def read(self, path, size=0, offset=0, id=None): """ Read the required bytes from the file and return a buffer containing the bytes. """ ## Read from the requested filehandle, which was set during 'open' if id is None: raise FuseOSError(EIO) vos.logger.debug("reading range: %s %d %d %d" % (path, size, offset, id)) try: fh = HandleWrapper.findHandle(id) except KeyError: raise FuseOSError(EIO) try: return fh.cacheFileHandle.read(size, offset) except CacheRetry: e = FuseOSError(EAGAIN) e.strerror = "Timeout waiting for file read" vos.logger.debug("Timeout Waiting for file read: %s", path) raise e
def create(self, path, flags, fi=None): """Create a node. Currently ignores the ownership mode @param path: the container/dataNode in VOSpace to be created @param flags: Read/Write settings (eg. 600) """ logger.debug("Creating a node: %s with flags %s" % (path, str(flags))) # Create is handle by the client. # This should fail if the basepath doesn't exist try: self.client.open(path, os.O_CREAT).close() node = self.getNode(path) parent = self.getNode(os.path.dirname(path)) # Force inheritance of group settings. node.groupread = parent.groupread node.groupwrite = parent.groupwrite if node.chmod(flags): # chmod returns True if the mode changed but doesn't do update. self.client.update(node) self.getNode(path, force=True) except Exception as e: logger.error(str(e)) logger.error("Error trying to create Node {0}".format(path)) f = FuseOSError(getattr(e, 'errno', EIO)) f.strerror = getattr(e, 'strerror', 'failed to create {0}'.format(path)) raise f ## now we can just open the file in the usual way and return the handle return self.open(path, os.O_WRONLY)
def write(self, path, data, size, offset, id=None): import ctypes if self.opt.readonly: vos.logger.debug("File system is readonly.. so writing 0 bytes\n") return 0 try: fh = HandleWrapper.findHandle(id) except KeyError: raise FuseOSError(EIO) if fh.readOnly: vos.logger.debug("file was not opened for writing") raise FuseOSError(EPERM) vos.logger.debug("%s -> %s" % (path, fh)) vos.logger.debug("%d --> %d" % (offset, offset + size)) try: return fh.cacheFileHandle.write(data, size, offset) except CacheRetry: e = FuseOSError(EAGAIN) e.strerror = "Timeout waiting for file write" vos.logger.debug("Timeout Waiting for file write: %s", path) raise e
def getNode(self, path, force=False, limit=0): """Use the client and pull the node from VOSpace. Currently force=False is the default... so we never check VOSpace to see if the node metadata is different from what we have. This doesn't keep the node metadata current but is faster if VOSpace is slow. """ vos.logger.debug("force? -> %s path -> %s" % (force, path)) ## Pull the node meta data from VOSpace. try: vos.logger.debug("requesting node %s from VOSpace" % (path)) node = self.client.getNode(path, force=force, limit=limit) except Exception as e: vos.logger.debug(str(e)) vos.logger.debug(type(e)) ex = FuseOSError(getattr(e, 'errno', ENOENT)) ex.filename = path ex.strerror = getattr(e, 'strerror', 'Error getting %s' % (path)) vos.logger.debug("failing with errno = %d" % ex.errno) raise ex return node
def create(self, path, flags): """Create a node. Currently ignores the ownership mode""" vos.logger.debug("Creating a node: %s with flags %s" % (path, str(flags))) # Create is handle by the client. # This should fail if the basepath doesn't exist try: self.client.open(path, os.O_CREAT).close() node = self.getNode(path) parent = self.getNode(os.path.dirname(path)) # Force inheritance of group settings. node.groupread = parent.groupread node.groupwrite = parent.groupwrite if node.chmod(flags): # chmod returns True if the mode changed but doesn't do update. self.client.update(node) node = self.getNode(path, force=True) except Exception as e: vos.logger.error(str(e)) vos.logger.error("Error trying to create Node %s" % (path)) f = FuseOSError(getattr(e, 'errno', EIO)) f.strerror = getattr(e, 'strerror', 'failed to create %s' % (path)) raise f ## now we can just open the file in the usual way and return the handle return self.open(path, os.O_WRONLY)
