Fix a bug in image shrinking code
[snf-image-creator] / image_creator / disk.py
index a283d7a..8582428 100644 (file)
@@ -84,13 +84,16 @@ class Disk(object):
         """Cleanup internal data. This needs to be called before the
         program ends.
         """
-        while len(self._devices):
-            device = self._devices.pop()
-            device.destroy()
-
-        while len(self._cleanup_jobs):
-            job, args = self._cleanup_jobs.pop()
-            job(*args)
+        try:
+            while len(self._devices):
+                device = self._devices.pop()
+                device.destroy()
+        finally:
+            # Make sure those are executed even if one of the device.destroy
+            # methods throws exeptions.
+            while len(self._cleanup_jobs):
+                job, args = self._cleanup_jobs.pop()
+                job(*args)
 
     def snapshot(self):
         """Creates a snapshot of the original source media of the Disk
@@ -114,12 +117,12 @@ class Disk(object):
 
         # Take a snapshot and return it to the user
         self.out.output("Snapshotting media source...", False)
-        size = blockdev('--getsize', sourcedev)
+        size = blockdev('--getsz', sourcedev)
         cowfd, cow = tempfile.mkstemp()
         os.close(cowfd)
         self._add_cleanup(os.unlink, cow)
-        # Create 1G cow sparse file
-        dd('if=/dev/null', 'of=%s' % cow, 'bs=1k', 'seek=%d' % (1024 * 1024))
+        # Create cow sparse file
+        dd('if=/dev/null', 'of=%s' % cow, 'bs=512', 'seek=%d' % int(size))
         cowdev = self._losetup(cow)
 
         snapshot = uuid.uuid4().hex
@@ -168,6 +171,7 @@ class DiskDevice(object):
         self.bootable = bootable
         self.progress_bar = None
         self.guestfs_device = None
+        self.size = 0
         self.meta = {}
 
         self.g = guestfs.GuestFS()
@@ -213,7 +217,7 @@ class DiskDevice(object):
                              "We only support images with one OS.")
         self.root = roots[0]
         self.guestfs_device = self.g.part_to_dev(self.root)
-        self.meta['SIZE'] = self.g.blockdev_getsize64(self.guestfs_device)
+        self.size = self.g.blockdev_getsize64(self.guestfs_device)
         self.meta['PARTITION_TABLE'] = \
             self.g.part_get_parttype(self.guestfs_device)
 
@@ -224,12 +228,14 @@ class DiskDevice(object):
     def destroy(self):
         """Destroy this DiskDevice instance."""
 
-        if self.guestfs_enabled:
-            self.g.umount_all()
-            self.g.sync()
-
-        # Close the guestfs handler if open
-        self.g.close()
+        # In new guestfs versions, there is a handy shutdown method for this
+        try:
+            if self.guestfs_enabled:
+                self.g.umount_all()
+                self.g.sync()
+        finally:
+            # Close the guestfs handler if open
+            self.g.close()
 
     def progress_callback(self, ev, eh, buf, array):
         position = array[2]
@@ -241,7 +247,8 @@ class DiskDevice(object):
         """Mount all disk partitions in a correct order."""
 
         mount = self.g.mount_ro if readonly else self.g.mount
-        self.out.output("Mounting image...", False)
+        msg = " read-only" if readonly else ""
+        self.out.output("Mounting the media%s..." % msg, False)
         mps = self.g.inspect_get_mountpoints(self.root)
 
         # Sort the keys to mount the fs in a correct order.
@@ -343,12 +350,12 @@ class DiskDevice(object):
             # Most disk manipulation programs leave 2048 sectors after the last
             # partition
             new_size = last_part['part_end'] + 1 + 2048 * sector_size
-            self.meta['SIZE'] = min(self.meta['SIZE'], new_size)
+            self.size = min(self.size, new_size)
             break
 
         if not re.match("ext[234]", fstype):
             self.out.warn("Don't know how to resize %s partitions." % fstype)
-            return self.meta['SIZE']
+            return self.size
 
         part_dev = "%s%d" % (self.guestfs_device, last_part['part_num'])
         self.g.e2fsck_f(part_dev)
@@ -374,7 +381,7 @@ class DiskDevice(object):
                     'num': partition['part_num'],
                     'start': partition['part_start'] / sector_size,
                     'end': partition['part_end'] / sector_size,
-                    'id': part_get_(partition['part_num']),
+                    'id': part_get_id(partition['part_num']),
                     'bootable': part_get_bootable(partition['part_num'])
                 })
 
@@ -383,7 +390,7 @@ class DiskDevice(object):
             # Recreate the extended partition
             extended = [p for p in partitions if self._is_extended(p)][0]
             part_del(extended['part_num'])
-            part_add('e', extended['part_start'], end)
+            part_add('e', extended['part_start'] / sector_size, end)
 
             # Create all the logical partitions back
             for l in logical:
@@ -405,19 +412,17 @@ class DiskDevice(object):
 
         new_size = (end + 1) * sector_size
 
-        assert (new_size <= self.meta['SIZE'])
+        assert (new_size <= self.size)
 
         if self.meta['PARTITION_TABLE'] == 'gpt':
             ptable = GPTPartitionTable(self.real_device)
-            self.meta['SIZE'] = ptable.shrink(new_size, self.meta['SIZE'])
+            self.size = ptable.shrink(new_size, self.size)
         else:
-            self.meta['SIZE'] = min(new_size + 2048 * sector_size,
-                                    self.meta['SIZE'])
+            self.size = min(new_size + 2048 * sector_size, self.size)
 
-        self.out.success("new size is %dMB" %
-                         ((self.meta['SIZE'] + MB - 1) // MB))
+        self.out.success("new size is %dMB" % ((self.size + MB - 1) // MB))
 
-        return self.meta['SIZE']
+        return self.size
 
     def dump(self, outfile):
         """Dumps the content of device into a file.
@@ -427,7 +432,7 @@ class DiskDevice(object):
         """
         MB = 2 ** 20
         blocksize = 4 * MB  # 4MB
-        size = self.meta['SIZE']
+        size = self.size
         progr_size = (size + MB - 1) // MB  # in MB
         progressbar = self.out.Progress(progr_size, "Dumping image file", 'mb')
 
@@ -438,7 +443,8 @@ class DiskDevice(object):
                 progressbar.next()
                 while left > 0:
                     length = min(left, blocksize)
-                    sent = sendfile(dst.fileno(), src.fileno(), offset, length)
+                    _, sent = sendfile(dst.fileno(), src.fileno(), offset,
+                        length)
                     offset += sent
                     left -= sent
                     progressbar.goto((size - left) // MB)