/*
* QEMU Block driver for NBD
*
+ * Copyright (c) 2019 Virtuozzo International GmbH.
+ * Copyright (C) 2016 Red Hat, Inc.
* Copyright (C) 2008 Bull S.A.S.
* Author: Laurent Vivier <Laurent.Vivier@bull.net>
*
*/
#include "qemu/osdep.h"
-#include "nbd-client.h"
-#include "block/qdict.h"
-#include "qapi/error.h"
+
+#include "trace.h"
#include "qemu/uri.h"
-#include "block/block_int.h"
-#include "qemu/module.h"
#include "qemu/option.h"
+#include "qemu/cutils.h"
+#include "qemu/main-loop.h"
+
#include "qapi/qapi-visit-sockets.h"
-#include "qapi/qobject-input-visitor.h"
-#include "qapi/qobject-output-visitor.h"
-#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
-#include "qemu/cutils.h"
-#define EN_OPTSTR ":exportname="
+#include "block/qdict.h"
+#include "block/nbd.h"
+#include "block/block_int.h"
+
+#define EN_OPTSTR ":exportname="
+#define MAX_NBD_REQUESTS 16
+
+#define HANDLE_TO_INDEX(bs, handle) ((handle) ^ (uint64_t)(intptr_t)(bs))
+#define INDEX_TO_HANDLE(bs, index) ((index) ^ (uint64_t)(intptr_t)(bs))
+
+typedef struct {
+ Coroutine *coroutine;
+ uint64_t offset; /* original offset of the request */
+ bool receiving; /* waiting for connection_co? */
+} NBDClientRequest;
+
+typedef enum NBDClientState {
+ NBD_CLIENT_CONNECTING_WAIT,
+ NBD_CLIENT_CONNECTING_NOWAIT,
+ NBD_CLIENT_CONNECTED,
+ NBD_CLIENT_QUIT
+} NBDClientState;
+
+typedef struct BDRVNBDState {
+ QIOChannelSocket *sioc; /* The master data channel */
+ QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
+ NBDExportInfo info;
+
+ CoMutex send_mutex;
+ CoQueue free_sema;
+ Coroutine *connection_co;
+ Coroutine *teardown_co;
+ QemuCoSleepState *connection_co_sleep_ns_state;
+ bool drained;
+ bool wait_drained_end;
+ int in_flight;
+ NBDClientState state;
+ int connect_status;
+ Error *connect_err;
+ bool wait_in_flight;
+
+ NBDClientRequest requests[MAX_NBD_REQUESTS];
+ NBDReply reply;
+ BlockDriverState *bs;
+
+ /* Connection parameters */
+ uint32_t reconnect_delay;
+ SocketAddress *saddr;
+ char *export, *tlscredsid;
+ QCryptoTLSCreds *tlscreds;
+ const char *hostname;
+ char *x_dirty_bitmap;
+} BDRVNBDState;
+
+static int nbd_client_connect(BlockDriverState *bs, Error **errp);
+
+static void nbd_clear_bdrvstate(BDRVNBDState *s)
+{
+ object_unref(OBJECT(s->tlscreds));
+ qapi_free_SocketAddress(s->saddr);
+ s->saddr = NULL;
+ g_free(s->export);
+ s->export = NULL;
+ g_free(s->tlscredsid);
+ s->tlscredsid = NULL;
+ g_free(s->x_dirty_bitmap);
+ s->x_dirty_bitmap = NULL;
+}
+
+static void nbd_channel_error(BDRVNBDState *s, int ret)
+{
+ if (ret == -EIO) {
+ if (s->state == NBD_CLIENT_CONNECTED) {
+ s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT :
+ NBD_CLIENT_CONNECTING_NOWAIT;
+ }
+ } else {
+ if (s->state == NBD_CLIENT_CONNECTED) {
+ qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+ }
+ s->state = NBD_CLIENT_QUIT;
+ }
+}
+
+static void nbd_recv_coroutines_wake_all(BDRVNBDState *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_client_detach_aio_context(BlockDriverState *bs)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc));
+}
+
+static void nbd_client_attach_aio_context_bh(void *opaque)
+{
+ BlockDriverState *bs = opaque;
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ /*
+ * 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, s->connection_co);
+ bdrv_dec_in_flight(bs);
+}
+
+static void nbd_client_attach_aio_context(BlockDriverState *bs,
+ AioContext *new_context)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ /*
+ * s->connection_co is either yielded from nbd_receive_reply or from
+ * nbd_co_reconnect_loop()
+ */
+ if (s->state == NBD_CLIENT_CONNECTED) {
