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 coroutine_fn GRAPH_RDLOCK 279 nbd_handle_updated_info(BlockDriverState *bs, Error **errp) 280 { 281 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 282 int ret; 283 284 if (s->x_dirty_bitmap) { 285 if (!s->info.base_allocation) { 286 error_setg(errp, "requested x-dirty-bitmap %s not found", 287 s->x_dirty_bitmap); 288 return -EINVAL; 289 } 290 if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { 291 s->alloc_depth = true; 292 } 293 } 294 295 if (s->info.flags & NBD_FLAG_READ_ONLY) { 296 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); 297 if (ret < 0) { 298 return ret; 299 } 300 } 301 302 if (s->info.flags & NBD_FLAG_SEND_FUA) { 303 bs->supported_write_flags = BDRV_REQ_FUA; 304 bs->supported_zero_flags |= BDRV_REQ_FUA; 305 } 306 307 if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { 308 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; 309 if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { 310 bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; 311 } 312 } 313 314 trace_nbd_client_handshake_success(s->export); 315 316 return 0; 317 } 318 319 int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, 320 bool blocking, Error **errp) 321 { 322 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 323 int ret; 324 IO_CODE(); 325 326 assert_bdrv_graph_readable(); 327 assert(!s->ioc); 328 329 s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); 330 if (!s->ioc) { 331 return -ECONNREFUSED; 332 } 333 334 yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, 335 bs); 336 337 ret = nbd_handle_updated_info(s->bs, NULL); 338 if (ret < 0) { 339 /* 340 * We have connected, but must fail for other reasons. 341 * Send NBD_CMD_DISC as a courtesy to the server. 342 */ 343 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 344 345 nbd_send_request(s->ioc, &request); 346 347 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 348 nbd_yank, bs); 349 object_unref(OBJECT(s->ioc)); 350 s->ioc = NULL; 351 352 return ret; 353 } 354 355 qio_channel_set_blocking(s->ioc, false, NULL); 356 qio_channel_set_follow_coroutine_ctx(s->ioc, true); 357 358 /* successfully connected */ 359 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 360 s->state = NBD_CLIENT_CONNECTED; 361 } 362 363 return 0; 364 } 365 366 /* Called with s->requests_lock held. */ 367 static bool nbd_client_connecting(BDRVNBDState *s) 368 { 369 return s->state == NBD_CLIENT_CONNECTING_WAIT || 370 s->state == NBD_CLIENT_CONNECTING_NOWAIT; 371 } 372 373 /* Called with s->requests_lock taken. */ 374 static void coroutine_fn GRAPH_RDLOCK nbd_reconnect_attempt(BDRVNBDState *s) 375 { 376 int ret; 377 bool blocking = s->state == NBD_CLIENT_CONNECTING_WAIT; 378 379 /* 380 * Now we are sure that nobody is accessing the channel, and no one will 381 * try until we set the state to CONNECTED. 382 */ 383 assert(nbd_client_connecting(s)); 384 assert(s->in_flight == 1); 385 386 trace_nbd_reconnect_attempt(s->bs->in_flight); 387 388 if (blocking && !s->reconnect_delay_timer) { 389 /* 390 * It's the first reconnect attempt after switching to 391 * NBD_CLIENT_CONNECTING_WAIT 392 */ 393 g_assert(s->reconnect_delay); 394 reconnect_delay_timer_init(s, 395 qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 396 s->reconnect_delay * NANOSECONDS_PER_SECOND); 397 } 398 399 /* Finalize previous connection if any */ 400 if (s->ioc) { 401 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 402 nbd_yank, s->bs); 403 object_unref(OBJECT(s->ioc)); 404 s->ioc = NULL; 405 } 406 407 qemu_mutex_unlock(&s->requests_lock); 408 ret = nbd_co_do_establish_connection(s->bs, blocking, NULL); 409 trace_nbd_reconnect_attempt_result(ret, s->bs->in_flight); 410 qemu_mutex_lock(&s->requests_lock); 411 412 /* 413 * The reconnect attempt is done (maybe successfully, maybe not), so 414 * we no longer need this timer. Delete it so it will not outlive 415 * this I/O request (so draining removes all timers). 416 */ 417 reconnect_delay_timer_del(s); 418 } 419 420 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t cookie, 421 Error **errp) 422 { 423 int ret; 424 uint64_t ind = COOKIE_TO_INDEX(cookie), ind2; 425 QEMU_LOCK_GUARD(&s->receive_mutex); 426 427 while (true) { 428 if (s->reply.cookie == cookie) { 429 /* We are done */ 430 return 0; 431 } 432 433 if (s->reply.cookie != 0) { 434 /* 435 * Some other request is being handled now. It should already be 436 * woken by whoever set s->reply.cookie (or never wait in this 437 * yield). So, we should not wake it here. 438 */ 439 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 440 assert(!s->requests[ind2].receiving); 441 442 s->requests[ind].receiving = true; 443 qemu_co_mutex_unlock(&s->receive_mutex); 444 445 qemu_coroutine_yield(); 446 /* 447 * We may be woken for 2 reasons: 448 * 1. From this function, executing in parallel coroutine, when our 449 * cookie is received. 450 * 2. From nbd_co_receive_one_chunk(), when previous request is 451 * finished and s->reply.cookie set to 0. 452 * Anyway, it's OK to lock the mutex and go to the next iteration. 453 */ 454 455 qemu_co_mutex_lock(&s->receive_mutex); 456 assert(!s->requests[ind].receiving); 457 continue; 458 } 459 460 /* We are under mutex and cookie is 0. We have to do the dirty work. */ 461 assert(s->reply.cookie == 0); 462 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, s->info.mode, errp); 463 if (ret == 0) { 464 ret = -EIO; 465 error_setg(errp, "server dropped connection"); 466 } 467 if (ret < 0) { 468 nbd_channel_error(s, ret); 469 return ret; 470 } 471 if (nbd_reply_is_structured(&s->reply) && 472 s->info.mode < NBD_MODE_STRUCTURED) { 473 nbd_channel_error(s, -EINVAL); 474 error_setg(errp, "unexpected structured reply"); 475 return -EINVAL; 476 } 477 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 478 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].coroutine) { 479 nbd_channel_error(s, -EINVAL); 480 error_setg(errp, "unexpected cookie value"); 481 return -EINVAL; 482 } 483 if (s->reply.cookie == cookie) { 484 /* We are done */ 485 return 0; 486 } 487 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 488 } 489 } 490 491 static int coroutine_fn GRAPH_RDLOCK 492 nbd_co_send_request(BlockDriverState *bs, NBDRequest *request, 493 QEMUIOVector *qiov) 494 { 495 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 496 int rc, i = -1; 497 498 qemu_mutex_lock(&s->requests_lock); 499 while (s->in_flight == MAX_NBD_REQUESTS || 500 (s->state != NBD_CLIENT_CONNECTED && s->in_flight > 0)) { 501 qemu_co_queue_wait(&s->free_sema, &s->requests_lock); 502 } 503 504 s->in_flight++; 505 if (s->state != NBD_CLIENT_CONNECTED) { 506 if (nbd_client_connecting(s)) { 507 nbd_reconnect_attempt(s); 508 qemu_co_queue_restart_all(&s->free_sema); 509 } 510 if (s->state != NBD_CLIENT_CONNECTED) { 511 rc = -EIO; 512 goto err; 513 } 514 } 515 516 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 517 if (s->requests[i].coroutine == NULL) { 518 break; 519 } 520 } 521 522 assert(i < MAX_NBD_REQUESTS); 523 s->requests[i].coroutine = qemu_coroutine_self(); 524 