From patchwork Thu Nov 15 14:21:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Aur=C3=A9lien_Aptel?= X-Patchwork-Id: 10684425 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 56FD013BF for ; Thu, 15 Nov 2018 14:22:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4616A2C810 for ; Thu, 15 Nov 2018 14:22:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 39EF92C820; Thu, 15 Nov 2018 14:22:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7E9382C810 for ; Thu, 15 Nov 2018 14:22:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388097AbeKPAab (ORCPT ); Thu, 15 Nov 2018 19:30:31 -0500 Received: from mx2.suse.de ([195.135.220.15]:42840 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732953AbeKPAab (ORCPT ); Thu, 15 Nov 2018 19:30:31 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 14E8CAD70; Thu, 15 Nov 2018 14:22:27 +0000 (UTC) From: Aurelien Aptel To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, Paulo Alcantara , Paulo Alcantara , Aurelien Aptel Subject: [PATCH v1 11/14] cifs: Add support for failover in cifs_reconnect() Date: Thu, 15 Nov 2018 15:21:00 +0100 Message-Id: <20181115142103.24617-12-aaptel@suse.com> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20181115142103.24617-1-aaptel@suse.com> References: <20181115142103.24617-1-aaptel@suse.com> Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Paulo Alcantara After failing to reconnect to original target, it will retry any target available from DFS cache. Signed-off-by: Paulo Alcantara Signed-off-by: Aurelien Aptel --- fs/cifs/cifs_fs_sb.h | 9 +++ fs/cifs/cifsglob.h | 7 ++ fs/cifs/connect.c | 189 ++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 204 insertions(+), 1 deletion(-) diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h index 63d7530f2e1d..42f0d67f1054 100644 --- a/fs/cifs/cifs_fs_sb.h +++ b/fs/cifs/cifs_fs_sb.h @@ -72,6 +72,15 @@ struct cifs_sb_info { char *mountdata; /* options received at mount time or via DFS refs */ struct delayed_work prune_tlinks; struct rcu_head rcu; + + /* only used when CIFS_MOUNT_USE_PREFIX_PATH is set */ char *prepath; + + /* + * Path initially provided by the mount call. We might connect + * to something different via DFS but we want to keep it to do + * failover properly. + */ + char *origin_fullpath; /* \\HOST\SHARE\[OPTIONAL PATH] */ }; #endif /* _CIFS_FS_SB_H */ diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 60c202bbcdfc..643633a3dc09 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -701,6 +701,13 @@ struct TCP_Server_Info { struct delayed_work reconnect; /* reconnect workqueue job */ struct mutex reconnect_mutex; /* prevent simultaneous reconnects */ unsigned long echo_interval; + + /* + * Number of targets available for reconnect. The more targets + * the more tasks have to wait to let the demultiplex thread + * reconnect. + */ + int nr_targets; }; static inline unsigned int diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index c4ce52818ed6..52d837d7bf57 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -57,6 +57,7 @@ #include "smb2proto.h" #include "smbdirect.h" #include "dns_resolve.h" +#include "cifsfs.h" #ifdef CONFIG_CIFS_DFS_UPCALL #include "dfs_cache.h" #endif @@ -321,6 +322,115 @@ static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink); static void cifs_prune_tlinks(struct work_struct *work); static int cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data, const char *devname, bool is_smb3); +static char *extract_hostname(const char *unc); + +#ifdef CONFIG_CIFS_DFS_UPCALL +struct super_cb_data { + struct TCP_Server_Info *server; + struct cifs_sb_info *cifs_sb; +}; + +/* These functions must be called with server->srv_mutex held */ + +static void super_cb(struct super_block *sb, void *arg) +{ + struct super_cb_data *d = arg; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *tcon; + + if (d->cifs_sb) + return; + + cifs_sb = CIFS_SB(sb); + tcon = cifs_sb_master_tcon(cifs_sb); + if (tcon->ses->server == d->server) + d->cifs_sb = cifs_sb; +} + +static inline struct cifs_sb_info * +find_super_by_tcp(struct TCP_Server_Info *server) +{ + struct super_cb_data d = { + .server = server, + .cifs_sb = NULL, + }; + + iterate_supers_type(&cifs_fs_type, super_cb, &d); + return d.cifs_sb ? d.cifs_sb : ERR_PTR(-ENOENT); +} + +static void reconn_inval_dfs_target(struct TCP_Server_Info *server, + struct cifs_sb_info *cifs_sb, + struct dfs_cache_tgt_list *tgt_list, + struct dfs_cache_tgt_iterator **tgt_it) +{ + const char *name; + int rc; + char *ipaddr = NULL; + char *unc; + int len; + + if (!cifs_sb->origin_fullpath || !tgt_list || !server->nr_targets) + return; + + if (!*tgt_it) { + *tgt_it = dfs_cache_get_tgt_iterator(tgt_list); + } else { + *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it); + if (!