1 /* $NetBSD: genfs_io.c,v 1.71 2017/10/28 00:37:13 pgoyette 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 1.71 2017/10/28 00:37:13 pgoyette Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/proc.h> 39 #include <sys/kernel.h> 40 #include <sys/mount.h> 41 #include <sys/vnode.h> 42 #include <sys/kmem.h> 43 #include <sys/kauth.h> 44 #include <sys/fstrans.h> 45 #include <sys/buf.h> 46 47 #include <miscfs/genfs/genfs.h> 48 #include <miscfs/genfs/genfs_node.h> 49 #include <miscfs/specfs/specdev.h> 50 51 #include <uvm/uvm.h> 52 #include <uvm/uvm_pager.h> 53 54 static int genfs_do_directio(struct vmspace *, vaddr_t, size_t, struct vnode *, 55 off_t, enum uio_rw); 56 static void genfs_dio_iodone(struct buf *); 57 58 static int genfs_getpages_read(struct vnode *, struct vm_page **, int, off_t, 59 off_t, bool, bool, bool, bool); 60 static int genfs_do_io(struct vnode *, off_t, vaddr_t, size_t, int, enum uio_rw, 61 void (*)(struct buf *)); 62 static void genfs_rel_pages(struct vm_page **, unsigned int); 63 static void genfs_markdirty(struct vnode *); 64 65 int genfs_maxdio = MAXPHYS; 66 67 static void 68 genfs_rel_pages(struct vm_page **pgs, unsigned int npages) 69 { 70 unsigned int i; 71 72 for (i = 0; i < npages; i++) { 73 struct vm_page *pg = pgs[i]; 74 75 if (pg == NULL || pg == PGO_DONTCARE) 76 continue; 77 KASSERT(uvm_page_locked_p(pg)); 78 if (pg->flags & PG_FAKE) { 79 pg->flags |= PG_RELEASED; 80 } 81 } 82 mutex_enter(&uvm_pageqlock); 83 uvm_page_unbusy(pgs, npages); 84 mutex_exit(&uvm_pageqlock); 85 } 86 87 static void 88 genfs_markdirty(struct vnode *vp) 89 { 90 struct genfs_node * const gp = VTOG(vp); 91 92 KASSERT(mutex_owned(vp->v_interlock)); 93 gp->g_dirtygen++; 94 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 95 vn_syncer_add_to_worklist(vp, filedelay); 96 } 97 if ((vp->v_iflag & (VI_WRMAP|VI_WRMAPDIRTY)) == VI_WRMAP) { 98 vp->v_iflag |= VI_WRMAPDIRTY; 99 } 100 } 101 102 /* 103 * generic VM getpages routine. 104 * Return PG_BUSY pages for the given range, 105 * reading from backing store if necessary. 106 */ 107 108 int 109 genfs_getpages(void *v) 110 { 111 struct vop_getpages_args /* { 112 struct vnode *a_vp; 113 voff_t a_offset; 114 struct vm_page **a_m; 115 int *a_count; 116 int a_centeridx; 117 vm_prot_t a_access_type; 118 int a_advice; 119 int a_flags; 120 } */ * const ap = v; 121 122 off_t diskeof, memeof; 123 int i, error, npages; 124 const int flags = ap->a_flags; 125 struct vnode * const vp = ap->a_vp; 126 struct uvm_object * const uobj = &vp->v_uobj; 127 const bool async = (flags & PGO_SYNCIO) == 0; 128 const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; 129 const bool overwrite = (flags & PGO_OVERWRITE) != 0; 130 const bool blockalloc = memwrite && (flags & PGO_NOBLOCKALLOC) == 0; 131 const bool glocked = (flags & PGO_GLOCKHELD) != 0; 132 bool holds_wapbl = false; 133 struct mount *trans_mount = NULL; 134 UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); 135 136 UVMHIST_LOG(ubchist, "vp %#jx off 0x%jx/%jx count %jd", 137 (uintptr_t)vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); 138 139 KASSERT(vp->v_type == VREG || vp->v_type == VDIR || 140 vp->v_type == VLNK || vp->v_type == VBLK); 141 142 error = vdead_check(vp, VDEAD_NOWAIT); 143 if (error) { 144 if ((flags & PGO_LOCKED) == 0) 145 mutex_exit(uobj->vmobjlock); 146 return error; 147 } 148 149 startover: 150 error = 0; 151 const voff_t origvsize = vp->v_size; 152 const off_t origoffset = ap->a_offset; 153 const int orignpages = *ap->a_count; 154 155 GOP_SIZE(vp, origvsize, &diskeof, 0); 156 if (flags & PGO_PASTEOF) { 157 off_t newsize; 158 #if defined(DIAGNOSTIC) 159 off_t writeeof; 160 #endif /* defined(DIAGNOSTIC) */ 161 162 newsize = MAX(origvsize, 163 origoffset + (orignpages << PAGE_SHIFT)); 164 GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_MEM); 165 #if defined(DIAGNOSTIC) 166 GOP_SIZE(vp, vp->v_writesize, &writeeof, GOP_SIZE_MEM); 167 if (newsize > round_page(writeeof)) { 168 panic("%s: past eof: %" PRId64 " vs. %" PRId64, 169 __func__, newsize, round_page(writeeof)); 170 } 171 #endif /* defined(DIAGNOSTIC) */ 172 } else { 173 GOP_SIZE(vp, origvsize, &memeof, GOP_SIZE_MEM); 174 } 175 KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); 176 KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); 177 KASSERT(orignpages > 0); 178 179 /* 180 * Bounds-check the request. 181 */ 182 183 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { 184 if ((flags & PGO_LOCKED) == 0) { 185 mutex_exit(uobj->vmobjlock); 186 } 187 UVMHIST_LOG(ubchist, "off 0x%jx count %jd goes past EOF 0x%jx", 188 origoffset, *ap->a_count, memeof,0); 189 error = EINVAL; 190 goto out_err; 191 } 192 193 /* uobj is locked */ 194 195 if ((flags & PGO_NOTIMESTAMP) == 0 && 196 (vp->v_type != VBLK || 197 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 198 int updflags = 0; 199 200 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) { 201 updflags = GOP_UPDATE_ACCESSED; 202 } 203 if (memwrite) { 204 updflags |= GOP_UPDATE_MODIFIED; 205 } 206 if (updflags != 0) { 207 GOP_MARKUPDATE(vp, updflags); 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 struct vm_page *pg; 218 219 KASSERT(!glocked); 220 npages = *ap->a_count; 221 #if defined(DEBUG) 222 for (i = 0; i < npages; i++) { 223 pg = ap->a_m[i]; 224 KASSERT(pg == NULL || pg == PGO_DONTCARE); 225 } 226 #endif /* defined(DEBUG) */ 227 nfound = uvn_findpages(uobj, origoffset, &npages, 228 ap->a_m, UFP_NOWAIT|UFP_NOALLOC|(memwrite ? UFP_NORDONLY : 0)); 229 KASSERT(npages == *ap->a_count); 230 if (nfound == 0) { 231 error = EBUSY; 232 goto out_err; 233 } 234 if (!genfs_node_rdtrylock(vp)) { 235 genfs_rel_pages(ap->a_m, npages); 236 237 /* 238 * restore the array. 239 */ 240 241 for (i = 0; i < npages; i++) { 242 pg = ap->a_m[i]; 243 244 if (pg != NULL && pg != PGO_DONTCARE) { 245 ap->a_m[i] = NULL; 246 } 247 KASSERT(ap->a_m[i] == NULL || 248 ap->a_m[i] == PGO_DONTCARE); 249 } 250 } else { 251 genfs_node_unlock(vp); 252 } 253 error = (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); 254 if (error == 0 && memwrite) { 255 genfs_markdirty(vp); 256 } 257 goto out_err; 258 } 259 mutex_exit(uobj->vmobjlock); 260 261 /* 262 * find the requested pages and make some simple checks. 263 * leave space in the page array for a whole block. 264 */ 265 266 const int fs_bshift = (vp->v_type != VBLK) ? 