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 { 421 int ret; 422 uint64_t ind = COOKIE_TO_INDEX(cookie), ind2; 423 QEMU_LOCK_GUARD(&s->receive_mutex); 424 425 while (true) { 426 if (s->reply.cookie == cookie) { 427 /* We are done */ 428 return 0; 429 } 430 431 if (s->reply.cookie != 0) { 432 /* 433 * Some other request is being handled now. It should already be 434 * woken by whoever set s->reply.cookie (or never wait in this 435 * yield). So, we should not wake it here. 436 */ 437 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 438 assert(!s->requests[ind2].receiving); 439 440 s->requests[ind].receiving = true; 441 qemu_co_mutex_unlock(&s->receive_mutex); 442 443 qemu_coroutine_yield(); 444 /* 445 * We may be woken for 2 reasons: 446 * 1. From this function, executing in parallel coroutine, when our 447 * cookie is received. 448 * 2. From nbd_co_receive_one_chunk(), when previous request is 449 * finished and s->reply.cookie set to 0. 450 * Anyway, it's OK to lock the mutex and go to the next iteration. 451 */ 452 453 qemu_co_mutex_lock(&s->receive_mutex); 454 assert(!s->requests[ind].receiving); 455 continue; 456 } 457 458 /* We are under mutex and cookie is 0. We have to do the dirty work. */ 459 assert(s->reply.cookie == 0); 460 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, NULL); 461 if (ret <= 0) { 462 ret = ret ? ret : -EIO; 463 nbd_channel_error(s, ret); 464 return ret; 465 } 466 if (nbd_reply_is_structured(&s->reply) && 467 s->info.mode < NBD_MODE_STRUCTURED) { 468 nbd_channel_error(s, -EINVAL); 469 return -EINVAL; 470 } 471 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 472 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].coroutine) { 473 nbd_channel_error(s, -EINVAL); 474 return -EINVAL; 475 } 476 if (s->reply.cookie == cookie) { 477 /* We are done */ 478 return 0; 479 } 480 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 481 } 482 } 483 484 static int coroutine_fn GRAPH_RDLOCK 485 nbd_co_send_request(BlockDriverState *bs, NBDRequest *request, 486 QEMUIOVector *qiov) 487 { 488 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 489 int rc, i = -1; 490 491 qemu_mutex_lock(&s->requests_lock); 492 while (s->in_flight == MAX_NBD_REQUESTS || 493 (s->state != NBD_CLIENT_CONNECTED && s->in_flight > 0)) { 494 qemu_co_queue_wait(&s->free_sema, &s->requests_lock); 495 } 496 497 s->in_flight++; 498 if (s->state != NBD_CLIENT_CONNECTED) { 499 if (nbd_client_connecting(s)) { 500 nbd_reconnect_attempt(s); 501 qemu_co_queue_restart_all(&s->free_sema); 502 } 503 if (s->state != NBD_CLIENT_CONNECTED) { 504 rc = -EIO; 505 goto err; 506 } 507 } 508 509 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 510 if (s->requests[i].coroutine == NULL) { 511 break; 512 } 513 } 514 515 assert(i < MAX_NBD_REQUESTS); 516 s->requests[i].coroutine = qemu_coroutine_self(); 517 s->requests[i].offset = request->from; 518 s->requests[i].receiving = false; 519 qemu_mutex_unlock(&s->requests_lock); 520 521 qemu_co_mutex_lock(&s->send_mutex); 522 request->cookie = INDEX_TO_COOKIE(i); 523 request->mode = s->info.mode; 524 525 assert(s->ioc); 526 527 if (qiov) { 528 qio_channel_set_cork(s->ioc, true); 529 rc = nbd_send_request(s->ioc, request); 530 if (rc >= 0 && qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 531 NULL) < 0) { 532 rc = -EIO; 533 } 534 qio_channel_set_cork(s->ioc, false); 535 } else { 536 rc = nbd_send_request(s->ioc, request); 537 } 538 qemu_co_mutex_unlock(&s->send_mutex); 539 540 if (rc < 0) { 541 qemu_mutex_lock(&s->requests_lock); 542 err: 543 nbd_channel_error_locked(s, rc); 544 if (i != -1) { 545 s->requests[i].coroutine = NULL; 546 } 547 s->in_flight--; 548 qemu_co_queue_next(&s->free_sema); 549 qemu_mutex_unlock(&s->requests_lock); 550 } 551 return rc; 552 } 553 554 static inline uint16_t payload_advance16(uint8_t **payload) 555 { 556 *payload += 2; 557 return lduw_be_p(*payload - 2); 558 } 559 560 static inline uint32_t payload_advance32(uint8_t **payload) 561 { 562 *payload += 4; 563 return ldl_be_p(*payload - 4); 564 } 565 566 static inline uint64_t payload_advance64(uint8_t **payload) 567 { 568 *payload += 8; 569 return ldq_be_p(*payload - 8); 570 } 571 572 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 573 NBDStructuredReplyChunk *chunk, 574 uint8_t *payload, uint64_t orig_offset, 575 QEMUIOVector *qiov, Error **errp) 576 { 577 uint64_t offset; 578 uint32_t hole_size; 579 580 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 581 error_setg(errp, "Protocol error: invalid payload for " 582 "NBD_REPLY_TYPE_OFFSET_HOLE"); 583 return -EINVAL; 584 } 585 586 offset = payload_advance64(&payload); 587 hole_size = payload_advance32(&payload); 588 589 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 590 offset > orig_offset + qiov->size - hole_size) { 591 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 592 " region"); 593 return -EINVAL; 594 } 595 if (s->info.min_block && 596 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 597 trace_nbd_structured_read_compliance("hole"); 598 } 599 600 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 601 602 return 0; 603 } 604 605 /* 606 * nbd_parse_blockstatus_payload 607 * Based on our request, we expect only one extent in reply, for the 608 * base:allocation context. 609 */ 610 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 611 NBDStructuredReplyChunk *chunk, 612 uint8_t *payload, uint64_t orig_length, 613 NBDExtent32 *extent, Error **errp) 614 { 615 uint32_t context_id; 616 617 /* The server succeeded, so it must have sent [at least] one extent */ 618 if (chunk->length < sizeof(context_id) + sizeof(*extent)) { 619 error_setg(errp, "Protocol error: invalid payload for " 620 "NBD_REPLY_TYPE_BLOCK_STATUS"); 621 return -EINVAL; 622 } 623 624 context_id = payload_advance32(&payload); 625 if (s->info.context_id != context_id) { 626 error_setg(errp, "Protocol error: unexpected context id %d for " 627 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 628 "id is %d", context_id, 629 s->info.context_id); 630 return -EINVAL; 631 } 632 633 extent->length = payload_advance32(&payload); 634 extent->flags = payload_advance32(&payload); 635 636 if (extent->length == 0) { 637 error_setg(errp, "Protocol error: server sent status chunk with " 638 "zero length"); 639 return -EINVAL; 640 } 641 642 /* 643 * A server sending unaligned block status is in violation of the 644 * protocol, but as qemu-nbd 3.1 is such a server (at least for 645 * POSIX files that are not a multiple of 512 bytes, since qemu 646 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 647 * still sees an implicit hole beyond the real EOF), it's nicer to 648 * work around the misbehaving server. If the request included 649 * more than the final unaligned block, truncate it back to an 650 * aligned result; if the request was only the final block, round 651 * up to the full block and change the status to fully-allocated 652 * (always a safe status, even if it loses information). 