nbd/client: Add x-dirty-bitmap to query bitmap from server
[qemu.git] / block / nbd-client.c
1 /*
2 * QEMU Block driver for NBD
3 *
4 * Copyright (C) 2016 Red Hat, Inc.
5 * Copyright (C) 2008 Bull S.A.S.
6 * Author: Laurent Vivier <Laurent.Vivier@bull.net>
7 *
8 * Some parts:
9 * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a copy
12 * of this software and associated documentation files (the "Software"), to deal
13 * in the Software without restriction, including without limitation the rights
14 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
15 * copies of the Software, and to permit persons to whom the Software is
16 * furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice shall be included in
19 * all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
24 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
27 * THE SOFTWARE.
28 */
29
30 #include "qemu/osdep.h"
31 #include "qapi/error.h"
32 #include "nbd-client.h"
33
34 #define HANDLE_TO_INDEX(bs, handle) ((handle) ^ (uint64_t)(intptr_t)(bs))
35 #define INDEX_TO_HANDLE(bs, index) ((index) ^ (uint64_t)(intptr_t)(bs))
36
37 static void nbd_recv_coroutines_wake_all(NBDClientSession *s)
38 {
39 int i;
40
41 for (i = 0; i < MAX_NBD_REQUESTS; i++) {
42 NBDClientRequest *req = &s->requests[i];
43
44 if (req->coroutine && req->receiving) {
45 aio_co_wake(req->coroutine);
46 }
47 }
48 }
49
50 static void nbd_teardown_connection(BlockDriverState *bs)
51 {
52 NBDClientSession *client = nbd_get_client_session(bs);
53
54 if (!client->ioc) { /* Already closed */
55 return;
56 }
57
58 /* finish any pending coroutines */
59 qio_channel_shutdown(client->ioc,
60 QIO_CHANNEL_SHUTDOWN_BOTH,
61 NULL);
62 BDRV_POLL_WHILE(bs, client->read_reply_co);
63
64 nbd_client_detach_aio_context(bs);
65 object_unref(OBJECT(client->sioc));
66 client->sioc = NULL;
67 object_unref(OBJECT(client->ioc));
68 client->ioc = NULL;
69 }
70
71 static coroutine_fn void nbd_read_reply_entry(void *opaque)
72 {
73 NBDClientSession *s = opaque;
74 uint64_t i;
75 int ret = 0;
76 Error *local_err = NULL;
77
78 while (!s->quit) {
79 assert(s->reply.handle == 0);
80 ret = nbd_receive_reply(s->ioc, &s->reply, &local_err);
81 if (local_err) {
82 error_report_err(local_err);
83 }
84 if (ret <= 0) {
85 break;
86 }
87
88 /* There's no need for a mutex on the receive side, because the
89 * handler acts as a synchronization point and ensures that only
90 * one coroutine is called until the reply finishes.
91 */
92 i = HANDLE_TO_INDEX(s, s->reply.handle);
93 if (i >= MAX_NBD_REQUESTS ||
94 !s->requests[i].coroutine ||
95 !s->requests[i].receiving ||
96 (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply))
97 {
98 break;
99 }
100
101 /* We're woken up again by the request itself. Note that there
102 * is no race between yielding and reentering read_reply_co. This
103 * is because:
104 *
105 * - if the request runs on the same AioContext, it is only
106 * entered after we yield
107 *
108 * - if the request runs on a different AioContext, reentering
109 * read_reply_co happens through a bottom half, which can only
110 * run after we yield.