267 vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; 268 const int fs_bsize = 1 << fs_bshift; 269 #define blk_mask (fs_bsize - 1) 270 #define trunc_blk(x) ((x) & ~blk_mask) 271 #define round_blk(x) (((x) + blk_mask) & ~blk_mask) 272 273 const int orignmempages = MIN(orignpages, 274 round_page(memeof - origoffset) >> PAGE_SHIFT); 275 npages = orignmempages; 276 const off_t startoffset = trunc_blk(origoffset); 277 const off_t endoffset = MIN( 278 round_page(round_blk(origoffset + (npages << PAGE_SHIFT))), 279 round_page(memeof)); 280 const int ridx = (origoffset - startoffset) >> PAGE_SHIFT; 281 282 const int pgs_size = sizeof(struct vm_page *) * 283 ((endoffset - startoffset) >> PAGE_SHIFT); 284 struct vm_page **pgs, *pgs_onstack[UBC_MAX_PAGES]; 285 286 if (pgs_size > sizeof(pgs_onstack)) { 287 pgs = kmem_zalloc(pgs_size, async ? KM_NOSLEEP : KM_SLEEP); 288 if (pgs == NULL) { 289 pgs = pgs_onstack; 290 error = ENOMEM; 291 goto out_err; 292 } 293 } else { 294 pgs = pgs_onstack; 295 (void)memset(pgs, 0, pgs_size); 296 } 297 298 UVMHIST_LOG(ubchist, "ridx %jd npages %jd startoff %jd endoff %jd", 299 ridx, npages, startoffset, endoffset); 300 301 if (trans_mount == NULL) { 302 trans_mount = vp->v_mount; 303 fstrans_start(trans_mount); 304 /* 305 * check if this vnode is still valid. 306 */ 307 mutex_enter(vp->v_interlock); 308 error = vdead_check(vp, 0); 309 mutex_exit(vp->v_interlock); 310 if (error) 311 goto out_err_free; 312 /* 313 * XXX: This assumes that we come here only via 314 * the mmio path 315 */ 316 if (blockalloc && vp->v_mount->mnt_wapbl) { 317 error = WAPBL_BEGIN(trans_mount); 318 if (error) 319 goto out_err_free; 320 holds_wapbl = true; 321 } 322 } 323 324 /* 325 * hold g_glock to prevent a race with truncate. 326 * 327 * check if our idea of v_size is still valid. 328 */ 329 330 KASSERT(!glocked || genfs_node_wrlocked(vp)); 331 if (!glocked) { 332 if (blockalloc) { 333 genfs_node_wrlock(vp); 334 } else { 335 genfs_node_rdlock(vp); 336 } 337 } 338 mutex_enter(uobj->vmobjlock); 339 if (vp->v_size < origvsize) { 340 if (!glocked) { 341 genfs_node_unlock(vp); 342 } 343 if (pgs != pgs_onstack) 344 kmem_free(pgs, pgs_size); 345 goto startover; 346 } 347 348 if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], 349 async ? UFP_NOWAIT : UFP_ALL) != orignmempages) { 350 if (!glocked) { 351 genfs_node_unlock(vp); 352 } 353 KASSERT(async != 0); 354 genfs_rel_pages(&pgs[ridx], orignmempages); 355 mutex_exit(uobj->vmobjlock); 356 error = EBUSY; 357 goto out_err_free; 358 } 359 360 /* 361 * if the pages are already resident, just return them. 362 */ 363 364 for (i = 0; i < npages; i++) { 365 struct vm_page *pg = pgs[ridx + i]; 366 367 if ((pg->flags & PG_FAKE) || 368 (blockalloc && (pg->flags & PG_RDONLY))) { 369 break; 370 } 371 } 372 if (i == npages) { 373 if (!glocked) { 374 genfs_node_unlock(vp); 375 } 376 UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); 377 npages += ridx; 378 goto out; 379 } 380 381 /* 382 * if PGO_OVERWRITE is set, don't bother reading the pages. 383 */ 384 385 if (overwrite) { 386 if (!glocked) { 387 genfs_node_unlock(vp); 388 } 389 UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); 390 391 for (i = 0; i < npages; i++) { 392 struct vm_page *pg = pgs[ridx + i]; 393 394 pg->flags &= ~(PG_RDONLY|PG_CLEAN); 395 } 396 npages += ridx; 397 goto out; 398 } 399 400 /* 401 * the page wasn't resident and we're not overwriting, 402 * so we're going to have to do some i/o. 403 * find any additional pages needed to cover the expanded range. 404 */ 405 406 npages = (endoffset - startoffset) >> PAGE_SHIFT; 407 if (startoffset != origoffset || npages != orignmempages) { 408 int npgs; 409 410 /* 411 * we need to avoid deadlocks caused by locking 412 * additional pages at lower offsets than pages we 413 * already have locked. unlock them all and start over. 414 */ 415 416 genfs_rel_pages(&pgs[ridx], orignmempages); 417 memset(pgs, 0, pgs_size); 418 419 UVMHIST_LOG(ubchist, "reset npages start 0x%jx end 0x%jx", 420 startoffset, endoffset, 0,0); 421 npgs = npages; 422 if (uvn_findpages(uobj, startoffset, &npgs, pgs, 423 async ? UFP_NOWAIT : UFP_ALL) != npages) { 424 if (!glocked) { 425 genfs_node_unlock(vp); 426 } 427 KASSERT(async != 0); 428 genfs_rel_pages(pgs, npages); 429 mutex_exit(uobj->vmobjlock); 430 error = EBUSY; 431 goto out_err_free; 432 } 433 } 434 435 mutex_exit(uobj->vmobjlock); 436 error = genfs_getpages_read(vp, pgs, npages, startoffset, diskeof, 437 async, memwrite, blockalloc, glocked); 438 if (!glocked) { 439 genfs_node_unlock(vp); 440 } 441 if (error == 0 && async) 442 goto out_err_free; 443 mutex_enter(uobj->vmobjlock); 444 445 /* 446 * we're almost done! release the pages... 447 * for errors, we free the pages. 448 * otherwise we activate them and mark them as valid and clean. 449 * also, unbusy pages that were not actually requested. 450 */ 451 452 if (error) { 453 genfs_rel_pages(pgs, npages); 454 mutex_exit(uobj->vmobjlock); 455 UVMHIST_LOG(ubchist, "returning error %jd", error,0,0,0); 456 goto out_err_free; 457 } 458 459 out: 460 UVMHIST_LOG(ubchist, "succeeding, npages %jd", npages,0,0,0); 461 error = 0; 462 mutex_enter(&uvm_pageqlock); 463 for (i = 0; i < npages; i++) { 464 struct vm_page *pg = pgs[i]; 465 if (pg == NULL) { 466 continue; 467 } 468 UVMHIST_LOG(ubchist, "examining pg %#jx flags 0x%jx", 469 (uintptr_t)pg, pg->flags, 0,0); 470 if (pg->flags & PG_FAKE && !overwrite) { 471 pg->flags &= ~(PG_FAKE); 472 pmap_clear_modify(pgs[i]); 473 } 474 KASSERT(!memwrite || !blockalloc || (pg->flags & PG_RDONLY) == 0); 475 if (i < ridx || i >= ridx + orignmempages || async) { 476 UVMHIST_LOG(ubchist, "unbusy pg %#jx offset 0x%jx", 477 (uintptr_t)pg, pg->offset,0,0); 478 if (pg->flags & PG_WANTED) { 479 wakeup(pg); 480 } 481 if (pg->flags & PG_FAKE) { 482 KASSERT(overwrite); 483 uvm_pagezero(pg); 484 } 485 if (pg->flags & PG_RELEASED) { 486 uvm_pagefree(pg); 487 continue; 488 } 489 uvm_pageenqueue(pg); 490 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE); 491 UVM_PAGE_OWN(pg, NULL); 492 } 493 } 494 mutex_exit(&uvm_pageqlock); 495 if (memwrite) { 496 genfs_markdirty(vp); 497 } 498 mutex_exit(uobj->vmobjlock); 499 if (ap->a_m != NULL) { 500 memcpy(ap->a_m, &pgs[ridx], 501 orignmempages * sizeof(struct vm_page *)); 502 } 503 504 out_err_free: 505 if (pgs != NULL && pgs != pgs_onstack) 506 kmem_free(pgs, pgs_size); 507 out_err: 508 if (trans_mount != NULL) { 509 if (holds_wapbl) 510 WAPBL_END(trans_mount); 511 fstrans_done(trans_mount); 512 } 513 return error; 514 } 515 516 /* 517 * genfs_getpages_read: Read the pages in with VOP_BMAP/VOP_STRATEGY. 