653 */ 654 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 655 s->info.min_block)) { 656 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 657 if (extent->length > s->info.min_block) { 658 extent->length = QEMU_ALIGN_DOWN(extent->length, 659 s->info.min_block); 660 } else { 661 extent->length = s->info.min_block; 662 extent->flags = 0; 663 } 664 } 665 666 /* 667 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 668 * sent us any more than one extent, nor should it have included 669 * status beyond our request in that extent. However, it's easy 670 * enough to ignore the server's noncompliance without killing the 671 * connection; just ignore trailing extents, and clamp things to 672 * the length of our request. 673 */ 674 if (chunk->length > sizeof(context_id) + sizeof(*extent)) { 675 trace_nbd_parse_blockstatus_compliance("more than one extent"); 676 } 677 if (extent->length > orig_length) { 678 extent->length = orig_length; 679 trace_nbd_parse_blockstatus_compliance("extent length too large"); 680 } 681 682 /* 683 * HACK: if we are using x-dirty-bitmaps to access 684 * qemu:allocation-depth, treat all depths > 2 the same as 2, 685 * since nbd_client_co_block_status is only expecting the low two 686 * bits to be set. 687 */ 688 if (s->alloc_depth && extent->flags > 2) { 689 extent->flags = 2; 690 } 691 692 return 0; 693 } 694 695 /* 696 * nbd_parse_error_payload 697 * on success @errp contains message describing nbd error reply 698 */ 699 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 700 uint8_t *payload, int *request_ret, 701 Error **errp) 702 { 703 uint32_t error; 704 uint16_t message_size; 705 706 assert(chunk->type & (1 << 15)); 707 708 if (chunk->length < sizeof(error) + sizeof(message_size)) { 709 error_setg(errp, 710 "Protocol error: invalid payload for structured error"); 711 return -EINVAL; 712 } 713 714 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 715 if (error == 0) { 716 error_setg(errp, "Protocol error: server sent structured error chunk " 717 "with error = 0"); 718 return -EINVAL; 719 } 720 721 *request_ret = -error; 722 message_size = payload_advance16(&payload); 723 724 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 725 error_setg(errp, "Protocol error: server sent structured error chunk " 726 "with incorrect message size"); 727 return -EINVAL; 728 } 729 730 /* TODO: Add a trace point to mention the server complaint */ 731 732 /* TODO handle ERROR_OFFSET */ 733 734 return 0; 735 } 736 737 static int coroutine_fn 738 nbd_co_receive_offset_data_payload(BDRVNBDState *s, uint64_t orig_offset, 739 QEMUIOVector *qiov, Error **errp) 740 { 741 QEMUIOVector sub_qiov; 742 uint64_t offset; 743 size_t data_size; 744 int ret; 745 NBDStructuredReplyChunk *chunk = &s->reply.structured; 746 747 assert(nbd_reply_is_structured(&s->reply)); 748 749 /* The NBD spec requires at least one byte of payload */ 750 if (chunk->length <= sizeof(offset)) { 751 error_setg(errp, "Protocol error: invalid payload for " 752 "NBD_REPLY_TYPE_OFFSET_DATA"); 753 return -EINVAL; 754 } 755 756 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 757 return -EIO; 758 } 759 760 data_size = chunk->length - sizeof(offset); 761 assert(data_size); 762 if (offset < orig_offset || data_size > qiov->size || 763 offset > orig_offset + qiov->size - data_size) { 764 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 765 " region"); 766 return -EINVAL; 767 } 768 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 769 trace_nbd_structured_read_compliance("data"); 770 } 771 772 qemu_iovec_init(&sub_qiov, qiov->niov); 773 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 774 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 775 qemu_iovec_destroy(&sub_qiov); 776 777 return ret < 0 ? -EIO : 0; 778 } 779 780 #define NBD_MAX_MALLOC_PAYLOAD 1000 781 static coroutine_fn int nbd_co_receive_structured_payload( 782 BDRVNBDState *s, void **payload, Error **errp) 783 { 784 int ret; 785 uint32_t len; 786 787 assert(nbd_reply_is_structured(&s->reply)); 788 789 len = s->reply.structured.length; 790 791 if (len == 0) { 792 return 0; 793 } 794 795 if (payload == NULL) { 796 error_setg(errp, "Unexpected structured payload"); 797 return -EINVAL; 798 } 799 800 if (len > NBD_MAX_MALLOC_PAYLOAD) { 801 error_setg(errp, "Payload too large"); 802 return -EINVAL; 803 } 804 805 *payload = g_new(char, len); 806 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 807 if (ret < 0) { 808 g_free(*payload); 809 *payload = NULL; 810 return ret; 811 } 812 813 return 0; 814 } 815 816 /* 817 * nbd_co_do_receive_one_chunk 818 * for simple reply: 819 * set request_ret to received reply error 820 * if qiov is not NULL: read payload to @qiov 821 * for structured reply chunk: 822 * if error chunk: read payload, set @request_ret, do not set @payload 823 * else if offset_data chunk: read payload data to @qiov, do not set @payload 824 * else: read payload to @payload 825 * 826 * If function fails, @errp contains corresponding error message, and the 827 * connection with the server is suspect. If it returns 0, then the 828 * transaction succeeded (although @request_ret may be a negative errno 829 * corresponding to the server's error reply), and errp is unchanged. 