111 */
112 aio_co_wake(s->requests[i].coroutine);
113 qemu_coroutine_yield();
114 }
115
116 s->quit = true;
117 nbd_recv_coroutines_wake_all(s);
118 s->read_reply_co = NULL;
119 }
120
121 static int nbd_co_send_request(BlockDriverState *bs,
122 NBDRequest *request,
123 QEMUIOVector *qiov)
124 {
125 NBDClientSession *s = nbd_get_client_session(bs);
126 int rc, i;
127
128 qemu_co_mutex_lock(&s->send_mutex);
129 while (s->in_flight == MAX_NBD_REQUESTS) {
130 qemu_co_queue_wait(&s->free_sema, &s->send_mutex);
131 }
132 s->in_flight++;
133
134 for (i = 0; i < MAX_NBD_REQUESTS; i++) {
135 if (s->requests[i].coroutine == NULL) {
136 break;
137 }
138 }
139
140 g_assert(qemu_in_coroutine());
141 assert(i < MAX_NBD_REQUESTS);
142
143 s->requests[i].coroutine = qemu_coroutine_self();
144 s->requests[i].offset = request->from;
145 s->requests[i].receiving = false;
146
147 request->handle = INDEX_TO_HANDLE(s, i);
148
149 if (s->quit) {
150 rc = -EIO;
151 goto err;
152 }
153 if (!s->ioc) {
154 rc = -EPIPE;
155 goto err;
156 }
157
158 if (qiov) {
159 qio_channel_set_cork(s->ioc, true);
160 rc = nbd_send_request(s->ioc, request);
161 if (rc >= 0 && !s->quit) {
162 if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov,
163 NULL) < 0) {
164 rc = -EIO;
165 }
166 } else if (rc >= 0) {
167 rc = -EIO;
168 }
169 qio_channel_set_cork(s->ioc, false);
170 } else {
171 rc = nbd_send_request(s->ioc, request);
172 }
173
174 err:
175 if (rc < 0) {
176 s->quit = true;
177 s->requests[i].coroutine = NULL;
178 s->in_flight--;
179 qemu_co_queue_next(&s->free_sema);
180 }
181 qemu_co_mutex_unlock(&s->send_mutex);
182 return rc;
183 }
184
185 static inline uint16_t payload_advance16(uint8_t **payload)
186 {
187 *payload += 2;
188 return lduw_be_p(*payload - 2);
189 }
190
191 static inline uint32_t payload_advance32(uint8_t **payload)
192 {
193 *payload += 4;
194 return ldl_be_p(*payload - 4);
195 }
196
197 static inline uint64_t payload_advance64(uint8_t **payload)
198 {
199 *payload += 8;
200 return ldq_be_p(*payload - 8);
201 }
202
203 static int nbd_parse_offset_hole_payload(NBDStructuredReplyChunk *chunk,
204 uint8_t *payload, uint64_t orig_offset,
205 QEMUIOVector *qiov, Error **errp)
206 {
207 uint64_t offset;
208 uint32_t hole_size;
209
210 if (chunk->length != sizeof(offset) + sizeof(hole_size)) {
211 error_setg(errp, "Protocol error: invalid payload for "
212 "NBD_REPLY_TYPE_OFFSET_HOLE");
213 return -EINVAL;
214 }
215
216 offset = payload_advance64(&payload);
217 hole_size = payload_advance32(&payload);
218
219 if (!hole_size || offset < orig_offset || hole_size > qiov->size ||
220 offset > orig_offset + qiov->size - hole_size) {
221 error_setg(errp, "Protocol error: server sent chunk exceeding requested"
222 " region");
223 return -EINVAL;
224 }
225
226 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size);
227
228 return 0;
229 }
230
231 /* nbd_parse_blockstatus_payload
232 * support only one extent in reply and only for
233 * base:allocation context
234 */
235 static int nbd_parse_blockstatus_payload(NBDClientSession *client,
236 NBDStructuredReplyChunk *chunk,
237 uint8_t *payload, uint64_t orig_length,
238 NBDExtent *extent, Error **errp)
239 {
240 uint32_t context_id;
241
242 if (chunk->length != sizeof(context_id) + sizeof(*extent)) {
243 error_setg(errp, "Protocol error: invalid payload for "
244 "NBD_REPLY_TYPE_BLOCK_STATUS");
245 return -EINVAL;
246 }
247
248 context_id = payload_advance32(&payload);
249 if (client->info.meta_base_allocation_id != context_id) {
250 error_setg(errp, "Protocol error: unexpected context id %d for "
251 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context "
252 "id is %d", context_id,
253 client->info.meta_base_allocation_id);
254 return -EINVAL;
255 }
256
257 extent->length = payload_advance32(&payload);
258 extent->flags = payload_advance32(&payload);
259
260 if (extent->length == 0 ||
261 (client->info.min_block && !QEMU_IS_ALIGNED(extent->length,
262 client->info.min_block))) {
263 error_setg(errp, "Protocol error: server sent status chunk with "
264 "invalid length");
265 return -EINVAL;