518 * 519 * "glocked" (which is currently not actually used) tells us not whether 520 * the genfs_node is locked on entry (it always is) but whether it was 521 * locked on entry to genfs_getpages. 522 */ 523 static int 524 genfs_getpages_read(struct vnode *vp, struct vm_page **pgs, int npages, 525 off_t startoffset, off_t diskeof, 526 bool async, bool memwrite, bool blockalloc, bool glocked) 527 { 528 struct uvm_object * const uobj = &vp->v_uobj; 529 const int fs_bshift = (vp->v_type != VBLK) ? 530 vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; 531 const int dev_bshift = (vp->v_type != VBLK) ? 532 vp->v_mount->mnt_dev_bshift : DEV_BSHIFT; 533 kauth_cred_t const cred = curlwp->l_cred; /* XXXUBC curlwp */ 534 size_t bytes, iobytes, tailstart, tailbytes, totalbytes, skipbytes; 535 vaddr_t kva; 536 struct buf *bp, *mbp; 537 bool sawhole = false; 538 int i; 539 int error = 0; 540 541 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 542 543 /* 544 * read the desired page(s). 545 */ 546 547 totalbytes = npages << PAGE_SHIFT; 548 bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); 549 tailbytes = totalbytes - bytes; 550 skipbytes = 0; 551 552 kva = uvm_pagermapin(pgs, npages, 553 UVMPAGER_MAPIN_READ | (async ? 0 : UVMPAGER_MAPIN_WAITOK)); 554 if (kva == 0) 555 return EBUSY; 556 557 mbp = getiobuf(vp, true); 558 mbp->b_bufsize = totalbytes; 559 mbp->b_data = (void *)kva; 560 mbp->b_resid = mbp->b_bcount = bytes; 561 mbp->b_cflags = BC_BUSY; 562 if (async) { 563 mbp->b_flags = B_READ | B_ASYNC; 564 mbp->b_iodone = uvm_aio_biodone; 565 } else { 566 mbp->b_flags = B_READ; 567 mbp->b_iodone = NULL; 568 } 569 if (async) 570 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 571 else 572 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 573 574 /* 575 * if EOF is in the middle of the range, zero the part past EOF. 576 * skip over pages which are not PG_FAKE since in that case they have 577 * valid data that we need to preserve. 578 */ 579 580 tailstart = bytes; 581 while (tailbytes > 0) { 582 const int len = PAGE_SIZE - (tailstart & PAGE_MASK); 583 584 KASSERT(len <= tailbytes); 585 if ((pgs[tailstart >> PAGE_SHIFT]->flags & PG_FAKE) != 0) { 586 memset((void *)(kva + tailstart), 0, len); 587 UVMHIST_LOG(ubchist, "tailbytes %#jx 0x%jx 0x%jx", 588 (uintptr_t)kva, tailstart, len, 0); 589 } 590 tailstart += len; 591 tailbytes -= len; 592 } 593 594 /* 595 * now loop over the pages, reading as needed. 596 */ 597 598 bp = NULL; 599 off_t offset; 600 for (offset = startoffset; 601 bytes > 0; 602 offset += iobytes, bytes -= iobytes) { 603 int run; 604 daddr_t lbn, blkno; 605 int pidx; 606 struct vnode *devvp; 607 608 /* 609 * skip pages which don't need to be read. 610 */ 611 612 pidx = (offset - startoffset) >> PAGE_SHIFT; 613 while ((pgs[pidx]->flags & PG_FAKE) == 0) { 614 size_t b; 615 616 KASSERT((offset & (PAGE_SIZE - 1)) == 0); 617 if ((pgs[pidx]->flags & PG_RDONLY)) { 618 sawhole = true; 619 } 620 b = MIN(PAGE_SIZE, bytes); 621 offset += b; 622 bytes -= b; 623 skipbytes += b; 624 pidx++; 625 UVMHIST_LOG(ubchist, "skipping, new offset 0x%jx", 626 offset, 0,0,0); 627 if (bytes == 0) { 628 goto loopdone; 629 } 630 } 631 632 /* 633 * bmap the file to find out the blkno to read from and 634 * how much we can read in one i/o. if bmap returns an error, 635 * skip the rest of the top-level i/o. 636 */ 637 638 lbn = offset >> fs_bshift; 639 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 640 if (error) { 641 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%jx -> %jd\n", 642 lbn,error,0,0); 643 skipbytes += bytes; 644 bytes = 0; 645 goto loopdone; 646 } 647 648 /* 649 * see how many pages can be read with this i/o. 650 * reduce the i/o size if necessary to avoid 651 * overwriting pages with valid data. 652 */ 653 654 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 655 bytes); 656 if (offset + iobytes > round_page(offset)) { 657 int pcount; 658 659 pcount = 1; 660 while (pidx + pcount < npages && 661 pgs[pidx + pcount]->flags & PG_FAKE) { 662 pcount++; 663 } 664 iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - 665 (offset - trunc_page(offset))); 666 } 667 668 /* 669 * if this block isn't allocated, zero it instead of 670 * reading it. unless we are going to allocate blocks, 671 * mark the pages we zeroed PG_RDONLY. 672 */ 673 674 if (blkno == (daddr_t)-1) { 675 int holepages = (round_page(offset + iobytes) - 676 trunc_page(offset)) >> PAGE_SHIFT; 677 UVMHIST_LOG(ubchist, "lbn 0x%jx -> HOLE", lbn,0,0,0); 678 679 sawhole = true; 680 memset((char *)kva + (offset - startoffset), 0, 681 iobytes); 682 skipbytes += iobytes; 683 684 mutex_enter(uobj->vmobjlock); 685 for (i = 0; i < holepages; i++) { 686 if (memwrite) { 687 pgs[pidx + i]->flags &= ~PG_CLEAN; 688 } 689 if (!blockalloc) { 690 pgs[pidx + i]->flags |= PG_RDONLY; 691 } 692 } 693 mutex_exit(uobj->vmobjlock); 694 continue; 695 } 696 697 /* 698 * allocate a sub-buf for this piece of the i/o 699 * (or just use mbp if there's only 1 piece), 700 * and start it going. 701 */ 702 703 if (offset == startoffset && iobytes == bytes) { 704 bp = mbp; 705 } else { 706 UVMHIST_LOG(ubchist, "vp %#jx bp %#jx num now %jd", 707 (uintptr_t)vp, (uintptr_t)bp, vp->v_numoutput, 0); 708 bp = getiobuf(vp, true); 709 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 710 } 711 bp->b_lblkno = 0; 712 713 /* adjust physical blkno for partial blocks */ 714 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 715 dev_bshift); 716 717 UVMHIST_LOG(ubchist, 718 "bp %#jx offset 0x%x bcount 0x%x blkno 0x%x", 719 (uintptr_t)bp, offset, bp->b_bcount, bp->b_blkno); 720 721 VOP_STRATEGY(devvp, bp); 722 } 723 724 loopdone: 725 nestiobuf_done(mbp, skipbytes, error); 726 if (async) { 727 UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); 728 return 0; 729 } 730 if (bp != NULL) { 731 error = biowait(mbp); 732 } 733 734 /* Remove the mapping (make KVA available as soon as possible) */ 735 uvm_pagermapout(kva, npages); 736 737 /* 738 * if this we encountered a hole then we have to do a little more work. 739 * for read faults, we marked the page PG_RDONLY so that future 740 * write accesses to the page will fault again. 741 * for write faults, we must make sure that the backing store for 742 * the page is completely allocated while the pages are locked. 