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 IO_CODE(); 317 318 assert(!s->ioc); 319 320 s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); 321 if (!s->ioc) { 322 return -ECONNREFUSED; 323 } 324 325 yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, 326 bs); 327 328 ret = nbd_handle_updated_info(s->bs, NULL); 329 if (ret < 0) { 330 /* 331 * We have connected, but must fail for other reasons. 332 * Send NBD_CMD_DISC as a courtesy to the server. 333 */ 334 NBDRequest request = { .type = NBD_CMD_DISC }; 335 336 nbd_send_request(s->ioc, &request); 337 338 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 339 nbd_yank, bs); 340 object_unref(OBJECT(s->ioc)); 341 s->ioc = NULL; 342 343 return ret; 344 } 345 346 qio_channel_set_blocking(s->ioc, false, NULL); 347 qio_channel_attach_aio_context(s->ioc, bdrv_get_aio_context(bs)); 348 349 /* successfully connected */ 350 s->state = NBD_CLIENT_CONNECTED; 351 qemu_co_queue_restart_all(&s->free_sema); 352 353 return 0; 354 } 355 356 /* called under s->send_mutex */ 357 static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) 358 { 359 assert(nbd_client_connecting(s)); 360 assert(s->in_flight == 0); 361 362 if (nbd_client_connecting_wait(s) && s->reconnect_delay && 363 !s->reconnect_delay_timer) 364 { 365 /* 366 * It's first reconnect attempt after switching to 367 * NBD_CLIENT_CONNECTING_WAIT 368 */ 369 reconnect_delay_timer_init(s, 370 qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 371 s->reconnect_delay * NANOSECONDS_PER_SECOND); 372 } 373 374 /* 375 * Now we are sure that nobody is accessing the channel, and no one will 376 * try until we set the state to CONNECTED. 377 */ 378 379 /* Finalize previous connection if any */ 380 if (s->ioc) { 381 qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); 382 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 383 nbd_yank, s->bs); 384 object_unref(OBJECT(s->ioc)); 385 s->ioc = NULL; 386 } 387 388 nbd_co_do_establish_connection(s->bs, NULL); 389 390 /* 391 * The reconnect attempt is done (maybe successfully, maybe not), so 392 * we no longer need this timer. Delete it so it will not outlive 393 * this I/O request (so draining removes all timers). 394 */ 395 reconnect_delay_timer_del(s); 396 } 397 398 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle) 399 { 400 int ret; 401 uint64_t ind = HANDLE_TO_INDEX(s, handle), ind2; 402 QEMU_LOCK_GUARD(&s->receive_mutex); 403 404 while (true) { 405 if (s->reply.handle == handle) { 406 /* We are done */ 407 return 0; 408 } 409 410 if (!nbd_client_connected(s)) { 411 return -EIO; 412 } 413 414 if (s->reply.handle != 0) { 415 /* 416 * Some other request is being handled now. It should already be 417 * woken by whoever set s->reply.handle (or never wait in this 418 * yield). So, we should not wake it here. 419 */ 420 ind2 = HANDLE_TO_INDEX(s, s->reply.handle); 421 assert(!s->requests[ind2].receiving); 422 423 s->requests[ind].receiving = true; 424 qemu_co_mutex_unlock(&s->receive_mutex); 425 426 qemu_coroutine_yield(); 427 /* 428 * We may be woken for 3 reasons: 429 * 1. From this function, executing in parallel coroutine, when our 430 * handle is received. 431 * 2. From nbd_channel_error(), when connection is lost. 432 * 3. From nbd_co_receive_one_chunk(), when previous request is 433 * finished and s->reply.handle set to 0. 434 * Anyway, it's OK to lock the mutex and go to the next iteration. 435 */ 436 437 qemu_co_mutex_lock(&s->receive_mutex); 438 assert(!s->requests[ind].receiving); 439 continue; 440 } 441 442 /* We are under mutex and handle is 0. We have to do the dirty work. */ 443 assert(s->reply.handle == 0); 444 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, NULL); 445 if (ret <= 0) { 446 ret = ret ? ret : -EIO; 447 nbd_channel_error(s, ret); 448 return ret; 449 } 450 if (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply) { 451 nbd_channel_error(s, -EINVAL); 452 return -EINVAL; 453 } 454 if (s->reply.handle == handle) { 455 /* We are done */ 456 return 0; 457 } 458 ind2 = HANDLE_TO_INDEX(s, s->reply.handle); 459 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].reply_possible) { 460 nbd_channel_error(s, -EINVAL); 461 return -EINVAL; 462 } 463 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 464 } 465 } 466 467 static int nbd_co_send_request(BlockDriverState *bs, 468 NBDRequest *request, 469 QEMUIOVector *qiov) 470 { 471 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 472 int rc, i = -1; 473 474 qemu_co_mutex_lock(&s->send_mutex); 475 476 while (s->in_flight == MAX_NBD_REQUESTS || 477 (!nbd_client_connected(s) && s->in_flight > 0)) 478 { 479 qemu_co_queue_wait(&s->free_sema, &s->send_mutex); 480 } 481 482 if (nbd_client_connecting(s)) { 483 nbd_reconnect_attempt(s); 484 } 485 486 if (!nbd_client_connected(s)) { 487 rc = -EIO; 488 goto err; 489 } 490 491 s->in_flight++; 492 493 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 494 if (s->requests[i].coroutine == NULL) { 495 break; 496 } 497 } 498 499 g_assert(qemu_in_coroutine()); 500 assert(i < MAX_NBD_REQUESTS); 501 502 s->requests[i].coroutine = qemu_coroutine_self(); 503 s->requests[i].offset = request->from; 504 s->requests[i].receiving = false; 505 s->requests[i].reply_possible = true; 506 507 request->handle = INDEX_TO_HANDLE(s, i); 508 509 assert(s->ioc); 510 511 if (qiov) { 512 qio_channel_set_cork(s->ioc, true); 513 rc = nbd_send_request(s->ioc, request); 514 if (nbd_client_connected(s) && rc >= 0) { 515 if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 516 NULL) < 0) { 517 rc = -EIO; 518 } 519 } else if (rc >= 0) { 520 rc = -EIO; 521 } 522 qio_channel_set_cork(s->ioc, false); 523 } else { 524 rc = nbd_send_request(s->ioc, request); 525 } 526 527 err: 528 if (rc < 0) { 529 nbd_channel_error(s, rc); 530 if (i != -1) { 531 s->requests[i].coroutine = NULL; 532 s->in_flight--; 533 qemu_co_queue_next(&s->free_sema); 534 } 535 } 536 qemu_co_mutex_unlock(&s->send_mutex); 537 return rc; 538 } 539 540 static inline uint16_t payload_advance16(uint8_t **payload) 541 { 542 *payload += 2; 543 return lduw_be_p(*payload - 2); 544 } 545 546 static inline uint32_t payload_advance32(uint8_t **payload) 547 { 548 *payload += 4; 549 return ldl_be_p(*payload - 4); 550 } 551 552 static inline uint64_t payload_advance64(uint8_t **payload) 553 { 554 *payload += 8; 555 return ldq_be_p(*payload - 8); 556 } 557 558 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 559 NBDStructuredReplyChunk *chunk, 560 uint8_t *payload, uint64_t orig_offset, 561 QEMUIOVector *qiov, Error **errp) 562 { 563 uint64_t offset; 564 uint32_t hole_size; 565 566 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 567 error_setg(errp, "Protocol error: invalid payload for " 568 "NBD_REPLY_TYPE_OFFSET_HOLE"); 569 return -EINVAL; 570 } 571 572 offset = payload_advance64(&payload); 573 hole_size = payload_advance32(&payload); 574 575 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 576 offset > orig_offset + qiov->size - hole_size) { 577 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 578 " region"); 579 return -EINVAL; 580 } 581 if (s->info.min_block && 582 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 583 trace_nbd_structured_read_compliance("hole"); 584 } 585 586 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 587 588 return 0; 589 } 590 591 /* 592 * nbd_parse_blockstatus_payload 593 * Based on our request, we expect only one extent in reply, for the 594 * base:allocation context. 