root / image_creator / disk.py @ 9297c398
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1 | d57775d4 | Nikos Skalkotos | #!/usr/bin/env python
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2 | d57775d4 | Nikos Skalkotos | |
3 | 3ccb2618 | Nikos Skalkotos | from image_creator.util import get_command |
4 | 3ccb2618 | Nikos Skalkotos | from clint.textui import progress |
5 | 3ccb2618 | Nikos Skalkotos | |
6 | d57775d4 | Nikos Skalkotos | import stat |
7 | d57775d4 | Nikos Skalkotos | import os |
8 | d57775d4 | Nikos Skalkotos | import tempfile |
9 | d57775d4 | Nikos Skalkotos | import uuid |
10 | d57775d4 | Nikos Skalkotos | import re |
11 | 1377b8a7 | Nikos Skalkotos | import sys |
12 | 1377b8a7 | Nikos Skalkotos | import guestfs |
13 | 1377b8a7 | Nikos Skalkotos | |
14 | 8c574358 | Nikos Skalkotos | |
15 | 8c574358 | Nikos Skalkotos | class DiskError(Exception): |
16 | 8c574358 | Nikos Skalkotos | pass
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17 | 8c574358 | Nikos Skalkotos | |
18 | 3ccb2618 | Nikos Skalkotos | dd = get_command('dd')
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19 | 3ccb2618 | Nikos Skalkotos | dmsetup = get_command('dmsetup')
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20 | 3ccb2618 | Nikos Skalkotos | losetup = get_command('losetup')
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21 | 3ccb2618 | Nikos Skalkotos | blockdev = get_command('blockdev')
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22 | 01a7cff3 | Nikos Skalkotos | |
23 | 01a7cff3 | Nikos Skalkotos | |
24 | d57775d4 | Nikos Skalkotos | class Disk(object): |
25 | 3b2f6619 | Nikos Skalkotos | """This class represents a hard disk hosting an Operating System
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26 | 3b2f6619 | Nikos Skalkotos |
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27 | 3b2f6619 | Nikos Skalkotos | A Disk instance never alters the source media it is created from.
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28 | 3b2f6619 | Nikos Skalkotos | Any change is done on a snapshot created by the device-mapper of
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29 | 3b2f6619 | Nikos Skalkotos | the Linux kernel.
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30 | 3b2f6619 | Nikos Skalkotos | """
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31 | d57775d4 | Nikos Skalkotos | |
32 | d57775d4 | Nikos Skalkotos | def __init__(self, source): |
33 | 3b2f6619 | Nikos Skalkotos | """Create a new Disk instance out of a source media. The source
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34 | 3b2f6619 | Nikos Skalkotos | media can be an image file, a block device or a directory."""
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35 | d57775d4 | Nikos Skalkotos | self._cleanup_jobs = []
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36 | d57775d4 | Nikos Skalkotos | self._devices = []
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37 | d57775d4 | Nikos Skalkotos | self.source = source
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38 | d57775d4 | Nikos Skalkotos | |
39 | d57775d4 | Nikos Skalkotos | def _add_cleanup(self, job, *args): |
40 | d57775d4 | Nikos Skalkotos | self._cleanup_jobs.append((job, args))
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41 | d57775d4 | Nikos Skalkotos | |
42 | d57775d4 | Nikos Skalkotos | def _losetup(self, fname): |
43 | 3ccb2618 | Nikos Skalkotos | loop = losetup('-f', '--show', fname) |
44 | 3ccb2618 | Nikos Skalkotos | loop = loop.strip() # remove the new-line char
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45 | 3ccb2618 | Nikos Skalkotos | self._add_cleanup(losetup, '-d', loop) |
46 | 3ccb2618 | Nikos Skalkotos | return loop
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47 | d57775d4 | Nikos Skalkotos | |
48 | d57775d4 | Nikos Skalkotos | def _dir_to_disk(self): |
49 | d57775d4 | Nikos Skalkotos | raise NotImplementedError |
50 | d57775d4 | Nikos Skalkotos | |
51 | d57775d4 | Nikos Skalkotos | def cleanup(self): |
52 | 3b2f6619 | Nikos Skalkotos | """Cleanup internal data. This needs to be called before the
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53 | 3b2f6619 | Nikos Skalkotos | program ends.
