From fcc4df5db9ffea1ed6e8697e64d16a10eb722c4a Mon Sep 17 00:00:00 2001
From: Nikos Skalkotos <skalkoto@grnet.gr>
Date: Mon, 9 Jun 2014 18:14:16 +0300
Subject: [PATCH] Add device attribute in Disk class
This attribute hosts the block device associated with this Disk
instance. This can be the original media if the source media is a block
device, a loop device of the original media if the original media is a
regular file or a loop device of a temporary object if the original
media is a directory.
---
image_creator/dialog_main.py | 7 +++++--
image_creator/disk.py | 28 ++++++++++++++++++----------
image_creator/main.py | 11 ++++++-----
3 files changed, 29 insertions(+), 17 deletions(-)
diff --git a/image_creator/dialog_main.py b/image_creator/dialog_main.py
index 88c295a..b5e2164 100644
--- a/image_creator/dialog_main.py
+++ b/image_creator/dialog_main.py
@@ -61,8 +61,11 @@ def create_image(d, media, out, tmp):
signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGTERM, signal_handler)
try:
- snapshot = disk.snapshot()
- image = disk.get_image(snapshot)
+ # There is no need to snapshot the media if it was created by the Disk
+ # instance as a temporary object.
+ device = disk.device if disk.source == '/' else disk.snapshot()
+
+ image = disk.get_image(device)
out.output("Collecting image metadata ...")
metadata = {}
diff --git a/image_creator/disk.py b/image_creator/disk.py
index 2dcbac3..d2212c2 100644
--- a/image_creator/disk.py
+++ b/image_creator/disk.py
@@ -72,6 +72,7 @@ class Disk(object):
"""
self._cleanup_jobs = []
self._images = []
+ self._device = None
self.source = source
self.out = output
self.meta = {}
@@ -123,29 +124,36 @@ class Disk(object):
job, args = self._cleanup_jobs.pop()
job(*args)
- def snapshot(self):
- """Creates a snapshot of the original source media of the Disk
- instance.
- """
+ @property
+ def device(self):
+ """Convert the source media into a block device"""
+
+ if self._device is not None:
+ return self._device
self.out.output("Examining source media `%s' ..." % self.source, False)
- sourcedev = self.source
mode = os.stat(self.source).st_mode
if stat.S_ISDIR(mode):
self.out.success('looks like a directory')
- return self._dir_to_disk()
+ self._device = self._dir_to_disk()
elif stat.S_ISREG(mode):
self.out.success('looks like an image file')
- sourcedev = self._losetup(self.source)
+ self._device = self._losetup(self.source)
elif not stat.S_ISBLK(mode):
raise FatalError("Invalid media source. Only block devices, "
"regular files and directories are supported.")
else:
self.out.success('looks like a block device')
+ self._device = self.source
- # Take a snapshot and return it to the user
+ return self._device
+
+ def snapshot(self):
+ """Creates a snapshot of the original source media of the Disk
+ instance.
+ """
self.out.output("Snapshotting media source ...", False)
- size = blockdev('--getsz', sourcedev)
+ size = blockdev('--getsz', self.device)
cowfd, cow = tempfile.mkstemp(dir=self.tmp)
os.close(cowfd)
self._add_cleanup(os.unlink, cow)
@@ -158,7 +166,7 @@ class Disk(object):
try:
try:
os.write(tablefd, "0 %d snapshot %s %s n 8" %
- (int(size), sourcedev, cowdev))
+ (int(size), self.device, cowdev))
finally:
os.close(tablefd)
diff --git a/image_creator/main.py b/image_creator/main.py
index 7b3b5c3..3532cbc 100644
--- a/image_creator/main.py
+++ b/image_creator/main.py
@@ -257,9 +257,10 @@ def image_creator():
signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGTERM, signal_handler)
try:
- snapshot = disk.snapshot()
-
- image = disk.get_image(snapshot, sysprep_params=options.sysprep_params)
+ # There is no need to snapshot the media if it was created by the Disk
+ # instance as a temporary object.
+ device = disk.device if disk.source == '/' else disk.snapshot()
+ image = disk.get_image(device, sysprep_params=options.sysprep_params)
if image.is_unsupported() and not options.allow_unsupported:
raise FatalError(
@@ -323,7 +324,7 @@ def image_creator():
os.path.basename(options.outfile)))
out.success('done')
- # Destroy the image instance. We only need the snapshot from now on
+ # Destroy the image instance. We only need the disk device from now on
disk.destroy_image(image)
out.output()
@@ -331,7 +332,7 @@ def image_creator():
uploaded_obj = ""
if options.upload:
out.output("Uploading image to the storage service:")
- with open(snapshot, 'rb') as f:
+ with open(device, 'rb') as f:
uploaded_obj = kamaki.upload(
f, size, options.upload,
"(1/3) Calculating block hashes",
--
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