ_NEXT(pg, listq); 877 continue; 878 } 879 off = pg->offset; 880 } else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 881 if (pg != NULL) { 882 wasclean = false; 883 } 884 off += PAGE_SIZE; 885 if (off < endoff) { 886 pg = uvm_pagelookup(uobj, off); 887 } 888 continue; 889 } 890 891 /* 892 * if the current page needs to be cleaned and it's busy, 893 * wait for it to become unbusy. 894 */ 895 896 yld = (l->l_cpu->ci_schedstate.spc_flags & 897 SPCF_SHOULDYIELD) && !pagedaemon; 898 if (pg->flags & PG_BUSY || yld) { 899 UVMHIST_LOG(ubchist, "busy %p", pg,0,0,0); 900 if (flags & PGO_BUSYFAIL && pg->flags & PG_BUSY) { 901 UVMHIST_LOG(ubchist, "busyfail %p", pg, 0,0,0); 902 error = EDEADLK; 903 if (busypg != NULL) 904 *busypg = pg; 905 break; 906 } 907 if (pagedaemon) { 908 /* 909 * someone has taken the page while we 910 * dropped the lock for fstrans_start. 911 */ 912 break; 913 } 914 if (by_list) { 915 TAILQ_INSERT_BEFORE(pg, &curmp, listq); 916 UVMHIST_LOG(ubchist, "curmp next %p", 917 TAILQ_NEXT(&curmp, listq), 0,0,0); 918 } 919 if (yld) { 920 simple_unlock(slock); 921 preempt(); 922 simple_lock(slock); 923 } else { 924 pg->flags |= PG_WANTED; 925 UVM_UNLOCK_AND_WAIT(pg, slock, 0, "genput", 0); 926 simple_lock(slock); 927 } 928 if (by_list) { 929 UVMHIST_LOG(ubchist, "after next %p", 930 TAILQ_NEXT(&curmp, listq), 0,0,0); 931 pg = TAILQ_NEXT(&curmp, listq); 932 TAILQ_REMOVE(&uobj->memq, &curmp, listq); 933 } else { 934 pg = uvm_pagelookup(uobj, off); 935 } 936 continue; 937 } 938 939 /* 940 * if we're freeing, remove all mappings of the page now. 941 * if we're cleaning, check if the page is needs to be cleaned. 942 */ 943 944 if (flags & PGO_FREE) { 945 pmap_page_protect(pg, VM_PROT_NONE); 946 } else if (flags & PGO_CLEANIT) { 947 948 /* 949 * if we still have some hope to pull this vnode off 950 * from the syncer queue, write-protect the page. 951 */ 952 953 if (cleanall && wasclean && 954 gp->g_dirtygen == dirtygen) { 955 956 /* 957 * uobj pages get wired only by uvm_fault 958 * where uobj is locked. 959 */ 960 961 if (pg->wire_count == 0) { 962 pmap_page_protect(pg, 963 VM_PROT_READ|VM_PROT_EXECUTE); 964 } else { 965 cleanall = false; 966 } 967 } 968 } 969 970 if (flags & PGO_CLEANIT) { 971 needs_clean = pmap_clear_modify(pg) || 972 (pg->flags & PG_CLEAN) == 0; 973 pg->flags |= PG_CLEAN; 974 } else { 975 needs_clean = false; 976 } 977 978 /* 979 * if we're cleaning, build a cluster. 980 * the cluster will consist of pages which are currently dirty, 981 * but they will be returned to us marked clean. 982 * if not cleaning, just operate on the one page. 983 */ 984 985 if (needs_clean) { 986 KDASSERT((vp->v_iflag & VI_ONWORKLST)); 987 wasclean = false; 988 memset(pgs, 0, sizeof(pgs)); 989 pg->flags |= PG_BUSY; 990 UVM_PAGE_OWN(pg, "genfs_putpages"); 991 992 /* 993 * first look backward. 