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 30 #include <sys/cdefs.h> 31 #include <sys/param.h> 32 #ifndef WITHOUT_CAPSICUM 33 #include <sys/capsicum.h> 34 #endif 35 #include <sys/queue.h> 36 #include <sys/errno.h> 37 #include <sys/stat.h> 38 #include <sys/ioctl.h> 39 #include <sys/disk.h> 40 41 #include <assert.h> 42 #ifndef WITHOUT_CAPSICUM 43 #include <capsicum_helpers.h> 44 #endif 45 #include <err.h> 46 #include <fcntl.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <pthread.h> 51 #include <pthread_np.h> 52 #include <signal.h> 53 #include <sysexits.h> 54 #include <unistd.h> 55 56 #include <machine/atomic.h> 57 #include <machine/vmm_snapshot.h> 58 59 #include "bhyverun.h" 60 #include "config.h" 61 #include "debug.h" 62 #include "mevent.h" 63 #include "pci_emul.h" 64 #include "block_if.h" 65 66 #define BLOCKIF_SIG 0xb109b109 67 68 #define BLOCKIF_NUMTHR 8 69 #define BLOCKIF_MAXREQ (BLOCKIF_RING_MAX + BLOCKIF_NUMTHR) 70 71 enum blockop { 72 BOP_READ, 73 BOP_WRITE, 74 BOP_FLUSH, 75 BOP_DELETE 76 }; 77 78 enum blockstat { 79 BST_FREE, 80 BST_BLOCK, 81 BST_PEND, 82 BST_BUSY, 83 BST_DONE 84 }; 85 86 struct blockif_elem { 87 TAILQ_ENTRY(blockif_elem) be_link; 88 struct blockif_req *be_req; 89 enum blockop be_op; 90 enum blockstat be_status; 91 pthread_t be_tid; 92 off_t be_block; 93 }; 94 95 struct blockif_ctxt { 96 unsigned int bc_magic; 97 int bc_fd; 98 int bc_ischr; 99 int bc_isgeom; 100 int bc_candelete; 101 int bc_rdonly; 102 off_t bc_size; 103 int bc_sectsz; 104 int bc_psectsz; 105 int bc_psectoff; 106 int bc_closing; 107 int bc_paused; 108 pthread_t bc_btid[BLOCKIF_NUMTHR]; 109 pthread_mutex_t bc_mtx; 110 pthread_cond_t bc_cond; 111 pthread_cond_t bc_work_done_cond; 112 blockif_resize_cb *bc_resize_cb; 113 void *bc_resize_cb_arg; 114 struct mevent *bc_resize_event; 115 116 /* Request elements and free/pending/busy queues */ 117 TAILQ_HEAD(, blockif_elem) bc_freeq; 118 TAILQ_HEAD(, blockif_elem) bc_pendq; 119 TAILQ_HEAD(, blockif_elem) bc_busyq; 120 struct blockif_elem bc_reqs[BLOCKIF_MAXREQ]; 121 int bc_bootindex; 122 }; 123 124 static pthread_once_t blockif_once = PTHREAD_ONCE_INIT; 125 126 struct blockif_sig_elem { 127 pthread_mutex_t bse_mtx; 128 pthread_cond_t bse_cond; 129 int bse_pending; 130 struct blockif_sig_elem *bse_next; 131 }; 132 133 static struct blockif_sig_elem *blockif_bse_head; 134 135 static int 136 blockif_enqueue(struct blockif_ctxt *bc, struct blockif_req *breq, 137 enum blockop op) 138 { 139 struct blockif_elem *be, *tbe; 140 off_t off; 141 int i; 142 143 be = TAILQ_FIRST(&bc->bc_freeq); 144 assert(be != NULL); 145 assert(be->be_status == BST_FREE); 146 TAILQ_REMOVE(&bc->bc_freeq, be, be_link); 147 be->be_req = breq; 148 be->be_op = op; 149 switch (op) { 150 case BOP_READ: 151 case BOP_WRITE: 152 case BOP_DELETE: 153 off = breq->br_offset; 154 for (i = 0; i < breq->br_iovcnt; i++) 155 off += breq->br_iov[i].iov_len; 156 break; 157 default: 158 off = OFF_MAX; 159 } 160 be->be_block = off; 