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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 9385EC433E1 for ; Thu, 18 Jun 2020 02:23:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7546E2193E for ; Thu, 18 Jun 2020 02:23:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592447009; bh=2D3kzws+KYsBXtr3Gt9Fxj/LRF9q8n+ybKuM2O2Gmxc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u/WHdUG0H5DUBkuCM82LYFCGWsC7Ug/PCC1VpI/a0/vro33gkPX3SsLhQ64vVCXRO ktBejK4B3FVGn4z+M8RhjI5QBWTkxjcp2a/mmFXvoB5O4kwvNkhIR0qE7zUv3H7lEm DrOildNNvvySKbaGOay2Azo96wyhvXlpOyLMMIQs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729537AbgFRBSD (ORCPT ); Wed, 17 Jun 2020 21:18:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:49328 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729862AbgFRBSA (ORCPT ); Wed, 17 Jun 2020 21:18:00 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3B063206F1; Thu, 18 Jun 2020 01:17:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592443080; bh=2D3kzws+KYsBXtr3Gt9Fxj/LRF9q8n+ybKuM2O2Gmxc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JwKxBux1K36WCMOs9+PLFhe/dd9MqHMl+C3aBVq9jxgXR8lCnSbM/OBFMaHR0Oy2U iO9M0HFXdfHPhLmBPVuWVRlJ3bi3Rty9gjjcpyAnbbB9tN8uEf11CQeO3+QUER/TAu 8Sa0xH5cOqNtwI+nZrogbb0/vVpuNdI3BZIcnV6k= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Paulo Alcantara , Aurelien Aptel , Steve French , Sasha Levin , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org Subject: [PATCH AUTOSEL 5.4 066/266] cifs: set up next DFS target before generic_ip_connect() Date: Wed, 17 Jun 2020 21:13:11 -0400 Message-Id: <20200618011631.604574-66-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618011631.604574-1-sashal@kernel.org> References: <20200618011631.604574-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 721b2560caa7..947c4aad5d6a 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -614,26 +614,26 @@ 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