1 /* 2 * QEMU Block driver for NBD 3 * 4 * Copyright (c) 2019 Virtuozzo International GmbH. 5 * Copyright (C) 2016 Red Hat, Inc. 6 * Copyright (C) 2008 Bull S.A.S. 7 * Author: Laurent Vivier <Laurent.Vivier@bull.net> 8 * 9 * Some parts: 10 * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws> 11 * 12 * Permission is hereby granted, free of charge, to any person obtaining a copy 13 * of this software and associated documentation files (the "Software"), to deal 14 * in the Software without restriction, including without limitation the rights 15 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 16 * copies of the Software, and to permit persons to whom the Software is 17 * furnished to do so, subject to the following conditions: 18 * 19 * The above copyright notice and this permission notice shall be included in 20 * all copies or substantial portions of the Software. 21 * 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 25 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 27 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 28 * THE SOFTWARE. 29 */ 30 31 #include "qemu/osdep.h" 32 33 #include "trace.h" 34 #include "qemu/uri.h" 35 #include "qemu/option.h" 36 #include "qemu/cutils.h" 37 #include "qemu/main-loop.h" 38 #include "qemu/atomic.h" 39 40 #include "qapi/qapi-visit-sockets.h" 41 #include "qapi/qmp/qstring.h" 42 #include "qapi/clone-visitor.h" 43 44 #include "block/qdict.h" 45 #include "block/nbd.h" 46 #include "block/block_int.h" 47 48 #include "qemu/yank.h" 49 50 #define EN_OPTSTR ":exportname=" 51 #define MAX_NBD_REQUESTS 16 52 53 #define HANDLE_TO_INDEX(bs, handle) ((handle) ^ (uint64_t)(intptr_t)(bs)) 54 #define INDEX_TO_HANDLE(bs, index) ((index) ^ (uint64_t)(intptr_t)(bs)) 55 56 typedef struct { 57 Coroutine *coroutine; 58 uint64_t offset; /* original offset of the request */ 59 bool receiving; /* waiting for connection_co? */ 60 } NBDClientRequest; 61 62 typedef enum NBDClientState { 63 NBD_CLIENT_CONNECTING_WAIT, 64 NBD_CLIENT_CONNECTING_NOWAIT, 65 NBD_CLIENT_CONNECTED, 66 NBD_CLIENT_QUIT 67 } NBDClientState; 68 69 typedef enum NBDConnectThreadState { 70 /* No thread, no pending results */ 71 CONNECT_THREAD_NONE, 72 73 /* Thread is running, no results for now */ 74 CONNECT_THREAD_RUNNING, 75 76 /* 77 * Thread is running, but requestor exited. Thread should close 78 * the new socket and free the connect state on exit. 79 */ 80 CONNECT_THREAD_RUNNING_DETACHED, 81 82 /* Thread finished, results are stored in a state */ 83 CONNECT_THREAD_FAIL, 84 CONNECT_THREAD_SUCCESS 85 } NBDConnectThreadState; 86 87 typedef struct NBDConnectThread { 88 /* Initialization constants */ 89 SocketAddress *saddr; /* address to connect to */ 90 /* 91 * Bottom half to schedule on completion. Scheduled only if bh_ctx is not 92 * NULL 93 */ 94 QEMUBHFunc *bh_func; 95 void *bh_opaque; 96 97 /* 98 * Result of last attempt. Valid in FAIL and SUCCESS states. 99 * If you want to steal error, don't forget to set pointer to NULL. 100 */ 101 QIOChannelSocket *sioc; 102 Error *err; 103 104 /* state and bh_ctx are protected by mutex */ 105 QemuMutex mutex; 106 NBDConnectThreadState state; /* current state of the thread */ 107 AioContext *bh_ctx; /* where to schedule bh (NULL means don't schedule) */ 108 } NBDConnectThread; 109 110 typedef struct BDRVNBDState { 111 QIOChannelSocket *sioc; /* The master data channel */ 112 QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */ 113 NBDExportInfo info; 114 115 CoMutex send_mutex; 116 CoQueue free_sema; 117 Coroutine *connection_co; 118 Coroutine *teardown_co; 119 QemuCoSleepState *connection_co_sleep_ns_state; 120 bool drained; 121 bool wait_drained_end; 122 int in_flight; 123 NBDClientState state; 124 int connect_status; 125 Error *connect_err; 126 bool wait_in_flight; 127 128 QEMUTimer *reconnect_delay_timer; 129 130 NBDClientRequest requests[MAX_NBD_REQUESTS]; 131 NBDReply reply; 132 BlockDriverState *bs; 133 134 /* Connection parameters */ 135 uint32_t reconnect_delay; 136 SocketAddress *saddr; 137 char *export, *tlscredsid; 138 QCryptoTLSCreds *tlscreds; 139 const char *hostname; 140 char *x_dirty_bitmap; 141 bool alloc_depth; 142 143 bool wait_connect; 144 NBDConnectThread *connect_thread; 145 } BDRVNBDState; 146 147 static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr, 148 Error **errp); 149 static int nbd_co_establish_connection(BlockDriverState *bs, Error **errp); 150 static void nbd_co_establish_connection_cancel(BlockDriverState *bs, 151 bool detach); 152 static int nbd_client_handshake(BlockDriverState *bs, Error **errp); 153 static void nbd_yank(void *opaque); 154 155 static void nbd_clear_bdrvstate(BDRVNBDState *s) 156 { 157 object_unref(OBJECT(s->tlscreds)); 158 qapi_free_SocketAddress(s->saddr); 159 s->saddr = NULL; 160 g_free(s->export); 161 s->export = NULL; 162 g_free(s->tlscredsid); 163 s->tlscredsid = NULL; 164 g_free(s->x_dirty_bitmap); 165 s->x_dirty_bitmap = NULL; 166 } 167 168 static void nbd_channel_error(BDRVNBDState *s, int ret) 169 { 170 if (ret == -EIO) { 171 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { 172 s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : 173 NBD_CLIENT_CONNECTING_NOWAIT; 174 } 175 } else { 176 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { 177 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 178 } 179 s->state = NBD_CLIENT_QUIT; 180 } 181 } 182 183 static void nbd_recv_coroutines_wake_all(BDRVNBDState *s) 184 { 185 int i; 186 187 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 188 NBDClientRequest *req = &s->requests[i]; 189 190 if (req->coroutine && req->receiving) { 191 aio_co_wake(req->coroutine); 192 } 193 } 194 } 195 196 static void reconnect_delay_timer_del(BDRVNBDState *s) 197 { 198 if (s->reconnect_delay_timer) { 199 timer_free(s->reconnect_delay_timer); 200 s->reconnect_delay_timer = NULL; 201 } 202 } 203 204 static void reconnect_delay_timer_cb(void *opaque) 205 { 206 BDRVNBDState *s = opaque; 207 208 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { 209 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 210 while (qemu_co_enter_next(&s->free_sema, NULL)) { 211 /* Resume all queued requests */ 212 } 213 } 214 215 reconnect_delay_timer_del(s); 216 } 217 218 static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 219 { 220 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTING_WAIT) { 221 return; 222 } 223 224 assert(!s->reconnect_delay_timer); 225 s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 226 QEMU_CLOCK_REALTIME, 227 SCALE_NS, 228 reconnect_delay_timer_cb, s); 229 timer_mod(s->reconnect_delay_timer, expire_time_ns); 230 } 231 232 static void nbd_client_detach_aio_context(BlockDriverState *bs) 233 { 234 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 235 236 /* Timer is deleted in nbd_client_co_drain_begin() */ 237 assert(!s->reconnect_delay_timer); 238 /* 239 * If reconnect is in progress we may have no ->ioc. It will be 240 * re-instantiated in the proper aio context once the connection is 241 * reestablished. 242 */ 243 if (s->ioc) { 244 qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); 245 } 246 } 247 248 static void nbd_client_attach_aio_context_bh(void *opaque) 249 { 250 BlockDriverState *bs = opaque; 251 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 252 253 if (s->connection_co) { 254 /* 255 * The node is still drained, so we know the coroutine has yielded in 256 * nbd_read_eof(), the only place where bs->in_flight can reach 0, or 257 * it is entered for the first time. Both places are safe for entering 258 * the coroutine. 259 */ 260 qemu_aio_coroutine_enter(bs->aio_context, s->connection_co); 261 } 262 bdrv_dec_in_flight(bs); 263 } 264 265 static void nbd_client_attach_aio_context(BlockDriverState *bs, 266 AioContext *new_context) 267 { 268 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 269 270 /* 271 * s->connection_co is either yielded from nbd_receive_reply or from 272 * nbd_co_reconnect_loop() 273 */ 274 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { 275 qio_channel_attach_aio_context(QIO_CHANNEL(s->ioc), new_context); 276 } 277 278 bdrv_inc_in_flight(bs); 279 280 /* 281 * Need to wait here for the BH to run because the BH must run while the 282 * node is still drained. 