tcg: Implement tcg_gen_gvec_3i()
[qemu/ar7.git] / block / nbd-client.c
blob790ecc1ee1cb346358122afb6769529ae7a30012
1 /*
2 * QEMU Block driver for NBD
4 * Copyright (C) 2016 Red Hat, Inc.
5 * Copyright (C) 2008 Bull S.A.S.
6 * Author: Laurent Vivier <Laurent.Vivier@bull.net>
8 * Some parts:
9 * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
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:
18 * The above copyright notice and this permission notice shall be included in
19 * all copies or substantial portions of the Software.
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.
30 #include "qemu/osdep.h"
32 #include "trace.h"
33 #include "qapi/error.h"
34 #include "nbd-client.h"
36 #define HANDLE_TO_INDEX(bs, handle) ((handle) ^ (uint64_t)(intptr_t)(bs))
37 #define INDEX_TO_HANDLE(bs, index) ((index) ^ (uint64_t)(intptr_t)(bs))
39 static void nbd_recv_coroutines_wake_all(NBDClientSession *s)
41 int i;
43 for (i = 0; i < MAX_NBD_REQUESTS; i++) {
44 NBDClientRequest *req = &s->requests[i];
46 if (req->coroutine && req->receiving) {
47 aio_co_wake(req->coroutine);
52 static void nbd_teardown_connection(BlockDriverState *bs)
54 NBDClientSession *client = nbd_get_client_session(bs);
56 assert(client->ioc);
58 /* finish any pending coroutines */
59 qio_channel_shutdown(client->ioc,
60 QIO_CHANNEL_SHUTDOWN_BOTH,
61 NULL);
62 BDRV_POLL_WHILE(bs, client->connection_co);
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;
71 static coroutine_fn void nbd_connection_entry(void *opaque)
73 NBDClientSession *s = opaque;
74 uint64_t i;
75 int ret = 0;
76 Error *local_err = NULL;
78 while (!s->quit) {
80 * The NBD client can only really be considered idle when it has
81 * yielded from qio_channel_readv_all_eof(), waiting for data. This is
82 * the point where the additional scheduled coroutine entry happens
83 * after nbd_client_attach_aio_context().
85 * Therefore we keep an additional in_flight reference all the time and
86 * only drop it temporarily here.
88 assert(s->reply.handle == 0);
89 ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, &local_err);
91 if (local_err) {
92 trace_nbd_read_reply_entry_fail(ret, error_get_pretty(local_err));
93 error_free(local_err);
95 if (ret <= 0) {
96 break;
99 /* There's no need for a mutex on the receive side, because the
100 * handler acts as a synchronization point and ensures that only
101 * one coroutine is called until the reply finishes.
103 i = HANDLE_TO_INDEX(s, s->reply.handle);
104 if (i >= MAX_NBD_REQUESTS ||
105 !s->requests[i].coroutine ||
106 !s->requests[i].receiving ||
107 (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply))
109 break;
112 /* We're woken up again by the request itself. Note that there
113 * is no race between yielding and reentering connection_co. This
114 * is because:
116 * - if the request runs on the same AioContext, it is only
117 * entered after we yield
119 * - if the request runs on a different AioContext, reentering
120 * connection_co happens through a bottom half, which can only
121 * run after we yield.
