Merge tag '5.9-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:
 "16 cifs/smb3 fixes, about half DFS related, two fixes for stable.

  Still working on and testing an additional set of fixes (including
  updates to mount, and some fallocate scenario improvements) for later
  in the merge window"

* tag '5.9-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: document and cleanup dfs mount
  cifs: only update prefix path of DFS links in cifs_tree_connect()
  cifs: fix double free error on share and prefix
  cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnect
  cifs: handle empty list of targets in cifs_reconnect()
  cifs: rename reconn_inval_dfs_target()
  cifs: reduce number of referral requests in DFS link lookups
  cifs: merge __{cifs,smb2}_reconnect[_tcon]() into cifs_tree_connect()
  cifs: convert to use be32_add_cpu()
  cifs: delete duplicated words in header files
  cifs: Remove the superfluous break
  cifs: smb1: Try failing back to SetFileInfo if SetPathInfo fails
  cifs`: handle ERRBaduid for SMB1
  cifs: remove unused variable 'server'
  smb3: warn on confusing error scenario with sec=krb5
  cifs: Fix leak when handling lease break for cached root fid

16 files changed, 560 insertions, 493 deletions

diff --git a/fs/cifs/cifsacl.h b/fs/cifs/cifsacl.h
index 17562ea00e18..45665ff87b64 100644
--- a/fs/cifs/cifsacl.h
+++ b/fs/cifs/cifsacl.h
@@ -132,7 +132,7 @@ struct cifs_ace {
 /*
  * The current SMB3 form of security descriptor is similar to what was used for
  * cifs (see above) but some fields are split, and fields in the struct below
- * matches names of fields to the the spec, MS-DTYP (see sections 2.4.5 and
+ * matches names of fields to the spec, MS-DTYP (see sections 2.4.5 and
  * 2.4.6). Note that "CamelCase" fields are used in this struct in order to
  * match the MS-DTYP and MS-SMB2 specs which define the wire format.
  */
@@ -178,7 +178,7 @@ struct smb3_acl {
 
 /*
  * Used to store the special 'NFS SIDs' used to persist the POSIX uid and gid
- * See See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
+ * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
  */
 struct owner_sid {
 	u8 Revision;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index f4b88cd02662..b296964b8afa 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1466,7 +1466,7 @@ struct cifsInodeInfo {
 	struct list_head llist;	/* locks helb by this inode */
 	/*
 	 * NOTE: Some code paths call down_read(lock_sem) twice, so
-	 * we must always use use cifs_down_write() instead of down_write()
+	 * we must always use cifs_down_write() instead of down_write()
 	 * for this semaphore to avoid deadlocks.
 	 */
 	struct rw_semaphore lock_sem;	/* protect the fields above */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 7a836ec0438e..bb68cbf81074 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -154,6 +154,7 @@ extern int decode_negTokenInit(unsigned char *security_blob, int length,
 extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len);
 extern void cifs_set_port(struct sockaddr *addr, const unsigned short int port);
 extern int map_smb_to_linux_error(char *buf, bool logErr);
+extern int map_and_check_smb_error(struct mid_q_entry *mid, bool logErr);
 extern void header_assemble(struct smb_hdr *, char /* command */ ,
 			    const struct cifs_tcon *, int /* length of
 			    fixed section (word count) in two byte units */);
@@ -271,6 +272,9 @@ extern void cifs_move_llist(struct list_head *source, struct list_head *dest);
 extern void cifs_free_llist(struct list_head *llist);
 extern void cifs_del_lock_waiters(struct cifsLockInfo *lock);
 
+extern int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon,
+			     const struct nls_table *nlsc);
+
 extern int cifs_negotiate_protocol(const unsigned int xid,
 				   struct cifs_ses *ses);
 extern int cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
@@ -344,7 +348,7 @@ extern int CIFSSMBQFSPosixInfo(const unsigned int xid, struct cifs_tcon *tcon,
 extern int CIFSSMBSetPathInfo(const unsigned int xid, struct cifs_tcon *tcon,
 			const char *fileName, const FILE_BASIC_INFO *data,
 			const struct nls_table *nls_codepage,
-			int remap_special_chars);
+			struct cifs_sb_info *cifs_sb);
 extern int CIFSSMBSetFileInfo(const unsigned int xid, struct cifs_tcon *tcon,
 			const FILE_BASIC_INFO *data, __u16 fid,
 			__u32 pid_of_opener);
@@ -613,8 +617,7 @@ int smb2_parse_query_directory(struct cifs_tcon *tcon, struct kvec *rsp_iov,
 
 struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server);
 void cifs_put_tcp_super(struct super_block *sb);
-int update_super_prepath(struct cifs_tcon *tcon, const char *prefix,
-			 size_t prefix_len);
+int update_super_prepath(struct cifs_tcon *tcon, char *prefix);
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
 static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index bf41ee048396..0e763d2dcf16 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -124,116 +124,6 @@ cifs_mark_open_files_invalid(struct cifs_tcon *tcon)
 	 */
 }
 
-#ifdef CONFIG_CIFS_DFS_UPCALL
-static int __cifs_reconnect_tcon(const struct nls_table *nlsc,
-				 struct cifs_tcon *tcon)
-{
-	int rc;
-	struct TCP_Server_Info *server = tcon->ses->server;
-	struct dfs_cache_tgt_list tl;
-	struct dfs_cache_tgt_iterator *it = NULL;
-	char *tree;
-	const char *tcp_host;
-	size_t tcp_host_len;
-	const char *dfs_host;
-	size_t dfs_host_len;
-
-	tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
-	if (!tree)
-		return -ENOMEM;
-
-	if (!tcon->dfs_path) {
-		if (tcon->ipc) {
-			scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$",
-				  server->hostname);
-			rc = CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
-		} else {
-			rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon, nlsc);
-		}
-		goto out;
-	}
-
-	rc = dfs_cache_noreq_find(tcon->dfs_path + 1, NULL, &tl);
-	if (rc)
-		goto out;
-
-	extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
-
-	for (it = dfs_cache_get_tgt_iterator(&tl); it;
-	     it = dfs_cache_get_next_tgt(&tl, it)) {
-		const char *share, *prefix;
-		size_t share_len, prefix_len;
-		bool target_match;
-
-		rc = dfs_cache_get_tgt_share(it, &share, &share_len, &prefix,
-					     &prefix_len);
-		if (rc) {
-			cifs_dbg(VFS, "%s: failed to parse target share %d\n",
-				 __func__, rc);
-			continue;
-		}
-
-		extract_unc_hostname(share, &dfs_host, &dfs_host_len);
-
-		if (dfs_host_len != tcp_host_len
-		    || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
-			cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n",
-				 __func__,
-				 (int)dfs_host_len, dfs_host,
-				 (int)tcp_host_len, tcp_host);
-
-			rc = match_target_ip(server, dfs_host, dfs_host_len,
-					     &target_match);
-			if (rc) {
-				cifs_dbg(VFS, "%s: failed to match target ip: %d\n",
-					 __func__, rc);
-				break;
-			}
-
-			if (!target_match) {
-				cifs_dbg(FYI, "%s: skipping target\n", __func__);
-				continue;
-			}
-		}
-
-		if (tcon->ipc) {
-			scnprintf(tree, MAX_TREE_SIZE, "\\\\%.*s\\IPC$",
-				  (int)share_len, share);
-			rc = CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
-		} else {
-			scnprintf(tree, MAX_TREE_SIZE, "\\%.*s", (int)share_len,
-				  share);
-			rc = CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
-			if (!rc) {
-				rc = update_super_prepath(tcon, prefix,
-							  prefix_len);
-				break;
-			}
-		}
-		if (rc == -EREMOTE)
-			break;
-	}
-
-	if (!rc) {
-		if (it)
-			rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1,
-							    it);
-		else
-			rc = -ENOENT;
-	}
-	dfs_cache_free_tgts(&tl);
-out:
-	kfree(tree);
-	return rc;
-}
-#else
-static inline int __cifs_reconnect_tcon(const struct nls_table *nlsc,
-					struct cifs_tcon *tcon)
-{
-	return CIFSTCon(0, tcon->ses, tcon->treeName, tcon, nlsc);
-}
-#endif
-
 /* reconnect the socket, tcon, and smb session if needed */
 static int
 cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
@@ -338,7 +228,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 	}
 