283 */ 284 aio_wait_bh_oneshot(new_context, nbd_client_attach_aio_context_bh, bs); 285 } 286 287 static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs) 288 { 289 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 290 291 s->drained = true; 292 if (s->connection_co_sleep_ns_state) { 293 qemu_co_sleep_wake(s->connection_co_sleep_ns_state); 294 } 295 296 nbd_co_establish_connection_cancel(bs, false); 297 298 reconnect_delay_timer_del(s); 299 300 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { 301 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 302 qemu_co_queue_restart_all(&s->free_sema); 303 } 304 } 305 306 static void coroutine_fn nbd_client_co_drain_end(BlockDriverState *bs) 307 { 308 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 309 310 s->drained = false; 311 if (s->wait_drained_end) { 312 s->wait_drained_end = false; 313 aio_co_wake(s->connection_co); 314 } 315 } 316 317 318 static void nbd_teardown_connection(BlockDriverState *bs) 319 { 320 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 321 322 if (s->ioc) { 323 /* finish any pending coroutines */ 324 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 325 } else if (s->sioc) { 326 /* abort negotiation */ 327 qio_channel_shutdown(QIO_CHANNEL(s->sioc), QIO_CHANNEL_SHUTDOWN_BOTH, 328 NULL); 329 } 330 331 s->state = NBD_CLIENT_QUIT; 332 if (s->connection_co) { 333 if (s->connection_co_sleep_ns_state) { 334 qemu_co_sleep_wake(s->connection_co_sleep_ns_state); 335 } 336 nbd_co_establish_connection_cancel(bs, true); 337 } 338 if (qemu_in_coroutine()) { 339 s->teardown_co = qemu_coroutine_self(); 340 /* connection_co resumes us when it terminates */ 341 qemu_coroutine_yield(); 342 s->teardown_co = NULL; 343 } else { 344 BDRV_POLL_WHILE(bs, s->connection_co); 345 } 346 assert(!s->connection_co); 347 } 348 349 static bool nbd_client_connecting(BDRVNBDState *s) 350 { 351 NBDClientState state = qatomic_load_acquire(&s->state); 352 return state == NBD_CLIENT_CONNECTING_WAIT || 353 state == NBD_CLIENT_CONNECTING_NOWAIT; 354 } 355 356 static bool nbd_client_connecting_wait(BDRVNBDState *s) 357 { 358 return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; 359 } 360 361 static void connect_bh(void *opaque) 362 { 363 BDRVNBDState *state = opaque; 364 365 assert(state->wait_connect); 366 state->wait_connect = false; 367 aio_co_wake(state->connection_co); 368 } 369 370 static void nbd_init_connect_thread(BDRVNBDState *s) 371 { 372 s->connect_thread = g_new(NBDConnectThread, 1); 373 374 *s->connect_thread = (NBDConnectThread) { 375 .saddr = QAPI_CLONE(SocketAddress, s->saddr), 376 .state = CONNECT_THREAD_NONE, 377 .bh_func = connect_bh, 378 .bh_opaque = s, 379 }; 380 381 qemu_mutex_init(&s->connect_thread->mutex); 382 } 383 384 static void nbd_free_connect_thread(NBDConnectThread *thr) 385 { 386 if (thr->sioc) { 387 qio_channel_close(QIO_CHANNEL(thr->sioc), NULL); 388 } 389 error_free(thr->err); 390 qapi_free_SocketAddress(thr->saddr); 391 g_free(thr); 392 } 393 394 static void *connect_thread_func(void *opaque) 395 { 396 NBDConnectThread *thr = opaque; 397 int ret; 398 bool do_free = false; 399 400 thr->sioc = qio_channel_socket_new(); 401 402 error_free(thr->err); 403 thr->err = NULL; 404 ret = qio_channel_socket_connect_sync(thr->sioc, thr->saddr, &thr->err); 405 if (ret < 0) { 406 object_unref(OBJECT(thr->sioc)); 407 thr->sioc = NULL; 408 } 409 410 qemu_mutex_lock(&thr->mutex); 411 412 switch (thr->state) { 413 case CONNECT_THREAD_RUNNING: 414 thr->state = ret < 0 ? CONNECT_THREAD_FAIL : CONNECT_THREAD_SUCCESS; 415 if (thr->bh_ctx) { 416 aio_bh_schedule_oneshot(thr->bh_ctx, thr->bh_func, thr->bh_opaque); 417 418 /* play safe, don't reuse bh_ctx on further connection attempts */ 419 thr->bh_ctx = NULL; 420 } 421 break; 422 case CONNECT_THREAD_RUNNING_DETACHED: 423 do_free = true; 424 break; 425 default: 426 abort(); 427 } 428 429 qemu_mutex_unlock(&thr->mutex); 430 431 if (do_free) { 432 nbd_free_connect_thread(thr); 433 } 434 435 return NULL; 436 } 437 438 static int coroutine_fn 439 nbd_co_establish_connection(BlockDriverState *bs, Error **errp) 440 { 441 int ret; 442 QemuThread thread; 443 BDRVNBDState *s = bs->opaque; 444 NBDConnectThread *thr = s->connect_thread; 445 446 if (!thr) { 447 /* detached */ 448 return -1; 449 } 450 451 qemu_mutex_lock(&thr->mutex); 452 453 switch (thr->state) { 454 case CONNECT_THREAD_FAIL: 455 case CONNECT_THREAD_NONE: 456 error_free(thr->err); 457 thr->err = NULL; 458 thr->state = CONNECT_THREAD_RUNNING; 459 qemu_thread_create(&thread, "nbd-connect", 460 connect_thread_func, thr, QEMU_THREAD_DETACHED); 461 break; 462 case CONNECT_THREAD_SUCCESS: 463 /* Previous attempt finally succeeded in background */ 464 thr->state = CONNECT_THREAD_NONE; 465 s->sioc = thr->sioc; 466 thr->sioc = NULL; 467 yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), 468 nbd_yank, bs); 469 qemu_mutex_unlock(&thr->mutex); 470 return 0; 471 case CONNECT_THREAD_RUNNING: 472 /* Already running, will wait */ 473 break; 474 default: 475 abort(); 476 } 477 478 thr->bh_ctx = qemu_get_current_aio_context(); 479 480 qemu_mutex_unlock(&thr->mutex); 481 482 483 /* 484 * We are going to wait for connect-thread finish, but 485 * nbd_client_co_drain_begin() can interrupt. 486 * 487 * Note that wait_connect variable is not visible for connect-thread. It 488 * doesn't need mutex protection, it used only inside home aio context of 489 * bs. 490 */ 491 s->wait_connect = true; 492 qemu_coroutine_yield(); 493 494 if (!s->connect_thread) { 495 /* detached */ 496 return -1; 497 } 498 assert(thr == s->connect_thread); 499 500 qemu_mutex_lock(&thr->mutex); 501 502 switch (thr->state) { 503 case CONNECT_THREAD_SUCCESS: 504 case CONNECT_THREAD_FAIL: 505 thr->state = CONNECT_THREAD_NONE; 506 error_propagate(errp, thr->err); 507 thr->err = NULL; 508 s->sioc = thr->sioc; 509 thr->sioc = NULL; 510 if (s->sioc) { 511 yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), 512 nbd_yank, bs); 513 } 514 ret = (s->sioc ? 0 : -1); 515 break; 516 case CONNECT_THREAD_RUNNING: 517 case CONNECT_THREAD_RUNNING_DETACHED: 518 /* 519 * Obviously, drained section wants to start. Report the attempt as 520 * failed. Still connect thread is executing in background, and its 521 * result may be used for next connection attempt. 522 */ 523 ret = -1; 524 error_setg(errp, "Connection attempt cancelled by other operation"); 525 break; 526 527 case CONNECT_THREAD_NONE: 528 /* 529 * Impossible. We've seen this thread running. So it should be 530 * running or at least give some results. 531 */ 532 abort(); 533 534 default: 535 abort(); 536 } 537 538 qemu_mutex_unlock(&thr->mutex); 539 540 return ret; 541 } 542 543 /* 544 * nbd_co_establish_connection_cancel 545 * Cancel nbd_co_establish_connection asynchronously: it will finish soon, to 546 * allow drained section to begin. 547 * 548 * If detach is true, also cleanup the state (or if thread is running, move it 549 * to CONNECT_THREAD_RUNNING_DETACHED state). s->connect_thread becomes NULL if 550 * detach is true. 551 */ 552 static void nbd_co_establish_connection_cancel(BlockDriverState *bs, 553 bool detach) 554 { 555 BDRVNBDState *s = bs->opaque; 556 NBDConnectThread *thr = s->connect_thread; 557 bool wake = false; 558 bool do_free = false; 559 560 qemu_mutex_lock(&thr->mutex); 561 562 if (thr->state == CONNECT_THREAD_RUNNING) { 563 /* We can cancel only in running state, when bh is not yet scheduled */ 564 thr->bh_ctx = NULL; 565 if (s->wait_connect) { 566 s->wait_connect = false; 567 wake = true; 568 } 569 if (detach) { 570 thr->state = CONNECT_THREAD_RUNNING_DETACHED; 571 s->connect_thread = NULL; 572 } 573 } else if (detach) { 574 do_free = true; 575 } 576 577 qemu_mutex_unlock(&thr->mutex); 578 579 if (do_free) { 580 nbd_free_connect_thread(thr); 581 s->connect_thread = NULL; 582 } 583 584 if (wake) { 585 aio_co_wake(s->connection_co); 586 } 587 } 588 589 static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) 590 { 591 int ret; 592 Error *local_err = NULL; 593 594 if (!nbd_client_connecting(s)) { 595 return; 596 } 597 598 /* Wait for completion of all in-flight requests */ 599 600 qemu_co_mutex_lock(&s->send_mutex); 601 602 while (s->in_flight > 0) { 603 qemu_co_mutex_unlock(&s->send_mutex); 604 nbd_recv_coroutines_wake_all(s); 605 s->wait_in_flight = true; 606 qemu_coroutine_yield(); 607 s->wait_in_flight = false; 608 qemu_co_mutex_lock(&s->send_mutex); 609 } 610 611 qemu_co_mutex_unlock(&s->send_mutex); 612 613 if (!nbd_client_connecting(s)) { 614 return; 615 } 616 617 /* 618 * Now we are sure that nobody is accessing the channel, and no one will 619 * try until we set the state to CONNECTED. 620 */ 621 622 /* Finalize previous connection if any */ 623 if (s->ioc) { 624 qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); 625 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 626 nbd_yank, s->bs); 627 object_unref(OBJECT(s->sioc)); 628 s->sioc = NULL; 629 object_unref(OBJECT(s->ioc)); 630 s->ioc = NULL; 631 } 632 633 if (nbd_co_establish_connection(s->bs, &local_err) < 0) { 634 ret = -ECONNREFUSED; 635 goto out; 636 } 637 638 bdrv_dec_in_flight(s->bs); 639 640 ret = nbd_client_handshake(s->bs, &local_err); 641 642 if (s->drained) { 643 s->wait_drained_end = true; 644 while (s->drained) { 645 /* 646 * We may be entered once from nbd_client_attach_aio_context_bh 647 * and then from nbd_client_co_drain_end. So here is a loop. 648 */ 649 qemu_coroutine_yield(); 650 } 651 } 652 bdrv_inc_in_flight(s->bs); 653 654 out: 655 s->connect_status = ret; 656 error_free(s->connect_err); 657 s->connect_err = NULL; 658 error_propagate(&s->connect_err, local_err); 659 660 if (ret >= 0) { 661 /* successfully connected */ 662 s->state = NBD_CLIENT_CONNECTED; 663 qemu_co_queue_restart_all(&s->free_sema); 664 } 665 } 666 667 static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState *s) 668 { 669 uint64_t timeout = 1 * NANOSECONDS_PER_SECOND; 670 uint64_t max_timeout = 16 * NANOSECONDS_PER_SECOND; 671 672 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { 673 reconnect_delay_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 674 s->reconnect_delay * NANOSECONDS_PER_SECOND); 675 } 676 677 nbd_reconnect_attempt(s); 678 679 while (nbd_client_connecting(s)) { 680 if (s->drained) { 681 bdrv_dec_in_flight(s->bs); 682 s->wait_drained_end = true; 683 while (s->drained) { 684 /* 685 * We may be entered once from nbd_client_attach_aio_context_bh 686 * and then from nbd_client_co_drain_end. So here is a loop. 687 */ 688 qemu_coroutine_yield(); 689 } 690 bdrv_inc_in_flight(s->bs); 691 } else { 692 qemu_co_sleep_ns_wakeable(QEMU_CLOCK_REALTIME, timeout, 693 &s->connection_co_sleep_ns_state); 694 if (s->drained) { 695 continue; 696 } 697 if (timeout < max_timeout) { 698 timeout *= 2; 699 } 700 } 701 702 nbd_reconnect_attempt(s); 703 } 704 705 reconnect_delay_timer_del(s); 706 } 707 708 static coroutine_fn void nbd_connection_entry(void *opaque) 709 { 710 BDRVNBDState *s = opaque; 711 uint64_t i; 712 int ret = 0; 713 Error *local_err = NULL; 714 715 while (qatomic_load_acquire(&s->state) != NBD_CLIENT_QUIT) { 716 /* 717 * The NBD client can only really be considered idle when it has 718 * yielded from qio_channel_readv_all_eof(), waiting for data. This is 719 * the point where the additional scheduled coroutine entry happens 720 * after nbd_client_attach_aio_context(). 