1 """FUSE driver for Arvados Keep
5 There is one `Operations` object per mount point. It is the entry point for all
6 read and write requests from the llfuse module.
8 The operations object owns an `Inodes` object. The inodes object stores the
9 mapping from numeric inode (used throughout the file system API to uniquely
10 identify files) to the Python objects that implement files and directories.
12 The `Inodes` object owns an `InodeCache` object. The inode cache records the
13 memory footprint of file system objects and when they are last used. When the
14 cache limit is exceeded, the least recently used objects are cleared.
16 File system objects inherit from `fresh.FreshBase` which manages the object lifecycle.
18 File objects inherit from `fusefile.File`. Key methods are `readfrom` and `writeto`
19 which implement actual reads and writes.
21 Directory objects inherit from `fusedir.Directory`. The directory object wraps
22 a Python dict which stores the mapping from filenames to directory entries.
23 Directory contents can be accessed through the Python operators such as `[]`
24 and `in`. These methods automatically check if the directory is fresh (up to
25 date) or stale (needs update) and will call `update` if necessary before
28 The general FUSE operation flow is as follows:
30 - The request handler is called with either an inode or file handle that is the
31 subject of the operation.
33 - Look up the inode using the Inodes table or the file handle in the
34 filehandles table to get the file system object.
36 - For methods that alter files or directories, check that the operation is
37 valid and permitted using _check_writable().
39 - Call the relevant method on the file system object.
43 The FUSE driver supports the Arvados event bus. When an event is received for
44 an object that is live in the inode cache, that object is immediately updated.
70 from fusedir import sanitize_filename, Directory, CollectionDirectory, MagicDirectory, TagsDirectory, ProjectDirectory, SharedDirectory, CollectionDirectoryBase
71 from fusefile import StringFile, FuseArvadosFile
73 _logger = logging.getLogger('arvados.arvados_fuse')
75 # Uncomment this to enable llfuse debug logging.
76 # log_handler = logging.StreamHandler()
77 # llogger = logging.getLogger('llfuse')
78 # llogger.addHandler(log_handler)
79 # llogger.setLevel(logging.DEBUG)
82 """Connects a numeric file handle to a File or Directory object that has
83 been opened by the client."""
85 def __init__(self, fh, obj):
94 return self.obj.flush()
97 class FileHandle(Handle):
98 """Connects a numeric file handle to a File object that has
99 been opened by the client."""
103 class DirectoryHandle(Handle):
104 """Connects a numeric file handle to a Directory object that has
105 been opened by the client."""
107 def __init__(self, fh, dirobj, entries):
108 super(DirectoryHandle, self).__init__(fh, dirobj)
109 self.entries = entries
112 class InodeCache(object):
113 """Records the memory footprint of objects and when they are last used.
115 When the cache limit is exceeded, the least recently used objects are
116 cleared. Clearing the object means discarding its contents to release
117 memory. The next time the object is accessed, it must be re-fetched from
118 the server. Note that the inode cache limit is a soft limit; the cache
119 limit may be exceeded if necessary to load very large objects, it may also
120 be exceeded if open file handles prevent objects from being cleared.
