From patchwork Wed Mar 31 19:36:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176133 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 0CE72C43619 for ; Wed, 31 Mar 2021 19:37:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6A4061059 for ; Wed, 31 Mar 2021 19:37:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236153AbhCaTg1 (ORCPT ); Wed, 31 Mar 2021 15:36:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:44430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235953AbhCaTgG (ORCPT ); Wed, 31 Mar 2021 15:36:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DDF5B6100C; Wed, 31 Mar 2021 19:36:05 +0000 (UTC) Subject: [PATCH v1 1/8] xprtrdma: Avoid Receive Queue wrapping From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:05 -0400 Message-ID: <161721936504.515226.14877637433211331378.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Commit e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") increased the number of Receive WRs that are posted by the client, but did not increase the size of the Receive Queue allocated during transport set-up. This is usually not an issue because RPCRDMA_BACKWARD_WRS is defined as (32) when SUNRPC_BACKCHANNEL is defined. In cases where it isn't, there is a real risk of Receive Queue wrapping. Fixes: e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") Signed-off-by: Chuck Lever Reviewed-By: Tom Talpey --- net/sunrpc/xprtrdma/frwr_ops.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c index 766a1048a48a..132df9b59ab4 100644 --- a/net/sunrpc/xprtrdma/frwr_ops.c +++ b/net/sunrpc/xprtrdma/frwr_ops.c @@ -257,6 +257,7 @@ int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device) ep->re_attr.cap.max_send_wr += 1; /* for ib_drain_sq */ ep->re_attr.cap.max_recv_wr = ep->re_max_requests; ep->re_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS; + ep->re_attr.cap.max_recv_wr += RPCRDMA_MAX_RECV_BATCH; ep->re_attr.cap.max_recv_wr += 1; /* for ib_drain_rq */ ep->re_max_rdma_segs = From patchwork Wed Mar 31 19:36:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176135 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 298A5C4363C for ; Wed, 31 Mar 2021 19:37:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C7A661059 for ; Wed, 31 Mar 2021 19:37:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236183AbhCaTg2 (ORCPT ); Wed, 31 Mar 2021 15:36:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:44448 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235991AbhCaTgM (ORCPT ); Wed, 31 Mar 2021 15:36:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 02A566100C; Wed, 31 Mar 2021 19:36:11 +0000 (UTC) Subject: [PATCH v1 2/8] xprtrdma: Do not post Receives after disconnect From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:11 -0400 Message-ID: <161721937122.515226.14731175629421422152.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Currently the Receive completion handler refreshes the Receive Queue whenever a successful Receive completion occurs. On disconnect, xprtrdma drains the Receive Queue. The first few Receive completions after a disconnect are typically successful, until the first flushed Receive. This means the Receive completion handler continues to post more Receive WRs after the drain sentinel has been posted. The late- posted Receives flush after the drain sentinel has completed, leading to a crash later in rpcrdma_xprt_disconnect(). To prevent this crash, xprtrdma has to ensure that the Receive handler stops posting Receives before ib_drain_rq() posts its drain sentinel. This patch is probably not sufficient to fully close that window, but does significantly reduce the opportunity for a crash to occur without incurring undue performance overhead. Cc: stable@vger.kernel.org # v5.7 Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index ec912cf9c618..1d88685badbe 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1371,8 +1371,10 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_ep *ep = r_xprt->rx_ep; + struct ib_qp_init_attr init_attr; struct ib_recv_wr *wr, *bad_wr; struct rpcrdma_rep *rep; + struct ib_qp_attr attr; int needed, count, rc; rc = 0; @@ -1385,6 +1387,11 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp) if (!temp) needed += RPCRDMA_MAX_RECV_BATCH; + if (ib_query_qp(ep->re_id->qp, &attr, IB_QP_STATE, &init_attr)) + goto out; + if (attr.qp_state == IB_QPS_ERR) + goto out; + /* fast path: all needed reps can be found on the free list */ wr = NULL; while (needed) { From patchwork Wed Mar 31 19:36:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176131 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D7CBDC43617 for ; Wed, 31 Mar 2021 19:37:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE4C1610A8 for ; Wed, 31 Mar 2021 19:37:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235991AbhCaTg2 (ORCPT ); Wed, 31 Mar 2021 15:36:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:44464 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236012AbhCaTgS (ORCPT ); Wed, 31 Mar 2021 15:36:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 196426100C; Wed, 31 Mar 2021 19:36:18 +0000 (UTC) Subject: [PATCH v1 3/8] xprtrdma: Put flushed Receives on free list instead of destroying them From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:17 -0400 Message-ID: <161721937732.515226.2170674299158077377.