1 /* 2 * QEMU Block driver for NBD 3 * 4 * Copyright (c) 2019 Virtuozzo International GmbH. 5 * Copyright Red Hat 6 * Copyright (C) 2008 Bull S.A.S. 7 * Author: Laurent Vivier <Laurent.Vivier@bull.net> 8 * 9 * Some parts: 10 * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws> 11 * 12 * Permission is hereby granted, free of charge, to any person obtaining a copy 13 * of this software and associated documentation files (the "Software"), to deal 14 * in the Software without restriction, including without limitation the rights 15 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 16 * copies of the Software, and to permit persons to whom the Software is 17 * furnished to do so, subject to the following conditions: 18 * 19 * The above copyright notice and this permission notice shall be included in 20 * all copies or substantial portions of the Software. 21 * 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 25 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 27 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 28 * THE SOFTWARE. 29 */ 30 31 #include "qemu/osdep.h" 32 33 #include "trace.h" 34 #include "qemu/uri.h" 35 #include "qemu/option.h" 36 #include "qemu/cutils.h" 37 #include "qemu/main-loop.h" 38 39 #include "qapi/qapi-visit-sockets.h" 40 #include "qapi/qmp/qstring.h" 41 #include "qapi/clone-visitor.h" 42 43 #include "block/qdict.h" 44 #include "block/nbd.h" 45 #include "block/block_int.h" 46 #include "block/coroutines.h" 47 48 #include "qemu/yank.h" 49 50 #define EN_OPTSTR ":exportname=" 51 #define MAX_NBD_REQUESTS 16 52 53 #define COOKIE_TO_INDEX(cookie) ((cookie) - 1) 54 #define INDEX_TO_COOKIE(index) ((index) + 1) 55 56 typedef struct { 57 Coroutine *coroutine; 58 uint64_t offset; /* original offset of the request */ 59 bool receiving; /* sleeping in the yield in nbd_receive_replies */ 60 } NBDClientRequest; 61 62 typedef enum NBDClientState { 63 NBD_CLIENT_CONNECTING_WAIT, 64 NBD_CLIENT_CONNECTING_NOWAIT, 65 NBD_CLIENT_CONNECTED, 66 NBD_CLIENT_QUIT 67 } NBDClientState; 68 69 typedef struct BDRVNBDState { 70 QIOChannel *ioc; /* The current I/O channel */ 71 NBDExportInfo info; 72 73 /* 74 * Protects state, free_sema, in_flight, requests[].coroutine, 75 * reconnect_delay_timer. 76 */ 77 QemuMutex requests_lock; 78 NBDClientState state; 79 CoQueue free_sema; 80 unsigned in_flight; 81 NBDClientRequest requests[MAX_NBD_REQUESTS]; 82 QEMUTimer *reconnect_delay_timer; 83 84 /* Protects sending data on the socket. */ 85 CoMutex send_mutex; 86 87 /* 88 * Protects receiving reply headers from the socket, as well as the 89 * fields reply and requests[].receiving 90 */ 91 CoMutex receive_mutex; 92 NBDReply reply; 93 94 QEMUTimer *open_timer; 95 96 BlockDriverState *bs; 97 98 /* Connection parameters */ 99 uint32_t reconnect_delay; 100 uint32_t open_timeout; 101 SocketAddress *saddr; 102 char *export; 103 char *tlscredsid; 104 QCryptoTLSCreds *tlscreds; 105 char *tlshostname; 106 char *x_dirty_bitmap; 107 bool alloc_depth; 108 109 NBDClientConnection *conn; 110 } BDRVNBDState; 111 112 static void nbd_yank(void *opaque); 113 114 static void nbd_clear_bdrvstate(BlockDriverState *bs) 115 { 116 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 117 118 nbd_client_connection_release(s->conn); 119 s->conn = NULL; 120 121 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 122 123 /* Must not leave timers behind that would access freed data */ 124 assert(!s->reconnect_delay_timer); 125 assert(!s->open_timer); 126 127 object_unref(OBJECT(s->tlscreds)); 128 qapi_free_SocketAddress(s->saddr); 129 s->saddr = NULL; 130 g_free(s->export); 131 s->export = NULL; 132 g_free(s->tlscredsid); 133 s->tlscredsid = NULL; 134 g_free(s->tlshostname); 135 s->tlshostname = NULL; 136 g_free(s->x_dirty_bitmap); 137 s->x_dirty_bitmap = NULL; 138 } 139 140 /* Called with s->receive_mutex taken. */ 141 static bool coroutine_fn nbd_recv_coroutine_wake_one(NBDClientRequest *req) 142 { 143 if (req->receiving) { 144 req->receiving = false; 145 aio_co_wake(req->coroutine); 146 return true; 147 } 148 149 return false; 150 } 151 152 static void coroutine_fn nbd_recv_coroutines_wake(BDRVNBDState *s) 153 { 154 int i; 155 156 QEMU_LOCK_GUARD(&s->receive_mutex); 157 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 158 if (nbd_recv_coroutine_wake_one(&s->requests[i])) { 159 return; 160 } 161 } 162 } 163 164 /* Called with s->requests_lock held. */ 165 static void coroutine_fn nbd_channel_error_locked(BDRVNBDState *s, int ret) 166 { 167 if (s->state == NBD_CLIENT_CONNECTED) { 168 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 169 } 170 171 if (ret == -EIO) { 172 if (s->state == NBD_CLIENT_CONNECTED) { 173 s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : 174 NBD_CLIENT_CONNECTING_NOWAIT; 175 } 176 } else { 177 s->state = NBD_CLIENT_QUIT; 178 } 179 } 180 181 static void coroutine_fn nbd_channel_error(BDRVNBDState *s, int ret) 182 { 183 QEMU_LOCK_GUARD(&s->requests_lock); 184 nbd_channel_error_locked(s, ret); 185 } 186 187 static void reconnect_delay_timer_del(BDRVNBDState *s) 188 { 189 if (s->reconnect_delay_timer) { 190 timer_free(s->reconnect_delay_timer); 191 s->reconnect_delay_timer = NULL; 192 } 193 } 194 195 static void reconnect_delay_timer_cb(void *opaque) 196 { 197 BDRVNBDState *s = opaque; 198 199 reconnect_delay_timer_del(s); 200 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 201 if (s->state != NBD_CLIENT_CONNECTING_WAIT) { 202 return; 203 } 204 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 205 } 206 nbd_co_establish_connection_cancel(s->conn); 207 } 208 209 static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 210 { 211 assert(!s->reconnect_delay_timer); 212 s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 213 QEMU_CLOCK_REALTIME, 214 SCALE_NS, 215 reconnect_delay_timer_cb, s); 216 timer_mod(s->reconnect_delay_timer, expire_time_ns); 217 } 218 219 static void nbd_teardown_connection(BlockDriverState *bs) 220 { 221 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 222 223 assert(!s->in_flight); 224 225 if (s->ioc) { 226 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 227 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 228 nbd_yank, s->bs); 229 object_unref(OBJECT(s->ioc)); 230 s->ioc = NULL; 231 } 232 233 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 234 s->state = NBD_CLIENT_QUIT; 235 } 236 } 237 238 static void open_timer_del(BDRVNBDState *s) 239 { 240 if (s->open_timer) { 241 timer_free(s->open_timer); 242 s->open_timer = NULL; 243 } 244 } 245 246 static void open_timer_cb(void *opaque) 247 { 248 BDRVNBDState *s = opaque; 249 250 nbd_co_establish_connection_cancel(s->conn); 251 open_timer_del(s); 252 } 253 254 static void open_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 255 { 256 assert(!s->open_timer); 257 s->open_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 258 QEMU_CLOCK_REALTIME, 259 SCALE_NS, 260 open_timer_cb, s); 261 timer_mod(s->open_timer, expire_time_ns); 262 } 263 264 static bool nbd_client_will_reconnect(BDRVNBDState *s) 265 { 266 /* 267 * Called only after a socket error, so this is not performance sensitive. 268 */ 269 QEMU_LOCK_GUARD(&s->requests_lock); 270 return s->state == NBD_CLIENT_CONNECTING_WAIT; 271 } 272 273 /* 274 * Update @bs with information learned during a completed negotiation process. 275 * Return failure if the server's advertised options are incompatible with the 276 * client's needs. 