830 */ 831 static coroutine_fn int nbd_co_do_receive_one_chunk( 832 BDRVNBDState *s, uint64_t cookie, bool only_structured, 833 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 834 { 835 int ret; 836 int i = COOKIE_TO_INDEX(cookie); 837 void *local_payload = NULL; 838 NBDStructuredReplyChunk *chunk; 839 840 if (payload) { 841 *payload = NULL; 842 } 843 *request_ret = 0; 844 845 ret = nbd_receive_replies(s, cookie); 846 if (ret < 0) { 847 error_setg(errp, "Connection closed"); 848 return -EIO; 849 } 850 assert(s->ioc); 851 852 assert(s->reply.cookie == cookie); 853 854 if (nbd_reply_is_simple(&s->reply)) { 855 if (only_structured) { 856 error_setg(errp, "Protocol error: simple reply when structured " 857 "reply chunk was expected"); 858 return -EINVAL; 859 } 860 861 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 862 if (*request_ret < 0 || !qiov) { 863 return 0; 864 } 865 866 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 867 errp) < 0 ? -EIO : 0; 868 } 869 870 /* handle structured reply chunk */ 871 assert(s->info.mode >= NBD_MODE_STRUCTURED); 872 chunk = &s->reply.structured; 873 874 if (chunk->type == NBD_REPLY_TYPE_NONE) { 875 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 876 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 877 " NBD_REPLY_FLAG_DONE flag set"); 878 return -EINVAL; 879 } 880 if (chunk->length) { 881 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 882 " nonzero length"); 883 return -EINVAL; 884 } 885 return 0; 886 } 887 888 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 889 if (!qiov) { 890 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 891 return -EINVAL; 892 } 893 894 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 895 qiov, errp); 896 } 897 898 if (nbd_reply_type_is_error(chunk->type)) { 899 payload = &local_payload; 900 } 901 902 ret = nbd_co_receive_structured_payload(s, payload, errp); 903 if (ret < 0) { 904 return ret; 905 } 906 907 if (nbd_reply_type_is_error(chunk->type)) { 908 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 909 g_free(local_payload); 910 return ret; 911 } 912 913 return 0; 914 } 915 916 /* 917 * nbd_co_receive_one_chunk 918 * Read reply, wake up connection_co and set s->quit if needed. 919 * Return value is a fatal error code or normal nbd reply error code 920 */ 921 static coroutine_fn int nbd_co_receive_one_chunk( 922 BDRVNBDState *s, uint64_t cookie, bool only_structured, 923 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 924 Error **errp) 925 { 926 int ret = nbd_co_do_receive_one_chunk(s, cookie, only_structured, 927 request_ret, qiov, payload, errp); 928 929 if (ret < 0) { 930 memset(reply, 0, sizeof(*reply)); 931 nbd_channel_error(s, ret); 932 } else { 933 /* For assert at loop start in nbd_connection_entry */ 934 *reply = s->reply; 935 } 936 s->reply.cookie = 0; 937 938 nbd_recv_coroutines_wake(s); 939 940 return ret; 941 } 942 943 typedef struct NBDReplyChunkIter { 944 int ret; 945 int request_ret; 946 Error *err; 947 bool done, only_structured; 948 } NBDReplyChunkIter; 949 950 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 951 int ret, Error **local_err) 952 { 953 assert(local_err && *local_err); 954 assert(ret < 0); 955 956 if (!iter->ret) { 957 iter->ret = ret; 958 error_propagate(&iter->err, *local_err); 959 } else { 960 error_free(*local_err); 961 } 962 963 *local_err = NULL; 964 } 965 966 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 967 { 968 assert(ret < 0); 969 970 if (!iter->request_ret) { 971 iter->request_ret = ret; 972 } 973 } 974 975 /* 976 * NBD_FOREACH_REPLY_CHUNK 977 * The pointer stored in @payload requires g_free() to free it. 978 */ 979 #define NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, structured, \ 980 qiov, reply, payload) \ 981 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 982 nbd_reply_chunk_iter_receive(s, &iter, cookie, qiov, reply, payload);) 983 984 /* 985 * nbd_reply_chunk_iter_receive 986 * The pointer stored in @payload requires g_free() to free it. 987 */ 988 static bool coroutine_fn nbd_reply_chunk_iter_receive(BDRVNBDState *s, 989 NBDReplyChunkIter *iter, 990 uint64_t cookie, 991 QEMUIOVector *qiov, 992 NBDReply *reply, 993 void **payload) 994 { 995 int ret, request_ret; 996 NBDReply local_reply; 997 NBDStructuredReplyChunk *chunk; 998 Error *local_err = NULL; 999 1000 if (iter->done) { 1001 /* Previous iteration was last. */ 1002 goto break_loop; 1003 } 1004 1005 if (reply == NULL) { 1006 reply = &local_reply; 1007 } 1008 1009 ret = nbd_co_receive_one_chunk(s, cookie, iter->only_structured, 1010 &request_ret, qiov, reply, payload, 1011 &local_err); 1012 if (ret < 0) { 1013 nbd_iter_channel_error(iter, ret, &local_err); 1014 } else if (request_ret < 0) { 1015 nbd_iter_request_error(iter, request_ret); 1016 } 1017 1018 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1019 if (nbd_reply_is_simple(reply) || iter->ret < 0) { 1020 goto break_loop; 1021 } 1022 1023 chunk = &reply->structured; 1024 iter->only_structured = true; 1025 1026 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1027 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1028 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1029 goto break_loop; 1030 } 1031 1032 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1033 /* This iteration is last. */ 1034 iter->done = true; 1035 } 1036 1037 /* Execute the loop body */ 1038 return true; 1039 1040 break_loop: 1041 qemu_mutex_lock(&s->requests_lock); 1042 s->requests[COOKIE_TO_INDEX(cookie)].coroutine = NULL; 1043 s->in_flight--; 1044 qemu_co_queue_next(&s->free_sema); 1045 qemu_mutex_unlock(&s->requests_lock); 1046 1047 return false; 1048 } 1049 1050 static int coroutine_fn 1051 nbd_co_receive_return_code(BDRVNBDState *s, uint64_t cookie, 1052 int *request_ret, Error **errp) 1053 { 1054 NBDReplyChunkIter iter; 1055 1056 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, NULL, NULL) { 1057 /* nbd_reply_chunk_iter_receive does all the work */ 1058 } 1059 1060 error_propagate(errp, iter.err); 1061 *request_ret = iter.request_ret; 1062 return iter.ret; 1063 } 1064 1065 static int coroutine_fn 1066 nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t cookie, 1067 uint64_t offset, QEMUIOVector *qiov, 1068 int *request_ret, Error **errp) 1069 { 1070 NBDReplyChunkIter iter; 1071 NBDReply reply; 1072 void *payload = NULL; 1073 Error *local_err = NULL; 1074 1075 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, 1076 s->info.mode >= NBD_MODE_STRUCTURED, 1077 qiov, &reply, &payload) 1078 { 1079 int ret; 1080 NBDStructuredReplyChunk *chunk = &reply.structured; 1081 1082 assert(nbd_reply_is_structured(&reply)); 1083 1084 switch (chunk->type) { 1085 case NBD_REPLY_TYPE_OFFSET_DATA: 1086 /* 1087 * special cased in nbd_co_receive_one_chunk, data is already 1088 * in qiov 1089 */ 1090 break; 1091 case NBD_REPLY_TYPE_OFFSET_HOLE: 1092 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1093 offset, qiov, &local_err); 1094 if (ret < 0) { 1095 nbd_channel_error(s, ret); 1096 nbd_iter_channel_error(&iter, ret, &local_err); 1097 } 1098 break; 1099 default: 1100 if (!nbd_reply_type_is_error(chunk->type)) { 1101 /* not allowed reply type */ 1102 nbd_channel_error(s, -EINVAL); 