124 def __init__(self, cap, min_entries=4):
125 self._entries = collections.OrderedDict()
127 self._counter = itertools.count(0)
130 self.min_entries = min_entries
135 def _remove(self, obj, clear):
136 if clear and not obj.clear():
137 _logger.debug("InodeCache could not clear %i in_use %s", obj.inode, obj.in_use())
139 self._total -= obj.cache_size
140 del self._entries[obj.cache_priority]
142 del self._by_uuid[obj.cache_uuid]
143 obj.cache_uuid = None
145 _logger.debug("InodeCache cleared %i total now %i", obj.inode, self._total)
149 if self._total > self.cap:
150 for key in list(self._entries.keys()):
151 if self._total < self.cap or len(self._entries) < self.min_entries:
153 self._remove(self._entries[key], True)
155 def manage(self, obj):
157 obj.cache_priority = next(self._counter)
158 obj.cache_size = obj.objsize()
159 self._entries[obj.cache_priority] = obj
160 obj.cache_uuid = obj.uuid()
162 self._by_uuid[obj.cache_uuid] = obj
163 self._total += obj.objsize()
164 _logger.debug("InodeCache touched %i (size %i) total now %i", obj.inode, obj.objsize(), self._total)
167 obj.cache_priority = None
169 def touch(self, obj):
171 if obj.cache_priority in self._entries:
172 self._remove(obj, False)
175 def unmanage(self, obj):
176 if obj.persisted() and obj.cache_priority in self._entries:
177 self._remove(obj, True)
179 def find(self, uuid):
180 return self._by_uuid.get(uuid)
182 class Inodes(object):
183 """Manage the set of inodes. This is the mapping from a numeric id
184 to a concrete File or Directory object"""
186 def __init__(self, inode_cache, encoding="utf-8"):
188 self._counter = itertools.count(llfuse.ROOT_INODE)
189 self.inode_cache = inode_cache
190 self.encoding = encoding
192 def __getitem__(self, item):
193 return self._entries[item]
195 def __setitem__(self, key, item):
196 self._entries[key] = item
199 return self._entries.iterkeys()
202 return self._entries.items()
204 def __contains__(self, k):
205 return k in self._entries
207 def touch(self, entry):
208 entry._atime = time.time()
209 self.inode_cache.touch(entry)
211 def add_entry(self, entry):
212 entry.inode = next(self._counter)
213 if entry.inode == llfuse.ROOT_INODE:
215 self._entries[entry.inode] = entry
216 self.inode_cache.manage(entry)
219 def del_entry(self, entry):
220 if entry.ref_count == 0:
221 _logger.debug("Deleting inode %i", entry.inode)
222 self.inode_cache.unmanage(entry)
223 llfuse.invalidate_inode(entry.inode)
225 del self._entries[entry.inode]
229 _logger.debug("del_entry on inode %i with refcount %i", entry.inode, entry.ref_count)
232 def catch_exceptions(orig_func):
233 """Catch uncaught exceptions and log them consistently."""
235 @functools.wraps(orig_func)
236 def catch_exceptions_wrapper(self, *args, **kwargs):
238 return orig_func(self, *args, **kwargs)
239 except llfuse.FUSEError:
241 except EnvironmentError as e:
242 raise llfuse.FUSEError(e.errno)
244 _logger.exception("Unhandled exception during FUSE operation")
245 raise llfuse.FUSEError(errno.EIO)
247 return catch_exceptions_wrapper
250 class Operations(llfuse.Operations):
251 """This is the main interface with llfuse.
253 The methods on this object are called by llfuse threads to service FUSE
254 events to query and read from the file system.
256 llfuse has its own global lock which is acquired before calling a request handler,
257 so request handlers do not run concurrently unless the lock is explicitly released
258 using 'with llfuse.lock_released:'
262 def __init__(self, uid, gid, encoding="utf-8", inode_cache=None, num_retries=4):
263 super(Operations, self).__init__()
266 inode_cache = InodeCache(cap=256*1024*1024)
267 self.inodes = Inodes(inode_cache, encoding=encoding)
271 # dict of inode to filehandle
272 self._filehandles = {}
273 self._filehandles_counter = itertools.count(0)
275 # Other threads that need to wait until the fuse driver
276 # is fully initialized should wait() on this event object.