595 */ 596 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 597 NBDStructuredReplyChunk *chunk, 598 uint8_t *payload, uint64_t orig_length, 599 NBDExtent *extent, Error **errp) 600 { 601 uint32_t context_id; 602 603 /* The server succeeded, so it must have sent [at least] one extent */ 604 if (chunk->length < sizeof(context_id) + sizeof(*extent)) { 605 error_setg(errp, "Protocol error: invalid payload for " 606 "NBD_REPLY_TYPE_BLOCK_STATUS"); 607 return -EINVAL; 608 } 609 610 context_id = payload_advance32(&payload); 611 if (s->info.context_id != context_id) { 612 error_setg(errp, "Protocol error: unexpected context id %d for " 613 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 614 "id is %d", context_id, 615 s->info.context_id); 616 return -EINVAL; 617 } 618 619 extent->length = payload_advance32(&payload); 620 extent->flags = payload_advance32(&payload); 621 622 if (extent->length == 0) { 623 error_setg(errp, "Protocol error: server sent status chunk with " 624 "zero length"); 625 return -EINVAL; 626 } 627 628 /* 629 * A server sending unaligned block status is in violation of the 630 * protocol, but as qemu-nbd 3.1 is such a server (at least for 631 * POSIX files that are not a multiple of 512 bytes, since qemu 632 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 633 * still sees an implicit hole beyond the real EOF), it's nicer to 634 * work around the misbehaving server. If the request included 635 * more than the final unaligned block, truncate it back to an 636 * aligned result; if the request was only the final block, round 637 * up to the full block and change the status to fully-allocated 638 * (always a safe status, even if it loses information). 639 */ 640 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 641 s->info.min_block)) { 642 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 643 if (extent->length > s->info.min_block) { 644 extent->length = QEMU_ALIGN_DOWN(extent->length, 645 s->info.min_block); 646 } else { 647 extent->length = s->info.min_block; 648 extent->flags = 0; 649 } 650 } 651 652 /* 653 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 654 * sent us any more than one extent, nor should it have included 655 * status beyond our request in that extent. However, it's easy 656 * enough to ignore the server's noncompliance without killing the 657 * connection; just ignore trailing extents, and clamp things to 658 * the length of our request. 659 */ 660 if (chunk->length > sizeof(context_id) + sizeof(*extent)) { 661 trace_nbd_parse_blockstatus_compliance("more than one extent"); 662 } 663 if (extent->length > orig_length) { 664 extent->length = orig_length; 665 trace_nbd_parse_blockstatus_compliance("extent length too large"); 666 } 667 668 /* 669 * HACK: if we are using x-dirty-bitmaps to access 670 * qemu:allocation-depth, treat all depths > 2 the same as 2, 671 * since nbd_client_co_block_status is only expecting the low two 672 * bits to be set. 673 */ 674 if (s->alloc_depth && extent->flags > 2) { 675 extent->flags = 2; 676 } 677 678 return 0; 679 } 680 681 /* 682 * nbd_parse_error_payload 683 * on success @errp contains message describing nbd error reply 684 */ 685 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 686 uint8_t *payload, int *request_ret, 687 Error **errp) 688 { 689 uint32_t error; 690 uint16_t message_size; 691 692 assert(chunk->type & (1 << 15)); 693 694 if (chunk->length < sizeof(error) + sizeof(message_size)) { 695 error_setg(errp, 696 "Protocol error: invalid payload for structured error"); 697 return -EINVAL; 698 } 699 700 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 701 if (error == 0) { 702 error_setg(errp, "Protocol error: server sent structured error chunk " 703 "with error = 0"); 704 return -EINVAL; 705 } 706 707 *request_ret = -error; 708 message_size = payload_advance16(&payload); 709 710 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 711 error_setg(errp, "Protocol error: server sent structured error chunk " 712 "with incorrect message size"); 713 return -EINVAL; 714 } 715 716 /* TODO: Add a trace point to mention the server complaint */ 717 718 /* TODO handle ERROR_OFFSET */ 719 720 return 0; 721 } 722 723 static int nbd_co_receive_offset_data_payload(BDRVNBDState *s, 724 uint64_t orig_offset, 725 QEMUIOVector *qiov, Error **errp) 726 { 727 QEMUIOVector sub_qiov; 728 uint64_t offset; 729 size_t data_size; 730 int ret; 731 NBDStructuredReplyChunk *chunk = &s->reply.structured; 732 733 assert(nbd_reply_is_structured(&s->reply)); 734 735 /* The NBD spec requires at least one byte of payload */ 736 if (chunk->length <= sizeof(offset)) { 737 error_setg(errp, "Protocol error: invalid payload for " 738 "NBD_REPLY_TYPE_OFFSET_DATA"); 739 return -EINVAL; 740 } 741 742 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 743 return -EIO; 744 } 745 746 data_size = chunk->length - sizeof(offset); 747 assert(data_size); 748 if (offset < orig_offset || data_size > qiov->size || 749 offset > orig_offset + qiov->size - data_size) { 750 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 751 " region"); 752 return -EINVAL; 753 } 754 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 755 trace_nbd_structured_read_compliance("data"); 756 } 757 758 qemu_iovec_init(&sub_qiov, qiov->niov); 759 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 760 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 761 qemu_iovec_destroy(&sub_qiov); 762 763 return ret < 0 ? -EIO : 0; 764 } 765 766 #define NBD_MAX_MALLOC_PAYLOAD 1000 767 static coroutine_fn int nbd_co_receive_structured_payload( 768 BDRVNBDState *s, void **payload, Error **errp) 769 { 770 int ret; 771 uint32_t len; 772 773 assert(nbd_reply_is_structured(&s->reply)); 774 775 len = s->reply.structured.length; 776 777 if (len == 0) { 778 return 0; 779 } 780 781 if (payload == NULL) { 782 error_setg(errp, "Unexpected