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