277 */ 278 static int nbd_handle_updated_info(BlockDriverState *bs, Error **errp) 279 { 280 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 281 int ret; 282 283 if (s->x_dirty_bitmap) { 284 if (!s->info.base_allocation) { 285 error_setg(errp, "requested x-dirty-bitmap %s not found", 286 s->x_dirty_bitmap); 287 return -EINVAL; 288 } 289 if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { 290 s->alloc_depth = true; 291 } 292 } 293 294 if (s->info.flags & NBD_FLAG_READ_ONLY) { 295 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); 296 if (ret < 0) { 297 return ret; 298 } 299 } 300 301 if (s->info.flags & NBD_FLAG_SEND_FUA) { 302 bs->supported_write_flags = BDRV_REQ_FUA; 303 bs->supported_zero_flags |= BDRV_REQ_FUA; 304 } 305 306 if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { 307 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; 308 if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { 309 bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; 310 } 311 } 312 313 trace_nbd_client_handshake_success(s->export); 314 315 return 0; 316 } 317 318 int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, 319 bool blocking, Error **errp) 320 { 321 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 322 int ret; 323 IO_CODE(); 324 325 assert_bdrv_graph_readable(); 326 assert(!s->ioc); 327 328 s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); 329 if (!s->ioc) { 330 return -ECONNREFUSED; 331 } 332 333 yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, 334 bs); 335 336 ret = nbd_handle_updated_info(s->bs, NULL); 337 if (ret < 0) { 338 /* 339 * We have connected, but must fail for other reasons. 340 * Send NBD_CMD_DISC as a courtesy to the server. 341 */ 342 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 343 344 nbd_send_request(s->ioc, &request); 345 346 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 347 nbd_yank, bs); 348 object_unref(OBJECT(s->ioc)); 349 s->ioc = NULL; 350 351 return ret; 352 } 353 354 qio_channel_set_blocking(s->ioc, false, NULL); 355 qio_channel_set_follow_coroutine_ctx(s->ioc, true); 356 357 /* successfully connected */ 358 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 359 s->state = NBD_CLIENT_CONNECTED; 360 } 361 362 return 0; 363 } 364 365 /* Called with s->requests_lock held. */ 366 static bool nbd_client_connecting(BDRVNBDState *s) 367 { 368 return s->state == NBD_CLIENT_CONNECTING_WAIT || 369 s->state == NBD_CLIENT_CONNECTING_NOWAIT; 370 } 371 372 /* Called with s->requests_lock taken. */ 373 static void coroutine_fn GRAPH_RDLOCK nbd_reconnect_attempt(BDRVNBDState *s) 374 { 375 int ret; 376 bool blocking = s->state == NBD_CLIENT_CONNECTING_WAIT; 377 378 /* 379 * Now we are sure that nobody is accessing the channel, and no one will 380 * try until we set the state to CONNECTED. 381 */ 382 assert(nbd_client_connecting(s)); 383 assert(s->in_flight == 1); 384 385 trace_nbd_reconnect_attempt(s->bs->in_flight); 386 387 if (blocking && !s->reconnect_delay_timer) { 388 /* 389 * It's the first reconnect attempt after switching to 390 * NBD_CLIENT_CONNECTING_WAIT 391 */ 392 g_assert(s->reconnect_delay); 393 reconnect_delay_timer_init(s, 394 qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 395 s->reconnect_delay * NANOSECONDS_PER_SECOND); 396 } 397 398 /* Finalize previous connection if any */ 399 if (s->ioc) { 400 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 401 nbd_yank, s->bs); 402 object_unref(OBJECT(s->ioc)); 403 s->ioc = NULL; 404 } 405 406 qemu_mutex_unlock(&s->requests_lock); 407 ret = nbd_co_do_establish_connection(s->bs, blocking, NULL); 408 trace_nbd_reconnect_attempt_result(ret, s->bs->in_flight); 409 qemu_mutex_lock(&s->requests_lock); 410 411 /* 412 * The reconnect attempt is done (maybe successfully, maybe not), so 413 * we no longer need this timer. Delete it so it will not outlive 414 * this I/O request (so draining removes all timers). 415 */ 416 reconnect_delay_timer_del(s); 417 } 418 419 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t cookie, 420 Error **errp) 421 { 422 int ret; 423 uint64_t ind = COOKIE_TO_INDEX(cookie), ind2; 424 QEMU_LOCK_GUARD(&s->receive_mutex); 425 426 while (true) { 427 if (s->reply.cookie == cookie) { 428 /* We are done */ 429 return 0; 430 } 431 432 if (s->reply.cookie != 0) { 433 /* 434 * Some other request is being handled now. It should already be 435 * woken by whoever set s->reply.cookie (or never wait in this 436 * yield). So, we should not wake it here. 437 */ 438 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 439 assert(!s->requests[ind2].receiving); 440 441 s->requests[ind].receiving = true; 442 qemu_co_mutex_unlock(&s->receive_mutex); 443 444 qemu_coroutine_yield(); 445 /* 446 * We may be woken for 2 reasons: 447 * 1. From this function, executing in parallel coroutine, when our 448 * cookie is received. 449 * 2. From nbd_co_receive_one_chunk(), when previous request is 450 * finished and s->reply.cookie set to 0. 451 * Anyway, it's OK to lock the mutex and go to the next iteration. 452 */ 453 454 qemu_co_mutex_lock(&s->receive_mutex); 455 assert(!s->requests[ind].receiving); 456 continue; 457 } 458 459 /* We are under mutex and cookie is 0. We have to do the dirty work. */ 460 assert(s->reply.cookie == 0); 461 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, s->info.mode, errp); 462 if (ret == 0) { 463 ret = -EIO; 464 error_setg(errp, "server dropped connection"); 465 } 466 if (ret < 0) { 467 nbd_channel_error(s, ret); 468 return ret; 469 } 470 if (nbd_reply_is_structured(&s->reply) && 471 s->info.mode < NBD_MODE_STRUCTURED) { 472 nbd_channel_error(s, -EINVAL); 473 error_setg(errp, "unexpected structured reply"); 474 return -EINVAL; 475 } 476 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 477 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].coroutine) { 478 nbd_channel_error(s, -EINVAL); 479 error_setg(errp, "unexpected cookie value"); 480 return -EINVAL; 481 } 482 if (s->reply.cookie == cookie) { 483 /* We are done */ 484 return 0; 485 } 486 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 487 } 488 } 489 490 static int coroutine_fn GRAPH_RDLOCK 491 nbd_co_send_request(BlockDriverState *bs, NBDRequest *request, 492 QEMUIOVector *qiov) 493 { 494 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 495 int rc, i = -1; 496 497 qemu_mutex_lock(&s->requests_lock); 498 while (s->in_flight == MAX_NBD_REQUESTS || 499 (s->state != NBD_CLIENT_CONNECTED && s->in_flight > 0)) { 500 qemu_co_queue_wait(&s->free_sema, &s->requests_lock); 501 } 502 503 s->in_flight++; 504 if (s->state != NBD_CLIENT_CONNECTED) { 505 if (nbd_client_connecting(s)) { 506 nbd_reconnect_attempt(s); 507 qemu_co_queue_restart_all(&s->free_sema); 508 } 509 if (s->state != NBD_CLIENT_CONNECTED) { 510 rc = -EIO; 511 goto err; 512 } 513 } 514 515 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 516 if (s->requests[i].coroutine == NULL) { 517 break; 518 } 519 } 520 521 assert(i < MAX_NBD_REQUESTS); 522 s->requests[i].coroutine = qemu_coroutine_self(); 523 s->requests[i].offset = request->from; 524 s->requests[i].receiving = false; 525 qemu_mutex_unlock(&s->requests_lock); 526 527 qemu_co_mutex_lock(&s->send_mutex); 528 request->cookie = INDEX_TO_COOKIE(i); 529 request->mode = s->info.mode; 530 531 assert(s->ioc); 532 533 if (qiov) { 534 qio_channel_set_cork(s->ioc, true); 535 rc = nbd_send_request(s->ioc, request); 536 if (rc >= 0 && qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 537 NULL) < 0) { 538 rc = -EIO; 539 } 540 qio_channel_set_cork(s->ioc, false); 541 } else { 542 rc = nbd_send_request(s->ioc, request); 543 } 544 qemu_co_mutex_unlock(&s->send_mutex); 545 546 if (rc < 0) { 547 qemu_mutex_lock(&s->requests_lock); 548 err: 549 nbd_channel_error_locked(s, rc); 550 if (i != -1) { 551 s->requests[i].coroutine = NULL; 552 } 553 s->in_flight--; 554 qemu_co_queue_next(&s->free_sema); 555 qemu_mutex_unlock(&s->requests_lock); 556 } 557 return rc; 558 } 559 560 