Support mounting freebsd ufs filesystems
[snf-image-creator] / image_creator / disk.py
index 2191df3..b4311f8 100644 (file)
 # or implied, of GRNET S.A.
 
 from image_creator.util import get_command
+from image_creator.util import try_fail_repeat
+from image_creator.util import free_space
 from image_creator.util import FatalError
-from image_creator.gpt import GPTPartitionTable
+from image_creator.bundle_volume import BundleVolume
+from image_creator.image import Image
+
 import stat
 import os
 import tempfile
 import uuid
-import re
-import sys
-import guestfs
-import time
-from sendfile import sendfile
-
+import shutil
 
 dd = get_command('dd')
 dmsetup = get_command('dmsetup')
@@ -51,6 +50,9 @@ losetup = get_command('losetup')
 blockdev = get_command('blockdev')
 
 
+TMP_CANDIDATES = ['/var/tmp', os.path.expanduser('~'), '/mnt']
+
+
 class Disk(object):
     """This class represents a hard disk hosting an Operating System
 
@@ -59,378 +61,137 @@ class Disk(object):
     the Linux kernel.
     """
 
-    def __init__(self, source, output):
+    def __init__(self, source, output, tmp=None):
         """Create a new Disk instance out of a source media. The source
-        media can be an image file, a block device or a directory."""
+        media can be an image file, a block device or a directory.
+        """
         self._cleanup_jobs = []
-        self._devices = []
+        self._images = []
         self.source = source
         self.out = output
+        self.meta = {}
+        self.tmp = tempfile.mkdtemp(prefix='.snf_image_creator.',
+                                    dir=self._get_tmp_dir(tmp))
+
+        self._add_cleanup(shutil.rmtree, self.tmp)
+
+    def _get_tmp_dir(self, default=None):
+        """Check tmp directory candidates and return the one with the most
+        available space.
+        """
+        if default is not None:
+            return default
+
+        space = map(free_space, TMP_CANDIDATES)
+
+        max_idx = 0
+        max_val = space[0]
+        for i, val in zip(range(len(space)), space):
+            if val > max_val:
+                max_val = val
+                max_idx = i
+
+        # Return the candidate path with more available space
+        return TMP_CANDIDATES[max_idx]
 
     def _add_cleanup(self, job, *args):
+        """Add a new job in the cleanup list"""
         self._cleanup_jobs.append((job, args))
 
     def _losetup(self, fname):
+        """Setup a loop device and add it to the cleanup list. The loop device
+        will be detached when cleanup is called.
+        """
         loop = losetup('-f', '--show', fname)
         loop = loop.strip()  # remove the new-line char
-        self._add_cleanup(losetup, '-d', loop)
+        self._add_cleanup(try_fail_repeat, losetup, '-d', loop)
         return loop
 
     def _dir_to_disk(self):
-        raise FatalError("Using a directory as media source is not supported "
-                         "yet!")
+        """Create a disk out of a directory"""
+        if self.source == '/':
+            bundle = BundleVolume(self.out, self.meta)
+            image = '%s/%s.diskdump' % (self.tmp, uuid.uuid4().hex)
+
+            def check_unlink(path):
+                if os.path.exists(path):
+                    os.unlink(path)
+
+            self._add_cleanup(check_unlink, image)
+            bundle.create_image(image)
+            return self._losetup(image)
+        raise FatalError("Using a directory as media source is supported")
 
     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._images):
+                image = self._images.pop()
+                image.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
         instance.
         """
 
-        self.out.output("Examining source media `%s'..." % self.source, False)
+        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._losetup(self._dir_to_disk())
+            return self._dir_to_disk()
         elif stat.S_ISREG(mode):
             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.")
+            raise FatalError("Invalid media source. Only block devices, "
+                             "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)
-        cowfd, cow = tempfile.mkstemp()
+        size = blockdev('--getsz', sourcedev)
+        cowfd, cow = tempfile.mkstemp(dir=self.tmp)
         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,
-            # although everything is cleaned up and the snapshot is not
-            # used by anyone. Add a 2 seconds delay to be on the safe side.
-            self._add_cleanup(time.sleep, 2)
+            self._add_cleanup(try_fail_repeat, dmsetup, 'remove', snapshot)
 
         finally:
             os.unlink(table)
         self.out.success('done')
         return "/dev/mapper/%s" % snapshot
 
-    def get_device(self, media):
-        """Returns a newly created DiskDevice instance."""
+    def get_image(self, media):
+        """Returns a newly created Image instance."""
 
