1 files changed, 226 insertions, 110 deletions

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index d7bad2c3af37..5eec8957f2a9 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -97,7 +97,7 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
 	return rc;
 }
 
-static void smb2_query_server_interfaces(struct work_struct *work)
+void smb2_query_server_interfaces(struct work_struct *work)
 {
 	int rc;
 	int xid;
@@ -116,18 +116,22 @@ static void smb2_query_server_interfaces(struct work_struct *work)
 	rc = server->ops->query_server_interfaces(xid, tcon, false);
 	free_xid(xid);
 
-	if (rc) {
-		if (rc == -EOPNOTSUPP)
-			return;
-
+	if (rc)
 		cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 				__func__, rc);
-	}
 
 	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
 }
 
+#define set_need_reco(server) \
+do { \
+	spin_lock(&server->srv_lock); \
+	if (server->tcpStatus != CifsExiting) \
+		server->tcpStatus = CifsNeedReconnect; \
+	spin_unlock(&server->srv_lock); \
+} while (0)
+
 /*
  * Update the tcpStatus for the server.
  * This is used to signal the cifsd thread to call cifs_reconnect
@@ -141,39 +145,45 @@ void
 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 				bool all_channels)
 {
-	struct TCP_Server_Info *pserver;
+	struct TCP_Server_Info *nserver;
 	struct cifs_ses *ses;
+	LIST_HEAD(reco);
 	int i;
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
 	/* if we need to signal just this channel */
 	if (!all_channels) {
-		spin_lock(&server->srv_lock);
-		if (server->tcpStatus != CifsExiting)
-			server->tcpStatus = CifsNeedReconnect;
-		spin_unlock(&server->srv_lock);
+		set_need_reco(server);
 		return;
 	}
 
-	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
-		if (cifs_ses_exiting(ses))
-			continue;
-		spin_lock(&ses->chan_lock);
-		for (i = 0; i < ses->chan_count; i++) {
-			if (!ses->chans[i].server)
+	if (SERVER_IS_CHAN(server))
+		server = server->primary_server;
+	scoped_guard(spinlock, &cifs_tcp_ses_lock) {
+		set_need_reco(server);
+		list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
+			spin_lock(&ses->ses_lock);
+			if (ses->ses_status == SES_EXITING) {
+				spin_unlock(&ses->ses_lock);
 				continue;
-
-			spin_lock(&ses->chans[i].server->srv_lock);
-			if (ses->chans[i].server->tcpStatus != CifsExiting)
-				ses->chans[i].server->tcpStatus = CifsNeedReconnect;
-			spin_unlock(&ses->chans[i].server->srv_lock);
+			}
+			spin_lock(&ses->chan_lock);
+			for (i = 1; i < ses->chan_count; i++) {
+				nserver = ses->chans[i].server;
+				if (!nserver)
+					continue;
+				nserver->srv_count++;
+				list_add(&nserver->rlist, &reco);
+			}
+			spin_unlock(&ses->chan_lock);
+			spin_unlock(&ses->ses_lock);
 		}
-		spin_unlock(&ses->chan_lock);
 	}
-	spin_unlock(&cifs_tcp_ses_lock);
+
+	list_for_each_entry_safe(server, nserver, &reco, rlist) {
+		list_del_init(&server->rlist);
+		set_need_reco(server);
+		cifs_put_tcp_session(server, 0);
+	}
 }
 
 /*
@@ -300,7 +310,6 @@ cifs_abort_connection(struct TCP_Server_Info *server)
 			 server->ssocket->flags);
 		sock_release(server->ssocket);
 		server->ssocket = NULL;
-		put_net(cifs_net_ns(server));
 	}
 	server->sequence_number = 0;
 	server->session_estab = false;
@@ -371,13 +380,20 @@ static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num
  *
  */
 static int __cifs_reconnect(struct TCP_Server_Info *server,
-			    bool mark_smb_session)
+			    bool mark_smb_session, bool once)
 {
 	int rc = 0;
 
 	if (!cifs_tcp_ses_needs_reconnect(server, 1))
 		return 0;
 
+	/*
+	 * if smb session has been marked for reconnect, also reconnect all
+	 * connections. This way, the other connections do not end up bad.
+	 */
+	if (mark_smb_session)
+		cifs_signal_cifsd_for_reconnect(server, mark_smb_session);
+
 	cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 
 	cifs_abort_connection(server);
@@ -386,7 +402,8 @@ static int __cifs_reconnect(struct TCP_Server_Info *server,
 		try_to_freeze();
 		cifs_server_lock(server);
 
