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