util_win32: make os_link more robust (issue 761)

On mapped drives, os_link() manages to create links but nlink() does not report them.

mercurial/util_win32.py

@@ -1,310 +1,319 b''
 # util_win32.py - utility functions that use win32 API
 #
 # Copyright 2005 Matt Mackall <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # This software may be used and distributed according to the terms of
 # the GNU General Public License, incorporated herein by reference.
 
 # Mark Hammond's win32all package allows better functionality on
 # Windows.  this module overrides definitions in util.py.  if not
 # available, import of this module will fail, and generic code will be
 # used.
 
 import win32api
 
 from i18n import _
 import errno, os, pywintypes, win32con, win32file, win32process
 import cStringIO, winerror
 from win32com.shell import shell,shellcon
 
 class WinError:
     winerror_map = {
         winerror.ERROR_ACCESS_DENIED: errno.EACCES,
         winerror.ERROR_ACCOUNT_DISABLED: errno.EACCES,
         winerror.ERROR_ACCOUNT_RESTRICTION: errno.EACCES,
         winerror.ERROR_ALREADY_ASSIGNED: errno.EBUSY,
         winerror.ERROR_ALREADY_EXISTS: errno.EEXIST,
         winerror.ERROR_ARITHMETIC_OVERFLOW: errno.ERANGE,
         winerror.ERROR_BAD_COMMAND: errno.EIO,
         winerror.ERROR_BAD_DEVICE: errno.ENODEV,
         winerror.ERROR_BAD_DRIVER_LEVEL: errno.ENXIO,
         winerror.ERROR_BAD_EXE_FORMAT: errno.ENOEXEC,
         winerror.ERROR_BAD_FORMAT: errno.ENOEXEC,
         winerror.ERROR_BAD_LENGTH: errno.EINVAL,
         winerror.ERROR_BAD_PATHNAME: errno.ENOENT,
         winerror.ERROR_BAD_PIPE: errno.EPIPE,
         winerror.ERROR_BAD_UNIT: errno.ENODEV,
         winerror.ERROR_BAD_USERNAME: errno.EINVAL,
         winerror.ERROR_BROKEN_PIPE: errno.EPIPE,
         winerror.ERROR_BUFFER_OVERFLOW: errno.ENAMETOOLONG,
         winerror.ERROR_BUSY: errno.EBUSY,
         winerror.ERROR_BUSY_DRIVE: errno.EBUSY,
         winerror.ERROR_CALL_NOT_IMPLEMENTED: errno.ENOSYS,
         winerror.ERROR_CANNOT_MAKE: errno.EACCES,
         winerror.ERROR_CANTOPEN: errno.EIO,
         winerror.ERROR_CANTREAD: errno.EIO,
         winerror.ERROR_CANTWRITE: errno.EIO,
         winerror.ERROR_CRC: errno.EIO,
         winerror.ERROR_CURRENT_DIRECTORY: errno.EACCES,
         winerror.ERROR_DEVICE_IN_USE: errno.EBUSY,
         winerror.ERROR_DEV_NOT_EXIST: errno.ENODEV,
         winerror.ERROR_DIRECTORY: errno.EINVAL,
         winerror.ERROR_DIR_NOT_EMPTY: errno.ENOTEMPTY,
         winerror.ERROR_DISK_CHANGE: errno.EIO,
         winerror.ERROR_DISK_FULL: errno.ENOSPC,
         winerror.ERROR_DRIVE_LOCKED: errno.EBUSY,
         winerror.ERROR_ENVVAR_NOT_FOUND: errno.EINVAL,
         winerror.ERROR_EXE_MARKED_INVALID: errno.ENOEXEC,
         winerror.ERROR_FILENAME_EXCED_RANGE: errno.ENAMETOOLONG,
         winerror.ERROR_FILE_EXISTS: errno.EEXIST,
         winerror.ERROR_FILE_INVALID: errno.ENODEV,
         winerror.ERROR_FILE_NOT_FOUND: errno.ENOENT,
         winerror.ERROR_GEN_FAILURE: errno.EIO,
         winerror.ERROR_HANDLE_DISK_FULL: errno.ENOSPC,
         winerror.ERROR_INSUFFICIENT_BUFFER: errno.ENOMEM,
         winerror.ERROR_INVALID_ACCESS: errno.EACCES,
         winerror.ERROR_INVALID_ADDRESS: errno.EFAULT,
