Current File : //usr/lib/python2.7/site-packages/yum/fssnapshots.py
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
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