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; 94 char *tlscredsid; 95 QCryptoTLSCreds *tlscreds; 96 char *tlshostname; 97 char *x_dirty_bitmap; 98 bool alloc_depth; 99 100 NBDClientConnection *conn; 101 } BDRVNBDState; 102 103 static void nbd_yank(void *opaque); 104 105 static void nbd_clear_bdrvstate(BlockDriverState *bs) 106 { 107 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 108 109 nbd_client_connection_release(s->conn); 110 s->conn = NULL; 111 112 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 113 114 /* Must not leave timers behind that would access freed data */ 115 assert(!s->reconnect_delay_timer); 116 assert(!s->open_timer); 117 118 object_unref(OBJECT(s->tlscreds)); 119 qapi_free_SocketAddress(s->saddr); 120 s->saddr = NULL; 121 g_free(s->export); 122 s->export = NULL; 123 g_free(s->tlscredsid); 124 s->tlscredsid = NULL; 125 g_free(s->tlshostname); 126 s->tlshostname = NULL; 127 g_free(s->x_dirty_bitmap); 128 s->x_dirty_bitmap = NULL; 129 } 130 131 static bool nbd_client_connected(BDRVNBDState *s) 132 { 133 return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED; 134 } 135 136 static bool nbd_recv_coroutine_wake_one(NBDClientRequest *req) 137 { 138 if (req->receiving) { 139 req->receiving = false; 140 aio_co_wake(req->coroutine); 141 return true; 142 } 143 144 return false; 145 } 146 147 static void nbd_recv_coroutines_wake(BDRVNBDState *s, bool all) 148 { 149 int i; 150 151 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 152 if (nbd_recv_coroutine_wake_one(&s->requests[i]) && !all) { 153 return; 154 } 155 } 156 } 157 158 static void nbd_channel_error(BDRVNBDState *s, int ret) 159 { 160 if (nbd_client_connected(s)) { 161 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 162 } 163 164 if (ret == -EIO) { 165 if (nbd_client_connected(s)) { 166 s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : 167 NBD_CLIENT_CONNECTING_NOWAIT; 168 } 169 } else { 170 s->state = NBD_CLIENT_QUIT; 171 } 172 173 nbd_recv_coroutines_wake(s, true); 174 } 175 176 static void reconnect_delay_timer_del(BDRVNBDState *s) 177 { 178 if (s->reconnect_delay_timer) { 179 timer_free(s->reconnect_delay_timer); 180 s->reconnect_delay_timer = NULL; 181 } 182 } 183 184 static void reconnect_delay_timer_cb(void *opaque) 185 { 186 BDRVNBDState *s = opaque; 187 188 if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { 189 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 190 nbd_co_establish_connection_cancel(s->conn); 191 while (qemu_co_enter_next(&s->free_sema, NULL)) { 192 /* Resume all queued requests */ 193 } 194 } 195 196 reconnect_delay_timer_del(s); 197 } 198 199 static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 200 { 201 if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTING_WAIT) { 202 return; 203 } 204 205 assert(!s->reconnect_delay_timer); 206 s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 207 QEMU_CLOCK_REALTIME, 208 SCALE_NS, 209 reconnect_delay_timer_cb, s); 210 timer_mod(s->reconnect_delay_timer, expire_time_ns); 211 } 212 213 static void nbd_teardown_connection(BlockDriverState *bs) 214 { 215 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 216 217 assert(!s->in_flight); 218 219 if (s->ioc) { 220 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 221 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 222 nbd_yank, s->bs); 223 object_unref(OBJECT(s->ioc)); 224 s->ioc = NULL; 225 } 226 227 s->state = NBD_CLIENT_QUIT; 228 } 229 230 static void open_timer_del(BDRVNBDState *s) 231 { 232 if (s->open_timer) { 233 timer_free(s->open_timer); 234 s->open_timer = NULL; 235 } 236 } 237 238 static void open_timer_cb(void *opaque) 239 { 240 BDRVNBDState *s = opaque; 241 242 nbd_co_establish_connection_cancel(s->conn); 243 open_timer_del(s); 244 } 245 246 static void open_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 247 { 248 assert(!s->open_timer); 249 s->open_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 250 QEMU_CLOCK_REALTIME, 251 SCALE_NS, 252 open_timer_cb, s); 253 timer_mod(s->open_timer, expire_time_ns); 254 } 255 256 static bool nbd_client_connecting(BDRVNBDState *s) 257 { 258 NBDClientState state = qatomic_load_acquire(&s->state); 259 return state == NBD_CLIENT_CONNECTING_WAIT || 260 state == NBD_CLIENT_CONNECTING_NOWAIT; 261 } 262 263 static bool nbd_client_connecting_wait(BDRVNBDState *s) 264 { 265 return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; 266 } 267 268 /* 269 * Update @bs with information learned during a completed negotiation process. 270 * Return failure if the server's advertised options are incompatible with the 271 * client's needs. 272 */ 273 static int nbd_handle_updated_info(BlockDriverState *bs, Error **errp) 274 { 275 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 276 int ret; 277 278 if (s->x_dirty_bitmap) { 279 if (!s->info.base_allocation) { 280 error_setg(errp, "requested x-dirty-bitmap %s not found", 281 s->x_dirty_bitmap); 282 return -EINVAL; 283 } 284 if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { 285 s->alloc_depth = true; 286 } 287 } 288 289 if (s->info.flags & NBD_FLAG_READ_ONLY) { 290 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); 291 if (ret < 0) { 292 return ret; 293 } 294 } 295 296 if (s->info.flags & NBD_FLAG_SEND_FUA) { 297 bs->supported_write_flags = BDRV_REQ_FUA; 298 bs->supported_zero_flags |= BDRV_REQ_FUA; 299 } 300 301 if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { 302 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; 303 if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { 304 bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; 305 } 306 } 307 308 trace_nbd_client_handshake_success(s->export); 309 310 return 0; 311 } 312 313 int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, 314 Error **errp) 315 { 316 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 317 int ret; 318 bool blocking = nbd_client_connecting_wait(s); 319 IO_CODE(); 320 321 assert(!s->ioc); 322 323 s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); 324 if (!s->ioc) { 325 return -ECONNREFUSED; 326 } 327 328 yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, 329 bs); 330 331 ret = nbd_handle_updated_info(s->bs, NULL); 332 if (ret < 0) { 333 /* 334 * We have connected, but must fail for other reasons. 335 * Send NBD_CMD_DISC as a courtesy to the server. 336 */ 337 NBDRequest request = { .type = NBD_CMD_DISC }; 338 339 nbd_send_request(s->ioc, &request); 340 341 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 342 nbd_yank, bs); 343 object_unref(OBJECT(s->ioc)); 344 s->ioc = NULL; 345 346 return ret; 347 } 348 349 qio_channel_set_blocking(s->ioc, false, NULL); 350 qio_channel_attach_aio_context(s->ioc, bdrv_get_aio_context(bs)); 351 352 /* successfully connected */ 353 s->state = NBD_CLIENT_CONNECTED; 354 qemu_co_queue_restart_all(&s->free_sema); 355 356 return 0; 357 } 358 359 /* called under s->send_mutex */ 360 static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) 361 { 362 assert(nbd_client_connecting(s)); 363 assert(s->in_flight == 0); 364 365 if (nbd_client_connecting_wait(s) && s->reconnect_delay && 366 !s->reconnect_delay_timer) 367 { 368 /* 369 * It's first reconnect attempt after switching to 370 * NBD_CLIENT_CONNECTING_WAIT 371 */ 372 reconnect_delay_timer_init(s, 373 qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 374 s->reconnect_delay * NANOSECONDS_PER_SECOND); 375 } 376 377 /* 378 * Now we are sure that nobody is accessing the channel, and no one will 379 * try until we set the state to CONNECTED. 