Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:32262 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762113AbdAIPGC (ORCPT ); Mon, 9 Jan 2017 10:06:02 -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: <20170109064224.GA3820@yuval-lap> Date: Mon, 9 Jan 2017 10:05:48 -0500 Cc: Sriharsha Basavapatna , Yuval Shaia , Linux NFS Mailing List , List Linux RDMA Mailing Message-Id: <5761AF19-DF8B-44CE-B744-C21464958041@oracle.com> References: <20170109103044.5590-1-sriharsha.basavapatna@broadcom.com> <20170109064224.GA3820@yuval-lap> To: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: > On Jan 9, 2017, at 1:42 AM, Yuval Shaia wrote: > > On Mon, Jan 09, 2017 at 04:00:44PM +0530, 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; > > Reviewed-by: Yuval Shaia Hi Bruce- Is it possible to take this in v4.10-rc ? -- Chuck Lever