-		if (!cifs_swn_set_server_dstaddr(server)) {
+		if (!cifs_swn_set_server_dstaddr(server) &&
+		    !SERVER_IS_CHAN(server)) {
 			/* resolve the hostname again to make sure that IP address is up-to-date */
 			rc = reconn_set_ipaddr_from_hostname(server);
 			cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
@@ -399,6 +416,9 @@ static int __cifs_reconnect(struct TCP_Server_Info *server,
 		if (rc) {
 			cifs_server_unlock(server);
 			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
+			/* If was asked to reconnect only once, do not try it more times */
+			if (once)
+				break;
 			msleep(3000);
 		} else {
 			atomic_inc(&tcpSesReconnectCount);
@@ -564,19 +584,33 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 	return rc;
 }
 
-int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
+static int
+_cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session, bool once)
 {
 	if (!server->leaf_fullpath)
-		return __cifs_reconnect(server, mark_smb_session);
+		return __cifs_reconnect(server, mark_smb_session, once);
 	return reconnect_dfs_server(server);
 }
 #else
-int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
+static int
+_cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session, bool once)
 {
-	return __cifs_reconnect(server, mark_smb_session);
+	return __cifs_reconnect(server, mark_smb_session, once);
 }
 #endif
 
+int
+cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
+{
+	return _cifs_reconnect(server, mark_smb_session, false);
+}
+
+static int
+cifs_reconnect_once(struct TCP_Server_Info *server)
+{
+	return _cifs_reconnect(server, true, true);
+}
+
 static void
 cifs_echo_request(struct work_struct *work)
 {
@@ -645,12 +679,12 @@ server_unresponsive(struct TCP_Server_Info *server)
 	/*
 	 * If we're in the process of mounting a share or reconnecting a session
 	 * and the server abruptly shut down (e.g. socket wasn't closed, packet
-	 * had been ACK'ed but no SMB response), don't wait longer than 20s to
-	 * negotiate protocol.
+	 * had been ACK'ed but no SMB response), don't wait longer than 20s from
+	 * when negotiate actually started.
 	 */
 	spin_lock(&server->srv_lock);
 	if (server->tcpStatus == CifsInNegotiate &&
-	    time_after(jiffies, server->lstrp + 20 * HZ)) {
+	    time_after(jiffies, server->neg_start + 20 * HZ)) {
 		spin_unlock(&server->srv_lock);
 		cifs_reconnect(server, false);
 		return true;
@@ -803,26 +837,110 @@ is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 		/* Regular SMB response */
 		return true;
 	case RFC1002_SESSION_KEEP_ALIVE:
+		/*
+		 * RFC 1002 session keep alive can sent by the server only when
+		 * we established a RFC 1002 session. But Samba servers send
+		 * RFC 1002 session keep alive also over port 445 on which
+		 * RFC 1002 session is not established.
+		 */
 		cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 		break;
 	case RFC1002_POSITIVE_SESSION_RESPONSE:
-		cifs_dbg(FYI, "RFC 1002 positive session response\n");
+		/*
+		 * RFC 1002 positive session response cannot be returned
+		 * for SMB request. RFC 1002 session response is handled
+		 * exclusively in ip_rfc1001_connect() function.
+		 */
+		cifs_server_dbg(VFS, "RFC 1002 positive session response (unexpected)\n");
+		cifs_reconnect(server, true);
 		break;
 	case RFC1002_NEGATIVE_SESSION_RESPONSE:
 		/*
 		 * We get this from Windows 98 instead of an error on
-		 * SMB negprot response.
-		 */
-		cifs_dbg(FYI, "RFC 1002 negative session response\n");
-		/* give server a second to clean up */
-		msleep(1000);
-		/*
-		 * Always try 445 first on reconnect since we get NACK
-		 * on some if we ever connected to port 139 (the NACK
-		 * is since we do not begin with RFC1001 session
-		 * initialize frame).
+		 * SMB negprot response, when we have not established
+		 * RFC 1002 session (which means ip_rfc1001_connect()
+		 * was skipped). Note that same still happens with
+		 * Windows Server 2022 when connecting via port 139.
+		 * So for this case when mount option -o nonbsessinit
+		 * was not specified, try to reconnect with establishing
+		 * RFC 1002 session. If new socket establishment with
+		 * RFC 1002 session was successful then return to the