 	cifs_mark_open_files_invalid(tcon);
-	rc = __cifs_reconnect_tcon(nls_codepage, tcon);
+	rc = cifs_tree_connect(0, tcon, nls_codepage);
 	mutex_unlock(&ses->session_mutex);
 	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
 
@@ -5913,10 +5803,42 @@ CIFSSMBSetFileDisposition(const unsigned int xid, struct cifs_tcon *tcon,
 	return rc;
 }
 
+static int
+CIFSSMBSetPathInfoFB(const unsigned int xid, struct cifs_tcon *tcon,
+		     const char *fileName, const FILE_BASIC_INFO *data,
+		     const struct nls_table *nls_codepage,
+		     struct cifs_sb_info *cifs_sb)
+{
+	int oplock = 0;
+	struct cifs_open_parms oparms;
+	struct cifs_fid fid;
+	int rc;
+
+	oparms.tcon = tcon;
+	oparms.cifs_sb = cifs_sb;
+	oparms.desired_access = GENERIC_WRITE;
+	oparms.create_options = cifs_create_options(cifs_sb, 0);
+	oparms.disposition = FILE_OPEN;
+	oparms.path = fileName;
+	oparms.fid = &fid;
+	oparms.reconnect = false;
+
+	rc = CIFS_open(xid, &oparms, &oplock, NULL);
+	if (rc)
+		goto out;
+
+	rc = CIFSSMBSetFileInfo(xid, tcon, data, fid.netfid, current->tgid);
+	CIFSSMBClose(xid, tcon, fid.netfid);
+out:
+
+	return rc;
+}
+
 int
 CIFSSMBSetPathInfo(const unsigned int xid, struct cifs_tcon *tcon,
 		   const char *fileName, const FILE_BASIC_INFO *data,
-		   const struct nls_table *nls_codepage, int remap)
+		   const struct nls_table *nls_codepage,
+		     struct cifs_sb_info *cifs_sb)
 {
 	TRANSACTION2_SPI_REQ *pSMB = NULL;
 	TRANSACTION2_SPI_RSP *pSMBr = NULL;
@@ -5925,6 +5847,7 @@ CIFSSMBSetPathInfo(const unsigned int xid, struct cifs_tcon *tcon,
 	int bytes_returned = 0;
 	char *data_offset;
 	__u16 params, param_offset, offset, byte_count, count;
+	int remap = cifs_remap(cifs_sb);
 
 	cifs_dbg(FYI, "In SetTimes\n");
 
@@ -5987,6 +5910,10 @@ SetTimesRetry:
 	if (rc == -EAGAIN)
 		goto SetTimesRetry;
 
+	if (rc == -EOPNOTSUPP)
+		return CIFSSMBSetPathInfoFB(xid, tcon, fileName, data,
+					    nls_codepage, cifs_sb);
+
 	return rc;
 }
 
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a61abde09ffe..7e3e5e2098eb 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -393,15 +393,14 @@ static inline int reconn_set_ipaddr(struct TCP_Server_Info *server)
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
 /* These functions must be called with server->srv_mutex held */
-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)
+static void reconn_set_next_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;
 
-	if (!cifs_sb || !cifs_sb->origin_fullpath || !tgt_list ||
-	    !server->nr_targets)
+	if (!cifs_sb || !cifs_sb->origin_fullpath)
 		return;
 
 	if (!*tgt_it) {
@@ -471,11 +470,13 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		sb = NULL;
 	} else {
 		cifs_sb = CIFS_SB(sb);
-
 		rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list);
-		if (rc && (rc != -EOPNOTSUPP)) {
-			cifs_server_dbg(VFS, "%s: no target servers for DFS failover\n",
-				 __func__);
+		if (rc) {
+			cifs_sb = NULL;
+			if (rc != -EOPNOTSUPP) {
+				cifs_server_dbg(VFS, "%s: no target servers for DFS failover\n",
+						__func__);
+			}
 		} else {
 			server->nr_targets = dfs_cache_get_nr_tgts(&tgt_list);
 		}
@@ -578,7 +579,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		 * feature is disabled, then we will retry last server we
 		 * connected to before.
 		 */
-		reconn_inval_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);
+		reconn_set_next_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);
 #endif
 		rc = reconn_set_ipaddr(server);
 		if (rc) {
@@ -4422,11 +4423,11 @@ build_unc_path_to_root(const struct smb_vol *vol,
 static int
 expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
 		    struct smb_vol *volume_info, struct cifs_sb_info *cifs_sb,
-		    int check_prefix)
+		    char *ref_path)
 {
 	int rc;
 	struct dfs_info3_param referral = {0};
-	char *full_path = NULL, *ref_path = NULL, *mdata = NULL;
+	char *full_path = NULL, *mdata = NULL;
 
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
 		return -EREMOTE;
@@ -4435,9 +4436,6 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
 	if (IS_ERR(full_path))
 		return PTR_ERR(full_path);
 
-	/* For DFS paths, skip the first '\' of the UNC */
-	ref_path = check_prefix ? full_path + 1 : volume_info->UNC + 1;
-
 	rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
 			    ref_path, &referral, NULL);
 	if (!rc) {
@@ -4500,13 +4498,10 @@ static int update_vol_info(const struct dfs_cache_tgt_iterator *tgt_it,
 	return 0;
 }
 
-static int setup_dfs_tgt_conn(const char *path,
+static int setup_dfs_tgt_conn(const char *path, const char *full_path,
 			      const struct dfs_cache_tgt_iterator *tgt_it,
-			      struct cifs_sb_info *cifs_sb,
-			      struct smb_vol *vol,
-			      unsigned int *xid,
-			      struct TCP_Server_Info **server,
-			      struct cifs_ses **ses,
+			      struct cifs_sb_info *cifs_sb, struct smb_vol *vol, unsigned int *xid,
+			      struct TCP_Server_Info **server, struct cifs_ses **ses,
 			      struct cifs_tcon **tcon)
 {
 	int rc;
@@ -4520,8 +4515,7 @@ static int setup_dfs_tgt_conn(const char *path,
 	if (rc)
 		return rc;
 