-        new_device = DiskDevice(media, self.out)
-        self._devices.append(new_device)
-        new_device.enable()
-        return new_device
+        image = Image(media, self.out)
+        self._images.append(image)
+        image.enable()
+        return image
 
-    def destroy_device(self, device):
-        """Destroys a DiskDevice instance previously created by
-        get_device method.
+    def destroy_image(self, image):
+        """Destroys an Image instance previously created by get_image method.
         """
-        self._devices.remove(device)
-        device.destroy()
-
-
-class DiskDevice(object):
-    """This class represents a block device hosting an Operating System
-    as created by the device-mapper.
-    """
-
-    def __init__(self, device, output, bootable=True):
-        """Create a new DiskDevice."""
-
-        self.real_device = device
-        self.out = output
-        self.bootable = bootable
-        self.progress_bar = None
-        self.guestfs_device = None
-        self.meta = {}
-
-        self.g = guestfs.GuestFS()
-        self.g.add_drive_opts(self.real_device, readonly=0)
-
-        # Before version 1.17.14 the recovery process, which is a fork of the
-        # original process that called libguestfs, did not close its inherited
-        # file descriptors. This can cause problems especially if the parent
-        # process has opened pipes. Since the recovery process is an optional
-        # 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))):
-            self.g.set_recovery_proc(1)
-            self.out.output("Enabling recovery proc")
-
-        #self.g.set_trace(1)
-        #self.g.set_verbose(1)
-
-        self.guestfs_enabled = False
-
-    def enable(self):
-        """Enable a newly created DiskDevice"""
-        self.progressbar = self.out.Progress(100, "Launching helper VM",
-                                             "percent")
-        eh = self.g.set_event_callback(self.progress_callback,
-                                                    guestfs.EVENT_PROGRESS)
-        self.g.launch()
-        self.guestfs_enabled = True
-        self.g.delete_event_callback(eh)
-        self.progressbar.success('done')
-        self.progressbar = None
-
-        self.out.output('Inspecting Operating System...', False)
-        roots = self.g.inspect_os()
-        if len(roots) == 0:
-            raise FatalError("No operating system found")
-        if len(roots) > 1:
-            raise FatalError("Multiple operating systems found."
-                            "We only support images with one filesystem.")
-        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.meta['PARTITION_TABLE'] = \
-                                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)
-        self.out.success('found a(n) %s system' % self.distro)
-
-    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()
-
-    def progress_callback(self, ev, eh, buf, array):
-        position = array[2]
-        total = array[3]
-
-        self.progressbar.goto((position * 100) // total)
-
-    def mount(self, readonly=False):
-        """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)
-        mps = self.g.inspect_get_mountpoints(self.root)
-
-        # Sort the keys to mount the fs in a correct order.
-        # / should be mounted befor /boot, etc
-        def compare(a, b):
-            if len(a[0]) > len(b[0]):
-                return 1
-            elif len(a[0]) == len(b[0]):
-                return 0
-            else:
-                return -1
-        mps.sort(compare)
-        for mp, dev in mps:
-            try:
-                mount(dev, mp)
-            except RuntimeError as msg:
-                self.out.warn("%s (ignored)" % msg)
-        self.out.success("done")
-
-    def umount(self):
-        """Umount all mounted filesystems."""
-        self.g.umount_all()
-
-    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']
-            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
-
-        partitions = self.g.part_list(self.guestfs_device)
-        last_partition = partitions[-1]
-
-        if is_logical(last_partition):
-            # The disk contains extended and logical partitions....
-            extended = [p for p in partitions if is_extended(p)][0]
-            last_primary = [p for p in partitions if p['part_num'] <= 4][-1]
-
-            # check if extended is the last primary partition