266 }
267
268 /* The server is allowed to send us extra information on the final
269 * extent; just clamp it to the length we requested. */
270 if (extent->length > orig_length) {
271 extent->length = orig_length;
272 }
273
274 return 0;
275 }
276
277 /* nbd_parse_error_payload
278 * on success @errp contains message describing nbd error reply
279 */
280 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk,
281 uint8_t *payload, int *request_ret,
282 Error **errp)
283 {
284 uint32_t error;
285 uint16_t message_size;
286
287 assert(chunk->type & (1 << 15));
288
289 if (chunk->length < sizeof(error) + sizeof(message_size)) {
290 error_setg(errp,
291 "Protocol error: invalid payload for structured error");
292 return -EINVAL;
293 }
294
295 error = nbd_errno_to_system_errno(payload_advance32(&payload));
296 if (error == 0) {
297 error_setg(errp, "Protocol error: server sent structured error chunk "
298 "with error = 0");
299 return -EINVAL;
300 }
301
302 *request_ret = -error;
303 message_size = payload_advance16(&payload);
304
305 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) {
306 error_setg(errp, "Protocol error: server sent structured error chunk "
307 "with incorrect message size");
308 return -EINVAL;
309 }
310
311 /* TODO: Add a trace point to mention the server complaint */
312
313 /* TODO handle ERROR_OFFSET */
314
315 return 0;
316 }
317
318 static int nbd_co_receive_offset_data_payload(NBDClientSession *s,
319 uint64_t orig_offset,
320 QEMUIOVector *qiov, Error **errp)
321 {
322 QEMUIOVector sub_qiov;
323 uint64_t offset;
324 size_t data_size;
325 int ret;
326 NBDStructuredReplyChunk *chunk = &s->reply.structured;
327
328 assert(nbd_reply_is_structured(&s->reply));
329
330 /* The NBD spec requires at least one byte of payload */
331 if (chunk->length <= sizeof(offset)) {
332 error_setg(errp, "Protocol error: invalid payload for "
333 "NBD_REPLY_TYPE_OFFSET_DATA");
334 return -EINVAL;
335 }
336
337 if (nbd_read(s->ioc, &offset, sizeof(offset), errp) < 0) {
338 return -EIO;
339 }
340 be64_to_cpus(&offset);
341
342 data_size = chunk->length - sizeof(offset);
343 assert(data_size);
344 if (offset < orig_offset || data_size > qiov->size ||
345 offset > orig_offset + qiov->size - data_size) {
346 error_setg(errp, "Protocol error: server sent chunk exceeding requested"
347 " region");
348 return -EINVAL;
349 }
350
351 qemu_iovec_init(&sub_qiov, qiov->niov);
352 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size);
353 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp);
354 qemu_iovec_destroy(&sub_qiov);
355
356 return ret < 0 ? -EIO : 0;
357 }
358
359 #define NBD_MAX_MALLOC_PAYLOAD 1000
360 /* nbd_co_receive_structured_payload
361 */
362 static coroutine_fn int nbd_co_receive_structured_payload(
363 NBDClientSession *s, void **payload, Error **errp)
364 {
365 int ret;
366 uint32_t len;
367
368 assert(nbd_reply_is_structured(&s->reply));
369
370 len = s->reply.structured.length;
371
372 if (len == 0) {
373 return 0;
374 }
375
376 if (payload == NULL) {
377 error_setg(errp, "Unexpected structured payload");
378 return -EINVAL;
379 }
380
381 if (len > NBD_MAX_MALLOC_PAYLOAD) {
382 error_setg(errp, "Payload too large");
383 return -EINVAL;
384 }
385
386 *payload = g_new(char, len);
387 ret = nbd_read(s->ioc, *payload, len, errp);
388 if (ret < 0) {
389 g_free(*payload);
390 *payload = NULL;
391 return ret;
392 }
393
394 return 0;
395 }
396
397 /* nbd_co_do_receive_one_chunk
398 * for simple reply:
399 * set request_ret to received reply error
400 * if qiov is not NULL: read payload to @qiov
401 * for structured reply chunk:
402 * if error chunk: read payload, set @request_ret, do not set @payload
403 * else if offset_data chunk: read payload data to @qiov, do not set @payload
404 * else: read payload to @payload
405 *
406 * If function fails, @errp contains corresponding error message, and the
407 * connection with the server is suspect. If it returns 0, then the
408 * transaction succeeded (although @request_ret may be a negative errno
409 * corresponding to the server's error reply), and errp is unchanged.
