From patchwork Mon Jun 14 07:33:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1491556 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org 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=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=LJ8b0mZ5; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4G3NdL4zxqz9sWl for ; Mon, 14 Jun 2021 17:39:50 +1000 (AEST) Received: from localhost ([::1]:48822 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lshCG-0007BY-Gu for incoming@patchwork.ozlabs.org; Mon, 14 Jun 2021 03:39:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35258) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lsh72-00066s-M6 for qemu-devel@nongnu.org; Mon, 14 Jun 2021 03:34:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:48265) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lsh70-0005Ba-TZ for qemu-devel@nongnu.org; Mon, 14 Jun 2021 03:34:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623656062; 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=XL9LfIfxRN2XjFCD+OVGMrlQ/snVijAp3KeI/NwqtF4=; b=LJ8b0mZ5eD8HeSHezZ9iWYu4Y2trRsGswLIY96lFJ9Ky+JYzFL9KYgYIXrMVZaYkgbHI9J N2sOU79kb9oV2X0eY7Cb0yDFK41/G+5gUbCuj+mOB3HDk6JwpSZmC7RLbGe/hVJdhmP/m3 UjlFCnTTI6qIN8ZZwVNaJz0fPVMBmaQ= 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-346-Woc9fdl4PnWrNZxHSpf0Tw-1; Mon, 14 Jun 2021 03:34:21 -0400 X-MC-Unique: Woc9fdl4PnWrNZxHSpf0Tw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 25126100C661; Mon, 14 Jun 2021 07:34:20 +0000 (UTC) Received: from localhost.localdomain (ovpn-113-49.ams2.redhat.com [10.36.113.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id DE6085D6A8; Mon, 14 Jun 2021 07:34:11 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v4 6/6] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState Date: Mon, 14 Jun 2021 09:33:50 +0200 Message-Id: <20210614073350.17048-7-eesposit@redhat.com> In-Reply-To: <20210614073350.17048-1-eesposit@redhat.com> References: <20210614073350.17048-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.199, 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=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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 , Emanuele Giuseppe Esposito , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" By adding acquire/release pairs, we ensure that .ret and .error_is_read fields are written by block_copy_dirty_clusters before .finished is true. The atomic here are necessary because the fields are concurrently modified also outside coroutines. Signed-off-by: Emanuele Giuseppe Esposito --- block/block-copy.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/block/block-copy.c b/block/block-copy.c index 6416929abd..5348e1f61b 100644 --- a/block/block-copy.c +++ b/block/block-copy.c @@ -53,14 +53,14 @@ typedef struct BlockCopyCallState { Coroutine *co; /* State */ - bool finished; + bool finished; /* atomic */ QemuCoSleep sleep; /* TODO: protect API with a lock */ /* To reference all call states from BlockCopyState */ QLIST_ENTRY(BlockCopyCallState) list; /* OUT parameters */ - bool cancelled; + bool cancelled; /* atomic */ /* Fields protected by lock in BlockCopyState */ bool error_is_read; int ret; @@ -650,7 +650,8 @@ block_copy_dirty_clusters(BlockCopyCallState *call_state) assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); assert(QEMU_IS_ALIGNED(bytes, s->cluster_size)); - while (bytes && aio_task_pool_status(aio) == 0 && !call_state->cancelled) { + while (bytes && aio_task_pool_status(aio) == 0 && + !qatomic_read(&call_state->cancelled)) { BlockCopyTask *task; int64_t status_bytes; @@ -761,7 +762,7 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state) do { ret = block_copy_dirty_clusters(call_state); - if (ret == 0 && !call_state->cancelled) { + if (ret == 0 && !qatomic_read(&call_state->cancelled)) { WITH_QEMU_LOCK_GUARD(&s->lock) { /* * Check that there is no task we still need to @@ -792,9 +793,9 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state) * 2. We have waited for some intersecting block-copy request * It may have failed and produced new dirty bits. */ - } while (ret > 0 && !call_state->cancelled); + } while (ret > 0 && !qatomic_read(&call_state->cancelled)); - call_state->finished = true; + qatomic_store_release(&call_state->finished, true); if (call_state->cb) { call_state->cb(call_state->cb_opaque); @@ -857,35 +858,37 @@ void block_copy_call_free(BlockCopyCallState *call_state) return; } - assert(call_state->finished); + assert(qatomic_load_acquire(&call_state->finished)); g_free(call_state); } bool block_copy_call_finished(BlockCopyCallState *call_state) { - return call_state->finished; + return qatomic_load_acquire(&call_state->finished); } bool block_copy_call_succeeded(BlockCopyCallState *call_state) { - return call_state->finished && !call_state->cancelled && - call_state->ret == 0; + return qatomic_load_acquire(&call_state->finished) && + !qatomic_read(&call_state->cancelled) && + call_state->ret == 0; } bool block_copy_call_failed(BlockCopyCallState *call_state) { - return call_state->finished && !call_state->cancelled && - call_state->ret < 0; + return qatomic_load_acquire(&call_state->finished) && + !qatomic_read(&call_state->cancelled) && + call_state->ret < 0; } bool block_copy_call_cancelled(BlockCopyCallState *call_state) { - return call_state->cancelled; + return qatomic_read(&call_state->cancelled); } int block_copy_call_status(BlockCopyCallState *call_state, bool *error_is_read) { - assert(call_state->finished); + assert(qatomic_load_acquire(&call_state->finished)); if (error_is_read) { *error_is_read = call_state->error_is_read; } @@ -894,7 +897,7 @@ int block_copy_call_status(BlockCopyCallState *call_state, bool *error_is_read) void block_copy_call_cancel(BlockCopyCallState *call_state) { - call_state->cancelled = true; + qatomic_set(&call_state->cancelled, true); block_copy_kick(call_state); }