on_f_sync Event

Fires when the OS needs to flush an open file's data out to storage.


class FUSEFSyncEventParams(object):
  def path() -> str: ...
  def file_context() -> int: ...
  def data_sync() -> int: ...
  def result() -> int: ...
  def result(value) -> None: ...

# In class FUSE:
def on_f_sync() -> Callable[[FUSEFSyncEventParams], None]: ...
def on_f_sync(event_hook: Callable[[FUSEFSyncEventParams], None]) -> None: ...


This event fires when the OS needs the virtual filesystem to flush data of the file out to storage which can happen at any time while the file is opened. The file to flush is identified by either Path or FileContext.

To handle this event properly, applications must flush the requested data, writing it out to their backend storage.

Linux: The non-zero of DataSync parameter indicates that only the user data should be flushed and not the metadata.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource isn't available, security checks failed, etc.), set it to a negative error code value (e.g. -ENOENT to indicate that the file does not exist) to report an appropriate error. Please refer to the Error Reporting and Handling topic for more information.

Copyright (c) 2021 Callback Technologies, Inc. - All rights reserved.
CBFS FUSE 2020 Python Edition - Version 20.0 [Build 7836]