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; /* sleeping in the yield in nbd_receive_replies */ 61 bool reply_possible; /* reply header not yet received */ 62 } NBDClientRequest; 63 64 typedef enum NBDClientState { 65 NBD_CLIENT_CONNECTING_WAIT, 66 NBD_CLIENT_CONNECTING_NOWAIT, 67 NBD_CLIENT_CONNECTED, 68 NBD_CLIENT_QUIT 69 } NBDClientState; 70 71 typedef struct BDRVNBDState { 72 QIOChannel *ioc; /* The current I/O channel */ 73 NBDExportInfo info; 74 75 CoMutex send_mutex; 76 CoQueue free_sema; 77 78 CoMutex receive_mutex; 79 int in_flight; 80 NBDClientState state; 81 82 QEMUTimer *reconnect_delay_timer; 83 QEMUTimer *open_timer; 84 85 NBDClientRequest requests[MAX_NBD_REQUESTS]; 86 NBDReply reply; 87 BlockDriverState *bs; 88 89 /* Connection parameters */ 90 uint32_t reconnect_delay; 91 uint32_t open_timeout; 92 SocketAddress *saddr; 93 char *export, *tlscredsid; 94 QCryptoTLSCreds *tlscreds; 95 const char *hostname; 96 char *x_dirty_bitmap; 97 bool alloc_depth; 98 99 NBDClientConnection *conn; 100 } BDRVNBDState; 101 102 static void nbd_yank(void *opaque); 103 104 static void nbd_clear_bdrvstate(BlockDriverState *bs) 105 { 106 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 107 108 nbd_client_connection_release(s->conn); 109 s->conn = NULL; 110 111 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 112 113 /* Must not leave timers behind that would access freed data */ 114 assert(!s->reconnect_delay_timer); 115 assert(!s->open_timer); 116 117 object_unref(OBJECT(s->tlscreds)); 118 qapi_free_SocketAddress(s->saddr); 119 s->saddr = NULL; 120 g_free(s->export); 121 s->export = NULL; 122 g_free(s->tlscredsid); 123 s->tlscredsid = NULL; 124 g_free(s->x_dirty_bitmap); 125 s->x_dirty_bitmap = NULL; 126 } 127 128 static bool nbd_client_connected(BDRVNBDState *s) 129 { 130 return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED; 131 } 132 133 static bool nbd_recv_coroutine_wake_one(NBDClientRequest *req) 134 { 135 if (req->receiving) { 136 req->receiving = false; 137 aio_co_wake(req->coroutine); 138 return true; 139 } 140 141 return false; 142 } 143 144 static void nbd_recv_coroutines_wake(BDRVNBDState *s, bool all) 145 { 146 int i; 147 148 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 149 if (nbd_recv_coroutine_wake_one(&s->requests[i]) && !all) { 150 return; 151 } 152 } 153 } 154 155 static void nbd_channel_error(BDRVNBDState *s, int ret) 156 { 157 if (nbd_client_connected(s)) { 158 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 159 } 160 161 if (ret == -EIO) { 162 if (nbd_client_connected(s)) { 163 s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : 164 NBD_CLIENT_CONNECTING_NOWAIT; 165 } 166 } else { 167 s->state = NBD_CLIENT_QUIT; 168 } 169 170 nbd_recv_coroutines_wake(s, true); 171 } 172 173 static void reconnect_delay_timer_del(BDRVNBDState *s) 174 { 175 if (s->reconnect_delay_timer) { 176 timer_free(s->reconnect_delay_timer); 177 s->reconnect_delay_timer = NULL; 178 } 179 } 180 181 static void reconnect_delay_timer_cb(void *opaque) 182 { 183 BDRVNBDState *s = opaque; 184 185 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { 186 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 187 nbd_co_establish_connection_cancel(s->conn); 188 while (qemu_co_enter_next(&s->free_sema, NULL)) { 189 /* Resume all queued requests */ 190 } 191 } 192 193 reconnect_delay_timer_del(s); 194 } 195 196 static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 197 { 198 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTING_WAIT) { 199 return; 200 } 201 202 assert(!s->reconnect_delay_timer); 203 s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 204 QEMU_CLOCK_REALTIME, 205 SCALE_NS, 206 reconnect_delay_timer_cb, s); 207 timer_mod(s->reconnect_delay_timer, expire_time_ns); 208 } 209 210 static void nbd_teardown_connection(BlockDriverState *bs) 211 { 212 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 213 214 assert(!s->in_flight); 215 216 if (s->ioc) { 217 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 218 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 219 nbd_yank, s->bs); 220 object_unref(OBJECT(s->ioc)); 221 s->ioc = NULL; 222 } 223 224 s->state = NBD_CLIENT_QUIT; 225 } 226 227 static void open_timer_del(BDRVNBDState *s) 228 { 229 if (s->open_timer) { 230 timer_free(s->open_timer); 231 s->open_timer = NULL; 232 } 233 } 234 235 static void open_timer_cb(void *opaque) 236 { 237 BDRVNBDState *s = opaque; 238 239 nbd_co_establish_connection_cancel(s->conn); 240 open_timer_del(s); 241 } 242 243 static void open_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 244 { 245 assert(!s->open_timer); 246 s->open_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 247 QEMU_CLOCK_REALTIME, 248 SCALE_NS, 249 open_timer_cb, s); 250 timer_mod(s->open_timer, expire_time_ns); 251 } 252 253 static bool nbd_client_connecting(BDRVNBDState *s) 254 { 255 NBDClientState state = qatomic_load_acquire(&s->state); 256 return state == NBD_CLIENT_CONNECTING_WAIT || 257 state == NBD_CLIENT_CONNECTING_NOWAIT; 258 } 259 260 static bool nbd_client_connecting_wait(BDRVNBDState *s) 261 { 262 return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; 263 } 264 265 /* 266 * Update @bs with information learned during a completed negotiation process. 267 * Return failure if the server's advertised options are incompatible with the 268 * client's needs. 269 */ 270 static int nbd_handle_updated_info(BlockDriverState *bs, Error **errp) 271 { 272 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 273 int ret; 274 275 if (s->x_dirty_bitmap) { 276 if (!s->info.base_allocation) { 277 error_setg(errp, "requested x-dirty-bitmap %s not found", 278 s->x_dirty_bitmap); 279 return -EINVAL; 280 } 281 if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { 282 s->alloc_depth = true; 283 } 284 } 285 286 if (s->info.flags & NBD_FLAG_READ_ONLY) { 287 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); 288 if (ret < 0) { 289 return ret; 290 } 291 } 292 293 if (s->info.flags & NBD_FLAG_SEND_FUA) { 294 bs->supported_write_flags = BDRV_REQ_FUA; 295 bs->supported_zero_flags |= BDRV_REQ_FUA; 296 } 297 298 if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { 299 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; 300 if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { 301 bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; 302 } 303 } 304 305 trace_nbd_client_handshake_success(s->export); 306 307 return 0; 308 } 309 310 int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, 311 Error **errp) 312 { 313 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 314 int ret; 315 bool blocking = nbd_client_connecting_wait(s); 316 317 assert(!s->ioc); 318 319 s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); 320 if (!s->ioc) { 321 return -ECONNREFUSED; 322 } 323 324 yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, 325 bs); 326 327 ret = nbd_handle_updated_info(s->bs, NULL); 328 if (ret < 0) { 329 /* 330 * We have connected, but must fail for other reasons. 331 * Send NBD_CMD_DISC as a courtesy to the server. 