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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id AFB52C433FE for ; Tue, 8 Nov 2022 21:21:50 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1osW0X-0004uV-Bc; Tue, 08 Nov 2022 16:19:45 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1osW0W-0004sO-0T for qemu-devel@nongnu.org; Tue, 08 Nov 2022 16:19:44 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1osW0U-0008Jn-Ij for qemu-devel@nongnu.org; Tue, 08 Nov 2022 16:19:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667942382; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8niXQ0M6oTwB9tXPfc7Cn0IZ933zxKEgw2jU2Axalj8=; b=JMZlZGB5ttN6+VPKeqsgIs4WLBqBR+KSaVJo+GAhXKJf5o3bvEAC2SEuZmVr2blFCNPpg2 5rZRvYmIdjr3YewanBohzx71RYtYenDy05zN9dwMbn2HekTrjSPukvST5JORrm3k1ZY4DL 4z7NdQ9ZjENwJaphWt+L5G8dJmC55vw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-265-xlxCvilGMl-ygSywgU2CMg-1; Tue, 08 Nov 2022 16:19:38 -0500 X-MC-Unique: xlxCvilGMl-ygSywgU2CMg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 680FD858F17; Tue, 8 Nov 2022 21:19:38 +0000 (UTC) Received: from localhost (unknown [10.39.192.85]) by smtp.corp.redhat.com (Postfix) with ESMTP id D4A7A2166B2C; Tue, 8 Nov 2022 21:19:37 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Emanuele Giuseppe Esposito , "Michael S. Tsirkin" , qemu-block@nongnu.org, Kevin Wolf , Hanna Reitz , Paolo Bonzini , Fam Zheng , Stefan Hajnoczi Subject: [PATCH 2/8] block-backend: enable_write_cache should be atomic Date: Tue, 8 Nov 2022 16:19:24 -0500 Message-Id: <20221108211930.876142-3-stefanha@redhat.com> In-Reply-To: <20221108211930.876142-1-stefanha@redhat.com> References: <20221108211930.876142-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Emanuele Giuseppe Esposito It is read from IO_CODE and written with BQL held, so setting it as atomic should be enough. Also remove the aiocontext lock that was sporadically taken around the set. Signed-off-by: Emanuele Giuseppe Esposito Reviewed-by: Stefan Hajnoczi Signed-off-by: Stefan Hajnoczi Message-Id: <20220609143727.1151816-3-eesposit@redhat.com> --- block/block-backend.c | 6 +++--- hw/block/virtio-blk.c | 4 ---- 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index c0c7d56c8d..949418cad4 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -60,7 +60,7 @@ struct BlockBackend { * can be used to restore those options in the new BDS on insert) */ BlockBackendRootState root_state; - bool enable_write_cache; + bool enable_write_cache; /* Atomic */ /* I/O stats (display with "info blockstats"). */ BlockAcctStats stats; @@ -1939,13 +1939,13 @@ bool blk_is_sg(BlockBackend *blk) bool blk_enable_write_cache(BlockBackend *blk) { IO_CODE(); - return blk->enable_write_cache; + return qatomic_read(&blk->enable_write_cache); } void blk_set_enable_write_cache(BlockBackend *blk, bool wce) { IO_CODE(); - blk->enable_write_cache = wce; + qatomic_set(&blk->enable_write_cache, wce); } void blk_activate(BlockBackend *blk, Error **errp) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index cdc6fd5979..96d00103a4 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -961,9 +961,7 @@ static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) memcpy(&blkcfg, config, s->config_size); - aio_context_acquire(blk_get_aio_context(s->blk)); blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); - aio_context_release(blk_get_aio_context(s->blk)); } static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, @@ -1031,11 +1029,9 @@ static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) * s->blk would erroneously be placed in writethrough mode. */ if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) { - aio_context_acquire(blk_get_aio_context(s->blk)); blk_set_enable_write_cache(s->blk, virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_WCE)); - aio_context_release(blk_get_aio_context(s->blk)); } } -- 2.38.1