410 */
411 static coroutine_fn int nbd_co_do_receive_one_chunk(
412 NBDClientSession *s, uint64_t handle, bool only_structured,
413 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp)
414 {
415 int ret;
416 int i = HANDLE_TO_INDEX(s, handle);
417 void *local_payload = NULL;
418 NBDStructuredReplyChunk *chunk;
419
420 if (payload) {
421 *payload = NULL;
422 }
423 *request_ret = 0;
424
425 /* Wait until we're woken up by nbd_read_reply_entry. */
426 s->requests[i].receiving = true;
427 qemu_coroutine_yield();
428 s->requests[i].receiving = false;
429 if (!s->ioc || s->quit) {
430 error_setg(errp, "Connection closed");
431 return -EIO;
432 }
433
434 assert(s->reply.handle == handle);
435
436 if (nbd_reply_is_simple(&s->reply)) {
437 if (only_structured) {
438 error_setg(errp, "Protocol error: simple reply when structured "
439 "reply chunk was expected");
440 return -EINVAL;
441 }
442
443 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error);
444 if (*request_ret < 0 || !qiov) {
445 return 0;
446 }
447
448 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov,
449 errp) < 0 ? -EIO : 0;
450 }
451
452 /* handle structured reply chunk */
453 assert(s->info.structured_reply);
454 chunk = &s->reply.structured;
455
456 if (chunk->type == NBD_REPLY_TYPE_NONE) {
457 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) {
458 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without"
459 " NBD_REPLY_FLAG_DONE flag set");
460 return -EINVAL;
461 }
462 if (chunk->length) {
463 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with"
464 " nonzero length");
465 return -EINVAL;
466 }
467 return 0;
468 }
469
470 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) {
471 if (!qiov) {
472 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk");
473 return -EINVAL;
474 }
475
476 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset,
477 qiov, errp);
478 }
479
480 if (nbd_reply_type_is_error(chunk->type)) {
481 payload = &local_payload;
482 }
483
484 ret = nbd_co_receive_structured_payload(s, payload, errp);
485 if (ret < 0) {
486 return ret;
487 }
488
489 if (nbd_reply_type_is_error(chunk->type)) {
490 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp);
491 g_free(local_payload);
492 return ret;
493 }
494
495 return 0;
496 }
497
498 /* nbd_co_receive_one_chunk
499 * Read reply, wake up read_reply_co and set s->quit if needed.
