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=-13.1 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,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 715A8C433E6 for ; Wed, 2 Sep 2020 08:11:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 523372087C for ; Wed, 2 Sep 2020 08:11:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599034299; bh=pu7BqtrRV3xB3IGB0NLz9sjE0SzpYaVLQiInsAAskDg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1AWtI+BE3HmRrUhbsooRMr28/GRQ39NodLIuoY/78/voJvXMgvugIQjxgIn5Mbl47 sbJr1hMLpN8dzjkVl2PFE/sQlZl8t6tSnq0HKNVQ3WDiyHBqgw0xQBzsNizkB6HBb/ 3eMM77xZQhZJHSZ7uzQ8PsgYXSo98qVI4JG4Vicg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726968AbgIBILh (ORCPT ); Wed, 2 Sep 2020 04:11:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:34178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726293AbgIBILf (ORCPT ); Wed, 2 Sep 2020 04:11:35 -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 B2DB820826; Wed, 2 Sep 2020 08:11:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599034294; bh=pu7BqtrRV3xB3IGB0NLz9sjE0SzpYaVLQiInsAAskDg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sLLSDaX4Eyx2qN5KuxWyWSVkPYtoRSzQGXOs+KT17Upbk0Qs1tMOj4FG0Nw8nC9+O gVESGXRQ1LeXgc8YUjiXsqIIZu32Ljc6JXioQbNbqkV45HzcaBLeW1fNtFcBPcpYvn WqaQkgSKpFKT7FeOzdzrafCgVYtvjHb+Sap6nKhw= From: Leon Romanovsky To: Doug Ledford , Jason Gunthorpe Cc: linux-rdma@vger.kernel.org Subject: [PATCH rdma-next 2/8] RDMA/cma: Make the locking for automatic state transition more clear Date: Wed, 2 Sep 2020 11:11:16 +0300 Message-Id: <20200902081122.745412-3-leon@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200902081122.745412-1-leon@kernel.org> References: <20200902081122.745412-1-leon@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Jason Gunthorpe Re-organize things so the state variable is not read unlocked. The first attempt to go directly from ADDR_BOUND immediately tells us if the ID is already bound, if we can't do that then the attempt inside rdma_bind_addr() to go from IDLE to ADDR_BOUND confirms the ID needs binding. Signed-off-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky --- drivers/infiniband/core/cma.c | 67 +++++++++++++++++++++++------------ 1 file changed, 45 insertions(+), 22 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 7ac9306ab5b3..901d1bd35603 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -3278,32 +3278,54 @@ static int cma_bind_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, return rdma_bind_addr(id, src_addr); } -int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, - const struct sockaddr *dst_addr, unsigned long timeout_ms) +/* + * If required, resolve the source address for bind and leave the id_priv in + * state RDMA_CM_ADDR_BOUND. This oddly uses the state to determine the prior + * calls made by ULP, a previously bound ID will not be re-bound and src_addr is + * ignored. + */ +static int resolve_prepare_src(struct rdma_id_private *id_priv, + struct sockaddr *src_addr, + const struct sockaddr *dst_addr) { - struct rdma_id_private *id_priv; int ret; - id_priv = container_of(id, struct rdma_id_private, id); memcpy(cma_dst_addr(id_priv), dst_addr, rdma_addr_size(dst_addr)); - if (id_priv->state == RDMA_CM_IDLE) { - ret = cma_bind_addr(id, src_addr, dst_addr); - if (ret) { - memset(cma_dst_addr(id_priv), 0, - rdma_addr_size(dst_addr)); - return ret; + if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_ADDR_QUERY)) { + /* For a well behaved ULP state will be RDMA_CM_IDLE */ + ret = cma_bind_addr(&id_priv->id, src_addr, dst_addr); + if (ret) + goto err_dst; + if (WARN_ON(!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, + RDMA_CM_ADDR_QUERY))) { + ret = -EINVAL; + goto err_dst; } } if (cma_family(id_priv) != dst_addr->sa_family) { - memset(cma_dst_addr(id_priv), 0, rdma_addr_size(dst_addr)); - return -EINVAL; + ret = -EINVAL; + goto err_state; } + return 0; - if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_ADDR_QUERY)) { - memset(cma_dst_addr(id_priv), 0, rdma_addr_size(dst_addr)); - return -EINVAL; - } +err_state: + cma_comp_exch(id_priv, RDMA_CM_ADDR_QUERY, RDMA_CM_ADDR_BOUND); +err_dst: + memset(cma_dst_addr(id_priv), 0, rdma_addr_size(dst_addr)); + return ret; +} + +int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, + const struct sockaddr *dst_addr, unsigned long timeout_ms) +{ + struct rdma_id_private *id_priv = + container_of(id, struct rdma_id_private, id); + int ret; + + ret = resolve_prepare_src(id_priv, src_addr, dst_addr); + if (ret) + return ret; if (cma_any_addr(dst_addr)) { ret = cma_resolve_loopback(id_priv); @@ -3676,20 +3698,21 @@ static int cma_check_linklocal(struct rdma_dev_addr *dev_addr, int rdma_listen(struct rdma_cm_id *id, int backlog) { - struct rdma_id_private *id_priv; + struct rdma_id_private *id_priv = + container_of(id, struct rdma_id_private, id); int ret; - id_priv = container_of(id, struct rdma_id_private, id); - if (id_priv->state == RDMA_CM_IDLE) { + if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_LISTEN)) { + /* For a well behaved ULP state will be RDMA_CM_IDLE */ id->route.addr.src_addr.ss_family = AF_INET; ret = rdma_bind_addr(id, cma_src_addr(id_priv)); if (ret) return ret; + if (WARN_ON(!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, + RDMA_CM_LISTEN))) + return -EINVAL; } - if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_LISTEN)) - return -EINVAL; - if (id_priv->reuseaddr) { ret = cma_bind_listen(id_priv); if (ret) -- 2.26.2