commit a2cfdea2aea698d0c0a61db5dce6855528f27b91
Author: Iustin Pop <iustin@google.com>
Date:   Wed Oct 24 13:30:40 2007 +0000

    Add DRBD8 class for handling drbd version 8.x
    
    This duplicates some code from the DRBDev class, but not very much, and
    it will be expanded with the new functionality available for the 8.x
    version. Currently the code is not accessible outside the module.
    
    This patch introduces a dependency on the pyparsing module.
    
    Reviewed-by: imsnah

diff --git a/lib/bdev.py b/lib/bdev.py
index 2d27ba7..76c6da1 100644
--- a/lib/bdev.py
+++ b/lib/bdev.py
@@ -24,6 +24,7 @@
 import re
 import time
 import errno
+import pyparsing as pyp
 
 from ganeti import utils
 from ganeti import logger
@@ -1549,6 +1550,535 @@ class DRBDev(BaseDRBD):
     """
     return self.Shutdown()
 
+class DRBD8(BaseDRBD):
+  """DRBD v8.x block device.
+
+  This implements the local host part of the DRBD device, i.e. it
+  doesn't do anything to the supposed peer. If you need a fully
+  connected DRBD pair, you need to use this class on both hosts.
+
+  The unique_id for the drbd device is the (local_ip, local_port,
+  remote_ip, remote_port) tuple, and it must have two children: the
+  data device and the meta_device. The meta device is checked for
+  valid size and is zeroed on create.
+
+  """
+  _DRBD_MAJOR = 147
+  _MAX_MINORS = 255
+  _PARSE_SHOW = None
+
+  def __init__(self, unique_id, children):
+    super(DRBD8, self).__init__(unique_id, children)
+    self.major = self._DRBD_MAJOR
+    [kmaj, kmin, kfix, api, proto] = self._GetVersion()
+    if kmaj != 8:
+      raise errors.BlockDeviceError("Mismatch in DRBD kernel version and"
+                                    " requested ganeti usage: kernel is"
+                                    " %s.%s, ganeti wants 8.x" % (kmaj, kmin))
+
+    if len(children) != 2:
+      raise ValueError("Invalid configuration data %s" % str(children))
+    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 4:
+      raise ValueError("Invalid configuration data %s" % str(unique_id))
+    self._lhost, self._lport, self._rhost, self._rport = unique_id
+    self.Attach()
+
+  @classmethod
+  def _InitMeta(cls, minor, dev_path):
+    """Initialize a meta device.
+
+    This will not work if the given minor is in use.
+
+    """
+    result = utils.RunCmd(["drbdmeta", "--force", cls._DevPath(minor),
+                           "v08", dev_path, "0", "create-md"])
+    if result.failed:
+      raise errors.BlockDeviceError("Can't initialize meta device: %s" %
+                                    result.output)
+
+  @classmethod
+  def _FindUnusedMinor(cls):
+    """Find an unused DRBD device.
+
+    This is specific to 8.x as the minors are allocated dynamically,
+    so non-existing numbers up to a max minor count are actually free.
+
+    """
+    data = cls._GetProcData()
+
+    unused_line = re.compile("^ *([0-9]+): cs:Unconfigured$")
+    used_line = re.compile("^ *([0-9]+): cs:")
+    highest = None
+    for line in data:
+      match = unused_line.match(line)
+      if match:
+        return int(match.group(1))
+      match = used_line.match(line)
+      if match:
+        minor = int(match.group(1))
+        highest = max(highest, minor)
+    if highest is None: # there are no minors in use at all
+      return 0
+    if highest >= cls._MAX_MINORS:
+      logger.Error("Error: no free drbd minors!")
+      raise errors.BlockDeviceError("Can't find a free DRBD minor")
+    return highest + 1
+
+  @classmethod
+  def _IsValidMeta(cls, meta_device):
+    """Check if the given meta device looks like a valid one.
+
+    """
+    minor = cls._FindUnusedMinor()
+    minor_path = cls._DevPath(minor)
+    result = utils.RunCmd(["drbdmeta", minor_path,
+                           "v08", meta_device, "0",
+                           "dstate"])
+    if result.failed:
+      logger.Error("Invalid meta device %s: %s" % (meta_device, result.output))
+      return False
+    return True
+
+  @classmethod
+  def _GetShowParser(cls):
+    """Return a parser for `drbd show` output.
+
+    This will either create or return an already-create parser for the
+    output of the command `drbd show`.
+
+    """
+    if cls._PARSE_SHOW is not None:
+      return cls._PARSE_SHOW
+
+    # pyparsing setup
+    lbrace = pyp.Literal("{").suppress()
+    rbrace = pyp.Literal("}").suppress()
+    semi = pyp.Literal(";").suppress()
+    # this also converts the value to an int
+    number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t:(l, [int(t[0])]))
+
+    comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
+    defa = pyp.Literal("_is_default").suppress()