static inline uint16_t payload_advance16(uint8_t **payload) 561 { 562 *payload += 2; 563 return lduw_be_p(*payload - 2); 564 } 565 566 static inline uint32_t payload_advance32(uint8_t **payload) 567 { 568 *payload += 4; 569 return ldl_be_p(*payload - 4); 570 } 571 572 static inline uint64_t payload_advance64(uint8_t **payload) 573 { 574 *payload += 8; 575 return ldq_be_p(*payload - 8); 576 } 577 578 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 579 NBDStructuredReplyChunk *chunk, 580 uint8_t *payload, uint64_t orig_offset, 581 QEMUIOVector *qiov, Error **errp) 582 { 583 uint64_t offset; 584 uint32_t hole_size; 585 586 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 587 error_setg(errp, "Protocol error: invalid payload for " 588 "NBD_REPLY_TYPE_OFFSET_HOLE"); 589 return -EINVAL; 590 } 591 592 offset = payload_advance64(&payload); 593 hole_size = payload_advance32(&payload); 594 595 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 596 offset > orig_offset + qiov->size - hole_size) { 597 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 598 " region"); 599 return -EINVAL; 600 } 601 if (s->info.min_block && 602 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 603 trace_nbd_structured_read_compliance("hole"); 604 } 605 606 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 607 608 return 0; 609 } 610 611 /* 612 * nbd_parse_blockstatus_payload 613 * Based on our request, we expect only one extent in reply, for the 614 * base:allocation context. 615 */ 616 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 617 NBDStructuredReplyChunk *chunk, 618 uint8_t *payload, uint64_t orig_length, 619 NBDExtent32 *extent, Error **errp) 620 { 621 uint32_t context_id; 622 623 /* The server succeeded, so it must have sent [at least] one extent */ 624 if (chunk->length < sizeof(context_id) + sizeof(*extent)) { 625 error_setg(errp, "Protocol error: invalid payload for " 626 "NBD_REPLY_TYPE_BLOCK_STATUS"); 627 return -EINVAL; 628 } 629 630 context_id = payload_advance32(&payload); 631 if (s->info.context_id != context_id) { 632 error_setg(errp, "Protocol error: unexpected context id %d for " 633 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 634 "id is %d", context_id, 635 s->info.context_id); 636 return -EINVAL; 637 } 638 639 extent->length = payload_advance32(&payload); 640 extent->flags = payload_advance32(&payload); 641 642 if (extent->length == 0) { 643 error_setg(errp, "Protocol error: server sent status chunk with " 644 "zero length"); 645 return -EINVAL; 646 } 647 648 /* 649 * A server sending unaligned block status is in violation of the 650 * protocol, but as qemu-nbd 3.1 is such a server (at least for 651 * POSIX files that are not a multiple of 512 bytes, since qemu 652 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 653 * still sees an implicit hole beyond the real EOF), it's nicer to 654 * work around the misbehaving server. If the request included 655 * more than the final unaligned block, truncate it back to an 656 * aligned result; if the request was only the final block, round 657 * up to the full block and change the status to fully-allocated 658 * (always a safe status, even if it loses information). 659 */ 660 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 661 s->info.min_block)) { 662 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 663 if (extent->length > s->info.min_block) { 664 extent->length = QEMU_ALIGN_DOWN(extent->length, 665 s->info.min_block); 666 } else { 667 extent->length = s->info.min_block; 668 extent->flags = 0; 669 } 670 } 671 672 /* 673 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 674 * sent us any more than one extent, nor should it have included 675 * status beyond our request in that extent. However, it's easy 676 * enough to ignore the server's noncompliance without killing the 677 * connection; just ignore trailing extents, and clamp things to 678 * the length of our request. 679 */ 680 if (chunk->length > sizeof(context_id) + sizeof(*extent)) { 681 trace_nbd_parse_blockstatus_compliance("more than one extent"); 682 } 683 if (extent->length > orig_length) { 684 extent->length = orig_length; 685 trace_nbd_parse_blockstatus_compliance("extent length too large"); 686 } 687 688 /* 689 * HACK: if we are using x-dirty-bitmaps to access 690 * qemu:allocation-depth, treat all depths > 2 the same as 2, 691 * since nbd_client_co_block_status is only expecting the low two 692 * bits to be set. 693 */ 694 if (s->alloc_depth && extent->flags > 2) { 695 extent->flags = 2; 696 } 697 698 return 0; 699 } 700 701 /* 702 * nbd_parse_error_payload 703 * on success @errp contains message describing nbd error reply 704 */ 705 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 706 uint8_t *payload, int *request_ret, 707 Error **errp) 708 { 709 uint32_t error; 710 uint16_t message_size; 711 712 assert(chunk->type & (1 << 15)); 713 714 if (chunk->length < sizeof(error) + sizeof(message_size)) { 715 error_setg(errp, 716 "Protocol error: invalid payload for structured error"); 717 return -EINVAL; 718 } 719 720 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 721 if (error == 0) { 722 error_setg(errp, "Protocol error: server sent structured error chunk " 723 "with error = 0"); 724 return -EINVAL; 725 } 726 727 *request_ret = -error; 728 message_size = payload_advance16(&payload); 729 730 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 731 error_setg(errp, "Protocol error: server sent structured error chunk " 732 "with incorrect message size"); 733 return -EINVAL; 734 } 735 736 /* TODO: Add a trace point to mention the server complaint */ 737 738 /* TODO handle ERROR_OFFSET */ 739 740 return 0; 741 } 742 743 static int coroutine_fn 744 nbd_co_receive_offset_data_payload(BDRVNBDState *s, uint64_t orig_offset, 745 QEMUIOVector *qiov, Error **errp) 746 { 747 QEMUIOVector sub_qiov; 748 uint64_t offset; 749 size_t data_size; 750 int ret; 751 NBDStructuredReplyChunk *chunk = &s->reply.structured; 752 753 assert(nbd_reply_is_structured(&s->reply)); 754 755 /* The NBD spec requires at least one byte of payload */ 756 if (chunk->length <= sizeof(offset)) { 757 error_setg(errp, "Protocol error: invalid payload for " 758 "NBD_REPLY_TYPE_OFFSET_DATA"); 759 return -EINVAL; 760 } 761 762 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 763 return -EIO; 764 } 765 766 data_size = chunk->length - sizeof(offset); 767 assert(data_size); 768 if (offset < orig_offset || data_size > qiov->size || 769 offset > orig_offset + qiov->size - data_size) { 770 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 771 " region"); 772 return -EINVAL; 773 } 774 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 775 trace_nbd_structured_read_compliance("data"); 776 } 777 778 qemu_iovec_init(&sub_qiov, qiov->niov); 779 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 780 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 781 qemu_iovec_destroy(&sub_qiov); 782 783 return ret < 0 ? -EIO : 0; 784 } 785 786 #define NBD_MAX_MALLOC_PAYLOAD 1000 787 static coroutine_fn int nbd_co_receive_structured_payload( 788 BDRVNBDState *s, void **payload, Error **errp) 789 { 790 int ret; 791 uint32_t len; 792 793 assert(nbd_reply_is_structured(&s->reply)); 794 795 len = s->reply.structured.length; 796 797 if (len == 0) { 798 return 0; 799 } 800 801 if (payload == NULL) { 802 error_setg(errp, "Unexpected structured payload"); 803 return -EINVAL; 804 } 805 806 if (len > NBD_MAX_MALLOC_PAYLOAD) { 807 error_setg(errp, "Payload too large"); 808 return -EINVAL; 809 } 810 811 *payload = g_new(char, len); 812 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 813 if (ret < 0) { 814 g_free(*payload); 815 *payload = NULL; 816 return ret; 817 } 818 819 return 0; 820 } 821 822 /* 823 * nbd_co_do_receive_one_chunk 824 * for simple reply: 825 * set request_ret to received reply error 826 * if qiov is not NULL: read payload to @qiov 827 * for structured reply chunk: 828 * if error chunk: read payload, set @request_ret, do not set @payload 829 * else if offset_data chunk: read payload data to @qiov, do not set @payload 830 * else: read payload to @payload 831 * 832 * If function fails, @errp contains corresponding error message, and the 833 * connection with the server is suspect. If it returns 0, then the 834 * transaction succeeded (although @request_ret may be a negative errno 835 * corresponding to the server's error reply), and errp is unchanged. 