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Defer destruction of an rpcrdma_rep until transport tear-down to avoid races between Receive completion and rpcrdma_reps_unmap(). Signed-off-by: Chuck Lever Reviewed-By: Tom Talpey --- net/sunrpc/xprtrdma/verbs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 1d88685badbe..92af272f9cc9 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -80,6 +80,8 @@ static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt, struct rpcrdma_sendctx *sc); static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt); static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt); +static void rpcrdma_rep_put(struct rpcrdma_buffer *buf, + struct rpcrdma_rep *rep); static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep); static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt); static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt); @@ -205,7 +207,7 @@ static void rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) out_flushed: rpcrdma_flush_disconnect(r_xprt, wc); - rpcrdma_rep_destroy(rep); + rpcrdma_rep_put(&r_xprt->rx_buf, rep); } static void rpcrdma_update_cm_private(struct rpcrdma_ep *ep, From patchwork Wed Mar 31 19:36:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176129 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=-13.8 required=3.0 tests=BAYES_00, 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 88AC5C43603 for ; Wed, 31 Mar 2021 19:37:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B8B3610A8 for ; Wed, 31 Mar 2021 19:37:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236237AbhCaTg3 (ORCPT ); Wed, 31 Mar 2021 15:36:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:44502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236084AbhCaTgY (ORCPT ); Wed, 31 Mar 2021 15:36:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2EC1C61056; Wed, 31 Mar 2021 19:36:24 +0000 (UTC) Subject: [PATCH v1 4/8] xprtrdma: Improve locking around rpcrdma_rep destruction From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:23 -0400 Message-ID: <161721938342.515226.14847295549827213112.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Currently rpcrdma_reps_destroy() assumes that, at transport tear-down, the content of the rb_free_reps list is the same as the content of the rb_all_reps list. Although that is usually true, using the rb_all_reps list should be more reliable because of the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; these two should both traverse the "all" list. Instead, ensure that all rpcrdma_reps are always destroyed whether they are on the rep free list or not. Also ensure that rpcrdma_rep destruction logic is protected by the rb_lock. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 92af272f9cc9..fe250d554695 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1000,16 +1000,23 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, return NULL; } -/* No locking needed here. This function is invoked only by the - * Receive completion handler, or during transport shutdown. - */ -static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) +static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep) { - list_del(&rep->rr_all); rpcrdma_regbuf_free(rep->rr_rdmabuf); kfree(rep); } +static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) +{ + struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf; + + spin_lock(&buf->rb_lock); + list_del(&rep->rr_all); + spin_unlock(&buf->rb_lock); + + rpcrdma_rep_destroy_locked(rep); +} + static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf) { struct llist_node *node; @@ -1042,8 +1049,18 @@ static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf) { struct rpcrdma_rep *rep; - while ((rep = rpcrdma_rep_get_locked(buf)) != NULL) - rpcrdma_rep_destroy(rep); + spin_lock(&buf->rb_lock); + while ((rep = list_first_entry_or_null(&buf->rb_all_reps, + struct rpcrdma_rep, + rr_all)) != NULL) { + list_del(&rep->rr_all); + spin_unlock(&buf->rb_lock); + + rpcrdma_rep_destroy_locked(rep); + + spin_lock(&buf->rb_lock); + } + spin_unlock(&buf->rb_lock); } /** From patchwork Wed Mar 31 19:36:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176137 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=-13.8 required=3.0 tests=BAYES_00, 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 E3076C43461 for ; Wed, 31 Mar 2021 19:37:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDF9061029 for ; Wed, 31 Mar 2021 19:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236280AbhCaThA (ORCPT ); Wed, 31 Mar 2021 15:37:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:44526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236268AbhCaTga (ORCPT ); Wed, 31 Mar 2021 15:36:30 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 480F761029; Wed, 31 Mar 2021 19:36:30 +0000 (UTC) Subject: [PATCH v1 5/8] xprtrdma: Improve commentary around rpcrdma_reps_unmap() From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:29 -0400 Message-ID: <161721938951.515226.17560651611000798100.