1 /* 2 * QEMU Block driver for NBD 3 * 4 * Copyright (c) 2019 Virtuozzo International GmbH. 5 * Copyright Red Hat 6 * Copyright (C) 2008 Bull S.A.S. 7 * Author: Laurent Vivier <Laurent.Vivier@bull.net> 8 * 9 * Some parts: 10 * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws> 11 * 12 * Permission is hereby granted, free of charge, to any person obtaining a copy 13 * of this software and associated documentation files (the "Software"), to deal 14 * in the Software without restriction, including without limitation the rights 15 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 16 * copies of the Software, and to permit persons to whom the Software is 17 * furnished to do so, subject to the following conditions: 18 * 19 * The above copyright notice and this permission notice shall be included in 20 * all copies or substantial portions of the Software. 21 * 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 25 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 27 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 28 * THE SOFTWARE. 29 */ 30 31 #include "qemu/osdep.h" 32 33 #include "trace.h" 34 #include "qemu/uri.h" 35 #include "qemu/option.h" 36 #include "qemu/cutils.h" 37 #include "qemu/main-loop.h" 38 39 #include "qapi/qapi-visit-sockets.h" 40 #include "qapi/qmp/qstring.h" 41 #include "qapi/clone-visitor.h" 42 43 #include "block/qdict.h" 44 #include "block/nbd.h" 45 #include "block/block_int.h" 46 #include "block/coroutines.h" 47 48 #include "qemu/yank.h" 49 50 #define EN_OPTSTR ":exportname=" 51 #define MAX_NBD_REQUESTS 16 52 53 #define COOKIE_TO_INDEX(cookie) ((cookie) - 1) 54 #define INDEX_TO_COOKIE(index) ((index) + 1) 55 56 typedef struct { 57 Coroutine *coroutine; 58 uint64_t offset; /* original offset of the request */ 59 bool receiving; /* sleeping in the yield in nbd_receive_replies */ 60 } NBDClientRequest; 61 62 typedef enum NBDClientState { 63 NBD_CLIENT_CONNECTING_WAIT, 64 NBD_CLIENT_CONNECTING_NOWAIT, 65 NBD_CLIENT_CONNECTED, 66 NBD_CLIENT_QUIT 67 } NBDClientState; 68 69 typedef struct BDRVNBDState { 70 QIOChannel *ioc; /* The current I/O channel */ 71 NBDExportInfo info; 72 73 /* 74 * Protects state, free_sema, in_flight, requests[].coroutine, 75 * reconnect_delay_timer. 76 */ 77 QemuMutex requests_lock; 78 NBDClientState state; 79 CoQueue free_sema; 80 unsigned in_flight; 81 NBDClientRequest requests[MAX_NBD_REQUESTS]; 82 QEMUTimer *reconnect_delay_timer; 83 84 /* Protects sending data on the socket. */ 85 CoMutex send_mutex; 86 87 /* 88 * Protects receiving reply headers from the socket, as well as the 89 * fields reply and requests[].receiving 90 */ 91 CoMutex receive_mutex; 92 NBDReply reply; 93 94 QEMUTimer *open_timer; 95 96 BlockDriverState *bs; 97 98 /* Connection parameters */ 99 uint32_t reconnect_delay; 100 uint32_t open_timeout; 101 SocketAddress *saddr; 102 char *export; 103 char *tlscredsid; 104 QCryptoTLSCreds *tlscreds; 105 char *tlshostname; 106 char *x_dirty_bitmap; 107 bool alloc_depth; 108 109 NBDClientConnection *conn; 110 } BDRVNBDState; 111 112 static void nbd_yank(void *opaque); 113 114 static void nbd_clear_bdrvstate(BlockDriverState *bs) 115 { 116 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 117 118 nbd_client_connection_release(s->conn); 119 s->conn = NULL; 120 121 yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); 122 123 /* Must not leave timers behind that would access freed data */ 124 assert(!s->reconnect_delay_timer); 125 assert(!s->open_timer); 126 127 object_unref(OBJECT(s->tlscreds)); 128 qapi_free_SocketAddress(s->saddr); 129 s->saddr = NULL; 130 g_free(s->export); 131 s->export = NULL; 132 g_free(s->tlscredsid); 133 s->tlscredsid = NULL; 134 g_free(s->tlshostname); 135 s->tlshostname = NULL; 136 g_free(s->x_dirty_bitmap); 137 s->x_dirty_bitmap = NULL; 138 } 139 140 /* Called with s->receive_mutex taken. */ 141 static bool coroutine_fn nbd_recv_coroutine_wake_one(NBDClientRequest *req) 142 { 143 if (req->receiving) { 144 req->receiving = false; 145 aio_co_wake(req->coroutine); 146 return true; 147 } 148 149 return false; 150 } 151 152 static void coroutine_fn nbd_recv_coroutines_wake(BDRVNBDState *s) 153 { 154 int i; 155 156 QEMU_LOCK_GUARD(&s->receive_mutex); 157 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 158 if (nbd_recv_coroutine_wake_one(&s->requests[i])) { 159 return; 160 } 161 } 162 } 163 164 /* Called with s->requests_lock held. */ 165 static void coroutine_fn nbd_channel_error_locked(BDRVNBDState *s, int ret) 166 { 167 if (s->state == NBD_CLIENT_CONNECTED) { 168 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 169 } 170 171 if (ret == -EIO) { 172 if (s->state == NBD_CLIENT_CONNECTED) { 173 s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : 174 NBD_CLIENT_CONNECTING_NOWAIT; 175 } 176 } else { 177 s->state = NBD_CLIENT_QUIT; 178 } 179 } 180 181 static void coroutine_fn nbd_channel_error(BDRVNBDState *s, int ret) 182 { 183 QEMU_LOCK_GUARD(&s->requests_lock); 184 nbd_channel_error_locked(s, ret); 185 } 186 187 static void reconnect_delay_timer_del(BDRVNBDState *s) 188 { 189 if (s->reconnect_delay_timer) { 190 timer_free(s->reconnect_delay_timer); 191 s->reconnect_delay_timer = NULL; 192 } 193 } 194 195 static void reconnect_delay_timer_cb(void *opaque) 196 { 197 BDRVNBDState *s = opaque; 198 199 reconnect_delay_timer_del(s); 200 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 201 if (s->state != NBD_CLIENT_CONNECTING_WAIT) { 202 return; 203 } 204 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 205 } 206 nbd_co_establish_connection_cancel(s->conn); 207 } 208 209 static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 210 { 211 assert(!s->reconnect_delay_timer); 212 s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 213 QEMU_CLOCK_REALTIME, 214 SCALE_NS, 215 reconnect_delay_timer_cb, s); 216 timer_mod(s->reconnect_delay_timer, expire_time_ns); 217 } 218 219 static void nbd_teardown_connection(BlockDriverState *bs) 220 { 221 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 222 223 assert(!s->in_flight); 224 225 if (s->ioc) { 226 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 227 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 228 nbd_yank, s->bs); 229 object_unref(OBJECT(s->ioc)); 230 s->ioc = NULL; 231 } 232 233 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 234 s->state = NBD_CLIENT_QUIT; 235 } 236 } 237 238 static void open_timer_del(BDRVNBDState *s) 239 { 240 if (s->open_timer) { 241 timer_free(s->open_timer); 242 s->open_timer = NULL; 243 } 244 } 245 246 static void open_timer_cb(void *opaque) 247 { 248 BDRVNBDState *s = opaque; 249 250 nbd_co_establish_connection_cancel(s->conn); 251 open_timer_del(s); 252 } 253 254 static void open_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) 255 { 256 assert(!s->open_timer); 257 s->open_timer = aio_timer_new(bdrv_get_aio_context(s->bs), 258 QEMU_CLOCK_REALTIME, 259 SCALE_NS, 260 open_timer_cb, s); 261 timer_mod(s->open_timer, expire_time_ns); 262 } 263 264 static bool nbd_client_will_reconnect(BDRVNBDState *s) 265 { 266 /* 267 * Called only after a socket error, so this is not performance sensitive. 268 */ 269 QEMU_LOCK_GUARD(&s->requests_lock); 270 return s->state == NBD_CLIENT_CONNECTING_WAIT; 271 } 272 273 /* 274 * Update @bs with information learned during a completed negotiation process. 275 * Return failure if the server's advertised options are incompatible with the 276 * client's needs. 