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 BF04EC433FE for ; Tue, 22 Nov 2022 09:17:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oxPOK-0004LY-VA; Tue, 22 Nov 2022 04:16:32 -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 1oxPOJ-0004KR-Da for qemu-devel@nongnu.org; Tue, 22 Nov 2022 04:16:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oxPOH-0006Pw-19 for qemu-devel@nongnu.org; Tue, 22 Nov 2022 04:16:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669108588; 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: in-reply-to:in-reply-to:references:references; bh=sxQpkVENMdB7ldlKzUEgPBiyomsSTOIj/gRjJP0KRKQ=; b=aXIvdlBJDZ3DeFC6QrD5Zo8hie0jGn0xCNJ+SOgVK1W8QEQI3PVuAZJUf4VEKVvOrwvTNb 62LPAdI4FYRvYlufI91t5zVFhxxuOLXf0EJymaefZTD80ujjtPHzkxztIFctgfSqn6vdmE GvrM0mPTKg9fSF80vKVpQvCCCvCkReM= 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-532-pvl_hjwbPhCFKirfYwIHVw-1; Tue, 22 Nov 2022 04:16:24 -0500 X-MC-Unique: pvl_hjwbPhCFKirfYwIHVw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 902B88027F5; Tue, 22 Nov 2022 09:16:23 +0000 (UTC) Received: from redhat.com (unknown [10.39.192.218]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 333FB17595; Tue, 22 Nov 2022 09:16:22 +0000 (UTC) Date: Tue, 22 Nov 2022 10:16:19 +0100 From: Kevin Wolf To: Emanuele Giuseppe Esposito Cc: qemu-block@nongnu.org, Hanna Reitz , John Snow , Vladimir Sementsov-Ogievskiy , Eric Blake , Fam Zheng , qemu-devel@nongnu.org Subject: Re: [PATCH v4 10/11] block: convert bdrv_create to generated_co_wrapper_simple Message-ID: References: <20221116122241.2856527-1-eesposit@redhat.com> <20221116122241.2856527-11-eesposit@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221116122241.2856527-11-eesposit@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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 Am 16.11.2022 um 13:22 hat Emanuele Giuseppe Esposito geschrieben: > This function is never called in coroutine context, therefore > instead of manually creating a new coroutine, delegate it to the > block-coroutine-wrapper script, defining it as g_c_w_simple. > > Signed-off-by: Emanuele Giuseppe Esposito At first I thought that "never called in coroutine context" was not entirely true because of paths like this: qcow2_co_create() -> bdrv_open_blockdev_ref() -> bdrv_open_inherit() -> bdrv_append_temp_snapshot() -> bdrv_create(). The only reason why it doesn't happen is that with a BlockdevRef, it's impossible to get BDRV_O_SNAPSHOT set, so bdrv_append_temp_snapshot() can't actually be called when you come from bdrv_open_blockdev_ref(). Of course, opening images in a coroutine is likely to already do similar things. We should probably drop out of coroutine context for bdrv_open to be safe. In practice, I suspect it might work anyway because nothing is going to wait on the current coroutine, but maybe better not to rely on it. Anyway, not a problem of your patch, it's just something it made me think of. > diff --git a/block.c b/block.c > index 7a4c3eb540..d3e168408a 100644 > --- a/block.c > +++ b/block.c > @@ -528,7 +528,7 @@ typedef struct CreateCo { > Error *err; > } CreateCo; > > -static int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename, > +int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename, > QemuOpts *opts, Error **errp) The indentation is off now. With this fixed: Reviewed-by: Kevin Wolf