*tgt_it) + *tgt_it = dfs_cache_get_tgt_iterator(tgt_list); + } + + cifs_dbg(FYI, "%s: UNC: %s\n", __func__, cifs_sb->origin_fullpath); + + name = dfs_cache_get_tgt_name(*tgt_it); + + kfree(server->hostname); + + server->hostname = extract_hostname(name); + if (!server->hostname) { + cifs_dbg(FYI, "%s: failed to extract hostname from target: %d\n", + __func__, -ENOMEM); + return; + } + + len = strlen(server->hostname) + 3; + + unc = kmalloc(len, GFP_KERNEL); + if (!unc) { + cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__); + return; + } + snprintf(unc, len, "\\\\%s", server->hostname); + + rc = dns_resolve_server_name_to_ip(unc, &ipaddr); + kfree(unc); + + if (rc < 0) { + cifs_dbg(FYI, "%s: Failed to resolve server part of %s to IP: %d\n", + __func__, server->hostname, rc); + return; + } + + rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr, + strlen(ipaddr)); + kfree(ipaddr); + + if (!rc) { + cifs_dbg(FYI, "%s: failed to get ipaddr out of hostname\n", + __func__); + } +} + +static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb, + struct dfs_cache_tgt_list *tl, + struct dfs_cache_tgt_iterator **it) +{ + if (!cifs_sb->origin_fullpath) + return -EOPNOTSUPP; + return dfs_cache_noreq_find(cifs_sb->origin_fullpath + 1, NULL, tl); +} +#endif /* * cifs tcp session reconnection @@ -339,8 +449,34 @@ cifs_reconnect(struct TCP_Server_Info *server) struct cifs_tcon *tcon; struct mid_q_entry *mid_entry; struct list_head retry_list; +#ifdef CONFIG_CIFS_DFS_UPCALL + struct cifs_sb_info *cifs_sb; + struct dfs_cache_tgt_list tgt_list; + struct dfs_cache_tgt_iterator *tgt_it = NULL; +#endif spin_lock(&GlobalMid_Lock); +#ifdef CONFIG_CIFS_DFS_UPCALL + cifs_sb = find_super_by_tcp(server); + if (IS_ERR(cifs_sb)) { + rc = PTR_ERR(cifs_sb); + } else { + rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list, &tgt_it); + if (rc) { + cifs_dbg(VFS, "%s: no target servers for DFS failover\n", + __func__); + } + } + if (!rc) { + server->nr_targets = dfs_cache_get_nr_tgts(&tgt_list); + } else { + server->nr_targets = 1; + cifs_dbg(VFS, "%s: will not do DFS failover: rc = %d\n", + __func__, rc); + } + cifs_dbg(FYI, "%s: will retry %d target(s)\n", __func__, + server->nr_targets); +#endif if (server->tcpStatus == CifsExiting) { /* the demux thread will exit normally next time through the loop */ @@ -414,14 +550,22 @@ cifs_reconnect(struct TCP_Server_Info *server) do { try_to_freeze(); - /* we should try only the port we connected to before */ mutex_lock(&server->srv_mutex); + /* + * 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. + */ 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 mutex_unlock(&server->srv_mutex); msleep(3000); } else { @@ -434,6 +578,22 @@ cifs_reconnect(struct TCP_Server_Info *server) } } while (server->tcpStatus == CifsNeedReconnect); +#ifdef CONFIG_CIFS_DFS_UPCALL + if (tgt_it) { + rc = dfs_cache_noreq_update_tgthint(cifs_sb->origin_fullpath + 1, + tgt_it); + if (rc) { + cifs_dbg(VFS, "%s: failed to update DFS target hint: rc = %d\n", + __func__, rc); + } + rc = dfs_cache_update_vol(cifs_sb->origin_fullpath, server); + if (rc) { + cifs_dbg(VFS, "%s: failed to update vol info in DFS cache: rc = %d\n", + __func__, rc); + } + } + dfs_cache_free_tgts(&tgt_list); +#endif if (server->tcpStatus == CifsNeedNegotiate) mod_delayed_work(cifsiod_wq, &server->echo, 0); @@ -2470,6 +2630,8 @@ cifs_get_tcp_session(struct smb_vol *volume_info) } tcp_ses->tcpStatus = CifsNeedNegotiate; + tcp_ses->nr_targets = 1; + /* thread spawned, put it on the list */ spin_lock(&cifs_tcp_ses_lock); list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list); @@ -4291,6 +4453,12 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) goto error; } + full_path = build_unc_path_to_root(vol, cifs_sb, true); + if (IS_ERR(full_path)) { + rc = PTR_ERR(full_path); + full_path = NULL; + goto error; + } /* * Perform an unconditional check for whether there are DFS * referrals for this path without prefix, to provide support @@ -4397,6 +4565,22 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) if (rc) goto error; + spin_lock(&cifs_tcp_ses_lock); + if (!tcon->dfs_path) { + /* Save full path in new tcon to do failover when reconnecting tcons */ + tcon->dfs_path = full_path; + full_path = NULL; + tcon->remap = cifs_remap(cifs_sb); + } + cifs_sb->origin_fullpath = kstrndup(tcon->dfs_path, + strlen(tcon->dfs_path), GFP_KERNEL); + if (!cifs_sb->origin_fullpath) { + spin_unlock(&cifs_tcp_ses_lock); + rc = -ENOMEM; + goto error; + } + spin_unlock(&cifs_tcp_ses_lock); + /* * After reconnecting to a different server, unique ids won't * match anymore, so we disable serverino. This prevents @@ -4638,6 +4822,9 @@ cifs_umount(struct cifs_sb_info *cifs_sb) kfree(cifs_sb->mountdata); kfree(cifs_sb->prepath); +#ifdef CONFIG_CIFS_DFS_UPCALL + kfree(cifs_sb->origin_fullpath); +#endif call_rcu(&cifs_sb->rcu, delayed_free); }