cifs: fix check of tcon dfs in smb1
For SMB1, the DFS flag should be checked against tcon->Flags rather
than tcon->share_flags. While at it, add an is_tcon_dfs() helper to
check for DFS capability in a more generic way.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index b296964..b565d83 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -2031,4 +2031,19 @@ static inline bool is_smb1_server(struct TCP_Server_Info *server)
return strcmp(server->vals->version_string, SMB1_VERSION_STRING) == 0;
}
+static inline bool is_tcon_dfs(struct cifs_tcon *tcon)
+{
+ /*
+ * For SMB1, see MS-CIFS 2.4.55 SMB_COM_TREE_CONNECT_ANDX (0x75) and MS-CIFS 3.3.4.4 DFS
+ * Subsystem Notifies That a Share Is a DFS Share.
+ *
+ * For SMB2+, see MS-SMB2 2.2.10 SMB2 TREE_CONNECT Response and MS-SMB2 3.3.4.14 Server
+ * Application Updates a Share.
+ */
+ if (!tcon || !tcon->ses || !tcon->ses->server)
+ return false;
+ return is_smb1_server(tcon->ses->server) ? tcon->Flags & SMB_SHARE_IS_IN_DFS :
+ tcon->share_flags & (SHI1005_FLAGS_DFS | SHI1005_FLAGS_DFS_ROOT);
+}
+
#endif /* _CIFS_GLOB_H */