123 aio_co_wake(s->requests[i].coroutine);
124 qemu_coroutine_yield();
127 s->quit = true;
128 nbd_recv_coroutines_wake_all(s);
129 bdrv_dec_in_flight(s->bs);
131 s->connection_co = NULL;
132 aio_wait_kick();
135 static int nbd_co_send_request(BlockDriverState *bs,
136 NBDRequest *request,
137 QEMUIOVector *qiov)
139 NBDClientSession *s = nbd_get_client_session(bs);
140 int rc, i;
142 qemu_co_mutex_lock(&s->send_mutex);
143 while (s->in_flight == MAX_NBD_REQUESTS) {
144 qemu_co_queue_wait(&s->free_sema, &s->send_mutex);
146 s->in_flight++;
148 for (i = 0; i < MAX_NBD_REQUESTS; i++) {
149 if (s->requests[i].coroutine == NULL) {
150 break;
154 g_assert(qemu_in_coroutine());
155 assert(i < MAX_NBD_REQUESTS);
157 s->requests[i].coroutine = qemu_coroutine_self();
158 s->requests[i].offset = request->from;
159 s->requests[i].receiving = false;
161 request->handle = INDEX_TO_HANDLE(s, i);
163 if (s->quit) {
164 rc = -EIO;
165 goto err;
167 assert(s->ioc);
169 if (qiov) {
170 qio_channel_set_cork(s->ioc, true);
171 rc = nbd_send_request(s->ioc, request);
172 if (rc >= 0 && !s->quit) {
173 if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov,
174 NULL) < 0) {
175 rc = -EIO;
177 } else if (rc >= 0) {
178 rc = -EIO;
180 qio_channel_set_cork(s->ioc, false);
181 } else {
182 rc = nbd_send_request(s->ioc, request);
185 err:
186 if (rc < 0) {
187 s->quit = true;
188 s->requests[i].coroutine = NULL;
189 s->in_flight--;
190 qemu_co_queue_next(&s->free_sema);
192 qemu_co_mutex_unlock(&s->send_mutex);
193 return rc;
196 static inline uint16_t payload_advance16(uint8_t **payload)
198 *payload += 2;
199 return lduw_be_p(*payload - 2);
202 static inline uint32_t payload_advance32(uint8_t **payload)
204 *payload += 4;
205 return ldl_be_p(*payload - 4);
208 static inline uint64_t payload_advance64(uint8_t **payload)
210 *payload += 8;
211 return ldq_be_p(*payload - 8);
214 static int nbd_parse_offset_hole_payload(NBDClientSession *client,
215 NBDStructuredReplyChunk *chunk,
216 uint8_t *payload, uint64_t orig_offset,
217 QEMUIOVector *qiov, Error **errp)
219 uint64_t offset;
220 uint32_t hole_size;
222 if (chunk->length != sizeof(offset) + sizeof(hole_size)) {
223 error_setg(errp, "Protocol error: invalid payload for "
224 "NBD_REPLY_TYPE_OFFSET_HOLE");
225 return -EINVAL;
228 offset = payload_advance64(&payload);
229 hole_size = payload_advance32(&payload);
231 if (!hole_size || offset < orig_offset || hole_size > qiov->size ||
232 offset > orig_offset + qiov->size - hole_size) {
233 error_setg(errp, "Protocol error: server sent chunk exceeding requested"
234 " region");
235 return -EINVAL;
237 if (client->info.min_block &&
238 !QEMU_IS_ALIGNED(hole_size, client->info.min_block)) {
239 trace_nbd_structured_read_compliance("hole");
242 qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size);
244 return 0;
247 /* nbd_parse_blockstatus_payload
248 * Based on our request, we expect only one extent in reply, for the
249 * base:allocation context.
251 static int nbd_parse_blockstatus_payload(NBDClientSession *client,
252 NBDStructuredReplyChunk *chunk,
253 uint8_t *payload, uint64_t orig_length,
254 NBDExtent *extent, Error **errp)
256 uint32_t context_id;
258 /* The server succeeded, so it must have sent [at least] one extent */
259 if (chunk->length < sizeof(context_id) + sizeof(*extent)) {
260 error_setg(errp, "Protocol error: invalid payload for "
261 "NBD_REPLY_TYPE_BLOCK_STATUS");
262 return -EINVAL;
265 context_id = payload_advance32(&payload);
266 if (client->info.context_id != context_id) {
267 error_setg(errp, "Protocol error: unexpected context id %d for "
268 "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context "
269 "id is %d", context_id,
270 client->info.context_id);
271 return -EINVAL;
274 extent->length = payload_advance32(&payload);
275 extent->flags = payload_advance32(&payload);
277 if (extent->length == 0) {
278 error_setg(errp, "Protocol error: server sent status chunk with "
279 "zero length");
280 return -EINVAL;
284 * A server sending unaligned block status is in violation of the
285 * protocol, but as qemu-nbd 3.1 is such a server (at least for
286 * POSIX files that are not a multiple of 512 bytes, since qemu
287 * rounds files up to 512-byte multiples but lseek(SEEK_HOLE)
288 * still sees an implicit hole beyond the real EOF), it's nicer to
289 * work around the misbehaving server. If the request included
290 * more than the final unaligned block, truncate it back to an
291 * aligned result; if the request was only the final block, round
292 * up to the full block and change the status to fully-allocated
293 * (always a safe status, even if it loses information).