277 self.initlock = threading.Event()
279 self.num_retries = num_retries
284 # Allow threads that are waiting for the driver to be finished
285 # initializing to continue
294 for k,v in self.inodes.items():
298 def access(self, inode, mode, ctx):
301 def listen_for_events(self, api_client):
302 self.events = arvados.events.subscribe(api_client,
303 [["event_type", "in", ["create", "update", "delete"]]],
307 def on_event(self, ev):
308 if 'event_type' in ev:
310 item = self.inodes.inode_cache.find(ev["object_uuid"])
313 if ev["object_kind"] == "arvados#collection":
314 new_attr = ev.get("properties") and ev["properties"].get("new_attributes") and ev["properties"]["new_attributes"]
315 record_version = (new_attr["modified_at"], new_attr["portable_data_hash"]) if new_attr else None
316 item.update(to_record_version=record_version)
320 oldowner = ev.get("properties") and ev["properties"].get("old_attributes") and ev["properties"]["old_attributes"].get("owner_uuid")
321 olditemparent = self.inodes.inode_cache.find(oldowner)
322 if olditemparent is not None:
323 olditemparent.invalidate()
324 olditemparent.update()
326 itemparent = self.inodes.inode_cache.find(ev["object_owner_uuid"])
327 if itemparent is not None:
328 itemparent.invalidate()
332 def getattr(self, inode):
333 if inode not in self.inodes:
334 raise llfuse.FUSEError(errno.ENOENT)
336 e = self.inodes[inode]
338 entry = llfuse.EntryAttributes()
341 entry.entry_timeout = 60
342 entry.attr_timeout = 60
344 entry.st_mode = stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH
345 if isinstance(e, Directory):
346 entry.st_mode |= stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH | stat.S_IFDIR
348 entry.st_mode |= stat.S_IFREG
349 if isinstance(e, FuseArvadosFile):
350 entry.st_mode |= stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
353 entry.st_mode |= stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH
356 entry.st_uid = self.uid
357 entry.st_gid = self.gid
360 entry.st_size = e.size()
362 entry.st_blksize = 512
363 entry.st_blocks = (entry.st_size/512)+1
364 entry.st_atime = int(e.atime())
365 entry.st_mtime = int(e.mtime())
366 entry.st_ctime = int(e.mtime())
371 def setattr(self, inode, attr):
372 entry = self.getattr(inode)
374 e = self.inodes[inode]
376 if attr.st_size is not None and isinstance(e, FuseArvadosFile):
377 with llfuse.lock_released:
378 e.arvfile.truncate(attr.st_size)
379 entry.st_size = e.arvfile.size()
384 def lookup(self, parent_inode, name):
385 name = unicode(name, self.inodes.encoding)
391 if parent_inode in self.inodes:
392 p = self.inodes[parent_inode]
394 inode = p.parent_inode
395 elif isinstance(p, Directory) and name in p:
396 inode = p[name].inode
399 _logger.debug("arv-mount lookup: parent_inode %i name '%s' inode %i",
400 parent_inode, name, inode)
401 self.inodes[inode].inc_ref()
402 return self.getattr(inode)
404 _logger.debug("arv-mount lookup: parent_inode %i name '%s' not found",
406 raise llfuse.FUSEError(errno.ENOENT)
409 def forget(self, inodes):
410 for inode, nlookup in inodes:
411 ent = self.inodes[inode]
412 _logger.debug("arv-mount forget: inode %i nlookup %i ref_count %i", inode, nlookup, ent.ref_count)
413 if ent.dec_ref(nlookup) == 0 and ent.dead:
414 self.inodes.del_entry(ent)
417 def open(self, inode, flags):
418 if inode in self.inodes:
419 p = self.inodes[inode]
421 raise llfuse.FUSEError(errno.ENOENT)
423 if isinstance(p, Directory):
424 raise llfuse.FUSEError(errno.EISDIR)
426 if ((flags & os.O_WRONLY) or (flags & os.O_RDWR)) and not p.writable():
427 raise llfuse.FUSEError(errno.EPERM)
429 fh = next(self._filehandles_counter)
430 self._filehandles[fh] = FileHandle(fh, p)
435 def read(self, fh, off, size):
