1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2013 Peter Grehan <grehan@freebsd.org> 5 * All rights reserved. 6 * Copyright 2020 Joyent, Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #ifndef WITHOUT_CAPSICUM 37 #include <sys/capsicum.h> 38 #endif 39 #include <sys/queue.h> 40 #include <sys/errno.h> 41 #include <sys/stat.h> 42 #include <sys/ioctl.h> 43 #include <sys/disk.h> 44 45 #include <assert.h> 46 #ifndef WITHOUT_CAPSICUM 47 #include <capsicum_helpers.h> 48 #endif 49 #include <err.h> 50 #include <fcntl.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <pthread.h> 55 #include <pthread_np.h> 56 #include <signal.h> 57 #include <sysexits.h> 58 #include <unistd.h> 59 60 #include <machine/atomic.h> 61 #include <machine/vmm_snapshot.h> 62 63 #include "bhyverun.h" 64 #include "config.h" 65 #include "debug.h" 66 #include "mevent.h" 67 #include "pci_emul.h" 68 #include "block_if.h" 69 70 #define BLOCKIF_SIG 0xb109b109 71 72 #define BLOCKIF_NUMTHR 8 73 #define BLOCKIF_MAXREQ (BLOCKIF_RING_MAX + BLOCKIF_NUMTHR) 74 75 enum blockop { 76 BOP_READ, 77 BOP_WRITE, 78 BOP_FLUSH, 79 BOP_DELETE 80 }; 81 82 enum blockstat { 83 BST_FREE, 84 BST_BLOCK, 85 BST_PEND, 86 BST_BUSY, 87 BST_DONE 88 }; 89 90 struct blockif_elem { 91 TAILQ_ENTRY(blockif_elem) be_link; 92 struct blockif_req *be_req; 93 enum blockop be_op; 94 enum blockstat be_status; 95 pthread_t be_tid; 96 off_t be_block; 97 }; 98 99 struct blockif_ctxt { 100 unsigned int bc_magic; 101 int bc_fd; 102 int bc_ischr; 103 int bc_isgeom; 104 int bc_candelete; 105 int bc_rdonly; 106 off_t bc_size; 107 int bc_sectsz; 108 int bc_psectsz; 109 int bc_psectoff; 110 int bc_closing; 111 int bc_paused; 112 pthread_t bc_btid[BLOCKIF_NUMTHR]; 113 pthread_mutex_t bc_mtx; 114 pthread_cond_t bc_cond; 115 pthread_cond_t bc_work_done_cond; 116 blockif_resize_cb *bc_resize_cb; 117 void *bc_resize_cb_arg; 118 struct mevent *bc_resize_event; 119 120 /* Request elements and free/pending/busy queues */ 121 TAILQ_HEAD(, blockif_elem) bc_freeq; 122 TAILQ_HEAD(, blockif_elem) bc_pendq; 123 TAILQ_HEAD(, blockif_elem) bc_busyq; 124 struct blockif_elem bc_reqs[BLOCKIF_MAXREQ]; 125 }; 126 127 static pthread_once_t blockif_once = PTHREAD_ONCE_INIT; 128 129 struct blockif_sig_elem { 130 pthread_mutex_t bse_mtx; 131 pthread_cond_t bse_cond; 132 int bse_pending; 133 struct blockif_sig_elem *bse_next; 134 }; 135 136 static struct blockif_sig_elem *blockif_bse_head; 137 138 static int 139 blockif_enqueue(struct blockif_ctxt *bc, struct blockif_req *breq, 140 enum blockop op) 141 { 142 struct blockif_elem *be, *tbe; 143 off_t off; 144 int i; 145 146 be = TAILQ_FIRST(&bc->bc_freeq); 147 assert(be != NULL); 148 assert(be->be_status == BST_FREE); 149 TAILQ_REMOVE(&bc->bc_freeq, be, be_link); 150 be->be_req = breq; 151 be->be_op = op; 152 switch (op) { 153 case BOP_READ: 154 case BOP_WRITE: 155 case BOP_DELETE: 156 off = breq->br_offset; 157 for (i = 0; i < breq->br_iovcnt; i++) 158 off += breq->br_iov[i].iov_len; 159 break; 160 default: 161 off = OFF_MAX; 162 } 163 be->be_block = off; 164 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) { 165 if (tbe->be_block == breq->br_offset) 166 break; 167 } 168 if (tbe == NULL) { 169 TAILQ_FOREACH(tbe, &bc->bc_busyq, be_link) { 170 if (tbe->be_block == breq->br_offset) 171 break; 172 } 173 } 174 if (tbe == NULL) 175 be->be_status = BST_PEND; 176 else 177 be->be_status = BST_BLOCK; 178 TAILQ_INSERT_TAIL(&bc->bc_pendq, be, be_link); 179 return (be->be_status == BST_PEND); 180 } 181 182 static int 183 blockif_dequeue(struct blockif_ctxt *bc, pthread_t t, struct blockif_elem **bep) 184 { 185 struct blockif_elem *be; 186 187 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) { 188 if (be->be_status == BST_PEND) 189 break; 190 assert(be->be_status == BST_BLOCK); 191 } 192 if (be == NULL) 193 return (0); 194 TAILQ_REMOVE(&bc->bc_pendq, be, be_link); 195 be->be_status = BST_BUSY; 196 be->be_tid = t; 197 TAILQ_INSERT_TAIL(&bc->bc_busyq, be, be_link); 198 *bep = be; 199 return (1); 200 } 201 202 static void 203 blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be) 204 { 205 struct blockif_elem *tbe; 206 207 if (be->be_status == BST_DONE || be->be_status == BST_BUSY) 208 TAILQ_REMOVE(&bc->bc_busyq, be, be_link); 209 else 210 TAILQ_REMOVE(&bc->bc_pendq, be, be_link); 211 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) { 212 if (tbe->be_req->br_offset == be->be_block) 213 tbe->be_status = BST_PEND; 214 } 215 be->be_tid = 0; 216 be->be_status = BST_FREE; 217 be->be_req = NULL; 218 TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link); 219 } 220 221 static int 222 blockif_flush_bc(struct blockif_ctxt *bc) 223 { 224 if (bc->bc_ischr) { 225 if (ioctl(bc->bc_fd, DIOCGFLUSH)) 226 return (errno); 227 } else if (fsync(bc->bc_fd)) 228 return (errno); 229 230 return (0); 231 } 232 233 static void 234 blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf) 235 { 236 struct spacectl_range range; 237 struct blockif_req *br; 238 off_t arg[2]; 239 ssize_t n; 240 size_t clen, len, off, boff, voff; 241 int i, err; 242 243 br = be->be_req; 244 assert(br->br_resid >= 0); 245 246 if (br->br_iovcnt <= 1) 247 buf = NULL; 248 err = 0; 249 switch (be->be_op) { 250 case BOP_READ: 251 if (buf == NULL) { 252 if ((n = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt, 253 br->br_offset)) < 0) 254 err = errno; 255 else 256 br->br_resid -= n; 257 break; 258 } 259 i = 0; 260 off = voff = 0; 261 while (br->br_resid > 0) { 262 len = MIN(br->br_resid, MAXPHYS); 263 n = pread(bc->bc_fd, buf, len, br->br_offset + off); 264 if (n < 0) { 265 err = errno; 266 break; 267 } 268 len = (size_t)n; 269 boff = 0; 270 do { 271 clen = MIN(len - boff, br->br_iov[i].iov_len - 272 voff); 273 memcpy((uint8_t *)br->br_iov[i].iov_base + voff, 274 buf + boff, clen); 275 if (clen < br->br_iov[i].iov_len - voff) 276 voff += clen; 277 else { 278 i++; 279 voff = 0; 280 } 281 boff += clen; 282 } while (boff < len); 283 off += len; 284 br->br_resid -= len; 285 } 286 break; 287 case BOP_WRITE: 288 if (bc->bc_rdonly) { 289 err = EROFS; 290 break; 291 } 292 if (buf == NULL) { 293 if ((n = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt, 294 br->br_offset)) < 0) 295 err = errno; 296 else 297 br->br_resid -= n; 298 break; 299 } 300 i = 0; 301 off = voff = 0; 302 while (br->br_resid > 0) { 303 len = MIN(br->br_resid, MAXPHYS); 304 boff = 0; 305 do { 306 clen = MIN(len - boff, br->br_iov[i].iov_len - 307 voff); 308 memcpy(buf + boff, 309 (uint8_t *)br->br_iov[i].iov_base + voff, 310 clen); 311 if (clen < br->br_iov[i].iov_len - voff) 312 voff += clen; 313 else { 314 i++; 315 voff = 0; 316 } 317 boff += clen; 318 } while (boff < len); 319 320 n = pwrite(bc->bc_fd, buf, len, br->br_offset + off); 321 if (n < 0) { 322 err = errno; 323 break; 324 } 325 off += n; 326 br->br_resid -= n; 327 } 328 break; 329 case BOP_FLUSH: 330 err = blockif_flush_bc(bc); 331 break; 332 case BOP_DELETE: 333 if (!bc->bc_candelete) 334 err = EOPNOTSUPP; 335 else if (bc->bc_rdonly) 336 err = EROFS; 337 else if (bc->bc_ischr) { 338 arg[0] = br->br_offset; 339 arg[1] = br->br_resid; 340 if (ioctl(bc->bc_fd, DIOCGDELETE, arg)) 341 err = errno; 342 else 343 br->br_resid = 0; 344 } else { 345 range.r_offset = br->br_offset; 346 range.r_len = br->br_resid; 347 348 while (range.r_len > 0) { 349 if (fspacectl(bc->bc_fd, SPACECTL_DEALLOC, 350 &range, 0, &range) != 0) { 351 err = errno; 352 break; 353 } 354 } 355 if (err == 0) 356 br->br_resid = 0; 357 } 358 break; 359 default: 360 err = EINVAL; 361 break; 362 } 363 364 be->be_status = BST_DONE; 365 366 (*br->br_callback)(br, err); 367 } 368 369 static inline bool 370 blockif_empty(const struct blockif_ctxt *bc) 371 { 372 return (TAILQ_EMPTY(&bc->bc_pendq) && TAILQ_EMPTY(&bc->bc_busyq)); 373 } 374 375 static void * 376 blockif_thr(void *arg) 377 { 378 struct blockif_ctxt *bc; 379 struct blockif_elem *be; 380 pthread_t t; 381 uint8_t *buf; 382 383 bc = arg; 384 if (bc->bc_isgeom) 385 buf = malloc(MAXPHYS); 386 else 387 buf = NULL; 388 t = pthread_self(); 389 390 pthread_mutex_lock(&bc->bc_mtx); 391 for (;;) { 392 while (blockif_dequeue(bc, t, &be)) { 393 pthread_mutex_unlock(&bc->bc_mtx); 394 blockif_proc(bc, be, buf); 395 pthread_mutex_lock(&bc->bc_mtx); 396 blockif_complete(bc, be); 397 } 398 399 /* If none to work, notify the main thread */ 400 if (blockif_empty(bc)) 401 pthread_cond_broadcast(&bc->bc_work_done_cond); 402 403 /* Check ctxt status here to see if exit requested */ 404 if (bc->bc_closing) 405 break; 406 407 pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx); 408 } 409 pthread_mutex_unlock(&bc->bc_mtx); 410 411 if (buf) 412 free(buf); 413 pthread_exit(NULL); 414 return (NULL); 415 } 416 417 static void 418 blockif_sigcont_handler(int signal __unused, enum ev_type type __unused, 419 void *arg __unused) 420 { 421 struct blockif_sig_elem *bse; 422 423 for (;;) { 424 /* 425 * Process the entire list even if not intended for 426 * this thread. 