Merge branch '5095-fuse-ls-takes-forever' closes #5095
[arvados.git] / services / fuse / arvados_fuse / __init__.py
index 607a9413fcf4bb56e2158a21676485d47264537a..71c4ee5a2c4b713aba669a51605f01736b02bfe0 100644 (file)
@@ -5,7 +5,6 @@
 import os
 import sys
 import llfuse
-from llfuse import FUSEError
 import errno
 import stat
 import threading
@@ -17,70 +16,75 @@ import apiclient
 import json
 import logging
 import time
+import _strptime
 import calendar
 import threading
+import itertools
+
+from arvados.util import portable_data_hash_pattern, uuid_pattern, collection_uuid_pattern, group_uuid_pattern, user_uuid_pattern, link_uuid_pattern
 
 _logger = logging.getLogger('arvados.arvados_fuse')
 
-portable_data_hash_pattern = re.compile(r'[0-9a-f]{32}\+\d+')
-uuid_pattern = re.compile(r'[a-z0-9]{5}-[a-z0-9]{5}-[a-z0-9]{15}')
-collection_uuid_pattern = re.compile(r'[a-z0-9]{5}-4zz18-[a-z0-9]{15}')
-group_uuid_pattern = re.compile(r'[a-z0-9]{5}-j7d0g-[a-z0-9]{15}')
-user_uuid_pattern = re.compile(r'[a-z0-9]{5}-tpzed-[a-z0-9]{15}')
-link_uuid_pattern = re.compile(r'[a-z0-9]{5}-o0j2j-[a-z0-9]{15}')
+# Match any character which FUSE or Linux cannot accommodate as part
+# of a filename. (If present in a collection filename, they will
+# appear as underscores in the fuse mount.)
+_disallowed_filename_characters = re.compile('[\x00/]')
 
 class SafeApi(object):
-    '''Threadsafe wrapper for API object.  This stores and returns a different api
-    object per thread, because httplib2 which underlies apiclient is not
-    threadsafe.
-    '''
+    """Threadsafe wrapper for API object.
+
+    This stores and returns a different api object per thread, because
+    httplib2 which underlies apiclient is not threadsafe.
+    """
 
     def __init__(self, config):
         self.host = config.get('ARVADOS_API_HOST')
-        self.token = config.get('ARVADOS_API_TOKEN')
+        self.api_token = config.get('ARVADOS_API_TOKEN')
         self.insecure = config.flag_is_true('ARVADOS_API_HOST_INSECURE')
         self.local = threading.local()
+        self.block_cache = arvados.KeepBlockCache()
 
     def localapi(self):
         if 'api' not in self.local.__dict__:
-            self.local.api = arvados.api('v1', False, self.host, self.token, self.insecure)
+            self.local.api = arvados.api(
+                version='v1',
+                host=self.host, token=self.api_token, insecure=self.insecure)
         return self.local.api
 
-    def collections(self):
-        return self.localapi().collections()
+    def localkeep(self):
+        if 'keep' not in self.local.__dict__:
+            self.local.keep = arvados.KeepClient(api_client=self.localapi(), block_cache=self.block_cache)
+        return self.local.keep
 
-    def links(self):
-        return self.localapi().links()
+    def __getattr__(self, name):
+        # Proxy nonexistent attributes to the local API client.
+        try:
+            return getattr(self.localapi(), name)
+        except AttributeError:
+            return super(SafeApi, self).__getattr__(name)
 
-    def groups(self):
-        return self.localapi().groups()
 
