From patchwork Mon Jan 3 14:21:26 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: 12702550 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 03420C433EF for ; Mon, 3 Jan 2022 14:22:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233530AbiACOWz (ORCPT ); Mon, 3 Jan 2022 09:22:55 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:53832 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233532AbiACOWf (ORCPT ); Mon, 3 Jan 2022 09:22:35 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 3A5BE60FA2; Mon, 3 Jan 2022 14:22:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02126C36AED; Mon, 3 Jan 2022 14:22:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1641219754; bh=ANoc2P3PKF78Aw0vx5vO+sdAaWuMjpHWxwAQ1v3mjog=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IeYpYZe25rRHFcUY3tf0TIcGETxlVLrZYz058khT6jbStqHoo+MMtJBhQmJqeV2QJ a1sVb36Hw/1LkKR1e1xbryQW7BFjuSswOL5gQYBTnaD9GUZRpNTvnaoZV5EOQoqVgC v8QItPpIAgm2i6seDggXJDapsM6SKhid7jev39Rc= 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 4.9 10/13] scsi: vmw_pvscsi: Set residual data length conditionally Date: Mon, 3 Jan 2022 15:21:26 +0100 Message-Id: <20220103142052.291553274@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220103142051.979780231@linuxfoundation.org> References: <20220103142051.979780231@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 @@ -581,9 +581,12 @@ 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;