994 */ 995 996 npages = MIN(maxpages >> 1, off >> PAGE_SHIFT); 997 nback = npages; 998 uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0], 999 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); 1000 if (nback) { 1001 memmove(&pgs[0], &pgs[npages - nback], 1002 nback * sizeof(pgs[0])); 1003 if (npages - nback < nback) 1004 memset(&pgs[nback], 0, 1005 (npages - nback) * sizeof(pgs[0])); 1006 else 1007 memset(&pgs[npages - nback], 0, 1008 nback * sizeof(pgs[0])); 1009 } 1010 1011 /* 1012 * then plug in our page of interest. 1013 */ 1014 1015 pgs[nback] = pg; 1016 1017 /* 1018 * then look forward to fill in the remaining space in 1019 * the array of pages. 1020 */ 1021 1022 npages = maxpages - nback - 1; 1023 uvn_findpages(uobj, off + PAGE_SIZE, &npages, 1024 &pgs[nback + 1], 1025 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); 1026 npages += nback + 1; 1027 } else { 1028 pgs[0] = pg; 1029 npages = 1; 1030 nback = 0; 1031 } 1032 1033 /* 1034 * apply FREE or DEACTIVATE options if requested. 1035 */ 1036 1037 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1038 uvm_lock_pageq(); 1039 } 1040 for (i = 0; i < npages; i++) { 1041 tpg = pgs[i]; 1042 KASSERT(tpg->uobject == uobj); 1043 if (by_list && tpg == TAILQ_NEXT(pg, listq)) 1044 pg = tpg; 1045 if (tpg->offset < startoff || tpg->offset >= endoff) 1046 continue; 1047 if (flags & PGO_DEACTIVATE && tpg->wire_count == 0) { 1048 (void) pmap_clear_reference(tpg); 1049 uvm_pagedeactivate(tpg); 1050 } else if (flags & PGO_FREE) { 1051 pmap_page_protect(tpg, VM_PROT_NONE); 1052 if (tpg->flags & PG_BUSY) { 1053 tpg->flags |= freeflag; 1054 if (pagedaemon) { 1055 uvmexp.paging++; 1056 uvm_pagedequeue(tpg); 1057 } 1058 } else { 1059 1060 /* 1061 * ``page is not busy'' 1062 * implies that npages is 1 1063 * and needs_clean is false. 1064 */ 1065 1066 nextpg = TAILQ_NEXT(tpg, listq); 1067 uvm_pagefree(tpg); 1068 if (pagedaemon) 1069 uvmexp.pdfreed++; 1070 } 1071 } 1072 } 1073 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1074 uvm_unlock_pageq(); 1075 } 1076 if (needs_clean) { 1077 modified = true; 1078 1079 /* 1080 * start the i/o. if we're traversing by list, 1081 * keep our place in the list with a marker page. 1082 */ 1083 1084 if (by_list) { 1085 TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp, 1086 listq); 1087 } 1088 simple_unlock(slock); 1089 error = GOP_WRITE(vp, pgs, npages, flags); 1090 simple_lock(slock); 1091 if (by_list) { 1092 pg = TAILQ_NEXT(&curmp, listq); 1093 TAILQ_REMOVE(&uobj->memq, &curmp, listq); 1094 } 1095 if (error) { 1096 break; 1097 } 1098 if (by_list) { 1099 continue; 1100 } 1101 } 1102 1103 /* 1104 * find the next page and continue if there was no error. 1105 */ 1106 1107 if (by_list) { 1108 if (nextpg) { 1109 pg = nextpg; 1110 nextpg = NULL; 1111 } else { 1112 pg = TAILQ_NEXT(pg, listq); 1113 } 1114 } else { 1115 off += (npages - nback) << PAGE_SHIFT; 1116 if (off < endoff) { 1117 pg = uvm_pagelookup(uobj, off); 1118 } 1119 } 1120 } 1121 if (by_list) { 1122 TAILQ_REMOVE(&uobj->memq, &endmp, listq); 1123 uvm_lwp_rele(l); 1124 } 1125 1126 if (modified && (vp->v_iflag & VI_WRMAPDIRTY) != 0 && 1127 (vp->v_type != VBLK || 1128 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 1129 GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED); 1130 } 1131 1132 /* 1133 * if we're cleaning and there was nothing to clean, 1134 * take us off the syncer list. if we started any i/o 1135 * and we're doing sync i/o, wait for all writes to finish. 