-    def users(self):
-        return self.localapi().users()
-        
 def convertTime(t):
-    '''Parse Arvados timestamp to unix time.'''
-    return calendar.timegm(time.strptime(t, "%Y-%m-%dT%H:%M:%SZ"))
+    """Parse Arvados timestamp to unix time."""
+    if not t:
+        return 0
+    try:
+        return calendar.timegm(time.strptime(t, "%Y-%m-%dT%H:%M:%SZ"))
+    except (TypeError, ValueError):
+        return 0
 
 def sanitize_filename(dirty):
-    '''Remove troublesome characters from filenames.'''
-    # http://www.dwheeler.com/essays/fixing-unix-linux-filenames.html
+    '''Replace disallowed filename characters with harmless "_".'''
     if dirty is None:
         return None
-
-    fn = ""
-    for c in dirty:
-        if (c >= '\x00' and c <= '\x1f') or c == '\x7f' or c == '/':
-            # skip control characters and /
-            continue
-        fn += c
-
-    # strip leading - or ~ and leading/trailing whitespace
-    stripped = fn.lstrip("-~ ").rstrip()
-    if len(stripped) > 0:
-        return stripped
+    elif dirty == '':
+        return '_'
+    elif dirty == '.':
+        return '_'
+    elif dirty == '..':
+        return '__'
     else:
-        return None
+        return _disallowed_filename_characters.sub('_', dirty)
 
 
 class FreshBase(object):
@@ -89,39 +93,35 @@ class FreshBase(object):
         self._stale = True
         self._poll = False
         self._last_update = time.time()
+        self._atime = time.time()
         self._poll_time = 60
 
     # Mark the value as stale
     def invalidate(self):
         self._stale = True
 
-    # Test if the entries dict is stale
+    # Test if the entries dict is stale.
     def stale(self):
         if self._stale:
             return True
         if self._poll:
-            return (self._last_update + self._poll_time) < time.time()
+            return (self._last_update + self._poll_time) < self._atime
         return False
 
     def fresh(self):
         self._stale = False
         self._last_update = time.time()
 
-    def ctime(self):
-        return 0
-
-    def mtime(self):
-        return 0
-
+    def atime(self):
+        return self._atime
 
 class File(FreshBase):
     '''Base for file objects.'''
 
-    def __init__(self, parent_inode, _ctime=0, _mtime=0):
+    def __init__(self, parent_inode, _mtime=0):
         super(File, self).__init__()
         self.inode = None
         self.parent_inode = parent_inode
-        self._ctime = _ctime
         self._mtime = _mtime
 
     def size(self):
@@ -130,9 +130,6 @@ class File(FreshBase):
     def readfrom(self, off, size):
         return ''
 
-    def ctime(self):
-        return self._ctime
-
     def mtime(self):
         return self._mtime
 
@@ -140,8 +137,8 @@ class File(FreshBase):
 class StreamReaderFile(File):
     '''Wraps a StreamFileReader as a file.'''
 
-    def __init__(self, parent_inode, reader, _ctime, _mtime):
-        super(StreamReaderFile, self).__init__(parent_inode, _ctime, _mtime)
+    def __init__(self, parent_inode, reader, _mtime):
+        super(StreamReaderFile, self).__init__(parent_inode, _mtime)
         self.reader = reader
 
     def size(self):
@@ -156,27 +153,26 @@ class StreamReaderFile(File):
 
 class StringFile(File):
     '''Wrap a simple string as a file'''
-    def __init__(self, parent_inode, contents, _ctime, _mtime):
-        super(StringFile, self).__init__(parent_inode, _ctime, _mtime)
+    def __init__(self, parent_inode, contents, _mtime):
+        super(StringFile, self).__init__(parent_inode, _mtime)
         self.contents = contents
 
     def size(self):
         return len(self.contents)
 
     def readfrom(self, off, size):
-        return self.contents[off:(off+size)]    
+        return self.contents[off:(off+size)]
 
 
 class ObjectFile(StringFile):
     '''Wrap a dict as a serialized json object.'''
 
     def __init__(self, parent_inode, obj):
-        super(ObjectFile, self).__init__(parent_inode, "", 0, 0)
+        super(ObjectFile, self).__init__(parent_inode, "", 0)
         self.uuid = obj['uuid']
         self.update(obj)
 
     def update(self, obj):
-        self._ctime = convertTime(obj['created_at']) if 'created_at' in obj else 0
         self._mtime = convertTime(obj['modified_at']) if 'modified_at' in obj else 0
         self.contents = json.dumps(obj, indent=4, sort_keys=True) + "\n"
 