+    dbl_quote = pyp.Literal('"').suppress()
+
+    keyword = pyp.Word(pyp.alphanums + '-')
+
+    # value types
+    value = pyp.Word(pyp.alphanums + '_-/.:')
+    quoted = dbl_quote + pyp.CharsNotIn('"') + dbl_quote
+    addr_port = (pyp.Word(pyp.nums + '.') + pyp.Literal(':').suppress() +
+                 number)
+    # meta device, extended syntax
+    meta_value = ((value ^ quoted) + pyp.Literal('[').suppress() +
+                  number + pyp.Word(']').suppress())
+
+    # a statement
+    stmt = (~rbrace + keyword + ~lbrace +
+            (addr_port ^ value ^ quoted ^ meta_value) +
+            pyp.Optional(defa) + semi +
+            pyp.Optional(pyp.restOfLine).suppress())
+
+    # an entire section
+    section_name = pyp.Word(pyp.alphas + '_')
+    section = section_name + lbrace + pyp.ZeroOrMore(pyp.Group(stmt)) + rbrace
+
+    bnf = pyp.ZeroOrMore(pyp.Group(section ^ stmt))
+    bnf.ignore(comment)
+
+    cls._PARSE_SHOW = bnf
+
+    return bnf
+
+  @classmethod
+  def _GetDevInfo(cls, minor):
+    """Get details about a given DRBD minor.
+
+    This return, if available, the local backing device (as a path)
+    and the local and remote (ip, port) information.
+
+    """
+    data = {}
+    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
+    if result.failed:
+      logger.Error("Can't display the drbd config: %s" % result.fail_reason)
+      return data
+    out = result.stdout
+    if not out:
+      return data
+
+    bnf = cls._GetShowParser()
+    # run pyparse
+
+    try:
+      results = bnf.parseString(out)
+    except pyp.ParseException, err:
+      raise errors.BlockDeviceError("Can't parse drbdsetup show output: %s" %
+                                    str(err))
+
+    # and massage the results into our desired format
+    for section in results:
+      sname = section[0]
+      if sname == "_this_host":
+        for lst in section[1:]:
+          if lst[0] == "disk":
+            data["local_dev"] = lst[1]
+          elif lst[0] == "meta-disk":
+            data["meta_dev"] = lst[1]
+            data["meta_index"] = lst[2]
+          elif lst[0] == "address":
+            data["local_addr"] = tuple(lst[1:])
+      elif sname == "_remote_host":
+        for lst in section[1:]:
+          if lst[0] == "address":
+            data["remote_addr"] = tuple(lst[1:])
+    return data
+
+  def _MatchesLocal(self, info):
+    """Test if our local config matches with an existing device.
+
+    The parameter should be as returned from `_GetDevInfo()`. This
+    method tests if our local backing device is the same as the one in
+    the info parameter, in effect testing if we look like the given
+    device.
+
+    """
+    backend = self._children[0]
+    if backend is not None:
+      retval = (info["local_dev"] == backend.dev_path)
+    else:
+      retval = ("local_dev" not in info)
+    meta = self._children[1]
+    if meta is not None:
+      retval = retval and (info["meta_dev"] == meta.dev_path)
+      retval = retval and (info["meta_index"] == 0)
+    else:
+      retval = retval and ("meta_dev" not in info and
+                           "meta_index" not in info)
+    return retval
+
+  def _MatchesNet(self, info):
+    """Test if our network config matches with an existing device.
+
+    The parameter should be as returned from `_GetDevInfo()`. This
+    method tests if our network configuration is the same as the one
+    in the info parameter, in effect testing if we look like the given
+    device.
+
+    """
+    if (((self._lhost is None and not ("local_addr" in info)) and
+         (self._rhost is None and not ("remote_addr" in info)))):
+      return True
+
+    if self._lhost is None:
+      return False
+
+    if not ("local_addr" in info and
+            "remote_addr" in info):
+      return False
+
+    retval = (info["local_addr"] == (self._lhost, self._lport))
+    retval = (retval and
+              info["remote_addr"] == (self._rhost, self._rport))
+    return retval
+
+  @classmethod
+  def _AssembleLocal(cls, minor, backend, meta):
+    """Configure the local part of a DRBD device.
+
+    This is the first thing that must be done on an unconfigured DRBD
+    device. And it must be done only once.
+
+    """
+    if not cls._IsValidMeta(meta):
+      return False
+    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disk",
+                           backend, meta, "0", "-e", "detach",
+                           "--create-device"])
+    if result.failed:
+      logger.Error("Can't attach local disk: %s" % result.output)
+    return not result.failed
+
+  @classmethod
+  def _AssembleNet(cls, minor, net_info, protocol,