427 */ 428 do { 429 bse = blockif_bse_head; 430 if (bse == NULL) 431 return; 432 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head, 433 (uintptr_t)bse, 434 (uintptr_t)bse->bse_next)); 435 436 pthread_mutex_lock(&bse->bse_mtx); 437 bse->bse_pending = 0; 438 pthread_cond_signal(&bse->bse_cond); 439 pthread_mutex_unlock(&bse->bse_mtx); 440 } 441 } 442 443 static void 444 blockif_init(void) 445 { 446 mevent_add(SIGCONT, EVF_SIGNAL, blockif_sigcont_handler, NULL); 447 (void) signal(SIGCONT, SIG_IGN); 448 } 449 450 int 451 blockif_legacy_config(nvlist_t *nvl, const char *opts) 452 { 453 char *cp, *path; 454 455 if (opts == NULL) 456 return (0); 457 458 cp = strchr(opts, ','); 459 if (cp == NULL) { 460 set_config_value_node(nvl, "path", opts); 461 return (0); 462 } 463 path = strndup(opts, cp - opts); 464 set_config_value_node(nvl, "path", path); 465 free(path); 466 return (pci_parse_legacy_config(nvl, cp + 1)); 467 } 468 469 struct blockif_ctxt * 470 blockif_open(nvlist_t *nvl, const char *ident) 471 { 472 char tname[MAXCOMLEN + 1]; 473 char name[MAXPATHLEN]; 474 const char *path, *pssval, *ssval; 475 char *cp; 476 struct blockif_ctxt *bc; 477 struct stat sbuf; 478 struct diocgattr_arg arg; 479 off_t size, psectsz, psectoff; 480 int extra, fd, i, sectsz; 481 int ro, candelete, geom, ssopt, pssopt; 482 int nodelete; 483 484 #ifndef WITHOUT_CAPSICUM 485 cap_rights_t rights; 486 cap_ioctl_t cmds[] = { DIOCGFLUSH, DIOCGDELETE, DIOCGMEDIASIZE }; 487 #endif 488 489 pthread_once(&blockif_once, blockif_init); 490 491 fd = -1; 492 extra = 0; 493 ssopt = 0; 494 ro = 0; 495 nodelete = 0; 496 497 if (get_config_bool_node_default(nvl, "nocache", false)) 498 extra |= O_DIRECT; 499 if (get_config_bool_node_default(nvl, "nodelete", false)) 500 nodelete = 1; 501 if (get_config_bool_node_default(nvl, "sync", false) || 502 get_config_bool_node_default(nvl, "direct", false)) 503 extra |= O_SYNC; 504 if (get_config_bool_node_default(nvl, "ro", false)) 505 ro = 1; 506 ssval = get_config_value_node(nvl, "sectorsize"); 507 if (ssval != NULL) { 508 ssopt = strtol(ssval, &cp, 10); 509 if (cp == ssval) { 510 EPRINTLN("Invalid sector size \"%s\"", ssval); 511 goto err; 512 } 513 if (*cp == '\0') { 514 pssopt = ssopt; 515 } else if (*cp == '/') { 516 pssval = cp + 1; 517 pssopt = strtol(pssval, &cp, 10); 518 if (cp == pssval || *cp != '\0') { 519 EPRINTLN("Invalid sector size \"%s\"", ssval); 520 goto err; 521 } 522 } else { 523 EPRINTLN("Invalid sector size \"%s\"", ssval); 524 goto err; 525 } 526 } 527 528 path = get_config_value_node(nvl, "path"); 529 if (path == NULL) { 530 EPRINTLN("Missing \"path\" for block device."); 531 goto err; 532 } 533 534 fd = open(path, (ro ? O_RDONLY : O_RDWR) | extra); 535 if (fd < 0 && !ro) { 536 /* Attempt a r/w