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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C884C4363A for ; Mon, 5 Oct 2020 16:02:42 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 835C9206DD for ; Mon, 5 Oct 2020 16:02:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PQ9aeIIH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 835C9206DD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53394 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kPSwi-00036v-JV for qemu-devel@archiver.kernel.org; Mon, 05 Oct 2020 12:02:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:32896) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kPSty-00015a-EQ for qemu-devel@nongnu.org; Mon, 05 Oct 2020 11:59:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:26804) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kPStq-0002DG-9c for qemu-devel@nongnu.org; Mon, 05 Oct 2020 11:59:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601913579; 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=UNF7vQhyvLveIcH0LkUirOla3WHTA58VFXcyLY7+IQw=; b=PQ9aeIIH5mW182uI2DqdsRkrwQWD8RiVakBLsJFzjcfGALJMEemoEQ7VTmV30ki2Ndonws OWGnBquc9rRL9pTI3CIXOy6BtMmEWl1sWXBIw88prGbVCMoez15lZZUVwL8n9caOVXedlc s0CoJry9ah+JwioHSBAM79b7iZYlKcg= 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-504-9_KCP4w9OQWra_i7_fRDvg-1; Mon, 05 Oct 2020 11:59:37 -0400 X-MC-Unique: 9_KCP4w9OQWra_i7_fRDvg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1322218C5218; Mon, 5 Oct 2020 15:59:36 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-113-145.ams2.redhat.com [10.36.113.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id C59BC60C11; Mon, 5 Oct 2020 15:59:34 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH v8 12/14] block: Add bdrv_co_enter()/leave() Date: Mon, 5 Oct 2020 17:58:53 +0200 Message-Id: <20201005155855.256490-13-kwolf@redhat.com> In-Reply-To: <20201005155855.256490-1-kwolf@redhat.com> References: <20201005155855.256490-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=63.128.21.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/05 01:25:11 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.733, 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_H5=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: kwolf@redhat.com, marcandre.lureau@gmail.com, armbru@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Add a pair of functions to temporarily move the current coroutine to the AioContext of a given BlockDriverState. Signed-off-by: Kevin Wolf --- include/block/block.h | 17 +++++++++++++++++ block.c | 23 +++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index 981ab5b314..b5fa7b2229 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -626,6 +626,23 @@ bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); */ AioContext *bdrv_get_aio_context(BlockDriverState *bs); +/** + * Move the current coroutine to the AioContext of @bs and return the old + * AioContext of the coroutine. Increase bs->in_flight so that draining @bs + * will wait for the operation to proceed until the corresponding + * bdrv_co_leave(). + * + * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as + * this will deadlock. + */ +AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs); + +/** + * Ends a section started by bdrv_co_enter(). Move the current coroutine back + * to old_ctx and decrease bs->in_flight again. + */ +void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx); + /** * Transfer control to @co in the aio context of @bs */ diff --git a/block.c b/block.c index f4b6dd5d3d..5eac2683b2 100644 --- a/block.c +++ b/block.c @@ -6372,6 +6372,29 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs) return bs ? bs->aio_context : qemu_get_aio_context(); } +AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs) +{ + Coroutine *self = qemu_coroutine_self(); + AioContext *old_ctx = qemu_coroutine_get_aio_context(self); + AioContext *new_ctx; + + /* + * Increase bs->in_flight to ensure that this operation is completed before + * moving the node to a different AioContext. Read new_ctx only afterwards. + */ + bdrv_inc_in_flight(bs); + + new_ctx = bdrv_get_aio_context(bs); + aio_co_reschedule_self(new_ctx); + return old_ctx; +} + +void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx) +{ + aio_co_reschedule_self(old_ctx); + bdrv_dec_in_flight(bs); +} + void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co) { aio_co_enter(bdrv_get_aio_context(bs), co); -- 2.25.4