View file File name : fssnapshots.py Content : import os import fnmatch import time from datetime import datetime import subprocess from yum import _ try: import lvm # Check that lvm2 is at least 2.2.99... In theory hacked versions of # .98 work, but meh. _ver = lvm.getVersion() # Looks liks: 2.02.84(2) (2011-02-09) _ver = _ver.split()[0] _ver = _ver.split('(')[0] _ver = tuple(map(int, _ver.split('.'))) if _ver < (2, 2, 99): lvm = None except: lvm = None _ver = None if lvm is not None: from lvm import LibLVMError class _ResultError(LibLVMError): """Exception raised for LVM calls resulting in bad return values.""" pass else: LibLVMError = None def _is_origin(lv): snap = lv.getAttr() # snap=(<value>, <is settable>) if not snap[0]: # Broken?? return None return snap[0][0] in ('o', 'O') def _is_snap(lv): snap = lv.getAttr() # snap=(<value>, <is settable>) if not snap[0]: # Broken?? return None return snap[0][0] in ('s', 'S') def _is_virt(lv): snap = lv.getAttr() # snap=(<value>, <is settable>) if not snap[0]: # Broken?? return None return snap[0][0] == 'v' def _vg_name2lv(vg, lvname): try: return vg.lvFromName(lvname) except: return None def _list_vg_names(): try: names = lvm.listVgNames() except LibLVMError: # Try to use the lvm binary instead names = [] if not names: # Could be just broken... p = subprocess.Popen(["/sbin/lvm", "vgs", "-o", "vg_name"], stdout=subprocess.PIPE, stderr=subprocess.PIPE) err = p.wait() if err: raise _ResultError(_("Failed to obtain volume group names")) output = p.communicate()[0] output = output.split('\n') if not output: return [] header = output[0].strip() if header != 'VG': return [] names = [] for name in output[1:]: if not name: break names.append(name.strip()) return names def _z_off(z, ctime=0): if len(z) == 5: # +0000 / -0130 / etc. off = int(z[1:3]) * 60 off += int(z[3:5]) off *= 60 if z[0] == '+': ctime -= off if z[0] == '-': ctime += off return ctime def _lv_ctime2utc(ctime): try: # Welcome to insanity ... d,t,z = ctime.split() ctime = time.strptime(d + ' ' + t, "%Y-%m-%d %H:%M:%S") ctime = time.mktime(ctime) if False: # Ignore the offset atm. ... we using this to delete older. cur_z = time.strftime("%z") if cur_z != z: # lol ... cur_z = _z_off(cur_z) z = _z_off(z) ctime += (cur_z - z) except: ctime = 0 return ctime def _lv_data(vg, lv): vgname = vg.getName() lvname = lv.getName() size = lv.getSize() origin = lv.getProperty("origin")[0] tags = lv.getTags() ctime = _lv_ctime2utc(lv.getProperty("lv_time")[0]) used = lv.getProperty("snap_percent")[0] used = float(used) used = used / (1 * 1000 * 1000) data = {'dev' : "%s/%s" % (vgname, lvname), 'ctime' : ctime, 'origin' : origin, 'origin_dev' : "%s/%s" % (vgname, origin), 'free' : vg.getFreeSize(), 'tags' : tags, 'size' : size, 'used' : used} return data def _log_traceback(func): """Decorator for _FSSnap methods that logs LVM tracebacks.""" def wrap(self, *args, **kwargs): try: return func(self, *args, **kwargs) except LibLVMError as e: if self._logger is not None: self._logger.exception(e) raise return wrap def lvmerr2str(exc): """Convert a LibLVMError instance to a readable error message.""" if type(exc) == LibLVMError and len(exc.args) == 2: # args[0] is the error number so ignore that return exc.args[1] else: return str(exc) class _FSSnap(object): # Old style was: vg/lv_root vg/lv_swap # New style is: fedora/root fedora/swap # New style is: redhat/root redhat/swap def __init__(self, root="/", lookup_mounts=True, devices=('!*/swap', '!