From patchwork Mon Jan 16 23:11:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13103922 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 413D2C67871 for ; Mon, 16 Jan 2023 23:20:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234089AbjAPXUa (ORCPT ); Mon, 16 Jan 2023 18:20:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55852 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235737AbjAPXT1 (ORCPT ); Mon, 16 Jan 2023 18:19:27 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D6C83253F for ; Mon, 16 Jan 2023 15:12:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673910713; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Nw4FQbdWbVj4MBsaopY4M6MScTLsVpfgXMad66KYZwU=; b=RjpdJDD3sLbe7gnvYV1G4r09VyO3HtvoRyFwJftJlu/7dYHqrHegEX9QrbeHEp/7Y5JrHL yH1Mzt6gLeiPH9rsTiyqKGiHFE+yJC/RXpuxXTjDPCMGAtU6CLdcUFusq1YHwYQSp6Pc0p srP+nU6Ap7+DvxNqKNhm8EpnzSWMq8Y= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-14-yziFx7y5NACL1vK30mvFNA-1; Mon, 16 Jan 2023 18:11:50 -0500 X-MC-Unique: yziFx7y5NACL1vK30mvFNA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7BA33380390A; Mon, 16 Jan 2023 23:11:49 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id AEA5240C6EC4; Mon, 16 Jan 2023 23:11:47 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH v6 31/34] cifs: Fix problem with encrypted RDMA data read From: David Howells To: Al Viro Cc: Steve French , Tom Talpey , Long Li , Namjae Jeon , Stefan Metzmacher , linux-cifs@vger.kernel.org, dhowells@redhat.com, Christoph Hellwig , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , Logan Gunthorpe , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 16 Jan 2023 23:11:47 +0000 Message-ID: <167391070712.2311931.8909671251130425914.stgit@warthog.procyon.org.uk> In-Reply-To: <167391047703.2311931.8115712773222260073.stgit@warthog.procyon.org.uk> References: <167391047703.2311931.8115712773222260073.stgit@warthog.procyon.org.uk> User-Agent: StGit/1.5 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org When the cifs client is talking to the ksmbd server by RDMA and the ksmbd server has "smb3 encryption = yes" in its config file, the normal PDU stream is encrypted, but the directly-delivered data isn't in the stream (and isn't encrypted), but is rather delivered by DDP/RDMA packets (at least with IWarp). Currently, the direct delivery fails with: buf can not contain only a part of read data WARNING: CPU: 0 PID: 4619 at fs/cifs/smb2ops.c:4731 handle_read_data+0x393/0x405 ... RIP: 0010:handle_read_data+0x393/0x405 ... smb3_handle_read_data+0x30/0x37 receive_encrypted_standard+0x141/0x224 cifs_demultiplex_thread+0x21a/0x63b kthread+0xe7/0xef ret_from_fork+0x22/0x30 The problem apparently stemming from the fact that it's trying to manage the decryption, but the data isn't in the smallbuf, the bigbuf or the page array). This can be fixed simply by inserting an extra case into handle_read_data() that checks to see if use_rdma_mr is true, and if it is, just setting rdata->got_bytes to the length of data delivered and allowing normal continuation. This can be seen in an IWarp packet trace. With the upstream code, it does a DDP/RDMA packet, which produces the warning above and then retries, retrieving the data inline, spread across several SMBDirect messages that get glued together into a single PDU. With the patch applied, only the DDP/RDMA packet is seen. Note that this doesn't happen if the server isn't told to encrypt stuff and it does also happen with softRoCE. Signed-off-by: David Howells cc: Steve French cc: Tom Talpey cc: Long Li cc: Namjae Jeon cc: Stefan Metzmacher cc: linux-cifs@vger.kernel.org Link: https://lore.kernel.org/r/166855224228.1998592.2212551359609792175.stgit@warthog.procyon.org.uk/ # v1 --- fs/cifs/smb2ops.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 387effcb905d..fabb1e135faa 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4720,6 +4720,9 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid, if (length < 0) return length; rdata->got_bytes = data_len; + } else if (use_rdma_mr) { + /* The data was delivered directly by RDMA. */ + rdata->got_bytes = data_len; } else { /* read response payload cannot be in both buf and pages */ WARN_ONCE(1, "buf can not contain only a part of read data");