def chmod(self, path, mode): """ Set the read/write groups on the VOSpace node based on chmod style modes. This function is a bit funny as the VOSpace spec sets the name of the read and write groups instead of having mode setting as a separate action. A chmod that adds group permission thus becomes a chgrp action. Here I use the logic that the new group will be inherited from the container group information. """ vos.logger.debug("Changing mode for %s to %d" % (path, mode)) node = self.getNode(path) parent = self.getNode(os.path.dirname(path)) if node.groupread == "NONE": node.groupread = parent.groupread if node.groupwrite == "NONE": node.groupwrite = parent.groupwrite # The 'node' object returned by getNode has a chmod method # that we now call to set the mod, since we set the group(s) # above. NOTE: If the parrent doesn't have group then NONE is # passed up and the groupwrite and groupread will be set tovos: # the string NONE. if node.chmod(mode): # Now set the time of change/modification on the path... # TODO: This has to be broken. Attributes may come from Cache if # the file is modified. Even if they don't come from the cache, # the getAttr method calls getNode with force=True, which returns # a different Node object than "node". The st_ctime value will be # updated on the newly replaced node in self.node[path] but # not in node, then node is pushed to vospace without the st_time # change, and then it is pulled back, overwriting the change that # was made in self.node[path]. Plus modifying the mtime of the file # is not conventional Unix behaviour. The mtime of the parent # directory would be changed. self.getattr(path)['st_ctime'] = time.time() ## if node.chmod returns false then no changes were made. try: self.client.update(node) self.getNode(path, force=True) except Exception as e: vos.logger.debug(str(e)) vos.logger.debug(type(e)) e = FuseOSError(getattr(e, 'errno', EIO)) e.filename = path e.strerror = getattr(e, 'strerror', 'failed to chmod on %s' % (path)) raise e
def __init__(self, root, cache_dir, options, conn=None, cache_limit=1024, cache_nodes=False, cache_max_flush_threads=10, secure_get=False): """Initialize the VOFS. cache_limit is in MB. The style here is to use dictionaries to contain information about the Node. The full VOSpace path is used as the Key for most of these dictionaries.""" self.cache_nodes = cache_nodes # Standard attributes of the Node # Where in the file system this Node is currently located self.loading_dir = {} # Command line options. self.opt = options # What is the 'root' of the VOSpace? (eg vos:MyVOSpace) self.root = root # VOSpace is a bit slow so we do some caching. self.cache = Cache(cache_dir, cache_limit, False, VOFS.cacheTimeout, maxFlushThreads=cache_max_flush_threads) # All communication with the VOSpace goes through this client # connection. try: self.client = vos.Client(root_node=root, conn=conn, transfer_shortcut=True, secure_get=secure_get) except Exception as e: e = FuseOSError(getattr(e, 'errno', EIO)) e.filename = root e.strerror = getattr(e, 'strerror', 'failed while making mount') raise e # Create a condition variable to get rid of those nasty sleeps self.condition = CacheCondition(lock=None, timeout=VOFS.cacheTimeout)
def readdir(self, path, id): """Send a list of entries in this directory""" vos.logger.debug("Getting directory list for %s " % (path)) ## reading from VOSpace can be slow, we'll do this in a thread import thread with self.condition: if not self.loading_dir.get(path, False): self.loading_dir[path] = True thread.start_new_thread(self.load_dir, (path, )) while self.loading_dir.get(path, False): vos.logger.debug("Waiting ... ") try: self.condition.wait() except CacheRetry: e = FuseOSError(EAGAIN) e.strerror = "Timeout waiting for directory listing" vos.logger.debug("Timeout Waiting for directory read: %s", path) raise e return ['.', '..'] + [e.name.encode('utf-8') for e in self.getNode( path, force=False, limit=None).getNodeList()]
