From patchwork Thu Jun 9 14:37:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1641329 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=M6uklU2E; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4LJnYn1S2Lz9s2R for ; Fri, 10 Jun 2022 01:09:16 +1000 (AEST) Received: from localhost ([::1]:46226 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nzJmc-0000T2-8K for incoming@patchwork.ozlabs.org; Thu, 09 Jun 2022 11:09:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36314) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nzJI4-0002MU-Jp for qemu-devel@nongnu.org; Thu, 09 Jun 2022 10:37:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:36186) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nzJI1-00071C-0w for qemu-devel@nongnu.org; Thu, 09 Jun 2022 10:37:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654785456; 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=7+odWRPv6aI0/Te11N77cSgsLRfMke9pMgyM7AzZdxE=; b=M6uklU2EGobVaLS9rlnPqcssVDan4eckgeiQlpga0PxudnOzLCSDwitYn9M+NLYv5mQyEg eUuqNU+PlT0xE1RS27EqFhunEj83WhPCNxnKcOwK+mKWiBuSAllXIpCnRe/OVcpNSx69MT Hel+51JywmUX4jMOrKJMXzH+JTS38kU= 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-54-hOZbtKL4MLKBQj3gMSW-WQ-1; Thu, 09 Jun 2022 10:37:33 -0400 X-MC-Unique: hOZbtKL4MLKBQj3gMSW-WQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C302F801E67; Thu, 9 Jun 2022 14:37:32 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 838D5492C3B; Thu, 9 Jun 2022 14:37:32 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Cc: Kevin Wolf , Hanna Reitz , Stefan Hajnoczi , "Michael S. Tsirkin" , Paolo Bonzini , Fam Zheng , qemu-devel@nongnu.org, Emanuele Giuseppe Esposito Subject: [PATCH 2/8] block-backend: enable_write_cache should be atomic Date: Thu, 9 Jun 2022 10:37:21 -0400 Message-Id: <20220609143727.1151816-3-eesposit@redhat.com> In-Reply-To: <20220609143727.1151816-1-eesposit@redhat.com> References: <20220609143727.1151816-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 --- 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 f425b00793..384e52d564 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; @@ -1972,13 +1972,13 @@ 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) { GLOBAL_STATE_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 8d0590cc76..191f75ce25 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -988,9 +988,7 @@ 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, @@ -1058,11 +1056,9 @@ 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)); } }