/usr/lib/python2.7/dist-packages/larch/fsck.py is in python-larch 1.20151025-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 | # Copyright 2010, 2011 Lars Wirzenius
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import logging
import sys
import tracing
import ttystatus
import larch
class Error(larch.Error):
def __init__(self, msg):
self.msg = 'Assertion failed: %s' % msg
class WorkItem(object):
'''A work item for fsck.
Subclass can optionally set the ``name`` attribute; the class name
is used by default.
'''
def __str__(self):
if hasattr(self, 'name'):
return self.name
else:
return self.__class__.__name__
def do(self):
pass
def __iter__(self):
return iter([self])
def warning(self, msg):
self.fsck.warning('warning: %s: %s' % (self.name, msg))
def error(self, msg):
self.fsck.error('ERROR: %s: %s' % (self.name, msg))
def get_node(self, node_id):
tracing.trace('node_id=%s' % node_id)
try:
return self.fsck.forest.node_store.get_node(node_id)
except larch.NodeMissing:
self.error(
'forest %s: node %s is missing' %
(self.fsck.forest_name, node_id))
def start_modification(self, node):
self.fsck.forest.node_store.start_modification(node)
def put_node(self, node):
tracing.trace('node.id=%s' % node.id)
return self.fsck.forest.node_store.put_node(node)
class CheckIndexNode(WorkItem):
def __init__(self, fsck, node):
self.fsck = fsck
self.node = node
self.name = (
'CheckIndexNode: checking index node %s in %s' %
(self.node.id, self.fsck.forest_name))
def do(self):
tracing.trace('node.id=%s' % self.node.id)
if type(self.node) != larch.IndexNode:
self.error(
'forest %s: node %s: '
'Expected to get an index node, got %s instead' %
(self.fsck.forest_name, self.node.id, type(self.node)))
return
if len(self.node) == 0:
self.error('forest %s: index node %s: No children' %
(self.fsck.forest_name, self.node.id))
return
# Increase refcounts for all children, and check that the child
# nodes exist. If the children are index nodes, create work
# items to check those. Leaf nodes get no further checking.
drop_keys = []
for key in self.node:
child_id = self.node[key]
seen_already = child_id in self.fsck.refcounts
self.fsck.count(child_id)
if not seen_already:
child = self.get_node(child_id)
if child is None:
drop_keys.append(key)
elif type(child) == larch.IndexNode:
yield CheckIndexNode(self.fsck, child)
# Fix references to missing children by dropping them.
if self.fsck.fix and drop_keys:
self.start_modification(self.node)
for key in drop_keys:
self.node.remove(key)
self.warning('index node %s: dropped key %s' %
(self.node.id, key.encode('hex')))
self.put_node(self.node)
class CheckForest(WorkItem):
def __init__(self, fsck):
self.fsck = fsck
self.name = 'CheckForest: forest %s' % self.fsck.forest_name
def do(self):
tracing.trace("CheckForest: checking forest %s" % self.name )
for tree in self.fsck.forest.trees:
self.fsck.count(tree.root.id)
root_node = self.get_node(tree.root.id)
tracing.trace('root_node.id=%s' % root_node.id)
yield CheckIndexNode(self.fsck, root_node)
class CheckRefcounts(WorkItem):
def __init__(self, fsck):
self.fsck = fsck
self.name = 'CheckRefcounts: refcounts in %s' % self.fsck.forest_name
def do(self):
tracing.trace(
'CheckRefcounts : %s nodes to check' %
len(self.fsck.refcounts) )
for node_id in self.fsck.refcounts:
tracing.trace('CheckRefcounts checking node %s' % node_id)
refcount = self.fsck.forest.node_store.get_refcount(node_id)
if refcount != self.fsck.refcounts[node_id]:
self.error(
'forest %s: node %s: refcount is %s but should be %s' %
(self.fsck.forest_name,
node_id,
refcount,
self.fsck.refcounts[node_id]))
if self.fsck.fix:
self.fsck.forest.node_store.set_refcount(
node_id, self.fsck.refcounts[node_id])
self.warning('node %s: refcount was set to %s' %
(node_id, self.fsck.refcounts[node_id]))
class CommitForest(WorkItem):
def __init__(self, fsck):
self.fsck = fsck
self.name = ('CommitForest: committing fixes to %s' %
self.fsck.forest_name)
def do(self):
tracing.trace('committing changes to %s' % self.fsck.forest_name)
self.fsck.forest.commit()
class Fsck(object):
'''Verify internal consistency of a larch.Forest.'''
def __init__(self, forest, warning, error, fix):
self.forest = forest
self.forest_name = getattr(
forest.node_store, 'dirname', 'in-memory forest')
self.warning = warning
self.error = error
self.fix = fix
self.refcounts = {}
def find_work(self):
yield CheckForest(self)
yield CheckRefcounts(self)
if self.fix:
yield CommitForest(self)
def count(self, node_id):
self.refcounts[node_id] = self.refcounts.get(node_id, 0) + 1
def run_work(self, work_generators, ts=None):
"""run work_generator.do() recursively as needed
work_generators : list of generators (eg list( self.find_work() ))
who return objects with .do() methods that
either return None or other generators.
if a ttystatus.TerminalStatus instance is passed as ts,
report fsck progress via ts
"""
while work_generators:
work_generator = work_generators.pop(0)
for work in work_generator:
if ts:
ts.increase('items', 1)
ts['item'] = work
generator_or_none = work.do()
if generator_or_none:
# Run new work before carrying-on with work_generators
# (required for proper refcount check)
work_generators.insert(0,generator_or_none)
def run_fsck(self, ts=None):
"""Runs full fsck
if a ttystatus.TerminalStatus instance is passed as ts,
report fsck progress via ts item/items updates
"""
# Make sure that we pass list( self.find_work() ) and not
# [ self.find_work() ] so that when CheckForest.do() returns
# work generators, the work generators are actually called
# before the CheckRefcounts check.
work_generators = list( self.find_work() )
self.run_work(work_generators, ts=ts)
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