161 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) { 162 if (tbe->be_block == breq->br_offset) 163 break; 164 } 165 if (tbe == NULL) { 166 TAILQ_FOREACH(tbe, &bc->bc_busyq, be_link) { 167 if (tbe->be_block == breq->br_offset) 168 break; 169 } 170 } 171 if (tbe == NULL) 172 be->be_status = BST_PEND; 173 else 174 be->be_status = BST_BLOCK; 175 TAILQ_INSERT_TAIL(&bc->bc_pendq, be, be_link); 176 return (be->be_status == BST_PEND); 177 } 178 179 static int 180 blockif_dequeue(struct blockif_ctxt *bc, pthread_t t, struct blockif_elem **bep) 181 { 182 struct blockif_elem *be; 183 184 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) { 185 if (be->be_status == BST_PEND) 186 break; 187 assert(be->be_status == BST_BLOCK); 188 } 189 if (be == NULL) 190 return (0); 191 TAILQ_REMOVE(&bc->bc_pendq, be, be_link); 192 be->be_status = BST_BUSY; 193 be->be_tid = t; 194 TAILQ_INSERT_TAIL(&bc->bc_busyq, be, be_link); 195 *bep = be; 196 return (1); 197 } 198 199 static void 200 blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be) 201 { 202 struct blockif_elem *tbe; 203 204 if (be->be_status == BST_DONE || be->be_status == BST_BUSY) 205 TAILQ_REMOVE(&bc->bc_busyq, be, be_link); 206 else 207 TAILQ_REMOVE(&bc->bc_pendq, be, be_link); 208 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) { 209 if (tbe->be_req->br_offset == be->be_block) 210 tbe->be_status = BST_PEND; 211 } 212 be->be_tid = 0; 213 be->be_status = BST_FREE; 214 be->be_req = NULL; 215 TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link); 216 } 217 218 static int 219 blockif_flush_bc(struct blockif_ctxt *bc) 220 { 221 if (bc->bc_ischr) { 222 if (ioctl(bc->bc_fd, DIOCGFLUSH)) 223 return (errno); 224 } else if (fsync(bc->bc_fd)) 225 return (errno); 226 227 return (0); 228 } 229 230 static void 231 blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf) 232 { 233 struct spacectl_range range; 234 struct blockif_req *br; 235 off_t arg[2]; 236 ssize_t n; 237 size_t clen, len, off, boff, voff; 238 int i, err; 239 240 br = be->be_req; 241 assert(br->br_resid >= 0); 242 243 if (br->br_iovcnt <= 1) 244 buf = NULL; 245 err = 0; 246 switch (be->be_op) { 247 case BOP_READ: 248 if (buf == NULL) { 249 if ((n = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt, 250 br->br_offset)) < 0) 251 err = errno; 252 else 253 br->br_resid -= n; 254 break; 255 } 256 i = 0; 257 off = voff = 0; 258 while (br->br_resid > 0) { 259 len = MIN(br->br_resid, MAXPHYS); 260 n = pread(bc->bc_fd, buf, len, br->br_offset + off); 261 if (n < 0) { 262 err = errno; 263 break; 264 } 265 len = (size_t)n; 266 boff = 0; 267 do { 268 clen = MIN(len - boff, br->br_iov[i].iov_len - 269 voff); 270 memcpy((uint8_t *)br->br_iov[i].iov_base + voff, 271 buf + boff, clen); 272 if (clen < br->br_iov[i].iov_len - voff) 273 voff += clen; 274 else { 275 i++; 276 voff = 0; 277 } 278 boff += clen; 279 } while (boff < len); 280 off += len; 281 br->br_resid -= len; 282 } 283 break; 284 case BOP_WRITE: 285 if (bc->bc_rdonly) { 286 err = EROFS; 287 break; 288 } 289 if (buf == NULL) { 290 if ((n = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt, 291 br->br_offset)) < 0) 292 err = errno; 293 else 294 br->br_resid -= n; 295 break; 296 } 297 i = 0; 298 off = voff = 0; 299 while (br->br_resid > 0) { 300 len = MIN(br->br_resid, MAXPHYS); 301 boff = 0; 302 do { 303 clen = MIN(len - boff, br->br_iov[i].iov_len - 304 voff); 305 memcpy(buf + boff, 306 (uint8_t *)br->br_iov[i].iov_base + voff, 307 clen); 308 if (clen < br->br_iov[i].iov_len - voff) 309 voff += clen; 310 else { 311 i++; 312 voff = 0; 313 } 314 boff += clen; 315 } while (boff < len); 316 317 n = pwrite(bc->bc_fd, buf, len, br->br_offset + off); 318 if (n < 0) { 319 err = errno; 320 break; 321 } 322 off += n; 323 br->br_resid -= n; 324 } 325 break; 326 case BOP_FLUSH: 327 err = blockif_flush_bc(bc); 328 break; 329 case BOP_DELETE: 330 if (!bc->bc_candelete) 331 err = EOPNOTSUPP; 332 else if (bc->bc_rdonly) 333 err = EROFS; 334 else if (bc->bc_ischr) { 335 arg[0] = br->br_offset; 336 arg[1] = br->br_resid; 337 if (ioctl(bc->bc_fd, DIOCGDELETE, arg)) 338 err = errno; 339 else 340 br->br_resid = 0; 341 } else { 342 range.r_offset = br->br_offset; 343 range.r_len = br->br_resid; 344 345 while (range.r_len > 0) { 346 if (fspacectl(bc->bc_fd, SPACECTL_DEALLOC, 347 &range, 0, &range) != 0) { 348 err = errno; 349 break; 350 } 351 } 352 if (err == 0) 353 br->br_resid = 0; 354 } 355 break; 356 default: 357 err = EINVAL; 358 break; 359 } 360 361 be->be_status = BST_DONE; 362 363 (*br->br_callback)(br, err); 364 } 365 366 static inline bool 367 blockif_empty(const struct blockif_ctxt *bc) 368 { 369 return (TAILQ_EMPTY(&bc->bc_pendq) && TAILQ_EMPTY(&bc->bc_busyq)); 370 } 371 372 static void * 373 blockif_thr(void *arg) 374 { 375 struct blockif_ctxt *bc; 376 struct blockif_elem *be; 377 pthread_t t; 378 uint8_t *buf; 379 380 bc = arg; 381 if (bc->bc_isgeom) 382 buf = malloc(MAXPHYS); 383 else 384 buf = NULL; 385 t = pthread_self(); 386 387 pthread_mutex_lock(&bc->bc_mtx); 388 for (;;) { 389 while (blockif_dequeue(bc, t, &be)) { 390 pthread_mutex_unlock(&bc->bc_mtx); 391 blockif_proc(bc, be, buf); 392 pthread_mutex_lock(&bc->bc_mtx); 393 blockif_complete(bc, be); 394 } 395 396 /* If none to work, notify the main thread */ 397 if (blockif_empty(bc)) 398 pthread_cond_broadcast(&bc->bc_work_done_cond); 399 400 /* Check ctxt status here to see if exit requested */ 401 if (bc->bc_closing) 402 break; 403 404 pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx); 405 } 406 pthread_mutex_unlock(&bc->bc_mtx); 407 408 if (buf) 409 free(buf); 410 pthread_exit(NULL); 411 return (NULL); 412 } 413 414 static void 415 blockif_sigcont_handler(int signal __unused, enum ev_type type __unused, 416 void *arg __unused) 417 { 418 struct blockif_sig_elem *bse; 419 420 for (;;) { 421 /* 422 * Process the entire list even if not intended for 423 * this thread. 