1136 */ 1137 1138 s = splbio(); 1139 if (cleanall && wasclean && gp->g_dirtygen == dirtygen && 1140 (vp->v_iflag & VI_ONWORKLST) != 0) { 1141 vp->v_iflag &= ~VI_WRMAPDIRTY; 1142 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 1143 vn_syncer_remove_from_worklist(vp); 1144 } 1145 splx(s); 1146 1147 #if !defined(DEBUG) 1148 skip_scan: 1149 #endif /* !defined(DEBUG) */ 1150 if (!wasclean && !async) { 1151 s = splbio(); 1152 /* 1153 * XXX - we want simple_unlock(&global_v_numoutput_slock); 1154 * but the slot in ltsleep() is taken! 1155 * XXX - try to recover from missed wakeups with a timeout.. 1156 * must think of something better. 1157 */ 1158 while (vp->v_numoutput != 0) { 1159 vp->v_iflag |= VI_BWAIT; 1160 UVM_UNLOCK_AND_WAIT(&vp->v_numoutput, slock, false, 1161 "genput2", hz); 1162 simple_lock(slock); 1163 } 1164 splx(s); 1165 } 1166 simple_unlock(slock); 1167 1168 if (has_trans) 1169 fstrans_done(vp->v_mount); 1170 1171 return (error); 1172 } 1173 1174 int 1175 genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1176 { 1177 off_t off; 1178 vaddr_t kva; 1179 size_t len; 1180 int error; 1181 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1182 1183 UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x", 1184 vp, pgs, npages, flags); 1185 1186 off = pgs[0]->offset; 1187 kva = uvm_pagermapin(pgs, npages, 1188 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1189 len = npages << PAGE_SHIFT; 1190 1191 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1192 uvm_aio_biodone); 1193 1194 return error; 1195 } 1196 1197 /* 1198 * Backend routine for doing I/O to vnode pages. Pages are already locked 1199 * and mapped into kernel memory. Here we just look up the underlying 1200 * device block addresses and call the strategy routine. 1201 */ 1202 1203 static int 1204 genfs_do_io(struct vnode *vp, off_t off, vaddr_t kva, size_t len, int flags, 1205 enum uio_rw rw, void (*iodone)(struct buf *)) 1206 { 1207 int s, error, run; 1208 int fs_bshift, dev_bshift; 1209 off_t eof, offset, startoffset; 1210 size_t bytes, iobytes, skipbytes; 1211 daddr_t lbn, blkno; 1212 struct buf *mbp, *bp; 1213 struct vnode *devvp; 1214 bool async = (flags & PGO_SYNCIO) == 0; 1215 bool write = rw == UIO_WRITE; 1216 int brw = write ? B_WRITE : B_READ; 1217 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1218 1219 UVMHIST_LOG(ubchist, "vp %p kva %p len 0x%x flags 0x%x", 1220 vp, kva, len, flags); 1221 1222 KASSERT(vp->v_size <= vp->v_writesize); 1223 GOP_SIZE(vp, vp->v_writesize, &eof, 0); 1224 if (vp->v_type != VBLK) { 1225 fs_bshift = vp->v_mount->mnt_fs_bshift; 1226 dev_bshift = vp->v_mount->mnt_dev_bshift; 1227 } else { 1228 fs_bshift = DEV_BSHIFT; 1229 dev_bshift = DEV_BSHIFT; 1230 } 1231 error = 0; 1232 startoffset = off; 1233 bytes = MIN(len, eof - startoffset); 1234 skipbytes = 0; 1235 KASSERT(bytes != 0); 1236 1237 if (write) { 1238 s = splbio(); 1239 simple_lock(&global_v_numoutput_slock); 1240 vp->v_numoutput += 2; 1241 simple_unlock(&global_v_numoutput_slock); 1242 splx(s); 1243 } 1244 mbp = getiobuf(); 1245 UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x", 1246 vp, mbp, vp->v_numoutput, bytes); 1247 mbp->b_bufsize = len; 1248 mbp->b_data = (void *)kva; 1249 mbp->b_resid = mbp->b_bcount = bytes; 1250 mbp->b_flags = B_BUSY | brw | B_AGE | (async ? (B_CALL | B_ASYNC) : 0); 1251 mbp->b_iodone = iodone; 1252 mbp->b_vp = vp; 1253 if (curlwp == uvm.pagedaemon_lwp) 1254 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 1255 else if (async) 1256 BIO_SETPRIO(mbp, BPRIO_TIMENONCRITICAL); 1257 else 1258 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 1259 1260 bp = NULL; 1261 for (offset = startoffset; 1262 bytes > 0; 1263 offset += iobytes, bytes -= iobytes) { 1264 lbn = offset >> fs_bshift; 1265 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 1266 if (error) { 1267 UVMHIST_LOG(ubchist, "VOP_BMAP() -> %d", error,0,0,0); 1268 skipbytes += bytes; 1269 bytes = 0; 1270 break; 1271 } 1272 1273 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 1274 bytes); 1275 if (blkno == (daddr_t)-1) { 1276 if (!write) { 1277 memset((char *)kva + (offset - startoffset), 0, 1278 iobytes); 1279 } 1280 skipbytes += iobytes; 1281 continue; 1282 } 1283 1284 /* if it's really one i/o, don't make a second buf */ 1285 if (offset == startoffset && iobytes == bytes) { 1286 bp = mbp; 1287 } else { 1288 UVMHIST_LOG(ubchist, "vp %p bp %p num now %d", 1289 vp, bp, vp->v_numoutput, 0); 1290 bp = getiobuf(); 1291 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 1292 } 1293 bp->b_lblkno = 0; 1294 1295 /* adjust physical blkno for partial blocks */ 1296 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 1297 dev_bshift); 1298 UVMHIST_LOG(ubchist, 1299 "vp %p offset 0x%x bcount 0x%x blkno 0x%x", 1300 vp, offset, bp->b_bcount, bp->b_blkno); 1301 1302 VOP_STRATEGY(devvp, bp); 1303 } 1304 if (skipbytes) { 1305 UVMHIST_LOG(ubchist, "skipbytes %d", skipbytes, 0,0,0); 1306 } 1307 nestiobuf_done(mbp, skipbytes, error); 1308 if (async) { 1309 UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); 1310 return (0); 1311 } 1312 UVMHIST_LOG(ubchist, "waiting for mbp %p", mbp,0,0,0); 1313 error = biowait(mbp); 1314 s = splbio(); 1315 (*iodone)(mbp); 1316 splx(s); 1317 UVMHIST_LOG(ubchist, "returning, error %d", error,0,0,0); 1318 return (error); 1319 } 1320 1321 /* 1322 * VOP_PUTPAGES() for vnodes which never have pages. 