380 */ 381 382 /* Finalize previous connection if any */ 383 if (s->ioc) { 384 qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); 385 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 386 nbd_yank, s->bs); 387 object_unref(OBJECT(s->ioc)); 388 s->ioc = NULL; 389 } 390 391 nbd_co_do_establish_connection(s->bs, NULL); 392 393 /* 394 * The reconnect attempt is done (maybe successfully, maybe not), so 395 * we no longer need this timer. Delete it so it will not outlive 396 * this I/O request (so draining removes all timers). 397 */ 398 reconnect_delay_timer_del(s); 399 } 400 401 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle) 402 { 403 int ret; 404 uint64_t ind = HANDLE_TO_INDEX(s, handle), ind2; 405 QEMU_LOCK_GUARD(&s->receive_mutex); 406 407 while (true) { 408 if (s->reply.handle == handle) { 409 /* We are done */ 410 return 0; 411 } 412 413 if (!nbd_client_connected(s)) { 414 return -EIO; 415 } 416 417 if (s->reply.handle != 0) { 418 /* 419 * Some other request is being handled now. It should already be 420 * woken by whoever set s->reply.handle (or never wait in this 421 * yield). So, we should not wake it here. 422 */ 423 ind2 = HANDLE_TO_INDEX(s, s->reply.handle); 424 assert(!s->requests[ind2].receiving); 425 426 s->requests[ind].receiving = true; 427 qemu_co_mutex_unlock(&s->receive_mutex); 428 429 qemu_coroutine_yield(); 430 /* 431 * We may be woken for 3 reasons: 432 * 1. From this function, executing in parallel coroutine, when our 433 * handle is received. 434 * 2. From nbd_channel_error(), when connection is lost. 435 * 3. From nbd_co_receive_one_chunk(), when previous request is 436 * finished and s->reply.handle set to 0. 437 * Anyway, it's OK to lock the mutex and go to the next iteration. 438 */ 439 440 qemu_co_mutex_lock(&s->receive_mutex); 441 assert(!s->requests[ind].receiving); 442 continue; 443 } 444 445 /* We are under mutex and handle is 0. We have to do the dirty work. */ 446 assert(s->reply.handle == 0); 447 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, NULL); 448 if (ret <= 0) { 449 ret = ret ? ret : -EIO; 450 nbd_channel_error(s, ret); 451 return ret; 452 } 453 if (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply) { 454 nbd_channel_error(s, -EINVAL); 455 return -EINVAL; 456 } 457 if (s->reply.handle == handle) { 458 /* We are done */ 459 return 0; 460 } 461 ind2 = HANDLE_TO_INDEX(s, s->reply.handle); 462 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].reply_possible) { 463 nbd_channel_error(s, -EINVAL); 464 return -EINVAL; 465 } 466 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 467 } 468 } 469 470 static int nbd_co_send_request(BlockDriverState *bs, 471 NBDRequest *request, 472 QEMUIOVector *qiov) 473 { 474 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 475 int rc, i = -1; 476 477 qemu_co_mutex_lock(&s->send_mutex); 478 479 while (s->in_flight == MAX_NBD_REQUESTS || 480 (!nbd_client_connected(s) && s->in_flight > 0)) 481 { 482 qemu_co_queue_wait(&s->free_sema, &s->send_mutex); 483 } 484 485 if (nbd_client_connecting(s)) { 486 nbd_reconnect_attempt(s); 487 } 488 489 if (!nbd_client_connected(s)) { 490 rc = -EIO; 491 goto err; 492 } 493 494 s->in_flight++; 495 496 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 497 if (s->requests[i].coroutine == NULL) { 498 break; 499 } 500 } 501 502 g_assert(qemu_in_coroutine()); 503 assert(i < MAX_NBD_REQUESTS); 504 505 s->requests[i].coroutine = qemu_coroutine_self(); 506 s->requests[i].offset = request->from; 507 s->requests[i].receiving = false; 508 s->requests[i].reply_possible = true; 509 510 request->handle = INDEX_TO_HANDLE(s, i); 511 512 assert(s->ioc); 513 514 if (qiov) { 515 qio_channel_set_cork(s->ioc, true); 516 rc = nbd_send_request(s->ioc, request); 517 if (nbd_client_connected(s) && rc >= 0) { 518 if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 519 NULL) < 0) { 520 rc = -EIO; 521 } 522 } else if (rc >= 0) { 523 rc = -EIO; 524 } 525 qio_channel_set_cork(s->ioc, false); 526 } else { 527 rc = nbd_send_request(s->ioc, request); 528 } 529 530 err: 531 if (rc < 0) { 532 nbd_channel_error(s, rc); 533 if (i != -1) { 534 s->requests[i].coroutine = NULL; 535 s->in_flight--; 536 } 537 qemu_co_queue_next(&s->free_sema); 538 } 539 qemu_co_mutex_unlock(&s->send_mutex); 540 return rc; 541 } 542 543 static inline uint16_t payload_advance16(uint8_t **payload) 544 { 545 *payload += 2; 546 return lduw_be_p(*payload - 2); 547 } 548 549 static inline uint32_t payload_advance32(uint8_t **payload) 550 { 551 *payload += 4; 552 return ldl_be_p(*payload - 4); 553 } 554 555 static inline uint64_t payload_advance64(uint8_t **payload) 556 { 557 *payload += 8; 558 return ldq_be_p(*payload - 8); 559 } 560 561 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 562 NBDStructuredReplyChunk *chunk, 563 uint8_t *payload, uint64_t orig_offset, 564 QEMUIOVector *qiov, Error **errp) 565 { 566 uint64_t offset; 567 uint32_t hole_size; 568 569 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 570 error_setg(errp, "Protocol error: invalid payload for " 571 "NBD_REPLY_TYPE_OFFSET_HOLE"); 572 return -EINVAL; 573 } 574 575 offset = payload_advance64(&payload); 576 hole_size = payload_advance32(&payload); 577 578 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 579 offset > orig_offset + qiov->size - hole_size) { 580 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 581 " region"); 582 return -EINVAL; 583 } 584 if (s->info.min_block && 585 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 586 trace_nbd_structured_read_compliance("hole"); 587 } 588 589 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 590 591 return 0; 592 } 593 594 /* 595 * nbd_parse_blockstatus_payload 596 * Based on our request, we expect only one extent in reply, for the 597 * base:allocation context. 598 */ 599 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 600 NBDStructuredReplyChunk *chunk, 601 uint8_t *payload, uint64_t orig_length, 602 NBDExtent *extent, Error **errp) 603 { 604 uint32_t context_id; 605 606 /* The server succeeded, so it must have sent [at least] one extent */ 607 if (chunk->length < sizeof(context_id) + sizeof(*extent)) { 608 error_setg(errp, "Protocol error: invalid payload for " 609 "NBD_REPLY_TYPE_BLOCK_STATUS"); 610 return -EINVAL; 611 } 612 613 context_id = payload_advance32(&payload); 614 if (s->info.context_id != context_id) { 615 error_setg(errp, "Protocol error: unexpected context id %d for " 616 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 617 "id is %d", context_id, 618 s->info.context_id); 619 return -EINVAL; 620 } 621 622 extent->length = payload_advance32(&payload); 623 extent->flags = payload_advance32(&payload); 624 625 if (extent->length == 0) { 626 error_setg(errp, "Protocol error: server sent status chunk with " 627 "zero length"); 628 return -EINVAL; 629 } 630 631 /* 632 * A server sending unaligned block status is in violation of the 633 * protocol, but as qemu-nbd 3.1 is such a server (at least for 634 * POSIX files that are not a multiple of 512 bytes, since qemu 635 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 636 * still sees an implicit hole beyond the real EOF), it's nicer to 637 * work around the misbehaving server. If the request included 638 * more than the final unaligned block, truncate it back to an 639 * aligned result; if the request was only the final block, round 640 * up to the full block and change the status to fully-allocated 641 * (always a safe status, even if it loses information). 