277 */ 278 static int nbd_handle_updated_info(BlockDriverState *bs, Error **errp) 279 { 280 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 281 int ret; 282 283 if (s->x_dirty_bitmap) { 284 if (!s->info.base_allocation) { 285 error_setg(errp, "requested x-dirty-bitmap %s not found", 286 s->x_dirty_bitmap); 287 return -EINVAL; 288 } 289 if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { 290 s->alloc_depth = true; 291 } 292 } 293 294 if (s->info.flags & NBD_FLAG_READ_ONLY) { 295 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); 296 if (ret < 0) { 297 return ret; 298 } 299 } 300 301 if (s->info.flags & NBD_FLAG_SEND_FUA) { 302 bs->supported_write_flags = BDRV_REQ_FUA; 303 bs->supported_zero_flags |= BDRV_REQ_FUA; 304 } 305 306 if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { 307 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; 308 if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { 309 bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; 310 } 311 } 312 313 trace_nbd_client_handshake_success(s->export); 314 315 return 0; 316 } 317 318 int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, 319 bool blocking, Error **errp) 320 { 321 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 322 int ret; 323 IO_CODE(); 324 325 assert_bdrv_graph_readable(); 326 assert(!s->ioc); 327 328 s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); 329 if (!s->ioc) { 330 return -ECONNREFUSED; 331 } 332 333 yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, 334 bs); 335 336 ret = nbd_handle_updated_info(s->bs, NULL); 337 if (ret < 0) { 338 /* 339 * We have connected, but must fail for other reasons. 340 * Send NBD_CMD_DISC as a courtesy to the server. 341 */ 342 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 343 344 nbd_send_request(s->ioc, &request); 345 346 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 347 nbd_yank, bs); 348 object_unref(OBJECT(s->ioc)); 349 s->ioc = NULL; 350 351 return ret; 352 } 353 354 qio_channel_set_blocking(s->ioc, false, NULL); 355 qio_channel_set_follow_coroutine_ctx(s->ioc, true); 356 357 /* successfully connected */ 358 WITH_QEMU_LOCK_GUARD(&s->requests_lock) { 359 s->state = NBD_CLIENT_CONNECTED; 360 } 361 362 return 0; 363 } 364 365 /* Called with s->requests_lock held. */ 366 static bool nbd_client_connecting(BDRVNBDState *s) 367 { 368 return s->state == NBD_CLIENT_CONNECTING_WAIT || 369 s->state == NBD_CLIENT_CONNECTING_NOWAIT; 370 } 371 372 /* Called with s->requests_lock taken. */ 373 static void coroutine_fn GRAPH_RDLOCK nbd_reconnect_attempt(BDRVNBDState *s) 374 { 375 int ret; 376 bool blocking = s->state == NBD_CLIENT_CONNECTING_WAIT; 377 378 /* 379 * Now we are sure that nobody is accessing the channel, and no one will 380 * try until we set the state to CONNECTED. 381 */ 382 assert(nbd_client_connecting(s)); 383 assert(s->in_flight == 1); 384 385 trace_nbd_reconnect_attempt(s->bs->in_flight); 386 387 if (blocking && !s->reconnect_delay_timer) { 388 /* 389 * It's the first reconnect attempt after switching to 390 * NBD_CLIENT_CONNECTING_WAIT 391 */ 392 g_assert(s->reconnect_delay); 393 reconnect_delay_timer_init(s, 394 qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 395 s->reconnect_delay * NANOSECONDS_PER_SECOND); 396 } 397 398 /* Finalize previous connection if any */ 399 if (s->ioc) { 400 yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), 401 nbd_yank, s->bs); 402 object_unref(OBJECT(s->ioc)); 403 s->ioc = NULL; 404 } 405 406 qemu_mutex_unlock(&s->requests_lock); 407 ret = nbd_co_do_establish_connection(s->bs, blocking, NULL); 408 trace_nbd_reconnect_attempt_result(ret, s->bs->in_flight); 409 qemu_mutex_lock(&s->requests_lock); 410 411 /* 412 * The reconnect attempt is done (maybe successfully, maybe not), so 413 * we no longer need this timer. Delete it so it will not outlive 414 * this I/O request (so draining removes all timers). 415 */ 416 reconnect_delay_timer_del(s); 417 } 418 419 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t cookie, 420 Error **errp) 421 { 422 int ret; 423 uint64_t ind = COOKIE_TO_INDEX(cookie), ind2; 424 QEMU_LOCK_GUARD(&s->receive_mutex); 425 426 while (true) { 427 if (s->reply.cookie == cookie) { 428 /* We are done */ 429 return 0; 430 } 431 432 if (s->reply.cookie != 0) { 433 /* 434 * Some other request is being handled now. It should already be 435 * woken by whoever set s->reply.cookie (or never wait in this 436 * yield). So, we should not wake it here. 437 */ 438 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 439 assert(!s->requests[ind2].receiving); 440 441 s->requests[ind].receiving = true; 442 qemu_co_mutex_unlock(&s->receive_mutex); 443 444 qemu_coroutine_yield(); 445 /* 446 * We may be woken for 2 reasons: 447 * 1. From this function, executing in parallel coroutine, when our 448 * cookie is received. 449 * 2. From nbd_co_receive_one_chunk(), when previous request is 450 * finished and s->reply.cookie set to 0. 451 * Anyway, it's OK to lock the mutex and go to the next iteration. 452 */ 453 454 qemu_co_mutex_lock(&s->receive_mutex); 455 assert(!s->requests[ind].receiving); 456 continue; 457 } 458 459 /* We are under mutex and cookie is 0. We have to do the dirty work. */ 460 assert(s->reply.cookie == 0); 461 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, s->info.mode, errp); 462 if (ret == 0) { 463 ret = -EIO; 464 error_setg(errp, "server dropped connection"); 465 } 466 if (ret < 0) { 467 nbd_channel_error(s, ret); 468 return ret; 469 } 470 if (nbd_reply_is_structured(&s->reply) && 471 s->info.mode < NBD_MODE_STRUCTURED) { 472 nbd_channel_error(s, -EINVAL); 473 error_setg(errp, "unexpected structured reply"); 474 return -EINVAL; 475 } 476 ind2 = COOKIE_TO_INDEX(s->reply.cookie); 477 if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].coroutine) { 478 nbd_channel_error(s, -EINVAL); 479 error_setg(errp, "unexpected cookie value"); 480 return -EINVAL; 481 } 482 if (s->reply.cookie == cookie) { 483 /* We are done */ 484 return 0; 485 } 486 nbd_recv_coroutine_wake_one(&s->requests[ind2]); 487 } 488 } 489 490 static int coroutine_fn GRAPH_RDLOCK 491 nbd_co_send_request(BlockDriverState *bs, NBDRequest *request, 492 QEMUIOVector *qiov) 493 { 494 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 495 int rc, i = -1; 496 497 qemu_mutex_lock(&s->requests_lock); 498 while (s->in_flight == MAX_NBD_REQUESTS || 499 (s->state != NBD_CLIENT_CONNECTED && s->in_flight > 0)) { 500 qemu_co_queue_wait(&s->free_sema, &s->requests_lock); 501 } 502 503 s->in_flight++; 504 if (s->state != NBD_CLIENT_CONNECTED) { 505 if (nbd_client_connecting(s)) { 506 nbd_reconnect_attempt(s); 507 qemu_co_queue_restart_all(&s->free_sema); 508 } 509 if (s->state != NBD_CLIENT_CONNECTED) { 510 rc = -EIO; 511 goto err; 512 } 513 } 514 515 for (i = 0; i < MAX_NBD_REQUESTS; i++) { 516 if (s->requests[i].coroutine == NULL) { 517 break; 518 } 519 } 520 521 assert(i < MAX_NBD_REQUESTS); 522 s->requests[i].coroutine = qemu_coroutine_self(); 523 s->requests[i].offset = request->from; 524 s->requests[i].receiving = false; 525 qemu_mutex_unlock(&s->requests_lock); 526 527 qemu_co_mutex_lock(&s->send_mutex); 528 request->cookie = INDEX_TO_COOKIE(i); 529 request->mode = s->info.mode; 530 531 assert(s->ioc); 532 533 if (qiov) { 534 qio_channel_set_cork(s->ioc, true); 535 rc = nbd_send_request(s->ioc, request); 536 if (rc >= 0 && qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, 537 NULL) < 0) { 538 rc = -EIO; 539 } 540 qio_channel_set_cork(s->ioc, false); 541 } else { 542 rc = nbd_send_request(s->ioc, request); 543 } 544 qemu_co_mutex_unlock(&s->send_mutex); 545 546 if (rc < 0) { 547 qemu_mutex_lock(&s->requests_lock); 548 err: 549 nbd_channel_error_locked(s, rc); 550 if (i != -1) { 551 s->requests[i].coroutine = NULL; 552 } 553 s->in_flight--; 554 qemu_co_queue_next(&s->free_sema); 555 qemu_mutex_unlock(&s->requests_lock); 556 } 557 return rc; 558 } 559 560 static inline uint16_t payload_advance16(uint8_t **payload) 561 { 562 *payload += 2; 563 return lduw_be_p(*payload - 2); 564 } 565 566 static inline uint32_t payload_advance32(uint8_t **payload) 567 { 568 *payload += 4; 569 return ldl_be_p(*payload - 4); 570 } 571 572 static inline uint64_t payload_advance64(uint8_t **payload) 573 { 574 *payload += 8; 575 return ldq_be_p(*payload - 8); 576 } 577 578 static int nbd_parse_offset_hole_payload(BDRVNBDState *s, 579 NBDStructuredReplyChunk *chunk, 580 uint8_t *payload, uint64_t orig_offset, 581 QEMUIOVector *qiov, Error **errp) 582 { 583 uint64_t offset; 584 uint32_t hole_size; 585 586 if (chunk->length != sizeof(offset) + sizeof(hole_size)) { 587 error_setg(errp, "Protocol error: invalid payload for " 588 "NBD_REPLY_TYPE_OFFSET_HOLE"); 589 return -EINVAL; 590 } 591 592 offset = payload_advance64(&payload); 593 hole_size = payload_advance32(&payload); 594 595 if (!hole_size || offset < orig_offset || hole_size > qiov->size || 596 offset > orig_offset + qiov->size - hole_size) { 597 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 598 " region"); 599 return -EINVAL; 600 } 601 if (s->info.min_block && 602 !