diff --git a/winsup/cygwin/local_includes/mount.h b/winsup/cygwin/local_includes/mount.h
index cb48a6840e..addd082e9a 100644
--- a/winsup/cygwin/local_includes/mount.h
+++ b/winsup/cygwin/local_includes/mount.h
@@ -47,6 +47,7 @@ enum fs_info_type
   ncfsd,
   afs,
   prlfs,
+  ramdisk,
   /* Always last. */
   max_fs_type
 };
@@ -117,6 +118,7 @@ class fs_info
   IMPLEMENT_FS_FLAG (ncfsd)
   IMPLEMENT_FS_FLAG (afs)
   IMPLEMENT_FS_FLAG (prlfs)
+  IMPLEMENT_FS_FLAG (ramdisk)
   fs_info_type what_fs () const { return status.fs_type; }
   bool got_fs () const { return status.fs_type != none; }
 
diff --git a/winsup/cygwin/local_includes/path.h b/winsup/cygwin/local_includes/path.h
index 74f831e53f..2e34f0e18a 100644
--- a/winsup/cygwin/local_includes/path.h
+++ b/winsup/cygwin/local_includes/path.h
@@ -387,6 +387,7 @@ class path_conv
   bool fs_is_ncfsd () const {return fs.is_ncfsd ();}
   bool fs_is_afs () const {return fs.is_afs ();}
   bool fs_is_prlfs () const {return fs.is_prlfs ();}
+  bool fs_is_ramdisk () const {return fs.is_ramdisk ();}
   fs_info_type fs_type () const {return fs.what_fs ();}
   ULONG fs_serial_number () const {return fs.serial_number ();}
   inline const char *set_path (const char *p)
diff --git a/winsup/cygwin/mm/mmap.cc b/winsup/cygwin/mm/mmap.cc
index 332c015a72..23bbc3a988 100644
--- a/winsup/cygwin/mm/mmap.cc
+++ b/winsup/cygwin/mm/mmap.cc
@@ -956,11 +956,10 @@ mmap (void *addr, size_t len, int prot, int flags, int fd, off_t off)
       HANDLE h;
       IO_STATUS_BLOCK io;
 
-      InitializeObjectAttributes (&attr, &ro_u_empty, fh->pc.objcaseinsensitive (),
-				  fh->get_handle (), NULL);
       status = NtOpenFile (&h,
 			   fh->get_access () | GENERIC_EXECUTE | SYNCHRONIZE,
-			   &attr, &io, FILE_SHARE_VALID_FLAGS,
+			   fh->pc.init_reopen_attr (attr, h), &io,
+			   FILE_SHARE_VALID_FLAGS,
 			   FILE_SYNCHRONOUS_IO_NONALERT
 			   | FILE_OPEN_FOR_BACKUP_INTENT);
       if (NT_SUCCESS (status))
diff --git a/winsup/cygwin/mount.cc b/winsup/cygwin/mount.cc
index 37152fb95a..148fb773ac 100644
--- a/winsup/cygwin/mount.cc
+++ b/winsup/cygwin/mount.cc
@@ -291,6 +291,17 @@ fs_info::update (PUNICODE_STRING upath, HANDLE in_vol)
   if (!NT_SUCCESS (status))
     ffdi.DeviceType = ffdi.Characteristics = 0;
 
+  if (upath->Buffer[5] == L':' && upath->Buffer[6] == L'\\')
+   {
+     WCHAR dos[3] = {upath->Buffer[4], upath->Buffer[5], L'\0'};
+     WCHAR dev[MAX_PATH];
+     if (QueryDosDeviceW (dos, dev, MAX_PATH))
+       {
+          is_ramdisk (wcsncmp (dev, L"\\Device\\Ramdisk", 15));
+          has_buggy_reopen (is_ramdisk ());
+       }
+   }
+
   if ((ffdi.Characteristics & FILE_REMOTE_DEVICE)
       || (!ffdi.DeviceType
 	  && RtlEqualUnicodePathPrefix (attr.ObjectName, &ro_u_uncp, TRUE)))
@@ -1710,6 +1721,7 @@ fs_names_t fs_names[] = {
     { "ncfsd", false },
     { "afs", false },
     { "prlfs", false },
+    { "ramdisk", false },
     { NULL, false }
 };