721 * 722 * Therefore we keep an additional in_flight reference all the time and 723 * only drop it temporarily here. 724 */ 725 726 if (nbd_client_connecting(s)) { 727 nbd_co_reconnect_loop(s); 728 } 729 730 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { 731 continue; 732 } 733 734 assert(s->reply.handle == 0); 735 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, &local_err); 736 737 if (local_err) { 738 trace_nbd_read_reply_entry_fail(ret, error_get_pretty(local_err)); 739 error_free(local_err); 740 local_err = NULL; 741 } 742 if (ret <= 0) { 743 nbd_channel_error(s, ret ? ret : -EIO); 744 continue; 745 } 746 747 /* 748 * There's no need for a mutex on the receive side, because the 749 * handler acts as a synchronization point and ensures that only 750 * one coroutine is called until the reply finishes. 751 */ 752 i = HANDLE_TO_INDEX(s, s->reply.handle); 753 if (i >= MAX_NBD_REQUESTS || 754 !s->requests[i].coroutine || 755 !s->requests[i].receiving || 756 (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply)) 757 { 758 nbd_channel_error(s, -EINVAL); 759 continue; 760 } 761 762 /* 763 * We're woken up again by the request itself. Note that there 764 * is no race between yielding and reentering connection_co. This 765 * is because: 766 * 767 * - if the request runs on the same AioContext, it is only 768 * entered after we yield 769 * 770 * - if the request runs on a different AioContext, reentering 771 * connection_co happens through a bottom half, which can only 772 * run after we yield. 773 */ 774 aio_co_wake(s->requests[i].coroutine); 775 qemu_coroutine_yield(); 776 } 777 778 qemu_co_queue_restart_all(&s->free_sema); 779 nbd_recv_coroutines_wake_all(s); 780 bdrv_dec_in_flight(s->bs); 781 782 s->connection_co = NULL; 783 if (s->ioc) { 784 qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); 785 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 786 nbd_yank, s->bs); 787 object_unref(OBJECT(s->sioc)); 788 s->sioc = NULL; 789 object_unref(OBJECT(s->ioc)); 790 s->ioc = NULL; 791 } 792 793 if (s->teardown_co) { 794 aio_co_wake(s->teardown_co); 795 } 796 aio_wait_kick(); 797 } 798 799 static int nbd_co_send_request(BlockDriverState *bs, 800 NBDRequest *request, 801 QEMUIOVector *qiov) 802 { 803 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 804 int rc, i = -1; 805 806 qemu_co_mutex_lock(&s->send_mutex); 807 while (s->in_flight == MAX_NBD_REQUESTS || nbd_client_connecting_wait(s)) { 808 qemu_co_queue_wait(&s->free_sema, &s->send_mutex); 809 } 810 811 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { 812 rc = -EIO; 813 goto err; 814 } 815 816 s->in_flight++; 817 818 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 819 if (s->requests[i].coroutine == NULL) { 820 break; 821 } 822 } 823 824 g_assert(qemu_in_coroutine()); 825 assert(i < MAX_NBD_REQUESTS); 826 827 s->requests[i].coroutine = qemu_coroutine_self(); 828 s->requests[i].offset = request->from; 829 s->requests[i].receiving = false; 830 831 request->handle = INDEX_TO_HANDLE(s, i); 832 833 assert(s->ioc); 834 835 if (qiov) { 836 qio_channel_set_cork(s->ioc, true); 837 rc = nbd_send_request(s->ioc, request); 838 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED && 839 rc >= 0) { 840 if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 841 NULL) < 0) { 842 rc = -EIO; 843 } 844 } else if (rc >= 0) { 845 rc = -EIO; 846 } 847 qio_channel_set_cork(s->ioc, false); 848 } else { 849 rc = nbd_send_request(s->ioc, request); 850 } 851 852 err: 853 if (rc < 0) { 854 nbd_channel_error(s, rc); 855 if (i != -1) { 856 s->requests[i].coroutine = NULL; 857 s->in_flight--; 858 } 859 if (s->in_flight == 0 && s->wait_in_flight) { 860 aio_co_wake(s->connection_co); 861 } else { 862 qemu_co_queue_next(&s->free_sema); 863 } 864 } 865 qemu_co_mutex_unlock(&s->send_mutex); 866 return rc; 867 } 868 869 static inline uint16_t payload_advance16(uint8_t **payload) 870 { 871 *payload += 2; 872 return lduw_be_p(*payload - 2); 873 } 874 875 static inline uint32_t payload_advance32(uint8_t **payload) 876 { 877 *payload += 4; 878 return ldl_be_p(*payload - 4); 879 } 880 881 static inline uint64_t payload_advance64(uint8_t **payload) 882 { 883 *payload += 8; 884 return ldq_be_p(*payload - 8); 885 } 886 887 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 888 NBDStructuredReplyChunk *chunk, 889 uint8_t *payload, uint64_t orig_offset, 890 QEMUIOVector *qiov, Error **errp) 891 { 892 uint64_t offset; 893 uint32_t hole_size; 894 895 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 896 error_setg(errp, "Protocol error: invalid payload for " 897 "NBD_REPLY_TYPE_OFFSET_HOLE"); 898 return -EINVAL; 899 } 900 901 offset = payload_advance64(&payload); 902 hole_size = payload_advance32(&payload); 903 904 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 905 offset > orig_offset + qiov->size - hole_size) { 906 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 907 " region"); 908 return -EINVAL; 909 } 910 if (s->info.min_block && 911 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 912 trace_nbd_structured_read_compliance("hole"); 913 } 914 915 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 916 917 return 0; 918 } 919 920 /* 921 * nbd_parse_blockstatus_payload 922 * Based on our request, we expect only one extent in reply, for the 923 * base:allocation context. 924 */ 925 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 926 NBDStructuredReplyChunk *chunk, 927 uint8_t *payload, uint64_t orig_length, 928 NBDExtent *extent, Error **errp) 929 { 930 uint32_t context_id; 931 932 /* The server succeeded, so it must have sent [at least] one extent */ 933 if (chunk->length < sizeof(context_id) + sizeof(*extent)) { 934 error_setg(errp, "Protocol error: invalid payload for " 935 "NBD_REPLY_TYPE_BLOCK_STATUS"); 936 return -EINVAL; 937 } 938 939 context_id = payload_advance32(&payload); 940 if (s->info.context_id != context_id) { 941 error_setg(errp, "Protocol error: unexpected context id %d for " 942 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 943 "id is %d", context_id, 944 s->info.context_id); 945 return -EINVAL; 946 } 947 948 extent->length = payload_advance32(&payload); 949 extent->flags = payload_advance32(&payload); 950 951 if (extent->length == 0) { 952 error_setg(errp, "Protocol error: server sent status chunk with " 953 "zero length"); 954 return -EINVAL; 955 } 956 957 /* 958 * A server sending unaligned block status is in violation of the 959 * protocol, but as qemu-nbd 3.1 is such a server (at least for 960 * POSIX files that are not a multiple of 512 bytes, since qemu 961 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 962 * still sees an implicit hole beyond the real EOF), it's nicer to 963 * work around the misbehaving server. If the request included 964 * more than the final unaligned block, truncate it back to an 965 * aligned result; if the request was only the final block, round 966 * up to the full block and change the status to fully-allocated 967 * (always a safe status, even if it loses information). 968 */ 969 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 970 s->info.min_block)) { 971 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 972 if (extent->length > s->info.min_block) { 973 extent->length = QEMU_ALIGN_DOWN(extent->length, 974 s->info.min_block); 975 } else { 976 extent->length = s->info.min_block; 977 extent->flags = 0; 978 } 979 } 980 981 /* 982 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 983 * sent us any more than one extent, nor should it have included 984 * status beyond our request in that extent. However, it's easy 985 * enough to ignore the server's noncompliance without killing the 986 * connection; just ignore trailing extents, and clamp things to 987 * the length of our request. 