@@ -196,6 +192,7 @@ class Directory(FreshBase):
             raise Exception("parent_inode should be an int")
         self.parent_inode = parent_inode
         self._entries = {}
+        self._mtime = time.time()
 
     #  Overriden by subclasses to implement logic to update the entries dict
     #  when the directory is stale
@@ -252,6 +249,7 @@ class Directory(FreshBase):
 
         oldentries = self._entries
         self._entries = {}
+        changed = False
         for i in items:
             name = sanitize_filename(fn(i))
             if name:
@@ -264,11 +262,17 @@ class Directory(FreshBase):
                     ent = new_entry(i)
                     if ent is not None:
                         self._entries[name] = self.inodes.add_entry(ent)
+                        changed = True
 
         # delete any other directory entries that were not in found in 'items'
-        for i in oldentries:            
+        for i in oldentries:
             llfuse.invalidate_entry(self.inode, str(i))
             self.inodes.del_entry(oldentries[i])
+            changed = True
+
+        if changed:
+            self._mtime = time.time()
+
         self.fresh()
 
     def clear(self):
@@ -280,35 +284,50 @@ class Directory(FreshBase):
                 n.clear()
             llfuse.invalidate_entry(self.inode, str(n))
             self.inodes.del_entry(oldentries[n])
+        llfuse.invalidate_inode(self.inode)
         self.invalidate()
 
+    def mtime(self):
+        return self._mtime
+
 
 class CollectionDirectory(Directory):
     '''Represents the root of a directory tree holding a collection.'''
 
-    def __init__(self, parent_inode, inodes, api, collection):
+    def __init__(self, parent_inode, inodes, api, num_retries, collection):
         super(CollectionDirectory, self).__init__(parent_inode)
         self.inodes = inodes
         self.api = api
+        self.num_retries = num_retries
         self.collection_object_file = None
         self.collection_object = None
         if isinstance(collection, dict):
             self.collection_locator = collection['uuid']
+            self._mtime = convertTime(collection.get('modified_at'))
         else:
             self.collection_locator = collection
+            self._mtime = 0
 
     def same(self, i):
         return i['uuid'] == self.collection_locator or i['portable_data_hash'] == self.collection_locator
 
-    def new_collection(self, new_collection_object):
+    # Used by arv-web.py to switch the contents of the CollectionDirectory
+    def change_collection(self, new_locator):
+        """Switch the contents of the CollectionDirectory.  Must be called with llfuse.lock held."""
+        self.collection_locator = new_locator
+        self.collection_object = None
+        self.update()
+
+    def new_collection(self, new_collection_object, coll_reader):
         self.collection_object = new_collection_object
 
+        self._mtime = convertTime(self.collection_object.get('modified_at'))
+
         if self.collection_object_file is not None:
             self.collection_object_file.update(self.collection_object)
 
         self.clear()
-        collection = arvados.CollectionReader(self.collection_object["manifest_text"], self.api)
-        for s in collection.all_streams():
+        for s in coll_reader.all_streams():
             cwd = self
             for part in s.name().split('/'):
                 if part != '' and part != '.':
@@ -317,35 +336,48 @@ class CollectionDirectory(Directory):
                         cwd._entries[partname] = self.inodes.add_entry(Directory(cwd.inode))
                     cwd = cwd._entries[partname]
             for k, v in s.files().items():
-                cwd._entries[sanitize_filename(k)] = self.inodes.add_entry(StreamReaderFile(cwd.inode, v, self.ctime(), self.mtime()))        
+                cwd._entries[sanitize_filename(k)] = self.inodes.add_entry(StreamReaderFile(cwd.inode, v, self.mtime()))
 
     def update(self):
         try:
             if self.collection_object is not None and portable_data_hash_pattern.match(self.collection_locator):
                 return True
 