836 */ 837 static coroutine_fn int nbd_co_do_receive_one_chunk( 838 BDRVNBDState *s, uint64_t cookie, bool only_structured, 839 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 840 { 841 int ret; 842 int i = COOKIE_TO_INDEX(cookie); 843 void *local_payload = NULL; 844 NBDStructuredReplyChunk *chunk; 845 846 if (payload) { 847 *payload = NULL; 848 } 849 *request_ret = 0; 850 851 ret = nbd_receive_replies(s, cookie, errp); 852 if (ret < 0) { 853 error_prepend(errp, "Connection closed: "); 854 return -EIO; 855 } 856 assert(s->ioc); 857 858 assert(s->reply.cookie == cookie); 859 860 if (nbd_reply_is_simple(&s->reply)) { 861 if (only_structured) { 862 error_setg(errp, "Protocol error: simple reply when structured " 863 "reply chunk was expected"); 864 return -EINVAL; 865 } 866 867 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 868 if (*request_ret < 0 || !qiov) { 869 return 0; 870 } 871 872 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 873 errp) < 0 ? -EIO : 0; 874 } 875 876 /* handle structured reply chunk */ 877 assert(s->info.mode >= NBD_MODE_STRUCTURED); 878 chunk = &s->reply.structured; 879 880 if (chunk->type == NBD_REPLY_TYPE_NONE) { 881 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 882 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 883 " NBD_REPLY_FLAG_DONE flag set"); 884 return -EINVAL; 885 } 886 if (chunk->length) { 887 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 888 " nonzero length"); 889 return -EINVAL; 890 } 891 return 0; 892 } 893 894 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 895 if (!qiov) { 896 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 897 return -EINVAL; 898 } 899 900 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 901 qiov, errp); 902 } 903 904 if (nbd_reply_type_is_error(chunk->type)) { 905 payload = &local_payload; 906 } 907 908 ret = nbd_co_receive_structured_payload(s, payload, errp); 909 if (ret < 0) { 910 return ret; 911 } 912 913 if (nbd_reply_type_is_error(chunk->type)) { 914 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 915 g_free(local_payload); 916 return ret; 917 } 918 919 return 0; 920 } 921 922 /* 923 * nbd_co_receive_one_chunk 924 * Read reply, wake up connection_co and set s->quit if needed. 925 * Return value is a fatal error code or normal nbd reply error code 926 */ 927 static coroutine_fn int nbd_co_receive_one_chunk( 928 BDRVNBDState *s, uint64_t cookie, bool only_structured, 929 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 930 Error **errp) 931 { 932 int ret = nbd_co_do_receive_one_chunk(s, cookie, only_structured, 933 request_ret, qiov, payload, errp); 934 935 if (ret < 0) { 936 memset(reply, 0, sizeof(*reply)); 937 nbd_channel_error(s, ret); 938 } else { 939 /* For assert at loop start in nbd_connection_entry */ 940 *reply = s->reply; 941 } 942 s->reply.cookie = 0; 943 944 nbd_recv_coroutines_wake(s); 945 946 return ret; 947 } 948 949 typedef struct NBDReplyChunkIter { 950 int ret; 951 int request_ret; 952 Error *err; 953 bool done, only_structured; 954 } NBDReplyChunkIter; 955 956 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 957 int ret, Error **local_err) 958 { 959 assert(local_err && *local_err); 960 assert(ret < 0); 961 962 if (!iter->ret) { 963 iter->ret = ret; 964 error_propagate(&iter->err, *local_err); 965 } else { 966 error_free(*local_err); 967 } 968 969 *local_err = NULL; 970 } 971 972 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 973 { 974 assert(ret < 0); 975 976 if (!iter->request_ret) { 977 iter->request_ret = ret; 978 } 979 } 980 981 /* 982 * NBD_FOREACH_REPLY_CHUNK 983 * The pointer stored in @payload requires g_free() to free it. 984 */ 985 #define NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, structured, \ 986 qiov, reply, payload) \ 987 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 988 nbd_reply_chunk_iter_receive(s, &iter, cookie, qiov, reply, payload);) 989 990 /* 991 * nbd_reply_chunk_iter_receive 992 * The pointer stored in @payload requires g_free() to free it. 993 */ 994 static bool coroutine_fn nbd_reply_chunk_iter_receive(BDRVNBDState *s, 995 NBDReplyChunkIter *iter, 996 uint64_t cookie, 997 QEMUIOVector *qiov, 998 NBDReply *reply, 999 void **payload) 1000 { 1001 int ret, request_ret; 1002 NBDReply local_reply; 1003 NBDStructuredReplyChunk *chunk; 1004 Error *local_err = NULL; 1005 1006 if (iter->done) { 1007 /* Previous iteration was last. */ 1008 goto break_loop; 1009 } 1010 1011 if (reply == NULL) { 1012 reply = &local_reply; 1013 } 1014 1015 ret = nbd_co_receive_one_chunk(s, cookie, iter->only_structured, 1016 &request_ret, qiov, reply, payload, 1017 &local_err); 1018 if (ret < 0) { 1019 nbd_iter_channel_error(iter, ret, &local_err); 1020 } else if (request_ret < 0) { 1021 nbd_iter_request_error(iter, request_ret); 1022 } 1023 1024 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1025 if (nbd_reply_is_simple(reply) || iter->ret < 0) { 1026 goto break_loop; 1027 } 1028 1029 chunk = &reply->structured; 1030 iter->only_structured = true; 1031 1032 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1033 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1034 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1035 goto break_loop; 1036 } 1037 1038 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1039 /* This iteration is last. */ 1040 iter->done = true; 1041 } 1042 1043 /* Execute the loop body */ 1044 return true; 1045 1046 break_loop: 1047 qemu_mutex_lock(&s->requests_lock); 1048 s->requests[COOKIE_TO_INDEX(cookie)].coroutine = NULL; 1049 s->in_flight--; 1050 qemu_co_queue_next(&s->free_sema); 1051 qemu_mutex_unlock(&s->requests_lock); 1052 1053 return false; 1054 } 1055 1056 static int coroutine_fn 1057 nbd_co_receive_return_code(BDRVNBDState *s, uint64_t cookie, 1058 int *request_ret, Error **errp) 1059 { 1060 NBDReplyChunkIter iter; 1061 1062 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, NULL, NULL) { 1063 /* nbd_reply_chunk_iter_receive does all the work */ 1064 } 1065 1066 error_propagate(errp, iter.err); 1067 *request_ret = iter.request_ret; 1068 return iter.ret; 1069 } 1070 1071 static int coroutine_fn 1072 nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t cookie, 1073 uint64_t offset, QEMUIOVector *qiov, 1074 int *request_ret, Error **errp) 1075 { 1076 NBDReplyChunkIter iter; 1077 NBDReply reply; 1078 void *payload = NULL; 1079 Error *local_err = NULL; 1080 1081 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, 1082 s->info.mode >= NBD_MODE_STRUCTURED, 1083 qiov, &reply, &payload) 1084 { 1085 int ret; 1086 NBDStructuredReplyChunk *chunk = &reply.structured; 1087 1088 assert(nbd_reply_is_structured(&reply)); 1089 1090 switch (chunk->type) { 1091 case NBD_REPLY_TYPE_OFFSET_DATA: 1092 /* 1093 * special cased in nbd_co_receive_one_chunk, data is already 1094 * in qiov 1095 */ 1096 break; 1097 case NBD_REPLY_TYPE_OFFSET_HOLE: 1098 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1099 