1103 error_setg(&local_err, 1104 "Unexpected reply type: %d (%s) for CMD_READ", 1105 chunk->type, nbd_reply_type_lookup(chunk->type)); 1106 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1107 } 1108 } 1109 1110 g_free(payload); 1111 payload = NULL; 1112 } 1113 1114 error_propagate(errp, iter.err); 1115 *request_ret = iter.request_ret; 1116 return iter.ret; 1117 } 1118 1119 static int coroutine_fn 1120 nbd_co_receive_blockstatus_reply(BDRVNBDState *s, uint64_t cookie, 1121 uint64_t length, NBDExtent32 *extent, 1122 int *request_ret, Error **errp) 1123 { 1124 NBDReplyChunkIter iter; 1125 NBDReply reply; 1126 void *payload = NULL; 1127 Error *local_err = NULL; 1128 bool received = false; 1129 1130 assert(!extent->length); 1131 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, &reply, &payload) { 1132 int ret; 1133 NBDStructuredReplyChunk *chunk = &reply.structured; 1134 1135 assert(nbd_reply_is_structured(&reply)); 1136 1137 switch (chunk->type) { 1138 case NBD_REPLY_TYPE_BLOCK_STATUS: 1139 if (received) { 1140 nbd_channel_error(s, -EINVAL); 1141 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1142 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1143 } 1144 received = true; 1145 1146 ret = nbd_parse_blockstatus_payload(s, &reply.structured, 1147 payload, length, extent, 1148 &local_err); 1149 if (ret < 0) { 1150 nbd_channel_error(s, ret); 1151 nbd_iter_channel_error(&iter, ret, &local_err); 1152 } 1153 break; 1154 default: 1155 if (!nbd_reply_type_is_error(chunk->type)) { 1156 nbd_channel_error(s, -EINVAL); 1157 error_setg(&local_err, 1158 "Unexpected reply type: %d (%s) " 1159 "for CMD_BLOCK_STATUS", 1160 chunk->type, nbd_reply_type_lookup(chunk->type)); 1161 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1162 } 1163 } 1164 1165 g_free(payload); 1166 payload = NULL; 1167 } 1168 1169 if (!extent->length && !iter.request_ret) { 1170 error_setg(&local_err, "Server did not reply with any status extents"); 1171 nbd_iter_channel_error(&iter, -EIO, &local_err); 1172 } 1173 1174 error_propagate(errp, iter.err); 1175 *request_ret = iter.request_ret; 1176 return iter.ret; 1177 } 1178 1179 static int coroutine_fn GRAPH_RDLOCK 1180 nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1181 QEMUIOVector *write_qiov) 1182 { 1183 int ret, request_ret; 1184 Error *local_err = NULL; 1185 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1186 1187 assert(request->type != NBD_CMD_READ); 1188 if (write_qiov) { 1189 assert(request->type == NBD_CMD_WRITE); 1190 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1191 } else { 1192 assert(request->type != NBD_CMD_WRITE); 1193 } 1194 1195 do { 1196 ret = nbd_co_send_request(bs, request, write_qiov); 1197 if (ret < 0) { 1198 continue; 1199 } 1200 1201 ret = nbd_co_receive_return_code(s, request->cookie, 1202 &request_ret, &local_err); 1203 if (local_err) { 1204 trace_nbd_co_request_fail(request->from, request->len, 1205 request->cookie, request->flags, 1206 request->type, 1207 nbd_cmd_lookup(request->type), 1208 ret, error_get_pretty(local_err)); 1209 error_free(local_err); 1210 local_err = NULL; 1211 } 1212 } while (ret < 0 && nbd_client_will_reconnect(s)); 1213 1214 return ret ? ret : request_ret; 1215 } 1216 1217 static int coroutine_fn GRAPH_RDLOCK 1218 nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1219 QEMUIOVector *qiov, BdrvRequestFlags flags) 1220 { 1221 int ret, request_ret; 1222 Error *local_err = NULL; 1223 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1224 NBDRequest request = { 1225 .type = NBD_CMD_READ, 1226 .from = offset, 1227 .len = bytes, 1228 }; 1229 1230 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1231 1232 if (!bytes) { 1233 return 0; 1234 } 1235 /* 1236 * Work around the fact that the block layer doesn't do 1237 * byte-accurate sizing yet - if the read exceeds the server's 1238 * advertised size because the block layer rounded size up, then 1239 * truncate the request to the server and tail-pad with zero. 1240 */ 1241 if (offset >= s->info.size) { 1242 assert(bytes < BDRV_SECTOR_SIZE); 1243 qemu_iovec_memset(qiov, 0, 0, bytes); 1244 return 0; 1245 } 1246 if (offset + bytes > s->info.size) { 1247 uint64_t slop = offset + bytes - s->info.size; 1248 1249 assert(slop < BDRV_SECTOR_SIZE); 1250 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1251 request.len -= slop; 1252 } 1253 1254 do { 1255 ret = nbd_co_send_request(bs, &request, NULL); 1256 if (ret < 0) { 1257 continue; 1258 } 1259 1260 ret = nbd_co_receive_cmdread_reply(s, request.cookie, offset, qiov, 1261 &request_ret, &local_err); 1262 if (local_err) { 1263 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1264 request.flags, request.type, 1265 nbd_cmd_lookup(request.type), 1266 ret, error_get_pretty(local_err)); 1267 error_free(local_err); 1268 local_err = NULL; 1269 } 1270 } while (ret < 0 && nbd_client_will_reconnect(s)); 1271 1272 return ret ? ret : request_ret; 1273 } 1274 1275 static int coroutine_fn GRAPH_RDLOCK 1276 nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, 1277 QEMUIOVector *qiov, BdrvRequestFlags flags) 1278 { 1279 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1280 NBDRequest request = { 1281 .type = NBD_CMD_WRITE, 1282 .from = offset, 1283 .len = bytes, 1284 }; 1285 1286 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1287 if (flags & BDRV_REQ_FUA) { 1288 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1289 request.flags |= NBD_CMD_FLAG_FUA; 1290 } 1291 1292 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1293 1294 if (!bytes) { 1295 return 0; 1296 } 1297 return nbd_co_request(bs, &request, qiov); 1298 } 1299 1300 static int coroutine_fn GRAPH_RDLOCK 1301 nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 1302 BdrvRequestFlags flags) 1303 { 1304 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1305 NBDRequest request = { 1306 .type = NBD_CMD_WRITE_ZEROES, 1307 .from = offset, 1308 .len = bytes, 1309 }; 1310 1311 /* rely on max_pwrite_zeroes */ 1312 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1313 1314 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1315 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1316 return -ENOTSUP; 1317 } 1318 1319 if (flags & BDRV_REQ_FUA) { 1320 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1321 request.flags |= NBD_CMD_FLAG_FUA; 1322 } 1323 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1324 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1325 } 1326 if (flags & BDRV_REQ_NO_FALLBACK) { 1327 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1328 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1329 } 1330 1331 if (!bytes) { 1332 return 0; 1333 } 1334 return nbd_co_request(bs, &request, NULL); 1335 } 1336 1337 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_flush(BlockDriverState *bs) 1338 { 1339 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1340 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1341 1342 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1343 return 0; 1344 } 1345 1346 request.from = 0; 1347 request.len = 0; 1348 1349 return nbd_co_request(bs, &request, NULL); 1350 } 1351 1352 static int coroutine_fn GRAPH_RDLOCK 1353 nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 1354 { 1355 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1356 NBDRequest request = { 1357 .type = NBD_CMD_TRIM, 1358 .from = offset, 1359 .len = bytes, 1360 }; 1361 1362 /* rely on max_pdiscard */ 1363 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1364 1365 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1366 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1367 return 0; 1368 } 1369 1370 return nbd_co_request(bs, &request, NULL); 1371 } 1372 1373 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_block_status( 1374 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1375 int64_t *pnum, int64_t *map, BlockDriverState **file) 1376 { 1377 int ret, request_ret; 1378 NBDExtent32 extent = { 0 }; 1379 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1380 Error *local_err = NULL; 1381 1382 NBDRequest request = { 1383 .type = NBD_CMD_BLOCK_STATUS, 1384 .from = offset, 1385 .len = MIN(bytes, s->info.size - offset), 1386 .flags = NBD_CMD_FLAG_REQ_ONE, 1387 }; 1388 1389 if (!s->info.base_allocation) { 1390 *pnum = bytes; 1391 *map = offset; 1392 *file = bs; 1393 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1394 } 1395 if (s->info.mode < NBD_MODE_EXTENDED) { 1396 request.len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1397 request.len); 1398 } 1399 1400 /* 1401 * Work around the fact that the block layer doesn't do 1402 * byte-accurate sizing yet - if the status request exceeds the 1403 * server's advertised size because the block layer rounded size 1404 * up, we truncated the request to the server (above), or are 1405 * called on just the hole. 1406 */ 1407 if (offset >= s->info.size) { 1408 *pnum = bytes; 1409 assert(bytes < BDRV_SECTOR_SIZE); 1410 /* Intentionally don't report offset_valid for the hole */ 1411 return BDRV_BLOCK_ZERO; 1412 } 1413 1414 if (s->info.min_block) { 1415 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1416 } 1417 do { 1418 ret = nbd_co_send_request(bs, &request, NULL); 1419 if (ret < 0) { 1420 continue; 1421 } 1422 1423 ret = nbd_co_receive_blockstatus_reply(s, request.cookie, bytes, 1424 &extent, &request_ret, 1425 &local_err); 1426 if (local_err) { 1427 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1428 request.flags, request.type, 1429 nbd_cmd_lookup(request.type), 1430 ret, error_get_pretty(local_err)); 1431 error_free(local_err); 1432 local_err = NULL; 1433 } 1434 } while (ret < 0 && nbd_client_will_reconnect(s)); 1435 1436 if (ret < 0 || request_ret < 0) { 1437 return ret ? ret : request_ret; 1438 } 1439 1440 assert(extent.length); 1441 *pnum = extent.length; 1442 *map = offset; 1443 *file = bs; 1444 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1445 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1446 BDRV_BLOCK_OFFSET_VALID; 1447 } 1448 1449 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1450 BlockReopenQueue *queue, Error **errp) 1451 { 1452 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1453 1454 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1455 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1456 return -EACCES; 1457 } 1458 return 0; 1459 } 1460 1461 static void nbd_yank(void *opaque) 1462 { 1463 BlockDriverState *bs = opaque; 1464 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1465 1466 QEMU_LOCK_GUARD(&s->requests_lock); 1467 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1468 s->state = NBD_CLIENT_QUIT; 1469 } 1470 1471 static void nbd_client_close(BlockDriverState *bs) 1472 { 1473 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1474 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 1475 1476 if (s->ioc) { 1477 nbd_send_request(s->ioc, &request); 1478 } 1479 1480 nbd_teardown_connection(bs); 1481 } 1482 1483 1484 /* 1485 * Parse nbd_open options 1486 */ 1487 1488 static int nbd_parse_uri(const char *filename, QDict *options) 1489 { 1490 URI *uri; 1491 const char *p; 1492 QueryParams *qp = NULL; 1493 int ret = 0; 1494 bool is_unix; 1495 1496 uri = uri_parse(filename); 1497 if (!uri) { 1498 return -EINVAL; 1499 } 1500 1501 /* transport */ 1502 if (!g_strcmp0(uri->scheme, "nbd")) { 1503 is_unix = false; 1504 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1505 is_unix = false; 1506 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1507 is_unix = true; 1508 } else { 1509 ret = -EINVAL; 1510 goto out; 1511 } 1512 1513 p = uri->path ? uri->path : ""; 1514 if (p[0] == '/') { 1515 p++; 1516 } 1517 if (p[0]) { 1518 qdict_put_str(options, "export", p); 1519 } 1520 1521 qp = query_params_parse(uri->query); 1522 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1523 ret = -EINVAL; 1524 goto out; 1525 } 1526 1527 if (is_unix) { 1528 /* nbd+unix:///export?socket=path */ 1529 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1530 ret = -EINVAL; 1531 goto out; 1532 } 1533 qdict_put_str(options, "server.type", "unix"); 1534 qdict_put_str(options, "server.path", qp->p[0].value); 1535 } else { 1536 QString *host; 1537 char *port_str; 1538 1539 /* nbd[+tcp]://host[:port]/export */ 1540 if (!uri->server) { 1541 ret = -EINVAL; 1542 goto out; 1543 } 1544 1545 /* strip braces from literal IPv6 address */ 1546 if (uri->server[0] == '[') { 1547 host = qstring_from_substr(uri->server, 1, 1548 strlen(uri->server) - 1); 1549 } else { 1550 host = qstring_from_str(uri->server); 1551 } 1552 1553 qdict_put_str(options, "server.type", "inet"); 1554 qdict_put(options, "server.host", host); 1555 1556 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1557 qdict_put_str(options, "server.port", port_str); 1558 g_free(port_str); 1559 } 1560 1561 out: 1562 if (qp) { 1563 query_params_free(qp); 1564 } 1565 uri_free(uri); 1566 return ret; 1567 } 1568 1569 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1570 { 1571 const QDictEntry *e; 1572 1573 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1574 if (!strcmp(e->key, "host") || 1575 !strcmp(e->key, "port") || 1576 !strcmp(e->key, "path") || 1577 !strcmp(e->key, "export") || 1578 strstart(e->key, "server.", NULL)) 1579 { 1580 error_setg(errp, "Option '%s' cannot be used with a file name", 1581 e->key); 1582 return true; 1583 } 1584 } 1585 1586 return false; 1587 } 1588 1589 static void nbd_parse_filename(const char *filename, QDict *options, 1590 Error **errp) 1591 { 1592 g_autofree char *file = NULL; 1593 char *export_name; 1594 const char *host_spec; 1595 const char *unixpath; 1596 1597 if (nbd_has_filename_options_conflict(options, errp)) { 1598 return; 1599 } 1600 1601 if (strstr(filename, "://")) { 1602 int ret = nbd_parse_uri(filename, options); 1603 if (ret < 0) { 1604 error_setg(errp, "No valid URL specified"); 1605 } 1606 return; 1607 } 1608 1609 file = g_strdup(filename); 1610 1611 export_name = strstr(file, EN_OPTSTR); 1612 if (export_name) { 1613 if (export_name[strlen(EN_OPTSTR)] == 0) { 1614 return; 1615 } 1616 export_name[0] = 0; /* truncate 'file' */ 1617 export_name += strlen(EN_OPTSTR); 1618 1619 qdict_put_str(options, "export", export_name); 1620 } 1621 1622 /* extract the host_spec - fail if it's not nbd:... */ 1623 if (!strstart(file, "nbd:", &host_spec)) { 1624 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1625 return; 1626 } 1627 1628 if (!*host_spec) { 1629 return; 1630 } 1631 1632 /* are we a UNIX or TCP socket? */ 1633 if (strstart(host_spec, "unix:", &unixpath)) { 1634 qdict_put_str(options, "server.type", "unix"); 1635 qdict_put_str(options, "server.path", unixpath); 1636 } else { 1637 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1638 1639 if (inet_parse(addr, host_spec, errp)) { 1640 goto out_inet; 1641 } 1642 1643 qdict_put_str(options, "server.type", "inet"); 1644 qdict_put_str(options, "server.host", addr->host); 1645 qdict_put_str(options, "server.port", addr->port); 1646 out_inet: 1647 qapi_free_InetSocketAddress(addr); 1648 } 1649 } 1650 1651 static bool nbd_process_legacy_socket_options(QDict *output_options, 1652 QemuOpts *legacy_opts, 1653 Error **errp) 1654 { 1655 const char *path = qemu_opt_get(legacy_opts, "path"); 1656 const char *host = qemu_opt_get(legacy_opts, "host"); 1657 const char *port = qemu_opt_get(legacy_opts, "port"); 1658 const QDictEntry *e; 1659 1660 if (!path && !host && !port) { 1661 return true; 1662 } 1663 1664 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1665 { 1666 if (strstart(e->key, "server.", NULL)) { 1667 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1668 "same time"); 1669 return false; 1670 } 1671 } 1672 1673 if (path && host) { 1674 error_setg(errp, "path and host may not be used at the same time"); 1675 return false; 1676 } else if (path) { 1677 if (port) { 1678 error_setg(errp, "port may not be used without host"); 1679 return false; 1680 } 1681 1682 qdict_put_str(output_options, "server.type", "unix"); 1683 qdict_put_str(output_options, "server.path", path); 1684 } else if (host) { 1685 qdict_put_str(output_options, "server.type", "inet"); 1686 qdict_put_str(output_options, "server.host", host); 1687 qdict_put_str(output_options, "server.port", 1688 port ?: stringify(NBD_DEFAULT_PORT)); 1689 } 1690 1691 return true; 1692 } 1693 1694 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1695 Error **errp) 1696 { 1697 SocketAddress *saddr = NULL; 1698 QDict *addr = NULL; 1699 Visitor *iv = NULL; 1700 1701 qdict_extract_subqdict(options, &addr, "server."); 1702 if (!qdict_size(addr)) { 1703 error_setg(errp, "NBD server address missing"); 1704 goto done; 1705 } 1706 1707 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1708 if (!iv) { 1709 goto done; 1710 } 1711 1712 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1713 goto done; 1714 } 1715 1716 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1717 qapi_free_SocketAddress(saddr); 1718 saddr = NULL; 1719 goto done; 1720 } 1721 1722 done: 1723 qobject_unref(addr); 1724 visit_free(iv); 1725 return saddr; 1726 } 1727 1728 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1729 { 1730 Object *obj; 1731 QCryptoTLSCreds *creds; 1732 1733 obj = object_resolve_path_component( 1734 object_get_objects_root(), id); 1735 if (!obj) { 1736 error_setg(errp, "No TLS credentials with id '%s'", 1737 id); 1738 return NULL; 1739 } 1740 creds = (QCryptoTLSCreds *) 1741 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1742 if (!creds) { 1743 error_setg(errp, "Object with id '%s' is not TLS credentials", 1744 id); 1745 return NULL; 1746 } 1747 1748 if (!qcrypto_tls_creds_check_endpoint(creds, 1749 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1750 errp)) { 1751 return NULL; 1752 } 1753 object_ref(obj); 1754 return creds; 1755 } 1756 1757 1758 static QemuOptsList nbd_runtime_opts = { 1759 .name = "nbd", 1760 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1761 .desc = { 1762 { 1763 .name = "host", 1764 .type = QEMU_OPT_STRING, 1765 .help = "TCP host to connect to", 1766 }, 1767 { 1768 .name = "port", 1769 .type = QEMU_OPT_STRING, 1770 .help = "TCP port to connect to", 1771 }, 1772 { 1773 .name = "path", 1774 .type = QEMU_OPT_STRING, 1775 .help = "Unix socket path to connect to", 1776 }, 1777 { 1778 .name = "export", 1779 .type = QEMU_OPT_STRING, 1780 .help = "Name of the NBD export to open", 1781 }, 1782 { 1783 .name = "tls-creds", 1784 .type = QEMU_OPT_STRING, 1785 .help = "ID of the TLS credentials to use", 1786 }, 1787 { 1788 .name = "tls-hostname", 1789 .type = QEMU_OPT_STRING, 1790 .help = "Override hostname for validating TLS x509 certificate", 1791 }, 1792 { 1793 .name = "x-dirty-bitmap", 1794 .type = QEMU_OPT_STRING, 1795 .help = "experimental: expose named dirty bitmap in place of " 1796 "block status", 1797 }, 1798 { 1799 .name = "reconnect-delay", 1800 .type = QEMU_OPT_NUMBER, 1801 .help = "On an unexpected disconnect, the nbd client tries to " 1802 "connect again until succeeding or encountering a serious " 1803 "error. During the first @reconnect-delay seconds, all " 1804 "requests are paused and will be rerun on a successful " 1805 "reconnect. After that time, any delayed requests and all " 1806 "future requests before a successful reconnect will " 1807 "immediately fail. Default 0", 1808 }, 1809 { 1810 .name = "open-timeout", 1811 .type = QEMU_OPT_NUMBER, 1812 .help = "In seconds. If zero, the nbd driver tries