332 */ 333 NBDRequest request = { .type = NBD_CMD_DISC }; 334 335 nbd_send_request(s->ioc, &request); 336 337 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 338 nbd_yank, bs); 339 object_unref(OBJECT(s->ioc)); 340 s->ioc = NULL; 341 342 return ret; 343 } 344 345 qio_channel_set_blocking(s->ioc, false, NULL); 346 qio_channel_attach_aio_context(s->ioc, bdrv_get_aio_context(bs)); 347 348 /* successfully connected */ 349 s->state = NBD_CLIENT_CONNECTED; 350 qemu_co_queue_restart_all(&s->free_sema); 351 352 return 0; 353 } 354 355 /* called under s->send_mutex */ 356 static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) 357 { 358 assert(nbd_client_connecting(s)); 359 assert(s->in_flight == 0); 360 361 if (nbd_client_connecting_wait(s) && s->reconnect_delay && 362 !s->reconnect_delay_timer) 363 { 364 /* 365 * It's first reconnect attempt after switching to 366 * NBD_CLIENT_CONNECTING_WAIT 367 */ 368 reconnect_delay_timer_init(s, 369 qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 370 s->reconnect_delay * NANOSECONDS_PER_SECOND); 371 } 372 373 /* 374 * Now we are sure that nobody is accessing the channel, and no one will 375 * try until we set the state to CONNECTED. 376 */ 377 378 /* Finalize previous connection if any */ 379 if (s->ioc) { 380 qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); 381 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 382 nbd_yank, s->bs); 383 object_unref(OBJECT(s->ioc)); 384 s->ioc = NULL; 385 } 386 387 nbd_co_do_establish_connection(s->bs, NULL); 388 389 /* 390 * The reconnect attempt is done (maybe successfully, maybe not), so 391 * we no longer need this timer. Delete it so it will not outlive 392 * this I/O request (so draining removes all timers). 393 */ 394 reconnect_delay_timer_del(s); 395 } 396 397 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle) 398 { 399 int ret; 400 uint64_t ind = HANDLE_TO_INDEX(s, handle), ind2; 401 QEMU_LOCK_GUARD(&s->receive_mutex); 402 403 while (true) { 404 if (s->reply.handle == handle) { 405 /* We are done */ 406 return 0; 407 } 408 409 if (!nbd_client_connected(s)) { 410 return -EIO; 411 } 412 413 if (s->reply.handle != 0) { 414 /* 415 * Some other request is being handled now. It should already be 416 * woken by whoever set s->reply.handle (or never wait in this 417 * yield). So, we should not wake it here. 418 */ 419 ind2 = HANDLE_TO_INDEX(s, s->reply.handle); 420 assert(!s->requests[ind2].receiving); 421 422 s->requests[ind].receiving = true; 423 qemu_co_mutex_unlock(&s->receive_mutex); 424 425 qemu_coroutine_yield(); 426 /* 427 * We may be woken for 3 reasons: 428 * 1. From this function, executing in parallel coroutine, when our 429 * handle is received. 430 * 2. From nbd_channel_error(), when connection is lost. 431 * 3. From nbd_co_receive_one_chunk(), when previous request is 432 * finished and s->reply.handle set to 0. 433 * Anyway, it's OK to lock the mutex and go to the next iteration. 434 */ 435 436 qemu_co_mutex_lock(&s->receive_mutex); 437 assert(!s->requests[ind].receiving); 438 continue; 439 } 440 441 /* We are under mutex and handle is 0. We have to do the dirty work. */ 442 assert(s->reply.handle == 0); 443 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, NULL); 444 if (ret <= 0) { 445 ret = ret ? ret : -EIO; 446 nbd_channel_error(s, ret); 447 return ret; 448 } 449 if (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply) { 450 nbd_channel_error(s, -EINVAL); 451 return -EINVAL; 452 } 453 if (s->reply.handle == handle) { 454 /* We are done */ 455 return 0; 456 } 457 ind2 = HANDLE_TO_INDEX(s, s->reply.handle); 458 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].reply_possible) { 459 nbd_channel_error(s, -EINVAL); 460 return -EINVAL; 461 } 462 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 463 } 464 } 465 466 static int nbd_co_send_request(BlockDriverState *bs, 467 NBDRequest *request, 468 QEMUIOVector *qiov) 469 { 470 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 471 int rc, i = -1; 472 473 qemu_co_mutex_lock(&s->send_mutex); 474 475 while (s->in_flight == MAX_NBD_REQUESTS || 476 (!nbd_client_connected(s) && s->in_flight > 0)) 477 { 478 qemu_co_queue_wait(&s->free_sema, &s->send_mutex); 479 } 480 481 if (nbd_client_connecting(s)) { 482 nbd_reconnect_attempt(s); 483 } 484 485 if (!nbd_client_connected(s)) { 486 rc = -EIO; 487 goto err; 488 } 489 490 s->in_flight++; 491 492 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 493 if (s->requests[i].coroutine == NULL) { 494 break; 495 } 496 } 497 498 g_assert(qemu_in_coroutine()); 499 assert(i < MAX_NBD_REQUESTS); 500 501 s->requests[i].coroutine = qemu_coroutine_self(); 502 s->requests[i].offset = request->from; 503 s->requests[i].receiving = false; 504 s->requests[i].reply_possible = true; 505 506 request->handle = INDEX_TO_HANDLE(s, i); 507 508 assert(s->ioc); 509 510 if (qiov) { 511 qio_channel_set_cork(s->ioc, true); 512 rc = nbd_send_request(s->ioc, request); 513 if (nbd_client_connected(s) && rc >= 0) { 514 if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 515 NULL) < 0) { 516 rc = -EIO; 517 } 518 } else if (rc >= 0) { 519 rc = -EIO; 520 } 521 qio_channel_set_cork(s->ioc, false); 522 } else { 523 rc = nbd_send_request(s->ioc, request); 524 } 525 526 err: 527 if (rc < 0) { 528 nbd_channel_error(s, rc); 529 if (i != -1) { 530 s->requests[i].coroutine = NULL; 531 s->in_flight--; 532 qemu_co_queue_next(&s->free_sema); 533 } 534 } 535 qemu_co_mutex_unlock(&s->send_mutex); 536 return rc; 537 } 538 539 static inline uint16_t payload_advance16(uint8_t **payload) 540 { 541 *payload += 2; 542 return lduw_be_p(*payload - 2); 543 } 544 545 static inline uint32_t payload_advance32(uint8_t **payload) 546 { 547 *payload += 4; 548 return ldl_be_p(*payload - 4); 549 } 550 551 static inline uint64_t payload_advance64(uint8_t **payload) 552 { 553 *payload += 8; 554 return ldq_be_p(*payload - 8); 555 } 556 557 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 558 NBDStructuredReplyChunk *chunk, 559 uint8_t *payload, uint64_t orig_offset, 560 QEMUIOVector *qiov, Error **errp) 561 { 562 uint64_t offset; 563 uint32_t hole_size; 564 565 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 566 error_setg(errp, "Protocol error: invalid payload for " 567 "NBD_REPLY_TYPE_OFFSET_HOLE"); 568 return -EINVAL; 569 } 570 571 offset = payload_advance64(&payload); 572 hole_size = payload_advance32(&payload); 573 574 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 575 offset > orig_offset + qiov->size - hole_size) { 576 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 577 " region"); 578 return -EINVAL; 579 } 580 if (s->info.min_block && 581 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 582 trace_nbd_structured_read_compliance("hole"); 583 } 584 585 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 586 587 return 0; 588 } 589 590 /* 591 * nbd_parse_blockstatus_payload 592 * Based on our request, we expect only one extent in reply, for the 593 * base:allocation context. 594 */ 595 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 596 NBDStructuredReplyChunk *chunk, 597 uint8_t *payload, uint64_t orig_length, 598 NBDExtent *extent, Error **errp) 599 { 600 uint32_t context_id; 601 602 /* The server succeeded, so it must have sent [at least] one extent */ 603 if (chunk->length < sizeof(context_id) + sizeof(*extent)) { 604 error_setg(errp, "Protocol error: invalid payload for " 605 "NBD_REPLY_TYPE_BLOCK_STATUS"); 606 return -EINVAL; 607 } 608 609 context_id = payload_advance32(&payload); 610 if (s->info.context_id != context_id) { 611 error_setg(errp, "Protocol error: unexpected context id %d for " 612 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 613 "id is %d", context_id, 614 s->info.context_id); 615 return -EINVAL; 616 } 617 618 extent->length = payload_advance32(&payload); 619 extent->flags = payload_advance32(&payload); 620 621 if (extent->length == 0) { 622 error_setg(errp, "Protocol error: server sent status chunk with " 623 "zero length"); 624 return -EINVAL; 625 } 626 627 /* 628 * A server sending unaligned block status is in violation of the 629 * protocol, but as qemu-nbd 3.1 is such a server (at least for 630 * POSIX files that are not a multiple of 512 bytes, since qemu 631 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 632 * still sees an implicit hole beyond the real EOF), it's nicer to 633 * work around the misbehaving server. If the request included 634 * more than the final unaligned block, truncate it back to an 635 * aligned result; if the request was only the final block, round 636 * up to the full block and change the status to fully-allocated 637 * (always a safe status, even if it loses information). 