From nobody Tue Dec 16 09:00:16 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1512590515530305.7121869508662; Wed, 6 Dec 2017 12:01:55 -0800 (PST) Received: from localhost ([::1]:57468 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMft7-0003O3-7e for importer@patchew.org; Wed, 06 Dec 2017 15:01:49 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50135) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMfCq-00019U-EK for qemu-devel@nongnu.org; Wed, 06 Dec 2017 14:18:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eMfCn-00019z-37 for qemu-devel@nongnu.org; Wed, 06 Dec 2017 14:18:08 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:48448) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eMfCm-00018o-Qf for qemu-devel@nongnu.org; Wed, 06 Dec 2017 14:18:05 -0500 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vB6JE3I5043514 for ; Wed, 6 Dec 2017 14:18:04 -0500 Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) by mx0a-001b2d01.pphosted.com with ESMTP id 2epmpw5esk-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 06 Dec 2017 14:18:03 -0500 Received: from localhost by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Dec 2017 12:18:03 -0700 Received: from b03cxnp07028.gho.boulder.ibm.com (9.17.130.15) by e35.co.us.ibm.com (192.168.1.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 6 Dec 2017 12:17:59 -0700 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id vB6JHxc64653382; Wed, 6 Dec 2017 12:17:59 -0700 Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 55D4CBE03B; Wed, 6 Dec 2017 12:17:59 -0700 (MST) Received: from localhost (unknown [9.80.93.86]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP id 04AADBE038; Wed, 6 Dec 2017 12:17:58 -0700 (MST) From: Michael Roth To: qemu-devel@nongnu.org Date: Wed, 6 Dec 2017 13:16:46 -0600 X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171206191648.18208-1-mdroth@linux.vnet.ibm.com> References: <20171206191648.18208-1-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17120619-0012-0000-0000-0000156B940E X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008161; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000244; SDB=6.00956379; UDB=6.00483442; IPR=6.00736416; BA=6.00005729; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00018387; XFM=3.00000015; UTC=2017-12-06 19:18:01 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17120619-0013-0000-0000-0000508FF790 Message-Id: <20171206191648.18208-54-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-12-06_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1712060273 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 53/55] nbd/client: Don't hard-disconnect on ESHUTDOWN from server X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Eric Blake The NBD spec says that a server may fail any transmission request with ESHUTDOWN when it is apparent that no further request from the client can be successfully honored. The client is supposed to then initiate a soft shutdown (wait for all remaining in-flight requests to be answered, then send NBD_CMD_DISC). However, since qemu's server never uses ESHUTDOWN errors, this code was mostly untested since its introduction in commit b6f5d3b5. More recently, I learned that nbdkit as the NBD server is able to send ESHUTDOWN errors, so I finally tested this code, and noticed that our client was special-casing ESHUTDOWN to cause a hard shutdown (immediate disconnect, with no NBD_CMD_DISC), but only if the server sends this error as a simple reply. Further investigation found that commit d2febedb introduced a regression where structured replies behave differently than simple replies - but that the structured reply behavior is more in line with the spec (even if we still lack code in nbd-client.c to properly quit sending further requests). So this patch reverts the portion of b6f5d3b5 that introduced an improper hard-disconnect special-case at the lower level, and leaves the future enhancement of a nicer soft-disconnect at the higher level for another day. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake Message-Id: <20171113194857.13933-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy (cherry picked from commit 01b05c66a3616d5a4adc39fc90962e9efaf791d1) Conflicts: nbd/client.c *drop dep on d2febedb Signed-off-by: Michael Roth --- nbd/client.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/nbd/client.c b/nbd/client.c index 4caff77119..f04e95542f 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -945,12 +945,6 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *r= eply, Error **errp) reply->handle =3D ldq_be_p(buf + 8); =20 reply->error =3D nbd_errno_to_system_errno(reply->error); - - if (reply->error =3D=3D ESHUTDOWN) { - /* This works even on mingw which lacks a native ESHUTDOWN */ - error_setg(errp, "server shutting down"); - return -EINVAL; - } trace_nbd_receive_reply(magic, reply->error, reply->handle); =20 if (magic !=3D NBD_REPLY_MAGIC) { --=20 2.11.0