-	mdata = cifs_compose_mount_options(cifs_sb->mountdata, path, &ref,
-					   &fake_devname);
+	mdata = cifs_compose_mount_options(cifs_sb->mountdata, full_path + 1, &ref, &fake_devname);
 	free_dfs_info_param(&ref);
 
 	if (IS_ERR(mdata)) {
@@ -4544,7 +4538,7 @@ static int setup_dfs_tgt_conn(const char *path,
 		mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon);
 		rc = mount_get_conns(&fake_vol, cifs_sb, xid, server, ses,
 				     tcon);
-		if (!rc) {
+		if (!rc || (*server && *ses)) {
 			/*
 			 * We were able to connect to new target server.
 			 * Update current volume info with new target server.
@@ -4556,14 +4550,10 @@ static int setup_dfs_tgt_conn(const char *path,
 	return rc;
 }
 
-static int mount_do_dfs_failover(const char *path,
-				 struct cifs_sb_info *cifs_sb,
-				 struct smb_vol *vol,
-				 struct cifs_ses *root_ses,
-				 unsigned int *xid,
-				 struct TCP_Server_Info **server,
-				 struct cifs_ses **ses,
-				 struct cifs_tcon **tcon)
+static int do_dfs_failover(const char *path, const char *full_path, struct cifs_sb_info *cifs_sb,
+			   struct smb_vol *vol, struct cifs_ses *root_ses, unsigned int *xid,
+			   struct TCP_Server_Info **server, struct cifs_ses **ses,
+			   struct cifs_tcon **tcon)
 {
 	int rc;
 	struct dfs_cache_tgt_list tgt_list;
@@ -4582,9 +4572,9 @@ static int mount_do_dfs_failover(const char *path,
 		if (rc)
 			break;
 		/* Connect to next DFS target */
-		rc = setup_dfs_tgt_conn(path, tgt_it, cifs_sb, vol, xid, server,
-					ses, tcon);
-		if (!rc || rc == -EACCES || rc == -EOPNOTSUPP)
+		rc = setup_dfs_tgt_conn(path, full_path, tgt_it, cifs_sb, vol, xid, server, ses,
+					tcon);
+		if (!rc || (*server && *ses))
 			break;
 	}
 	if (!rc) {
@@ -4754,207 +4744,210 @@ static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol,
 }
 
 #ifdef CONFIG_CIFS_DFS_UPCALL
-static inline void set_root_tcon(struct cifs_sb_info *cifs_sb,
-				 struct cifs_tcon *tcon,
-				 struct cifs_tcon **root)
+static void set_root_ses(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
+			 struct cifs_ses **root_ses)
 {
-	spin_lock(&cifs_tcp_ses_lock);
-	tcon->tc_count++;
-	tcon->remap = cifs_remap(cifs_sb);
-	spin_unlock(&cifs_tcp_ses_lock);
-	*root = tcon;
+	if (ses) {
+		spin_lock(&cifs_tcp_ses_lock);
+		ses->ses_count++;
+		ses->tcon_ipc->remap = cifs_remap(cifs_sb);
+		spin_unlock(&cifs_tcp_ses_lock);
+	}
+	*root_ses = ses;
+}
+
+static void put_root_ses(struct cifs_ses *ses)
+{
+	if (ses)
+		cifs_put_smb_ses(ses);
+}
+
+/* Check if a path component is remote and then update @dfs_path accordingly */
+static int check_dfs_prepath(struct cifs_sb_info *cifs_sb, struct smb_vol *vol,
+			     const unsigned int xid, struct TCP_Server_Info *server,
+			     struct cifs_tcon *tcon, char **dfs_path)
+{
+	char *path, *s;
+	char sep = CIFS_DIR_SEP(cifs_sb), tmp;
+	char *npath;
+	int rc = 0;
+	int added_treename = tcon->Flags & SMB_SHARE_IS_IN_DFS;
+	int skip = added_treename;
+
+	path = cifs_build_path_to_root(vol, cifs_sb, tcon, added_treename);
+	if (!path)
+		return -ENOMEM;
+
+	/*
+	 * Walk through the path components in @path and check if they're accessible. In case any of
+	 * the components is -EREMOTE, then update @dfs_path with the next DFS referral request path
+	 * (NOT including the remaining components).
+	 */
+	s = path;
+	do {
+		/* skip separators */
+		while (*s && *s == sep)
+			s++;
+		if (!*s)
+			break;
+		/* next separator */
+		while (*s && *s != sep)
+			s++;
+		/*
+		 * if the treename is added, we then have to skip the first
+		 * part within the separators
+		 */
+		if (skip) {
+			skip = 0;
+			continue;
+		}
+		tmp = *s;
+		*s = 0;
+		rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, path);
+		if (rc && rc == -EREMOTE) {
+			struct smb_vol v = {NULL};
+			/* if @path contains a tree name, skip it in the prefix path */
+			if (added_treename) {
+				rc = cifs_parse_devname(path, &v);
+				if (rc)
+					break;
+				rc = -EREMOTE;
+				npath = build_unc_path_to_root(&v, cifs_sb, true);
+				cifs_cleanup_volume_info_contents(&v);
+			} else {
+				v.UNC = vol->UNC;
+				v.prepath = path + 1;
+				npath = build_unc_path_to_root(&v, cifs_sb, true);
+			}
+			if (IS_ERR(npath)) {
+				rc = PTR_ERR(npath);
+				break;
+			}
+			kfree(*dfs_path);
+			*dfs_path = npath;
+		}
+		*s = tmp;
+	} while (rc == 0);
+
+	kfree(path);
+	return rc;
 }
 
 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)
 {
 	int rc = 0;
 	unsigned int xid;
-	struct cifs_ses *ses;
-	struct cifs_tcon *root_tcon = NULL;
+	struct TCP_Server_Info *server = NULL;
+	struct cifs_ses *ses = NULL, *root_ses = NULL;
 	struct cifs_tcon *tcon = NULL;
-	struct TCP_Server_Info *server;
-	char *root_path = NULL, *full_path = NULL;
-	char *old_mountdata, *origin_mountdata = NULL;
-	int count;
+	int count = 0;
+	char *ref_path = NULL, *full_path = NULL;
+	char *oldmnt = NULL;
+	char *mntdata = NULL;
 