436 _logger.debug("arv-mount read %i %i %i", fh, off, size)
437 if fh in self._filehandles:
438 handle = self._filehandles[fh]
440 raise llfuse.FUSEError(errno.EBADF)
442 self.inodes.touch(handle.obj)
445 return handle.obj.readfrom(off, size, self.num_retries)
446 except arvados.errors.NotFoundError as e:
447 _logger.error("Block not found: " + str(e))
448 raise llfuse.FUSEError(errno.EIO)
451 def write(self, fh, off, buf):
452 _logger.debug("arv-mount write %i %i %i", fh, off, len(buf))
453 if fh in self._filehandles:
454 handle = self._filehandles[fh]
456 raise llfuse.FUSEError(errno.EBADF)
458 if not handle.obj.writable():
459 raise llfuse.FUSEError(errno.EPERM)
461 self.inodes.touch(handle.obj)
463 return handle.obj.writeto(off, buf, self.num_retries)
466 def release(self, fh):
467 if fh in self._filehandles:
469 self._filehandles[fh].flush()
470 except EnvironmentError as e:
471 raise llfuse.FUSEError(e.errno)
473 _logger.exception("Flush error")
474 self._filehandles[fh].release()
475 del self._filehandles[fh]
476 self.inodes.inode_cache.cap_cache()
478 def releasedir(self, fh):
482 def opendir(self, inode):
483 _logger.debug("arv-mount opendir: inode %i", inode)
485 if inode in self.inodes:
486 p = self.inodes[inode]
488 raise llfuse.FUSEError(errno.ENOENT)
490 if not isinstance(p, Directory):
491 raise llfuse.FUSEError(errno.ENOTDIR)
493 fh = next(self._filehandles_counter)
494 if p.parent_inode in self.inodes:
495 parent = self.inodes[p.parent_inode]
497 raise llfuse.FUSEError(errno.EIO)
502 self._filehandles[fh] = DirectoryHandle(fh, p, [('.', p), ('..', parent)] + list(p.items()))
506 def readdir(self, fh, off):
507 _logger.debug("arv-mount readdir: fh %i off %i", fh, off)
509 if fh in self._filehandles:
510 handle = self._filehandles[fh]
512 raise llfuse.FUSEError(errno.EBADF)
514 _logger.debug("arv-mount handle.dirobj %s", handle.obj)
517 while e < len(handle.entries):
518 if handle.entries[e][1].inode in self.inodes:
519 yield (handle.entries[e][0].encode(self.inodes.encoding), self.getattr(handle.entries[e][1].inode), e+1)
524 st = llfuse.StatvfsData()
525 st.f_bsize = 128 * 1024
538 def _check_writable(self, inode_parent):
539 if inode_parent in self.inodes:
540 p = self.inodes[inode_parent]
542 raise llfuse.FUSEError(errno.ENOENT)
544 if not isinstance(p, Directory):
545 raise llfuse.FUSEError(errno.ENOTDIR)
548 raise llfuse.FUSEError(errno.EPERM)
553 def create(self, inode_parent, name, mode, flags, ctx):
554 p = self._check_writable(inode_parent)
557 # The file entry should have been implicitly created by callback.
559 fh = next(self._filehandles_counter)
560 self._filehandles[fh] = FileHandle(fh, f)
564 return (fh, self.getattr(f.inode))
567 def mkdir(self, inode_parent, name, mode, ctx):
568 _logger.debug("arv-mount mkdir: %i '%s' %o", inode_parent, name, mode)
570 p = self._check_writable(inode_parent)
573 # The dir entry should have been implicitly created by callback.
577 return self.getattr(d.inode)
580 def unlink(self, inode_parent, name):
581 _logger.debug("arv-mount unlink: %i '%s'", inode_parent, name)
582 p = self._check_writable(inode_parent)
586 def rmdir(self, inode_parent, name):
587 _logger.debug("arv-mount rmdir: %i '%s'", inode_parent, name)
588 p = self._check_writable(inode_parent)
592 def rename(self, inode_parent_old, name_old, inode_parent_new, name_new):
593 _logger.debug("arv-mount rename: %i '%s' %i '%s'", inode_parent_old, name_old, inode_parent_new, name_new)
594 src = self._check_writable(inode_parent_old)
595 dest = self._check_writable(inode_parent_new)
596 dest.rename(name_old, name_new, src)
600 if fh in self._filehandles:
601 self._filehandles[fh].flush()
603 def fsync(self, fh, datasync):
606 def fsyncdir(self, fh, datasync):