+            if self.collection_locator is None:
+                self.fresh()
+                return True
+
             with llfuse.lock_released:
-                new_collection_object = self.api.collections().get(uuid=self.collection_locator).execute()
+                coll_reader = arvados.CollectionReader(
+                    self.collection_locator, self.api, self.api.localkeep(),
+                    num_retries=self.num_retries)
+                new_collection_object = coll_reader.api_response() or {}
+                # If the Collection only exists in Keep, there will be no API
+                # response.  Fill in the fields we need.
+                if 'uuid' not in new_collection_object:
+                    new_collection_object['uuid'] = self.collection_locator
                 if "portable_data_hash" not in new_collection_object:
                     new_collection_object["portable_data_hash"] = new_collection_object["uuid"]
+                if 'manifest_text' not in new_collection_object:
+                    new_collection_object['manifest_text'] = coll_reader.manifest_text()
+                coll_reader.normalize()
             # end with llfuse.lock_released, re-acquire lock
 
             if self.collection_object is None or self.collection_object["portable_data_hash"] != new_collection_object["portable_data_hash"]:
-                self.new_collection(new_collection_object)
+                self.new_collection(new_collection_object, coll_reader)
 
             self.fresh()
             return True
-        except apiclient.errors.HttpError as e:
-            if e.resp.status == 404:
-                _logger.warn("arv-mount %s: not found", self.collection_locator)
-            else:
-                _logger.error("arv-mount %s: error", self.collection_locator)
-                _logger.exception(detail)
-        except Exception as detail:
-            _logger.error("arv-mount %s: error", self.collection_locator)
-            if "manifest_text" in self.collection_object:
+        except arvados.errors.NotFoundError:
+            _logger.exception("arv-mount %s: error", self.collection_locator)
+        except arvados.errors.ArgumentError as detail:
+            _logger.warning("arv-mount %s: error %s", self.collection_locator, detail)
+            if self.collection_object is not None and "manifest_text" in self.collection_object:
+                _logger.warning("arv-mount manifest_text is: %s", self.collection_object["manifest_text"])
+        except Exception:
+            _logger.exception("arv-mount %s: error", self.collection_locator)
+            if self.collection_object is not None and "manifest_text" in self.collection_object:
                 _logger.error("arv-mount manifest_text is: %s", self.collection_object["manifest_text"])
-            _logger.exception(detail)                
         return False
 
     def __getitem__(self, item):
@@ -364,14 +396,6 @@ class CollectionDirectory(Directory):
         else:
             return super(CollectionDirectory, self).__contains__(k)
 
-    def ctime(self):
-        self.checkupdate()
-        return convertTime(self.collection_object["created_at"]) if self.collection_object is not None and 'created_at' in self.collection_object else 0
-
-    def mtime(self):
-        self.checkupdate()
-        return convertTime(self.collection_object["modified_at"]) if self.collection_object is not None and 'modified_at' in self.collection_object else 0
-
 
 class MagicDirectory(Directory):
     '''A special directory that logically contains the set of all extant keep
@@ -383,15 +407,8 @@ class MagicDirectory(Directory):
     to readdir().
     '''
 
-    def __init__(self, parent_inode, inodes, api):
-        super(MagicDirectory, self).__init__(parent_inode)
-        self.inodes = inodes
-        self.api = api
-        self.readme_file = None
-
-    def __contains__(self, k):
-        if self.readme_file is None:
-            text = '''This directory provides access to Arvados collections as subdirectories listed
+    README_TEXT = '''
+This directory provides access to Arvados collections as subdirectories listed
 by uuid (in the form 'zzzzz-4zz18-1234567890abcde') or portable data hash (in
 the form '1234567890abcdefghijklmnopqrstuv+123').
 