500 * Return value is a fatal error code or normal nbd reply error code
501 */
502 static coroutine_fn int nbd_co_receive_one_chunk(
503 NBDClientSession *s, uint64_t handle, bool only_structured,
504 QEMUIOVector *qiov, NBDReply *reply, void **payload, Error **errp)
505 {
506 int request_ret;
507 int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured,
508 &request_ret, qiov, payload, errp);
509
510 if (ret < 0) {
511 s->quit = true;
512 } else {
513 /* For assert at loop start in nbd_read_reply_entry */
514 if (reply) {
515 *reply = s->reply;
516 }
517 s->reply.handle = 0;
518 ret = request_ret;
519 }
520
521 if (s->read_reply_co) {
522 aio_co_wake(s->read_reply_co);
523 }
524
525 return ret;
526 }
527
528 typedef struct NBDReplyChunkIter {
529 int ret;
530 bool fatal;
531 Error *err;
532 bool done, only_structured;
533 } NBDReplyChunkIter;
534
535 static void nbd_iter_error(NBDReplyChunkIter *iter, bool fatal,
536 int ret, Error **local_err)
537 {
538 assert(ret < 0);
539
540 if ((fatal && !iter->fatal) || iter->ret == 0) {
541 if (iter->ret != 0) {
542 error_free(iter->err);
543 iter->err = NULL;
544 }
545 iter->fatal = fatal;
546 iter->ret = ret;
547 error_propagate(&iter->err, *local_err);
548 } else {
549 error_free(*local_err);
550 }
551
552 *local_err = NULL;
553 }
554
555 /* NBD_FOREACH_REPLY_CHUNK
556 */
557 #define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \
558 qiov, reply, payload) \
559 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \
560 nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);)
561
562 /* nbd_reply_chunk_iter_receive
563 */
564 static bool nbd_reply_chunk_iter_receive(NBDClientSession *s,
565 NBDReplyChunkIter *iter,
566 uint64_t handle,
567 QEMUIOVector *qiov, NBDReply *reply,
568 void **payload)
569 {
570 int ret;
571 NBDReply local_reply;
572 NBDStructuredReplyChunk *chunk;
573 Error *local_err = NULL;
574 if (s->quit) {
575 error_setg(&local_err, "Connection closed");
576 nbd_iter_error(iter, true, -EIO, &local_err);
577 goto break_loop;
578 }
579
580 if (iter->done) {
581 /* Previous iteration was last. */
582 goto break_loop;
583 }
584
585 if (reply == NULL) {
586 reply = &local_reply;
587 }
588
589 ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured,
590 qiov, reply, payload, &local_err);
591 if (ret < 0) {
592 /* If it is a fatal error s->quit is set by nbd_co_receive_one_chunk */
593 nbd_iter_error(iter, s->quit, ret, &local_err);
594 }
595
596 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */
597 if (nbd_reply_is_simple(&s->reply) || s->quit) {
598 goto break_loop;
599 }
600
601 chunk = &reply->structured;
602 iter->only_structured = true;
603
604 if (chunk->type == NBD_REPLY_TYPE_NONE) {
605 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */
606 assert(chunk->flags & NBD_REPLY_FLAG_DONE);
607 goto break_loop;
608 }
609
610 if (chunk->flags & NBD_REPLY_FLAG_DONE) {
611 /* This iteration is last. */
612 iter->done = true;
613 }
614
615 /* Execute the loop body */
616 return true;
617
618 break_loop:
619 s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL;
620
621 qemu_co_mutex_lock(&s->send_mutex);
622 s->in_flight--;
623 qemu_co_queue_next(&s->free_sema);
624 qemu_co_mutex_unlock(&s->send_mutex);
625
626 return false;
627 }
628
629 static int nbd_co_receive_return_code(NBDClientSession *s, uint64_t handle,
630 Error **errp)
631 {
632 NBDReplyChunkIter iter;
633
634 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) {
635 /* nbd_reply_chunk_iter_receive does all the work */
