def mdremove(mdname):
# check if md exists
if mdname not in get_mdnames():
raise errors.MDNotFoundError(
'Error while removing md: md %s not found' % mdname)
# FIXME: The issue faced was quiet hard to reproduce and to figure out the
# root cause. For unknown reason already removed md device is
# unexpectedly returning back after a while from time to time making
# new md device creation to fail.
# Still the actual reason of its failure is unknown, but after a
# searching on a web a mention was found about a race in udev
# http://dev.bizo.com/2012/07/mdadm-device-or-resource-busy.html
# The article recommends to disable udev's queue entirely during md
# device manipulation which sounds rather unappropriate for our case.
# And the link to original post on mailing list suggests to execute
# `udevadm settle` before removing the md device.
# here -> http://permalink.gmane.org/gmane.linux.raid/34027
# So, what was done. `udevadm settle` calls were placed just
# before any of `mdadm` calls and the analizyng the logs was started.
# According to the manual `settle` is an option that "Watches the
# udev event queue, and exits if all current events are handled".
# That means it will wait for udev's finishing of processing the
# events. According to the logs noticeable delay had been recognized
# between `udevadm settle` and the next `mdadm` call.
# The delay was about 150-200ms or even bigger. It was appeared
# right before the `mdadm --stop` call. That just means that udev was
# too busy with events when we start to modifiy md devices hard.
# Thus `udevadm settle` is helping to avoid the later failure and
# to prevent strange behaviour of md device.
utils.udevadm_settle()
utils.execute('mdadm', '--stop', mdname, check_exit_code=[0])
utils.execute('mdadm', '--remove', mdname, check_exit_code=[0, 1])
def mdremove(mdname):
# check if md exists
if mdname not in get_mdnames():
raise errors.MDNotFoundError(
'Error while removing md: md %s not found' % mdname)
# FIXME: The issue faced was quiet hard to reproduce and to figure out the
# root cause. For unknown reason already removed md device is
# unexpectedly returning back after a while from time to time making
# new md device creation to fail.
# Still the actual reason of its failure is unknown, but after a
# searching on a web a mention was found about a race in udev
# http://dev.bizo.com/2012/07/mdadm-device-or-resource-busy.html
# The article recommends to disable udev's queue entirely during md
# device manipulation which sounds rather unappropriate for our case.
# And the link to original post on mailing list suggests to execute
# `udevadm settle` before removing the md device.
# here -> http://permalink.gmane.org/gmane.linux.raid/34027
# So, what was done. `udevadm settle` calls were placed just
# before any of `mdadm` calls and the analizyng the logs was started.
# According to the manual `settle` is an option that "Watches the
# udev event queue, and exits if all current events are handled".
# That means it will wait for udev's finishing of processing the
# events. According to the logs noticeable delay had been recognized
# between `udevadm settle` and the next `mdadm` call.
# The delay was about 150-200ms or even bigger. It was appeared
# right before the `mdadm --stop` call. That just means that udev was
# too busy with events when we start to modifiy md devices hard.
# Thus `udevadm settle` is helping to avoid the later failure and
# to prevent strange behaviour of md device.
utils.udevadm_settle()
utils.execute('mdadm', '--stop', mdname, check_exit_code=[0])
utils.execute('mdadm', '--remove', mdname, check_exit_code=[0, 1])
def set_partition_flag(dev, num, flag, state='on'):
"""Sets flag on a partition
:param dev: A device file, e.g. /dev/sda.
:param num: Partition number
:param flag: Flag name. Must be one of 'bios_grub', 'legacy_boot',
'boot', 'raid', 'lvm'
:param state: Desiable flag state. 'on' or 'off'. Default is 'on'.