+ qio_channel_attach_aio_context(QIO_CHANNEL(s->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);
+}
+
+static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ s->drained = true;
+ if (s->connection_co_sleep_ns_state) {
+ qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
+ }
+}
+
+static void coroutine_fn nbd_client_co_drain_end(BlockDriverState *bs)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ s->drained = false;
+ if (s->wait_drained_end) {
+ s->wait_drained_end = false;
+ aio_co_wake(s->connection_co);
+ }
+}
+
+
+static void nbd_teardown_connection(BlockDriverState *bs)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ if (s->state == NBD_CLIENT_CONNECTED) {
+ /* finish any pending coroutines */
+ assert(s->ioc);
+ qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+ }
+ s->state = NBD_CLIENT_QUIT;
+ if (s->connection_co) {
+ if (s->connection_co_sleep_ns_state) {
+ qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
+ }
+ }
+ if (qemu_in_coroutine()) {
+ s->teardown_co = qemu_coroutine_self();
+ /* connection_co resumes us when it terminates */
+ qemu_coroutine_yield();
+ s->teardown_co = NULL;
+ } else {
+ BDRV_POLL_WHILE(bs, s->connection_co);
+ }
+ assert(!s->connection_co);
+}
+
+static bool nbd_client_connecting(BDRVNBDState *s)
+{
+ return s->state == NBD_CLIENT_CONNECTING_WAIT ||
+ s->state == NBD_CLIENT_CONNECTING_NOWAIT;
+}
+
+static bool nbd_client_connecting_wait(BDRVNBDState *s)
+{
+ return s->state == NBD_CLIENT_CONNECTING_WAIT;
+}
+
+static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
+{
+ Error *local_err = NULL;
+
+ if (!nbd_client_connecting(s)) {
+ return;
+ }
+
+ /* Wait for completion of all in-flight requests */
+
+ qemu_co_mutex_lock(&s->send_mutex);
+
+ while (s->in_flight > 0) {
+ qemu_co_mutex_unlock(&s->send_mutex);
+ nbd_recv_coroutines_wake_all(s);
+ s->wait_in_flight = true;
+ qemu_coroutine_yield();
+ s->wait_in_flight = false;
+ qemu_co_mutex_lock(&s->send_mutex);
+ }
+
+ qemu_co_mutex_unlock(&s->send_mutex);
+
+ if (!nbd_client_connecting(s)) {
+ return;
+ }
+
+ /*
+ * Now we are sure that nobody is accessing the channel, and no one will
+ * try until we set the state to CONNECTED.
+ */
+
+ /* Finalize previous connection if any */
+ if (s->ioc) {
+ nbd_client_detach_aio_context(s->bs);
+ object_unref(OBJECT(s->sioc));
+ s->sioc = NULL;
+ object_unref(OBJECT(s->ioc));
+ s->ioc = NULL;
+ }
+
+ s->connect_status = nbd_client_connect(s->bs, &local_err);
+ error_free(s->connect_err);
+ s->connect_err = NULL;
+ error_propagate(&s->connect_err, local_err);
+
+ if (s->connect_status < 0) {
+ /* failed attempt */
+ return;
+ }
+
+ /* successfully connected */
+ s->state = NBD_CLIENT_CONNECTED;
+ qemu_co_queue_restart_all(&s->free_sema);
+}
+
+static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState *s)
+{
+ uint64_t start_time_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ uint64_t delay_ns = s->reconnect_delay * NANOSECONDS_PER_SECOND;
+ uint64_t timeout = 1 * NANOSECONDS_PER_SECOND;
+ uint64_t max_timeout = 16 * NANOSECONDS_PER_SECOND;
+
+ nbd_reconnect_attempt(s);
+
+ while (nbd_client_connecting(s)) {
+ if (s->state == NBD_CLIENT_CONNECTING_WAIT &&
+ qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - start_time_ns > delay_ns)
+ {
+ s->state = NBD_CLIENT_CONNECTING_NOWAIT;
+ qemu_co_queue_restart_all(&s->free_sema);
+ }
+
+ qemu_co_sleep_ns_wakeable(QEMU_CLOCK_REALTIME, timeout,
+ &s->connection_co_sleep_ns_state);
+ if (s->drained) {
+ bdrv_dec_in_flight(s->bs);
+ s->wait_drained_end = true;
+ while (s->drained) {
+ /*
+ * We may be entered once from nbd_client_attach_aio_context_bh
+ * and then from nbd_client_co_drain_end. So here is a loop.