636 }
637
638 error_propagate(errp, iter.err);
639 return iter.ret;
640 }
641
642 static int nbd_co_receive_cmdread_reply(NBDClientSession *s, uint64_t handle,
643 uint64_t offset, QEMUIOVector *qiov,
644 Error **errp)
645 {
646 NBDReplyChunkIter iter;
647 NBDReply reply;
648 void *payload = NULL;
649 Error *local_err = NULL;
650
651 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply,
652 qiov, &reply, &payload)
653 {
654 int ret;
655 NBDStructuredReplyChunk *chunk = &reply.structured;
656
657 assert(nbd_reply_is_structured(&reply));
658
659 switch (chunk->type) {
660 case NBD_REPLY_TYPE_OFFSET_DATA:
661 /* special cased in nbd_co_receive_one_chunk, data is already
662 * in qiov */
663 break;
664 case NBD_REPLY_TYPE_OFFSET_HOLE:
665 ret = nbd_parse_offset_hole_payload(&reply.structured, payload,
666 offset, qiov, &local_err);
667 if (ret < 0) {
668 s->quit = true;
669 nbd_iter_error(&iter, true, ret, &local_err);
670 }
671 break;
672 default:
673 if (!nbd_reply_type_is_error(chunk->type)) {
674 /* not allowed reply type */
675 s->quit = true;
676 error_setg(&local_err,
677 "Unexpected reply type: %d (%s) for CMD_READ",
678 chunk->type, nbd_reply_type_lookup(chunk->type));
679 nbd_iter_error(&iter, true, -EINVAL, &local_err);
680 }
681 }
682
683 g_free(payload);
684 payload = NULL;
685 }
686
687 error_propagate(errp, iter.err);
688 return iter.ret;
689 }
690
691 static int nbd_co_receive_blockstatus_reply(NBDClientSession *s,
692 uint64_t handle, uint64_t length,
693 NBDExtent *extent, Error **errp)
694 {
695 NBDReplyChunkIter iter;
696 NBDReply reply;
697 void *payload = NULL;
698 Error *local_err = NULL;
699 bool received = false;
700
701 assert(!extent->length);
702 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply,
703 NULL, &reply, &payload)
704 {
705 int ret;
706 NBDStructuredReplyChunk *chunk = &reply.structured;
707
708 assert(nbd_reply_is_structured(&reply));
709
710 switch (chunk->type) {
711 case NBD_REPLY_TYPE_BLOCK_STATUS:
712 if (received) {
713 s->quit = true;
714 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply");
715 nbd_iter_error(&iter, true, -EINVAL, &local_err);
716 }
717 received = true;
718
719 ret = nbd_parse_blockstatus_payload(s, &reply.structured,
720 payload, length, extent,
721 &local_err);
722 if (ret < 0) {
723 s->quit = true;
724 nbd_iter_error(&iter, true, ret, &local_err);
725 }
726 break;
727 default:
728 if (!nbd_reply_type_is_error(chunk->type)) {
729 s->quit = true;
730 error_setg(&local_err,
731 "Unexpected reply type: %d (%s) "
732 "for CMD_BLOCK_STATUS",
733 chunk->type, nbd_reply_type_lookup(chunk->type));
734 nbd_iter_error(&iter, true, -EINVAL, &local_err);
735 }
736 }
737
738 g_free(payload);
739 payload = NULL;
740 }
741
742 if (!extent->length && !iter.err) {
743 error_setg(&iter.err,
744 "Server did not reply with any status extents");
745 if (!iter.ret) {
746 iter.ret = -EIO;
747 }
748 }
749 error_propagate(errp, iter.err);
750 return iter.ret;
751 }
752
753 static int nbd_co_request(BlockDriverState *bs, NBDRequest *request,
754 QEMUIOVector *write_qiov)
755 {
756 int ret;
757 Error *local_err = NULL;
758 NBDClientSession *client = nbd_get_client_session(bs);
759
760 assert(request->type != NBD_CMD_READ);
761 if (write_qiov) {
762 assert(request->type == NBD_CMD_WRITE);
763 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov));
764 } else {
765 assert(request->type != NBD_CMD_WRITE);
766 }
767 ret = nbd_co_send_request(bs, request, write_qiov);
768 if (ret < 0) {
769 return ret;