988 */ 989 if (chunk->length > sizeof(context_id) + sizeof(*extent)) { 990 trace_nbd_parse_blockstatus_compliance("more than one extent"); 991 } 992 if (extent->length > orig_length) { 993 extent->length = orig_length; 994 trace_nbd_parse_blockstatus_compliance("extent length too large"); 995 } 996 997 /* 998 * HACK: if we are using x-dirty-bitmaps to access 999 * qemu:allocation-depth, treat all depths > 2 the same as 2, 1000 * since nbd_client_co_block_status is only expecting the low two 1001 * bits to be set. 1002 */ 1003 if (s->alloc_depth && extent->flags > 2) { 1004 extent->flags = 2; 1005 } 1006 1007 return 0; 1008 } 1009 1010 /* 1011 * nbd_parse_error_payload 1012 * on success @errp contains message describing nbd error reply 1013 */ 1014 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 1015 uint8_t *payload, int *request_ret, 1016 Error **errp) 1017 { 1018 uint32_t error; 1019 uint16_t message_size; 1020 1021 assert(chunk->type & (1 << 15)); 1022 1023 if (chunk->length < sizeof(error) + sizeof(message_size)) { 1024 error_setg(errp, 1025 "Protocol error: invalid payload for structured error"); 1026 return -EINVAL; 1027 } 1028 1029 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 1030 if (error == 0) { 1031 error_setg(errp, "Protocol error: server sent structured error chunk " 1032 "with error = 0"); 1033 return -EINVAL; 1034 } 1035 1036 *request_ret = -error; 1037 message_size = payload_advance16(&payload); 1038 1039 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 1040 error_setg(errp, "Protocol error: server sent structured error chunk " 1041 "with incorrect message size"); 1042 return -EINVAL; 1043 } 1044 1045 /* TODO: Add a trace point to mention the server complaint */ 1046 1047 /* TODO handle ERROR_OFFSET */ 1048 1049 return 0; 1050 } 1051 1052 static int nbd_co_receive_offset_data_payload(BDRVNBDState *s, 1053 uint64_t orig_offset, 1054 QEMUIOVector *qiov, Error **errp) 1055 { 1056 QEMUIOVector sub_qiov; 1057 uint64_t offset; 1058 size_t data_size; 1059 int ret; 1060 NBDStructuredReplyChunk *chunk = &s->reply.structured; 1061 1062 assert(nbd_reply_is_structured(&s->reply)); 1063 1064 /* The NBD spec requires at least one byte of payload */ 1065 if (chunk->length <= sizeof(offset)) { 1066 error_setg(errp, "Protocol error: invalid payload for " 1067 "NBD_REPLY_TYPE_OFFSET_DATA"); 1068 return -EINVAL; 1069 } 1070 1071 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 1072 return -EIO; 1073 } 1074 1075 data_size = chunk->length - sizeof(offset); 1076 assert(data_size); 1077 if (offset < orig_offset || data_size > qiov->size || 1078 offset > orig_offset + qiov->size - data_size) { 1079 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 1080 " region"); 1081 return -EINVAL; 1082 } 1083 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 1084 trace_nbd_structured_read_compliance("data"); 1085 } 1086 1087 qemu_iovec_init(&sub_qiov, qiov->niov); 1088 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 1089 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 1090 qemu_iovec_destroy(&sub_qiov); 1091 1092 return ret < 0 ? -EIO : 0; 1093 } 1094 1095 #define NBD_MAX_MALLOC_PAYLOAD 1000 1096 static coroutine_fn int nbd_co_receive_structured_payload( 1097 BDRVNBDState *s, void **payload, Error **errp) 1098 { 1099 int ret; 1100 uint32_t len; 1101 1102 assert(nbd_reply_is_structured(&s->reply)); 1103 1104 len = s->reply.structured.length; 1105 1106 if (len == 0) { 1107 return 0; 1108 } 1109 1110 if (payload == NULL) { 1111 error_setg(errp, "Unexpected structured payload"); 1112 return -EINVAL; 1113 } 1114 1115 if (len > NBD_MAX_MALLOC_PAYLOAD) { 1116 error_setg(errp, "Payload too large"); 1117 return -EINVAL; 1118 } 1119 1120 *payload = g_new(char, len); 1121 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 1122 if (ret < 0) { 1123 g_free(*payload); 1124 *payload = NULL; 1125 return ret; 1126 } 1127 1128 return 0; 1129 } 1130 1131 /* 1132 * nbd_co_do_receive_one_chunk 1133 * for simple reply: 1134 * set request_ret to received reply error 1135 * if qiov is not NULL: read payload to @qiov 1136 * for structured reply chunk: 1137 * if error chunk: read payload, set @request_ret, do not set @payload 1138 * else if offset_data chunk: read payload data to @qiov, do not set @payload 1139 * else: read payload to @payload 1140 * 1141 * If function fails, @errp contains corresponding error message, and the 1142 * connection with the server is suspect. If it returns 0, then the 1143 * transaction succeeded (although @request_ret may be a negative errno 1144 * corresponding to the server's error reply), and errp is unchanged. 1145 */ 1146 static coroutine_fn int nbd_co_do_receive_one_chunk( 1147 BDRVNBDState *s, uint64_t handle, bool only_structured, 1148 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 1149 { 1150 int ret; 1151 int i = HANDLE_TO_INDEX(s, handle); 1152 void *local_payload = NULL; 1153 NBDStructuredReplyChunk *chunk; 1154 1155 if (payload) { 1156 *payload = NULL; 1157 } 1158 *request_ret = 0; 1159 1160 /* Wait until we're woken up by nbd_connection_entry. */ 1161 s->requests[i].receiving = true; 1162 qemu_coroutine_yield(); 1163 s->requests[i].receiving = false; 1164 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { 1165 error_setg(errp, "Connection closed"); 1166 return -EIO; 1167 } 1168 assert(s->ioc); 1169 1170 assert(s->reply.handle == handle); 1171 1172 if (nbd_reply_is_simple(&s->reply)) { 1173 if (only_structured) { 1174 error_setg(errp, "Protocol error: simple reply when structured " 1175 "reply chunk was expected"); 1176 return -EINVAL; 1177 } 1178 1179 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 1180 if (*request_ret < 0 || !qiov) { 1181 return 0; 1182 } 1183 1184 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 1185 errp) < 0 ? -EIO : 0; 1186 } 1187 1188 /* handle structured reply chunk */ 1189 assert(s->info.structured_reply); 1190 chunk = &s->reply.structured; 1191 1192 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1193 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 1194 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 1195 " NBD_REPLY_FLAG_DONE flag set"); 1196 return -EINVAL; 1197 } 1198 if (chunk->length) { 1199 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 1200 " nonzero length"); 1201 return -EINVAL; 1202 } 1203 return 0; 1204 } 1205 1206 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 1207 if (!qiov) { 1208 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 1209 return -EINVAL; 1210 } 1211 1212 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 1213 qiov, errp); 1214 } 1215 1216 if (nbd_reply_type_is_error(chunk->type)) { 1217 payload = &local_payload; 1218 } 1219 1220 ret = nbd_co_receive_structured_payload(s, payload, errp); 1221 if (ret < 0) { 1222 return ret; 1223 } 1224 1225 if (nbd_reply_type_is_error(chunk->type)) { 1226 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 1227 g_free(local_payload); 1228 return ret; 1229 } 1230 1231 return 0; 1232 } 1233 1234 /* 1235 * nbd_co_receive_one_chunk 1236 * Read reply, wake up connection_co and set s->quit if needed. 1237 * Return value is a fatal error code or normal nbd reply error code 1238 */ 1239 static coroutine_fn int nbd_co_receive_one_chunk( 1240 BDRVNBDState *s, uint64_t handle, bool only_structured, 1241 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 1242 Error **errp) 1243 { 1244 int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured, 1245 request_ret, qiov, payload, errp); 1246 1247 if (ret < 0) { 1248 memset(reply, 0, sizeof(*reply)); 1249 nbd_channel_error(s, ret); 1250 } else { 1251 /* For assert at loop start in nbd_connection_entry */ 1252 *reply = s->reply; 1253 } 1254 s->reply.handle = 0; 1255 1256 if (s->connection_co && !s->wait_in_flight) { 1257 /* 1258 * We must check s->wait_in_flight, because we may entered by 1259 * nbd_recv_coroutines_wake_all(), in this case we should not 1260 * wake connection_co here, it will woken by last request. 1261 */ 1262 aio_co_wake(s->connection_co); 1263 } 1264 1265 return ret; 1266 } 1267 1268 typedef struct NBDReplyChunkIter { 1269 int ret; 1270 int request_ret; 1271 Error *err; 1272 bool done, only_structured; 1273 } NBDReplyChunkIter; 1274 1275 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 1276 int ret, Error **local_err) 1277 { 1278 assert(local_err && *local_err); 1279 assert(ret < 0); 1280 1281 if (!iter->ret) { 1282 iter->ret = ret; 1283 error_propagate(&iter->err, *local_err); 1284 } else { 1285 error_free(*local_err); 1286 } 1287 1288 *local_err = NULL; 1289 } 1290 1291 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 1292 { 1293 assert(ret < 0); 1294 1295 if (!iter->request_ret) { 1296 iter->request_ret = ret; 1297 } 1298 } 1299 1300 /* 1301 * NBD_FOREACH_REPLY_CHUNK 1302 * The pointer stored in @payload requires g_free() to free it. 1303 */ 1304 #define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \ 1305 qiov, reply, payload) \ 1306 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 1307 nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);) 1308 1309 /* 1310 * nbd_reply_chunk_iter_receive 1311 * The pointer stored in @payload requires g_free() to free it. 1312 */ 1313 static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, 1314 NBDReplyChunkIter *iter, 1315 uint64_t handle, 1316 QEMUIOVector *qiov, NBDReply *reply, 1317 void **payload) 1318 { 1319 int ret, request_ret; 1320 NBDReply