From da63bb4e15cfbbc06b8b19df56d714f8f04f94f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Nussbaumer?= <rn@google.com>
Date: Mon, 25 Oct 2010 16:30:34 +0200
Subject: [PATCH] Second iteration over backend.BlockdevWipe
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This patch now uses dd entirely to wipe the disk, make it
much easier to wipe in blocks so we can give interactive feedback
about the status.
Signed-off-by: RenΓ© Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>
---
lib/backend.py | 30 ++++++++++++++++++++++++------
lib/constants.py | 3 ++-
2 files changed, 26 insertions(+), 7 deletions(-)
diff --git a/lib/backend.py b/lib/backend.py
index 8abe5a676..3df63960c 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -1287,32 +1287,50 @@ def BlockdevCreate(disk, size, owner, on_primary, info):
return device.unique_id
-def _WipeDevice(path):
+def _WipeDevice(path, offset, size):
"""This function actually wipes the device.
@param path: The path to the device to wipe
+ @param offset: The offset in MiB in the file
+ @param size: The size in MiB to write
"""
- result = utils.RunCmd("%s%s" % (constants.WIPE_CMD, utils.ShellQuote(path)))
+ cmd = [constants.DD_CMD, "if=/dev/zero", "seek=%d" % offset,
+ "bs=%d" % constants.WIPE_BLOCK_SIZE, "oflag=direct", "of=%s" % path,
+ "count=%d" % size]
+ result = utils.RunCmd(cmd)
if result.failed:
_Fail("Wipe command '%s' exited with error: %s; output: %s", result.cmd,
result.fail_reason, result.output)
-def BlockdevWipe(disk):
+def BlockdevWipe(disk, offset, size):
"""Wipes a block device.
@type disk: L{objects.Disk}
@param disk: the disk object we want to wipe
+ @type offset: int
+ @param offset: The offset in MiB in the file
+ @type size: int
+ @param size: The size in MiB to write
"""
try:
rdev = _RecursiveFindBD(disk)
- except errors.BlockDeviceError, err:
- _Fail("Cannot execute wipe for device %s: device not found", err)
+ except errors.BlockDeviceError:
+ rdev = None
+
+ if not rdev:
+ _Fail("Cannot execute wipe for device %s: device not found", disk.iv_name)
+
+ # Do cross verify some of the parameters
+ if offset > rdev.size:
+ _Fail("Offset is bigger than device size")
+ if (offset + size) > rdev.size:
+ _Fail("The provided offset and size to wipe is bigger than device size")
- _WipeDevice(rdev.dev_path)
+ _WipeDevice(rdev.dev_path, offset, size)
def BlockdevRemove(disk):
diff --git a/lib/constants.py b/lib/constants.py
index b66b6eb4d..b4e9a37ff 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -96,7 +96,8 @@ CONFD_GROUP = _autoconf.CONFD_GROUP
NODED_USER = _autoconf.NODED_USER
# Wipe
-WIPE_CMD = _autoconf.WIPE_CMD
+DD_CMD = "dd"
+WIPE_BLOCK_SIZE = 1024**2
# file paths
DATA_DIR = _autoconf.LOCALSTATEDIR + "/lib/ganeti"
--
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