-
Notifications
You must be signed in to change notification settings - Fork 0
/
freyafs.py
250 lines (201 loc) · 8.73 KB
/
freyafs.py
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
238
239
240
241
242
243
244
245
246
247
248
249
250
import errno
import math
import os
import json
from pathlib import Path
from fuse import FuseOSError, Operations
from cache import Cache
from metadata import Metadata
from structure import PathInfo, PathStructure
from utils.persist import generate_key, load_from_file, save_to_file
class FreyaFS(Operations):
def __init__(self, root, mountpoint, memory_cap, eviction_technique, dump_metadata):
self.root = Path(root)
self.filename = self.root / '.freyafs'
self.cids = {}
self.key = generate_key(ask_confirm=not os.path.exists(self.filename))
data = load_from_file(self.key, self.filename)
if data is not None:
self.structure = PathStructure.from_dict(data['structure'])
self.metadata = Metadata.from_dict(root=self.root, data=data['metadata'])
self.cids = data['cids']
else:
self.structure = PathStructure()
self.metadata = Metadata(root=self.root)
self.metadata.add_dir(path=self.structure['/'])
# Keep track of open files
self.cache: Cache = Cache(
root=self.root,
memory_cap=memory_cap,
eviction_technique=eviction_technique,
ipfs_cids=self.cids)
print(f'[*] FreyaFS mounted at {mountpoint}')
print(f'FreyaFS will persist your encrypted data at {root}.')
if memory_cap is not None and memory_cap is not math.inf:
print(f'[i] Cache memory cap set at {memory_cap} B (eviction with {eviction_technique.value}).')
if dump_metadata:
print('[i] Some information about the file system')
print('[i] Files')
for path_id, cids in self.cids.items():
info = self.metadata[PathInfo.make(path_id)]
print(f'> ID: {path_id}')
print(f' Size: {info.stats["st_size"]}')
print(f' On disk size (encrypted): {os.path.getsize((self.root / path_id).absolute())}')
print(f' Number of CIDs: {len(cids)}')
print('[i] FreyaFS metadata')
to_write = {
'structure': self.structure.to_dict(),
'metadata': self.metadata.to_dict(),
'cids': self.cids,
}
print(f'> In memory size (JSON): {len(json.dumps(to_write))}')
print(f'> On disk size (encrypted): {os.path.getsize(self.filename)}')
def dump(self):
to_write = {
'structure': self.structure.to_dict(),
'metadata': self.metadata.to_dict(),
'cids': self.cids,
}
save_to_file(self.key, self.filename, to_write)
# --------------------------------------------------------------------- Helpers
def _actual_path(self, path: str):
path_info = self.structure[path]
actual_path = (self.root / path_info.path_id).absolute()
return actual_path
def _cids(self, path: str):
path_info = self.structure[path]
return self.cids[path_info.path_id]
# --------------------------------------------------------------------- Filesystem methods
def access(self, path, mode):
if path not in self.structure:
raise FuseOSError(errno.EACCES)
def chmod(self, path, mode):
path_info = self.structure[path]
self.metadata[path_info].chmod(mode)
def chown(self, path, uid, gid):
path_info = self.structure[path]
self.metadata[path_info].chown(uid, gid)
# Attributi di path (file o cartella)
def getattr(self, path, fh=None):
if path not in self.structure:
raise FuseOSError(errno.ENOENT)
path_info = self.structure.get(path, follow_symlinks=False)
info = self.metadata[path_info]
return info.stats
def readdir(self, path, fh):
yield '.'
yield '..'
for x in self.structure.contents(path):
yield x
def readlink(self, path):
path_info = self.structure.get(path, follow_symlinks=False)
actual_path = path_info.link_to_path
if actual_path.startswith('/'):
# Path name is absolute, sanitize it.
return os.path.relpath(actual_path, self.root)
else:
return actual_path
def mknod(self, path, mode, dev):
actual_path = self._actual_path(path)
return os.mknod(actual_path, mode, dev)
def rmdir(self, path):
path_info = self.structure[path]
del self.structure[path]
del self.metadata[path_info]
def mkdir(self, path, mode):
path_info = PathInfo.make_only_id()
self.structure.add(path, path_info)
self.metadata.add_dir(path_info, mode)
def statfs(self, path):
actual_path = self._actual_path(path)
stv = os.statvfs(actual_path)
return dict((key, getattr(stv, key)) for key in ('f_bavail', 'f_bfree',
'f_blocks', 'f_bsize',
'f_favail', 'f_ffree', 'f_files', 'f_flag',
'f_frsize', 'f_namemax'))
def unlink(self, path):
path_info = self.structure.get(path, follow_symlinks=False)
del self.structure[path]
del self.cids[path_info.path_id]
meta = self.metadata[path_info]
if meta.is_dir():
del self.metadata[path_info]
return
# Meta is file: decrement st_nlink and remove on 0
meta.dec_nlink()
if meta.nlink == 0:
del self.metadata[path_info]
os.remove(self.root / path_info.path_id)
# Used for SOFT links
def symlink(self, name, target):
path_info = PathInfo.make_symlink(target)
self.structure.add(name, path_info)
self.metadata.add_soft_link(path_info, mode=0o777)
# The pointed path is kept in memory at all times for speed,
# but the symlink files contain also the path as their content
self.cache.create(path_info)
bytes_written, size = self.cache.write_bytes(path_info, target.encode('utf-8'), 0)
self.metadata[path_info].set_size(size)
self.cache.flush(path_info)
self.cache.release(path_info)
def rename(self, old, new):
# Renaming only moves around stuff, but does not rename actual files
# on disk, nor fake names. So there is no need to update the cache.
self.structure.rename(old, new)
# Used for HARD links
def link(self, name, target):
info = self.structure.add_hard_link(name, target)
self.metadata[info].inc_nlink()
def utimens(self, path, times=None):
path_info = self.structure[path]
self.metadata[path_info].utimens(times)
# --------------------------------------------------------------------- File methods
def open(self, path, flags):
if path not in self.structure:
raise FuseOSError(errno.ENOENT)
path_info = self.structure[path]
self.cache.open(path_info, self.metadata[path_info].stats['st_mtime'])
return 0
def create(self, path, mode, fi=None):
path_info = PathInfo.make()
self.structure.add(path, path_info)
self.metadata.add_file(path_info, mode)
self.cache.create(path_info)
return 0
def read(self, path, length, offset, fh):
path_info = self.structure[path]
if path_info in self.cache:
return self.cache.read_bytes(path_info, offset, length)
os.lseek(fh, offset, os.SEEK_SET)
return os.read(fh, length)
def write(self, path, buf, offset, fh):
path_info = self.structure[path]
if path_info in self.cache:
bytes_written, size = self.cache.write_bytes(path_info, buf, offset)
self.metadata[path_info].set_size(size)
return bytes_written
os.lseek(fh, offset, os.SEEK_SET)
return os.write(fh, buf)
def truncate(self, path, length, fh=None):
path_info = self.structure[path]
if path_info in self.cache:
self.cache.truncate_bytes(path_info, length)
self.metadata[path_info].set_size(length)
return
actual_path = self._actual_path(path)
with open(actual_path, 'r+') as f:
f.truncate(length)
def flush(self, path, fh):
path_info = self.structure[path]
if path_info in self.cache:
self.cache.flush(path_info, force=True)
return 0
return os.fsync(fh)
def release(self, path, fh):
path_info = self.structure[path]
if path_info in self.cache:
self.cache.release(path_info)
return 0
return os.close(fh)
def fsync(self, path, fdatasync, fh):
return self.flush(path, fh)