         winerror.ERROR_INVALID_BLOCK: errno.EFAULT,
         winerror.ERROR_INVALID_DATA: errno.EINVAL,
         winerror.ERROR_INVALID_DRIVE: errno.ENODEV,
         winerror.ERROR_INVALID_EXE_SIGNATURE: errno.ENOEXEC,
         winerror.ERROR_INVALID_FLAGS: errno.EINVAL,
         winerror.ERROR_INVALID_FUNCTION: errno.ENOSYS,
         winerror.ERROR_INVALID_HANDLE: errno.EBADF,
         winerror.ERROR_INVALID_LOGON_HOURS: errno.EACCES,
         winerror.ERROR_INVALID_NAME: errno.EINVAL,
         winerror.ERROR_INVALID_OWNER: errno.EINVAL,
         winerror.ERROR_INVALID_PARAMETER: errno.EINVAL,
         winerror.ERROR_INVALID_PASSWORD: errno.EPERM,
         winerror.ERROR_INVALID_PRIMARY_GROUP: errno.EINVAL,
         winerror.ERROR_INVALID_SIGNAL_NUMBER: errno.EINVAL,
         winerror.ERROR_INVALID_TARGET_HANDLE: errno.EIO,
         winerror.ERROR_INVALID_WORKSTATION: errno.EACCES,
         winerror.ERROR_IO_DEVICE: errno.EIO,
         winerror.ERROR_IO_INCOMPLETE: errno.EINTR,
         winerror.ERROR_LOCKED: errno.EBUSY,
         winerror.ERROR_LOCK_VIOLATION: errno.EACCES,
         winerror.ERROR_LOGON_FAILURE: errno.EACCES,
         winerror.ERROR_MAPPED_ALIGNMENT: errno.EINVAL,
         winerror.ERROR_META_EXPANSION_TOO_LONG: errno.E2BIG,
         winerror.ERROR_MORE_DATA: errno.EPIPE,
         winerror.ERROR_NEGATIVE_SEEK: errno.ESPIPE,
         winerror.ERROR_NOACCESS: errno.EFAULT,
         winerror.ERROR_NONE_MAPPED: errno.EINVAL,
         winerror.ERROR_NOT_ENOUGH_MEMORY: errno.ENOMEM,
         winerror.ERROR_NOT_READY: errno.EAGAIN,
         winerror.ERROR_NOT_SAME_DEVICE: errno.EXDEV,
         winerror.ERROR_NO_DATA: errno.EPIPE,
         winerror.ERROR_NO_MORE_SEARCH_HANDLES: errno.EIO,
         winerror.ERROR_NO_PROC_SLOTS: errno.EAGAIN,
         winerror.ERROR_NO_SUCH_PRIVILEGE: errno.EACCES,
         winerror.ERROR_OPEN_FAILED: errno.EIO,
         winerror.ERROR_OPEN_FILES: errno.EBUSY,
         winerror.ERROR_OPERATION_ABORTED: errno.EINTR,
         winerror.ERROR_OUTOFMEMORY: errno.ENOMEM,
         winerror.ERROR_PASSWORD_EXPIRED: errno.EACCES,
         winerror.ERROR_PATH_BUSY: errno.EBUSY,
         winerror.ERROR_PATH_NOT_FOUND: errno.ENOENT,
         winerror.ERROR_PIPE_BUSY: errno.EBUSY,
         winerror.ERROR_PIPE_CONNECTED: errno.EPIPE,
         winerror.ERROR_PIPE_LISTENING: errno.EPIPE,
         winerror.ERROR_PIPE_NOT_CONNECTED: errno.EPIPE,
         winerror.ERROR_PRIVILEGE_NOT_HELD: errno.EACCES,
         winerror.ERROR_READ_FAULT: errno.EIO,
         winerror.ERROR_SEEK: errno.EIO,
         winerror.ERROR_SEEK_ON_DEVICE: errno.ESPIPE,
         winerror.ERROR_SHARING_BUFFER_EXCEEDED: errno.ENFILE,
         winerror.ERROR_SHARING_VIOLATION: errno.EACCES,
         winerror.ERROR_STACK_OVERFLOW: errno.ENOMEM,
         winerror.ERROR_SWAPERROR: errno.ENOENT,
         winerror.ERROR_TOO_MANY_MODULES: errno.EMFILE,
         winerror.ERROR_TOO_MANY_OPEN_FILES: errno.EMFILE,
         winerror.ERROR_UNRECOGNIZED_MEDIA: errno.ENXIO,
         winerror.ERROR_UNRECOGNIZED_VOLUME: errno.ENODEV,
         winerror.ERROR_WAIT_NO_CHILDREN: errno.ECHILD,
         winerror.ERROR_WRITE_FAULT: errno.EIO,
         winerror.ERROR_WRITE_PROTECT: errno.EROFS,
         }
 
