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