1 files changed, 483 insertions, 211 deletions

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 2372538a1211..dd12f3eb61dc 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -72,10 +72,8 @@ static void cifs_prune_tlinks(struct work_struct *work);
  */
 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
 {
-	int rc;
-	int len;
-	char *unc;
 	struct sockaddr_storage ss;
+	int rc;
 
 	if (!server->hostname)
 		return -EINVAL;
@@ -84,36 +82,22 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
 	if (server->hostname[0] == '\0')
 		return 0;
 
-	len = strlen(server->hostname) + 3;
-
-	unc = kmalloc(len, GFP_KERNEL);
-	if (!unc) {
-		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
-		return -ENOMEM;
-	}
-	scnprintf(unc, len, "\\\\%s", server->hostname);
-
 	spin_lock(&server->srv_lock);
 	ss = server->dstaddr;
 	spin_unlock(&server->srv_lock);
 
-	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
-	kfree(unc);
-
-	if (rc < 0) {
-		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
-			 __func__, server->hostname, rc);
-	} else {
+	rc = dns_resolve_name(server->dns_dom, server->hostname,
+			      strlen(server->hostname),
+			      (struct sockaddr *)&ss);
+	if (!rc) {
 		spin_lock(&server->srv_lock);
 		memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 		spin_unlock(&server->srv_lock);
-		rc = 0;
 	}
-
 	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;
@@ -132,18 +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
@@ -157,39 +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);
+	}
 }
 
 /*
@@ -327,21 +321,21 @@ cifs_abort_connection(struct TCP_Server_Info *server)
 	/* mark submitted MIDs for retry and issue callback */
 	INIT_LIST_HEAD(&retry_list);
 	cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
-	spin_lock(&server->mid_lock);
+	spin_lock(&server->mid_queue_lock);
 	list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 		kref_get(&mid->refcount);
 		if (mid->mid_state == MID_REQUEST_SUBMITTED)
 			mid->mid_state = MID_RETRY_NEEDED;
 		list_move(&mid->qhead, &retry_list);
-		mid->mid_flags |= MID_DELETED;
+		mid->deleted_from_q = true;
 	}
-	spin_unlock(&server->mid_lock);
+	spin_unlock(&server->mid_queue_lock);
 	cifs_server_unlock(server);
 
 	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 	list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 		list_del_init(&mid->qhead);
-		mid->callback(mid);
+		mid_execute_callback(mid);
 		release_mid(mid);
 	}
 
@@ -364,7 +358,7 @@ static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num
 	}
 
 	cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
-	trace_smb3_reconnect(server->CurrentMid, server->conn_id,
+	trace_smb3_reconnect(server->current_mid, server->conn_id,
 			     server->hostname);
 	server->tcpStatus = CifsNeedReconnect;
 
@@ -386,13 +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);
@@ -401,7 +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);
@@ -414,6 +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);
@@ -438,7 +443,8 @@ static int __cifs_reconnect(struct TCP_Server_Info *server,
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
-static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
+static int __reconnect_target_locked(struct TCP_Server_Info *server,
+				     const char *target)
 {
 	int rc;
 	char *hostname;
@@ -471,34 +477,43 @@ static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const cha
 	return rc;
 }
 
-static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
-				     struct dfs_cache_tgt_iterator **target_hint)
+static int reconnect_target_locked(struct TCP_Server_Info *server,
+				   struct dfs_cache_tgt_list *tl,
+				   struct dfs_cache_tgt_iterator **target_hint)
 {
-	int rc;
 	struct dfs_cache_tgt_iterator *tit;
+	int rc;
 
 	*target_hint = NULL;
 
 	/* If dfs target list is empty, then reconnect to last server */
 	tit = dfs_cache_get_tgt_iterator(tl);
 	if (!tit)
-		return __reconnect_target_unlocked(server, server->hostname);
+		return __reconnect_target_locked(server, server->hostname);
 