642 */ 643 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 644 s->info.min_block)) { 645 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 646 if (extent->length > s->info.min_block) { 647 extent->length = QEMU_ALIGN_DOWN(extent->length, 648 s->info.min_block); 649 } else { 650 extent->length = s->info.min_block; 651 extent->flags = 0; 652 } 653 } 654 655 /* 656 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 657 * sent us any more than one extent, nor should it have included 658 * status beyond our request in that extent. However, it's easy 659 * enough to ignore the server's noncompliance without killing the 660 * connection; just ignore trailing extents, and clamp things to 661 * the length of our request. 662 */ 663 if (chunk->length > sizeof(context_id) + sizeof(*extent)) { 664 trace_nbd_parse_blockstatus_compliance("more than one extent"); 665 } 666 if (extent->length > orig_length) { 667 extent->length = orig_length; 668 trace_nbd_parse_blockstatus_compliance("extent length too large"); 669 } 670 671 /* 672 * HACK: if we are using x-dirty-bitmaps to access 673 * qemu:allocation-depth, treat all depths > 2 the same as 2, 674 * since nbd_client_co_block_status is only expecting the low two 675 * bits to be set. 676 */ 677 if (s->alloc_depth && extent->flags > 2) { 678 extent->flags = 2; 679 } 680 681 return 0; 682 } 683 684 /* 685 * nbd_parse_error_payload 686 * on success @errp contains message describing nbd error reply 687 */ 688 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 689 uint8_t *payload, int *request_ret, 690 Error **errp) 691 { 692 uint32_t error; 693 uint16_t message_size; 694 695 assert(chunk->type & (1 << 15)); 696 697 if (chunk->length < sizeof(error) + sizeof(message_size)) { 698 error_setg(errp, 699 "Protocol error: invalid payload for structured error"); 700 return -EINVAL; 701 } 702 703 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 704 if (error == 0) { 705 error_setg(errp, "Protocol error: server sent structured error chunk " 706 "with error = 0"); 707 return -EINVAL; 708 } 709 710 *request_ret = -error; 711 message_size = payload_advance16(&payload); 712 713 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 714 error_setg(errp, "Protocol error: server sent structured error chunk " 715 "with incorrect message size"); 716 return -EINVAL; 717 } 718 719 /* TODO: Add a trace point to mention the server complaint */ 720 721 /* TODO handle ERROR_OFFSET */ 722 723 return 0; 724 } 725 726 static int nbd_co_receive_offset_data_payload(BDRVNBDState *s, 727 uint64_t orig_offset, 728 QEMUIOVector *qiov, Error **errp) 729 { 730 QEMUIOVector sub_qiov; 731 uint64_t offset; 732 size_t data_size; 733 int ret; 734 NBDStructuredReplyChunk *chunk = &s->reply.structured; 735 736 assert(nbd_reply_is_structured(&s->reply)); 737 738 /* The NBD spec requires at least one byte of payload */ 739 if (chunk->length <= sizeof(offset)) { 740 error_setg(errp, "Protocol error: invalid payload for " 741 "NBD_REPLY_TYPE_OFFSET_DATA"); 742 return -EINVAL; 743 } 744 745 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 746 return -EIO; 747 } 748 749 data_size = chunk->length - sizeof(offset); 750 assert(data_size); 751 if (offset < orig_offset || data_size > qiov->size || 752 offset > orig_offset + qiov->size - data_size) { 753 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 754 " region"); 755 return -EINVAL; 756 } 757 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 758 trace_nbd_structured_read_compliance("data"); 759 } 760 761 qemu_iovec_init(&sub_qiov, qiov->niov); 762 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 763 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 764 qemu_iovec_destroy(&sub_qiov); 765 766 return ret < 0 ? -EIO : 0; 767 } 768 769 #define NBD_MAX_MALLOC_PAYLOAD 1000 770 static coroutine_fn int nbd_co_receive_structured_payload( 771 BDRVNBDState *s, void **payload, Error **errp) 772 { 773 int ret; 774 uint32_t len; 775 776 assert(nbd_reply_is_structured(&s->reply)); 777 778 len = s->reply.structured.length; 779 780 if (len == 0) { 781 return 0; 782 } 783 784 if (payload == NULL) { 785 error_setg(errp, "Unexpected structured payload"); 786 return -EINVAL; 787 } 788 789 if (len > NBD_MAX_MALLOC_PAYLOAD) { 790 error_setg(errp, "Payload too large"); 791 return -EINVAL; 792 } 793 794 *payload = g_new(char, len); 795 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 796 if (ret < 0) { 797 g_free(*payload); 798 *payload = NULL; 799 return ret; 800 } 801 802 return 0; 803 } 804 805 /* 806 * nbd_co_do_receive_one_chunk 807 * for simple reply: 808 * set request_ret to received reply error 809 * if qiov is not NULL: read payload to @qiov 810 * for structured reply chunk: 811 * if error chunk: read payload, set @request_ret, do not set @payload 812 * else if offset_data chunk: read payload data to @qiov, do not set @payload 813 * else: read payload to @payload 814 * 815 * If function fails, @errp contains corresponding error message, and the 816 * connection with the server is suspect. If it returns 0, then the 817 * transaction succeeded (although @request_ret may be a negative errno 818 * corresponding to the server's error reply), and errp is unchanged. 819 */ 820 static coroutine_fn int nbd_co_do_receive_one_chunk( 821 BDRVNBDState *s, uint64_t handle, bool only_structured, 822 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 823 { 824 int ret; 825 int i = HANDLE_TO_INDEX(s, handle); 826 void *local_payload = NULL; 827 NBDStructuredReplyChunk *chunk; 828 829 if (payload) { 830 *payload = NULL; 831 } 832 *request_ret = 0; 833 834 nbd_receive_replies(s, handle); 835 if (!nbd_client_connected(s)) { 836 error_setg(errp, "Connection closed"); 837 return -EIO; 838 } 839 assert(s->ioc); 840 841 assert(s->reply.handle == handle); 842 843 if (nbd_reply_is_simple(&s->reply)) { 844 if (only_structured) { 845 error_setg(errp, "Protocol error: simple reply when structured " 846 "reply chunk was expected"); 847 return -EINVAL; 848 } 849 850 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 851 if (*request_ret < 0 || !qiov) { 852 return 0; 853 } 854 855 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 856 errp) < 0 ? -EIO : 0; 857 } 858 859 /* handle structured reply chunk */ 860 assert(s->info.structured_reply); 861 chunk = &s->reply.structured; 862 863 if (chunk->type == NBD_REPLY_TYPE_NONE) { 864 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 865 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 866 " NBD_REPLY_FLAG_DONE flag set"); 867 return -EINVAL; 868 } 869 if (chunk->length) { 870 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 871 " nonzero length"); 872 return -EINVAL; 873 } 874 return 0; 875 } 876 877 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 878 if (!qiov) { 879 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 880 return -EINVAL; 881 } 882 883 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 884 qiov, errp); 885 } 886 887 if (nbd_reply_type_is_error(chunk->type)) { 888 payload = &local_payload; 889 } 890 891 ret = nbd_co_receive_structured_payload(s, payload, errp); 892 if (ret < 0) { 893 return ret; 894 } 895 896 if (nbd_reply_type_is_error(chunk->type)) { 897 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 898 g_free(local_payload); 899 return ret; 900 } 901 902 return 0; 903 } 904 905 /* 906 * nbd_co_receive_one_chunk 907 * Read reply, wake up connection_co and set s->quit if needed. 