Return-Path: Received: from fieldses.org ([173.255.197.46]:58740 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945898AbbHGRgR (ORCPT ); Fri, 7 Aug 2015 13:36:17 -0400 Date: Fri, 7 Aug 2015 13:36:16 -0400 From: "J. Bruce Fields" To: Steve Wise Cc: dledford@redhat.com, linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH] svcrdma: limit FRMR page list lengths to device max Message-ID: <20150807173616.GD15313@fieldses.org> References: <20150807163539.EFDEFE0ACC@smtp.ogc.us> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20150807163539.EFDEFE0ACC@smtp.ogc.us> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, Aug 07, 2015 at 11:11:20AM -0500, Steve Wise wrote: > Svcrdma was incorrectly allocating fastreg MRs and page lists using > RPCSVC_MAXPAGES, which can exceed the device capabilities. So limit > the depth to the minimum of RPCSVC_MAXPAGES and xprt->sc_frmr_pg_list_len. > > Signed-off-by: Steve Wise > --- > Doug, this patch needs to be added after this commit: > > e20684a xprtrdma, svcrdma: Convert to ib_alloc_mr > > and before these commits: > > af78181 cxgb3: Support ib_alloc_mr verb > b7e06cd iw_cxgb4: Support ib_alloc_mr verb > > This will avoid a bisect window where NFSRDMA over cxgb4 is broken. > > Bruce, please ACK if this commit looks good, and also if you're ok with > this flowing through Doug's rdma tree due to the dependencies. Fine by me. On a quick check the only pending change in my tree nearby there is 31193fe5f6fb "svcrdma: Remove svc_rdma_fastreg()", which shouldn't conflict. Acked-by: J. Bruce Fields --b. > --- > net/sunrpc/xprtrdma/svc_rdma_transport.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c > index 8752a2d..11d5133 100644 > --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c > +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c > @@ -733,17 +733,19 @@ static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt) > struct ib_mr *mr; > struct ib_fast_reg_page_list *pl; > struct svc_rdma_fastreg_mr *frmr; > + u32 num_sg; > > frmr = kmalloc(sizeof(*frmr), GFP_KERNEL); > if (!frmr) > goto err; > > - mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, RPCSVC_MAXPAGES); > + num_sg = min_t(u32, RPCSVC_MAXPAGES, xprt->sc_frmr_pg_list_len); > + mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, num_sg); > if (IS_ERR(mr)) > goto err_free_frmr; > > pl = ib_alloc_fast_reg_page_list(xprt->sc_cm_id->device, > - RPCSVC_MAXPAGES); > + num_sg); > if (IS_ERR(pl)) > goto err_free_mr; > > -- > 1.7.1