743 */ 744 745 if (!error && sawhole && blockalloc) { 746 error = GOP_ALLOC(vp, startoffset, 747 npages << PAGE_SHIFT, 0, cred); 748 UVMHIST_LOG(ubchist, "gop_alloc off 0x%jx/0x%jx -> %jd", 749 startoffset, npages << PAGE_SHIFT, error,0); 750 if (!error) { 751 mutex_enter(uobj->vmobjlock); 752 for (i = 0; i < npages; i++) { 753 struct vm_page *pg = pgs[i]; 754 755 if (pg == NULL) { 756 continue; 757 } 758 pg->flags &= ~(PG_CLEAN|PG_RDONLY); 759 UVMHIST_LOG(ubchist, "mark dirty pg %#jx", 760 (uintptr_t)pg, 0, 0, 0); 761 } 762 mutex_exit(uobj->vmobjlock); 763 } 764 } 765 766 putiobuf(mbp); 767 return error; 768 } 769 770 /* 771 * generic VM putpages routine. 772 * Write the given range of pages to backing store. 773 * 774 * => "offhi == 0" means flush all pages at or after "offlo". 775 * => object should be locked by caller. we return with the 776 * object unlocked. 777 * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). 778 * thus, a caller might want to unlock higher level resources 779 * (e.g. vm_map) before calling flush. 780 * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, we will not block 781 * => if PGO_ALLPAGES is set, then all pages in the object will be processed. 782 * => NOTE: we rely on the fact that the object's memq is a TAILQ and 783 * that new pages are inserted on the tail end of the list. thus, 784 * we can make a complete pass through the object in one go by starting 785 * at the head and working towards the tail (new pages are put in 786 * front of us). 787 * => NOTE: we are allowed to lock the page queues, so the caller 788 * must not be holding the page queue lock. 789 * 790 * note on "cleaning" object and PG_BUSY pages: 791 * this routine is holding the lock on the object. the only time 792 * that it can run into a PG_BUSY page that it does not own is if 793 * some other process has started I/O on the page (e.g. either 794 * a pagein, or a pageout). if the PG_BUSY page is being paged 795 * in, then it can not be dirty (!PG_CLEAN) because no one has 796 * had a chance to modify it yet. if the PG_BUSY page is being 797 * paged out then it means that someone else has already started 798 * cleaning the page for us (how nice!). in this case, if we 799 * have syncio specified, then after we make our pass through the 800 * object we need to wait for the other PG_BUSY pages to clear 801 * off (i.e. we need to do an iosync). also note that once a 802 * page is PG_BUSY it must stay in its object until it is un-busyed. 803 * 804 * note on page traversal: 805 * we can traverse the pages in an object either by going down the 806 * linked list in "uobj->memq", or we can go over the address range 807 * by page doing hash table lookups for each address. depending 808 * on how many pages are in the object it may be cheaper to do one 809 * or the other. we set "by_list" to true if we are using memq. 810 * if the cost of a hash lookup was equal to the cost of the list 811 * traversal we could compare the number of pages in the start->stop 812 * range to the total number of pages in the object. however, it 813 * seems that a hash table lookup is more expensive than the linked 814 * list traversal, so we multiply the number of pages in the 815 * range by an estimate of the relatively higher cost of the hash lookup. 816 */ 817 818 int 819 genfs_putpages(void *v) 820 { 821 struct vop_putpages_args /* { 822 struct vnode *a_vp; 823 voff_t a_offlo; 824 voff_t a_offhi; 825 int a_flags; 826 } */ * const ap = v; 827 828 return genfs_do_putpages(ap->a_vp, ap->a_offlo, ap->a_offhi, 829 ap->a_flags, NULL); 830 } 831 832 int 833 genfs_do_putpages(struct vnode *vp, off_t startoff, off_t endoff, 834 int origflags, struct vm_page **busypg) 835 { 836 struct uvm_object * const uobj = &vp->v_uobj; 837 kmutex_t * const slock = uobj->vmobjlock; 838 off_t off; 839 int i, error, npages, nback; 840 int freeflag; 841 /* 842 * This array is larger than it should so that it's size is constant. 843 * The right size is MAXPAGES. 844 */ 845 struct vm_page *pgs[MAXPHYS / MIN_PAGE_SIZE]; 846 #define MAXPAGES (MAXPHYS / PAGE_SIZE) 847 struct vm_page *pg, *nextpg, *tpg, curmp, endmp; 848 bool wasclean, by_list, needs_clean, yld; 849 bool async = (origflags & PGO_SYNCIO) == 0; 850 bool pagedaemon = curlwp == uvm.pagedaemon_lwp; 851 struct lwp * const l = curlwp ? curlwp : &lwp0; 852 struct genfs_node * const gp = VTOG(vp); 853 struct mount *trans_mp; 854 int flags; 855 int dirtygen; 856 bool modified; 857 bool holds_wapbl; 858 bool cleanall; 859 bool onworklst; 860 861 UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); 862 863 KASSERT(origflags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); 864 KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); 865 KASSERT(startoff < endoff || endoff == 0); 866 867 UVMHIST_LOG(ubchist, "vp %#jx pages %jd off 0x%jx len 0x%jx", 868 (uintptr_t)vp, uobj->uo_npages, startoff, endoff - startoff); 869 870 trans_mp = NULL; 871 holds_wapbl = false; 872 873 retry: 874 modified = false; 875 flags = origflags; 876 KASSERT((vp->v_iflag & VI_ONWORKLST) != 0 || 877 (vp->v_iflag & VI_WRMAPDIRTY) == 0); 878 if (uobj->uo_npages == 0) { 879 if (vp->v_iflag & VI_ONWORKLST) { 880 vp->v_iflag &= ~VI_WRMAPDIRTY; 881 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 882 vn_syncer_remove_from_worklist(vp); 883 } 884 if (trans_mp) { 885 if (holds_wapbl) 886 WAPBL_END(trans_mp); 887 fstrans_done(trans_mp); 888 } 889 mutex_exit(slock); 890 return (0); 891 } 892 893 /* 894 * the vnode has pages, set up to process the request. 895 */ 896 897 if (trans_mp == NULL && (flags & PGO_CLEANIT) != 0) { 898 if (pagedaemon) { 899 /* Pagedaemon must not sleep here. */ 900 trans_mp = vp->v_mount; 901 error = fstrans_start_nowait(trans_mp); 902 if (error) { 903 mutex_exit(slock); 904 return error; 905 } 906 } else { 907 /* 908 * Cannot use vdeadcheck() here as this operation 909 * usually gets used from VOP_RECLAIM(). Test for 910 * change of v_mount instead and retry on change. 