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { 603 trace_nbd_structured_read_compliance("hole"); 604 } 605 606 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); 607 608 return 0; 609 } 610 611 /* 612 * nbd_parse_blockstatus_payload 613 * Based on our request, we expect only one extent in reply, for the 614 * base:allocation context. 615 */ 616 static int nbd_parse_blockstatus_payload(BDRVNBDState *s, 617 NBDStructuredReplyChunk *chunk, 618 uint8_t *payload, bool wide, 619 uint64_t orig_length, 620 NBDExtent64 *extent, Error **errp) 621 { 622 uint32_t context_id; 623 uint32_t count; 624 size_t ext_len = wide ? sizeof(*extent) : sizeof(NBDExtent32); 625 size_t pay_len = sizeof(context_id) + wide * sizeof(count) + ext_len; 626 627 /* The server succeeded, so it must have sent [at least] one extent */ 628 if (chunk->length < pay_len) { 629 error_setg(errp, "Protocol error: invalid payload for " 630 "NBD_REPLY_TYPE_BLOCK_STATUS"); 631 return -EINVAL; 632 } 633 634 context_id = payload_advance32(&payload); 635 if (s->info.context_id != context_id) { 636 error_setg(errp, "Protocol error: unexpected context id %d for " 637 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " 638 "id is %d", context_id, 639 s->info.context_id); 640 return -EINVAL; 641 } 642 643 if (wide) { 644 count = payload_advance32(&payload); 645 extent->length = payload_advance64(&payload); 646 extent->flags = payload_advance64(&payload); 647 } else { 648 count = 0; 649 extent->length = payload_advance32(&payload); 650 extent->flags = payload_advance32(&payload); 651 } 652 653 if (extent->length == 0) { 654 error_setg(errp, "Protocol error: server sent status chunk with " 655 "zero length"); 656 return -EINVAL; 657 } 658 659 /* 660 * A server sending unaligned block status is in violation of the 661 * protocol, but as qemu-nbd 3.1 is such a server (at least for 662 * POSIX files that are not a multiple of 512 bytes, since qemu 663 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) 664 * still sees an implicit hole beyond the real EOF), it's nicer to 665 * work around the misbehaving server. If the request included 666 * more than the final unaligned block, truncate it back to an 667 * aligned result; if the request was only the final block, round 668 * up to the full block and change the status to fully-allocated 669 * (always a safe status, even if it loses information). 670 */ 671 if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, 672 s->info.min_block)) { 673 trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); 674 if (extent->length > s->info.min_block) { 675 extent->length = QEMU_ALIGN_DOWN(extent->length, 676 s->info.min_block); 677 } else { 678 extent->length = s->info.min_block; 679 extent->flags = 0; 680 } 681 } 682 683 /* 684 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have 685 * sent us any more than one extent, nor should it have included 686 * status beyond our request in that extent. Furthermore, a wide 687 * server should have replied with an accurate count (we left 688 * count at 0 for a narrow server). However, it's easy enough to 689 * ignore the server's noncompliance without killing the 690 * connection; just ignore trailing extents, and clamp things to 691 * the length of our request. 692 */ 693 if (count != wide || chunk->length > pay_len) { 694 trace_nbd_parse_blockstatus_compliance("unexpected extent count"); 695 } 696 if (extent->length > orig_length) { 697 extent->length = orig_length; 698 trace_nbd_parse_blockstatus_compliance("extent length too large"); 699 } 700 701 /* 702 * HACK: if we are using x-dirty-bitmaps to access 703 * qemu:allocation-depth, treat all depths > 2 the same as 2, 704 * since nbd_client_co_block_status is only expecting the low two 705 * bits to be set. 706 */ 707 if (s->alloc_depth && extent->flags > 2) { 708 extent->flags = 2; 709 } 710 711 return 0; 712 } 713 714 /* 715 * nbd_parse_error_payload 716 * on success @errp contains message describing nbd error reply 717 */ 718 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, 719 uint8_t *payload, int *request_ret, 720 Error **errp) 721 { 722 uint32_t error; 723 uint16_t message_size; 724 725 assert(chunk->type & (1 << 15)); 726 727 if (chunk->length < sizeof(error) + sizeof(message_size)) { 728 error_setg(errp, 729 "Protocol error: invalid payload for structured error"); 730 return -EINVAL; 731 } 732 733 error = nbd_errno_to_system_errno(payload_advance32(&payload)); 734 if (error == 0) { 735 error_setg(errp, "Protocol error: server sent structured error chunk " 736 "with error = 0"); 737 return -EINVAL; 738 } 739 740 *request_ret = -error; 741 message_size = payload_advance16(&payload); 742 743 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { 744 error_setg(errp, "Protocol error: server sent structured error chunk " 745 "with incorrect message size"); 746 return -EINVAL; 747 } 748 749 /* TODO: Add a trace point to mention the server complaint */ 750 751 /* TODO handle ERROR_OFFSET */ 752 753 return 0; 754 } 755 756 static int coroutine_fn 757 nbd_co_receive_offset_data_payload(BDRVNBDState *s, uint64_t orig_offset, 758 QEMUIOVector *qiov, Error **errp) 759 { 760 QEMUIOVector sub_qiov; 761 uint64_t offset; 762 size_t data_size; 763 int ret; 764 NBDStructuredReplyChunk *chunk = &s->reply.structured; 765 766 assert(nbd_reply_is_structured(&s->reply)); 767 768 /* The NBD spec requires at least one byte of payload */ 769 if (chunk->length <= sizeof(offset)) { 770 error_setg(errp, "Protocol error: invalid payload for " 771 "NBD_REPLY_TYPE_OFFSET_DATA"); 772 return -EINVAL; 773 } 774 775 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { 776 return -EIO; 777 } 778 779 data_size = chunk->length - sizeof(offset); 780 assert(data_size); 781 if (offset < orig_offset || data_size > qiov->size || 782 offset > orig_offset + qiov->size - data_size) { 783 error_setg(errp, "Protocol error: server sent chunk exceeding requested" 784 " region"); 785 return -EINVAL; 786 } 787 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { 788 trace_nbd_structured_read_compliance("data"); 789 } 790 791 qemu_iovec_init(&sub_qiov, qiov->niov); 792 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); 793 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); 794 qemu_iovec_destroy(&sub_qiov); 795 796 return ret < 0 ? -EIO : 0; 797 } 798 799 #define NBD_MAX_MALLOC_PAYLOAD 1000 800 static coroutine_fn int nbd_co_receive_structured_payload( 801 BDRVNBDState *s, void **payload, Error **errp) 802 { 803 int ret; 804 uint32_t len; 805 806 assert(nbd_reply_is_structured(&s->reply)); 807 808 len = s->reply.structured.length; 809 810 if (len == 0) { 811 return 0; 812 } 813 814 if (payload == NULL) { 815 error_setg(errp, "Unexpected structured payload"); 816 return -EINVAL; 817 } 818 819 if (len > NBD_MAX_MALLOC_PAYLOAD) { 820 error_setg(errp, "Payload too large"); 821 return -EINVAL; 822 } 823 824 *payload = g_new(char, len); 825 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); 826 if (ret < 0) { 827 g_free(*payload); 828 *payload = NULL; 829 return ret; 830 } 831 832 return 0; 833 } 834 835 /* 836 * nbd_co_do_receive_one_chunk 837 * for simple reply: 838 * set request_ret to received reply error 839 * if qiov is not NULL: read payload to @qiov 840 * for structured reply chunk: 841 * if error chunk: read payload, set @request_ret, do not set @payload 842 * else if offset_data chunk: read payload data to @qiov, do not set @payload 843 * else: read payload to @payload 844 * 845 * If function fails, @errp contains corresponding error message, and the 846 * connection with the server is suspect. If it returns 0, then the 847 * transaction succeeded (although @request_ret may be a negative errno 848 * corresponding to the server's error reply), and errp is unchanged. 