1323 */ 1324 1325 int 1326 genfs_null_putpages(void *v) 1327 { 1328 struct vop_putpages_args /* { 1329 struct vnode *a_vp; 1330 voff_t a_offlo; 1331 voff_t a_offhi; 1332 int a_flags; 1333 } */ *ap = v; 1334 struct vnode *vp = ap->a_vp; 1335 1336 KASSERT(vp->v_uobj.uo_npages == 0); 1337 simple_unlock(&vp->v_interlock); 1338 return (0); 1339 } 1340 1341 int 1342 genfs_compat_getpages(void *v) 1343 { 1344 struct vop_getpages_args /* { 1345 struct vnode *a_vp; 1346 voff_t a_offset; 1347 struct vm_page **a_m; 1348 int *a_count; 1349 int a_centeridx; 1350 vm_prot_t a_access_type; 1351 int a_advice; 1352 int a_flags; 1353 } */ *ap = v; 1354 1355 off_t origoffset; 1356 struct vnode *vp = ap->a_vp; 1357 struct uvm_object *uobj = &vp->v_uobj; 1358 struct vm_page *pg, **pgs; 1359 vaddr_t kva; 1360 int i, error, orignpages, npages; 1361 struct iovec iov; 1362 struct uio uio; 1363 kauth_cred_t cred = curlwp->l_cred; 1364 bool write = (ap->a_access_type & VM_PROT_WRITE) != 0; 1365 1366 error = 0; 1367 origoffset = ap->a_offset; 1368 orignpages = *ap->a_count; 1369 pgs = ap->a_m; 1370 1371 if (write && (vp->v_iflag & VI_ONWORKLST) == 0) { 1372 vn_syncer_add_to_worklist(vp, filedelay); 1373 } 1374 if (ap->a_flags & PGO_LOCKED) { 1375 uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, 1376 UFP_NOWAIT|UFP_NOALLOC| (write ? UFP_NORDONLY : 0)); 1377 1378 return (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 1379 } 1380 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) { 1381 simple_unlock(&uobj->vmobjlock); 1382 return (EINVAL); 1383 } 1384 if ((ap->a_flags & PGO_SYNCIO) == 0) { 1385 simple_unlock(&uobj->vmobjlock); 1386 return 0; 1387 } 1388 npages = orignpages; 1389 uvn_findpages(uobj, origoffset, &npages, pgs, UFP_ALL); 1390 simple_unlock(&uobj->vmobjlock); 1391 kva = uvm_pagermapin(pgs, npages, 1392 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1393 for (i = 0; i < npages; i++) { 1394 pg = pgs[i]; 1395 if ((pg->flags & PG_FAKE) == 0) { 1396 continue; 1397 } 1398 iov.iov_base = (char *)kva + (i << PAGE_SHIFT); 1399 iov.iov_len = PAGE_SIZE; 1400 uio.uio_iov = &iov; 1401 uio.uio_iovcnt = 1; 1402 uio.uio_offset = origoffset + (i << PAGE_SHIFT); 1403 uio.uio_rw = UIO_READ; 1404 uio.uio_resid = PAGE_SIZE; 1405 UIO_SETUP_SYSSPACE(&uio); 1406 /* XXX vn_lock */ 1407 error = VOP_READ(vp, &uio, 0, cred); 1408 if (error) { 1409 break; 1410 } 1411 if (uio.uio_resid) { 1412 memset(iov.iov_base, 0, uio.uio_resid); 1413 } 1414 } 1415 uvm_pagermapout(kva, npages); 1416 simple_lock(&uobj->vmobjlock); 1417 uvm_lock_pageq(); 1418 for (i = 0; i < npages; i++) { 1419 pg = pgs[i]; 1420 if (error && (pg->flags & PG_FAKE) != 0) { 1421 pg->flags |= PG_RELEASED; 1422 } else { 1423 pmap_clear_modify(pg); 1424 uvm_pageactivate(pg); 1425 } 1426 } 1427 if (error) { 1428 uvm_page_unbusy(pgs, npages); 1429 } 1430 uvm_unlock_pageq(); 1431 simple_unlock(&uobj->vmobjlock); 1432 return (error); 1433 } 1434 1435 int 1436 genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, 1437 int flags) 1438 { 1439 off_t offset; 1440 struct iovec iov; 1441 struct uio uio; 1442 kauth_cred_t cred = curlwp->l_cred; 1443 struct buf *bp; 1444 vaddr_t kva; 1445 int s, error; 1446 1447 offset = pgs[0]->offset; 1448 kva = uvm_pagermapin(pgs, npages, 1449 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1450 1451 iov.iov_base = (void *)kva; 1452 iov.iov_len = npages << PAGE_SHIFT; 1453 uio.uio_iov = &iov; 1454 uio.uio_iovcnt = 1; 1455 uio.uio_offset = offset; 1456 