Add "Running System" button in media selection
[snf-image-creator] / image_creator / disk.py
index 6cd910b..40e1316 100644 (file)
@@ -45,9 +45,6 @@ import time
 from sendfile import sendfile
 
 
-class DiskError(Exception):
-    pass
-
 dd = get_command('dd')
 dmsetup = get_command('dmsetup')
 losetup = get_command('losetup')
@@ -80,19 +77,23 @@ class Disk(object):
         return loop
 
     def _dir_to_disk(self):
-        raise NotImplementedError
+        raise FatalError("Using a directory as media source is not supported "
+                         "yet!")
 
     def cleanup(self):
         """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
@@ -103,32 +104,32 @@ class Disk(object):
         sourcedev = self.source
         mode = os.stat(self.source).st_mode
         if stat.S_ISDIR(mode):
-            success('looks like a directory')
+            self.out.success('looks like a directory')
             return self._losetup(self._dir_to_disk())
         elif stat.S_ISREG(mode):
-            success('looks like an image file')
+            self.out.success('looks like an image file')
             sourcedev = self._losetup(self.source)
         elif not stat.S_ISBLK(mode):
             raise ValueError("Invalid media source. Only block devices, "
-                            "regular files and directories are supported.")
+                             "regular files and directories are supported.")
         else:
             self.out.success('looks like a block device')
 
         # 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
         tablefd, table = tempfile.mkstemp()
         try:
-            os.write(tablefd, "0 %d snapshot %s %s n 8" % \
-                                        (int(size), sourcedev, cowdev))
+            os.write(tablefd, "0 %d snapshot %s %s n 8" %
+                              (int(size), sourcedev, cowdev))
             dmsetup('create', snapshot, table)
             self._add_cleanup(dmsetup, 'remove', snapshot)
             # Sometimes dmsetup remove fails with Device or resource busy,
@@ -170,6 +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()
@@ -182,9 +184,10 @@ class DiskDevice(object):
         # feature of libguestfs, it's better to disable it.
         self.g.set_recovery_proc(0)
         version = self.g.version()
-        if version['major'] > 1 or (version['major'] == 1 and
-            (version['minor'] >= 18 or \
-            (version['minor'] == 17 and version['release'] >= 14))):
+        if version['major'] > 1 or \
+            (version['major'] == 1 and (version['minor'] >= 18 or
+                                        (version['minor'] == 17 and
+                                         version['release'] >= 14))):
             self.g.set_recovery_proc(1)
             self.out.output("Enabling recovery proc")
 
@@ -198,7 +201,7 @@ class DiskDevice(object):
         self.progressbar = self.out.Progress(100, "Launching helper VM",
                                              "percent")
         eh = self.g.set_event_callback(self.progress_callback,
-                                                    guestfs.EVENT_PROGRESS)
+                                       guestfs.EVENT_PROGRESS)
         self.g.launch()
         self.guestfs_enabled = True
         self.g.delete_event_callback(eh)
@@ -211,12 +214,12 @@ class DiskDevice(object):
             raise FatalError("No operating system found")
         if len(roots) > 1:
             raise FatalError("Multiple operating systems found."
-                            "We only support images with one filesystem.")
+                             "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)
+            self.g.part_get_parttype(self.guestfs_device)
 
         self.ostype = self.g.inspect_get_type(self.root)
         self.distro = self.g.inspect_get_distro(self.root)
@@ -225,12 +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]
@@ -242,7 +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.
@@ -269,13 +275,13 @@ class DiskDevice(object):
     def _last_partition(self):
         if self.meta['PARTITION_TABLE'] not in 'msdos' 'gpt':
             msg = "Unsupported partition table: %s. Only msdos and gpt " \
-            "partition tables are supported" % self.meta['PARTITION_TABLE']
+                "partition tables are supported" % self.meta['PARTITION_TABLE']
             raise FatalError(msg)
 
-        is_extended = lambda p: self.g.part_get_mbr_id(
-                                    self.guestfs_device, p['part_num']) == 5
-        is_logical = lambda p: self.meta['PARTITION_TABLE'] != 'msdos' and \
-                                                            p['part_num'] > 4
+        is_extended = lambda p: \
+            self.g.part_get_mbr_id(self.guestfs_device, p['part_num']) == 5
+        is_logical = lambda p: \
+            self.meta['PARTITION_TABLE'] != 'msdos' and p['part_num'] > 4
 
         partitions = self.g.part_list(self.guestfs_device)
         last_partition = partitions[-1]
@@ -300,28 +306,31 @@ class DiskDevice(object):
 
