Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:22451 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761650AbdADSUZ (ORCPT ); Wed, 4 Jan 2017 13:20:25 -0500 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [PATCH] svcrdma: avoid duplicate dma unmapping during error recovery From: Chuck Lever In-Reply-To: <20170104160329.24436-1-sriharsha.basavapatna@broadcom.com> Date: Wed, 4 Jan 2017 13:20:04 -0500 Cc: Linux NFS Mailing List , List Linux RDMA Mailing , Sagi Grimberg Message-Id: References: <20170104160329.24436-1-sriharsha.basavapatna@broadcom.com> To: Sriharsha Basavapatna Sender: linux-nfs-owner@vger.kernel.org List-ID: > On Jan 4, 2017, at 11:03 AM, Sriharsha Basavapatna wrote: > > In rdma_read_chunk_frmr() when ib_post_send() fails, the error code path > invokes ib_dma_unmap_sg() to unmap the sg list. It then invokes > svc_rdma_put_frmr() which in turn tries to unmap the same sg list through > ib_dma_unmap_sg() again. This second unmap is invalid and could lead to > problems when the iova being unmapped is subsequently reused. Remove > the call to unmap in rdma_read_chunk_frmr() and let svc_rdma_put_frmr() > handle it. > > Fixes: 412a15c0fe53 ("svcrdma: Port to new memory registration API") > Cc: stable@vger.kernel.org > Signed-off-by: Sriharsha Basavapatna Reviewed-by: Chuck Lever > --- > net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > index 57d35fbb1c28..172b537f8cfc 100644 > --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > @@ -347,8 +347,6 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt, > atomic_inc(&rdma_stat_read); > return ret; > err: > - ib_dma_unmap_sg(xprt->sc_cm_id->device, > - frmr->sg, frmr->sg_nents, frmr->direction); > svc_rdma_put_context(ctxt, 0); > svc_rdma_put_frmr(xprt, frmr); > return ret; > -- > 2.11.0.258.ge05806da9 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Chuck Lever