diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index f4465b6ea..4522fe6ef 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,14 @@
+2010-04-29  Corinna Vinschen  <corinna@vinschen.de>
+
+	* external.cc (cygwin_internal): Add CW_CVT_MNT_OPTS to allow mount
+	flag parsing.  Add CW_LST_MNT_OPTS case to allow mount flag listing.
+	* mount.cc (fstab_read_flags): Rename from read_flags.  Make externally
+	available.  Change input string to char ** to allow returning faulty
+	option.  Add flag for avoiding debug output.
+	(fstab_list_flags): New function to create list of options.
+	* include/sys/cygwin.h (cygwin_getinfo_types): Add CW_CVT_MNT_OPTS and
+	CW_LST_MNT_OPTS.
+
 2010-04-28  Corinna Vinschen  <corinna@vinschen.de>
 
 	* mount.cc (compare_flags): New function.
diff --git a/winsup/cygwin/external.cc b/winsup/cygwin/external.cc
index bbf675a64..c8cbd9370 100644
--- a/winsup/cygwin/external.cc
+++ b/winsup/cygwin/external.cc
@@ -474,6 +474,40 @@ cygwin_internal (cygwin_getinfo_types t, ...)
 	  internal_setlocale ();
 	  res = 0;
 	}
+	break;
+      case CW_CVT_MNT_OPTS:
+	{
+	  extern bool fstab_read_flags (char **, unsigned &, bool);
+	  char **option_string = va_arg (arg, char **);
+	  if (!option_string || !*option_string)
+	    set_errno (EINVAL);
+	  else
+	    {
+	      unsigned *pflags = va_arg (arg, unsigned *);
+	      unsigned flags = 0;
+	      if (fstab_read_flags (option_string, flags, true))
+		{
+		  if (pflags)
+		    *pflags = flags;
+		  res = 0;
+		}
+	    }
+	}
+	break;
+      case CW_LST_MNT_OPTS:
+	{
+	  extern char *fstab_list_flags ();
+	  char **option_string = va_arg (arg, char **);
+	  if (!option_string)
+	    set_errno (EINVAL);
+	  else
+	    {
+	      *option_string = fstab_list_flags ();
+	      if (*option_string)
+		res = 0;
+	    }
+	}
+	break;
 
       default:
 	set_errno (ENOSYS);
diff --git a/winsup/cygwin/include/sys/cygwin.h b/winsup/cygwin/include/sys/cygwin.h
index 6c04dc8e1..425fd82fd 100644
--- a/winsup/cygwin/include/sys/cygwin.h
+++ b/winsup/cygwin/include/sys/cygwin.h
@@ -146,7 +146,9 @@ typedef enum
     CW_EXIT_PROCESS,
     CW_SET_EXTERNAL_TOKEN,
     CW_GET_INSTKEY,
-    CW_INT_SETLOCALE
+    CW_INT_SETLOCALE,
+    CW_CVT_MNT_OPTS,
+    CW_LST_MNT_OPTS
   } cygwin_getinfo_types;
 
 /* Token type for CW_SET_EXTERNAL_TOKEN */
diff --git a/winsup/cygwin/mount.cc b/winsup/cygwin/mount.cc
index 528c8b65a..a11ed34a8 100644
--- a/winsup/cygwin/mount.cc
+++ b/winsup/cygwin/mount.cc
@@ -953,36 +953,60 @@ compare_flags (const void *a, const void *b)
   return strcmp (oa->name, ob->name);
 }
 
-static bool
-read_flags (char *options, unsigned &flags)
+extern "C" bool
+fstab_read_flags (char **options, unsigned &flags, bool external)
 {
   opt key;
 
-  while (*options)
+  while (**options)
     {
-      char *p = strchr (options, ',');
+      char *p = strchr (*options, ',');
       if (p)
 	*p++ = '\0';
       else
-	p = strchr (options, '\0');
+	p = strchr (*options, '\0');
       
-      key.name = options;
-      opt *o = (opt *) bsearch (&key, oopts, sizeof oopts / sizeof (opt),
+      key.name = *options;
+      opt *o = (opt *) bsearch (&key, oopts,
+				sizeof oopts / sizeof (opt),
 				sizeof (opt), compare_flags);
       if (!o)
 	{
-	  system_printf ("invalid fstab option - '%s'", options);
+	  if (!external)
+	    system_printf ("invalid fstab option - '%s'", *options);
 	  return false;
 	}
       if (o->clear)
 	flags &= ~o->val;
       else
 	flags |= o->val;
-      options = p;
+      *options = p;
     }
   return true;
 }
 
+extern "C" char *
+fstab_list_flags ()
+{
+  size_t len = 0;
+  opt *o;
+
+  for (o = oopts; o < (oopts + (sizeof (oopts) / sizeof (oopts[0]))); o++)
+    len += strlen (o->name) + 1;
+  char *buf = (char *) malloc (len);
+  if (buf)
+    {
+      char *bp = buf;
+      for (o = oopts; o < (oopts + (sizeof (oopts) / sizeof (oopts[0]))); o++)
+      	{
+	  bp = stpcpy (bp, o->name);
+	  *bp++ = ',';
+	}
+      *--bp = '\0';
+    }
+  return buf;
+}
+
 bool
 mount_info::from_fstab_line (char *line, bool user)
 {
@@ -1021,7 +1045,7 @@ mount_info::from_fstab_line (char *line, bool user)
   unsigned mount_flags = MOUNT_SYSTEM | MOUNT_BINARY;
   if (!strcmp (fs_type, "cygdrive"))
     mount_flags |= MOUNT_NOPOSIX;
-  if (!read_flags (c, mount_flags))
+  if (!fstab_read_flags (&c, mount_flags, false))
     return true;
   if (user)
     mount_flags &= ~MOUNT_SYSTEM;