295 if (client->info.min_block && !QEMU_IS_ALIGNED(extent->length,
296 client->info.min_block)) {
297 trace_nbd_parse_blockstatus_compliance("extent length is unaligned");
298 if (extent->length > client->info.min_block) {
299 extent->length = QEMU_ALIGN_DOWN(extent->length,
300 client->info.min_block);
301 } else {
302 extent->length = client->info.min_block;
303 extent->flags = 0;
308 * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have
309 * sent us any more than one extent, nor should it have included
310 * status beyond our request in that extent. However, it's easy
311 * enough to ignore the server's noncompliance without killing the
312 * connection; just ignore trailing extents, and clamp things to
313 * the length of our request.
315 if (chunk->length > sizeof(context_id) + sizeof(*extent)) {
316 trace_nbd_parse_blockstatus_compliance("more than one extent");
318 if (extent->length > orig_length) {
319 extent->length = orig_length;
320 trace_nbd_parse_blockstatus_compliance("extent length too large");
323 return 0;
326 /* nbd_parse_error_payload
327 * on success @errp contains message describing nbd error reply
329 static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk,
330 uint8_t *payload, int *request_ret,
331 Error **errp)
333 uint32_t error;
334 uint16_t message_size;
336 assert(chunk->type & (1 << 15));
338 if (chunk->length < sizeof(error) + sizeof(message_size)) {
339 error_setg(errp,
340 "Protocol error: invalid payload for structured error");
341 return -EINVAL;
344 error = nbd_errno_to_system_errno(payload_advance32(&payload));
345 if (error == 0) {
346 error_setg(errp, "Protocol error: server sent structured error chunk "
347 "with error = 0");
348 return -EINVAL;
351 *request_ret = -error;
352 message_size = payload_advance16(&payload);
354 if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) {
355 error_setg(errp, "Protocol error: server sent structured error chunk "
356 "with incorrect message size");
357 return -EINVAL;
360 /* TODO: Add a trace point to mention the server complaint */
362 /* TODO handle ERROR_OFFSET */
364 return 0;
367 static int nbd_co_receive_offset_data_payload(NBDClientSession *s,
368 uint64_t orig_offset,
369 QEMUIOVector *qiov, Error **errp)
371 QEMUIOVector sub_qiov;
372 uint64_t offset;
373 size_t data_size;
374 int ret;
375 NBDStructuredReplyChunk *chunk = &s->reply.structured;
377 assert(nbd_reply_is_structured(&s->reply));
379 /* The NBD spec requires at least one byte of payload */
380 if (chunk->length <= sizeof(offset)) {
381 error_setg(errp, "Protocol error: invalid payload for "
382 "NBD_REPLY_TYPE_OFFSET_DATA");
383 return -EINVAL;
386 if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) {
387 return -EIO;
390 data_size = chunk->length - sizeof(offset);
391 assert(data_size);
392 if (offset < orig_offset || data_size > qiov->size ||
393 offset > orig_offset + qiov->size - data_size) {
394 error_setg(errp, "Protocol error: server sent chunk exceeding requested"
395 " region");
396 return -EINVAL;
398 if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) {
399 trace_nbd_structured_read_compliance("data");
402 qemu_iovec_init(&sub_qiov, qiov->niov);
403 qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size);
404 ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp);
405 qemu_iovec_destroy(&sub_qiov);
407 return ret < 0 ? -EIO : 0;
410 #define NBD_MAX_MALLOC_PAYLOAD 1000
411 /* nbd_co_receive_structured_payload
413 static coroutine_fn int nbd_co_receive_structured_payload(
414 NBDClientSession *s, void **payload, Error **errp)
416 int ret;
417 uint32_t len;
419 assert(nbd_reply_is_structured(&s->reply));
421 len = s->reply.structured.length;
423 if (len == 0) {
424 return 0;
427 if (payload == NULL) {
428 error_setg(errp, "Unexpected structured payload");
429 return -EINVAL;
432 if (len > NBD_MAX_MALLOC_PAYLOAD) {
433 error_setg(errp, "Payload too large");
434 return -EINVAL;
437 *payload = g_new(char, len);
438 ret = nbd_read(s->ioc, *payload, len, "structured payload", errp);
439 if (ret < 0) {
440 g_free(*payload);
441 *payload = NULL;
442 return ret;
445 return 0;
448 /* nbd_co_do_receive_one_chunk
449 * for simple reply:
450 * set request_ret to received reply error
451 * if qiov is not NULL: read payload to @qiov
452 * for structured reply chunk:
453 * if error chunk: read payload, set @request_ret, do not set @payload
454 * else if offset_data chunk: read payload data to @qiov, do not set @payload
455 * else: read payload to @payload
457 * If function fails, @errp contains corresponding error message, and the
458 * connection with the server is suspect. If it returns 0, then the
459 * transaction succeeded (although @request_ret may be a negative errno
460 * corresponding to the server's error reply), and errp is unchanged.