908 * Return value is a fatal error code or normal nbd reply error code 909 */ 910 static coroutine_fn int nbd_co_receive_one_chunk( 911 BDRVNBDState *s, uint64_t handle, bool only_structured, 912 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 913 Error **errp) 914 { 915 int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured, 916 request_ret, qiov, payload, errp); 917 918 if (ret < 0) { 919 memset(reply, 0, sizeof(*reply)); 920 nbd_channel_error(s, ret); 921 } else { 922 /* For assert at loop start in nbd_connection_entry */ 923 *reply = s->reply; 924 } 925 s->reply.handle = 0; 926 927 nbd_recv_coroutines_wake(s, false); 928 929 return ret; 930 } 931 932 typedef struct NBDReplyChunkIter { 933 int ret; 934 int request_ret; 935 Error *err; 936 bool done, only_structured; 937 } NBDReplyChunkIter; 938 939 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 940 int ret, Error **local_err) 941 { 942 assert(local_err && *local_err); 943 assert(ret < 0); 944 945 if (!iter->ret) { 946 iter->ret = ret; 947 error_propagate(&iter->err, *local_err); 948 } else { 949 error_free(*local_err); 950 } 951 952 *local_err = NULL; 953 } 954 955 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 956 { 957 assert(ret < 0); 958 959 if (!iter->request_ret) { 960 iter->request_ret = ret; 961 } 962 } 963 964 /* 965 * NBD_FOREACH_REPLY_CHUNK 966 * The pointer stored in @payload requires g_free() to free it. 967 */ 968 #define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \ 969 qiov, reply, payload) \ 970 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 971 nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);) 972 973 /* 974 * nbd_reply_chunk_iter_receive 975 * The pointer stored in @payload requires g_free() to free it. 976 */ 977 static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, 978 NBDReplyChunkIter *iter, 979 uint64_t handle, 980 QEMUIOVector *qiov, NBDReply *reply, 981 void **payload) 982 { 983 int ret, request_ret; 984 NBDReply local_reply; 985 NBDStructuredReplyChunk *chunk; 986 Error *local_err = NULL; 987 if (!nbd_client_connected(s)) { 988 error_setg(&local_err, "Connection closed"); 989 nbd_iter_channel_error(iter, -EIO, &local_err); 990 goto break_loop; 991 } 992 993 if (iter->done) { 994 /* Previous iteration was last. */ 995 goto break_loop; 996 } 997 998 if (reply == NULL) { 999 reply = &local_reply; 1000 } 1001 1002 ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured, 1003 &request_ret, qiov, reply, payload, 1004 &local_err); 1005 if (ret < 0) { 1006 nbd_iter_channel_error(iter, ret, &local_err); 1007 } else if (request_ret < 0) { 1008 nbd_iter_request_error(iter, request_ret); 1009 } 1010 1011 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1012 if (nbd_reply_is_simple(reply) || !nbd_client_connected(s)) { 1013 goto break_loop; 1014 } 1015 1016 chunk = &reply->structured; 1017 iter->only_structured = true; 1018 1019 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1020 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1021 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1022 goto break_loop; 1023 } 1024 1025 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1026 /* This iteration is last. */ 1027 iter->done = true; 1028 } 1029 1030 /* Execute the loop body */ 1031 return true; 1032 1033 break_loop: 1034 s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL; 1035 1036 qemu_co_mutex_lock(&s->send_mutex); 1037 s->in_flight--; 1038 qemu_co_queue_next(&s->free_sema); 1039 qemu_co_mutex_unlock(&s->send_mutex); 1040 1041 return false; 1042 } 1043 1044 static int nbd_co_receive_return_code(BDRVNBDState *s, uint64_t handle, 1045 int *request_ret, Error **errp) 1046 { 1047 NBDReplyChunkIter iter; 1048 1049 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) { 1050 /* nbd_reply_chunk_iter_receive does all the work */ 1051 } 1052 1053 error_propagate(errp, iter.err); 1054 *request_ret = iter.request_ret; 1055 return iter.ret; 1056 } 1057 1058 static int nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t handle, 1059 uint64_t offset, QEMUIOVector *qiov, 1060 int *request_ret, Error **errp) 1061 { 1062 NBDReplyChunkIter iter; 1063 NBDReply reply; 1064 void *payload = NULL; 1065 Error *local_err = NULL; 1066 1067 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, 1068 qiov, &reply, &payload) 1069 { 1070 int ret; 1071 NBDStructuredReplyChunk *chunk = &reply.structured; 1072 1073 assert(nbd_reply_is_structured(&reply)); 1074 1075 switch (chunk->type) { 1076 case NBD_REPLY_TYPE_OFFSET_DATA: 1077 /* 1078 * special cased in nbd_co_receive_one_chunk, data is already 1079 * in qiov 1080 */ 1081 break; 1082 case NBD_REPLY_TYPE_OFFSET_HOLE: 1083 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1084 offset, qiov, &local_err); 1085 if (ret < 0) { 1086 nbd_channel_error(s, ret); 1087 nbd_iter_channel_error(&iter, ret, &local_err); 1088 } 1089 break; 1090 default: 1091 if (!nbd_reply_type_is_error(chunk->type)) { 1092 /* not allowed reply type */ 1093 nbd_channel_error(s, -EINVAL); 1094 error_setg(&local_err, 1095 "Unexpected reply type: %d (%s) for CMD_READ", 1096 chunk->type, nbd_reply_type_lookup(chunk->type)); 1097 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1098 } 1099 } 1100 1101 g_free(payload); 1102 payload = NULL; 1103 } 1104 1105 error_propagate(errp, iter.err); 1106 *request_ret = iter.request_ret; 1107 return iter.ret; 1108 } 1109 1110 static int nbd_co_receive_blockstatus_reply(BDRVNBDState *s, 1111 uint64_t handle, uint64_t length, 1112 NBDExtent *extent, 1113 int *request_ret, Error **errp) 1114 { 1115 NBDReplyChunkIter iter; 1116 NBDReply reply; 1117 void *payload = NULL; 1118 Error *local_err = NULL; 1119 bool received = false; 1120 1121 assert(!extent->length); 1122 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { 1123 int ret; 1124 NBDStructuredReplyChunk *chunk = &reply.structured; 1125 1126 assert(nbd_reply_is_structured(&reply)); 1127 1128 switch (chunk->type) { 1129 case NBD_REPLY_TYPE_BLOCK_STATUS: 1130 if (received) { 1131 nbd_channel_error(s, -EINVAL); 1132 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1133 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1134 } 1135 received = true; 1136 1137 ret = nbd_parse_blockstatus_payload(s, &reply.structured, 1138 payload, length, extent, 1139 &local_err); 1140 if (ret < 0) { 1141 nbd_channel_error(s, ret); 1142 nbd_iter_channel_error(&iter, ret, &local_err); 1143 } 1144 break; 1145 default: 1146 if (!nbd_reply_type_is_error(chunk->type)) { 1147 nbd_channel_error(s, -EINVAL); 1148 error_setg(&local_err, 1149 "Unexpected reply type: %d (%s) " 1150 "for CMD_BLOCK_STATUS", 1151 chunk->type, nbd_reply_type_lookup(chunk->type)); 1152 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1153 } 1154 } 1155 1156 g_free(payload); 1157 payload = NULL; 1158 } 1159 1160 if (!extent->length && !iter.request_ret) { 1161 error_setg(&local_err, "Server did not reply with any status extents"); 1162 nbd_iter_channel_error(&iter, -EIO, &local_err); 1163 } 1164 1165 error_propagate(errp, iter.err); 1166 *request_ret = iter.request_ret; 1167 return iter.ret; 1168 } 1169 1170 static int nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1171 QEMUIOVector *write_qiov) 1172 { 1173 int ret, request_ret; 1174 Error *local_err = NULL; 1175 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1176 1177 assert(request->type != NBD_CMD_READ); 1178 if (write_qiov) { 1179 assert(request->type == NBD_CMD_WRITE); 1180 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1181 } else { 1182 assert(request->type != NBD_CMD_WRITE); 1183 } 1184 1185 do { 1186 ret = nbd_co_send_request(bs, request, write_qiov); 1187 if (ret < 0) { 1188 continue; 1189 } 1190 1191 ret = nbd_co_receive_return_code(s, request->handle, 1192 &request_ret, &local_err); 1193 if (local_err) { 1194 trace_nbd_co_request_fail(request->from, request->len, 1195 request->handle, request->flags, 1196 request->type, 1197 nbd_cmd_lookup(request->type), 1198 ret, error_get_pretty(local_err)); 1199 error_free(local_err); 1200 local_err = NULL; 1201 } 1202 } while (ret < 0 && nbd_client_connecting_wait(s)); 1203 1204 return ret ? ret : request_ret; 1205 } 1206 1207 static int nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, 1208 int64_t bytes, QEMUIOVector *qiov, 1209 BdrvRequestFlags flags) 1210 { 1211 int ret, request_ret; 1212 Error *local_err = NULL; 1213 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1214 NBDRequest request = { 1215 .type = NBD_CMD_READ, 1216 .from = offset, 1217 .len = bytes, 1218 }; 1219 1220 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1221 assert(!flags); 1222 1223 if (!bytes) { 1224 return 0; 1225 } 1226 /* 1227 * Work around the fact that the block layer doesn't do 1228 * byte-accurate sizing yet - if the read exceeds the server's 1229 * advertised size because the block layer rounded size up, then 1230 * truncate the request to the server and tail-pad with zero. 1231 */ 1232 if (offset >= s->info.size) { 1233 assert(bytes < BDRV_SECTOR_SIZE); 1234 qemu_iovec_memset(qiov, 0, 0, bytes); 1235 return 0; 1236 } 1237 if (offset + bytes > s->info.size) { 1238 uint64_t slop = offset + bytes - s->info.size; 1239 1240 assert(slop < BDRV_SECTOR_SIZE); 1241 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1242 request.len -= slop; 1243 } 1244 1245 do { 1246 ret = nbd_co_send_request(bs, &request, NULL); 1247 if (ret < 0) { 1248 continue; 1249 } 1250 1251 ret = nbd_co_receive_cmdread_reply(s, request.handle, offset, qiov, 1252 &request_ret, &local_err); 1253 if (local_err) { 1254 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1255 request.flags, request.type, 1256 nbd_cmd_lookup(request.type), 1257 ret, error_get_pretty(local_err)); 1258 error_free(local_err); 1259 local_err = NULL; 1260 } 1261 } while (ret < 0 && nbd_client_connecting_wait(s)); 1262 1263 return ret ? ret : request_ret; 1264 } 1265 1266 static int nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, 1267 int64_t bytes, QEMUIOVector *qiov, 1268 BdrvRequestFlags flags) 1269 { 1270 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1271 NBDRequest request = { 1272 .type = NBD_CMD_WRITE, 1273 .from = offset, 1274 .len = bytes, 1275 }; 1276 1277 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1278 if (flags & BDRV_REQ_FUA) { 1279 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1280 request.flags |= NBD_CMD_FLAG_FUA; 1281 } 1282 1283 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1284 1285 if (!bytes) { 1286 return 0; 1287 } 1288 return nbd_co_request(bs, &request, qiov); 1289 } 1290 1291 static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, 1292 int64_t bytes, BdrvRequestFlags flags) 1293 { 1294 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1295 NBDRequest request = { 1296 .type = NBD_CMD_WRITE_ZEROES, 1297 .from = offset, 1298 .len = bytes, /* .len is uint32_t actually */ 1299 }; 1300 1301 assert(bytes <= UINT32_MAX); /* rely on max_pwrite_zeroes */ 1302 1303 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1304 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1305 return -ENOTSUP; 1306 } 1307 1308 if (flags & BDRV_REQ_FUA) { 1309 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1310 request.flags |= NBD_CMD_FLAG_FUA; 1311 } 1312 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1313 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1314 } 1315 if (flags & BDRV_REQ_NO_FALLBACK) { 1316 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1317 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1318 } 1319 1320 if (!bytes) { 1321 return 0; 1322 } 1323 return nbd_co_request(bs, &request, NULL); 1324 } 1325 1326 static int nbd_client_co_flush(BlockDriverState *bs) 1327 { 1328 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1329 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1330 1331 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1332 return 0; 1333 } 1334 1335 request.from = 0; 1336 request.len = 0; 1337 1338 return nbd_co_request(bs, &request, NULL); 1339 } 1340 1341 static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, 1342 int64_t bytes) 1343 { 1344 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1345 NBDRequest request = { 1346 .type = NBD_CMD_TRIM, 1347 .from = offset, 1348 .len = bytes, /* len is uint32_t */ 1349 }; 1350 1351 assert(bytes <= UINT32_MAX); /* rely on max_pdiscard */ 1352 1353 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1354 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1355 return 0; 1356 } 1357 1358 return nbd_co_request(bs, &request, NULL); 1359 } 1360 1361 static int coroutine_fn nbd_client_co_block_status( 1362 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1363 int64_t *pnum, int64_t *map, BlockDriverState **file) 1364 { 1365 int ret, request_ret; 1366 NBDExtent extent = { 0 }; 1367 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1368 Error *local_err = NULL; 1369 1370 NBDRequest request = { 1371 .type = NBD_CMD_BLOCK_STATUS, 1372 .from = offset, 1373 .len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1374 MIN(bytes, s->info.size - offset)), 1375 .flags = NBD_CMD_FLAG_REQ_ONE, 1376 }; 1377 1378 if (!s->info.base_allocation) { 1379 *pnum = bytes; 1380 *map = offset; 1381 *file = bs; 1382 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1383 } 1384 1385 /* 1386 * Work around the fact that the block layer doesn't do 1387 * byte-accurate sizing yet - if the status request exceeds the 1388 * server's advertised size because the block layer rounded size 1389 * up, we truncated the request to the server (above), or are 1390 * called on just the hole. 1391 */ 1392 if (offset >= s->info.size) { 1393 *pnum = bytes; 1394 assert(bytes < BDRV_SECTOR_SIZE); 1395 /* Intentionally don't report offset_valid for the hole */ 1396 return BDRV_BLOCK_ZERO; 1397 } 1398 1399 if (s->info.min_block) { 1400 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1401 } 1402 do { 1403 ret = nbd_co_send_request(bs, &request, NULL); 1404 if (ret < 0) { 1405 continue; 1406 } 1407 1408 ret = nbd_co_receive_blockstatus_reply(s, request.handle, bytes, 1409 &extent, &request_ret, 1410 &local_err); 1411 if (local_err) { 1412 trace_nbd_co_request_fail(request.from, request.len, request.handle, 1413 request.flags, request.type, 1414 nbd_cmd_lookup(request.type), 1415 ret, error_get_pretty(local_err)); 1416 error_free(local_err); 1417 local_err = NULL; 1418 } 1419 } while (ret < 0 && nbd_client_connecting_wait(s)); 1420 1421 if (ret < 0 || request_ret < 0) { 1422 return ret ? ret : request_ret; 1423 } 1424 1425 assert(extent.length); 1426 *pnum = extent.length; 1427 *map = offset; 1428 *file = bs; 1429 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1430 