424 */ 425 do { 426 bse = blockif_bse_head; 427 if (bse == NULL) 428 return; 429 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head, 430 (uintptr_t)bse, 431 (uintptr_t)bse->bse_next)); 432 433 pthread_mutex_lock(&bse->bse_mtx); 434 bse->bse_pending = 0; 435 pthread_cond_signal(&bse->bse_cond); 436 pthread_mutex_unlock(&bse->bse_mtx); 437 } 438 } 439 440 static void 441 blockif_init(void) 442 { 443 mevent_add(SIGCONT, EVF_SIGNAL, blockif_sigcont_handler, NULL); 444 (void) signal(SIGCONT, SIG_IGN); 445 } 446 447 int 448 blockif_legacy_config(nvlist_t *nvl, const char *opts) 449 { 450 char *cp, *path; 451 452 if (opts == NULL) 453 return (0); 454 455 cp = strchr(opts, ','); 456 if (cp == NULL) { 457 set_config_value_node(nvl, "path", opts); 458 return (0); 459 } 460 path = strndup(opts, cp - opts); 461 set_config_value_node(nvl, "path", path); 462 free(path); 463 return (pci_parse_legacy_config(nvl, cp + 1)); 464 } 465 466 int 467 blockif_add_boot_device(struct pci_devinst *const pi, 468 struct blockif_ctxt *const bc) 469 { 470 if (bc->bc_bootindex < 0) 471 return (0); 472 473 return (pci_emul_add_boot_device(pi, bc->bc_bootindex)); 474 } 475 476 struct blockif_ctxt * 477 blockif_open(nvlist_t *nvl, const char *ident) 478 { 479 char tname[MAXCOMLEN + 1]; 480 char name[MAXPATHLEN]; 481 const char *path, *pssval, *ssval, *bootindex_val; 482 char *cp; 483 struct blockif_ctxt *bc; 484 struct stat sbuf; 485 struct diocgattr_arg arg; 486 off_t size, psectsz, psectoff; 487 int extra, fd, i, sectsz; 488 int ro, candelete, geom, ssopt, pssopt; 489 int nodelete; 490 int bootindex; 491 492 #ifndef WITHOUT_CAPSICUM 493 cap_rights_t rights; 494 cap_ioctl_t cmds[] = { DIOCGFLUSH, DIOCGDELETE, DIOCGMEDIASIZE }; 495 #endif 496 497 pthread_once(&blockif_once, blockif_init); 498 499 fd = -1; 500 extra = 0; 501 ssopt = 0; 502 ro = 0; 503 nodelete = 0; 504 bootindex = -1; 505 506 if (get_config_bool_node_default(nvl, "nocache", false)) 507 extra |= O_DIRECT; 508 if (get_config_bool_node_default(nvl, "nodelete", false)) 509 nodelete = 1; 510 if (get_config_bool_node_default(nvl, "sync", false) || 511 get_config_bool_node_default(nvl, "direct", false)) 512 extra |= O_SYNC; 513 if (get_config_bool_node_default(nvl, "ro", false)) 514 ro = 1; 515 ssval = get_config_value_node(nvl, "sectorsize"); 516 if (ssval != NULL) { 517 ssopt = strtol(ssval, &cp, 10); 518 if (cp == ssval) { 519 EPRINTLN("Invalid sector size \"%s\"", ssval); 520 goto err; 521 } 522 if (*cp == '\0') { 523 pssopt = ssopt; 524 } else if (*cp == '/') { 525 pssval = cp + 1; 526 pssopt = strtol(pssval, &cp, 10); 527 if (cp == pssval || *cp != '\0') { 528 EPRINTLN("Invalid sector size \"%s\"", ssval); 529 goto err; 530 } 531 } else { 532 EPRINTLN("Invalid sector size \"%s\"", ssval); 533 goto err; 534 } 535 } 536 537 bootindex_val = get_config_value_node(nvl, "bootindex"); 538 if (bootindex_val != NULL) { 539 bootindex = atoi(bootindex_val); 540 } 541 542 path = get_config_value_node(nvl, "path"); 543 if (path == NULL) { 544 EPRINTLN("Missing \"path\" for block device."); 545 goto err; 546 } 547 548 fd = open(path, (ro ? O_RDONLY : O_RDWR) | extra); 549 if (fd < 0 && !ro) { 550 /* Attempt a r/w fail with a r/o open */ 551 fd = open(path, O_RDONLY | extra); 552 ro = 1; 553 } 554 555 if (fd < 0) { 556 warn("Could not open backing file: %s", path); 557 goto err; 558 } 559 560 if (fstat(fd, &sbuf) < 0) { 561 warn("Could not stat backing file %s", path); 562 goto err; 563 } 564 565 #ifndef WITHOUT_CAPSICUM 566 cap_rights_init(&rights, CAP_FSYNC, CAP_IOCTL, CAP_READ, CAP_SEEK, 567 CAP_WRITE, CAP_FSTAT, CAP_EVENT, CAP_FPATHCONF); 568 if (ro) 569 cap_rights_clear(&rights, CAP_FSYNC, CAP_WRITE); 570 571 if (caph_rights_limit(fd, &rights) == -1) 572 errx(EX_OSERR, "Unable to apply rights for sandbox"); 573 #endif 574 575 /* 576 * Deal with raw devices 577 */ 578 size = sbuf.st_size; 579 sectsz = DEV_BSIZE; 580 psectsz = psectoff = 0; 581 candelete = geom = 0; 582 if (S_ISCHR(sbuf.st_mode)) { 583 if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 || 584 ioctl(fd, DIOCGSECTORSIZE, §sz)) { 585 perror("Could not fetch dev blk/sector size"); 586 goto err; 587 } 588 assert(size != 0); 589 assert(sectsz != 0); 590 if (ioctl(fd, DIOCGSTRIPESIZE, &psectsz) == 0 && psectsz > 0) 591 ioctl(fd, DIOCGSTRIPEOFFSET, &psectoff); 592 strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name)); 593 arg.len = sizeof(arg.value.i); 594 if (nodelete == 0 && ioctl(fd, DIOCGATTR, &arg) == 0) 595 candelete = arg.value.i; 596 if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0) 597 geom = 1; 598 } else { 599 psectsz = sbuf.st_blksize; 600 /* Avoid fallback implementation */ 601 candelete = fpathconf(fd, _PC_DEALLOC_PRESENT) == 1; 602 } 603 604 #ifndef WITHOUT_CAPSICUM 605 if (caph_ioctls_limit(fd, cmds, nitems(cmds)) == -1) 606 errx(EX_OSERR, "Unable to apply rights for sandbox"); 607 #endif 608 609 if (ssopt != 0) { 610 if (!powerof2(ssopt) || !powerof2(pssopt) || ssopt < 512 || 611 ssopt > pssopt) { 612 EPRINTLN("Invalid sector size %d/%d", 613 ssopt, pssopt); 614 goto err; 615 } 616 617 /* 618 * Some backend drivers (e.g. cd0, ada0) require that the I/O 619 * size be a multiple of the device's sector size. 620 * 621 * Validate that the emulated sector size complies with this 622 * requirement. 623 */ 624 if (S_ISCHR(sbuf.st_mode)) { 625 if (ssopt < sectsz || (ssopt % sectsz) != 0) { 626 EPRINTLN("Sector size %d incompatible " 627 "with underlying device sector size %d", 628 ssopt, sectsz); 629 goto err; 630 } 631 } 632 633 sectsz = ssopt; 634 psectsz = pssopt; 635 psectoff = 0; 636 } 637 638 bc = calloc(1, sizeof(struct blockif_ctxt)); 639 if (bc == NULL) { 640 perror("calloc"); 641 goto err; 642 } 643 644 bc->bc_magic = BLOCKIF_SIG; 645 bc->bc_fd = fd; 646 bc->bc_ischr = S_ISCHR(sbuf.st_mode); 647 bc->bc_isgeom = geom; 648 bc->bc_candelete = candelete; 649 bc->bc_rdonly = ro; 650 bc->bc_size = size; 651 bc->bc_sectsz = sectsz; 652 bc->bc_psectsz = psectsz; 653 bc->bc_psectoff = psectoff; 