Fix write caching; implement more FUSE functions

* write caching was broken in multiple ways
* implemented chmod, rename, truncate, unlink, and utimens
This commit is contained in:
Jarno Seppänen 2014-04-29 23:58:54 +03:00
parent dd20a5a478
commit fb9731868f
1 changed files with 84 additions and 23 deletions

107
gpgfs.py
View File

@ -25,6 +25,7 @@ def decrypt(gpg, path):
if not res.ok:
raise IOError, "decryption failed, %s" % path
data = zlib.decompress(res.data)
log.debug('decrypted %s' % path)
return data
def encrypt(gpg, keyid, path, data):
@ -34,6 +35,7 @@ def encrypt(gpg, keyid, path, data):
raise IOError, "encryption failed, keyid %s, path %s" % (keyid, path)
with file(path, 'w') as fd:
fd.write(res.data)
log.debug('encrypted %s' % path)
class Entry:
'''
@ -79,7 +81,7 @@ def write_dict(fd, dct):
elif isinstance(val, Entry):
buf.write('E')
children.append(val)
elif isinstance(val, int):
elif isinstance(val, (int, long)):
buf.write('I')
buf.write(struct.pack('<I', val))
elif isinstance(val, str):
@ -89,7 +91,7 @@ def write_dict(fd, dct):
buf.write('U')
write_atom(buf, val.encode('utf8'))
else:
raise TypeError, val
raise TypeError, type(val)
write_atom(fd, buf.getvalue())
for c in children:
write_dict(fd, c)
@ -156,15 +158,13 @@ class GpgFs(LoggingMixIn, fuse.Operations):
self.root = read_index(self.gpg, self.index_path)
else:
self.root = Entry(type=ENT_DIR, children={},
st_mode=0755,
st_mtime=int(time.time()),
st_ctime=int(time.time()))
self._write_index()
log.info('created %s', self.index_path)
self.fd = 0
self.write_path = None
self.write_buf = []
self.write_pos = 0
self.write_dirty = False
self._clear_write_cache()
def _write_index(self):
write_index(self.gpg, self.keyid, self.index_path, self.root)
@ -181,8 +181,22 @@ class GpgFs(LoggingMixIn, fuse.Operations):
node = node.children[name]
return node
def _clear_write_cache(self):
self.write_path = None
self.write_buf = []
self.write_len = 0
self.write_dirty = False
def chmod(self, path, mode):
raise fuse.FuseOSError(ENOSYS)
# sanitize mode (clear setuid/gid/sticky bits)
mode &= 0777
ent = self._find(path)
if ent.type == ENT_DIR:
ent.st_mode = mode
self._write_index()
else:
encpath = self.encroot + '/' + ent.path
os.chmod(encpath, mode)
def chown(self, path, uid, gid):
raise fuse.FuseOSError(ENOSYS)
@ -198,18 +212,18 @@ class GpgFs(LoggingMixIn, fuse.Operations):
encdir = self.encroot + '/' + encpath[:2]
if not os.path.exists(encdir):
os.mkdir(encdir, 0755)
with file(self.encroot + '/' + encpath, 'w'):
pass
fd = os.open(self.encroot + '/' + encpath,
os.O_WRONLY | os.O_CREAT, mode & 0777)
os.close(fd)
self._write_index()
self.fd += 1
return self.fd
def flush(self, path, fh):
log.debug('flush %s', path)
if not (path is not None and
path == self.write_path and self.write_dirty):
if not self.write_dirty:
log.debug('nothing to flush')
return 0
ent = self._find(path)
ent = self._find(self.write_path)
encpath = self.encroot + '/' + ent.path
buf = ''.join(self.write_buf)
encrypt(self.gpg, self.keyid, encpath, buf)
@ -217,6 +231,7 @@ class GpgFs(LoggingMixIn, fuse.Operations):
self._write_index()
self.write_buf = [buf]
self.write_dirty = False
log.debug('flushed %d bytes to %s', len(buf), self.write_path)
return 0
def getattr(self, path, fh = None):
@ -225,9 +240,11 @@ class GpgFs(LoggingMixIn, fuse.Operations):
except KeyError:
