From nobody Tue Feb 10 15:01:36 2026 Delivered-To: importer2@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1623659543091765.1614749569904; Mon, 14 Jun 2021 01:32:23 -0700 (PDT) Received: from localhost ([::1]:46560 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lsi18-00056q-35 for importer2@patchew.org; Mon, 14 Jun 2021 04:32:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44114) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lshyY-0002HZ-Hk for qemu-devel@nongnu.org; Mon, 14 Jun 2021 04:29:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:38636) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lshyW-0005pn-TJ for qemu-devel@nongnu.org; Mon, 14 Jun 2021 04:29:42 -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-358-AVlyBwNDNICK9xoAN4NGoA-1; Mon, 14 Jun 2021 04:29:38 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id ED6A1107ACF6; Mon, 14 Jun 2021 08:29:37 +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 ECE6E5D9D3; Mon, 14 Jun 2021 08:29:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623659380; 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=sq0zn2MR504VMOSmeUVt0uGq5nK0p95DRBi9lImC/S0=; b=MtlVWOCDWo1Zuto3qHxyRx5YAx+j92QTwKn3YZvzlxGVdq79L1Cnpp3nj40XqykiIzKaC6 blGceDnLpIVKrnnkNB3+W5Nb27SRn8OYnllL8CA2DKJYm7wtg5NZmgN15ULRXtfFbTEGpj N9k2Yp1luwz8+roQUFfwW4OCI/M3OuE= X-MC-Unique: AVlyBwNDNICK9xoAN4NGoA-1 From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v5 1/6] blkdebug: refactor removal of a suspended request Date: Mon, 14 Jun 2021 10:29:26 +0200 Message-Id: <20210614082931.24925-2-eesposit@redhat.com> In-Reply-To: <20210614082931.24925-1-eesposit@redhat.com> References: <20210614082931.24925-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; 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 , Paolo Bonzini , Eric Blake Errors-To: qemu-devel-bounces+importer2=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Extract to a separate function. Do not rely on FOREACH_SAFE, which is only "safe" if the *current* node is removed---not if another node is removed. Instead, just walk the entire list from the beginning when asked to resume all suspended requests with a given tag. Co-developed-by: Paolo Bonzini Signed-off-by: Emanuele Giuseppe Esposito Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake --- block/blkdebug.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/block/blkdebug.c b/block/blkdebug.c index 2c0b9b0ee8..5ccbfcab42 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -793,7 +793,6 @@ static void suspend_request(BlockDriverState *bs, Blkde= bugRule *rule) printf("blkdebug: Resuming request '%s'\n", r.tag); } =20 - QLIST_REMOVE(&r, next); g_free(r.tag); } =20 @@ -869,25 +868,40 @@ static int blkdebug_debug_breakpoint(BlockDriverState= *bs, const char *event, return 0; } =20 -static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag) +static int resume_req_by_tag(BDRVBlkdebugState *s, const char *tag, bool a= ll) { - BDRVBlkdebugState *s =3D bs->opaque; - BlkdebugSuspendedReq *r, *next; + BlkdebugSuspendedReq *r; =20 - QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) { +retry: + /* + * No need for _SAFE, since a different coroutine can remove another n= ode + * (not the current one) in this list, and when the current one is rem= oved + * the iteration starts back from beginning anyways. + */ + QLIST_FOREACH(r, &s->suspended_reqs, next) { if (!strcmp(r->tag, tag)) { + QLIST_REMOVE(r, next); qemu_coroutine_enter(r->co); + if (all) { + goto retry; + } return 0; } } return -ENOENT; } =20 +static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag) +{ + BDRVBlkdebugState *s =3D bs->opaque; + + return resume_req_by_tag(s, tag, false); +} + static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) { BDRVBlkdebugState *s =3D bs->opaque; - BlkdebugSuspendedReq *r, *r_next; BlkdebugRule *rule, *next; int i, ret =3D -ENOENT; =20 @@ -900,11 +914,8 @@ static int blkdebug_debug_remove_breakpoint(BlockDrive= rState *bs, } } } - QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) { - if (!strcmp(r->tag, tag)) { - qemu_coroutine_enter(r->co); - ret =3D 0; - } + if (resume_req_by_tag(s, tag, true) =3D=3D 0) { + ret =3D 0; } return ret; } --=20 2.31.1