--- /dev/null
+import os
+import stat
+from ceph_volume import process
+
+
+def get_partuuid(device):
+ """
+ If a device is a partition, it will probably have a PARTUUID on it that
+ will persist and can be queried against `blkid` later to detect the actual
+ device
+ """
+ out, err, rc = process.call(
+ ['blkid', '-s', 'PARTUUID', '-o', 'value', device]
+ )
+ return ' '.join(out).strip()
+
+
+def get_device_from_partuuid(partuuid):
+ """
+ If a device has a partuuid, query blkid so that it can tell us what that
+ device is
+ """
+ out, err, rc = process.call(
+ ['blkid', '-t', 'PARTUUID="%s"' % partuuid, '-o', 'device']
+ )
+ return ' '.join(out).strip()
+
+
+def _stat_is_device(stat_obj):
+ """
+ Helper function that will interpret ``os.stat`` output directly, so that other
+ functions can call ``os.stat`` once and interpret that result several times
+ """
+ return stat.S_ISBLK(stat_obj)
+
+
+def lsblk(device, columns=None):
+ """
+ Create a dictionary of identifying values for a device using ``lsblk``.
+ Each supported column is a key, in its *raw* format (all uppercase
+ usually). ``lsblk`` has support for certain "columns" (in blkid these
+ would be labels), and these columns vary between distributions and
+ ``lsblk`` versions. The newer versions support a richer set of columns,
+ while older ones were a bit limited.
+
+ These are the default lsblk columns reported which are safe to use for
+ Ubuntu 14.04.5 LTS:
+
+ NAME device name
+ KNAME internal kernel device name
+ MAJ:MIN major:minor device number
+ FSTYPE filesystem type
+ MOUNTPOINT where the device is mounted
+ LABEL filesystem LABEL
+ UUID filesystem UUID
+ RO read-only device
+ RM removable device
+ MODEL device identifier
+ SIZE size of the device
+ STATE state of the device
+ OWNER user name
+ GROUP group name
+ MODE device node permissions
+ ALIGNMENT alignment offset
+ MIN-IO minimum I/O size
+ OPT-IO optimal I/O size
+ PHY-SEC physical sector size
+ LOG-SEC logical sector size
+ ROTA rotational device
+ SCHED I/O scheduler name
+ RQ-SIZE request queue size
+ TYPE device type
+ DISC-ALN discard alignment offset
+ DISC-GRAN discard granularity
+ DISC-MAX discard max bytes
+ DISC-ZERO discard zeroes data
+
+ There is a bug in ``lsblk`` where using all the available (supported)
+ columns will result in no output (!), in order to workaround this the
+ following columns have been removed from the default reporting columns:
+
+ * RQ-SIZE (request queue size)
+ * MIN-IO minimum I/O size
+ * OPT-IO optimal I/O size
+
+ These should be available however when using `columns`. For example::
+
+ >>> lsblk('/dev/sda1', columns=['OPT-IO'])
+ {'OPT-IO': '0'}
+
+ Normal CLI output, as filtered by the flags in this function will look like ::
+
+ $ lsblk --nodeps -P -o NAME,KNAME,MAJ:MIN,FSTYPE,MOUNTPOINT
+ NAME="sda1" KNAME="sda1" MAJ:MIN="8:1" FSTYPE="ext4" MOUNTPOINT="/"
+
+ :param columns: A list of columns to report as keys in its original form.
+ """
+ default_columns = [
+ 'NAME', 'KNAME', 'MAJ:MIN', 'FSTYPE', 'MOUNTPOINT', 'LABEL', 'UUID',
+ 'RO', 'RM', 'MODEL', 'SIZE', 'STATE', 'OWNER', 'GROUP', 'MODE',
+ 'ALIGNMENT', 'PHY-SEC', 'LOG-SEC', 'ROTA', 'SCHED', 'TYPE', 'DISC-ALN',
+ 'DISC-GRAN', 'DISC-MAX', 'DISC-ZERO'
+ ]
+ device = device.rstrip('/')
+ columns = columns or default_columns
+ # --nodeps -> Avoid adding children/parents to the device, only give information
+ # on the actual device we are querying for
+ # -P -> Produce pairs of COLUMN="value"
+ # -o -> Use the columns specified or default ones provided by this function
+ command = ['lsblk', '--nodeps', '-P', '-o']
+ command.append(','.join(columns))
+ command.append(device)
+ out, err, rc = process.call(command)
+
+ if rc != 0:
+ return {}
+
+ # parse the COLUMN="value" output to construct the dictionary
+ pairs = ' '.join(out).split()
+ parsed = {}
+ for pair in pairs:
+ try:
+ column, value = pair.split('=')
+ except ValueError:
+ continue
+ parsed[column] = value.strip().strip().strip('"')
+ return parsed
+
+
+def _lsblk_type(device):
+ """
+ Helper function that will use the ``TYPE`` label output of ``lsblk`` to determine
+ if a device is a partition or disk.
+ It does not process the output to return a boolean, but it does process it to return the
+ """
+ out, err, rc = process.call(
+ ['blkid', '-s', 'PARTUUID', '-o', 'value', device]
+ )
+ return ' '.join(out).strip()
+
+
+def is_device(dev):
+ """
+ Boolean to determine if a given device is a block device (**not**
+ a partition!)
+
+ For example: /dev/sda would return True, but not /dev/sdc1
+ """
+ if not os.path.exists(dev):
+ return False
+ # use lsblk first, fall back to using stat
+ TYPE = lsblk(dev).get('TYPE')
+ if TYPE:
+ return TYPE == 'disk'
+
+ # fallback to stat
+ return _stat_is_device(os.lstat(dev).st_mode)
+ if stat.S_ISBLK(os.lstat(dev)):
+ return True
+ return False
+
+
+def is_partition(dev):
+ """
+ Boolean to determine if a given device is a partition, like /dev/sda1
+ """
+ if not os.path.exists(dev):
+ return False
+ # use lsblk first, fall back to using stat
+ TYPE = lsblk(dev).get('TYPE')
+ if TYPE:
+ return TYPE == 'part'
+
+ # fallback to stat
+ stat_obj = os.stat(dev)
+ if _stat_is_device(stat_obj.st_mode):
+ return False
+
+ major = os.major(stat_obj.st_rdev)
+ minor = os.minor(stat_obj.st_rdev)
+ if os.path.exists('/sys/dev/block/%d:%d/partition' % (major, minor)):
+ return True
+ return False
Code Review / stor4nfv.git / blobdiff