the connection " 1813 "only once, and fails to open if the connection fails. " 1814 "If non-zero, the nbd driver will repeat connection " 1815 "attempts until successful or until @open-timeout seconds " 1816 "have elapsed. Default 0", 1817 }, 1818 { /* end of list */ } 1819 }, 1820 }; 1821 1822 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1823 Error **errp) 1824 { 1825 BDRVNBDState *s = bs->opaque; 1826 QemuOpts *opts; 1827 int ret = -EINVAL; 1828 1829 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1830 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1831 goto error; 1832 } 1833 1834 /* Translate @host, @port, and @path to a SocketAddress */ 1835 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1836 goto error; 1837 } 1838 1839 /* Pop the config into our state object. Exit if invalid. */ 1840 s->saddr = nbd_config(s, options, errp); 1841 if (!s->saddr) { 1842 goto error; 1843 } 1844 1845 s->export = g_strdup(qemu_opt_get(opts, "export")); 1846 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1847 error_setg(errp, "export name too long to send to server"); 1848 goto error; 1849 } 1850 1851 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1852 if (s->tlscredsid) { 1853 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1854 if (!s->tlscreds) { 1855 goto error; 1856 } 1857 1858 s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); 1859 if (!s->tlshostname && 1860 s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1861 s->tlshostname = g_strdup(s->saddr->u.inet.host); 1862 } 1863 } 1864 1865 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1866 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1867 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1868 goto error; 1869 } 1870 1871 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1872 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1873 1874 ret = 0; 1875 1876 error: 1877 qemu_opts_del(opts); 1878 return ret; 1879 } 1880 1881 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1882 Error **errp) 1883 { 1884 int ret; 1885 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1886 1887 s->bs = bs; 1888 qemu_mutex_init(&s->requests_lock); 1889 qemu_co_queue_init(&s->free_sema); 1890 qemu_co_mutex_init(&s->send_mutex); 1891 qemu_co_mutex_init(&s->receive_mutex); 1892 1893 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1894 return -EEXIST; 1895 } 1896 1897 ret = nbd_process_options(bs, options, errp); 1898 if (ret < 0) { 1899 goto fail; 1900 } 1901 1902 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1903 s->x_dirty_bitmap, s->tlscreds, 1904 s->tlshostname); 1905 1906 if (s->open_timeout) { 1907 nbd_client_connection_enable_retry(s->conn); 1908 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1909 s->open_timeout * NANOSECONDS_PER_SECOND); 1910 } 1911 1912 s->state = NBD_CLIENT_CONNECTING_WAIT; 1913 ret = nbd_do_establish_connection(bs, true, errp); 1914 if (ret < 0) { 1915 goto fail; 1916 } 1917 1918 /* 1919 * The connect attempt is done, so we no longer need this timer. 1920 * Delete it, because we do not want it to be around when this node 1921 * is drained or closed. 1922 */ 1923 open_timer_del(s); 1924 1925 nbd_client_connection_enable_retry(s->conn); 1926 1927 return 0; 1928 1929 fail: 1930 open_timer_del(s); 1931 nbd_clear_bdrvstate(bs); 1932 return ret; 1933 } 1934 1935 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1936 { 1937 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1938 uint32_t min = s->info.min_block; 1939 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1940 1941 /* 1942 * If the server did not advertise an alignment: 1943 * - a size that is not sector-aligned implies that an alignment 1944 * of 1 can be used to access those tail bytes 1945 * - advertisement of block status requires an alignment of 1, so 1946 * that we don't violate block layer constraints that block 1947 * status is always aligned (as we can't control whether the 1948 * server will report sub-sector extents, such as a hole at EOF 1949 * on an unaligned POSIX file) 1950 * - otherwise, assume the server is so old that we are safer avoiding 1951 * sub-sector requests 1952 */ 1953 if (!min) { 1954 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1955 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1956 } 1957 1958 bs->bl.request_alignment = min; 1959 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1960 bs->bl.max_pwrite_zeroes = max; 1961 bs->bl.max_transfer = max; 1962 1963 /* 1964 * Assume that if the server supports extended headers, it also 1965 * supports unlimited size zero and trim commands. 1966 */ 1967 if (s->info.mode >= NBD_MODE_EXTENDED) { 1968 bs->bl.max_pdiscard = bs->bl.max_pwrite_zeroes = 0; 1969 } 1970 1971 if (s->info.opt_block && 1972 s->info.opt_block > bs->bl.opt_transfer) { 1973 bs->bl.opt_transfer = s->info.opt_block; 1974 } 1975 } 1976 1977 static void nbd_close(BlockDriverState *bs) 1978 { 1979 nbd_client_close(bs); 1980 nbd_clear_bdrvstate(bs); 1981 } 1982 1983 /* 1984 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 1985 * to a smaller size with exact=false, there is no reason to fail the 1986 * operation. 1987 * 1988 * Preallocation mode is ignored since it does not seems useful to fail when 1989 * we never change anything. 1990 */ 1991 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 1992 bool exact, PreallocMode prealloc, 1993 BdrvRequestFlags flags, Error **errp) 1994 { 1995 BDRVNBDState *s = bs->opaque; 1996 1997 if (offset != s->info.size && exact) { 1998 error_setg(errp, "Cannot resize NBD nodes"); 1999 return -ENOTSUP; 2000 } 2001 2002 if (offset > s->info.size) { 2003 error_setg(errp, "Cannot grow NBD nodes"); 2004 return -EINVAL; 2005 } 2006 2007 return 0; 2008 } 2009 2010 static int64_t coroutine_fn nbd_co_getlength(BlockDriverState *bs) 2011 { 2012 BDRVNBDState *s = bs->opaque; 2013 2014 return s->info.size; 2015 } 2016 2017 static void nbd_refresh_filename(BlockDriverState *bs) 2018 { 2019 BDRVNBDState *s = bs->opaque; 2020 const char *host = NULL, *port = NULL, *path = NULL; 2021 size_t len = 0; 2022 2023 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 2024 const InetSocketAddress *inet = &s->saddr->u.inet; 2025 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 2026 host = inet->host; 2027 port = inet->port; 2028 } 2029 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2030 path = s->saddr->u.q_unix.path; 2031 } /* else can't represent as pseudo-filename */ 2032 