638 */ 639 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 640 s->info.min_block)) { 641 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 642 if (extent->length > s->info.min_block) { 643 extent->length = QEMU_ALIGN_DOWN(extent->length, 644 s->info.min_block); 645 } else { 646 extent->length = s->info.min_block; 647 extent->flags = 0; 648 } 649 } 650 651 /* 652 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 653 * sent us any more than one extent, nor should it have included 654 * status beyond our request in that extent. However, it's easy 655 * enough to ignore the server's noncompliance without killing the 656 * connection; just ignore trailing extents, and clamp things to 657 * the length of our request. 658 */ 659 if (chunk->length > sizeof(context_id) + sizeof(*extent)) { 660 trace_nbd_parse_blockstatus_compliance("more than one extent"); 661 } 662 if (extent->length > orig_length) { 663 extent->length = orig_length; 664 trace_nbd_parse_blockstatus_compliance("extent length too large"); 665 } 666 667 /* 668 * HACK: if we are using x-dirty-bitmaps to access 669 * qemu:allocation-depth, treat all depths > 2 the same as 2, 670 * since nbd_client_co_block_status is only expecting the low two 671 * bits to be set. 672 */ 673 if (s->alloc_depth && extent->flags > 2) { 674 extent->flags = 2; 675 } 676 677 return 0; 678 } 679 680 /* 681 * nbd_parse_error_payload 682 * on success @errp contains message describing nbd error reply 683 */ 684 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 685 uint8_t *payload, int *request_ret, 686 Error **errp) 687 { 688 uint32_t error; 689 uint16_t message_size; 690 691 assert(chunk->type & (1 << 15)); 692 693 if (chunk->length < sizeof(error) + sizeof(message_size)) { 694 error_setg(errp, 695 "Protocol error: invalid payload for structured error"); 696 return -EINVAL; 697 } 698 699 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 700 if (error == 0) { 701 error_setg(errp, "Protocol error: server sent structured error chunk " 702 "with error = 0"); 703 return -EINVAL; 704 } 705 706 *request_ret = -error; 707 message_size = payload_advance16(&payload); 708 709 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 710 error_setg(errp, "Protocol error: server sent structured error chunk " 711 "with incorrect message size"); 712 return -EINVAL; 713 } 714 715 /* TODO: Add a trace point to mention the server complaint */ 716 717 /* TODO handle ERROR_OFFSET */ 718 719 return 0; 720 } 721 722 static int nbd_co_receive_offset_data_payload(BDRVNBDState *s, 723 uint64_t orig_offset, 724 QEMUIOVector *qiov, Error **errp) 725 { 726 QEMUIOVector sub_qiov; 727 uint64_t offset; 728 size_t data_size; 729 int ret; 730 NBDStructuredReplyChunk *chunk = &s->reply.structured; 731 732 assert(nbd_reply_is_structured(&s->reply)); 733 734 /* The NBD spec requires at least one byte of payload */ 735 if (chunk->length <= sizeof(offset)) { 736 error_setg(errp, "Protocol error: invalid payload for " 737 "NBD_REPLY_TYPE_OFFSET_DATA"); 738 return -EINVAL; 739 } 740 741 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 742 return -EIO; 743 } 744 745 data_size = chunk->length - sizeof(offset); 746 assert(data_size); 747 if (offset < orig_offset || data_size > qiov->size || 748 offset > orig_offset + qiov->size - data_size) { 749 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 750 " region"); 751 return -EINVAL; 752 } 753 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 754 trace_nbd_structured_read_compliance("data"); 755 } 756 757 qemu_iovec_init(&sub_qiov, qiov->niov); 758 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 759 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 760 qemu_iovec_destroy(&sub_qiov); 761 762 return ret < 0 ? -EIO : 0; 763 } 764 765 #define NBD_MAX_MALLOC_PAYLOAD 1000 766 static coroutine_fn int nbd_co_receive_structured_payload( 767 BDRVNBDState *s, void **payload, Error **errp) 768 { 769 int ret; 770 uint32_t len; 771 772 assert(nbd_reply_is_structured(&s->reply)); 773 774 len = s->reply.structured.length; 775 776 if (len == 0) { 777 return 0; 778 } 779 780 if (payload == NULL) { 781 error_setg(errp, "Unexpected structured payload"); 782 return -EINVAL; 783 } 784 785 if (len > NBD_MAX_MALLOC_PAYLOAD) { 786 error_setg(errp, "Payload too large"); 787 return -EINVAL; 788 } 789 790 *payload = g_new(char, len); 791 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 792 if (ret < 0) { 793 g_free(*payload); 794 *payload = NULL; 795 return ret; 796 } 797 798 return 0; 799 } 800 801 /* 802 * nbd_co_do_receive_one_chunk 803 * for simple reply: 804 * set request_ret to received reply error 805 * if qiov is not NULL: read payload to @qiov 806 * for structured reply chunk: 807 * if error chunk: read payload, set @request_ret, do not set @payload 808 * else if offset_data chunk: read payload data to @qiov, do not set @payload 809 * else: read payload to @payload 810 * 811 * If function fails, @errp contains corresponding error message, and the 812 * connection with the server is suspect. If it returns 0, then the 813 * transaction succeeded (although @request_ret may be a negative errno 814 * corresponding to the server's error reply), and errp is unchanged. 815 */ 816 static coroutine_fn int nbd_co_do_receive_one_chunk( 817 BDRVNBDState *s, uint64_t handle, bool only_structured, 818 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 819 { 820 int ret; 821 int i = HANDLE_TO_INDEX(s, handle); 822 void *local_payload = NULL; 823 NBDStructuredReplyChunk *chunk; 824 825 if (payload) { 826 *payload = NULL; 827 } 828 *request_ret = 0; 829 830 nbd_receive_replies(s, handle); 831 if (!nbd_client_connected(s)) { 832 error_setg(errp, "Connection closed"); 833 return -EIO; 834 } 835 assert(s->ioc); 836 837 assert(s->reply.handle == handle); 838 839 if (nbd_reply_is_simple(&s->reply)) { 840 if (only_structured) { 841 error_setg(errp, "Protocol error: simple reply when structured " 842 "reply chunk was expected"); 843 return -EINVAL; 844 } 845 846 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 847 if (*request_ret < 0 || !qiov) { 848 return 0; 849 } 850 851 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 852 errp) < 0 ? -EIO : 0; 853 } 854 855 /* handle structured reply chunk */ 856 assert(s->info.structured_reply); 857 chunk = &s->reply.structured; 858 859 if (chunk->type == NBD_REPLY_TYPE_NONE) { 860 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 861 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 862 " NBD_REPLY_FLAG_DONE flag set"); 863 return -EINVAL; 864 } 865 if (chunk->length) { 866 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 867 " nonzero length"); 868 return -EINVAL; 869 } 870 return 0; 871 } 872 873 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 874 if (!qiov) { 875 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 876 return -EINVAL; 877 } 878 879 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 880 qiov, errp); 881 } 882 883 if (nbd_reply_type_is_error(chunk->type)) { 884 payload = &local_payload; 885 } 886 887 ret = nbd_co_receive_structured_payload(s, payload, errp); 888 if (ret < 0) { 889 return ret; 890 } 891 892 if (nbd_reply_type_is_error(chunk->type)) { 893 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 894 g_free(local_payload); 895 return ret; 896 } 897 898 return 0; 899 } 900 901 /* 902 * nbd_co_receive_one_chunk 903 * Read reply, wake up connection_co and set s->quit if needed. 