Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:24621 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932822AbbELSTg convert rfc822-to-8bit (ORCPT ); Tue, 12 May 2015 14:19:36 -0400 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: [PATCH v2 02/16] xprtrdma: Warn when there are orphaned IB objects From: Chuck Lever In-Reply-To: <5552428D.7010907@Netapp.com> Date: Tue, 12 May 2015 14:20:00 -0400 Cc: linux-rdma@vger.kernel.org, Linux NFS Mailing List Message-Id: References: <20150511174401.31263.79596.stgit@manet.1015granger.net> <20150511180235.31263.71754.stgit@manet.1015granger.net> <5552428D.7010907@Netapp.com> To: Anna Schumaker Sender: linux-nfs-owner@vger.kernel.org List-ID: On May 12, 2015, at 2:12 PM, Anna Schumaker wrote: > Hi Chuck, > > On 05/11/2015 02:02 PM, Chuck Lever wrote: >> WARN during transport destruction if ib_dealloc_pd() fails. This is >> a sign that xprtrdma orphaned one or more RDMA API objects at some >> point, which can pin lower layer kernel modules and cause shutdown >> to hang. > > I'm curious, what would cause an RDMA object to get orphaned in the first place? A leaked object means there?s a software bug in the API consumer, which is xprtrdma in this case. xprtrdma is supposed to track and clean up every object it creates. > Is there any way to prevent that? The usual thing to do is find and fix the bug that allowed the leak. > Anna > >> >> Signed-off-by: Chuck Lever >> Reviewed-by: Steve Wise >> Reviewed-by: Sagi Grimberg >> Reviewed-by: Devesh Sharma >> --- >> net/sunrpc/xprtrdma/verbs.c | 10 +++++----- >> 1 file changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c >> index 4870d27..51900e6 100644 >> --- a/net/sunrpc/xprtrdma/verbs.c >> +++ b/net/sunrpc/xprtrdma/verbs.c >> @@ -702,17 +702,17 @@ rpcrdma_ia_close(struct rpcrdma_ia *ia) >> dprintk("RPC: %s: ib_dereg_mr returned %i\n", >> __func__, rc); >> } >> + >> if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) { >> if (ia->ri_id->qp) >> rdma_destroy_qp(ia->ri_id); >> rdma_destroy_id(ia->ri_id); >> ia->ri_id = NULL; >> } >> - if (ia->ri_pd != NULL && !IS_ERR(ia->ri_pd)) { >> - rc = ib_dealloc_pd(ia->ri_pd); >> - dprintk("RPC: %s: ib_dealloc_pd returned %i\n", >> - __func__, rc); >> - } >> + >> + /* If the pd is still busy, xprtrdma missed freeing a resource */ >> + if (ia->ri_pd && !IS_ERR(ia->ri_pd)) >> + WARN_ON(ib_dealloc_pd(ia->ri_pd)); >> } >> >> /* >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > -- > 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 chuck[dot]lever[at]oracle[dot]com