From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3FA7EC433E2 for ; Sun, 6 Sep 2020 14:30:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E68182080A for ; Sun, 6 Sep 2020 14:30:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599402618; bh=dJhQbQ3cJjVwJyssRQ7zNyNSbfTW94IW0atFm6h5So0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=FTfBEz/hS0j53RBbORmL/07ltNCLCbUQ6k3iw4CPDOq0wGVRUkXHrTHJeiopJPhtq o6NgopAWOLgiBxq8oj8Rnmsn7IDxhJs+IQMoKh1C7sLWNajdMwjlJfMgeB0rgfC+i7 p3SSJh9oW9JEUeFLOlyeq6FRel9fdqR03k4fRc+Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728940AbgIFOZZ (ORCPT ); Sun, 6 Sep 2020 10:25:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:58042 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728957AbgIFOYi (ORCPT ); Sun, 6 Sep 2020 10:24:38 -0400 Received: from localhost (unknown [213.57.247.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8A19B207BC; Sun, 6 Sep 2020 14:24:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599402244; bh=dJhQbQ3cJjVwJyssRQ7zNyNSbfTW94IW0atFm6h5So0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bEichCto4MgGVwp6kRP/eHT8L/iFBMfCFL2G/s2j36rfqUZY6f0+6qdQgRB9OMsu8 TyTieDy3Za93rSXcqh1DXKLwVVg6seRNj3kguC9Mc0PxJ3jhpyrNn7qnmeRg1p5nQD PsjKQ/Svy2f5z0Mf3cAJgoer4rwUmC1Z4nc34nk4= Date: Sun, 6 Sep 2020 17:24:00 +0300 From: Leon Romanovsky To: Jason Gunthorpe Cc: Doug Ledford , linux-rdma@vger.kernel.org Subject: Re: [PATCH rdma-next v1 13/13] RDMA/restrack: Drop valid restrack field as source of ambiguity Message-ID: <20200906142400.GG55261@unreal> References: <20200830101436.108487-1-leon@kernel.org> <20200830101436.108487-14-leon@kernel.org> <20200903162148.GA1552408@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903162148.GA1552408@nvidia.com> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Thu, Sep 03, 2020 at 01:21:48PM -0300, Jason Gunthorpe wrote: > On Sun, Aug 30, 2020 at 01:14:36PM +0300, Leon Romanovsky wrote: > > From: Leon Romanovsky > > > > The valid field was needed to distinguish between supported/not > > supported QPs, after the create_qp was changed to support all types, > > that field can be dropped and the code simplified a little bit. > > > > Signed-off-by: Leon Romanovsky > > drivers/infiniband/core/restrack.c | 29 ++++++++--------------------- > > include/rdma/restrack.h | 9 --------- > > 2 files changed, 8 insertions(+), 30 deletions(-) > > > > diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c > > index 4caaa6312105..fb5345c8bd89 100644 > > +++ b/drivers/infiniband/core/restrack.c > > @@ -143,7 +143,7 @@ static struct ib_device *res_to_dev(struct rdma_restrack_entry *res) > > return container_of(res, struct rdma_counter, res)->device; > > default: > > WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type); > > - return NULL; > > + return ERR_PTR(-EINVAL); > > } > > } > > > > @@ -223,7 +223,7 @@ int __must_check rdma_restrack_add(struct rdma_restrack_entry *res) > > struct rdma_restrack_root *rt; > > int ret = 0; > > > > - if (!dev) > > + if (IS_ERR_OR_NULL(dev)) > > return -ENODEV; > > > > if (res->no_track) > > @@ -261,10 +261,7 @@ int __must_check rdma_restrack_add(struct rdma_restrack_entry *res) > > } > > > > out: > > - if (ret) > > - return ret; > > - res->valid = true; > > - return 0; > > + return ret; > > } > > EXPORT_SYMBOL(rdma_restrack_add); > > > > @@ -323,25 +320,16 @@ EXPORT_SYMBOL(rdma_restrack_put); > > */ > > void rdma_restrack_del(struct rdma_restrack_entry *res) > > { > > + struct ib_device *dev = res_to_dev(res); > > struct rdma_restrack_entry *old; > > struct rdma_restrack_root *rt; > > - struct ib_device *dev; > > > > - if (!res->valid) { > > - if (res->task) { > > - put_task_struct(res->task); > > - res->task = NULL; > > - } > > - return; > > - } > > - > > - if (res->no_track) > > + WARN_ONCE(!dev && res->type != RDMA_RESTRACK_CM_ID, > > + "IB device should be set for restrack type %s", > > + type2str(res->type)); > > + if (res->no_track || IS_ERR_OR_NULL(dev)) > > goto out; > > > > - dev = res_to_dev(res); > > - if (WARN_ON(!dev)) > > - return; > > - > > rt = &dev->res[res->type]; > > old = xa_erase(&rt->xa, res->id); > > How does this work without valid? > > xa_alloc is called in rdma_restrack_add() and previously it was safe > to call res_track_del() on unadded things. > > Now there are problems, like __ib_alloc_cq_user() does calls > restrack_del without doing restrack_ad() Maybe I missed it, but I don't see it in the code. After this series is applied, the rdma_restrack_del() can be called only on rdma_restrack_add(). This ensure that ->valid is not needed any more. Everything that is not added to DB uses rdma_restrack_new() call, which will be released by rdma_restrack_put(). > > > @@ -351,7 +339,6 @@ void rdma_restrack_del(struct rdma_restrack_entry *res) > > WARN_ON(old != res); > > So this WARN_ON should trigger? It helps to find the places with calls to rdma_restrack_del() without rdma_restrack_add() before. > > I don't think this can escape a bit that says that id is in the > xarray. Not needed, because of separation between _add() and _new(). > > I'd say no_track is a flag to add to rdma_restrack_add(), not a bit in > the struct. The bit in the struct is 'valid' aka > 'added_to_xarray'. The no_track flag simply doesn't set valid. > > Jason