structured payload"); 783 return -EINVAL; 784 } 785 786 if (len > NBD_MAX_MALLOC_PAYLOAD) { 787 error_setg(errp, "Payload too large"); 788 return -EINVAL; 789 } 790 791 *payload = g_new(char, len); 792 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 793 if (ret < 0) { 794 g_free(*payload); 795 *payload = NULL; 796 return ret; 797 } 798 799 return 0; 800 } 801 802 /* 803 * nbd_co_do_receive_one_chunk 804 * for simple reply: 805 * set request_ret to received reply error 806 * if qiov is not NULL: read payload to @qiov 807 * for structured reply chunk: 808 * if error chunk: read payload, set @request_ret, do not set @payload 809 * else if offset_data chunk: read payload data to @qiov, do not set @payload 810 * else: read payload to @payload 811 * 812 * If function fails, @errp contains corresponding error message, and the 813 * connection with the server is suspect. If it returns 0, then the 814 * transaction succeeded (although @request_ret may be a negative errno 815 * corresponding to the server's error reply), and errp is unchanged. 816 */ 817 static coroutine_fn int nbd_co_do_receive_one_chunk( 818 BDRVNBDState *s, uint64_t handle, bool only_structured, 819 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 820 { 821 int ret; 822 int i = HANDLE_TO_INDEX(s, handle); 823 void *local_payload = NULL; 824 NBDStructuredReplyChunk *chunk; 825 826 if (payload) { 827 *payload = NULL; 828 } 829 *request_ret = 0; 830 831 nbd_receive_replies(s, handle); 832 if (!nbd_client_connected(s)) { 833 error_setg(errp, "Connection closed"); 834 return -EIO; 835 } 836 assert(s->ioc); 837 838 assert(s->reply.handle == handle); 839 840 if (nbd_reply_is_simple(&s->reply)) { 841 if (only_structured) { 842 error_setg(errp, "Protocol error: simple reply when structured " 843 "reply chunk was expected"); 844 return -EINVAL; 845 } 846 847 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 848 if (*request_ret < 0 || !qiov) { 849 return 0; 850 } 851 852 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 853 errp) < 0 ? -EIO : 0; 854 } 855 856 /* handle structured reply chunk */ 857 assert(s->info.structured_reply); 858 chunk = &s->reply.structured; 859 860 if (chunk->type == NBD_REPLY_TYPE_NONE) { 861 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 862 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 863 " NBD_REPLY_FLAG_DONE flag set"); 864 return -EINVAL; 865 } 866 if (chunk->length) { 867 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 868 " nonzero length"); 869 return -EINVAL; 870 } 871 return 0; 872 } 873 874 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 875 if (!qiov) { 876 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 877 return -EINVAL; 878 } 879 880 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 881 qiov, errp); 882 } 883 884 if (nbd_reply_type_is_error(chunk->type)) { 885 payload = &local_payload; 886 } 887 888 ret = nbd_co_receive_structured_payload(s, payload, errp); 889 if (ret < 0) { 890 return ret; 891 } 892 893 if (nbd_reply_type_is_error(chunk->type)) { 894 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 895 g_free(local_payload); 896 return ret; 897 } 898 899 return 0; 900 } 901 902 /* 903 * nbd_co_receive_one_chunk 904 * Read reply, wake up connection_co and set s->quit if needed. 905 * Return value is a fatal error code or normal nbd reply error code 906 */ 907 static coroutine_fn int nbd_co_receive_one_chunk( 908 BDRVNBDState *s, uint64_t handle, bool only_structured, 909 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 910 Error **errp) 911 { 912 int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured, 913 request_ret, qiov, payload, errp); 914 915 if (ret < 0) { 916 memset(reply, 0, sizeof(*reply)); 917 nbd_channel_error(s, ret); 918 } else { 919 /* For assert at loop start in nbd_connection_entry */ 920 *reply = s->reply; 921 } 922 s->reply.handle = 0; 923 924 nbd_recv_coroutines_wake(s, false); 925 926 return ret; 927 } 928 929 typedef struct NBDReplyChunkIter { 930 int ret; 931 int request_ret; 932 Error *err; 933 bool done, only_structured; 934 } NBDReplyChunkIter; 935 936 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 937 int ret, Error **local_err) 938 { 939 assert(local_err && *local_err); 940 assert(ret < 0); 941 942 if (!iter->ret) { 943 iter->ret = ret; 944 error_propagate(&iter->err, *local_err); 945 } else { 946 error_free(*local_err); 947 } 948 949 *local_err = NULL; 950 } 951 952 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 953 { 954 assert(ret < 0); 955 956 if (!iter->request_ret) { 957 iter->request_ret = ret; 958 } 959 } 960 961 /* 962 * NBD_FOREACH_REPLY_CHUNK 963 * The pointer stored in @payload requires g_free() to free it. 964 */ 965 #define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \ 966 qiov, reply, payload) \ 967 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 968 nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);) 969 970 /* 971 * nbd_reply_chunk_iter_receive 972 * The pointer stored in @payload requires g_free() to free it. 973 */ 974 static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, 975 NBDReplyChunkIter *iter, 976 uint64_t handle, 977 QEMUIOVector *qiov, NBDReply *reply, 978 void **payload) 979 { 980 int ret, request_ret; 981 NBDReply local_reply; 982 NBDStructuredReplyChunk *chunk; 983 Error *local_err = NULL; 984 if (!nbd_client_connected(s)) { 985 error_setg(&local_err, "Connection closed"); 986 nbd_iter_channel_error(iter, -EIO, &local_err); 987 goto break_loop; 988 } 989 990 if (iter->done) { 991 /* Previous iteration was last. */ 992 goto break_loop; 993 } 994 995 if (reply == NULL) { 996 reply = &local_reply; 997 } 998 999 ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured, 1000 &request_ret, qiov, reply, payload, 1001 &local_err); 1002 if (ret < 0) { 1003 nbd_iter_channel_error(iter, ret, &local_err); 1004 } else if (request_ret < 0) { 1005 nbd_iter_request_error(iter, request_ret); 1006 } 1007 1008 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1009 if (nbd_reply_is_simple(reply) || !nbd_client_connected(s)) { 1010 goto break_loop; 1011 } 1012 1013 chunk = &reply->structured; 1014 iter->only_structured = true; 1015 1016 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1017 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1018 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1019 goto break_loop; 1020 } 1021 1022 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1023 /* This iteration is last. */ 1024 iter->done = true; 1025 } 1026 1027 /* Execute the loop body */ 1028 return true; 1029 1030 break_loop: 1031 s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL; 1032 1033 qemu_co_mutex_lock(&s->send_mutex); 1034 s->in_flight--; 1035 qemu_co_queue_next(&s->free_sema); 1036 qemu_co_mutex_unlock(&s->send_mutex); 1037 1038 return false; 1039 } 1040 1041 static int nbd_co_receive_return_code(BDRVNBDState *s, uint64_t handle, 1042 int *request_ret, Error **errp) 1043 { 1044 NBDReplyChunkIter iter; 1045 1046 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) { 1047 /* nbd_reply_chunk_iter_receive does all the work */ 1048 } 1049 1050 error_propagate(errp, iter.err); 1051 *request_ret = iter.request_ret; 1052 return iter.ret; 1053 } 1054 1055 static int nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t handle, 1056 uint64_t offset, QEMUIOVector *qiov, 1057 int *request_ret, Error **errp) 1058 { 1059 NBDReplyChunkIter iter; 1060 NBDReply reply; 1061 void *payload = NULL; 1062 Error *local_err = NULL; 1063 1064 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, 1065 qiov, &reply, &payload) 1066 { 1067 int ret; 1068 NBDStructuredReplyChunk *chunk = &reply.structured; 1069 1070 assert(nbd_reply_is_structured(&reply)); 1071 1072 switch (chunk->type) { 1073 case NBD_REPLY_TYPE_OFFSET_DATA: 1074 /* 1075 * special cased in nbd_co_receive_one_chunk, data is already 1076 * in qiov 1077 */ 1078 break; 1079 case NBD_REPLY_TYPE_OFFSET_HOLE: 1080 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1081 offset, qiov, &local_err); 1082 if (ret < 0) { 1083 nbd_channel_error(s, ret); 1084 nbd_iter_channel_error(&iter, ret, &local_err); 1085 } 1086 break; 1087 default: 1088 if (!nbd_reply_type_is_error(chunk->type)) { 1089 /* not allowed reply type */ 1090 nbd_channel_error(s, -EINVAL); 1091 error_setg(&local_err, 1092 "Unexpected reply type: %d (%s) for CMD_READ", 1093 chunk->type, nbd_reply_type_lookup(chunk->type)); 1094 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1095 } 1096 } 1097 1098 g_free(payload); 1099 payload = NULL; 1100 } 1101 1102 error_propagate(errp, iter.err); 1103 *request_ret = iter.request_ret; 1104 return iter.ret; 1105 } 1106 1107 static int nbd_co_receive_blockstatus_reply(BDRVNBDState *s, 1108 uint64_t handle, uint64_t length, 1109 NBDExtent *extent, 1110 int *request_ret, Error **errp) 1111 { 1112 NBDReplyChunkIter iter; 1113 NBDReply reply; 1114 void *payload = NULL; 1115 Error *local_err = NULL; 1116 bool received = false; 1117 1118 assert(!extent->length); 1119 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { 1120 int ret; 1121 NBDStructuredReplyChunk *chunk = &reply.structured; 1122 1123 assert(nbd_reply_is_structured(&reply)); 1124 1125 switch (chunk->type) { 1126 case NBD_REPLY_TYPE_BLOCK_STATUS: 1127 if (received) { 1128 nbd_channel_error(s, -EINVAL); 1129 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1130 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1131 } 1132 received = true; 1133 1134 ret = nbd_parse_blockstatus_payload(s, &reply.structured, 1135 payload, length, extent, 1136 &local_err); 1137 if (ret < 0) { 1138 nbd_channel_error(s, ret); 1139 nbd_iter_channel_error(&iter, ret, &local_err); 1140 } 1141 break; 1142 default: 1143 if (!nbd_reply_type_is_error(chunk->type)) { 1144 nbd_channel_error(s, -EINVAL); 1145 error_setg(&local_err, 1146 "Unexpected reply type: %d (%s) " 1147 "for CMD_BLOCK_STATUS", 1148 chunk->type, nbd_reply_type_lookup(chunk->type)); 1149 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1150 } 1151 } 1152 1153 g_free(payload); 1154 payload = NULL; 1155 } 1156 1157 if (!extent->length && !iter.request_ret) { 1158 error_setg(&local_err, "Server did not reply with any status extents"); 1159 nbd_iter_channel_error(&iter, -EIO, &local_err); 1160 } 1161 1162 error_propagate(errp, iter.err); 1163 *request_ret = iter.request_ret; 1164 return iter.ret; 1165 } 1166 1167 static int nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1168 QEMUIOVector *write_qiov) 1169 { 1170 int ret, request_ret; 1171 Error *local_err = NULL; 1172 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1173 1174 assert(request->type != NBD_CMD_READ); 1175 if (write_qiov) { 1176 assert(request->type == NBD_CMD_WRITE); 1177 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1178 } else { 1179 assert(request->type != NBD_CMD_WRITE); 1180 } 1181 1182 do { 1183 ret = nbd_co_send_request(bs, request, write_qiov); 1184 if (ret < 0) { 1185 continue; 1186 } 1187 1188 ret = nbd_co_receive_return_code(s, request->handle, 1189 &request_ret, &local_err); 1190 if (local_err) { 1191 trace_nbd_co_request_fail(request->from, request->len, 1192 request->handle, request->flags, 1193 request->type, 1194 nbd_cmd_lookup(request->type), 1195 ret, error_get_pretty(local_err)); 1196 error_free(local_err); 1197 local_err = NULL; 1198 } 1199 } while (ret < 0 && nbd_client_connecting_wait(s)); 1200 1201 return ret ? ret : request_ret; 1202 } 1203 1204 static int nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, 1205 int64_t bytes, QEMUIOVector *qiov, 1206 BdrvRequestFlags flags) 1207 { 1208 int ret, request_ret; 1209 Error *local_err = NULL; 1210 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1211 NBDRequest request = { 1212 .type = NBD_CMD_READ, 1213 .from = offset, 1214 .len = bytes, 1215 }; 1216 1217 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1218 assert(!flags); 1219 1220 if (!bytes) { 1221 return 0; 1222 } 1223 /* 1224 * Work around the fact that the block layer doesn't do 1225 * byte-accurate sizing yet - if the read exceeds the server's 1226 * advertised size because the block layer rounded size up, then 1227 * truncate the request to the server and tail-pad with zero. 1228 */ 1229 if (offset >= s->info.size) { 1230 assert(bytes < BDRV_SECTOR_SIZE); 1231 qemu_iovec_memset(qiov, 0, 0, bytes); 1232 return 0; 1233 } 1234 if (offset + bytes > s->info.size) { 1235 uint64_t slop = offset + bytes - s->info.size; 1236 1237 assert(slop < BDRV_SECTOR_SIZE); 1238 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1239 request.len -= slop; 1240 } 1241 1242 do { 1243 ret = nbd_co_send_request(bs, &request, NULL); 1244 if (ret < 0) { 1245 continue; 1246 } 1247 1248 ret = nbd_co_receive_cmdread_reply(s, request.handle, offset, qiov, 1249 &request_ret, &local_err); 1250 if (local_err) { 1251 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1252 request.flags, request.type, 1253 nbd_cmd_lookup(request.type), 1254 ret, error_get_pretty(local_err)); 1255 error_free(local_err); 1256 local_err = NULL; 1257 } 1258 } while (ret < 0 && nbd_client_connecting_wait(s)); 1259 1260 return ret ? ret : request_ret; 1261 } 1262 1263 static int nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, 1264 int64_t bytes, QEMUIOVector *qiov, 1265 BdrvRequestFlags