911 */ 912 mutex_exit(slock); 913 trans_mp = vp->v_mount; 914 fstrans_start(trans_mp); 915 if (vp->v_mount != trans_mp) { 916 fstrans_done(trans_mp); 917 trans_mp = NULL; 918 } else { 919 holds_wapbl = (trans_mp->mnt_wapbl && 920 (origflags & PGO_JOURNALLOCKED) == 0); 921 if (holds_wapbl) { 922 error = WAPBL_BEGIN(trans_mp); 923 if (error) { 924 fstrans_done(trans_mp); 925 return error; 926 } 927 } 928 } 929 mutex_enter(slock); 930 goto retry; 931 } 932 } 933 934 error = 0; 935 wasclean = (vp->v_numoutput == 0); 936 off = startoff; 937 if (endoff == 0 || flags & PGO_ALLPAGES) { 938 endoff = trunc_page(LLONG_MAX); 939 } 940 by_list = (uobj->uo_npages <= 941 ((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_TREE_PENALTY); 942 943 /* 944 * if this vnode is known not to have dirty pages, 945 * don't bother to clean it out. 946 */ 947 948 if ((vp->v_iflag & VI_ONWORKLST) == 0) { 949 #if !defined(DEBUG) 950 if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == 0) { 951 goto skip_scan; 952 } 953 #endif /* !defined(DEBUG) */ 954 flags &= ~PGO_CLEANIT; 955 } 956 957 /* 958 * start the loop. when scanning by list, hold the last page 959 * in the list before we start. pages allocated after we start 960 * will be added to the end of the list, so we can stop at the 961 * current last page. 962 */ 963 964 cleanall = (flags & PGO_CLEANIT) != 0 && wasclean && 965 startoff == 0 && endoff == trunc_page(LLONG_MAX) && 966 (vp->v_iflag & VI_ONWORKLST) != 0; 967 dirtygen = gp->g_dirtygen; 968 freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED; 969 if (by_list) { 970 curmp.flags = PG_MARKER; 971 endmp.flags = PG_MARKER; 972 pg = TAILQ_FIRST(&uobj->memq); 973 TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq.queue); 974 } else { 975 pg = uvm_pagelookup(uobj, off); 976 } 977 nextpg = NULL; 978 while (by_list || off < endoff) { 979 980 /* 981 * if the current page is not interesting, move on to the next. 982 */ 983 984 KASSERT(pg == NULL || pg->uobject == uobj || 985 (pg->flags & PG_MARKER) != 0); 986 KASSERT(pg == NULL || 987 (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || 988 (pg->flags & (PG_BUSY|PG_MARKER)) != 0); 989 if (by_list) { 990 if (pg == &endmp) { 991 break; 992 } 993 if (pg->flags & PG_MARKER) { 994 pg = TAILQ_NEXT(pg, listq.queue); 995 continue; 996 } 997 if (pg->offset < startoff || pg->offset >= endoff || 998 pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 999 if (pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 1000 wasclean = false; 1001 } 1002 pg = TAILQ_NEXT(pg, listq.queue); 1003 continue; 1004 } 1005 off = pg->offset; 1006 } else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { 1007 if (pg != NULL) { 1008 wasclean = false; 1009 } 1010 off += PAGE_SIZE; 1011 if (off < endoff) { 1012 pg = uvm_pagelookup(uobj, off); 1013 } 1014 continue; 1015 } 1016 1017 /* 1018 * if the current page needs to be cleaned and it's busy, 1019 * wait for it to become unbusy. 1020 */ 1021 1022 yld = (l->l_cpu->ci_schedstate.spc_flags & 1023 SPCF_SHOULDYIELD) && !pagedaemon; 1024 if (pg->flags & PG_BUSY || yld) { 1025 UVMHIST_LOG(ubchist, "busy %#jx", (uintptr_t)pg, 1026 0, 0, 0); 1027 if (flags & PGO_BUSYFAIL && pg->flags & PG_BUSY) { 1028 UVMHIST_LOG(ubchist, "busyfail %#jx", 1029 (uintptr_t)pg, 0, 0, 0); 1030 error = EDEADLK; 1031 if (busypg != NULL) 1032 *busypg = pg; 1033 break; 1034 } 1035 if (pagedaemon) { 1036 /* 1037 * someone has taken the page while we 1038 * dropped the lock for fstrans_start. 1039 */ 1040 break; 1041 } 1042 if (by_list) { 1043 TAILQ_INSERT_BEFORE(pg, &curmp, listq.queue); 1044 UVMHIST_LOG(ubchist, "curmp next %#jx", 1045 (uintptr_t)TAILQ_NEXT(&curmp, listq.queue), 1046 0, 0, 0); 1047 } 1048 if (yld) { 1049 mutex_exit(slock); 1050 preempt(); 1051 mutex_enter(slock); 1052 } else { 1053 pg->flags |= PG_WANTED; 1054 UVM_UNLOCK_AND_WAIT(pg, slock, 0, "genput", 0); 1055 mutex_enter(slock); 1056 } 1057 if (by_list) { 1058 UVMHIST_LOG(ubchist, "after next %#jx", 1059 (uintptr_t)TAILQ_NEXT(&curmp, listq.queue), 1060 0, 0, 0); 1061 pg = TAILQ_NEXT(&curmp, listq.queue); 1062 TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); 1063 } else { 1064 pg = uvm_pagelookup(uobj, off); 1065 } 1066 continue; 1067 } 1068 1069 /* 1070 * if we're freeing, remove all mappings of the page now. 1071 * if we're cleaning, check if the page is needs to be cleaned. 1072 */ 1073 1074 if (flags & PGO_FREE) { 1075 pmap_page_protect(pg, VM_PROT_NONE); 1076 } else if (flags & PGO_CLEANIT) { 1077 1078 /* 1079 * if we still have some hope to pull this vnode off 1080 * from the syncer queue, write-protect the page. 1081 */ 1082 1083 if (cleanall && wasclean && 1084 gp->g_dirtygen == dirtygen) { 1085 1086 /* 1087 * uobj pages get wired only by uvm_fault 1088 * where uobj is locked. 1089 */ 1090 1091 if (pg->wire_count == 0) { 1092 pmap_page_protect(pg, 1093 VM_PROT_READ|VM_PROT_EXECUTE); 1094 } else { 1095 cleanall = false; 1096 } 1097 } 1098 } 1099 1100 if (flags & PGO_CLEANIT) { 1101 needs_clean = pmap_clear_modify(pg) || 1102 (pg->flags & PG_CLEAN) == 0; 1103 pg->flags |= PG_CLEAN; 1104 } else { 1105 needs_clean = false; 1106 } 1107 1108 /* 1109 * if we're cleaning, build a cluster. 1110 * the cluster will consist of pages which are currently dirty, 1111 * but they will be returned to us marked clean. 1112 * if not cleaning, just operate on the one page. 1113 */ 1114 1115 if (needs_clean) { 1116 KDASSERT((vp->v_iflag & VI_ONWORKLST)); 1117 wasclean = false; 1118 memset(pgs, 0, sizeof(pgs)); 1119 pg->flags |= PG_BUSY; 1120 UVM_PAGE_OWN(pg, "genfs_putpages"); 1121 1122 /* 1123 * first look backward. 1124 */ 1125 1126 npages = MIN(MAXPAGES >> 1, off >> PAGE_SHIFT); 1127 nback = npages; 1128 uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0], 1129 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); 1130 if (nback) { 1131 memmove(&pgs[0], &pgs[npages - nback], 1132 nback * sizeof(pgs[0])); 1133 if (npages - nback < nback) 1134 memset(&pgs[nback], 0, 1135 (npages - nback) * sizeof(pgs[0])); 1136 else 1137 memset(&pgs[npages - nback], 0, 1138 nback * sizeof(pgs[0])); 1139 } 1140 1141 /* 1142 * then plug in our page of interest. 1143 */ 1144 1145 pgs[nback] = pg; 1146 1147 /* 1148 * then look forward to fill in the remaining space in 1149 * the array of pages. 1150 */ 1151 1152 npages = MAXPAGES - nback - 1; 1153 uvn_findpages(uobj, off + PAGE_SIZE, &npages, 1154 &pgs[nback + 1], 1155 UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); 1156 npages += nback + 1; 1157 } else { 1158 pgs[0] = pg; 1159 npages = 1; 1160 nback = 0; 1161 } 1162 1163 /* 1164 * apply FREE or DEACTIVATE options if requested. 