uio.uio_rw = UIO_WRITE; 1457 uio.uio_resid = npages << PAGE_SHIFT; 1458 UIO_SETUP_SYSSPACE(&uio); 1459 /* XXX vn_lock */ 1460 error = VOP_WRITE(vp, &uio, 0, cred); 1461 1462 s = splbio(); 1463 V_INCR_NUMOUTPUT(vp); 1464 splx(s); 1465 1466 bp = getiobuf(); 1467 bp->b_flags = B_BUSY | B_WRITE | B_AGE; 1468 bp->b_vp = vp; 1469 bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift; 1470 bp->b_data = (char *)kva; 1471 bp->b_bcount = npages << PAGE_SHIFT; 1472 bp->b_bufsize = npages << PAGE_SHIFT; 1473 bp->b_resid = 0; 1474 bp->b_error = error; 1475 uvm_aio_aiodone(bp); 1476 return (error); 1477 } 1478 1479 /* 1480 * Process a uio using direct I/O. If we reach a part of the request 1481 * which cannot be processed in this fashion for some reason, just return. 1482 * The caller must handle some additional part of the request using 1483 * buffered I/O before trying direct I/O again. 1484 */ 1485 1486 void 1487 genfs_directio(struct vnode *vp, struct uio *uio, int ioflag) 1488 { 1489 struct vmspace *vs; 1490 struct iovec *iov; 1491 vaddr_t va; 1492 size_t len; 1493 const int mask = DEV_BSIZE - 1; 1494 int error; 1495 1496 /* 1497 * We only support direct I/O to user space for now. 1498 */ 1499 1500 if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) { 1501 return; 1502 } 1503 1504 /* 1505 * If the vnode is mapped, we would need to get the getpages lock 1506 * to stabilize the bmap, but then we would get into trouble whil e 1507 * locking the pages if the pages belong to this same vnode (or a 1508 * multi-vnode cascade to the same effect). Just fall back to 1509 * buffered I/O if the vnode is mapped to avoid this mess. 1510 */ 1511 1512 if (vp->v_vflag & VV_MAPPED) { 1513 return; 1514 } 1515 1516 /* 1517 * Do as much of the uio as possible with direct I/O. 1518 */ 1519 1520 vs = uio->uio_vmspace; 1521 while (uio->uio_resid) { 1522 iov = uio->uio_iov; 1523 if (iov->iov_len == 0) { 1524 uio->uio_iov++; 1525 uio->uio_iovcnt--; 1526 continue; 1527 } 1528 va = (vaddr_t)iov->iov_base; 1529 len = MIN(iov->iov_len, genfs_maxdio); 1530 len &= ~mask; 1531 1532 /* 1533 * If the next chunk is smaller than DEV_BSIZE or extends past 1534 * the current EOF, then fall back to buffered I/O. 1535 */ 1536 1537 if (len == 0 || uio->uio_offset + len > vp->v_size) { 1538 return; 1539 } 1540 1541 /* 1542 * Check alignment. The file offset must be at least 1543 * sector-aligned. The exact constraint on memory alignment 1544 * is very hardware-dependent, but requiring sector-aligned 1545 * addresses there too is safe. 1546 */ 1547 1548 if (uio->uio_offset & mask || va & mask) { 1549 return; 1550 } 1551 error = genfs_do_directio(vs, va, len, vp, uio->uio_offset, 1552 uio->uio_rw); 1553 if (error) { 1554 break; 1555 } 1556 iov->iov_base = (char *)iov->iov_base + len; 1557 iov->iov_len -= len; 1558 uio->uio_offset += len; 1559 uio->uio_resid -= len; 1560 } 1561 } 1562 1563 /* 1564 * Iodone routine for direct I/O. We don't do much here since the request is 1565 * always synchronous, so the caller will do most of the work after biowait(). 