         ATTENTION: make sure unmount is called before shrink
         """
-        get_fstype = lambda p: self.g.vfs_type("%s%d" % \
-                                        (self.guestfs_device, p['part_num']))
-        is_logical = lambda p: self.meta['PARTITION_TABLE'] == 'msdos' and \
-                                                            p['part_num'] > 4
-        is_extended = lambda p: self.meta['PARTITION_TABLE'] == 'msdos' and \
-                self.g.part_get_mbr_id(self.guestfs_device, p['part_num']) == 5
+        get_fstype = lambda p: \
+            self.g.vfs_type("%s%d" % (self.guestfs_device, p['part_num']))
+        is_logical = lambda p: \
+            self.meta['PARTITION_TABLE'] == 'msdos' and p['part_num'] > 4
+        is_extended = lambda p: \
+            self.meta['PARTITION_TABLE'] == 'msdos' and \
+            self.g.part_get_mbr_id(self.guestfs_device, p['part_num']) == 5
 
         part_add = lambda ptype, start, stop: \
-                    self.g.part_add(self.guestfs_device, ptype, start, stop)
+            self.g.part_add(self.guestfs_device, ptype, start, stop)
         part_del = lambda p: self.g.part_del(self.guestfs_device, p)
         part_get_id = lambda p: self.g.part_get_mbr_id(self.guestfs_device, p)
-        part_set_id = lambda p, id: self.g.part_set_mbr_id(
-                                                    self.guestfs_device, p, id)
-        part_get_bootable = lambda p: self.g.part_get_bootable(
-                                                        self.guestfs_device, p)
-        part_set_bootable = lambda p, bootable: self.g.part_set_bootable(
-                                            self.guestfs_device, p, bootable)
+        part_set_id = lambda p, id: \
+            self.g.part_set_mbr_id(self.guestfs_device, p, id)
+        part_get_bootable = lambda p: \
+            self.g.part_get_bootable(self.guestfs_device, p)
+        part_set_bootable = lambda p, bootable: \
+            self.g.part_set_bootable(self.guestfs_device, p, bootable)
 
         MB = 2 ** 20
 
         self.out.output("Shrinking image (this may take a while)...", False)
 
+        sector_size = self.g.blockdev_getss(self.guestfs_device)
+
         last_part = None
         fstype = None
         while True:
@@ -330,20 +339,23 @@ class DiskDevice(object):
 
             if fstype == 'swap':
                 self.meta['SWAP'] = "%d:%s" % \
-                        (last_part['part_num'],
-                        (last_part['part_size'] + MB - 1) // MB)
+                    (last_part['part_num'],
+                     (last_part['part_size'] + MB - 1) // MB)
                 part_del(last_part['part_num'])
                 continue
             elif is_extended(last_part):
                 part_del(last_part['part_num'])
                 continue
 
-            self.meta['SIZE'] = last_part['part_end'] + 1
+            # Most disk manipulation programs leave 2048 sectors after the last
+            # partition
+            new_size = last_part['part_end'] + 1 + 2048 * sector_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)
@@ -355,7 +367,6 @@ class DiskDevice(object):
         block_cnt = int(
             filter(lambda x: x[0] == 'Block count', out)[0][1])
 
-        sector_size = self.g.blockdev_getss(self.guestfs_device)
         start = last_part['part_start'] / sector_size
         end = start + (block_size * block_cnt) / sector_size - 1
 
@@ -400,15 +411,18 @@ class DiskDevice(object):
                 part_set_id(last_part['part_num'], last_part['id'])
 
         new_size = (end + 1) * sector_size
-        self.out.success("new size is %dMB" % ((new_size + MB - 1) // MB))
+
+        assert (new_size <= self.size)
 
         if self.meta['PARTITION_TABLE'] == 'gpt':
             ptable = GPTPartitionTable(self.real_device)
-            self.meta['SIZE'] = ptable.shrink(new_size)
+            self.size = ptable.shrink(new_size, self.size)
         else:
-            self.meta['SIZE'] = new_size
+            self.size = min(new_size + 2048 * sector_size, self.size)
+
+        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.
@@ -418,7 +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')
 
@@ -429,7 +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)