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1431 BDRV_BLOCK_OFFSET_VALID; 1432 } 1433 1434 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1435 BlockReopenQueue *queue, Error **errp) 1436 { 1437 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1438 1439 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1440 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1441 return -EACCES; 1442 } 1443 return 0; 1444 } 1445 1446 static void nbd_yank(void *opaque) 1447 { 1448 BlockDriverState *bs = opaque; 1449 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1450 1451 qatomic_store_release(&s->state, NBD_CLIENT_QUIT); 1452 qio_channel_shutdown(QIO_CHANNEL(s->ioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1453 } 1454 1455 static void nbd_client_close(BlockDriverState *bs) 1456 { 1457 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1458 NBDRequest request = { .type = NBD_CMD_DISC }; 1459 1460 if (s->ioc) { 1461 nbd_send_request(s->ioc, &request); 1462 } 1463 1464 nbd_teardown_connection(bs); 1465 } 1466 1467 1468 /* 1469 * Parse nbd_open options 1470 */ 1471 1472 static int nbd_parse_uri(const char *filename, QDict *options) 1473 { 1474 URI *uri; 1475 const char *p; 1476 QueryParams *qp = NULL; 1477 int ret = 0; 1478 bool is_unix; 1479 1480 uri = uri_parse(filename); 1481 if (!uri) { 1482 return -EINVAL; 1483 } 1484 1485 /* transport */ 1486 if (!g_strcmp0(uri->scheme, "nbd")) { 1487 is_unix = false; 1488 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1489 is_unix = false; 1490 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1491 is_unix = true; 1492 } else { 1493 ret = -EINVAL; 1494 goto out; 1495 } 1496 1497 p = uri->path ? uri->path : ""; 1498 if (p[0] == '/') { 1499 p++; 1500 } 1501 if (p[0]) { 1502 qdict_put_str(options, "export", p); 1503 } 1504 1505 qp = query_params_parse(uri->query); 1506 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1507 ret = -EINVAL; 1508 goto out; 1509 } 1510 1511 if (is_unix) { 1512 /* nbd+unix:///export?socket=path */ 1513 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1514 ret = -EINVAL; 1515 goto out; 1516 } 1517 qdict_put_str(options, "server.type", "unix"); 1518 qdict_put_str(options, "server.path", qp->p[0].value); 1519 } else { 1520 QString *host; 1521 char *port_str; 1522 1523 /* nbd[+tcp]://host[:port]/export */ 1524 if (!uri->server) { 1525 ret = -EINVAL; 1526 goto out; 1527 } 1528 1529 /* strip braces from literal IPv6 address */ 1530 if (uri->server[0] == '[') { 1531 host = qstring_from_substr(uri->server, 1, 1532 strlen(uri->server) - 1); 1533 } else { 1534 host = qstring_from_str(uri->server); 1535 } 1536 1537 qdict_put_str(options, "server.type", "inet"); 1538 qdict_put(options, "server.host", host); 1539 1540 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1541 qdict_put_str(options, "server.port", port_str); 1542 g_free(port_str); 1543 } 1544 1545 out: 1546 if (qp) { 1547 query_params_free(qp); 1548 } 1549 uri_free(uri); 1550 return ret; 1551 } 1552 1553 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1554 { 1555 const QDictEntry *e; 1556 1557 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1558 if (!strcmp(e->key, "host") || 1559 !strcmp(e->key, "port") || 1560 !strcmp(e->key, "path") || 1561 !strcmp(e->key, "export") || 1562 strstart(e->key, "server.", NULL)) 1563 { 1564 error_setg(errp, "Option '%s' cannot be used with a file name", 1565 e->key); 1566 return true; 1567 } 1568 } 1569 1570 return false; 1571 } 1572 1573 static void nbd_parse_filename(const char *filename, QDict *options, 1574 Error **errp) 1575 { 1576 g_autofree char *file = NULL; 1577 char *export_name; 1578 const char *host_spec; 1579 const char *unixpath; 1580 1581 if (nbd_has_filename_options_conflict(options, errp)) { 1582 return; 1583 } 1584 1585 if (strstr(filename, "://")) { 1586 int ret = nbd_parse_uri(filename, options); 1587 if (ret < 0) { 1588 error_setg(errp, "No valid URL specified"); 1589 } 1590 return; 1591 } 1592 1593 file = g_strdup(filename); 1594 1595 export_name = strstr(file, EN_OPTSTR); 1596 if (export_name) { 1597 if (export_name[strlen(EN_OPTSTR)] == 0) { 1598 return; 1599 } 1600 export_name[0] = 0; /* truncate 'file' */ 1601 export_name += strlen(EN_OPTSTR); 1602 1603 qdict_put_str(options, "export", export_name); 1604 } 1605 1606 /* extract the host_spec - fail if it's not nbd:... */ 1607 if (!strstart(file, "nbd:", &host_spec)) { 1608 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1609 return; 1610 } 1611 1612 if (!*host_spec) { 1613 return; 1614 } 1615 1616 /* are we a UNIX or TCP socket? */ 1617 if (strstart(host_spec, "unix:", &unixpath)) { 1618 qdict_put_str(options, "server.type", "unix"); 1619 qdict_put_str(options, "server.path", unixpath); 1620 } else { 1621 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1622 1623 if (inet_parse(addr, host_spec, errp)) { 1624 goto out_inet; 1625 } 1626 1627 qdict_put_str(options, "server.type", "inet"); 1628 qdict_put_str(options, "server.host", addr->host); 1629 qdict_put_str(options, "server.port", addr->port); 1630 out_inet: 1631 qapi_free_InetSocketAddress(addr); 1632 } 1633 } 1634 1635 static bool nbd_process_legacy_socket_options(QDict *output_options, 1636 QemuOpts *legacy_opts, 1637 Error **errp) 1638 { 1639 const char *path = qemu_opt_get(legacy_opts, "path"); 1640 const char *host = qemu_opt_get(legacy_opts, "host"); 1641 const char *port = qemu_opt_get(legacy_opts, "port"); 1642 const QDictEntry *e; 1643 1644 if (!path && !host && !port) { 1645 return true; 1646 } 1647 1648 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1649 { 1650 if (strstart(e->key, "server.", NULL)) { 1651 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1652 "same time"); 1653 return false; 1654 } 1655 } 1656 1657 if (path && host) { 1658 error_setg(errp, "path and host may not be used at the same time"); 1659 return false; 1660 } else if (path) { 1661 if (port) { 1662 error_setg(errp, "port may not be used without host"); 1663 return false; 1664 } 1665 1666 qdict_put_str(output_options, "server.type", "unix"); 1667 qdict_put_str(output_options, "server.path", path); 1668 } else if (host) { 1669 qdict_put_str(output_options, "server.type", "inet"); 1670 qdict_put_str(output_options, "server.host", host); 1671 qdict_put_str(output_options, "server.port", 1672 port ?: stringify(NBD_DEFAULT_PORT)); 1673 } 1674 1675 return true; 1676 } 1677 1678 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1679 Error **errp) 1680 { 1681 SocketAddress *saddr = NULL; 1682 QDict *addr = NULL; 1683 Visitor *iv = NULL; 1684 1685 qdict_extract_subqdict(options, &addr, "server."); 1686 if (!qdict_size(addr)) { 1687 error_setg(errp, "NBD server address missing"); 1688 goto done; 1689 } 1690 1691 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1692 if (!iv) { 1693 goto done; 1694 } 1695 1696 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1697 goto done; 1698 } 1699 1700 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1701 qapi_free_SocketAddress(saddr); 1702 saddr = NULL; 1703 goto done; 1704 } 1705 1706 done: 1707 qobject_unref(addr); 1708 visit_free(iv); 1709 return saddr; 1710 } 1711 1712 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1713 { 1714 Object *obj; 1715 QCryptoTLSCreds *creds; 1716 1717 obj = object_resolve_path_component( 1718 object_get_objects_root(), id); 1719 if (!obj) { 1720 error_setg(errp, "No TLS credentials with id '%s'", 1721 id); 1722 