From patchwork Mon Mar 30 18:04:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Long Li X-Patchwork-Id: 11466177 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 520E514B4 for ; Mon, 30 Mar 2020 18:04:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FD2820771 for ; Mon, 30 Mar 2020 18:04:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxonhyperv.com header.i=@linuxonhyperv.com header.b="OJ2fuHRD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727745AbgC3SET (ORCPT ); Mon, 30 Mar 2020 14:04:19 -0400 Received: from linux.microsoft.com ([13.77.154.182]:42362 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727815AbgC3SES (ORCPT ); Mon, 30 Mar 2020 14:04:18 -0400 Received: by linux.microsoft.com (Postfix, from userid 1004) id 6B38020B46F0; Mon, 30 Mar 2020 11:04:17 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6B38020B46F0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxonhyperv.com; s=default; t=1585591457; bh=f6uuZ8AQmEmQPNxvCDcaE9ajAQMzpT8US7URBUmbX+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:Reply-To:From; b=OJ2fuHRDWI1KPvCxE2Rjw286mDUXEhZI+eImjVbM2bUtOENhxgueC+bFCcAF3CaVC 5HjEOZo7M5UdrYfaxfntwnfeeQTekV4fLCxlMFWxKLaqx1JSB2d6pLS1udk5QncUSi QBNr6NXbXfer42QDESpKDpRZgx4CXIfiJ0mxn6fc= From: longli@linuxonhyperv.com To: Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org Cc: Long Li Subject: [PATCH 2/2] cifs: smbd: Check send queue size before posting a send Date: Mon, 30 Mar 2020 11:04:07 -0700 Message-Id: <1585591447-11741-2-git-send-email-longli@linuxonhyperv.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1585591447-11741-1-git-send-email-longli@linuxonhyperv.com> References: <1585591447-11741-1-git-send-email-longli@linuxonhyperv.com> Reply-To: longli@microsoft.com Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Long Li Sometimes the remote peer may return more send credits than the send queue depth. If all the send credits are used to post senasd, we may overflow the send queue. Fix this by checking the send queue size before posting a send. Signed-off-by: Long Li --- fs/cifs/smbdirect.c | 11 ++++++++++- fs/cifs/smbdirect.h | 1 + 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 79d8dcbd0034..c7ef2d7ce0ef 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -287,6 +287,7 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc) if (atomic_dec_and_test(&request->info->send_pending)) wake_up(&request->info->wait_send_pending); + wake_up(&request->info->wait_post_send); mempool_free(request, request->info->request_mempool); } @@ -939,7 +940,14 @@ static int smbd_post_send(struct smbd_connection *info, send_wr.opcode = IB_WR_SEND; send_wr.send_flags = IB_SEND_SIGNALED; - atomic_inc(&info->send_pending); +wait_sq: + wait_event(info->wait_post_send, + atomic_read(&info->send_pending) < info->send_credit_target); + if (unlikely(atomic_inc_return(&info->send_pending) > + info->send_credit_target)) { + atomic_dec(&info->send_pending); + goto wait_sq; + } rc = ib_post_send(info->id->qp, &send_wr, NULL); if (rc) { @@ -1733,6 +1741,7 @@ static struct smbd_connection *_smbd_get_connection( init_waitqueue_head(&info->wait_send_pending); atomic_set(&info->send_pending, 0); + init_waitqueue_head(&info->wait_post_send); INIT_WORK(&info->disconnect_work, smbd_disconnect_rdma_work); INIT_WORK(&info->post_send_credits_work, smbd_post_send_credits); diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h index f70c7119a456..07c8f5638c39 100644 --- a/fs/cifs/smbdirect.h +++ b/fs/cifs/smbdirect.h @@ -114,6 +114,7 @@ struct smbd_connection { /* Activity accoutning */ atomic_t send_pending; wait_queue_head_t wait_send_pending; + wait_queue_head_t wait_post_send; /* Receive queue */ struct list_head receive_queue;