-            if last_primary['part_num'] > extended['part_num']:
-                last_partition = last_primary
-
-        return last_partition
-
-    def shrink(self):
-        """Shrink the disk.
-
-        This is accomplished by shrinking the last filesystem in the
-        disk and then updating the partition table. The new disk size
-        (in bytes) is returned.
-
-        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
-
-        part_add = lambda 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)
-
-        MB = 2 ** 20
-
-        self.out.output("Shrinking image (this may take a while)...", False)
-
-        last_part = None
-        fstype = None
-        while True:
-            last_part = self._last_partition()
-            fstype = get_fstype(last_part)
-
-            if fstype == 'swap':
-                self.meta['SWAP'] = "%d:%s" % \
-                        (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
-            break
-
-        if not re.match("ext[234]", fstype):
-            self.out.warn("Don't know how to resize %s partitions." % fstype)
-            return self.meta['SIZE']
-
-        part_dev = "%s%d" % (self.guestfs_device, last_part['part_num'])
-        self.g.e2fsck_f(part_dev)
-        self.g.resize2fs_M(part_dev)
-
-        out = self.g.tune2fs_l(part_dev)
-        block_size = int(
-            filter(lambda x: x[0] == 'Block size', out)[0][1])
-        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
-
-        if is_logical(last_part):
-            partitions = self.g.part_list(self.guestfs_device)
-
-            logical = []  # logical partitions
-            for partition in partitions:
-                if partition['part_num'] < 4:
-                    continue
-                logical.append({
-                    'num': partition['part_num'],
-                    'start': partition['part_start'] / sector_size,
-                    'end': partition['part_end'] / sector_size,
-                    'id': part_get_(partition['part_num']),
-                    'bootable': part_get_bootable(partition['part_num'])
-                })
-
-            logical[-1]['end'] = end  # new end after resize
-
-            # 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)
-
-            # Create all the logical partitions back
-            for l in logical:
-                part_add('l', l['start'], l['end'])
-                part_set_id(l['num'], l['id'])
-                part_set_bootable(l['num'], l['bootable'])
-        else:
-            # Recreate the last partition
-            if self.meta['PARTITION_TABLE'] == 'msdos':
-                last_part['id'] = part_get_id(last_part['part_num'])
-
-            last_part['bootable'] = part_get_bootable(last_part['part_num'])
-            part_del(last_part['part_num'])
-            part_add('p', start, end)
-            part_set_bootable(last_part['part_num'], last_part['bootable'])
-
-            if self.meta['PARTITION_TABLE'] == 'msdos':
-                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))
-
-        if self.meta['PARTITION_TABLE'] == 'gpt':
-            ptable = GPTPartitionTable(self.real_device)
-            self.meta['SIZE'] = ptable.shrink(new_size)
-        else:
-            self.meta['SIZE'] = new_size
-
-        return self.meta['SIZE']
-
-    def dump(self, outfile):
-        """Dumps the content of device into a file.
-
-        This method will only dump the actual payload, found by reading the
-        partition table. Empty space in the end of the device will be ignored.
-        """
-        MB = 2 ** 20
-        blocksize = 4 * MB  # 4MB
-        size = self.meta['SIZE']
-        progr_size = (size + MB - 1) // MB  # in MB
-        progressbar = self.out.Progress(progr_size, "Dumping image file", 'mb')
-
-        with open(self.real_device, 'r') as src:
-            with open(outfile, "w") as dst:
-                left = size
-                offset = 0
-                progressbar.next()
-                while left > 0:
-                    length = min(left, blocksize)
-                    sent = sendfile(dst.fileno(), src.fileno(), offset, length)
-                    offset += sent
-                    left -= sent
-                    progressbar.goto((size - left) // MB)
-        progressbar.success('image file %s was successfully created' % outfile)
+        self._images.remove(image)
+        image.destroy()
 
 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :