From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41AF6C48BE5 for ; Tue, 15 Jun 2021 21:04:07 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DB055613B6 for ; Tue, 15 Jun 2021 21:04:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB055613B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51678 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltGEA-0005b7-2k for qemu-devel@archiver.kernel.org; Tue, 15 Jun 2021 17:04:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58328) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltFz8-0002kh-LP for qemu-devel@nongnu.org; Tue, 15 Jun 2021 16:48:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:50035) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltFz1-0001BJ-1q for qemu-devel@nongnu.org; Tue, 15 Jun 2021 16:48:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623790106; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8iBpRtC0NrALa44ob+kWRWI5IIL6PR0RL+YVsIDMG98=; b=G+ycXXuQHv8D7/mqsdihBxZXzdCP8FABsypKDBxLXdOjciwh9e90nMR0jwbopCy6lAlUzQ 1P5awIkGCWFu/mlX2zCXIVZ/c54cMJb3M6Bnxuw6Hf4HCg33OhpdgkNu2R/wuK/svu2pjV pxqY+6r3NlyA1ddcvKXdtiutFSdEZw8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-479-t56aIzLYNfWOJqgt28RR2w-1; Tue, 15 Jun 2021 16:48:24 -0400 X-MC-Unique: t56aIzLYNfWOJqgt28RR2w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6F5DD100C609; Tue, 15 Jun 2021 20:48:23 +0000 (UTC) Received: from blue.redhat.com (ovpn-114-191.phx2.redhat.com [10.3.114.191]) by smtp.corp.redhat.com (Postfix) with ESMTP id 052925D9CA; Tue, 15 Jun 2021 20:48:22 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Subject: [PULL 22/34] nbd/client-connection: implement connection retry Date: Tue, 15 Jun 2021 15:47:44 -0500 Message-Id: <20210615204756.281505-23-eblake@redhat.com> In-Reply-To: <20210615204756.281505-1-eblake@redhat.com> References: <20210615204756.281505-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.197, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , "open list:Network Block Dev..." , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy Add an option for a thread to retry connecting until it succeeds. We'll use nbd/client-connection both for reconnect and for initial connection in nbd_open(), so we need a possibility to use same NBDClientConnection instance to connect once in nbd_open() and then use retry semantics for reconnect. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20210610100802.5888-21-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake [eblake: grammar tweak] Signed-off-by: Eric Blake --- include/block/nbd.h | 2 ++ nbd/client-connection.c | 56 +++++++++++++++++++++++++++++++---------- 2 files changed, 45 insertions(+), 13 deletions(-) diff --git a/include/block/nbd.h b/include/block/nbd.h index 5d86e6a393ff..5bb54d831c8a 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -409,6 +409,8 @@ const char *nbd_err_lookup(int err); /* nbd/client-connection.c */ typedef struct NBDClientConnection NBDClientConnection; +void nbd_client_connection_enable_retry(NBDClientConnection *conn); + NBDClientConnection *nbd_client_connection_new(const SocketAddress *saddr, bool do_negotiation, const char *export_name, diff --git a/nbd/client-connection.c b/nbd/client-connection.c index 4ed37cd73fa1..032b38ed3e9b 100644 --- a/nbd/client-connection.c +++ b/nbd/client-connection.c @@ -35,6 +35,7 @@ struct NBDClientConnection { QCryptoTLSCreds *tlscreds; NBDExportInfo initial_info; bool do_negotiation; + bool do_retry; QemuMutex mutex; @@ -61,6 +62,15 @@ struct NBDClientConnection { Coroutine *wait_co; }; +/* + * The function isn't protected by any mutex, only call it when the client + * connection attempt has not yet started. + */ +void nbd_client_connection_enable_retry(NBDClientConnection *conn) +{ + conn->do_retry = true; +} + NBDClientConnection *nbd_client_connection_new(const SocketAddress *saddr, bool do_negotiation, const char *export_name, @@ -155,24 +165,44 @@ static void *connect_thread_func(void *opaque) NBDClientConnection *conn = opaque; int ret; bool do_free; + uint64_t timeout = 1; + uint64_t max_timeout = 16; - conn->sioc = qio_channel_socket_new(); + while (true) { + conn->sioc = qio_channel_socket_new(); - error_free(conn->err); - conn->err = NULL; - conn->updated_info = conn->initial_info; + 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); - if (ret < 0) { - object_unref(OBJECT(conn->sioc)); - conn->sioc = NULL; + ret = nbd_connect(conn->sioc, conn->saddr, + conn->do_negotiation ? &conn->updated_info : NULL, + conn->tlscreds, &conn->ioc, &conn->err); + + /* + * conn->updated_info will finally be returned to the user. Clear the + * pointers to our internally allocated strings, which are IN parameters + * of nbd_receive_negotiate() and therefore nbd_connect(). Caller + * shoudn't be interested in these fields. + */ + conn->updated_info.x_dirty_bitmap = NULL; + conn->updated_info.name = NULL; + + if (ret < 0) { + object_unref(OBJECT(conn->sioc)); + conn->sioc = NULL; + if (conn->do_retry) { + sleep(timeout); + if (timeout < max_timeout) { + timeout *= 2; + } + continue; + } + } + + break; } - conn->updated_info.x_dirty_bitmap = NULL; - conn->updated_info.name = NULL; - qemu_mutex_lock(&conn->mutex); assert(conn->running); -- 2.31.1