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54 | 3b2f6619 | Nikos Skalkotos | """
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55 | 1377b8a7 | Nikos Skalkotos | while len(self._devices): |
56 | 1377b8a7 | Nikos Skalkotos | device = self._devices.pop()
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57 | 1377b8a7 | Nikos Skalkotos | device.destroy() |
58 | 8c574358 | Nikos Skalkotos | |
59 | d57775d4 | Nikos Skalkotos | while len(self._cleanup_jobs): |
60 | d57775d4 | Nikos Skalkotos | job, args = self._cleanup_jobs.pop()
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61 | d57775d4 | Nikos Skalkotos | job(*args) |
62 | d57775d4 | Nikos Skalkotos | |
63 | d57775d4 | Nikos Skalkotos | def get_device(self): |
64 | 3b2f6619 | Nikos Skalkotos | """Returns a newly created DiskDevice instance.
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65 | c408053f | Nikos Skalkotos |
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66 | 3b2f6619 | Nikos Skalkotos | This instance is a snapshot of the original source media of
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67 | 3b2f6619 | Nikos Skalkotos | the Disk instance.
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68 | 3b2f6619 | Nikos Skalkotos | """
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69 | d57775d4 | Nikos Skalkotos | sourcedev = self.source
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70 | d57775d4 | Nikos Skalkotos | mode = os.stat(self.source).st_mode
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71 | d57775d4 | Nikos Skalkotos | if stat.S_ISDIR(mode):
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72 | d57775d4 | Nikos Skalkotos | return self._losetup(self._dir_to_disk()) |
73 | d57775d4 | Nikos Skalkotos | elif stat.S_ISREG(mode):
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74 | d57775d4 | Nikos Skalkotos | sourcedev = self._losetup(self.source) |
75 | d57775d4 | Nikos Skalkotos | elif not stat.S_ISBLK(mode): |
76 | d57775d4 | Nikos Skalkotos | raise ValueError("Value for self.source is invalid") |
77 | d57775d4 | Nikos Skalkotos | |
78 | d57775d4 | Nikos Skalkotos | # Take a snapshot and return it to the user
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79 | d57775d4 | Nikos Skalkotos | size = blockdev('--getsize', sourcedev)
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80 | d57775d4 | Nikos Skalkotos | cowfd, cow = tempfile.mkstemp() |
81 | d57775d4 | Nikos Skalkotos | self._add_cleanup(os.unlink, cow)
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82 | 8c574358 | Nikos Skalkotos | # Create 1G cow sparse file
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83 | 8c574358 | Nikos Skalkotos | dd('if=/dev/null', 'of=%s' % cow, 'bs=1k', 'seek=%d' % (1024 * 1024)) |
84 | d57775d4 | Nikos Skalkotos | cowdev = self._losetup(cow)
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85 | d57775d4 | Nikos Skalkotos | |
86 | d57775d4 | Nikos Skalkotos | snapshot = uuid.uuid4().hex |
87 | d57775d4 | Nikos Skalkotos | tablefd, table = tempfile.mkstemp() |
88 | d57775d4 | Nikos Skalkotos | try:
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89 | d57775d4 | Nikos Skalkotos | os.write(tablefd, "0 %d snapshot %s %s n 8" % \
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90 | d57775d4 | Nikos Skalkotos | (int(size), sourcedev, cowdev))
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91 | d57775d4 | Nikos Skalkotos | dmsetup('create', snapshot, table)
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92 | d57775d4 | Nikos Skalkotos | self._add_cleanup(dmsetup, 'remove', snapshot) |
93 | d57775d4 | Nikos Skalkotos | finally:
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94 | d57775d4 | Nikos Skalkotos | os.unlink(table) |
95 | d57775d4 | Nikos Skalkotos | |
96 | 1377b8a7 | Nikos Skalkotos | new_device = DiskDevice("/dev/mapper/%s" % snapshot)
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97 | d57775d4 | Nikos Skalkotos | self._devices.append(new_device)
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98 | d57775d4 | Nikos Skalkotos | return new_device
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99 | d57775d4 | Nikos Skalkotos | |
100 | 1377b8a7 | Nikos Skalkotos | def destroy_device(self, device): |
101 | 3b2f6619 | Nikos Skalkotos | """Destroys a DiskDevice instance previously created by
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102 | 3b2f6619 | Nikos Skalkotos | get_device method.