654 pthread_mutex_init(&bc->bc_mtx, NULL); 655 pthread_cond_init(&bc->bc_cond, NULL); 656 bc->bc_paused = 0; 657 pthread_cond_init(&bc->bc_work_done_cond, NULL); 658 TAILQ_INIT(&bc->bc_freeq); 659 TAILQ_INIT(&bc->bc_pendq); 660 TAILQ_INIT(&bc->bc_busyq); 661 bc->bc_bootindex = bootindex; 662 for (i = 0; i < BLOCKIF_MAXREQ; i++) { 663 bc->bc_reqs[i].be_status = BST_FREE; 664 TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link); 665 } 666 667 for (i = 0; i < BLOCKIF_NUMTHR; i++) { 668 pthread_create(&bc->bc_btid[i], NULL, blockif_thr, bc); 669 snprintf(tname, sizeof(tname), "blk-%s-%d", ident, i); 670 pthread_set_name_np(bc->bc_btid[i], tname); 671 } 672 673 return (bc); 674 err: 675 if (fd >= 0) 676 close(fd); 677 return (NULL); 678 } 679 680 static void 681 blockif_resized(int fd, enum ev_type type __unused, void *arg) 682 { 683 struct blockif_ctxt *bc; 684 struct stat sb; 685 off_t mediasize; 686 687 if (fstat(fd, &sb) != 0) 688 return; 689 690 if (S_ISCHR(sb.st_mode)) { 691 if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) < 0) { 692 EPRINTLN("blockif_resized: get mediasize failed: %s", 693 strerror(errno)); 694 return; 695 } 696 } else 697 mediasize = sb.st_size; 698 699 bc = arg; 700 pthread_mutex_lock(&bc->bc_mtx); 701 if (mediasize != bc->bc_size) { 702 bc->bc_size = mediasize; 703 bc->bc_resize_cb(bc, bc->bc_resize_cb_arg, bc->bc_size); 704 } 705 pthread_mutex_unlock(&bc->bc_mtx); 706 } 707 708 int 709 blockif_register_resize_callback(struct blockif_ctxt *bc, blockif_resize_cb *cb, 710 void *cb_arg) 711 { 712 struct stat sb; 713 int err; 714 715 if (cb == NULL) 716 return (EINVAL); 717 718 err = 0; 719 720 pthread_mutex_lock(&bc->bc_mtx); 721 if (bc->bc_resize_cb != NULL) { 722 err = EBUSY; 723 goto out; 724 } 725 726 assert(bc->bc_closing == 0); 727 728 if (fstat(bc->bc_fd, &sb) != 0) { 729 err = errno; 730 goto out; 731 } 732 733 bc->bc_resize_event = mevent_add_flags(bc->bc_fd, EVF_VNODE, 734 EVFF_ATTRIB, blockif_resized, bc); 735 if (bc->bc_resize_event == NULL) { 736 err = ENXIO; 737 goto out; 738 } 739 740 bc->bc_resize_cb = cb; 741 bc->bc_resize_cb_arg = cb_arg; 742 out: 743 pthread_mutex_unlock(&bc->bc_mtx); 744 745 return (err); 746 } 747 748 static int 749 blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq, 750 enum blockop op) 751 { 752 int err; 753 754 err = 0; 755 756 pthread_mutex_lock(&bc->bc_mtx); 757 assert(!bc->bc_paused); 758 if (!TAILQ_EMPTY(&bc->bc_freeq)) { 759 /* 760 * Enqueue and inform the block i/o thread 761 * that there is work available 762 */ 763 if (blockif_enqueue(bc, breq, op)) 764 pthread_cond_signal(&bc->bc_cond); 765 } else { 766 /* 767 * Callers are not allowed to enqueue more than 768 * the specified blockif queue limit. Return an 769 * error to indicate that the queue length has been 770 * exceeded. 