local_reply; 1321 NBDStructuredReplyChunk *chunk; 1322 Error *local_err = NULL; 1323 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { 1324 error_setg(&local_err, "Connection closed"); 1325 nbd_iter_channel_error(iter, -EIO, &local_err); 1326 goto break_loop; 1327 } 1328 1329 if (iter->done) { 1330 /* Previous iteration was last. */ 1331 goto break_loop; 1332 } 1333 1334 if (reply == NULL) { 1335 reply = &local_reply; 1336 } 1337 1338 ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured, 1339 &request_ret, qiov, reply, payload, 1340 &local_err); 1341 if (ret < 0) { 1342 nbd_iter_channel_error(iter, ret, &local_err); 1343 } else if (request_ret < 0) { 1344 nbd_iter_request_error(iter, request_ret); 1345 } 1346 1347 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1348 if (nbd_reply_is_simple(reply) || 1349 qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { 1350 goto break_loop; 1351 } 1352 1353 chunk = &reply->structured; 1354 iter->only_structured = true; 1355 1356 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1357 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1358 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1359 goto break_loop; 1360 } 1361 1362 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1363 /* This iteration is last. */ 1364 iter->done = true; 1365 } 1366 1367 /* Execute the loop body */ 1368 return true; 1369 1370 break_loop: 1371 s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL; 1372 1373 qemu_co_mutex_lock(&s->send_mutex); 1374 s->in_flight--; 1375 if (s->in_flight == 0 && s->wait_in_flight) { 1376 aio_co_wake(s->connection_co); 1377 } else { 1378 qemu_co_queue_next(&s->free_sema); 1379 } 1380 qemu_co_mutex_unlock(&s->send_mutex); 1381 1382 return false; 1383 } 1384 1385 static int nbd_co_receive_return_code(BDRVNBDState *s, uint64_t handle, 1386 int *request_ret, Error **errp) 1387 { 1388 NBDReplyChunkIter iter; 1389 1390 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) { 1391 /* nbd_reply_chunk_iter_receive does all the work */ 1392 } 1393 1394 error_propagate(errp, iter.err); 1395 *request_ret = iter.request_ret; 1396 return iter.ret; 1397 } 1398 1399 static int nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t handle, 1400 uint64_t offset, QEMUIOVector *qiov, 1401 int *request_ret, Error **errp) 1402 { 1403 NBDReplyChunkIter iter; 1404 NBDReply reply; 1405 void *payload = NULL; 1406 Error *local_err = NULL; 1407 1408 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, 1409 qiov, &reply, &payload) 1410 { 1411 int ret; 1412 NBDStructuredReplyChunk *chunk = &reply.structured; 1413 1414 assert(nbd_reply_is_structured(&reply)); 1415 1416 switch (chunk->type) { 1417 case NBD_REPLY_TYPE_OFFSET_DATA: 1418 /* 1419 * special cased in nbd_co_receive_one_chunk, data is already 1420 * in qiov 1421 */ 1422 break; 1423 case NBD_REPLY_TYPE_OFFSET_HOLE: 1424 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1425 offset, qiov, &local_err); 1426 if (ret < 0) { 1427 nbd_channel_error(s, ret); 1428 nbd_iter_channel_error(&iter, ret, &local_err); 1429 } 1430 break; 1431 default: 1432 if (!nbd_reply_type_is_error(chunk->type)) { 1433 /* not allowed reply type */ 1434 nbd_channel_error(s, -EINVAL); 1435 error_setg(&local_err, 1436 "Unexpected reply type: %d (%s) for CMD_READ", 1437 chunk->type, nbd_reply_type_lookup(chunk->type)); 1438 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1439 } 1440 } 1441 1442 g_free(payload); 1443 payload = NULL; 1444 } 1445 1446 error_propagate(errp, iter.err); 1447 *request_ret = iter.request_ret; 1448 return iter.ret; 1449 } 1450 1451 static int nbd_co_receive_blockstatus_reply(BDRVNBDState *s, 1452 uint64_t handle, uint64_t length, 1453 NBDExtent *extent, 1454 int *request_ret, Error **errp) 1455 { 1456 NBDReplyChunkIter iter; 1457 NBDReply reply; 1458 void *payload = NULL; 1459 Error *local_err = NULL; 1460 bool received = false; 1461 1462 assert(!extent->length); 1463 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { 1464 int ret; 1465 NBDStructuredReplyChunk *chunk = &reply.structured; 1466 1467 assert(nbd_reply_is_structured(&reply)); 1468 1469 switch (chunk->type) { 1470 case NBD_REPLY_TYPE_BLOCK_STATUS: 1471 if (received) { 1472 nbd_channel_error(s, -EINVAL); 1473 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1474 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1475 } 1476 received = true; 1477 1478 ret = nbd_parse_blockstatus_payload(s, &reply.structured, 1479 payload, length, extent, 1480 &local_err); 1481 if (ret < 0) { 1482 nbd_channel_error(s, ret); 1483 nbd_iter_channel_error(&iter, ret, &local_err); 1484 } 1485 break; 1486 default: 1487 if (!nbd_reply_type_is_error(chunk->type)) { 1488 nbd_channel_error(s, -EINVAL); 1489 error_setg(&local_err, 1490 "Unexpected reply type: %d (%s) " 1491 "for CMD_BLOCK_STATUS", 1492 chunk->type, nbd_reply_type_lookup(chunk->type)); 1493 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1494 } 1495 } 1496 1497 g_free(payload); 1498 payload = NULL; 1499 } 1500 1501 if (!extent->length && !iter.request_ret) { 1502 error_setg(&local_err, "Server did not reply with any status extents"); 1503 nbd_iter_channel_error(&iter, -EIO, &local_err); 1504 } 1505 1506 error_propagate(errp, iter.err); 1507 *request_ret = iter.request_ret; 1508 return iter.ret; 1509 } 1510 1511 static int nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1512 QEMUIOVector *write_qiov) 1513 { 1514 int ret, request_ret; 1515 Error *local_err = NULL; 1516 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1517 1518 assert(request->type != NBD_CMD_READ); 1519 if (write_qiov) { 1520 assert(request->type == NBD_CMD_WRITE); 1521 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1522 } else { 1523 assert(request->type != NBD_CMD_WRITE); 1524 } 1525 1526 do { 1527 ret = nbd_co_send_request(bs, request, write_qiov); 1528 if (ret < 0) { 1529 continue; 1530 } 1531 1532 ret = nbd_co_receive_return_code(s, request->handle, 1533 &request_ret, &local_err); 1534 if (local_err) { 1535 trace_nbd_co_request_fail(request->from, request->len, 1536 request->handle, request->flags, 1537 request->type, 1538 nbd_cmd_lookup(request->type), 1539 ret, error_get_pretty(local_err)); 1540 error_free(local_err); 1541 local_err = NULL; 1542 } 1543 } while (ret < 0 && nbd_client_connecting_wait(s)); 1544 1545 return ret ? ret : request_ret; 1546 } 1547 1548 static int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset, 1549 uint64_t bytes, QEMUIOVector *qiov, int flags) 1550 { 1551 int ret, request_ret; 1552 Error *local_err = NULL; 1553 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1554 NBDRequest request = { 1555 .type = NBD_CMD_READ, 1556 .from = offset, 1557 .len = bytes, 1558 }; 1559 1560 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1561 assert(!flags); 1562 1563 if (!bytes) { 1564 return 0; 1565 } 1566 /* 1567 * Work around the fact that the block layer doesn't do 1568 * byte-accurate sizing yet - if the read exceeds the server's 1569 * advertised size because the block layer rounded size up, then 1570 * truncate the request to the server and tail-pad with zero. 1571 */ 1572 if (offset >= s->info.size) { 1573 assert(bytes < BDRV_SECTOR_SIZE); 1574 qemu_iovec_memset(qiov, 0, 0, bytes); 1575 return 0; 1576 } 1577 if (offset + bytes > s->info.size) { 1578 uint64_t slop = offset + bytes - s->info.size; 1579 1580 assert(slop < BDRV_SECTOR_SIZE); 1581 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1582 request.len -= slop; 1583 } 1584 1585 do { 1586 ret = nbd_co_send_request(bs, &request, NULL); 1587 if (ret < 0) { 1588 continue; 1589 } 1590 1591 ret = nbd_co_receive_cmdread_reply(s, request.handle, offset, qiov, 1592 &request_ret, &local_err); 1593 if (local_err) { 1594 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1595 request.flags, request.type, 1596 nbd_cmd_lookup(request.type), 1597 ret, error_get_pretty(local_err)); 1598 error_free(local_err); 1599 local_err = NULL; 1600 } 1601 } while (ret < 0 && nbd_client_connecting_wait(s)); 1602 1603 return ret ? ret : request_ret; 1604 } 1605 1606 static int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset, 1607 uint64_t bytes, QEMUIOVector *qiov, int flags) 1608 { 1609 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1610 NBDRequest request = { 1611 .type = NBD_CMD_WRITE, 1612 .from = offset, 1613 .len = bytes, 1614 }; 1615 1616 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1617 if (flags & BDRV_REQ_FUA) { 1618 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1619 request.flags |= NBD_CMD_FLAG_FUA; 1620 } 1621 1622 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1623 1624 if (!bytes) { 1625 return 0; 1626 } 1627 return nbd_co_request(bs, &request, qiov); 1628 } 1629 1630 static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, 1631 int bytes, BdrvRequestFlags flags) 1632 { 1633 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1634 NBDRequest request = { 1635 .type = NBD_CMD_WRITE_ZEROES, 1636 .from = offset, 1637 .len = bytes, 1638 }; 1639 1640 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1641 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1642 return -ENOTSUP; 1643 } 1644 1645 if (flags & BDRV_REQ_FUA) { 