     def __init__(self, err):
         self.win_errno, self.win_function, self.win_strerror = err
         if self.win_strerror.endswith('.'):
             self.win_strerror = self.win_strerror[:-1]
 
 class WinIOError(WinError, IOError):
     def __init__(self, err, filename=None):
         WinError.__init__(self, err)
         IOError.__init__(self, self.winerror_map.get(self.win_errno, 0),
                          self.win_strerror)
         self.filename = filename
 
 class WinOSError(WinError, OSError):
     def __init__(self, err):
         WinError.__init__(self, err)
         OSError.__init__(self, self.winerror_map.get(self.win_errno, 0),
                          self.win_strerror)
 
 def os_link(src, dst):
-    # NB will only succeed on NTFS
     try:
         win32file.CreateHardLink(dst, src)
+        # CreateHardLink sometimes succeeds on mapped drives but
+        # following nlinks() returns 1. Check it now and bail out.
+        if nlinks(src) < 2:
+            try:
+                win32file.DeleteFile(dst)
+            except:
+                pass
+            # Fake hardlinking error
+            raise WinOSError((18, 'CreateHardLink', 'The system cannot '
+                              'move the file to a different disk drive'))
     except pywintypes.error, details:
         raise WinOSError(details)
 
 def nlinks(pathname):
     """Return number of hardlinks for the given file."""
     try:
         fh = win32file.CreateFile(pathname,
             win32file.GENERIC_READ, win32file.FILE_SHARE_READ,
             None, win32file.OPEN_EXISTING, 0, None)
         res = win32file.GetFileInformationByHandle(fh)
         fh.Close()
         return res[7]
     except pywintypes.error:
         return os.lstat(pathname).st_nlink
 
 def testpid(pid):
     '''return True if pid is still running or unable to
     determine, False otherwise'''
     try:
         handle = win32api.OpenProcess(
             win32con.PROCESS_QUERY_INFORMATION, False, pid)
         if handle:
             status = win32process.GetExitCodeProcess(handle)
             return status == win32con.STILL_ACTIVE
     except pywintypes.error, details:
         return details[0] != winerror.ERROR_INVALID_PARAMETER
     return True
 
 def system_rcpath_win32():
     '''return default os-specific hgrc search path'''
     proc = win32api.GetCurrentProcess()
     try:
         # This will fail on windows < NT
         filename = win32process.GetModuleFileNameEx(proc, 0)
     except:
         filename = win32api.GetModuleFileName(0)
     return [os.path.join(os.path.dirname(filename), 'mercurial.ini')]
 