771 */ 772 err = E2BIG; 773 } 774 pthread_mutex_unlock(&bc->bc_mtx); 775 776 return (err); 777 } 778 779 int 780 blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq) 781 { 782 assert(bc->bc_magic == BLOCKIF_SIG); 783 return (blockif_request(bc, breq, BOP_READ)); 784 } 785 786 int 787 blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq) 788 { 789 assert(bc->bc_magic == BLOCKIF_SIG); 790 return (blockif_request(bc, breq, BOP_WRITE)); 791 } 792 793 int 794 blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq) 795 { 796 assert(bc->bc_magic == BLOCKIF_SIG); 797 return (blockif_request(bc, breq, BOP_FLUSH)); 798 } 799 800 int 801 blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq) 802 { 803 assert(bc->bc_magic == BLOCKIF_SIG); 804 return (blockif_request(bc, breq, BOP_DELETE)); 805 } 806 807 int 808 blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq) 809 { 810 struct blockif_elem *be; 811 812 assert(bc->bc_magic == BLOCKIF_SIG); 813 814 pthread_mutex_lock(&bc->bc_mtx); 815 /* XXX: not waiting while paused */ 816 817 /* 818 * Check pending requests. 819 */ 820 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) { 821 if (be->be_req == breq) 822 break; 823 } 824 if (be != NULL) { 825 /* 826 * Found it. 827 */ 828 blockif_complete(bc, be); 829 pthread_mutex_unlock(&bc->bc_mtx); 830 831 return (0); 832 } 833 834 /* 835 * Check in-flight requests. 836 */ 837 TAILQ_FOREACH(be, &bc->bc_busyq, be_link) { 838 if (be->be_req == breq) 839 break; 840 } 841 if (be == NULL) { 842 /* 843 * Didn't find it. 844 */ 845 pthread_mutex_unlock(&bc->bc_mtx); 846 return (EINVAL); 847 } 848 849 /* 850 * Interrupt the processing thread to force it return 851 * prematurely via it's normal callback path. 852 */ 853 while (be->be_status == BST_BUSY) { 854 struct blockif_sig_elem bse, *old_head; 855 856 pthread_mutex_init(&bse.bse_mtx, NULL); 857 pthread_cond_init(&bse.bse_cond, NULL); 858 859 bse.bse_pending = 1; 860 861 do { 862 old_head = blockif_bse_head; 863 bse.bse_next = old_head; 864 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head, 865 (uintptr_t)old_head, 866 (uintptr_t)&bse)); 867 868 pthread_kill(be->be_tid, SIGCONT); 869 870 pthread_mutex_lock(&bse.bse_mtx); 871 while (bse.bse_pending) 872 pthread_cond_wait(&bse.bse_cond, &bse.bse_mtx); 873 pthread_mutex_unlock(&bse.bse_mtx); 874 } 875 876 pthread_mutex_unlock(&bc->bc_mtx); 877 878 /* 879 * The processing thread has been interrupted. Since it's not 880 * clear if the callback has been invoked yet, return EBUSY. 881 */ 882 return (EBUSY); 883 } 884 885 int 886 blockif_close(struct blockif_ctxt *bc) 887 { 888 void *jval; 889 int i; 890 891 assert(bc->bc_magic == BLOCKIF_SIG); 892 893 /* 894 * Stop the block i/o thread 895 */ 896 pthread_mutex_lock(&bc->bc_mtx); 897 bc->bc_closing = 1; 898 if (bc->bc_resize_event != NULL) 899 mevent_disable(bc->bc_resize_event); 900 pthread_mutex_unlock(&bc->bc_mtx); 901 pthread_cond_broadcast(&bc->bc_cond); 902 for (i = 0; i < BLOCKIF_NUMTHR; i++) 903 pthread_join(bc->bc_btid[i], &jval); 904 905 /* XXX Cancel queued i/o's ??? */ 906 907 /* 908 * Release resources 909 */ 910 bc->bc_magic = 0; 911 close(bc->bc_fd); 912 free(bc); 913 914 return (0); 915 } 916 917 /* 918 * Return virtual C/H/S values for a given block. Use the algorithm 919 * outlined in the VHD specification to calculate values. 