+                   dual_pri=False, hmac=None, secret=None):
+    """Configure the network part of the device.
+
+    """
+    lhost, lport, rhost, rport = net_info
+    args = ["drbdsetup", cls._DevPath(minor), "net",
+            "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport),
+            protocol]
+    if dual_pri:
+      args.append("-m")
+    if hmac and secret:
+      args.extend(["-a", hmac, "-x", secret])
+    result = utils.RunCmd(args)
+    if result.failed:
+      logger.Error("Can't setup network for dbrd device: %s" %
+                   result.fail_reason)
+      return False
+
+    timeout = time.time() + 10
+    ok = False
+    while time.time() < timeout:
+      info = cls._GetDevInfo(minor)
+      if not "local_addr" in info or not "remote_addr" in info:
+        time.sleep(1)
+        continue
+      if (info["local_addr"] != (lhost, lport) or
+          info["remote_addr"] != (rhost, rport)):
+        time.sleep(1)
+        continue
+      ok = True
+      break
+    if not ok:
+      logger.Error("Timeout while configuring network")
+      return False
+    return True
+
+  def SetSyncSpeed(self, kbytes):
+    """Set the speed of the DRBD syncer.
+
+    """
+    children_result = super(DRBD8, self).SetSyncSpeed(kbytes)
+    if self.minor is None:
+      logger.Info("Instance not attached to a device")
+      return False
+    result = utils.RunCmd(["drbdsetup", self.dev_path, "syncer", "-r", "%d" %
+                           kbytes])
+    if result.failed:
+      logger.Error("Can't change syncer rate: %s " % result.fail_reason)
+    return not result.failed and children_result
+
+  def GetSyncStatus(self):
+    """Returns the sync status of the device.
+
+    Returns:
+     (sync_percent, estimated_time)
+
+    If sync_percent is None, it means all is ok
+    If estimated_time is None, it means we can't esimate
+    the time needed, otherwise it's the time left in seconds
+
+    """
+    if self.minor is None and not self.Attach():
+      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")
+    proc_info = self._MassageProcData(self._GetProcData())
+    if self.minor not in proc_info:
+      raise errors.BlockDeviceError("Can't find myself in /proc (minor %d)" %
+                                    self.minor)
+    line = proc_info[self.minor]
+    match = re.match("^.*sync'ed: *([0-9.]+)%.*"
+                     " finish: ([0-9]+):([0-9]+):([0-9]+) .*$", line)
+    if match:
+      sync_percent = float(match.group(1))
+      hours = int(match.group(2))
+      minutes = int(match.group(3))
+      seconds = int(match.group(4))
+      est_time = hours * 3600 + minutes * 60 + seconds
+    else:
+      sync_percent = None
+      est_time = None
+    match = re.match("^ *[0-9]+: cs:([^ ]+).*$", line)
+    if not match:
+      raise errors.BlockDeviceError("Can't find my data in /proc (minor %d)" %
+                                    self.minor)
+    client_state = match.group(1)
+    is_degraded = client_state != "Connected"
+    return sync_percent, est_time, is_degraded
+
+  def GetStatus(self):
+    """Compute the status of the DRBD device
+
+    Note that DRBD devices don't have the STATUS_EXISTING state.
+
+    """
+    if self.minor is None and not self.Attach():
+      return self.STATUS_UNKNOWN
+
+    data = self._GetProcData()
+    match = re.compile("^ *%d: cs:[^ ]+ st:(Primary|Secondary)/.*$" %
+                       self.minor)
+    for line in data:
+      mresult = match.match(line)
+      if mresult:
+        break
+    else:
+      logger.Error("Can't find myself!")
+      return self.STATUS_UNKNOWN
+
+    state = mresult.group(2)
+    if state == "Primary":
+      result = self.STATUS_ONLINE
+    else:
+      result = self.STATUS_STANDBY
+
+    return result
+
+  def Open(self, force=False):
+    """Make the local state primary.
+
+    If the 'force' parameter is given, the '--do-what-I-say' parameter
+    is given. Since this is a pottentialy dangerous operation, the
+    force flag should be only given after creation, when it actually
+    has to be given.
+
+    """
+    if self.minor is None and not self.Attach():
+      logger.Error("DRBD cannot attach to a device during open")
+      return False
+    cmd = ["drbdsetup", self.dev_path, "primary"]
+    if force:
+      cmd.append("-o")
+    result = utils.RunCmd(cmd)
+    if result.failed:
+      logger.Error("Can't make drbd device primary: %s" % result.output)
+      return False
+    return True
+
+  def Close(self):
+    """Make the local state secondary.
+
+    This will, of course, fail if the device is in use.
+
+    """
+    if self.minor is None and not self.Attach():