 	/* Otherwise, try every dfs target in @tl */
-	for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
-		rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
+	do {
+		const char *target = dfs_cache_get_tgt_name(tit);
+
+		spin_lock(&server->srv_lock);
+		if (server->tcpStatus != CifsNeedReconnect) {
+			spin_unlock(&server->srv_lock);
+			return -ECONNRESET;
+		}
+		spin_unlock(&server->srv_lock);
+		rc = __reconnect_target_locked(server, target);
 		if (!rc) {
 			*target_hint = tit;
 			break;
 		}
-	}
+	} while ((tit = dfs_cache_get_next_tgt(tl, tit)));
 	return rc;
 }
 
 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 {
 	struct dfs_cache_tgt_iterator *target_hint = NULL;
-
+	const char *ref_path = server->leaf_fullpath + 1;
 	DFS_CACHE_TGT_LIST(tl);
 	int num_targets = 0;
 	int rc = 0;
@@ -511,10 +526,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 	 * refreshing the referral, so, in this case, default it to 1.
 	 */
-	mutex_lock(&server->refpath_lock);
-	if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
+	if (!dfs_cache_noreq_find(ref_path, NULL, &tl))
 		num_targets = dfs_cache_get_nr_tgts(&tl);
-	mutex_unlock(&server->refpath_lock);
 	if (!num_targets)
 		num_targets = 1;
 
@@ -534,7 +547,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 		try_to_freeze();
 		cifs_server_lock(server);
 
-		rc = reconnect_target_unlocked(server, &tl, &target_hint);
+		rc = reconnect_target_locked(server, &tl, &target_hint);
 		if (rc) {
 			/* Failed to reconnect socket */
 			cifs_server_unlock(server);
@@ -558,9 +571,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
 		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 	} while (server->tcpStatus == CifsNeedReconnect);
 
-	mutex_lock(&server->refpath_lock);
-	dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
-	mutex_unlock(&server->refpath_lock);
+	dfs_cache_noreq_update_tgthint(ref_path, target_hint);
 	dfs_cache_free_tgts(&tl);
 
 	/* Need to set up echo worker again once connection has been established */
@@ -573,24 +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)
 {
-	mutex_lock(&server->refpath_lock);
-	if (!server->leaf_fullpath) {
-		mutex_unlock(&server->refpath_lock);
-		return __cifs_reconnect(server, mark_smb_session);
-	}
-	mutex_unlock(&server->refpath_lock);
-
+	if (!server->leaf_fullpath)
+		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)
 {
@@ -659,12 +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;
@@ -817,26 +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.
+		 * 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_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).
-		 */
-		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_queue_lock);
+			list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
+				kref_get(&mid->refcount);
+				list_move(&mid->qhead, &dispose_list);
+				mid->deleted_from_q = true;
+			}
+			spin_unlock(&server->mid_queue_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_execute_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:
@@ -853,7 +957,7 @@ dequeue_mid(struct mid_q_entry *mid, bool malformed)
 #ifdef CONFIG_CIFS_STATS2
 	mid->when_received = jiffies;
 #endif
-	spin_lock(&mid->server->mid_lock);
+	spin_lock(&mid->server->mid_queue_lock);
 	if (!malformed)
 		mid->mid_state = MID_RESPONSE_RECEIVED;
 	else
@@ -862,13 +966,13 @@ dequeue_mid(struct mid_q_entry *mid, bool malformed)
 	 * Trying to handle/dequeue a mid after the send_recv()
 	 * function has finished processing it is a bug.
 	 */
-	if (mid->mid_flags & MID_DELETED) {
-		spin_unlock(&mid->server->mid_lock);
+	if (mid->deleted_from_q == true) {
+		spin_unlock(&mid->server->mid_queue_lock);
 		pr_warn_once("trying to dequeue a deleted mid\n");
 	} else {
 		list_del_init(&mid->qhead);
-		mid->mid_flags |= MID_DELETED;
-		spin_unlock(&mid->server->mid_lock);
+		mid->deleted_from_q = true;
+		spin_unlock(&mid->server->mid_queue_lock);
 	}
 }
 