offset, qiov, &local_err); 1100 if (ret < 0) { 1101 nbd_channel_error(s, ret); 1102 nbd_iter_channel_error(&iter, ret, &local_err); 1103 } 1104 break; 1105 default: 1106 if (!nbd_reply_type_is_error(chunk->type)) { 1107 /* not allowed reply type */ 1108 nbd_channel_error(s, -EINVAL); 1109 error_setg(&local_err, 1110 "Unexpected reply type: %d (%s) for CMD_READ", 1111 chunk->type, nbd_reply_type_lookup(chunk->type)); 1112 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1113 } 1114 } 1115 1116 g_free(payload); 1117 payload = NULL; 1118 } 1119 1120 error_propagate(errp, iter.err); 1121 *request_ret = iter.request_ret; 1122 return iter.ret; 1123 } 1124 1125 static int coroutine_fn 1126 nbd_co_receive_blockstatus_reply(BDRVNBDState *s, uint64_t cookie, 1127 uint64_t length, NBDExtent32 *extent, 1128 int *request_ret, Error **errp) 1129 { 1130 NBDReplyChunkIter iter; 1131 NBDReply reply; 1132 void *payload = NULL; 1133 Error *local_err = NULL; 1134 bool received = false; 1135 1136 assert(!extent->length); 1137 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, &reply, &payload) { 1138 int ret; 1139 NBDStructuredReplyChunk *chunk = &reply.structured; 1140 1141 assert(nbd_reply_is_structured(&reply)); 1142 1143 switch (chunk->type) { 1144 case NBD_REPLY_TYPE_BLOCK_STATUS: 1145 if (received) { 1146 nbd_channel_error(s, -EINVAL); 1147 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1148 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1149 } 1150 received = true; 1151 1152 ret = nbd_parse_blockstatus_payload(s, &reply.structured, 1153 payload, length, extent, 1154 &local_err); 1155 if (ret < 0) { 1156 nbd_channel_error(s, ret); 1157 nbd_iter_channel_error(&iter, ret, &local_err); 1158 } 1159 break; 1160 default: 1161 if (!nbd_reply_type_is_error(chunk->type)) { 1162 nbd_channel_error(s, -EINVAL); 1163 error_setg(&local_err, 1164 "Unexpected reply type: %d (%s) " 1165 "for CMD_BLOCK_STATUS", 1166 chunk->type, nbd_reply_type_lookup(chunk->type)); 1167 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1168 } 1169 } 1170 1171 g_free(payload); 1172 payload = NULL; 1173 } 1174 1175 if (!extent->length && !iter.request_ret) { 1176 error_setg(&local_err, "Server did not reply with any status extents"); 1177 nbd_iter_channel_error(&iter, -EIO, &local_err); 1178 } 1179 1180 error_propagate(errp, iter.err); 1181 *request_ret = iter.request_ret; 1182 return iter.ret; 1183 } 1184 1185 static int coroutine_fn GRAPH_RDLOCK 1186 nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1187 QEMUIOVector *write_qiov) 1188 { 1189 int ret, request_ret; 1190 Error *local_err = NULL; 1191 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1192 1193 assert(request->type != NBD_CMD_READ); 1194 if (write_qiov) { 1195 assert(request->type == NBD_CMD_WRITE); 1196 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1197 } else { 1198 assert(request->type != NBD_CMD_WRITE); 1199 } 1200 1201 do { 1202 ret = nbd_co_send_request(bs, request, write_qiov); 1203 if (ret < 0) { 1204 continue; 1205 } 1206 1207 ret = nbd_co_receive_return_code(s, request->cookie, 1208 &request_ret, &local_err); 1209 if (local_err) { 1210 trace_nbd_co_request_fail(request->from, request->len, 1211 request->cookie, request->flags, 1212 request->type, 1213 nbd_cmd_lookup(request->type), 1214 ret, error_get_pretty(local_err)); 1215 error_free(local_err); 1216 local_err = NULL; 1217 } 1218 } while (ret < 0 && nbd_client_will_reconnect(s)); 1219 1220 return ret ? ret : request_ret; 1221 } 1222 1223 static int coroutine_fn GRAPH_RDLOCK 1224 nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1225 QEMUIOVector *qiov, BdrvRequestFlags flags) 1226 { 1227 int ret, request_ret; 1228 Error *local_err = NULL; 1229 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1230 NBDRequest request = { 1231 .type = NBD_CMD_READ, 1232 .from = offset, 1233 .len = bytes, 1234 }; 1235 1236 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1237 1238 if (!bytes) { 1239 return 0; 1240 } 1241 /* 1242 * Work around the fact that the block layer doesn't do 1243 * byte-accurate sizing yet - if the read exceeds the server's 1244 * advertised size because the block layer rounded size up, then 1245 * truncate the request to the server and tail-pad with zero. 1246 */ 1247 if (offset >= s->info.size) { 1248 assert(bytes < BDRV_SECTOR_SIZE); 1249 qemu_iovec_memset(qiov, 0, 0, bytes); 1250 return 0; 1251 } 1252 if (offset + bytes > s->info.size) { 1253 uint64_t slop = offset + bytes - s->info.size; 1254 1255 assert(slop < BDRV_SECTOR_SIZE); 1256 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1257 request.len -= slop; 1258 } 1259 1260 do { 1261 ret = nbd_co_send_request(bs, &request, NULL); 1262 if (ret < 0) { 1263 continue; 1264 } 1265 1266 ret = nbd_co_receive_cmdread_reply(s, request.cookie, offset, qiov, 1267 &request_ret, &local_err); 1268 if (local_err) { 1269 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1270 request.flags, request.type, 1271 nbd_cmd_lookup(request.type), 1272 ret, error_get_pretty(local_err)); 1273 error_free(local_err); 1274 local_err = NULL; 1275 } 1276 } while (ret < 0 && nbd_client_will_reconnect(s)); 1277 1278 return ret ? ret : request_ret; 1279 } 1280 1281 static int coroutine_fn GRAPH_RDLOCK 1282 nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, 1283 QEMUIOVector *qiov, BdrvRequestFlags flags) 1284 { 1285 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1286 NBDRequest request = { 1287 .type = NBD_CMD_WRITE, 1288 .from = offset, 1289 .len = bytes, 1290 }; 1291 1292 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1293 if (flags & BDRV_REQ_FUA) { 1294 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1295 request.flags |= NBD_CMD_FLAG_FUA; 1296 } 1297 1298 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1299 1300 if (!bytes) { 1301 return 0; 1302 } 1303 return nbd_co_request(bs, &request, qiov); 1304 } 1305 1306 static int coroutine_fn GRAPH_RDLOCK 1307 nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 1308 BdrvRequestFlags flags) 1309 { 1310 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1311 NBDRequest request = { 1312 .type = NBD_CMD_WRITE_ZEROES, 1313 .from = offset, 1314 .len = bytes, 1315 }; 1316 1317 /* rely on max_pwrite_zeroes */ 1318 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1319 1320 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1321 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1322 return -ENOTSUP; 1323 } 1324 1325 if (flags & BDRV_REQ_FUA) { 1326 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1327 request.flags |= NBD_CMD_FLAG_FUA; 1328 } 1329 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1330 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1331 } 1332 if (flags & BDRV_REQ_NO_FALLBACK) { 1333 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1334 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1335 } 1336 1337 if (!bytes) { 1338 return 0; 1339 } 1340 return nbd_co_request(bs, &request, NULL); 1341 } 1342 1343 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_flush(BlockDriverState *bs) 1344 { 1345 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1346 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1347 1348 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1349 return 0; 1350 } 1351 1352 request.from = 0; 1353 request.len = 0; 1354 1355 return nbd_co_request(bs, &request, NULL); 1356 } 1357 1358 static int coroutine_fn GRAPH_RDLOCK 1359 nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 1360 { 1361 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1362 NBDRequest request = { 1363 .type = NBD_CMD_TRIM, 1364 .from = offset, 1365 .len = bytes, 1366 }; 1367 1368 /* rely on max_pdiscard */ 1369 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1370 1371 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1372 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1373 return 0; 1374 } 1375 1376 return nbd_co_request(bs, &request, NULL); 1377 } 1378 1379 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_block_status( 1380 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1381 int64_t *pnum, int64_t *map, BlockDriverState **file) 1382 { 1383 int ret, request_ret; 1384 NBDExtent32 extent = { 0 }; 1385 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1386 Error *local_err = NULL; 1387 1388 NBDRequest request = { 1389 .type = NBD_CMD_BLOCK_STATUS, 1390 .from = offset, 1391 .len = MIN(bytes, s->info.size - offset), 1392 .flags = NBD_CMD_FLAG_REQ_ONE, 1393 }; 1394 1395 if (!s->info.base_allocation) { 1396 *pnum = bytes; 1397 *map = offset; 1398 *file = bs; 1399 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1400 } 1401 if (s->info.mode < NBD_MODE_EXTENDED) { 1402 request.len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1403 request.len); 1404 } 1405 1406 /* 1407 * Work around the fact that the block layer doesn't do 1408 * byte-accurate sizing yet - if the status request exceeds the 1409 * server's advertised size because the block layer rounded size 1410 * up, we truncated the request to the server (above), or are 1411 * called on just the hole. 1412 */ 1413 if (offset >= s->info.size) { 1414 *pnum = bytes; 1415 assert(bytes < BDRV_SECTOR_SIZE); 1416 /* Intentionally don't report offset_valid for the hole */ 1417 return BDRV_BLOCK_ZERO; 1418 } 1419 1420 if (s->info.min_block) { 1421 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1422 } 1423 do { 1424 ret = nbd_co_send_request(bs, &request, NULL); 1425 if (ret < 0) { 1426 continue; 1427 } 1428 1429 ret = nbd_co_receive_blockstatus_reply(s, request.cookie, bytes, 1430 &extent, &request_ret, 1431 &local_err); 1432 if (local_err) { 1433 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1434 request.flags, request.type, 1435 nbd_cmd_lookup(request.type), 1436 ret, error_get_pretty(local_err)); 1437 error_free(local_err); 1438 local_err = NULL; 1439 } 1440 } while (ret < 0 && nbd_client_will_reconnect(s)); 1441 1442 if (ret < 0 || request_ret < 0) { 1443 return ret ? ret : request_ret; 1444 } 1445 1446 assert(extent.length); 1447 *pnum = extent.length; 1448 *map = offset; 1449 *file = bs; 1450 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1451 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1452 BDRV_BLOCK_OFFSET_VALID; 1453 } 1454 1455 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1456 BlockReopenQueue *queue, Error **errp) 1457 { 1458 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1459 1460 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1461 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1462 return -EACCES; 1463 } 1464 return 0; 1465 } 1466 1467 static void nbd_yank(void *opaque) 1468 { 1469 BlockDriverState *bs = opaque; 1470 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1471 1472 QEMU_LOCK_GUARD(&s->requests_lock); 1473 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1474 s->state = NBD_CLIENT_QUIT; 1475 } 1476 1477 static void nbd_client_close(BlockDriverState *bs) 1478 { 1479 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1480 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 1481 1482 if (s->ioc) { 1483 nbd_send_request(s->ioc, &request); 1484 } 1485 1486 nbd_teardown_connection(bs); 1487 } 1488 1489 1490 /* 1491 * Parse nbd_open options 1492 */ 1493 1494 static int nbd_parse_uri(const char *filename, QDict *options) 1495 { 1496 URI *uri; 1497 const char *p; 1498 QueryParams *qp = NULL; 1499 int ret = 0; 1500 bool is_unix; 1501 1502 uri = uri_parse(filename); 1503 if (!uri) { 1504 return -EINVAL; 1505 } 1506 1507 /* transport */ 1508 if (!g_strcmp0(uri->scheme, "nbd")) { 1509 is_unix = false; 1510 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1511 is_unix = false; 1512 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1513 is_unix = true; 1514 } else { 1515 ret = -EINVAL; 1516 goto out; 1517 } 1518 1519 p = uri->path ? uri->path : ""; 1520 if (p[0] == '/') { 1521 p++; 1522 } 1523 if (p[0]) { 1524 qdict_put_str(options, "export", p); 1525 } 1526 1527 qp = query_params_parse(uri->query); 1528 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1529 ret = -EINVAL; 1530 goto out; 1531 } 1532 1533 if (is_unix) { 1534 /* nbd+unix:///export?socket=path */ 1535 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1536 ret = -EINVAL; 1537 goto out; 1538 } 1539 qdict_put_str(options, "server.type", "unix"); 1540 qdict_put_str(options, "server.path", qp->p[0].value); 1541 } else { 1542 QString *host; 1543 char *port_str; 1544 1545 /* nbd[+tcp]://host[:port]/export */ 1546 if (!uri->server) { 1547 ret = -EINVAL; 1548 goto out; 1549 } 1550 1551 /* strip braces from literal IPv6 address */ 1552 if (uri->server[0] == '[') { 1553 host = qstring_from_substr(uri->server, 1, 1554 strlen(uri->server) - 1); 1555 } else { 1556 host = qstring_from_str(uri->server); 1557 } 1558 1559 qdict_put_str(options, "server.type", "inet"); 1560 qdict_put(options, "server.host", host); 1561 1562 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1563 qdict_put_str(options, "server.port", port_str); 1564 g_free(port_str); 1565 } 1566 1567 out: 1568 if (qp) { 1569 query_params_free(qp); 1570 } 1571 uri_free(uri); 1572 return ret; 1573 } 1574 1575 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1576 { 1577 const QDictEntry *e; 1578 1579 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1580 if (!strcmp(e->key, "host") || 1581 !strcmp(e->key, "port") || 1582 !strcmp(e->key, "path") || 1583 !strcmp(e->key, "export") || 1584 strstart(e->key, "server.", NULL)) 1585 { 1586 error_setg(errp, "Option '%s' cannot be used with a file name", 1587 e->key); 1588 return true; 1589 } 1590 } 1591 1592 return false; 1593 } 1594 1595 static void nbd_parse_filename(const char *filename, QDict *options, 1596 Error **errp) 1597 { 1598 g_autofree char *file = NULL; 1599 char *export_name; 1600 const char *host_spec; 1601 const char *unixpath; 1602 1603 if (nbd_has_filename_options_conflict(options, errp)) { 1604 return; 1605 } 1606 1607 if (strstr(filename, "://")) { 1608 int ret = nbd_parse_uri(filename, options); 1609 if (ret < 0) { 1610 error_setg(errp, "No valid URL specified"); 1611 } 1612 return; 1613 } 1614 1615 file = g_strdup(filename); 1616 1617 export_name = strstr(file, EN_OPTSTR); 1618 if (export_name) { 1619 if (export_name[strlen(EN_OPTSTR)] == 0) { 1620 return; 1621 } 1622 export_name[0] = 0; /* truncate 'file' */ 1623 export_name += strlen(EN_OPTSTR); 1624 1625 qdict_put_str(options, "export", export_name); 1626 } 1627 1628 /* extract the host_spec - fail if it's not nbd:... */ 1629 if (!strstart(file, "nbd:", &host_spec)) { 1630 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1631 return; 1632 } 1633 1634 if (!