From patchwork Fri Mar 12 09:22:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 12134037 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5564CC433DB for ; Fri, 12 Mar 2021 09:25:37 +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 C89B464FD5 for ; Fri, 12 Mar 2021 09:25:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C89B464FD5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38174 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lKe35-0005z5-St for qemu-devel@archiver.kernel.org; Fri, 12 Mar 2021 04:25:35 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51854) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lKe0F-00008o-Vt for qemu-devel@nongnu.org; Fri, 12 Mar 2021 04:22:39 -0500 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:47134) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lKe0E-000401-2r for qemu-devel@nongnu.org; Fri, 12 Mar 2021 04:22:39 -0500 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-379-PQuxDDBiNhWs1NVmHYjAaw-1; Fri, 12 Mar 2021 04:22:26 -0500 X-MC-Unique: PQuxDDBiNhWs1NVmHYjAaw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D00B683DD61; Fri, 12 Mar 2021 09:22:25 +0000 (UTC) Received: from bahia.redhat.com (ovpn-113-236.ams2.redhat.com [10.36.113.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2EFD16A967; Fri, 12 Mar 2021 09:22:24 +0000 (UTC) From: Greg Kurz To: qemu-devel@nongnu.org Subject: [PATCH v2 1/7] vhost-user: Drop misleading EAGAIN checks in slave_read() Date: Fri, 12 Mar 2021 10:22:06 +0100 Message-Id: <20210312092212.782255-2-groug@kaod.org> In-Reply-To: <20210312092212.782255-1-groug@kaod.org> References: <20210312092212.782255-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Received-SPF: softfail client-ip=207.211.30.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665 autolearn=no 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: =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , "Michael S. Tsirkin" , "Dr. David Alan Gilbert" , Greg Kurz , virtio-fs@redhat.com, Stefan Hajnoczi , Vivek Goyal Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" slave_read() checks EAGAIN when reading or writing to the socket fails. This gives the impression that the slave channel is in non-blocking mode, which is certainly not the case with the current code base. And the rest of the code isn't actually ready to cope with non-blocking I/O. Just drop the checks everywhere in this function for the sake of clarity. Signed-off-by: Greg Kurz Reviewed-by: Stefan Hajnoczi --- hw/virtio/vhost-user.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 2fdd5daf74bb..6af9b43a7232 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -1420,7 +1420,7 @@ static void slave_read(void *opaque) do { size = recvmsg(u->slave_fd, &msgh, 0); - } while (size < 0 && (errno == EINTR || errno == EAGAIN)); + } while (size < 0 && errno == EINTR); if (size != VHOST_USER_HDR_SIZE) { error_report("Failed to read from slave."); @@ -1452,7 +1452,7 @@ static void slave_read(void *opaque) /* Read payload */ do { size = read(u->slave_fd, &payload, hdr.size); - } while (size < 0 && (errno == EINTR || errno == EAGAIN)); + } while (size < 0 && errno == EINTR); if (size != hdr.size) { error_report("Failed to read payload from slave."); @@ -1503,7 +1503,7 @@ static void slave_read(void *opaque) do { size = writev(u->slave_fd, iovec, ARRAY_SIZE(iovec)); - } while (size < 0 && (errno == EINTR || errno == EAGAIN)); + } while (size < 0 && errno == EINTR); if (size != VHOST_USER_HDR_SIZE + hdr.size) { error_report("Failed to send msg reply to slave.");