770 }
771
772 ret = nbd_co_receive_return_code(client, request->handle, &local_err);
773 if (local_err) {
774 error_report_err(local_err);
775 }
776 return ret;
777 }
778
779 int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,
780 uint64_t bytes, QEMUIOVector *qiov, int flags)
781 {
782 int ret;
783 Error *local_err = NULL;
784 NBDClientSession *client = nbd_get_client_session(bs);
785 NBDRequest request = {
786 .type = NBD_CMD_READ,
787 .from = offset,
788 .len = bytes,
789 };
790
791 assert(bytes <= NBD_MAX_BUFFER_SIZE);
792 assert(!flags);
793
794 if (!bytes) {
795 return 0;
796 }
797 ret = nbd_co_send_request(bs, &request, NULL);
798 if (ret < 0) {
799 return ret;
800 }
801
802 ret = nbd_co_receive_cmdread_reply(client, request.handle, offset, qiov,
803 &local_err);
804 if (local_err) {
805 error_report_err(local_err);
806 }
807 return ret;
808 }
809
810 int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,
811 uint64_t bytes, QEMUIOVector *qiov, int flags)
812 {
813 NBDClientSession *client = nbd_get_client_session(bs);
814 NBDRequest request = {
815 .type = NBD_CMD_WRITE,
816 .from = offset,
817 .len = bytes,
818 };
819
820 assert(!(client->info.flags & NBD_FLAG_READ_ONLY));
821 if (flags & BDRV_REQ_FUA) {
822 assert(client->info.flags & NBD_FLAG_SEND_FUA);
823 request.flags |= NBD_CMD_FLAG_FUA;
824 }
825
826 assert(bytes <= NBD_MAX_BUFFER_SIZE);
827
828 if (!bytes) {
829 return 0;
830 }
831 return nbd_co_request(bs, &request, qiov);
832 }
833
834 int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
835 int bytes, BdrvRequestFlags flags)
836 {
837 NBDClientSession *client = nbd_get_client_session(bs);
838 NBDRequest request = {
839 .type = NBD_CMD_WRITE_ZEROES,
840 .from = offset,
841 .len = bytes,
842 };
843
844 assert(!(client->info.flags & NBD_FLAG_READ_ONLY));
845 if (!(client->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) {
846 return -ENOTSUP;
847 }
848
849 if (flags & BDRV_REQ_FUA) {
850 assert(client->info.flags & NBD_FLAG_SEND_FUA);
851 request.flags |= NBD_CMD_FLAG_FUA;
852 }
853 if (!(flags & BDRV_REQ_MAY_UNMAP)) {
854 request.flags |= NBD_CMD_FLAG_NO_HOLE;
855 }
856
857 if (!bytes) {
858 return 0;
859 }
860 return nbd_co_request(bs, &request, NULL);
861 }
862
863 int nbd_client_co_flush(BlockDriverState *bs)
864 {
865 NBDClientSession *client = nbd_get_client_session(bs);
866 NBDRequest request = { .type = NBD_CMD_FLUSH };
867
868 if (!(client->info.flags & NBD_FLAG_SEND_FLUSH)) {
869 return 0;
870 }
871
872 request.from = 0;
873 request.len = 0;
874
875 return nbd_co_request(bs, &request, NULL);
876 }
877
878 int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
879 {
880 NBDClientSession *client = nbd_get_client_session(bs);
881 NBDRequest request = {
882 .type = NBD_CMD_TRIM,
883 .from = offset,
884 .len = bytes,
885 };
886
887 assert(!(client->info.flags & NBD_FLAG_READ_ONLY));
888 if (!(client->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) {
889 return 0;
890 }
891
892 return nbd_co_request(bs, &request, NULL);
893 }
894
895 int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs,
896 bool want_zero,
897 int64_t offset, int64_t bytes,
898 int64_t *pnum, int64_t *map,
899 BlockDriverState **file)
900 {
901 int64_t ret;
902 NBDExtent extent = { 0 };
903 NBDClientSession *client = nbd_get_client_session(bs);
904 Error *local_err = NULL;
905
906 NBDRequest request = {
907 .type = NBD_CMD_BLOCK_STATUS,
908 .from = offset,
909 .len = MIN(MIN_NON_ZERO(QEMU_ALIGN_DOWN(INT_MAX,
910 bs->bl.request_alignment),