+ */
+ qemu_coroutine_yield();
+ }
+ bdrv_inc_in_flight(s->bs);
+ }
+ if (timeout < max_timeout) {
+ timeout *= 2;
+ }
+
+ nbd_reconnect_attempt(s);
+ }
+}
+
+static coroutine_fn void nbd_connection_entry(void *opaque)
+{
+ BDRVNBDState *s = opaque;
+ uint64_t i;
+ int ret = 0;
+ Error *local_err = NULL;
+
+ while (s->state != NBD_CLIENT_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.
+ */
+
+ if (nbd_client_connecting(s)) {
+ nbd_co_reconnect_loop(s);
+ }
+
+ if (s->state != NBD_CLIENT_CONNECTED) {
+ continue;
+ }
+
+ 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);
+ local_err = NULL;
+ }
+ if (ret <= 0) {
+ nbd_channel_error(s, ret ? ret : -EIO);
+ continue;
+ }
+
+ /*
+ * 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))
+ {
+ nbd_channel_error(s, -EINVAL);
+ continue;
+ }
+
+ /*
+ * 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();
+ }
+
+ qemu_co_queue_restart_all(&s->free_sema);
+ nbd_recv_coroutines_wake_all(s);
+ bdrv_dec_in_flight(s->bs);
+
+ s->connection_co = NULL;
+ if (s->ioc) {
+ nbd_client_detach_aio_context(s->bs);
+ object_unref(OBJECT(s->sioc));
+ s->sioc = NULL;
+ object_unref(OBJECT(s->ioc));
+ s->ioc = NULL;
+ }
+
+ if (s->teardown_co) {
+ aio_co_wake(s->teardown_co);
+ }
+ aio_wait_kick();
+}
+
+static int nbd_co_send_request(BlockDriverState *bs,
+ NBDRequest *request,
+ QEMUIOVector *qiov)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ int rc, i = -1;
+
+ qemu_co_mutex_lock(&s->send_mutex);
+ while (s->in_flight == MAX_NBD_REQUESTS || nbd_client_connecting_wait(s)) {
+ qemu_co_queue_wait(&s->free_sema, &s->send_mutex);
+ }
+
+ if (s->state != NBD_CLIENT_CONNECTED) {
+ rc = -EIO;
+ goto err;
+ }
+
+ 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);
+
+ assert(s->ioc);
+
+ if (qiov) {
+ qio_channel_set_cork(s->ioc, true);
+ rc = nbd_send_request(s->ioc, request);
+ if (rc >= 0 && s->state == NBD_CLIENT_CONNECTED) {
+ 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) {
+ nbd_channel_error(s, rc);
+ if (i != -1) {
+ s->requests[i].coroutine = NULL;
+ s->in_flight--;
+ }
+ if (s->in_flight == 0 && s->wait_in_flight) {
+ aio_co_wake(s->connection_co);
+ } else {
+ 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(BDRVNBDState *s,
+ 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 (s->info.min_block &&
+ !QEMU_IS_ALIGNED(hole_size, s->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(BDRVNBDState *s,
+ 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 (s->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,
+ s->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 (s->info.min_block && !QEMU_IS_ALIGNED(extent->length,
+ s->info.min_block)) {
+ trace_nbd_parse_blockstatus_compliance("extent length is unaligned");
+ if (extent->length > s->info.min_block) {
+ extent->length = QEMU_ALIGN_DOWN(extent->length,
+ s->info.min_block);
+ } else {
+ extent->length = s->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(BDRVNBDState *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
+static coroutine_fn int nbd_co_receive_structured_payload(
+ BDRVNBDState *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(
+ BDRVNBDState *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->state != NBD_CLIENT_CONNECTED) {
+ 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(
+ BDRVNBDState *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) {
+ memset(reply, 0, sizeof(*reply));
+ nbd_channel_error(s, ret);
+ } else {
+ /* For assert at loop start in nbd_connection_entry */
+ *reply = s->reply;
+ }
+ s->reply.handle = 0;
+
+ if (s->connection_co && !s->wait_in_flight) {
+ /*
+ * We must check s->wait_in_flight, because we may entered by
+ * nbd_recv_coroutines_wake_all(), in this case we should not
+ * wake connection_co here, it will woken by last request.