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103 | 3b2f6619 | Nikos Skalkotos | """
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104 | 1377b8a7 | Nikos Skalkotos | self._devices.remove(device)
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105 | 1377b8a7 | Nikos Skalkotos | device.destroy() |
106 | 1377b8a7 | Nikos Skalkotos | |
107 | 8c574358 | Nikos Skalkotos | |
108 | 586da0a0 | Nikos Skalkotos | def progress_generator(total): |
109 | 586da0a0 | Nikos Skalkotos | position = 0;
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110 | 586da0a0 | Nikos Skalkotos | for i in progress.bar(range(total)): |
111 | 586da0a0 | Nikos Skalkotos | if i < position:
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112 | 586da0a0 | Nikos Skalkotos | continue
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113 | 586da0a0 | Nikos Skalkotos | position = yield
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114 | e7c01d1e | Nikos Skalkotos | yield #suppress the StopIteration exception |
115 | 586da0a0 | Nikos Skalkotos | |
116 | 586da0a0 | Nikos Skalkotos | |
117 | d57775d4 | Nikos Skalkotos | class DiskDevice(object): |
118 | 3b2f6619 | Nikos Skalkotos | """This class represents a block device hosting an Operating System
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119 | 3b2f6619 | Nikos Skalkotos | as created by the device-mapper.
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120 | 3b2f6619 | Nikos Skalkotos | """
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121 | d57775d4 | Nikos Skalkotos | |
122 | 8c574358 | Nikos Skalkotos | def __init__(self, device, bootable=True): |
123 | 3b2f6619 | Nikos Skalkotos | """Create a new DiskDevice."""
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124 | 333ff548 | Nikos Skalkotos | self.device = device
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125 | 1377b8a7 | Nikos Skalkotos | self.bootable = bootable
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126 | 586da0a0 | Nikos Skalkotos | self.progress_bar = None |
127 | 1377b8a7 | Nikos Skalkotos | |
128 | 1377b8a7 | Nikos Skalkotos | self.g = guestfs.GuestFS()
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129 | 586da0a0 | Nikos Skalkotos | self.g.add_drive_opts(device, readonly=0) |
130 | 0d5a999d | Nikos Skalkotos | |
131 | 586da0a0 | Nikos Skalkotos | #self.g.set_trace(1)
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132 | 586da0a0 | Nikos Skalkotos | #self.g.set_verbose(1)
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133 | 0d5a999d | Nikos Skalkotos | |
134 | 586da0a0 | Nikos Skalkotos | eh = self.g.set_event_callback(self.progress_callback, guestfs.EVENT_PROGRESS) |
135 | 1377b8a7 | Nikos Skalkotos | self.g.launch()
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136 | 586da0a0 | Nikos Skalkotos | self.g.delete_event_callback(eh)
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137 | 586da0a0 | Nikos Skalkotos | |
138 | 1377b8a7 | Nikos Skalkotos | roots = self.g.inspect_os()
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139 | 1377b8a7 | Nikos Skalkotos | if len(roots) == 0: |
140 | 1377b8a7 | Nikos Skalkotos | raise DiskError("No operating system found") |
141 | 1377b8a7 | Nikos Skalkotos | if len(roots) > 1: |
142 | 1377b8a7 | Nikos Skalkotos | raise DiskError("Multiple operating systems found") |
143 | 1377b8a7 | Nikos Skalkotos | |
144 | 1377b8a7 | Nikos Skalkotos | self.root = roots[0] |
145 | aa2062ba | Nikos Skalkotos | self.ostype = self.g.inspect_get_type(self.root) |
146 | aa2062ba | Nikos Skalkotos | self.distro = self.g.inspect_get_distro(self.root) |
147 | 8c574358 | Nikos Skalkotos | |
148 | 1377b8a7 | Nikos Skalkotos | def destroy(self): |
149 | 3b2f6619 | Nikos Skalkotos | """Destroy this DiskDevice instance."""