920 */ 921 void 922 blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s) 923 { 924 off_t sectors; /* total sectors of the block dev */ 925 off_t hcyl; /* cylinders times heads */ 926 uint16_t secpt; /* sectors per track */ 927 uint8_t heads; 928 929 assert(bc->bc_magic == BLOCKIF_SIG); 930 931 sectors = bc->bc_size / bc->bc_sectsz; 932 933 /* Clamp the size to the largest possible with CHS */ 934 if (sectors > 65535L * 16 * 255) 935 sectors = 65535L * 16 * 255; 936 937 if (sectors >= 65536L * 16 * 63) { 938 secpt = 255; 939 heads = 16; 940 hcyl = sectors / secpt; 941 } else { 942 secpt = 17; 943 hcyl = sectors / secpt; 944 heads = (hcyl + 1023) / 1024; 945 946 if (heads < 4) 947 heads = 4; 948 949 if (hcyl >= (heads * 1024) || heads > 16) { 950 secpt = 31; 951 heads = 16; 952 hcyl = sectors / secpt; 953 } 954 if (hcyl >= (heads * 1024)) { 955 secpt = 63; 956 heads = 16; 957 hcyl = sectors / secpt; 958 } 959 } 960 961 *c = hcyl / heads; 962 *h = heads; 963 *s = secpt; 964 } 965 966 /* 967 * Accessors 968 */ 969 off_t 970 blockif_size(struct blockif_ctxt *bc) 971 { 972 assert(bc->bc_magic == BLOCKIF_SIG); 973 return (bc->bc_size); 974 } 975 976 int 977 blockif_sectsz(struct blockif_ctxt *bc) 978 { 979 assert(bc->bc_magic == BLOCKIF_SIG); 980 return (bc->bc_sectsz); 981 } 982 983 void 984 blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off) 985 { 986 assert(bc->bc_magic == BLOCKIF_SIG); 987 *size = bc->bc_psectsz; 988 *off = bc->bc_psectoff; 989 } 990 991 int 992 blockif_queuesz(struct blockif_ctxt *bc) 993 { 994 assert(bc->bc_magic == BLOCKIF_SIG); 995 return (BLOCKIF_MAXREQ - 1); 996 } 997 998 int 999 blockif_is_ro(struct blockif_ctxt *bc) 1000 { 1001 assert(bc->bc_magic == BLOCKIF_SIG); 1002 return (bc->bc_rdonly); 1003 } 1004 1005 int 1006 blockif_candelete(struct blockif_ctxt *bc) 1007 { 1008 assert(bc->bc_magic == BLOCKIF_SIG); 1009 return (bc->bc_candelete); 1010 } 1011 1012 #ifdef BHYVE_SNAPSHOT 1013 void 1014 blockif_pause(struct blockif_ctxt *bc) 1015 { 1016 assert(bc != NULL); 1017 assert(bc->bc_magic == BLOCKIF_SIG); 1018 1019 pthread_mutex_lock(&bc->bc_mtx); 1020 bc->bc_paused = 1; 1021 1022 /* The interface is paused. Wait for workers to finish their work */ 1023 while (!blockif_empty(bc)) 1024 pthread_cond_wait(&bc->bc_work_done_cond, &bc->bc_mtx); 1025 pthread_mutex_unlock(&bc->bc_mtx); 1026 1027 if (!bc->bc_rdonly && blockif_flush_bc(bc)) 1028 EPRINTLN("%s: [WARN] failed to flush backing file.", 1029 __func__); 1030 } 1031 1032 void 1033 blockif_resume(struct blockif_ctxt *bc) 1034 { 1035 assert(bc != NULL); 1036 assert(bc->bc_magic == BLOCKIF_SIG); 1037 1038 pthread_mutex_lock(&bc->bc_mtx); 1039 bc->bc_paused = 0; 1040 pthread_mutex_unlock(&bc->bc_mtx); 1041 } 1042 #endif /* BHYVE_SNAPSHOT */ 1043