fail with a r/o open */ 537 fd = open(path, O_RDONLY | extra); 538 ro = 1; 539 } 540 541 if (fd < 0) { 542 warn("Could not open backing file: %s", path); 543 goto err; 544 } 545 546 if (fstat(fd, &sbuf) < 0) { 547 warn("Could not stat backing file %s", path); 548 goto err; 549 } 550 551 #ifndef WITHOUT_CAPSICUM 552 cap_rights_init(&rights, CAP_FSYNC, CAP_IOCTL, CAP_READ, CAP_SEEK, 553 CAP_WRITE, CAP_FSTAT, CAP_EVENT, CAP_FPATHCONF); 554 if (ro) 555 cap_rights_clear(&rights, CAP_FSYNC, CAP_WRITE); 556 557 if (caph_rights_limit(fd, &rights) == -1) 558 errx(EX_OSERR, "Unable to apply rights for sandbox"); 559 #endif 560 561 /* 562 * Deal with raw devices 563 */ 564 size = sbuf.st_size; 565 sectsz = DEV_BSIZE; 566 psectsz = psectoff = 0; 567 candelete = geom = 0; 568 if (S_ISCHR(sbuf.st_mode)) { 569 if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 || 570 ioctl(fd, DIOCGSECTORSIZE, §sz)) { 571 perror("Could not fetch dev blk/sector size"); 572 goto err; 573 } 574 assert(size != 0); 575 assert(sectsz != 0); 576 if (ioctl(fd, DIOCGSTRIPESIZE, &psectsz) == 0 && psectsz > 0) 577 ioctl(fd, DIOCGSTRIPEOFFSET, &psectoff); 578 strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name)); 579 arg.len = sizeof(arg.value.i); 580 if (nodelete == 0 && ioctl(fd, DIOCGATTR, &arg) == 0) 581 candelete = arg.value.i; 582 if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0) 583 geom = 1; 584 } else { 585 psectsz = sbuf.st_blksize; 586 /* Avoid fallback implementation */ 587 candelete = fpathconf(fd, _PC_DEALLOC_PRESENT) == 1; 588 } 589 590 #ifndef WITHOUT_CAPSICUM 591 if (caph_ioctls_limit(fd, cmds, nitems(cmds)) == -1) 592 errx(EX_OSERR, "Unable to apply rights for sandbox"); 593 #endif 594 595 if (ssopt != 0) { 596 if (!powerof2(ssopt) || !powerof2(pssopt) || ssopt < 512 || 597 ssopt > pssopt) { 598 EPRINTLN("Invalid sector size %d/%d", 599 ssopt, pssopt); 600 goto err; 601 } 602 603 /* 604 * Some backend drivers (e.g. cd0, ada0) require that the I/O 605 * size be a multiple of the device's sector size. 606 * 607 * Validate that the emulated sector size complies with this 608 * requirement. 609 */ 610 if (S_ISCHR(sbuf.st_mode)) { 611 if (ssopt < sectsz || (ssopt % sectsz) != 0) { 612 EPRINTLN("Sector size %d incompatible " 613 "with underlying device sector size %d", 614 ssopt, sectsz); 615 goto err; 616 } 617 } 618 619 sectsz = ssopt; 620 psectsz = pssopt; 621 psectoff = 0; 622 } 623 624 bc = calloc(1, sizeof(struct blockif_ctxt)); 625 if (bc == NULL) { 626 perror("calloc"); 627 goto err; 628 } 629 630 bc->bc_magic = BLOCKIF_SIG; 631 bc->bc_fd = fd; 632 bc->bc_ischr = S_ISCHR(sbuf.st_mode); 633 bc->bc_isgeom = geom; 634 bc->bc_candelete = candelete; 635 bc->bc_rdonly = ro; 636 bc->bc_size = size; 637 bc->bc_sectsz = sectsz; 638 bc->bc_psectsz = psectsz; 639 bc->bc_psectoff = psectoff; 640 pthread_mutex_init(&bc->bc_mtx, NULL); 641 pthread_cond_init(&bc->bc_cond, NULL); 642 bc->bc_paused = 0; 643 pthread_cond_init(&bc->bc_work_done_cond, NULL); 644 TAILQ_INIT(&bc->bc_freeq); 645 TAILQ_INIT(&bc->bc_pendq); 646 TAILQ_INIT(&bc->bc_busyq); 647 for (i = 0; i < BLOCKIF_MAXREQ; i++) { 648 bc->bc_reqs[i].be_status = BST_FREE; 649 TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link); 650 } 651 652 for (i = 0; i < BLOCKIF_NUMTHR; i++) { 653 pthread_create(&bc->bc_btid[i], NULL, blockif_thr, bc); 654 snprintf(tname, sizeof(tname), "blk-%s-%d", ident, i); 655 pthread_set_name_np(bc->bc_btid[i], tname); 656 } 657 658 return (bc); 659 err: 660 if (fd >= 0) 661 close(fd); 662 return (NULL); 663 } 664 665 static void 666 blockif_resized(int fd, enum ev_type type __unused, void *arg) 667 { 668 struct blockif_ctxt *bc; 669 struct stat sb; 670 off_t mediasize; 671 672 if (fstat(fd, &sb) != 0) 673 return; 674 675 if (S_ISCHR(sb.st_mode)) { 676 if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) < 0) { 677 EPRINTLN("blockif_resized: get mediasize failed: %s", 678 strerror(errno)); 679 return; 680 } 681 } else 682 mediasize = sb.st_size; 683 684 bc = arg; 685 pthread_mutex_lock(&bc->bc_mtx); 686 if (mediasize != bc->bc_size) { 687 bc->bc_size = mediasize; 688 bc->bc_resize_cb(bc, bc->bc_resize_cb_arg, bc->bc_size); 689 } 690 pthread_mutex_unlock(&bc->bc_mtx); 691 } 692 693 int 694 blockif_register_resize_callback(struct blockif_ctxt *bc, blockif_resize_cb *cb, 695 void *cb_arg) 696 { 697 struct stat sb; 698 int err; 699 700 if (cb == NULL) 701 return (EINVAL); 702 703 err = 0; 704 705 pthread_mutex_lock(&bc->bc_mtx); 706 if (bc->bc_resize_cb != NULL) { 707 err = EBUSY; 708 goto out; 709 } 710 711 assert(bc->bc_closing == 0); 712 713 if (fstat(bc->bc_fd, &sb) != 0) { 714 err = errno; 715 goto out; 716 } 717 718 bc->bc_resize_event = mevent_add_flags(bc->bc_fd, EVF_VNODE, 719 EVFF_ATTRIB, blockif_resized, bc); 720 if (bc->bc_resize_event == NULL) { 721 err = ENXIO; 722 goto out; 723 } 724 725 bc->bc_resize_cb = cb; 726 bc->bc_resize_cb_arg = cb_arg; 727 out: 728 pthread_mutex_unlock(&bc->bc_mtx); 729 730 return (err); 731 } 732 733 static int 734 blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq, 735 enum blockop op) 736 { 737 int err; 738 739 err = 0; 740 741 pthread_mutex_lock(&bc->bc_mtx); 742 assert(!bc->bc_paused); 743 if (!TAILQ_EMPTY(&bc->bc_freeq)) { 744 /* 745 * Enqueue and inform the block i/o thread 746 * that there is work available 747 */ 748 if (blockif_enqueue(bc, breq, op)) 749 pthread_cond_signal(&bc->bc_cond); 750 } else { 751 /* 752 * Callers are not allowed to enqueue more than 753 * the specified blockif queue limit. Return an 754 * error to indicate that the queue length has been 755 * exceeded. 