1646 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1647 request.flags |= NBD_CMD_FLAG_FUA; 1648 } 1649 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1650 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1651 } 1652 if (flags & BDRV_REQ_NO_FALLBACK) { 1653 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1654 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1655 } 1656 1657 if (!bytes) { 1658 return 0; 1659 } 1660 return nbd_co_request(bs, &request, NULL); 1661 } 1662 1663 static int nbd_client_co_flush(BlockDriverState *bs) 1664 { 1665 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1666 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1667 1668 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1669 return 0; 1670 } 1671 1672 request.from = 0; 1673 request.len = 0; 1674 1675 return nbd_co_request(bs, &request, NULL); 1676 } 1677 1678 static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, 1679 int bytes) 1680 { 1681 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1682 NBDRequest request = { 1683 .type = NBD_CMD_TRIM, 1684 .from = offset, 1685 .len = bytes, 1686 }; 1687 1688 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1689 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1690 return 0; 1691 } 1692 1693 return nbd_co_request(bs, &request, NULL); 1694 } 1695 1696 static int coroutine_fn nbd_client_co_block_status( 1697 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1698 int64_t *pnum, int64_t *map, BlockDriverState **file) 1699 { 1700 int ret, request_ret; 1701 NBDExtent extent = { 0 }; 1702 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1703 Error *local_err = NULL; 1704 1705 NBDRequest request = { 1706 .type = NBD_CMD_BLOCK_STATUS, 1707 .from = offset, 1708 .len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1709 MIN(bytes, s->info.size - offset)), 1710 .flags = NBD_CMD_FLAG_REQ_ONE, 1711 }; 1712 1713 if (!s->info.base_allocation) { 1714 *pnum = bytes; 1715 *map = offset; 1716 *file = bs; 1717 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1718 } 1719 1720 /* 1721 * Work around the fact that the block layer doesn't do 1722 * byte-accurate sizing yet - if the status request exceeds the 1723 * server's advertised size because the block layer rounded size 1724 * up, we truncated the request to the server (above), or are 1725 * called on just the hole. 1726 */ 1727 if (offset >= s->info.size) { 1728 *pnum = bytes; 1729 assert(bytes < BDRV_SECTOR_SIZE); 1730 /* Intentionally don't report offset_valid for the hole */ 1731 return BDRV_BLOCK_ZERO; 1732 } 1733 1734 if (s->info.min_block) { 1735 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1736 } 1737 do { 1738 ret = nbd_co_send_request(bs, &request, NULL); 1739 if (ret < 0) { 1740 continue; 1741 } 1742 1743 ret = nbd_co_receive_blockstatus_reply(s, request.handle, bytes, 1744 &extent, &request_ret, 1745 &local_err); 1746 if (local_err) { 1747 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1748 request.flags, request.type, 1749 nbd_cmd_lookup(request.type), 1750 ret, error_get_pretty(local_err)); 1751 error_free(local_err); 1752 local_err = NULL; 1753 } 1754 } while (ret < 0 && nbd_client_connecting_wait(s)); 1755 1756 if (ret < 0 || request_ret < 0) { 1757 return ret ? ret : request_ret; 1758 } 1759 1760 assert(extent.length); 1761 *pnum = extent.length; 1762 *map = offset; 1763 *file = bs; 1764 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1765 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1766 BDRV_BLOCK_OFFSET_VALID; 1767 } 1768 1769 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1770 BlockReopenQueue *queue, Error **errp) 1771 { 1772 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1773 1774 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1775 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1776 return -EACCES; 1777 } 1778 return 0; 1779 } 1780 1781 static void nbd_yank(void *opaque) 1782 { 1783 BlockDriverState *bs = opaque; 1784 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1785 1786 qatomic_store_release(&s->state, NBD_CLIENT_QUIT); 1787 qio_channel_shutdown(QIO_CHANNEL(s->sioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1788 } 1789 1790 static void nbd_client_close(BlockDriverState *bs) 1791 { 1792 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1793 NBDRequest request = { .type = NBD_CMD_DISC }; 1794 1795 if (s->ioc) { 1796 nbd_send_request(s->ioc, &request); 1797 } 1798 1799 nbd_teardown_connection(bs); 1800 } 1801 1802 static int nbd_establish_connection(BlockDriverState *bs, 1803 SocketAddress *saddr, 1804 Error **errp) 1805 { 1806 ERRP_GUARD(); 1807 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1808 1809 s->sioc = qio_channel_socket_new(); 1810 qio_channel_set_name(QIO_CHANNEL(s->sioc), "nbd-client"); 1811 1812 qio_channel_socket_connect_sync(s->sioc, saddr, errp); 1813 if (*errp) { 1814 object_unref(OBJECT(s->sioc)); 1815 s->sioc = NULL; 1816 return -1; 1817 } 1818 1819 yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), nbd_yank, bs); 1820 qio_channel_set_delay(QIO_CHANNEL(s->sioc), false); 1821 1822 return 0; 1823 } 1824 1825 /* nbd_client_handshake takes ownership on s->sioc. On failure it's unref'ed. */ 1826 static int nbd_client_handshake(BlockDriverState *bs, Error **errp) 1827 { 1828 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1829 AioContext *aio_context = bdrv_get_aio_context(bs); 1830 int ret; 1831 1832 trace_nbd_client_handshake(s->export); 1833 qio_channel_set_blocking(QIO_CHANNEL(s->sioc), false, NULL); 1834 qio_channel_attach_aio_context(QIO_CHANNEL(s->sioc), aio_context); 1835 1836 s->info.request_sizes = true; 1837 s->info.structured_reply = true; 1838 s->info.base_allocation = true; 1839 s->info.x_dirty_bitmap = g_strdup(s->x_dirty_bitmap); 1840 s->info.name = g_strdup(s->export ?: ""); 1841 ret = nbd_receive_negotiate(aio_context, QIO_CHANNEL(s->sioc), s->tlscreds, 1842 s->hostname, &s->ioc, &s->info, errp); 1843 g_free(s->info.x_dirty_bitmap); 1844 g_free(s->info.name); 1845 if (ret < 0) { 1846 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), 1847 nbd_yank, bs); 1848 object_unref(OBJECT(s->sioc)); 1849 s->sioc = NULL; 1850 return ret; 1851 } 1852 if (s->x_dirty_bitmap) { 1853 if (!s->info.base_allocation) { 1854 error_setg(errp, "requested x-dirty-bitmap %s not found", 1855 s->x_dirty_bitmap); 1856 ret = -EINVAL; 1857 goto fail; 1858 } 1859 if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { 1860 s->alloc_depth = true; 1861 } 1862 } 1863 if (s->info.flags & NBD_FLAG_READ_ONLY) { 1864 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); 1865 if (ret < 0) { 1866 goto fail; 1867 } 1868 } 1869 if (s->info.flags & NBD_FLAG_SEND_FUA) { 1870 bs->supported_write_flags = BDRV_REQ_FUA; 1871 bs->supported_zero_flags |= BDRV_REQ_FUA; 1872 } 1873 if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { 1874 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; 1875 if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { 1876 bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; 1877 } 1878 } 1879 1880 if (!s->ioc) { 1881 s->ioc = QIO_CHANNEL(s->sioc); 1882 object_ref(OBJECT(s->ioc)); 1883 } 1884 1885 trace_nbd_client_handshake_success(s->export); 1886 1887 return 0; 1888 1889 fail: 1890 /* 1891 * We have connected, but must fail for other reasons. 1892 * Send NBD_CMD_DISC as a courtesy to the server. 1893 */ 1894 { 1895 NBDRequest request = { .type = NBD_CMD_DISC }; 1896 1897 nbd_send_request(s->ioc ?: QIO_CHANNEL(s->sioc), &request); 1898 1899 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), 1900 nbd_yank, bs); 1901 object_unref(OBJECT(s->sioc)); 1902 s->sioc = NULL; 1903 1904 return ret; 1905 } 1906 } 1907 1908 /* 1909 * Parse nbd_open options 1910 */ 1911 1912 static int nbd_parse_uri(const char *filename, QDict *options) 1913 { 1914 URI *uri; 1915 const char *p; 1916 QueryParams *qp = NULL; 1917 int ret = 0; 1918 bool is_unix; 1919 1920 uri = uri_parse(filename); 1921 if (!uri) { 1922 return -EINVAL; 1923 } 1924 1925 /* transport */ 1926 if (!g_strcmp0(uri->scheme, "nbd")) { 1927 is_unix = false; 1928 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1929 is_unix = false; 1930 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1931 is_unix = true; 1932 } else { 1933 ret = -EINVAL; 1934 goto out; 1935 } 1936 1937 p = uri->path ? uri->path : ""; 1938 if (p[0] == '/') { 1939 p++; 1940 } 1941 if (p[0]) { 1942 qdict_put_str(options, "export", p); 1943 } 1944 1945 qp = query_params_parse(uri->query); 1946 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1947 ret = -EINVAL; 1948 goto out; 1949 } 1950 1951 if (is_unix) { 1952 /* nbd+unix:///export?socket=path */ 1953 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1954 ret = -EINVAL; 1955 goto out; 1956 } 1957 qdict_put_str(options, "server.type", "unix"); 1958 qdict_put_str(options, "server.path", qp->p[0].value); 1959 } else { 1960 QString *host; 1961 char *port_str; 1962 1963 /* nbd[+tcp]://host[:port]/export */ 1964 if (!uri->server) { 1965 ret = -EINVAL; 1966 goto out; 1967 } 1968 1969 /* strip braces from literal IPv6 address */ 1970 if (uri->server[0] == '[') { 1971 host = qstring_from_substr(uri->server, 1, 1972 