911 client->info.max_block), bytes),
912 .flags = NBD_CMD_FLAG_REQ_ONE,
913 };
914
915 if (!client->info.base_allocation) {
916 *pnum = bytes;
917 return BDRV_BLOCK_DATA;
918 }
919
920 ret = nbd_co_send_request(bs, &request, NULL);
921 if (ret < 0) {
922 return ret;
923 }
924
925 ret = nbd_co_receive_blockstatus_reply(client, request.handle, bytes,
926 &extent, &local_err);
927 if (local_err) {
928 error_report_err(local_err);
929 }
930 if (ret < 0) {
931 return ret;
932 }
933
934 assert(extent.length);
935 *pnum = extent.length;
936 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) |
937 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0);
938 }
939
940 void nbd_client_detach_aio_context(BlockDriverState *bs)
941 {
942 NBDClientSession *client = nbd_get_client_session(bs);
943 qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc));
944 }
945
946 void nbd_client_attach_aio_context(BlockDriverState *bs,
947 AioContext *new_context)
948 {
949 NBDClientSession *client = nbd_get_client_session(bs);
950 qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), new_context);
951 aio_co_schedule(new_context, client->read_reply_co);
952 }
953
954 void nbd_client_close(BlockDriverState *bs)
955 {
956 NBDClientSession *client = nbd_get_client_session(bs);
957 NBDRequest request = { .type = NBD_CMD_DISC };
958
959 if (client->ioc == NULL) {
960 return;
961 }
962
963 nbd_send_request(client->ioc, &request);
964
965 nbd_teardown_connection(bs);
966 }
967
968 int nbd_client_init(BlockDriverState *bs,
969 QIOChannelSocket *sioc,
970 const char *export,
971 QCryptoTLSCreds *tlscreds,
972 const char *hostname,
973 const char *x_dirty_bitmap,
974 Error **errp)
975 {
976 NBDClientSession *client = nbd_get_client_session(bs);
977 int ret;
978
979 /* NBD handshake */
980 logout("session init %s\n", export);
981 qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL);
982
983 client->info.request_sizes = true;
984 client->info.structured_reply = true;
985 client->info.base_allocation = true;
986 client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);
987 ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
988 tlscreds, hostname,
989 &client->ioc, &client->info, errp);
990 g_free(client->info.x_dirty_bitmap);
991 if (ret < 0) {
992 logout("Failed to negotiate with the NBD server\n");
993 return ret;
994 }
995 if (client->info.flags & NBD_FLAG_READ_ONLY &&
996 !bdrv_is_read_only(bs)) {
997 error_setg(errp,
998 "request for write access conflicts with read-only export");
999 return -EACCES;
1000 }
1001 if (client->info.flags & NBD_FLAG_SEND_FUA) {
1002 bs->supported_write_flags = BDRV_REQ_FUA;
1003 bs->supported_zero_flags |= BDRV_REQ_FUA;
1004 }
1005 if (client->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) {
1006 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP;
1007 }
1008
1009 qemu_co_mutex_init(&client->send_mutex);
1010 qemu_co_queue_init(&client->free_sema);
1011 client->sioc = sioc;
1012 object_ref(OBJECT(client->sioc));
1013
1014 if (!client->ioc) {
1015 client->ioc = QIO_CHANNEL(sioc);
1016 object_ref(OBJECT(client->ioc));
1017 }
1018
1019 /* Now that we're connected, set the socket to be non-blocking and
1020 * kick the reply mechanism. */
1021 qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
1022 client->read_reply_co = qemu_coroutine_create(nbd_read_reply_entry, client);
1023 nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
1024
1025 logout("Established connection with NBD server\n");
1026 return 0;
1027 }