def readdir(self, path, id): """Send a list of entries in this directory""" vos.logger.debug("Getting directory list for %s " % (path)) ## reading from VOSpace can be slow, we'll do this in a thread import thread with self.condition: if not self.loading_dir.get(path, False): self.loading_dir[path] = True thread.start_new_thread(self.load_dir, (path, )) while self.loading_dir.get(path, False): vos.logger.debug("Waiting ... ") try: self.condition.wait() except CacheRetry: e = FuseOSError(EAGAIN) e.strerror = "Timeout waiting for directory listing" vos.logger.debug("Timeout Waiting for directory read: %s", path) raise e return ['.', '..'] + [ e.name.encode('utf-8') for e in self.getNode(path, force=False, limit=None).getNodeList() ]
def open(self, path, flags, *mode): """Open file with the desired modes Here we return a handle to the cached version of the file which is updated if older and out of synce with VOSpace. """ vos.logger.debug("Opening %s with flags %s" % (path, flag2mode(flags))) node = None # according to man for open(2), flags must contain one of O_RDWR, # O_WRONLY or O_RDONLY. Because O_RDONLY=0 and options other than # O_RDWR, O_WRONLY and O_RDONLY may be present, # readonly = (flags == O_RDONLY) and readonly = (flags | # O_RDONLY) # won't work. The only way to detect if it's a read only is to check # whether the other two flags are absent. readOnly = ((flags & (os.O_RDWR | os.O_WRONLY)) == 0) mustExist = not ((flags & os.O_CREAT) == os.O_CREAT) cacheFileAttrs = self.cache.getAttr(path) if cacheFileAttrs is None and not readOnly: # file in the cache not in the process of being modified. # see if this node already exists in the cache; if not get info # from vospace try: node = self.getNode(path) except IOError as e: if e.errno == 404: # file does not exist if not flags & os.O_CREAT: # file doesn't exist unless created raise FuseOSError(ENOENT) else: raise FuseOSError(e.errno) ### check if this file is locked, if locked on vospace then don't open locked = False if node and node.props.get('islocked', False): vos.logger.debug("%s is locked." % path) locked = True if not readOnly and node and not locked: if node.type == "vos:DataNode": parentNode = self.getNode(os.path.dirname(path), force=False, limit=1) if parentNode.props.get('islocked', False): vos.logger.debug("%s is locked by parent node." % path) locked = True elif node.type == "vos:LinkNode": try: # sometimes targetNodes aren't internal... so then not # locked targetNode = self.getNode(node.target, force=False, limit=1) if targetNode.props.get('islocked', False): vos.logger.debug("%s target node is locked." % path) locked = True else: targetParentNode = self.getNode(os.path.dirname( node.target), force=False, limit=1) if targetParentNode.props.get('islocked', False): vos.logger.debug( "%s is locked by target parent node." % path) locked = True except Exception as e: vos.logger.error("Got an error while checking for lock: " + str(e)) pass if locked and not readOnly: # file is locked, cannot write e = FuseOSError(ENOENT) e.strerror = "Cannot create locked file" vos.logger.debug("Cannot create locked file: %s", path) raise e myProxy = MyIOProxy(self, path) if node is not None: myProxy.setSize(int(node.props.get('length'))) myProxy.setMD5(node.props.get('MD5')) # new file in cache library or if no node information (node not in # vospace). handle = self.cache.open(path, flags & os.O_WRONLY != 0, mustExist, myProxy, self.cache_nodes) if flags & os.O_TRUNC != 0: handle.truncate(0) if node is not None: handle.setHeader(myProxy.getSize(), myProxy.getMD5()) return HandleWrapper(handle, readOnly).getId()