@@ -997,23 +1101,23 @@ clean_demultiplex_info(struct TCP_Server_Info *server)
 		struct list_head *tmp, *tmp2;
 		LIST_HEAD(dispose_list);
 
-		spin_lock(&server->mid_lock);
+		spin_lock(&server->mid_queue_lock);
 		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 			cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 			kref_get(&mid_entry->refcount);
 			mid_entry->mid_state = MID_SHUTDOWN;
 			list_move(&mid_entry->qhead, &dispose_list);
-			mid_entry->mid_flags |= MID_DELETED;
+			mid_entry->deleted_from_q = true;
 		}
-		spin_unlock(&server->mid_lock);
+		spin_unlock(&server->mid_queue_lock);
 
 		/* now walk dispose list and issue callbacks */
 		list_for_each_safe(tmp, tmp2, &dispose_list) {
 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 			cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 			list_del_init(&mid_entry->qhead);
-			mid_entry->callback(mid_entry);
+			mid_execute_callback(mid_entry);
 			release_mid(mid_entry);
 		}
 		/* 1/8th of sec is more than enough time for them to exit */
@@ -1039,6 +1143,7 @@ clean_demultiplex_info(struct TCP_Server_Info *server)
 
 	put_net(cifs_net_ns(server));
 	kfree(server->leaf_fullpath);
+	kfree(server->hostname);
 	kfree(server);
 
 	length = atomic_dec_return(&tcpSesAllocCount);
@@ -1137,7 +1242,7 @@ smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 		spin_unlock(&server->req_lock);
 		wake_up(&server->request_q);
 
-		trace_smb3_hdr_credits(server->CurrentMid,
+		trace_smb3_hdr_credits(server->current_mid,
 				server->conn_id, server->hostname, scredits,
 				le16_to_cpu(shdr->CreditRequest), in_flight);
 		cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
@@ -1289,7 +1394,7 @@ next_pdu:
 				}
 
 				if (!mids[i]->multiRsp || mids[i]->multiEnd)
-					mids[i]->callback(mids[i]);
+					mid_execute_callback(mids[i]);
 
 				release_mid(mids[i]);
 			} else if (server->ops->is_oplock_break &&
@@ -1535,42 +1640,10 @@ static int match_server(struct TCP_Server_Info *server,
 	if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
 			       (struct sockaddr *)&server->srcaddr))
 		return 0;
-	/*
-	 * When matching cifs.ko superblocks (@match_super == true), we can't
-	 * really match either @server->leaf_fullpath or @server->dstaddr
-	 * directly since this @server might belong to a completely different
-	 * server -- in case of domain-based DFS referrals or DFS links -- as
-	 * provided earlier by mount(2) through 'source' and 'ip' options.
-	 *
-	 * Otherwise, match the DFS referral in @server->leaf_fullpath or the
-	 * destination address in @server->dstaddr.
-	 *
-	 * When using 'nodfs' mount option, we avoid sharing it with DFS
-	 * connections as they might failover.
-	 */
-	if (!match_super) {
-		if (!ctx->nodfs) {
-			if (server->leaf_fullpath) {
-				if (!ctx->leaf_fullpath ||
-				    strcasecmp(server->leaf_fullpath,
-					       ctx->leaf_fullpath))
-					return 0;
-			} else if (ctx->leaf_fullpath) {
-				return 0;
-			}
-		} else if (server->leaf_fullpath) {
-			return 0;
-		}
-	}
 
