From patchwork Mon Jul 12 06:09:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 474493 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 D9DFDC07E9B for ; Mon, 12 Jul 2021 06:26:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C12756121F for ; Mon, 12 Jul 2021 06:26:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235399AbhGLG2v (ORCPT ); Mon, 12 Jul 2021 02:28:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:45894 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231796AbhGLG1w (ORCPT ); Mon, 12 Jul 2021 02:27:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 351E561176; Mon, 12 Jul 2021 06:24:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626071062; bh=elGwtORI2akq7wv+zMLThIEO7Hpn7kctPpnt+j/OysA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LpZUAOVx/VMpE+o7/yDV0rP4vlzqMHFVcW0JSyQhTANcYdJfVvqatPsCrU8qWy2kD kNty4kLFeycYka7u32OV9Q3PdepY29eGwTksPZFn4ItDxhwA4Ol5EXounveebdkwow LmfPZ9mWtEvOThG4axnOdgJ05eJoc4iI6kFPXtGI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhu Yanjun , Bob Pearson , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.4 215/348] RDMA/rxe: Fix qp reference counting for atomic ops Date: Mon, 12 Jul 2021 08:09:59 +0200 Message-Id: <20210712060730.082583958@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060659.886176320@linuxfoundation.org> References: <20210712060659.886176320@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Bob Pearson [ Upstream commit 15ae1375ea91ae2dee6f12d71a79d8c0a10a30bf ] Currently the rdma_rxe driver attempts to protect atomic responder resources by taking a reference to the qp which is only freed when the resource is recycled for a new read or atomic operation. This means that in normal circumstances there is almost always an extra qp reference once an atomic operation has been executed which prevents cleaning up the qp and associated pd and cqs when the qp is destroyed. This patch removes the call to rxe_add_ref() in send_atomic_ack() and the call to rxe_drop_ref() in free_rd_atomic_resource(). If the qp is destroyed while a peer is retrying an atomic op it will cause the operation to fail which is acceptable. Link: https://lore.kernel.org/r/20210604230558.4812-1-rpearsonhpe@gmail.com Reported-by: Zhu Yanjun Fixes: 86af61764151 ("IB/rxe: remove unnecessary skb_clone") Signed-off-by: Bob Pearson Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rxe/rxe_qp.c | 1 - drivers/infiniband/sw/rxe/rxe_resp.c | 2 -- 2 files changed, 3 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c index d427a343c09f..53166b9ae67e 100644 --- a/drivers/infiniband/sw/rxe/rxe_qp.c +++ b/drivers/infiniband/sw/rxe/rxe_qp.c @@ -152,7 +152,6 @@ static void free_rd_atomic_resources(struct rxe_qp *qp) void free_rd_atomic_resource(struct rxe_qp *qp, struct resp_res *res) { if (res->type == RXE_ATOMIC_MASK) { - rxe_drop_ref(qp); kfree_skb(res->atomic.skb); } else if (res->type == RXE_READ_MASK) { if (res->read.mr) diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index c4a8195bf670..186152bf7951 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -993,8 +993,6 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt, goto out; } - rxe_add_ref(qp); - res = &qp->resp.resources[qp->resp.res_head]; free_rd_atomic_resource(qp, res); rxe_advance_resp_resource(qp);