From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-829916-1521666712-2-8887091796309415488 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, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, UNPARSEABLE_RELAY 0.001, 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=1521666712; b=Wb4h2zmTErghVX2nuh9dy7p5ef/fvZdZoj+Vq8lVChZWBy3 B+/RM8kUSwm5aYYnM4j/0TCMfmYfSfCQdT7yGUfy4LsyA32ESlEn+Aas7xEaKRE5 2xJByi4sxAWcbZThZodWePekQXDC70sY/Jdfmjo9PB7rorFaJKJhJjIPCp9O++3v Zo+woNujprW1mAXG47Hef9OoJt6dW/9hd+SzokDr+yAiMA2u23Y08lgEM0uIZ2rv DV/b16Axw8cTYvGYwW9kziaZYJ5YJwJB+GgBg9KJYmkc4njTzp7PooiCjPQ+N4tX VEa9vy056sx/A1063wQWQbrw9+x+/q1feMXNNoQ== 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= 1521666712; bh=cichXeIOP6AIi7buphbai/x8EGoqP3rGSGYAPLgY8TE=; b=O qBnSlUPpNN3qPjeqYFRJEQznwUv+sK3QFJiP1hTYrX4/HFEWCFi1xhwPItGhLRTU 0gwOE9iXwfAvzcbFEAm6j9iSa3V4+Dk4bbwW5639M2sC2z5KpePCEiAiiN8b2UZb fuLzh8rLJSQN0ekWNnrkom4hINW3c/fLfi5oRrJgpVnnZMgU49v1uU/ydN9WL+Cw +Sllhdw+oETNvVHFO1s4YdiISh0AJSYBRWHTkOo/5ruu0kuqnFk4INWSADpzhmuO 5sdV+sJTeI7vj8njUi9b4dRxde0WNQ3GnQz+FdLQjH67Qr9w2oGr8zZoPtqkc3Eh qSDE0zc6EN56clKD0NPhw== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=oracle.com header.i=@oracle.com header.b=P5hH3VxF x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=corp-2017-10-26; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=oracle.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-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=oracle.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=oracle.com header.i=@oracle.com header.b=P5hH3VxF x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=corp-2017-10-26; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=oracle.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-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=oracle.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753347AbeCUVLi (ORCPT ); Wed, 21 Mar 2018 17:11:38 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:52004 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753210AbeCUVLf (ORCPT ); Wed, 21 Mar 2018 17:11:35 -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, Juergen Gross , linux-kernel@vger.kernel.org References: <20180315024322.27429-1-simon@invisiblethingslab.com> From: Boris Ostrovsky Message-ID: Date: Wed, 21 Mar 2018 17:13:21 -0400 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-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8839 signatures=668695 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1803200127 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 03/14/2018 10:43 PM, 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 Applied the series to for-linus-4.17 -boris