849 */ 850 static coroutine_fn int nbd_co_do_receive_one_chunk( 851 BDRVNBDState *s, uint64_t cookie, bool only_structured, 852 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) 853 { 854 int ret; 855 int i = COOKIE_TO_INDEX(cookie); 856 void *local_payload = NULL; 857 NBDStructuredReplyChunk *chunk; 858 859 if (payload) { 860 *payload = NULL; 861 } 862 *request_ret = 0; 863 864 ret = nbd_receive_replies(s, cookie, errp); 865 if (ret < 0) { 866 error_prepend(errp, "Connection closed: "); 867 return -EIO; 868 } 869 assert(s->ioc); 870 871 assert(s->reply.cookie == cookie); 872 873 if (nbd_reply_is_simple(&s->reply)) { 874 if (only_structured) { 875 error_setg(errp, "Protocol error: simple reply when structured " 876 "reply chunk was expected"); 877 return -EINVAL; 878 } 879 880 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); 881 if (*request_ret < 0 || !qiov) { 882 return 0; 883 } 884 885 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, 886 errp) < 0 ? -EIO : 0; 887 } 888 889 /* handle structured reply chunk */ 890 assert(s->info.mode >= NBD_MODE_STRUCTURED); 891 chunk = &s->reply.structured; 892 893 if (chunk->type == NBD_REPLY_TYPE_NONE) { 894 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { 895 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" 896 " NBD_REPLY_FLAG_DONE flag set"); 897 return -EINVAL; 898 } 899 if (chunk->length) { 900 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" 901 " nonzero length"); 902 return -EINVAL; 903 } 904 return 0; 905 } 906 907 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { 908 if (!qiov) { 909 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); 910 return -EINVAL; 911 } 912 913 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, 914 qiov, errp); 915 } 916 917 if (nbd_reply_type_is_error(chunk->type)) { 918 payload = &local_payload; 919 } 920 921 ret = nbd_co_receive_structured_payload(s, payload, errp); 922 if (ret < 0) { 923 return ret; 924 } 925 926 if (nbd_reply_type_is_error(chunk->type)) { 927 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); 928 g_free(local_payload); 929 return ret; 930 } 931 932 return 0; 933 } 934 935 /* 936 * nbd_co_receive_one_chunk 937 * Read reply, wake up connection_co and set s->quit if needed. 938 * Return value is a fatal error code or normal nbd reply error code 939 */ 940 static coroutine_fn int nbd_co_receive_one_chunk( 941 BDRVNBDState *s, uint64_t cookie, bool only_structured, 942 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, 943 Error **errp) 944 { 945 int ret = nbd_co_do_receive_one_chunk(s, cookie, only_structured, 946 request_ret, qiov, payload, errp); 947 948 if (ret < 0) { 949 memset(reply, 0, sizeof(*reply)); 950 nbd_channel_error(s, ret); 951 } else { 952 /* For assert at loop start in nbd_connection_entry */ 953 *reply = s->reply; 954 } 955 s->reply.cookie = 0; 956 957 nbd_recv_coroutines_wake(s); 958 959 return ret; 960 } 961 962 typedef struct NBDReplyChunkIter { 963 int ret; 964 int request_ret; 965 Error *err; 966 bool done, only_structured; 967 } NBDReplyChunkIter; 968 969 static void nbd_iter_channel_error(NBDReplyChunkIter *iter, 970 int ret, Error **local_err) 971 { 972 assert(local_err && *local_err); 973 assert(ret < 0); 974 975 if (!iter->ret) { 976 iter->ret = ret; 977 error_propagate(&iter->err, *local_err); 978 } else { 979 error_free(*local_err); 980 } 981 982 *local_err = NULL; 983 } 984 985 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) 986 { 987 assert(ret < 0); 988 989 if (!iter->request_ret) { 990 iter->request_ret = ret; 991 } 992 } 993 994 /* 995 * NBD_FOREACH_REPLY_CHUNK 996 * The pointer stored in @payload requires g_free() to free it. 997 */ 998 #define NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, structured, \ 999 qiov, reply, payload) \ 1000 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ 1001 nbd_reply_chunk_iter_receive(s, &iter, cookie, qiov, reply, payload);) 1002 1003 /* 1004 * nbd_reply_chunk_iter_receive 1005 * The pointer stored in @payload requires g_free() to free it. 1006 */ 1007 static bool coroutine_fn nbd_reply_chunk_iter_receive(BDRVNBDState *s, 1008 NBDReplyChunkIter *iter, 1009 uint64_t cookie, 1010 QEMUIOVector *qiov, 1011 NBDReply *reply, 1012 void **payload) 1013 { 1014 int ret, request_ret; 1015 NBDReply local_reply; 1016 NBDStructuredReplyChunk *chunk; 1017 Error *local_err = NULL; 1018 1019 if (iter->done) { 1020 /* Previous iteration was last. */ 1021 goto break_loop; 1022 } 1023 1024 if (reply == NULL) { 1025 reply = &local_reply; 1026 } 1027 1028 ret = nbd_co_receive_one_chunk(s, cookie, iter->only_structured, 1029 &request_ret, qiov, reply, payload, 1030 &local_err); 1031 if (ret < 0) { 1032 nbd_iter_channel_error(iter, ret, &local_err); 1033 } else if (request_ret < 0) { 1034 nbd_iter_request_error(iter, request_ret); 1035 } 1036 1037 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ 1038 if (nbd_reply_is_simple(reply) || iter->ret < 0) { 1039 goto break_loop; 1040 } 1041 1042 chunk = &reply->structured; 1043 iter->only_structured = true; 1044 1045 if (chunk->type == NBD_REPLY_TYPE_NONE) { 1046 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ 1047 assert(chunk->flags & NBD_REPLY_FLAG_DONE); 1048 goto break_loop; 1049 } 1050 1051 if (chunk->flags & NBD_REPLY_FLAG_DONE) { 1052 /* This iteration is last. */ 1053 iter->done = true; 1054 } 1055 1056 /* Execute the loop body */ 1057 return true; 1058 1059 break_loop: 1060 qemu_mutex_lock(&s->requests_lock); 1061 s->requests[COOKIE_TO_INDEX(cookie)].coroutine = NULL; 1062 s->in_flight--; 1063 qemu_co_queue_next(&s->free_sema); 1064 qemu_mutex_unlock(&s->requests_lock); 1065 1066 return false; 1067 } 1068 1069 static int coroutine_fn 1070 nbd_co_receive_return_code(BDRVNBDState *s, uint64_t cookie, 1071 int *request_ret, Error **errp) 1072 { 1073 NBDReplyChunkIter iter; 1074 1075 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, NULL, NULL) { 1076 /* nbd_reply_chunk_iter_receive does all the work */ 1077 } 1078 1079 error_propagate(errp, iter.err); 1080 *request_ret = iter.request_ret; 1081 return iter.ret; 1082 } 1083 1084 static int coroutine_fn 1085 nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t cookie, 1086 uint64_t offset, QEMUIOVector *qiov, 1087 int *request_ret, Error **errp) 1088 { 1089 NBDReplyChunkIter iter; 1090 NBDReply reply; 1091 void *payload = NULL; 1092 Error *local_err = NULL; 1093 1094 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, 1095 s->info.mode >= NBD_MODE_STRUCTURED, 1096 qiov, &reply, &payload) 1097 { 1098 int ret; 1099 NBDStructuredReplyChunk *chunk = &reply.structured; 1100 1101 assert(nbd_reply_is_structured(&reply)); 1102 1103 switch (chunk->type) { 1104 case NBD_REPLY_TYPE_OFFSET_DATA: 1105 /* 1106 * special cased in nbd_co_receive_one_chunk, data is already 1107 * in qiov 1108 */ 1109 break; 1110 case NBD_REPLY_TYPE_OFFSET_HOLE: 1111 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, 1112 offset, qiov, &local_err); 1113 if (ret < 0) { 1114 nbd_channel_error(s, ret); 1115 nbd_iter_channel_error(&iter, ret, &local_err); 1116 } 1117 break; 1118 default: 1119 if (!nbd_reply_type_is_error(chunk->type)) { 1120 /* not allowed reply type */ 1121 nbd_channel_error(s, -EINVAL); 1122 error_setg(&local_err, 1123 "Unexpected reply type: %d (%s) for CMD_READ", 1124 chunk->type, nbd_reply_type_lookup(chunk->type)); 1125 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1126 } 1127 } 1128 1129 g_free(payload); 1130 payload = NULL; 1131 } 1132 1133 error_propagate(errp, iter.err); 1134 *request_ret = iter.request_ret; 1135 return iter.ret; 1136 } 1137 1138 static int coroutine_fn 1139 nbd_co_receive_blockstatus_reply(BDRVNBDState *s, uint64_t cookie, 1140 uint64_t length, NBDExtent64 *extent, 1141 int *request_ret, Error **errp) 1142 { 1143 NBDReplyChunkIter iter; 1144 NBDReply reply; 1145 void *payload = NULL; 1146 Error *local_err = NULL; 1147 bool received = false; 1148 1149 assert(!extent->length); 1150 NBD_FOREACH_REPLY_CHUNK(s, iter, cookie, false, NULL, &reply, &payload) { 1151 int ret; 1152 NBDStructuredReplyChunk *chunk = &reply.structured; 1153 bool wide; 1154 1155 assert(nbd_reply_is_structured(&reply)); 1156 1157 switch (chunk->type) { 1158 case NBD_REPLY_TYPE_BLOCK_STATUS_EXT: 1159 case NBD_REPLY_TYPE_BLOCK_STATUS: 1160 wide = chunk->type == NBD_REPLY_TYPE_BLOCK_STATUS_EXT; 1161 if ((s->info.mode >= NBD_MODE_EXTENDED) != wide) { 1162 trace_nbd_extended_headers_compliance("block_status"); 1163 } 1164 if (received) { 1165 nbd_channel_error(s, -EINVAL); 1166 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); 1167 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1168 } 1169 received = true; 1170 1171 ret = nbd_parse_blockstatus_payload( 1172 s, &reply.structured, payload, wide, 1173 length, extent, &local_err); 1174 if (ret < 0) { 1175 nbd_channel_error(s, ret); 1176 nbd_iter_channel_error(&iter, ret, &local_err); 1177 } 1178 break; 1179 default: 1180 if (!nbd_reply_type_is_error(chunk->type)) { 1181 nbd_channel_error(s, -EINVAL); 1182 error_setg(&local_err, 1183 "Unexpected reply type: %d (%s) " 1184 "for CMD_BLOCK_STATUS", 1185 chunk->type, nbd_reply_type_lookup(chunk->type)); 1186 nbd_iter_channel_error(&iter, -EINVAL, &local_err); 1187 } 1188 } 1189 1190 g_free(payload); 1191 payload = NULL; 1192 } 1193 1194 if (!extent->length && !iter.request_ret) { 1195 error_setg(&local_err, "Server did not reply with any status extents"); 1196 nbd_iter_channel_error(&iter, -EIO, &local_err); 1197 } 1198 1199 error_propagate(errp, iter.err); 1200 *request_ret = iter.request_ret; 1201 return iter.ret; 1202 } 1203 1204 static int coroutine_fn GRAPH_RDLOCK 1205 nbd_co_request(BlockDriverState *bs, NBDRequest *request, 1206 QEMUIOVector *write_qiov) 1207 { 1208 int ret, request_ret; 1209 Error *local_err = NULL; 1210 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1211 1212 assert(request->type != NBD_CMD_READ); 1213 if (write_qiov) { 1214 assert(request->type == NBD_CMD_WRITE); 1215 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); 1216 } else { 1217 assert(request->type != NBD_CMD_WRITE); 1218 } 1219 1220 do { 1221 ret = nbd_co_send_request(bs, request, write_qiov); 1222 if (ret < 0) { 1223 continue; 1224 } 1225 1226 ret = nbd_co_receive_return_code(s, request->cookie, 1227 &request_ret, &local_err); 1228 if (local_err) { 1229 trace_nbd_co_request_fail(request->from, request->len, 1230 request->cookie, request->flags, 1231 request->type, 1232 nbd_cmd_lookup(request->type), 1233 ret, error_get_pretty(local_err)); 1234 error_free(local_err); 1235 local_err = NULL; 1236 } 1237 } while (ret < 0 && nbd_client_will_reconnect(s)); 1238 1239 return ret ? ret : request_ret; 1240 } 1241 1242 static int coroutine_fn GRAPH_RDLOCK 1243 nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 1244 QEMUIOVector *qiov, BdrvRequestFlags flags) 1245 { 1246 int ret, request_ret; 1247 Error *local_err = NULL; 1248 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1249 NBDRequest request = { 1250 .type = NBD_CMD_READ, 1251 .from = offset, 1252 .len = bytes, 1253 }; 1254 1255 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1256 1257 if (!bytes) { 1258 return 0; 1259 } 1260 /* 1261 * Work around the fact that the block layer doesn't do 1262 * byte-accurate sizing yet - if the read exceeds the server's 1263 * advertised size because the block layer rounded size up, then 1264 * truncate the request to the server and tail-pad with zero. 1265 */ 1266 if (offset >= s->info.size) { 1267 assert(bytes < BDRV_SECTOR_SIZE); 1268 qemu_iovec_memset(qiov, 0, 0, bytes); 1269 return 0; 1270 } 1271 if (offset + bytes > s->info.size) { 1272 uint64_t slop = offset + bytes - s->info.size; 1273 1274 assert(slop < BDRV_SECTOR_SIZE); 1275 qemu_iovec_memset(qiov, bytes - slop, 0, slop); 1276 request.len -= slop; 1277 } 1278 1279 do { 1280 ret = nbd_co_send_request(bs, &request, NULL); 1281 if (ret < 0) { 1282 continue; 1283 } 1284 1285 ret = nbd_co_receive_cmdread_reply(s, request.cookie, offset, qiov, 1286 &request_ret, &local_err); 1287 if (local_err) { 1288 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1289 request.flags, request.type, 1290 nbd_cmd_lookup(request.type), 1291 ret, error_get_pretty(local_err)); 1292 error_free(local_err); 1293 local_err = NULL; 1294 } 1295 } while (ret < 0 && nbd_client_will_reconnect(s)); 1296 1297 return ret ? ret : request_ret; 1298 } 1299 1300 static int coroutine_fn GRAPH_RDLOCK 1301 nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, 1302 QEMUIOVector *qiov, BdrvRequestFlags flags) 1303 { 1304 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1305 NBDRequest request = { 1306 .type = NBD_CMD_WRITE, 1307 .from = offset, 1308 .len = bytes, 1309 }; 1310 1311 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1312 if (flags & BDRV_REQ_FUA) { 1313 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1314 request.flags |= NBD_CMD_FLAG_FUA; 1315 } 1316 1317 assert(bytes <= NBD_MAX_BUFFER_SIZE); 1318 1319 if (!bytes) { 1320 return 0; 1321 } 1322 return nbd_co_request(bs, &request, qiov); 1323 } 1324 1325 static int coroutine_fn GRAPH_RDLOCK 1326 nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 1327 BdrvRequestFlags flags) 1328 { 1329 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1330 NBDRequest request = { 1331 .type = NBD_CMD_WRITE_ZEROES, 1332 .from = offset, 1333 .len = bytes, 1334 }; 1335 1336 /* rely on max_pwrite_zeroes */ 1337 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1338 1339 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1340 if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { 1341 return -ENOTSUP; 1342 } 1343 1344 if (flags & BDRV_REQ_FUA) { 1345 assert(s->info.flags & NBD_FLAG_SEND_FUA); 1346 request.flags |= NBD_CMD_FLAG_FUA; 1347 } 1348 if (!(flags & BDRV_REQ_MAY_UNMAP)) { 1349 request.flags |= NBD_CMD_FLAG_NO_HOLE; 1350 } 1351 if (flags & BDRV_REQ_NO_FALLBACK) { 1352 assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); 1353 request.flags |= NBD_CMD_FLAG_FAST_ZERO; 1354 } 1355 1356 if (!bytes) { 1357 return 0; 1358 } 1359 return nbd_co_request(bs, &request, NULL); 1360 } 1361 1362 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_flush(BlockDriverState *bs) 1363 { 1364 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1365 NBDRequest request = { .type = NBD_CMD_FLUSH }; 1366 1367 if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { 1368 return 0; 1369 } 1370 1371 request.from = 0; 1372 request.len = 0; 1373 1374 return nbd_co_request(bs, &request, NULL); 1375 } 1376 1377 static int coroutine_fn GRAPH_RDLOCK 1378 nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 1379 { 1380 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1381 NBDRequest request = { 1382 .type = NBD_CMD_TRIM, 1383 .from = offset, 1384 .len = bytes, 1385 }; 1386 1387 /* rely on max_pdiscard */ 1388 assert(bytes <= UINT32_MAX || s->info.mode >= NBD_MODE_EXTENDED); 1389 1390 assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); 1391 if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { 1392 return 0; 1393 } 1394 1395 return nbd_co_request(bs, &request, NULL); 1396 } 1397 1398 static int coroutine_fn GRAPH_RDLOCK nbd_client_co_block_status( 1399 BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, 1400 int64_t *pnum, int64_t *map, BlockDriverState **file) 1401 { 1402 int ret, request_ret; 1403 NBDExtent64 extent = { 0 }; 1404 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1405 Error *local_err = NULL; 1406 1407 NBDRequest request = { 1408 .type = NBD_CMD_BLOCK_STATUS, 1409 .from = offset, 1410 .len = MIN(bytes, s->info.size - offset), 1411 .flags = NBD_CMD_FLAG_REQ_ONE, 1412 }; 1413 1414 if (!s->info.base_allocation) { 1415 *pnum = bytes; 1416 *map = offset; 1417 *file = bs; 1418 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 1419 } 1420 if (s->info.mode < NBD_MODE_EXTENDED) { 1421 request.len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), 1422 request.len); 1423 } 1424 