s->requests[i].offset = request->from; 525 s->requests[i].receiving = false; 526 qemu_mutex_unlock(&s->requests_lock); 527 528 qemu_co_mutex_lock(&s->send_mutex); 529 request->cookie = INDEX_TO_COOKIE(i); 530 request->mode = s->info.mode; 531 532 assert(s->ioc); 533 534 if (qiov) { 535 qio_channel_set_cork(s->ioc, true); 536 rc = nbd_send_request(s->ioc, request); 537 if (rc >= 0 && qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 538 NULL) < 0) { 539 rc = -EIO; 540 } 541 qio_channel_set_cork(s->ioc, false); 542 } else { 543 rc = nbd_send_request(s->ioc, request); 544 } 545 qemu_co_mutex_unlock(&s->send_mutex); 546 547 if (rc < 0) { 548 qemu_mutex_lock(&s->requests_lock); 549 err: 550 nbd_channel_error_locked(s, rc); 551 if (i != -1) { 552 s->requests[i].coroutine = NULL; 553 } 554 s->in_flight--; 555 qemu_co_queue_next(&s->free_sema); 556 qemu_mutex_unlock(&s->requests_lock); 557 } 558 return rc; 559 } 560 561 static inline uint16_t payload_advance16(uint8_t **payload) 562 { 563 *payload += 2; 564 return lduw_be_p(*payload - 2); 565 } 566 567 static inline uint32_t payload_advance32(uint8_t **payload) 568 { 569 *payload += 4; 570 return ldl_be_p(*payload - 4); 571 } 572 573 static inline uint64_t payload_advance64(uint8_t **payload) 574 { 575 *payload += 8; 576 return ldq_be_p(*payload - 8); 577 } 578 579 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 580 NBDStructuredReplyChunk *chunk, 581 uint8_t *payload, uint64_t orig_offset, 582 QEMUIOVector *qiov, Error **errp) 583 { 584 uint64_t offset; 585 uint32_t hole_size; 586 587 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 588 error_setg(errp, "Protocol error: invalid payload for " 589 "NBD_REPLY_TYPE_OFFSET_HOLE"); 590 return -EINVAL; 591 } 592 593 offset = payload_advance64(&payload); 594 hole_size = payload_advance32(&payload); 595 596 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 597 offset > orig_offset + qiov->size - hole_size) { 598 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 599 " region"); 600 return -EINVAL; 601 } 602 if (s->info.min_block && 603 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 604 trace_nbd_structured_read_compliance("hole"); 605 } 606 607 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 608 609 return 0; 610 } 611 612 /* 613 * nbd_parse_blockstatus_payload 614 * Based on our request, we expect only one extent in reply, for the 615 * base:allocation context. 616 */ 617 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 618 NBDStructuredReplyChunk *chunk, 619 uint8_t *payload, bool wide, 620 uint64_t orig_length, 621 NBDExtent64 *extent, Error **errp) 622 { 623 uint32_t context_id; 624 uint32_t count; 625 size_t ext_len = wide ? sizeof(*extent) : sizeof(NBDExtent32); 626 size_t pay_len = sizeof(context_id) + wide * sizeof(count) + ext_len; 627 628 /* The server succeeded, so it must have sent [at least] one extent */ 629 if (chunk->length < pay_len) { 630 error_setg(errp, "Protocol error: invalid payload for " 631 "NBD_REPLY_TYPE_BLOCK_STATUS"); 632 return -EINVAL; 633 } 634 635 context_id = payload_advance32(&payload); 636 if (s->info.context_id != context_id) { 637 error_setg(errp, "Protocol error: unexpected context id %d for " 638 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 639 "id is %d", context_id, 640 s->info.context_id); 641 return -EINVAL; 642 } 643 644 if (wide) { 645 count = payload_advance32(&payload); 646 extent->length = payload_advance64(&payload); 647 extent->flags = payload_advance64(&payload); 648 } else { 649 count = 0; 650 extent->length = payload_advance32(&payload); 651 extent->flags = payload_advance32(&payload); 652 } 653 654 if (extent->length == 0) { 655 error_setg(errp, "Protocol error: server sent status chunk with " 656 "zero length"); 657 return -EINVAL; 658 } 659 660 /* 661 * A server sending unaligned block status is in violation of the 662 * protocol, but as qemu-nbd 3.1 is such a server (at least for 663 * POSIX files that are not a multiple of 512 bytes, since qemu 664 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 665 * still sees an implicit hole beyond the real EOF), it's nicer to 666 * work around the misbehaving server. If the request included 667 * more than the final unaligned block, truncate it back to an 668 * aligned result; if the request was only the final block, round 669 * up to the full block and change the status to fully-allocated 670 * (always a safe status, even if it loses information). 671 */ 672 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 673 s->info.min_block)) { 674 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 675 if (extent->length > s->info.min_block) { 676 extent->length = QEMU_ALIGN_DOWN(extent->length, 677 s->info.min_block); 678 } else { 679 extent->length = s->info.min_block; 680 extent->flags = 0; 681 } 682 } 683 684 /* 685 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 686 * sent us any more than one extent, nor should it have included 687 * status beyond our request in that extent. Furthermore, a wide 688 * server should have replied with an accurate count (we left 689 * count at 0 for a narrow server). However, it's easy enough to 690 * ignore the server's noncompliance without killing the 691 * connection; just ignore trailing extents, and clamp things to 692 * the length of our request. 693 */ 694 if (count != wide || chunk->length > pay_len) { 695 trace_nbd_parse_blockstatus_compliance("unexpected extent count"); 696 } 697 if (extent->length > orig_length) { 698 extent->length = orig_length; 699 trace_nbd_parse_blockstatus_compliance("extent length too large"); 700 } 701 702 /* 703 * HACK: if we are using x-dirty-bitmaps to access 704 * qemu:allocation-depth, treat all depths > 2 the same as 2, 705 * since nbd_client_co_block_status is only expecting the low two 706 * bits to be set. 707 */ 708 if (s->alloc_depth && extent->flags > 2) { 709 extent->flags = 2; 710 } 711 712 return 0; 713 } 714 715 /* 716 * nbd_parse_error_payload 717 * on success @errp contains message describing nbd error reply 718 */ 719 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 720 uint8_t *payload, int *request_ret, 721 Error **errp) 722 { 723 uint32_t error; 724 uint16_t message_size; 725 726 assert(chunk->type & (1 << 15)); 727 728 if (chunk->length < sizeof(error) + sizeof(message_size)) { 729 error_setg(errp, 730 "Protocol error: invalid payload for structured error"); 731 return -EINVAL; 732 } 733 734 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 735 if (error == 0) { 736 error_setg(errp, "Protocol error: server sent structured error chunk " 737 "with error = 0"); 738 return -EINVAL; 739 } 740 741 *request_ret = -error; 742 message_size = payload_advance16(&payload); 743 744 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 745 error_setg(errp, "Protocol error: server sent structured error chunk " 746 "with incorrect message size"); 747 return -EINVAL; 748 } 749 750 /* TODO: Add a trace point to mention the server complaint */ 751 752 /* TODO handle ERROR_OFFSET */ 753 754 return 0; 755 } 756 757 static int coroutine_fn 758 