diff options
Diffstat (limited to 'block/nbd-client.c')
| -rw-r--r-- | block/nbd-client.c | 1226 |
1 files changed, 0 insertions, 1226 deletions
diff --git a/block/nbd-client.c b/block/nbd-client.c deleted file mode 100644 index 790ecc1ee1..0000000000 --- a/block/nbd-client.c +++ /dev/null @@ -1,1226 +0,0 @@ -/* - * QEMU Block driver for NBD - * - * Copyright (C) 2016 Red Hat, Inc. - * Copyright (C) 2008 Bull S.A.S. - * Author: Laurent Vivier <Laurent.Vivier@bull.net> - * - * Some parts: - * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws> - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ - -#include "qemu/osdep.h" - -#include "trace.h" -#include "qapi/error.h" -#include "nbd-client.h" - -#define HANDLE_TO_INDEX(bs, handle) ((handle) ^ (uint64_t)(intptr_t)(bs)) -#define INDEX_TO_HANDLE(bs, index) ((index) ^ (uint64_t)(intptr_t)(bs)) - -static void nbd_recv_coroutines_wake_all(NBDClientSession *s) -{ - int i; - - for (i = 0; i < MAX_NBD_REQUESTS; i++) { - NBDClientRequest *req = &s->requests[i]; - - if (req->coroutine && req->receiving) { - aio_co_wake(req->coroutine); - } - } -} - -static void nbd_teardown_connection(BlockDriverState *bs) -{ - NBDClientSession *client = nbd_get_client_session(bs); - - assert(client->ioc); - - /* finish any pending coroutines */ - qio_channel_shutdown(client->ioc, - QIO_CHANNEL_SHUTDOWN_BOTH, - NULL); - BDRV_POLL_WHILE(bs, client->connection_co); - - nbd_client_detach_aio_context(bs); - object_unref(OBJECT(client->sioc)); - client->sioc = NULL; - object_unref(OBJECT(client->ioc)); - client->ioc = NULL; -} - -static coroutine_fn void nbd_connection_entry(void *opaque) -{ - NBDClientSession *s = opaque; - uint64_t i; - int ret = 0; - Error *local_err = NULL; - - while (!s->quit) { - /* - * The NBD client can only really be considered idle when it has - * yielded from qio_channel_readv_all_eof(), waiting for data. This is - * the point where the additional scheduled coroutine entry happens - * after nbd_client_attach_aio_context(). - * - * Therefore we keep an additional in_flight reference all the time and - * only drop it temporarily here. - */ - assert(s->reply.handle == 0); - ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, &local_err); - - if (local_err) { - trace_nbd_read_reply_entry_fail(ret, error_get_pretty(local_err)); - error_free(local_err); - } - if (ret <= 0) { - break; - } - - /* There's no need for a mutex on the receive side, because the - * handler acts as a synchronization point and ensures that only - * one coroutine is called until the reply finishes. - */ - i = HANDLE_TO_INDEX(s, s->reply.handle); - if (i >= MAX_NBD_REQUESTS || - !s->requests[i].coroutine || - !s->requests[i].receiving || - (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply)) - { - break; - } - - /* We're woken up again by the request itself. Note that there - * is no race between yielding and reentering connection_co. This - * is because: - * - * - if the request runs on the same AioContext, it is only - * entered after we yield - * - * - if the request runs on a different AioContext, reentering - * connection_co happens through a bottom half, which can only - * run after we yield. - */ - aio_co_wake(s->requests[i].coroutine); - qemu_coroutine_yield(); - } - - s->quit = true; - nbd_recv_coroutines_wake_all(s); - bdrv_dec_in_flight(s->bs); - - s->connection_co = NULL; - aio_wait_kick(); -} - -static int nbd_co_send_request(BlockDriverState *bs, - NBDRequest *request, - QEMUIOVector *qiov) -{ - NBDClientSession *s = nbd_get_client_session(bs); - int rc, i; - - qemu_co_mutex_lock(&s->send_mutex); - while (s->in_flight == MAX_NBD_REQUESTS) { - qemu_co_queue_wait(&s->free_sema, &s->send_mutex); - } - s->in_flight++; - - for (i = 0; i < MAX_NBD_REQUESTS; i++) { - if (s->requests[i].coroutine == NULL) { - break; - } - } - - g_assert(qemu_in_coroutine()); - assert(i < MAX_NBD_REQUESTS); - - s->requests[i].coroutine = qemu_coroutine_self(); - s->requests[i].offset = request->from; - s->requests[i].receiving = false; - - request->handle = INDEX_TO_HANDLE(s, i); - - if (s->quit) { - rc = -EIO; - goto err; - } - assert(s->ioc); - - if (qiov) { - qio_channel_set_cork(s->ioc, true); - rc = nbd_send_request(s->ioc, request); - if (rc >= 0 && !s->quit) { - if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, - NULL) < 0) { - rc = -EIO; - } - } else if (rc >= 0) { - rc = -EIO; - } - qio_channel_set_cork(s->ioc, false); - } else { - rc = nbd_send_request(s->ioc, request); - } - -err: - if (rc < 0) { - s->quit = true; - s->requests[i].coroutine = NULL; - s->in_flight--; - qemu_co_queue_next(&s->free_sema); - } - qemu_co_mutex_unlock(&s->send_mutex); - return rc; -} - -static inline uint16_t payload_advance16(uint8_t **payload) -{ - *payload += 2; - return lduw_be_p(*payload - 2); -} - -static inline uint32_t payload_advance32(uint8_t **payload) -{ - *payload += 4; - return ldl_be_p(*payload - 4); -} - -static inline uint64_t payload_advance64(uint8_t **payload) -{ - *payload += 8; - return ldq_be_p(*payload - 8); -} - -static int nbd_parse_offset_hole_payload(NBDClientSession *client, - NBDStructuredReplyChunk *chunk, - uint8_t *payload, uint64_t orig_offset, - QEMUIOVector *qiov, Error **errp) -{ - uint64_t offset; - uint32_t hole_size; - - if (chunk->length != sizeof(offset) + sizeof(hole_size)) { - error_setg(errp, "Protocol error: invalid payload for " - "NBD_REPLY_TYPE_OFFSET_HOLE"); - return -EINVAL; - } - - offset = payload_advance64(&payload); - hole_size = payload_advance32(&payload); - - if (!hole_size || offset < orig_offset || hole_size > qiov->size || - offset > orig_offset + qiov->size - hole_size) { - error_setg(errp, "Protocol error: server sent chunk exceeding requested" - " region"); - return -EINVAL; - } - if (client->info.min_block && - !QEMU_IS_ALIGNED(hole_size, client->info.min_block)) { - trace_nbd_structured_read_compliance("hole"); - } - - qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); - - return 0; -} - -/* nbd_parse_blockstatus_payload - * Based on our request, we expect only one extent in reply, for the - * base:allocation context. - */ -static int nbd_parse_blockstatus_payload(NBDClientSession *client, - NBDStructuredReplyChunk *chunk, - uint8_t *payload, uint64_t orig_length, - NBDExtent *extent, Error **errp) -{ - uint32_t context_id; - - /* The server succeeded, so it must have sent [at least] one extent */ - if (chunk->length < sizeof(context_id) + sizeof(*extent)) { - error_setg(errp, "Protocol error: invalid payload for " - "NBD_REPLY_TYPE_BLOCK_STATUS"); - return -EINVAL; - } - - context_id = payload_advance32(&payload); - if (client->info.context_id != context_id) { - error_setg(errp, "Protocol error: unexpected context id %d for " - "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " - "id is %d", context_id, - client->info.context_id); - return -EINVAL; - } - - extent->length = payload_advance32(&payload); - extent->flags = payload_advance32(&payload); - - if (extent->length == 0) { - error_setg(errp, "Protocol error: server sent status chunk with " - "zero length"); - return -EINVAL; - } - - /* - * A server sending unaligned block status is in violation of the - * protocol, but as qemu-nbd 3.1 is such a server (at least for - * POSIX files that are not a multiple of 512 bytes, since qemu - * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) - * still sees an implicit hole beyond the real EOF), it's nicer to - * work around the misbehaving server. If the request included - * more than the final unaligned block, truncate it back to an - * aligned result; if the request was only the final block, round - * up to the full block and change the status to fully-allocated - * (always a safe status, even if it loses information). - */ - if (client->info.min_block && !QEMU_IS_ALIGNED(extent->length, - client->info.min_block)) { - trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); - if (extent->length > client->info.min_block) { - extent->length = QEMU_ALIGN_DOWN(extent->length, - client->info.min_block); - } else { - extent->length = client->info.min_block; - extent->flags = 0; - } - } - - /* - * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have - * sent us any more than one extent, nor should it have included - * status beyond our request in that extent. However, it's easy - * enough to ignore the server's noncompliance without killing the - * connection; just ignore trailing extents, and clamp things to - * the length of our request. - */ - if (chunk->length > sizeof(context_id) + sizeof(*extent)) { - trace_nbd_parse_blockstatus_compliance("more than one extent"); - } - if (extent->length > orig_length) { - extent->length = orig_length; - trace_nbd_parse_blockstatus_compliance("extent length too large"); - } - - return 0; -} - -/* nbd_parse_error_payload - * on success @errp contains message describing nbd error reply - */ -static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, - uint8_t *payload, int *request_ret, - Error **errp) -{ - uint32_t error; - uint16_t message_size; - - assert(chunk->type & (1 << 15)); - - if (chunk->length < sizeof(error) + sizeof(message_size)) { - error_setg(errp, - "Protocol error: invalid payload for structured error"); - return -EINVAL; - } - - error = nbd_errno_to_system_errno(payload_advance32(&payload)); - if (error == 0) { - error_setg(errp, "Protocol error: server sent structured error chunk " - "with error = 0"); - return -EINVAL; - } - - *request_ret = -error; - message_size = payload_advance16(&payload); - - if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { - error_setg(errp, "Protocol error: server sent structured error chunk " - "with incorrect message size"); - return -EINVAL; - } - - /* TODO: Add a trace point to mention the server complaint */ - - /* TODO handle ERROR_OFFSET */ - - return 0; -} - -static int nbd_co_receive_offset_data_payload(NBDClientSession *s, - uint64_t orig_offset, - QEMUIOVector *qiov, Error **errp) -{ - QEMUIOVector sub_qiov; - uint64_t offset; - size_t data_size; - int ret; - NBDStructuredReplyChunk *chunk = &s->reply.structured; - - assert(nbd_reply_is_structured(&s->reply)); - - /* The NBD spec requires at least one byte of payload */ - if (chunk->length <= sizeof(offset)) { - error_setg(errp, "Protocol error: invalid payload for " - "NBD_REPLY_TYPE_OFFSET_DATA"); - return -EINVAL; - } - - if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { - return -EIO; - } - - data_size = chunk->length - sizeof(offset); - assert(data_size); - if (offset < orig_offset || data_size > qiov->size || - offset > orig_offset + qiov->size - data_size) { - error_setg(errp, "Protocol error: server sent chunk exceeding requested" - " region"); - return -EINVAL; - } - if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { - trace_nbd_structured_read_compliance("data"); - } - - qemu_iovec_init(&sub_qiov, qiov->niov); - qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); - ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); - qemu_iovec_destroy(&sub_qiov); - - return ret < 0 ? -EIO : 0; -} - -#define NBD_MAX_MALLOC_PAYLOAD 1000 -/* nbd_co_receive_structured_payload - */ -static coroutine_fn int nbd_co_receive_structured_payload( - NBDClientSession *s, void **payload, Error **errp) -{ - int ret; - uint32_t len; - - assert(nbd_reply_is_structured(&s->reply)); - - len = s->reply.structured.length; - - if (len == 0) { - return 0; - } - - if (payload == NULL) { - error_setg(errp, "Unexpected structured payload"); - return -EINVAL; - } - - if (len > NBD_MAX_MALLOC_PAYLOAD) { - error_setg(errp, "Payload too large"); - return -EINVAL; - } - - *payload = g_new(char, len); - ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); - if (ret < 0) { - g_free(*payload); - *payload = NULL; - return ret; - } - - return 0; -} - -/* nbd_co_do_receive_one_chunk - * for simple reply: - * set request_ret to received reply error - * if qiov is not NULL: read payload to @qiov - * for structured reply chunk: - * if error chunk: read payload, set @request_ret, do not set @payload - * else if offset_data chunk: read payload data to @qiov, do not set @payload - * else: read payload to @payload - * - * If function fails, @errp contains corresponding error message, and the - * connection with the server is suspect. If it returns 0, then the - * transaction succeeded (although @request_ret may be a negative errno - * corresponding to the server's error reply), and errp is unchanged. - */ -static coroutine_fn int nbd_co_do_receive_one_chunk( - NBDClientSession *s, uint64_t handle, bool only_structured, - int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) -{ - int ret; - int i = HANDLE_TO_INDEX(s, handle); - void *local_payload = NULL; - NBDStructuredReplyChunk *chunk; - - if (payload) { - *payload = NULL; - } - *request_ret = 0; - - /* Wait until we're woken up by nbd_connection_entry. */ - s->requests[i].receiving = true; - qemu_coroutine_yield(); - s->requests[i].receiving = false; - if (s->quit) { - error_setg(errp, "Connection closed"); - return -EIO; - } - assert(s->ioc); - - assert(s->reply.handle == handle); - - if (nbd_reply_is_simple(&s->reply)) { - if (only_structured) { - error_setg(errp, "Protocol error: simple reply when structured " - "reply chunk was expected"); - return -EINVAL; - } - - *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); - if (*request_ret < 0 || !qiov) { - return 0; - } - - return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, - errp) < 0 ? -EIO : 0; - } - - /* handle structured reply chunk */ - assert(s->info.structured_reply); - chunk = &s->reply.structured; - - if (chunk->type == NBD_REPLY_TYPE_NONE) { - if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { - error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" - " NBD_REPLY_FLAG_DONE flag set"); - return -EINVAL; - } - if (chunk->length) { - error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" - " nonzero length"); - return -EINVAL; - } - return 0; - } - - if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { - if (!qiov) { - error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); - return -EINVAL; - } - - return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, - qiov, errp); - } - - if (nbd_reply_type_is_error(chunk->type)) { - payload = &local_payload; - } - - ret = nbd_co_receive_structured_payload(s, payload, errp); - if (ret < 0) { - return ret; - } - - if (nbd_reply_type_is_error(chunk->type)) { - ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); - g_free(local_payload); - return ret; - } - - return 0; -} - -/* nbd_co_receive_one_chunk - * Read reply, wake up connection_co and set s->quit if needed. - * Return value is a fatal error code or normal nbd reply error code - */ -static coroutine_fn int nbd_co_receive_one_chunk( - NBDClientSession *s, uint64_t handle, bool only_structured, - int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, - Error **errp) -{ - int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured, - request_ret, qiov, payload, errp); - - if (ret < 0) { - s->quit = true; - } else { - /* For assert at loop start in nbd_connection_entry */ - if (reply) { - *reply = s->reply; - } - s->reply.handle = 0; - } - - if (s->connection_co) { - aio_co_wake(s->connection_co); - } - - return ret; -} - -typedef struct NBDReplyChunkIter { - int ret; - int request_ret; - Error *err; - bool done, only_structured; -} NBDReplyChunkIter; - -static void nbd_iter_channel_error(NBDReplyChunkIter *iter, - int ret, Error **local_err) -{ - assert(ret < 0); - - if (!iter->ret) { - iter->ret = ret; - error_propagate(&iter->err, *local_err); - } else { - error_free(*local_err); - } - - *local_err = NULL; -} - -static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) -{ - assert(ret < 0); - - if (!iter->request_ret) { - iter->request_ret = ret; - } -} - -/* NBD_FOREACH_REPLY_CHUNK - */ -#define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \ - qiov, reply, payload) \ - for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ - nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);) - -/* nbd_reply_chunk_iter_receive - */ -static bool nbd_reply_chunk_iter_receive(NBDClientSession *s, - NBDReplyChunkIter *iter, - uint64_t handle, - QEMUIOVector *qiov, NBDReply *reply, - void **payload) -{ - int ret, request_ret; - NBDReply local_reply; - NBDStructuredReplyChunk *chunk; - Error *local_err = NULL; - if (s->quit) { - error_setg(&local_err, "Connection closed"); - nbd_iter_channel_error(iter, -EIO, &local_err); - goto break_loop; - } - - if (iter->done) { - /* Previous iteration was last. */ - goto break_loop; - } - - if (reply == NULL) { - reply = &local_reply; - } - - ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured, - &request_ret, qiov, reply, payload, - &local_err); - if (ret < 0) { - nbd_iter_channel_error(iter, ret, &local_err); - } else if (request_ret < 0) { - nbd_iter_request_error(iter, request_ret); - } - - /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ - if (nbd_reply_is_simple(reply) || s->quit) { - goto break_loop; - } - - chunk = &reply->structured; - iter->only_structured = true; - - if (chunk->type == NBD_REPLY_TYPE_NONE) { - /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ - assert(chunk->flags & NBD_REPLY_FLAG_DONE); - goto break_loop; - } - - if (chunk->flags & NBD_REPLY_FLAG_DONE) { - /* This iteration is last. */ - iter->done = true; - } - - /* Execute the loop body */ - return true; - -break_loop: - s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL; - - qemu_co_mutex_lock(&s->send_mutex); - s->in_flight--; - qemu_co_queue_next(&s->free_sema); - qemu_co_mutex_unlock(&s->send_mutex); - - return false; -} - -static int nbd_co_receive_return_code(NBDClientSession *s, uint64_t handle, - int *request_ret, Error **errp) -{ - NBDReplyChunkIter iter; - - NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) { - /* nbd_reply_chunk_iter_receive does all the work */ - } - - error_propagate(errp, iter.err); - *request_ret = iter.request_ret; - return iter.ret; -} - -static int nbd_co_receive_cmdread_reply(NBDClientSession *s, uint64_t handle, - uint64_t offset, QEMUIOVector *qiov, - int *request_ret, Error **errp) -{ - NBDReplyChunkIter iter; - NBDReply reply; - void *payload = NULL; - Error *local_err = NULL; - - NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, - qiov, &reply, &payload) - { - int ret; - NBDStructuredReplyChunk *chunk = &reply.structured; - - assert(nbd_reply_is_structured(&reply)); - - switch (chunk->type) { - case NBD_REPLY_TYPE_OFFSET_DATA: - /* special cased in nbd_co_receive_one_chunk, data is already - * in qiov */ - break; - case NBD_REPLY_TYPE_OFFSET_HOLE: - ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, - offset, qiov, &local_err); - if (ret < 0) { - s->quit = true; - nbd_iter_channel_error(&iter, ret, &local_err); - } - break; - default: - if (!nbd_reply_type_is_error(chunk->type)) { - /* not allowed reply type */ - s->quit = true; - error_setg(&local_err, - "Unexpected reply type: %d (%s) for CMD_READ", - chunk->type, nbd_reply_type_lookup(chunk->type)); - nbd_iter_channel_error(&iter, -EINVAL, &local_err); - } - } - - g_free(payload); - payload = NULL; - } - - error_propagate(errp, iter.err); - *request_ret = iter.request_ret; - return iter.ret; -} - -static int nbd_co_receive_blockstatus_reply(NBDClientSession *s, - uint64_t handle, uint64_t length, - NBDExtent *extent, - int *request_ret, Error **errp) -{ - NBDReplyChunkIter iter; - NBDReply reply; - void *payload = NULL; - Error *local_err = NULL; - bool received = false; - - assert(!extent->length); - NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { - int ret; - NBDStructuredReplyChunk *chunk = &reply.structured; - - assert(nbd_reply_is_structured(&reply)); - - switch (chunk->type) { - case NBD_REPLY_TYPE_BLOCK_STATUS: - if (received) { - s->quit = true; - error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); - nbd_iter_channel_error(&iter, -EINVAL, &local_err); - } - received = true; - - ret = nbd_parse_blockstatus_payload(s, &reply.structured, - payload, length, extent, - &local_err); - if (ret < 0) { - s->quit = true; - nbd_iter_channel_error(&iter, ret, &local_err); - } - break; - default: - if (!nbd_reply_type_is_error(chunk->type)) { - s->quit = true; - error_setg(&local_err, - "Unexpected reply type: %d (%s) " - "for CMD_BLOCK_STATUS", - chunk->type, nbd_reply_type_lookup(chunk->type)); - nbd_iter_channel_error(&iter, -EINVAL, &local_err); - } - } - - g_free(payload); - payload = NULL; - } - - if (!extent->length && !iter.request_ret) { - error_setg(&local_err, "Server did not reply with any status extents"); - nbd_iter_channel_error(&iter, -EIO, &local_err); - } - - error_propagate(errp, iter.err); - *request_ret = iter.request_ret; - return iter.ret; -} - -static int nbd_co_request(BlockDriverState *bs, NBDRequest *request, - QEMUIOVector *write_qiov) -{ - int ret, request_ret; - Error *local_err = NULL; - NBDClientSession *client = nbd_get_client_session(bs); - - assert(request->type != NBD_CMD_READ); - if (write_qiov) { - assert(request->type == NBD_CMD_WRITE); - assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); - } else { - assert(request->type != NBD_CMD_WRITE); - } - ret = nbd_co_send_request(bs, request, write_qiov); - if (ret < 0) { - return ret; - } - - ret = nbd_co_receive_return_code(client, request->handle, - &request_ret, &local_err); - if (local_err) { - trace_nbd_co_request_fail(request->from, request->len, request->handle, - request->flags, request->type, - nbd_cmd_lookup(request->type), - ret, error_get_pretty(local_err)); - error_free(local_err); - } - return ret ? ret : request_ret; -} - -int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset, - uint64_t bytes, QEMUIOVector *qiov, int flags) -{ - int ret, request_ret; - Error *local_err = NULL; - NBDClientSession *client = nbd_get_client_session(bs); - NBDRequest request = { - .type = NBD_CMD_READ, - .from = offset, - .len = bytes, - }; - - assert(bytes <= NBD_MAX_BUFFER_SIZE); - assert(!flags); - - if (!bytes) { - return 0; - } - /* - * Work around the fact that the block layer doesn't do - * byte-accurate sizing yet - if the read exceeds the server's - * advertised size because the block layer rounded size up, then - * truncate the request to the server and tail-pad with zero. - */ - if (offset >= client->info.size) { - assert(bytes < BDRV_SECTOR_SIZE); - qemu_iovec_memset(qiov, 0, 0, bytes); - return 0; - } - if (offset + bytes > client->info.size) { - uint64_t slop = offset + bytes - client->info.size; - - assert(slop < BDRV_SECTOR_SIZE); - qemu_iovec_memset(qiov, bytes - slop, 0, slop); - request.len -= slop; - } - - ret = nbd_co_send_request(bs, &request, NULL); - if (ret < 0) { - return ret; - } - - ret = nbd_co_receive_cmdread_reply(client, request.handle, offset, qiov, - &request_ret, &local_err); - if (local_err) { - trace_nbd_co_request_fail(request.from, request.len, request.handle, - request.flags, request.type, - nbd_cmd_lookup(request.type), - ret, error_get_pretty(local_err)); - error_free(local_err); - } - return ret ? ret : request_ret; -} - -int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset, - uint64_t bytes, QEMUIOVector *qiov, int flags) -{ - NBDClientSession *client = nbd_get_client_session(bs); - NBDRequest request = { - .type = NBD_CMD_WRITE, - .from = offset, - .len = bytes, - }; - - assert(!(client->info.flags & NBD_FLAG_READ_ONLY)); - if (flags & BDRV_REQ_FUA) { - assert(client->info.flags & NBD_FLAG_SEND_FUA); - request.flags |= NBD_CMD_FLAG_FUA; - } - - assert(bytes <= NBD_MAX_BUFFER_SIZE); - - if (!bytes) { - return 0; - } - return nbd_co_request(bs, &request, qiov); -} - -int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, - int bytes, BdrvRequestFlags flags) -{ - NBDClientSession *client = nbd_get_client_session(bs); - NBDRequest request = { - .type = NBD_CMD_WRITE_ZEROES, - .from = offset, - .len = bytes, - }; - - assert(!(client->info.flags & NBD_FLAG_READ_ONLY)); - if (!(client->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { - return -ENOTSUP; - } - - if (flags & BDRV_REQ_FUA) { - assert(client->info.flags & NBD_FLAG_SEND_FUA); - request.flags |= NBD_CMD_FLAG_FUA; - } - if (!(flags & BDRV_REQ_MAY_UNMAP)) { - request.flags |= NBD_CMD_FLAG_NO_HOLE; - } - - if (!bytes) { - return 0; - } - return nbd_co_request(bs, &request, NULL); -} - -int nbd_client_co_flush(BlockDriverState *bs) -{ - NBDClientSession *client = nbd_get_client_session(bs); - NBDRequest request = { .type = NBD_CMD_FLUSH }; - - if (!(client->info.flags & NBD_FLAG_SEND_FLUSH)) { - return 0; - } - - request.from = 0; - request.len = 0; - - return nbd_co_request(bs, &request, NULL); -} - -int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) -{ - NBDClientSession *client = nbd_get_client_session(bs); - NBDRequest request = { - .type = NBD_CMD_TRIM, - .from = offset, - .len = bytes, - }; - - assert(!(client->info.flags & NBD_FLAG_READ_ONLY)); - if (!(client->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { - return 0; - } - - return nbd_co_request(bs, &request, NULL); -} - -int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs, - bool want_zero, - int64_t offset, int64_t bytes, - int64_t *pnum, int64_t *map, - BlockDriverState **file) -{ - int ret, request_ret; - NBDExtent extent = { 0 }; - NBDClientSession *client = nbd_get_client_session(bs); - Error *local_err = NULL; - - NBDRequest request = { - .type = NBD_CMD_BLOCK_STATUS, - .from = offset, - .len = MIN(MIN_NON_ZERO(QEMU_ALIGN_DOWN(INT_MAX, - bs->bl.request_alignment), - client->info.max_block), - MIN(bytes, client->info.size - offset)), - .flags = NBD_CMD_FLAG_REQ_ONE, - }; - - if (!client->info.base_allocation) { - *pnum = bytes; - *map = offset; - *file = bs; - return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; - } - - /* - * Work around the fact that the block layer doesn't do - * byte-accurate sizing yet - if the status request exceeds the - * server's advertised size because the block layer rounded size - * up, we truncated the request to the server (above), or are - * called on just the hole. - */ - if (offset >= client->info.size) { - *pnum = bytes; - assert(bytes < BDRV_SECTOR_SIZE); - /* Intentionally don't report offset_valid for the hole */ - return BDRV_BLOCK_ZERO; - } - - if (client->info.min_block) { - assert(QEMU_IS_ALIGNED(request.len, client->info.min_block)); - } - ret = nbd_co_send_request(bs, &request, NULL); - if (ret < 0) { - return ret; - } - - ret = nbd_co_receive_blockstatus_reply(client, request.handle, bytes, - &extent, &request_ret, &local_err); - if (local_err) { - trace_nbd_co_request_fail(request.from, request.len, request.handle, - request.flags, request.type, - nbd_cmd_lookup(request.type), - ret, error_get_pretty(local_err)); - error_free(local_err); - } - if (ret < 0 || request_ret < 0) { - return ret ? ret : request_ret; - } - - assert(extent.length); - *pnum = extent.length; - *map = offset; - *file = bs; - return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | - (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | - BDRV_BLOCK_OFFSET_VALID; -} - -void nbd_client_detach_aio_context(BlockDriverState *bs) -{ - NBDClientSession *client = nbd_get_client_session(bs); - qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc)); -} - -static void nbd_client_attach_aio_context_bh(void *opaque) -{ - BlockDriverState *bs = opaque; - NBDClientSession *client = nbd_get_client_session(bs); - - /* The node is still drained, so we know the coroutine has yielded in - * nbd_read_eof(), the only place where bs->in_flight can reach 0, or it is - * entered for the first time. Both places are safe for entering the - * coroutine.