From patchwork Mon Jan 3 14:24:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 529725 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F9D7C43217 for ; Mon, 3 Jan 2022 14:31:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234601AbiACObT (ORCPT ); Mon, 3 Jan 2022 09:31:19 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:33044 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234871AbiACOaF (ORCPT ); Mon, 3 Jan 2022 09:30:05 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 55D87B80EF1; Mon, 3 Jan 2022 14:30:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F617C36AEB; Mon, 3 Jan 2022 14:30:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1641220203; bh=+rPLnKknIZSktPz1CQ2xZo8naZzCjPMPwwbuURqYrl8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WmXk88/6/kKjyd2D5CkHfqS8DlJh4RjnkpGGOZPpdQcwLfe2+kAcS0JI4O75Bde+m Mlub4m4BHajHOgCui3D2xeB9K9KMIG9XWLQsQ45VqITIklmvgLAT4omapy+/P+MIFE YJNtb2hp6xPahY02rq3STIGJFNgUdydLjuBgS1iM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matt Wang , "Martin K. Petersen" , Vishal Bhakta , VMware PV-Drivers , "James E.J. Bottomley" , linux-scsi@vger.kernel.org, Alexey Makhalov , Shmulik Ladkani Subject: [PATCH 5.10 43/48] scsi: vmw_pvscsi: Set residual data length conditionally Date: Mon, 3 Jan 2022 15:24:20 +0100 Message-Id: <20220103142054.922995054@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220103142053.466768714@linuxfoundation.org> References: <20220103142053.466768714@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Alexey Makhalov commit 142c779d05d1fef75134c3cb63f52ccbc96d9e1f upstream. The PVSCSI implementation in the VMware hypervisor under specific configuration ("SCSI Bus Sharing" set to "Physical") returns zero dataLen in the completion descriptor for READ CAPACITY(16). As a result, the kernel can not detect proper disk geometry. This can be recognized by the kernel message: [ 0.776588] sd 1:0:0:0: [sdb] Sector size 0 reported, assuming 512. The PVSCSI implementation in QEMU does not set dataLen at all, keeping it zeroed. This leads to a boot hang as was reported by Shmulik Ladkani. It is likely that the controller returns the garbage at the end of the buffer. Residual length should be set by the driver in that case. The SCSI layer will erase corresponding data. See commit bdb2b8cab439 ("[SCSI] erase invalid data returned by device") for details. Commit e662502b3a78 ("scsi: vmw_pvscsi: Set correct residual data length") introduced the issue by setting residual length unconditionally, causing the SCSI layer to erase the useful payload beyond dataLen when this value is returned as 0. As a result, considering existing issues in implementations of PVSCSI controllers, we do not want to call scsi_set_resid() when dataLen == 0. Calling scsi_set_resid() has no effect if dataLen equals buffer length. Link: https://lore.kernel.org/lkml/20210824120028.30d9c071@blondie/ Link: https://lore.kernel.org/r/20211220190514.55935-1-amakhalov@vmware.com Fixes: e662502b3a78 ("scsi: vmw_pvscsi: Set correct residual data length") Cc: Matt Wang Cc: Martin K. Petersen Cc: Vishal Bhakta Cc: VMware PV-Drivers Cc: James E.J. Bottomley Cc: linux-scsi@vger.kernel.org Cc: stable@vger.kernel.org Reported-and-suggested-by: Shmulik Ladkani Signed-off-by: Alexey Makhalov Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/vmw_pvscsi.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/scsi/vmw_pvscsi.c +++ b/drivers/scsi/vmw_pvscsi.c @@ -591,9 +591,12 @@ static void pvscsi_complete_request(stru * Commands like INQUIRY may transfer less data than * requested by the initiator via bufflen. Set residual * count to make upper layer aware of the actual amount - * of data returned. + * of data returned. There are cases when controller + * returns zero dataLen with non zero data - do not set + * residual count in that case. */ - scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen); + if (e->dataLen && (e->dataLen < scsi_bufflen(cmd))) + scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen); cmd->result = (DID_OK << 16); break;