462 static coroutine_fn int nbd_co_do_receive_one_chunk(
463 NBDClientSession *s, uint64_t handle, bool only_structured,
464 int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp)
466 int ret;
467 int i = HANDLE_TO_INDEX(s, handle);
468 void *local_payload = NULL;
469 NBDStructuredReplyChunk *chunk;
471 if (payload) {
472 *payload = NULL;
474 *request_ret = 0;
476 /* Wait until we're woken up by nbd_connection_entry. */
477 s->requests[i].receiving = true;
478 qemu_coroutine_yield();
479 s->requests[i].receiving = false;
480 if (s->quit) {
481 error_setg(errp, "Connection closed");
482 return -EIO;
484 assert(s->ioc);
486 assert(s->reply.handle == handle);
488 if (nbd_reply_is_simple(&s->reply)) {
489 if (only_structured) {
490 error_setg(errp, "Protocol error: simple reply when structured "
491 "reply chunk was expected");
492 return -EINVAL;
495 *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error);
496 if (*request_ret < 0 || !qiov) {
497 return 0;
500 return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov,
501 errp) < 0 ? -EIO : 0;
504 /* handle structured reply chunk */
505 assert(s->info.structured_reply);
506 chunk = &s->reply.structured;
508 if (chunk->type == NBD_REPLY_TYPE_NONE) {
509 if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) {
510 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without"
511 " NBD_REPLY_FLAG_DONE flag set");
512 return -EINVAL;
514 if (chunk->length) {
515 error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with"
516 " nonzero length");
517 return -EINVAL;
519 return 0;
522 if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) {
523 if (!qiov) {
524 error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk");
525 return -EINVAL;
528 return nbd_co_receive_offset_data_payload(s, s->requests[i].offset,
529 qiov, errp);
532 if (nbd_reply_type_is_error(chunk->type)) {
533 payload = &local_payload;
536 ret = nbd_co_receive_structured_payload(s, payload, errp);
537 if (ret < 0) {
538 return ret;
541 if (nbd_reply_type_is_error(chunk->type)) {
542 ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp);
543 g_free(local_payload);
544 return ret;
547 return 0;
550 /* nbd_co_receive_one_chunk
551 * Read reply, wake up connection_co and set s->quit if needed.
552 * Return value is a fatal error code or normal nbd reply error code
554 static coroutine_fn int nbd_co_receive_one_chunk(
555 NBDClientSession *s, uint64_t handle, bool only_structured,
556 int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload,
557 Error **errp)
559 int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured,
560 request_ret, qiov, payload, errp);
562 if (ret < 0) {
563 s->quit = true;
564 } else {
565 /* For assert at loop start in nbd_connection_entry */
566 if (reply) {
567 *reply = s->reply;
569 s->reply.handle = 0;
572 if (s->connection_co) {
573 aio_co_wake(s->connection_co);
576 return ret;
579 typedef struct NBDReplyChunkIter {
580 int ret;
581 int request_ret;
582 Error *err;
583 bool done, only_structured;
584 } NBDReplyChunkIter;
586 static void nbd_iter_channel_error(NBDReplyChunkIter *iter,
587 int ret, Error **local_err)
589 assert(ret < 0);
591 if (!iter->ret) {
592 iter->ret = ret;
593 error_propagate(&iter->err, *local_err);
594 } else {
595 error_free(*local_err);
598 *local_err = NULL;
601 static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret)
603 assert(ret < 0);
605 if (!iter->request_ret) {
606 iter->request_ret = ret;
610 /* NBD_FOREACH_REPLY_CHUNK
612 #define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \
613 qiov, reply, payload) \
614 for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \
615 nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);)
617 /* nbd_reply_chunk_iter_receive
619 static bool nbd_reply_chunk_iter_receive(NBDClientSession *s,
620 NBDReplyChunkIter *iter,
621 uint64_t handle,
622 QEMUIOVector *qiov, NBDReply *reply,
623 void **payload)
625 int ret, request_ret;
626 NBDReply local_reply;
627 NBDStructuredReplyChunk *chunk;
