Use os.statvfs to determine free disk space

[ganeti-local] / lib / storage / filestorage.py

diff --git a/lib/storage/filestorage.py b/lib/storage/filestorage.py
index 65c963c..3e64018 100644 (file)
--- a/lib/storage/filestorage.py
+++ b/lib/storage/filestorage.py
@@ -23,56 +23,26 @@
 
 """
 
-from ganeti import errors
-from ganeti import utils
-
-DF_M_UNIT = 'M'
-DF_MIN_NUM_COLS = 4
-DF_NUM_LINES = 2
-
-
-def _ParseDfResult(dfresult):
-  """Parses the output of the call of the 'df' tool.
+import os
 
-     @type dfresult: string
-     @param dfresult: output of the 'df' call
-     @return: tuple (size, free) of the total and free disk space in MebiBytes
-  """
-  df_lines = dfresult.splitlines()
-  if len(df_lines) != DF_NUM_LINES:
-    raise errors.CommandError("'df' output has wrong number of lines: %s" %
-                              len(df_lines))
-  df_values = df_lines[1].strip().split()
-  if len(df_values) < DF_MIN_NUM_COLS:
-    raise errors.CommandError("'df' output does not have enough columns: %s" %
-                              len(df_values))
-  size_str = df_values[1]
-  if size_str[-1] != DF_M_UNIT:
-    raise errors.CommandError("'df': 'size' not given in Mebibytes.")
-  free_str = df_values[3]
-  if free_str[-1] != DF_M_UNIT:
-    raise errors.CommandError("'df': 'free' not given in Mebibytes.")
-  size = int(size_str[:-1])
-  free = int(free_str[:-1])
-  return (size, free)
+from ganeti import errors
 
 
-def GetSpaceInfo(path, _parsefn=_ParseDfResult):
+def GetSpaceInfo(path):
   """Retrieves the free and total space of the device where the file is
      located.
 
      @type path: string
      @param path: Path of the file whose embracing device's capacity is
        reported.
-     @type _parsefn: function
-     @param _parsefn: Function that parses the output of the 'df' command;
-       given as parameter to make this code more testable.
-     @return: a dictionary containing 'vg_size' and 'vg_free'
+     @return: a dictionary containing 'vg_size' and 'vg_free' given in MebiBytes
+
   """
-  cmd = ['df', '-BM', path]
-  result = utils.RunCmd(cmd)
-  if result.failed:
-    raise errors.CommandError("Failed to run 'df' command: %s - %s" %
-                              (result.fail_reason, result.output))
-  (size, free) = _parsefn(result.stdout)
-  return {"vg_size": size, "vg_free": free}
+  try:
+    result = os.statvfs(path)
+    free = (result.f_frsize * result.f_bavail) / (1024 * 1024)
+    size = (result.f_frsize * result.f_blocks) / (1024 * 1024)
+    return {"vg_size": size, "vg_free": free}
+  except OSError, e:
+    raise errors.CommandError("Failed to retrieve file system information about"
+                              " path: %s - %s" % (path, e.strerror))