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