+ */
+ aio_co_wake(s->connection_co);
+ }
+
+ return ret;
+}
-typedef struct BDRVNBDState {
- NBDClientSession client;
+typedef struct NBDReplyChunkIter {
+ int ret;
+ int request_ret;
+ Error *err;
+ bool done, only_structured;
+} NBDReplyChunkIter;
- /* For nbd_refresh_filename() */
- SocketAddress *saddr;
- char *export, *tlscredsid;
-} BDRVNBDState;
+static void nbd_iter_channel_error(NBDReplyChunkIter *iter,
+ int ret, Error **local_err)
+{
+ assert(local_err && *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
+ * The pointer stored in @payload requires g_free() to free it.
+ */
+#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
+ * The pointer stored in @payload requires g_free() to free it.
+ */
+static bool nbd_reply_chunk_iter_receive(BDRVNBDState *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->state != NBD_CLIENT_CONNECTED) {
+ 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->state != NBD_CLIENT_CONNECTED) {
+ 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--;
+ if (s->in_flight == 0 && s->wait_in_flight) {
+ aio_co_wake(s->connection_co);
+ } else {
+ qemu_co_queue_next(&s->free_sema);
+ }
+ qemu_co_mutex_unlock(&s->send_mutex);
+
+ return false;
+}
+
+static int nbd_co_receive_return_code(BDRVNBDState *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(BDRVNBDState *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) {
+ nbd_channel_error(s, ret);
+ nbd_iter_channel_error(&iter, ret, &local_err);
+ }
+ break;
+ default:
+ if (!nbd_reply_type_is_error(chunk->type)) {
+ /* not allowed reply type */
+ nbd_channel_error(s, -EINVAL);
+ 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(BDRVNBDState *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) {
+ nbd_channel_error(s, -EINVAL);
+ 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) {
+ nbd_channel_error(s, ret);
+ nbd_iter_channel_error(&iter, ret, &local_err);
+ }
+ break;
+ default:
+ if (!nbd_reply_type_is_error(chunk->type)) {
+ nbd_channel_error(s, -EINVAL);
+ 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;
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ 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);
+ }
+
+ do {
+ ret = nbd_co_send_request(bs, request, write_qiov);
+ if (ret < 0) {
+ continue;
+ }
+
+ ret = nbd_co_receive_return_code(s, 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);
+ local_err = NULL;
+ }
+ } while (ret < 0 && nbd_client_connecting_wait(s));
+
+ return ret ? ret : request_ret;
+}
+
+static 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;
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ 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 >= s->info.size) {
+ assert(bytes < BDRV_SECTOR_SIZE);
+ qemu_iovec_memset(qiov, 0, 0, bytes);
+ return 0;
+ }
+ if (offset + bytes > s->info.size) {
+ uint64_t slop = offset + bytes - s->info.size;
+
+ assert(slop < BDRV_SECTOR_SIZE);
+ qemu_iovec_memset(qiov, bytes - slop, 0, slop);
+ request.len -= slop;
+ }
+
+ do {
+ ret = nbd_co_send_request(bs, &request, NULL);
+ if (ret < 0) {
+ continue;
+ }
+
+ ret = nbd_co_receive_cmdread_reply(s, 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);
+ local_err = NULL;
+ }
+ } while (ret < 0 && nbd_client_connecting_wait(s));
+
+ return ret ? ret : request_ret;
+}
+
+static int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, QEMUIOVector *qiov, int flags)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ NBDRequest request = {
+ .type = NBD_CMD_WRITE,
+ .from = offset,
+ .len = bytes,
+ };
+
+ assert(!(s->info.flags & NBD_FLAG_READ_ONLY));
+ if (flags & BDRV_REQ_FUA) {
+ assert(s->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);
+}
+
+static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
+ int bytes, BdrvRequestFlags flags)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ NBDRequest request = {
+ .type = NBD_CMD_WRITE_ZEROES,
+ .from = offset,
+ .len = bytes,
+ };
+
+ assert(!(s->info.flags & NBD_FLAG_READ_ONLY));
+ if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) {
+ return -ENOTSUP;
+ }
+
+ if (flags & BDRV_REQ_FUA) {
+ assert(s->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 (flags & BDRV_REQ_NO_FALLBACK) {
+ assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO);
+ request.flags |= NBD_CMD_FLAG_FAST_ZERO;
+ }
+
+ if (!bytes) {
+ return 0;
+ }
+ return nbd_co_request(bs, &request, NULL);
+}
+
+static int nbd_client_co_flush(BlockDriverState *bs)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ NBDRequest request = { .type = NBD_CMD_FLUSH };
+
+ if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) {
+ return 0;
+ }
+
+ request.from = 0;
+ request.len = 0;
+
+ return nbd_co_request(bs, &request, NULL);
+}
+
+static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset,
+ int bytes)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ NBDRequest request = {
+ .type = NBD_CMD_TRIM,
+ .from = offset,
+ .len = bytes,
+ };
+
+ assert(!(s->info.flags & NBD_FLAG_READ_ONLY));
+ if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) {
+ return 0;
+ }
+
+ return nbd_co_request(bs, &request, NULL);
+}
+
+static 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 };
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ Error *local_err = NULL;
+
+ NBDRequest request = {
+ .type = NBD_CMD_BLOCK_STATUS,
+ .from = offset,
+ .len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment),
+ MIN(bytes, s->info.size - offset)),
+ .flags = NBD_CMD_FLAG_REQ_ONE,
+ };
+
+ if (!s->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 >= s->info.size) {
+ *pnum = bytes;
+ assert(bytes < BDRV_SECTOR_SIZE);
+ /* Intentionally don't report offset_valid for the hole */
+ return BDRV_BLOCK_ZERO;
+ }
+
+ if (s->info.min_block) {
+ assert(QEMU_IS_ALIGNED(request.len, s->info.min_block));
+ }
+ do {
+ ret = nbd_co_send_request(bs, &request, NULL);
+ if (ret < 0) {
+ continue;
+ }
+
+ ret = nbd_co_receive_blockstatus_reply(s, 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);
+ local_err = NULL;
+ }
+ } while (ret < 0 && nbd_client_connecting_wait(s));
+
+ 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;
+}
+
+static int nbd_client_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque;
+
+ if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) {
+ error_setg(errp, "Can't reopen read-only NBD mount as read/write");
+ return -EACCES;
+ }
+ return 0;
+}
+
+static void nbd_client_close(BlockDriverState *bs)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ NBDRequest request = { .type = NBD_CMD_DISC };
+
+ if (s->ioc) {
+ nbd_send_request(s->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, Error **errp)
+{
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+ int ret;
+
+ /*
+ * establish TCP connection, return error if it fails
+ * TODO: Configurable retry-until-timeout behaviour.
+ */
+ QIOChannelSocket *sioc = nbd_establish_connection(s->saddr, errp);
+
+ if (!sioc) {
+ return -ECONNREFUSED;
+ }
+
+ /* NBD handshake */
+ trace_nbd_client_connect(s->export);
+ qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
+ qio_channel_attach_aio_context(QIO_CHANNEL(sioc), aio_context);
+
+ s->info.request_sizes = true;
+ s->info.structured_reply = true;
+ s->info.base_allocation = true;
+ s->info.x_dirty_bitmap = g_strdup(s->x_dirty_bitmap);
+ s->info.name = g_strdup(s->export ?: "");
+ ret = nbd_receive_negotiate(aio_context, QIO_CHANNEL(sioc), s->tlscreds,
+ s->hostname, &s->ioc, &s->info, errp);
+ g_free(s->info.x_dirty_bitmap);
+ g_free(s->info.name);
+ if (ret < 0) {
+ object_unref(OBJECT(sioc));
+ return ret;
+ }
+ if (s->x_dirty_bitmap && !s->info.base_allocation) {
+ error_setg(errp, "requested x-dirty-bitmap %s not found",
+ s->x_dirty_bitmap);
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (s->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 (s->info.flags & NBD_FLAG_SEND_FUA) {
+ bs->supported_write_flags = BDRV_REQ_FUA;
+ bs->supported_zero_flags |= BDRV_REQ_FUA;
+ }
+ if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) {
+ bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP;
+ if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) {
+ bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK;
+ }
+ }
+
+ s->sioc = sioc;
+
+ if (!s->ioc) {
+ s->ioc = QIO_CHANNEL(sioc);
+ object_ref(OBJECT(s->ioc));
+ }
+
+ trace_nbd_client_connect_success(s->export);
+
+ return 0;
+
+ fail:
+ /*
+ * We have connected, but must fail for other reasons.