2033 if (path && s->export) { 2034 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2035 "nbd+unix:///%s?socket=%s", s->export, path); 2036 } else if (path && !s->export) { 2037 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2038 "nbd+unix://?socket=%s", path); 2039 } else if (host && s->export) { 2040 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2041 "nbd://%s:%s/%s", host, port, s->export); 2042 } else if (host && !s->export) { 2043 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2044 "nbd://%s:%s", host, port); 2045 } 2046 if (len >= sizeof(bs->exact_filename)) { 2047 /* Name is too long to represent exactly, so leave it empty. */ 2048 bs->exact_filename[0] = '\0'; 2049 } 2050 } 2051 2052 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2053 { 2054 /* The generic bdrv_dirname() implementation is able to work out some 2055 * directory name for NBD nodes, but that would be wrong. So far there is no 2056 * specification for how "export paths" would work, so NBD does not have 2057 * directory names. */ 2058 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2059 return NULL; 2060 } 2061 2062 static const char *const nbd_strong_runtime_opts[] = { 2063 "path", 2064 "host", 2065 "port", 2066 "export", 2067 "tls-creds", 2068 "tls-hostname", 2069 "server.", 2070 2071 NULL 2072 }; 2073 2074 static void nbd_cancel_in_flight(BlockDriverState *bs) 2075 { 2076 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2077 2078 reconnect_delay_timer_del(s); 2079 2080 qemu_mutex_lock(&s->requests_lock); 2081 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2082 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2083 } 2084 qemu_mutex_unlock(&s->requests_lock); 2085 2086 nbd_co_establish_connection_cancel(s->conn); 2087 } 2088 2089 static void nbd_attach_aio_context(BlockDriverState *bs, 2090 AioContext *new_context) 2091 { 2092 BDRVNBDState *s = bs->opaque; 2093 2094 /* The open_timer is used only during nbd_open() */ 2095 assert(!s->open_timer); 2096 2097 /* 2098 * The reconnect_delay_timer is scheduled in I/O paths when the 2099 * connection is lost, to cancel the reconnection attempt after a 2100 * given time. Once this attempt is done (successfully or not), 2101 * nbd_reconnect_attempt() ensures the timer is deleted before the 2102 * respective I/O request is resumed. 2103 * Since the AioContext can only be changed when a node is drained, 2104 * the reconnect_delay_timer cannot be active here. 2105 */ 2106 assert(!s->reconnect_delay_timer); 2107 } 2108 2109 static void nbd_detach_aio_context(BlockDriverState *bs) 2110 { 2111 BDRVNBDState *s = bs->opaque; 2112 2113 assert(!s->open_timer); 2114 assert(!s->reconnect_delay_timer); 2115 } 2116 2117 static BlockDriver bdrv_nbd = { 2118 .format_name = "nbd", 2119 .protocol_name = "nbd", 2120 .instance_size = sizeof(BDRVNBDState), 2121 .bdrv_parse_filename = nbd_parse_filename, 2122 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2123 .create_opts = &bdrv_create_opts_simple, 2124 .bdrv_file_open = nbd_open, 2125 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2126 .bdrv_co_preadv = nbd_client_co_preadv, 2127 .bdrv_co_pwritev = nbd_client_co_pwritev, 2128 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2129 .bdrv_close = nbd_close, 2130 .bdrv_co_flush_to_os = nbd_client_co_flush, 2131 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2132 .bdrv_refresh_limits = nbd_refresh_limits, 2133 .bdrv_co_truncate = nbd_co_truncate, 2134 .bdrv_co_getlength = nbd_co_getlength, 2135 .bdrv_refresh_filename = nbd_refresh_filename, 2136 .bdrv_co_block_status = nbd_client_co_block_status, 2137 .bdrv_dirname = nbd_dirname, 2138 .strong_runtime_opts = nbd_strong_runtime_opts, 2139 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2140 2141 .bdrv_attach_aio_context = nbd_attach_aio_context, 2142 .bdrv_detach_aio_context = nbd_detach_aio_context, 2143 }; 2144 2145 static BlockDriver bdrv_nbd_tcp = { 2146 .format_name = "nbd", 2147 .protocol_name = "nbd+tcp", 2148 .instance_size = sizeof(BDRVNBDState), 2149 .bdrv_parse_filename = nbd_parse_filename, 2150 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2151 .create_opts = &bdrv_create_opts_simple, 2152 .bdrv_file_open = nbd_open, 2153 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2154 .bdrv_co_preadv = nbd_client_co_preadv, 2155 .bdrv_co_pwritev = nbd_client_co_pwritev, 2156 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2157 .bdrv_close = nbd_close, 2158 .bdrv_co_flush_to_os = nbd_client_co_flush, 2159 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2160 .bdrv_refresh_limits = nbd_refresh_limits, 2161 .bdrv_co_truncate = nbd_co_truncate, 2162 .bdrv_co_getlength = nbd_co_getlength, 2163 .bdrv_refresh_filename = nbd_refresh_filename, 2164 .bdrv_co_block_status = nbd_client_co_block_status, 2165 .bdrv_dirname = nbd_dirname, 2166 .strong_runtime_opts = nbd_strong_runtime_opts, 2167 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2168 2169 .bdrv_attach_aio_context = nbd_attach_aio_context, 2170 .bdrv_detach_aio_context = nbd_detach_aio_context, 2171 }; 2172 2173 static BlockDriver bdrv_nbd_unix = { 2174 .format_name = "nbd", 2175 .protocol_name = "nbd+unix", 2176 .instance_size = sizeof(BDRVNBDState), 2177 .bdrv_parse_filename = nbd_parse_filename, 2178 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2179 .create_opts = &bdrv_create_opts_simple, 2180 .bdrv_file_open = nbd_open, 2181 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2182 .bdrv_co_preadv = nbd_client_co_preadv, 2183 .bdrv_co_pwritev = nbd_client_co_pwritev, 2184 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2185 .bdrv_close = nbd_close, 2186 .bdrv_co_flush_to_os = nbd_client_co_flush, 2187 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2188 .bdrv_refresh_limits = nbd_refresh_limits, 2189 .bdrv_co_truncate = nbd_co_truncate, 2190 .bdrv_co_getlength = nbd_co_getlength, 2191 .bdrv_refresh_filename = nbd_refresh_filename, 2192 .bdrv_co_block_status = nbd_client_co_block_status, 2193 .bdrv_dirname = nbd_dirname, 2194 .strong_runtime_opts = nbd_strong_runtime_opts, 2195 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2196 2197 .bdrv_attach_aio_context = nbd_attach_aio_context, 2198 .bdrv_detach_aio_context = nbd_detach_aio_context, 2199 }; 2200 2201 static void bdrv_nbd_init(void) 2202 { 2203 bdrv_register(&bdrv_nbd); 2204 bdrv_register(&bdrv_nbd_tcp); 2205 bdrv_register(&bdrv_nbd_unix); 2206 } 2207 2208 block_init(bdrv_nbd_init); 2209