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Mon, 17 May 2021 10:51:09 -0400 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-589-PJ1wyg06PWyT5TPuv35KLg-1; Mon, 17 May 2021 10:51:04 -0400 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 1AB8B80ED8E; Mon, 17 May 2021 14:51:03 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-113-23.ams2.redhat.com [10.36.113.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3934C5D6D7; Mon, 17 May 2021 14:51:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621263066; 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=33QIVLtuBhoIzq+RHDiCreoWe4oLY1whxlrAWafcQ1Y=; b=E7DstBCJRG32Eq9ohizaWVNTv5U76oOrQ/Dqu9xtlaQpm3zKSIG+UJOApx5MMcQqFwtO8Z N5lno6aDYHEvaJZxCcfXmL4Rn5KmoKJr5AoLtjSAsbw7P2ThE3fXScvHnIofGaourWcjsB pL1DmQtJeTkUMrLpXhB3gmDZo7gd39g= X-MC-Unique: PJ1wyg06PWyT5TPuv35KLg-1 From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v3 4/5] blkdebug: do not suspend in the middle of QLIST_FOREACH_SAFE Date: Mon, 17 May 2021 16:50:48 +0200 Message-Id: <20210517145049.55268-5-eesposit@redhat.com> In-Reply-To: <20210517145049.55268-1-eesposit@redhat.com> References: <20210517145049.55268-1-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 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=216.205.24.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.374, 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 , Emanuele Giuseppe Esposito , qemu-devel@nongnu.org, Max Reitz , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" That would be unsafe in case a rule other than the current one is removed while the coroutine has yielded. Keep FOREACH_SAFE because suspend_request deletes the current rule. After this patch, *all* matching rules are deleted before suspending the coroutine, rather than just one. This doesn't affect the existing testcases. Use actions_count to see how many yield to issue. Co-developed-by: Paolo Bonzini Signed-off-by: Emanuele Giuseppe Esposito Reviewed-by: Vladimir Sementsov-Ogievskiy --- block/blkdebug.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/block/blkdebug.c b/block/blkdebug.c index 388b5ed615..dffd869b32 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -789,7 +789,6 @@ static void suspend_request(BlockDriverState *bs, Blkde= bugRule *rule) if (!qtest_enabled()) { printf("blkdebug: Suspended request '%s'\n", r->tag); } - qemu_coroutine_yield(); } =20 static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, @@ -834,6 +833,12 @@ static void blkdebug_debug_event(BlockDriverState *bs,= BlkdebugEvent event) QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) { process_rule(bs, rule, actions_count); } + + while (actions_count[ACTION_SUSPEND] > 0) { + qemu_coroutine_yield(); + actions_count[ACTION_SUSPEND]--; + } + s->state =3D s->new_state; } =20 --=20 2.30.2