@@ -399,10 +416,27 @@ Note that this directory will appear empty until you attempt to access a
 specific collection subdirectory (such as trying to 'cd' into it), at which
 point the collection will actually be looked up on the server and the directory
 will appear if it exists.
-'''
-            self.readme_file = self.inodes.add_entry(StringFile(self.inode, text, 0, 0))
-            self._entries["README"] = self.readme_file
+'''.lstrip()
 
+    def __init__(self, parent_inode, inodes, api, num_retries):
+        super(MagicDirectory, self).__init__(parent_inode)
+        self.inodes = inodes
+        self.api = api
+        self.num_retries = num_retries
+
+    def __setattr__(self, name, value):
+        super(MagicDirectory, self).__setattr__(name, value)
+        # When we're assigned an inode, add a README.
+        if ((name == 'inode') and (self.inode is not None) and
+              (not self._entries)):
+            self._entries['README'] = self.inodes.add_entry(
+                StringFile(self.inode, self.README_TEXT, time.time()))
+            # If we're the root directory, add an identical by_id subdirectory.
+            if self.inode == llfuse.ROOT_INODE:
+                self._entries['by_id'] = self.inodes.add_entry(MagicDirectory(
+                        self.inode, self.inodes, self.api, self.num_retries))
+
+    def __contains__(self, k):
         if k in self._entries:
             return True
 
@@ -410,7 +444,8 @@ will appear if it exists.
             return False
 
         try:
-            e = self.inodes.add_entry(CollectionDirectory(self.inode, self.inodes, self.api, k))
+            e = self.inodes.add_entry(CollectionDirectory(
+                    self.inode, self.inodes, self.api, self.num_retries, k))
             if e.update():
                 self._entries[k] = e
                 return True
@@ -435,8 +470,8 @@ class RecursiveInvalidateDirectory(Directory):
             super(RecursiveInvalidateDirectory, self).invalidate()
             for a in self._entries:
                 self._entries[a].invalidate()
-        except Exception as e:
-            _logger.exception(e)
+        except Exception:
+            _logger.exception()
         finally:
             if self.inode == llfuse.ROOT_INODE:
                 llfuse.lock.release()
@@ -445,24 +480,25 @@ class RecursiveInvalidateDirectory(Directory):
 class TagsDirectory(RecursiveInvalidateDirectory):
     '''A special directory that contains as subdirectories all tags visible to the user.'''
 
-    def __init__(self, parent_inode, inodes, api, poll_time=60):
+    def __init__(self, parent_inode, inodes, api, num_retries, poll_time=60):
         super(TagsDirectory, self).__init__(parent_inode)
         self.inodes = inodes
         self.api = api
-        #try:
-        #    arvados.events.subscribe(self.api, [['object_uuid', 'is_a', 'arvados#link']], lambda ev: self.invalidate())
-        #except:
+        self.num_retries = num_retries
         self._poll = True
         self._poll_time = poll_time
 
     def update(self):
         with llfuse.lock_released:
-            tags = self.api.links().list(filters=[['link_class', '=', 'tag']], select=['name'], distinct = True).execute()
+            tags = self.api.links().list(
+                filters=[['link_class', '=', 'tag']],
+                select=['name'], distinct=True
+                ).execute(num_retries=self.num_retries)
         if "items" in tags:
             self.merge(tags['items'],
-                       lambda i: i['name'] if 'name' in i else i['uuid'],
-                       lambda a, i: a.tag == i,
-                       lambda i: TagDirectory(self.inode, self.inodes, self.api, i['name'], poll=self._poll, poll_time=self._poll_time))
+                       lambda i: i['name'],
+                       lambda a, i: a.tag == i['name'],
+                       lambda i: TagDirectory(self.inode, self.inodes, self.api, self.num_retries, i['name'], poll=self._poll, poll_time=self._poll_time))
 
 
 class TagDirectory(Directory):
@@ -470,46 +506,53 @@ class TagDirectory(Directory):
     to the user that are tagged with a particular tag.
     '''
 