 	rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon);
-	if (!rc && tcon) {
-		/* If not a standalone DFS root, then check if path is remote */
-		rc = dfs_cache_find(xid, ses, cifs_sb->local_nls,
-				    cifs_remap(cifs_sb), vol->UNC + 1, NULL,
-				    NULL);
-		if (rc) {
-			rc = is_path_remote(cifs_sb, vol, xid, server, tcon);
-			if (!rc)
-				goto out;
-			if (rc != -EREMOTE)
-				goto error;
-		}
-	}
 	/*
-	 * If first DFS target server went offline and we failed to connect it,
-	 * server and ses pointers are NULL at this point, though we still have
-	 * chance to get a cached DFS referral in expand_dfs_referral() and
-	 * retry next target available in it.
+	 * Unconditionally try to get an DFS referral (even cached) to determine whether it is an
+	 * DFS mount.
 	 *
-	 * If a NULL ses ptr is passed to dfs_cache_find(), a lookup will be
-	 * performed against DFS path and *no* requests will be sent to server
-	 * for any new DFS referrals. Hence it's safe to skip checking whether
-	 * server or ses ptr is NULL.
+	 * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
+	 * to respond with PATH_NOT_COVERED to requests that include the prefix.
 	 */
-	if (rc == -EACCES || rc == -EOPNOTSUPP)
-		goto error;
-
-	root_path = build_unc_path_to_root(vol, cifs_sb, false);
-	if (IS_ERR(root_path)) {
-		rc = PTR_ERR(root_path);
-		root_path = NULL;
-		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
-	 * for DFS referrals from w2k8 servers which don't seem to respond
-	 * with PATH_NOT_COVERED to requests that include the prefix.
-	 * Chase the referral if found, otherwise continue normally.
-	 */
-	old_mountdata = cifs_sb->mountdata;
-	(void)expand_dfs_referral(xid, ses, vol, cifs_sb, false);
-
-	if (cifs_sb->mountdata == NULL) {
-		rc = -ENOENT;
-		goto error;
+	if (dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), vol->UNC + 1, NULL,
+			   NULL)) {
+		/* No DFS referral was returned.  Looks like a regular share. */
+		if (rc)
+			goto error;
+		/* Check if it is fully accessible and then mount it */
+		rc = is_path_remote(cifs_sb, vol, xid, server, tcon);
+		if (!rc)
+			goto out;
+		if (rc != -EREMOTE)
+			goto error;
 	}
-
-	/* Save DFS root volume information for DFS refresh worker */
-	origin_mountdata = kstrndup(cifs_sb->mountdata,
-				    strlen(cifs_sb->mountdata), GFP_KERNEL);
-	if (!origin_mountdata) {
+	/* Save mount options */
+	mntdata = kstrndup(cifs_sb->mountdata, strlen(cifs_sb->mountdata), GFP_KERNEL);
+	if (!mntdata) {
 		rc = -ENOMEM;
 		goto error;
 	}
-
-	if (cifs_sb->mountdata != old_mountdata) {
-		/* If we were redirected, reconnect to new target server */
-		mount_put_conns(cifs_sb, xid, server, ses, tcon);
-		rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon);
-	}
-	if (rc) {
-		if (rc == -EACCES || rc == -EOPNOTSUPP)
-			goto error;
-		/* Perform DFS failover to any other DFS targets */
-		rc = mount_do_dfs_failover(root_path + 1, cifs_sb, vol, NULL,
-					   &xid, &server, &ses, &tcon);
-		if (rc)
-			goto error;
-	}
-
-	kfree(root_path);
-	root_path = build_unc_path_to_root(vol, cifs_sb, false);
-	if (IS_ERR(root_path)) {
-		rc = PTR_ERR(root_path);
-		root_path = NULL;
+	/* Get path of DFS root */
+	ref_path = build_unc_path_to_root(vol, cifs_sb, false);
+	if (IS_ERR(ref_path)) {
+		rc = PTR_ERR(ref_path);
+		ref_path = NULL;
 		goto error;
 	}
-	/* Cache out resolved root server */
-	(void)dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
-			     root_path + 1, NULL, NULL);
-	kfree(root_path);
-	root_path = NULL;
-
-	set_root_tcon(cifs_sb, tcon, &root_tcon);
-
-	for (count = 1; ;) {
-		if (!rc && tcon) {
-			rc = is_path_remote(cifs_sb, vol, xid, server, tcon);
-			if (!rc || rc != -EREMOTE)
-				break;
-		}
-		/*
-		 * BB: when we implement proper loop detection,
-		 *     we will remove this check. But now we need it
-		 *     to prevent an indefinite loop if 'DFS tree' is
-		 *     misconfigured (i.e. has loops).
-		 */
-		if (count++ > MAX_NESTED_LINKS) {
-			rc = -ELOOP;
-			break;
-		}
 
+	set_root_ses(cifs_sb, ses, &root_ses);
+	do {
+		/* Save full path of last DFS path we used to resolve final target server */
 		kfree(full_path);
-		full_path = build_unc_path_to_root(vol, cifs_sb, true);
+		full_path = build_unc_path_to_root(vol, cifs_sb, !!count);
 		if (IS_ERR(full_path)) {
 			rc = PTR_ERR(full_path);
-			full_path = NULL;
 			break;
 		}
-
-		old_mountdata = cifs_sb->mountdata;
-		rc = expand_dfs_referral(xid, root_tcon->ses, vol, cifs_sb,
-					 true);
+		/* Chase referral */
+		oldmnt = cifs_sb->mountdata;
+		rc = expand_dfs_referral(xid, root_ses, vol, cifs_sb, ref_path + 1);
 		if (rc)
 			break;
-
-		if (cifs_sb->mountdata != old_mountdata) {
+		/* Connect to new DFS target only if we were redirected */
+		if (oldmnt != cifs_sb->mountdata) {
 			mount_put_conns(cifs_sb, xid, server, ses, tcon);
-			rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses,
-					     &tcon);
-			/*
-			 * Ensure that DFS referrals go through new root server.
-			 */
-			if (!rc && tcon &&
-			    (tcon->share_flags & (SHI1005_FLAGS_DFS |
-						  SHI1005_FLAGS_DFS_ROOT))) {
-				cifs_put_tcon(root_tcon);
-				set_root_tcon(cifs_sb, tcon, &root_tcon);
-			}
+			rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon);
 		}
-		if (rc) {
-			if (rc == -EACCES || rc == -EOPNOTSUPP)
-				break;
-			/* Perform DFS failover to any other DFS targets */
-			rc = mount_do_dfs_failover(full_path + 1, cifs_sb, vol,
-						   root_tcon->ses, &xid,
-						   &server, &ses, &tcon);
-			if (rc == -EACCES || rc == -EOPNOTSUPP || !server ||
-			    !ses)
-				goto error;
+		if (rc && !server && !ses) {
+			/* Failed to connect. Try to connect to other targets in the referral. */
+			rc = do_dfs_failover(ref_path + 1, full_path, cifs_sb, vol, root_ses, &xid,
+					     &server, &ses, &tcon);
 		}
-	}
-	cifs_put_tcon(root_tcon);
+		if (rc == -EACCES || rc == -EOPNOTSUPP || !server || !ses)
+			break;
+		if (!tcon)
+			continue;
+		/* Make sure that requests go through new root servers */
+		if (tcon->share_flags & (SHI1005_FLAGS_DFS | SHI1005_FLAGS_DFS_ROOT)) {
+			put_root_ses(root_ses);
+			set_root_ses(cifs_sb, ses, &root_ses);
+		}
+		/* Check for remaining path components and then continue chasing them (-EREMOTE) */
+		rc = check_dfs_prepath(cifs_sb, vol, xid, server, tcon, &ref_path);
+		/* Prevent recursion on broken link referrals */
+		if (rc == -EREMOTE && ++count > MAX_NESTED_LINKS)
+			rc = -ELOOP;
+	} while (rc == -EREMOTE);
 
