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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A70ACC433DF for ; Tue, 23 Jun 2020 20:04:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8413C2145D for ; Tue, 23 Jun 2020 20:04:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592942661; bh=H3qIbqGd1WjyK0/fZVWrc7oncYZArdjABl6fgpBU420=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BSGjf1rCgppkD55Zm4tCU1DsfVjgtMSrP56J4fP9XG2texJaxXb23AAdrmw3K7iYn 1G43hAMAvkel8WN2kt2qYyFbc8TbgB6jZbkjV3JxNe0UXDr+EPXwjFqmsdPNtvMT0u qYU2s/ZTrZK1AukLudFyyzCgfo4fHbrwJ7tz2eE0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387542AbgFWUET (ORCPT ); Tue, 23 Jun 2020 16:04:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:42508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388150AbgFWUEN (ORCPT ); Tue, 23 Jun 2020 16:04:13 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 2338C2082F; Tue, 23 Jun 2020 20:04:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592942652; bh=H3qIbqGd1WjyK0/fZVWrc7oncYZArdjABl6fgpBU420=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Iv4AQlARc/cOab1bpR+in/1eCpuqi1hUrfkYXeg2Z5MuF5I06UaMrtJtCixov2676 diyCmH+9foNzfl1BOlUNJAEOCbG45Qa5VAUNf3sB1XlEwChu5+zAlB8fCeeGfxo/Sp g8KawAcsaiL5YUh3Ab0A08ekrl8pjrxCtKFbys0I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Paulo Alcantara (SUSE)" , Aurelien Aptel , Steve French , Sasha Levin Subject: [PATCH 5.7 083/477] cifs: set up next DFS target before generic_ip_connect() Date: Tue, 23 Jun 2020 21:51:20 +0200 Message-Id: <20200623195411.529694650@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195407.572062007@linuxfoundation.org> References: <20200623195407.572062007@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paulo Alcantara [ Upstream commit aaa3aef34d3ab9499a5c7633823429f7a24e6dff ] If we mount a very specific DFS link \\FS0.FOO.COM\dfs\link -> \FS0\share1, \FS1\share2 where its target list contains NB names ("FS0" & "FS1") rather than FQDN ones ("FS0.FOO.COM" & "FS1.FOO.COM"), we end up connecting to \FOO\share1 but server->hostname will have "FOO.COM". The reason is because both "FS0" and "FS0.FOO.COM" resolve to same IP address and they share same TCP server connection, but "FS0.FOO.COM" was the first hostname set -- which is OK. However, if the echo thread timeouts and we still have a good connection to "FS0", in cifs_reconnect() rc = generic_ip_connect(server) -> success if (rc) { ... reconn_inval_dfs_target(server, cifs_sb, &tgt_list, &tgt_it); ... } ... it successfully reconnects to "FS0" server but does not set up next DFS target - which should be the same target server "\FS0\share1" - and server->hostname remains set to "FS0.FOO.COM" rather than "FS0", as reconn_inval_dfs_target() would have it set to "FS0" if called earlier. Finally, in __smb2_reconnect(), the reconnect of tcons would fail because tcon->ses->server->hostname (FS0.FOO.COM) does not match DFS target's hostname (FS0). Fix that by calling reconn_inval_dfs_target() before generic_ip_connect() so server->hostname will get updated correctly prior to reconnecting its tcons in __smb2_reconnect(). With "cifs: handle hostnames that resolve to same ip in failover" patch - The above problem would not occur. - We could save an DNS query to find out that they both resolve to the same ip address. Signed-off-by: Paulo Alcantara (SUSE) Reviewed-by: Aurelien Aptel Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/cifs/connect.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 28268ed461b82..47b9fbb70bf5e 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -572,26 +572,26 @@ cifs_reconnect(struct TCP_Server_Info *server) try_to_freeze(); mutex_lock(&server->srv_mutex); +#ifdef CONFIG_CIFS_DFS_UPCALL /* * Set up next DFS target server (if any) for reconnect. If DFS * feature is disabled, then we will retry last server we * connected to before. */ + reconn_inval_dfs_target(server, cifs_sb, &tgt_list, &tgt_it); +#endif + rc = reconn_set_ipaddr(server); + if (rc) { + cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n", + __func__, rc); + } + if (cifs_rdma_enabled(server)) rc = smbd_reconnect(server); else rc = generic_ip_connect(server); if (rc) { cifs_dbg(FYI, "reconnect error %d\n", rc); -#ifdef CONFIG_CIFS_DFS_UPCALL - reconn_inval_dfs_target(server, cifs_sb, &tgt_list, - &tgt_it); -#endif - rc = reconn_set_ipaddr(server); - if (rc) { - cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n", - __func__, rc); - } mutex_unlock(&server->srv_mutex); msleep(3000); } else { -- 2.25.1