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150 | 1377b8a7 | Nikos Skalkotos | self.g.umount_all()
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151 | 1377b8a7 | Nikos Skalkotos | self.g.sync()
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152 | 1377b8a7 | Nikos Skalkotos | # Close the guestfs handler
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153 | aa2062ba | Nikos Skalkotos | self.g.close()
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154 | 8c574358 | Nikos Skalkotos | |
155 | 586da0a0 | Nikos Skalkotos | def progress_callback(self, ev, eh, buf, array): |
156 | 586da0a0 | Nikos Skalkotos | position = array[2]
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157 | 586da0a0 | Nikos Skalkotos | total = array[3]
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158 | 586da0a0 | Nikos Skalkotos | |
159 | 586da0a0 | Nikos Skalkotos | if self.progress_bar is None: |
160 | 586da0a0 | Nikos Skalkotos | self.progress_bar = progress_generator(total)
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161 | 586da0a0 | Nikos Skalkotos | self.progress_bar.next()
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162 | 586da0a0 | Nikos Skalkotos | |
163 | 586da0a0 | Nikos Skalkotos | self.progress_bar.send(position)
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164 | 586da0a0 | Nikos Skalkotos | |
165 | 586da0a0 | Nikos Skalkotos | if position == total:
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166 | 586da0a0 | Nikos Skalkotos | self.progress_bar = None |
167 | 586da0a0 | Nikos Skalkotos | |
168 | 1377b8a7 | Nikos Skalkotos | def mount(self): |
169 | 3b2f6619 | Nikos Skalkotos | """Mount all disk partitions in a correct order."""
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170 | 0d5a999d | Nikos Skalkotos | mps = self.g.inspect_get_mountpoints(self.root) |
171 | 8c574358 | Nikos Skalkotos | |
172 | 1377b8a7 | Nikos Skalkotos | # Sort the keys to mount the fs in a correct order.
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173 | 1377b8a7 | Nikos Skalkotos | # / should be mounted befor /boot, etc
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174 | 8c574358 | Nikos Skalkotos | def compare(a, b): |
175 | 8c574358 | Nikos Skalkotos | if len(a[0]) > len(b[0]): |
176 | 8c574358 | Nikos Skalkotos | return 1 |
177 | 8c574358 | Nikos Skalkotos | elif len(a[0]) == len(b[0]): |
178 | 8c574358 | Nikos Skalkotos | return 0 |
179 | 8c574358 | Nikos Skalkotos | else:
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180 | 8c574358 | Nikos Skalkotos | return -1 |
181 | 1377b8a7 | Nikos Skalkotos | mps.sort(compare) |
182 | 1377b8a7 | Nikos Skalkotos | for mp, dev in mps: |
183 | 1377b8a7 | Nikos Skalkotos | try:
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184 | 1377b8a7 | Nikos Skalkotos | self.g.mount(dev, mp)
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185 | 1377b8a7 | Nikos Skalkotos | except RuntimeError as msg: |
186 | 1377b8a7 | Nikos Skalkotos | print "%s (ignored)" % msg |
187 | d57775d4 | Nikos Skalkotos | |
188 | 8c574358 | Nikos Skalkotos | def umount(self): |
189 | 3b2f6619 | Nikos Skalkotos | """Umount all mounted filesystems."""
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190 | 8c574358 | Nikos Skalkotos | self.g.umount_all()
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191 | 8c574358 | Nikos Skalkotos | |
192 | 8c574358 | Nikos Skalkotos | def shrink(self): |
193 | 3b2f6619 | Nikos Skalkotos | """Shrink the disk.
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194 | 3b2f6619 | Nikos Skalkotos |
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195 | 3b2f6619 | Nikos Skalkotos | This is accomplished by shrinking the last filesystem in the
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196 | 3b2f6619 | Nikos Skalkotos | disk and then updating the partition table. The new disk size
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197 | 3b2f6619 | Nikos Skalkotos | (in bytes) is returned.
