From patchwork Wed Mar 17 12:16:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 1454624 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=ONPyVNbF; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4F0q0b0HcQz9sTD for ; Wed, 17 Mar 2021 23:17:19 +1100 (AEDT) Received: from localhost ([::1]:46540 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMV6z-0002EZ-1G for incoming@patchwork.ozlabs.org; Wed, 17 Mar 2021 08:17:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57188) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMV6X-0002CP-93; Wed, 17 Mar 2021 08:16:49 -0400 Received: from mail-ej1-x62f.google.com ([2a00:1450:4864:20::62f]:38053) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lMV6S-0007hu-FY; Wed, 17 Mar 2021 08:16:48 -0400 Received: by mail-ej1-x62f.google.com with SMTP id mj10so2235197ejb.5; Wed, 17 Mar 2021 05:16:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=gKFdhh/Nl+B5HCHrzntCbboHzkUyX7zK92u6DKCbmu4=; b=ONPyVNbFq7SvXHVkaYyKh/8/nUSszeFezpZ32aaqNFE4s7r1X0Mr0W3gtZT7oNm6rG t/UVP11aqgC2w2KUHWO5nx37B7SaTMVrrtYUCtTDAAqt2a2IMXzoh26Zqy2Ce6kVNqyQ BcPXARmsCUPtA9/gTQwfPYmnpQ6Vado3RYSlvfXL2pTe6eAbwuQeM2aaaU6qvE5bDmKq 4E1QA3fnyL+nswAV2aJZ3sRd+RX9p5r8pyncp7gBrqhTi0RotLhbVLUFGuXkFbdhU6M/ 2cKN4NfTu1osCNE8j4NcZmrsDgJRytteNqmt6xupbeAGrbcw1rG8N2Bej95pS693gwED Lqhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=gKFdhh/Nl+B5HCHrzntCbboHzkUyX7zK92u6DKCbmu4=; b=iF7xgSsx29uNijQgQe5+kGRWh6vRad+3j8fUphlUSbkSwyXqCzPjCjgmHedTyivJAe 68j3GQtt57XjYs7gNXz0Y33kuQoTX7Nnn6ePoKn3EOg2TXESjdTQnGeyhH9U+9gW9/HR yYNsK7ljYITj+1/oKM+tZPo9vtzTk4iJCsC5LWDpALsMWRm9s1bzwtxbBBdHi2RGZcy1 JHvJx3DvbufpmyWdPTjevb0i/9zLcjbEQGiWzwxAIFoR3cJ23YKCDsrXejUZLjEV+PUR jTaLkTb6RZIHMivofSNKq4EeZLTiNDsI9MyXRfP97pDHO/mLzxOetj1diL4sAVuXlTaa FRAg== X-Gm-Message-State: AOAM533lrlBMzyHGwUDSxKB7W9UuAld7KuNtFMqfu3UTaGmrU3CSaZjA G8Nqs+Sa2lfdh61xDST29B1mrsgQJZo= X-Google-Smtp-Source: ABdhPJxqZcur0xH/iWwO01FpY5+FYYdFlCOERvH0sLYsBoK6u7CxtMQxiO/jQHnlsRUP9odkmjewXg== X-Received: by 2002:a17:906:bfcc:: with SMTP id us12mr35834954ejb.266.1615983402947; Wed, 17 Mar 2021 05:16:42 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id gq25sm11520996ejb.85.2021.03.17.05.16.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Mar 2021 05:16:42 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PATCH v4 0/6] coroutine rwlock downgrade fix, minor VDI changes Date: Wed, 17 Mar 2021 13:16:35 +0100 Message-Id: <20210317121641.215714-1-pbonzini@redhat.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::62f; envelope-from=paolo.bonzini@gmail.com; helo=mail-ej1-x62f.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: david.edmondson@oracle.com, kwolf@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" This is a resubmit of David Edmondson's series at https://patchew.org/QEMU/20210309144015.557477-1-david.edmondson@oracle.com/. After closer analysis on IRC, the CoRwLock's attempt to ensure fairness turned out to be flawed. Therefore, this series reimplements CoRwLock without using a CoQueue. Tracking whether each queued coroutine is a reader/writer makes it possible to never wake a writer when only readers should be allowed and vice versa. v3->v4: fix upgrade and add a test for that, too David Edmondson (4): block/vdi: When writing new bmap entry fails, don't leak the buffer block/vdi: Don't assume that blocks are larger than VdiHeader coroutine/mutex: Store the coroutine in the CoWaitRecord only once test-coroutine: Add rwlock downgrade test Paolo Bonzini (2): coroutine-lock: reimplement CoRwLock to fix downgrade bug test-coroutine: add rwlock upgrade test block/vdi.c | 11 ++- include/qemu/coroutine.h | 17 ++-- tests/unit/test-coroutine.c | 161 ++++++++++++++++++++++++++++++++++++ util/qemu-coroutine-lock.c | 149 +++++++++++++++++++++------------ 4 files changed, 274 insertions(+), 64 deletions(-)