*host_spec) { 1635 return; 1636 } 1637 1638 /* are we a UNIX or TCP socket? */ 1639 if (strstart(host_spec, "unix:", &unixpath)) { 1640 qdict_put_str(options, "server.type", "unix"); 1641 qdict_put_str(options, "server.path", unixpath); 1642 } else { 1643 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1644 1645 if (inet_parse(addr, host_spec, errp)) { 1646 goto out_inet; 1647 } 1648 1649 qdict_put_str(options, "server.type", "inet"); 1650 qdict_put_str(options, "server.host", addr->host); 1651 qdict_put_str(options, "server.port", addr->port); 1652 out_inet: 1653 qapi_free_InetSocketAddress(addr); 1654 } 1655 } 1656 1657 static bool nbd_process_legacy_socket_options(QDict *output_options, 1658 QemuOpts *legacy_opts, 1659 Error **errp) 1660 { 1661 const char *path = qemu_opt_get(legacy_opts, "path"); 1662 const char *host = qemu_opt_get(legacy_opts, "host"); 1663 const char *port = qemu_opt_get(legacy_opts, "port"); 1664 const QDictEntry *e; 1665 1666 if (!path && !host && !port) { 1667 return true; 1668 } 1669 1670 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1671 { 1672 if (strstart(e->key, "server.", NULL)) { 1673 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1674 "same time"); 1675 return false; 1676 } 1677 } 1678 1679 if (path && host) { 1680 error_setg(errp, "path and host may not be used at the same time"); 1681 return false; 1682 } else if (path) { 1683 if (port) { 1684 error_setg(errp, "port may not be used without host"); 1685 return false; 1686 } 1687 1688 qdict_put_str(output_options, "server.type", "unix"); 1689 qdict_put_str(output_options, "server.path", path); 1690 } else if (host) { 1691 qdict_put_str(output_options, "server.type", "inet"); 1692 qdict_put_str(output_options, "server.host", host); 1693 qdict_put_str(output_options, "server.port", 1694 port ?: stringify(NBD_DEFAULT_PORT)); 1695 } 1696 1697 return true; 1698 } 1699 1700 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1701 Error **errp) 1702 { 1703 SocketAddress *saddr = NULL; 1704 QDict *addr = NULL; 1705 Visitor *iv = NULL; 1706 1707 qdict_extract_subqdict(options, &addr, "server."); 1708 if (!qdict_size(addr)) { 1709 error_setg(errp, "NBD server address missing"); 1710 goto done; 1711 } 1712 1713 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1714 if (!iv) { 1715 goto done; 1716 } 1717 1718 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1719 goto done; 1720 } 1721 1722 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1723 qapi_free_SocketAddress(saddr); 1724 saddr = NULL; 1725 goto done; 1726 } 1727 1728 done: 1729 qobject_unref(addr); 1730 visit_free(iv); 1731 return saddr; 1732 } 1733 1734 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1735 { 1736 Object *obj; 1737 QCryptoTLSCreds *creds; 1738 1739 obj = object_resolve_path_component( 1740 object_get_objects_root(), id); 1741 if (!obj) { 1742 error_setg(errp, "No TLS credentials with id '%s'", 1743 id); 1744 return NULL; 1745 } 1746 creds = (QCryptoTLSCreds *) 1747 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1748 if (!creds) { 1749 error_setg(errp, "Object with id '%s' is not TLS credentials", 1750 id); 1751 return NULL; 1752 } 1753 1754 if (!qcrypto_tls_creds_check_endpoint(creds, 1755 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1756 errp)) { 1757 return NULL; 1758 } 1759 object_ref(obj); 1760 return creds; 1761 } 1762 1763 1764 static QemuOptsList nbd_runtime_opts = { 1765 .name = "nbd", 1766 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1767 .desc = { 1768 { 1769 .name = "host", 1770 .type = QEMU_OPT_STRING, 1771 .help = "TCP host to connect to", 1772 }, 1773 { 1774 .name = "port", 1775 .type = QEMU_OPT_STRING, 1776 .help = "TCP port to connect to", 1777 }, 1778 { 1779 .name = "path", 1780 .type = QEMU_OPT_STRING, 1781 .help = "Unix socket path to connect to", 1782 }, 1783 { 1784 .name = "export", 1785 .type = QEMU_OPT_STRING, 1786 .help = "Name of the NBD export to open", 1787 }, 1788 { 1789 .name = "tls-creds", 1790 .type = QEMU_OPT_STRING, 1791 .help = "ID of the TLS credentials to use", 1792 }, 1793 { 1794 .name = "tls-hostname", 1795 .type = QEMU_OPT_STRING, 1796 .help = "Override hostname for validating TLS x509 certificate", 1797 }, 1798 { 1799 .name = "x-dirty-bitmap", 1800 .type = QEMU_OPT_STRING, 1801 .help = "experimental: expose named dirty bitmap in place of " 1802 "block status", 1803 }, 1804 { 1805 .name = "reconnect-delay", 1806 .type = QEMU_OPT_NUMBER, 1807 .help = "On an unexpected disconnect, the nbd client tries to " 1808 "connect again until succeeding or encountering a serious " 1809 "error. During the first @reconnect-delay seconds, all " 1810 "requests are paused and will be rerun on a successful " 1811 "reconnect. After that time, any delayed requests and all " 1812 "future requests before a successful reconnect will " 1813 "immediately fail. Default 0", 1814 }, 1815 { 1816 .name = "open-timeout", 1817 .type = QEMU_OPT_NUMBER, 1818 .help = "In seconds. If zero, the nbd driver tries the connection " 1819 "only once, and fails to open if the connection fails. " 1820 "If non-zero, the nbd driver will repeat connection " 1821 "attempts until successful or until @open-timeout seconds " 1822 "have elapsed. Default 0", 1823 }, 1824 { /* end of list */ } 1825 }, 1826 }; 1827 1828 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1829 Error **errp) 1830 { 1831 BDRVNBDState *s = bs->opaque; 1832 QemuOpts *opts; 1833 int ret = -EINVAL; 1834 1835 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1836 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1837 goto error; 1838 } 1839 1840 /* Translate @host, @port, and @path to a SocketAddress */ 1841 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1842 goto error; 1843 } 1844 1845 /* Pop the config into our state object. Exit if invalid. */ 1846 s->saddr = nbd_config(s, options, errp); 1847 if (!s->saddr) { 1848 goto error; 1849 } 1850 1851 s->export = g_strdup(qemu_opt_get(opts, "export")); 1852 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1853 error_setg(errp, "export name too long to send to server"); 1854 goto error; 1855 } 1856 1857 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1858 if (s->tlscredsid) { 1859 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1860 if (!s->tlscreds) { 1861 goto error; 1862 } 1863 1864 s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); 1865 if (!s->tlshostname && 1866 s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1867 s->tlshostname = g_strdup(s->saddr->u.inet.host); 1868 } 1869 } 1870 1871 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1872 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1873 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1874 goto error; 1875 } 1876 1877 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1878 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1879 1880 ret = 0; 1881 1882 error: 1883 qemu_opts_del(opts); 1884 return ret; 1885 } 1886 1887 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1888 Error **errp) 1889 { 1890 int ret; 1891 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1892 1893 s->bs = bs; 1894 qemu_mutex_init(&s->requests_lock); 1895 qemu_co_queue_init(&s->free_sema); 1896 qemu_co_mutex_init(&s->send_mutex); 1897 qemu_co_mutex_init(&s->receive_mutex); 1898 1899 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1900 return -EEXIST; 1901 } 1902 1903 ret = nbd_process_options(bs, options, errp); 1904 if (ret < 0) { 1905 goto fail; 1906 } 1907 1908 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1909 s->x_dirty_bitmap, s->tlscreds, 1910 s->tlshostname); 1911 1912 if (s->open_timeout) { 1913 nbd_client_connection_enable_retry(s->conn); 1914 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1915 s->open_timeout * NANOSECONDS_PER_SECOND); 1916 } 1917 1918 s->state = NBD_CLIENT_CONNECTING_WAIT; 1919 ret = nbd_do_establish_connection(bs, true, errp); 1920 if (ret < 0) { 1921 goto fail; 1922 } 1923 1924 /* 1925 * The connect attempt is done, so we no longer need this timer. 1926 * Delete it, because we do not want it to be around when this node 1927 * is drained or closed. 