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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 74B60C4361B for ; Fri, 18 Dec 2020 15:15:34 +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 0C77B23AFD for ; Fri, 18 Dec 2020 15:15:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C77B23AFD 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]:42500 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kqHTg-0003p4-VO for qemu-devel@archiver.kernel.org; Fri, 18 Dec 2020 10:15:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53678) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kqHRS-0001nb-Ev for qemu-devel@nongnu.org; Fri, 18 Dec 2020 10:13:14 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:26567) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kqHRQ-0005J7-Gq for qemu-devel@nongnu.org; Fri, 18 Dec 2020 10:13:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608304391; 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=VjNjrx90XKG//IjNFwwul7DqKmA9bmAOojMsq5hElc8=; b=Uu4wlKgAbyLpuJiP6dMP+NXdumTp6I96inCFxxRKP6Ky6UTO8D/oxOByF2crgc1dIiex6R PwE/bbn+/58qdpFcdriKSq3H0/rqWxC87BGf0DK+2sB3Wqoc763Jyr7SvnNeMvzpeODWXk 1CaiwYZYLIdBmzpgOBeyb39OOaXoaEc= 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-172-swVfubwrPXm_Ek86nJHTnw-1; Fri, 18 Dec 2020 10:13:09 -0500 X-MC-Unique: swVfubwrPXm_Ek86nJHTnw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 82663B8101; Fri, 18 Dec 2020 15:13:08 +0000 (UTC) Received: from localhost (ovpn-114-84.ams2.redhat.com [10.36.114.84]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 25F632C154; Fri, 18 Dec 2020 15:13:07 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PULL 07/30] block/io: split out bdrv_find_conflicting_request Date: Fri, 18 Dec 2020 16:12:26 +0100 Message-Id: <20201218151249.715731-8-mreitz@redhat.com> In-Reply-To: <20201218151249.715731-1-mreitz@redhat.com> References: <20201218151249.715731-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@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=mreitz@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_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 , Peter Maydell , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy To be reused in separate. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Stefan Hajnoczi Message-Id: <20201021145859.11201-4-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz --- block/io.c | 71 +++++++++++++++++++++++++++++++----------------------- 1 file changed, 41 insertions(+), 30 deletions(-) diff --git a/block/io.c b/block/io.c index 27370107b2..640136b8bc 100644 --- a/block/io.c +++ b/block/io.c @@ -754,43 +754,54 @@ static bool tracked_request_overlaps(BdrvTrackedRequest *req, return true; } +/* Called with self->bs->reqs_lock held */ +static BdrvTrackedRequest * +bdrv_find_conflicting_request(BdrvTrackedRequest *self) +{ + BdrvTrackedRequest *req; + + QLIST_FOREACH(req, &self->bs->tracked_requests, list) { + if (req == self || (!req->serialising && !self->serialising)) { + continue; + } + if (tracked_request_overlaps(req, self->overlap_offset, + self->overlap_bytes)) + { + /* + * Hitting this means there was a reentrant request, for + * example, a block driver issuing nested requests. This must + * never happen since it means deadlock. + */ + assert(qemu_coroutine_self() != req->co); + + /* + * If the request is already (indirectly) waiting for us, or + * will wait for us as soon as it wakes up, then just go on + * (instead of producing a deadlock in the former case). + */ + if (!req->waiting_for) { + return req; + } + } + } + + return NULL; +} + static bool coroutine_fn bdrv_wait_serialising_requests_locked(BlockDriverState *bs, BdrvTrackedRequest *self) { BdrvTrackedRequest *req; - bool retry; bool waited = false; - do { - retry = false; - QLIST_FOREACH(req, &bs->tracked_requests, list) { - if (req == self || (!req->serialising && !self->serialising)) { - continue; - } - if (tracked_request_overlaps(req, self->overlap_offset, - self->overlap_bytes)) - { - /* Hitting this means there was a reentrant request, for - * example, a block driver issuing nested requests. This must - * never happen since it means deadlock. - */ - assert(qemu_coroutine_self() != req->co); - - /* If the request is already (indirectly) waiting for us, or - * will wait for us as soon as it wakes up, then just go on - * (instead of producing a deadlock in the former case). */ - if (!req->waiting_for) { - self->waiting_for = req; - qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); - self->waiting_for = NULL; - retry = true; - waited = true; - break; - } - } - } - } while (retry); + while ((req = bdrv_find_conflicting_request(self))) { + self->waiting_for = req; + qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); + self->waiting_for = NULL; + waited = true; + } + return waited; } -- 2.29.2