*/lv_swap'), logger=None): if not lvm or os.geteuid(): devices = [] self.version = _ver # Parts of the API seem to work even when lvm is not actually installed, hence the path test self.available = bool(lvm and os.path.exists("/sbin/lvm")) self.postfix_static = "_yum_" self._postfix = None self._root = root self._devs = devices self._vgname_list = None # Logger object to be used for LVM traceback logging self._logger = logger if not self._devs: return @property def _vgnames(self): if self._vgname_list is None: self._vgname_list = _list_vg_names() if self.available else [] return self._vgname_list def _use_dev(self, vgname, lv=None): if lv is not None: if _is_snap(lv) or _is_virt(lv): # Don't look at these. return False found_neg = False for dev in self._devs: if '/' not in dev: # Bad... continue neg = False if dev[0] == '!': found_neg = True neg = True dev = dev[1:] vgn,lvn = dev.split('/', 1) if '/' in lvn: continue if not fnmatch.fnmatch(vgname, vgn): continue if lvn == '*': return not neg if lv is None: return None lvname = lv.getName() if not fnmatch.fnmatch(lvname, lvn): continue return not neg return found_neg @_log_traceback def has_space(self, percentage=100): """ See if we have enough space to try a snapshot. """ ret = False for vgname in self._vgnames: use = self._use_dev(vgname) if use is not None and not use: continue vg = lvm.vgOpen(vgname, 'r') if not vg: raise _ResultError( _("Unknown error when opening volume group ") + vgname) vgfsize = vg.getFreeSize() lvssize = 0 for lv in vg.listLVs(): if not self._use_dev(vgname, lv): continue lvssize += lv.getSize() vg.close() if not lvssize: continue ret = True if (lvssize * percentage) > (100*vgfsize): return False return ret @_log_traceback def snapshot(self, percentage=100, prefix='', postfix=None, tags={}): """ Attempt to take a snapshot, note that errors can happen after this function succeeds. """ if postfix is None: postfix = '%s%s' % (self.postfix_static, datetime.now().strftime("%Y%m%d%H%M%S.%f")) ret = [] for vgname in self._vgnames: use = self._use_dev(vgname) if use is not None and not use: continue vg = lvm.vgOpen(vgname, 'w') if not vg: raise _ResultError( _("Unknown error when opening volume group ") + vgname) for lv in vg.listLVs(): lvname = lv.getName() if not self._use_dev(vgname, lv): continue nlvname = "%s%s%s" % (prefix, lvname, postfix) nlv = lv.snapshot(nlvname, (lv.getSize() * percentage) / 100) if not nlv: # Failed here ... continuing seems bad. vg.close() raise _ResultError( _("Unknown error when creating snapshot ") + nlvname) odev = "%s/%s" % (vgname, lvname) ndev = "%s/%s" % (vgname, nlvname) # FIXME: yum_fssnapshot_pre_lv_name=<blah> eq_tags = set() for val in (ndev, odev, '*'): for tag in tags.get(val, []): if '=' in tag: eq_tag_key,eq_tag_val = tag.split('=', 1) if eq_tag_key in eq_tags: continue eq_tags.add(eq_tag_key) nlv.addTag(tag) ret.append((odev, ndev)) vg.close() return ret @_log_traceback def old_snapshots(self): """ List data for old snapshots. """ ret = [] for vgname in self._vgnames: # We could filter out the VGs using _use_dev() but this way we'll # see stuff after changing config. options. vg = lvm.vgOpen(vgname, 'w') if not vg: raise _ResultError( _("Unknown error when opening volume group ") + vgname) for lv in vg.listLVs(): if not _is_snap(lv): # No snapshot means, we don't care. continue ret.append(_lv_data(vg, lv)) vg.close() return ret @_log_traceback def del_snapshots(self, devices=[]): """ Remove snapshots. """ if not lvm: return [] ret = [] togo = {} for dev in devices: vgname,lvname = dev.split('/') if vgname not in togo: togo[vgname] = set([lvname]) else: togo[vgname].add(lvname) for vgname in togo: vg = lvm.vgOpen(vgname, 'w') if not vg: raise _ResultError( _("Unknown error when opening volume group ") + vgname) for lvname in togo[vgname]: lv = _vg_name2lv(vg, lvname) if not lv: continue if not _is_snap(lv): # No snapshot means don't try to delete! continue ret.append(_lv_data(vg, lv)) lv.remove() vg.close() return ret