+		 * mid's caller -EAGAIN, so it can retry the request.
 		 */
-		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
+		if (!cifs_rdma_enabled(server) &&
+		    server->tcpStatus == CifsInNegotiate &&
+		    !server->with_rfc1001 &&
+		    server->rfc1001_sessinit != 0) {
+			int rc, mid_rc;
+			struct mid_q_entry *mid, *nmid;
+			LIST_HEAD(dispose_list);
+
+			cifs_dbg(FYI, "RFC 1002 negative session response during SMB Negotiate, retrying with NetBIOS session\n");
+
+			/*
+			 * Before reconnect, delete all pending mids for this
+			 * server, so reconnect would not signal connection
+			 * aborted error to mid's callbacks. Note that for this
+			 * server there should be exactly one pending mid
+			 * corresponding to SMB1/SMB2 Negotiate packet.
+			 */
+			spin_lock(&server->mid_lock);
+			list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
+				kref_get(&mid->refcount);
+				list_move(&mid->qhead, &dispose_list);
+				mid->mid_flags |= MID_DELETED;
+			}
+			spin_unlock(&server->mid_lock);
+
+			/* Now try to reconnect once with NetBIOS session. */
+			server->with_rfc1001 = true;
+			rc = cifs_reconnect_once(server);
+
+			/*
+			 * If reconnect was successful then indicate -EAGAIN
+			 * to mid's caller. If reconnect failed with -EAGAIN
+			 * then mask it as -EHOSTDOWN, so mid's caller would
+			 * know that it failed.
+			 */
+			if (rc == 0)
+				mid_rc = -EAGAIN;
+			else if (rc == -EAGAIN)
+				mid_rc = -EHOSTDOWN;
+			else
+				mid_rc = rc;
+
+			/*
+			 * After reconnect (either successful or unsuccessful)
+			 * deliver reconnect status to mid's caller via mid's
+			 * callback. Use MID_RC state which indicates that the
+			 * return code should be read from mid_rc member.
+			 */
+			list_for_each_entry_safe(mid, nmid, &dispose_list, qhead) {
+				list_del_init(&mid->qhead);
+				mid->mid_rc = mid_rc;
+				mid->mid_state = MID_RC;
+				mid->callback(mid);
+				release_mid(mid);
+			}
+
+			/*
+			 * If reconnect failed then wait two seconds. In most
+			 * cases we were been called from the mount context and
+			 * delivered failure to mid's callback will stop this
+			 * receiver task thread and fails the mount process.
+			 * So wait two seconds to prevent another reconnect
+			 * in this task thread, which would be useless as the
+			 * mount context will fail at all.
+			 */
+			if (rc != 0)
+				msleep(2000);
+		} else {
+			cifs_server_dbg(VFS, "RFC 1002 negative session response (unexpected)\n");
+			cifs_reconnect(server, true);
+		}
+		break;
+	case RFC1002_RETARGET_SESSION_RESPONSE:
+		cifs_server_dbg(VFS, "RFC 1002 retarget session response (unexpected)\n");
 		cifs_reconnect(server, true);
 		break;
 	default:
@@ -973,13 +1091,9 @@ clean_demultiplex_info(struct TCP_Server_Info *server)
 	msleep(125);
 	if (cifs_rdma_enabled(server))
 		smbd_destroy(server);
-
 	if (server->ssocket) {
 		sock_release(server->ssocket);
 		server->ssocket = NULL;
-
-		/* Release netns reference for the socket. */
-		put_net(cifs_net_ns(server));
 	}
 
 	if (!list_empty(&server->pending_mid_q)) {
@@ -1027,7 +1141,6 @@ clean_demultiplex_info(struct TCP_Server_Info *server)
 		 */
 	}
 
-	/* Release netns reference for this server. */
 	put_net(cifs_net_ns(server));
 	kfree(server->leaf_fullpath);
 	kfree(server->hostname);
@@ -1673,8 +1786,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 
 	tcp_ses->ops = ctx->ops;
 	tcp_ses->vals = ctx->vals;
-
-	/* Grab netns reference for this server. */
 	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
 
 	tcp_ses->sign = ctx->sign;
@@ -1701,6 +1812,8 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 		ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
 	memcpy(tcp_ses->server_RFC1001_name,
 		ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
+	tcp_ses->rfc1001_sessinit = ctx->rfc1001_sessinit;
+	tcp_ses->with_rfc1001 = false;
 	tcp_ses->session_estab = false;
 	tcp_ses->sequence_number = 0;
 	tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
@@ -1731,12 +1844,8 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 	 */
 	tcp_ses->tcpStatus = CifsNew;
 	++tcp_ses->srv_count;
+	tcp_ses->echo_interval = ctx->echo_interval * HZ;
 