nbd_co_receive_offset_data_payload(BDRVNBDState *s, uint64_t orig_offset, 759 QEMUIOVector *qiov, Error **errp) 760 { 761 QEMUIOVector sub_qiov; 762 uint64_t offset; 763 size_t data_size; 764 int ret; 765 NBDStructuredReplyChunk *chunk = &s->reply.structured; 766 767 assert(nbd_reply_is_structured(&s->reply)); 768 769 /* The NBD spec requires at least one byte of payload */ 770 if (chunk->length <= sizeof(offset)) { 771 error_setg(errp, "Protocol error: invalid payload for " 772 "NBD_REPLY_TYPE_OFFSET_DATA"); 773 return -EINVAL; 774 } 775 776 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 777 return -EIO; 778 } 779 780 data_size = chunk->length - sizeof(offset); 781 assert(data_size); 782 if (offset < orig_offset || data_size > qiov->size || 783 offset > orig_offset + qiov->size - data_size) { 784 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 785 " region"); 786 return -EINVAL; 787 } 788 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 789 trace_nbd_structured_read_compliance("data"); 790 } 791 792 qemu_iovec_init(&sub_qiov, qiov->niov); 793 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 794 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 795 qemu_iovec_destroy(&sub_qiov); 796 797 return ret < 0 ? -EIO : 0; 798 } 799 800 #define NBD_MAX_MALLOC_PAYLOAD 1000 801 static coroutine_fn int nbd_co_receive_structured_payload( 802 BDRVNBDState *s, void **payload, Error **errp) 803 { 804 int ret; 805 uint32_t len; 806 807 assert(nbd_reply_is_structured(&s->reply)); 808 809 len = s->reply.structured.length; 810 811 if (len == 0) { 812 return 0; 813 } 814 815 if (payload == NULL) { 816 error_setg(errp, "Unexpected structured payload"); 817 return -EINVAL; 818 } 819 820 if (len > NBD_MAX_MALLOC_PAYLOAD) { 821 error_setg(errp, "Payload too large"); 822 return -EINVAL; 823 } 824 825 *payload = g_new(char, len); 826 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 827 if (ret < 0) { 828 g_free(*payload); 829 *payload = NULL; 830 return ret; 831 } 832 833 return 0; 834 } 835 836 /* 837 * nbd_co_do_receive_one_chunk 838 * for simple reply: 839 * set request_ret to received reply error 840 * if qiov is not NULL: read payload to @qiov 841 * for structured reply chunk: 842 * if error chunk: read payload, set @request_ret, do not set @payload 843 * else if offset_data chunk: read payload data to @qiov, do not set @payload 844 * else: read payload to @payload 845 * 846 * If function fails, @errp contains corresponding error message, and the 847 * connection with the server is suspect. If it returns 0, then the 848 * transaction succeeded (although @request_ret may be a negative errno 849 * corresponding to the server's error reply), and errp is unchanged. 850 */ 851 static coroutine_fn int nbd_co_do_receive_one_chunk( 852 BDRVNBDState *s, uint64_t cookie, bool only_structured, 853 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 854 { 855 int ret; 856 int i = COOKIE_TO_INDEX(cookie); 857 void *local_payload = NULL; 858 NBDStructuredReplyChunk *chunk; 859 860 if (payload) { 861 *payload = NULL; 862 } 863 *request_ret = 0; 864 865 ret = nbd_receive_replies(s, cookie, errp); 866 if (ret < 0) { 867 error_prepend(errp, "Connection closed: "); 868 return -EIO; 869 } 870 assert(s->ioc); 871 872 assert(s->reply.cookie == cookie); 873 874 if (nbd_reply_is_simple(&s->reply)) { 875 if (only_structured) { 876 error_setg(errp, "Protocol error: simple reply when structured " 877 "reply chunk was expected"); 878 return -EINVAL; 879 } 880 881 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 882 if (*request_ret < 0 || !qiov) { 883 return 0; 884 } 885 886 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 887 errp) < 0 ? -EIO : 0; 888 } 889 890 /* handle structured reply chunk */ 891 assert(s->info.mode >= NBD_MODE_STRUCTURED); 892 chunk = &s->reply.structured; 893 894 if (chunk->type == NBD_REPLY_TYPE_NONE) { 895 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 896 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 897 " NBD_REPLY_FLAG_DONE flag set"); 898 return -EINVAL; 899 } 900 if (chunk->length) { 901 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 902 " nonzero length"); 903 return -EINVAL; 904 } 905 return 0; 906 } 907 908 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 909 if (!qiov) { 910 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 911 return -EINVAL; 912 } 913 914 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 915 qiov, errp); 916 } 917 918 if (nbd_reply_type_is_error(chunk->type)) { 919 payload = &local_payload; 920 } 921 922 ret = nbd_co_receive_structured_payload(s, payload, errp); 923 if (ret < 0) { 924 return ret; 925 } 926 927 if (nbd_reply_type_is_error(chunk->type)) { 928 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 929 g_free(local_payload); 930 return ret; 931 } 932 933 return 0; 934 } 935 936 /* 937 * nbd_co_receive_one_chunk 938 * Read reply, wake up connection_co and set s->quit if needed. 939 * Return value is a fatal error code or normal nbd reply error code 940 */ 941 static coroutine_fn int nbd_co_receive_one_chunk( 942 BDRVNBDState *s, uint64_t cookie, bool only_structured, 943 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 944 Error **errp) 945 { 946 int ret = nbd_co_do_receive_one_chunk(s, cookie, only_structured, 947 request_ret, qiov, payload, errp); 948 949 if (ret < 0) { 950 memset(reply, 0, sizeof(*reply)); 951 nbd_channel_error(s, ret); 952 } else { 953 /* For assert at loop start in nbd_connection_entry */ 954 *reply = s->reply; 955 } 956 s->reply.cookie = 0; 957 958 nbd_recv_coroutines_wake(s); 959 960 return ret; 961 } 962 963 typedef struct NBDReplyChunkIter { 964 int ret; 965 int request_ret; 966 Error *err; 967 bool done, only_structured; 968 } NBDReplyChunkIter; 969 970 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 971 int ret, Error **local_err) 972 { 973 assert(local_err && *local_err); 974 assert(ret < 0); 975 976 if (!iter->ret) { 977 iter->ret = ret; 978 error_propagate(&iter->err, *local_err); 979 } else { 980 error_free(*local_err); 981 } 982 983 *local_err = NULL; 984 } 985 986 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 987 { 988 assert(ret < 0); 989 990 if (!iter->request_ret) { 991 iter->request_ret = ret; 992 } 993 } 994 995 /* 996 * NBD_FOREACH_REPLY_CHUNK 997 * The pointer stored in @payload requires g_free() to free it. 998 */ 999 #define NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, structured, \ 1000 qiov, reply, payload) \ 1001 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 1002 nbd_reply_chunk_iter_receive(s, &iter, cookie, qiov, reply, payload);) 1003 1004 /* 1005 * nbd_reply_chunk_iter_receive 1006 * The pointer stored in @payload requires g_free() to free it. 1007 */ 1008 static bool coroutine_fn nbd_reply_chunk_iter_receive(BDRVNBDState *s, 1009 NBDReplyChunkIter *iter, 1010 uint64_t cookie, 1011 QEMUIOVector *qiov, 1012 NBDReply *reply, 1013 void **payload) 1014 { 1015 int ret, request_ret; 1016 NBDReply local_reply; 1017 NBDStructuredReplyChunk *chunk; 1018 Error *local_err = NULL; 1019 1020 if (iter->done) { 1021 /* Previous iteration was last. */ 1022 goto break_loop; 1023 } 1024 1025 if (reply == NULL) { 1026 reply = &local_reply; 1027 } 1028 1029 ret = nbd_co_receive_one_chunk(s, cookie, iter->only_structured, 1030 &request_ret, qiov, reply, payload, 1031 &local_err); 1032 if (ret < 0) { 1033 nbd_iter_channel_error(iter, ret, &local_err); 1034 } else if (request_ret < 0) { 1035 nbd_iter_request_error(iter, request_ret); 1036 } 1037 1038 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1039 if (nbd_reply_is_simple(reply) || iter->ret < 0) { 1040 goto break_loop; 1041 } 1042 1043 chunk = &reply->structured; 1044 iter->only_structured = true; 1045 1046 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1047 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1048 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1049 goto break_loop; 1050 } 1051 1052 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1053 /* This iteration is last. */ 1054 iter->done = true; 1055 } 1056 1057 /* Execute the loop body */ 1058 return true; 1059 1060 break_loop: 1061 qemu_mutex_lock(&s->requests_lock); 1062 s->requests[COOKIE_TO_INDEX(cookie)].coroutine = NULL; 1063 s->in_flight--; 1064 qemu_co_queue_next(&s->free_sema); 1065 qemu_mutex_unlock(&s->requests_lock); 1066 1067 return false; 1068 } 1069 1070 static int coroutine_fn 1071 nbd_co_receive_return_code(BDRVNBDState *s, uint64_t cookie, 1072 int *request_ret, Error **errp) 1073 { 1074 NBDReplyChunkIter iter; 1075 1076 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, NULL, NULL) { 1077 /* nbd_reply_chunk_iter_receive does all the work */ 1078 } 1079 1080 error_propagate(errp, iter.err); 1081 *request_ret = iter.request_ret; 1082 return iter.ret; 1083 } 1084 1085 static int coroutine_fn 1086 nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t cookie, 1087 uint64_t offset, QEMUIOVector *qiov, 1088 int *request_ret, Error **errp) 1089 { 1090 NBDReplyChunkIter iter; 1091 NBDReply reply; 1092 void *payload = NULL; 1093 Error *local_err = NULL; 1094 1095 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, 1096 s->info.mode >= NBD_MODE_STRUCTURED, 1097 qiov, &reply, &payload) 1098 { 1099 int ret; 1100 NBDStructuredReplyChunk *chunk = &reply.structured; 1101 1102 assert(nbd_reply_is_structured(&reply)); 1103 1104 switch (chunk->type) { 1105 case NBD_REPLY_TYPE_OFFSET_DATA: 1106 /* 1107 * special cased in nbd_co_receive_one_chunk, data is already 1108 * in qiov 1109 */ 1110 break; 1111 case NBD_REPLY_TYPE_OFFSET_HOLE: 1112 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1113 offset, qiov, &local_err); 1114 if (ret < 0) { 1115 nbd_channel_error(s, ret); 1116 nbd_iter_channel_error(&iter, ret, &local_err); 1117 } 1118 break; 1119 default: 1120 if (!nbd_reply_type_is_error(chunk->type)) { 1121 /* not allowed reply type */ 1122 nbd_channel_error(s, -EINVAL); 1123 error_setg(&local_err, 1124 "Unexpected reply type: %d (%s) for CMD_READ", 1125 chunk->type, nbd_reply_type_lookup(chunk->type)); 1126 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1127 } 1128 } 1129 1130 g_free(payload); 1131 payload = NULL; 1132 } 1133 1134 error_propagate(errp, iter.err); 1135 *request_ret = iter.request_ret; 1136 return iter.ret; 1137 } 1138 1139 static int coroutine_fn 1140 nbd_co_receive_blockstatus_reply(BDRVNBDState *s, uint64_t cookie, 1141 uint64_t length, NBDExtent64 *extent, 1142 int *request_ret, Error **errp) 1143 { 1144 NBDReplyChunkIter iter; 1145 NBDReply reply; 1146 void *payload = NULL; 1147 Error *local_err = NULL; 1148 bool received = false; 1149 1150 assert(!extent->length); 1151 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, &reply, &payload) { 1152 int ret; 1153 NBDStructuredReplyChunk *chunk = &reply.structured; 1154 bool wide; 1155 1156 assert(nbd_reply_is_structured(&reply)); 1157 1158 switch (chunk->type) { 1159 case NBD_REPLY_TYPE_BLOCK_STATUS_EXT: 1160 case NBD_REPLY_TYPE_BLOCK_STATUS: 1161 wide = chunk->type == NBD_REPLY_TYPE_BLOCK_STATUS_EXT; 1162 if ((s->info.mode >= NBD_MODE_EXTENDED) != wide) { 1163 trace_nbd_extended_headers_compliance("block_status"); 1164 } 1165 if (received) { 1166 nbd_channel_error(s, -EINVAL); 1167 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1168 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1169 } 1170 received = true; 1171 1172 ret = nbd_parse_blockstatus_payload( 1173 s, &reply.structured, payload, wide, 1174 length, extent, &local_err); 1175 if (ret < 0) { 1176 nbd_channel_error(s, ret); 1177 nbd_iter_channel_error(&iter, ret, &local_err); 1178 } 1179 break; 1180 default: 1181 if (!nbd_reply_type_is_error(chunk->type)) { 1182 nbd_channel_error(s, -EINVAL); 1183 error_setg(&local_err, 1184 "Unexpected reply type: %d (%s) " 1185 "for CMD_BLOCK_STATUS", 1186 chunk->type, nbd_reply_type_lookup(chunk->type)); 1187 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1188 } 1189 } 1190 1191 g_free(payload); 1192 payload = NULL; 1193 } 1194 1195 if (!extent->length && !iter.request_ret) { 1196 error_setg(&local_err, "Server did not reply with any status extents"); 1197 nbd_iter_channel_error(&iter, -EIO, &local_err); 1198 } 1199 1200 error_propagate(errp, iter.err); 1201 *request_ret = iter.request_ret; 1202 return iter.ret; 1203 } 1204 1205 static int coroutine_fn GRAPH_RDLOCK 1206 nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1207 QEMUIOVector *write_qiov) 1208 { 1209 int ret, request_ret; 1210 Error *local_err = NULL; 1211 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1212 1213 assert(request->type != NBD_CMD_READ); 1214 if (write_qiov) { 1215 assert(request->type == NBD_CMD_WRITE); 1216 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1217 } else { 1218 assert(request->type != NBD_CMD_WRITE); 1219 } 1220 1221 do { 1222 ret = nbd_co_send_request(bs, request, write_qiov); 1223 if (ret < 0) { 1224 continue; 1225 } 1226 1227 ret = nbd_co_receive_return_code(s, request->cookie, 1228 &request_ret, &local_err); 1229 if (local_err) { 1230 trace_nbd_co_request_fail(request->from, request->len, 1231 request->cookie, request->flags, 1232 request->type, 1233 nbd_cmd_lookup(request->type), 1234 ret, error_get_pretty(local_err)); 1235 error_free(local_err); 1236 local_err = NULL; 1237 } 1238 } while (ret < 0 && nbd_client_will_reconnect(s)); 1239 1240 return ret ? ret : request_ret; 1241 } 1242 1243 static int coroutine_fn GRAPH_RDLOCK 1244 nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1245 QEMUIOVector *qiov, BdrvRequestFlags flags) 1246 { 1247 int ret, request_ret; 1248 Error *local_err = NULL; 1249 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1250 NBDRequest request = { 1251 .type = NBD_CMD_READ, 1252 .from = offset, 1253 .len = bytes, 1254 }; 1255 1256 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1257 1258 if (!bytes) { 1259 return 0; 1260 } 1261 /* 1262 * Work around the fact that the block layer doesn't do 1263 * byte-accurate sizing yet - if the read exceeds the server's 1264 * advertised size because the block layer rounded size up, then 1265 * truncate the request to the server and tail-pad with zero. 1266 */ 1267 if (offset >= s->info.size) { 1268 assert(bytes < BDRV_SECTOR_SIZE); 1269 qemu_iovec_memset(qiov, 0, 0, bytes); 1270 return 0; 1271 } 1272 if (offset + bytes > s->info.size) { 1273 uint64_t slop = offset + bytes - s->info.size; 1274 1275 assert(slop < BDRV_SECTOR_SIZE); 1276 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1277 request.len -= slop; 1278 } 1279 1280 do { 1281 ret = nbd_co_send_request(bs, &request, NULL); 1282 if (ret < 0) { 1283 continue; 1284 } 1285 1286 ret = nbd_co_receive_cmdread_reply(s, request.cookie, offset, qiov, 1287 &request_ret, &local_err); 1288 if (local_err) { 1289 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1290 request.flags, request.type, 1291 nbd_cmd_lookup(request.type), 1292 ret, error_get_pretty(local_err)); 1293 error_free(local_err); 1294 local_err = NULL; 1295 } 1296 } while (ret < 0 && nbd_client_will_reconnect(s)); 1297 1298 return ret ? ret : request_ret; 1299 } 1300 1301 static int coroutine_fn GRAPH_RDLOCK 1302 nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, 1303 QEMUIOVector *qiov, BdrvRequestFlags flags) 1304 { 1305 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1306 NBDRequest request = { 1307 .type = NBD_CMD_WRITE, 1308 .from = offset, 1309 .len = bytes, 1310 }; 1311 1312 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1313 if (flags & BDRV_REQ_FUA) { 1314 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1315 request.flags |= NBD_CMD_FLAG_FUA; 1316 } 1317 1318 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1319 1320 if (!bytes) { 1321 return 0; 1322 } 1323 return nbd_co_request(bs, &request, qiov); 1324 } 1325 1326 static int coroutine_fn GRAPH_RDLOCK 1327 nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 1328 BdrvRequestFlags flags) 1329 { 1330 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1331 NBDRequest request = { 1332 .type = NBD_CMD_WRITE_ZEROES, 1333 .from = offset, 1334 .len = bytes, 1335 }; 1336 1337 /* rely on max_pwrite_zeroes */ 1338 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1339 1340 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1341 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1342 return -ENOTSUP; 1343 } 1344 1345 if (flags & BDRV_REQ_FUA) { 1346 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1347 request.flags |= NBD_CMD_FLAG_FUA; 1348 } 1349 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1350 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1351 } 1352 if (flags & BDRV_REQ_NO_FALLBACK) { 1353 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1354 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1355 } 1356 1357 if (!bytes) { 1358 return 0; 1359 } 1360 return nbd_co_request(bs, &request, NULL); 1361 } 1362 1363 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_flush(BlockDriverState *bs) 1364 { 1365 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1366 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1367 1368 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1369 return 0; 1370 } 1371 1372 request.from = 0; 1373 request.len = 0; 1374 1375 return nbd_co_request(bs, &request, NULL); 1376 } 1377 1378 static int coroutine_fn GRAPH_RDLOCK 1379 nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 1380 { 1381 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1382 NBDRequest request = { 1383 .type = NBD_CMD_TRIM, 1384 .from = offset, 1385 .len = bytes, 1386 }; 1387 1388 /* rely on max_pdiscard */ 1389 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1390 1391 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1392 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1393 return 0; 1394 } 1395 1396 return nbd_co_request(bs, &request, NULL); 1397 } 1398 1399 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_block_status( 1400 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1401 int64_t *pnum, int64_t *map, BlockDriverState **file) 1402 { 1403 int ret, request_ret; 1404 NBDExtent64 extent = { 0 }; 1405 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1406 Error *local_err = NULL; 1407 1408 NBDRequest request = { 1409 .type = NBD_CMD_BLOCK_STATUS, 1410 .from = offset, 1411 .len = MIN(bytes, s->info.size - offset), 1412 .flags = NBD_CMD_FLAG_REQ_ONE, 1413 }; 1414 1415 if (!s->info.base_allocation) { 1416 *pnum = bytes; 1417 *map = offset; 1418 *file = bs; 1419 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1420 } 1421 if (s->info.mode < NBD_MODE_EXTENDED) { 1422 request.len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1423 request.len); 1424 } 1425 1426 /* 1427 * Work around the fact that the block layer doesn't do 1428 * byte-accurate sizing yet - if the status request exceeds the 1429 * server's advertised size because the block layer rounded size 1430 * up, we truncated the request to the server (above), or are 1431 * called on just the hole. 1432 */ 1433 if (offset >= s->info.size) { 1434 *pnum = bytes; 1435 assert(bytes < BDRV_SECTOR_SIZE); 1436 /* Intentionally don't report offset_valid for the hole */ 1437 return BDRV_BLOCK_ZERO; 1438 } 1439 1440 if (s->info.min_block) { 1441 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1442 } 1443 do { 1444 ret = nbd_co_send_request(bs, &request, NULL); 1445 if (ret < 0) { 1446 continue; 1447 } 1448 1449 ret = nbd_co_receive_blockstatus_reply(s, request.cookie, bytes, 1450 &extent, &request_ret, 1451 &local_err); 1452 if (local_err) { 1453 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1454 request.flags, request.type, 1455 nbd_cmd_lookup(request.type), 1456 ret, error_get_pretty(local_err)); 1457 error_free(local_err); 1458 local_err = NULL; 1459 } 1460 } while (ret < 0 && nbd_client_will_reconnect(s)); 1461 1462 if (ret < 0 || request_ret < 0) { 1463 return ret ? ret : request_ret; 1464 } 1465 1466 assert(extent.length); 1467 *pnum = extent.length; 1468 *map = offset; 1469 *file = bs; 1470 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1471 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1472 BDRV_BLOCK_OFFSET_VALID; 1473 } 1474 1475 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1476 BlockReopenQueue *queue, Error **errp) 1477 { 1478 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1479 1480 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1481 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1482 return -EACCES; 1483 } 1484 return 0; 1485 } 1486 1487 static void nbd_yank(void *opaque) 1488 { 1489 BlockDriverState *bs = opaque; 1490 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1491 1492 QEMU_LOCK_GUARD(&s->requests_lock); 1493 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1494 s->state = NBD_CLIENT_QUIT; 1495 } 1496 1497 static void nbd_client_close(BlockDriverState *bs) 1498 { 1499 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1500 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 1501 1502 if (s->ioc) { 1503 nbd_send_request(s->ioc, &request); 1504 } 1505 1506 nbd_teardown_connection(bs); 1507 } 1508 1509 1510 /* 1511 * Parse nbd_open options 1512 */ 1513 1514 static int nbd_parse_uri(const char *filename, QDict *options) 1515 { 1516 