FSync Event

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

Syntax

• C++

ANSI (Cross Platform)
virtual int FireFSync(FUSEFSyncEventParams *e);

typedef struct {
  const char *Path;
  int FileContext;
  int DataSync;
  int Result;
  int reserved;
} FUSEFSyncEventParams;

Unicode (Windows)
virtual INT FireFSync(FUSEFSyncEventParams *e);

typedef struct {
  LPCWSTR Path;
  INT FileContext;
  INT DataSync;
  INT Result;
  INT reserved;
} FUSEFSyncEventParams;

#define EID_FUSE_FSYNC 10

virtual INT CBFSFUSE_CALL FireFSync(LPWSTR &lpszPath, INT &iFileContext, INT &iDataSync, INT &iResult);

Remarks

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.