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