:returns: None
"""
LOG.debug('Trying to set partition flag: dev=%s num=%s flag=%s state=%s' %
(dev, num, flag, state))
# parted supports more flags but we are interested in
# setting only this subset of them.
# not all of these flags are compatible with one another.
if flag not in ('bios_grub', 'legacy_boot', 'boot', 'raid', 'lvm'):
raise errors.WrongPartitionSchemeError(
'Unsupported partition flag: %s' % flag)
if state not in ('on', 'off'):
raise errors.WrongPartitionSchemeError(
'Wrong partition flag state: %s' % state)
utils.udevadm_settle()
out, err = utils.execute('parted', '-s', dev, 'set', str(num),
flag, state, check_exit_code=[0, 1])
LOG.debug('Parted output: \n%s' % out)
reread_partitions(dev, out=out)
def make_partition(dev, begin, end, ptype):
LOG.debug('Trying to create a partition: dev=%s begin=%s end=%s' %
(dev, begin, end))
if ptype not in ('primary', 'logical'):
raise errors.WrongPartitionSchemeError(
'Wrong partition type: %s' % ptype)
# check begin >= end
if begin >= end:
raise errors.WrongPartitionSchemeError(
'Wrong boundaries: begin >= end')
# check if begin and end are inside one of free spaces available
if not any(x['fstype'] == 'free' and begin >= x['begin'] and
end <= x['end'] for x in info(dev)['parts']):
raise errors.WrongPartitionSchemeError(
'Invalid boundaries: begin and end '
'are not inside available free space')
utils.udevadm_settle()
out, err = utils.execute(
'parted', '-a', 'optimal', '-s', dev, 'unit', 'MiB',
'mkpart', ptype, str(begin), str(end), check_exit_code=[0, 1])
LOG.debug('Parted output: \n%s' % out)
reread_partitions(dev, out=out)
def set_partition_flag(dev, num, flag, state='on'):
"""Sets flag on a partition
:param dev: A device file, e.g. /dev/sda.
:param num: Partition number
:param flag: Flag name. Must be one of 'bios_grub', 'legacy_boot',
'boot', 'raid', 'lvm'
:param state: Desiable flag state. 'on' or 'off'. Default is 'on'.
:returns: None
"""
LOG.debug('Trying to set partition flag: dev=%s num=%s flag=%s state=%s' %
(dev, num, flag, state))
# parted supports more flags but we are interested in
# setting only this subset of them.
# not all of these flags are compatible with one another.
if flag not in ('bios_grub', 'legacy_boot', 'boot', 'raid', 'lvm'):
raise errors.WrongPartitionSchemeError(
'Unsupported partition flag: %s' % flag)
if state not in ('on', 'off'):
raise errors.WrongPartitionSchemeError(
'Wrong partition flag state: %s' % state)
utils.udevadm_settle()
out, err = utils.execute('parted', '-s', dev, 'set', str(num),
flag, state, check_exit_code=[0, 1])
LOG.debug('Parted output: \n%s' % out)
reread_partitions(dev, out=out)
def remove_partition(dev, num):
LOG.debug('Trying to remove partition: dev=%s num=%s' % (dev, num))
if not any(x['fstype'] != 'free' and x['num'] == num
for x in info(dev)['parts']):
raise errors.PartitionNotFoundError('Partition %s not found' % num)
utils.udevadm_settle()
out, err = utils.execute('parted', '-s', dev, 'rm',
str(num), check_exit_code=[0, 1])
reread_partitions(dev, out=out)
def remove_partition(dev, num):
LOG.debug('Trying to remove partition: dev=%s num=%s' % (dev, num))
if not any(x['fstype'] != 'free' and x['num'] == num
for x in info(dev)['parts']):
raise errors.PartitionNotFoundError('Partition %s not found' % num)
utils.udevadm_settle()
out, err = utils.execute('parted', '-s', dev, 'rm',
str(num), check_exit_code=[0, 1])
reread_partitions(dev, out=out)
def set_gpt_type(dev, num, type_guid):
"""Sets guid on a partition.
:param dev: A device file, e.g. /dev/sda.
:param num: Partition number
:param type_guid: Partition type guid. Must be one of those listed
on this page http://en.wikipedia.org/wiki/GUID_Partition_Table.