URI *uri; 1517 const char *p; 1518 QueryParams *qp = NULL; 1519 int ret = 0; 1520 bool is_unix; 1521 1522 uri = uri_parse(filename); 1523 if (!uri) { 1524 return -EINVAL; 1525 } 1526 1527 /* transport */ 1528 if (!g_strcmp0(uri->scheme, "nbd")) { 1529 is_unix = false; 1530 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1531 is_unix = false; 1532 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1533 is_unix = true; 1534 } else { 1535 ret = -EINVAL; 1536 goto out; 1537 } 1538 1539 p = uri->path ? uri->path : ""; 1540 if (p[0] == '/') { 1541 p++; 1542 } 1543 if (p[0]) { 1544 qdict_put_str(options, "export", p); 1545 } 1546 1547 qp = query_params_parse(uri->query); 1548 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1549 ret = -EINVAL; 1550 goto out; 1551 } 1552 1553 if (is_unix) { 1554 /* nbd+unix:///export?socket=path */ 1555 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1556 ret = -EINVAL; 1557 goto out; 1558 } 1559 qdict_put_str(options, "server.type", "unix"); 1560 qdict_put_str(options, "server.path", qp->p[0].value); 1561 } else { 1562 QString *host; 1563 char *port_str; 1564 1565 /* nbd[+tcp]://host[:port]/export */ 1566 if (!uri->server) { 1567 ret = -EINVAL; 1568 goto out; 1569 } 1570 1571 /* strip braces from literal IPv6 address */ 1572 if (uri->server[0] == '[') { 1573 host = qstring_from_substr(uri->server, 1, 1574 strlen(uri->server) - 1); 1575 } else { 1576 host = qstring_from_str(uri->server); 1577 } 1578 1579 qdict_put_str(options, "server.type", "inet"); 1580 qdict_put(options, "server.host", host); 1581 1582 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1583 qdict_put_str(options, "server.port", port_str); 1584 g_free(port_str); 1585 } 1586 1587 out: 1588 if (qp) { 1589 query_params_free(qp); 1590 } 1591 uri_free(uri); 1592 return ret; 1593 } 1594 1595 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1596 { 1597 const QDictEntry *e; 1598 1599 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1600 if (!strcmp(e->key, "host") || 1601 !strcmp(e->key, "port") || 1602 !strcmp(e->key, "path") || 1603 !strcmp(e->key, "export") || 1604 strstart(e->key, "server.", NULL)) 1605 { 1606 error_setg(errp, "Option '%s' cannot be used with a file name", 1607 e->key); 1608 return true; 1609 } 1610 } 1611 1612 return false; 1613 } 1614 1615 static void nbd_parse_filename(const char *filename, QDict *options, 1616 Error **errp) 1617 { 1618 g_autofree char *file = NULL; 1619 char *export_name; 1620 const char *host_spec; 1621 const char *unixpath; 1622 1623 if (nbd_has_filename_options_conflict(options, errp)) { 1624 return; 1625 } 1626 1627 if (strstr(filename, "://")) { 1628 int ret = nbd_parse_uri(filename, options); 1629 if (ret < 0) { 1630 error_setg(errp, "No valid URL specified"); 1631 } 1632 return; 1633 } 1634 1635 file = g_strdup(filename); 1636 1637 export_name = strstr(file, EN_OPTSTR); 1638 if (export_name) { 1639 if (export_name[strlen(EN_OPTSTR)] == 0) { 1640 return; 1641 } 1642 export_name[0] = 0; /* truncate 'file' */ 1643 export_name += strlen(EN_OPTSTR); 1644 1645 qdict_put_str(options, "export", export_name); 1646 } 1647 1648 /* extract the host_spec - fail if it's not nbd:... */ 1649 if (!strstart(file, "nbd:", &host_spec)) { 1650 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1651 return; 1652 } 1653 1654 if (!*host_spec) { 1655 return; 1656 } 1657 1658 /* are we a UNIX or TCP socket? */ 1659 if (strstart(host_spec, "unix:", &unixpath)) { 1660 qdict_put_str(options, "server.type", "unix"); 1661 qdict_put_str(options, "server.path", unixpath); 1662 } else { 1663 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1664 1665 if (inet_parse(addr, host_spec, errp)) { 1666 goto out_inet; 1667 } 1668 1669 qdict_put_str(options, "server.type", "inet"); 1670 qdict_put_str(options, "server.host", addr->host); 1671 qdict_put_str(options, "server.port", addr->port); 1672 out_inet: 1673 qapi_free_InetSocketAddress(addr); 1674 } 1675 } 1676 1677 static bool nbd_process_legacy_socket_options(QDict *output_options, 1678 QemuOpts *legacy_opts, 1679 Error **errp) 1680 { 1681 const char *path = qemu_opt_get(legacy_opts, "path"); 1682 const char *host = qemu_opt_get(legacy_opts, "host"); 1683 const char *port = qemu_opt_get(legacy_opts, "port"); 1684 const QDictEntry *e; 1685 1686 if (!path && !host && !port) { 1687 return true; 1688 } 1689 1690 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1691 { 1692 if (strstart(e->key, "server.", NULL)) { 1693 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1694 "same time"); 1695 return false; 1696 } 1697 } 1698 1699 if (path && host) { 1700 error_setg(errp, "path and host may not be used at the same time"); 1701 return false; 1702 } else if (path) { 1703 if (port) { 1704 error_setg(errp, "port may not be used without host"); 1705 return false; 1706 } 1707 1708 qdict_put_str(output_options, "server.type", "unix"); 1709 qdict_put_str(output_options, "server.path", path); 1710 } else if (host) { 1711 qdict_put_str(output_options, "server.type", "inet"); 1712 qdict_put_str(output_options, "server.host", host); 1713 qdict_put_str(output_options, "server.port", 1714 port ?: stringify(NBD_DEFAULT_PORT)); 1715 } 1716 1717 return true; 1718 } 1719 1720 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1721 Error **errp) 1722 { 1723 SocketAddress *saddr = NULL; 1724 QDict *addr = NULL; 1725 Visitor *iv = NULL; 1726 1727 qdict_extract_subqdict(options, &addr, "server."); 1728 if (!qdict_size(addr)) { 1729 error_setg(errp, "NBD server address missing"); 1730 goto done; 1731 } 1732 1733 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1734 if (!iv) { 1735 goto done; 1736 } 1737 1738 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1739 goto done; 1740 } 1741 1742 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1743 qapi_free_SocketAddress(saddr); 1744 saddr = NULL; 1745 goto done; 1746 } 1747 1748 done: 1749 qobject_unref(addr); 1750 visit_free(iv); 1751 return saddr; 1752 } 1753 1754 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1755 { 1756 Object *obj; 1757 QCryptoTLSCreds *creds; 1758 1759 obj = object_resolve_path_component( 1760 object_get_objects_root(), id); 1761 if (!obj) { 1762 error_setg(errp, "No TLS credentials with id '%s'", 1763 id); 1764 return NULL; 1765 } 1766 creds = (QCryptoTLSCreds *) 1767 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1768 if (!creds) { 1769 error_setg(errp, "Object with id '%s' is not TLS credentials", 1770 id); 1771 return NULL; 1772 } 1773 1774 if (!qcrypto_tls_creds_check_endpoint(creds, 1775 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1776 errp)) { 1777 return NULL; 1778 } 1779 object_ref(obj); 1780 return creds; 1781 } 1782 1783 1784 static QemuOptsList nbd_runtime_opts = { 1785 .name = "nbd", 1786 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1787 .desc = { 1788 { 1789 .name = "host", 1790 .type = QEMU_OPT_STRING, 1791 .help = "TCP host to connect to", 1792 }, 1793 { 1794 .name = "port", 1795 .type = QEMU_OPT_STRING, 1796 .help = "TCP port to connect to", 1797 }, 1798 { 1799 .name = "path", 