+ * Send NBD_CMD_DISC as a courtesy to the server.
+ */
+ {
+ NBDRequest request = { .type = NBD_CMD_DISC };
+
+ nbd_send_request(s->ioc ?: QIO_CHANNEL(sioc), &request);
+
+ object_unref(OBJECT(sioc));
+
+ return ret;
+ }
+}
+
+/*
+ * Parse nbd_open options
+ */
static int nbd_parse_uri(const char *filename, QDict *options)
{
goto out;
}
- p = uri->path ? uri->path : "/";
- p += strspn(p, "/");
+ p = uri->path ? uri->path : "";
+ if (p[0] == '/') {
+ p++;
+ }
if (p[0]) {
qdict_put_str(options, "export", p);
}
static void nbd_parse_filename(const char *filename, QDict *options,
Error **errp)
{
- char *file;
+ g_autofree char *file = NULL;
char *export_name;
const char *host_spec;
const char *unixpath;
export_name = strstr(file, EN_OPTSTR);
if (export_name) {
if (export_name[strlen(EN_OPTSTR)] == 0) {
- goto out;
+ return;
}
export_name[0] = 0; /* truncate 'file' */
export_name += strlen(EN_OPTSTR);
/* extract the host_spec - fail if it's not nbd:... */
if (!strstart(file, "nbd:", &host_spec)) {
error_setg(errp, "File name string for NBD must start with 'nbd:'");
- goto out;
+ return;
}
if (!*host_spec) {
- goto out;
+ return;
}
/* are we a UNIX or TCP socket? */
out_inet:
qapi_free_InetSocketAddress(addr);
}
-
-out:
- g_free(file);
}
static bool nbd_process_legacy_socket_options(QDict *output_options,
return saddr;
}
-NBDClientSession *nbd_get_client_session(BlockDriverState *bs)
-{
- BDRVNBDState *s = bs->opaque;
- return &s->client;
-}
-
static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
{
Object *obj;
.help = "experimental: expose named dirty bitmap in place of "
"block status",
},
+ {
+ .name = "reconnect-delay",
+ .type = QEMU_OPT_NUMBER,
+ .help = "On an unexpected disconnect, the nbd client tries to "
+ "connect again until succeeding or encountering a serious "
+ "error. During the first @reconnect-delay seconds, all "
+ "requests are paused and will be rerun on a successful "
+ "reconnect. After that time, any delayed requests and all "
+ "future requests before a successful reconnect will "
+ "immediately fail. Default 0",
+ },
{ /* end of list */ }
},
};
-static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
- Error **errp)
+static int nbd_process_options(BlockDriverState *bs, QDict *options,
+ Error **errp)
{
BDRVNBDState *s = bs->opaque;
- QemuOpts *opts = NULL;
+ QemuOpts *opts;
Error *local_err = NULL;
- QCryptoTLSCreds *tlscreds = NULL;
- const char *hostname = NULL;
int ret = -EINVAL;
opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort);
}
s->export = g_strdup(qemu_opt_get(opts, "export"));
+ if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) {
+ error_setg(errp, "export name too long to send to server");
+ goto error;
+ }
s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds"));
if (s->tlscredsid) {
- tlscreds = nbd_get_tls_creds(s->tlscredsid, errp);
- if (!tlscreds) {
+ s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp);
+ if (!s->tlscreds) {
goto error;
}
error_setg(errp, "TLS only supported over IP sockets");
goto error;
}
- hostname = s->saddr->u.inet.host;
+ s->hostname = s->saddr->u.inet.host;
}
- /* NBD handshake */
- ret = nbd_client_init(bs, s->saddr, s->export, tlscreds, hostname,
- qemu_opt_get(opts, "x-dirty-bitmap"), errp);
+ s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap"));
+ if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) {
+ error_setg(errp, "x-dirty-bitmap query too long to send to server");
+ goto error;
+ }
+
+ s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0);
+