-	/*
-	 * Match for a regular connection (address/hostname/port) which has no
-	 * DFS referrals set.
-	 */
-	if (!server->leaf_fullpath &&
-	    (strcasecmp(server->hostname, ctx->server_hostname) ||
-	     !match_server_address(server, addr) ||
-	     !match_port(server, addr)))
+	if (strcasecmp(server->hostname, ctx->server_hostname) ||
+	    !match_server_address(server, addr) ||
+	    !match_port(server, addr))
 		return 0;
 
 	if (!match_security(server, ctx))
@@ -1665,8 +1738,6 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
 	kfree_sensitive(server->session_key.response);
 	server->session_key.response = NULL;
 	server->session_key.len = 0;
-	kfree(server->hostname);
-	server->hostname = NULL;
 
 	task = xchg(&server->tsk, NULL);
 	if (task)
@@ -1706,6 +1777,8 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 			goto out_err;
 		}
 	}
+	if (ctx->dns_dom)
+		strscpy(tcp_ses->dns_dom, ctx->dns_dom);
 
 	if (ctx->nosharesock)
 		tcp_ses->nosharesock = true;
@@ -1715,6 +1788,7 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 	tcp_ses->vals = ctx->vals;
 	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
 
+	tcp_ses->sign = ctx->sign;
 	tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
 	tcp_ses->noblockcnt = ctx->rootfs;
 	tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
@@ -1738,6 +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 */
@@ -1746,15 +1822,13 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 	tcp_ses->compression.requested = ctx->compress;
 	spin_lock_init(&tcp_ses->req_lock);
 	spin_lock_init(&tcp_ses->srv_lock);
-	spin_lock_init(&tcp_ses->mid_lock);
+	spin_lock_init(&tcp_ses->mid_queue_lock);
+	spin_lock_init(&tcp_ses->mid_counter_lock);
 	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
 	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
 	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
 	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
 	mutex_init(&tcp_ses->reconnect_mutex);
-#ifdef CONFIG_CIFS_DFS_UPCALL
-	mutex_init(&tcp_ses->refpath_lock);
-#endif
 	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
 	       sizeof(tcp_ses->srcaddr));
 	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
@@ -1771,12 +1845,8 @@ 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");
@@ -1864,9 +1934,8 @@ static int match_session(struct cifs_ses *ses,
 			 struct smb3_fs_context *ctx,
 			 bool match_super)
 {
-	if (ctx->sectype != Unspecified &&
-	    ctx->sectype != ses->sectype)
-		return 0;
+	struct TCP_Server_Info *server = ses->server;
+	enum securityEnum ctx_sec, ses_sec;
 
 	if (!match_super && ctx->dfs_root_ses != ses->dfs_root_ses)
 		return 0;
@@ -1878,11 +1947,20 @@ static int match_session(struct cifs_ses *ses,
 	if (ses->chan_max < ctx->max_channels)
 		return 0;
 
-	switch (ses->sectype) {
+	ctx_sec = server->ops->select_sectype(server, ctx->sectype);
+	ses_sec = server->ops->select_sectype(server, ses->sectype);
+
+	if (ctx_sec != ses_sec)
+		return 0;
+
+	switch (ctx_sec) {
+	case IAKerb:
 	case Kerberos:
 		if (!uid_eq(ctx->cred_uid, ses->cred_uid))
 			return 0;
 		break;
+	case NTLMv2:
+	case RawNTLMSSP:
 	default:
 		/* NULL username means anonymous session */
 		if (ses->user_name == NULL) {
@@ -2267,12 +2345,13 @@ cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
 struct cifs_ses *
 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
 {
-	int rc = 0;
-	int retries = 0;
-	unsigned int xid;
-	struct cifs_ses *ses;
-	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
+	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
+	struct cifs_ses *ses;
+	unsigned int xid;
+	int retries = 0;
+	size_t len;
+	int rc = 0;
 
 	xid = get_xid();
 
@@ -2362,6 +2441,14 @@ retry_old_session:
 		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
 		if (!ses->domainName)
 			goto get_ses_fail;
+
+		len = strnlen(ctx->domainname, CIFS_MAX_DOMAINNAME_LEN);
+		if (!cifs_netbios_name(ctx->domainname, len)) {
+			ses->dns_dom = kstrndup(ctx->domainname,
+						len, GFP_KERNEL);
+			if (!ses->dns_dom)
+				goto get_ses_fail;
+		}
 	}
 
 	strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
@@ -2371,6 +2458,7 @@ retry_old_session:
 	ses->cred_uid = ctx->cred_uid;
 	ses->linux_uid = ctx->linux_uid;
 