1165 */ 1166 1167 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1168 mutex_enter(&uvm_pageqlock); 1169 } 1170 for (i = 0; i < npages; i++) { 1171 tpg = pgs[i]; 1172 KASSERT(tpg->uobject == uobj); 1173 if (by_list && tpg == TAILQ_NEXT(pg, listq.queue)) 1174 pg = tpg; 1175 if (tpg->offset < startoff || tpg->offset >= endoff) 1176 continue; 1177 if (flags & PGO_DEACTIVATE && tpg->wire_count == 0) { 1178 uvm_pagedeactivate(tpg); 1179 } else if (flags & PGO_FREE) { 1180 pmap_page_protect(tpg, VM_PROT_NONE); 1181 if (tpg->flags & PG_BUSY) { 1182 tpg->flags |= freeflag; 1183 if (pagedaemon) { 1184 uvm_pageout_start(1); 1185 uvm_pagedequeue(tpg); 1186 } 1187 } else { 1188 1189 /* 1190 * ``page is not busy'' 1191 * implies that npages is 1 1192 * and needs_clean is false. 1193 */ 1194 1195 nextpg = TAILQ_NEXT(tpg, listq.queue); 1196 uvm_pagefree(tpg); 1197 if (pagedaemon) 1198 uvmexp.pdfreed++; 1199 } 1200 } 1201 } 1202 if (flags & (PGO_DEACTIVATE|PGO_FREE)) { 1203 mutex_exit(&uvm_pageqlock); 1204 } 1205 if (needs_clean) { 1206 modified = true; 1207 1208 /* 1209 * start the i/o. if we're traversing by list, 1210 * keep our place in the list with a marker page. 1211 */ 1212 1213 if (by_list) { 1214 TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp, 1215 listq.queue); 1216 } 1217 mutex_exit(slock); 1218 error = GOP_WRITE(vp, pgs, npages, flags); 1219 mutex_enter(slock); 1220 if (by_list) { 1221 pg = TAILQ_NEXT(&curmp, listq.queue); 1222 TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); 1223 } 1224 if (error) { 1225 break; 1226 } 1227 if (by_list) { 1228 continue; 1229 } 1230 } 1231 1232 /* 1233 * find the next page and continue if there was no error. 1234 */ 1235 1236 if (by_list) { 1237 if (nextpg) { 1238 pg = nextpg; 1239 nextpg = NULL; 1240 } else { 1241 pg = TAILQ_NEXT(pg, listq.queue); 1242 } 1243 } else { 1244 off += (npages - nback) << PAGE_SHIFT; 1245 if (off < endoff) { 1246 pg = uvm_pagelookup(uobj, off); 1247 } 1248 } 1249 } 1250 if (by_list) { 1251 TAILQ_REMOVE(&uobj->memq, &endmp, listq.queue); 1252 } 1253 1254 if (modified && (vp->v_iflag & VI_WRMAPDIRTY) != 0 && 1255 (vp->v_type != VBLK || 1256 (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { 1257 GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED); 1258 } 1259 1260 /* 1261 * if we're cleaning and there was nothing to clean, 1262 * take us off the syncer list. if we started any i/o 1263 * and we're doing sync i/o, wait for all writes to finish. 1264 */ 1265 1266 if (cleanall && wasclean && gp->g_dirtygen == dirtygen && 1267 (vp->v_iflag & VI_ONWORKLST) != 0) { 1268 #if defined(DEBUG) 1269 TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { 1270 if ((pg->flags & (PG_FAKE | PG_MARKER)) != 0) { 1271 continue; 1272 } 1273 if ((pg->flags & PG_CLEAN) == 0) { 1274 printf("%s: %p: !CLEAN\n", __func__, pg); 1275 } 1276 if (pmap_is_modified(pg)) { 1277 printf("%s: %p: modified\n", __func__, pg); 1278 } 1279 } 1280 #endif /* defined(DEBUG) */ 1281 vp->v_iflag &= ~VI_WRMAPDIRTY; 1282 if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) 1283 vn_syncer_remove_from_worklist(vp); 1284 } 1285 1286 #if !defined(DEBUG) 1287 skip_scan: 1288 #endif /* !defined(DEBUG) */ 1289 1290 /* Wait for output to complete. */ 1291 if (!wasclean && !async && vp->v_numoutput != 0) { 1292 while (vp->v_numoutput != 0) 1293 cv_wait(&vp->v_cv, slock); 1294 } 1295 onworklst = (vp->v_iflag & VI_ONWORKLST) != 0; 1296 mutex_exit(slock); 1297 1298 if ((flags & PGO_RECLAIM) != 0 && onworklst) { 1299 /* 1300 * in the case of PGO_RECLAIM, ensure to make the vnode clean. 1301 * retrying is not a big deal because, in many cases, 1302 * uobj->uo_npages is already 0 here. 1303 */ 1304 mutex_enter(slock); 1305 goto retry; 1306 } 1307 1308 if (trans_mp) { 1309 if (holds_wapbl) 1310 WAPBL_END(trans_mp); 1311 fstrans_done(trans_mp); 1312 } 1313 1314 return (error); 1315 } 1316 1317 int 1318 genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1319 { 1320 off_t off; 1321 vaddr_t kva; 1322 size_t len; 1323 int error; 1324 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1325 1326 UVMHIST_LOG(ubchist, "vp %#jx pgs %#jx npages %jd flags 0x%jx", 1327 (uintptr_t)vp, (uintptr_t)pgs, npages, flags); 1328 1329 off = pgs[0]->offset; 1330 kva = uvm_pagermapin(pgs, npages, 1331 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1332 len = npages << PAGE_SHIFT; 1333 1334 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1335 uvm_aio_biodone); 1336 1337 return error; 1338 } 1339 1340 int 1341 genfs_gop_write_rwmap(struct vnode *vp, struct vm_page **pgs, int npages, int flags) 1342 { 1343 off_t off; 1344 vaddr_t kva; 1345 size_t len; 1346 int error; 1347 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1348 1349 UVMHIST_LOG(ubchist, "vp %#jx pgs %#jx npages %jd flags 0x%jx", 1350 (uintptr_t)vp, (uintptr_t)pgs, npages, flags); 1351 1352 off = pgs[0]->offset; 1353 kva = uvm_pagermapin(pgs, npages, 1354 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1355 len = npages << PAGE_SHIFT; 1356 1357 error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, 1358 uvm_aio_biodone); 1359 1360 return error; 1361 } 1362 1363 /* 1364 * Backend routine for doing I/O to vnode pages. Pages are already locked 1365 * and mapped into kernel memory. Here we just look up the underlying 1366 * device block addresses and call the strategy routine. 1367 */ 1368 1369 static int 1370 genfs_do_io(struct vnode *vp, off_t off, vaddr_t kva, size_t len, int flags, 1371 enum uio_rw rw, void (*iodone)(struct buf *)) 1372 { 1373 int s, error; 1374 int fs_bshift, dev_bshift; 1375 off_t eof, offset, startoffset; 1376 size_t bytes, iobytes, skipbytes; 1377 struct buf *mbp, *bp; 1378 const bool async = (flags & PGO_SYNCIO) == 0; 1379 const bool lazy = (flags & PGO_LAZY) == 0; 1380 const bool iowrite = rw == UIO_WRITE; 1381 const int brw = iowrite ? B_WRITE : B_READ; 1382 UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); 1383 1384 UVMHIST_LOG(ubchist, "vp %#jx kva %#jx len 0x%jx flags 0x%jx", 1385 (uintptr_t)vp, (uintptr_t)kva, len, flags); 1386 1387 KASSERT(vp->v_size <= vp->v_writesize); 1388 GOP_SIZE(vp, vp->v_writesize, &eof, 0); 1389 if (vp->v_type != VBLK) { 1390 fs_bshift = vp->v_mount->mnt_fs_bshift; 1391 dev_bshift = vp->v_mount->mnt_dev_bshift; 1392 } else { 1393 fs_bshift = DEV_BSHIFT; 1394 dev_bshift = DEV_BSHIFT; 1395 } 1396 error = 0; 1397 startoffset = off; 1398 bytes = MIN(len, eof - startoffset); 1399 skipbytes = 0; 1400 KASSERT(bytes != 0); 1401 1402 if (iowrite) { 1403 mutex_enter(vp->v_interlock); 1404 vp->v_numoutput += 2; 1405 mutex_exit(vp->v_interlock); 1406 } 1407 mbp = getiobuf(vp, true); 1408 UVMHIST_LOG(ubchist, "vp %#jx mbp %#jx num now %jd bytes 0x%jx", 1409 (uintptr_t)vp, (uintptr_t)mbp, vp->v_numoutput, bytes); 1410 mbp->b_bufsize = len; 1411 mbp->b_data = (void *)kva; 1412 mbp->b_resid = mbp->b_bcount = bytes; 1413 mbp->b_cflags = BC_BUSY | BC_AGE; 1414 if (async) { 1415 mbp->b_flags = brw | B_ASYNC; 1416 mbp->b_iodone = iodone; 1417 } else { 1418 mbp->b_flags = brw; 1419 mbp->b_iodone = NULL; 1420 } 1421 if (curlwp == uvm.pagedaemon_lwp) 1422 BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); 1423 else if (async || lazy) 1424 BIO_SETPRIO(mbp, BPRIO_TIMENONCRITICAL); 1425 else 1426 BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); 1427 1428 bp = NULL; 1429 for (offset = startoffset; 1430 bytes > 0; 1431 offset += iobytes, bytes -= iobytes) { 1432 int run; 1433 daddr_t lbn, blkno; 1434 struct vnode *devvp; 1435 1436 /* 1437 * bmap the file to find out the blkno to read from and 1438 * how much we can read in one i/o. if bmap returns an error, 1439 * skip the rest of the top-level i/o. 1440 */ 1441 1442 lbn = offset >> fs_bshift; 1443 error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); 1444 if (error) { 1445 UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%jx -> %jd\n", 1446 lbn, error, 0, 0); 1447 skipbytes += bytes; 1448 bytes = 0; 1449 goto loopdone; 1450 } 1451 1452 /* 1453 * see how many pages can be read with this i/o. 1454 * reduce the i/o size if necessary to avoid 1455 * overwriting pages with valid data. 1456 */ 1457 1458 iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, 1459 bytes); 1460 1461 /* 1462 * if this block isn't allocated, zero it instead of 1463 * reading it. unless we are going to allocate blocks, 1464 * mark the pages we zeroed PG_RDONLY. 1465 */ 1466 1467 if (blkno == (daddr_t)-1) { 1468 if (!iowrite) { 1469 memset((char *)kva + (offset - startoffset), 0, 1470 iobytes); 1471 } 1472 skipbytes += iobytes; 1473 continue; 1474 } 1475 1476 /* 1477 * allocate a sub-buf for this piece of the i/o 1478 * (or just use mbp if there's only 1 piece), 1479 * and start it going. 1480 */ 1481 1482 if (offset == startoffset && iobytes == bytes) { 1483 bp = mbp; 1484 } else { 1485 UVMHIST_LOG(ubchist, "vp %#jx bp %#jx num now %jd", 1486 (uintptr_t)vp, (uintptr_t)bp, vp->v_numoutput, 0); 1487 bp = getiobuf(vp, true); 1488 nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); 1489 } 1490 bp->b_lblkno = 0; 1491 1492 /* adjust physical blkno for partial blocks */ 1493 bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> 1494 dev_bshift); 1495 1496 UVMHIST_LOG(ubchist, 1497 "bp %#jx offset 0x%jx bcount 0x%jx blkno 0x%jx", 1498 (uintptr_t)bp, offset, bp->b_bcount, bp->b_blkno); 1499 1500 VOP_STRATEGY(devvp, bp); 1501 } 1502 1503 loopdone: 1504 if (skipbytes) { 1505 UVMHIST_LOG(ubchist, "skipbytes %jd", skipbytes, 0,0,0); 1506 } 1507 nestiobuf_done(mbp, skipbytes, error); 1508 if (async) { 1509 UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); 1510 return (0); 1511 } 1512 UVMHIST_LOG(ubchist, "waiting for mbp %#jx", (uintptr_t)mbp, 0, 0, 0); 1513 error = biowait(mbp); 1514 s = splbio(); 1515 (*iodone)(mbp); 1516 splx(s); 1517 UVMHIST_LOG(ubchist, "returning, error %jd", error, 0, 0, 0); 1518 return (error); 1519 } 1520 1521 int 1522 genfs_compat_getpages(void *v) 1523 { 1524 struct vop_getpages_args /* { 1525 struct vnode *a_vp; 1526 voff_t a_offset; 1527 struct vm_page **a_m; 1528 int *a_count; 1529 int a_centeridx; 1530 vm_prot_t a_access_type; 1531 int a_advice; 1532 int a_flags; 1533 } */ *ap = v; 1534 1535 off_t origoffset; 1536 struct vnode *vp = ap->a_vp; 1537 struct uvm_object *uobj = &vp->v_uobj; 1538 struct vm_page *pg, **pgs; 1539 vaddr_t kva; 1540 int i, error, orignpages, npages; 1541 struct iovec iov; 1542 struct uio uio; 1543 kauth_cred_t cred = curlwp->l_cred; 1544 const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; 1545 1546 error = 0; 1547 origoffset = ap->a_offset; 1548 orignpages = *ap->a_count; 1549 pgs = ap->a_m; 1550 1551 if (ap->a_flags & PGO_LOCKED) { 1552 uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, 1553 UFP_NOWAIT|UFP_NOALLOC| (memwrite ? UFP_NORDONLY : 0)); 1554 1555 error = ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0; 1556 if (error == 0 && memwrite) { 1557 genfs_markdirty(vp); 1558 } 1559 return error; 1560 } 1561 if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) { 1562 mutex_exit(uobj->vmobjlock); 1563 return EINVAL; 1564 } 1565 if ((ap->a_flags & PGO_SYNCIO) == 0) { 1566 mutex_exit(uobj->vmobjlock); 1567 return 0; 1568 } 1569 npages = orignpages; 1570 uvn_findpages(uobj, origoffset, &npages, pgs, UFP_ALL); 1571 mutex_exit(uobj->vmobjlock); 1572 kva = uvm_pagermapin(pgs, npages, 1573 UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); 1574 for (i = 0; i < npages; i++) { 1575 pg = pgs[i]; 1576 if ((pg->flags & PG_FAKE) == 0) { 1577 continue; 1578 } 1579 iov.iov_base = (char *)kva + (i << PAGE_SHIFT); 1580 iov.iov_len = PAGE_SIZE; 1581 uio.uio_iov = &iov; 1582 uio.uio_iovcnt = 1; 1583 uio.uio_offset = origoffset + (i << PAGE_SHIFT); 1584 uio.uio_rw = UIO_READ; 1585 uio.uio_resid = PAGE_SIZE; 1586 UIO_SETUP_SYSSPACE(&uio); 1587 /* XXX vn_lock */ 1588 error = VOP_READ(vp, &uio, 0, cred); 1589 if (error) { 1590 break; 1591 } 1592 if (uio.uio_resid) { 1593 memset(iov.iov_base, 0, uio.uio_resid); 1594 } 1595 } 1596 uvm_pagermapout(kva, npages); 1597 mutex_enter(uobj->vmobjlock); 1598 mutex_enter(&uvm_pageqlock); 1599 for (i = 0; i < npages; i++) { 1600 pg = pgs[i]; 1601 if (error && (pg->flags & PG_FAKE) != 0) { 1602 pg->flags |= PG_RELEASED; 1603 } else { 1604 pmap_clear_modify(pg); 1605 uvm_pageactivate(pg); 1606 } 1607 } 1608 if (error) { 1609 uvm_page_unbusy(pgs, npages); 1610 } 1611 mutex_exit(&uvm_pageqlock); 1612 if (error == 0 && memwrite) { 1613 genfs_markdirty(vp); 1614 } 1615 mutex_exit(uobj->vmobjlock); 1616 return error; 1617 } 1618 1619 int 1620 genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, 1621 int flags) 1622 { 1623 off_t offset; 1624 struct iovec iov; 1625 struct uio uio; 1626 kauth_cred_t cred = curlwp->l_cred; 1627 struct buf *bp; 1628 vaddr_t kva; 1629 int error; 1630 1631 offset = pgs[0]->offset; 1632 kva = uvm_pagermapin(pgs, npages, 1633 UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); 1634 1635 iov.iov_base = (void *)kva; 1636 iov.iov_len = npages << PAGE_SHIFT; 1637 uio.uio_iov = &iov; 1638 uio.uio_iovcnt = 1; 1639 uio.uio_offset = offset; 1640 uio.uio_rw = UIO_WRITE; 1641 uio.uio_resid = npages << PAGE_SHIFT; 1642 UIO_SETUP_SYSSPACE(&uio); 1643 /* XXX vn_lock */ 1644 error = VOP_WRITE(vp, &uio, 0, cred); 1645 1646 mutex_enter(vp->v_interlock); 1647 vp->v_numoutput++; 1648 mutex_exit(vp->v_interlock); 1649 1650 bp = getiobuf(vp, true); 1651 bp->b_cflags = BC_BUSY | BC_AGE; 1652 bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift; 1653 bp->b_data = (char *)kva; 1654 bp->b_bcount = npages << PAGE_SHIFT; 1655 bp->b_bufsize = npages << PAGE_SHIFT; 1656 bp->b_resid = 0; 1657 bp->b_error = error; 1658 uvm_aio_aiodone(bp); 1659 return (error); 1660 } 1661 1662 /* 1663 * Process a uio using direct I/O. If we reach a part of the request 1664 * which cannot be processed in this fashion for some reason, just return. 