+ ret = 0;
error:
- if (tlscreds) {
- object_unref(OBJECT(tlscreds));
- }
if (ret < 0) {
- qapi_free_SocketAddress(s->saddr);
- g_free(s->export);
- g_free(s->tlscredsid);
+ nbd_clear_bdrvstate(s);
}
qemu_opts_del(opts);
return ret;
}
+static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ int ret;
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+ ret = nbd_process_options(bs, options, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ s->bs = bs;
+ qemu_co_mutex_init(&s->send_mutex);
+ qemu_co_queue_init(&s->free_sema);
+
+ ret = nbd_client_connect(bs, errp);
+ if (ret < 0) {
+ nbd_clear_bdrvstate(s);
+ return ret;
+ }
+ /* successfully connected */
+ s->state = NBD_CLIENT_CONNECTED;
+
+ s->connection_co = qemu_coroutine_create(nbd_connection_entry, s);
+ bdrv_inc_in_flight(bs);
+ aio_co_schedule(bdrv_get_aio_context(bs), s->connection_co);
+
+ return 0;
+}
+
static int nbd_co_flush(BlockDriverState *bs)
{
return nbd_client_co_flush(bs);
static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
{
- NBDClientSession *s = nbd_get_client_session(bs);
+ BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
uint32_t min = s->info.min_block;
uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block);
- bs->bl.request_alignment = min ? min : BDRV_SECTOR_SIZE;
- bs->bl.max_pdiscard = max;
+ /*
+ * If the server did not advertise an alignment:
+ * - a size that is not sector-aligned implies that an alignment
+ * of 1 can be used to access those tail bytes
+ * - advertisement of block status requires an alignment of 1, so
+ * that we don't violate block layer constraints that block
+ * status is always aligned (as we can't control whether the
+ * server will report sub-sector extents, such as a hole at EOF
+ * on an unaligned POSIX file)
+ * - otherwise, assume the server is so old that we are safer avoiding
+ * sub-sector requests
+ */
+ if (!min) {
+ min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) ||
+ s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE;
+ }
+
+ bs->bl.request_alignment = min;
+ bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min);
bs->bl.max_pwrite_zeroes = max;
bs->bl.max_transfer = max;
BDRVNBDState *s = bs->opaque;
nbd_client_close(bs);
-
- qapi_free_SocketAddress(s->saddr);
- g_free(s->export);
- g_free(s->tlscredsid);
+ nbd_clear_bdrvstate(s);
}
static int64_t nbd_getlength(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
- return s->client.info.size;
-}
-
-static void nbd_detach_aio_context(BlockDriverState *bs)
-{
- nbd_client_detach_aio_context(bs);
-}
-
-static void nbd_attach_aio_context(BlockDriverState *bs,
- AioContext *new_context)
-{
- nbd_client_attach_aio_context(bs, new_context);
+ return s->info.size;
}
static void nbd_refresh_filename(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
const char *host = NULL, *port = NULL, *path = NULL;
+ size_t len = 0;
if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) {
const InetSocketAddress *inet = &s->saddr->u.inet;
} /* else can't represent as pseudo-filename */
if (path && s->export) {
- snprintf(bs->exact_filename, sizeof(bs->exact_filename),
- "nbd+unix:///%s?socket=%s", s->export, path);
+ len = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
+ "nbd+unix:///%s?socket=%s", s->export, path);
} else if (path && !s->export) {
- snprintf(bs->exact_filename, sizeof(bs->exact_filename),
- "nbd+unix://?socket=%s", path);
+ len = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
+ "nbd+unix://?socket=%s", path);
} else if (host && s->export) {