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index fe250d554695..b68fc81a78fb 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1034,6 +1034,10 @@ static void rpcrdma_rep_put(struct rpcrdma_buffer *buf, llist_add(&rep->rr_node, &buf->rb_free_reps); } +/* Caller must ensure the QP is quiescent (RQ is drained) before + * invoking this function, to guarantee rb_all_reps is not + * changing. + */ static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; @@ -1041,7 +1045,7 @@ static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt) list_for_each_entry(rep, &buf->rb_all_reps, rr_all) { rpcrdma_regbuf_dma_unmap(rep->rr_rdmabuf); - rep->rr_temp = true; + rep->rr_temp = true; /* Mark this rep for destruction */ } } From patchwork Wed Mar 31 19:36:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176139 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 CD823C43460 for ; Wed, 31 Mar 2021 19:37:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9D1561056 for ; Wed, 31 Mar 2021 19:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236292AbhCaThB (ORCPT ); Wed, 31 Mar 2021 15:37:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:44544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235975AbhCaTgg (ORCPT ); Wed, 31 Mar 2021 15:36:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5F02D6101E; Wed, 31 Mar 2021 19:36:36 +0000 (UTC) Subject: [PATCH v1 6/8] xprtrdma: Improve locking around rpcrdma_rep creation From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:35 -0400 Message-ID: <161721939561.515226.1183996972792305822.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Serialize the use of the rb_all_reps list during rep creation and destruction. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index b68fc81a78fb..2fde805edb64 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -956,13 +956,11 @@ static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt) rpcrdma_req_reset(req); } -/* No locking needed here. This function is called only by the - * Receive completion handler. - */ static noinline struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, bool temp) { + struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_rep *rep; rep = kzalloc(sizeof(*rep), GFP_KERNEL); @@ -989,7 +987,10 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov; rep->rr_recv_wr.num_sge = 1; rep->rr_temp = temp; - list_add(&rep->rr_all, &r_xprt->rx_buf.rb_all_reps); + + spin_lock(&buf->rb_lock); + list_add(&rep->rr_all, &buf->rb_all_reps); + spin_unlock(&buf->rb_lock); return rep; out_free_regbuf: From patchwork Wed Mar 31 19:36:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176143 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 28653C43470 for ; Wed, 31 Mar 2021 19:37:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 135366100C for ; Wed, 31 Mar 2021 19:37:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236294AbhCaThB (ORCPT ); Wed, 31 Mar 2021 15:37:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:44560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235933AbhCaTgm (ORCPT ); Wed, 31 Mar 2021 15:36:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 780826101E; Wed, 31 Mar 2021 19:36:42 +0000 (UTC) Subject: [PATCH v1 7/8] xprtrdma: Fix cwnd update ordering From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:41 -0400 Message-ID: <161721940170.515226.389858159579607870.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org After a reconnect, the reply handler is opening the cwnd (and thus enabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs() can post enough Receive WRs to receive their replies. This causes an RNR and the new connection is lost immediately. The race is most clearly exposed when KASAN and disconnect injection are enabled. This slows down rpcrdma_rep_create() considerably. Fixes: 2ae50ad68cd7 ("xprtrdma: Close window between waking RPC senders and posting Receives") Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/rpc_rdma.c | 3 ++- net/sunrpc/xprtrdma/verbs.c | 10 +++++----- net/sunrpc/xprtrdma/xprt_rdma.h | 2 +- 3 files changed, 8 insertions(+), 7 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 292f066d006e..21ddd78a8c35 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1430,9 +1430,10 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep) credits = 1; /* don't deadlock */ else if (credits > r_xprt->rx_ep->re_max_requests) credits = r_xprt->rx_ep->re_max_requests; + rpcrdma_post_recvs(r_xprt, credits + (buf->rb_bc_srv_max_requests << 1), + false); if (buf->rb_credits != credits) rpcrdma_update_cwnd(r_xprt, credits); - rpcrdma_post_recvs(r_xprt, false); req = rpcr_to_rdmar(rqst); if (unlikely(req->rl_reply)) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 2fde805edb64..82489f527ece 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -537,7 +537,7 @@ int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt) * outstanding Receives. */ rpcrdma_ep_get(ep); - rpcrdma_post_recvs(r_xprt, true); + rpcrdma_post_recvs(r_xprt, 1, true); rc = rdma_connect(ep->re_id, &ep->re_remote_cma); if (rc) @@ -1388,10 +1388,11 @@ int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) /** * rpcrdma_post_recvs - Refill the Receive Queue * @r_xprt: controlling transport instance - * @temp: mark Receive buffers to be deleted after use + * @needed: current credit grant + * @temp: mark Receive buffers to be deleted after one use * */ -void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp) +void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_ep *ep = r_xprt->rx_ep; @@ -1399,12 +1400,11 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp) struct ib_recv_wr *wr, *bad_wr; struct rpcrdma_rep *rep; struct ib_qp_attr attr; - int needed, count, rc; + int count, rc; rc = 0; count = 0; - needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1); if (likely(ep->re_receive_count > needed)) goto out; needed -= ep->re_receive_count; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index fe3be985e239..28af11fbe643 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -461,7 +461,7 @@ int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt); void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt); int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); -void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp); +void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp); /* * Buffer calls - xprtrdma/verbs.c From patchwork Wed Mar 31 19:36:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12176141 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=-13.8 required=3.0 tests=BAYES_00, 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 07800C43600 for ; Wed, 31 Mar 2021 19:37:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E69B861056 for ; Wed, 31 Mar 2021 19:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236305AbhCaThC (ORCPT ); Wed, 31 Mar 2021 15:37:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:44586 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236273AbhCaTgt (ORCPT ); Wed, 31 Mar 2021 15:36:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 98FA76101E; Wed, 31 Mar 2021 19:36:48 +0000 (UTC) Subject: [PATCH v1 8/8] xprtrdma: Delete rpcrdma_recv_buffer_put() From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Wed, 31 Mar 2021 15:36:47 -0400 Message-ID: <161721940781.515226.1062442154050129042.stgit@manet.1015granger.net> In-Reply-To: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> References: <161721926778.515226.9805598788670386587.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Clean up: The name recv_buffer_put() is a vestige of older code, and the function is just a wrapper for the newer rpcrdma_rep_put(). In most of the existing call sites, a pointer to the owning rpcrdma_buffer is already available. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/backchannel.c | 4 +++- net/sunrpc/xprtrdma/rpc_rdma.c | 4 ++-- net/sunrpc/xprtrdma/verbs.c | 24 ++++++++---------------- net/sunrpc/xprtrdma/xprt_rdma.h | 2 +- 4 files changed, 14 insertions(+), 20 deletions(-) diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c index a249837d6a55..1151efd09b27 100644 --- a/net/sunrpc/xprtrdma/backchannel.c +++ b/net/sunrpc/xprtrdma/backchannel.c @@ -155,9 +155,11 @@ void xprt_rdma_bc_destroy(struct rpc_xprt *xprt, unsigned int reqs) void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst) { struct rpcrdma_req *req = rpcr_to_rdmar(rqst); + struct rpcrdma_rep *rep = req->rl_reply; struct rpc_xprt *xprt = rqst->rq_xprt; + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); - rpcrdma_recv_buffer_put(req->rl_reply); + rpcrdma_rep_put(&r_xprt->rx_buf, rep); req->rl_reply = NULL; spin_lock(&xprt->bc_pa_lock); diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 21ddd78a8c35..be4e888e78a3 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1437,7 +1437,7 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep) req = rpcr_to_rdmar(rqst); if (unlikely(req->rl_reply)) - rpcrdma_recv_buffer_put(req->rl_reply); + rpcrdma_rep_put(buf, req->rl_reply); req->rl_reply = rep; rep->rr_rqst = rqst; @@ -1465,5 +1465,5 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep) trace_xprtrdma_reply_short_err(rep); out: - rpcrdma_recv_buffer_put(rep); + rpcrdma_rep_put(buf, rep); } diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 82489f527ece..fd4cce149001 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -80,8 +80,6 @@ static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt, struct rpcrdma_sendctx *sc); static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt); static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt); -static void rpcrdma_rep_put(struct rpcrdma_buffer *buf, - struct rpcrdma_rep *rep); static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep); static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt); static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt); @@ -1029,8 +1027,13 @@ static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf) return llist_entry(node, struct rpcrdma_rep, rr_node); } -static void rpcrdma_rep_put(struct rpcrdma_buffer *buf, - struct rpcrdma_rep *rep) +/** + * rpcrdma_rep_put - Release rpcrdma_rep back to free list + * @buf: buffer pool + * @rep: rep to release + * + */ +void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep) { llist_add(&rep->rr_node, &buf->rb_free_reps); } @@ -1245,17 +1248,6 @@ void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req) spin_unlock(&buffers->rb_lock); } -/** - * rpcrdma_recv_buffer_put - Release rpcrdma_rep back to free list - * @rep: rep to release - * - * Used after error conditions. - */ -void rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep) -{ - rpcrdma_rep_put(&rep->rr_rxprt->rx_buf, rep); -} - /* Returns a pointer to a rpcrdma_regbuf object, or NULL. * * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for @@ -1449,7 +1441,7 @@ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp) rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr); wr = wr->next; - rpcrdma_recv_buffer_put(rep); + rpcrdma_rep_put(buf, rep); --count; } } diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 28af11fbe643..1b02d6bd86e9 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -480,7 +480,7 @@ void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt); struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req); -void rpcrdma_recv_buffer_put(struct rpcrdma_rep *); +void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep); bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags);