From 6f695a2e78afd18d1ee9146ec7e866cca35b1e2d Mon Sep 17 00:00:00 2001
From: Manuel Franceschini <manuel.franceschini@gmail.com>
Date: Sat, 5 Apr 2008 12:47:44 +0000
Subject: [PATCH] Add FileStorage class
This is the representation of file VBDs on the backend. It's the first
implementation an supports only raw files.
Reviewed-by: iustinp
---
lib/bdev.py | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 114 insertions(+)
diff --git a/lib/bdev.py b/lib/bdev.py
index 3d89aea08..8ba593022 100644
--- a/lib/bdev.py
+++ b/lib/bdev.py
@@ -25,6 +25,7 @@ import re
import time
import errno
import pyparsing as pyp
+import os
from ganeti import utils
from ganeti import logger
@@ -2175,11 +2176,124 @@ class DRBD8(BaseDRBD):
return cls(unique_id, children)
+class FileStorage(BlockDev):
+ """File device.
+
+ This class represents the a file storage backend device.
+
+ The unique_id for the file device is a (file_driver, file_path) tuple.
+
+ """
+ def __init__(self, unique_id, children):
+ """Initalizes a file device backend.
+
+ """
+ if children:
+ raise errors.BlockDeviceError("Invalid setup for file device")
+ super(FileStorage, self).__init__(unique_id, children)
+ if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
+ raise ValueError("Invalid configuration data %s" % str(unique_id))
+ self.driver = unique_id[0]
+ self.dev_path = unique_id[1]
+
+ def Assemble(self):
+ """Assemble the device.
+
+ Checks whether the file device exists, raises BlockDeviceError otherwise.
+
+ """
+ if not os.path.exists(self.dev_path):
+ raise errors.BlockDeviceError("File device '%s' does not exist." %
+ self.dev_path)
+ return True
+
+ def Shutdown(self):
+ """Shutdown the device.
+
+ This is a no-op for the file type, as we don't deacivate
+ the file on shutdown.
+
+ """
+ return True
+
+ def Open(self, force=False):
+ """Make the device ready for I/O.
+
+ This is a no-op for the file type.
+
+ """
+ pass
+
+ def Close(self):
+ """Notifies that the device will no longer be used for I/O.
+
+ This is a no-op for the file type.
+
+ """
+ pass
+
+ def Remove(self):
+ """Remove the file backing the block device.
+
+ Returns:
+ boolean indicating wheter removal of file was successful or not.
+
+ """
+ if not os.path.exists(self.dev_path):
+ return True
+ try:
+ os.remove(self.dev_path)
+ return True
+ except OSError, err:
+ logger.Error("Can't remove file '%s': %s"
+ % (self.dev_path, err))
+ return False
+
+ def Attach(self):
+ """Attach to an existing file.
+
+ Check if this file already exists.
+
+ Returns:
+ boolean indicating if file exists or not.
+
+ """
+ if os.path.exists(self.dev_path):
+ return True
+ return False
+
+ @classmethod
+ def Create(cls, unique_id, children, size):
+ """Create a new file.
+
+ Args:
+ children:
+ size: integer size of file in MiB
+
+ Returns:
+ A ganeti.bdev.FileStorage object.
+
+ """
+ if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
+ raise ValueError("Invalid configuration data %s" % str(unique_id))
+ dev_path = unique_id[1]
+ try:
+ f = open(dev_path, 'w')
+ except IOError, err:
+ raise BlockDeviceError("Could not create '%'" % err)
+ else:
+ f.truncate(size * 1024 * 1024)
+ f.close()
+
+ return FileStorage(unique_id, children)
+
+
DEV_MAP = {
constants.LD_LV: LogicalVolume,
constants.LD_MD_R1: MDRaid1,
constants.LD_DRBD7: DRBDev,
constants.LD_DRBD8: DRBD8,
+ constants.LD_FILE: FileStorage,
}
--
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