 	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_ATOMIC);
+	put_root_ses(root_ses);
+	root_ses = NULL;
+	kfree(ref_path);
+	ref_path = NULL;
+	/*
+	 * Store DFS full path in both superblock and tree connect structures.
+	 *
+	 * For DFS root mounts, the prefix path (cifs_sb->prepath) is preserved during reconnect so
+	 * only the root path is set in cifs_sb->origin_fullpath and tcon->dfs_path. And for DFS
+	 * links, the prefix path is included in both and may be changed during reconnect.  See
+	 * cifs_tree_connect().
+	 */
+	cifs_sb->origin_fullpath = kstrndup(full_path, strlen(full_path), GFP_KERNEL);
 	if (!cifs_sb->origin_fullpath) {
-		spin_unlock(&cifs_tcp_ses_lock);
 		rc = -ENOMEM;
 		goto error;
 	}
+	spin_lock(&cifs_tcp_ses_lock);
+	tcon->dfs_path = full_path;
+	full_path = NULL;
+	tcon->remap = cifs_remap(cifs_sb);
 	spin_unlock(&cifs_tcp_ses_lock);
 
-	rc = dfs_cache_add_vol(origin_mountdata, vol, cifs_sb->origin_fullpath);
-	if (rc) {
-		kfree(cifs_sb->origin_fullpath);
+	/* Add original volume information for DFS cache to be used when refreshing referrals */
+	rc = dfs_cache_add_vol(mntdata, vol, cifs_sb->origin_fullpath);
+	if (rc)
 		goto error;
-	}
 	/*
 	 * After reconnecting to a different server, unique ids won't
 	 * match anymore, so we disable serverino. This prevents
@@ -4976,9 +4969,11 @@ out:
 	return mount_setup_tlink(cifs_sb, ses, tcon);
 
 error:
+	kfree(ref_path);
 	kfree(full_path);
-	kfree(root_path);
-	kfree(origin_mountdata);
+	kfree(mntdata);
+	kfree(cifs_sb->origin_fullpath);
+	put_root_ses(root_ses);
 	mount_put_conns(cifs_sb, xid, server, ses, tcon);
 	return rc;
 }
@@ -5114,8 +5109,7 @@ CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 	bcc_ptr += strlen("?????");
 	bcc_ptr += 1;
 	count = bcc_ptr - &pSMB->Password[0];
-	pSMB->hdr.smb_buf_length = cpu_to_be32(be32_to_cpu(
-					pSMB->hdr.smb_buf_length) + count);
+	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
 	pSMB->ByteCount = cpu_to_le16(count);
 
 	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
@@ -5533,3 +5527,115 @@ cifs_prune_tlinks(struct work_struct *work)
 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
 				TLINK_IDLE_EXPIRE);
 }
+
+#ifdef CONFIG_CIFS_DFS_UPCALL
+int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
+{
+	int rc;
+	struct TCP_Server_Info *server = tcon->ses->server;
+	const struct smb_version_operations *ops = server->ops;
+	struct dfs_cache_tgt_list tl;
+	struct dfs_cache_tgt_iterator *it = NULL;
+	char *tree;
+	const char *tcp_host;
+	size_t tcp_host_len;
+	const char *dfs_host;
+	size_t dfs_host_len;
+	char *share = NULL, *prefix = NULL;
+	struct dfs_info3_param ref = {0};
+	bool isroot;
+
+	tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
+	if (!tree)
+		return -ENOMEM;
+
+	if (!tcon->dfs_path) {
+		if (tcon->ipc) {
+			scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
+			rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
+		} else {
+			rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
+		}
+		goto out;
+	}
+
+	rc = dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl);
+	if (rc)
+		goto out;
+	isroot = ref.server_type == DFS_TYPE_ROOT;
+	free_dfs_info_param(&ref);
+
+	extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
+
+	for (it = dfs_cache_get_tgt_iterator(&tl); it; it = dfs_cache_get_next_tgt(&tl, it)) {
+		bool target_match;
+
+		kfree(share);
+		kfree(prefix);
+		share = NULL;
+		prefix = NULL;
+
+		rc = dfs_cache_get_tgt_share(tcon->dfs_path + 1, it, &share, &prefix);
+		if (rc) {
+			cifs_dbg(VFS, "%s: failed to parse target share %d\n",
+				 __func__, rc);
+			continue;
+		}
+
+		extract_unc_hostname(share, &dfs_host, &dfs_host_len);
+
+		if (dfs_host_len != tcp_host_len
+		    || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
+			cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
+				 dfs_host, (int)tcp_host_len, tcp_host);
+
+			rc = match_target_ip(server, dfs_host, dfs_host_len, &target_match);
+			if (rc) {
+				cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
+				break;
+			}
+
+			if (!target_match) {
+				cifs_dbg(FYI, "%s: skipping target\n", __func__);
+				continue;
+			}
+		}
+
+		if (tcon->ipc) {
+			scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", share);
+			rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
+		} else {
+			scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
+			rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
+			/* Only handle prefix paths of DFS link targets */
+			if (!rc && !isroot) {
+				rc = update_super_prepath(tcon, prefix);
+				break;
+			}
+		}
+		if (rc == -EREMOTE)
+			break;
+	}
+
+	kfree(share);
+	kfree(prefix);
+
+	if (!rc) {
+		if (it)
+			rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1, it);
+		else
+			rc = -ENOENT;
+	}
+	dfs_cache_free_tgts(&tl);
+out:
+	kfree(tree);
+	return rc;
+}
+#else
+int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
+{
+	const struct smb_version_operations *ops = tcon->ses->server->ops;
+
+	return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
+}
+#endif
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index df81c718d2fa..a44f58bbf7ab 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -29,6 +29,7 @@
 
 struct cache_dfs_tgt {
 	char *name;
+	int path_consumed;
 	struct list_head list;
 };
 
@@ -350,7 +351,7 @@ static inline struct timespec64 get_expire_time(int ttl)
 }
 
 /* Allocate a new DFS target */
-static struct cache_dfs_tgt *alloc_target(const char *name)
+static struct cache_dfs_tgt *alloc_target(const char *name, int path_consumed)
 {
 	struct cache_dfs_tgt *t;
 
@@ -362,6 +363,7 @@ static struct cache_dfs_tgt *alloc_target(const char *name)
 		kfree(t);
 		return ERR_PTR(-ENOMEM);
 	}
+	t->path_consumed = path_consumed;
 	INIT_LIST_HEAD(&t->list);
 	return t;
 }
@@ -384,7 +386,7 @@ static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs,
 	for (i = 0; i < numrefs; i++) {
 		struct cache_dfs_tgt *t;
 
