From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-4136612-1521110022-2-1092268570039175166 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='utf-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1521110021; b=rJgbakqkItS0Pyc331UCInan2fHQZS3mtTsHAQBYilW45IV CjPC5zqwGdAWghoBfx0erZnb5HBLEVIgG2prgHLKxb1DkxMtp3BtcTI3CQk1LiwE I2MyrworK5ycYCoBcFAMMlC/in4Jf97y/2Fc5crJf0JiHCeJI2ZG+zLjPcITBsis u5wtSr1N2U4gFEa85PGUv8FKf7NdS69ItuD8hMpHPZ5YvBWDS0HE3H4QpI/dveJR qYzTin3juzPT2ZQ48FxsIoio7nxdqFzng2+6PMc+6uUYXd5yN7cTiBgDx7E12Qku cwDZfp/RnDLvl93tlWas2rst1T1kU5ZFEMTg9EA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=subject:to:cc:references:from:message-id :date:mime-version:in-reply-to:content-type :content-transfer-encoding:sender:list-id; s=arctest; t= 1521110021; bh=dS6V5zy3R7KE2+3Wh0cjrTMEHtJf2GKXbKw9CNB/SJ4=; b=r c78S5s9x/jP1S46A6GD7V1TY4Up7JWsznlxhGfaGVIii6IyeKjWSlesZElfFEq9X ha4zJ9YzbZQQIff+jOmDKcViA0XgG7MBmT2xqGSLdYFU9EDYpi16is2uXva2iJL0 Ud71n/d63O7TeBLyi5PBSwirf1neRKNsx36zFJw3FWL+rze1Opz49q2URhflWK4E /ZoxxuvDoYL8K8CTb9UPPtGO8B57UtwuCssLTVGwYf2UeBMyopwZc3dQuNaSUawS eMP+GQsQLx+qfGUJP5CxCS6aHvg+lFmwMUdlkgH1tBO3HyAmobVF8B3zUl/NbibQ JSuoePHbppXd1XweL1Fqw== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=suse.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=suse.com header.result=pass header_is_org_domain=yes Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=suse.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-category=clean score=-100 state=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=suse.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751482AbeCOKdj (ORCPT ); Thu, 15 Mar 2018 06:33:39 -0400 Received: from mx2.suse.de ([195.135.220.15]:53895 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751467AbeCOKdi (ORCPT ); Thu, 15 Mar 2018 06:33:38 -0400 Subject: Re: [PATCH v2 1/3] xen: xenbus_dev_frontend: Fix XS_TRANSACTION_END handling To: Simon Gaiser , xen-devel@lists.xenproject.org Cc: stable@vger.kernel.org, Boris Ostrovsky , linux-kernel@vger.kernel.org References: <20180315024322.27429-1-simon@invisiblethingslab.com> From: Juergen Gross Message-ID: <3e626882-eac6-12db-9f5e-a75994bbdf2d@suse.com> Date: Thu, 15 Mar 2018 11:33:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180315024322.27429-1-simon@invisiblethingslab.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 15/03/18 03:43, Simon Gaiser wrote: > Commit fd8aa9095a95 ("xen: optimize xenbus driver for multiple > concurrent xenstore accesses") made a subtle change to the semantic of > xenbus_dev_request_and_reply() and xenbus_transaction_end(). > > Before on an error response to XS_TRANSACTION_END > xenbus_dev_request_and_reply() would not decrement the active > transaction counter. But xenbus_transaction_end() has always counted the > transaction as finished regardless of the response. > > The new behavior is that xenbus_dev_request_and_reply() and > xenbus_transaction_end() will always count the transaction as finished > regardless the response code (handled in xs_request_exit()). > > But xenbus_dev_frontend tries to end a transaction on closing of the > device if the XS_TRANSACTION_END failed before. Trying to close the > transaction twice corrupts the reference count. So fix this by also > considering a transaction closed if we have sent XS_TRANSACTION_END once > regardless of the return code. > > Cc: # 4.11 > Fixes: fd8aa9095a95 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses") > Signed-off-by: Simon Gaiser Reviewed-by: Juergen Gross Juergen