904 * Return value is a fatal error code or normal nbd reply error code 905 */ 906 static coroutine_fn int nbd_co_receive_one_chunk( 907 BDRVNBDState *s, uint64_t handle, bool only_structured, 908 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 909 Error **errp) 910 { 911 int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured, 912 request_ret, qiov, payload, errp); 913 914 if (ret < 0) { 915 memset(reply, 0, sizeof(*reply)); 916 nbd_channel_error(s, ret); 917 } else { 918 /* For assert at loop start in nbd_connection_entry */ 919 *reply = s->reply; 920 } 921 s->reply.handle = 0; 922 923 nbd_recv_coroutines_wake(s, false); 924 925 return ret; 926 } 927 928 typedef struct NBDReplyChunkIter { 929 int ret; 930 int request_ret; 931 Error *err; 932 bool done, only_structured; 933 } NBDReplyChunkIter; 934 935 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 936 int ret, Error **local_err) 937 { 938 assert(local_err && *local_err); 939 assert(ret < 0); 940 941 if (!iter->ret) { 942 iter->ret = ret; 943 error_propagate(&iter->err, *local_err); 944 } else { 945 error_free(*local_err); 946 } 947 948 *local_err = NULL; 949 } 950 951 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 952 { 953 assert(ret < 0); 954 955 if (!iter->request_ret) { 956 iter->request_ret = ret; 957 } 958 } 959 960 /* 961 * NBD_FOREACH_REPLY_CHUNK 962 * The pointer stored in @payload requires g_free() to free it. 963 */ 964 #define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \ 965 qiov, reply, payload) \ 966 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 967 nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);) 968 969 /* 970 * nbd_reply_chunk_iter_receive 971 * The pointer stored in @payload requires g_free() to free it. 972 */ 973 static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, 974 NBDReplyChunkIter *iter, 975 uint64_t handle, 976 QEMUIOVector *qiov, NBDReply *reply, 977 void **payload) 978 { 979 int ret, request_ret; 980 NBDReply local_reply; 981 NBDStructuredReplyChunk *chunk; 982 Error *local_err = NULL; 983 if (!nbd_client_connected(s)) { 984 error_setg(&local_err, "Connection closed"); 985 nbd_iter_channel_error(iter, -EIO, &local_err); 986 goto break_loop; 987 } 988 989 if (iter->done) { 990 /* Previous iteration was last. */ 991 goto break_loop; 992 } 993 994 if (reply == NULL) { 995 reply = &local_reply; 996 } 997 998 ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured, 999 &request_ret, qiov, reply, payload, 1000 &local_err); 1001 if (ret < 0) { 1002 nbd_iter_channel_error(iter, ret, &local_err); 1003 } else if (request_ret < 0) { 1004 nbd_iter_request_error(iter, request_ret); 1005 } 1006 1007 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1008 if (nbd_reply_is_simple(reply) || !nbd_client_connected(s)) { 1009 goto break_loop; 1010 } 1011 1012 chunk = &reply->structured; 1013 iter->only_structured = true; 1014 1015 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1016 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1017 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1018 goto break_loop; 1019 } 1020 1021 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1022 /* This iteration is last. */ 1023 iter->done = true; 1024 } 1025 1026 /* Execute the loop body */ 1027 return true; 1028 1029 break_loop: 1030 s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL; 1031 1032 qemu_co_mutex_lock(&s->send_mutex); 1033 s->in_flight--; 1034 qemu_co_queue_next(&s->free_sema); 1035 qemu_co_mutex_unlock(&s->send_mutex); 1036 1037 return false; 1038 } 1039 1040 static int nbd_co_receive_return_code(BDRVNBDState *s, uint64_t handle, 1041 int *request_ret, Error **errp) 1042 { 1043 NBDReplyChunkIter iter; 1044 1045 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) { 1046 /* nbd_reply_chunk_iter_receive does all the work */ 1047 } 1048 1049 error_propagate(errp, iter.err); 1050 *request_ret = iter.request_ret; 1051 return iter.ret; 1052 } 1053 1054 static int nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t handle, 1055 uint64_t offset, QEMUIOVector *qiov, 1056 int *request_ret, Error **errp) 1057 { 1058 NBDReplyChunkIter iter; 1059 NBDReply reply; 1060 void *payload = NULL; 1061 Error *local_err = NULL; 1062 1063 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, 1064 qiov, &reply, &payload) 1065 { 1066 int ret; 1067 NBDStructuredReplyChunk *chunk = &reply.structured; 1068 1069 assert(nbd_reply_is_structured(&reply)); 1070 1071 switch (chunk->type) { 1072 case NBD_REPLY_TYPE_OFFSET_DATA: 1073 /* 1074 * special cased in nbd_co_receive_one_chunk, data is already 1075 * in qiov 1076 */ 1077 break; 1078 case NBD_REPLY_TYPE_OFFSET_HOLE: 1079 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1080 offset, qiov, &local_err); 1081 if (ret < 0) { 1082 nbd_channel_error(s, ret); 1083 nbd_iter_channel_error(&iter, ret, &local_err); 1084 } 1085 break; 1086 default: 1087 if (!nbd_reply_type_is_error(chunk->type)) { 1088 /* not allowed reply type */ 1089 nbd_channel_error(s, -EINVAL); 1090 error_setg(&local_err, 1091 "Unexpected reply type: %d (%s) for CMD_READ", 1092 chunk->type, nbd_reply_type_lookup(chunk->type)); 1093 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1094 } 1095 } 1096 1097 g_free(payload); 1098 payload = NULL; 1099 } 1100 1101 error_propagate(errp, iter.err); 1102 *request_ret = iter.request_ret; 1103 return iter.ret; 1104 } 1105 1106 static int nbd_co_receive_blockstatus_reply(BDRVNBDState *s, 1107 uint64_t handle, uint64_t length, 1108 NBDExtent *extent, 1109 int *request_ret, Error **errp) 1110 { 1111 NBDReplyChunkIter iter; 1112 NBDReply reply; 1113 void *payload = NULL; 1114 Error *local_err = NULL; 1115 bool received = false; 1116 1117 assert(!extent->length); 1118 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { 1119 int ret; 1120 NBDStructuredReplyChunk *chunk = &reply.structured; 1121 1122 assert(nbd_reply_is_structured(&reply)); 1123 1124 switch (chunk->type) { 1125 case NBD_REPLY_TYPE_BLOCK_STATUS: 1126 if (received) { 1127 nbd_channel_error(s, -EINVAL); 1128 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1129 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1130 } 1131 received = true; 1132 1133 ret = nbd_parse_blockstatus_payload(s, &reply.structured, 1134 payload, length, extent, 1135 &local_err); 1136 if (ret < 0) { 1137 nbd_channel_error(s, ret); 1138 nbd_iter_channel_error(&iter, ret, &local_err); 1139 } 1140 break; 1141 default: 1142 if (!nbd_reply_type_is_error(chunk->type)) { 1143 nbd_channel_error(s, -EINVAL); 1144 error_setg(&local_err, 1145 "Unexpected reply type: %d (%s) " 1146 "for CMD_BLOCK_STATUS", 1147 chunk->type, nbd_reply_type_lookup(chunk->type)); 1148 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1149 } 1150 } 1151 1152 g_free(payload); 1153 payload = NULL; 1154 } 1155 1156 if (!extent->length && !iter.request_ret) { 1157 error_setg(&local_err, "Server did not reply with any status extents"); 1158 nbd_iter_channel_error(&iter, -EIO, &local_err); 1159 } 1160 1161 error_propagate(errp, iter.err); 1162 *request_ret = iter.request_ret; 1163 return iter.ret; 1164 } 1165 1166 static int nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1167 QEMUIOVector *write_qiov) 1168 { 1169 int ret, request_ret; 1170 Error *local_err = NULL; 1171 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1172 1173 assert(request->type != NBD_CMD_READ); 1174 if (write_qiov) { 1175 assert(request->type == NBD_CMD_WRITE); 1176 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1177 } else { 1178 assert(request->type != NBD_CMD_WRITE); 1179 } 1180 1181 do { 1182 ret = nbd_co_send_request(bs, request, write_qiov); 1183 if (ret < 0) { 1184 continue; 1185 } 1186 1187 ret = nbd_co_receive_return_code(s, request->handle, 1188 &request_ret, &local_err); 1189 if (local_err) { 1190 trace_nbd_co_request_fail(request->from, request->len, 1191 request->handle, request->flags, 1192 request->type, 1193 nbd_cmd_lookup(request->type), 1194 ret, error_get_pretty(local_err)); 1195 error_free(local_err); 1196 local_err = NULL; 1197 } 1198 } while (ret < 0 && nbd_client_connecting_wait(s)); 1199 1200 return ret ? ret : request_ret; 1201 } 1202 1203 static int nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, 1204 int64_t bytes, QEMUIOVector *qiov, 1205 BdrvRequestFlags flags) 1206 { 1207 int ret, request_ret; 1208 Error *local_err = NULL; 1209 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1210 NBDRequest request = { 1211 .type = NBD_CMD_READ, 1212 .from = offset, 1213 .len = bytes, 1214 }; 1215 1216 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1217 assert(!flags); 1218 1219 if (!bytes) { 1220 return 0; 1221 } 1222 /* 1223 * Work around the fact that the block layer doesn't do 1224 * byte-accurate sizing yet - if the read exceeds the server's 1225 * advertised size because the block layer rounded size up, then 1226 * truncate the request to the server and tail-pad with zero. 1227 */ 1228 if (offset >= s->info.size) { 1229 assert(bytes < BDRV_SECTOR_SIZE); 1230 qemu_iovec_memset(qiov, 0, 0, bytes); 1231 return 0; 1232 } 1233 if (offset + bytes > s->info.size) { 1234 uint64_t slop = offset + bytes - s->info.size; 1235 1236 assert(slop < BDRV_SECTOR_SIZE); 1237 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1238 request.len -= slop; 1239 } 1240 1241 do { 1242 ret = nbd_co_send_request(bs, &request, NULL); 1243 if (ret < 0) { 1244 continue; 1245 } 1246 1247 ret = nbd_co_receive_cmdread_reply(s, request.handle, offset, qiov, 1248 &request_ret, &local_err); 1249 if (local_err) { 1250 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1251 request.flags, request.type, 1252 nbd_cmd_lookup(request.type), 1253 ret, error_get_pretty(local_err)); 1254 error_free(local_err); 1255 local_err = NULL; 1256 } 1257 } while (ret < 0 && nbd_client_connecting_wait(s)); 1258 1259 return ret ? ret : request_ret; 1260 } 1261 1262 static int nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, 1263 int64_t bytes, QEMUIOVector *qiov, 1264 BdrvRequestFlags flags) 1265 { 1266 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1267 NBDRequest request = { 1268 .type = NBD_CMD_WRITE, 1269 .from = offset, 1270 .len = bytes, 1271 }; 1272 1273 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1274 if (flags & BDRV_REQ_FUA) { 1275 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1276 request.flags |= NBD_CMD_FLAG_FUA; 1277 } 1278 1279 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1280 1281 if (!bytes) { 1282 return 0; 1283 } 1284 return nbd_co_request(bs, &request, qiov); 1285 } 1286 1287 static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, 1288 int64_t bytes, BdrvRequestFlags flags) 1289 { 1290 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1291 NBDRequest request = { 1292 .type = NBD_CMD_WRITE_ZEROES, 1293 .from = offset, 1294 .len = bytes, /* .len is uint32_t actually */ 1295 }; 1296 1297 assert(bytes <= UINT32_MAX); /* rely on max_pwrite_zeroes */ 1298 1299 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1300 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1301 return -ENOTSUP; 1302 } 1303 1304 if (flags & BDRV_REQ_FUA) { 1305 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1306 request.flags |= NBD_CMD_FLAG_FUA; 1307 } 1308 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1309 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1310 } 1311 if (flags & BDRV_REQ_NO_FALLBACK) { 1312 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1313 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1314 } 1315 1316 if (!bytes) { 1317 return 0; 1318 } 1319 return nbd_co_request(bs, &request, NULL); 1320 } 1321 1322 static int nbd_client_co_flush(BlockDriverState *bs) 1323 { 1324 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1325 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1326 1327 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1328 return 0; 1329 } 1330 1331 request.from = 0; 1332 request.len = 0; 1333 1334 return nbd_co_request(bs, &request, NULL); 1335 } 1336 1337 static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, 1338 int64_t bytes) 1339 { 1340 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1341 NBDRequest request = { 1342 .type = NBD_CMD_TRIM, 1343 .from = offset, 1344 .len = bytes, /* len is uint32_t */ 1345 }; 1346 1347 assert(bytes <= UINT32_MAX); /* rely on max_pdiscard */ 1348 1349 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1350 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1351 return 0; 1352 } 1353 1354 return nbd_co_request(bs, &request, NULL); 1355 } 1356 1357 static int coroutine_fn nbd_client_co_block_status( 1358 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1359 int64_t *pnum, int64_t *map, BlockDriverState **file) 1360 { 1361 int ret, request_ret; 1362 NBDExtent extent = { 0 }; 1363 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1364 Error *local_err = NULL; 1365 1366 NBDRequest request = { 1367 .type = NBD_CMD_BLOCK_STATUS, 1368 .from = offset, 1369 .len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1370 MIN(bytes, s->info.size - offset)), 1371 .flags = NBD_CMD_FLAG_REQ_ONE, 1372 }; 1373 1374 if (!s->info.base_allocation) { 1375 *pnum = bytes; 1376 *map = offset; 1377 *file = bs; 1378 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1379 } 1380 1381 /* 1382 * Work around the fact that the block layer doesn't do 1383 * byte-accurate sizing yet - if the status request exceeds the 1384 * server's advertised size because the block layer rounded size 1385 * up, we truncated the request to the server (above), or are 1386 * called on just the hole. 1387 */ 1388 if (offset >= s->info.size) { 1389 *pnum = bytes; 1390 assert(bytes < BDRV_SECTOR_SIZE); 1391 /* Intentionally don't report offset_valid for the hole */ 1392 return BDRV_BLOCK_ZERO; 1393 } 1394 1395 if (s->info.min_block) { 1396 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1397 } 1398 do { 1399 ret = nbd_co_send_request(bs, &request, NULL); 1400 if (ret < 0) { 1401 continue; 1402 } 1403 1404 ret = nbd_co_receive_blockstatus_reply(s, request.handle, bytes, 1405 &extent, &request_ret, 1406 &local_err); 1407 if (local_err) { 1408 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1409 request.flags, request.type, 1410 nbd_cmd_lookup(request.type), 1411 ret, error_get_pretty(local_err)); 1412 