-    def __init__(self, parent_inode, inodes, api, tag, poll=False, poll_time=60):
+    def __init__(self, parent_inode, inodes, api, num_retries, tag,
+                 poll=False, poll_time=60):
         super(TagDirectory, self).__init__(parent_inode)
         self.inodes = inodes
         self.api = api
+        self.num_retries = num_retries
         self.tag = tag
         self._poll = poll
         self._poll_time = poll_time
 
     def update(self):
         with llfuse.lock_released:
-            taggedcollections = self.api.links().list(filters=[['link_class', '=', 'tag'],
-                                                   ['name', '=', self.tag],
-                                                   ['head_uuid', 'is_a', 'arvados#collection']],
-                                          select=['head_uuid']).execute()
+            taggedcollections = self.api.links().list(
+                filters=[['link_class', '=', 'tag'],
+                         ['name', '=', self.tag],
+                         ['head_uuid', 'is_a', 'arvados#collection']],
+                select=['head_uuid']
+                ).execute(num_retries=self.num_retries)
         self.merge(taggedcollections['items'],
                    lambda i: i['head_uuid'],
                    lambda a, i: a.collection_locator == i['head_uuid'],
-                   lambda i: CollectionDirectory(self.inode, self.inodes, self.api, i['head_uuid']))
+                   lambda i: CollectionDirectory(self.inode, self.inodes, self.api, self.num_retries, i['head_uuid']))
 
 
-class ProjectDirectory(RecursiveInvalidateDirectory):
+class ProjectDirectory(Directory):
     '''A special directory that contains the contents of a project.'''
 
-    def __init__(self, parent_inode, inodes, api, project_object, poll=False, poll_time=60):
+    def __init__(self, parent_inode, inodes, api, num_retries, project_object,
+                 poll=False, poll_time=60):
         super(ProjectDirectory, self).__init__(parent_inode)
         self.inodes = inodes
         self.api = api
+        self.num_retries = num_retries
         self.project_object = project_object
-        self.project_object_file = ObjectFile(self.inode, self.project_object)
-        self.inodes.add_entry(self.project_object_file)
+        self.project_object_file = None
         self.uuid = project_object['uuid']
+        self._poll = poll
+        self._poll_time = poll_time
 
     def createDirectory(self, i):
         if collection_uuid_pattern.match(i['uuid']):
-            return CollectionDirectory(self.inode, self.inodes, self.api, i)
+            return CollectionDirectory(self.inode, self.inodes, self.api, self.num_retries, i)
         elif group_uuid_pattern.match(i['uuid']):
-            return ProjectDirectory(self.inode, self.inodes, self.api, i, self._poll, self._poll_time)
+            return ProjectDirectory(self.inode, self.inodes, self.api, self.num_retries, i, self._poll, self._poll_time)
         elif link_uuid_pattern.match(i['uuid']):
             if i['head_kind'] == 'arvados#collection' or portable_data_hash_pattern.match(i['head_uuid']):
-                return CollectionDirectory(self.inode, self.inodes, self.api, i['head_uuid'])
+                return CollectionDirectory(self.inode, self.inodes, self.api, self.num_retries, i['head_uuid'])
             else:
                 return None
         elif uuid_pattern.match(i['uuid']):
@@ -518,6 +561,10 @@ class ProjectDirectory(RecursiveInvalidateDirectory):
             return None
 
     def update(self):
+        if self.project_object_file == None:
+            self.project_object_file = ObjectFile(self.inode, self.project_object)
+            self.inodes.add_entry(self.project_object_file)
+
         def namefn(i):
             if 'name' in i:
                 if i['name'] is None or len(i['name']) == 0:
@@ -530,7 +577,7 @@ class ProjectDirectory(RecursiveInvalidateDirectory):
                     return i['name']
                 elif 'kind' in i and i['kind'].startswith('arvados#'):
                     # something else
-                    return "{}.{}".format(i['name'], i['kind'][8:])                    
+                    return "{}.{}".format(i['name'], i['kind'][8:])
             else:
                 return None
 
@@ -545,14 +592,20 @@ class ProjectDirectory(RecursiveInvalidateDirectory):
 
         with llfuse.lock_released:
             if group_uuid_pattern.match(self.uuid):
-                self.project_object = self.api.groups().get(uuid=self.uuid).execute()
+                self.project_object = self.api.groups().get(
+                    uuid=self.uuid).execute(num_retries=self.num_retries)
             elif user_uuid_pattern.match(self.uuid):
-                self.project_object = self.api.users().get(uuid=self.uuid).execute()
+                self.project_object = self.api.users().get(
+                    uuid=self.uuid).execute(num_retries=self.num_retries)
 