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198 | 3b2f6619 | Nikos Skalkotos | """
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199 | 8c574358 | Nikos Skalkotos | dev = self.g.part_to_dev(self.root) |
200 | 8c574358 | Nikos Skalkotos | parttype = self.g.part_get_parttype(dev)
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201 | 8c574358 | Nikos Skalkotos | if parttype != 'msdos': |
202 | 8c574358 | Nikos Skalkotos | raise DiskError("You have a %s partition table. " |
203 | 8c574358 | Nikos Skalkotos | "Only msdos partitions are supported" % parttype)
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204 | 8c574358 | Nikos Skalkotos | |
205 | 8c574358 | Nikos Skalkotos | last_partition = self.g.part_list(dev)[-1] |
206 | 8c574358 | Nikos Skalkotos | |
207 | 8c574358 | Nikos Skalkotos | if last_partition['part_num'] > 4: |
208 | 8c574358 | Nikos Skalkotos | raise DiskError("This disk contains logical partitions. " |
209 | 8c574358 | Nikos Skalkotos | "Only primary partitions are supported.")
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210 | 8c574358 | Nikos Skalkotos | |
211 | 8c574358 | Nikos Skalkotos | part_dev = "%s%d" % (dev, last_partition['part_num']) |
212 | 8c574358 | Nikos Skalkotos | fs_type = self.g.vfs_type(part_dev)
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213 | 8c574358 | Nikos Skalkotos | if not re.match("ext[234]", fs_type): |
214 | a1a5ca4b | Nikos Skalkotos | print "Warning: Don't know how to resize %s partitions." % vfs_type |
215 | 8c574358 | Nikos Skalkotos | return
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216 | 8c574358 | Nikos Skalkotos | |
217 | 8c574358 | Nikos Skalkotos | self.g.e2fsck_f(part_dev)
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218 | 8c574358 | Nikos Skalkotos | self.g.resize2fs_M(part_dev)
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219 | 8c574358 | Nikos Skalkotos | output = self.g.tune2fs_l(part_dev)
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220 | 8c574358 | Nikos Skalkotos | block_size = int(filter(lambda x: x[0] == 'Block size', output)[0][1]) |
221 | 8c574358 | Nikos Skalkotos | block_cnt = int(filter(lambda x: x[0] == 'Block count', output)[0][1]) |
222 | 8c574358 | Nikos Skalkotos | |
223 | 8c574358 | Nikos Skalkotos | sector_size = self.g.blockdev_getss(dev)
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224 | 8c574358 | Nikos Skalkotos | |
225 | 8c574358 | Nikos Skalkotos | start = last_partition['part_start'] / sector_size
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226 | 8c574358 | Nikos Skalkotos | end = start + (block_size * block_cnt) / sector_size - 1
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227 | 8c574358 | Nikos Skalkotos | |
228 | c408053f | Nikos Skalkotos | self.g.part_del(dev, last_partition['part_num']) |
229 | c408053f | Nikos Skalkotos | self.g.part_add(dev, 'p', start, end) |
230 | c408053f | Nikos Skalkotos | |
231 | e3aac3f9 | Nikos Skalkotos | return (end + 1) * sector_size |
232 | e3aac3f9 | Nikos Skalkotos | |
233 | c408053f | Nikos Skalkotos | def size(self): |
234 | c408053f | Nikos Skalkotos | """Returns the "payload" size of the device.
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235 | c408053f | Nikos Skalkotos |
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236 | c408053f | Nikos Skalkotos | The size returned by this method is the size of the space occupied by
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237 | c408053f | Nikos Skalkotos | the partitions (including the space before the first partition).
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238 | c408053f | Nikos Skalkotos | """
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239 | c408053f | Nikos Skalkotos | dev = self.g.part_to_dev(self.root) |
240 | c408053f | Nikos Skalkotos | last = self.g.part_list(dev)[-1] |
241 | c408053f | Nikos Skalkotos | |
242 | c408053f | Nikos Skalkotos | return last['part_end'] |
243 | 8c574358 | Nikos Skalkotos | |
244 | d57775d4 | Nikos Skalkotos | # vim: set sta sts=4 shiftwidth=4 sw=4 et ai : |