error_free(local_err); 1413 local_err = NULL; 1414 } 1415 } while (ret < 0 && nbd_client_connecting_wait(s)); 1416 1417 if (ret < 0 || request_ret < 0) { 1418 return ret ? ret : request_ret; 1419 } 1420 1421 assert(extent.length); 1422 *pnum = extent.length; 1423 *map = offset; 1424 *file = bs; 1425 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1426 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1427 BDRV_BLOCK_OFFSET_VALID; 1428 } 1429 1430 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1431 BlockReopenQueue *queue, Error **errp) 1432 { 1433 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1434 1435 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1436 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1437 return -EACCES; 1438 } 1439 return 0; 1440 } 1441 1442 static void nbd_yank(void *opaque) 1443 { 1444 BlockDriverState *bs = opaque; 1445 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1446 1447 qatomic_store_release(&s->state, NBD_CLIENT_QUIT); 1448 qio_channel_shutdown(QIO_CHANNEL(s->ioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1449 } 1450 1451 static void nbd_client_close(BlockDriverState *bs) 1452 { 1453 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1454 NBDRequest request = { .type = NBD_CMD_DISC }; 1455 1456 if (s->ioc) { 1457 nbd_send_request(s->ioc, &request); 1458 } 1459 1460 nbd_teardown_connection(bs); 1461 } 1462 1463 1464 /* 1465 * Parse nbd_open options 1466 */ 1467 1468 static int nbd_parse_uri(const char *filename, QDict *options) 1469 { 1470 URI *uri; 1471 const char *p; 1472 QueryParams *qp = NULL; 1473 int ret = 0; 1474 bool is_unix; 1475 1476 uri = uri_parse(filename); 1477 if (!uri) { 1478 return -EINVAL; 1479 } 1480 1481 /* transport */ 1482 if (!g_strcmp0(uri->scheme, "nbd")) { 1483 is_unix = false; 1484 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1485 is_unix = false; 1486 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1487 is_unix = true; 1488 } else { 1489 ret = -EINVAL; 1490 goto out; 1491 } 1492 1493 p = uri->path ? uri->path : ""; 1494 if (p[0] == '/') { 1495 p++; 1496 } 1497 if (p[0]) { 1498 qdict_put_str(options, "export", p); 1499 } 1500 1501 qp = query_params_parse(uri->query); 1502 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1503 ret = -EINVAL; 1504 goto out; 1505 } 1506 1507 if (is_unix) { 1508 /* nbd+unix:///export?socket=path */ 1509 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1510 ret = -EINVAL; 1511 goto out; 1512 } 1513 qdict_put_str(options, "server.type", "unix"); 1514 qdict_put_str(options, "server.path", qp->p[0].value); 1515 } else { 1516 QString *host; 1517 char *port_str; 1518 1519 /* nbd[+tcp]://host[:port]/export */ 1520 if (!uri->server) { 1521 ret = -EINVAL; 1522 goto out; 1523 } 1524 1525 /* strip braces from literal IPv6 address */ 1526 if (uri->server[0] == '[') { 1527 host = qstring_from_substr(uri->server, 1, 1528 strlen(uri->server) - 1); 1529 } else { 1530 host = qstring_from_str(uri->server); 1531 } 1532 1533 qdict_put_str(options, "server.type", "inet"); 1534 qdict_put(options, "server.host", host); 1535 1536 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1537 qdict_put_str(options, "server.port", port_str); 1538 g_free(port_str); 1539 } 1540 1541 out: 1542 if (qp) { 1543 query_params_free(qp); 1544 } 1545 uri_free(uri); 1546 return ret; 1547 } 1548 1549 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1550 { 1551 const QDictEntry *e; 1552 1553 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1554 if (!strcmp(e->key, "host") || 1555 !strcmp(e->key, "port") || 1556 !strcmp(e->key, "path") || 1557 !strcmp(e->key, "export") || 1558 strstart(e->key, "server.", NULL)) 1559 { 1560 error_setg(errp, "Option '%s' cannot be used with a file name", 1561 e->key); 1562 return true; 1563 } 1564 } 1565 1566 return false; 1567 } 1568 1569 static void nbd_parse_filename(const char *filename, QDict *options, 1570 Error **errp) 1571 { 1572 g_autofree char *file = NULL; 1573 char *export_name; 1574 const char *host_spec; 1575 const char *unixpath; 1576 1577 if (nbd_has_filename_options_conflict(options, errp)) { 1578 return; 1579 } 1580 1581 if (strstr(filename, "://")) { 1582 int ret = nbd_parse_uri(filename, options); 1583 if (ret < 0) { 1584 error_setg(errp, "No valid URL specified"); 1585 } 1586 return; 1587 } 1588 1589 file = g_strdup(filename); 1590 1591 export_name = strstr(file, EN_OPTSTR); 1592 if (export_name) { 1593 if (export_name[strlen(EN_OPTSTR)] == 0) { 1594 return; 1595 } 1596 export_name[0] = 0; /* truncate 'file' */ 1597 export_name += strlen(EN_OPTSTR); 1598 1599 qdict_put_str(options, "export", export_name); 1600 } 1601 1602 /* extract the host_spec - fail if it's not nbd:... */ 1603 if (!strstart(file, "nbd:", &host_spec)) { 1604 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1605 return; 1606 } 1607 1608 if (!*host_spec) { 1609 return; 1610 } 1611 1612 /* are we a UNIX or TCP socket? */ 1613 if (strstart(host_spec, "unix:", &unixpath)) { 1614 qdict_put_str(options, "server.type", "unix"); 1615 qdict_put_str(options, "server.path", unixpath); 1616 } else { 1617 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1618 1619 if (inet_parse(addr, host_spec, errp)) { 1620 goto out_inet; 1621 } 1622 1623 qdict_put_str(options, "server.type", "inet"); 1624 qdict_put_str(options, "server.host", addr->host); 1625 qdict_put_str(options, "server.port", addr->port); 1626 out_inet: 1627 qapi_free_InetSocketAddress(addr); 1628 } 1629 } 1630 1631 static bool nbd_process_legacy_socket_options(QDict *output_options, 1632 QemuOpts *legacy_opts, 1633 Error **errp) 1634 { 1635 const char *path = qemu_opt_get(legacy_opts, "path"); 1636 const char *host = qemu_opt_get(legacy_opts, "host"); 1637 const char *port = qemu_opt_get(legacy_opts, "port"); 1638 const QDictEntry *e; 1639 1640 if (!path && !host && !port) { 1641 return true; 1642 } 1643 1644 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1645 { 1646 if (strstart(e->key, "server.", NULL)) { 1647 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1648 "same time"); 1649 return false; 1650 } 1651 } 1652 1653 if (path && host) { 1654 error_setg(errp, "path and host may not be used at the same time"); 1655 return false; 1656 } else if (path) { 1657 if (port) { 1658 error_setg(errp, "port may not be used without host"); 1659 return false; 1660 } 1661 1662 qdict_put_str(output_options, "server.type", "unix"); 1663 qdict_put_str(output_options, "server.path", path); 1664 } else if (host) { 1665 qdict_put_str(output_options, "server.type", "inet"); 1666 qdict_put_str(output_options, "server.host", host); 1667 qdict_put_str(output_options, "server.port", 1668 port ?: stringify(NBD_DEFAULT_PORT)); 1669 } 1670 1671 return true; 1672 } 1673 1674 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1675 Error **errp) 1676 { 1677 SocketAddress *saddr = NULL; 1678 QDict *addr = NULL; 1679 Visitor *iv = NULL; 1680 1681 qdict_extract_subqdict(options, &addr, "server."); 1682 if (!qdict_size(addr)) { 1683 error_setg(errp, "NBD server address missing"); 1684 goto done; 1685 } 1686 1687 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1688 if (!iv) { 1689 goto done; 1690 } 1691 1692 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1693 goto done; 1694 } 1695 1696 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1697 qapi_free_SocketAddress(saddr); 1698 saddr = NULL; 1699 goto done; 1700 } 1701 1702 done: 1703 qobject_unref(addr); 1704 visit_free(iv); 1705 return saddr; 1706 } 1707 