flags) 1266 { 1267 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1268 NBDRequest request = { 1269 .type = NBD_CMD_WRITE, 1270 .from = offset, 1271 .len = bytes, 1272 }; 1273 1274 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1275 if (flags & BDRV_REQ_FUA) { 1276 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1277 request.flags |= NBD_CMD_FLAG_FUA; 1278 } 1279 1280 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1281 1282 if (!bytes) { 1283 return 0; 1284 } 1285 return nbd_co_request(bs, &request, qiov); 1286 } 1287 1288 static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, 1289 int64_t bytes, BdrvRequestFlags flags) 1290 { 1291 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1292 NBDRequest request = { 1293 .type = NBD_CMD_WRITE_ZEROES, 1294 .from = offset, 1295 .len = bytes, /* .len is uint32_t actually */ 1296 }; 1297 1298 assert(bytes <= UINT32_MAX); /* rely on max_pwrite_zeroes */ 1299 1300 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1301 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1302 return -ENOTSUP; 1303 } 1304 1305 if (flags & BDRV_REQ_FUA) { 1306 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1307 request.flags |= NBD_CMD_FLAG_FUA; 1308 } 1309 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1310 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1311 } 1312 if (flags & BDRV_REQ_NO_FALLBACK) { 1313 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1314 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1315 } 1316 1317 if (!bytes) { 1318 return 0; 1319 } 1320 return nbd_co_request(bs, &request, NULL); 1321 } 1322 1323 static int nbd_client_co_flush(BlockDriverState *bs) 1324 { 1325 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1326 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1327 1328 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1329 return 0; 1330 } 1331 1332 request.from = 0; 1333 request.len = 0; 1334 1335 return nbd_co_request(bs, &request, NULL); 1336 } 1337 1338 static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, 1339 int64_t bytes) 1340 { 1341 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1342 NBDRequest request = { 1343 .type = NBD_CMD_TRIM, 1344 .from = offset, 1345 .len = bytes, /* len is uint32_t */ 1346 }; 1347 1348 assert(bytes <= UINT32_MAX); /* rely on max_pdiscard */ 1349 1350 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1351 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1352 return 0; 1353 } 1354 1355 return nbd_co_request(bs, &request, NULL); 1356 } 1357 1358 static int coroutine_fn nbd_client_co_block_status( 1359 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1360 int64_t *pnum, int64_t *map, BlockDriverState **file) 1361 { 1362 int ret, request_ret; 1363 NBDExtent extent = { 0 }; 1364 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1365 Error *local_err = NULL; 1366 1367 NBDRequest request = { 1368 .type = NBD_CMD_BLOCK_STATUS, 1369 .from = offset, 1370 .len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1371 MIN(bytes, s->info.size - offset)), 1372 .flags = NBD_CMD_FLAG_REQ_ONE, 1373 }; 1374 1375 if (!s->info.base_allocation) { 1376 *pnum = bytes; 1377 *map = offset; 1378 *file = bs; 1379 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1380 } 1381 1382 /* 1383 * Work around the fact that the block layer doesn't do 1384 * byte-accurate sizing yet - if the status request exceeds the 1385 * server's advertised size because the block layer rounded size 1386 * up, we truncated the request to the server (above), or are 1387 * called on just the hole. 1388 */ 1389 if (offset >= s->info.size) { 1390 *pnum = bytes; 1391 assert(bytes < BDRV_SECTOR_SIZE); 1392 /* Intentionally don't report offset_valid for the hole */ 1393 return BDRV_BLOCK_ZERO; 1394 } 1395 1396 if (s->info.min_block) { 1397 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1398 } 1399 do { 1400 ret = nbd_co_send_request(bs, &request, NULL); 1401 if (ret < 0) { 1402 continue; 1403 } 1404 1405 ret = nbd_co_receive_blockstatus_reply(s, request.handle, bytes, 1406 &extent, &request_ret, 1407 &local_err); 1408 if (local_err) { 1409 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1410 request.flags, request.type, 1411 nbd_cmd_lookup(request.type), 1412 ret, error_get_pretty(local_err)); 1413 error_free(local_err); 1414 local_err = NULL; 1415 } 1416 } while (ret < 0 && nbd_client_connecting_wait(s)); 1417 1418 if (ret < 0 || request_ret < 0) { 1419 return ret ? ret : request_ret; 1420 } 1421 1422 assert(extent.length); 1423 *pnum = extent.length; 1424 *map = offset; 1425 *file = bs; 1426 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1427 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1428 BDRV_BLOCK_OFFSET_VALID; 1429 } 1430 1431 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1432 BlockReopenQueue *queue, Error **errp) 1433 { 1434 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1435 1436 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1437 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1438 return -EACCES; 1439 } 1440 return 0; 1441 } 1442 1443 static void nbd_yank(void *opaque) 1444 { 1445 BlockDriverState *bs = opaque; 1446 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1447 1448 qatomic_store_release(&s->state, NBD_CLIENT_QUIT); 1449 qio_channel_shutdown(QIO_CHANNEL(s->ioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1450 } 1451 1452 static void nbd_client_close(BlockDriverState *bs) 1453 { 1454 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1455 NBDRequest request = { .type = NBD_CMD_DISC }; 1456 1457 if (s->ioc) { 1458 nbd_send_request(s->ioc, &request); 1459 } 1460 1461 nbd_teardown_connection(bs); 1462 } 1463 1464 1465 /* 1466 * Parse nbd_open options 1467 */ 1468 1469 static int nbd_parse_uri(const char *filename, QDict *options) 1470 { 1471 URI *uri; 1472 const char *p; 1473 QueryParams *qp = NULL; 1474 int ret = 0; 1475 bool is_unix; 1476 1477 uri = uri_parse(filename); 1478 if (!uri) { 1479 return -EINVAL; 1480 } 1481 1482 /* transport */ 1483 if (!g_strcmp0(uri->scheme, "nbd")) { 1484 is_unix = false; 1485 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1486 is_unix = false; 1487 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1488 is_unix = true; 1489 } else { 1490 ret = -EINVAL; 1491 goto out; 1492 } 1493 1494 p = uri->path ? uri->path : ""; 1495 if (p[0] == '/') { 1496 p++; 1497 } 1498 if (p[0]) { 1499 qdict_put_str(options, "export", p); 1500 } 1501 1502 qp = query_params_parse(uri->query); 1503 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1504 ret = -EINVAL; 1505 goto out; 1506 } 1507 1508 if (is_unix) { 1509 /* nbd+unix:///export?socket=path */ 1510 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1511 ret = -EINVAL; 1512 goto out; 1513 } 1514 qdict_put_str(options, "server.type", "unix"); 1515 qdict_put_str(options, "server.path", qp->p[0].value); 1516 } else { 1517 QString *host; 1518 char *port_str; 1519 1520 /* nbd[+tcp]://host[:port]/export */ 1521 if (!uri->server) { 1522 ret = -EINVAL; 1523 goto out; 1524 } 1525 1526 /* strip braces from literal IPv6 address */ 1527 if (uri->server[0] == '[') { 1528 host = qstring_from_substr(uri->server, 1, 1529 strlen(uri->server) - 1); 1530 } else { 1531 host = qstring_from_str(uri->server); 1532 } 1533 1534 qdict_put_str(options, "server.type", "inet"); 1535 qdict_put(options, "server.host", host); 1536 1537 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1538 qdict_put_str(options, "server.port", port_str); 1539 g_free(port_str); 1540 } 1541 1542 out: 1543 if (qp) { 1544 query_params_free(qp); 1545 } 1546 uri_free(uri); 1547 return ret; 1548 } 1549 1550 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1551 { 1552 const QDictEntry *e; 1553 1554 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1555 if (!strcmp(e->key, "host") || 1556 !strcmp(e->key, "port") || 1557 !strcmp(e->key, "path") || 1558 !strcmp(e->key, "export") || 1559 strstart(e->key, "server.", NULL)) 1560 { 1561 error_setg(errp, "Option '%s' cannot be used with a file name", 1562 e->key); 1563 return true; 1564 } 1565 } 1566 1567 return false; 1568 } 1569 1570 static void nbd_parse_filename(const char *filename, QDict *options, 1571 Error **errp) 1572 { 1573 g_autofree char *file = NULL; 1574 char *export_name; 1575 const char *host_spec; 1576 const char *unixpath; 1577 1578 if (nbd_has_filename_options_conflict(options, errp)) { 1579 return; 1580 } 1581 1582 if (strstr(filename, "://")) { 1583 int ret = nbd_parse_uri(filename, options); 1584 if (ret < 0) { 1585 error_setg(errp, "No valid URL specified"); 1586 } 1587 return; 1588 } 1589 1590 file = g_strdup(filename); 1591 1592 export_name = strstr(file, EN_OPTSTR); 1593 if (export_name) { 1594 if (export_name[strlen(EN_OPTSTR)] == 0) { 1595 return; 1596 } 1597 export_name[0] = 0; /* truncate 'file' */ 1598 export_name += strlen(EN_OPTSTR); 1599 1600 qdict_put_str(options, "export", export_name); 1601 } 1602 1603 /* extract the host_spec - fail if it's not nbd:... */ 1604 if (!strstart(file, "nbd:", &host_spec)) { 1605 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1606 return; 1607 } 1608 1609 if (!*host_spec) { 1610 return; 1611 } 1612 1613 /* are we a UNIX or TCP socket? */ 1614 if (strstart(host_spec, "unix:", &unixpath)) { 1615 qdict_put_str(options, "server.type", "unix"); 1616 qdict_put_str(options, "server.path", unixpath); 1617 } else { 1618 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1619 1620 if (inet_parse(addr, host_spec, errp)) { 1621 goto out_inet; 1622 } 1623 1624 qdict_put_str(options, "server.type", "inet"); 1625 qdict_put_str(options, "server.host", addr->host); 1626 qdict_put_str(options, "server.port", addr->port); 1627 out_inet: 1628 qapi_free_InetSocketAddress(addr); 1629 } 1630 } 1631 1632 static bool nbd_process_legacy_socket_options(QDict *output_options, 1633 QemuOpts *legacy_opts, 1634 Error **errp) 1635 { 1636 const char *path = qemu_opt_get(legacy_opts, "path"); 1637 const char *host = qemu_opt_get(legacy_opts, "host"); 1638 const char *port = qemu_opt_get(legacy_opts, "port"); 1639 const QDictEntry *e; 1640 1641 if (!path && !host && !port) { 1642 return true; 1643 } 1644 1645 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1646 { 1647 if (strstart(e->key, "server.", NULL)) { 1648 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1649 "same time"); 1650 return false; 1651 } 1652 } 1653 1654 if (path && host) { 1655 error_setg(errp, "path and host may not be used at the same time"); 1656 return false; 1657 } else if (path) { 1658 if (port) { 1659 error_setg(errp, "port may not be used without host"); 1660 return false; 1661 } 1662 1663 qdict_put_str(output_options, "server.type", "unix"); 1664 qdict_put_str(output_options, "server.path", path); 1665 } else if (host) { 1666 qdict_put_str(output_options, "server.type", "inet"); 1667 qdict_put_str(output_options, "server.host", host); 1668 qdict_put_str(output_options, "server.port", 1669 port ?: stringify(NBD_DEFAULT_PORT)); 1670 } 1671 1672 return true; 1673 } 1674 1675 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1676 Error **errp) 1677 { 1678 SocketAddress *saddr = NULL; 1679 QDict *addr = NULL; 1680 Visitor *iv = NULL; 1681 1682 qdict_extract_subqdict(options, &addr, "server."); 1683 if (!qdict_size(addr)) { 1684 error_setg(errp, "NBD server address missing"); 1685 goto done; 1686 } 1687 1688 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1689 if (!iv) { 1690 goto done; 1691 } 1692 1693 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1694 goto done; 1695 } 1696 1697 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1698 qapi_free_SocketAddress(saddr); 1699 saddr = NULL; 1700 goto done; 1701 } 1702 1703 done: 1704 qobject_unref(addr); 1705 visit_free(iv); 1706 return saddr; 1707 } 1708 1709 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1710 { 1711 Object *obj; 1712 QCryptoTLSCreds *creds; 1713 1714 obj = object_resolve_path_component( 1715 object_get_objects_root(), id); 1716 if (!obj) { 1717 error_setg(errp, "No TLS credentials with id '%s'", 1718 id); 1719 return NULL; 1720 } 1721 creds = (QCryptoTLSCreds *) 1722 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1723 if (!creds) { 1724 error_setg(errp, "Object with id '%s' is not TLS credentials", 1725 id); 1726 return NULL; 1727 } 1728 1729 if (!qcrypto_tls_creds_check_endpoint(creds, 1730 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1731 errp)) { 1732 return NULL; 1733 } 1734 object_ref(obj); 1735 return creds; 1736 } 1737 1738 1739 static QemuOptsList nbd_runtime_opts = { 1740 .name = "nbd", 1741 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1742 .desc = { 1743 { 1744 .name = "host", 1745 .type = QEMU_OPT_STRING, 1746 .help = "TCP host to connect to", 1747 }, 1748 { 1749 .name = "port", 1750 .type = QEMU_OPT_STRING, 1751 .help = "TCP port to connect to", 1752 }, 1753 { 1754 .name = "path", 1755 .type = QEMU_OPT_STRING, 1756 .help = "Unix socket path to connect to", 1757 }, 1758 { 1759 .name = "export", 1760 .type = QEMU_OPT_STRING, 1761 .help = "Name of the NBD export to open", 1762 }, 1763 { 1764 .name = "tls-creds", 1765 .type = QEMU_OPT_STRING, 1766 .help = "ID of the TLS credentials to use", 1767 }, 1768 { 1769 .name = "x-dirty-bitmap", 1770 .type = QEMU_OPT_STRING, 