return NULL; 1723 } 1724 creds = (QCryptoTLSCreds *) 1725 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1726 if (!creds) { 1727 error_setg(errp, "Object with id '%s' is not TLS credentials", 1728 id); 1729 return NULL; 1730 } 1731 1732 if (!qcrypto_tls_creds_check_endpoint(creds, 1733 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1734 errp)) { 1735 return NULL; 1736 } 1737 object_ref(obj); 1738 return creds; 1739 } 1740 1741 1742 static QemuOptsList nbd_runtime_opts = { 1743 .name = "nbd", 1744 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1745 .desc = { 1746 { 1747 .name = "host", 1748 .type = QEMU_OPT_STRING, 1749 .help = "TCP host to connect to", 1750 }, 1751 { 1752 .name = "port", 1753 .type = QEMU_OPT_STRING, 1754 .help = "TCP port to connect to", 1755 }, 1756 { 1757 .name = "path", 1758 .type = QEMU_OPT_STRING, 1759 .help = "Unix socket path to connect to", 1760 }, 1761 { 1762 .name = "export", 1763 .type = QEMU_OPT_STRING, 1764 .help = "Name of the NBD export to open", 1765 }, 1766 { 1767 .name = "tls-creds", 1768 .type = QEMU_OPT_STRING, 1769 .help = "ID of the TLS credentials to use", 1770 }, 1771 { 1772 .name = "tls-hostname", 1773 .type = QEMU_OPT_STRING, 1774 .help = "Override hostname for validating TLS x509 certificate", 1775 }, 1776 { 1777 .name = "x-dirty-bitmap", 1778 .type = QEMU_OPT_STRING, 1779 .help = "experimental: expose named dirty bitmap in place of " 1780 "block status", 1781 }, 1782 { 1783 .name = "reconnect-delay", 1784 .type = QEMU_OPT_NUMBER, 1785 .help = "On an unexpected disconnect, the nbd client tries to " 1786 "connect again until succeeding or encountering a serious " 1787 "error. During the first @reconnect-delay seconds, all " 1788 "requests are paused and will be rerun on a successful " 1789 "reconnect. After that time, any delayed requests and all " 1790 "future requests before a successful reconnect will " 1791 "immediately fail. Default 0", 1792 }, 1793 { 1794 .name = "open-timeout", 1795 .type = QEMU_OPT_NUMBER, 1796 .help = "In seconds. If zero, the nbd driver tries the connection " 1797 "only once, and fails to open if the connection fails. " 1798 "If non-zero, the nbd driver will repeat connection " 1799 "attempts until successful or until @open-timeout seconds " 1800 "have elapsed. Default 0", 1801 }, 1802 { /* end of list */ } 1803 }, 1804 }; 1805 1806 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1807 Error **errp) 1808 { 1809 BDRVNBDState *s = bs->opaque; 1810 QemuOpts *opts; 1811 int ret = -EINVAL; 1812 1813 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1814 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1815 goto error; 1816 } 1817 1818 /* Translate @host, @port, and @path to a SocketAddress */ 1819 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1820 goto error; 1821 } 1822 1823 /* Pop the config into our state object. Exit if invalid. */ 1824 s->saddr = nbd_config(s, options, errp); 1825 if (!s->saddr) { 1826 goto error; 1827 } 1828 1829 s->export = g_strdup(qemu_opt_get(opts, "export")); 1830 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1831 error_setg(errp, "export name too long to send to server"); 1832 goto error; 1833 } 1834 1835 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1836 if (s->tlscredsid) { 1837 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1838 if (!s->tlscreds) { 1839 goto error; 1840 } 1841 1842 s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); 1843 if (!s->tlshostname && 1844 s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1845 s->tlshostname = g_strdup(s->saddr->u.inet.host); 1846 } 1847 } 1848 1849 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1850 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1851 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1852 goto error; 1853 } 1854 1855 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1856 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1857 1858 ret = 0; 1859 1860 error: 1861 qemu_opts_del(opts); 1862 return ret; 1863 } 1864 1865 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1866 Error **errp) 1867 { 1868 int ret; 1869 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1870 1871 s->bs = bs; 1872 qemu_co_mutex_init(&s->send_mutex); 1873 qemu_co_queue_init(&s->free_sema); 1874 qemu_co_mutex_init(&s->receive_mutex); 1875 1876 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1877 return -EEXIST; 1878 } 1879 1880 ret = nbd_process_options(bs, options, errp); 1881 if (ret < 0) { 1882 goto fail; 1883 } 1884 1885 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1886 s->x_dirty_bitmap, s->tlscreds, 1887 s->tlshostname); 1888 1889 if (s->open_timeout) { 1890 nbd_client_connection_enable_retry(s->conn); 1891 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1892 s->open_timeout * NANOSECONDS_PER_SECOND); 1893 } 1894 1895 s->state = NBD_CLIENT_CONNECTING_WAIT; 1896 ret = nbd_do_establish_connection(bs, errp); 1897 if (ret < 0) { 1898 goto fail; 1899 } 1900 1901 /* 1902 * The connect attempt is done, so we no longer need this timer. 1903 * Delete it, because we do not want it to be around when this node 1904 * is drained or closed. 1905 */ 1906 open_timer_del(s); 1907 1908 nbd_client_connection_enable_retry(s->conn); 1909 1910 return 0; 1911 1912 fail: 1913 open_timer_del(s); 1914 nbd_clear_bdrvstate(bs); 1915 return ret; 1916 } 1917 1918 static int nbd_co_flush(BlockDriverState *bs) 1919 { 1920 return nbd_client_co_flush(bs); 1921 } 1922 1923 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1924 { 1925 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1926 uint32_t min = s->info.min_block; 1927 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1928 1929 /* 1930 * If the server did not advertise an alignment: 1931 * - a size that is not sector-aligned implies that an alignment 1932 * of 1 can be used to access those tail bytes 1933 * - advertisement of block status requires an alignment of 1, so 1934 * that we don't violate block layer constraints that block 1935 * status is always aligned (as we can't control whether the 1936 * server will report sub-sector extents, such as a hole at EOF 1937 * on an unaligned POSIX file) 1938 * - otherwise, assume the server is so old that we are safer avoiding 1939 * sub-sector requests 1940 */ 1941 if (!min) { 1942 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1943 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1944 } 1945 1946 bs->bl.request_alignment = min; 1947 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1948 bs->bl.max_pwrite_zeroes = max; 1949 bs->bl.max_transfer = max; 1950 1951 if (s->info.opt_block && 1952 s->info.opt_block > bs->bl.opt_transfer) { 1953 bs->bl.opt_transfer = s->info.opt_block; 1954 } 1955 } 1956 1957 static void nbd_close(BlockDriverState *bs) 1958 { 1959 nbd_client_close(bs); 1960 nbd_clear_bdrvstate(bs); 1961 } 1962 1963 /* 1964 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 1965 * to a smaller size with exact=false, there is no reason to fail the 1966 * operation. 1967 * 1968 * Preallocation mode is ignored since it does not seems useful to fail when 1969 * we never change anything. 