-            contents = arvados.util.list_all(self.api.groups().contents, uuid=self.uuid)
+            contents = arvados.util.list_all(self.api.groups().contents,
+                                             self.num_retries, uuid=self.uuid)
             # Name links will be obsolete soon, take this out when there are no more pre-#3036 in use.
-            contents += arvados.util.list_all(self.api.links().list, filters=[['tail_uuid', '=', self.uuid], ['link_class', '=', 'name']])
-            
+            contents += arvados.util.list_all(
+                self.api.links().list, self.num_retries,
+                filters=[['tail_uuid', '=', self.uuid],
+                         ['link_class', '=', 'name']])
+
         # end with llfuse.lock_released, re-acquire lock
 
         self.merge(contents,
@@ -573,31 +626,25 @@ class ProjectDirectory(RecursiveInvalidateDirectory):
         else:
             return super(ProjectDirectory, self).__contains__(k)
 
-    def ctime(self):
-        return convertTime(self.project_object["created_at"]) if "created_at" in self.project_object else 0
-
-    def mtime(self):
-        return convertTime(self.project_object["modified_at"]) if "modified_at" in self.project_object  else 0
 
-
-class SharedDirectory(RecursiveInvalidateDirectory):
+class SharedDirectory(Directory):
     '''A special directory that represents users or groups who have shared projects with me.'''
 
-    def __init__(self, parent_inode, inodes, api, exclude, poll=False, poll_time=60):
+    def __init__(self, parent_inode, inodes, api, num_retries, exclude,
+                 poll=False, poll_time=60):
         super(SharedDirectory, self).__init__(parent_inode)
-        self.current_user = api.users().current().execute()
         self.inodes = inodes
         self.api = api
-
-        # try:
-        #     arvados.events.subscribe(self.api, [], lambda ev: self.invalidate())
-        # except:
+        self.num_retries = num_retries
+        self.current_user = api.users().current().execute(num_retries=num_retries)
         self._poll = True
         self._poll_time = poll_time
 
     def update(self):
         with llfuse.lock_released:
-            all_projects = arvados.util.list_all(self.api.groups().list, filters=[['group_class','=','project']])
+            all_projects = arvados.util.list_all(
+                self.api.groups().list, self.num_retries,
+                filters=[['group_class','=','project']])
             objects = {}
             for ob in all_projects:
                 objects[ob['uuid']] = ob
@@ -609,8 +656,12 @@ class SharedDirectory(RecursiveInvalidateDirectory):
                     roots.append(ob)
                     root_owners[ob['owner_uuid']] = True
 
-            lusers = arvados.util.list_all(self.api.users().list, filters=[['uuid','in', list(root_owners)]])
-            lgroups = arvados.util.list_all(self.api.groups().list, filters=[['uuid','in', list(root_owners)]])
+            lusers = arvados.util.list_all(
+                self.api.users().list, self.num_retries,
+                filters=[['uuid','in', list(root_owners)]])
+            lgroups = arvados.util.list_all(
+                self.api.groups().list, self.num_retries,
+                filters=[['uuid','in', list(root_owners)]])
 
             users = {}
             groups = {}
@@ -639,9 +690,9 @@ class SharedDirectory(RecursiveInvalidateDirectory):
             self.merge(contents.items(),
                        lambda i: i[0],
                        lambda a, i: a.uuid == i[1]['uuid'],
-                       lambda i: ProjectDirectory(self.inode, self.inodes, self.api, i[1], poll=self._poll, poll_time=self._poll_time))
-        except Exception as e:
-            _logger.exception(e)
+                       lambda i: ProjectDirectory(self.inode, self.inodes, self.api, self.num_retries, i[1], poll=self._poll, poll_time=self._poll_time))
+        except Exception:
+            _logger.exception()
 
 
 class FileHandle(object):
@@ -659,7 +710,7 @@ class Inodes(object):
 