628 Error *local_err = NULL;
629 if (s->quit) {
630 error_setg(&local_err, "Connection closed");
631 nbd_iter_channel_error(iter, -EIO, &local_err);
632 goto break_loop;
635 if (iter->done) {
636 /* Previous iteration was last. */
637 goto break_loop;
640 if (reply == NULL) {
641 reply = &local_reply;
644 ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured,
645 &request_ret, qiov, reply, payload,
646 &local_err);
647 if (ret < 0) {
648 nbd_iter_channel_error(iter, ret, &local_err);
649 } else if (request_ret < 0) {
650 nbd_iter_request_error(iter, request_ret);
653 /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */
654 if (nbd_reply_is_simple(reply) || s->quit) {
655 goto break_loop;
658 chunk = &reply->structured;
659 iter->only_structured = true;
661 if (chunk->type == NBD_REPLY_TYPE_NONE) {
662 /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */
663 assert(chunk->flags & NBD_REPLY_FLAG_DONE);
664 goto break_loop;
667 if (chunk->flags & NBD_REPLY_FLAG_DONE) {
668 /* This iteration is last. */
669 iter->done = true;
672 /* Execute the loop body */
673 return true;
675 break_loop:
676 s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL;
678 qemu_co_mutex_lock(&s->send_mutex);
679 s->in_flight--;
680 qemu_co_queue_next(&s->free_sema);
681 qemu_co_mutex_unlock(&s->send_mutex);
683 return false;
686 static int nbd_co_receive_return_code(NBDClientSession *s, uint64_t handle,
687 int *request_ret, Error **errp)
689 NBDReplyChunkIter iter;
691 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) {
692 /* nbd_reply_chunk_iter_receive does all the work */
695 error_propagate(errp, iter.err);
696 *request_ret = iter.request_ret;
697 return iter.ret;
700 static int nbd_co_receive_cmdread_reply(NBDClientSession *s, uint64_t handle,
701 uint64_t offset, QEMUIOVector *qiov,
702 int *request_ret, Error **errp)
704 NBDReplyChunkIter iter;
705 NBDReply reply;
706 void *payload = NULL;
707 Error *local_err = NULL;
709 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply,
710 qiov, &reply, &payload)
712 int ret;
713 NBDStructuredReplyChunk *chunk = &reply.structured;
715 assert(nbd_reply_is_structured(&reply));
717 switch (chunk->type) {
718 case NBD_REPLY_TYPE_OFFSET_DATA:
719 /* special cased in nbd_co_receive_one_chunk, data is already
720 * in qiov */
721 break;
722 case NBD_REPLY_TYPE_OFFSET_HOLE:
723 ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload,
724 offset, qiov, &local_err);
725 if (ret < 0) {
726 s->quit = true;
727 nbd_iter_channel_error(&iter, ret, &local_err);
729 break;
730 default:
731 if (!nbd_reply_type_is_error(chunk->type)) {
732 /* not allowed reply type */
733 s->quit = true;
734 error_setg(&local_err,
735 "Unexpected reply type: %d (%s) for CMD_READ",
736 chunk->type, nbd_reply_type_lookup(chunk->type));
737 nbd_iter_channel_error(&iter, -EINVAL, &local_err);
741 g_free(payload);
742 payload = NULL;
745 error_propagate(errp, iter.err);
746 *request_ret = iter.request_ret;
747 return iter.ret;
750 static int nbd_co_receive_blockstatus_reply(NBDClientSession *s,
751 uint64_t handle, uint64_t length,
752 NBDExtent *extent,
753 int *request_ret, Error **errp)
755 NBDReplyChunkIter iter;
756 NBDReply reply;
757 void *payload = NULL;
758 Error *local_err = NULL;
759 bool received = false;
761 assert(!extent->length);
762 NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) {
763 int ret;
764 NBDStructuredReplyChunk *chunk = &reply.structured;
766 assert(nbd_reply_is_structured(&reply));
768 switch (chunk->type) {
769 case NBD_REPLY_TYPE_BLOCK_STATUS:
770 if (received) {
771 s->quit = true;
772 error_setg(&local_err, "Several BLOCK_STATUS chunks in reply");
773 nbd_iter_channel_error(&iter, -EINVAL, &local_err);
775 received = true;
777 ret = nbd_parse_blockstatus_payload(s, &reply.structured,
778 payload, length, extent,
779 &local_err);
780 if (ret < 0) {
781 s->quit = true;
782 nbd_iter_channel_error(&iter, ret, &local_err);
784 break;
785 default:
786 if (!nbd_reply_type_is_error(chunk->type)) {
787 s->quit = true;