1708 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1709 { 1710 Object *obj; 1711 QCryptoTLSCreds *creds; 1712 1713 obj = object_resolve_path_component( 1714 object_get_objects_root(), id); 1715 if (!obj) { 1716 error_setg(errp, "No TLS credentials with id '%s'", 1717 id); 1718 return NULL; 1719 } 1720 creds = (QCryptoTLSCreds *) 1721 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1722 if (!creds) { 1723 error_setg(errp, "Object with id '%s' is not TLS credentials", 1724 id); 1725 return NULL; 1726 } 1727 1728 if (!qcrypto_tls_creds_check_endpoint(creds, 1729 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1730 errp)) { 1731 return NULL; 1732 } 1733 object_ref(obj); 1734 return creds; 1735 } 1736 1737 1738 static QemuOptsList nbd_runtime_opts = { 1739 .name = "nbd", 1740 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1741 .desc = { 1742 { 1743 .name = "host", 1744 .type = QEMU_OPT_STRING, 1745 .help = "TCP host to connect to", 1746 }, 1747 { 1748 .name = "port", 1749 .type = QEMU_OPT_STRING, 1750 .help = "TCP port to connect to", 1751 }, 1752 { 1753 .name = "path", 1754 .type = QEMU_OPT_STRING, 1755 .help = "Unix socket path to connect to", 1756 }, 1757 { 1758 .name = "export", 1759 .type = QEMU_OPT_STRING, 1760 .help = "Name of the NBD export to open", 1761 }, 1762 { 1763 .name = "tls-creds", 1764 .type = QEMU_OPT_STRING, 1765 .help = "ID of the TLS credentials to use", 1766 }, 1767 { 1768 .name = "x-dirty-bitmap", 1769 .type = QEMU_OPT_STRING, 1770 .help = "experimental: expose named dirty bitmap in place of " 1771 "block status", 1772 }, 1773 { 1774 .name = "reconnect-delay", 1775 .type = QEMU_OPT_NUMBER, 1776 .help = "On an unexpected disconnect, the nbd client tries to " 1777 "connect again until succeeding or encountering a serious " 1778 "error. During the first @reconnect-delay seconds, all " 1779 "requests are paused and will be rerun on a successful " 1780 "reconnect. After that time, any delayed requests and all " 1781 "future requests before a successful reconnect will " 1782 "immediately fail. Default 0", 1783 }, 1784 { 1785 .name = "open-timeout", 1786 .type = QEMU_OPT_NUMBER, 1787 .help = "In seconds. If zero, the nbd driver tries the connection " 1788 "only once, and fails to open if the connection fails. " 1789 "If non-zero, the nbd driver will repeat connection " 1790 "attempts until successful or until @open-timeout seconds " 1791 "have elapsed. Default 0", 1792 }, 1793 { /* end of list */ } 1794 }, 1795 }; 1796 1797 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1798 Error **errp) 1799 { 1800 BDRVNBDState *s = bs->opaque; 1801 QemuOpts *opts; 1802 int ret = -EINVAL; 1803 1804 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1805 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1806 goto error; 1807 } 1808 1809 /* Translate @host, @port, and @path to a SocketAddress */ 1810 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1811 goto error; 1812 } 1813 1814 /* Pop the config into our state object. Exit if invalid. */ 1815 s->saddr = nbd_config(s, options, errp); 1816 if (!s->saddr) { 1817 goto error; 1818 } 1819 1820 s->export = g_strdup(qemu_opt_get(opts, "export")); 1821 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1822 error_setg(errp, "export name too long to send to server"); 1823 goto error; 1824 } 1825 1826 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1827 if (s->tlscredsid) { 1828 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1829 if (!s->tlscreds) { 1830 goto error; 1831 } 1832 1833 /* TODO SOCKET_ADDRESS_KIND_FD where fd has AF_INET or AF_INET6 */ 1834 if (s->saddr->type != SOCKET_ADDRESS_TYPE_INET) { 1835 error_setg(errp, "TLS only supported over IP sockets"); 1836 goto error; 1837 } 1838 s->hostname = s->saddr->u.inet.host; 1839 } 1840 1841 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1842 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1843 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1844 goto error; 1845 } 1846 1847 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1848 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1849 1850 ret = 0; 1851 1852 error: 1853 qemu_opts_del(opts); 1854 return ret; 1855 } 1856 1857 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1858 Error **errp) 1859 { 1860 int ret; 1861 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1862 1863 s->bs = bs; 1864 qemu_co_mutex_init(&s->send_mutex); 1865 qemu_co_queue_init(&s->free_sema); 1866 qemu_co_mutex_init(&s->receive_mutex); 1867 1868 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1869 return -EEXIST; 1870 } 1871 1872 ret = nbd_process_options(bs, options, errp); 1873 if (ret < 0) { 1874 goto fail; 1875 } 1876 1877 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1878 s->x_dirty_bitmap, s->tlscreds); 1879 1880 if (s->open_timeout) { 1881 nbd_client_connection_enable_retry(s->conn); 1882 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1883 s->open_timeout * NANOSECONDS_PER_SECOND); 1884 } 1885 1886 s->state = NBD_CLIENT_CONNECTING_WAIT; 1887 ret = nbd_do_establish_connection(bs, errp); 1888 if (ret < 0) { 1889 goto fail; 1890 } 1891 1892 /* 1893 * The connect attempt is done, so we no longer need this timer. 1894 * Delete it, because we do not want it to be around when this node 1895 * is drained or closed. 1896 */ 1897 open_timer_del(s); 1898 1899 nbd_client_connection_enable_retry(s->conn); 1900 1901 return 0; 1902 1903 fail: 1904 open_timer_del(s); 1905 nbd_clear_bdrvstate(bs); 1906 return ret; 1907 } 1908 1909 static int nbd_co_flush(BlockDriverState *bs) 1910 { 1911 return nbd_client_co_flush(bs); 1912 } 1913 1914 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1915 { 1916 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1917 uint32_t min = s->info.min_block; 1918 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1919 1920 /* 1921 * If the server did not advertise an alignment: 1922 * - a size that is not sector-aligned implies that an alignment 1923 * of 1 can be used to access those tail bytes 1924 * - advertisement of block status requires an alignment of 1, so 1925 * that we don't violate block layer constraints that block 1926 * status is always aligned (as we can't control whether the 1927 * server will report sub-sector extents, such as a hole at EOF 1928 * on an unaligned POSIX file) 1929 * - otherwise, assume the server is so old that we are safer avoiding 1930 * sub-sector requests 1931 */ 1932 if (!min) { 1933 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1934 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1935 } 1936 1937 bs->bl.request_alignment = min; 1938 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1939 bs->bl.max_pwrite_zeroes = max; 1940 bs->bl.max_transfer = max; 1941 1942 if (s->info.opt_block && 1943 s->info.opt_block > bs->bl.opt_transfer) { 1944 bs->bl.opt_transfer = s->info.opt_block; 1945 } 1946 } 1947 1948 static void nbd_close(BlockDriverState *bs) 1949 { 1950 nbd_client_close(bs); 1951 nbd_clear_bdrvstate(bs); 1952 } 1953 1954 /* 1955 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 1956 * to a smaller size with exact=false, there is no reason to fail the 1957 * operation. 1958 * 1959 * Preallocation mode is ignored since it does not seems useful to fail when 1960 * we never change anything. 