-		t = alloc_target(refs[i].node_name);
+		t = alloc_target(refs[i].node_name, refs[i].path_consumed);
 		if (IS_ERR(t)) {
 			free_tgts(ce);
 			return PTR_ERR(t);
@@ -490,16 +492,7 @@ static int add_cache_entry(const char *path, unsigned int hash,
 	return 0;
 }
 
-/*
- * Find a DFS cache entry in hash table and optionally check prefix path against
- * @path.
- * Use whole path components in the match.
- * Must be called with htable_rw_lock held.
- *
- * Return ERR_PTR(-ENOENT) if the entry is not found.
- */
-static struct cache_entry *lookup_cache_entry(const char *path,
-					      unsigned int *hash)
+static struct cache_entry *__lookup_cache_entry(const char *path)
 {
 	struct cache_entry *ce;
 	unsigned int h;
@@ -517,9 +510,75 @@ static struct cache_entry *lookup_cache_entry(const char *path,
 
 	if (!found)
 		ce = ERR_PTR(-ENOENT);
+	return ce;
+}
+
+/*
+ * Find a DFS cache entry in hash table and optionally check prefix path against
+ * @path.
+ * Use whole path components in the match.
+ * Must be called with htable_rw_lock held.
+ *
+ * Return ERR_PTR(-ENOENT) if the entry is not found.
+ */
+static struct cache_entry *lookup_cache_entry(const char *path, unsigned int *hash)
+{
+	struct cache_entry *ce = ERR_PTR(-ENOENT);
+	unsigned int h;
+	int cnt = 0;
+	char *npath;
+	char *s, *e;
+	char sep;
+
+	npath = kstrndup(path, strlen(path), GFP_KERNEL);
+	if (!npath)
+		return ERR_PTR(-ENOMEM);
+
+	s = npath;
+	sep = *npath;
+	while ((s = strchr(s, sep)) && ++cnt < 3)
+		s++;
+
+	if (cnt < 3) {
+		h = cache_entry_hash(path, strlen(path));
+		ce = __lookup_cache_entry(path);
+		goto out;
+	}
+	/*
+	 * Handle paths that have more than two path components and are a complete prefix of the DFS
+	 * referral request path (@path).
+	 *
+	 * See MS-DFSC 3.2.5.5 "Receiving a Root Referral Request or Link Referral Request".
+	 */
+	h = cache_entry_hash(npath, strlen(npath));
+	e = npath + strlen(npath) - 1;
+	while (e > s) {
+		char tmp;
+
+		/* skip separators */
+		while (e > s && *e == sep)
+			e--;
+		if (e == s)
+			goto out;
+
+		tmp = *(e+1);
+		*(e+1) = 0;
+
+		ce = __lookup_cache_entry(npath);
+		if (!IS_ERR(ce)) {
+			h = cache_entry_hash(npath, strlen(npath));
+			break;
+		}
+
+		*(e+1) = tmp;
+		/* backward until separator */
+		while (e > s && *e != sep)
+			e--;
+	}
+out:
 	if (hash)
 		*hash = h;
-
+	kfree(npath);
 	return ce;
 }
 
@@ -773,6 +832,7 @@ static int get_targets(struct cache_entry *ce, struct dfs_cache_tgt_list *tl)
 			rc = -ENOMEM;
 			goto err_free_it;
 		}
+		it->it_path_consumed = t->path_consumed;
 
 		if (ce->tgthint == t)
 			list_add(&it->it_list, head);
@@ -1263,23 +1323,26 @@ void dfs_cache_del_vol(const char *fullpath)
 /**
  * dfs_cache_get_tgt_share - parse a DFS target
  *
+ * @path: DFS full path
  * @it: DFS target iterator.
  * @share: tree name.
- * @share_len: length of tree name.
  * @prefix: prefix path.
- * @prefix_len: length of prefix path.
  *
  * Return zero if target was parsed correctly, otherwise non-zero.
  */
-int dfs_cache_get_tgt_share(const struct dfs_cache_tgt_iterator *it,
-			    const char **share, size_t *share_len,
-			    const char **prefix, size_t *prefix_len)
+int dfs_cache_get_tgt_share(char *path, const struct dfs_cache_tgt_iterator *it,
+			    char **share, char **prefix)
 {
-	char *s, sep;
+	char *s, sep, *p;
+	size_t len;
+	size_t plen1, plen2;
 
-	if (!it || !share || !share_len || !prefix || !prefix_len)
+	if (!it || !path || !share || !prefix || strlen(path) < it->it_path_consumed)
 		return -EINVAL;
 
+	*share = NULL;
+	*prefix = NULL;
+
 	sep = it->it_name[0];
 	if (sep != '\\' && sep != '/')
 		return -EINVAL;
@@ -1288,13 +1351,38 @@ int dfs_cache_get_tgt_share(const struct dfs_cache_tgt_iterator *it,
 	if (!s)
 		return -EINVAL;
 
+	/* point to prefix in target node */
 	s = strchrnul(s + 1, sep);
 
-	*share = it->it_name;
-	*share_len = s - it->it_name;
-	*prefix = *s ? s + 1 : s;
-	*prefix_len = &it->it_name[strlen(it->it_name)] - *prefix;
+	/* extract target share */
+	*share = kstrndup(it->it_name, s - it->it_name, GFP_KERNEL);
+	if (!*share)
+		return -ENOMEM;
 
+	/* skip separator */
+	if (*s)
+		s++;
+	/* point to prefix in DFS path */
+	p = path + it->it_path_consumed;
+	if (*p == sep)
+		p++;
+
+	/* merge prefix paths from DFS path and target node */
+	plen1 = it->it_name + strlen(it->it_name) - s;
+	plen2 = path + strlen(path) - p;
+	if (plen1 || plen2) {
+		len = plen1 + plen2 + 2;
+		*prefix = kmalloc(len, GFP_KERNEL);
+		if (!*prefix) {
+			kfree(*share);
+			*share = NULL;
+			return -ENOMEM;
+		}
+		if (plen1)
+			scnprintf(*prefix, len, "%.*s%c%.*s", (int)plen1, s, sep, (int)plen2, p);
+		else
+			strscpy(*prefix, p, len);
+	}
 	return 0;
 }
 
diff --git a/fs/cifs/dfs_cache.h b/fs/cifs/dfs_cache.h
index bf94d08cfb5a..3d7c05194536 100644
--- a/fs/cifs/dfs_cache.h
+++ b/fs/cifs/dfs_cache.h
@@ -19,6 +19,7 @@ struct dfs_cache_tgt_list {
 
 struct dfs_cache_tgt_iterator {
 	char *it_name;
+	int it_path_consumed;
 	struct list_head it_list;
 };
 