*/ - qemu_aio_coroutine_enter(bs->aio_context, client->connection_co); - bdrv_dec_in_flight(bs); -} - -void nbd_client_attach_aio_context(BlockDriverState *bs, - AioContext *new_context) -{ - NBDClientSession *client = nbd_get_client_session(bs); - qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), new_context); - - bdrv_inc_in_flight(bs); - - /* Need to wait here for the BH to run because the BH must run while the - * node is still drained. */ - aio_wait_bh_oneshot(new_context, nbd_client_attach_aio_context_bh, bs); -} - -void nbd_client_close(BlockDriverState *bs) -{ - NBDClientSession *client = nbd_get_client_session(bs); - NBDRequest request = { .type = NBD_CMD_DISC }; - - assert(client->ioc); - - nbd_send_request(client->ioc, &request); - - nbd_teardown_connection(bs); -} - -static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr, - Error **errp) -{ - QIOChannelSocket *sioc; - Error *local_err = NULL; - - sioc = qio_channel_socket_new(); - qio_channel_set_name(QIO_CHANNEL(sioc), "nbd-client"); - - qio_channel_socket_connect_sync(sioc, saddr, &local_err); - if (local_err) { - object_unref(OBJECT(sioc)); - error_propagate(errp, local_err); - return NULL; - } - - qio_channel_set_delay(QIO_CHANNEL(sioc), false); - - return sioc; -} - -static int nbd_client_connect(BlockDriverState *bs, - SocketAddress *saddr, - const char *export, - QCryptoTLSCreds *tlscreds, - const char *hostname, - const char *x_dirty_bitmap, - Error **errp) -{ - NBDClientSession *client = nbd_get_client_session(bs); - int ret; - - /* - * establish TCP connection, return error if it fails - * TODO: Configurable retry-until-timeout behaviour. - */ - QIOChannelSocket *sioc = nbd_establish_connection(saddr, errp); - - if (!sioc) { - return -ECONNREFUSED; - } - - /* NBD handshake */ - logout("session init %s\n", export); - qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL); - - client->info.request_sizes = true; - client->info.structured_reply = true; - client->info.base_allocation = true; - client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap); - client->info.name = g_strdup(export ?: ""); - ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), tlscreds, hostname, - &client->ioc, &client->info, errp); - g_free(client->info.x_dirty_bitmap); - g_free(client->info.name); - if (ret < 0) { - logout("Failed to negotiate with the NBD server\n"); - object_unref(OBJECT(sioc)); - return ret; - } - if (x_dirty_bitmap && !client->info.base_allocation) { - error_setg(errp, "requested x-dirty-bitmap %s not found", - x_dirty_bitmap); - ret = -EINVAL; - goto fail; - } - if (client->info.flags & NBD_FLAG_READ_ONLY) { - ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); - if (ret < 0) { - goto fail; - } - } - if (client->info.flags & NBD_FLAG_SEND_FUA) { - bs->supported_write_flags = BDRV_REQ_FUA; - bs->supported_zero_flags |= BDRV_REQ_FUA; - } - if (client->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { - bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; - } - - client->sioc = sioc; - - if (!client->ioc) { - client->ioc = QIO_CHANNEL(sioc); - object_ref(OBJECT(client->ioc)); - } - - /* Now that we're connected, set the socket to be non-blocking and - * kick the reply mechanism. */ - qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL); - client->connection_co = qemu_coroutine_create(nbd_connection_entry, client); - bdrv_inc_in_flight(bs); - nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs)); - - logout("Established connection with NBD server\n"); - return 0; - - fail: - /* - * We have connected, but must fail for other reasons. The - * connection is still blocking; send NBD_CMD_DISC as a courtesy - * to the server. - */ - { - NBDRequest request = { .type = NBD_CMD_DISC }; - - nbd_send_request(client->ioc ?: QIO_CHANNEL(sioc), &request); - - object_unref(OBJECT(sioc)); - - return ret; - } -} - -int nbd_client_init(BlockDriverState *bs, - SocketAddress *saddr, - const char *export, - QCryptoTLSCreds *tlscreds, - const char *hostname, - const char *x_dirty_bitmap, - Error **errp) -{ - NBDClientSession *client = nbd_get_client_session(bs); - - client->bs = bs; - qemu_co_mutex_init(&client->send_mutex); - qemu_co_queue_init(&client->free_sema); - - return nbd_client_connect(bs, saddr, export, tlscreds, hostname, - x_dirty_bitmap, errp); -} |