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
235
236
237
|
# 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 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):
try:
return self.fsck.forest.node_store.get_node(node_id)
except larch.NodeMissing:
self.error('node %s is missing' % node_id)
class CheckNode(WorkItem):
def __init__(self, fsck, node_id):
self.fsck = fsck
self.node_id = node_id
self.name = 'node %s' % node_id
def do(self):
tracing.trace('checking node %s' % self.node_id)
node = self.get_node(self.node_id)
if node:
if type(node) not in [larch.IndexNode, larch.LeafNode]:
self.error('node must be an index or leaf node')
return
keys = node.keys()
if self.fsck.forest.node_store.get_refcount(node.id) <= 0:
self.warning('node refcount must be > 0')
if not len(keys):
self.warning('node must have keys')
if sorted(keys) != keys:
self.error('node keys must be sorted')
if sorted(set(keys)) != keys:
self.error('node keys must be unique')
encoded = self.fsck.forest.node_store.codec.encode(node)
if len(encoded) > self.fsck.forest.node_store.node_size:
self.warning('node is too large')
if len(encoded) == 0:
self.warning('node has zero size when encoded')
if self.fsck.fix and type(node) == larch.IndexNode:
tracing.trace('checking and fixing index node %s' %
self.node_id)
keys = []
for key in node:
child_id = node[key]
if self.get_node(child_id):
keys.append(key)
else:
tracing.trace('child %s is missing' % child_id)
if keys != node.keys():
tracing.trace('Replacing index node %s with fixed copy' %
self.node_id)
new_node = larch.IndexNode(node.id, keys,
[node[k] for k in keys])
self.fsck.forest.node_store.put_node(new_node)
tracing.trace('fixed it: %s' % new_node.keys())
class CheckRoot(WorkItem):
def __init__(self, fsck, root_id):
self.fsck = fsck
self.root_id = root_id
self.name = 'root node %s' % root_id
def do(self):
tracing.trace('checking root node %s' % self.root_id)
node = self.get_node(self.root_id)
if node:
if self.fsck.forest.node_store.get_refcount(self.root_id) != 1:
self.warning('root refcount must be 1')
if type(node) != larch.IndexNode:
self.error('root must be an index node')
else:
self.error('missing root node %s' % self.root_id)
class CheckRecursively(WorkItem):
def __init__(self, fsck, root_id, seen):
self.fsck = fsck
self.root_id = root_id
self.name = 'tree %s' % root_id
self.seen = seen
def do(self):
tracing.trace('checking recursive from root node %s' % self.root_id)
for node, minkey, maxkey in self.walk(self.root_id):
if node.id not in self.seen:
tracing.trace('checking node %s' % node.id)
self.seen.add(node.id)
keys = node.keys()
if keys:
if keys[0] < minkey:
self.error('node %s: first key is too small' % node.id)
if keys[-1] > maxkey:
self.error('node %s: last key is too large' % node.id)
def walk(self, root_id):
def walker(node_id, minkey, maxkey, expected_type):
expected_child = None
node = self.get_node(node_id)
if node:
yield node, minkey, maxkey
if type(node) == larch.IndexNode:
tracing.trace('recursively found index node %s' % node.id)
keys = node.keys()
tracing.trace('keys: %s' % repr(keys))
for i, key in enumerate(keys):
child_id = node[key]
if i + 1 < len(keys):
next_key = keys[i+1]
else:
next_key = maxkey
if expected_child is None:
child = self.get_node(child_id)
if child:
expected_child = type(child)
for x in walker(child_id, key, next_key,
expected_child):
yield x
else:
if expected_type == larch.IndexNode:
self.error('cannot find index node %s' % node_id)
elif expected_type == larch.LeafNode:
self.error('cannot find leaf node %s' % node_id)
else:
self.error('cannot find node of unknown type %s' % node_id)
ns = self.fsck.forest.node_store
tree_minkey = chr(0) * ns.codec.key_bytes
tree_maxkey = chr(255) * ns.codec.key_bytes
for x in walker(root_id, tree_minkey, tree_maxkey, larch.IndexNode):
yield x
class CheckExtraNodes(WorkItem):
def __init__(self, fsck):
self.fsck = fsck
self.seen = set()
self.name = 'extra nodes'
def do(self):
tracing.trace('checking for extra nodes')
for node_id in self.fsck.forest.node_store.list_nodes():
if node_id not in self.seen:
self.warning('node %d is not part of the tree' % node_id)
class CommitForest(WorkItem):
def __init__(self, fsck):
self.fsck = fsck
self.name = 'committing fixes'
def do(self):
tracing.trace('committing changes to forest')
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.warning = warning
self.error = error
self.fix = fix
self.work = []
def find_work(self):
for node_id in self.forest.node_store.list_nodes():
tracing.trace('found node %s' % node_id)
self.work.append(CheckNode(self, node_id))
for tree in self.forest.trees:
self.work.append(CheckRoot(self, tree.root.id))
extra = CheckExtraNodes(self)
for tree in self.forest.trees:
self.work.append(CheckRecursively(self, tree.root.id, extra.seen))
self.work.append(extra)
if self.fix:
self.work.append(CommitForest(self))
|
