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