756 */ 757 err = E2BIG; 758 } 759 pthread_mutex_unlock(&bc->bc_mtx); 760 761 return (err); 762 } 763 764 int 765 blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq) 766 { 767 assert(bc->bc_magic == BLOCKIF_SIG); 768 return (blockif_request(bc, breq, BOP_READ)); 769 } 770 771 int 772 blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq) 773 { 774 assert(bc->bc_magic == BLOCKIF_SIG); 775 return (blockif_request(bc, breq, BOP_WRITE)); 776 } 777 778 int 779 blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq) 780 { 781 assert(bc->bc_magic == BLOCKIF_SIG); 782 return (blockif_request(bc, breq, BOP_FLUSH)); 783 } 784 785 int 786 blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq) 787 { 788 assert(bc->bc_magic == BLOCKIF_SIG); 789 return (blockif_request(bc, breq, BOP_DELETE)); 790 } 791 792 int 793 blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq) 794 { 795 struct blockif_elem *be; 796 797 assert(bc->bc_magic == BLOCKIF_SIG); 798 799 pthread_mutex_lock(&bc->bc_mtx); 800 /* XXX: not waiting while paused */ 801 802 /* 803 * Check pending requests. 804 */ 805 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) { 806 if (be->be_req == breq) 807 break; 808 } 809 if (be != NULL) { 810 /* 811 * Found it. 812 */ 813 blockif_complete(bc, be); 814 pthread_mutex_unlock(&bc->bc_mtx); 815 816 return (0); 817 } 818 819 /* 820 * Check in-flight requests. 821 */ 822 TAILQ_FOREACH(be, &bc->bc_busyq, be_link) { 823 if (be->be_req == breq) 824 break; 825 } 826 if (be == NULL) { 827 /* 828 * Didn't find it. 829 */ 830 pthread_mutex_unlock(&bc->bc_mtx); 831 return (EINVAL); 832 } 833 834 /* 835 * Interrupt the processing thread to force it return 836 * prematurely via it's normal callback path. 837 */ 838 while (be->be_status == BST_BUSY) { 839 struct blockif_sig_elem bse, *old_head; 840 841 pthread_mutex_init(&bse.bse_mtx, NULL); 842 pthread_cond_init(&bse.bse_cond, NULL); 843 844 bse.bse_pending = 1; 845 846 do { 847 old_head = blockif_bse_head; 848 bse.bse_next = old_head; 849 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head, 850 (uintptr_t)old_head, 851 (uintptr_t)&bse)); 852 853 pthread_kill(be->be_tid, SIGCONT); 854 855 pthread_mutex_lock(&bse.bse_mtx); 856 while (bse.bse_pending) 857 pthread_cond_wait(&bse.bse_cond, &bse.bse_mtx); 858 pthread_mutex_unlock(&bse.bse_mtx); 859 } 860 861 pthread_mutex_unlock(&bc->bc_mtx); 862 863 /* 864 * The processing thread has been interrupted. Since it's not 865 * clear if the callback has been invoked yet, return EBUSY. 866 */ 867 return (EBUSY); 868 } 869 870 int 871 blockif_close(struct blockif_ctxt *bc) 872 { 873 void *jval; 874 int i; 875 876 assert(bc->bc_magic == BLOCKIF_SIG); 877 878 /* 879 * Stop the block i/o thread 880 */ 881 pthread_mutex_lock(&bc->bc_mtx); 882 bc->bc_closing = 1; 883 if (bc->bc_resize_event != NULL) 884 mevent_disable(bc->bc_resize_event); 885 pthread_mutex_unlock(&bc->bc_mtx); 886 pthread_cond_broadcast(&bc->bc_cond); 887 for (i = 0; i < BLOCKIF_NUMTHR; i++) 888 pthread_join(bc->bc_btid[i], &jval); 889 890 /* XXX Cancel queued i/o's ??? */ 891 892 /* 893 * Release resources 894 */ 895 bc->bc_magic = 0; 896 close(bc->bc_fd); 897 free(bc); 898 899 return (0); 900 } 901 902 /* 903 * Return virtual C/H/S values for a given block. Use the algorithm 904 * outlined in the VHD specification to calculate values. 