 def user_rcpath_win32():
     '''return os-specific hgrc search path to the user dir'''
     userdir = os.path.expanduser('~')
     if sys.getwindowsversion() != 2 and userdir == '~':
         # We are on win < nt: fetch the APPDATA directory location and use
         # the parent directory as the user home dir.
         appdir = shell.SHGetPathFromIDList(
             shell.SHGetSpecialFolderLocation(0, shellcon.CSIDL_APPDATA))
         userdir = os.path.dirname(appdir)
     return os.path.join(userdir, 'mercurial.ini')
 
 class posixfile_nt(object):
     '''file object with posix-like semantics.  on windows, normal
     files can not be deleted or renamed if they are open. must open
     with win32file.FILE_SHARE_DELETE. this flag does not exist on
     windows < nt, so do not use this class there.'''
 
     # tried to use win32file._open_osfhandle to pass fd to os.fdopen,
     # but does not work at all. wrap win32 file api instead.
 
     def __init__(self, name, mode='rb'):
         access = 0
         if 'r' in mode or '+' in mode:
             access |= win32file.GENERIC_READ
         if 'w' in mode or 'a' in mode or '+' in mode:
             access |= win32file.GENERIC_WRITE
         if 'r' in mode:
             creation = win32file.OPEN_EXISTING
         elif 'a' in mode:
             creation = win32file.OPEN_ALWAYS
         else:
             creation = win32file.CREATE_ALWAYS
         try:
             self.handle = win32file.CreateFile(name,
                                                access,
                                                win32file.FILE_SHARE_READ |
                                                win32file.FILE_SHARE_WRITE |
                                                win32file.FILE_SHARE_DELETE,
                                                None,
                                                creation,
                                                win32file.FILE_ATTRIBUTE_NORMAL,
                                                0)
         except pywintypes.error, err:
             raise WinIOError(err, name)
         self.closed = False
         self.name = name
         self.mode = mode
 
     def __iter__(self):
         for line in self.read().splitlines(True):
             yield line
 
     def read(self, count=-1):
         try:
             cs = cStringIO.StringIO()
             while count:
                 wincount = int(count)
                 if wincount == -1:
                     wincount = 1048576
                 val, data = win32file.ReadFile(self.handle, wincount)
                 if not data: break
                 cs.write(data)
                 if count != -1:
                     count -= len(data)
             return cs.getvalue()
         except pywintypes.error, err:
             raise WinIOError(err)
 
     def write(self, data):
         try:
             if 'a' in self.mode:
                 win32file.SetFilePointer(self.handle, 0, win32file.FILE_END)
             nwrit = 0
             while nwrit < len(data):
                 val, nwrit = win32file.WriteFile(self.handle, data)
                 data = data[nwrit:]
         except pywintypes.error, err:
             raise WinIOError(err)
 
     def seek(self, pos, whence=0):
         try:
             win32file.SetFilePointer(self.handle, int(pos), whence)
         except pywintypes.error, err:
             raise WinIOError(err)
 
     def tell(self):
         try:
             return win32file.SetFilePointer(self.handle, 0,
                                             win32file.FILE_CURRENT)
         except pywintypes.error, err:
             raise WinIOError(err)
 
     def close(self):
         if not self.closed:
             self.handle = None
             self.closed = True
 
     def flush(self):
         try:
             win32file.FlushFileBuffers(self.handle)
         except pywintypes.error, err:
             raise WinIOError(err)
 
     def truncate(self, pos=0):
         try:
             win32file.SetFilePointer(self.handle, int(pos),
                                      win32file.FILE_BEGIN)
             win32file.SetEndOfFile(self.handle)
         except pywintypes.error, err:
             raise WinIOError(err)
 
 getuser_fallback = win32api.GetUserName
 
 def set_signal_handler_win32():
     """Register a termination handler for console events including
     CTRL+C. python signal handlers do not work well with socket
     operations.
     """
     def handler(event):
         win32process.ExitProcess(1)
     win32api.SetConsoleCtrlHandler(handler)