1771 .help = "experimental: expose named dirty bitmap in place of " 1772 "block status", 1773 }, 1774 { 1775 .name = "reconnect-delay", 1776 .type = QEMU_OPT_NUMBER, 1777 .help = "On an unexpected disconnect, the nbd client tries to " 1778 "connect again until succeeding or encountering a serious " 1779 "error. During the first @reconnect-delay seconds, all " 1780 "requests are paused and will be rerun on a successful " 1781 "reconnect. After that time, any delayed requests and all " 1782 "future requests before a successful reconnect will " 1783 "immediately fail. Default 0", 1784 }, 1785 { 1786 .name = "open-timeout", 1787 .type = QEMU_OPT_NUMBER, 1788 .help = "In seconds. If zero, the nbd driver tries the connection " 1789 "only once, and fails to open if the connection fails. " 1790 "If non-zero, the nbd driver will repeat connection " 1791 "attempts until successful or until @open-timeout seconds " 1792 "have elapsed. Default 0", 1793 }, 1794 { /* end of list */ } 1795 }, 1796 }; 1797 1798 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1799 Error **errp) 1800 { 1801 BDRVNBDState *s = bs->opaque; 1802 QemuOpts *opts; 1803 int ret = -EINVAL; 1804 1805 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1806 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1807 goto error; 1808 } 1809 1810 /* Translate @host, @port, and @path to a SocketAddress */ 1811 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1812 goto error; 1813 } 1814 1815 /* Pop the config into our state object. Exit if invalid. */ 1816 s->saddr = nbd_config(s, options, errp); 1817 if (!s->saddr) { 1818 goto error; 1819 } 1820 1821 s->export = g_strdup(qemu_opt_get(opts, "export")); 1822 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1823 error_setg(errp, "export name too long to send to server"); 1824 goto error; 1825 } 1826 1827 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1828 if (s->tlscredsid) { 1829 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1830 if (!s->tlscreds) { 1831 goto error; 1832 } 1833 1834 /* TODO SOCKET_ADDRESS_KIND_FD where fd has AF_INET or AF_INET6 */ 1835 if (s->saddr->type != SOCKET_ADDRESS_TYPE_INET) { 1836 error_setg(errp, "TLS only supported over IP sockets"); 1837 goto error; 1838 } 1839 s->hostname = s->saddr->u.inet.host; 1840 } 1841 1842 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1843 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1844 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1845 goto error; 1846 } 1847 1848 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1849 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1850 1851 ret = 0; 1852 1853 error: 1854 qemu_opts_del(opts); 1855 return ret; 1856 } 1857 1858 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1859 Error **errp) 1860 { 1861 int ret; 1862 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1863 1864 s->bs = bs; 1865 qemu_co_mutex_init(&s->send_mutex); 1866 qemu_co_queue_init(&s->free_sema); 1867 qemu_co_mutex_init(&s->receive_mutex); 1868 1869 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1870 return -EEXIST; 1871 } 1872 1873 ret = nbd_process_options(bs, options, errp); 1874 if (ret < 0) { 1875 goto fail; 1876 } 1877 1878 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1879 s->x_dirty_bitmap, s->tlscreds); 1880 1881 if (s->open_timeout) { 1882 nbd_client_connection_enable_retry(s->conn); 1883 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1884 s->open_timeout * NANOSECONDS_PER_SECOND); 1885 } 1886 1887 s->state = NBD_CLIENT_CONNECTING_WAIT; 1888 ret = nbd_do_establish_connection(bs, errp); 1889 if (ret < 0) { 1890 goto fail; 1891 } 1892 1893 /* 1894 * The connect attempt is done, so we no longer need this timer. 1895 * Delete it, because we do not want it to be around when this node 1896 * is drained or closed. 1897 */ 1898 open_timer_del(s); 1899 1900 nbd_client_connection_enable_retry(s->conn); 1901 1902 return 0; 1903 1904 fail: 1905 open_timer_del(s); 1906 nbd_clear_bdrvstate(bs); 1907 return ret; 1908 } 1909 1910 static int nbd_co_flush(BlockDriverState *bs) 1911 { 1912 return nbd_client_co_flush(bs); 1913 } 1914 1915 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1916 { 1917 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1918 uint32_t min = s->info.min_block; 1919 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1920 1921 /* 1922 * If the server did not advertise an alignment: 1923 * - a size that is not sector-aligned implies that an alignment 1924 * of 1 can be used to access those tail bytes 1925 * - advertisement of block status requires an alignment of 1, so 1926 * that we don't violate block layer constraints that block 1927 * status is always aligned (as we can't control whether the 1928 * server will report sub-sector extents, such as a hole at EOF 1929 * on an unaligned POSIX file) 1930 * - otherwise, assume the server is so old that we are safer avoiding 1931 * sub-sector requests 1932 */ 1933 if (!min) { 1934 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1935 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1936 } 1937 1938 bs->bl.request_alignment = min; 1939 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1940 bs->bl.max_pwrite_zeroes = max; 1941 bs->bl.max_transfer = max; 1942 1943 if (s->info.opt_block && 1944 s->info.opt_block > bs->bl.opt_transfer) { 1945 bs->bl.opt_transfer = s->info.opt_block; 1946 } 1947 } 1948 1949 static void nbd_close(BlockDriverState *bs) 1950 { 1951 nbd_client_close(bs); 1952 nbd_clear_bdrvstate(bs); 1953 } 1954 1955 /* 1956 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 1957 * to a smaller size with exact=false, there is no reason to fail the 1958 * operation. 1959 * 1960 * Preallocation mode is ignored since it does not seems useful to fail when 1961 * we never change anything. 