1970 */ 1971 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 1972 bool exact, PreallocMode prealloc, 1973 BdrvRequestFlags flags, Error **errp) 1974 { 1975 BDRVNBDState *s = bs->opaque; 1976 1977 if (offset != s->info.size && exact) { 1978 error_setg(errp, "Cannot resize NBD nodes"); 1979 return -ENOTSUP; 1980 } 1981 1982 if (offset > s->info.size) { 1983 error_setg(errp, "Cannot grow NBD nodes"); 1984 return -EINVAL; 1985 } 1986 1987 return 0; 1988 } 1989 1990 static int64_t nbd_getlength(BlockDriverState *bs) 1991 { 1992 BDRVNBDState *s = bs->opaque; 1993 1994 return s->info.size; 1995 } 1996 1997 static void nbd_refresh_filename(BlockDriverState *bs) 1998 { 1999 BDRVNBDState *s = bs->opaque; 2000 const char *host = NULL, *port = NULL, *path = NULL; 2001 size_t len = 0; 2002 2003 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 2004 const InetSocketAddress *inet = &s->saddr->u.inet; 2005 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 2006 host = inet->host; 2007 port = inet->port; 2008 } 2009 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2010 path = s->saddr->u.q_unix.path; 2011 } /* else can't represent as pseudo-filename */ 2012 2013 if (path && s->export) { 2014 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2015 "nbd+unix:///%s?socket=%s", s->export, path); 2016 } else if (path && !s->export) { 2017 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2018 "nbd+unix://?socket=%s", path); 2019 } else if (host && s->export) { 2020 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2021 "nbd://%s:%s/%s", host, port, s->export); 2022 } else if (host && !s->export) { 2023 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2024 "nbd://%s:%s", host, port); 2025 } 2026 if (len >= sizeof(bs->exact_filename)) { 2027 /* Name is too long to represent exactly, so leave it empty. */ 2028 bs->exact_filename[0] = '\0'; 2029 } 2030 } 2031 2032 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2033 { 2034 /* The generic bdrv_dirname() implementation is able to work out some 2035 * directory name for NBD nodes, but that would be wrong. So far there is no 2036 * specification for how "export paths" would work, so NBD does not have 2037 * directory names. */ 2038 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2039 return NULL; 2040 } 2041 2042 static const char *const nbd_strong_runtime_opts[] = { 2043 "path", 2044 "host", 2045 "port", 2046 "export", 2047 "tls-creds", 2048 "tls-hostname", 2049 "server.", 2050 2051 NULL 2052 }; 2053 2054 static void nbd_cancel_in_flight(BlockDriverState *bs) 2055 { 2056 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2057 2058 reconnect_delay_timer_del(s); 2059 2060 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2061 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2062 qemu_co_queue_restart_all(&s->free_sema); 2063 } 2064 2065 nbd_co_establish_connection_cancel(s->conn); 2066 } 2067 2068 static void nbd_attach_aio_context(BlockDriverState *bs, 2069 AioContext *new_context) 2070 { 2071 BDRVNBDState *s = bs->opaque; 2072 2073 /* The open_timer is used only during nbd_open() */ 2074 assert(!s->open_timer); 2075 2076 /* 2077 * The reconnect_delay_timer is scheduled in I/O paths when the 2078 * connection is lost, to cancel the reconnection attempt after a 2079 * given time. Once this attempt is done (successfully or not), 2080 * nbd_reconnect_attempt() ensures the timer is deleted before the 2081 * respective I/O request is resumed. 2082 * Since the AioContext can only be changed when a node is drained, 2083 * the reconnect_delay_timer cannot be active here. 2084 */ 2085 assert(!s->reconnect_delay_timer); 2086 2087 if (s->ioc) { 2088 qio_channel_attach_aio_context(s->ioc, new_context); 2089 } 2090 } 2091 2092 static void nbd_detach_aio_context(BlockDriverState *bs) 2093 { 2094 BDRVNBDState *s = bs->opaque; 2095 2096 assert(!s->open_timer); 2097 assert(!s->reconnect_delay_timer); 2098 2099 if (s->ioc) { 2100 qio_channel_detach_aio_context(s->ioc); 2101 } 2102 } 2103 2104 static BlockDriver bdrv_nbd = { 2105 .format_name = "nbd", 2106 .protocol_name = "nbd", 2107 .instance_size = sizeof(BDRVNBDState), 2108 .bdrv_parse_filename = nbd_parse_filename, 2109 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2110 .create_opts = &bdrv_create_opts_simple, 2111 .bdrv_file_open = nbd_open, 2112 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2113 .bdrv_co_preadv = nbd_client_co_preadv, 2114 .bdrv_co_pwritev = nbd_client_co_pwritev, 2115 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2116 .bdrv_close = nbd_close, 2117 .bdrv_co_flush_to_os = nbd_co_flush, 2118 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2119 .bdrv_refresh_limits = nbd_refresh_limits, 2120 .bdrv_co_truncate = nbd_co_truncate, 2121 .bdrv_getlength = nbd_getlength, 2122 .bdrv_refresh_filename = nbd_refresh_filename, 2123 .bdrv_co_block_status = nbd_client_co_block_status, 2124 .bdrv_dirname = nbd_dirname, 2125 .strong_runtime_opts = nbd_strong_runtime_opts, 2126 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2127 2128 .bdrv_attach_aio_context = nbd_attach_aio_context, 2129 .bdrv_detach_aio_context = nbd_detach_aio_context, 2130 }; 2131 2132 static BlockDriver bdrv_nbd_tcp = { 2133 .format_name = "nbd", 2134 .protocol_name = "nbd+tcp", 2135 .instance_size = sizeof(BDRVNBDState), 2136 .bdrv_parse_filename = nbd_parse_filename, 2137 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2138 .create_opts = &bdrv_create_opts_simple, 2139 .bdrv_file_open = nbd_open, 2140 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2141 .bdrv_co_preadv = nbd_client_co_preadv, 2142 .bdrv_co_pwritev = nbd_client_co_pwritev, 2143 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2144 .bdrv_close = nbd_close, 2145 .bdrv_co_flush_to_os = nbd_co_flush, 2146 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2147 .bdrv_refresh_limits = nbd_refresh_limits, 2148 .bdrv_co_truncate = nbd_co_truncate, 2149 .bdrv_getlength = nbd_getlength, 2150 .bdrv_refresh_filename = nbd_refresh_filename, 2151 .bdrv_co_block_status = nbd_client_co_block_status, 2152 .bdrv_dirname = nbd_dirname, 2153 .strong_runtime_opts = nbd_strong_runtime_opts, 2154 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2155 2156 .bdrv_attach_aio_context = nbd_attach_aio_context, 2157 .bdrv_detach_aio_context = nbd_detach_aio_context, 2158 }; 2159 2160 static BlockDriver bdrv_nbd_unix = { 2161 .format_name = "nbd", 2162 .protocol_name = "nbd+unix", 2163 .instance_size = sizeof(BDRVNBDState), 2164 .bdrv_parse_filename = nbd_parse_filename, 2165 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2166 .create_opts = &bdrv_create_opts_simple, 2167 .bdrv_file_open = nbd_open, 2168 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2169 .bdrv_co_preadv = nbd_client_co_preadv, 2170 .bdrv_co_pwritev = nbd_client_co_pwritev, 2171 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2172 .bdrv_close = nbd_close, 2173 .bdrv_co_flush_to_os = nbd_co_flush, 2174 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2175 .bdrv_refresh_limits = nbd_refresh_limits, 2176 .bdrv_co_truncate = nbd_co_truncate, 2177 .bdrv_getlength = nbd_getlength, 2178 .bdrv_refresh_filename = nbd_refresh_filename, 2179 .bdrv_co_block_status = nbd_client_co_block_status, 2180 .bdrv_dirname = nbd_dirname, 2181 .strong_runtime_opts = nbd_strong_runtime_opts, 2182 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2183 2184 .bdrv_attach_aio_context = nbd_attach_aio_context, 2185 .bdrv_detach_aio_context = nbd_detach_aio_context, 2186 }; 2187 2188 static void bdrv_nbd_init(void) 2189 { 2190 bdrv_register(&bdrv_nbd); 2191 bdrv_register(&bdrv_nbd_tcp); 2192 bdrv_register(&bdrv_nbd_unix); 2193 } 2194 2195 block_init(bdrv_nbd_init); 2196