This method does not check whether type_guid is valid or not.
:returns: None
"""
# TODO(kozhukalov): check whether type_guid is valid
LOG.debug('Setting partition GUID: dev=%s num=%s guid=%s' %
(dev, num, type_guid))
utils.udevadm_settle()
utils.execute('sgdisk', '--typecode=%s:%s' % (num, type_guid),
dev, check_exit_code=[0])
def set_gpt_type(dev, num, type_guid):
"""Sets guid on a partition.
:param dev: A device file, e.g. /dev/sda.
:param num: Partition number
:param type_guid: Partition type guid. Must be one of those listed
on this page http://en.wikipedia.org/wiki/GUID_Partition_Table.
This method does not check whether type_guid is valid or not.
:returns: None
"""
# TODO(kozhukalov): check whether type_guid is valid
LOG.debug('Setting partition GUID: dev=%s num=%s guid=%s' %
(dev, num, type_guid))
utils.udevadm_settle()
utils.execute('sgdisk', '--typecode=%s:%s' % (num, type_guid),
dev, check_exit_code=[0])
def make_label(dev, label='gpt'):
"""Creates partition label on a device.
:param dev: A device file, e.g. /dev/sda.
:param label: Partition label type 'gpt' or 'msdos'. Optional.
:returns: None
"""
LOG.debug('Trying to create %s partition table on device %s' %
(label, dev))
if label not in ('gpt', 'msdos'):
raise errors.WrongPartitionLabelError(
'Wrong partition label type: %s' % label)
utils.udevadm_settle()
out, err = utils.execute('parted', '-s', dev, 'mklabel', label,
check_exit_code=[0, 1])
LOG.debug('Parted output: \n%s' % out)
reread_partitions(dev, out=out)
def make_label(dev, label='gpt'):
"""Creates partition label on a device.
:param dev: A device file, e.g. /dev/sda.
:param label: Partition label type 'gpt' or 'msdos'. Optional.
:returns: None
"""
LOG.debug('Trying to create %s partition table on device %s' %
(label, dev))
if label not in ('gpt', 'msdos'):
raise errors.WrongPartitionLabelError(
'Wrong partition label type: %s' % label)
utils.udevadm_settle()
out, err = utils.execute('parted', '-s', dev, 'mklabel', label,
check_exit_code=[0, 1])
LOG.debug('Parted output: \n%s' % out)
reread_partitions(dev, out=out)
def reread_partitions(dev, out='Device or resource busy', timeout=60):
# The reason for this method to exist is that old versions of parted
# use ioctl(fd, BLKRRPART, NULL) to tell Linux to re-read partitions.
# This system call does not work sometimes. So we try to re-read partition
# table several times. Besides partprobe uses BLKPG instead, which
# is better than BLKRRPART for this case. BLKRRPART tells Linux to re-read
# partitions while BLKPG tells Linux which partitions are available
# BLKPG is usually used as a fallback system call.
begin = time.time()
while 'Device or resource busy' in out:
if time.time() > begin + timeout:
raise errors.BaseError('Unable to re-read partition table on'
'device %s' % dev)
LOG.debug('Last time output contained "Device or resource busy". '
'Trying to re-read partition table on device %s' % dev)
time.sleep(2)
out, err = utils.execute('partprobe', dev, check_exit_code=[0, 1])
LOG.debug('Partprobe output: \n%s' % out)
utils.udevadm_settle()
def reread_partitions(dev, out='Device or resource busy', timeout=60):
# The reason for this method to exist is that old versions of parted
# use ioctl(fd, BLKRRPART, NULL) to tell Linux to re-read partitions.
# This system call does not work sometimes. So we try to re-read partition
# table several times. Besides partprobe uses BLKPG instead, which
# is better than BLKRRPART for this case. BLKRRPART tells Linux to re-read
# partitions while BLKPG tells Linux which partitions are available
# BLKPG is usually used as a fallback system call.
begin = time.time()
while 'Device or resource busy' in out:
if time.time() > begin + timeout:
raise errors.BaseError('Unable to re-read partition table on'
'device %s' % dev)
LOG.debug('Last time output contained "Device or resource busy". '
'Trying to re-read partition table on device %s' % dev)
time.sleep(2)
out, err = utils.execute('partprobe', dev, check_exit_code=[0, 1])
LOG.debug('Partprobe output: \n%s' % out)
utils.udevadm_settle()
def make_partition(dev, begin, end, ptype, alignment='optimal'):
"""Creates a partition on the device.