+      logger.Info("Instance not attached to a device")
+      raise errors.BlockDeviceError("Can't find device")
+    result = utils.RunCmd(["drbdsetup", self.dev_path, "secondary"])
+    if result.failed:
+      logger.Error("Can't switch drbd device to secondary: %s" % result.output)
+      raise errors.BlockDeviceError("Can't switch drbd device to secondary")
+
+  def Attach(self):
+    """Find a DRBD device which matches our config and attach to it.
+
+    In case of partially attached (local device matches but no network
+    setup), we perform the network attach. If successful, we re-test
+    the attach if can return success.
+
+    """
+    for minor in self._GetUsedDevs():
+      info = self._GetDevInfo(minor)
+      match_l = self._MatchesLocal(info)
+      match_r = self._MatchesNet(info)
+      if match_l and match_r:
+        break
+      if match_l and not match_r and "local_addr" not in info:
+        res_r = self._AssembleNet(minor,
+                                  (self._lhost, self._lport,
+                                   self._rhost, self._rport),
+                                  "C")
+        if res_r and self._MatchesNet(self._GetDevInfo(minor)):
+          break
+    else:
+      minor = None
+
+    self._SetFromMinor(minor)
+    return minor is not None
+
+  def Assemble(self):
+    """Assemble the drbd.
+
+    Method:
+      - if we have a local backing device, we bind to it by:
+        - checking the list of used drbd devices
+        - check if the local minor use of any of them is our own device
+        - if yes, abort?
+        - if not, bind
+      - if we have a local/remote net info:
+        - redo the local backing device step for the remote device
+        - check if any drbd device is using the local port,
+          if yes abort
+        - check if any remote drbd device is using the remote
+          port, if yes abort (for now)
+        - bind our net port
+        - bind the remote net port
+
+    """
+    self.Attach()
+    if self.minor is not None:
+      logger.Info("Already assembled")
+      return True
+
+    result = super(DRBD8, self).Assemble()
+    if not result:
+      return result
+
+    minor = self._FindUnusedMinor()
+    need_localdev_teardown = False
+    if self._children[0]:
+      result = self._AssembleLocal(minor, self._children[0].dev_path,
+                                   self._children[1].dev_path)
+      if not result:
+        return False
+      need_localdev_teardown = True
+    if self._lhost and self._lport and self._rhost and self._rport:
+      result = self._AssembleNet(minor,
+                                 (self._lhost, self._lport,
+                                  self._rhost, self._rport),
+                                 "C")
+      if not result:
+        if need_localdev_teardown:
+          # we will ignore failures from this
+          logger.Error("net setup failed, tearing down local device")
+          self._ShutdownAll(minor)
+        return False
+    self._SetFromMinor(minor)
+    return True
+
+  @classmethod
+  def _ShutdownAll(cls, minor):
+    """Deactivate the device.
+
+    This will, of course, fail if the device is in use.
+
+    """
+    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
+    if result.failed:
+      logger.Error("Can't shutdown drbd device: %s" % result.output)
+    return not result.failed
+
+  def Shutdown(self):
+    """Shutdown the DRBD device.
+
+    """
+    if self.minor is None and not self.Attach():
+      logger.Info("DRBD device not attached to a device during Shutdown")
+      return True
+    if not self._ShutdownAll(self.minor):
+      return False
+    self.minor = None
+    self.dev_path = None
+    return True
+
+  def Remove(self):
+    """Stub remove for DRBD devices.
+
+    """
+    return self.Shutdown()
+
+  @classmethod
+  def Create(cls, unique_id, children, size):
+    """Create a new DRBD8 device.
+
+    Since DRBD devices are not created per se, just assembled, this
+    function only initializes the metadata.
+
+    """
+    if len(children) != 2:
+      raise errors.ProgrammerError("Invalid setup for the drbd device")
+    meta = children[1]
+    meta.Assemble()
+    if not meta.Attach():
+      raise errors.BlockDeviceError("Can't attach to meta device")
+    if not cls._CheckMetaSize(meta.dev_path):
+      raise errors.BlockDeviceError("Invalid meta device size")
+    cls._InitMeta(cls._FindUnusedMinor(), meta.dev_path)
+    if not cls._IsValidMeta(meta.dev_path):
+      raise errors.BlockDeviceError("Cannot initalize meta device")
+    return cls(unique_id, children)
+
 
 DEV_MAP = {
   constants.LD_LV: LogicalVolume,
