diff options
| -rw-r--r-- | nbd/client-connection.c | 50 |
1 files changed, 34 insertions, 16 deletions
diff --git a/nbd/client-connection.c b/nbd/client-connection.c index 695f855754..722998c985 100644 --- a/nbd/client-connection.c +++ b/nbd/client-connection.c @@ -39,16 +39,18 @@ struct NBDClientConnection { QemuMutex mutex; + NBDExportInfo updated_info; /* - * @sioc and @err represent a connection attempt. While running - * is true, they are only used by the connection thread, and mutex - * locking is not needed. Once the thread finishes, - * nbd_co_establish_connection then steals these pointers while - * under the mutex. + * @sioc represents a successful result. While thread is running, @sioc is + * used only by thread and not protected by mutex. When thread is not + * running, @sioc is stolen by nbd_co_establish_connection() under mutex. */ - NBDExportInfo updated_info; QIOChannelSocket *sioc; QIOChannel *ioc; + /* + * @err represents previous attempt. It may be copied by + * nbd_co_establish_connection() when it reports failure. + */ Error *err; /* All further fields are accessed only under mutex */ @@ -170,18 +172,18 @@ static void *connect_thread_func(void *opaque) qemu_mutex_lock(&conn->mutex); while (!conn->detached) { + Error *local_err = NULL; + assert(!conn->sioc); conn->sioc = qio_channel_socket_new(); qemu_mutex_unlock(&conn->mutex); - error_free(conn->err); - conn->err = NULL; conn->updated_info = conn->initial_info; ret = nbd_connect(conn->sioc, conn->saddr, conn->do_negotiation ? &conn->updated_info : NULL, - conn->tlscreds, &conn->ioc, &conn->err); + conn->tlscreds, &conn->ioc, &local_err); /* * conn->updated_info will finally be returned to the user. Clear the @@ -194,6 +196,10 @@ static void *connect_thread_func(void *opaque) qemu_mutex_lock(&conn->mutex); + error_free(conn->err); + conn->err = NULL; + error_propagate(&conn->err, local_err); + if (ret < 0) { object_unref(OBJECT(conn->sioc)); conn->sioc = NULL; @@ -311,14 +317,17 @@ nbd_co_establish_connection(NBDClientConnection *conn, NBDExportInfo *info, } conn->running = true; - error_free(conn->err); - conn->err = NULL; qemu_thread_create(&thread, "nbd-connect", connect_thread_func, conn, QEMU_THREAD_DETACHED); } if (!blocking) { - error_setg(errp, "No connection at the moment"); + if (conn->err) { + error_propagate(errp, error_copy(conn->err)); + } else { + error_setg(errp, "No connection at the moment"); + } + return NULL; } @@ -339,14 +348,23 @@ nbd_co_establish_connection(NBDClientConnection *conn, NBDExportInfo *info, * attempt as failed, but leave the connection thread running, * to reuse it for the next connection attempt. */ - error_setg(errp, "Connection attempt cancelled by other operation"); + if (conn->err) { + error_propagate(errp, error_copy(conn->err)); + } else { + error_setg(errp, + "Connection attempt cancelled by other operation"); + } + return NULL; } else { - error_propagate(errp, conn->err); - conn->err = NULL; - if (!conn->sioc) { + /* Thread finished. There must be either error or sioc */ + assert(!conn->err != !conn->sioc); + + if (conn->err) { + error_propagate(errp, error_copy(conn->err)); return NULL; } + if (conn->do_negotiation) { memcpy(info, &conn->updated_info, sizeof(*info)); if (conn->ioc) { |