1425 /* 1426 * Work around the fact that the block layer doesn't do 1427 * byte-accurate sizing yet - if the status request exceeds the 1428 * server's advertised size because the block layer rounded size 1429 * up, we truncated the request to the server (above), or are 1430 * called on just the hole. 1431 */ 1432 if (offset >= s->info.size) { 1433 *pnum = bytes; 1434 assert(bytes < BDRV_SECTOR_SIZE); 1435 /* Intentionally don't report offset_valid for the hole */ 1436 return BDRV_BLOCK_ZERO; 1437 } 1438 1439 if (s->info.min_block) { 1440 assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); 1441 } 1442 do { 1443 ret = nbd_co_send_request(bs, &request, NULL); 1444 if (ret < 0) { 1445 continue; 1446 } 1447 1448 ret = nbd_co_receive_blockstatus_reply(s, request.cookie, bytes, 1449 &extent, &request_ret, 1450 &local_err); 1451 if (local_err) { 1452 trace_nbd_co_request_fail(request.from, request.len, request.cookie, 1453 request.flags, request.type, 1454 nbd_cmd_lookup(request.type), 1455 ret, error_get_pretty(local_err)); 1456 error_free(local_err); 1457 local_err = NULL; 1458 } 1459 } while (ret < 0 && nbd_client_will_reconnect(s)); 1460 1461 if (ret < 0 || request_ret < 0) { 1462 return ret ? ret : request_ret; 1463 } 1464 1465 assert(extent.length); 1466 *pnum = extent.length; 1467 *map = offset; 1468 *file = bs; 1469 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | 1470 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | 1471 BDRV_BLOCK_OFFSET_VALID; 1472 } 1473 1474 static int nbd_client_reopen_prepare(BDRVReopenState *state, 1475 BlockReopenQueue *queue, Error **errp) 1476 { 1477 BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; 1478 1479 if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { 1480 error_setg(errp, "Can't reopen read-only NBD mount as read/write"); 1481 return -EACCES; 1482 } 1483 return 0; 1484 } 1485 1486 static void nbd_yank(void *opaque) 1487 { 1488 BlockDriverState *bs = opaque; 1489 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1490 1491 QEMU_LOCK_GUARD(&s->requests_lock); 1492 qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1493 s->state = NBD_CLIENT_QUIT; 1494 } 1495 1496 static void nbd_client_close(BlockDriverState *bs) 1497 { 1498 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1499 NBDRequest request = { .type = NBD_CMD_DISC, .mode = s->info.mode }; 1500 1501 if (s->ioc) { 1502 nbd_send_request(s->ioc, &request); 1503 } 1504 1505 nbd_teardown_connection(bs); 1506 } 1507 1508 1509 /* 1510 * Parse nbd_open options 1511 */ 1512 1513 static int nbd_parse_uri(const char *filename, QDict *options) 1514 { 1515 URI *uri; 1516 const char *p; 1517 QueryParams *qp = NULL; 1518 int ret = 0; 1519 bool is_unix; 1520 1521 uri = uri_parse(filename); 1522 if (!uri) { 1523 return -EINVAL; 1524 } 1525 1526 /* transport */ 1527 if (!g_strcmp0(uri->scheme, "nbd")) { 1528 is_unix = false; 1529 } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { 1530 is_unix = false; 1531 } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { 1532 is_unix = true; 1533 } else { 1534 ret = -EINVAL; 1535 goto out; 1536 } 1537 1538 p = uri->path ? uri->path : ""; 1539 if (p[0] == '/') { 1540 p++; 1541 } 1542 if (p[0]) { 1543 qdict_put_str(options, "export", p); 1544 } 1545 1546 qp = query_params_parse(uri->query); 1547 if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { 1548 ret = -EINVAL; 1549 goto out; 1550 } 1551 1552 if (is_unix) { 1553 /* nbd+unix:///export?socket=path */ 1554 if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { 1555 ret = -EINVAL; 1556 goto out; 1557 } 1558 qdict_put_str(options, "server.type", "unix"); 1559 qdict_put_str(options, "server.path", qp->p[0].value); 1560 } else { 1561 QString *host; 1562 char *port_str; 1563 1564 /* nbd[+tcp]://host[:port]/export */ 1565 if (!uri->server) { 1566 ret = -EINVAL; 1567 goto out; 1568 } 1569 1570 /* strip braces from literal IPv6 address */ 1571 if (uri->server[0] == '[') { 1572 host = qstring_from_substr(uri->server, 1, 1573 strlen(uri->server) - 1); 1574 } else { 1575 host = qstring_from_str(uri->server); 1576 } 1577 1578 qdict_put_str(options, "server.type", "inet"); 1579 qdict_put(options, "server.host", host); 1580 1581 port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); 1582 qdict_put_str(options, "server.port", port_str); 1583 g_free(port_str); 1584 } 1585 1586 out: 1587 if (qp) { 1588 query_params_free(qp); 1589 } 1590 uri_free(uri); 1591 return ret; 1592 } 1593 1594 static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) 1595 { 1596 const QDictEntry *e; 1597 1598 for (e = qdict_first(options); e; e = qdict_next(options, e)) { 1599 if (!strcmp(e->key, "host") || 1600 !strcmp(e->key, "port") || 1601 !strcmp(e->key, "path") || 1602 !strcmp(e->key, "export") || 1603 strstart(e->key, "server.", NULL)) 1604 { 1605 error_setg(errp, "Option '%s' cannot be used with a file name", 1606 e->key); 1607 return true; 1608 } 1609 } 1610 1611 return false; 1612 } 1613 1614 static void nbd_parse_filename(const char *filename, QDict *options, 1615 Error **errp) 1616 { 1617 g_autofree char *file = NULL; 1618 char *export_name; 1619 const char *host_spec; 1620 const char *unixpath; 1621 1622 if (nbd_has_filename_options_conflict(options, errp)) { 1623 return; 1624 } 1625 1626 if (strstr(filename, "://")) { 1627 int ret = nbd_parse_uri(filename, options); 1628 if (ret < 0) { 1629 error_setg(errp, "No valid URL specified"); 1630 } 1631 return; 1632 } 1633 1634 file = g_strdup(filename); 1635 1636 export_name = strstr(file, EN_OPTSTR); 1637 if (export_name) { 1638 if (export_name[strlen(EN_OPTSTR)] == 0) { 1639 return; 1640 } 1641 export_name[0] = 0; /* truncate 'file' */ 1642 export_name += strlen(EN_OPTSTR); 1643 1644 qdict_put_str(options, "export", export_name); 1645 } 1646 1647 /* extract the host_spec - fail if it's not nbd:... */ 1648 if (!strstart(file, "nbd:", &host_spec)) { 1649 error_setg(errp, "File name string for NBD must start with 'nbd:'"); 1650 return; 1651 } 1652 1653 if (!*host_spec) { 1654 return; 1655 } 1656 1657 /* are we a UNIX or TCP socket? */ 1658 if (strstart(host_spec, "unix:", &unixpath)) { 1659 qdict_put_str(options, "server.type", "unix"); 1660 qdict_put_str(options, "server.path", unixpath); 1661 } else { 1662 InetSocketAddress *addr = g_new(InetSocketAddress, 1); 1663 1664 if (inet_parse(addr, host_spec, errp)) { 1665 goto out_inet; 1666 } 1667 1668 qdict_put_str(options, "server.type", "inet"); 1669 qdict_put_str(options, "server.host", addr->host); 1670 qdict_put_str(options, "server.port", addr->port); 1671 out_inet: 1672 qapi_free_InetSocketAddress(addr); 1673 } 1674 } 1675 1676 static bool nbd_process_legacy_socket_options(QDict *output_options, 1677 QemuOpts *legacy_opts, 1678 Error **errp) 1679 { 1680 const char *path = qemu_opt_get(legacy_opts, "path"); 1681 const char *host = qemu_opt_get(legacy_opts, "host"); 1682 const char *port = qemu_opt_get(legacy_opts, "port"); 1683 const QDictEntry *e; 1684 1685 if (!path && !host && !port) { 1686 return true; 1687 } 1688 1689 for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) 1690 { 1691 if (strstart(e->key, "server.", NULL)) { 1692 error_setg(errp, "Cannot use 'server' and path/host/port at the " 1693 "same time"); 1694 return false; 1695 } 1696 } 1697 1698 if (path && host) { 1699 error_setg(errp, "path and host may not be used at the same time"); 1700 return false; 1701 } else if (path) { 1702 if (port) { 1703 error_setg(errp, "port may not be used without host"); 1704 return false; 1705 } 1706 1707 qdict_put_str(output_options, "server.type", "unix"); 1708 qdict_put_str(output_options, "server.path", path); 1709 } else if (host) { 1710 qdict_put_str(output_options, "server.type", "inet"); 1711 qdict_put_str(output_options, "server.host", host); 1712 qdict_put_str(output_options, "server.port", 1713 port ?: stringify(NBD_DEFAULT_PORT)); 1714 } 1715 1716 return true; 1717 } 1718 1719 static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, 1720 Error **errp) 1721 { 1722 SocketAddress *saddr = NULL; 1723 QDict *addr = NULL; 1724 Visitor *iv = NULL; 1725 1726 qdict_extract_subqdict(options, &addr, "server."); 1727 if (!qdict_size(addr)) { 1728 error_setg(errp, "NBD server address missing"); 1729 goto done; 1730 } 1731 1732 iv = qobject_input_visitor_new_flat_confused(addr, errp); 1733 if (!iv) { 1734 goto done; 1735 } 1736 1737 if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { 1738 goto done; 1739 } 1740 1741 if (socket_address_parse_named_fd(saddr, errp) < 0) { 1742 qapi_free_SocketAddress(saddr); 1743 saddr = NULL; 1744 goto done; 1745 } 1746 1747 done: 1748 qobject_unref(addr); 1749 visit_free(iv); 1750 return saddr; 1751 } 1752 1753 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) 1754 { 1755 Object *obj; 1756 QCryptoTLSCreds *creds; 1757 1758 obj = object_resolve_path_component( 1759 object_get_objects_root(), id); 1760 if (!obj) { 1761 error_setg(errp, "No TLS credentials with id '%s'", 1762 id); 1763 return NULL; 1764 } 1765 creds = (QCryptoTLSCreds *) 1766 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); 1767 if (!creds) { 1768 error_setg(errp, "Object with id '%s' is not TLS credentials", 1769 id); 1770 return NULL; 1771 } 1772 1773 if (!qcrypto_tls_creds_check_endpoint(creds, 1774 QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, 1775 errp)) { 1776 return NULL; 1777 } 1778 object_ref(obj); 1779 return creds; 1780 } 1781 1782 1783 static QemuOptsList nbd_runtime_opts = { 1784 .name = "nbd", 1785 .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), 1786 .desc = { 1787 { 1788 .name = "host", 1789 .type = QEMU_OPT_STRING, 1790 .help = "TCP host to connect to", 1791 }, 1792 { 1793 .name = "port", 1794 .type = QEMU_OPT_STRING, 1795 .help = "TCP port to connect to", 1796 }, 1797 { 1798 .name = "path", 1799 .type = QEMU_OPT_STRING, 1800 .help = "Unix socket path to connect to", 1801 }, 1802 { 1803 .name = "export", 1804 .type = QEMU_OPT_STRING, 1805 .help = "Name of the NBD export to open", 1806 }, 1807 { 1808 .name = "tls-creds", 1809 .type = QEMU_OPT_STRING, 1810 .help = "ID of the TLS credentials to use", 1811 }, 1812 { 1813 .name = "tls-hostname", 1814 .type = QEMU_OPT_STRING, 1815 .help = "Override hostname for validating TLS x509 certificate", 1816 }, 1817 { 1818 .name = "x-dirty-bitmap", 1819 .type = QEMU_OPT_STRING, 1820 .help = "experimental: expose named dirty bitmap in place of " 1821 "block status", 1822 }, 1823 { 1824 .name = "reconnect-delay", 1825 .type = QEMU_OPT_NUMBER, 1826 .help = "On an unexpected disconnect, the nbd client tries to " 1827 "connect again until succeeding or encountering a serious " 1828 "error. During the first @reconnect-delay seconds, all " 1829 "requests are paused and will be rerun on a successful " 1830 "reconnect. After that time, any delayed requests and all " 1831 "future requests before a successful reconnect will " 1832 "immediately fail. Default 0", 1833 }, 1834 { 1835 .name = "open-timeout", 1836 .type = QEMU_OPT_NUMBER, 1837 .help = "In seconds. If zero, the nbd driver tries the connection " 1838 "only once, and fails to open if the connection fails. " 1839 "If non-zero, the nbd driver will repeat connection " 1840 "attempts until successful or until @open-timeout seconds " 1841 "have elapsed. Default 0", 1842 }, 1843 { /* end of list */ } 1844 }, 1845 }; 1846 1847 static int nbd_process_options(BlockDriverState *bs, QDict *options, 1848 Error **errp) 1849 { 1850 BDRVNBDState *s = bs->opaque; 1851 QemuOpts *opts; 1852 int ret = -EINVAL; 1853 1854 opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); 1855 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1856 goto error; 1857 } 1858 1859 /* Translate @host, @port, and @path to a SocketAddress */ 1860 if (!nbd_process_legacy_socket_options(options, opts, errp)) { 1861 goto error; 1862 } 1863 1864 /* Pop the config into our state object. Exit if invalid. */ 1865 s->saddr = nbd_config(s, options, errp); 1866 if (!s->saddr) { 1867 goto error; 1868 } 1869 1870 s->export = g_strdup(qemu_opt_get(opts, "export")); 1871 if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { 1872 error_setg(errp, "export name too long to send to server"); 1873 goto error; 1874 } 1875 1876 s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); 1877 if (s->tlscredsid) { 1878 s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); 1879 if (!s->tlscreds) { 1880 goto error; 1881 } 1882 1883 s->tlshostname = g_strdup(qemu_opt_get(opts, "tls-hostname")); 1884 if (!s->tlshostname && 1885 s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 1886 s->tlshostname = g_strdup(s->saddr->u.inet.host); 1887 } 1888 } 1889 1890 s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); 1891 if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { 1892 error_setg(errp, "x-dirty-bitmap query too long to send to server"); 1893 goto error; 1894 } 1895 1896 s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); 1897 s->open_timeout = qemu_opt_get_number(opts, "open-timeout", 0); 1898 1899 ret = 0; 1900 1901 error: 1902 qemu_opts_del(opts); 1903 return ret; 1904 } 1905 1906 static int nbd_open(BlockDriverState *bs, QDict *options, int flags, 1907 Error **errp) 1908 { 1909 int ret; 1910 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1911 1912 s->bs = bs; 1913 qemu_mutex_init(&s->requests_lock); 1914 qemu_co_queue_init(&s->free_sema); 1915 qemu_co_mutex_init(&s->send_mutex); 1916 qemu_co_mutex_init(&s->receive_mutex); 1917 1918 if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { 1919 return -EEXIST; 1920 } 1921 1922 ret = nbd_process_options(bs, options, errp); 1923 if (ret < 0) { 1924 goto fail; 1925 } 1926 1927 s->conn = nbd_client_connection_new(s->saddr, true, s->export, 1928 s->x_dirty_bitmap, s->tlscreds, 1929 s->tlshostname); 1930 1931 if (s->open_timeout) { 1932 nbd_client_connection_enable_retry(s->conn); 1933 open_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + 1934 s->open_timeout * NANOSECONDS_PER_SECOND); 1935 } 1936 1937 s->state = NBD_CLIENT_CONNECTING_WAIT; 1938 ret = nbd_do_establish_connection(bs, true, errp); 1939 if (ret < 0) { 1940 goto fail; 1941 } 1942 1943 /* 1944 * The connect attempt is done, so we no longer need this timer. 1945 * Delete it, because we do not want it to be around when this node 1946 * is drained or closed. 1947 */ 1948 open_timer_del(s); 1949 1950 nbd_client_connection_enable_retry(s->conn); 1951 1952 return 0; 1953 1954 fail: 1955 open_timer_del(s); 1956 nbd_clear_bdrvstate(bs); 1957 return ret; 1958 } 1959 1960 static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) 1961 { 1962 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 1963 uint32_t min = s->info.min_block; 1964 uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); 1965 1966 /* 1967 * If the server did not advertise an alignment: 1968 * - a size that is not sector-aligned implies that an alignment 1969 * of 1 can be used to access those tail bytes 1970 * - advertisement of block status requires an alignment of 1, so 1971 * that we don't violate block layer constraints that block 1972 * status is always aligned (as we can't control whether the 1973 * server will report sub-sector extents, such as a hole at EOF 1974 * on an unaligned POSIX file) 1975 * - otherwise, assume the server is so old that we are safer avoiding 1976 * sub-sector requests 1977 */ 1978 if (!min) { 1979 min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || 1980 s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; 1981 } 1982 1983 bs->bl.request_alignment = min; 1984 bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); 1985 bs->bl.max_pwrite_zeroes = max; 1986 bs->bl.max_transfer = max; 1987 1988 /* 1989 * Assume that if the server supports extended headers, it also 1990 * supports unlimited size zero and trim commands. 1991 */ 1992 if (s->info.mode >= NBD_MODE_EXTENDED) { 1993 bs->bl.max_pdiscard = bs->bl.max_pwrite_zeroes = 0; 1994 } 1995 1996 if (s->info.opt_block && 1997 s->info.opt_block > bs->bl.opt_transfer) { 1998 bs->bl.opt_transfer = s->info.opt_block; 1999 } 2000 } 2001 2002 static void nbd_close(BlockDriverState *bs) 2003 { 2004 nbd_client_close(bs); 2005 nbd_clear_bdrvstate(bs); 2006 } 2007 2008 /* 2009 * NBD cannot truncate, but if the caller asks to truncate to the same size, or 2010 * to a smaller size with exact=false, there is no reason to fail the 2011 * operation. 