1800 .type = QEMU_OPT_STRING, 1801 .help = "Unix socket path to connect to", 1802 }, 1803 { 1804 .name = "export", 1805 .type = QEMU_OPT_STRING, 1806 .help = "Name of the NBD export to open", 1807 }, 1808 { 1809 .name = "tls-creds", 1810 .type = QEMU_OPT_STRING, 1811 .help = "ID of the TLS credentials to use", 1812 }, 1813 { 1814 .name = "tls-hostname", 1815 .type = QEMU_OPT_STRING, 1816 .help = "Override hostname for validating TLS x509 certificate", 1817 }, 1818 { 1819 .name = "x-dirty-bitmap", 1820 .type = QEMU_OPT_STRING, 1821 .help = "experimental: expose named dirty bitmap in place of " 1822 "block status", 1823 }, 1824 { 1825 .name = "reconnect-delay", 1826 .type = QEMU_OPT_NUMBER, 1827 .help = "On an unexpected disconnect, the nbd client tries to " 1828 "connect again until succeeding or encountering a serious " 1829 "error. During the first @reconnect-delay seconds, all " 1830 "requests are paused and will be rerun on a successful " 1831 "reconnect. After that time, any delayed requests and all " 1832 "future requests before a successful reconnect will " 1833 "immediately fail. Default 0", 1834 }, 1835 { 1836 .name = "open-timeout", 1837 .type = QEMU_OPT_NUMBER, 1838 .help = "In seconds. If zero, the nbd driver tries the connection " 1839 "only once, and fails to open if the connection fails. " 1840 "If non-zero, the nbd driver will repeat connection " 1841 "attempts until successful or until @open-timeout seconds " 1842 "have elapsed. Default 0", 1843 }, 1844 { /* end of list */ } 1845 }, 1846 }; 1847 1848 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1849 Error **errp) 1850 { 1851 BDRVNBDState *s = bs->opaque; 1852 QemuOpts *opts; 1853 int ret = -EINVAL; 1854 1855 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1856 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1857 goto error; 1858 } 1859 1860 /* Translate @host, @port, and @path to a SocketAddress */ 1861 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1862 goto error; 1863 } 1864 1865 /* Pop the config into our state object. Exit if invalid. */ 1866 s->saddr = nbd_config(s, options, errp); 1867 if (!s->saddr) { 1868 goto error; 1869 } 1870 1871 s->export = g_strdup(qemu_opt_get(opts, "export")); 1872 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1873 error_setg(errp, "export name too long to send to server"); 1874 goto error; 1875 } 1876 1877 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1878 if (s->tlscredsid) { 1879 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1880 if (!s->tlscreds) { 1881 goto error; 1882 } 1883 1884 s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); 1885 if (!s->tlshostname && 1886 s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1887 s->tlshostname = g_strdup(s->saddr->u.inet.host); 1888 } 1889 } 1890 1891 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1892 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1893 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1894 goto error; 1895 } 1896 1897 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1898 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1899 1900 ret = 0; 1901 1902 error: 1903 qemu_opts_del(opts); 1904 return ret; 1905 } 1906 1907 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1908 Error **errp) 1909 { 1910 int ret; 1911 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1912 1913 s->bs = bs; 1914 qemu_mutex_init(&s->requests_lock); 1915 qemu_co_queue_init(&s->free_sema); 1916 qemu_co_mutex_init(&s->send_mutex); 1917 qemu_co_mutex_init(&s->receive_mutex); 1918 1919 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1920 return -EEXIST; 1921 } 1922 1923 ret = nbd_process_options(bs, options, errp); 1924 if (ret < 0) { 1925 goto fail; 1926 } 1927 1928 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1929 s->x_dirty_bitmap, s->tlscreds, 1930 s->tlshostname); 1931 1932 if (s->open_timeout) { 1933 nbd_client_connection_enable_retry(s->conn); 1934 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1935 s->open_timeout * NANOSECONDS_PER_SECOND); 1936 } 1937 1938 s->state = NBD_CLIENT_CONNECTING_WAIT; 1939 ret = nbd_do_establish_connection(bs, true, errp); 1940 if (ret < 0) { 1941 goto fail; 1942 } 1943 1944 /* 1945 * The connect attempt is done, so we no longer need this timer. 1946 * Delete it, because we do not want it to be around when this node 1947 * is drained or closed. 1948 */ 1949 open_timer_del(s); 1950 1951 nbd_client_connection_enable_retry(s->conn); 1952 1953 return 0; 1954 1955 fail: 1956 open_timer_del(s); 1957 nbd_clear_bdrvstate(bs); 1958 return ret; 1959 } 1960 1961 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1962 { 1963 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1964 uint32_t min = s->info.min_block; 1965 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1966 1967 /* 1968 * If the server did not advertise an alignment: 1969 * - a size that is not sector-aligned implies that an alignment 1970 * of 1 can be used to access those tail bytes 1971 * - advertisement of block status requires an alignment of 1, so 1972 * that we don't violate block layer constraints that block 1973 * status is always aligned (as we can't control whether the 1974 * server will report sub-sector extents, such as a hole at EOF 1975 * on an unaligned POSIX file) 1976 * - otherwise, assume the server is so old that we are safer avoiding 1977 * sub-sector requests 1978 */ 1979 if (!min) { 1980 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1981 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1982 } 1983 1984 bs->bl.request_alignment = min; 1985 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1986 bs->bl.max_pwrite_zeroes = max; 1987 bs->bl.max_transfer = max; 1988 1989 /* 1990 * Assume that if the server supports extended headers, it also 1991 * supports unlimited size zero and trim commands. 1992 */ 1993 if (s->info.mode >= NBD_MODE_EXTENDED) { 1994 bs->bl.max_pdiscard = bs->bl.max_pwrite_zeroes = 0; 1995 } 1996 1997 if (s->info.opt_block && 1998 s->info.opt_block > bs->bl.opt_transfer) { 1999 bs->bl.opt_transfer = s->info.opt_block; 2000 } 2001 } 2002 2003 static void nbd_close(BlockDriverState *bs) 2004 { 2005 nbd_client_close(bs); 2006 nbd_clear_bdrvstate(bs); 2007 } 2008 2009 /* 2010 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 2011 * to a smaller size with exact=false, there is no reason to fail the 2012 * operation. 2013 * 2014 * Preallocation mode is ignored since it does not seems useful to fail when 2015 * we never change anything. 