1961 */ 1962 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 1963 bool exact, PreallocMode prealloc, 1964 BdrvRequestFlags flags, Error **errp) 1965 { 1966 BDRVNBDState *s = bs->opaque; 1967 1968 if (offset != s->info.size && exact) { 1969 error_setg(errp, "Cannot resize NBD nodes"); 1970 return -ENOTSUP; 1971 } 1972 1973 if (offset > s->info.size) { 1974 error_setg(errp, "Cannot grow NBD nodes"); 1975 return -EINVAL; 1976 } 1977 1978 return 0; 1979 } 1980 1981 static int64_t nbd_getlength(BlockDriverState *bs) 1982 { 1983 BDRVNBDState *s = bs->opaque; 1984 1985 return s->info.size; 1986 } 1987 1988 static void nbd_refresh_filename(BlockDriverState *bs) 1989 { 1990 BDRVNBDState *s = bs->opaque; 1991 const char *host = NULL, *port = NULL, *path = NULL; 1992 size_t len = 0; 1993 1994 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1995 const InetSocketAddress *inet = &s->saddr->u.inet; 1996 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 1997 host = inet->host; 1998 port = inet->port; 1999 } 2000 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2001 path = s->saddr->u.q_unix.path; 2002 } /* else can't represent as pseudo-filename */ 2003 2004 if (path && s->export) { 2005 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2006 "nbd+unix:///%s?socket=%s", s->export, path); 2007 } else if (path && !s->export) { 2008 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2009 "nbd+unix://?socket=%s", path); 2010 } else if (host && s->export) { 2011 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2012 "nbd://%s:%s/%s", host, port, s->export); 2013 } else if (host && !s->export) { 2014 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2015 "nbd://%s:%s", host, port); 2016 } 2017 if (len >= sizeof(bs->exact_filename)) { 2018 /* Name is too long to represent exactly, so leave it empty. */ 2019 bs->exact_filename[0] = '\0'; 2020 } 2021 } 2022 2023 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2024 { 2025 /* The generic bdrv_dirname() implementation is able to work out some 2026 * directory name for NBD nodes, but that would be wrong. So far there is no 2027 * specification for how "export paths" would work, so NBD does not have 2028 * directory names. */ 2029 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2030 return NULL; 2031 } 2032 2033 static const char *const nbd_strong_runtime_opts[] = { 2034 "path", 2035 "host", 2036 "port", 2037 "export", 2038 "tls-creds", 2039 "server.", 2040 2041 NULL 2042 }; 2043 2044 static void nbd_cancel_in_flight(BlockDriverState *bs) 2045 { 2046 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2047 2048 reconnect_delay_timer_del(s); 2049 2050 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2051 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2052 qemu_co_queue_restart_all(&s->free_sema); 2053 } 2054 2055 nbd_co_establish_connection_cancel(s->conn); 2056 } 2057 2058 static void nbd_attach_aio_context(BlockDriverState *bs, 2059 AioContext *new_context) 2060 { 2061 BDRVNBDState *s = bs->opaque; 2062 2063 /* The open_timer is used only during nbd_open() */ 2064 assert(!s->open_timer); 2065 2066 /* 2067 * The reconnect_delay_timer is scheduled in I/O paths when the 2068 * connection is lost, to cancel the reconnection attempt after a 2069 * given time. Once this attempt is done (successfully or not), 2070 * nbd_reconnect_attempt() ensures the timer is deleted before the 2071 * respective I/O request is resumed. 2072 * Since the AioContext can only be changed when a node is drained, 2073 * the reconnect_delay_timer cannot be active here. 2074 */ 2075 assert(!s->reconnect_delay_timer); 2076 2077 if (s->ioc) { 2078 qio_channel_attach_aio_context(s->ioc, new_context); 2079 } 2080 } 2081 2082 static void nbd_detach_aio_context(BlockDriverState *bs) 2083 { 2084 BDRVNBDState *s = bs->opaque; 2085 2086 assert(!s->open_timer); 2087 assert(!s->reconnect_delay_timer); 2088 2089 if (s->ioc) { 2090 qio_channel_detach_aio_context(s->ioc); 2091 } 2092 } 2093 2094 static BlockDriver bdrv_nbd = { 2095 .format_name = "nbd", 2096 .protocol_name = "nbd", 2097 .instance_size = sizeof(BDRVNBDState), 2098 .bdrv_parse_filename = nbd_parse_filename, 2099 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2100 .create_opts = &bdrv_create_opts_simple, 2101 .bdrv_file_open = nbd_open, 2102 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2103 .bdrv_co_preadv = nbd_client_co_preadv, 2104 .bdrv_co_pwritev = nbd_client_co_pwritev, 2105 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2106 .bdrv_close = nbd_close, 2107 .bdrv_co_flush_to_os = nbd_co_flush, 2108 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2109 .bdrv_refresh_limits = nbd_refresh_limits, 2110 .bdrv_co_truncate = nbd_co_truncate, 2111 .bdrv_getlength = nbd_getlength, 2112 .bdrv_refresh_filename = nbd_refresh_filename, 2113 .bdrv_co_block_status = nbd_client_co_block_status, 2114 .bdrv_dirname = nbd_dirname, 2115 .strong_runtime_opts = nbd_strong_runtime_opts, 2116 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2117 2118 .bdrv_attach_aio_context = nbd_attach_aio_context, 2119 .bdrv_detach_aio_context = nbd_detach_aio_context, 2120 }; 2121 2122 static BlockDriver bdrv_nbd_tcp = { 2123 .format_name = "nbd", 2124 .protocol_name = "nbd+tcp", 2125 .instance_size = sizeof(BDRVNBDState), 2126 .bdrv_parse_filename = nbd_parse_filename, 2127 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2128 .create_opts = &bdrv_create_opts_simple, 2129 .bdrv_file_open = nbd_open, 2130 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2131 .bdrv_co_preadv = nbd_client_co_preadv, 2132 .bdrv_co_pwritev = nbd_client_co_pwritev, 2133 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2134 .bdrv_close = nbd_close, 2135 .bdrv_co_flush_to_os = nbd_co_flush, 2136 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2137 .bdrv_refresh_limits = nbd_refresh_limits, 2138 .bdrv_co_truncate = nbd_co_truncate, 2139 .bdrv_getlength = nbd_getlength, 2140 .bdrv_refresh_filename = nbd_refresh_filename, 2141 .bdrv_co_block_status = nbd_client_co_block_status, 2142 .bdrv_dirname = nbd_dirname, 2143 .strong_runtime_opts = nbd_strong_runtime_opts, 2144 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2145 2146 .bdrv_attach_aio_context = nbd_attach_aio_context, 2147 .bdrv_detach_aio_context = nbd_detach_aio_context, 2148 }; 2149 2150 static BlockDriver bdrv_nbd_unix = { 2151 .format_name = "nbd", 2152 .protocol_name = "nbd+unix", 2153 .instance_size = sizeof(BDRVNBDState), 2154 .bdrv_parse_filename = nbd_parse_filename, 2155 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2156 .create_opts = &bdrv_create_opts_simple, 2157 .bdrv_file_open = nbd_open, 2158 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2159 .bdrv_co_preadv = nbd_client_co_preadv, 2160 .bdrv_co_pwritev = nbd_client_co_pwritev, 2161 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2162 .bdrv_close = nbd_close, 2163 .bdrv_co_flush_to_os = nbd_co_flush, 2164 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2165 .bdrv_refresh_limits = nbd_refresh_limits, 2166 .bdrv_co_truncate = nbd_co_truncate, 2167 .bdrv_getlength = nbd_getlength, 2168 .bdrv_refresh_filename = nbd_refresh_filename, 2169 .bdrv_co_block_status = nbd_client_co_block_status, 2170 .bdrv_dirname = nbd_dirname, 2171 .strong_runtime_opts = nbd_strong_runtime_opts, 2172 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2173 2174 .bdrv_attach_aio_context = nbd_attach_aio_context, 2175 .bdrv_detach_aio_context = nbd_detach_aio_context, 2176 }; 2177 2178 static void bdrv_nbd_init(void) 2179 { 2180 bdrv_register(&bdrv_nbd); 2181 bdrv_register(&bdrv_nbd_tcp); 2182 bdrv_register(&bdrv_nbd_unix); 2183 } 2184 2185 block_init(bdrv_nbd_init); 2186