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=-19.1 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, USER_AGENT_GIT autolearn=unavailable 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 84F4DC433FE for ; Thu, 16 Sep 2021 17:21:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7298460D07 for ; Thu, 16 Sep 2021 17:21:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243422AbhIPRW3 (ORCPT ); Thu, 16 Sep 2021 13:22:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:39806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350318AbhIPRN4 (ORCPT ); Thu, 16 Sep 2021 13:13:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9B6C161B5E; Thu, 16 Sep 2021 16:39:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631810347; bh=6ed0M8Qv7TyQiv70xGGs3LM9tc4vfK35qFJzMqQ/o+c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MxkN1VkxAlhQ8RoeVqFqcJYmEm6ZXymekQoY3x+y7W+Kd9pHB8JOsnEaheXJhwHD/ xngznHu3wljX66iDWV1UqKET45kfBZRtYYGBkDBDRgkOF9mC49ojJnIN/g5m3GH9eB dV0NmR+y/Lmb7ov5HEIPiKh7oIcrA7ojF/9JHS+Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Anna Schumaker , Sasha Levin Subject: [PATCH 5.14 108/432] SUNRPC/xprtrdma: Fix reconnection locking Date: Thu, 16 Sep 2021 17:57:37 +0200 Message-Id: <20210916155814.427055057@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155810.813340753@linuxfoundation.org> References: <20210916155810.813340753@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Trond Myklebust [ Upstream commit f99fa50880f5300fbbb3c0754ddc7f8738d24fe7 ] The xprtrdma client code currently relies on the task that initiated the connect to hold the XPRT_LOCK for the duration of the connection attempt. If the task is woken early, due to some other event, then that lock could get released early. Avoid races by using the same mechanism that the socket code uses of transferring lock ownership to the RDMA connect worker itself. That frees us to call rpcrdma_xprt_disconnect() directly since we're now guaranteed exclusion w.r.t. other callers. Fixes: 4cf44be6f1e8 ("xprtrdma: Fix recursion into rpcrdma_xprt_disconnect()") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- net/sunrpc/xprt.c | 2 ++ net/sunrpc/xprtrdma/transport.c | 11 +++++------ 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index bddd354a0076..d55e980521da 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -873,6 +873,7 @@ bool xprt_lock_connect(struct rpc_xprt *xprt, spin_unlock(&xprt->transport_lock); return ret; } +EXPORT_SYMBOL_GPL(xprt_lock_connect); void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) { @@ -889,6 +890,7 @@ void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) spin_unlock(&xprt->transport_lock); wake_up_bit(&xprt->state, XPRT_LOCKED); } +EXPORT_SYMBOL_GPL(xprt_unlock_connect); /** * xprt_connect - schedule a transport connect operation diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 9c2ffc67c0fd..975aef16ad34 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -250,12 +250,9 @@ xprt_rdma_connect_worker(struct work_struct *work) xprt->stat.connect_start; xprt_set_connected(xprt); rc = -EAGAIN; - } else { - /* Force a call to xprt_rdma_close to clean up */ - spin_lock(&xprt->transport_lock); - set_bit(XPRT_CLOSE_WAIT, &xprt->state); - spin_unlock(&xprt->transport_lock); - } + } else + rpcrdma_xprt_disconnect(r_xprt); + xprt_unlock_connect(xprt, r_xprt); xprt_wake_pending_tasks(xprt, rc); } @@ -489,6 +486,8 @@ xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task) struct rpcrdma_ep *ep = r_xprt->rx_ep; unsigned long delay; + WARN_ON_ONCE(!xprt_lock_connect(xprt, task, r_xprt)); + delay = 0; if (ep && ep->re_connect_status != 0) { delay = xprt_reconnect_delay(xprt); -- 2.30.2