788 error_setg(&local_err,
789 "Unexpected reply type: %d (%s) "
790 "for CMD_BLOCK_STATUS",
791 chunk->type, nbd_reply_type_lookup(chunk->type));
792 nbd_iter_channel_error(&iter, -EINVAL, &local_err);
796 g_free(payload);
797 payload = NULL;
800 if (!extent->length && !iter.request_ret) {
801 error_setg(&local_err, "Server did not reply with any status extents");
802 nbd_iter_channel_error(&iter, -EIO, &local_err);
805 error_propagate(errp, iter.err);
806 *request_ret = iter.request_ret;
807 return iter.ret;
810 static int nbd_co_request(BlockDriverState *bs, NBDRequest *request,
811 QEMUIOVector *write_qiov)
813 int ret, request_ret;
814 Error *local_err = NULL;
815 NBDClientSession *client = nbd_get_client_session(bs);
817 assert(request->type != NBD_CMD_READ);
818 if (write_qiov) {
819 assert(request->type == NBD_CMD_WRITE);
820 assert(request->len == iov_size(write_qiov->iov, write_qiov->niov));
821 } else {
822 assert(request->type != NBD_CMD_WRITE);
824 ret = nbd_co_send_request(bs, request, write_qiov);
825 if (ret < 0) {
826 return ret;
829 ret = nbd_co_receive_return_code(client, request->handle,
830 &request_ret, &local_err);
831 if (local_err) {
832 trace_nbd_co_request_fail(request->from, request->len, request->handle,
833 request->flags, request->type,
834 nbd_cmd_lookup(request->type),
835 ret, error_get_pretty(local_err));
836 error_free(local_err);
838 return ret ? ret : request_ret;
841 int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,
842 uint64_t bytes, QEMUIOVector *qiov, int flags)
844 int ret, request_ret;
845 Error *local_err = NULL;
846 NBDClientSession *client = nbd_get_client_session(bs);
847 NBDRequest request = {
848 .type = NBD_CMD_READ,
849 .from = offset,
850 .len = bytes,
853 assert(bytes <= NBD_MAX_BUFFER_SIZE);
854 assert(!flags);
856 if (!bytes) {
857 return 0;
860 * Work around the fact that the block layer doesn't do
861 * byte-accurate sizing yet - if the read exceeds the server's
862 * advertised size because the block layer rounded size up, then
863 * truncate the request to the server and tail-pad with zero.
865 if (offset >= client->info.size) {
866 assert(bytes < BDRV_SECTOR_SIZE);
867 qemu_iovec_memset(qiov, 0, 0, bytes);
868 return 0;
870 if (offset + bytes > client->info.size) {
871 uint64_t slop = offset + bytes - client->info.size;
873 assert(slop < BDRV_SECTOR_SIZE);
874 qemu_iovec_memset(qiov, bytes - slop, 0, slop);
875 request.len -= slop;
878 ret = nbd_co_send_request(bs, &request, NULL);
879 if (ret < 0) {
880 return ret;
883 ret = nbd_co_receive_cmdread_reply(client, request.handle, offset, qiov,
884 &request_ret, &local_err);
885 if (local_err) {
886 trace_nbd_co_request_fail(request.from, request.len, request.handle,
887 request.flags, request.type,
888 nbd_cmd_lookup(request.type),
889 ret, error_get_pretty(local_err));
890 error_free(local_err);
892 return ret ? ret : request_ret;
895 int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,
896 uint64_t bytes, QEMUIOVector *qiov, int flags)
898 NBDClientSession *client = nbd_get_client_session(bs);
899 NBDRequest request = {
900 .type = NBD_CMD_WRITE,
901 .from = offset,
902 .len = bytes,
905 assert(!(client->info.flags & NBD_FLAG_READ_ONLY));
906 if (flags & BDRV_REQ_FUA) {
907 assert(client->info.flags & NBD_FLAG_SEND_FUA);
908 request.flags |= NBD_CMD_FLAG_FUA;
911 assert(bytes <= NBD_MAX_BUFFER_SIZE);
913 if (!bytes) {
914 return 0;
916 return nbd_co_request(bs, &request, qiov);
919 int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
920 int bytes, BdrvRequestFlags flags)
922 NBDClientSession *client = nbd_get_client_session(bs);
923 NBDRequest request = {
924 .type = NBD_CMD_WRITE_ZEROES,
925 .from = offset,
926 .len = bytes,
929 assert(!(client->info.flags & NBD_FLAG_READ_ONLY));
930 if (!(client->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) {
931 return -ENOTSUP;
934 if (flags & BDRV_REQ_FUA) {
935 assert(client->info.flags & NBD_FLAG_SEND_FUA);
936 request.flags |= NBD_CMD_FLAG_FUA;
938 if (!(flags & BDRV_REQ_MAY_UNMAP)) {