-	if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
-		ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
-		tcp_ses->echo_interval = ctx->echo_interval * HZ;
-	else
-		tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
 	if (tcp_ses->rdma) {
 #ifndef CONFIG_CIFS_SMB_DIRECT
 		cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
@@ -1804,7 +1913,6 @@ smbd_connected:
 out_err_crypto_release:
 	cifs_crypto_secmech_release(tcp_ses);
 
-	/* Release netns reference for this server. */
 	put_net(cifs_net_ns(tcp_ses));
 
 out_err:
@@ -1813,10 +1921,8 @@ out_err:
 			cifs_put_tcp_session(tcp_ses->primary_server, false);
 		kfree(tcp_ses->hostname);
 		kfree(tcp_ses->leaf_fullpath);
-		if (tcp_ses->ssocket) {
+		if (tcp_ses->ssocket)
 			sock_release(tcp_ses->ssocket);
-			put_net(cifs_net_ns(tcp_ses));
-		}
 		kfree(tcp_ses);
 	}
 	return ERR_PTR(rc);
@@ -2457,6 +2563,8 @@ static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 		return 0;
 	if (tcon->nodelete != ctx->nodelete)
 		return 0;
+	if (tcon->posix_extensions != ctx->linux_ext)
+		return 0;
 	return 1;
 }
 
@@ -2772,20 +2880,14 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 	tcon->max_cached_dirs = ctx->max_cached_dirs;
 	tcon->nodelete = ctx->nodelete;
 	tcon->local_lease = ctx->local_lease;
-	INIT_LIST_HEAD(&tcon->pending_opens);
 	tcon->status = TID_GOOD;
 
-	INIT_DELAYED_WORK(&tcon->query_interfaces,
-			  smb2_query_server_interfaces);
 	if (ses->server->dialect >= SMB30_PROT_ID &&
 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
 		/* schedule query interfaces poll */
 		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
 	}
-#ifdef CONFIG_CIFS_DFS_UPCALL
-	INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
-#endif
 	spin_lock(&cifs_tcp_ses_lock);
 	list_add(&tcon->tcon_list, &ses->tcon_list);
 	spin_unlock(&cifs_tcp_ses_lock);
@@ -3221,6 +3323,7 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
 		return -EIO;
 	}
 
+	server->with_rfc1001 = true;
 	return 0;
 }
 
@@ -3257,24 +3360,17 @@ generic_ip_connect(struct TCP_Server_Info *server)
 		socket = server->ssocket;
 	} else {
 		struct net *net = cifs_net_ns(server);
+		struct sock *sk;
 
-		rc = sock_create_kern(net, sfamily, SOCK_STREAM, IPPROTO_TCP, &server->ssocket);
+		rc = sock_create_kern(net, sfamily, SOCK_STREAM,
+				      IPPROTO_TCP, &server->ssocket);
 		if (rc < 0) {
 			cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
 			return rc;
 		}
 
-		/*
-		 * Grab netns reference for the socket.
-		 *
-		 * This reference will be released in several situations:
-		 * - In the failure path before the cifsd thread is started.
-		 * - In the all place where server->socket is released, it is
-		 *   also set to NULL.
-		 * - Ultimately in clean_demultiplex_info(), during the final
-		 *   teardown.
-		 */
-		get_net(net);
+		sk = server->ssocket->sk;
+		sk_net_refcnt_upgrade(sk);
 
 		/* BB other socket options to set KEEPALIVE, NODELAY? */
 		cifs_dbg(FYI, "Socket created\n");
@@ -3326,13 +3422,21 @@ generic_ip_connect(struct TCP_Server_Info *server)
 	if (rc < 0) {
 		cifs_dbg(FYI, "Error %d connecting to server\n", rc);
 		trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
-		put_net(cifs_net_ns(server));
 		sock_release(socket);
 		server->ssocket = NULL;
 		return rc;
 	}
 	trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
-	if (sport == htons(RFC1001_PORT))
+
+	/*
+	 * Establish RFC1001 NetBIOS session when it was explicitly requested
+	 * by mount option -o nbsessinit, or when connecting to default RFC1001
+	 * server port (139) and it was not explicitly disabled by mount option
+	 * -o nonbsessinit.
+	 */
+	if (server->with_rfc1001 ||
+	    server->rfc1001_sessinit == 1 ||
+	    (server->rfc1001_sessinit == -1 && sport == htons(RFC1001_PORT)))
 		rc = ip_rfc1001_connect(server);
 
 	return rc;
@@ -3481,6 +3585,7 @@ int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
 	struct smb3_fs_context *ctx = cifs_sb->ctx;
 
