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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 BC4E8C43387 for ; Tue, 15 Jan 2019 16:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A7BB20645 for ; Tue, 15 Jan 2019 16:56:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547571407; bh=h8iaHFq7l8+LiqpGoyvbqMa6qdU2Bxrxi9r/1Q5RcYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uiGtELzMwd8fLp03V8l6SEGNFDFJP9b2IZN1SbOutVHwZNER818mWneTHJOgPReoT dYqt/WAU8l068Ha4O5EtG6XRLcYRf7LuvF76yigZ0Ezn+iLQExWdaIFf4bquW0I6VU 3uRu60l8zQl0LBuO9w/RKOLN7QFKiIwTbZZ9SQJw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730706AbfAOQ4r (ORCPT ); Tue, 15 Jan 2019 11:56:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:58192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732777AbfAOQl0 (ORCPT ); Tue, 15 Jan 2019 11:41:26 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 CC6662054F; Tue, 15 Jan 2019 16:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547570485; bh=h8iaHFq7l8+LiqpGoyvbqMa6qdU2Bxrxi9r/1Q5RcYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y0cGUHa4WgjY1FE4JWRUEbS65DYSVIF80gc9RjF4E48Fz2TqZRP+b2pejYZxw+Paj re+tJdnDlUz/oTpMMXj1S8m/D0rX+I2SERrEA1ugjgWMNpt/FnUbILSv1qlTFvU/Cg bAgDkn23ZSK6hZ2IClXYOifl++xT/zV0eu3qtx7E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Shilovsky , Steve French Subject: [PATCH 4.19 12/50] CIFS: Fix credit computation for compounded requests Date: Tue, 15 Jan 2019 17:35:48 +0100 Message-Id: <20190115154910.672683956@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190115154909.933241945@linuxfoundation.org> References: <20190115154909.933241945@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Shilovsky commit 8544f4aa9dd19a04d1244dae10feecc813ccf175 upstream. In SMB3 protocol every part of the compound chain consumes credits individually, so we need to call wait_for_free_credits() for each of the PDUs in the chain. If an operation is interrupted, we must ensure we return all credits taken from the server structure back. Without this patch server can sometimes disconnect the session due to credit mismatches, especially when first operation(s) are large writes. Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French CC: Stable Signed-off-by: Greg Kroah-Hartman --- fs/cifs/transport.c | 59 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 41 insertions(+), 18 deletions(-) --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -786,7 +786,8 @@ compound_send_recv(const unsigned int xi int i, j, rc = 0; int timeout, optype; struct mid_q_entry *midQ[MAX_COMPOUND]; - unsigned int credits = 0; + bool cancelled_mid[MAX_COMPOUND] = {false}; + unsigned int credits[MAX_COMPOUND] = {0}; char *buf; timeout = flags & CIFS_TIMEOUT_MASK; @@ -804,13 +805,31 @@ compound_send_recv(const unsigned int xi return -ENOENT; /* - * Ensure that we do not send more than 50 overlapping requests - * to the same server. We may make this configurable later or - * use ses->maxReq. + * Ensure we obtain 1 credit per request in the compound chain. + * It can be optimized further by waiting for all the credits + * at once but this can wait long enough if we don't have enough + * credits due to some heavy operations in progress or the server + * not granting us much, so a fallback to the current approach is + * needed anyway. */ - rc = wait_for_free_request(ses->server, timeout, optype); - if (rc) - return rc; + for (i = 0; i < num_rqst; i++) { + rc = wait_for_free_request(ses->server, timeout, optype); + if (rc) { + /* + * We haven't sent an SMB packet to the server yet but + * we already obtained credits for i requests in the + * compound chain - need to return those credits back + * for future use. Note that we need to call add_credits + * multiple times to match the way we obtained credits + * in the first place and to account for in flight + * requests correctly. + */ + for (j = 0; j < i; j++) + add_credits(ses->server, 1, optype); + return rc; + } + credits[i] = 1; + } /* * Make sure that we sign in the same order that we send on this socket @@ -826,8 +845,10 @@ compound_send_recv(const unsigned int xi for (j = 0; j < i; j++) cifs_delete_mid(midQ[j]); mutex_unlock(&ses->server->srv_mutex); + /* Update # of requests on wire to server */ - add_credits(ses->server, 1, optype); + for (j = 0; j < num_rqst; j++) + add_credits(ses->server, credits[j], optype); return PTR_ERR(midQ[i]); } @@ -874,17 +895,16 @@ compound_send_recv(const unsigned int xi if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) { midQ[i]->mid_flags |= MID_WAIT_CANCELLED; midQ[i]->callback = DeleteMidQEntry; - spin_unlock(&GlobalMid_Lock); - add_credits(ses->server, 1, optype); - return rc; + cancelled_mid[i] = true; } spin_unlock(&GlobalMid_Lock); } } for (i = 0; i < num_rqst; i++) - if (midQ[i]->resp_buf) - credits += ses->server->ops->get_credits(midQ[i]); + if (!cancelled_mid[i] && midQ[i]->resp_buf + && (midQ[i]->mid_state == MID_RESPONSE_RECEIVED)) + credits[i] = ses->server->ops->get_credits(midQ[i]); for (i = 0; i < num_rqst; i++) { if (rc < 0) @@ -892,8 +912,9 @@ compound_send_recv(const unsigned int xi rc = cifs_sync_mid_result(midQ[i], ses->server); if (rc != 0) { - add_credits(ses->server, credits, optype); - return rc; + /* mark this mid as cancelled to not free it below */ + cancelled_mid[i] = true; + goto out; } if (!midQ[i]->resp_buf || @@ -940,9 +961,11 @@ out: * This is prevented above by using a noop callback that will not * wake this thread except for the very last PDU. */ - for (i = 0; i < num_rqst; i++) - cifs_delete_mid(midQ[i]); - add_credits(ses->server, credits, optype); + for (i = 0; i < num_rqst; i++) { + if (!cancelled_mid[i]) + cifs_delete_mid(midQ[i]); + add_credits(ses->server, credits[i], optype); + } return rc; }