939 request.flags |= NBD_CMD_FLAG_NO_HOLE;
942 if (!bytes) {
943 return 0;
945 return nbd_co_request(bs, &request, NULL);
948 int nbd_client_co_flush(BlockDriverState *bs)
950 NBDClientSession *client = nbd_get_client_session(bs);
951 NBDRequest request = { .type = NBD_CMD_FLUSH };
953 if (!(client->info.flags & NBD_FLAG_SEND_FLUSH)) {
954 return 0;
957 request.from = 0;
958 request.len = 0;
960 return nbd_co_request(bs, &request, NULL);
963 int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
965 NBDClientSession *client = nbd_get_client_session(bs);
966 NBDRequest request = {
967 .type = NBD_CMD_TRIM,
968 .from = offset,
969 .len = bytes,
972 assert(!(client->info.flags & NBD_FLAG_READ_ONLY));
973 if (!(client->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) {
974 return 0;
977 return nbd_co_request(bs, &request, NULL);
980 int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs,
981 bool want_zero,
982 int64_t offset, int64_t bytes,
983 int64_t *pnum, int64_t *map,
984 BlockDriverState **file)
986 int ret, request_ret;
987 NBDExtent extent = { 0 };
988 NBDClientSession *client = nbd_get_client_session(bs);
989 Error *local_err = NULL;
991 NBDRequest request = {
992 .type = NBD_CMD_BLOCK_STATUS,
993 .from = offset,
994 .len = MIN(MIN_NON_ZERO(QEMU_ALIGN_DOWN(INT_MAX,
995 bs->bl.request_alignment),
996 client->info.max_block),
997 MIN(bytes, client->info.size - offset)),
998 .flags = NBD_CMD_FLAG_REQ_ONE,
1001 if (!client->info.base_allocation) {
1002 *pnum = bytes;
1003 *map = offset;
1004 *file = bs;
1005 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
1009 * Work around the fact that the block layer doesn't do
1010 * byte-accurate sizing yet - if the status request exceeds the
1011 * server's advertised size because the block layer rounded size
1012 * up, we truncated the request to the server (above), or are
1013 * called on just the hole.
1015 if (offset >= client->info.size) {
1016 *pnum = bytes;
1017 assert(bytes < BDRV_SECTOR_SIZE);
1018 /* Intentionally don't report offset_valid for the hole */
1019 return BDRV_BLOCK_ZERO;
1022 if (client->info.min_block) {
1023 assert(QEMU_IS_ALIGNED(request.len, client->info.min_block));
1025 ret = nbd_co_send_request(bs, &request, NULL);
1026 if (ret < 0) {
1027 return ret;
1030 ret = nbd_co_receive_blockstatus_reply(client, request.handle, bytes,
1031 &extent, &request_ret, &local_err);
1032 if (local_err) {
1033 trace_nbd_co_request_fail(request.from, request.len, request.handle,
1034 request.flags, request.type,
1035 nbd_cmd_lookup(request.type),
1036 ret, error_get_pretty(local_err));
1037 error_free(local_err);
1039 if (ret < 0 || request_ret < 0) {
1040 return ret ? ret : request_ret;
1043 assert(extent.length);
1044 *pnum = extent.length;
1045 *map = offset;
1046 *file = bs;
1047 return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) |
1048 (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) |
1049 BDRV_BLOCK_OFFSET_VALID;
1052 void nbd_client_detach_aio_context(BlockDriverState *bs)
1054 NBDClientSession *client = nbd_get_client_session(bs);
1055 qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc));
1058 static void nbd_client_attach_aio_context_bh(void *opaque)
1060 BlockDriverState *bs = opaque;
1061 NBDClientSession *client = nbd_get_client_session(bs);
1063 /* The node is still drained, so we know the coroutine has yielded in
1064 * nbd_read_eof(), the only place where bs->in_flight can reach 0, or it is
1065 * entered for the first time. Both places are safe for entering the
1066 * coroutine.*/
1067 qemu_aio_coroutine_enter(bs->aio_context, client->connection_co);
1068 bdrv_dec_in_flight(bs);
1071 void nbd_client_attach_aio_context(BlockDriverState *bs,
1072 AioContext *new_context)
1074 NBDClientSession *client = nbd_get_client_session(bs);
1075 qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), new_context);
1077 bdrv_inc_in_flight(bs);
1079 /* Need to wait here for the BH to run because the BH must run while the
1080 * node is still drained. */
1081 aio_wait_bh_oneshot(new_context, nbd_client_attach_aio_context_bh, bs);
1084 void nbd_client_close(BlockDriverState *bs)
1086 NBDClientSession *client = nbd_get_client_session(bs);
1087 NBDRequest request = { .type = NBD_CMD_DISC };
1089 assert(client->ioc);
1091 nbd_send_request(client->ioc, &request);
1093 nbd_teardown_connection(bs);
1096 static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
1097 Error **errp)
1099 QIOChannelSocket *sioc;
1100 Error *local_err = NULL;
1102 sioc = qio_channel_socket_new();
1103 qio_channel_set_name(QIO_CHANNEL(sioc), "nbd-client");
1105 qio_channel_socket_connect_sync(sioc, saddr, &local_err);
1106 if (local_err) {
1107 object_unref(OBJECT(sioc));
1108 error_propagate(errp, local_err);
1109 return NULL;
1112 qio_channel_set_delay(QIO_CHANNEL(sioc), false);
1114 return sioc;
1117 static int nbd_client_connect(BlockDriverState *bs,
1118 SocketAddress *saddr,
1119 const char *export,
1120 QCryptoTLSCreds *tlscreds,
1121 const char *hostname,
1122 const char *x_dirty_bitmap,
1123 Error **errp)
1125 NBDClientSession *client = nbd_get_client_session(bs);
1126 int ret;
1129 * establish TCP connection, return error if it fails
1130 * TODO: Configurable retry-until-timeout behaviour.
1132 QIOChannelSocket *sioc = nbd_establish_connection(saddr, errp);
1134 if (!sioc) {
1135 return -ECONNREFUSED;
1138 /* NBD handshake */
1139 logout("session init %s\n", export);
1140 qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL);
1142 client->info.request_sizes = true;
1143 client->info.structured_reply = true;
1144 client->info.base_allocation = true;
1145 client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);
1146 client->info.name = g_strdup(export ?: "");
1147 ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), tlscreds, hostname,
1148 &client->ioc, &client->info, errp);
1149 g_free(client->info.x_dirty_bitmap);
1150 g_free(client->info.name);
1151 if (ret < 0) {
1152 logout("Failed to negotiate with the NBD server\n");
1153 object_unref(OBJECT(sioc));
1154 return ret;
1156 if (x_dirty_bitmap && !client->info.base_allocation) {
1157 error_setg(errp, "requested x-dirty-bitmap %s not found",
1158 x_dirty_bitmap);
1159 ret = -EINVAL;
1160 goto fail;
1162 if (client->info.flags & NBD_FLAG_READ_ONLY) {
1163 ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp);
1164 if (ret < 0) {
1165 goto fail;
1168 if (client->info.flags & NBD_FLAG_SEND_FUA) {
1169 bs->supported_write_flags = BDRV_REQ_FUA;
1170 bs->supported_zero_flags |= BDRV_REQ_FUA;
1172 if (client->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) {
1173 bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP;
1176 client->sioc = sioc;
1178 if (!client->ioc) {
1179 client->ioc = QIO_CHANNEL(sioc);
1180 object_ref(OBJECT(client->ioc));
1183 /* Now that we're connected, set the socket to be non-blocking and
1184 * kick the reply mechanism. */
1185 qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
1186 client->connection_co = qemu_coroutine_create(nbd_connection_entry, client);
1187 bdrv_inc_in_flight(bs);
1188 nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
1190 logout("Established connection with NBD server\n");
1191 return 0;
1193 fail:
1195 * We have connected, but must fail for other reasons. The
1196 * connection is still blocking; send NBD_CMD_DISC as a courtesy
1197 * to the server.
1200 NBDRequest request = { .type = NBD_CMD_DISC };
1202 nbd_send_request(client->ioc ?: QIO_CHANNEL(sioc), &request);
1204 object_unref(OBJECT(sioc));
1206 return ret;
1210 int nbd_client_init(BlockDriverState *bs,
1211 SocketAddress *saddr,
1212 const char *export,
1213 QCryptoTLSCreds *tlscreds,
1214 const char *hostname,
1215 const char *x_dirty_bitmap,
1216 Error **errp)
1218 NBDClientSession *client = nbd_get_client_session(bs);
1220 client->bs = bs;
1221 qemu_co_mutex_init(&client->send_mutex);
1222 qemu_co_queue_init(&client->free_sema);
1224 return nbd_client_connect(bs, saddr, export, tlscreds, hostname,
1225 x_dirty_bitmap, errp);