@@ -48,10 +49,8 @@ extern int dfs_cache_add_vol(char *mntdata, struct smb_vol *vol,
 extern int dfs_cache_update_vol(const char *fullpath,
 				struct TCP_Server_Info *server);
 extern void dfs_cache_del_vol(const char *fullpath);
-
-extern int dfs_cache_get_tgt_share(const struct dfs_cache_tgt_iterator *it,
-				   const char **share, size_t *share_len,
-				   const char **prefix, size_t *prefix_len);
+extern int dfs_cache_get_tgt_share(char *path, const struct dfs_cache_tgt_iterator *it,
+				   char **share, char **prefix);
 
 static inline struct dfs_cache_tgt_iterator *
 dfs_cache_get_next_tgt(struct dfs_cache_tgt_list *tl,
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index ce95801e9b66..3989d08396ac 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1086,7 +1086,6 @@ smb311_posix_get_inode_info(struct inode **inode,
 		    struct super_block *sb, unsigned int xid)
 {
 	struct cifs_tcon *tcon;
-	struct TCP_Server_Info *server;
 	struct tcon_link *tlink;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 	bool adjust_tz = false;
@@ -1100,7 +1099,6 @@ smb311_posix_get_inode_info(struct inode **inode,
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
 	tcon = tlink_tcon(tlink);
-	server = tcon->ses->server;
 
 	/*
 	 * 1. Fetch file metadata
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index e44d049142d0..764234803071 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -1164,8 +1164,7 @@ static inline void cifs_put_tcon_super(struct super_block *sb)
 }
 #endif
 
-int update_super_prepath(struct cifs_tcon *tcon, const char *prefix,
-			 size_t prefix_len)
+int update_super_prepath(struct cifs_tcon *tcon, char *prefix)
 {
 	struct super_block *sb;
 	struct cifs_sb_info *cifs_sb;
@@ -1179,8 +1178,8 @@ int update_super_prepath(struct cifs_tcon *tcon, const char *prefix,
 
 	kfree(cifs_sb->prepath);
 
-	if (*prefix && prefix_len) {
-		cifs_sb->prepath = kstrndup(prefix, prefix_len, GFP_ATOMIC);
+	if (prefix && *prefix) {
+		cifs_sb->prepath = kstrndup(prefix, strlen(prefix), GFP_ATOMIC);
 		if (!cifs_sb->prepath) {
 			rc = -ENOMEM;
 			goto out;
diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index b7ca4960d4ca..0e728aac67e9 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -881,6 +881,33 @@ map_smb_to_linux_error(char *buf, bool logErr)
 	return rc;
 }
 
+int
+map_and_check_smb_error(struct mid_q_entry *mid, bool logErr)
+{
+	int rc;
+	struct smb_hdr *smb = (struct smb_hdr *)mid->resp_buf;
+
+	rc = map_smb_to_linux_error((char *)smb, logErr);
+	if (rc == -EACCES && !(smb->Flags2 & SMBFLG2_ERR_STATUS)) {
+		/* possible ERRBaduid */
+		__u8 class = smb->Status.DosError.ErrorClass;
+		__u16 code = le16_to_cpu(smb->Status.DosError.Error);
+
+		/* switch can be used to handle different errors */
+		if (class == ERRSRV && code == ERRbaduid) {
+			cifs_dbg(FYI, "Server returned 0x%x, reconnecting session...\n",
+				code);
+			spin_lock(&GlobalMid_Lock);
+			if (mid->server->tcpStatus != CifsExiting)
+				mid->server->tcpStatus = CifsNeedReconnect;
+			spin_unlock(&GlobalMid_Lock);
+		}
+	}
+
+	return rc;
+}
+
+
 /*
  * calculate the size of the SMB message based on the fixed header
  * portion, the number of word parameters and the data portion of the message
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 5d05bd2822d2..69cd5856621b 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -938,8 +938,7 @@ sess_sendreceive(struct sess_data *sess_data)
 	struct kvec rsp_iov = { NULL, 0 };
 
 	count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
-	smb_buf->smb_buf_length =
-		cpu_to_be32(be32_to_cpu(smb_buf->smb_buf_length) + count);
+	be32_add_cpu(&smb_buf->smb_buf_length, count);
 	put_bcc(count, smb_buf);
 
 	rc = SendReceive2(sess_data->xid, sess_data->ses,
@@ -1705,7 +1704,6 @@ static int select_sec(struct cifs_ses *ses, struct sess_data *sess_data)
 #else
 		cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
 		return -ENOSYS;
-		break;
 #endif /* CONFIG_CIFS_UPCALL */
 	case RawNTLMSSP:
 		sess_data->func = sess_auth_rawntlmssp_negotiate;
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index 197ed455e657..80287c26cfac 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -688,7 +688,7 @@ cifs_mkdir_setinfo(struct inode *inode, const char *full_path,
 	dosattrs = cifsInode->cifsAttrs|ATTR_READONLY;
 	info.Attributes = cpu_to_le32(dosattrs);
 	rc = CIFSSMBSetPathInfo(xid, tcon, full_path, &info, cifs_sb->local_nls,
-				cifs_remap(cifs_sb));
+				cifs_sb);
 	if (rc == 0)
 		cifsInode->cifsAttrs = dosattrs;
 }
@@ -783,7 +783,7 @@ smb_set_file_info(struct inode *inode, const char *full_path,
 	tcon = tlink_tcon(tlink);
 
 	rc = CIFSSMBSetPathInfo(xid, tcon, full_path, buf, cifs_sb->local_nls,
-				cifs_remap(cifs_sb));
+				cifs_sb);
 	if (rc == 0) {
 		cinode->cifsAttrs = le32_to_cpu(buf->Attributes);
 		goto out;
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 157992864ce7..d88e2683626e 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -508,15 +508,31 @@ cifs_ses_oplock_break(struct work_struct *work)
 	kfree(lw);
 }
 
+static void
+smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
+			      __le32 new_lease_state)
+{
+	struct smb2_lease_break_work *lw;
+
+	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
+	if (!lw) {
+		cifs_put_tlink(tlink);
+		return;
+	}
+
+	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
+	lw->tlink = tlink;
+	lw->lease_state = new_lease_state;
+	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
+	queue_work(cifsiod_wq, &lw->lease_break);
+}
+
 static bool
-smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
-		    struct smb2_lease_break_work *lw)
+smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
 {
-	bool found;
 	__u8 lease_state;
 	struct list_head *tmp;
 	struct cifsFileInfo *cfile;
-	struct cifs_pending_open *open;
 	struct cifsInodeInfo *cinode;
 	int ack_req = le32_to_cpu(rsp->Flags &
 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
@@ -546,22 +562,29 @@ smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
 		cfile->oplock_level = lease_state;
 
 		cifs_queue_oplock_break(cfile);
-		kfree(lw);
 		return true;
 	}
 
-	found = false;
+	return false;
+}
+
+static struct cifs_pending_open *
+smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
+				  struct smb2_lease_break *rsp)
+{
+	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
+	int ack_req = le32_to_cpu(rsp->Flags &
+				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
+	struct cifs_pending_open *open;
+	struct cifs_pending_open *found = NULL;
+
 	list_for_each_entry(open, &tcon->pending_opens, olist) {
 		if (memcmp(open->lease_key, rsp->LeaseKey,
 			   SMB2_LEASE_KEY_SIZE))
 			continue;
 
 		if (!found && ack_req) {
-			found = true;
-			memcpy(lw->lease_key, open->lease_key,
-			       SMB2_LEASE_KEY_SIZE);
-			lw->tlink = cifs_get_tlink(open->tlink);
-			queue_work(cifsiod_wq, &lw->lease_break);
+			found = open;
 		}
 
 		cifs_dbg(FYI, "found in the pending open list\n");
@@ -582,14 +605,7 @@ smb2_is_valid_lease_break(char *buffer)
 	struct TCP_Server_Info *server;
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
-	struct smb2_lease_break_work *lw;
-
-	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
-	if (!lw)
-		return false;
-
-	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
-	lw->lease_state = rsp->NewLeaseState;
+	struct cifs_pending_open *open;
 
 	cifs_dbg(FYI, "Checking for lease break\n");
 