strlen(uri->server) - 1); 1973 } else { 1974 host = qstring_from_str(uri->server); 1975 } 1976 1977 qdict_put_str(options, "server.type", "inet"); 1978 qdict_put(options, "server.host", host); 1979 1980 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1981 qdict_put_str(options, "server.port", port_str); 1982 g_free(port_str); 1983 } 1984 1985 out: 1986 if (qp) { 1987 query_params_free(qp); 1988 } 1989 uri_free(uri); 1990 return ret; 1991 } 1992 1993 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1994 { 1995 const QDictEntry *e; 1996 1997 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1998 if (!strcmp(e->key, "host") || 1999 !strcmp(e->key, "port") || 2000 !strcmp(e->key, "path") || 2001 !strcmp(e->key, "export") || 2002 strstart(e->key, "server.", NULL)) 2003 { 2004 error_setg(errp, "Option '%s' cannot be used with a file name", 2005 e->key); 2006 return true; 2007 } 2008 } 2009 2010 return false; 2011 } 2012 2013 static void nbd_parse_filename(const char *filename, QDict *options, 2014 Error **errp) 2015 { 2016 g_autofree char *file = NULL; 2017 char *export_name; 2018 const char *host_spec; 2019 const char *unixpath; 2020 2021 if (nbd_has_filename_options_conflict(options, errp)) { 2022 return; 2023 } 2024 2025 if (strstr(filename, "://")) { 2026 int ret = nbd_parse_uri(filename, options); 2027 if (ret < 0) { 2028 error_setg(errp, "No valid URL specified"); 2029 } 2030 return; 2031 } 2032 2033 file = g_strdup(filename); 2034 2035 export_name = strstr(file, EN_OPTSTR); 2036 if (export_name) { 2037 if (export_name[strlen(EN_OPTSTR)] == 0) { 2038 return; 2039 } 2040 export_name[0] = 0; /* truncate 'file' */ 2041 export_name += strlen(EN_OPTSTR); 2042 2043 qdict_put_str(options, "export", export_name); 2044 } 2045 2046 /* extract the host_spec - fail if it's not nbd:... */ 2047 if (!strstart(file, "nbd:", &host_spec)) { 2048 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 2049 return; 2050 } 2051 2052 if (!*host_spec) { 2053 return; 2054 } 2055 2056 /* are we a UNIX or TCP socket? */ 2057 if (strstart(host_spec, "unix:", &unixpath)) { 2058 qdict_put_str(options, "server.type", "unix"); 2059 qdict_put_str(options, "server.path", unixpath); 2060 } else { 2061 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 2062 2063 if (inet_parse(addr, host_spec, errp)) { 2064 goto out_inet; 2065 } 2066 2067 qdict_put_str(options, "server.type", "inet"); 2068 qdict_put_str(options, "server.host", addr->host); 2069 qdict_put_str(options, "server.port", addr->port); 2070 out_inet: 2071 qapi_free_InetSocketAddress(addr); 2072 } 2073 } 2074 2075 static bool nbd_process_legacy_socket_options(QDict *output_options, 2076 QemuOpts *legacy_opts, 2077 Error **errp) 2078 { 2079 const char *path = qemu_opt_get(legacy_opts, "path"); 2080 const char *host = qemu_opt_get(legacy_opts, "host"); 2081 const char *port = qemu_opt_get(legacy_opts, "port"); 2082 const QDictEntry *e; 2083 2084 if (!path && !host && !port) { 2085 return true; 2086 } 2087 2088 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 2089 { 2090 if (strstart(e->key, "server.", NULL)) { 2091 error_setg(errp, "Cannot use 'server' and path/host/port at the " 2092 "same time"); 2093 return false; 2094 } 2095 } 2096 2097 if (path && host) { 2098 error_setg(errp, "path and host may not be used at the same time"); 2099 return false; 2100 } else if (path) { 2101 if (port) { 2102 error_setg(errp, "port may not be used without host"); 2103 return false; 2104 } 2105 2106 qdict_put_str(output_options, "server.type", "unix"); 2107 qdict_put_str(output_options, "server.path", path); 2108 } else if (host) { 2109 qdict_put_str(output_options, "server.type", "inet"); 2110 qdict_put_str(output_options, "server.host", host); 2111 qdict_put_str(output_options, "server.port", 2112 port ?: stringify(NBD_DEFAULT_PORT)); 2113 } 2114 2115 return true; 2116 } 2117 2118 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 2119 Error **errp) 2120 { 2121 SocketAddress *saddr = NULL; 2122 QDict *addr = NULL; 2123 Visitor *iv = NULL; 2124 2125 qdict_extract_subqdict(options, &addr, "server."); 2126 if (!qdict_size(addr)) { 2127 error_setg(errp, "NBD server address missing"); 2128 goto done; 2129 } 2130 2131 iv = qobject_input_visitor_new_flat_confused(addr, errp); 2132 if (!iv) { 2133 goto done; 2134 } 2135 2136 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 2137 goto done; 2138 } 2139 2140 done: 2141 qobject_unref(addr); 2142 visit_free(iv); 2143 return saddr; 2144 } 2145 2146 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 2147 { 2148 Object *obj; 2149 QCryptoTLSCreds *creds; 2150 2151 obj = object_resolve_path_component( 2152 object_get_objects_root(), id); 2153 if (!obj) { 2154 error_setg(errp, "No TLS credentials with id '%s'", 2155 id); 2156 return NULL; 2157 } 2158 creds = (QCryptoTLSCreds *) 2159 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 2160 if (!creds) { 2161 error_setg(errp, "Object with id '%s' is not TLS credentials", 2162 id); 2163 return NULL; 2164 } 2165 2166 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) { 2167 error_setg(errp, 2168 "Expecting TLS credentials with a client endpoint"); 2169 return NULL; 2170 } 2171 object_ref(obj); 2172 return creds; 2173 } 2174 2175 2176 static QemuOptsList nbd_runtime_opts = { 2177 .name = "nbd", 2178 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 2179 .desc = { 2180 { 2181 .name = "host", 2182 .type = QEMU_OPT_STRING, 2183 .help = "TCP host to connect to", 2184 }, 2185 { 2186 .name = "port", 2187 .type = QEMU_OPT_STRING, 2188 .help = "TCP port to connect to", 2189 }, 2190 { 2191 .name = "path", 2192 .type = QEMU_OPT_STRING, 2193 .help = "Unix socket path to connect to", 2194 }, 2195 { 2196 .name = "export", 2197 .type = QEMU_OPT_STRING, 2198 .help = "Name of the NBD export to open", 2199 }, 2200 { 2201 .name = "tls-creds", 2202 .type = QEMU_OPT_STRING, 2203 .help = "ID of the TLS credentials to use", 2204 }, 2205 { 2206 .name = "x-dirty-bitmap", 2207 .type = QEMU_OPT_STRING, 2208 .help = "experimental: expose named dirty bitmap in place of " 2209 "block status", 2210 }, 2211 { 2212 .name = "reconnect-delay", 2213 .type = QEMU_OPT_NUMBER, 2214 .help = "On an unexpected disconnect, the nbd client tries to " 2215 "connect again until succeeding or encountering a serious " 2216 "error. During the first @reconnect-delay seconds, all " 2217 "requests are paused and will be rerun on a successful " 2218 "reconnect. After that time, any delayed requests and all " 2219 "future requests before a successful reconnect will " 2220 "immediately fail. Default 0", 2221 }, 2222 { /* end of list */ } 2223 }, 2224 }; 2225 2226 static int nbd_process_options(BlockDriverState *bs, QDict *options, 2227 Error **errp) 2228 { 2229 BDRVNBDState *s = bs->opaque; 2230 QemuOpts *opts; 2231 int ret = -EINVAL; 2232 2233 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 2234 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 2235 goto error; 2236 } 2237 2238 /* Translate @host, @port, and @path to a SocketAddress */ 2239 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 2240 goto error; 2241 } 2242 2243 /* Pop the config into our state object. Exit if invalid. */ 2244 s->saddr = nbd_config(s, options, errp); 2245 if (!s->saddr) { 2246 goto error; 2247 } 2248 2249 s->export = g_strdup(qemu_opt_get(opts, "export")); 2250 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 2251 error_setg(errp, "export name too long to send to server"); 2252 goto error; 2253 } 2254 2255 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 2256 if (s->tlscredsid) { 2257 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 2258 if (!s->tlscreds) { 2259 goto error; 2260 } 2261 2262 /* TODO SOCKET_ADDRESS_KIND_FD where fd has AF_INET or AF_INET6 */ 2263 if (s->saddr->type != SOCKET_ADDRESS_TYPE_INET) { 2264 error_setg(errp, "TLS only supported over IP sockets"); 2265 goto error; 2266 } 2267 s->hostname = s->saddr->u.inet.host; 2268 } 2269 2270 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 2271 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 2272 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 2273 goto error; 2274 } 2275 2276 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 2277 2278 ret = 0; 2279 2280 error: 2281 if (ret < 0) { 2282 nbd_clear_bdrvstate(s); 2283 } 2284 qemu_opts_del(opts); 2285 return ret; 2286 } 2287 2288 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 2289 Error **errp) 2290 { 2291 int ret; 2292 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2293 2294 ret = nbd_process_options(bs, options, errp); 2295 if (ret < 0) { 2296 return ret; 2297 } 2298 2299 s->bs = bs; 2300 qemu_co_mutex_init(&s->send_mutex); 2301 qemu_co_queue_init(&s->free_sema); 2302 2303 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 2304 return -EEXIST; 2305 } 2306 2307 /* 2308 * establish TCP connection, return error if it fails 2309 * TODO: Configurable retry-until-timeout behaviour. 