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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C37A7C7EE29 for ; Fri, 2 Jun 2023 18:43:09 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q59il-0007MY-UZ; Fri, 02 Jun 2023 14:41:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1q59ii-0007Lj-6U; Fri, 02 Jun 2023 14:41:52 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1q59if-0005az-Q2; Fri, 02 Jun 2023 14:41:51 -0400 Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 352IBRgf013371; Fri, 2 Jun 2023 18:41:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding : mime-version; s=pp1; bh=z0b1j8uC/vtCaiaJ08mxJ9ip1I4yqLednFShkQ78Xls=; b=ebZuvjR2Y0L9mDOfcuhdXvyGPO9duZ4T/Qw6XtUHrKD5n6s8KL8dKyaov6pS6T1wbIA5 K4T9kf4CC6m46rBgidZ+GtI9pZfdRjVIhyzthq3VrewGw1kWg8jVfWgLAvCeyxamjBUY cMPS7lQLRQqDCKmMja/CcgxwDsnJAkL6WvrOc6lbmlLDwIjgDb4979+lvPduSyWYEH8Q FJ1UTe2ehj2wg5P4NJ/LwunvM93RR+3sR12H449bRts6mxtomBpPS28SgT28kptPw4xs fUFONWC2G9ddfF9HVE7G/imhuAHAnxgjoK8Cjmdr752BKDMXeFSeLqhOo5WJ16cmdCAO CQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3qymrsspm6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 02 Jun 2023 18:41:41 +0000 Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 352IR3L8007151; Fri, 2 Jun 2023 18:41:39 GMT Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3qymrsspkp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 02 Jun 2023 18:41:39 +0000 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 352A298Q017380; Fri, 2 Jun 2023 18:41:38 GMT Received: from smtprelay07.dal12v.mail.ibm.com ([9.208.130.99]) by ppma03dal.us.ibm.com (PPS) with ESMTPS id 3qu9g5cb3s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 02 Jun 2023 18:41:38 +0000 Received: from smtpav03.dal12v.mail.ibm.com (smtpav03.dal12v.mail.ibm.com [10.241.53.102]) by smtprelay07.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 352Ifb5O38929008 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 2 Jun 2023 18:41:37 GMT Received: from smtpav03.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 32B9E5805A; Fri, 2 Jun 2023 18:41:37 +0000 (GMT) Received: from smtpav03.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9A9645803F; Fri, 2 Jun 2023 18:41:35 +0000 (GMT) Received: from [9.61.34.174] (unknown [9.61.34.174]) by smtpav03.dal12v.mail.ibm.com (Postfix) with ESMTP; Fri, 2 Jun 2023 18:41:35 +0000 (GMT) Message-ID: <638895f7-78b8-6e15-bbf8-916fc1513287@linux.ibm.com> Date: Fri, 2 Jun 2023 14:41:35 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PULL v2 02/16] block/file-posix: introduce helper functions for sysfs attributes Content-Language: en-US To: Sam Li Cc: Stefan Hajnoczi , qemu-devel@nongnu.org, Richard Henderson , Paolo Bonzini , Thomas Huth , =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= , Julia Suvorova , Aarushi Mehta , Kevin Wolf , kvm@vger.kernel.org, =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , Markus Armbruster , Cornelia Huck , Raphael Norwitz , qemu-block@nongnu.org, "Michael S. Tsirkin" , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Hanna Reitz , Eric Blake , Stefano Garzarella , Fam Zheng , Hannes Reinecke , Damien Le Moal , Dmitry Fomichev References: <20230515160506.1776883-1-stefanha@redhat.com> <20230515160506.1776883-3-stefanha@redhat.com> <8b0ced3c-2fb5-2479-fe78-f4956ac037a6@linux.ibm.com> From: Matthew Rosato In-Reply-To: Content-Type: text/plain; charset=UTF-8 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: BVFqtsEMssgDK4UDw7gVbrVfpoaTw8tW X-Proofpoint-ORIG-GUID: vqBETeB1CUUrFwKzmmQZQQFpTVXeefeE Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-02_14,2023-06-02_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 suspectscore=0 malwarescore=0 bulkscore=0 phishscore=0 clxscore=1011 mlxscore=0 impostorscore=0 spamscore=0 priorityscore=1501 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2306020142 Received-SPF: pass client-ip=148.163.158.5; envelope-from=mjrosato@linux.ibm.com; helo=mx0b-001b2d01.pphosted.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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.095, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 6/2/23 2:18 PM, Sam Li wrote: > Matthew Rosato 于2023年6月1日周四 02:21写道： >> >> On 5/15/23 12:04 PM, Stefan Hajnoczi wrote: >>> From: Sam Li >>> >>> Use get_sysfs_str_val() to get the string value of device >>> zoned model. Then get_sysfs_zoned_model() can convert it to >>> BlockZoneModel type of QEMU. >>> >>> Use get_sysfs_long_val() to get the long value of zoned device >>> information. >> >> Hi Stefan, Sam, >> >> I am having an issue on s390x using virtio-blk-{pci,ccw} backed by an NVMe partition, and I've bisected the root cause to this commit. >> >> I noticed that tests which use the partition e.g. /dev/nvme0n1p1 as a backing device would fail, but those that use the namespace e.g. /dev/nvme0n1 would still succeed. The root issue appears to be that the block device associated with the partition does not have a "max_segments" attribute, and prior to this patch hdev_get_max_segment() would return -ENOENT in this case. After this patch, however, QEMU is instead crashing. It looks like g_file_get_contents is returning 0 with a len == 0 if the specified sysfs path does not exist. The following diff on top seems to resolve the issue for me: >> >> >> diff --git a/block/file-posix.c b/block/file-posix.c >> index 0ab158efba2..eeb0247c74e 100644 >> --- a/block/file-posix.c >> +++ b/block/file-posix.c >> @@ -1243,7 +1243,7 @@ static int get_sysfs_str_val(struct stat *st, const char *attribute, >> major(st->st_rdev), minor(st->st_rdev), >> attribute); >> ret = g_file_get_contents(sysfspath, val, &len, NULL); >> - if (ret == -1) { >> + if (ret == -1 || len == 0) { >> return -ENOENT; >> } >> > > Hi Matthew, > > Thanks for the information. After some checking, I think the bug here > is that g_file_get_contens returns g_boolean value and the error case > will return 0 instead of -1 in my previous code. Can the following > line fix your issue on the s390x device? > > + if (ret == FALSE) { > > https://docs.gtk.org/glib/func.file_get_contents.html Hi Sam, Ah, good point, I didn't notice file_get_contents was meant to be a bool return and wondered why I was getting a return of 0 in the failing case, hence the check for len == 0. Anyway, yes, I verified that checking for ret == FALSE fixes the issue. FWIW, along the same line I also checked that this works: if (!g_file_get_contents(sysfspath, val, &len, NULL)) { return -ENOENT; } which I personally think looks cleaner and matches the other uses of g_file_get_contents in QEMU. Could also get rid of ret and just return 0 at the bottom of the function. Thanks, Matt