+	ses->unicode = ctx->unicode;
 	ses->sectype = ctx->sectype;
 	ses->sign = ctx->sign;
 
@@ -2476,6 +2564,8 @@ 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;
 }
 
@@ -2791,20 +2881,14 @@ 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);
@@ -2879,6 +2963,10 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
 		return 0;
 	if (old->ctx->reparse_type != new->ctx->reparse_type)
 		return 0;
+	if (old->ctx->nonativesocket != new->ctx->nonativesocket)
+		return 0;
+	if (old->ctx->symlink_type != new->ctx->symlink_type)
+		return 0;
 
 	return 1;
 }
@@ -3044,6 +3132,44 @@ bind_socket(struct TCP_Server_Info *server)
 }
 
 static int
+smb_recv_kvec(struct TCP_Server_Info *server, struct msghdr *msg, size_t *recv)
+{
+	int rc = 0;
+	int retries = 0;
+	int msg_flags = server->noblocksnd ? MSG_DONTWAIT : 0;
+
+	*recv = 0;
+
+	while (msg_data_left(msg)) {
+		rc = sock_recvmsg(server->ssocket, msg, msg_flags);
+		if (rc == -EAGAIN) {
+			retries++;
+			if (retries >= 14 ||
+			    (!server->noblocksnd && (retries > 2))) {
+				cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
+						server->ssocket);
+				return -EAGAIN;
+			}
+			msleep(1 << retries);
+			continue;
+		}
+
+		if (rc < 0)
+			return rc;
+
+		if (rc == 0) {
+			cifs_dbg(FYI, "Received no data (TCP RST)\n");
+			return -ECONNABORTED;
+		}
+
+		/* recv was at least partially successful */
+		*recv += rc;
+		retries = 0; /* in case we get ENOSPC on the next send */
+	}
+	return 0;
+}
+
+static int
 ip_rfc1001_connect(struct TCP_Server_Info *server)
 {
 	int rc = 0;
@@ -3053,8 +3179,12 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
 	 * sessinit is sent but no second negprot
 	 */
 	struct rfc1002_session_packet req = {};
-	struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
+	struct rfc1002_session_packet resp = {};
+	struct msghdr msg = {};
+	struct kvec iov = {};
 	unsigned int len;
+	size_t sent;
+	size_t recv;
 
 	req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
 
@@ -3083,19 +3213,119 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
 	 * As per rfc1002, @len must be the number of bytes that follows the
 	 * length field of a rfc1002 session request payload.
 	 */
-	len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
+	len = sizeof(req.trailer.session_req);
+	req.type = RFC1002_SESSION_REQUEST;
+	req.flags = 0;
+	req.length = cpu_to_be16(len);
+	len += offsetof(typeof(req), trailer.session_req);
+	iov.iov_base = &req;
+	iov.iov_len = len;
+	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, len);
+	rc = smb_send_kvec(server, &msg, &sent);
+	if (rc < 0 || len != sent)
+		return (rc == -EINTR || rc == -EAGAIN) ? rc : -ECONNABORTED;
 