905 */ 906 void 907 blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s) 908 { 909 off_t sectors; /* total sectors of the block dev */ 910 off_t hcyl; /* cylinders times heads */ 911 uint16_t secpt; /* sectors per track */ 912 uint8_t heads; 913 914 assert(bc->bc_magic == BLOCKIF_SIG); 915 916 sectors = bc->bc_size / bc->bc_sectsz; 917 918 /* Clamp the size to the largest possible with CHS */ 919 if (sectors > 65535L * 16 * 255) 920 sectors = 65535L * 16 * 255; 921 922 if (sectors >= 65536L * 16 * 63) { 923 secpt = 255; 924 heads = 16; 925 hcyl = sectors / secpt; 926 } else { 927 secpt = 17; 928 hcyl = sectors / secpt; 929 heads = (hcyl + 1023) / 1024; 930 931 if (heads < 4) 932 heads = 4; 933 934 if (hcyl >= (heads * 1024) || heads > 16) { 935 secpt = 31; 936 heads = 16; 937 hcyl = sectors / secpt; 938 } 939 if (hcyl >= (heads * 1024)) { 940 secpt = 63; 941 heads = 16; 942 hcyl = sectors / secpt; 943 } 944 } 945 946 *c = hcyl / heads; 947 *h = heads; 948 *s = secpt; 949 } 950 951 /* 952 * Accessors 953 */ 954 off_t 955 blockif_size(struct blockif_ctxt *bc) 956 { 957 assert(bc->bc_magic == BLOCKIF_SIG); 958 return (bc->bc_size); 959 } 960 961 int 962 blockif_sectsz(struct blockif_ctxt *bc) 963 { 964 assert(bc->bc_magic == BLOCKIF_SIG); 965 return (bc->bc_sectsz); 966 } 967 968 void 969 blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off) 970 { 971 assert(bc->bc_magic == BLOCKIF_SIG); 972 *size = bc->bc_psectsz; 973 *off = bc->bc_psectoff; 974 } 975 976 int 977 blockif_queuesz(struct blockif_ctxt *bc) 978 { 979 assert(bc->bc_magic == BLOCKIF_SIG); 980 return (BLOCKIF_MAXREQ - 1); 981 } 982 983 int 984 blockif_is_ro(struct blockif_ctxt *bc) 985 { 986 assert(bc->bc_magic == BLOCKIF_SIG); 987 return (bc->bc_rdonly); 988 } 989 990 int 991 blockif_candelete(struct blockif_ctxt *bc) 992 { 993 assert(bc->bc_magic == BLOCKIF_SIG); 994 return (bc->bc_candelete); 995 } 996 997 #ifdef BHYVE_SNAPSHOT 998 void 999 blockif_pause(struct blockif_ctxt *bc) 1000 { 1001 assert(bc != NULL); 1002 assert(bc->bc_magic == BLOCKIF_SIG); 1003 1004 pthread_mutex_lock(&bc->bc_mtx); 1005 bc->bc_paused = 1; 1006 1007 /* The interface is paused. Wait for workers to finish their work */ 1008 while (!blockif_empty(bc)) 1009 pthread_cond_wait(&bc->bc_work_done_cond, &bc->bc_mtx); 1010 pthread_mutex_unlock(&bc->bc_mtx); 1011 1012 if (!bc->bc_rdonly && blockif_flush_bc(bc)) 1013 fprintf(stderr, "%s: [WARN] failed to flush backing file.\r\n", 1014 __func__); 1015 } 1016 1017 void 1018 blockif_resume(struct blockif_ctxt *bc) 1019 { 1020 assert(bc != NULL); 1021 assert(bc->bc_magic == BLOCKIF_SIG); 1022 1023 pthread_mutex_lock(&bc->bc_mtx); 1024 bc->bc_paused = 0; 1025 pthread_mutex_unlock(&bc->bc_mtx); 1026 } 1027 #endif /* BHYVE_SNAPSHOT */ 1028