:param dev: A device file, e.g. /dev/sda.
:param begin: Beginning of the partition.
:param end: Ending of the partition.
:param ptype: Partition type: primary or logical.
:param alignment: Set alignment mode for newly created partitions,
valid alignment types are: none, cylinder, minimal, optimal. For more
information about this you can find in GNU parted manual.
:returns: None
"""
LOG.debug('Trying to create a partition: dev=%s begin=%s end=%s' %
(dev, begin, end))
if ptype not in ('primary', 'logical'):
raise errors.WrongPartitionSchemeError(
'Wrong partition type: %s' % ptype)
if alignment not in PARTITION_ALIGMENT:
raise errors.WrongPartitionSchemeError(
'Wrong partition alignment requested: %s' % alignment)
# check begin >= end
if begin >= end:
raise errors.WrongPartitionSchemeError(
'Wrong boundaries: begin >= end')
# check if begin and end are inside one of free spaces available
if not any(x['fstype'] == 'free' and begin >= x['begin'] and
end <= x['end'] for x in info(dev)['parts']):
raise errors.WrongPartitionSchemeError(
'Invalid boundaries: begin and end '
'are not inside available free space')
utils.udevadm_settle()
out, err = utils.execute(
'parted', '-a', alignment, '-s', dev, 'unit', 'MiB',
'mkpart', ptype, str(begin), str(end), check_exit_code=[0, 1])
LOG.debug('Parted output: \n%s' % out)
reread_partitions(dev, out=out)
def info(dev):
utils.udevadm_settle()
parted_output = utils.execute('parted', '-s', dev, '-m',
'unit', 'MiB',
'print free',
check_exit_code=[0])[0]
LOG.debug('Parted info output: \n%s' % parted_output)
result = parse_partition_info(parted_output)
file_output = utils.execute('file', '-sk', dev,
check_exit_code=[0])[0]
LOG.debug('File info output: \n%s' % file_output)
result['generic']['has_bootloader'] = 'boot sector' in file_output
for part in result['parts']:
blkid_output = utils.execute('blkid -s UUID -o value',
part['name'],
check_exit_code=False)[0].strip()
LOG.debug('Blkid output: \n%s' % blkid_output)
part['uuid'] = blkid_output
LOG.debug('Info result: %s' % result)
return result
def info(dev):
utils.udevadm_settle()
parted_output = utils.execute('parted', '-s', dev, '-m',
'unit', 'MiB',
'print free',
check_exit_code=[0])[0]
LOG.debug('Parted info output: \n%s' % parted_output)
result = parse_partition_info(parted_output)
file_output = utils.execute('file', '-sk', dev,
check_exit_code=[0])[0]
LOG.debug('File info output: \n%s' % file_output)
result['generic']['has_bootloader'] = 'boot sector' in file_output
for part in result['parts']:
blkid_output = utils.execute('blkid -s UUID -o value',
part['name'],
check_exit_code=False)[0].strip()
LOG.debug('Blkid output: \n%s' % blkid_output)
part['uuid'] = blkid_output
LOG.debug('Info result: %s' % result)
return result
def test_udevadm_settle(self, mock_exec):
utils.udevadm_settle()
mock_exec.assert_called_once_with("udevadm", "settle", check_exit_code=[0])
def test_udevadm_settle(self, mock_exec):
utils.udevadm_settle()
mock_exec.assert_called_once_with('udevadm',
'settle',
check_exit_code=[0])