-	smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
-	rc = smb_send(server, smb_buf, len);
 	/*
 	 * RFC1001 layer in at least one server requires very short break before
 	 * negprot presumably because not expecting negprot to follow so fast.
-	 * This is a simple solution that works without complicating the code
-	 * and causes no significant slowing down on mount for everyone else
+	 * For example DOS SMB servers cannot process negprot if it was received
+	 * before the server sent response for SESSION_REQUEST packet. So, wait
+	 * for the response, read it and parse it as it can contain useful error
+	 * information (e.g. specified server name was incorrect). For example
+	 * even the latest Windows Server 2022 SMB1 server over port 139 send
+	 * error if its server name was in SESSION_REQUEST packet incorrect.
+	 * Nowadays usage of port 139 is not common, so waiting for reply here
+	 * does not slowing down mounting of common case (over port 445).
 	 */
-	usleep_range(1000, 2000);
+	len = offsetof(typeof(resp), trailer);
+	iov.iov_base = &resp;
+	iov.iov_len = len;
+	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, len);
+	rc = smb_recv_kvec(server, &msg, &recv);
+	if (rc < 0 || recv != len)
+		return (rc == -EINTR || rc == -EAGAIN) ? rc : -ECONNABORTED;
+
+	switch (resp.type) {
+	case RFC1002_POSITIVE_SESSION_RESPONSE:
+		if (be16_to_cpu(resp.length) != 0) {
+			cifs_dbg(VFS, "RFC 1002 positive session response but with invalid non-zero length %u\n",
+				 be16_to_cpu(resp.length));
+			return -EIO;
+		}
+		cifs_dbg(FYI, "RFC 1002 positive session response");
+		break;
+	case RFC1002_NEGATIVE_SESSION_RESPONSE:
+		/* Read RFC1002 response error code and convert it to errno in rc */
+		len = sizeof(resp.trailer.neg_ses_resp_error_code);
+		iov.iov_base = &resp.trailer.neg_ses_resp_error_code;
+		iov.iov_len = len;
+		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, len);
+		if (be16_to_cpu(resp.length) == len &&
+		    smb_recv_kvec(server, &msg, &recv) == 0 &&
+		    recv == len) {
+			cifs_dbg(VFS, "RFC 1002 negative session response with error 0x%x\n",
+				 resp.trailer.neg_ses_resp_error_code);
+			switch (resp.trailer.neg_ses_resp_error_code) {
+			case RFC1002_NOT_LISTENING_CALLED:
+				/* server does not listen for specified server name */
+				fallthrough;
+			case RFC1002_NOT_PRESENT:
+				/* server name is incorrect */
+				rc = -ENOENT;
+				cifs_dbg(VFS, "Server rejected NetBIOS servername %.15s\n",
+					 server->server_RFC1001_name[0] ?
+					 server->server_RFC1001_name :
+					 DEFAULT_CIFS_CALLED_NAME);
+				cifs_dbg(VFS, "Specify correct NetBIOS servername in source path or with -o servern= option\n");
+				break;
+			case RFC1002_NOT_LISTENING_CALLING:
+				/* client name was not accepted by server */
+				rc = -EACCES;
+				cifs_dbg(VFS, "Server rejected NetBIOS clientname %.15s\n",
+					 server->workstation_RFC1001_name[0] ?
+					 server->workstation_RFC1001_name :
+					 "LINUX_CIFS_CLNT");
+				cifs_dbg(VFS, "Specify correct NetBIOS clientname with -o netbiosname= option\n");
+				break;
+			case RFC1002_INSUFFICIENT_RESOURCE:
+				/* remote server resource error */
+				rc = -EREMOTEIO;
+				break;
+			case RFC1002_UNSPECIFIED_ERROR:
+			default:
+				/* other/unknown error */
+				rc = -EIO;
+				break;
+			}
+		} else {
+			cifs_dbg(VFS, "RFC 1002 negative session response\n");
+			rc = -EIO;
+		}
+		return rc;
+	case RFC1002_RETARGET_SESSION_RESPONSE:
+		cifs_dbg(VFS, "RFC 1002 retarget session response\n");
+		if (be16_to_cpu(resp.length) == sizeof(resp.trailer.retarget_resp)) {
+			len = sizeof(resp.trailer.retarget_resp);
+			iov.iov_base = &resp.trailer.retarget_resp;
+			iov.iov_len = len;
+			iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, len);
+			if (smb_recv_kvec(server, &msg, &recv) == 0 && recv == len) {
+				cifs_dbg(VFS, "Server wants to redirect connection\n");
+				cifs_dbg(VFS, "Remount with options -o ip=%pI4,port=%u\n",
+					 &resp.trailer.retarget_resp.retarget_ip_addr,
+					 be16_to_cpu(resp.trailer.retarget_resp.port));
+			}
+		}
+		cifs_dbg(VFS, "Closing connection\n");
+		/* FIXME: Should we automatically redirect to new retarget_resp server? */
+		return -EMULTIHOP;
+	default:
+		cifs_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", resp.type);
+		return -EIO;
+	}
 