raise fuse.FuseOSError(ENOENT)
if ent.type == ENT_DIR:
return dict(st_mode = stat.S_IFDIR | 0755, st_size = 0,
return dict(st_mode = stat.S_IFDIR | ent.st_mode, st_size = 0,
st_ctime = ent.st_ctime, st_mtime = ent.st_mtime,
st_atime = 0, st_nlink = 3)
# ensure st_size is up-to-date
self.flush(path, 0)
encpath = self.encroot + '/' + ent.path
s = os.stat(encpath)
return dict(st_mode = s.st_mode, st_size = ent.st_size,
@ -245,6 +262,7 @@ class GpgFs(LoggingMixIn, fuse.Operations):
path = path.rsplit('/', 1)[-1]
assert path not in dir.children
dir.children[path] = Entry(type=ENT_DIR, children={},
st_mode=(mode & 0777),
st_mtime=int(time.time()),
st_ctime=int(time.time()))
self._write_index()
@ -253,6 +271,7 @@ class GpgFs(LoggingMixIn, fuse.Operations):
return 0
def read(self, path, size, offset, fh):
self.flush(path, 0)
ent = self._find(path)
assert ent.type == ENT_FILE
encpath = self.encroot + '/' + ent.path
@ -270,7 +289,18 @@ class GpgFs(LoggingMixIn, fuse.Operations):
raise fuse.FuseOSError(ENOSYS)
def rename(self, old, new):
raise fuse.FuseOSError(ENOSYS)
self.flush(old, 0)
self._clear_write_cache()
old_dir = self._find(old, parent=True)
old_name = old.rsplit('/', 1)[-1]
new_dir = self._find(new, parent=True)
new_name = new.rsplit('/', 1)[-1]
if new_name in new_dir.children:
ent = new_dir.children[new_name]
if ent.type == ENT_FILE:
os.remove(self.encroot + '/' + ent.path)
new_dir.children[new_name] = old_dir.children.pop(old_name)
self._write_index()
def rmdir(self, path):
raise fuse.FuseOSError(ENOSYS)
@ -285,13 +315,44 @@ class GpgFs(LoggingMixIn, fuse.Operations):
raise fuse.FuseOSError(ENOSYS)
def truncate(self, path, length, fh = None):
raise fuse.FuseOSError(ENOSYS)
self.flush(path, 0)
self._clear_write_cache()
ent = self._find(path)
encpath = self.encroot + '/' + ent.path
if length == 0:
with open(encpath, 'r+') as f:
f.truncate(0)
else:
buf = decrypt(self.gpg, encpath)
buf = buf[:length]
encrypt(self.gpg, self.keyid, encpath, buf)
ent.st_size = length
self._write_index()
def unlink(self, path, times = None):
raise fuse.FuseOSError(ENOSYS)
def unlink(self, path):
if self.write_path == path:
# no need to flush afterwards
self._clear_write_cache()
dir = self._find(path, parent=True)
name = path.rsplit('/', 1)[-1]
encpath = self.encroot + '/' + dir.children[name].path
os.remove(encpath)
del dir.children[name]
self._write_index()
def utimens(self, path, times = None):
raise fuse.FuseOSError(ENOSYS)
ent = self._find(path)
if ent.type == ENT_DIR:
if times is None:
ent.st_mtime = int(time.time())
else:
ent.st_mtime = times[1]
self._write_index()
else:
# flush may mess with mtime
self.flush(path, 0)
encpath = self.encroot + '/' + ent.path
os.utime(encpath, times)
def write(self, path, data, offset, fh):
ent = self._find(path)
@ -300,16 +361,16 @@ class GpgFs(LoggingMixIn, fuse.Operations):
self.flush(self.write_path, None)
buf = decrypt(self.gpg, encpath)
self.write_buf = [buf]
self.write_pos = len(buf)
self.write_len = len(buf)
self.write_path = path
if offset == self.write_pos:
if offset == self.write_len:
self.write_buf.append(data)
self.write_pos += len(data)
self.write_len += len(data)
else:
buf = ''.join(self.write_buf)
buf = buf[:offset] + data + buf[offset + len(data):]
self.write_buf = [buf]
self.write_pos = len(buf)
self.write_len = len(buf)
self.write_dirty = True
return len(data)