From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752317AbaCQU47 (ORCPT ); Mon, 17 Mar 2014 16:56:59 -0400 Received: from smtp-outbound-1.vmware.com ([208.91.2.12]:39043 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752275AbaCQU44 (ORCPT ); Mon, 17 Mar 2014 16:56:56 -0400 Date: Mon, 17 Mar 2014 13:56:55 -0700 (PDT) From: Arvind Kumar To: James Bottomley Cc: VMware PV-Drivers , linux-scsi@vger.kernel.org, "Linux-Kernel@Vger. Kernel. Org" , Josh Boyer Message-ID: <325692752.47738484.1395089815603.JavaMail.root@vmware.com> In-Reply-To: <1395076090.2227.29.camel@dabdike.int.hansenpartnership.com> References: <1395076090.2227.29.camel@dabdike.int.hansenpartnership.com> Subject: Re: DMA-API mapping errors in vmw_pvscsi MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.113.163.68] X-Mailer: Zimbra 8.0.3_GA_5664 (ZimbraWebClient - FF26 (Linux)/8.0.3_GA_5664) Thread-Topic: DMA-API mapping errors in vmw_pvscsi Thread-Index: Dxwtf7EpXGWFw7UDAZH/Aa/GCMm5hw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >It's missing checking in two places: from pci_map_single() and on >scsi_dma_map(). In the latter case, pvscsi_map_buffers needs to return >an error code and then pvscsi_queue_ring can return -1. Agreed! And in addition to that pvscsi_queue_ring() also calls pci_map_single() to map the sense buffer, which should also have the check. And if pvscsi_map_buffers() fails then we need to unmap the sense buffer too. We already have an internal bug filed and we are working on this. Thanks! Arvind ----- Original Message ----- From: "James Bottomley" Bottomley@HansenPartnership.com> To: "Josh Boyer" Cc: "Arvind Kumar" , "VMware PV-Drivers" , linux-scsi@vger.kernel.org, "Linux-Kernel@Vger. Kernel. Org" vger.kernel.org> Sent: Monday, March 17, 2014 10:08:10 AM Subject: Re: DMA-API mapping errors in vmw_pvscsi On Mon, 2014-03-17 at 12:52 -0400, Josh Boyer wrote: > Hi All, > > We've had a few reports[1][2] now on the vmw_pvscsi driver throwing > DMA-API mapping errors when the DMA_API_DEBUG option is enabled. I've > included one from a recent 3.14-rc6 kernel below. Looking at > vmw_pvscsi.c, I can see pvscsi_map_buffers is missing the calls to > pci_dma_mapping_error, which is what causes the warnings to be thrown. > > However, I'm not familiar with this driver and I can't see what the > proper error path should be in this case. pvscsi_map_buffers is a > void function and doesn't currently have the ability to return an > error to the caller. Even if it did, I'm not sure what the proper > response to an error should be. Thoughts? It's missing checking in two places: from pci_map_single() and on scsi_dma_map(). In the latter case, pvscsi_map_buffers needs to return an error code and then pvscsi_queue_ring can return -1. James