2016 */ 2017 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 2018 bool exact, PreallocMode prealloc, 2019 BdrvRequestFlags flags, Error **errp) 2020 { 2021 BDRVNBDState *s = bs->opaque; 2022 2023 if (offset != s->info.size && exact) { 2024 error_setg(errp, "Cannot resize NBD nodes"); 2025 return -ENOTSUP; 2026 } 2027 2028 if (offset > s->info.size) { 2029 error_setg(errp, "Cannot grow NBD nodes"); 2030 return -EINVAL; 2031 } 2032 2033 return 0; 2034 } 2035 2036 static int64_t coroutine_fn nbd_co_getlength(BlockDriverState *bs) 2037 { 2038 BDRVNBDState *s = bs->opaque; 2039 2040 return s->info.size; 2041 } 2042 2043 static void nbd_refresh_filename(BlockDriverState *bs) 2044 { 2045 BDRVNBDState *s = bs->opaque; 2046 const char *host = NULL, *port = NULL, *path = NULL; 2047 size_t len = 0; 2048 2049 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 2050 const InetSocketAddress *inet = &s->saddr->u.inet; 2051 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 2052 host = inet->host; 2053 port = inet->port; 2054 } 2055 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2056 path = s->saddr->u.q_unix.path; 2057 } /* else can't represent as pseudo-filename */ 2058 2059 if (path && s->export) { 2060 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2061 "nbd+unix:///%s?socket=%s", s->export, path); 2062 } else if (path && !s->export) { 2063 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2064 "nbd+unix://?socket=%s", path); 2065 } else if (host && s->export) { 2066 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2067 "nbd://%s:%s/%s", host, port, s->export); 2068 } else if (host && !s->export) { 2069 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2070 "nbd://%s:%s", host, port); 2071 } 2072 if (len >= sizeof(bs->exact_filename)) { 2073 /* Name is too long to represent exactly, so leave it empty. */ 2074 bs->exact_filename[0] = '\0'; 2075 } 2076 } 2077 2078 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2079 { 2080 /* The generic bdrv_dirname() implementation is able to work out some 2081 * directory name for NBD nodes, but that would be wrong. So far there is no 2082 * specification for how "export paths" would work, so NBD does not have 2083 * directory names. */ 2084 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2085 return NULL; 2086 } 2087 2088 static const char *const nbd_strong_runtime_opts[] = { 2089 "path", 2090 "host", 2091 "port", 2092 "export", 2093 "tls-creds", 2094 "tls-hostname", 2095 "server.", 2096 2097 NULL 2098 }; 2099 2100 static void nbd_cancel_in_flight(BlockDriverState *bs) 2101 { 2102 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2103 2104 reconnect_delay_timer_del(s); 2105 2106 qemu_mutex_lock(&s->requests_lock); 2107 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2108 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2109 } 2110 qemu_mutex_unlock(&s->requests_lock); 2111 2112 nbd_co_establish_connection_cancel(s->conn); 2113 } 2114 2115 static void nbd_attach_aio_context(BlockDriverState *bs, 2116 AioContext *new_context) 2117 { 2118 BDRVNBDState *s = bs->opaque; 2119 2120 /* The open_timer is used only during nbd_open() */ 2121 assert(!s->open_timer); 2122 2123 /* 2124 * The reconnect_delay_timer is scheduled in I/O paths when the 2125 * connection is lost, to cancel the reconnection attempt after a 2126 * given time. Once this attempt is done (successfully or not), 2127 * nbd_reconnect_attempt() ensures the timer is deleted before the 2128 * respective I/O request is resumed. 2129 * Since the AioContext can only be changed when a node is drained, 2130 * the reconnect_delay_timer cannot be active here. 2131 */ 2132 assert(!s->reconnect_delay_timer); 2133 } 2134 2135 static void nbd_detach_aio_context(BlockDriverState *bs) 2136 { 2137 BDRVNBDState *s = bs->opaque; 2138 2139 assert(!s->open_timer); 2140 assert(!s->reconnect_delay_timer); 2141 } 2142 2143 static BlockDriver bdrv_nbd = { 2144 .format_name = "nbd", 2145 .protocol_name = "nbd", 2146 .instance_size = sizeof(BDRVNBDState), 2147 .bdrv_parse_filename = nbd_parse_filename, 2148 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2149 .create_opts = &bdrv_create_opts_simple, 2150 .bdrv_file_open = nbd_open, 2151 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2152 .bdrv_co_preadv = nbd_client_co_preadv, 2153 .bdrv_co_pwritev = nbd_client_co_pwritev, 2154 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2155 .bdrv_close = nbd_close, 2156 .bdrv_co_flush_to_os = nbd_client_co_flush, 2157 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2158 .bdrv_refresh_limits = nbd_refresh_limits, 2159 .bdrv_co_truncate = nbd_co_truncate, 2160 .bdrv_co_getlength = nbd_co_getlength, 2161 .bdrv_refresh_filename = nbd_refresh_filename, 2162 .bdrv_co_block_status = nbd_client_co_block_status, 2163 .bdrv_dirname = nbd_dirname, 2164 .strong_runtime_opts = nbd_strong_runtime_opts, 2165 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2166 2167 .bdrv_attach_aio_context = nbd_attach_aio_context, 2168 .bdrv_detach_aio_context = nbd_detach_aio_context, 2169 }; 2170 2171 static BlockDriver bdrv_nbd_tcp = { 2172 .format_name = "nbd", 2173 .protocol_name = "nbd+tcp", 2174 .instance_size = sizeof(BDRVNBDState), 2175 .bdrv_parse_filename = nbd_parse_filename, 2176 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2177 .create_opts = &bdrv_create_opts_simple, 2178 .bdrv_file_open = nbd_open, 2179 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2180 .bdrv_co_preadv = nbd_client_co_preadv, 2181 .bdrv_co_pwritev = nbd_client_co_pwritev, 2182 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2183 .bdrv_close = nbd_close, 2184 .bdrv_co_flush_to_os = nbd_client_co_flush, 2185 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2186 .bdrv_refresh_limits = nbd_refresh_limits, 2187 .bdrv_co_truncate = nbd_co_truncate, 2188 .bdrv_co_getlength = nbd_co_getlength, 2189 .bdrv_refresh_filename = nbd_refresh_filename, 2190 .bdrv_co_block_status = nbd_client_co_block_status, 2191 .bdrv_dirname = nbd_dirname, 2192 .strong_runtime_opts = nbd_strong_runtime_opts, 2193 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2194 2195 .bdrv_attach_aio_context = nbd_attach_aio_context, 2196 .bdrv_detach_aio_context = nbd_detach_aio_context, 2197 }; 2198 2199 static BlockDriver bdrv_nbd_unix = { 2200 .format_name = "nbd", 2201 .protocol_name = "nbd+unix", 2202 .instance_size = sizeof(BDRVNBDState), 2203 .bdrv_parse_filename = nbd_parse_filename, 2204 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2205 .create_opts = &bdrv_create_opts_simple, 2206 .bdrv_file_open = nbd_open, 2207 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2208 .bdrv_co_preadv = nbd_client_co_preadv, 2209 .bdrv_co_pwritev = nbd_client_co_pwritev, 2210 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2211 .bdrv_close = nbd_close, 2212 .bdrv_co_flush_to_os = nbd_client_co_flush, 2213 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2214 .bdrv_refresh_limits = nbd_refresh_limits, 2215 .bdrv_co_truncate = nbd_co_truncate, 2216 .bdrv_co_getlength = nbd_co_getlength, 2217 .bdrv_refresh_filename = nbd_refresh_filename, 2218 .bdrv_co_block_status = nbd_client_co_block_status, 2219 .bdrv_dirname = nbd_dirname, 2220 .strong_runtime_opts = nbd_strong_runtime_opts, 2221 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2222 2223 .bdrv_attach_aio_context = nbd_attach_aio_context, 2224 .bdrv_detach_aio_context = nbd_detach_aio_context, 2225 }; 2226 2227 static void bdrv_nbd_init(void) 2228 { 2229 bdrv_register(&bdrv_nbd); 2230 bdrv_register(&bdrv_nbd_tcp); 2231 bdrv_register(&bdrv_nbd_unix); 2232 } 2233 2234 block_init(bdrv_nbd_init); 2235