     def __init__(self):
         self._entries = {}
-        self._counter = llfuse.ROOT_INODE
+        self._counter = itertools.count(llfuse.ROOT_INODE)
 
     def __getitem__(self, item):
         return self._entries[item]
@@ -677,9 +728,8 @@ class Inodes(object):
         return k in self._entries
 
     def add_entry(self, entry):
-        entry.inode = self._counter
+        entry.inode = next(self._counter)
         self._entries[entry.inode] = entry
-        self._counter += 1
         return entry
 
     def del_entry(self, entry):
@@ -695,12 +745,13 @@ class Operations(llfuse.Operations):
     so request handlers do not run concurrently unless the lock is explicitly released
     using "with llfuse.lock_released:"'''
 
-    def __init__(self, uid, gid):
+    def __init__(self, uid, gid, encoding="utf-8"):
         super(Operations, self).__init__()
 
         self.inodes = Inodes()
         self.uid = uid
         self.gid = gid
+        self.encoding = encoding
 
         # dict of inode to filehandle
         self._filehandles = {}
@@ -733,6 +784,8 @@ class Operations(llfuse.Operations):
         entry.st_mode = stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH
         if isinstance(e, Directory):
             entry.st_mode |= stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH | stat.S_IFDIR
+        elif isinstance(e, StreamReaderFile):
+            entry.st_mode |= stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH | stat.S_IFREG
         else:
             entry.st_mode |= stat.S_IFREG
 
@@ -744,16 +797,15 @@ class Operations(llfuse.Operations):
         entry.st_size = e.size()
 
         entry.st_blksize = 512
-        entry.st_blocks = (e.size()/512)
-        if e.size()/512 != 0:
-            entry.st_blocks += 1
-        entry.st_atime = 0
-        entry.st_mtime = e.mtime()
-        entry.st_ctime = e.ctime()
+        entry.st_blocks = (e.size()/512)+1
+        entry.st_atime = int(e.atime())
+        entry.st_mtime = int(e.mtime())
+        entry.st_ctime = int(e.mtime())
 
         return entry
 
     def lookup(self, parent_inode, name):
+        name = unicode(name, self.encoding)
         _logger.debug("arv-mount lookup: parent_inode %i name %s",
                       parent_inode, name)
         inode = None
@@ -765,7 +817,7 @@ class Operations(llfuse.Operations):
                 p = self.inodes[parent_inode]
                 if name == '..':
                     inode = p.parent_inode
-                elif name in p:
+                elif isinstance(p, Directory) and name in p:
                     inode = p[name].inode
 
         if inode != None:
@@ -797,10 +849,17 @@ class Operations(llfuse.Operations):
         else:
             raise llfuse.FUSEError(errno.EBADF)
 
+        # update atime
+        handle.entry._atime = time.time()
+
         try:
             with llfuse.lock_released:
                 return handle.entry.readfrom(off, size)
-        except:
+        except arvados.errors.NotFoundError as e:
+            _logger.warning("Block not found: " + str(e))
+            raise llfuse.FUSEError(errno.EIO)
+        except Exception:
+            _logger.exception()
             raise llfuse.FUSEError(errno.EIO)
 
     def release(self, fh):
@@ -825,6 +884,9 @@ class Operations(llfuse.Operations):
         else:
             raise llfuse.FUSEError(errno.EIO)
 
+        # update atime
+        p._atime = time.time()
+
         self._filehandles[fh] = FileHandle(fh, [('.', p), ('..', parent)] + list(p.items()))
         return fh
 
@@ -841,7 +903,10 @@ class Operations(llfuse.Operations):
         e = off
         while e < len(handle.entry):
             if handle.entry[e][1].inode in self.inodes:
-                yield (handle.entry[e][0], self.getattr(handle.entry[e][1].inode), e+1)
+                try:
+                    yield (handle.entry[e][0].encode(self.encoding), self.getattr(handle.entry[e][1].inode), e+1)
+                except UnicodeEncodeError:
+                    pass
             e += 1
 
     def releasedir(self, fh):