2012 * 2013 * Preallocation mode is ignored since it does not seems useful to fail when 2014 * we never change anything. 2015 */ 2016 static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, 2017 bool exact, PreallocMode prealloc, 2018 BdrvRequestFlags flags, Error **errp) 2019 { 2020 BDRVNBDState *s = bs->opaque; 2021 2022 if (offset != s->info.size && exact) { 2023 error_setg(errp, "Cannot resize NBD nodes"); 2024 return -ENOTSUP; 2025 } 2026 2027 if (offset > s->info.size) { 2028 error_setg(errp, "Cannot grow NBD nodes"); 2029 return -EINVAL; 2030 } 2031 2032 return 0; 2033 } 2034 2035 static int64_t coroutine_fn nbd_co_getlength(BlockDriverState *bs) 2036 { 2037 BDRVNBDState *s = bs->opaque; 2038 2039 return s->info.size; 2040 } 2041 2042 static void nbd_refresh_filename(BlockDriverState *bs) 2043 { 2044 BDRVNBDState *s = bs->opaque; 2045 const char *host = NULL, *port = NULL, *path = NULL; 2046 size_t len = 0; 2047 2048 if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { 2049 const InetSocketAddress *inet = &s->saddr->u.inet; 2050 if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { 2051 host = inet->host; 2052 port = inet->port; 2053 } 2054 } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { 2055 path = s->saddr->u.q_unix.path; 2056 } /* else can't represent as pseudo-filename */ 2057 2058 if (path && s->export) { 2059 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2060 "nbd+unix:///%s?socket=%s", s->export, path); 2061 } else if (path && !s->export) { 2062 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2063 "nbd+unix://?socket=%s", path); 2064 } else if (host && s->export) { 2065 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2066 "nbd://%s:%s/%s", host, port, s->export); 2067 } else if (host && !s->export) { 2068 len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), 2069 "nbd://%s:%s", host, port); 2070 } 2071 if (len >= sizeof(bs->exact_filename)) { 2072 /* Name is too long to represent exactly, so leave it empty. */ 2073 bs->exact_filename[0] = '\0'; 2074 } 2075 } 2076 2077 static char *nbd_dirname(BlockDriverState *bs, Error **errp) 2078 { 2079 /* The generic bdrv_dirname() implementation is able to work out some 2080 * directory name for NBD nodes, but that would be wrong. So far there is no 2081 * specification for how "export paths" would work, so NBD does not have 2082 * directory names. */ 2083 error_setg(errp, "Cannot generate a base directory for NBD nodes"); 2084 return NULL; 2085 } 2086 2087 static const char *const nbd_strong_runtime_opts[] = { 2088 "path", 2089 "host", 2090 "port", 2091 "export", 2092 "tls-creds", 2093 "tls-hostname", 2094 "server.", 2095 2096 NULL 2097 }; 2098 2099 static void nbd_cancel_in_flight(BlockDriverState *bs) 2100 { 2101 BDRVNBDState *s = (BDRVNBDState *)bs->opaque; 2102 2103 reconnect_delay_timer_del(s); 2104 2105 qemu_mutex_lock(&s->requests_lock); 2106 if (s->state == NBD_CLIENT_CONNECTING_WAIT) { 2107 s->state = NBD_CLIENT_CONNECTING_NOWAIT; 2108 } 2109 qemu_mutex_unlock(&s->requests_lock); 2110 2111 nbd_co_establish_connection_cancel(s->conn); 2112 } 2113 2114 static void nbd_attach_aio_context(BlockDriverState *bs, 2115 AioContext *new_context) 2116 { 2117 BDRVNBDState *s = bs->opaque; 2118 2119 /* The open_timer is used only during nbd_open() */ 2120 assert(!s->open_timer); 2121 2122 /* 2123 * The reconnect_delay_timer is scheduled in I/O paths when the 2124 * connection is lost, to cancel the reconnection attempt after a 2125 * given time. Once this attempt is done (successfully or not), 2126 * nbd_reconnect_attempt() ensures the timer is deleted before the 2127 * respective I/O request is resumed. 2128 * Since the AioContext can only be changed when a node is drained, 2129 * the reconnect_delay_timer cannot be active here. 2130 */ 2131 assert(!s->reconnect_delay_timer); 2132 } 2133 2134 static void nbd_detach_aio_context(BlockDriverState *bs) 2135 { 2136 BDRVNBDState *s = bs->opaque; 2137 2138 assert(!s->open_timer); 2139 assert(!s->reconnect_delay_timer); 2140 } 2141 2142 static BlockDriver bdrv_nbd = { 2143 .format_name = "nbd", 2144 .protocol_name = "nbd", 2145 .instance_size = sizeof(BDRVNBDState), 2146 .bdrv_parse_filename = nbd_parse_filename, 2147 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2148 .create_opts = &bdrv_create_opts_simple, 2149 .bdrv_file_open = nbd_open, 2150 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2151 .bdrv_co_preadv = nbd_client_co_preadv, 2152 .bdrv_co_pwritev = nbd_client_co_pwritev, 2153 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2154 .bdrv_close = nbd_close, 2155 .bdrv_co_flush_to_os = nbd_client_co_flush, 2156 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2157 .bdrv_refresh_limits = nbd_refresh_limits, 2158 .bdrv_co_truncate = nbd_co_truncate, 2159 .bdrv_co_getlength = nbd_co_getlength, 2160 .bdrv_refresh_filename = nbd_refresh_filename, 2161 .bdrv_co_block_status = nbd_client_co_block_status, 2162 .bdrv_dirname = nbd_dirname, 2163 .strong_runtime_opts = nbd_strong_runtime_opts, 2164 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2165 2166 .bdrv_attach_aio_context = nbd_attach_aio_context, 2167 .bdrv_detach_aio_context = nbd_detach_aio_context, 2168 }; 2169 2170 static BlockDriver bdrv_nbd_tcp = { 2171 .format_name = "nbd", 2172 .protocol_name = "nbd+tcp", 2173 .instance_size = sizeof(BDRVNBDState), 2174 .bdrv_parse_filename = nbd_parse_filename, 2175 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2176 .create_opts = &bdrv_create_opts_simple, 2177 .bdrv_file_open = nbd_open, 2178 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2179 .bdrv_co_preadv = nbd_client_co_preadv, 2180 .bdrv_co_pwritev = nbd_client_co_pwritev, 2181 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2182 .bdrv_close = nbd_close, 2183 .bdrv_co_flush_to_os = nbd_client_co_flush, 2184 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2185 .bdrv_refresh_limits = nbd_refresh_limits, 2186 .bdrv_co_truncate = nbd_co_truncate, 2187 .bdrv_co_getlength = nbd_co_getlength, 2188 .bdrv_refresh_filename = nbd_refresh_filename, 2189 .bdrv_co_block_status = nbd_client_co_block_status, 2190 .bdrv_dirname = nbd_dirname, 2191 .strong_runtime_opts = nbd_strong_runtime_opts, 2192 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2193 2194 .bdrv_attach_aio_context = nbd_attach_aio_context, 2195 .bdrv_detach_aio_context = nbd_detach_aio_context, 2196 }; 2197 2198 static BlockDriver bdrv_nbd_unix = { 2199 .format_name = "nbd", 2200 .protocol_name = "nbd+unix", 2201 .instance_size = sizeof(BDRVNBDState), 2202 .bdrv_parse_filename = nbd_parse_filename, 2203 .bdrv_co_create_opts = bdrv_co_create_opts_simple, 2204 .create_opts = &bdrv_create_opts_simple, 2205 .bdrv_file_open = nbd_open, 2206 .bdrv_reopen_prepare = nbd_client_reopen_prepare, 2207 .bdrv_co_preadv = nbd_client_co_preadv, 2208 .bdrv_co_pwritev = nbd_client_co_pwritev, 2209 .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, 2210 .bdrv_close = nbd_close, 2211 .bdrv_co_flush_to_os = nbd_client_co_flush, 2212 .bdrv_co_pdiscard = nbd_client_co_pdiscard, 2213 .bdrv_refresh_limits = nbd_refresh_limits, 2214 .bdrv_co_truncate = nbd_co_truncate, 2215 .bdrv_co_getlength = nbd_co_getlength, 2216 .bdrv_refresh_filename = nbd_refresh_filename, 2217 .bdrv_co_block_status = nbd_client_co_block_status, 2218 .bdrv_dirname = nbd_dirname, 2219 .strong_runtime_opts = nbd_strong_runtime_opts, 2220 .bdrv_cancel_in_flight = nbd_cancel_in_flight, 2221 2222 .bdrv_attach_aio_context = nbd_attach_aio_context, 2223 .bdrv_detach_aio_context = nbd_detach_aio_context, 2224 }; 2225 2226 static void bdrv_nbd_init(void) 2227 { 2228 bdrv_register(&bdrv_nbd); 2229 bdrv_register(&bdrv_nbd_tcp); 2230 bdrv_register(&bdrv_nbd_unix); 2231 } 2232 2233 block_init(bdrv_nbd_init); 2234