1928 */ 1929 open_timer_del(s); 1930 1931 nbd_client_connection_enable_retry(s->conn); 1932 1933 return 0; 1934 1935 fail: 1936 open_timer_del(s); 1937 nbd_clear_bdrvstate(bs); 1938 return ret; 1939 } 1940 1941 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1942 { 1943 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1944 uint32_t min = s->info.min_block; 1945 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1946 1947 /* 1948 * If the server did not advertise an alignment: 1949 * - a size that is not sector-aligned implies that an alignment 1950 * of 1 can be used to access those tail bytes 1951 * - advertisement of block status requires an alignment of 1, so 1952 * that we don't violate block layer constraints that block 1953 * status is always aligned (as we can't control whether the 1954 * server will report sub-sector extents, such as a hole at EOF 1955 * on an unaligned POSIX file) 1956 * - otherwise, assume the server is so old that we are safer avoiding 1957 * sub-sector requests 1958 */ 1959 if (!min) { 1960 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1961 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1962 } 1963 1964 bs->bl.request_alignment = min; 1965 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1966 bs->bl.max_pwrite_zeroes = max; 1967 bs->bl.max_transfer = max; 1968 1969 /* 1970 * Assume that if the server supports extended headers, it also 1971 * supports unlimited size zero and trim commands. 1972 */ 1973 if (s->info.mode >= NBD_MODE_EXTENDED) { 1974 bs->bl.max_pdiscard = bs->bl.max_pwrite_zeroes = 0; 1975 } 1976 1977 if (s->info.opt_block && 1978 s->info.opt_block > bs->bl.opt_transfer) { 1979 bs->bl.opt_transfer = s->info.opt_block; 1980 } 1981 } 1982 1983 static void nbd_close(BlockDriverState *bs) 1984 { 1985 nbd_client_close(bs); 1986 nbd_clear_bdrvstate(bs); 1987 } 1988 1989 /* 1990 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 1991 * to a smaller size with exact=false, there is no reason to fail the 1992 * operation. 1993 * 1994 * Preallocation mode is ignored since it does not seems useful to fail when 1995 * we never change anything. 1996 */ 1997 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 1998 bool exact, PreallocMode prealloc, 1999 BdrvRequestFlags flags, Error **errp) 2000 { 2001 BDRVNBDState *s = bs->opaque; 2002 2003 if (offset != s->info.size && exact) { 2004 error_setg(errp, "Cannot resize NBD nodes"); 2005 return -ENOTSUP; 2006 } 2007 2008 if (offset > s->info.size) { 2009 error_setg(errp, "Cannot grow NBD nodes"); 2010 return -EINVAL; 2011 } 2012 2013 return 0; 2014 } 2015 2016 static int64_t coroutine_fn nbd_co_getlength(BlockDriverState *bs) 2017 { 2018 BDRVNBDState *s = bs->opaque; 2019 2020 return s->info.size; 2021 } 2022 2023 static void nbd_refresh_filename(BlockDriverState *bs) 2024 { 2025 BDRVNBDState *s = bs->opaque; 2026 const char *host = NULL, *port = NULL, *path = NULL; 2027 size_t len = 0; 2028 2029 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 2030 const InetSocketAddress *inet = &s->saddr->u.inet; 2031 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 2032 host = inet->host; 2033 port = inet->port; 2034 } 2035 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2036 path = s->saddr->u.q_unix.path; 2037 } /* else can't represent as pseudo-filename */ 2038 2039 if (path && s->export) { 2040 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2041 "nbd+unix:///%s?socket=%s", s->export, path); 2042 } else if (path && !s->export) { 2043 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2044 "nbd+unix://?socket=%s", path); 2045 } else if (host && s->export) { 2046 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2047 "nbd://%s:%s/%s", host, port, s->export); 2048 } else if (host && !s->export) { 2049 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2050 "nbd://%s:%s", host, port); 2051 } 2052 if (len >= sizeof(bs->exact_filename)) { 2053 /* Name is too long to represent exactly, so leave it empty. */ 2054 bs->exact_filename[0] = '\0'; 2055 } 2056 } 2057 2058 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2059 { 2060 /* The generic bdrv_dirname() implementation is able to work out some 2061 * directory name for NBD nodes, but that would be wrong. So far there is no 2062 * specification for how "export paths" would work, so NBD does not have 2063 * directory names. */ 2064 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2065 return NULL; 2066 } 2067 2068 static const char *const nbd_strong_runtime_opts[] = { 2069 "path", 2070 "host", 2071 "port", 2072 "export", 2073 "tls-creds", 2074 "tls-hostname", 2075 "server.", 2076 2077 NULL 2078 }; 2079 2080 static void nbd_cancel_in_flight(BlockDriverState *bs) 2081 { 2082 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2083 2084 reconnect_delay_timer_del(s); 2085 2086 qemu_mutex_lock(&s->requests_lock); 2087 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2088 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2089 } 2090 qemu_mutex_unlock(&s->requests_lock); 2091 2092 nbd_co_establish_connection_cancel(s->conn); 2093 } 2094 2095 static void nbd_attach_aio_context(BlockDriverState *bs, 2096 AioContext *new_context) 2097 { 2098 BDRVNBDState *s = bs->opaque; 2099 2100 /* The open_timer is used only during nbd_open() */ 2101 assert(!s->open_timer); 2102 2103 /* 2104 * The reconnect_delay_timer is scheduled in I/O paths when the 2105 * connection is lost, to cancel the reconnection attempt after a 2106 * given time. Once this attempt is done (successfully or not), 2107 * nbd_reconnect_attempt() ensures the timer is deleted before the 2108 * respective I/O request is resumed. 2109 * Since the AioContext can only be changed when a node is drained, 2110 * the reconnect_delay_timer cannot be active here. 2111 */ 2112 assert(!s->reconnect_delay_timer); 2113 } 2114 2115 static void nbd_detach_aio_context(BlockDriverState *bs) 2116 { 2117 BDRVNBDState *s = bs->opaque; 2118 2119 assert(!s->open_timer); 2120 assert(!s->reconnect_delay_timer); 2121 } 2122 2123 static BlockDriver bdrv_nbd = { 2124 .format_name = "nbd", 2125 .protocol_name = "nbd", 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_client_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_co_getlength = nbd_co_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_tcp = { 2152 .format_name = "nbd", 2153 .protocol_name = "nbd+tcp", 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_client_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_co_getlength = nbd_co_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 BlockDriver bdrv_nbd_unix = { 2180 .format_name = "nbd", 2181 .protocol_name = "nbd+unix", 2182 .instance_size = sizeof(BDRVNBDState), 2183 .bdrv_parse_filename = nbd_parse_filename, 2184 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2185 .create_opts = &bdrv_create_opts_simple, 2186 .bdrv_file_open = nbd_open, 2187 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2188 .bdrv_co_preadv = nbd_client_co_preadv, 2189 .bdrv_co_pwritev = nbd_client_co_pwritev, 2190 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2191 .bdrv_close = nbd_close, 2192 .bdrv_co_flush_to_os = nbd_client_co_flush, 2193 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2194 .bdrv_refresh_limits = nbd_refresh_limits, 2195 .bdrv_co_truncate = nbd_co_truncate, 2196 .bdrv_co_getlength = nbd_co_getlength, 2197 .bdrv_refresh_filename = nbd_refresh_filename, 2198 .bdrv_co_block_status = nbd_client_co_block_status, 2199 .bdrv_dirname = nbd_dirname, 2200 .strong_runtime_opts = nbd_strong_runtime_opts, 2201 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2202 2203 .bdrv_attach_aio_context = nbd_attach_aio_context, 2204 .bdrv_detach_aio_context = nbd_detach_aio_context, 2205 }; 2206 2207 static void bdrv_nbd_init(void) 2208 { 2209 bdrv_register(&bdrv_nbd); 2210 bdrv_register(&bdrv_nbd_tcp); 2211 bdrv_register(&bdrv_nbd_unix); 2212 } 2213 2214 block_init(bdrv_nbd_init); 2215