win32: implement util.getfstype() This will allow NTFS to be added to the hardlink whitelist, and resume creating hardlinks in transactions (which was disabled globally in 07a92bbd02e5; see also e5ce49a30146). I opted to report "cifs" for remote volumes because this shows in `hg debugfs`, which also reports that hardlinks are supported for these volumes. So being able to distinguish it from "unknown" seems useful. The documentation [1] seems to indicate that SMB isn't supported by these functions, but experimenting shows that mapped drives are reported as "NTFS" on Windows 7. I don't have a second Windows machine, but instead shared a temp directory on C:\. In this setup, both of the following were detected as 'cifs' with the explicit GetDriveType() check: Z:\repo>hg ci -A C:\>hg -R \\hostname\temp\repo ci -A # (without Z:\ being mapped) It looks like this is called 6 times to add and commit a single new file, so I'm a little surprised this isn't cached. [1] https://msdn.microsoft.com/en-us/library/windows/desktop/aa364993(v=vs.85).aspx

--- a/mercurial/windows.py	Sat Dec 30 21:07:03 2017 -0500
+++ b/mercurial/windows.py	Fri Dec 29 21:28:19 2017 -0500
@@ -32,6 +32,7 @@
 osutil = policy.importmod(r'osutil')
 
 executablepath = win32.executablepath
+getfstype = win32.getfstype
 getuser = win32.getuser
 hidewindow = win32.hidewindow
 makedir = win32.makedir
@@ -226,13 +227,6 @@
 def checklink(path):
     return False
 
-def getfstype(dirpath):
-    '''Get the filesystem type name from a directory (best-effort)
-
-    Returns None if we are unsure. Raises OSError on ENOENT, EPERM, etc.
-    '''
-    return None
-
 def setbinary(fd):
     # When run without console, pipes may expose invalid
     # fileno(), usually set to -1.