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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 494FBC433FE for ; Thu, 10 Dec 2020 14:58:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05C18206D5 for ; Thu, 10 Dec 2020 14:58:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725947AbgLJO62 (ORCPT ); Thu, 10 Dec 2020 09:58:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726931AbgLJO53 (ORCPT ); Thu, 10 Dec 2020 09:57:29 -0500 Received: from mail-ed1-x544.google.com (mail-ed1-x544.google.com [IPv6:2a00:1450:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D2C0C0613CF for ; Thu, 10 Dec 2020 06:56:49 -0800 (PST) Received: by mail-ed1-x544.google.com with SMTP id u19so5808593edx.2 for ; Thu, 10 Dec 2020 06:56:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloud.ionos.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZL5eMnJUZR33II2tRNEvHV28YGyV0efiJaemSe8WAL8=; b=akIU4qVngXp7tUxsTpmsploSNjsFnVTgliaKCHs2wM5h2N2p5Xd+m9mEqSPvN0u8GF 4Ng44A0bv8WlQdrthC9XeSLV5M9krm9sRVWDqeeSDKz5ezOMoyecZ4m5zF0sP1GMcUaB LMgLx8LqDYrw8TIf9jlQsyDfK63qvpDFPYCETvNt5GHpiNN/jhEPgMLlsNEPrZqxT8aB nrDcJCT1Ac6HTVxf7qvmysQv+WhvqnV3gvGGy2DHM9cL83tJ6XzIpNgDcaNxki17Erus yibBkCqzFSZJwpaIMWGOwaLMytZHDKLwBA41xV/vVpX1tSUnrdnsrvW+IiVbbHBS9bUY xglA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZL5eMnJUZR33II2tRNEvHV28YGyV0efiJaemSe8WAL8=; b=Wp0LUBTRIjTRz8BR7ThJCQ+ufjl0rJjD2/isUSZQFRfm/RGaPDrSrCtiZLheJammCW xPxKfGoSrwXzUOj+mzirOsKX+bnfU0gssUlSl6J6c9lpOXxkHAV67674+Y1emc6znP6/ 0Ov6+3pe/j+oUhnYt7zvCIreSyBa+nqabfPg7HFueO9O0vq/sp7ErXsBn7dczysLi3M8 7gZlzdp0G/f9CQLHf4CjYXZuqB9ZvJaWSEHdvs7Hsa2Y4G+l1p/XRMru7k5HRe2s80M/ Qwq7OYsC2ewHeqyNUleOjb6Px3LjHeQg+QJvekFTPlwEWAxz1X9Q+F5cQNQqRGERs36g VJ9g== X-Gm-Message-State: AOAM531j9B4rXRCZJwBsPu/fBYvXlsS9GKRAej2OfonCpxiClYpHx3xj 5Y/ecfljoqnkGWRginb2qbNLMhaLwVMk//7Kzlls+70ttxbc2Q== X-Google-Smtp-Source: ABdhPJw5auWCqQHSJm24bEJ2kXtOw4b4XpqDDSCaH0x+ylCi8syeGkKj4TMOwTEOtK/X5cOUD5/hLMvmLVUl/5xZDCs= X-Received: by 2002:a05:6402:a53:: with SMTP id bt19mr7282780edb.104.1607612207423; Thu, 10 Dec 2020 06:56:47 -0800 (PST) MIME-Version: 1.0 References: <20201209164542.61387-1-jinpu.wang@cloud.ionos.com> <20201209164542.61387-3-jinpu.wang@cloud.ionos.com> In-Reply-To: <20201209164542.61387-3-jinpu.wang@cloud.ionos.com> From: Jinpu Wang Date: Thu, 10 Dec 2020 15:56:15 +0100 Message-ID: Subject: Re: [PATCH for-next 02/18] RMDA/rtrs-srv: Occasionally flush ongoing session closing To: linux-rdma@vger.kernel.org Cc: Bart Van Assche , Leon Romanovsky , Doug Ledford , Jason Gunthorpe , Danil Kipnis , Guoqing Jiang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Wed, Dec 9, 2020 at 5:45 PM Jack Wang wrote: > > If there are many establishments/teardowns, we need to make sure > we do not consume too much system memory. Thus let on going > session closing to finish before accepting new connection. > > Inspired by commit 777dc82395de ("nvmet-rdma: occasionally flush ongoing controller teardown") > Signed-off-by: Jack Wang > Reviewed-by: Guoqing Jiang Please ignore this one, it could lead to deadlock, due to the fact cma_ib_req_handler is holding mutex_lock(&listen_id->handler_mutex) when calling into rtrs_rdma_connect, we call close_work which will call rdma_destroy_id, which could try to hold the same handler_mutex, so deadlock. Sorry & thanks! Jack > --- > drivers/infiniband/ulp/rtrs/rtrs-srv.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c > index ed4628f032bb..0a2202c28b54 100644 > --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c > +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c > @@ -1791,6 +1791,10 @@ static int rtrs_rdma_connect(struct rdma_cm_id *cm_id, > err = -ENOMEM; > goto reject_w_err; > } > + if (!cid) { > + /* Let inflight session teardown complete */ > + flush_workqueue(rtrs_wq); > + } > mutex_lock(&srv->paths_mutex); > sess = __find_sess(srv, &msg->sess_uuid); > if (sess) { > -- > 2.25.1 >