1566 */ 1567 1568 static void 1569 genfs_dio_iodone(struct buf *bp) 1570 { 1571 int s; 1572 1573 KASSERT((bp->b_flags & B_ASYNC) == 0); 1574 s = splbio(); 1575 if ((bp->b_flags & (B_READ | B_AGE)) == B_AGE) { 1576 vwakeup(bp); 1577 } 1578 putiobuf(bp); 1579 splx(s); 1580 } 1581 1582 /* 1583 * Process one chunk of a direct I/O request. 1584 */ 1585 1586 static int 1587 genfs_do_directio(struct vmspace *vs, vaddr_t uva, size_t len, struct vnode *vp, 1588 off_t off, enum uio_rw rw) 1589 { 1590 struct vm_map *map; 1591 struct pmap *upm, *kpm; 1592 size_t klen = round_page(uva + len) - trunc_page(uva); 1593 off_t spoff, epoff; 1594 vaddr_t kva, puva; 1595 paddr_t pa; 1596 vm_prot_t prot; 1597 int error, rv, poff, koff; 1598 const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | 1599 (rw == UIO_WRITE ? PGO_FREE : 0); 1600 1601 /* 1602 * For writes, verify that this range of the file already has fully 1603 * allocated backing store. If there are any holes, just punt and 1604 * make the caller take the buffered write path. 1605 */ 1606 1607 if (rw == UIO_WRITE) { 1608 daddr_t lbn, elbn, blkno; 1609 int bsize, bshift, run; 1610 1611 bshift = vp->v_mount->mnt_fs_bshift; 1612 bsize = 1 << bshift; 1613 lbn = off >> bshift; 1614 elbn = (off + len + bsize - 1) >> bshift; 1615 while (lbn < elbn) { 1616 error = VOP_BMAP(vp, lbn, NULL, &blkno, &run); 1617 if (error) { 1618 return error; 1619 } 1620 if (blkno == (daddr_t)-1) { 1621 return ENOSPC; 1622 } 1623 lbn += 1 + run; 1624 } 1625 } 1626 1627 /* 1628 * Flush any cached pages for parts of the file that we're about to 1629 * access. If we're writing, invalidate pages as well. 1630 */ 1631 1632 spoff = trunc_page(off); 1633 epoff = round_page(off + len); 1634 simple_lock(&vp->v_interlock); 1635 error = VOP_PUTPAGES(vp, spoff, epoff, pgoflags); 1636 if (error) { 1637 return error; 1638 } 1639 1640 /* 1641 * Wire the user pages and remap them into kernel memory. 1642 */ 1643 1644 prot = rw == UIO_READ ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 1645 error = uvm_vslock(vs, (void *)uva, len, prot); 1646 if (error) { 1647 return error; 1648 } 1649 1650 map = &vs->vm_map; 1651 upm = vm_map_pmap(map); 1652 kpm = vm_map_pmap(kernel_map); 1653 kva = uvm_km_alloc(kernel_map, klen, 0, 1654 UVM_KMF_VAONLY | UVM_KMF_WAITVA); 1655 puva = trunc_page(uva); 1656 for (poff = 0; poff < klen; poff += PAGE_SIZE) { 1657 rv = pmap_extract(upm, puva + poff, &pa); 1658 KASSERT(rv); 1659 pmap_enter(kpm, kva + poff, pa, prot, prot | PMAP_WIRED); 1660 } 1661 pmap_update(kpm); 1662 1663 /* 1664 * Do the I/O. 1665 */ 1666 1667 koff = uva - trunc_page(uva); 1668 error = genfs_do_io(vp, off, kva + koff, len, PGO_SYNCIO, rw, 1669 genfs_dio_iodone); 1670 1671 /* 1672 * Tear down the kernel mapping. 1673 */ 1674 1675 pmap_remove(kpm, kva, kva + klen); 1676 pmap_update(kpm); 1677 uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY); 1678 1679 /* 1680 * Unwire the user pages. 1681 */ 1682 1683 uvm_vsunlock(vs, (void *)uva, len); 1684 return error; 1685 } 1686