1665 * The caller must handle some additional part of the request using 1666 * buffered I/O before trying direct I/O again. 1667 */ 1668 1669 void 1670 genfs_directio(struct vnode *vp, struct uio *uio, int ioflag) 1671 { 1672 struct vmspace *vs; 1673 struct iovec *iov; 1674 vaddr_t va; 1675 size_t len; 1676 const int mask = DEV_BSIZE - 1; 1677 int error; 1678 bool need_wapbl = (vp->v_mount && vp->v_mount->mnt_wapbl && 1679 (ioflag & IO_JOURNALLOCKED) == 0); 1680 1681 /* 1682 * We only support direct I/O to user space for now. 1683 */ 1684 1685 if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) { 1686 return; 1687 } 1688 1689 /* 1690 * If the vnode is mapped, we would need to get the getpages lock 1691 * to stabilize the bmap, but then we would get into trouble while 1692 * locking the pages if the pages belong to this same vnode (or a 1693 * multi-vnode cascade to the same effect). Just fall back to 1694 * buffered I/O if the vnode is mapped to avoid this mess. 1695 */ 1696 1697 if (vp->v_vflag & VV_MAPPED) { 1698 return; 1699 } 1700 1701 if (need_wapbl) { 1702 error = WAPBL_BEGIN(vp->v_mount); 1703 if (error) 1704 return; 1705 } 1706 1707 /* 1708 * Do as much of the uio as possible with direct I/O. 1709 */ 1710 1711 vs = uio->uio_vmspace; 1712 while (uio->uio_resid) { 1713 iov = uio->uio_iov; 1714 if (iov->iov_len == 0) { 1715 uio->uio_iov++; 1716 uio->uio_iovcnt--; 1717 continue; 1718 } 1719 va = (vaddr_t)iov->iov_base; 1720 len = MIN(iov->iov_len, genfs_maxdio); 1721 len &= ~mask; 1722 1723 /* 1724 * If the next chunk is smaller than DEV_BSIZE or extends past 1725 * the current EOF, then fall back to buffered I/O. 1726 */ 1727 1728 if (len == 0 || uio->uio_offset + len > vp->v_size) { 1729 break; 1730 } 1731 1732 /* 1733 * Check alignment. The file offset must be at least 1734 * sector-aligned. The exact constraint on memory alignment 1735 * is very hardware-dependent, but requiring sector-aligned 1736 * addresses there too is safe. 1737 */ 1738 1739 if (uio->uio_offset & mask || va & mask) { 1740 break; 1741 } 1742 error = genfs_do_directio(vs, va, len, vp, uio->uio_offset, 1743 uio->uio_rw); 1744 if (error) { 1745 break; 1746 } 1747 iov->iov_base = (char *)iov->iov_base + len; 1748 iov->iov_len -= len; 1749 uio->uio_offset += len; 1750 uio->uio_resid -= len; 1751 } 1752 1753 if (need_wapbl) 1754 WAPBL_END(vp->v_mount); 1755 } 1756 1757 /* 1758 * Iodone routine for direct I/O. We don't do much here since the request is 1759 * always synchronous, so the caller will do most of the work after biowait(). 1760 */ 1761 1762 static void 1763 genfs_dio_iodone(struct buf *bp) 1764 { 1765 1766 KASSERT((bp->b_flags & B_ASYNC) == 0); 1767 if ((bp->b_flags & B_READ) == 0 && (bp->b_cflags & BC_AGE) != 0) { 1768 mutex_enter(bp->b_objlock); 1769 vwakeup(bp); 1770 mutex_exit(bp->b_objlock); 1771 } 1772 putiobuf(bp); 1773 } 1774 1775 /* 1776 * Process one chunk of a direct I/O request. 1777 */ 1778 1779 static int 1780 genfs_do_directio(struct vmspace *vs, vaddr_t uva, size_t len, struct vnode *vp, 1781 off_t off, enum uio_rw rw) 1782 { 1783 struct vm_map *map; 1784 struct pmap *upm, *kpm __unused; 1785 size_t klen = round_page(uva + len) - trunc_page(uva); 1786 off_t spoff, epoff; 1787 vaddr_t kva, puva; 1788 paddr_t pa; 1789 vm_prot_t prot; 1790 int error, rv __diagused, poff, koff; 1791 const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED | 1792 (rw == UIO_WRITE ? PGO_FREE : 0); 1793 1794 /* 1795 * For writes, verify that this range of the file already has fully 1796 * allocated backing store. If there are any holes, just punt and 1797 * make the caller take the buffered write path. 1798 */ 1799 1800 if (rw == UIO_WRITE) { 1801 daddr_t lbn, elbn, blkno; 1802 int bsize, bshift, run; 1803 1804 bshift = vp->v_mount->mnt_fs_bshift; 1805 bsize = 1 << bshift; 1806 lbn = off >> bshift; 1807 elbn = (off + len + bsize - 1) >> bshift; 1808 while (lbn < elbn) { 1809 error = VOP_BMAP(vp, lbn, NULL, &blkno, &run); 1810 if (error) { 1811 return error; 1812 } 1813 if (blkno == (daddr_t)-1) { 1814 return ENOSPC; 1815 } 1816 lbn += 1 + run; 1817 } 1818 } 1819 1820 /* 1821 * Flush any cached pages for parts of the file that we're about to 1822 * access. If we're writing, invalidate pages as well. 1823 */ 1824 1825 spoff = trunc_page(off); 1826 epoff = round_page(off + len); 1827 mutex_enter(vp->v_interlock); 1828 error = VOP_PUTPAGES(vp, spoff, epoff, pgoflags); 1829 if (error) { 1830 return error; 1831 } 1832 1833 /* 1834 * Wire the user pages and remap them into kernel memory. 1835 */ 1836 1837 prot = rw == UIO_READ ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 1838 error = uvm_vslock(vs, (void *)uva, len, prot); 1839 if (error) { 1840 return error; 1841 } 1842 1843 map = &vs->vm_map; 1844 upm = vm_map_pmap(map); 1845 kpm = vm_map_pmap(kernel_map); 1846 puva = trunc_page(uva); 1847 kva = uvm_km_alloc(kernel_map, klen, atop(puva) & uvmexp.colormask, 1848 UVM_KMF_VAONLY | UVM_KMF_WAITVA | UVM_KMF_COLORMATCH); 1849 for (poff = 0; poff < klen; poff += PAGE_SIZE) { 1850 rv = pmap_extract(upm, puva + poff, &pa); 1851 KASSERT(rv); 1852 pmap_kenter_pa(kva + poff, pa, prot, PMAP_WIRED); 1853 } 1854 pmap_update(kpm); 1855 1856 /* 1857 * Do the I/O. 1858 */ 1859 1860 koff = uva - trunc_page(uva); 1861 error = genfs_do_io(vp, off, kva + koff, len, PGO_SYNCIO, rw, 1862 genfs_dio_iodone); 1863 1864 /* 1865 * Tear down the kernel mapping. 1866 */ 1867 1868 pmap_kremove(kva, klen); 1869 pmap_update(kpm); 1870 uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY); 1871 1872 /* 1873 * Unwire the user pages. 1874 */ 1875 1876 uvm_vsunlock(vs, (void *)uva, len); 1877 return error; 1878 } 1879