Master format free space

blivet/blivet.py

@@ -1352,7 +1352,7 @@ def fileSystemFreeSpace(self):
             if device.format.exists:
                 free += device.format.free
             else:
-                free += device.size
+                free += device.format.freeSpaceEstimate(device.size)
 
         return free
 

blivet/formats/fs.py

@@ -72,6 +72,11 @@ class FS(DeviceFormat):
     _sizeinfoClass = fssize.UnimplementedFSSize
     _syncClass = fssync.UnimplementedFSSync
     _writelabelClass = fswritelabel.UnimplementedFSWriteLabel
+    # This constant is aquired by testing some filesystems
+    # and it's giving us percentage of space left after the format.
+    # This number is more guess then precise number because this
+    # value is already unpredictable and can change in the future...
+    _MetadataSizeFactor = 1.0
 
     def __init__(self, **kwargs):
         """
@@ -168,6 +173,18 @@ def dict(self):
                   "mountable": self.mountable})
         return d
 
+    @classmethod
+    def freeSpaceEstimate(cls, device_size):
+        """ Get estimated free space when format will be done on device
+            with size ``device_size``.
+            This is more guess then precise number.
+
+            :param device_size: original device size
+            :type device_size: ``Size`` object
+            :return: estimated free size after format
+        """
+        return device_size * cls._MetadataSizeFactor
+
     def labeling(self):
         """Returns True if this filesystem uses labels, otherwise False.
 
@@ -337,7 +354,6 @@ def free(self):
         """
         return max(Size(0), self.currentSize - self.minSize)
 
-
     def _preCreate(self, **kwargs):
         super(FS, self)._preCreate(**kwargs)
         if not self._mkfs.available:
@@ -807,6 +823,7 @@ class Ext2FS(FS):
     _sizeinfoClass = fssize.Ext2FSSize
     _writelabelClass = fswritelabel.Ext2FSWriteLabel
     partedSystem = fileSystemType["ext2"]
+    _MetadataSizeFactor = 0.93 # ext2 metadata may take 7% of space
 
 register_device_format(Ext2FS)
 
@@ -823,6 +840,7 @@ class Ext3FS(Ext2FS):
     # with regard to this maximum filesystem size, but if they're doing such
     # things they should know the implications of their chosen block size.
     _maxSize = Size("16 TiB")
+    _MetadataSizeFactor = 0.90 # ext3 metadata may take 10% of space
 
 register_device_format(Ext3FS)
 
@@ -834,6 +852,7 @@ class Ext4FS(Ext3FS):
     _mkfsClass = fsmkfs.Ext4FSMkfs
     partedSystem = fileSystemType["ext4"]
     _maxSize = Size("1 EiB")
+    _MetadataSizeFactor = 0.85 # ext4 metadata may take 15% of space
 
 register_device_format(Ext4FS)
 
@@ -852,6 +871,7 @@ class FATFS(FS):
     _mountClass = fsmount.FATFSMount
     _readlabelClass = fsreadlabel.DosFSReadLabel
     _writelabelClass = fswritelabel.DosFSWriteLabel
+    _MetadataSizeFactor = 0.99 # fat metadata may take 1% of space
     # FIXME this should be fat32 in some cases
     partedSystem = fileSystemType["fat16"]
 
@@ -883,6 +903,7 @@ class BTRFS(FS):
     _minSize = Size("256 MiB")
     _maxSize = Size("16 EiB")
     _mkfsClass = fsmkfs.BTRFSMkfs
+    _MetadataSizeFactor = 0.80 # btrf metadata may take 20% of space
     # FIXME parted needs to be taught about btrfs so that we can set the
     # partition table type correctly for btrfs partitions
     # partedSystem = fileSystemType["btrfs"]
@@ -946,6 +967,7 @@ class JFS(FS):
     _mkfsClass = fsmkfs.JFSMkfs
     _sizeinfoClass = fssize.JFSSize
     _writelabelClass = fswritelabel.JFSWriteLabel
+    _MetadataSizeFactor = 0.99 # jfs metadata may take 1% of space
     partedSystem = fileSystemType["jfs"]
 
     @property
@@ -971,6 +993,7 @@ class ReiserFS(FS):
     _mkfsClass = fsmkfs.ReiserFSMkfs
     _sizeinfoClass = fssize.ReiserFSSize
     _writelabelClass = fswritelabel.ReiserFSWriteLabel
+    _MetadataSizeFactor = 0.98 # reiserfs metadata may take 2% of space
     partedSystem = fileSystemType["reiserfs"]
 
     @property
@@ -997,6 +1020,7 @@ class XFS(FS):
     _sizeinfoClass = fssize.XFSSize
     _syncClass = fssync.XFSSync
     _writelabelClass = fswritelabel.XFSWriteLabel
+    _MetadataSizeFactor = 0.97 # xfs metadata may take 3% of space
     partedSystem = fileSystemType["xfs"]
 
 

blivet/size.py

@@ -303,16 +303,25 @@ def __reduce__(self):
         return (self.__class__, (self.convertTo(),))
 
     def __add__(self, other, context=None):
+        # because float is not automatically converted to Decimal type
+        if isinstance(other, float):
+            other = Decimal(other)
         return Size(Decimal.__add__(self, other))
 
     # needed to make sum() work with Size arguments
     def __radd__(self, other, context=None):
+        if isinstance(other, float):
+            other = Decimal(other)
         return Size(Decimal.__radd__(self, other))
 
     def __sub__(self, other, context=None):
+        if isinstance(other, float):
+            other = Decimal(other)
         return Size(Decimal.__sub__(self, other))
 
     def __mul__(self, other, context=None):
+        if isinstance(other, float):
+            other = Decimal(other)
         return Size(Decimal.__mul__(self, other))
     __rmul__ = __mul__