 	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
+	INIT_LIST_HEAD(&cifs_sb->tcon_sb_link);
 
 	spin_lock_init(&cifs_sb->tlink_tree_lock);
 	cifs_sb->tlink_tree = RB_ROOT;
@@ -3618,9 +3723,15 @@ int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
 		goto out;
 	}
 
-	/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
-	if (tcon->posix_extensions)
+	/*
+	 * if new SMB3.11 POSIX extensions are supported, do not change anything in the
+	 * path (i.e., do not remap / and \ and do not map any special characters)
+	 */
+	if (tcon->posix_extensions) {
 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
+		cifs_sb->mnt_cifs_flags &= ~(CIFS_MOUNT_MAP_SFM_CHR |
+					     CIFS_MOUNT_MAP_SPECIAL_CHR);
+	}
 
 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 	/* tell server which Unix caps we support */
@@ -3657,28 +3768,7 @@ int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
 		}
 	}
 
-	/*
-	 * Clamp the rsize/wsize mount arguments if they are too big for the server
-	 * and set the rsize/wsize to the negotiated values if not passed in by
-	 * the user on mount
-	 */
-	if ((cifs_sb->ctx->wsize == 0) ||
-	    (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) {
-		cifs_sb->ctx->wsize =
-			round_down(server->ops->negotiate_wsize(tcon, ctx), PAGE_SIZE);
-		/*
-		 * in the very unlikely event that the server sent a max write size under PAGE_SIZE,
-		 * (which would get rounded down to 0) then reset wsize to absolute minimum eg 4096
-		 */
-		if (cifs_sb->ctx->wsize == 0) {
-			cifs_sb->ctx->wsize = PAGE_SIZE;
-			cifs_dbg(VFS, "wsize too small, reset to minimum ie PAGE_SIZE, usually 4096\n");
-		}
-	}
-	if ((cifs_sb->ctx->rsize == 0) ||
-	    (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
-		cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
-
+	cifs_negotiate_iosize(server, cifs_sb->ctx, tcon);
 	/*
 	 * The cookie is initialized from volume info returned above.
 	 * Inside cifs_fscache_get_super_cookie it checks
@@ -3713,6 +3803,10 @@ static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 	tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
 	spin_unlock(&cifs_sb->tlink_tree_lock);
 
+	spin_lock(&tcon->sb_list_lock);
+	list_add(&cifs_sb->tcon_sb_link, &tcon->cifs_sb_list);
+	spin_unlock(&tcon->sb_list_lock);
+
 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
 				TLINK_IDLE_EXPIRE);
 	return 0;
@@ -4054,9 +4148,19 @@ cifs_umount(struct cifs_sb_info *cifs_sb)
 	struct rb_root *root = &cifs_sb->tlink_tree;
 	struct rb_node *node;
 	struct tcon_link *tlink;
+	struct cifs_tcon *tcon = NULL;
 
 	cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
 
+	if (cifs_sb->master_tlink) {
+		tcon = cifs_sb->master_tlink->tl_tcon;
+		if (tcon) {
+			spin_lock(&tcon->sb_list_lock);
+			list_del_init(&cifs_sb->tcon_sb_link);
+			spin_unlock(&tcon->sb_list_lock);
+		}
+	}
+
 	spin_lock(&cifs_sb->tlink_tree_lock);
 	while ((node = rb_first(root))) {
 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
@@ -4078,11 +4182,13 @@ int
 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
 			struct TCP_Server_Info *server)
 {
+	bool in_retry = false;
 	int rc = 0;
 
 	if (!server->ops->need_neg || !server->ops->negotiate)
 		return -ENOSYS;
 
+retry:
 	/* only send once per connect */
 	spin_lock(&server->srv_lock);
 	if (server->tcpStatus != CifsGood &&
@@ -4098,10 +4204,20 @@ cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
 		return 0;
 	}
 
+	server->lstrp = jiffies;
 	server->tcpStatus = CifsInNegotiate;
+	server->neg_start = jiffies;
 	spin_unlock(&server->srv_lock);
 
 	rc = server->ops->negotiate(xid, ses, server);
+	if (rc == -EAGAIN) {
+		/* Allow one retry attempt */
+		if (!in_retry) {
+			in_retry = true;
+			goto retry;
+		}
+		rc = -EHOSTDOWN;
+	}
 	if (rc == 0) {
 		spin_lock(&server->srv_lock);
 		if (server->tcpStatus == CifsInNegotiate)