2310 */ 2311 if (nbd_establish_connection(bs, s->saddr, errp) < 0) { 2312 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 2313 return -ECONNREFUSED; 2314 } 2315 2316 ret = nbd_client_handshake(bs, errp); 2317 if (ret < 0) { 2318 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 2319 nbd_clear_bdrvstate(s); 2320 return ret; 2321 } 2322 /* successfully connected */ 2323 s->state = NBD_CLIENT_CONNECTED; 2324 2325 nbd_init_connect_thread(s); 2326 2327 s->connection_co = qemu_coroutine_create(nbd_connection_entry, s); 2328 bdrv_inc_in_flight(bs); 2329 aio_co_schedule(bdrv_get_aio_context(bs), s->connection_co); 2330 2331 return 0; 2332 } 2333 2334 static int nbd_co_flush(BlockDriverState *bs) 2335 { 2336 return nbd_client_co_flush(bs); 2337 } 2338 2339 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 2340 { 2341 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2342 uint32_t min = s->info.min_block; 2343 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 2344 2345 /* 2346 * If the server did not advertise an alignment: 2347 * - a size that is not sector-aligned implies that an alignment 2348 * of 1 can be used to access those tail bytes 2349 * - advertisement of block status requires an alignment of 1, so 2350 * that we don't violate block layer constraints that block 2351 * status is always aligned (as we can't control whether the 2352 * server will report sub-sector extents, such as a hole at EOF 2353 * on an unaligned POSIX file) 2354 * - otherwise, assume the server is so old that we are safer avoiding 2355 * sub-sector requests 2356 */ 2357 if (!min) { 2358 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 2359 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 2360 } 2361 2362 bs->bl.request_alignment = min; 2363 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 2364 bs->bl.max_pwrite_zeroes = max; 2365 bs->bl.max_transfer = max; 2366 2367 if (s->info.opt_block && 2368 s->info.opt_block > bs->bl.opt_transfer) { 2369 bs->bl.opt_transfer = s->info.opt_block; 2370 } 2371 } 2372 2373 static void nbd_close(BlockDriverState *bs) 2374 { 2375 BDRVNBDState *s = bs->opaque; 2376 2377 nbd_client_close(bs); 2378 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 2379 nbd_clear_bdrvstate(s); 2380 } 2381 2382 /* 2383 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 2384 * to a smaller size with exact=false, there is no reason to fail the 2385 * operation. 2386 * 2387 * Preallocation mode is ignored since it does not seems useful to fail when 2388 * we never change anything. 2389 */ 2390 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 2391 bool exact, PreallocMode prealloc, 2392 BdrvRequestFlags flags, Error **errp) 2393 { 2394 BDRVNBDState *s = bs->opaque; 2395 2396 if (offset != s->info.size && exact) { 2397 error_setg(errp, "Cannot resize NBD nodes"); 2398 return -ENOTSUP; 2399 } 2400 2401 if (offset > s->info.size) { 2402 error_setg(errp, "Cannot grow NBD nodes"); 2403 return -EINVAL; 2404 } 2405 2406 return 0; 2407 } 2408 2409 static int64_t nbd_getlength(BlockDriverState *bs) 2410 { 2411 BDRVNBDState *s = bs->opaque; 2412 2413 return s->info.size; 2414 } 2415 2416 static void nbd_refresh_filename(BlockDriverState *bs) 2417 { 2418 BDRVNBDState *s = bs->opaque; 2419 const char *host = NULL, *port = NULL, *path = NULL; 2420 size_t len = 0; 2421 2422 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 2423 const InetSocketAddress *inet = &s->saddr->u.inet; 2424 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 2425 host = inet->host; 2426 port = inet->port; 2427 } 2428 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2429 path = s->saddr->u.q_unix.path; 2430 } /* else can't represent as pseudo-filename */ 2431 2432 if (path && s->export) { 2433 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2434 "nbd+unix:///%s?socket=%s", s->export, path); 2435 } else if (path && !s->export) { 2436 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2437 "nbd+unix://?socket=%s", path); 2438 } else if (host && s->export) { 2439 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2440 "nbd://%s:%s/%s", host, port, s->export); 2441 } else if (host && !s->export) { 2442 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2443 "nbd://%s:%s", host, port); 2444 } 2445 if (len >= sizeof(bs->exact_filename)) { 2446 /* Name is too long to represent exactly, so leave it empty. */ 2447 bs->exact_filename[0] = '\0'; 2448 } 2449 } 2450 2451 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2452 { 2453 /* The generic bdrv_dirname() implementation is able to work out some 2454 * directory name for NBD nodes, but that would be wrong. So far there is no 2455 * specification for how "export paths" would work, so NBD does not have 2456 * directory names. */ 2457 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2458 return NULL; 2459 } 2460 2461 static const char *const nbd_strong_runtime_opts[] = { 2462 "path", 2463 "host", 2464 "port", 2465 "export", 2466 "tls-creds", 2467 "server.", 2468 2469 NULL 2470 }; 2471 2472 static void nbd_cancel_in_flight(BlockDriverState *bs) 2473 { 2474 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2475 2476 reconnect_delay_timer_del(s); 2477 2478 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2479 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2480 qemu_co_queue_restart_all(&s->free_sema); 2481 } 2482 } 2483 2484 static BlockDriver bdrv_nbd = { 2485 .format_name = "nbd", 2486 .protocol_name = "nbd", 2487 .instance_size = sizeof(BDRVNBDState), 2488 .bdrv_parse_filename = nbd_parse_filename, 2489 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2490 .create_opts = &bdrv_create_opts_simple, 2491 .bdrv_file_open = nbd_open, 2492 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2493 .bdrv_co_preadv = nbd_client_co_preadv, 2494 .bdrv_co_pwritev = nbd_client_co_pwritev, 2495 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2496 .bdrv_close = nbd_close, 2497 .bdrv_co_flush_to_os = nbd_co_flush, 2498 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2499 .bdrv_refresh_limits = nbd_refresh_limits, 2500 .bdrv_co_truncate = nbd_co_truncate, 2501 .bdrv_getlength = nbd_getlength, 2502 .bdrv_detach_aio_context = nbd_client_detach_aio_context, 2503 .bdrv_attach_aio_context = nbd_client_attach_aio_context, 2504 .bdrv_co_drain_begin = nbd_client_co_drain_begin, 2505 .bdrv_co_drain_end = nbd_client_co_drain_end, 2506 .bdrv_refresh_filename = nbd_refresh_filename, 2507 .bdrv_co_block_status = nbd_client_co_block_status, 2508 .bdrv_dirname = nbd_dirname, 2509 .strong_runtime_opts = nbd_strong_runtime_opts, 2510 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2511 }; 2512 2513 static BlockDriver bdrv_nbd_tcp = { 2514 .format_name = "nbd", 2515 .protocol_name = "nbd+tcp", 2516 .instance_size = sizeof(BDRVNBDState), 2517 .bdrv_parse_filename = nbd_parse_filename, 2518 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2519 .create_opts = &bdrv_create_opts_simple, 2520 .bdrv_file_open = nbd_open, 2521 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2522 .bdrv_co_preadv = nbd_client_co_preadv, 2523 .bdrv_co_pwritev = nbd_client_co_pwritev, 2524 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2525 .bdrv_close = nbd_close, 2526 .bdrv_co_flush_to_os = nbd_co_flush, 2527 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2528 .bdrv_refresh_limits = nbd_refresh_limits, 2529 .bdrv_co_truncate = nbd_co_truncate, 2530 .bdrv_getlength = nbd_getlength, 2531 .bdrv_detach_aio_context = nbd_client_detach_aio_context, 2532 .bdrv_attach_aio_context = nbd_client_attach_aio_context, 2533 .bdrv_co_drain_begin = nbd_client_co_drain_begin, 2534 .bdrv_co_drain_end = nbd_client_co_drain_end, 2535 .bdrv_refresh_filename = nbd_refresh_filename, 2536 .bdrv_co_block_status = nbd_client_co_block_status, 2537 .bdrv_dirname = nbd_dirname, 2538 .strong_runtime_opts = nbd_strong_runtime_opts, 2539 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2540 }; 2541 2542 static BlockDriver bdrv_nbd_unix = { 2543 .format_name = "nbd", 2544 .protocol_name = "nbd+unix", 2545 .instance_size = sizeof(BDRVNBDState), 2546 .bdrv_parse_filename = nbd_parse_filename, 2547 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2548 .create_opts = &bdrv_create_opts_simple, 2549 .bdrv_file_open = nbd_open, 2550 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2551 .bdrv_co_preadv = nbd_client_co_preadv, 2552 .bdrv_co_pwritev = nbd_client_co_pwritev, 2553 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2554 .bdrv_close = nbd_close, 2555 .bdrv_co_flush_to_os = nbd_co_flush, 2556 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2557 .bdrv_refresh_limits = nbd_refresh_limits, 2558 .bdrv_co_truncate = nbd_co_truncate, 2559 .bdrv_getlength = nbd_getlength, 2560 .bdrv_detach_aio_context = nbd_client_detach_aio_context, 2561 .bdrv_attach_aio_context = nbd_client_attach_aio_context, 2562 .bdrv_co_drain_begin = nbd_client_co_drain_begin, 2563 .bdrv_co_drain_end = nbd_client_co_drain_end, 2564 .bdrv_refresh_filename = nbd_refresh_filename, 2565 .bdrv_co_block_status = nbd_client_co_block_status, 2566 .bdrv_dirname = nbd_dirname, 2567 .strong_runtime_opts = nbd_strong_runtime_opts, 2568 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2569 }; 2570 2571 static void bdrv_nbd_init(void) 2572 { 2573 bdrv_register(&bdrv_nbd); 2574 bdrv_register(&bdrv_nbd_tcp); 2575 bdrv_register(&bdrv_nbd_unix); 2576 } 2577 2578 block_init(bdrv_nbd_init); 2579