-	return rc;
+	server->with_rfc1001 = true;
+	return 0;
 }
 
 static int
@@ -3133,18 +3363,15 @@ generic_ip_connect(struct TCP_Server_Info *server)
 		struct net *net = cifs_net_ns(server);
 		struct sock *sk;
 
-		rc = __sock_create(net, sfamily, SOCK_STREAM,
-				   IPPROTO_TCP, &server->ssocket, 1);
+		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;
 		}
 
 		sk = server->ssocket->sk;
-		__netns_tracker_free(net, &sk->ns_tracker, false);
-		sk->sk_net_refcnt = 1;
-		get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
-		sock_inuse_add(net, 1);
+		sk_net_refcnt_upgrade(sk);
 
 		/* BB other socket options to set KEEPALIVE, NODELAY? */
 		cifs_dbg(FYI, "Socket created\n");
@@ -3201,7 +3428,16 @@ generic_ip_connect(struct TCP_Server_Info *server)
 		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;
@@ -3350,6 +3586,7 @@ 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;
@@ -3487,9 +3724,15 @@ 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 */
@@ -3526,28 +3769,7 @@ 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
@@ -3582,6 +3804,10 @@ 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;
@@ -3923,9 +4149,19 @@ 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);
@@ -3947,11 +4183,13 @@ 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 &&
@@ -3968,9 +4206,18 @@ cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
 	}
 
 	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)
@@ -3993,7 +4240,7 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
 		   struct TCP_Server_Info *server,
 		   struct nls_table *nls_info)
 {
-	int rc = -ENOSYS;
+	int rc = 0;
 	struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
 	struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
@@ -4045,6 +4292,26 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
 		if (!linuxExtEnabled)
 			ses->capabilities &= (~server->vals->cap_unix);
 
+		/*
+		 * Check if the server supports specified encoding mode.
+		 * Zero value in vals->cap_unicode indidcates that chosen
+		 * protocol dialect does not support non-UNICODE mode.
+		 */
+		if (ses->unicode == 1 && server->vals->cap_unicode != 0 &&
+		    !(server->capabilities & server->vals->cap_unicode)) {
+			cifs_dbg(VFS, "Server does not support mounting in UNICODE mode\n");
+			rc = -EOPNOTSUPP;
+		} else if (ses->unicode == 0 && server->vals->cap_unicode == 0) {
+			cifs_dbg(VFS, "Server does not support mounting in non-UNICODE mode\n");
+			rc = -EOPNOTSUPP;
+		} else if (ses->unicode == 0) {
+			/*
+			 * When UNICODE mode was explicitly disabled then
+			 * do not announce client UNICODE capability.
+			 */
+			ses->capabilities &= (~server->vals->cap_unicode);
+		}
+
 		if (ses->auth_key.response) {
 			cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
 				 ses->auth_key.response);
@@ -4057,8 +4324,12 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
 	cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
 		 server->sec_mode, server->capabilities, server->timeAdj);
 
-	if (server->ops->sess_setup)
-		rc = server->ops->sess_setup(xid, ses, server, nls_info);
+	if (!rc) {
+		if (server->ops->sess_setup)
+			rc = server->ops->sess_setup(xid, ses, server, nls_info);
+		else
+			rc = -ENOSYS;
+	}
 
 	if (rc) {
 		cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
@@ -4128,6 +4399,7 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 	ctx->seal = master_tcon->seal;
 	ctx->witness = master_tcon->use_witness;
 	ctx->dfs_root_ses = master_tcon->ses->dfs_root_ses;
+	ctx->unicode = master_tcon->ses->unicode;
 
 	rc = cifs_set_vol_auth(ctx, master_tcon->ses);
 	if (rc) {