@@ -607,11 +623,27 @@ smb2_is_valid_lease_break(char *buffer)
 				spin_lock(&tcon->open_file_lock);
 				cifs_stats_inc(
 				    &tcon->stats.cifs_stats.num_oplock_brks);
-				if (smb2_tcon_has_lease(tcon, rsp, lw)) {
+				if (smb2_tcon_has_lease(tcon, rsp)) {
 					spin_unlock(&tcon->open_file_lock);
 					spin_unlock(&cifs_tcp_ses_lock);
 					return true;
 				}
+				open = smb2_tcon_find_pending_open_lease(tcon,
+									 rsp);
+				if (open) {
+					__u8 lease_key[SMB2_LEASE_KEY_SIZE];
+					struct tcon_link *tlink;
+
+					tlink = cifs_get_tlink(open->tlink);
+					memcpy(lease_key, open->lease_key,
+					       SMB2_LEASE_KEY_SIZE);
+					spin_unlock(&tcon->open_file_lock);
+					spin_unlock(&cifs_tcp_ses_lock);
+					smb2_queue_pending_open_break(tlink,
+								      lease_key,
+								      rsp->NewLeaseState);
+					return true;
+				}
 				spin_unlock(&tcon->open_file_lock);
 
 				if (tcon->crfid.is_valid &&
@@ -629,7 +661,6 @@ smb2_is_valid_lease_break(char *buffer)
 		}
 	}
 	spin_unlock(&cifs_tcp_ses_lock);
-	kfree(lw);
 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
 	return false;
 }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 2f4cdd290c46..24c2ac360591 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -152,117 +152,6 @@ out:
 	return;
 }
 
-#ifdef CONFIG_CIFS_DFS_UPCALL
-static int __smb2_reconnect(const struct nls_table *nlsc,
-			    struct cifs_tcon *tcon)
-{
-	int rc;
-	struct TCP_Server_Info *server = tcon->ses->server;
-	struct dfs_cache_tgt_list tl;
-	struct dfs_cache_tgt_iterator *it = NULL;
-	char *tree;
-	const char *tcp_host;
-	size_t tcp_host_len;
-	const char *dfs_host;
-	size_t dfs_host_len;
-
-	tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
-	if (!tree)
-		return -ENOMEM;
-
-	if (!tcon->dfs_path) {
-		if (tcon->ipc) {
-			scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$",
-				  server->hostname);
-			rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
-		} else {
-			rc = SMB2_tcon(0, tcon->ses, tcon->treeName, tcon,
-				       nlsc);
-		}
-		goto out;
-	}
-
-	rc = dfs_cache_noreq_find(tcon->dfs_path + 1, NULL, &tl);
-	if (rc)
-		goto out;
-
-	extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
-
-	for (it = dfs_cache_get_tgt_iterator(&tl); it;
-	     it = dfs_cache_get_next_tgt(&tl, it)) {
-		const char *share, *prefix;
-		size_t share_len, prefix_len;
-		bool target_match;
-
-		rc = dfs_cache_get_tgt_share(it, &share, &share_len, &prefix,
-					     &prefix_len);
-		if (rc) {
-			cifs_dbg(VFS, "%s: failed to parse target share %d\n",
-				 __func__, rc);
-			continue;
-		}
-
-		extract_unc_hostname(share, &dfs_host, &dfs_host_len);
-
-		if (dfs_host_len != tcp_host_len
-		    || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
-			cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n",
-				 __func__,
-				 (int)dfs_host_len, dfs_host,
-				 (int)tcp_host_len, tcp_host);
-
-			rc = match_target_ip(server, dfs_host, dfs_host_len,
-					     &target_match);
-			if (rc) {
-				cifs_dbg(VFS, "%s: failed to match target ip: %d\n",
-					 __func__, rc);
-				break;
-			}
-
-			if (!target_match) {
-				cifs_dbg(FYI, "%s: skipping target\n", __func__);
-				continue;
-			}
-		}
-
-		if (tcon->ipc) {
-			scnprintf(tree, MAX_TREE_SIZE, "\\\\%.*s\\IPC$",
-				  (int)share_len, share);
-			rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
-		} else {
-			scnprintf(tree, MAX_TREE_SIZE, "\\%.*s", (int)share_len,
-				  share);
-			rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
-			if (!rc) {
-				rc = update_super_prepath(tcon, prefix,
-							  prefix_len);
-				break;
-			}
-		}
-		if (rc == -EREMOTE)
-			break;
-	}
-
-	if (!rc) {
-		if (it)
-			rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1,
-							    it);
-		else
-			rc = -ENOENT;
-	}
-	dfs_cache_free_tgts(&tl);
-out:
-	kfree(tree);
-	return rc;
-}
-#else
-static inline int __smb2_reconnect(const struct nls_table *nlsc,
-				   struct cifs_tcon *tcon)
-{
-	return SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
-}
-#endif
-
 static int
 smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 	       struct TCP_Server_Info *server)
@@ -409,7 +298,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 	if (tcon->use_persistent)
 		tcon->need_reopen_files = true;
 
-	rc = __smb2_reconnect(nls_codepage, tcon);
+	rc = cifs_tree_connect(0, tcon, nls_codepage);
 	mutex_unlock(&tcon->ses->session_mutex);
 
 	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
@@ -1387,6 +1276,8 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data)
 	spnego_key = cifs_get_spnego_key(ses);
 	if (IS_ERR(spnego_key)) {
 		rc = PTR_ERR(spnego_key);
+		if (rc == -ENOKEY)
+			cifs_dbg(VFS, "Verify user has a krb5 ticket and keyutils is installed\n");
 		spnego_key = NULL;
 		goto out;
 	}
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 236814d61248..c3f1baf5bde2 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -31,7 +31,7 @@
  * Note that, due to trying to use names similar to the protocol specifications,
  * there are many mixed case field names in the structures below.  Although
  * this does not match typical Linux kernel style, it is necessary to be
- * be able to match against the protocol specfication.
+ * able to match against the protocol specfication.
  *
  * SMB2 commands
  * Some commands have minimal (wct=0,bcc=0), or uninteresting, responses
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 84433d0653f9..ac7632482736 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -936,7 +936,7 @@ cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 	}
 
 	/* BB special case reconnect tid and uid here? */
-	return map_smb_to_linux_error(mid->resp_buf, log_error);
+	return map_and_check_smb_error(mid, log_error);
 }
 
 struct mid_q_entry *