1962 */ 1963 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 1964 bool exact, PreallocMode prealloc, 1965 BdrvRequestFlags flags, Error **errp) 1966 { 1967 BDRVNBDState *s = bs->opaque; 1968 1969 if (offset != s->info.size && exact) { 1970 error_setg(errp, "Cannot resize NBD nodes"); 1971 return -ENOTSUP; 1972 } 1973 1974 if (offset > s->info.size) { 1975 error_setg(errp, "Cannot grow NBD nodes"); 1976 return -EINVAL; 1977 } 1978 1979 return 0; 1980 } 1981 1982 static int64_t nbd_getlength(BlockDriverState *bs) 1983 { 1984 BDRVNBDState *s = bs->opaque; 1985 1986 return s->info.size; 1987 } 1988 1989 static void nbd_refresh_filename(BlockDriverState *bs) 1990 { 1991 BDRVNBDState *s = bs->opaque; 1992 const char *host = NULL, *port = NULL, *path = NULL; 1993 size_t len = 0; 1994 1995 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1996 const InetSocketAddress *inet = &s->saddr->u.inet; 1997 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 1998 host = inet->host; 1999 port = inet->port; 2000 } 2001 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2002 path = s->saddr->u.q_unix.path; 2003 } /* else can't represent as pseudo-filename */ 2004 2005 if (path && s->export) { 2006 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2007 "nbd+unix:///%s?socket=%s", s->export, path); 2008 } else if (path && !s->export) { 2009 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2010 "nbd+unix://?socket=%s", path); 2011 } else if (host && s->export) { 2012 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2013 "nbd://%s:%s/%s", host, port, s->export); 2014 } else if (host && !s->export) { 2015 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2016 "nbd://%s:%s", host, port); 2017 } 2018 if (len >= sizeof(bs->exact_filename)) { 2019 /* Name is too long to represent exactly, so leave it empty. */ 2020 bs->exact_filename[0] = '\0'; 2021 } 2022 } 2023 2024 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2025 { 2026 /* The generic bdrv_dirname() implementation is able to work out some 2027 * directory name for NBD nodes, but that would be wrong. So far there is no 2028 * specification for how "export paths" would work, so NBD does not have 2029 * directory names. */ 2030 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2031 return NULL; 2032 } 2033 2034 static const char *const nbd_strong_runtime_opts[] = { 2035 "path", 2036 "host", 2037 "port", 2038 "export", 2039 "tls-creds", 2040 "server.", 2041 2042 NULL 2043 }; 2044 2045 static void nbd_cancel_in_flight(BlockDriverState *bs) 2046 { 2047 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2048 2049 reconnect_delay_timer_del(s); 2050 2051 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2052 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2053 qemu_co_queue_restart_all(&s->free_sema); 2054 } 2055 2056 nbd_co_establish_connection_cancel(s->conn); 2057 } 2058 2059 static void nbd_attach_aio_context(BlockDriverState *bs, 2060 AioContext *new_context) 2061 { 2062 BDRVNBDState *s = bs->opaque; 2063 2064 /* The open_timer is used only during nbd_open() */ 2065 assert(!s->open_timer); 2066 2067 /* 2068 * The reconnect_delay_timer is scheduled in I/O paths when the 2069 * connection is lost, to cancel the reconnection attempt after a 2070 * given time. Once this attempt is done (successfully or not), 2071 * nbd_reconnect_attempt() ensures the timer is deleted before the 2072 * respective I/O request is resumed. 2073 * Since the AioContext can only be changed when a node is drained, 2074 * the reconnect_delay_timer cannot be active here. 2075 */ 2076 assert(!s->reconnect_delay_timer); 2077 2078 if (s->ioc) { 2079 qio_channel_attach_aio_context(s->ioc, new_context); 2080 } 2081 } 2082 2083 static void nbd_detach_aio_context(BlockDriverState *bs) 2084 { 2085 BDRVNBDState *s = bs->opaque; 2086 2087 assert(!s->open_timer); 2088 assert(!s->reconnect_delay_timer); 2089 2090 if (s->ioc) { 2091 qio_channel_detach_aio_context(s->ioc); 2092 } 2093 } 2094 2095 static BlockDriver bdrv_nbd = { 2096 .format_name = "nbd", 2097 .protocol_name = "nbd", 2098 .instance_size = sizeof(BDRVNBDState), 2099 .bdrv_parse_filename = nbd_parse_filename, 2100 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2101 .create_opts = &bdrv_create_opts_simple, 2102 .bdrv_file_open = nbd_open, 2103 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2104 .bdrv_co_preadv = nbd_client_co_preadv, 2105 .bdrv_co_pwritev = nbd_client_co_pwritev, 2106 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2107 .bdrv_close = nbd_close, 2108 .bdrv_co_flush_to_os = nbd_co_flush, 2109 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2110 .bdrv_refresh_limits = nbd_refresh_limits, 2111 .bdrv_co_truncate = nbd_co_truncate, 2112 .bdrv_getlength = nbd_getlength, 2113 .bdrv_refresh_filename = nbd_refresh_filename, 2114 .bdrv_co_block_status = nbd_client_co_block_status, 2115 .bdrv_dirname = nbd_dirname, 2116 .strong_runtime_opts = nbd_strong_runtime_opts, 2117 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2118 2119 .bdrv_attach_aio_context = nbd_attach_aio_context, 2120 .bdrv_detach_aio_context = nbd_detach_aio_context, 2121 }; 2122 2123 static BlockDriver bdrv_nbd_tcp = { 2124 .format_name = "nbd", 2125 .protocol_name = "nbd+tcp", 2126 .instance_size = sizeof(BDRVNBDState), 2127 .bdrv_parse_filename = nbd_parse_filename, 2128 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2129 .create_opts = &bdrv_create_opts_simple, 2130 .bdrv_file_open = nbd_open, 2131 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2132 .bdrv_co_preadv = nbd_client_co_preadv, 2133 .bdrv_co_pwritev = nbd_client_co_pwritev, 2134 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2135 .bdrv_close = nbd_close, 2136 .bdrv_co_flush_to_os = nbd_co_flush, 2137 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2138 .bdrv_refresh_limits = nbd_refresh_limits, 2139 .bdrv_co_truncate = nbd_co_truncate, 2140 .bdrv_getlength = nbd_getlength, 2141 .bdrv_refresh_filename = nbd_refresh_filename, 2142 .bdrv_co_block_status = nbd_client_co_block_status, 2143 .bdrv_dirname = nbd_dirname, 2144 .strong_runtime_opts = nbd_strong_runtime_opts, 2145 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2146 2147 .bdrv_attach_aio_context = nbd_attach_aio_context, 2148 .bdrv_detach_aio_context = nbd_detach_aio_context, 2149 }; 2150 2151 static BlockDriver bdrv_nbd_unix = { 2152 .format_name = "nbd", 2153 .protocol_name = "nbd+unix", 2154 .instance_size = sizeof(BDRVNBDState), 2155 .bdrv_parse_filename = nbd_parse_filename, 2156 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2157 .create_opts = &bdrv_create_opts_simple, 2158 .bdrv_file_open = nbd_open, 2159 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2160 .bdrv_co_preadv = nbd_client_co_preadv, 2161 .bdrv_co_pwritev = nbd_client_co_pwritev, 2162 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2163 .bdrv_close = nbd_close, 2164 .bdrv_co_flush_to_os = nbd_co_flush, 2165 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2166 .bdrv_refresh_limits = nbd_refresh_limits, 2167 .bdrv_co_truncate = nbd_co_truncate, 2168 .bdrv_getlength = nbd_getlength, 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 .bdrv_attach_aio_context = nbd_attach_aio_context, 2176 .bdrv_detach_aio_context = nbd_detach_aio_context, 2177 }; 2178 2179 static void bdrv_nbd_init(void) 2180 { 2181 bdrv_register(&bdrv_nbd); 2182 bdrv_register(&bdrv_nbd_tcp); 2183 bdrv_register(&bdrv_nbd_unix); 2184 } 2185 2186 block_init(bdrv_nbd_init); 2187