- snprintf(bs->exact_filename, sizeof(bs->exact_filename),
- "nbd://%s:%s/%s", host, port, s->export);
+ len = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
+ "nbd://%s:%s/%s", host, port, s->export);
} else if (host && !s->export) {
- snprintf(bs->exact_filename, sizeof(bs->exact_filename),
- "nbd://%s:%s", host, port);
+ len = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
+ "nbd://%s:%s", host, port);
+ }
+ if (len > sizeof(bs->exact_filename)) {
+ /* Name is too long to represent exactly, so leave it empty. */
+ bs->exact_filename[0] = '\0';
}
}
.protocol_name = "nbd",
.instance_size = sizeof(BDRVNBDState),
.bdrv_parse_filename = nbd_parse_filename,
+ .bdrv_co_create_opts = bdrv_co_create_opts_simple,
+ .create_opts = &bdrv_create_opts_simple,
.bdrv_file_open = nbd_open,
+ .bdrv_reopen_prepare = nbd_client_reopen_prepare,
.bdrv_co_preadv = nbd_client_co_preadv,
.bdrv_co_pwritev = nbd_client_co_pwritev,
.bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes,
.bdrv_co_pdiscard = nbd_client_co_pdiscard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
- .bdrv_detach_aio_context = nbd_detach_aio_context,
- .bdrv_attach_aio_context = nbd_attach_aio_context,
+ .bdrv_detach_aio_context = nbd_client_detach_aio_context,
+ .bdrv_attach_aio_context = nbd_client_attach_aio_context,
+ .bdrv_co_drain_begin = nbd_client_co_drain_begin,
+ .bdrv_co_drain_end = nbd_client_co_drain_end,
.bdrv_refresh_filename = nbd_refresh_filename,
.bdrv_co_block_status = nbd_client_co_block_status,
.bdrv_dirname = nbd_dirname,
.protocol_name = "nbd+tcp",
.instance_size = sizeof(BDRVNBDState),
.bdrv_parse_filename = nbd_parse_filename,
+ .bdrv_co_create_opts = bdrv_co_create_opts_simple,
+ .create_opts = &bdrv_create_opts_simple,
.bdrv_file_open = nbd_open,
+ .bdrv_reopen_prepare = nbd_client_reopen_prepare,
.bdrv_co_preadv = nbd_client_co_preadv,
.bdrv_co_pwritev = nbd_client_co_pwritev,
.bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes,
.bdrv_co_pdiscard = nbd_client_co_pdiscard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
- .bdrv_detach_aio_context = nbd_detach_aio_context,
- .bdrv_attach_aio_context = nbd_attach_aio_context,
+ .bdrv_detach_aio_context = nbd_client_detach_aio_context,
+ .bdrv_attach_aio_context = nbd_client_attach_aio_context,
+ .bdrv_co_drain_begin = nbd_client_co_drain_begin,
+ .bdrv_co_drain_end = nbd_client_co_drain_end,
.bdrv_refresh_filename = nbd_refresh_filename,
.bdrv_co_block_status = nbd_client_co_block_status,
.bdrv_dirname = nbd_dirname,
.protocol_name = "nbd+unix",
.instance_size = sizeof(BDRVNBDState),
.bdrv_parse_filename = nbd_parse_filename,
+ .bdrv_co_create_opts = bdrv_co_create_opts_simple,
+ .create_opts = &bdrv_create_opts_simple,
.bdrv_file_open = nbd_open,
+ .bdrv_reopen_prepare = nbd_client_reopen_prepare,
.bdrv_co_preadv = nbd_client_co_preadv,
.bdrv_co_pwritev = nbd_client_co_pwritev,
.bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes,
.bdrv_co_pdiscard = nbd_client_co_pdiscard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
- .bdrv_detach_aio_context = nbd_detach_aio_context,
- .bdrv_attach_aio_context = nbd_attach_aio_context,
+ .bdrv_detach_aio_context = nbd_client_detach_aio_context,
+ .bdrv_attach_aio_context = nbd_client_attach_aio_context,
+ .bdrv_co_drain_begin = nbd_client_co_drain_begin,
+ .bdrv_co_drain_end = nbd_client_co_drain_end,
.bdrv_refresh_filename = nbd_refresh_filename,
.bdrv_co_block_status = nbd_client_co_block_status,
.bdrv_dirname = nbd_dirname,
projects / mirror_qemu.git / blobdiff